Method for producing blocked isocyanate compounds and method for producing isocyanate compounds

Abstract

Provided is a method for producing a blocked isocyanate compound, the method comprising a reaction step of reacting a primary amine compound, a carbonic acid derivative, and a blocking agent by means of heat treatment in the presence of at least one compound selected from the group consisting of a secondary amine compound represented by general formula (I) and a tertiary amine compound represented by general formula (II) to obtain a blocked isocyanate compound. Also provided is a method for producing an isocyanate compound, the method comprising a reaction step of decomposing a blocked isocyanate compound into a blocking agent and an isocyanate compound by means of heat treatment in the presence of at least one compound selected from the group consisting of a secondary amine compound represented by general formula (I) and a tertiary amine compound represented by general formula (II) to obtain the isocyanate compound. [Chemical formula 1]

Description

[Technical Field]

[0001] The present invention relates to a method for producing a blocked isocyanate compound and a method for producing an isocyanate compound. This application claims priority based on Japanese Patent Application Nos. 2021-199646 and 2021-199647, filed on December 8, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] Isocyanates are widely used as raw materials for manufacturing polyurethane foams, paints, adhesives, etc. The main industrial method for producing isocyanates is the reaction of an amine compound with phosgene (the phosgene process), and almost all of the isocyanates produced worldwide are produced by the phosgene process. However, the phosgene process has many problems.

[0003] First, it uses a large amount of phosgene as a raw material, which is highly toxic and requires special care in its handling to prevent worker exposure, and special equipment for waste removal.

[0004] Second, the phosgene process produces a large amount of highly corrosive hydrogen chloride as a by-product, necessitating a process to remove the hydrogen chloride. Furthermore, the isocyanates produced often contain hydrolyzable chlorine. Therefore, the use of isocyanates produced by the phosgene process can adversely affect the weather resistance and heat resistance of polyurethane products. Given these circumstances, a method for producing isocyanates without using phosgene is desired.

[0005] In addition, since isocyanates are highly reactive and easily react with compounds such as water, in order to improve stability, they are sometimes converted into blocked isocyanates, and the blocking agent is dissociated by heating to regenerate the isocyanates before use. Blocked isocyanates have low reactivity with active hydrogen compounds, can be stored stably, and are less toxic than isocyanates, making them useful as one-component paints, adhesives, and molding compounds. Blocked isocyanates also have the property of dissociating into isocyanates and blocking agents upon thermal decomposition. Therefore, by decomposing blocked isocyanates into isocyanates and blocking agents by thermal decomposition and separating the resulting isocyanates and blocking agents after or simultaneously with thermal decomposition, they can be used as raw materials for isocyanate production, which is useful. On the other hand, the isocyanate production process by thermal decomposition of blocked isocyanates requires a higher reaction temperature than the isocyanate production process using phosgene, which can lead to problems with thermal denaturation and coloration. Therefore, in order to use the obtained isocyanate as a product, it is necessary to purify the isocyanate to a desired level depending on the application, and this process incurs a great deal of cost.

[0006] Various methods for producing blocked isocyanates are known, including, for example, a method of producing a blocked isocyanate by directly reacting an isocyanate with a blocking agent, a method of producing a blocked isocyanate by reacting a carbamic acid chloride obtained by reacting an amine with phosgene with the blocking agent, a method of producing a blocked isocyanate by reacting a carbamic acid with a blocking agent and a condensing agent, a method of producing a blocked isocyanate by reacting an amine with a carbonic acid derivative to produce a blocked isocyanate containing a compound derived from the carbonic acid derivative, and a method of producing a blocked isocyanate by reacting an amine with a carbonic acid derivative and a blocking agent.

[0007] Among these, the method of producing a blocked isocyanate by reacting an amine, a carbonic acid derivative, and a blocking agent is useful because it 1) does not require the use of expensive isocyanates, 2) does not require the use of highly toxic phosgene or carbamic acid chloride, and 3) does not require the handling of chemically unstable carbamic acid or the use of expensive condensing agents. Examples of methods for producing such blocked isocyanates include a method of producing a carbamate from an amine, urea, and an alcohol (see, for example, Patent Document 1), a method of producing a tri-substituted urea from an amine, urea, and a secondary amine (see, for example, Patent Document 2), and a method of producing an N-substituted carbamic acid ester by reacting a compound having a ureido group obtained by reacting an amine and urea with an aromatic hydroxy composition containing an aromatic hydroxy compound (see, for example, Patent Document 3).

[0008] Also known is a method of reacting a starting blocked isocyanate with a blocking agent via an addition-elimination reaction to obtain a blocked isocyanate different from the starting blocked isocyanate. Similar to the method of producing a blocked isocyanate by reacting an amine, a carbonic acid derivative, and a blocking agent, these are useful production methods in terms of the above 1) to 3). Examples of production methods for such blocked isocyanates include a method of reacting an alkyl carbamate with a phenolic compound to obtain an aryl carbamate (see, for example, Patent Document 11), and a method of reacting a compound having a urea bond with a compound having a hydroxy group to obtain a carbamate (see, for example, Non-Patent Document 2).

[0009] On the other hand, the reaction of an amine, a carbonic acid derivative, and a blocking agent to obtain a blocked isocyanate generally requires heating. Similarly, a method of reacting a starting blocked isocyanate with a blocking agent via an addition-elimination reaction to obtain a different blocked isocyanate generally requires heating. These methods require high reaction temperatures to proceed rapidly on an industrial scale. For these reasons, thermal denaturation and coloration during production become a problem. Therefore, when using the resulting blocked isocyanate as a final product or when obtaining a colorless or low-color isocyanate with minimal thermal denaturation by thermal decomposition of the blocked isocyanate, it is necessary to purify the blocked isocyanate or isocyanate to a desired level depending on the application, which incurs significant costs. To prevent such thermal denaturation and coloration of the blocked isocyanate, it is possible to produce the blocked isocyanate compound under an inert gas atmosphere or use various antioxidants.

[0010] Antioxidants that can be considered for this purpose include antioxidants used to prevent the discoloration of isocyanates, such as phenolic antioxidants such as BHT, triarylphosphine compounds (see, for example, Patent Document 4), and phosphorus-based antioxidants such as trialkylphosphate compounds (see, for example, Patent Document 5).In addition, methods have been considered in which isocyanates are brought into contact with ozone-containing gas to reduce discoloration (see, for example, Patent Document 6), and methods for producing isocyanates with reduced discoloration by irradiating them with light having a wavelength of 200 to 600 nm (see, for example, Patent Document 7).

[0011] On the other hand, compounds having an amino group bonded to an aromatic carbon atom are known to be easily oxidized and cause discoloration (see, for example, Patent Document 8). Therefore, as described in Patent Document 9, for example, compounds having an amino group bonded to an aromatic carbon atom may be used in products where discoloration is not an issue, such as rubber deterioration inhibitors, but are not used in products where discoloration is an issue.

[0012] However, the process of contacting ozone-containing gas and reducing discoloration due to light irradiation require special equipment, which leads to complex equipment and leaves room for improvement in the discoloration reduction effect. Furthermore, phenolic antioxidants such as BHT can produce discoloring compounds such as stilbene quinone structures through oxidation, as described in Non-Patent Document 1, leaving room for improvement in the discoloration reduction effect. Furthermore, triarylphosphine compounds, which are phosphorus-based antioxidants, are highly nucleophilic and are undesirable, particularly in the reaction to obtain blocked isocyanates from amines, carbonic acid derivatives, and blocking agents, because the presence of isocyanate functional groups in the reaction system accelerates irreversible modification of the isocyanate functional groups, or because modification accelerates under thermal decomposition temperature conditions of the blocked isocyanates. Furthermore, trialkyl phosphate compounds are also known as carbodiimidation catalysts, and heating them in the presence of isocyanate functional groups generated in the reaction system not only promotes carbodiimidation, but also causes the generated carbodiimide to react with isocyanate to form a uretonimine structure, which undesirably increases the amount of by-products and the viscosity of the reaction solution.

[0013] As described above, there is room for improvement in the conventional methods with respect to the problems of thermal denaturation and coloration in the process of producing a blocked isocyanate from an amine, a carbonic acid derivative, and a blocking agent.

[0014] Furthermore, as described above, there is room for improvement in the conventional methods with regard to the problems of thermal denaturation and coloration that occur when a blocked isocyanate compound is thermally decomposed. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] U.S. Patent No. 2,409,712 [Patent Document 2] German Patent No. 1064051 [Patent Document 3] International Publication No. 2011 / 021258 [Patent Document 4] U.S. Patent No. 2,957,903 Specification [Patent Document 5] Japanese Unexamined Patent Application Publication No. Sho 49-075505 [Patent Document 6] Japanese Unexamined Patent Application Publication No. Hei 8-291129 [Patent Document 7] Japanese Patent Application Publication No. 2012-506465 [Patent Document 8] Japanese Unexamined Patent Application Publication No. Sho 59-042346 [Patent Document 9] Japanese Patent No. 3,051,523 Gazette [Patent Document 10] Japanese Patent No. 3,051,523 Gazette [Patent Document 11] Japanese Patent No. 4,859,255 Gazette [Non-Patent Document]

[0016] [Non-Patent Document 1] Cook C. D. et al., “Oxidation of Hindered Phenols. III. The Rearrangement of the 2,6-Di-t-butyl-4-methylphenoxy Radical”, J. Am. Chem. Soc., Vol. 77, pp. 1783-1785, 1955. [Non-Patent Document 2] Hutchby M et al., “Hindered Ureas as Masked Isocyanates: Facile Carbamoylation of Nucleophiles under Neutral Conditions”, Angew. Chem. Int. Ed., Vol. 48, Issue 46, pp. 8721-8724, 2009. [Summary of the Invention] [Problems to be Solved by the Invention]

[0017] The present invention has been made in view of the above circumstances, and provides a method for producing a blocked isocyanate compound that is inhibited from being thermally modified and discolored.

[0018] The present invention has been made in view of the above circumstances, and provides a method for producing an isocyanate compound that is inhibited from being thermally denatured and discolored. [Means for solving the problem]

[0019] That is, the present invention includes the following aspects. (1) A method for producing a blocked isocyanate compound, comprising a reaction step of reacting a primary amine compound, a carbonic acid derivative, and a blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I) and a tertiary amine compound represented by the following general formula (II), to obtain a blocked isocyanate compound:

[0020] [ka]

[0021] In general formula (I), R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0022] [ka]

[0023] In general formula (II), R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R22 , R 22 and R 23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group.

[0024] (2) The method for producing a blocked isocyanate compound according to (1), wherein the blocking agent comprises one or more compounds selected from the group consisting of hydroxy compounds, amine compounds, and ammonia. (3) The method for producing a blocked isocyanate compound according to (1) or (2), wherein the primary amine compound is an amine compound represented by the following general formula (III):

[0025] [ka]

[0026] In general formula (III), R 31 is an organic group having a valence of n31, where n31 is an integer of 1 or more and 12 or less.

[0027] (4) The method for producing a blocked isocyanate compound according to any one of (1) to (3), wherein the blocking agent is an aromatic hydroxy compound represented by the following general formula (IV-1):

[0028] [ka]

[0029] In general formula (IV-1), ring A 41 is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. 41R is a hydrogen atom, a halogen atom, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkyloxycarbonyl group having from 1 to 20 carbon atoms, an alkylcarbonyloxy group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aryloxy group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or an aralkyloxy group having from 7 to 20 carbon atoms. 41 is ring A 41 may bond to form a ring structure. In addition, n41 is an integer of 1 or more and 10 or less.

[0030] (5) The method for producing a blocked isocyanate compound according to any one of (1) to (3), wherein the blocking agent is an aliphatic hydroxy compound represented by the following general formula (IV-2):

[0031] [ka]

[0032] In general formula (IV-2), R 42 is a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 24 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

[0033] (6) The method for producing a blocked isocyanate compound according to any one of (1) to (3), wherein the blocking agent is a secondary amine compound represented by the following general formula (V):

[0034] [ka]

[0035] In general formula (V), R 51 and R 52 R is each independently a monovalent organic group. 51 and R 52 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond.

[0036] (7) The method for producing a blocked isocyanate compound according to any one of (1) to (6), wherein the carbonic acid derivative is a compound represented by the following general formula (VI):

[0037] [ka]

[0038] In general formula (VI), R 61 and R 62 are each independently an amino group, a substituted or unsubstituted alkoxy group having from 1 to 20 carbon atoms, or an aryloxy group having from 6 to 20 carbon atoms, or a substituted or unsubstituted alkylamino group having from 1 to 20 carbon atoms, or an arylamino group having from 6 to 20 carbon atoms.

[0039] (8) The method for producing a blocked isocyanate compound according to any one of (1) to (7), wherein in the reaction step, the oxygen concentration in the gas supplied is 21% by volume or less, based on the total volume of the gas. (9) The method for producing a blocked isocyanate compound according to any one of (1) to (8), wherein in the reaction step, the amount of one or more compounds selected from the group consisting of the secondary amine compound represented by general formula (I) and the tertiary amine compound represented by general formula (II) below is 1 ppm by mass or more relative to the total mass of the primary amine compound and the blocking agent: (10) The method for producing a blocked isocyanate compound according to any one of (1) to (9), wherein the reaction step simultaneously contains a secondary amine compound represented by general formula (I) and a tertiary amine compound represented by general formula (II).

[0040] (11) A method for producing an isocyanate compound, comprising a reaction step of decomposing a blocked isocyanate compound into a blocking agent and an isocyanate compound by heat treatment in the presence of one or more compounds selected from the group consisting of secondary amine compounds represented by the following general formula (I) and tertiary amine compounds represented by the following general formula (II), thereby obtaining the isocyanate compound:

[0041] [ka]

[0042] In general formula (I), R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0043] [ka]

[0044] In general formula (II), R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R 22 , R 22 and R 23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group.

[0045] (12) The method for producing an isocyanate compound according to (11), wherein the blocking agent comprises one or more compounds selected from the group consisting of hydroxy compounds, amine compounds, and ammonia. (13) The method for producing an isocyanate compound according to (11) or (12), wherein the isocyanate compound is an isocyanate compound represented by the following general formula (VII):

[0046] [ka]

[0047] In general formula (VII), R 71 is an organic group having a valence of n71, where n71 is an integer of 1 or more and 12 or less.

[0048] (14) The method for producing an isocyanate compound according to any one of (11) to (13), wherein the blocking agent is an aromatic hydroxy compound represented by the following general formula (IV-1):

[0049] [ka]

[0050] In general formula (IV-1), ring A 41 is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. 41 R is a hydrogen atom, a halogen atom, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkyloxycarbonyl group having from 1 to 20 carbon atoms, an alkylcarbonyloxy group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aryloxy group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or an aralkyloxy group having from 7 to 20 carbon atoms. 41 is ring A 41 may bond to form a ring structure. In addition, n41 is an integer of 1 or more and 10 or less.

[0051] (15) The method for producing an isocyanate compound according to any one of (11) to (13), wherein the blocking agent is an aliphatic hydroxy compound represented by the following general formula (IV-2):

[0052] [ka]

[0053] In general formula (IV-2), R 42 is a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 24 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

[0054] (16) The method for producing an isocyanate compound according to any one of (11) to (13), wherein the blocking agent is a secondary amine compound represented by the following general formula (V):

[0055] [ka]

[0056] In general formula (V), R 51 and R 52 R is each independently a monovalent organic group. 51 and R 52 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond.

[0057] (17) The method for producing an isocyanate compound according to any one of (11) to (16), wherein in the reaction step, the oxygen concentration in the gas supplied is 21% by volume or less based on the total volume of the gas. (18) The method for producing an isocyanate compound according to any one of (11) to (17), wherein in the reaction step, the amount of one or more compounds selected from the group consisting of the secondary amine compound represented by the general formula (I) and the tertiary amine compound represented by the following general formula (II) is 1 ppm by mass or more relative to the reaction liquid: (19) The method for producing an isocyanate compound according to any one of (11) to (18), wherein the reaction step simultaneously contains a secondary amine compound represented by the general formula (I) and a tertiary amine compound represented by the general formula (II).

[0058] (20) A first reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I) and a tertiary amine compound represented by the following general formula (II) to obtain a blocked isocyanate compound; a reaction step of decomposing the blocked isocyanate compound into the first blocking agent and an isocyanate compound by heat treatment in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I) and a tertiary amine compound represented by the following general formula (II), thereby obtaining the isocyanate compound; A method for producing an isocyanate compound, comprising:

[0059] [ka]

[0060] (In general formula (I), R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0061] [ka]

[0062] (In general formula (II), R 21 , R 22 , and R 23R is each independently a monovalent organic group. 21 and R 22 , R 22 and R 23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group.

[0063] (21) A method for producing a blocked isocyanate compound, comprising an addition-elimination reaction step of reacting a first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I) and a tertiary amine compound represented by the following general formula (II), to obtain a second blocked isocyanate compound: the second blocking agent is a compound different from the first blocking agent that blocks the isocyanate group of the first blocked isocyanate compound, The first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0064] [ka]

[0065] (In general formula (I), R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0066] [ka]

[0067] (In general formula (II), R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R 22 , R 22 and R 23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group.

[0068] (22) The method for producing a blocked isocyanate compound according to (21), wherein the isocyanate compound used in the production of the first blocked isocyanate compound includes an isocyanate compound represented by the following general formula (VII):

[0069] [ka]

[0070] (In general formula (VII), R 71 is an organic group with a valence of n71, where n71 is an integer of 1 or more and 12 or less.

[0071] (23) The method for producing a blocked isocyanate compound according to (21) or (22), wherein the first blocking agent contains one or more compounds selected from the group consisting of hydroxy compounds, amine compounds, and ammonia. (24) The method for producing a blocked isocyanate compound according to any one of (21) to (23), wherein the first blocking agent contains an aromatic hydroxy compound represented by the following general formula (IV-1):

[0072] [ka]

[0073] (In general formula (IV-1), ring A 41 is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. 41 R is a hydrogen atom, a halogen atom, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkyloxycarbonyl group having from 1 to 20 carbon atoms, an alkylcarbonyloxy group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aryloxy group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or an aralkyloxy group having from 7 to 20 carbon atoms. 41 is ring A 41 may bond with to form a ring structure. n41 is an integer of 1 or more and 10 or less.

[0074] (25) The method for producing a blocked isocyanate compound according to any one of (21) to (23), wherein the first blocking agent contains an aliphatic hydroxy compound represented by the following general formula (IV-2):

[0075] [ka]

[0076] (In general formula (IV-2), R 42 is a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 24 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

[0077] (26) The method for producing a blocked isocyanate compound according to any one of (21) to (23), wherein the first blocking agent contains a secondary amine compound represented by the following general formula (V):

[0078] [ka]

[0079] (In general formula (V), R51 and R 52 R is each independently a monovalent organic group. 51 and R 52 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond.

[0080] (27) The method for producing a blocked isocyanate compound according to any one of (21) to (26), wherein the second blocking agent contains one or more compounds selected from the group consisting of hydroxy compounds and amine compounds. (28) The method for producing a blocked isocyanate compound according to any one of (21) to (27), wherein the second blocking agent contains an aromatic hydroxy compound represented by the following general formula (IV-1):

[0081] [ka]

[0082] (In general formula (IV-1), ring A 41 is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. 41 is a hydrogen atom, a halogen atom, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkyloxycarbonyl group having from 1 to 20 carbon atoms, an alkylcarbonyloxy group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aryloxy group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or an aralkyloxy group having from 7 to 20 carbon atoms. 41 is ring A 41 may bond with to form a ring structure. n41 is an integer of 1 or more and 10 or less.

[0083] (29) The method for producing a blocked isocyanate compound according to any one of (21) to (27), wherein the second blocking agent contains an aliphatic hydroxy compound represented by the following general formula (IV-2):

[0084] [ka]

[0085] (In general formula (IV-2), R 42 is a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 24 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

[0086] (30) The method for producing a blocked isocyanate compound according to any one of (21) to (27), wherein the second blocking agent contains a secondary amine compound represented by the following general formula (V):

[0087] [ka]

[0088] (In general formula (V), R 51 and R 52 R is each independently a monovalent organic group. 51 and R 52 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond.

[0089] (31) The method for producing a blocked isocyanate compound according to any one of (21) to (30), wherein in the addition-elimination reaction step, the oxygen concentration in the gas supplied is 21% by volume or less, based on the total volume of the gas. (32) The method for producing a blocked isocyanate compound according to any one of (21) to (31), wherein in the addition-elimination reaction step, the amount of one or more compounds selected from the group consisting of the secondary amine compound represented by general formula (I) and the tertiary amine compound represented by the following general formula (II) is 1 ppm by mass or more relative to the reaction solution: (33) The method for producing a blocked isocyanate compound according to any one of (21) to (32), wherein the addition-elimination reaction step simultaneously contains a secondary amine compound represented by general formula (I) and a tertiary amine compound represented by general formula (II).

[0090] (34) A reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by general formula (I) and a tertiary amine compound represented by general formula (II) to obtain a first blocked isocyanate compound; an addition-elimination reaction step of reacting the first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence or absence of one or more compounds selected from the group consisting of the secondary amine compound represented by the general formula (I) and the tertiary amine compound represented by the general formula (II), to obtain a second blocked isocyanate compound; Including, the second blocking agent is a compound different from the first blocking agent and the third blocking agent derived from the carbonic acid derivative, The method for producing a blocked isocyanate compound, wherein the first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0091] [ka]

[0092] (In general formula (I), R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0093] [ka]

[0094] (In general formula (II), R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R 22 , R 22 and R 23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group.

[0095] (35) A first reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by general formula (I) and a tertiary amine compound represented by general formula (II) to obtain a blocked isocyanate compound; an addition-elimination reaction step of reacting the first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence or absence of one or more compounds selected from the group consisting of the secondary amine compound represented by the general formula (I) and the tertiary amine compound represented by the general formula (II), to obtain a second blocked isocyanate compound; a second reaction step of decomposing the second blocked isocyanate compound into a second blocking agent and an isocyanate compound by heat treatment in the presence or absence of one or more compounds selected from the group consisting of the secondary amine compound represented by the general formula (I) and the tertiary amine compound represented by the general formula (II), thereby obtaining the isocyanate compound; Including, the second blocking agent is a compound different from the first blocking agent and the third blocking agent derived from the carbonic acid derivative, The first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0096] [ka]

[0097] (In general formula (I), R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0098] [ka]

[0099] (In general formula (II), R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R 22 , R 22 and R 23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group. [Effects of the Invention]

[0100] According to the method for producing a blocked isocyanate compound of the above aspect, it is possible to provide a method for producing a blocked isocyanate compound in which thermal denaturation and coloration are suppressed.

[0101] Furthermore, according to the method for producing an isocyanate compound of the above aspect, it is possible to provide a method for producing an isocyanate compound in which thermal denaturation and coloration are suppressed. DETAILED DESCRIPTION OF THE INVENTION

[0102] Hereinafter, an embodiment for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The present embodiment is an example for explaining the present invention, and the present invention is not limited to the present embodiment. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0103] In this specification, the term "active hydrogen" refers to a hydrogen atom bonded to an oxygen atom, a sulfur atom, or a nitrogen atom, and a hydrogen atom of an active methylene group, such as a hydrogen atom contained in an atomic group such as an -OH group, a -C(=O)OH group, a -C(=O)H group, a -SH group, a -NH group, a -NH- group, or a -C(=O)-C(-H)-C(=O)- group.

[0104] The manufacturing method according to this embodiment includes: a first reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by general formula (I) described below and a tertiary amine compound represented by general formula (II) described below to obtain a blocked isocyanate compound; a second reaction step of thermally decomposing the blocked polyisocyanate compound into an isocyanate compound and the first blocking agent in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound represented by general formula (I) described below and a tertiary amine compound represented by general formula (II) described below, to obtain the isocyanate compound; The present invention relates to a method for producing an isocyanate compound, comprising the steps of:

[0105] At least in the first reaction step, and preferably in both the first and second reaction steps, the reaction is carried out in the presence of one or more compounds selected from the group consisting of secondary amine compounds represented by general formula (I) and tertiary amine compounds represented by general formula (II), which will be described later. As a result, in the first reaction step, a blocked isocyanate compound in which thermal modification and coloration are suppressed is obtained. Meanwhile, in the second reaction step, an isocyanate compound in which thermal modification and coloration are suppressed is obtained.

[0106] Alternatively, the production method according to the present embodiment is a method for producing a blocked isocyanate compound, comprising an addition-elimination reaction step of reacting a first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence of one or more compounds selected from the group consisting of secondary amine compounds represented by general formula (I) described below and tertiary amine compounds represented by general formula (II) described below, to obtain a second blocked isocyanate compound.

[0107] The second blocking agent is a compound different from the first blocking agent that blocks the isocyanate group of the first blocked isocyanate compound.

[0108] The first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0109] In the addition-elimination reaction step, the reaction is carried out in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by general formula (I) described later and a tertiary amine compound represented by general formula (II) described later, thereby obtaining a blocked isocyanate compound that is inhibited from thermal denaturation and coloration in the addition-elimination reaction step.

[0110] Alternatively, the production method of this embodiment can be carried out by combining at least two steps out of the first reaction step, the addition-elimination reaction step, and the second reaction step.

[0111] That is, the manufacturing method of this embodiment is as follows: a reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by general formula (I) described below and a tertiary amine compound represented by general formula (II) described below to obtain a first blocked isocyanate compound; an addition-elimination reaction step of reacting the first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence or absence of one or more compounds selected from the group consisting of the secondary amine compound represented by the general formula (I) and the tertiary amine compound represented by the general formula (II), to obtain a second blocked isocyanate compound; The present invention relates to a method for producing a blocked isocyanate compound, comprising the steps of:

[0112] The second blocking agent is a compound different from the first blocking agent and the third blocking agent derived from the carbonic acid derivative.

[0113] The first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0114] an addition-elimination reaction step of reacting a first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence of a secondary amine compound represented by general formula (I) described below and a tertiary amine compound represented by general formula (II) described below to obtain a second blocked isocyanate compound; a reaction step of decomposing the second blocked isocyanate compound into a second blocking agent and an isocyanate compound by heat treatment in the presence or absence of one or more compounds selected from the group consisting of the secondary amine compound represented by the general formula (I) and the tertiary amine compound represented by the general formula (II), thereby obtaining the isocyanate compound; The present invention relates to a method for producing an isocyanate compound, comprising the steps of:

[0115] The second blocking agent is a compound different from the first blocking agent that blocks the isocyanate group of the first blocked isocyanate compound.

[0116] The first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0117] Alternatively, the manufacturing method of this embodiment is a first reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by general formula (I) described below and a tertiary amine compound represented by general formula (II) described below to obtain a blocked isocyanate compound; an addition-elimination reaction step of reacting the first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence or absence of one or more compounds selected from the group consisting of the secondary amine compound represented by the general formula (I) and the tertiary amine compound represented by the general formula (II), to obtain a second blocked isocyanate compound; a second reaction step of decomposing the second blocked isocyanate compound into a second blocking agent and an isocyanate compound by heat treatment in the presence or absence of one or more compounds selected from the group consisting of the secondary amine compound represented by the general formula (I) and the tertiary amine compound represented by the general formula (II), thereby obtaining the isocyanate compound; The present invention relates to a method for producing an isocyanate compound, comprising the steps of:

[0118] The second blocking agent is a compound different from the first blocking agent and the third blocking agent derived from a carbonic acid derivative, which will be described in detail later as a compound derived from a carbonic acid derivative.

[0119] The first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0120] Hereinafter, the first reaction step, the addition-elimination reaction step, and the second reaction step will be described in detail, respectively, as a method for producing a blocked isocyanate compound according to a first embodiment, a method for producing a blocked isocyanate compound according to a second embodiment, and a method for producing an isocyanate compound according to a third embodiment. In addition, as methods for producing an isocyanate compound that combine the above-mentioned steps, a method for producing an isocyanate compound according to a fourth embodiment and a method for producing an isocyanate compound according to a fifth embodiment will also be described.

[0121] <<Method for producing blocked isocyanate compound according to the first embodiment>> The method for producing a blocked isocyanate compound of this embodiment (hereinafter may be simply referred to as the "production method of the first embodiment") includes a reaction step (hereinafter may be referred to as the "first reaction step") of reacting a primary amine compound, a carbonic acid derivative, and a blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I) (hereinafter may be referred to as the "secondary amine compound (I)") and a tertiary amine compound represented by the following general formula (II) (hereinafter may be referred to as the "tertiary amine compound (II)"), to obtain a blocked isocyanate compound.

[0122] [ka]

[0123] In general formula (I), R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0124] [ka]

[0125] In general formula (II), R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R 22 , R 22 and R 23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group.

[0126] The inventors discovered that the problems of thermal denaturation and coloration can be solved by producing a blocked isocyanate by reacting a primary amine compound, a carbonic acid derivative, and a blocking agent in the presence of a specific amine compound having an aromatic group, and thus completed the present invention.

[0127] As described above, compounds having an amino group bonded to an aromatic carbon atom have been known to be easily oxidized and discolored. Therefore, although compounds having an amino group bonded to an aromatic carbon atom are sometimes used in products where discoloration is not an issue, such as rubber deterioration inhibitors, they are not used in products where discoloration is an issue. Surprisingly, the manufacturing method of the first embodiment has now revealed for the first time that the use of a specific amine compound having an aromatic group not only does not cause discoloration problems, but also exhibits a particularly remarkable effect of improving (suppressing) thermal denaturation and discoloration.

[0128] Therefore, the production method of the first embodiment can also be said to be a method for improving thermal denaturation and coloration that occur during the production of a blocked isocyanate compound, or a method for suppressing thermal denaturation and coloration that occur during the production of a blocked isocyanate compound.

[0129] Next, each step of the manufacturing method according to the first embodiment will be described in detail below.

[0130] <First reaction step> In the first reaction step, a primary amine compound, a carbonic acid derivative, and a blocking agent are reacted by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound (I) and a tertiary amine compound (II) to obtain a blocked isocyanate compound.

[0131] In the first reaction step, the amount of secondary amine compound (I) present in the composition is preferably large in order to reduce coloration of the blocked isocyanate compound and the blocked isocyanate composition. Specifically, the amount of secondary amine compound (I) present is preferably greater than 0 mass%, more preferably 1 ppm by mass or greater, even more preferably 1 mass% or greater, and particularly preferably 50 mass% or greater, relative to the total mass of the primary amine compound and the blocking agent. On the other hand, if the amount of secondary amine compound (I) present in the composition containing the blocked isocyanate compound is large, the basicity of the secondary amine compound (I) may accelerate at least one of the modification of the isocyanate compound and the modification of the blocked isocyanate compound. Therefore, the amount of secondary amine compound (I) present is preferably less than 1000 mass%, more preferably less than 100 mass%, even more preferably 90 mass% or less, particularly preferably 80 mass% or less, and most preferably 50 mass% or less, relative to the total mass of the primary amine compound and the blocking agent. It is also possible to add a combination of two or more secondary amine compounds (I) to a composition containing a primary amine compound, a carbonic acid derivative, and a blocking agent. The thermal denaturation and discoloration suppression effect of the secondary amine compound (I) varies depending on the chemical structure of the secondary amine compound, and the inclusion of two or more secondary amine compounds can enhance the thermal denaturation and discoloration suppression effect.

[0132] In the first reaction step, the amount of tertiary amine compound (II) present in the composition is preferably large in order to reduce coloration of the blocked isocyanate compound and the blocked isocyanate composition. Specifically, the amount of tertiary amine compound (II) present is preferably greater than 0 mass%, more preferably 1 ppm by mass or greater, even more preferably 1 mass% or greater, and particularly preferably 50 mass% or greater, relative to the total mass of the primary amine compound and the blocking agent. On the other hand, when the amount of tertiary amine compound (II) present in the composition containing the blocked isocyanate compound is large, the basicity of the tertiary amine compound (II) may accelerate at least one of the modification of the isocyanate compound and the modification of the blocked isocyanate compound. Therefore, the amount of tertiary amine compound (II) present is preferably less than 1000 mass%, more preferably less than 100 mass%, even more preferably 90 mass% or less, particularly preferably 80 mass% or less, and most preferably 50 mass% or less, relative to the total mass of the primary amine compound and the blocking agent. It is also possible to add a combination of two or more tertiary amine compounds (II) to a composition containing a primary amine compound, a carbonic acid derivative, and a blocking agent. The thermal denaturation and discoloration suppression effect of the tertiary amine compound (I) varies depending on the chemical structure of the tertiary amine compound, and by including two or more tertiary amine compounds, it is possible to enhance the thermal denaturation and discoloration suppression effect.

[0133] The secondary amine compound (I) and the tertiary amine compound (II) may be added alone to a composition containing a primary amine compound, a carbonic acid derivative, and a blocking agent, or both the secondary amine compound (I) and the tertiary amine compound (II) may be added. Comparing the secondary amine compound (I) and the tertiary amine compound (II), the secondary amine compound (I) has a stronger effect of reducing discoloration at high temperatures. On the other hand, the tertiary amine compound (II) has a lower temperature dependency in the effect of reducing discoloration, and therefore, can achieve a discoloration reduction effect over a wide temperature range.

[0134] Furthermore, because the secondary amine compound (I) has an active hydrogen group, a portion of the blocking agent in the blocked isocyanate compound is replaced by the secondary amine compound (I). As a result, urea groups formed by the reaction of the secondary amine compound (I) with the isocyanate group may remain in the blocked isocyanate compound. Since the above-mentioned reaction does not occur, the tertiary amine compound (II) is more preferred.

[0135] Furthermore, if the secondary amine compound (I) and the tertiary amine compound (II) are contained simultaneously, there is a problem that, for example, when recovering the secondary amine compound (I) and the tertiary amine compound (II), the separation operation becomes complicated. However, the secondary amine compound (I) and the tertiary amine compound (II) exhibit different effects in suppressing thermal denaturation and coloration, and in addition, they exhibit a synergistic effect in suppressing thermal denaturation and coloration. Therefore, it is preferable to contain the secondary amine compound (I) and the tertiary amine compound (II) simultaneously.

[0136] In the first reaction step, the total amount of the secondary amine compound (I) and the tertiary amine compound (II) present is not particularly limited. However, in order to reduce the coloration of the blocked isocyanate compound and the blocked isocyanate composition, a larger amount is preferable. Specifically, the total amount of the secondary amine compound (I) and the tertiary amine compound (II) present is preferably greater than 0% by mass, more preferably 1 ppm by mass or greater, even more preferably 1% by mass or greater, and particularly preferably 50% by mass or greater, based on the total mass of the primary amine compound and the blocking agent. On the other hand, if the amount of the secondary amine compound (I) present in the composition containing the blocked isocyanate compound is large, the basicity of the secondary amine compound (I) and the tertiary amine compound (II) may accelerate at least one of the modification of the isocyanate compound and the modification of the blocked isocyanate compound. Therefore, the total amount of the secondary amine compound (I) and the tertiary amine compound (II) present is preferably less than 1000% by mass, more preferably less than 100% by mass, even more preferably 90% by mass or less, particularly preferably 80% by mass or less, and most preferably 50% by mass or less, based on the total mass of the primary amine compound and the blocking agent.

[0137] Furthermore, by combining one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) with an antioxidant different from the one or more secondary amine compounds (I) and tertiary amine compounds (II), the thermal denaturation and discoloration suppression effect can be further enhanced. Furthermore, by combining secondary amine compounds (I) and tertiary amine compounds (II) with an antioxidant, the thermal denaturation and discoloration suppression effect can be further enhanced.

[0138] The antioxidant other than the secondary amine compound (I) and the tertiary amine compound (II) is not particularly limited as long as it is an antioxidant that enhances the thermal denaturation and discoloration suppression effect, but phenolic antioxidants or phosphorus-based antioxidants are more preferred as they are particularly effective in suppressing discoloration. Among them, phenolic antioxidants are preferred because they have a particularly high effect of preventing thermal denaturation and discoloration when combined with the secondary amine compound (I) and the tertiary amine compound (II).

[0139] In the first reaction step, the ratio of the amounts of the primary amine compound and the blocking agent added can be selected arbitrarily. Generally, however, the first reaction step is generally carried out at a ratio such that the molar amount of amino groups in the primary amine compound and the molar amount of active hydrogen groups in the blocking agent are 1:1, or such that the molar amount of the active hydrogen groups in the blocking agent is greater than the molar amount of amino groups in the primary amine compound.

[0140] In the first reaction step, the ratio of the amounts of the primary amine compound and the blocking agent added can be selected arbitrarily. When expressed as a mass ratio, it is usually preferable that the blocking agent be present in an amount that is in excess of the primary amine compound. For example, the mass ratio of the primary amine compound and the blocking agent added can be 1:1 to 1:999.

[0141] In the first reaction step, the ratio of the amounts of the primary amine compound and the carbonic acid derivative added can be selected arbitrarily, but it is generally carried out such that the ratio of the molar amount of amino groups in the primary amine compound to the molar amount of carbonyl groups in the carbonic acid derivative is in the range of 1:0.5 to 1:20.

[0142] In addition, in the first reaction step, the ratio of the amounts of the primary amine compound and the carbonic acid derivative added can be selected arbitrarily, but when expressed as a mass ratio, the amount of the carbonic acid derivative added can be, for example, a mass ratio of the primary amine compound and the carbonic acid derivative added of 1:0.01 to 1:99.

[0143] In the first reaction step, the combination of the primary amine compound, carbonic acid derivative, blocking agent, secondary amine compound (I), and tertiary amine compound (II) can be selected arbitrarily. However, when distillation separation is performed in the first reaction step, the progress of the reaction can be promoted by actively extracting the compound derived from the carbonic acid derivative from the system. From this viewpoint, it is preferable that the boiling point of the compound derived from the carbonic acid derivative is lower than that of the blocking agent. In addition, since coloration can be reduced, it is preferable that the secondary amine compound (I) and the tertiary amine compound (II) are present in the resulting blocked isocyanate composition. Also, from this viewpoint, it is preferable that the boiling points of the secondary amine compound (I) and the tertiary amine compound (II) are higher than that of the compound derived from the carbonic acid derivative. Here, the compound derived from the carbonic acid derivative is R represented by the general formula (VI) described below. 61 or R 62 The compound is a compound in which an active hydrogen is bonded to the carbonic acid derivative, and is obtained by liberation from the carbonic acid derivative. Specifically, the compound is a hydroxy compound, ammonia, or a primary or secondary amine compound.

[0144] The reaction temperature is not particularly limited and is appropriately selected depending on the reaction rate between the primary amine compound, the carbonic acid derivative, and the blocking agent, as well as the degree of thermal denaturation and coloration. From the viewpoint of suppressing the denaturation of the blocked isocyanate compound, the reaction temperature is preferably 350°C or lower, more preferably 300°C or lower, and even more preferably 260°C or lower. On the other hand, a low reaction temperature may require setting the condenser temperature at a low temperature, which may require new equipment. From this viewpoint, the reaction temperature is preferably 50°C or higher, more preferably 80°C or higher, and even more preferably 100°C or higher. Furthermore, the coloration reduction effect during the production of a blocked isocyanate compound in the presence of a secondary amine compound (I) becomes more pronounced as the temperature increases. From this viewpoint, the reaction temperature for the production of the blocked isocyanate is preferably 120°C or higher, more preferably 160°C or higher, and even more preferably 200°C or higher.

[0145] The reaction pressure may be reduced, normal, or increased, depending on the type of compound used and the reaction temperature. Generally, the absolute pressure is 20 Pa or more and 2×10 7 It is performed in the range of Pa or less.

[0146] The first reaction step may be carried out in the presence of oxygen. When the first reaction step is carried out in the presence of oxygen, the amount of oxygen present in the blocked isocyanate compound production apparatus is preferably reduced because thermal denaturation and coloration of the blocked isocyanate compound may occur. On the other hand, in the case of a large-scale production facility, reducing the amount of oxygen present in the blocked isocyanate compound production apparatus requires reducing air leakage into the production facility, which requires stricter design standards for the facility and increases equipment costs. From this perspective, the oxygen concentration in the gas supplied to the first reaction step is preferably controlled at a high level, preferably greater than 0% by volume, more preferably greater than 0.0001% by volume, and even more preferably greater than 0.001% by volume.

[0147] In the first reaction step, the presence of one or more compounds selected from the group consisting of a secondary amine compound (I) and a tertiary amine compound (II) reduces thermal denaturation and coloration of the blocked isocyanate compound, even in the presence of oxygen. On the other hand, an increase in the amount of oxygen present is undesirable because it promotes thermal denaturation and coloration, as described above, and therefore requires increased amounts of the secondary amine compound (I) and the tertiary amine compound to suppress thermal denaturation and coloration. From this perspective, it is preferable to operate the reactor under low oxygen concentrations in the gas supplied to the first reaction step. The oxygen concentration is preferably controlled to 21% by volume or less, more preferably 10% by volume or less, even more preferably 1% by volume or less, even more preferably 0.1% by volume or less, particularly preferably 0.01% by volume or less, and most preferably 0.001% by volume or less, based on the total volume of the gas. The oxygen concentration can be measured using known techniques, such as conventional gas chromatography or an electrochemical trace oxygen analyzer.

[0148] In the first reaction step, any solvent may be used in any proportion. The solvent is preferably an inert solvent that does not have reactivity with primary amine compounds, carbonic acid derivatives, blocking agents, blocked isocyanate compounds, etc. Such solvents are preferably ester-based solvents, ether-based solvents, phosphate ester-based solvents, hydrocarbon-based solvents, aromatic hydrocarbon-based solvents, or carbonic acid derivative-based solvents.

[0149] In the first reaction step, the reaction mixture containing the primary amine compound, the carbonic acid derivative, and the blocking agent may contain any metal in any proportion. The metal may be in the form of a complex or a solid. While the metal reduces the thermal decomposition temperature of the blocked isocyanate compound and promotes the reaction between the primary amine compound and the carbonic acid derivative, it may also cause thermal denaturation, deterioration, and coloration. Therefore, the metal content is preferably less than 10% by mass, more preferably less than 1% by mass, and even more preferably less than 0.1 ppm by mass, relative to the mass of the blocked isocyanate compound.

[0150] In the first reaction step, the reaction mixture containing the primary amine compound, the carbonic acid derivative, and the blocking agent may contain an organic acid, an inorganic acid, an organic base, or an inorganic base. These acids and bases act as catalysts in the thermal decomposition of the blocked isocyanate, reducing the temperature required for thermal decomposition and promoting the reaction between the primary amine compound and the carbonic acid derivative. On the other hand, these acids and bases also act as catalysts for side reactions in the thermal decomposition of the blocked isocyanate. From this perspective, the content of these organic acids, inorganic acids, organic bases, and inorganic bases is preferably less than 10% by mass, more preferably less than 1% by mass, even more preferably less than 0.1% by mass, and particularly preferably less than 1 ppb by mass, relative to the mass of the blocked isocyanate compound.

[0151] In the first reaction step, the blocked isocyanate compound is obtained as a composition containing the blocked isocyanate compound (hereinafter, may be referred to as a "blocked isocyanate composition").

[0152] The blocked isocyanate composition refers to a composition containing more than 0 wt % and 100 wt % or less of a blocked isocyanate compound. The blocked isocyanate composition is not particularly limited except that it contains a blocked isocyanate compound, and may contain a solvent, a blocking agent, an isocyanate, a catalyst, a primary amine compound, and the like in any proportion.

[0153] In view of the above, the blocked isocyanate composition may be used as it is as the blocked isocyanate compound, or the blocked isocyanate compound may be purified from the blocked isocyanate composition and then used.

[0154] (Reaction Apparatus) The reaction apparatus is not particularly limited, and known blocked isocyanate production apparatuses can be used. For example, a method can be used in which a mixture containing a primary amine compound, a carbonic acid derivative, and a blocking agent is added to a vessel connected to one or more apparatuses selected from the group consisting of condensers and processing apparatuses, the vessel is heated to produce the blocked isocyanate compound, and then, or simultaneously, vapor containing compounds derived from the carbonic acid derivative is introduced into the condenser or processing apparatus to synthesize the blocked isocyanate compound in a batchwise manner. Alternatively, a method can be used in which a mixture containing a primary amine compound, a carbonic acid derivative, and a blocking agent is continuously introduced into a distillation column heated to a predetermined reaction temperature, and vapor containing compounds derived from the carbonic acid derivative produced simultaneously with the production of the blocked isocyanate compound is separated to continuously obtain the blocked isocyanate compound. Alternatively, a blocked isocyanate compound can be produced by partially or completely reacting a primary amine compound and a carbonic acid derivative in the presence or absence of a blocking agent, and then using the resulting reaction product to produce the blocked isocyanate compound.

[0155] The material of the reaction apparatus for the portion that comes into contact with the mixture containing the primary amine compound, the carbonic acid derivative, and the blocking agent, and the composition containing the blocked isocyanate compound produced by the reaction, may be any known material as long as it does not have adverse effects such as denaturing the primary amine compound, the carbonic acid derivative, the blocking agent, the blocked isocyanate compound, and other components contained therein. Specific examples of such materials include steel, stainless steel, ceramic, carbon, and materials lined with these materials.

[0156] When a distillation apparatus is used, the type of the distillation apparatus is not particularly limited, and various known distillation apparatuses can be used, such as a batch distillation apparatus, a simple distillation apparatus, a multi-stage distillation column, a continuous multi-stage distillation column, or a packed column, or a distillation apparatus that combines these.

[0157] The distillation column used here can have two or more theoretical plates. However, if the number of theoretical plates is large, the multi-stage distillation column will become huge and may be difficult to implement industrially, so the number of theoretical plates is generally 500 or less.

[0158] Any type of distillation column can be used as long as it is typically used as a multi-stage distillation column, such as a plate column type using trays such as bubble trays, perforated trays, valve trays, and countercurrent trays, or a packed column type filled with various packings such as Raschig rings, Lessing rings, Paul rings, Berle saddles, Intalox saddles, Dixon packing, McMahon packing, Helipack, Sulzer packing, and Melapack. Furthermore, a mixed plate-packed column type having both tray sections and sections filled with packings is also preferably used.

[0159] Next, the raw materials used in the production method of the first embodiment and the resulting products will be described in detail below.

[0160] <Secondary amine compounds (I)> The secondary amine compound (I) is a compound represented by the following general formula (I).

[0161] [ka]

[0162] In general formula (I), R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0163] It is known that compounds having an amino group directly bonded to an aromatic ring can become discolored by exposure to oxygen and other factors. However, it has been surprisingly discovered that secondary amine compound (I) exhibits a discoloration-reducing effect. While the cause of this effect is unclear, it is generally known that thermal denaturation and discoloration occur during the process of producing blocked isocyanate compounds from amines, carbonic acid derivatives, and blocking agents. This is presumed to be due to the oxidation and thermal denaturation of the blocked isocyanate compound itself or the isocyanate compound present as a reaction intermediate. It is presumed that secondary amine compound (I) acts on oxidants such as oxygen, and functions as an antioxidant that is oxidized in place of the isocyanate compound or its derivative present in the equilibrium reaction during the process of producing blocked isocyanate compounds by reacting amines, carbonic acid derivatives, and blocking agents. It is also presumed that secondary amine compound (I) is converted into a colorless or low-coloring substance upon heating. Furthermore, secondary amine compound (I) is an amine-based compound that is generally believed to promote the modification of blocked isocyanate compounds and isocyanate compounds present as reaction intermediates, but the promotion of modification observed in general aliphatic amine compounds and heterocyclic amine compounds is not observed or is only slight. This is presumably because secondary amine compound (I) has an aromatic group directly bonded to the nitrogen atom, resulting in low electron density on the nitrogen atom and poor nucleophilicity, and because the substituent bonded to the nitrogen atom causes significant steric hindrance around the nitrogen atom.

[0164] [R 11 and R 12 ] R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group. Among them, R 11 and R 12is preferably a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 70 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 70 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

[0165] R 11 and R 12 The aliphatic hydrocarbon group in has 1 or more and 70 or less carbon atoms, preferably 1 or more and 20 or less, more preferably 1 or more and 12 or less, and even more preferably 1 or more and 10 or less carbon atoms. R 11 and R 12 Specific examples of the aliphatic hydrocarbon group in the formula (I) include a methyl group, an ethyl group, a propyl group (each isomer), a butyl group (each isomer), a pentyl group (each isomer), a hexyl group (each isomer), a heptyl group (each isomer), an octyl group (each isomer), a nonyl group (each isomer), a decyl group (each isomer), an undecyl group (each isomer), a dodecyl group (each isomer), a tridecyl group (each isomer), a tetra ... Examples of such alkyl groups include tetradecyl groups (each isomer), pentadecyl groups (each isomer), hexadecyl groups (each isomer), heptadecyl groups (each isomer), octadecyl groups (each isomer), nonadecyl groups (each isomer), and eicosyl groups (each isomer); and cycloalkyl groups such as cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, cyclooctyl groups, cyclononyl groups, and cyclodecyl groups.

[0166] R 11 and R 12 The aromatic hydrocarbon group in has 6 or more and 70 or less carbon atoms, preferably 6 or more and 20 or less, more preferably 6 or more and 12 or less, and even more preferably 6 or more and 10 or less carbon atoms. R 11 and R 12 Specific examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, and a phenanthryl group.

[0167] R 11 and R 12 Examples of the substituent on the aliphatic hydrocarbon group in the formula (I) include an aromatic hydrocarbon group, a hydroxyl group, a cyano group, and a halogen atom.

[0168] R 11 and R 12 Examples of the substituent on the aromatic hydrocarbon group in the formula (I) include an aliphatic hydrocarbon group, a hydroxyl group, a cyano group, and a halogen atom.

[0169] The aromatic hydrocarbon group as a substituent of the aliphatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms, and specific examples thereof include those exemplified above.

[0170] The aliphatic hydrocarbon group as a substituent of the aromatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and specific examples thereof include those exemplified above.

[0171] Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0172] Preferred secondary amine compounds (I) are not particularly limited, but from the viewpoint of ease of availability, include compounds represented by the following general formulas (I-1) to (I-3) (hereinafter, each may be referred to as "secondary amine compound (I-1)" etc.).

[0173] [ka]

[0174] In general formula (I-1), R 111 is the above R 11 and R 12 is the same as R 112 represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having from 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having from 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n111 represents the number of substituents and is an integer of from 0 to 5.

[0175] [ka]

[0176] In general formula (I-2), R 121 R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. 122 represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having from 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having from 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n121 represents the number of substituents and is an integer of from 0 to 4.

[0177] [ka]

[0178] In general formula (I-3), R 131 is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. 131 is -O-, -NH-, or -C(=O)-. 132 represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having from 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having from 6 to 12 carbon atoms, which may have an ether group. n131 represents the number of substituents and is an integer of from 0 to 4.

[0179] [R 112 and R 122 ] R 112 and R 122 are each a substituent on the benzene ring.

[0180] R 112 and R 122 are each independently a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

[0181] R112 and R 122 The aliphatic hydrocarbon group and aromatic hydrocarbon group in R 11 and R 12 Among them, R 112 and R 122 is preferably each independently an unsubstituted monovalent aliphatic hydrocarbon group having from 1 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, or a propyl group (each isomer).

[0182] [R 132 ] R 132 is a substituent on the benzene ring.

[0183] R 132 is a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group.

[0184] R 132 The aliphatic hydrocarbon group and aromatic hydrocarbon group in R 11 and R 12 Among them, R 132 is preferably an unsubstituted monovalent aliphatic hydrocarbon group having from 1 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, or a propyl group (each isomer).

[0185] [n111, n121 and n131] n111 represents the number of substituents and is an integer of 0 or more and 5 or less, preferably an integer of 0 or more and 3 or less, and more preferably 0 or 1.

[0186] n121 and n131 each represent the number of substituents and are an integer of 0 or more and 4 or less, preferably an integer of 0 or more and 3 or less, and more preferably 0 or 1.

[0187] [R 121 and R 131 ] R121 and R 131 The divalent aliphatic hydrocarbon group in may be saturated or unsaturated.

[0188] R 121 and R 131 Examples of the divalent saturated aliphatic hydrocarbon group include alkylene groups having 1 to 12 carbon atoms and alkylidene groups having 2 to 12 carbon atoms.

[0189] Examples of alkylene groups having 1 to 12 carbon atoms include chain alkylene groups having 1 to 12 carbon atoms and cyclic alkylene groups having 3 to 12 carbon atoms.

[0190] Examples of the chain alkylene group having from 1 to 12 carbon atoms include linear or branched chain alkylene groups having from 1 to 12 carbon atoms. Specific examples of the linear or branched chain alkylene group having from 1 to 12 carbon atoms include a methylene group, an ethylene group, a propylene group, a trimethylene group, a pentylene group, a tetramethylene group, a propane-1,2-diyl group, an n-hexylene group, a pentamethylene group, a butane-1,3-diyl group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, and a dodecamethylene group.

[0191] Examples of the cyclic alkylene group having 3 to 12 carbon atoms include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a cyclononylene group, a cyclodecylene group, a cycloundecylene group, and a cyclocyclododecylene group.

[0192] Examples of alkylidene groups having 2 to 12 carbon atoms include chain alkylidene groups having 2 to 12 carbon atoms and cyclic alkylidene groups having 3 to 12 carbon atoms.

[0193] Examples of the chain alkylidene group having from 2 to 12 carbon atoms include a linear or branched chain alkylidene group having from 2 to 12 carbon atoms. Specific examples of the linear or branched chain alkylidene group having from 2 to 12 carbon atoms include an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, a pentylidene group, a hexylidene group, a heptylidene group, an octylidene group, a nonylidene group, a decylidene group, an undecylidene group, and a dodecylidene group.

[0194] Examples of cyclic alkylidene groups having 3 to 12 carbon atoms include a cyclopropylidene group, a cyclobutylidene group, a cyclohexylidene group, a 3,5,5-trimethylcyclohexylidene group, a cycloheptylidene group, a cyclooctylidene group, a cyclononylidene group, a cyclodecylidene group, a cycloundecylidene group, and a cyclododecylidene group.

[0195] R 121 and R 131 Examples of the divalent unsaturated aliphatic hydrocarbon group include alkenylene groups having 2 to 12 carbon atoms, alkadienylene groups having 2 to 12 carbon atoms, and alkynylene groups having 2 to 12 carbon atoms.

[0196] Examples of the alkenylene group having 2 to 12 carbon atoms include a chain alkenylene group having 2 to 12 carbon atoms and a cyclic alkenylene group having 3 to 12 carbon atoms.

[0197] Examples of the chain alkenylene group having from 2 to 12 carbon atoms include linear or branched chain alkenylene groups having from 2 to 12 carbon atoms. Specific examples of the linear or branched chain alkenylene group having from 2 to 12 carbon atoms include a vinylene group, a propenylene group, an isopropenylene group, a butenylene group, a pentenylene group, a hexenylene group, a heptenylene group, an octenylene group, a nonenylene group, a decenylene group, an undecenylene group, and a dodecenylene group.

[0198] Examples of cyclic alkenylene groups having 3 to 12 carbon atoms include a cyclopropenylene group, a cyclobutenylene group, a cyclopentenylene group, a cyclohexenylene group, a cycloheptenylene group, a cyclooctenylene group, a cyclononenylene group, a cyclodecenylene group, a cycloundecenylene group, and a cyclododecenylene group.

[0199] Examples of the alkadienylene group having 3 to 12 carbon atoms include a chain alkadienylene group having 3 to 12 carbon atoms and a cyclic alkadienylene group having 4 to 12 carbon atoms.

[0200] Examples of the chain alkadienylene group having from 3 to 12 carbon atoms include a linear or branched chain alkadienylene group having from 3 to 12 carbon atoms. Specific examples of the linear or branched chain alkadienylene group having from 3 to 12 carbon atoms include a propadienylene group, a butadienylene group, a 2-ethylbutadienylene group, a pentadienylene group, a hexadienylene group, a heptadienylene group, an octadienylene group, a nonadienylene group, a decadienylene group, an undecadienylene group, and a dodecadienylene group.

[0201] Examples of cyclic alkadienylene groups having 4 to 12 carbon atoms include a cyclobutadienylene group, a cyclopentadienylene group, a cyclohexadienylene group, a cycloheptadienylene group, a cyclooctadienylene group, a cyclononadienylene group, a cyclodecadienylene group, a cycloundecadienylene group, and a cyclododecadienylene group.

[0202] Examples of the alkynylene group having 2 to 12 carbon atoms include a chain alkynylene group having 2 to 12 carbon atoms and a cyclic alkynylene group having 4 to 12 carbon atoms.

[0203] Examples of the chain alkynylene group having from 2 to 12 carbon atoms include linear or branched chain alkynylene groups having from 2 to 12 carbon atoms. Specific examples of the linear or branched chain alkynylene group having from 2 to 12 carbon atoms include an ethynylene group, a propynylene group, an isopropynylene group, a butynylene group, a pentynylene group, a hexynylene group, a heptynylene group, an octynylene group, a nonynylene group, a dequinylene group, an undecynylene group, and a dodecynylene group.

[0204] Examples of cyclic alkynylene groups having 4 to 12 carbon atoms include a cyclobutynylene group, a cyclopentynylene group, a cyclohexynylene group, a cycloheptynylene group, a cyclooctynylene group, a cyclononynylene group, a cyclodecynylene group, a cycloundecynylene group, and a cyclododecynylene group.

[0205] Among the above-mentioned secondary amine compounds (I-1) to (I-3), those in which the amino group bonded to the aromatic hydrocarbon is bonded to an aliphatic hydrocarbon are preferred, as they have a higher coloration-reducing effect, compared to compounds in which the amino group bonded to the aromatic hydrocarbon is directly bonded to the aromatic hydrocarbon or compounds in which the amino group bonded to the aromatic hydrocarbon is directly bonded to an unsaturated hydrocarbon.

[0206] From the viewpoint of thermal stability, it is preferable that the structure be composed only of carbon atoms and hydrogen atoms, excluding the monovalent secondary amino group directly bonded to the aromatic hydrocarbon.

[0207] That is, preferred secondary amine compounds (I-1) include those represented by the formula: 111 is a monovalent aliphatic hydrocarbon group, and R 112 is preferably an unsubstituted aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and n111 is preferably 0 or 1.

[0208] More preferred secondary amine compounds (I-1) include those represented by the formula: 111 is a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and R 112is preferably a methyl group or an ethyl group, and n111 is preferably 0 or 1.

[0209] Preferred secondary amine compounds (I-2) include those represented by the formula: 121 is a divalent aliphatic hydrocarbon group, and R 122 is preferably an unsubstituted aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and n121 is preferably 0 or 1.

[0210] More preferred secondary amine compounds (I-2) include those represented by the formula: 121 is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and R 122 is preferably a methyl group or an ethyl group, and n121 is preferably 0 or 1.

[0211] Preferred secondary amine compounds (I-3) include those represented by the formula: 131 is a divalent aliphatic hydrocarbon group, and R 132 is preferably an unsubstituted aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and n131 is preferably 0 or 1.

[0212] More preferred secondary amine compounds (I-3) include those represented by the formula: 131 is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and R 132 is preferably a methyl group or an ethyl group, and n131 is preferably 0 or 1.

[0213] Specific examples of preferred secondary amine compounds (I-1) include N-methylaniline, N-ethylaniline, N-propylaniline (each isomer), N-butylaniline (each isomer), N-pentylaniline (each isomer), N-hexylaniline (each isomer), N-heptylaniline (each isomer), N-octylaniline (each isomer), and N-nonylaniline (each isomer). toluidine), N-decylaniline (each isomer), N-methyltoluidine (each isomer), N-ethyltoluidine (each isomer), N-propyltoluidine (each isomer), N-butyltoluidine (each isomer), N-pentyltoluidine (each isomer), N-hexyltoluidine (each isomer), N-heptyltoluidine (each isomer), N-octyltoluidine (each isomer), N-aryl Examples of the aniline include toluidine (each isomer), N-arylaniline, 3-(phenylamino)propionitrile, 3-(O-toluylamino)propionitrile, 2-anilinoethanol, fluoro-N-methylaniline (each isomer), chloro-N-methylaniline (each isomer), bromo-N-methylaniline (each isomer), iodo-N-methylaniline (each isomer), fluoro-N-ethylaniline (each isomer), chloro-N-ethylaniline (each isomer), bromo-N-ethylaniline (each isomer), iodo-N-ethylaniline (each isomer), fluoro-N-propylaniline (each isomer), chloro-N-propylaniline (each isomer), bromo-N-propylaniline (each isomer), and iodo-N-propylaniline (each isomer).

[0214] Specific examples of preferred secondary amine compounds (I-2) include 2,3-dihydro-4(1H)-quinolinone, diphenylamine, indoline, methylindoline (each isomer), 1,2,3,4-tetrahydroquinoline, and methyl 1,2,3,4-tetrahydroquinoline (each isomer).

[0215] Specific examples of preferred secondary amine compounds (I-3) include 3,4-dihydro-2H-1,4-benzoxazine.

[0216] Among these, as the secondary amine compound (I), N-alkylaniline compounds such as N-methylaniline, N-ethylaniline, N-propylaniline (each isomer), N-butylaniline (each isomer), N-pentylaniline (each isomer), N-hexylaniline (each isomer), N-heptylaniline (each isomer), N-octylaniline (each isomer), N-nonylaniline (each isomer), and N-decylaniline (each isomer) are preferred because they have high thermal stability as a compound and a higher coloration suppression effect. N-alkyltoluidine compounds such as N-propyltoluidine (each isomer), N-butyltoluidine (each isomer), N-pentyltoluidine (each isomer), N-hexyltoluidine (each isomer), N-heptyltoluidine (each isomer), N-octyltoluidine (each isomer), N-nonyltoluidine (each isomer), and N-decyltoluidine (each isomer); or aromatic cyclic amine compounds such as indoline, methylindoline (each isomer), 1,2,3,4-tetrahydroquinoline, and methyl 1,2,3,4-tetrahydroquinoline (each isomer) are preferred.

[0217] <Tertiary amine compounds (II)> The tertiary amine compound (II) is a compound represented by the following general formula (II).

[0218] [ka]

[0219] In general formula (II), R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R 22 , R 22 and R 23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22, and R 23 At least one of the groups has an aromatic group.

[0220] It is known that compounds having an amino group directly bonded to an aromatic ring can become discolored by exposure to oxygen and other factors. However, it has been surprisingly discovered that tertiary amine compound (II) exhibits a discoloration-reducing effect. While the cause of this effect is unclear, it is generally known that thermal denaturation and discoloration occur during the process of producing blocked isocyanate compounds from amines, carbonic acid derivatives, and blocking agents. This is presumed to be due to the oxidation and thermal denaturation of the blocked isocyanate compound itself or the isocyanate compound present as a reaction intermediate. It is presumed that tertiary amine compound (II) acts on oxidants such as oxygen, and functions as an antioxidant that is oxidized in place of the isocyanate compound or its derivative present in the equilibrium reaction during the process of producing blocked isocyanate compounds by reacting an amine, a carbonic acid derivative, and a blocking agent. It is also presumed that the tertiary amine compound (II) is converted into a colorless or low-coloring substance upon heating. Furthermore, the tertiary amine compound (II) is an amine-based compound that is generally believed to promote the modification of blocked isocyanate compounds and isocyanate compounds present as reaction intermediates, but the promotion of modification observed in general aliphatic amine compounds and heterocyclic amine compounds is not observed or is only slight. This is presumably because the tertiary amine compound (II) has an aromatic group directly bonded to the nitrogen atom, resulting in low electron density on the nitrogen atom and poor nucleophilicity, and because the substituent bonded to the nitrogen atom causes significant steric hindrance around the nitrogen atom.

[0221] [R 21 , R 22 , and R 23 ] R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R 22 , R 22 and R 23 , and R 23 and R 21may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group.

[0222] Among them, R 21 , R 22 , and R 23 is preferably a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 70 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 70 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

[0223] R 21 , R 22 , and R 23 The monovalent aliphatic hydrocarbon group and the monovalent aromatic hydrocarbon group in 11 and R 12 The same examples as those exemplified in

[0224] Preferred examples of the tertiary amine compound (II) include, but are not limited to, compounds represented by the following general formulas (II-1) to (II-3) (hereinafter, each of which may be referred to as "tertiary amine compound (II-1)" or the like) from the viewpoint of ease of availability.

[0225] [ka]

[0226] In general formula (II-1), R 211 and R 212 is the above R 11 and R 12 is the same as R 213 represents a substituent on the benzene ring, and the above R 112 n211 represents the number of substituents and is the same as n111 above.

[0227] [ka]

[0228] In general formula (II-2), R 221 is the above R 11 and R 12 is the same as R 222 is the above R 121 is the same as R 221 and R 222 may be bonded to each other to form a carbon-carbon bond. 223 represents a substituent on the benzene ring, and the above R 122 n221 represents the number of substituents and is the same as n121 above.

[0229] [ka]

[0230] In general formula (II-3), R 231 is the above R 11 and R 12 is the same as R 232 is the above R 131 is the same as R 231 and R 232 may be bonded to each other to form a carbon-carbon bond. 231 is the above Z 131 is the same as R 233 represents a substituent on the benzene ring, and the above R 122 n231 represents the number of substituents and is the same as n131 above.

[0231] Among the above-mentioned tertiary amine compounds (II-1) to (II-3), compounds in which the amino group bonded to the aromatic hydrocarbon is bonded to an aliphatic hydrocarbon are preferred because they have a higher coloration reduction effect than compounds in which the amino group bonded to the aromatic hydrocarbon is directly bonded to the aromatic hydrocarbon or compounds in which the amino group bonded to the aromatic hydrocarbon is directly bonded to an unsaturated hydrocarbon.

[0232] From the viewpoint of thermal stability, it is preferable that the structure be composed only of carbon atoms and hydrogen atoms, excluding the monovalent secondary amino group directly bonded to the aromatic hydrocarbon.

[0233] That is, preferred secondary amine compounds (II-1) include those represented by the formula: 211 and R 212 is a monovalent aliphatic hydrocarbon group, and R 213 is preferably an unsubstituted aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and n211 is preferably 0 or 1.

[0234] More preferred secondary amine compounds (II-1) include those represented by the formula: 211 and R 212 is a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and R 213 is preferably a methyl group or an ethyl group, and n211 is preferably 0 or 1.

[0235] Preferred secondary amine compounds (II-2) include those represented by the formula: 221 is a monovalent aliphatic hydrocarbon group, and R 222 is a divalent aliphatic hydrocarbon group, and R 223 is preferably an unsubstituted aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and n221 is preferably 0 or 1.

[0236] More preferred secondary amine compounds (II-2) include those represented by the formula: 221 is a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and R 222 is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and R 221 and R 222 are bonded to each other to form carbon-carbon bonds, and R 223 is preferably a methyl group or an ethyl group, and n221 is preferably 0 or 1.

[0237] Preferred secondary amine compounds (II-3) include those represented by the formula: 231is a monovalent aliphatic hydrocarbon group, and R 232 is a divalent aliphatic hydrocarbon group, and R 233 is preferably an unsubstituted aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and n231 is preferably 0 or 1.

[0238] More preferred secondary amine compounds (II-3) include those represented by the formula: 231 is a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and R 232 is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and R 221 and R 222 are bonded to each other to form carbon-carbon bonds, and R 233 is preferably a methyl group or an ethyl group, and n231 is preferably 0 or 1.

[0239] Specific examples of preferred tertiary amine compounds (II-1) include N,N-dimethylaniline, N-methyl-N-ethylaniline, N,N-diethylaniline, N-methyl-N-propylaniline (each isomer), N-ethyl-N-propylaniline (each isomer), N,N-dipropylaniline (each isomer), N-methyl-N-butylaniline (each isomer), N-ethyl-N-butylaniline (each isomer), and N-propyl-N-butylaniline. (each isomer), N,N-dibutylaniline (each isomer), N-methyl-N-pentylaniline (each isomer), N-ethyl-N-pentylaniline (each isomer), N-propyl-N-pentylaniline (each isomer), N-butyl-N-pentylaniline (each isomer), N,N-dipentylaniline (each isomer), N-methyl-N-hexylaniline (each isomer), N-ethyl-N-hexylaniline (each isomer), N-propyl-N-hexylaniline N-butyl-N-hexylaniline (each isomer), N-pentyl-N-hexylaniline (each isomer), N,N-dihexylaniline (each isomer), N-methyl-N-heptylaniline (each isomer), N-ethyl-N-heptylaniline (each isomer), N-propyl-N-heptylaniline (each isomer), N-butyl-N-heptylaniline (each isomer), N-pentyl-N-heptylaniline (each isomer), N-hexyl-N-heptylaniline N-butylaniline (each isomer), N,N-diheptylaniline (each isomer), N-methyl-N-octylaniline (each isomer), N-ethyl-N-octylaniline (each isomer), N-propyl-N-octylaniline (each isomer), N-butyl-N-octylaniline (each isomer), N-pentyl-N-octylaniline (each isomer), N-hexyl-N-octylaniline (each isomer), N-heptyl-N-octylaniline (each isomer), N,N-Dioctylaniline (each isomer), N-Methyl-N-nonylaniline (each isomer), N-Ethyl-N-nonylaniline (each isomer), N-Propyl-N-nonylaniline (each isomer), N-Butyl-N-nonylaniline (each isomer), N-Pentyl-N-nonylaniline (each isomer), N-Hexyl-N-nonylaniline (each isomer), N-Heptyl-N-nonylaniline (each isomer), N-Octyl-N-nonylaniline (each isomer), N,N-Dinonylaniline (each isomer), N-Methyl-N -decylaniline (each isomer), N-ethyl-N-decylaniline (each isomer), N-propyl-N-decylaniline (each isomer), N-butyl-N-decylaniline (each isomer), N-pentyl-N-decylaniline (each isomer), N-hexyl-N-decylaniline (each isomer), N-heptyl-N-decylaniline (each isomer), N-octyl-N-decylaniline (each isomer), N-nonyl-N-decylaniline (each isomer), N,N-didecylaniline (each isomer), N,N-dimethyltoluol Toluidine (each isomer), N-methyl-N-ethyltoluidine (each isomer), N,N-diethyltoluidine (each isomer), N-methyl-N-propyltoluidine (each isomer), N-ethyl-N-propyltoluidine (each isomer), N,N-dipropyltoluidine (each isomer), N-methyl-N-butyltoluidine (each isomer), N-ethyl-N-butyltoluidine (each isomer), N-propyl-N-butyltoluidine (each isomer), N,N-dibutyltoluidine (each isomer), N-methyl-N-pentyltoluidine Toluidine (each isomer), N-ethyl-N-pentyltoluidine (each isomer), N-propyl-N-pentyltoluidine (each isomer), N-butyl-N-pentyltoluidine (each isomer), N,N-dipentyltoluidine (each isomer), N-methyl-N-hexyltoluidine (each isomer), N-ethyl-N-hexyltoluidine (each isomer), N-propyl-N-hexyltoluidine (each isomer), N-butyl-N-hexyltoluidine (each isomer), N-pentyl-N-hexyltoluidine (each isomer),N-Dihexyltoluidine (each isomer), N-methyl-N-heptyltoluidine (each isomer), N-ethyl-N-heptyltoluidine (each isomer), N-propyl-N-heptyltoluidine (each isomer), N-butyl-N-heptyltoluidine (each isomer), N-pentyl-N-heptyltoluidine (each isomer), N-hexyl-N-heptyltoluidine (each isomer), N,N-diheptyltoluidine (each isomer), N-methyl-N-octyltoluidine (each isomer), N-ethyl-N-octyltoluidine Toluidine (each isomer), N-propyl-N-octyltoluidine (each isomer), N-butyl-N-octyltoluidine (each isomer), N-pentyl-N-octyltoluidine (each isomer), N-hexyl-N-octyltoluidine (each isomer), N-heptyl-N-octyltoluidine (each isomer), N,N-dioctyltoluidine (each isomer), N-methyl-N-nonyltoluidine (each isomer), N-ethyl-N-nonyltoluidine (each isomer), N-propyl-N-nonyltoluidine (each isomer), N-butyl-N-nonyltoluidine (each isomer), N-pentyl-N-nonyltoluidine (each isomer), N-hexyl-N-nonyltoluidine (each isomer), N-heptyl-N-nonyltoluidine (each isomer), N-octyl-N-nonyltoluidine (each isomer), N,N-dinonyltoluidine (each isomer), N-methyl-N-decyltoluidine (each isomer), N-ethyl-N-decyltoluidine (each isomer), N-propyl-N-decyltoluidine (each isomer), N-butyl-N-decyltoluidine (each isomer), N-pentyl-N-decyl toluidine (each isomer), N-hexyl-N-decyl toluidine (each isomer), N-heptyl-N-decyl toluidine (each isomer), N-octyl-N-decyl toluidine (each isomer), N-nonyl-N-decyl toluidine (each isomer), N,N-didecyl toluidine (each isomer), N,N-diarylaniline, N-aryl-N-methylaniline, N,N-diaryl toluidine (each isomer), 3,3'-(phenylazanediyl)dipropanenitrile, 3,3'-(o-Tolylazanediyl)dipropanenitrile (each isomer), N-methyl-N-phenylaniline, N-ethyl-N-phenylaniline, N-propyl-N-phenylaniline (each isomer), N-butyl-N-phenylaniline (each isomer), N-pentyl-N-phenylaniline (each isomer), N-hexyl-N-phenylaniline (each isomer), N-heptyl-N-phenylaniline (each isomer), N-octyl-N-phenylaniline (each isomer), N-nonyl-N-phenylaniline (each isomer), N-decyl-N-phenylaniline (each isomer), N-phenyldiethanolamine, fluoro-N,N- Examples of such aniline include dimethylaniline (each isomer), chloro-N,N-dimethylaniline (each isomer), bromo-N,N-dimethylaniline (each isomer), iodo-N,N-dimethylaniline (each isomer), fluoro-N,N-diethylaniline (each isomer), chloro-N,N-diethylaniline (each isomer), bromo-N,N-diethylaniline (each isomer), iodo-N,N-diethylaniline (each isomer), fluoro-N,N-dipropylaniline (each isomer), chloro-N,N-dipropylaniline (each isomer), bromo-N,N-dipropylaniline (each isomer), and iodo-N,N-dipropylaniline (each isomer).

[0240] Specific examples of preferred tertiary amine compounds (II-2) include 1-methyl-2,3-dihydro-4(1H)-quinolinone, N-methylindoline, N-ethylindoline, N-propylindoline (each isomer), N-butylindoline (each isomer), N-pentylindoline (each isomer), N-hexylindoline (each isomer), N-heptylindoline (each isomer), N-octylindoline (each isomer), N-heptylindoline (each isomer), N-nonylindoline (each isomer), N-decylindoline (each isomer), N-methyl-1,2,3,4-tetrahydroquinoline, N-ethyl-1,2, Examples include 3,4-tetrahydroquinoline, N-propyl-1,2,3,4-tetrahydroquinoline (each isomer), N-butyl-1,2,3,4-tetrahydroquinoline (each isomer), N-pentyl-1,2,3,4-tetrahydroquinoline (each isomer), N-hexyl-1,2,3,4-tetrahydroquinoline (each isomer), N-heptyl-1,2,3,4-tetrahydroquinoline (each isomer), N-octyl-1,2,3,4-tetrahydroquinoline (each isomer), N-nonyl-1,2,3,4-tetrahydroquinoline (each isomer), and N-decyl-1,2,3,4-tetrahydroquinoline (each isomer).

[0241] A specific example of a preferred tertiary amine compound (II-3) is 4-methyl-3,4-dihydro-2H-1,4-benzoxazine.

[0242] Among these, as the tertiary amine compound (II), N,N-dimethylaniline, N-methyl-N-ethylaniline, N,N-diethylaniline, N-methyl-N-propylaniline (each isomer), N-ethyl-N-propylaniline (each isomer), N,N-dipropylaniline (each isomer), N-methyl-N-butylaniline (each isomer), N-ethyl-N-butylaniline (each isomer), and N-ethyl-N-butylaniline (each isomer) are preferred because of their high thermal stability as compounds and their high coloration suppression effect. ), N-propyl-N-butylaniline (each isomer), N,N-dibutylaniline (each isomer), N-methyl-N-pentylaniline (each isomer), N-ethyl-N-pentylaniline (each isomer), N-propyl-N-pentylaniline (each isomer), N-butyl-N-pentylaniline (each isomer), N,N-dipentylaniline (each isomer), N-methyl-N-hexylaniline (each isomer), N-ethyl-N-hexylaniline (each isomer), N-propyl N-propyl-N-hexylaniline (each isomer), N-butyl-N-hexylaniline (each isomer), N-pentyl-N-hexylaniline (each isomer), N,N-dihexylaniline (each isomer), N-methyl-N-heptylaniline (each isomer), N-ethyl-N-heptylaniline (each isomer), N-propyl-N-heptylaniline (each isomer), N-butyl-N-heptylaniline (each isomer), N-pentyl-N-heptylaniline (each isomer), N-hexyl N-heptyl-N-heptylaniline (each isomer), N,N-diheptylaniline (each isomer), N-methyl-N-octylaniline (each isomer), N-ethyl-N-octylaniline (each isomer), N-propyl-N-octylaniline (each isomer), N-butyl-N-octylaniline (each isomer), N-pentyl-N-octylaniline (each isomer), N-hexyl-N-octylaniline (each isomer), N-heptyl-N-octylaniline (each isomer), N,N-Dioctylaniline (each isomer), N-Methyl-N-nonylaniline (each isomer), N-Ethyl-N-nonylaniline (each isomer), N-Propyl-N-nonylaniline (each isomer), N-Butyl-N-nonylaniline (each isomer), N-Pentyl-N-nonylaniline (each isomer), N-Hexyl-N-nonylaniline (each isomer), N-Heptyl-N-nonylaniline (each isomer), N-Octyl-N-nonylaniline (each isomer), N,N-Dinonylaniline (each isomer), N-Methyl-N-decylaniline N,N-dialkylaniline compounds such as N-isopropyl-N-decylaniline (each isomer), N-ethyl-N-decylaniline (each isomer), N-propyl-N-decylaniline (each isomer), N-butyl-N-decylaniline (each isomer), N-pentyl-N-decylaniline (each isomer), N-hexyl-N-decylaniline (each isomer), N-heptyl-N-decylaniline (each isomer), N-octyl-N-decylaniline (each isomer), N-nonyl-N-decylaniline (each isomer), and N,N-didecylaniline (each isomer); N-dimethyltoluidine (each isomer), N-methyl-N-ethyltoluidine (each isomer), N,N-diethyltoluidine (each isomer), N-methyl-N-propyltoluidine (each isomer), N-ethyl-N-propyltoluidine (each isomer), N,N-dipropyltoluidine (each isomer), N-methyl-N-butyltoluidine (each isomer), N-ethyl-N-butyltoluidine (each isomer), N-propyl-N-butyltoluidine (each isomer), N,N-dibutyltoluidine (each isomer), N-methyl-N-pentyltoluidine N-ethyl toluidine (each isomer), N-ethyl-N-pentyl toluidine (each isomer), N-propyl-N-pentyl toluidine (each isomer), N-butyl-N-pentyl toluidine (each isomer), N,N-dipentyl toluidine (each isomer), N-methyl-N-hexyl toluidine (each isomer), N-ethyl-N-hexyl toluidine (each isomer), N-propyl-N-hexyl toluidine (each isomer), N-butyl-N-hexyl toluidine (each isomer), N-pentyl-N-hexyl toluidine (each isomer)N-Dihexyltoluidine (each isomer), N-methyl-N-heptyltoluidine (each isomer), N-ethyl-N-heptyltoluidine (each isomer), N-propyl-N-heptyltoluidine (each isomer), N-butyl-N-heptyltoluidine (each isomer), N-pentyl-N-heptyltoluidine (each isomer), N-hexyl-N-heptyltoluidine (each isomer), N,N-diheptyltoluidine (each isomer), N-methyl-N-octyltoluidine (each isomer) isomer), N-ethyl-N-octyl toluidine (each isomer), N-propyl-N-octyl toluidine (each isomer), N-butyl-N-octyl toluidine (each isomer), N-pentyl-N-octyl toluidine (each isomer), N-hexyl-N-octyl toluidine (each isomer), N-heptyl-N-octyl toluidine (each isomer), N,N-dioctyl toluidine (each isomer), N-methyl-N-nonyl toluidine (each isomer), N-ethyl-N-nonyl N-nonyltoluidine (each isomer), N-propyl-N-nonyltoluidine (each isomer), N-butyl-N-nonyltoluidine (each isomer), N-pentyl-N-nonyltoluidine (each isomer), N-hexyl-N-nonyltoluidine (each isomer), N-heptyl-N-nonyltoluidine (each isomer), N-octyl-N-nonyltoluidine (each isomer), N,N-dinonyltoluidine (each isomer), N-methyl-N-decyltoluidine (each isomer), N-ethyl- N-decyl toluidine (each isomer), N-propyl-N-decyl toluidine (each isomer), N-butyl-N-decyl toluidine (each isomer), N-pentyl-N-decyl toluidine (each isomer), N-hexyl-N-decyl toluidine (each isomer), N-heptyl-N-decyl toluidine (each isomer), N-octyl-N-decyl toluidine (each isomer), N-nonyl-N-decyl toluidine (each isomer), N,N-didecyl toluidine (each isomer), etc.N-Dialkyltoluidine compounds; or N-methylindoline, N-ethylindoline, N-propylindoline (each isomer), N-butylindoline (each isomer), N-pentylindoline (each isomer), N-hexylindoline (each isomer), N-heptylindoline (each isomer), N-octylindoline (each isomer), N-heptylindoline (each isomer), N-nonylindoline (each isomer), N-decylindoline (each isomer), N-methyl-1,2,3,4-tetrahydroquinoline, N-ethyl-1,2,3,4-tetrahydroquinoline, N-propyl-1,2,3 Preferred are N-alkyl aromatic cyclic amines such as N-4-tetrahydroquinoline (each isomer), N-butyl-1,2,3,4-tetrahydroquinoline (each isomer), N-pentyl-1,2,3,4-tetrahydroquinoline (each isomer), N-hexyl-1,2,3,4-tetrahydroquinoline (each isomer), N-heptyl-1,2,3,4-tetrahydroquinoline (each isomer), N-octyl-1,2,3,4-tetrahydroquinoline (each isomer), N-nonyl-1,2,3,4-tetrahydroquinoline (each isomer), and N-decyl-1,2,3,4-tetrahydroquinoline (each isomer).

[0243] <Phenol-based antioxidant> The phenolic antioxidant used in combination with the secondary amine compound (I) and the tertiary amine compound (II) is not particularly limited, and may be any compound having one or more hydroxy groups bonded to an aromatic ring in the molecule. Specific examples of the phenolic antioxidant include phenol, methylphenol (each isomer), ethylphenol (each isomer), propylphenol (each isomer), butylphenol (each isomer), pentylphenol (each isomer), hexylphenol (each isomer), heptylphenol (each isomer), octylphenol (each isomer), nonylphenol (each isomer), decylphenol (each isomer), undecylphenol (each isomer), tridecylphenol (each isomer), tetradecylphenol, ... Isopropylphenol (each isomer), octadecylphenol (each isomer), nonadecylphenol (each isomer), icosylphenol (each isomer), cyclopentylphenol (each isomer), cyclohexylphenol (each isomer), dimethylphenol (each isomer), methylethylphenol (each isomer), diethylphenol (each isomer), methylpropylphenol (each isomer), ethylpropylphenol (each isomer), dipropylphenol (each isomer), methylbutylphenol (each isomer) , ethylbutylphenol (each isomer), propylbutylphenol (each isomer), dibutylphenol (each isomer), trimethylphenol (each isomer), methyldiethylphenol (each isomer), dimethylethylphenol (each isomer), triethylphenol (each isomer), methyldipropylphenol (each isomer), dimethylpropylphenol (each isomer), tripropylphenol (each isomer), ethyldipropylphenol (each isomer), diethylpropylphenol (each isomer), Methyl dibutylphenol (each isomer), dimethyl butylphenol (each isomer), ethyl dibutylphenol (each isomer), diethyl butylphenol (each isomer), propyl dibutylphenol (each isomer), dipropyl butylphenol (each isomer), tributylphenol (each isomer), naphthol (each isomer), methyl naphthol (each isomer), ethyl naphthol (each isomer), propyl naphthol (each isomer), butyl naphthol (each isomer), tetrahydronaphthalen-1-ol,Phenol-based blocking agents having a hydrocarbon group such as tetrahydronaphthalen-2-ol, hydroxyphenylphenylmethane (each isomer), hydroxyphenylphenylethane (each isomer), hydroxyphenylphenylpropane (each isomer), hydroxyphenylphenylbutane (each isomer), 4-α-cumylphenol, 2,4-di-α-cumylphenol, etc.; methoxyphenol (each isomer), ethoxyphenol (each isomer), propoxyphenol (each isomer), butoxyphenol (each isomer), pentoxyphenol (each isomer), hexoxyphenol, etc. Diphenol (each isomer), heptoxyphenol (each isomer), octoxyphenol (each isomer), methoxymethylphenol (each isomer), methoxyethylphenol (each isomer), methoxypropylphenol (each isomer), methoxybutylphenol (each isomer), ethoxymethylphenol (each isomer), ethoxyethylphenol (each isomer), ethoxypropylphenol (each isomer), ethoxybutylphenol (each isomer), propoxymethylphenol (each isomer), propoxyethylphenol (each isomer), propoxypropyl Phenol (each isomer), butoxymethylphenol (each isomer), butoxyethylphenol (each isomer), butoxypropylphenol (each isomer), butoxybutylphenol, and phenols having halogen groups, such as fluorophenol (each isomer), difluorophenol (each isomer), trifluorophenol (each isomer), tetrafluorophenol (each isomer), pentafluorophenol (each isomer), chlorophenol (each isomer), dichlorophenol (each isomer), trichlorophenol (each isomer), tetrachlorophenol ( each isomer), pentachlorophenol (each isomer), bromophenol (each isomer), dibromophenol (each isomer), tribromophenol (each isomer), tetrabromophenol (each isomer), pentabromophenol (each isomer), iodophenol (each isomer), diiodophenol (each isomer), triiodophenol (each isomer), tetraiodophenol (each isomer), pentaiodophenol (each isomer), phenolic blocking agents having a carbonyl group, such as methyl salicylate, ethyl salicylate, propyl salicylate (each isomer),Examples of such salicylate include butyl salicylate (each isomer), pentyl salicylate (each isomer), hexyl salicylate (each isomer), heptyl salicylate (each isomer), octyl salicylate (each isomer), nonyl salicylate (each isomer), decyl salicylate (each isomer), undecyl salicylate (each isomer), dodecyl salicylate (each isomer), tetradecyl salicylate (each isomer), octadecyl salicylate (each isomer), and acetylphenol.

[0244] Among these, phenol, 2,6-di-tert-butyl-4-methylphenol, and 3-(tert-butyl)-4-methoxyphenol are preferred because of their availability, and 2,6-di-tert-butyl-4-methylphenol and 3-(tert-butyl)-4-methoxyphenol are more preferred because of their availability and high coloration-reducing effect.

[0245] <Primary amine compounds> As the primary amine compound, a compound represented by the following general formula (III) (hereinafter, sometimes referred to as "primary amine compound (III)") is preferably used.

[0246] [ka]

[0247] In general formula (III), R 31 is an organic group having a valence of n31, where n31 is an integer of 1 or more and 12 or less.

[0248] R 31 is an organic group with a valence of n31. That is, it is an organic group with a valence of 1 to 12. Among them, R 31 The alkyl group is preferably an organic group consisting of carbon atoms, oxygen atoms, and hydrogen atoms, and more preferably an organic group having no active hydrogen atoms.

[0249] R 31The aliphatic hydrocarbon group in is preferably an alkylene group or an alkanetriyl group, a cycloalkyl group, a cycloalkylene group or a cycloalkanetriyl group, or a group composed of the alkyl group, the alkylene group or the alkanetriyl group and the cycloalkyl group, the cycloalkylene group or the cycloalkanetriyl group, and more preferably a linear or branched alkylene group or an alkanetriyl group, a cycloalkylene group or a cycloalkanetriyl group, or a group composed of the alkylene group or the alkanetriyl group and the cycloalkyl group, the cycloalkylene group or the cycloalkanetriyl group.

[0250] Examples of the linear or branched alkylene group include a methylene group, an ethylene group, a propylene group, a trimethylene group, a pentylene group, an n-hexylene group, and a decamethylene group. Examples of the cycloalkylene group include a cyclobutylene group, a cyclopentylene group, and a cyclohexylene group.

[0251] Examples of the linear or branched alkanetriyl group include a hexanetriyl group, a nonanetriyl group, and a decanetriyl group.

[0252] Examples of the cycloalkanetriyl group include a cyclopropanetriyl group, a cyclobutanetriyl group, a cyclopentanetriyl group, and a cyclohexanetriyl group.

[0253] R 31 The aromatic hydrocarbon group in is preferably a substituted or unsubstituted group having an aromatic ring with 6 to 13 carbon atoms. Examples of the substituent include an alkyl group, an aryl group, and an aralkyl group. The aromatic ring may be an aromatic hydrocarbon ring or a heteroaromatic ring, and specific examples include a benzene ring, a naphthalene ring, and a pyridine ring.

[0254] Preferred primary amine compounds include monofunctional primary amine compounds, bifunctional primary amine compounds, and polyfunctional primary amine compounds.

[0255] Examples of monofunctional primary amine compounds include methylamine, ethylamine, propylamine (each isomer), butylamine (each isomer), pentylamine (each isomer), hexylamine (each isomer), heptylamine (each isomer), octylamine (each isomer), nonylamine (each isomer), decylamine (each isomer), undecylamine (each isomer), dodecylamine (each isomer), tridecylamine (each isomer), tetradecylamine (each isomer), pentadecylamine (each isomer), primary amine compounds having saturated hydrocarbon groups, such as 2-aminomethyl acrylate, 2-aminoethyl acrylate, 2-aminopropyl acrylate (each isomer), 2-aminobutyl acrylate (each isomer), 2-aminomethyl methacrylate, 2-aminoethyl methacrylate, 2-aminopropyl methacrylate (each isomer); primary amine compounds having an unsaturated bond, such as (S)-2-amino-3-tert-butoxypropionate (each isomer), 2-aminobutyl methacrylate (each isomer), phenylamine, and benzylamine; methyl (S)-2-amino-3-tert-butoxypropionate, ethyl (S)(S)-2-amino-3-tert-butoxypropionate, propyl (S)-2-amino-3-tert-butoxypropionate (each isomer), butyl (S)-2-amino-3-tert-butoxypropionate (each isomer), and (S)-2-amino- Primary amine compounds having an ether group, such as pentyl 3-tert-butoxypropionate (each isomer), hexyl (S)-2-amino-3-tert-butoxypropionate (each isomer), and dodecyl (S)-2-amino-3-tert-butoxypropionate (each isomer); primary amine compounds having a halogen group, such as fluorophenylamine (each isomer), chlorophenylamine (each isomer), bromophenylamine (each isomer), and iodophenylamine (each isomer);Examples of primary amine compounds having a carbonyl group include glycine methyl ester, glycine ethyl ester, glycine propyl ester (each isomer), glycine butyl ester (each isomer), glycine pentyl ester (each isomer), glycine hexyl ester (each isomer), glycine dodecyl ester (each isomer), leucine methyl ester, leucine ethyl ester, leucine propyl ester (each isomer), leucine butyl ester (each isomer), leucine pentyl ester (each isomer), leucine hexyl ester (each isomer), and leucine dodecyl ester (each isomer);

[0256] Examples of bifunctional primary amine compounds include dimethylene diamine, trimethylene diamine (each isomer), tetramethylene diamine (each isomer), pentamethylene diamine (each isomer), hexamethylene diamine (each isomer), heptamethylene diamine (each isomer), octamethylene diamine (each isomer), cyclohexane diamine (each isomer), methylcyclohexane diamine (each isomer), isophorone diamine (each isomer), dicyclohexylmethane diamine (each isomer), dimethylpropane diamine (each isomer), di Methylpentanediamine (each isomer), dimethylhexanediamine (each isomer), dimethylheptanediamine (each isomer), dimethyloctanediamine (each isomer), dimethylnonanediamine (each isomer), dimethyldecanediamine (each isomer), methylethylpropanediamine (each isomer), methylethylbutanediamine (each isomer), methylethylpentanediamine (each isomer), methylethylhexanediamine (each isomer), methylethylheptanediamine (each isomer), methylethyloctanediamine (each isomer), Primary amine compounds having saturated hydrocarbon groups, such as diethylpropanediamine (each isomer), diethylpentanediamine (each isomer), diethylhexanediamine (each isomer), diethylheptanediamine (each isomer), diethyloctanediamine (each isomer), and diethylnonanediamine (each isomer); diphenylmethanediamine (each isomer), tolylenediamine (each isomer), naphthalenediamine (each isomer), xylylenediamine (each isomer), tetramethylxylylenediamine (each isomer), methylenebis(diisoamido)amine, Examples of the amine compounds include primary amine compounds having an unsaturated hydrocarbon group, such as oxybis(phenylene)diamine (each isomer), oxybis(phenylene)diamine (each isomer), carbonylbis(phenylene)diamine (each isomer), butenediamine (each isomer), and butynylenediamine; and primary amine compounds having an ester group, such as lysine methyl ester, lysine ethyl ester, lysine propyl ester (each isomer), lysine butyl ester (each isomer), lysine pentyl ester (each isomer), and lysine hexyl ester (each isomer).

[0257] Examples of polyfunctional amines include propanetriamine, butanetriamine (each isomer), pentanetriamine (each isomer), hexanetriamine (each isomer), heptanetriamine (each isomer), octanetriamine (each isomer), nonanetriamine (each isomer), decanetriamine (each isomer), undecanetriamine (each isomer), dodecanetriamine (each isomer), tridecanetriamine (each isomer), tetradecanetriamine (each isomer), pentadecanetriamine (each isomer), hexadecanetriamine (each isomer), heptadecanetriamine (each isomer), and octadecanetriamine (each isomer). primary amine compounds having saturated hydrocarbon groups such as methyl methyl amine (methyl methyl amine isomer), nonadecanetriamine (each isomer), and icosanetriamine (each isomer); primary amine compounds having unsaturated hydrocarbon groups such as polymeric MDA (each isomer); primary amine compounds having ester groups such as 2-aminoethyl 2,6-diaminehexanoate; and primary amine compounds having difunctional or higher functional amino groups with isocyanurate groups, primary amine compounds having difunctional or higher functional amino groups with biuret groups, and primary amine compounds having difunctional or higher functional amino groups with allophanate groups.

[0258] <Blocking agent> The blocking agent may be any compound that has an active hydrogen group, reacts with an isocyanate group to form a bond, and is capable of producing a blocked isocyanate compound from a primary amine compound, a carbonic acid derivative, and a blocking agent, and that can be decomposed into an isocyanate compound and a blocking agent by thermal decomposition. Examples of such blocking agents include alcohol-based, phenol-based (hereinafter, alcohol-based and phenol-based blocking agents may be collectively referred to as "hydroxy compounds"), thiol-based, amine and ammonia-based, oxime-based, hydroxylamine-based, and active methylene-based blocking agents. Among these, from the viewpoint of the stability of the blocking agent in the reaction of heating a primary amine compound, a carbonic acid derivative, and a blocking agent to produce a blocked isocyanate compound, blocking agents composed of a hydroxy compound, amine and ammonia-based, or hydroxylamine-based blocking agents are preferred, blocking agents composed of a hydroxy compound or amine and ammonia-based blocking agents are more preferred, and blocking agents composed of a hydroxy compound, blocking agents composed of an amine compound, or ammonia are even more preferred. Furthermore, in obtaining a blocked isocyanate compound, it is particularly preferable to use a blocking agent with high nucleophilicity, because this agent is capable of reacting preferentially with an isocyanate group and increases the yield of the blocked isocyanate compound. When comparing phenol-based blocking agents, alcohol-based blocking agents, amine- and ammonia-based blocking agents, and hydroxylamine-based blocking agents from the viewpoint of the nucleophilicity of the blocking agent, the ranking is generally as follows: hydroxylamine-based blocking agents < phenol-based blocking agents < alcohol-based blocking agents < amine- and ammonia-based blocking agents.

[0259] [Phenol-based blocking agent] The phenolic blocking agent is not particularly limited as long as it is a compound having a hydroxyl group bonded to an aromatic ring. However, due to ease of availability, a blocking agent having a phenol group or a naphthol group is preferred. It may be a compound having a hydroxyl group bonded to one aromatic ring in the molecule, or a compound having hydroxyl groups bonded to two or more aromatic rings in the molecule. When a compound having hydroxyl groups bonded to two or more aromatic rings in the molecule is used as a blocking agent, the resulting blocked isocyanate compound contains high-molecular-weight blocked isocyanates, which increase the viscosity of the blocked isocyanate composition containing the blocked isocyanate compound and sometimes cause gelation, making the production of the blocked isocyanate compound and the blocked isocyanate composition difficult. Therefore, it is preferred to use a compound having a hydroxyl group bonded to one aromatic ring in the molecule as a phenolic blocking agent.

[0260] Preferred examples of the phenol-based blocking agent include compounds represented by the following general formula (IV-1) (hereinafter, sometimes referred to as "phenol-based blocking agent (IV-1)").

[0261] [ka]

[0262] In general formula (IV-1), ring A 41 is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. 41 R is a hydrogen atom, a halogen atom, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkyloxycarbonyl group having from 1 to 20 carbon atoms, an alkylcarbonyloxy group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aryloxy group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or an aralkyloxy group having from 7 to 20 carbon atoms. 41 is ring A 41 may bond to form a ring structure. In addition, n41 is an integer of 1 or more and 10 or less.

[0263] (R 41 ) R 41 Examples of the alkyl group having 1 to 20 carbon atoms in the formula (I) include a methyl group, an ethyl group, a propyl group (each isomer), a butyl group (each isomer), a pentyl group (each isomer), a hexyl group (each isomer), a heptyl group (each isomer), an octyl group (each isomer), a nonyl group (each isomer), a decyl group (each isomer), a dodecyl group (each isomer), and an octadecyl group (each isomer).

[0264] R 41 Examples of the alkoxy group having 1 to 20 carbon atoms in the formula (I) include a methoxy group, an ethoxy group, a propoxy group (each isomer), a butyloxy group (each isomer), a pentyloxy group (each isomer), a hexyloxy group (each isomer), a heptyloxy group (each isomer), an octyloxy group (each isomer), a nonyloxy group (each isomer), a decyloxy group (each isomer), a dodecyloxy group (each isomer), and an octadecyloxy group (each isomer).

[0265] R 41 Examples of the alkyloxycarbonyl group having 1 to 20 carbon atoms in the formula (I) include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group (each isomer), a butyloxycarbonyl group (each isomer), a pentyloxycarbonyl group (each isomer), a hexyloxycarbonyl group (each isomer), a heptyloxycarbonyl group (each isomer), an octyloxycarbonyl group (each isomer), a nonyloxycarbonyl group (each isomer), a decyloxycarbonyl group (each isomer), a dodecyloxycarbonyl group (each isomer), and an octadecyloxycarbonyl group (each isomer).

[0266] R 41Examples of the alkylcarbonyloxy group having 1 to 20 carbon atoms in the formula (I) include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group (each isomer), a butylcarbonyloxy group (each isomer), a pentylcarbonyloxy group (each isomer), a hexylcarbonyloxy group (each isomer), a heptylcarbonyloxy group (each isomer), an octylcarbonyloxy group (each isomer), a nonylcarbonyloxy group (each isomer), a decylcarbonyloxy group (each isomer), a dodecylcarbonyloxy group (each isomer), and an octadecylcarbonyloxy group (each isomer).

[0267] R 41 Examples of the aryl group having 6 to 20 carbon atoms in the formula include a phenyl group and a naphthyl group.

[0268] R 41 Examples of the aryl group having an alkyl group as a substituent in the formula (I) include a methylphenyl group (each isomer), an ethylphenyl group (each isomer), a propylphenyl group (each isomer), a butylphenyl group (each isomer), a pentylphenyl group (each isomer), a hexylphenyl group (each isomer), a heptylphenyl group (each isomer), an octylphenyl group (each isomer), a nonylphenyl group (each isomer), a decylphenyl group (each isomer), a biphenyl group (each isomer), a diphenyl group (each isomer), a dimethyl ... Examples of the phenyl group include a methylphenyl group (each isomer), a diethylphenyl group (each isomer), a dipropylphenyl group (each isomer), a dibutylphenyl group (each isomer), a dipentylphenyl group (each isomer), a dihexylphenyl group (each isomer), a diheptylphenyl group (each isomer), a terphenyl group (each isomer), a trimethylphenyl group (each isomer), a triethylphenyl group (each isomer), a tripropylphenyl group (each isomer), and a tributylphenyl group (each isomer).

[0269] R 41Examples of the aryloxy group having 6 to 20 carbon atoms in the formula (I) include a phenoxy group, a methylphenoxy group (each isomer), an ethylphenoxy group (each isomer), a propylphenoxy group (each isomer), a butylphenoxy group (each isomer), a pentylphenoxy group (each isomer), a hexylphenoxy group (each isomer), a heptylphenoxy group (each isomer), an octylphenoxy group (each isomer), a nonylphenoxy group (each isomer), a decylphenoxy group (each isomer), a phenylphenoxy group (each isomer), Examples include dimethylphenoxy group (each isomer), diethylphenoxy group (each isomer), dipropylphenoxy group (each isomer), dibutylphenoxy group (each isomer), dipentylphenoxy group (each isomer), dihexylphenoxy group (each isomer), diheptylphenoxy group (each isomer), diphenylphenoxy group (each isomer), trimethylphenoxy group (each isomer), triethylphenoxy group (each isomer), tripropylphenoxy group (each isomer), and tributylphenoxy group (each isomer).

[0270] R 41 Examples of the aralkyl group having 7 to 20 carbon atoms in the formula (I) include a phenylmethyl group, a phenylethyl group (each isomer), a phenylpropyl group (each isomer), a phenylbutyl group (each isomer), a phenylpentyl group (each isomer), a phenylhexyl group (each isomer), a phenylheptyl group (each isomer), a phenyloctyl group (each isomer), and a phenylnonyl group (each isomer).

[0271] R 41 Examples of the aralkyloxy group having 7 to 20 carbon atoms in the formula (I) include a phenylmethoxy group, a phenylethoxy group (each isomer), a phenylpropyloxy group (each isomer), a phenylbutyloxy group (each isomer), a phenylpentyloxy group (each isomer), a phenylhexyloxy group (each isomer), a phenylheptyloxy group (each isomer), a phenyloctyloxy group (each isomer), and a phenylnonyloxy group (each isomer).

[0272] (A 41 ) Ring A 41is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. 41 may be a monocyclic ring, a polycyclic ring, or a condensed ring.

[0273] Ring A 41 Specific examples of the ring A include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a naphthacene ring, a chrysene ring, a pyrene ring, a triphenylene ring, a pentalene ring, an azulene ring, a heptalene ring, an indacene ring, a biphenylene ring, an acenaphthylene ring, an aceanthrylene ring, and an acephenanthrylene ring. 41 As the ring, a benzene ring, a naphthalene ring, or an anthracene ring is preferable, and a benzene ring is more preferable.

[0274] In addition, these rings may be the same as those described above in R 41 R may have a substituent other than 41 The substituents other than R 41 The same examples as those given in R 41 and RR 41 The substituents other than the group are different functional groups.

[0275] (n41) n41 is a substituent R 41 It indicates the number of, and is an integer between 1 and 10.

[0276] Preferred phenolic blocking agents (IV-1) include, for example, phenol, methylphenol (each isomer), ethylphenol (each isomer), propylphenol (each isomer), butylphenol (each isomer), pentylphenol (each isomer), hexylphenol (each isomer), heptylphenol (each isomer), octylphenol (each isomer), nonylphenol (each isomer), decylphenol (each isomer), undecylphenol (each isomer), tridecylphenol (each isomer), tetradecylphenol (each isomer), octadecylphenol, ... Isopropylphenol (each isomer), nonadecylphenol (each isomer), icosylphenol (each isomer), cyclopentylphenol (each isomer), cyclohexylphenol (each isomer), dimethylphenol (each isomer), methylethylphenol (each isomer), diethylphenol (each isomer), methylpropylphenol (each isomer), ethylpropylphenol (each isomer), dipropylphenol (each isomer), methylbutylphenol (each isomer), ethylbutylphenol (each isomer), propylbutylphenol (each isomer), Djibutanol Dimethylphenol (each isomer), trimethylphenol (each isomer), methyldiethylphenol (each isomer), dimethylethylphenol (each isomer), triethylphenol (each isomer), methyldipropylphenol (each isomer), dimethylpropylphenol (each isomer), tripropylphenol (each isomer), ethyldipropylphenol (each isomer), diethylpropylphenol (each isomer), methyldibutylphenol (each isomer), dimethylbutylphenol (each isomer), ethyldibutylphenol (each isomer), diethylbutyl Phenol (each isomer), propyl dibutylphenol (each isomer), dipropyl butylphenol (each isomer), tributylphenol (each isomer), naphthol (each isomer), methyl naphthol (each isomer), ethyl naphthol (each isomer), propyl naphthol (each isomer), butyl naphthol (each isomer), tetrahydronaphthalen-1-ol, tetrahydronaphthalen-2-ol, hydroxyphenyl phenyl methane (each isomer), hydroxyphenyl phenyl ethane (each isomer), hydroxyphenyl phenyl propane (each isomer),Hydroxyphenyl phenyl butane (each isomer); methoxyphenol (each isomer), ethoxyphenol (each isomer), propoxyphenol (each isomer), butoxyphenol (each isomer), pentoxyphenol (each isomer), hexoxyphenol (each isomer), heptoxyphenol (each isomer), octoxyphenol (each isomer), methoxymethylphenol (each isomer), methoxyethylphenol (each isomer), methoxypropylphenol (each isomer), methoxybutylphenol (each isomer), ethoxymethylphenol Phenol-based blocking agents having an ether group, such as benzophenone (each isomer), ethoxyethylphenol (each isomer), ethoxypropylphenol (each isomer), ethoxybutylphenol (each isomer), propoxymethylphenol (each isomer), propoxyethylphenol (each isomer), propoxypropylphenol (each isomer), butoxymethylphenol (each isomer), butoxyethylphenol (each isomer), butoxypropylphenol (each isomer), and butoxybutylphenol; fluorophenols (each isomer), difluorophenols (each isomer), isomer), trifluorophenol (each isomer), tetrafluorophenol (each isomer), pentafluorophenol (each isomer), chlorophenol (each isomer), dichlorophenol (each isomer), trichlorophenol (each isomer), tetrachlorophenol (each isomer), pentachlorophenol (each isomer), bromophenol (each isomer), dibromophenol (each isomer), tribromophenol (each isomer), tetrabromophenol (each isomer), pentabromophenol (each isomer), iodophenol (each isomer), diiodo Phenol-based blocking agents having a halogen group, such as phenol (each isomer), triiodophenol (each isomer), tetraiodophenol (each isomer), and pentaiodophenol (each isomer); methyl salicylate, ethyl salicylate, propyl salicylate (each isomer), butyl salicylate (each isomer), pentyl salicylate (each isomer), hexyl salicylate (each isomer), heptyl salicylate (each isomer), octyl salicylate (each isomer), nonyl salicylate (each isomer), decyl salicylate (each isomer), and undecyl salicylate (each isomer),Examples of suitable blocking agents include phenolic blocking agents having a carbonyl group, such as dodecyl salicylate (each isomer), tetradecyl salicylate (each isomer), octadecyl salicylate (each isomer), and acetylphenol.

[0277] [Alcohol-based blocking agent] The alcohol-based blocking agent is not particularly limited as long as it is an aliphatic compound having a hydroxyl group, and may be an aliphatic compound having one hydroxyl group in the molecule or two or more hydroxyl groups in the molecule. When an aliphatic compound having two or more hydroxyl groups in the molecule is used as a blocking agent, the resulting blocked isocyanate contains high-molecular-weight blocked isocyanates, which increase the viscosity of the blocked isocyanate composition containing the blocked isocyanate and sometimes cause gelation, making the production of the blocked isocyanate and the blocked isocyanate composition difficult. Therefore, it is more preferable to use an aliphatic compound having one hydroxyl group in the molecule.

[0278] A preferred example of the alcohol-based blocking agent is a compound represented by the following general formula (IV-2) (hereinafter, sometimes referred to as "alcohol-based blocking agent (IV-2)").

[0279] [ka]

[0280] In general formula (IV-2), R 42 is a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 24 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

[0281] (R 42 ) R 42 The aliphatic hydrocarbon group in has 1 or more and 24 or less carbon atoms, preferably 1 or more and 20 or less carbon atoms, and more preferably 1 or more and 12 or less carbon atoms.

[0282] R 42The aliphatic hydrocarbon group in may be saturated or unsaturated.

[0283] R 42 Examples of the aliphatic hydrocarbon group in the formula include saturated or unsaturated monovalent hydrocarbon groups having 1 to 12 carbon atoms.

[0284] Examples of saturated monovalent hydrocarbon groups having from 1 to 12 carbon atoms include alkyl groups having from 1 to 12 carbon atoms. Examples of alkyl groups having from 1 to 12 carbon atoms include linear alkyl groups having from 1 to 12 carbon atoms and cyclic alkyl groups having from 3 to 12 carbon atoms.

[0285] Examples of the chain alkyl group having from 1 to 12 carbon atoms include linear or branched chain alkyl groups having from 1 to 12 carbon atoms. Specific examples of the linear or branched chain alkyl group having from 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a neopentyl group, a tert-pentyl group, a 2,3-dimethylpropyl group, a 1-ethylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, an n-hexyl group, an isobutyl group, ... isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an isopropyl group, an iso Examples include a hexyl group, a hexan-2-yl group, a hexan-3-yl group, a 2-methylpentyl group, a 3-methylpentyl group, a 1,1,2-trimethylpropyl group, a 3,3-dimethylbutyl group, an n-heptyl group, a heptan-2-yl group, a heptan-3-yl group, a heptan-4-yl group, an n-octyl group, an octan-2-yl group, an octan-3-yl group, an octan-4-yl group, an n-nonyl group, an n-decyl group, an n-undecyl group, and an n-dodecyl group.

[0286] Examples of cyclic alkyl groups having 3 to 12 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, and cyclododecyl groups.

[0287] Examples of the unsaturated monovalent hydrocarbon group having from 2 to 12 carbon atoms include alkenyl groups having from 2 to 12 carbon atoms, alkadienyl groups having from 3 to 12 carbon atoms, and alkynyl groups having from 2 to 12 carbon atoms.

[0288] Examples of the alkenyl group having 2 to 12 carbon atoms include a chain alkenyl group having 2 to 18 carbon atoms and a cyclic alkenyl group having 3 to 12 carbon atoms.

[0289] Examples of the chain alkenyl group having from 2 to 12 carbon atoms include linear or branched chain alkenyl groups having from 2 to 12 carbon atoms. Specific examples of the linear or branched chain alkenyl group having from 2 to 12 carbon atoms include vinyl groups, aryl groups, propenyl groups, isopropenyl groups, 1-methylpropenyl groups, 2-methylpropenyl groups, butenyl groups, pentenyl groups, isopentenyl groups, hexenyl groups, heptenyl groups, octenyl groups, nonenyl groups, decenyl groups, undecenyl groups, and dodecenyl groups.

[0290] Examples of cyclic alkenyl groups having 3 to 12 carbon atoms include a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a methylcycloheptenyl group, a methylcyclooctenyl group, a methylcyclononenyl group, a methylcyclodecenyl group, a methylcycloundecenyl group, and a methylcyclododecenyl group.

[0291] Examples of the alkadienyl group having 3 to 12 carbon atoms include a chain alkadienyl group having 3 to 12 carbon atoms and a cyclic alkadienyl group having 3 to 12 carbon atoms.

[0292] Examples of the chain alkadienyl group having from 3 to 12 carbon atoms include linear or branched alkadienyl groups having from 3 to 12 carbon atoms. Specific examples of the linear or branched alkadienyl group having from 3 to 12 carbon atoms include a propadienyl group, a butadienyl group, a pentadienyl group, a 2-methylpentadienyl group, a hexadienyl group, a heptadienyl group, an octadienyl group, a nonadienyl group, a decadienyl group, an undecadienyl group, and a dodecadienyl group.

[0293] Examples of cyclic alkadienyl groups having 3 to 12 carbon atoms include a cyclopropadienyl group, a cyclobutadienyl group, a cyclopentadienyl group, a cyclohexadienyl group, a cycloheptadienyl group, a cyclooctadienyl group, a cyclononadienyl group, a cyclodecadienyl group, a cycloundecadienyl group, and a cyclododecadienyl group.

[0294] Examples of the alkynyl group having 2 to 12 carbon atoms include a chain alkynyl group having 2 to 12 carbon atoms and a cyclic alkynyl group having 3 to 12 carbon atoms.

[0295] Examples of the chain alkynyl group having from 2 to 12 carbon atoms include a linear or branched alkynyl group having from 2 to 12 carbon atoms. Specific examples of the linear or branched alkynyl group having from 2 to 12 carbon atoms include an ethynyl group, a propynyl group, a 2-methylpropynyl group, a butynyl group, a 2-methylbutynyl group, a pentynyl group, a hexynyl group, a heptynyl group, an octynyl group, a nonynyl group, a decynyl group, an undecynyl group, and a dodecynyl group.

[0296] Examples of cyclic alkynyl groups having 3 to 12 carbon atoms include a cyclopropynyl group, a cyclobutynyl group, a cyclopentynyl group, a cyclohexynyl group, a cycloheptynyl group, a cyclooctynyl group, a cyclononynyl group, a cyclodecynyl group, a cycloundecynyl group, and a cyclododecynyl group.

[0297] R 42Examples of the substituent of the aliphatic hydrocarbon group in the formula include a halogen atom and an amino group.

[0298] Specific examples of preferred alcohol-based blocking agents (IV-2) include methanol, ethanol, propanol (each isomer), butanol (each isomer), pentanol (each isomer), hexanol (each isomer), octanol (each isomer), nonanol (each isomer), decanol (each isomer), undecanol (each isomer), dodecanol (each isomer), tridecanol (each isomer), tetradecanol (each isomer), pentadecanol (each isomer), hexadecanol (each isomer), heptadecanol (each isomer), octadecanol (each isomer), isomer), nonadecanol (each isomer), icosanol (each isomer), cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, decahydronaphthalen-1-ol, decahydronaphthalen-2-ol, methylcyclopentanol (each isomer), ethylcyclohexanol (each isomer), propylcyclohexanol (each isomer), pentylcyclohexanol (each isomer), hexylcyclohexanol (each isomer), dimethylcyclohexanol (each isomer), methylethylcyclohexanol (each isomer), diene Ethylcyclohexanol (each isomer), methylpropylcyclohexanol (each isomer), ethylpropylcyclohexanol (each isomer), dipropylcyclohexanol (each isomer), methylbutylcyclohexanol (each isomer), ethylbutylcyclohexanol (each isomer), propylbutylcyclohexanol (each isomer), dibutylcyclohexanol (each isomer), trimethylcyclohexanol (each isomer), methyldiethylcyclohexanol (each isomer), dimethylethylcyclohexanol (each isomer), triethylcyclo Hexanol (each isomer), methyl dipropyl cyclohexanol (each isomer), dimethyl propyl cyclohexanol (each isomer), ethyl dipropyl cyclohexanol (each isomer), diethyl propyl cyclohexanol (each isomer), tripropyl cyclohexanol (each isomer), methyl dibutyl cyclohexanol (each isomer), dimethyl butyl cyclohexanol (each isomer), ethyl dibutyl cyclohexanol (each isomer), diethyl butyl cyclohexanol (each isomer), propyl dibutyl cyclohexanol (each isomer),Alcohol-based blocking agents having saturated hydrocarbon groups, such as dipropylbutylcyclohexanol (each isomer) and tributylcyclohexanol (each isomer); alcohol-based blocking agents having unsaturated hydrocarbon groups, such as 2-propen-1-ol, 2-buten-1-ol, 3-buten-1-ol, 2-penten-1-ol, 3-penten-1-ol, 4-penten-1-ol, 2-hexen-1-ol, 3-hexen-1-ol, 4-hexen-1-ol, 5-hexen-1-ol, and benzyl alcohol; 1-methoxyethanol Alcohol-based blocking agents having an ether group, such as 1-ethoxyethanol, 1-propoxyethanol, 1-butoxyethanol, 1-pentoxyethanol, 1-hexoxyethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-propoxy-2-propanol, 1-butoxy-2-propanol, 1-pentoxy-2-propanol, and 1-butoxy-2-propanol; fluoromethanol, chloromethanol, bromomethanol, iodomethanol, difluoromethanol, and dichloromethanol. , dibromomethanol, diiodomethanol, trifluoromethanol, trichloromethanol, tribromomethanol, triiodomethanol, 2-fluoroethanol, 2-chloroethanol, 2-bromoethanol, 2-iodoethanol, 2,2-difluoroethanol, 2,2-dichloroethanol, 2,2-dibromoethanol, 2,2-diiodoethanol, 2,2,2-trifluoroethanol, 2,2,2-trichloroethanol, 2,2,2-tribromoethanol, 2,2,2-triiodoethanol, 2,2 ,3,3,3-Pentafluoropropanol, 2,2,3,3,3-pentachloropropanol, 2,2,3,3,3-pentabromopropanol, 2,2,3,3,3-pentaiodopropanol, 2,2,2-trifluoro-1-trifluoromethylethanol, 2,2,2-trichloro-1-trichloromethylethanol, 2,2,2-tribromo-1-tribromomethylethanol, 2,2,2-triiodo-1-triiodomethylethanol, 1,1,1,3,3,3-hexafluoro-2-trifluoromethylpropanol,1,1,1,3,3,3-Hexachloro-2-trichloromethylpropanol, 1,1,1,3,3,3-Hexabromo-2-tribromomethylpropanol, 1,1,1,3,3,3-Hexaiodo-2-triiodomethylpropanol, 2,2,3,3,4,4,5,5-Octafluoro-1-pentanol, 2,2,3,3,4,4,5,5-Octachloro-1-pentanol, 2,2,3,3,4,4,5,5-Octabromo-1-pentanol, 2,2,3,3,4,4,5,5-Octaiodo-1-pentanol, Hexafluoroisopropyl Alcohols having halogen groups such as propanol, hexachloroisopropanol, hexabromoisopropanol, hexaiodoisopropanol, 2-fluorobenzyl alcohol, 2-chlorobenzyl alcohol, 2-bromobenzyl alcohol, 2-iodobenzyl alcohol, 3-fluorobenzyl alcohol, 3-chlorobenzyl alcohol, 3-bromobenzyl alcohol, 3-iodobenzyl alcohol, 4-fluorobenzyl alcohol, 4-chlorobenzyl alcohol, 4-bromobenzyl alcohol, and 4-iodobenzyl alcohol Cholesterol-based blocking agents; hydroxy acid esters, etc., methyl glycolate, ethyl glycolate, propyl glycolate (each isomer), butyl glycolate (each isomer), pentyl glycolate (each isomer), hexyl glycolate (each isomer), dodecyl glycolate (each isomer), methyl lactate, ethyl lactate, propyl lactate (each isomer), butyl glycolate (each isomer), pentyl glycolate (each isomer), hexyl glycolate (each isomer), dodecyl glycolate (each isomer), methyl tartronate, ethyl tartronate, propyl tartronate Tartronic acid (each isomer), butyl tartronate (each isomer), pentyl tartronate (each isomer), hexyl tartronate (each isomer), dodecyl tartronate (each isomer), methyl 2-hydroxybutyrate, ethyl 2-hydroxybutyrate, propyl 2-hydroxybutyrate (each isomer), butyl 2-hydroxybutyrate (each isomer), pentyl 2-hydroxybutyrate (each isomer), hexyl 2-hydroxybutyrate (each isomer), dodecyl 2-hydroxybutyrate (each isomer), methyl 3-hydroxybutyrate, ethyl 3-hydroxybutyrate, propyl 3-hydroxybutyrate (each isomer),Butyl 3-hydroxybutyrate (each isomer), pentyl 3-hydroxybutyrate (each isomer), hexyl 3-hydroxybutyrate (each isomer), dodecyl 3-hydroxybutyrate (each isomer), methyl 4-hydroxybutyrate, ethyl 4-hydroxybutyrate, propyl 4-hydroxybutyrate (each isomer), butyl 4-hydroxybutyrate (each isomer), pentyl 4-hydroxybutyrate (each isomer), hexyl 4-hydroxybutyrate (each isomer), dodecyl 4-hydroxybutyrate (each isomer), dimethyl malate, diethyl malate, dipropyl malate (each isomer), dipentyl malate (each isomer), dihexyl malate (each isomer), didodecyl malate (each isomer), trimethyl citrate, triethyl citrate, tripropyl citrate (each isomer), tributyl citrate (each isomer), tripentyl citrate (each isomer) Examples of blocking agents include alcohol-based blocking agents having a carbonyl group, such as hydroxy-2-propanone, hydroxy-2-butanone, hydroxy-2-pentanone, hydroxy-2-hexanone, hydroxy-3-butanone, hydroxy-3-pentanone, and hydroxy-3-hexanone; and alcohol-based blocking agents having an amino group, such as 2-(dimethylamino)ethanol, 3-(dimethylamino)propanol, 4-(dimethylamino)pentanol, and 5-(dimethylamino)hexanol.

[0299] [Amine and ammonia-based blocking agents] As the amine and ammonia-based blocking agent, an amine compound having a primary or secondary amino group as the active hydrogen group, or ammonia, can be used. When a primary amine compound or ammonia is used as the blocking agent, the primary amine compound or ammonia, which is the blocking agent, reacts with the carbonic acid derivative, making it difficult to obtain the desired blocked isocyanate compound. Therefore, it is preferable to use an amine compound having a secondary amino group.

[0300] The amine and ammonia-based blocking agent may be an amine compound having one amino group in the molecule, or may be an amine compound having two or more amino groups in the molecule. When an amine compound having two or more amino groups in the molecule is used as a blocking agent, the resulting blocked isocyanate compound contains a high-molecular-weight blocked isocyanate compound, which increases the viscosity of the blocked isocyanate composition containing the blocked isocyanate compound and sometimes causes gelation, making the production of the blocked isocyanate compound and the blocked isocyanate composition difficult. Therefore, it is preferable to use an amine compound having one amino group in the molecule as the amine and ammonia-based blocking agent.

[0301] Preferred examples of the amine and ammonia-based blocking agents include secondary amine compounds represented by the following general formula (V) (hereinafter, sometimes referred to as "secondary amine compound (V)").

[0302] [ka]

[0303] In general formula (V), R 51 and R 52 R is each independently a monovalent organic group. 51 and R 52 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond.

[0304] (R 51 and R 52 ) R 51 and R 52 R is each independently a monovalent organic group. 51 and R 52 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond.

[0305] Among them, R 51 and R 52 is preferably a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 70 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 70 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

[0306] R 51 and R 52 The aliphatic hydrocarbon group in has 1 or more and 70 or less carbon atoms, preferably 1 or more and 20 or less, more preferably 1 or more and 12 or less, and even more preferably 1 or more and 10 or less carbon atoms.

[0307] R 51 and R 52 Specific examples of the aliphatic hydrocarbon group in the formula (I) include a methyl group, an ethyl group, a propyl group (each isomer), a butyl group (each isomer), a pentyl group (each isomer), a hexyl group (each isomer), a heptyl group (each isomer), an octyl group (each isomer), a nonyl group (each isomer), a decyl group (each isomer), an undecyl group (each isomer), a dodecyl group (each isomer), a tridecyl group (each isomer), a tetra ... Examples of such alkyl groups include tetradecyl groups (each isomer), pentadecyl groups (each isomer), hexadecyl groups (each isomer), heptadecyl groups (each isomer), octadecyl groups (each isomer), nonadecyl groups (each isomer), and eicosyl groups (each isomer); and cycloalkyl groups such as cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, cyclooctyl groups, cyclononyl groups, and cyclodecyl groups.

[0308] R 51 and R 52 The aromatic hydrocarbon group in has 6 or more and 70 or less carbon atoms, preferably 6 or more and 20 or less, more preferably 6 or more and 12 or less, and even more preferably 6 or more and 10 or less carbon atoms.

[0309] R 51 and R 52 Specific examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, and a phenanthryl group.

[0310] R51 and R 52 Examples of the substituent on the aliphatic hydrocarbon group in the formula (I) include an aromatic hydrocarbon group, a hydroxyl group, a cyano group, and a halogen atom.

[0311] R 51 and R 52 Examples of the substituent on the aromatic hydrocarbon group in the formula (I) include an aliphatic hydrocarbon group, a hydroxyl group, a cyano group, and a halogen atom.

[0312] The aromatic hydrocarbon group as a substituent of the aliphatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms, and specific examples thereof include those exemplified above.

[0313] The aliphatic hydrocarbon group as a substituent of the aromatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and specific examples thereof include those exemplified above. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0314] Preferred secondary amine compounds (V) include those represented by the formula: 51 and R 52Examples of compounds in which is an aliphatic hydrocarbon group include dimethylamine, methylethylamine, diethylamine, methylpropylamine (each isomer), ethylpropylamine (each isomer), dipropylamine (each isomer), methylbutylamine (each isomer), ethylbutylamine (each isomer), propylbutylamine (each isomer), dibutylamine (each isomer), methylpentylamine (each isomer), ethylpentylamine (each isomer), propylpentylamine (each isomer), butylpentylamine, amine (each isomer), dipentylamine (each isomer), methylhexylamine (each isomer), ethylhexylamine (each isomer), propylhexylamine (each isomer), pentylhexylamine (each isomer), dihexylamine (each isomer), methylheptylamine (each isomer), ethylheptylamine (each isomer), propylheptylamine (each isomer), pentylheptylamine (each isomer), hexylheptylamine (each isomer), diheptylamine (each isomer), methyloctylamine (each Secondary amine compounds having saturated aliphatic hydrocarbon groups, such as (isomers) ethyl octylamine (each isomer), propyl octylamine (each isomer), pentyl octylamine (each isomer), hexyl octylamine (each isomer), heptyl octylamine (each isomer), dioctylamine (each isomer), didecylamine (each isomer), and didodecylamine (each isomer); N-(2-methoxyethyl)methylamine, N-(2-ethoxyethyl)methylamine, and N-(2-propoxyethyl)methylamine secondary amine compounds having a saturated aliphatic hydrocarbon group having an ether group, such as N-(2-butoxyethyl)methylamine, N-(2-pentoxyethyl)methylamine, N-(2-hexoxyethyl)methylamine, N-(2-methoxyethyl)ethylamine, N-(2-ethoxyethyl)ethylamine, N-(2-propoxyethyl)ethylamine, N-(2-butoxyethyl)ethylamine, N-(2-pentoxyethyl)ethylamine, and N-(2-hexoxyethyl)ethylamine;Bis(fluoromethyl)amine, bis(chloromethyl)amine, bis(bromomethyl)amine, bis(iodomethyl)amine, bis(difluoromethyl)amine, bis(dichloromethyl)amine, bis(dibromomethyl)amine, bis(diiodomethyl)amine, bis(trifluoromethyl)amine, bis(trichloromethyl)amine, bis(tribromomethyl)amine, bis(triiodomethyl)amine, bis(2,2,2-trifluoroethyl)amine, bis(2,2 ,2-trichloroethyl)amine, bis(2,2,2-tribromoethyl)amine, bis(2,2,2-triiodoethyl)amine, bis(2,2,3,3,3-pentafluoropropyl)amine, bis(2,2,3,3,3-pentachloropropyl)amine, bis(2,2,3,3,3-pentabromopropyl)amine, bis(2,2,3,3,3-pentaiodopropyl)amine, bis(2,2,2-trifluoro-1-trifluoromethylethyl)amine, bis(2 ,2,2-trichloro-1-trichloromethylethyl)amine, bis(2,2,2-tribromo-1-tribromomethylethyl)amine, bis(2,2,2-triiodo-1-triiodomethylethyl)amine, bis(1,1,1,3,3,3-hexafluoro-2-trifluoromethylpropyl)amine, bis(1,1,1,3,3,3-hexachloro-2-trichloromethylpropyl)amine, bis(1,1,1,3,3,3-hexabromo-2-tribromomethylpropyl)amine secondary amine compounds having a halogen group, such as bis(1,1,1,3,3,3-hexaiodo-2-triiodomethylpropyl)amine, and bis(1,1,1,3,3,3-hexaiodo-2-triiodomethylpropyl)amine; secondary amine compounds having a carbonyl group, such as dimethyliminodiacetate, diethyliminodiacetate, dipropyliminodiacetate, dibutyliminodiacetate, dipentyliminodiacetate, dihexyliminodiacetate, N-methylglycine ethyl, and N-ethylglycine ethyl;

[0315] Further, examples of amine-based blocking agents other than the compounds exemplified above include pyrrolidine, methylpyrrolidine (each isomer), ethylpyrrolidine (each isomer), propylpyrrolidine (each isomer), butylpyrrolidine (each isomer), dimethylpyrrolidine (each isomer), methylethylpyrrolidine (each isomer), diethylpyrrolidine (each isomer), piperidine, methylpiperidine (each isomer), ethylpiper ... Isopropylpiperidine (each isomer), butylpiperidine (each isomer), dimethylpiperidine (each isomer), methylethylpiperidine (each isomer), diethylpiperidine (each isomer), azepane, methylazepane (each isomer), ethylazepane (each isomer), propylazepane (each isomer), butylazepane (each isomer), dimethylazepane (each isomer), methylethylazepane (each isomer), diethylazepane (each isomer), imidazoline -al, methylpiperazine, pyrrole, etc.; methylbenzylamine, ethylbenzylamine, propylbenzylamine (each isomer), butylbenzylamine (each isomer), pentylbenzylamine (each isomer), hexylbenzylamine (each isomer), etc.; morpholine, methylmorpholine (each isomer), ethylmorpholine (each isomer), propylmorpholine (each isomer), butylmorpholine (each isomer), dimethylmorpholine (each isomer), and amine-based blocking agents having an ether group, such as methylethylmorpholine (each isomer), methylethylmorpholine (each isomer), diethylmorpholine (each isomer), methylpropylmorpholine (each isomer), ethylpropylmorpholine (each isomer), dipropylmorpholine (each isomer), methylbutylmorpholine (each isomer), ethylbutylmorpholine (each isomer), propylbutylmorpholine (each isomer), and dibutylmorpholine (each isomer).

[0316] In addition, as an amine-based blocking agent other than the above-mentioned compounds, the compounds exemplified as the secondary amine compounds (I) may be used. The compounds exemplified as the secondary amine compounds (I) are R 51 and R 52is an aliphatic hydrocarbon group, the compound (V) has a lower basicity and a relatively small effect on the modification of blocked isocyanate compounds and isocyanate compounds. When the compounds exemplified as the secondary amine compounds (I) are used as amine-based blocking agents, the secondary amine compound used to improve thermal modification and coloration and the secondary amine compound used as a blocking agent may be the same or different.

[0317] [Hydroxylamine blocking agent] The hydroxylamine-based blocking agent is not particularly limited and may be a hydroxylamine compound having one hydroxylamine structure per molecule, or may be a hydroxylamine compound having two or more hydroxylamine structures per molecule. When a hydroxylamine compound having two or more hydroxylamine structures per molecule is used as a blocking agent, the resulting blocked isocyanate compound contains a high-molecular-weight blocked isocyanate compound, which increases the viscosity of the blocked isocyanate composition containing the blocked isocyanate compound and sometimes causes gelation, making the production of the blocked isocyanate compound and the blocked isocyanate composition difficult. Therefore, it is preferable to use a hydroxylamine compound having one hydroxylamine structure per molecule as the hydroxylamine-based blocking agent.

[0318] Examples of hydroxylamine compounds having one hydroxylamine structure in the molecule include dimethylhydroxylamine, methylethylhydroxylamine, diethylhydroxylamine, methylpropylhydroxylamine (each isomer), ethylpropylhydroxylamine (each isomer), dipropylhydroxylamine (each isomer), methylbutylhydroxylamine (each isomer), ethylbutylhydroxylamine (each isomer), dibutylhydroxylamine (each isomer), N-hydroxysuccinimide, and N-hydroxyphthalimide.

[0319] While the above-mentioned blocking agents can be used alone, it is also effective to use two or more of them in combination. For example, when a blocking agent with low nucleophilicity and a blocking agent with high nucleophilicity are used in combination, the blocking agent with high nucleophilicity reacts with the blocked isocyanate group formed by blocking an isocyanate group with a carbonic acid derivative (hereinafter, sometimes referred to as a "blocked isocyanate group derived from a carbonic acid derivative"), contributing to a reduction in the blocked isocyanate functional group derived from the carbonic acid derivative. Therefore, a blocking agent with high nucleophilicity is more preferred. Furthermore, it is even more preferable to use a blocking agent with nucleophilicity equal to or greater than that of at least one compound derived from a carbonic acid derivative. Examples of blocking agents with high nucleophilicity are as described above.

[0320] <Carbonate derivatives> The carbonic acid derivative is not particularly limited, but a compound represented by the following general formula (VI) (hereinafter, sometimes referred to as "carbonic acid derivative (VI)") is preferably used because of its easy availability.

[0321] [ka]

[0322] In general formula (VI), R 61 and R 62 are each independently an amino group, a substituted or unsubstituted alkoxy group having from 1 to 20 carbon atoms, or an aryloxy group having from 6 to 20 carbon atoms, or a substituted or unsubstituted alkylamino group having from 1 to 20 carbon atoms, or an arylamino group having from 6 to 20 carbon atoms.

[0323] [R 61 and R 62 ] R 61 and R 62 may be the same as or different from each other.

[0324] R 61 and R 62Examples of the alkoxy group having 1 to 20 carbon atoms in the formula include a methoxy group, an ethoxy group, a propyloxy group (each isomer), a butoxy group (each isomer), and a hexyloxy group (each isomer).

[0325] R 61 and R 62 Examples of the aryloxy group having 6 to 20 carbon atoms in the formula include a phenoxy group and a naphthyloxy group.

[0326] R 61 and R 62 Examples of the alkylamino group having 1 to 20 carbon atoms in the formula include a methylamino group, an ethylamino group, a propylamino group (each isomer), a butylamino group (each isomer), and a hexylamino group (each isomer).

[0327] R 61 and R 62 Examples of the arylamino group having 6 to 20 carbon atoms in the formula (I) include a phenylamino group and a naphthylamino group.

[0328] Examples of the substituents that the alkoxy group, aryloxy group, alkylamino group, and arylamino group may have include alkyl groups and alkoxy groups.

[0329] Among them, R 61 and R 62 is preferably each independently an amino group, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, or a substituted or unsubstituted arylamino group having 6 to 20 carbon atoms.

[0330] Preferred carbonic acid derivatives (VI) include, for example, urea compounds, N-unsubstituted carbamic acid esters, carbonate esters, and N-substituted carbamic acid esters.

[0331] [Urea compound] A urea compound is a compound having at least one urea bond in the molecule. The urea compound is not particularly limited, and may be a urea compound having one urea bond in the molecule, or a urea compound having two or more urea bonds in the molecule. When a urea compound having two or more urea bonds in the molecule is used, a high molecular weight component is contained in the reaction, making it difficult to produce a blocked isocyanate compound and a blocked isocyanate composition. Therefore, it is preferable to use a compound having one urea bond in the molecule as the urea compound. Among compounds having one urea bond in the molecule, a compound represented by the following general formula (VI-1) (hereinafter, sometimes referred to as "urea compound (VI-1)") is more preferable.

[0332] [ka]

[0333] In general formula (VI-1), R 611 , R 612 , R 613 , and R 614 R are each independently an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a hydrogen atom. 611 and R 612 The total number of carbon atoms constituting R is an integer of 0 to 20, 613 and R 614 The total number of carbon atoms constituting the group is an integer of 0 to 20.

[0334] (R 611 , R 612 , R 613 , and R 614 ) R 611 , R 612 , R 613 , and R 614 may be the same as or different from each other.

[0335] R 611 , R 612 , R 613 , and R 614Examples of the alkyl group having 1 to 20 carbon atoms in the formula (I) include a methyl group, an ethyl group, a propyl group (each isomer), a butyl group (each isomer), a pentyl group (each isomer), a hexyl group (each isomer), a heptyl group (each isomer), an octyl group (each isomer), a nonyl group (each isomer), a decyl group (each isomer), an undecyl group (each isomer), a dodecyl group (each isomer), a tridecyl group (each isomer), Examples of alkyl groups include tetradecyl groups (each isomer), pentadecyl groups (each isomer), hexadecyl groups (each isomer), heptadecyl groups (each isomer), octadecyl groups (each isomer), nonadecyl groups (each isomer), and eicosyl groups (each isomer); and cycloalkyl groups such as cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, cyclooctyl groups, cyclononyl groups, and cyclodecyl groups.

[0336] R 611 , R 612 , R 613 , and R 614 Examples of the aralkyl group having 1 to 20 carbon atoms in the formula include a benzyl group.

[0337] R 611 , R 612 , R 613 , and R 614 Examples of the aryl group having 6 to 20 carbon atoms in the formula (I) include a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, and a phenanthryl group.

[0338] Preferred urea compounds (VI-1) include urea, methyl urea, ethyl urea, propyl urea (each isomer), butyl urea (each isomer), pentyl urea (each isomer), hexyl urea (each isomer), heptyl urea (each isomer), octylurea (each isomer), nonyl urea (each isomer), decyl urea (each isomer), undecyl urea (each isomer), dodecyl urea (each isomer), tridecyl urea (each isomer), tetradecyl urea (each isomer), pentadecyl urea (each isomer), hexadecyl urea (each isomer), heptadecyl urea (each isomer), octylurea, and the like. Tadecyl urea (each isomer), nonadecyl urea (each isomer), icosyl urea (each isomer), phenyl urea, N-(methylphenyl) urea (each isomer), N-(ethylphenyl) urea (each isomer), N-(propylphenyl) urea (each isomer), N-(butylphenyl) urea (each isomer), N-(pentylphenyl) urea (each isomer), N-(hexylphenyl) urea (each isomer), N-(heptylphenyl) urea (each isomer), N-(octylphenyl) urea (each isomer), N-(nonylphenyl) urea (each isomer), N-(decylphenyl) N-(diphenyl)urea (each isomer), N-biphenylurea (each isomer), N-(dimethylphenyl)urea (each isomer), N-(diethylphenyl)urea (each isomer), N-(dipropylphenyl)urea (each isomer), N-(dibutylphenyl)urea (each isomer), N-(dipentylphenyl)urea (each isomer), N-(dihexylphenyl)urea, N-(diheptylphenyl)urea, N-terphenylurea (each isomer), N-(trimethylphenyl)urea (each isomer), N-(triethylphenyl)urea (each isomer), N-(tripropylphenyl)urea )urea (each isomer), N-(tributylphenyl)urea (each isomer), N-(phenylmethyl)urea, N-(phenylethyl)urea (each isomer), N-(phenylpropyl)urea (each isomer), N-(phenylbutyl)urea (each isomer), N-(phenylpentyl)urea (each isomer), N-(phenylhexyl)urea (each isomer), N-(phenylheptyl)urea (each isomer), N-(phenyloctyl)urea (each isomer), N-(phenylnonyl)urea (each isomer), N,N'-dimethylurea, N-methyl-N'-ethylurea, N,N'-Diethylurea, N-methyl-N'-propylurea (each isomer), N-ethyl-N'-propylurea (each isomer), N,N'-dipropylurea (each isomer), N-methyl-N'-butylurea (each isomer), N-ethyl-N'-butylurea (each isomer), N-propyl-N'-butylurea (each isomer), N,N'-dibutylurea (each isomer), N-methyl-N'-pentylurea (each isomer), N-ethyl-N'-pentylurea (each isomer), N-propyl-N'-pentylurea (each isomer), N-butylurea N-butyl-N'-pentylurea (each isomer), N,N'-dipentylurea (each isomer), N-methyl-N'-hexylurea (each isomer), N-ethyl-N'-hexylurea (each isomer), N-propyl-N'-hexylurea (each isomer), N-butyl-N'-hexylurea (each isomer), N-pentyl-N'-hexylurea (each isomer), N,N'-dihexylurea (each isomer), N-methyl-N'-heptylurea (each isomer), N-ethyl-N'-heptylurea (each isomer), N-propyl-N'-heptylurea N-octylurea (each isomer), N-butyl-N'-heptylurea (each isomer), N-pentyl-N'-heptylurea (each isomer), N-hexyl-N'-heptylurea (each isomer), N,N'-diheptylurea (each isomer), N-methyl-N'-octylurea (each isomer), N-ethyl-N'-octylurea (each isomer), N-propyl-N'-octylurea (each isomer), N-butyl-N'-octylurea (each isomer), N-pentyl-N'-octylurea (each isomer), N-hexyl-N'-octylurea N-nonylurea (each isomer), N-heptyl-N'-octylurea (each isomer), N,N'-dioctylurea (each isomer), N-methyl-N'-nonylurea (each isomer), N-ethyl-N'-nonylurea (each isomer), N-propyl-N'-nonylurea (each isomer), N-butyl-N'-nonylurea (each isomer), N-pentyl-N'-nonylurea (each isomer), N-hexyl-N'-nonylurea (each isomer), N-heptyl-N'-nonylurea (each isomer), N-octyl-N'-nonylurea (each isomer), N,N'-Dinonylurea (each isomer), N-methyl-N'-decylurea (each isomer), N-ethyl-N'-decylurea (each isomer), N-propyl-N'-decylurea (each isomer), N-butyl-N'-decylurea (each isomer), N-pentyl-N'-decylurea (each isomer), N-hexyl-N'-decylurea (each isomer), N-heptyl-N'-decylurea (each isomer), N-octyl-N'-decylurea (each isomer), N-nonyl-N'-decylurea (each isomer), N,N'-didecyl Urea (each isomer), N-methyl-N'-undecylurea (each isomer), N-ethyl-N'-undecylurea (each isomer), N-propyl-N'-undecylurea (each isomer), N-butyl-N'-undecylurea (each isomer), N-pentyl-N'-undecylurea (each isomer), N-hexyl-N'-undecylurea (each isomer), N-heptyl-N'-undecylurea (each isomer), N-octyl-N'-undecylurea (each isomer), N-nonyl-N'-undecylurea (each isomer ), N-decyl-N'-undecylurea (each isomer), N,N'-diundecylurea (each isomer), N-methyl-N'-dodecylurea (each isomer), N-ethyl-N'-dodecylurea (each isomer), N-propyl-N'-dodecylurea (each isomer), N-butyl-N'-dodecylurea (each isomer), N-pentyl-N'-dodecylurea (each isomer), N-hexyl-N'-dodecylurea (each isomer), N-heptyl-N'-dodecylurea (each isomer), N-octyl-N'-dodecylurea (each isomer), N-nonyl-N'-dodecylurea (each isomer), N-decyl-N'-dodecylurea (each isomer), N-undecyl-N'-dodecylurea (each isomer), N,N'-didodecylurea (each isomer), N-methyl-N'-phenylurea, N-ethyl-N'-phenylurea, N-propyl-N'-phenylurea (each isomer), N-butyl-N'-phenylurea (each isomer), N-pentyl-N'-phenylurea (each isomer), N-hexyl-N'-phenylurea (each isomer), N,N'-Diphenylurea, N-methyl-N'-methylphenylurea, N-ethyl-N'-methylphenylurea, N-propyl-N'-methylphenylurea (each isomer), N-butyl-N'-methylphenylurea (each isomer), N-pentyl-N'-methylphenylurea (each isomer), N-hexyl-N'-methylphenylurea (each isomer), N-phenyl-N'-methylphenylurea, N,N'-dimethylphenylurea, N-methyl-N'-ethylphenylurea (each isomer), N-ethyl-N'-ethylphenylurea (each isomer) , N-propyl-N'-ethylphenylurea (each isomer), N-butyl-N'-ethylphenylurea (each isomer), N-pentyl-N'-ethylphenylurea (each isomer), N-hexyl-N'-ethylphenylurea (each isomer), N-phenyl-N'-ethylphenylurea (each isomer), N-methylphenyl-N'-ethylphenylurea (each isomer), N,N'-diethylphenylurea (each isomer), N,N-dimethylurea, N-methyl-N-ethylurea, N,N-diethylurea, N-methyl-N-propylurea (each isomer), N-Ethyl-N-propyl urea (each isomer), N,N-dipropyl urea (each isomer), N-methyl-N-butyl urea (each isomer), N-ethyl-N-butyl urea (each isomer), N-propyl-N-butyl urea (each isomer), N,N-dibutyl urea (each isomer), N-methyl-N-pentyl urea (each isomer), N-ethyl-N-pentyl urea (each isomer), N-propyl-N-pentyl urea (each isomer), N-butyl-N-pentyl urea (each isomer), N,N-dipentyl urea (each isomer), N-methyl-N-hexyl urea (each isomer) isomer), N-ethyl-N-hexylurea (each isomer), N-propyl-N-hexylurea (each isomer), N-butyl-N-hexylurea (each isomer), N-pentyl-N-hexylurea (each isomer), N,N-dihexylurea (each isomer), N-methyl-N-heptylurea (each isomer), N-ethyl-N-heptylurea (each isomer), N-propyl-N-heptylurea (each isomer), N-butyl-N-heptylurea (each isomer), N-pentyl-N-heptylurea (each isomer), N-hexyl-N-heptylurea (each isomer), N,N-Diheptylurea (each isomer), N-methyl-N-octylurea (each isomer), N-ethyl-N-octylurea (each isomer), N-propyl-N-octylurea (each isomer), N-butyl-N-octylurea (each isomer), N-pentyl-N-octylurea (each isomer), N-hexyl-N-octylurea (each isomer), N-heptyl-N-octylurea (each isomer), N,N-dioctylurea (each isomer), N-methyl-N-nonylurea ( N-ethyl-N-nonyl urea (each isomer), N-propyl-N-nonyl urea (each isomer), N-butyl-N-nonyl urea (each isomer), N-pentyl-N-nonyl urea (each isomer), N-hexyl-N-nonyl urea (each isomer), N-heptyl-N-nonyl urea (each isomer), N-octyl-N-nonyl urea (each isomer), N,N-dinonyl urea (each isomer), N-methyl-N-decyl urea (each isomer), N-ethyl-N-decyl Urea (each isomer), N-propyl-N-decylurea (each isomer), N-butyl-N-decylurea (each isomer), N-pentyl-N-decylurea (each isomer), N-hexyl-N-decylurea (each isomer), N-heptyl-N-decylurea (each isomer), N-octyl-N-decylurea (each isomer), N-nonyl-N-decylurea (each isomer), N,N-didecylurea (each isomer), N-methyl-N-undecylurea (each isomer), N-ethyl- N-undecylurea (each isomer), N-propyl-N-undecylurea (each isomer), N-butyl-N-undecylurea (each isomer), N-pentyl-N-undecylurea (each isomer), N-hexyl-N-undecylurea (each isomer), N-heptyl-N-undecylurea (each isomer), N-octyl-N-undecylurea (each isomer), N-nonyl-N-undecylurea (each isomer), N-decyl-N-undecylurea (each isomer), N,N-Diundecylurea (each isomer), N-Methyl-N-dodecylurea (each isomer), N-Ethyl-N-dodecylurea (each isomer), N-Propyl-N-dodecylurea (each isomer), N-Butyl-N-dodecylurea (each isomer), N-Pentyl-N-dodecylurea (each isomer), N-Hexyl-N-dodecylurea (each isomer), N-Heptyl-N- Dodecylurea (each isomer), N-octyl-N-dodecylurea (each isomer), N-nonyl-N-dodecylurea (each isomer), N-decyl-N-dodecylurea (each isomer), N-undecyl-N-dodecylurea (each isomer), N,N-didodecylurea (each isomer), N-methyl-N-phenylurea, N-ethyl-N-phenylurea, N-propyl- N-Phenylurea (each isomer), N-butyl-N-phenylurea (each isomer), N-pentyl-N-phenylurea (each isomer), N-hexyl-N-phenylurea (each isomer), N,N-diphenylurea, N-methyl-N-methylphenylurea, N-ethyl-N-methylphenylurea, N-propyl-N-methylphenylurea (each isomer), N-butyl-N-methylphenylurea (each isomer), N-pentyl-N-methylphenylurea (each isomer), N-hexyl-N-methylphenylurea (each isomer), N-phenyl-N-methylphenylurea, N,N-dimethylphenylurea, N-methyl-N-ethylphenylurea (each isomer), N-ethyl-N-ethylphenylurea (each isomer), N-Propyl-N-ethylphenylurea (each isomer), N-butyl-N-ethylphenylurea (each isomer), N-pentyl-N-ethylphenylurea (each isomer), N-hexyl-N-ethylphenylurea (each isomer), N-phenyl-N-ethylphenylurea (each isomer), N-methylphenyl-N-ethylphenylurea (each isomer), N,N-diethylphenylurea (each isomer), morpholine-4-carboxamide, piperidine-4-carboxamide, pyrrolidine-4-carboxamide, 1H-imidazole-1- Carboxamide, N,N,N'-trimethylurea, N-ethyl-N,N'-dimethylurea, N-ethyl-N,N'-dimethylurea, N,N,N'-trimethylurea, N-ethyl-N'N'-dimethylurea, N,N,N'-triethylurea, N-propyl-N'N'-dimethylurea (each isomer), N-propyl-N'N'-diethylurea (each isomer), N,N,N'-tripropylurea (each isomer), N-butyl-N'N'-dimethylurea (each isomer), N-butyl-N'N'-diethylurea (each isomer), N-butyl-N N'-Dipropylurea (each isomer), N,N,N'-tributylurea (each isomer), N-pentyl-N'N'-dimethylurea (each isomer), N-pentyl-N'N'-diethylurea (each isomer), N-pentyl-N'N'-dipropylurea (each isomer), N-pentyl-N'N'-dibutylurea (each isomer), N,N,N'-tripentylurea (each isomer), N-hexyl-N'N'-dimethylurea (each isomer), N-hexyl-N'N'-diethylurea (each isomer), N-hexyl-N'N'-dipropylurea (each isomer) isomer), N-hexyl-N'N'-dibutylurea (each isomer), N-hexyl-N'N'-dipentylurea (each isomer), N,N,N'-trihexylurea (each isomer), N-heptyl-N'N'-dimethylurea (each isomer), N-heptyl-N'N'-diethylurea (each isomer), N-heptyl-N'N'-dipropylurea (each isomer), N-heptyl-N'N'-dibutylurea (each isomer), N-heptyl-N'N'-dipentylurea (each isomer), N-heptyl-N'N'-dihexylurea (each isomer), N,N,N'-Triheptylurea (each isomer), N-octyl-N'N'-dimethylurea (each isomer), N-octyl-N'N'-diethylurea (each isomer), N-octyl-N'N'-dipropylurea (each isomer), N-octyl-N'N'-dibutylurea (each isomer), N-octyl-N'N'-dipentylurea (each isomer), N-octyl-N'N'-dihexylurea (each isomer), N-octyl-N'N'-diheptylurea (each isomer), N,N,N'-trioctylurea (each isomer), N-nonyl-N'N'-dimethylurea ( N-nonyl-N'N'-diethylurea (each isomer), N-nonyl-N'N'-dipropylurea (each isomer), N-nonyl-N'N'-dibutylurea (each isomer), N-nonyl-N'N'-dipentylurea (each isomer), N-nonyl-N'N'-dihexylurea (each isomer), N-nonyl-N'N'-diheptylurea (each isomer), N-nonyl-N'N'-dioctylurea (each isomer), N,N,N'-trinonylurea (each isomer), N-decyl-N'N'-dimethylurea (each isomer), N-decyl-N'N'-diethylurea N-decylurea (each isomer), N-decyl-N'N'-dipropylurea (each isomer), N-decyl-N'N'-dibutylurea (each isomer), N-decyl-N'N'-dipentylurea (each isomer), N-decyl-N'N'-dihexylurea (each isomer), N-decyl-N'N'-diheptylurea (each isomer), N-decyl-N'N'-dioctylurea (each isomer), N-decyl-N'N'-dinonylurea (each isomer), N,N,N'-tridecylurea (each isomer), N-undecyl-N'N'-dimethylurea (each isomer), N-undecyl N-undecyl-N'N'-diethylurea (each isomer), N-undecyl-N'N'-dipropylurea (each isomer), N-undecyl-N'N'-dibutylurea (each isomer), N-undecyl-N'N'-dipentylurea (each isomer), N-undecyl-N'N'-dihexylurea (each isomer), N-undecyl-N'N'-diheptylurea (each isomer), N-undecyl-N'N'-dioctylurea (each isomer), N-undecyl-N'N'-dinonylurea (each isomer), N-undecyl-N'N'-didecylurea (each isomer), N,N,N'-triundecylurea (each isomer), N-dodecyl-N'N'-dimethylurea (each isomer), N-dodecyl-N'N'-diethylurea (each isomer), N-dodecyl-N'N'-dipropylurea (each isomer), N-dodecyl-N'N'-dibutylurea (each isomer), N-dodecyl-N'N'-dipentylurea (each isomer), N-dodecyl-N'N'-dihexylurea (each isomer), N-dodecyl-N'N'-diheptylurea (each isomer), N-dodecyl-N'N'-dioctylurea (each isomer), N-dodecyl-N'N'-dinonylurea (each isomer), N-Dodecyl-N'N'-didecylurea (each isomer), N-Dodecyl-N'N'-diundecylurea (each isomer), N,N,N'-tridodecylurea (each isomer), N-Phenyl-N'N'-dimethylurea, N-Phenyl-N'N'-diethylurea, N-Phenyl-N'N'-dipropylurea (each isomer), N-Phenyl-N'N'-dibutylurea (each isomer), N-Phenyl-N'N'-dipentylurea (each isomer), N-Phenyl-N'N'-dihexylurea (each isomer), N,N,N'-triphenylurea, N-Methylphenyl-N'N'-dimethyl Urea, N-methylphenyl-N'N'-diethylurea, N-methylphenyl-N'N'-dipropylurea (each isomer), N-methylphenyl-N'N'-dibutylurea (each isomer), N-methylphenyl-N'N'-dipentylurea (each isomer), N-methylphenyl-N'N'-dihexylurea (each isomer), N-methylphenyl-N'N'-diphenylurea, N,N,N'-trimethylphenylurea, N-ethylphenyl-N'N'-dimethylurea (each isomer), N-ethylphenyl-N'N'-diethylurea (each isomer), N-ethylphenyl-N' N'-Dipropylurea (each isomer), N-ethylphenyl-N'N'-dibutylurea (each isomer), N-ethylphenyl-N'N'-dipentylurea (each isomer), N-ethylphenyl-N'N'-dihexylurea (each isomer), N-ethylphenyl-N'N'-diphenylurea (each isomer), N-ethylphenyl-N'N'-dimethylphenylurea (each isomer), N,N,N'-triethylphenylurea (each isomer), N,N,N',N'-tetramethylurea, N,N,N',N'-tetraethylurea, N,N,N',N'-Tetrapropylurea (each isomer), N,N,N',N'-Tetrapropylurea (each isomer), N,N,N',N'-Tetrabutylurea (each isomer), N,N,N',N'-Tetrabutylurea (each isomer), N,N,N',N'-Tetrapentylurea (each isomer), N,N,N',N'-Tetrapentylurea (each isomer) isomer), N,N,N',N'-tetrahexylurea (each isomer), N,N,N',N'-tetrahexylurea (each isomer), N,N,N',N'-tetraheptylurea (each isomer), N,N,N',N'-tetraheptylurea (each isomer), N,N,N',N'-tetraoctylurea (each isomer), N,N,N',N'-tetraoctylurea N,N,N',N'-tetranonyl urea (each isomer), N,N,N',N'-tetranonyl urea (each isomer), N,N,N',N'-tetradecyl urea (each isomer), N,N,N',N'-tetradecyl urea (each isomer), N,N,N',N'-tetraundecyl urea (each isomer), N,N,N',N Examples of suitable urea compounds include N,N,N',N'-tetraundecylurea (each isomer), N,N,N',N'-tetradodecylurea (each isomer), N,N,N',N'-tetradodecylurea (each isomer), 4,4'-carbonyldimorpholine, 1,1'-carbonyldipiperidine, 1,1'-carbonyldipyrrolidine, and 1,1'-carbonyldiimidazole.

[0339] Among these, urea is more preferable because it is easily available and inexpensive; 1-substituted urea or 1,2-disubstituted urea is more preferable because it can be easily obtained by reacting urea with a primary amine; or 1,1-disubstituted urea is more preferable because it can be easily obtained by reacting urea with a secondary amine.

[0340] [Carbamic acid ester] A carbamic acid ester is a compound having at least one carbamic acid ester structure in the molecule. The carbamic acid ester is not particularly limited, and may be a carbamic acid ester having one carbamic acid ester structure in the molecule, or a carbamic acid ester having two or more carbamic acid ester structures in the molecule. When a carbamic acid ester having two or more carbamic acid ester structures in the molecule is used, high molecular weight components are included in the reaction, making it difficult to produce a blocked isocyanate compound and a blocked isocyanate composition. Therefore, it is preferable to use a compound having one carbamic acid ester structure in the molecule as the carbamic acid ester.

[0341] Among compounds having one carbamate structure in the molecule, a compound represented by the following general formula (VI-2) (hereinafter, sometimes referred to as "carbamate (VI-2)") is preferred.

[0342] [ka]

[0343] In general formula (VI-2), R 621 is an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. 622 and R 623 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0344] (R 621 , R 622 and R 623 ) R 622 and R 623 may be the same as or different from each other.

[0345] R 621 , R 622 and R 623The alkyl group, aralkyl group, and aryl group in 611 , R 612 , R 613 , and R 614 The same examples as those exemplified above are included.

[0346] Preferred carbamic acid esters (VI-2) include methyl carbamate, ethyl carbamate, propyl carbamate (each isomer), butyl carbamate (each isomer), pentyl carbamate (each isomer), hexyl carbamate (each isomer), heptyl carbamate (each isomer), octyl carbamate (each isomer), nonyl carbamate (each isomer), decyl carbamate (each isomer), undecyl carbamate (each isomer), dodecyl carbamate (each isomer), tridecyl carbamate (each isomer), and tetradecyl carbamate (each isomer). ), pentadecyl carbamate (each isomer), hexadecyl carbamate (each isomer), heptadecyl carbamate (each isomer), octadecyl carbamate (each isomer), nonadecyl carbamate (each isomer), icosyl carbamate (each isomer), phenyl carbamate, methylphenyl carbamate (each isomer), ethylphenyl carbamate (each isomer), propylphenyl carbamate (each isomer), butylphenyl carbamate (each isomer), pentylphenyl carbamate (each isomer), hexylphenyl carbamate (phenyl) (each isomer), (heptylphenyl) carbamate (each isomer), (octylphenyl) carbamate (each isomer), (nonylphenyl) carbamate (each isomer), (decylphenyl) carbamate (each isomer), (undecylphenyl) carbamate (each isomer), (dodecylphenyl) carbamate (each isomer), (biphenyl) carbamate (each isomer), (terphenyl) carbamate (each isomer), (dimethylphenyl) carbamate (each isomer), (diethylphenyl) carbamate (each isomer), (dipropylphenyl) carbamate phenyl) (each isomer), dibutylphenyl carbamate (each isomer), dipentylphenyl carbamate (each isomer), dihexylphenyl carbamate (each isomer), diheptylphenyl carbamate (each isomer), dioctylphenyl carbamate (each isomer), dinonylphenyl carbamate (each isomer), didecylphenyl carbamate (each isomer), diundecylphenyl carbamate (each isomer), didodecylphenyl carbamate (each isomer), trimethylphenyl carbamate (each isomer),Triethylphenyl carbamate (each isomer), tripropylphenyl carbamate (each isomer), tributylphenyl carbamate (each isomer), tripentylphenyl carbamate (each isomer), trihexylphenyl carbamate (each isomer), triheptylphenyl carbamate (each isomer), trioctylphenyl carbamate (each isomer), trinonylphenyl carbamate (each isomer), tridecylphenyl carbamate (each isomer), triundecylphenyl carbamate (each isomer), tridodecylphenyl carbamate (each isomer), phenylmethyl carbamate, phenylethyl carbamate (each isomer), phenylpropyl carbamate (each isomer), phenylbutyl carbamate (each isomer), 2-Methoxyethyl carbamate, 2-ethoxyethyl carbamate, 2-propoxyethyl carbamate (each isomer), 2-butoxyethyl carbamate (each isomer), 1-methoxypropan-2-yl carbamate, 1-ethoxypropan-2-yl carbamate, 1-propoxypropan-2-yl carbamate (each isomer), 1-butoxypropan-2-yl carbamate (each isomer), 2-methoxypropyl carbamate, 2-ethoxypropyl carbamate, 2-propoxypropyl carbamate N-unsubstituted carbamic acid esters such as 2-propyl (each isomer), 2-butoxypropyl carbamate (each isomer), and 2-phenoxyethyl carbamate (each isomer); methyl N-methylcarbamate, ethyl N-methylcarbamate, ethyl N-ethylcarbamate, propyl N-methylcarbamate (each isomer), propyl N-ethylcarbamate (each isomer), propyl N-propylcarbamate (each isomer), butyl N-methylcarbamate (each isomer), butyl N-ethylcarbamate (each isomer), and butyl N-propylcarbamate (each isomer). isomer), butyl N-butylcarbamate (each isomer), pentyl N-methylcarbamate (each isomer), pentyl N-ethylcarbamate (each isomer), pentyl N-propylcarbamate (each isomer), pentyl N-butylcarbamate (each isomer), pentyl N-pentylcarbamate (each isomer), hexyl N-methylcarbamate (each isomer), hexyl N-ethylcarbamate (each isomer), hexyl N-propylcarbamate (each isomer), hexyl N-butylcarbamate (each isomer), hexyl N-pentylcarbamate (each isomer) , hexyl N-hexylcarbamate (each isomer), heptyl N-methylcarbamate (each isomer), heptyl N-ethylcarbamate (each isomer), heptyl N-propylcarbamate (each isomer), heptyl N-butylcarbamate (each isomer), heptyl N-pentylcarbamate (each isomer), heptyl N-hexylcarbamate (each isomer), heptyl N-heptylcarbamate (each isomer), octyl N-methylcarbamate (each isomer), octyl N-ethylcarbamate (each isomer), octyl N-propylcarbamate (each isomer),Octyl N-butylcarbamate (each isomer), octyl N-pentylcarbamate (each isomer), octyl N-hexylcarbamate (each isomer), octyl N-heptylcarbamate (each isomer), octyl N-octylcarbamate (each isomer), nonyl N-methylcarbamate (each isomer), nonyl N-ethylcarbamate (each isomer), nonyl N-propylcarbamate (each isomer), nonyl N-butylcarbamate (each isomer), nonyl N-pentylcarbamate (each isomer), nonyl N-hexylcarbamate (each isomer), nonyl N-heptylcarbamate (each isomer) isomer), nonyl N-octylcarbamate (each isomer), nonyl N-nonylcarbamate (each isomer), decyl N-methylcarbamate (each isomer), decyl N-ethylcarbamate (each isomer), decyl N-propylcarbamate (each isomer), decyl N-butylcarbamate (each isomer), decyl N-pentylcarbamate (each isomer), decyl N-hexylcarbamate (each isomer), decyl N-heptylcarbamate (each isomer), decyl N-octylcarbamate (each isomer), decyl N-nonylcarbamate (each isomer), decyl N-decylcarbamate (each isomer), N-Methyl undecyl carbamate (each isomer), N-ethyl undecyl carbamate (each isomer), N-propyl undecyl carbamate (each isomer), N-butyl undecyl carbamate (each isomer), N-pentyl undecyl carbamate (each isomer), N-hexyl undecyl carbamate (each isomer), N-heptyl undecyl carbamate (each isomer), N-octyl undecyl carbamate (each isomer), N-nonyl undecyl carbamate (each isomer), N-decyl undecyl carbamate (each isomer), N-undecyl carbamate undecyl carbamate (each isomer), dodecyl N-methylcarbamate (each isomer), dodecyl N-ethylcarbamate (each isomer), dodecyl N-propylcarbamate (each isomer), dodecyl N-butylcarbamate (each isomer), dodecyl N-pentylcarbamate (each isomer), dodecyl N-hexylcarbamate (each isomer), dodecyl N-heptylcarbamate (each isomer), dodecyl N-octylcarbamate (each isomer), dodecyl N-nonylcarbamate (each isomer), dodecyl N-decylcarbamate (each isomer), N-undecyl Dodecyl N-carbamate (each isomer), dodecyl N-dodecylcarbamate (each isomer), phenyl N-methylcarbamate, phenyl N-ethylcarbamate, phenyl N-propylcarbamate (each isomer), phenyl N-butylcarbamate (each isomer), phenyl N-pentylcarbamate (each isomer), phenyl N-hexylcarbamate (each isomer), phenyl N-phenylcarbamate, methylphenyl N-methylcarbamate, methylphenyl N-ethylcarbamate, methylphenyl N-propylcarbamate (each isomer), N -methylphenyl butylcarbamate (each isomer), methylphenyl N-pentylcarbamate (each isomer), methylphenyl N-hexylcarbamate (each isomer), methylphenyl N-phenylcarbamate, methylphenyl N-methylphenylcarbamate, ethylphenyl N-methylcarbamate (each isomer), ethylphenyl N-ethylcarbamate (each isomer), ethylphenyl N-propylcarbamate (each isomer), ethylphenyl N-butylcarbamate (each isomer), ethylphenyl N-pentylcarbamate (each isomer),N-Hexylcarbamic acid ethyl phenyl (each isomer), N-phenylcarbamic acid ethyl phenyl (each isomer), N-methylphenylcarbamic acid ethyl phenyl (each isomer), N-ethylphenylcarbamic acid ethyl phenyl (each isomer), Methyl N,N-dimethylcarbamate, methyl N,N-diethylcarbamate, methyl N,N-dipropylcarbamate, methyl N,N-dibutylcarbamate, methyl N,N-dipentylcarbamate, methyl N,N-dihexylcarbamate, methyl N,N-diheptylcarbamate, methyl N,N-dioctylcarbamate, methyl N,N-dinonylcarbamate, methyl N,N-didecylcarbamate, methyl N,N-diundecylcarbamate, methyl N,N-didodecylcarbamate, ethyl N,N-dimethylcarbamate, N,N- Ethyl diethylcarbamate, Ethyl N,N-dipropylcarbamate, Ethyl N,N-dibutylcarbamate, Ethyl N,N-dipentylcarbamate, Ethyl N,N-dihexylcarbamate, Ethyl N,N-diheptylcarbamate, Ethyl N,N-dioctylcarbamate, Ethyl N,N-dinonylcarbamate, Ethyl N,N-didecylcarbamate, Ethyl N,N-diundecylcarbamate, Ethyl N,N-didodecylcarbamate, Propyl N,N-dimethylcarbamate, Propyl N,N-diethylcarbamate, N,N-dipropyl Propylcarbamate, Propyl N,N-Dibutylcarbamate, Propyl N,N-Dipentylcarbamate, Propyl N,N-Dihexylcarbamate, Propyl N,N-Diheptylcarbamate, Propyl N,N-Dioctylcarbamate, Propyl N,N-Dinonylcarbamate, Propyl N,N-Didecylcarbamate, Propyl N,N-Diundecylcarbamate, Propyl N,N-Didodecylcarbamate, Butyl N,N-Dimethylcarbamate, Butyl N,N-Diethylcarbamate, Butyl N,N-Dipropylcarbamate, N ,N-Butyl dibutylcarbamate, N,N-butyl dipentylcarbamate, N,N-butyl dihexylcarbamate, N,N-butyl diheptylcarbamate, N,N-butyl dioctylcarbamate, N,N-butyl dinonylcarbamate, N,N-butyl didecylcarbamate, N,N-butyl diundecylcarbamate, N,N-butyl didodecylcarbamate, N,N-pentyl dimethylcarbamate, N,N-pentyl diethylcarbamate, N,N-pentyl dipropylcarbamate, N,N-pentyl dibutylcarbamate, N,Pentyl N-dipentylcarbamate, pentyl N,N-dihexylcarbamate, pentyl N,N-diheptylcarbamate, pentyl N,N-dioctylcarbamate, pentyl N,N-dinonylcarbamate, pentyl N,N-didecylcarbamate, pentyl N,N-diundecylcarbamate, pentyl N,N-didodecylcarbamate, hexyl N,N-dimethylcarbamate, hexyl N,N-diethylcarbamate, hexyl N,N-dipropylcarbamate, N,N-dibutylcarbamate Hexyl N,N-dipentylcarbamate, hexyl N,N-dihexylcarbamate, hexyl N,N-diheptylcarbamate, hexyl N,N-dioctylcarbamate, hexyl N,N-dinonylcarbamate, hexyl N,N-didecylcarbamate, hexyl N,N-diundecylcarbamate, hexyl N,N-didodecylcarbamate, heptyl N,N-dimethylcarbamate, heptyl N,N-diethylcarbamate, N,N-dipropylcarbamate Heptyl N,N-dibutylcarbamate, Heptyl N,N-dipentylcarbamate, Heptyl N,N-dihexylcarbamate, Heptyl N,N-diheptylcarbamate, Heptyl N,N-dioctylcarbamate, Heptyl N,N-dinonylcarbamate, Heptyl N,N-didecylcarbamate, Heptyl N,N-diundecylcarbamate, Heptyl N,N-didodecylcarbamate, Octyl N,N-dimethylcarbamate, Octyl N,N-diethylcarbamate Examples of N-substituted carbamates include octyl N,N-dipropylcarbamate, octyl N,N-dibutylcarbamate, octyl N,N-dipentylcarbamate, octyl N,N-dihexylcarbamate, octyl N,N-diheptylcarbamate, octyl N,N-dioctylcarbamate, octyl N,N-dinonylcarbamate, octyl N,N-didecylcarbamate, octyl N,N-diundecylcarbamate, and octyl N,N-didodecylcarbamate. Among these, N-unsubstituted carbamic acid esters are more preferred because they can be easily obtained by reacting urea, which is readily available and inexpensive, with an alcohol.

[0347] [Carbonate ester] Carbonate esters are compounds having at least one carbonate ester structure in the molecule. The carbonate ester is not particularly limited, and may be a carbonate ester having one carbonate ester structure in the molecule, or a carbonate ester having two or more carbonate ester structures in the molecule. When a carbonate ester having two or more carbonate ester structures in the molecule is used, high molecular weight components are included in the reaction, making it difficult to produce a blocked isocyanate compound and a blocked isocyanate composition. Therefore, it is more preferable to use a compound having one carbonate ester structure in the molecule as the carbonate ester. Among compounds having one carbonate ester structure in the molecule, a compound represented by the following general formula (VI-3) (hereinafter, sometimes referred to as "carbonate ester (VI-3)") is more preferable.

[0348] [ka]

[0349] In general formula (VI-3), R 631 and R 632 are each independently an aralkyl group having 7 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0350] (R 631 and R 632 ) R 631 and R 632 may be the same as or different from each other.

[0351] R 631 and R 632 The alkyl group, aralkyl group, and aryl group in 611 , R 612 , R 613 , and R 614 The same examples as those exemplified above are included.

[0352] Preferred carbonates (VI-3) include dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl propyl carbonate (each isomer), ethyl propyl carbonate (each isomer), dipropyl carbonate (each isomer), methyl butyl carbonate (each isomer), ethyl butyl carbonate (each isomer), propyl butyl carbonate (each isomer), dibutyl carbonate (each isomer), methyl pentyl carbonate (each isomer), ethyl pentyl carbonate (each isomer), propyl pentyl carbonate (each isomer), butyl pentyl carbonate (each isomer), dipentyl carbonate (each isomer), methyl hexyl carbonate (each isomer), and ethyl carbonate. Hexyl (each isomer), propyl hexyl carbonate (each isomer), butyl hexyl carbonate (each isomer), pentyl hexyl carbonate (each isomer), dihexyl carbonate (each isomer), methyl heptyl carbonate (each isomer), ethyl heptyl carbonate (each isomer), propyl heptyl carbonate (each isomer), butyl heptyl carbonate (each isomer), pentyl heptyl carbonate (each isomer), hexyl heptyl carbonate (each isomer), diheptyl carbonate (each isomer), methyl octyl carbonate (each isomer), ethyl octyl carbonate (each isomer), propyl octyl carbonate (each isomer), butyl octyl carbonate (each isomer) octyl carbonate (each isomer), pentyl octyl carbonate (each isomer), hexyl octyl carbonate (each isomer), heptyl octyl carbonate (each isomer), dioctyl carbonate (each isomer), methyl nonyl carbonate (each isomer), ethyl nonyl carbonate (each isomer), propyl nonyl carbonate (each isomer), butyl nonyl carbonate (each isomer), pentyl nonyl carbonate (each isomer), hexyl nonyl carbonate (each isomer), heptyl nonyl carbonate (each isomer), octyl nonyl carbonate (each isomer), dinonyl carbonate (each isomer), methyl decyl carbonate (each isomer), ethyl decyl carbonate (each isomer), propyl decyl carbonate (each isomer ), butyldecyl carbonate (each isomer), pentyldecyl carbonate (each isomer), hexyldecyl carbonate (each isomer), heptyldecyl carbonate (each isomer), octyldecyl carbonate (each isomer), nonyldecyl carbonate (each isomer), didecyl carbonate (each isomer), methylundecyl carbonate (each isomer), ethylundecyl carbonate (each isomer), propylundecyl carbonate (each isomer), butylundecyl carbonate (each isomer), pentylundecyl carbonate (each isomer), hexylundecyl carbonate (each isomer), heptylundecyl carbonate (each isomer), octylundecyl carbonate (each isomer),Nonylundecyl carbonate (each isomer), decylundecyl carbonate (each isomer), diundecyl carbonate (each isomer), methyldodecyl carbonate (each isomer), ethyldodecyl carbonate (each isomer), propyldodecyl carbonate (each isomer), butyldodecyl carbonate (each isomer), pentyldodecyl carbonate (each isomer), hexyldodecyl carbonate (each isomer), heptyldodecyl carbonate (each isomer), octyldodecyl carbonate (each isomer), nonyldodecyl carbonate (each isomer), decyldodecyl carbonate (each isomer), undecyldodecyl carbonate (each isomer), didodecyl carbonate (each isomer), methylphenyl carbonate, ethylphenyl carbonate, propylphenyl carbonate (each isomer), butylphenyl carbonate (each isomer), pentylphenyl carbonate (each isomer), hexylphenyl carbonate ( Examples of the carbonates include diphenyl carbonate, methyl methyl phenyl carbonate, ethyl methyl phenyl carbonate, propyl methyl phenyl carbonate (each isomer), butyl methyl phenyl carbonate (each isomer), pentyl methyl phenyl carbonate (each isomer), hexyl methyl phenyl carbonate (each isomer), phenyl methyl phenyl carbonate, dimethyl phenyl carbonate, methyl ethyl phenyl carbonate (each isomer), ethyl ethyl phenyl carbonate (each isomer), propyl ethyl phenyl carbonate (each isomer), butyl ethyl phenyl carbonate (each isomer), pentyl ethyl phenyl carbonate (each isomer), hexyl ethyl phenyl carbonate (each isomer), phenyl ethyl phenyl carbonate (each isomer), methyl phenyl ethyl phenyl carbonate (each isomer), and diethyl phenyl carbonate (each isomer).

[0353] <Blocked isocyanate compounds> The blocked isocyanate compound is a compound having a blocked isocyanate group that can be dissociated into a blocking agent and an isocyanate group by heat, as shown in the following reaction formula.

[0354] [ka]

[0355] In the above reaction formula, BL-H is a blocking agent, which is an organic compound having an active hydrogen group. a is na is a valent organic group, and the R 31 is the same as

[0356] The blocked isocyanate compound may be any compound having an isocyanate group in which one or more isocyanate groups of an isocyanate compound derived from the primary amine compound are blocked with a blocking agent. When the secondary amine compound (I) is used, the blocked isocyanate compound may have a structure in which an isocyanate group and the secondary amine compound (I) form a bond.

[0357] The isocyanate compound before blocking is not particularly limited, and examples thereof include pentamethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylenebis(cyclohexane isocyanate), 4-isocyanatomethyl-1,8-octamethylene diisocyanate, diisocyanatotoluene, 4,4'-diphenylmethane diisocyanate, etc. Therefore, preferred examples of blocked isocyanate compounds are compounds in which one or more isocyanate groups of these isocyanate compounds are blocked with the above-mentioned blocking agents.

[0358] <<Method for producing blocked isocyanate compound according to the second embodiment>> The method for producing a blocked isocyanate compound of this embodiment (hereinafter, sometimes simply referred to as the "production method of the second embodiment") is a method for producing a blocked isocyanate compound, comprising an addition-elimination reaction step of reacting a first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence of one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) to obtain a second blocked isocyanate compound.

[0359] The second blocking agent is a compound different from the first blocking agent that blocks the isocyanate group of the first blocked isocyanate compound.

[0360] The first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0361] The inventors discovered that the problems of thermal denaturation and coloration can be solved by reacting a first blocked isocyanate compound with a second blocking agent, which is different from the first blocking agent that blocks the isocyanate groups of the first blocked isocyanate compound, through heat treatment in the presence of a specific amine compound having an aromatic group, to produce a second blocked isocyanate compound having a structure different from that of the first blocked isocyanate compound, and thus completed the present invention.

[0362] Therefore, the production method of the second embodiment can also be said to be a method for improving thermal denaturation and coloration that occur when producing a blocked isocyanate compound, or a method for suppressing thermal denaturation and coloration that occur when producing a blocked isocyanate compound.

[0363] Next, each step of the manufacturing method according to the second embodiment will be described in detail below.

[0364] <Addition-elimination reaction step> The addition-elimination reaction is carried out by heating the blocking agent BL a -H and BL b When the blocked isocyanate compound on the left side of the following reaction formula is the first blocked isocyanate compound used as a raw material, the blocking agent BL a -H is a first blocking agent that blocks the isocyanate group of the first blocked isocyanate compound, the blocking agent BL b -H represents the second blocking agent, and the blocked isocyanate compound on the right side of the following formula corresponds to the second blocked isocyanate compound. The second blocking agent is a compound different from the first blocking agent. Furthermore, the first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0365] [ka]

[0366] In the above reaction formula, BL a -H and BL b -H are blocking agents with different chemical structures, and are organic compounds with active hydrogen groups. b is an nb-valent organic group.

[0367] In the addition-elimination reaction step, the amount of secondary amine compound (I) present in the composition is preferably large in order to reduce coloration of the second blocked isocyanate compound and the blocked isocyanate composition. Specifically, the amount of secondary amine compound (I) present is preferably greater than 0% by mass, more preferably 1 ppm by mass or greater, even more preferably 1% by mass or greater, and particularly preferably 50% by mass or greater, relative to the total mass of the first blocked isocyanate compound and the second blocking agent. On the other hand, when the amount of secondary amine compound (I) present in the composition containing the blocked isocyanate compound is large, the basicity of the secondary amine compound (I) may accelerate at least one of the modification of the isocyanate compound and the modification of the blocked isocyanate compound. Therefore, the amount of secondary amine compound (I) present is preferably less than 1000% by mass, more preferably less than 100% by mass, even more preferably 90% by mass or less, particularly preferably 80% by mass or less, and most preferably 50% by mass or less, relative to the total mass of the primary amine compound and the second blocking agent. It is also possible to add a combination of two or more secondary amine compounds (I) to a composition containing a first blocked isocyanate compound and a second blocking agent. The thermal degradation and discoloration suppression effect of the secondary amine compound (I) varies depending on the chemical structure of the secondary amine compound, and the inclusion of two or more secondary amine compounds can enhance the thermal degradation and discoloration suppression effect.

[0368] In the addition-elimination reaction step, the amount of tertiary amine compound (II) present in the composition is preferably large in order to reduce coloration of the second blocked isocyanate compound and the blocked isocyanate composition. Specifically, the amount of tertiary amine compound (II) present is preferably greater than 0 mass%, more preferably 1 mass ppm or more, even more preferably 1 mass% or more, and particularly preferably 50 mass% or more, relative to the total mass of the reaction solution. On the other hand, when the amount of tertiary amine compound (II) present in the composition containing the blocked isocyanate compound is large, the basicity of the tertiary amine compound (II) may accelerate at least one of the modification of the isocyanate compound and the modification of the blocked isocyanate compound. Therefore, the amount of tertiary amine compound (II) present is preferably less than 1000 mass%, more preferably less than 100 mass%, even more preferably 90 mass% or less, particularly preferably 80 mass% or less, and most preferably 50 mass% or less, relative to the total mass of the reaction solution. It is also possible to add a combination of two or more tertiary amine compounds (II) to a composition containing a first blocked isocyanate compound and a second blocking agent. The thermal degradation and discoloration suppression effect of the tertiary amine compound (I) varies depending on the chemical structure of the tertiary amine compound, and the inclusion of two or more tertiary amine compounds can enhance the thermal degradation and discoloration suppression effect.

[0369] The secondary amine compound (I) and the tertiary amine compound (II) may be added alone to a composition containing a first blocked isocyanate compound and a second blocking agent, or both the secondary amine compound (I) and the tertiary amine compound (II) may be added. Comparing the secondary amine compound (I) and the tertiary amine compound (II), the secondary amine compound (I) has a stronger effect of reducing discoloration at high temperatures. On the other hand, the tertiary amine compound (II) exhibits a lower temperature dependency of the discoloration-reducing effect, and therefore exhibits a discoloration-reducing effect over a wider temperature range.

[0370] Furthermore, because the secondary amine compound (I) has an active hydrogen group, a portion of the blocking agent in the second blocked isocyanate compound is replaced by the secondary amine compound (I). As a result, urea groups formed by the reaction of the secondary amine compound (I) with the isocyanate group may remain in the blocked isocyanate compound. Since the above-mentioned reaction does not occur, the tertiary amine compound (II) is more preferred.

[0371] Furthermore, if the secondary amine compound (I) and the tertiary amine compound (II) are contained simultaneously, there is a problem that, for example, when recovering the secondary amine compound (I) and the tertiary amine compound (II), the separation operation becomes complicated. However, the secondary amine compound (I) and the tertiary amine compound (II) exhibit different effects in suppressing thermal denaturation and coloration, and in addition, they exhibit a synergistic effect in suppressing thermal denaturation and coloration. Therefore, it is preferable to contain the secondary amine compound (I) and the tertiary amine compound (II) simultaneously.

[0372] In the addition-elimination reaction step, the total amount of the secondary amine compound (I) and the tertiary amine compound (II) present is not particularly limited. However, in order to reduce the coloration of the second blocked isocyanate compound and the blocked isocyanate composition, a larger amount is preferable. Specifically, the total amount of the secondary amine compound (I) and the tertiary amine compound (II) present is preferably greater than 0% by mass, more preferably 1 ppm by mass or more, even more preferably 1% by mass or more, and particularly preferably 50% by mass or more, based on the total mass of the first blocked isocyanate compound and the second blocking agent. On the other hand, if the amount of the secondary amine compound (I) present in the composition containing the second blocked isocyanate compound is large, the basicity of the secondary amine compound (I) and the tertiary amine compound (II) may accelerate at least one of the modification of the isocyanate compound and the modification of the second blocked isocyanate compound. Therefore, the total amount of the secondary amine compound (I) and the tertiary amine compound (II) present is preferably less than 1000% by mass, more preferably less than 100% by mass, even more preferably 90% by mass or less, particularly preferably 80% by mass or less, and most preferably 50% by mass or less, based on the total mass of the first blocked isocyanate compound and the second blocking agent.

[0373] Furthermore, by combining one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) with an antioxidant different from the one or more secondary amine compounds (I) and tertiary amine compounds (II), the thermal denaturation and discoloration suppression effect can be further enhanced. Furthermore, by combining secondary amine compounds (I) and tertiary amine compounds (II) with an antioxidant, the thermal denaturation and discoloration suppression effect can be further enhanced.

[0374] The antioxidant other than the secondary amine compound (I) and the tertiary amine compound (II) is not particularly limited as long as it is an antioxidant that enhances the thermal denaturation and discoloration suppression effect, but phenolic antioxidants or phosphorus-based antioxidants are more preferred as they are particularly effective in suppressing discoloration. Among them, phenolic antioxidants are preferred because they have a particularly high effect of preventing thermal denaturation and discoloration when combined with the secondary amine compound (I) and the tertiary amine compound (II).

[0375] In the addition-elimination reaction step, the ratio of the amounts of the first blocked isocyanate compound and the second blocking agent added can be selected as desired, but typically, the reaction is carried out at a ratio such that the ratio of the molar amount of carbonyl groups in the first blocked isocyanate compound to the molar amount of active hydrogen groups in the first blocking agent is 1:1, or such that the molar amount of active hydrogen groups in the second blocking agent is greater than the molar amount of carbonyl groups in the first blocked isocyanate compound.

[0376] In the addition-elimination reaction step, the weight ratio of the amounts of the first blocked isocyanate compound and the second blocking agent added can be selected arbitrarily.

[0377] In the addition-elimination reaction step, the combination of the first blocked isocyanate compound, the second blocking agent, the secondary amine compound (I), and the tertiary amine compound (II) can be selected arbitrarily. However, when distillation separation is performed in the reaction step, the progress of the reaction can be promoted by actively withdrawing the first blocking agent from the system. From this viewpoint, it is preferable that the boiling point of the first blocking agent is lower than that of the second blocking agent.

[0378] The reaction temperature is not particularly limited and is appropriately selected depending on the reaction rate, thermal denaturation, and degree of coloration of the first blocked isocyanate compound and the second blocking agent. From the viewpoint of suppressing the denaturation of the first blocked isocyanate compound and / or the second blocked isocyanate compound, the reaction temperature is preferably 350°C or lower, more preferably 300°C or lower, and even more preferably 260°C or lower. On the other hand, a low reaction temperature may require setting the condenser temperature at a low temperature, which may require additional equipment. From this viewpoint, the reaction temperature is preferably 50°C or higher, more preferably 80°C or higher, and even more preferably 100°C or higher. Furthermore, the coloration reduction effect during the production of a blocked isocyanate compound in the presence of a secondary amine compound (I) becomes more pronounced as the temperature increases. From this viewpoint, the reaction temperature for the production of a blocked isocyanate is preferably 120°C or higher, more preferably 160°C or higher, and even more preferably 200°C or higher.

[0379] The reaction pressure may vary depending on the type of compound used and the reaction temperature, but may be reduced pressure, normal pressure, or increased pressure, and is usually carried out within the range of 20 Pa or more and 2×10 7 Pa or less in absolute pressure.

[0380] The addition-elimination reaction step may be carried out in the presence of oxygen. When the reaction step is carried out in the presence of oxygen, the amount of oxygen present in the blocked isocyanate production equipment is preferably reduced because thermal denaturation and coloration of the blocked isocyanate compound may occur. On the other hand, when considering a large-scale production facility, reducing the amount of oxygen present in the production equipment for a blocked isocyanate compound requires reducing air leakage into the production facility, which results in stricter design standards for the facility and increased facility costs. From this perspective, the oxygen concentration in the gas supplied to the reaction step is preferably controlled at a high level, preferably greater than 0% by volume, more preferably greater than 0.0001% by volume, and even more preferably greater than 0.001% by volume.

[0381] In the addition-elimination reaction step, the presence of one or more compounds selected from the group consisting of secondary amine compound (I) and tertiary amine compound (II) can reduce thermal denaturation and coloration of the blocked isocyanate compound, even in the presence of oxygen. On the other hand, an increase in the amount of oxygen present is undesirable because it promotes thermal denaturation and coloration, as described above, and therefore requires increased amounts of secondary amine compound (I) and tertiary amine compound (II) used to suppress thermal denaturation and coloration. From this perspective, it is preferable to operate the reaction step under low oxygen concentrations, preferably controlled to 21% by volume or less, more preferably 10% by volume or less, even more preferably 1% by volume or less, even more preferably 0.1% by volume or less, particularly preferably 0.01% by volume or less, and most preferably 0.001% by volume or less, based on the total volume of gas. The oxygen concentration can be measured using known techniques, such as conventional gas chromatography or an electrochemical trace oxygen analyzer.

[0382] In the addition-elimination reaction step, any solvent may be used in any proportion. The solvent is preferably an inert solvent that is not reactive with the first blocked isocyanate compound, the first blocking agent, the second blocking agent, and the second blocked isocyanate compound. Such a solvent is preferably an ester solvent, an ether solvent, a phosphate ester solvent, a hydrocarbon solvent, an aromatic hydrocarbon solvent, or a carbonic acid derivative solvent.

[0383] In the addition-elimination reaction step, the reaction mixture containing the first blocked isocyanate compound and the second blocking agent may contain any metal in any proportion. The metal may be in the form of a complex or a solid. While the metal promotes the addition-elimination reaction between the first blocked isocyanate compound and the second blocking agent, it may also cause thermal denaturation, deterioration, and coloration. Therefore, the metal content is preferably less than 10% by mass, more preferably less than 1% by mass, and even more preferably less than 0.1 ppm by mass, relative to the mass of the first blocked isocyanate compound.

[0384] In the addition-elimination reaction step, the reaction mixture containing the first blocked isocyanate compound and the second blocking agent may contain an organic acid, an inorganic acid, an organic base, or an inorganic base. These acids and bases act as catalysts in the addition-elimination reaction between the first blocked isocyanate compound and the second blocking agent, thereby reducing the temperature required for the reaction. On the other hand, these acids and bases also act as catalysts for the modification reaction of the blocked isocyanate. From this perspective, the content of these organic acids, inorganic acids, organic bases, and inorganic bases is preferably less than 10% by mass, more preferably less than 1% by mass, even more preferably less than 0.1% by mass, and particularly preferably less than 1 ppb by mass, relative to the mass of the first blocked isocyanate compound.

[0385] In the addition-elimination reaction step, the second blocked isocyanate compound is obtained as a composition containing the second blocked isocyanate compound (hereinafter, sometimes referred to as a "blocked isocyanate composition").

[0386] The blocked isocyanate composition refers to a composition containing more than 0 wt % and 100 wt % or less of a blocked isocyanate compound. The blocked isocyanate composition is not particularly limited except that it contains a blocked isocyanate compound, and may contain a solvent, a blocking agent, an isocyanate, a catalyst, a primary amine compound, and the like in any proportion.

[0387] In view of the above, the blocked isocyanate composition may be used as it is as the blocked isocyanate compound, or the blocked isocyanate compound may be purified from the blocked isocyanate composition and then used.

[0388] (Reaction Apparatus) The reaction apparatus is not particularly limited, and known reaction apparatuses for addition-elimination reactions can be used. For example, a method can be used in which a mixture containing a first blocked isocyanate compound and a second blocking agent is added to a vessel connected to one or more apparatuses selected from the group consisting of condensers and treatment apparatuses, the vessel is heated to produce the second blocked isocyanate compound, and then or simultaneously, vapor containing the first blocking agent is introduced into the condenser or treatment apparatus to synthesize the second blocked isocyanate compound in a batchwise manner. Alternatively, a method can be used in which a mixture containing a first blocked isocyanate compound and a second blocking agent is continuously introduced into a distillation column heated to a predetermined reaction temperature, and the vapor containing the first blocking agent produced simultaneously with the production of the second blocked isocyanate compound is separated to continuously obtain the second blocked isocyanate compound.

[0389] The material of the reaction apparatus for the portions that come into contact with the mixture containing the first blocked isocyanate compound, the first blocking agent, the second blocking agent, and the second blocked isocyanate compound, and the composition containing the second blocked isocyanate compound produced by the reaction, may be any known material as long as it does not adversely affect the first blocked isocyanate compound, the first blocking agent, the second blocking agent, and the second blocked isocyanate compound. Specific examples of such materials include steel, stainless steel, ceramic, carbon, and materials lined with these materials.

[0390] When a distillation apparatus is used, the type of the distillation apparatus is not particularly limited, and various known distillation apparatuses can be used, such as a batch distillation apparatus, a simple distillation apparatus, a multi-stage distillation column, a continuous multi-stage distillation column, or a packed column, or a distillation apparatus that combines these.

[0391] The distillation column used here can have two or more theoretical plates. However, if the number of theoretical plates is large, the multi-stage distillation column will become huge and may be difficult to implement industrially, so the number of theoretical plates is generally 500 or less.

[0392] Any type of distillation column can be used as long as it is typically used as a multi-stage distillation column, such as a plate column type using trays such as bubble trays, perforated trays, valve trays, and countercurrent trays, or a packed column type filled with various packings such as Raschig rings, Lessing rings, Paul rings, Berle saddles, Intalox saddles, Dixon packing, McMahon packing, Helipack, Sulzer packing, and Melapack. Furthermore, a mixed plate-packed column type having both tray sections and sections filled with packings is also preferably used.

[0393] Next, the raw materials used in the production method of the second embodiment and the resulting product will be described in detail below.

[0394] <First blocked isocyanate compound and first blocking agent> The first blocked isocyanate compound is a compound having a blocked isocyanate group that can be dissociated into a first blocking agent and an isocyanate group by heat, as shown in the following reaction formula: When the first blocked isocyanate compound is represented on the right side of the following reaction formula, the first blocking agent that blocks the isocyanate group of the first blocked isocyanate compound represents the blocking agent corresponding to BL-H on the left side.

[0395] [ka]

[0396] In the above reaction formula, BL-H is a blocking agent, which is an organic compound having an active hydrogen group. a is n a is a valent organic group, and the R 31is the same as

[0397] [First blocked isocyanate compound] Examples of the first blocked isocyanate compound include blocked isocyanate compounds obtained by formally reacting an isocyanate compound, which is a raw material for the second blocked isocyanate compound, with the above-mentioned blocking agents (alcohol-based, phenol-based, thiol-based, amine and ammonia-based, oxime-based, hydroxylamine-based, and active methylene-based blocking agents). Other examples include blocked isocyanate compounds produced by a method for producing a blocked isocyanate compound, which includes a reaction step of reacting a primary amine compound, a carbonic acid derivative, and a blocking agent by heat treatment to obtain the blocked isocyanate compound.

[0398] [First blocking agent] The first blocking agent may be any compound that has an active hydrogen group, reacts with an isocyanate group to form a bond, and is thermally decomposed into an isocyanate compound and a blocking agent. Examples of such blocking agents include alcohol-based, phenol-based (hereinafter, alcohol-based and phenol-based blocking agents may be collectively referred to as "hydroxy compounds"), thiol-based, amine and ammonia-based, oxime-based, hydroxylamine-based, and active methylene-based blocking agents.

[0399] Among these, from the viewpoint of the stability of the blocking agent during thermal decomposition, blocking agents consisting of hydroxy compounds, amine and ammonia-based, or hydroxylamine-based blocking agents are preferred. Furthermore, phenol-based, amine-based, or hydroxylamine-based blocking agents, or ammonia are more preferred because they cause less denaturation of the isocyanate compound during thermal decomposition. Furthermore, phenol-based blocking agents are even more preferred because they have particularly high stability during thermal decomposition and cause less denaturation of the isocyanate compound during thermal decomposition.

[0400] Furthermore, when obtaining the second blocked isocyanate compound by the addition-elimination reaction, it is particularly preferable to use, as the first blocking agent, a blocking agent having lower nucleophilicity than the second blocking agent, because this improves the reactivity between the first blocked isocyanate compound and the second blocking agent and increases the yield of the second blocked isocyanate compound.

[0401] When comparing phenol-based blocking agents, alcohol-based blocking agents, amine-based and ammonia-based blocking agents, and hydroxylamine-based blocking agents from the standpoint of nucleophilicity of the blocking agents, the general ranking is hydroxylamine-based blocking agents < phenol-based blocking agents < alcohol-based blocking agents < amine-based and ammonia-based blocking agents.

[0402] [Phenol-based blocking agent] The phenol-based blocking agent is not particularly limited as long as it is a compound having a hydroxyl group bonded to an aromatic ring, but a blocking agent having a phenol group or a naphthol group is preferred due to its ease of availability. It may be a compound having a hydroxyl group bonded to one aromatic ring in the molecule, or a compound having hydroxyl groups bonded to two or more aromatic rings in the molecule. When a compound having hydroxyl groups bonded to two or more aromatic rings in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the compound having hydroxyl groups bonded to the aromatic ring. Therefore, it is preferable to use a compound having a hydroxyl group bonded to one aromatic ring in the molecule as a phenol-based blocking agent.

[0403] Preferred phenol-based blocking agents include those exemplified above in the "Method for producing a blocked isocyanate compound according to the first embodiment."

[0404] [Alcohol-based blocking agent] The alcohol-based blocking agent is not particularly limited as long as it is an aliphatic compound having a hydroxyl group, and may be an aliphatic compound having one hydroxyl group in the molecule or two or more hydroxyl groups in the molecule. When an aliphatic compound having two or more hydroxyl groups in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the aliphatic compound having a hydroxyl group. Therefore, it is more preferable to use an aliphatic compound having one hydroxyl group in the molecule.

[0405] Preferred examples of the alcohol-based blocking agent include the same as those exemplified in the above "Method for producing a blocked isocyanate compound according to the first embodiment."

[0406] [Amine and ammonia-based blocking agents] As the amine and ammonia-based blocking agent, an amine compound having a primary or secondary amino group as the active hydrogen group or ammonia can be used. When a primary amine compound or ammonia is used as the blocking agent, the urea bond formed by the reaction of the primary amine compound or ammonia with an isocyanate compound has two possible cleavage directions during thermal decomposition, so that an isocyanate compound is formed on the primary amine compound used as the blocking agent, making it difficult to obtain the desired isocyanate compound. Therefore, it is preferable to use an amine compound having a secondary amino group.

[0407] The amine and ammonia-based blocking agent may be an amine compound having one amino group in the molecule, or may be an amine compound having two or more amino groups in the molecule. When an amine compound having two or more amino groups in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the amine compound. Therefore, it is preferable to use an amine compound having one amino group in the molecule as the amine and ammonia-based blocking agent.

[0408] Preferred amine and ammonia-based blocking agents include those exemplified above in the "Method for producing a blocked isocyanate compound according to the first embodiment."

[0409] [Hydroxylamine blocking agent] The hydroxylamine-based blocking agent is not particularly limited, and may be a hydroxylamine compound having one hydroxylamine structure in the molecule, or a hydroxylamine compound having two or more hydroxylamine structures in the molecule. When a hydroxylamine compound having two or more hydroxylamine structures in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the hydroxylamine compound. Therefore, it is preferable to use a hydroxylamine compound having one hydroxylamine structure in the molecule as a hydroxylamine-based blocking agent.

[0410] Examples of the hydroxylamine compound having one hydroxylamine structure in the molecule include the same compounds as those exemplified in the above "Method for producing a blocked isocyanate compound according to the first embodiment."

[0411] <Second blocking agent> The second blocking agent may be any compound that has an active hydrogen group, reacts with an isocyanate group to form a bond, and can be decomposed into an isocyanate compound and a blocking agent by thermal decomposition.

[0412] Examples of such blocking agents include alcohol-based, phenol-based (hereinafter, alcohol-based and phenol-based blocking agents may be collectively referred to as "hydroxy compounds"), thiol-based, amine and ammonia-based, oxime-based, hydroxylamine-based, and active methylene-based blocking agents.

[0413] Among these, from the viewpoint of the stability of the blocking agent during thermal decomposition, blocking agents consisting of hydroxy compounds, amine and ammonia-based, or hydroxylamine-based blocking agents are preferred. Furthermore, phenol-based, amine-based, or hydroxylamine-based blocking agents, or ammonia are more preferred because they cause less denaturation of the isocyanate compound during thermal decomposition. Furthermore, phenol-based blocking agents are even more preferred because they have particularly high stability during thermal decomposition and cause less denaturation of the isocyanate compound during thermal decomposition.

[0414] On the other hand, when obtaining the second blocked isocyanate compound by the addition-elimination reaction, it is particularly preferable to use, as the second blocking agent, a blocking agent that is more nucleophilic than the first blocking agent, because this improves the reactivity between the first blocked isocyanate compound and the second blocking agent and increases the yield of the second blocked isocyanate compound.

[0415] When comparing phenol-based blocking agents, alcohol-based blocking agents, amine-based and ammonia-based blocking agents, and hydroxylamine-based blocking agents from the standpoint of nucleophilicity of the blocking agents, the general ranking is hydroxylamine-based blocking agents < phenol-based blocking agents < alcohol-based blocking agents < amine-based and ammonia-based blocking agents.

[0416] Furthermore, when using a method in which a second blocked isocyanate compound is produced by an addition-elimination reaction, and then or simultaneously therewith, vapor containing the first blocking agent is introduced into a condenser or treatment device to synthesize the second blocked isocyanate compound in a batchwise manner, or a method in which a mixture containing the first blocked isocyanate compound and a mixture containing the second blocking agent is continuously introduced into a distillation column heated to a predetermined reaction temperature, and vapor containing the first blocking agent produced simultaneously with the production of the second blocked isocyanate compound is separated to continuously obtain the second blocked isocyanate compound, it is preferable that the boiling point of the second blocking agent be equal to or higher than the boiling point of the first blocking agent.

[0417] [Phenol-based blocking agent] The phenol-based blocking agent is not particularly limited as long as it is a compound having a hydroxyl group bonded to an aromatic ring, but a blocking agent having a phenol group or a naphthol group is preferred due to its ease of availability. It may be a compound having a hydroxyl group bonded to one aromatic ring in the molecule, or a compound having hydroxyl groups bonded to two or more aromatic rings in the molecule. When a compound having hydroxyl groups bonded to two or more aromatic rings in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the compound having hydroxyl groups bonded to the aromatic ring. Therefore, it is preferable to use a compound having a hydroxyl group bonded to one aromatic ring in the molecule as a phenol-based blocking agent.

[0418] Preferred phenol-based blocking agents include those exemplified above in the "Method for producing a blocked isocyanate compound according to the first embodiment."

[0419] [Alcohol-based blocking agent] The alcohol-based blocking agent is not particularly limited as long as it is an aliphatic compound having a hydroxyl group, and may be an aliphatic compound having one hydroxyl group in the molecule or two or more hydroxyl groups in the molecule. When an aliphatic compound having two or more hydroxyl groups in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the aliphatic compound having a hydroxyl group. Therefore, it is more preferable to use an aliphatic compound having one hydroxyl group in the molecule.

[0420] Preferred examples of the alcohol-based blocking agent include the same as those exemplified in the above "Method for producing a blocked isocyanate compound according to the first embodiment."

[0421] [Amine and ammonia-based blocking agents] As the amine and ammonia-based blocking agent, an amine compound having a primary or secondary amino group as the active hydrogen group or ammonia can be used. When a primary amine compound or ammonia is used as the blocking agent, the urea bond formed by the reaction of the primary amine compound or ammonia with an isocyanate compound has two possible cleavage directions during thermal decomposition, so that an isocyanate compound is formed on the primary amine compound used as the blocking agent, making it difficult to obtain the desired isocyanate compound. Therefore, it is preferable to use an amine compound having a secondary amino group.

[0422] The amine and ammonia-based blocking agent may be an amine compound having one amino group in the molecule, or may be an amine compound having two or more amino groups in the molecule. When an amine compound having two or more amino groups in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the amine compound. Therefore, it is preferable to use an amine compound having one amino group in the molecule as the amine and ammonia-based blocking agent.

[0423] Preferred amine and ammonia-based blocking agents include those exemplified above in the "Method for producing a blocked isocyanate compound according to the first embodiment."

[0424] [Hydroxylamine blocking agent] The hydroxylamine-based blocking agent is not particularly limited, and may be a hydroxylamine compound having one hydroxylamine structure in the molecule, or a hydroxylamine compound having two or more hydroxylamine structures in the molecule. When a hydroxylamine compound having two or more hydroxylamine structures in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the hydroxylamine compound. Therefore, it is preferable to use a hydroxylamine compound having one hydroxylamine structure in the molecule as a hydroxylamine-based blocking agent.

[0425] Examples of the hydroxylamine compound having one hydroxylamine structure in the molecule include the same compounds as those exemplified in the above "Method for producing a blocked isocyanate compound according to the first embodiment."

[0426] Although the above-mentioned blocking agents can be used alone, it is also effective to use two or more blocking agents in combination. For example, when a blocking agent with low nucleophilicity and a blocking agent with high nucleophilicity are used in combination, the blocking agent with high nucleophilicity reacts with the blocked isocyanate group formed by blocking an isocyanate group with the first blocking agent (hereinafter, sometimes referred to as the "blocked isocyanate group derived from the first blocked isocyanate"), contributing to a reduction in the blocked isocyanate group derived from the first blocked isocyanate. Therefore, it is preferable to use at least one blocking agent, and preferably all blocking agents, that are more nucleophilic than the first blocking agent. Note that the blocking agents with high nucleophilicity are as described above.

[0427] <<Method for producing an isocyanate compound according to the third embodiment>> The method for producing an isocyanate compound of this embodiment (hereinafter, sometimes simply referred to as the "production method of the third embodiment") includes a reaction step (hereinafter, sometimes referred to as the "thermal decomposition step" or "second reaction step") of decomposing a blocked isocyanate compound into a blocking agent and an isocyanate compound by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I) (hereinafter, sometimes referred to as the "secondary amine compound (I)") and a tertiary amine compound represented by the following general formula (II) (hereinafter, sometimes referred to as the "tertiary amine compound (II)"), thereby obtaining the isocyanate compound.

[0428] [ka]

[0429] In general formula (I), R 11 and R12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0430] [ka]

[0431] In general formula (II), R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R 22 , R 22 and R 23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group.

[0432] The inventors have found that the problems of thermal denaturation and coloration can be solved by thermally decomposing a blocked isocyanate compound in the presence of a specific amine compound having an aromatic group to produce a free blocking agent and an isocyanate compound, and have completed the present invention.

[0433] As described above, compounds having an amino group bonded to an aromatic carbon atom have been known to be easily oxidized and discolored. Therefore, although compounds having an amino group bonded to an aromatic carbon atom are sometimes used in products where discoloration is not an issue, such as rubber deterioration inhibitors, they are not used in products where discoloration is an issue. Surprisingly, the manufacturing method of the third embodiment has now been shown for the first time to exhibit a particularly remarkable effect of improving (suppressing) thermal denaturation and discoloration by using a specific amine compound having an aromatic group, far from causing discoloration problems.

[0434] Therefore, the production method of the third embodiment can also be said to be a method for improving thermal denaturation and coloration that occur when an isocyanate compound is produced from a blocked isocyanate compound, or a method for suppressing thermal denaturation and coloration that occur when an isocyanate compound is produced from a blocked isocyanate compound.

[0435] Next, each step of the manufacturing method according to the third embodiment will be described in detail below.

[0436] <Pyrolysis process> In the thermal decomposition step, the blocked isocyanate compound is decomposed into a blocking agent and an isocyanate compound by heat treatment in the presence of one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II), thereby obtaining the isocyanate compound.

[0437] In the thermal decomposition step, the amount of secondary amine compound (I) present in the composition is preferably large in order to reduce the coloration of the isocyanate compound and the isocyanate composition. Specifically, the amount is preferably greater than 0 mass%, more preferably 1 mass ppm or more, even more preferably 1 mass% or more, and particularly preferably 50 mass% or more, relative to the total mass of the reaction solution. On the other hand, if the amount of secondary amine compound (I) present in the composition containing the isocyanate compound is large, the basicity of the secondary amine compound (I) may promote the modification of the isocyanate compound. Therefore, the amount of secondary amine compound (I) present is preferably less than 100 mass%, more preferably 90 mass% or less, even more preferably 80 mass% or less, and particularly preferably 50 mass% or less, relative to the total mass of the reaction solution. It is also possible to add two or more secondary amine compounds (I) in combination to the reaction solution. The thermal denaturation and discoloration suppression effect of the secondary amine compound (I) varies depending on the chemical structure of the secondary amine compound, and by including two or more types of secondary amine compounds, it is possible to enhance the thermal denaturation and discoloration suppression effect.

[0438] In the thermal decomposition step, the amount of tertiary amine compound (II) present in the composition is preferably large in order to reduce the coloration of the isocyanate compound and the isocyanate composition. Specifically, the amount of tertiary amine compound (II) present is preferably greater than 0 mass%, more preferably 1 mass ppm or more, even more preferably 1 mass% or more, and particularly preferably 50 mass% or more, relative to the total mass of the reaction solution. On the other hand, if the amount of tertiary amine compound (II) present in the composition containing the blocked isocyanate compound is large, the basicity of the tertiary amine compound (II) may promote the modification of the isocyanate compound. Therefore, the amount of tertiary amine compound (II) present is preferably less than 100 mass%, more preferably 90 mass% or less, even more preferably 80 mass% or less, and particularly preferably 50 mass% or less, relative to the total mass of the reaction solution. It is also possible to add two or more tertiary amine compounds (II) in combination to the reaction solution. The thermal denaturation and discoloration suppression effect of the tertiary amine compound (I) varies depending on the chemical structure of the tertiary amine compound, and by including two or more types of tertiary amine compounds, it is possible to enhance the thermal denaturation and discoloration suppression effect.

[0439] The secondary amine compound (I) and the tertiary amine compound (II) may be added to the reaction solution either alone or together. Comparing the secondary amine compound (I) and the tertiary amine compound (II), the secondary amine compound (I) has a stronger effect of reducing coloration at high temperatures. On the other hand, the tertiary amine compound (II) exhibits a lower temperature dependency in the effect of reducing coloration, and therefore exhibits a coloration-reducing effect over a wider temperature range.

[0440] Furthermore, because the secondary amine compound (I) has an active hydrogen group, a portion of the blocking agent in the blocked isocyanate compound is replaced by the secondary amine compound (I). As a result, urea groups formed by the reaction of the secondary amine compound (I) with the isocyanate group may remain in the blocked isocyanate compound. Since the above-mentioned reaction does not occur, the tertiary amine compound (II) is more preferred.

[0441] Furthermore, if the secondary amine compound (I) and the tertiary amine compound (II) are contained simultaneously, there is a problem that, for example, when recovering the secondary amine compound (I) and the tertiary amine compound (II), the separation operation becomes complicated. However, the secondary amine compound (I) and the tertiary amine compound (II) exhibit different effects in suppressing thermal denaturation and coloration, and in addition, they exhibit a synergistic effect in suppressing thermal denaturation and coloration. Therefore, it is preferable to contain the secondary amine compound (I) and the tertiary amine compound (II) simultaneously.

[0442] In the thermal decomposition step, the total amount of the secondary amine compound (I) and the tertiary amine compound (II) present is not particularly limited. However, in order to reduce the coloration of the isocyanate compound and the isocyanate composition, a larger amount is preferable. Specifically, the total amount of the secondary amine compound (I) and the tertiary amine compound (II) present is preferably greater than 0 mass% relative to the total mass of the reaction solution, more preferably 1 mass ppm or more, even more preferably 1 mass% or more, and particularly preferably 50 mass% or more. On the other hand, when the amount of the secondary amine compound (I) present in the composition containing the blocked isocyanate compound is large, the basicity of the secondary amine compound (I) and the tertiary amine compound (II) may accelerate at least one of the modification of the isocyanate compound and the modification of the blocked isocyanate compound. Therefore, the total amount of the secondary amine compound (I) and the tertiary amine compound (II) present is preferably less than 100% by mass, more preferably 90% by mass or less, even more preferably 80% by mass or less, and particularly preferably 50% by mass or less, based on the total mass of the reaction solution.

[0443] Furthermore, when the secondary amine compound (I) and the tertiary amine compound (II) are added simultaneously to the reaction solution, the mass ratio of the secondary amine compound (I) to the tertiary amine compound (II) can be arbitrarily changed depending on the purpose. When aiming to suppress coloration under high-temperature conditions, it is preferable that the amount of the secondary amine compound (I) is greater than the amount of the tertiary amine compound (II). On the other hand, when a portion of the blocking agent in the blocked isocyanate compound is replaced with the secondary amine compound (I), and there is concern that urea groups formed by the reaction of the active hydrogen groups of the secondary amine compound (I) with the isocyanate groups remain in the resulting isocyanate compound, it is preferable that the amount of the tertiary amine compound (II) is greater than the amount of the secondary amine compound (I).

[0444] Furthermore, by combining one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) with an antioxidant different from the one or more secondary amine compounds (I) and tertiary amine compounds (II), the thermal denaturation and discoloration suppression effect can be further enhanced. Furthermore, by combining secondary amine compounds (I) and tertiary amine compounds (II) with an antioxidant, the thermal denaturation and discoloration suppression effect can be further enhanced.

[0445] The antioxidant other than the secondary amine compound (I) and the tertiary amine compound (II) is not particularly limited as long as it is an antioxidant that enhances the thermal denaturation and discoloration suppression effect, but phenolic antioxidants or phosphorus-based antioxidants are more preferred as they are particularly effective in suppressing discoloration. Among them, phenolic antioxidants are preferred because they have a particularly high effect of preventing thermal denaturation and discoloration when combined with the secondary amine compound (I) and the tertiary amine compound (II).

[0446] In the thermal decomposition step, the combination of the blocked isocyanate compound with one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) can be arbitrarily selected. The combination of the blocking agent used in the blocked isocyanate compound with the blocked isocyanate compound and one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) can also be arbitrarily selected. For example, when the isocyanate compound and the blocking agent are separated by distillation simultaneously with the thermal decomposition of the blocked isocyanate compound, the presence of one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) in the resulting composition containing the isocyanate compound is preferred because it reduces coloration. From this perspective, it is also preferred that the one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) have a boiling point different from that of the blocking agent. In particular, when the boiling point of the blocking agent is lower than that of the isocyanate compound obtained by thermal decomposition, it is preferable that one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) have a higher boiling point than that of the blocking agent. On the other hand, when the boiling point of the blocking agent is higher than that of the isocyanate compound obtained by thermal decomposition, it is preferable that one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) have a lower boiling point than that of the blocking agent. When the boiling point relationship between the blocking agent and one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) satisfies the above-mentioned relationship, when the isocyanate compound and the blocking agent are separated by distillation simultaneously with thermal decomposition, the blocking agent can be separated in a state in which one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) are present in the composition containing the isocyanate compound.

[0447] The reaction temperature (thermal decomposition temperature of the blocked isocyanate compound) is not particularly limited and is appropriately selected depending on the rate at which the blocked isocyanate compound decomposes into the blocking agent and the isocyanate, and the degree of thermal denaturation and coloration. From the viewpoint of suppressing the denaturation of the isocyanate compound, the reaction temperature is preferably 350°C or lower, more preferably 300°C or lower, and even more preferably 260°C or lower. On the other hand, a low reaction temperature may require setting the condenser temperature at a low temperature, which may require additional equipment. From this viewpoint, the reaction temperature is preferably 50°C or higher, more preferably 80°C or higher, and even more preferably 100°C or higher. Furthermore, when obtaining an isocyanate compound and a blocking agent by thermal decomposition of the blocked isocyanate compound in the presence of a secondary amine compound (I), the coloration reduction effect becomes more pronounced as the temperature increases. From this viewpoint, the reaction temperature is preferably 120°C or higher, more preferably 160°C or higher, and even more preferably 200°C or higher.

[0448] The reaction pressure may be reduced, normal, or increased, depending on the type of compound used and the reaction temperature. Generally, the absolute pressure is 20 Pa or more and 2×10 7 It is performed in the range of Pa or less.

[0449] The thermal decomposition step may be carried out in the presence of oxygen. When the thermal decomposition step is carried out in the presence of oxygen, the amount of oxygen present in the thermal decomposition apparatus for the blocked isocyanate compound is preferably reduced because thermal denaturation and coloration of the isocyanate compound may occur. On the other hand, when considering a large-scale production facility, in order to reduce the amount of oxygen present in the thermal decomposition apparatus for the blocked isocyanate compound, it is necessary to reduce air leakage into the production facility, which results in stricter design standards for the facility and increased facility costs. From this perspective, it is preferable to control the oxygen concentration in the gas supplied to the thermal decomposition step under high conditions, preferably at more than 0% by volume, more preferably at more than 0.0001% by volume, and even more preferably at more than 0.001% by volume.

[0450] In the thermal decomposition step, the presence of one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) can reduce thermal denaturation and coloration of the isocyanate compound, even in the presence of oxygen. On the other hand, an increase in the amount of oxygen present is undesirable because it promotes thermal denaturation and coloration, as described above, and therefore requires increased amounts of secondary amine compounds (I) and tertiary amine compounds to suppress thermal denaturation and coloration. From this perspective, it is preferable to operate the thermal decomposition step under low oxygen concentrations, preferably controlled to 21% by volume or less, more preferably 10% by volume or less, even more preferably 1% by volume or less, even more preferably 0.1% by volume or less, particularly preferably 0.01% by volume or less, and most preferably 0.001% by volume or less, based on the total volume of gas. The oxygen concentration can be measured using known techniques, such as conventional gas chromatography or an electrochemical trace oxygen analyzer.

[0451] In the thermal decomposition step, any solvent may be used in any proportion. The solvent is preferably an inert solvent that is not reactive with the blocked isocyanate compound. Such solvents are preferably ester-based solvents, ether-based solvents, phosphate ester-based solvents, hydrocarbon-based solvents, aromatic hydrocarbon-based solvents, or carbonic acid derivative-based solvents. The amount of solvent used is not particularly limited, but may be, for example, more than 0% by mass and less than 100% by mass, 10% by mass or more and 90% by mass or less, 20% by mass or more and 85% by mass or less, or 30% by mass or more and 80% by mass or less, relative to the total mass of the reaction solution.

[0452] In the thermal decomposition step, the reaction solution may contain any metal in any proportion. The metal may be in the form of a complex or a solid. While the metal reduces the thermal decomposition temperature of the blocked isocyanate compound, it may also cause thermal denaturation, deterioration, and coloration. Therefore, the metal content is preferably less than 10% by mass, more preferably less than 1% by mass, and even more preferably less than 0.1 ppm by mass, relative to the mass of the blocked isocyanate compound.

[0453] In the thermal decomposition step, the reaction solution may contain an organic acid, an inorganic acid, an organic base, or an inorganic base. These acids and bases act as catalysts in the thermal decomposition of the blocked isocyanate, thereby reducing the temperature required for thermal decomposition. On the other hand, these acids and bases also act as catalysts for side reactions in the thermal decomposition of the blocked isocyanate. From this viewpoint, the content of these organic acids, inorganic acids, organic bases, and inorganic bases is preferably less than 10% by mass, more preferably less than 1% by mass, even more preferably less than 0.1% by mass, and particularly preferably less than 1 ppb by mass, relative to the mass of the blocked isocyanate compound.

[0454] In the thermal decomposition step, the isocyanate compound is obtained as a composition containing the isocyanate compound (hereinafter, sometimes referred to as an "isocyanate composition").

[0455] The isocyanate composition refers to a composition containing more than 0 wt % and 100 wt % or less of an isocyanate compound. The isocyanate composition is not particularly limited except that it contains an isocyanate compound, and may contain, in addition to the isocyanate compound, a secondary amine compound (I), a tertiary amine compound (II), a solvent, a blocking agent, a blocked isocyanate compound, a catalyst, and the like in any proportion.

[0456] In view of the above, the isocyanate composition may be used as it is as the isocyanate compound, or the isocyanate compound may be purified from the isocyanate composition and then used.

[0457] (pyrolysis equipment) The thermal decomposition apparatus for the blocked isocyanate compound is not particularly limited, and known thermal decomposition apparatuses can be used. For example, a method can be used in which a composition containing a blocked isocyanate compound is placed in a container connected to a condenser, the container is heated to thermally decompose the blocked isocyanate compound, and vapor containing a blocking agent produced thereafter or simultaneously with the thermal decomposition is introduced into the condenser to separate the isocyanate compound and the blocking agent in a batchwise manner; a method can be used in which a composition containing a blocked isocyanate compound is continuously introduced into a distillation column heated to a temperature equal to or higher than the thermal decomposition temperature of the blocked isocyanate compound, and the blocking agent and the isocyanate compound produced simultaneously with the thermal decomposition of the blocked isocyanate compound are separated to continuously obtain free isocyanate compound and blocking agent; or a method can be used in which a blocked isocyanate compound is introduced into an evaporator or thin film heated to a temperature equal to or higher than the thermal decomposition temperature of the blocked isocyanate compound, and vapor containing the blocking agent and the isocyanate compound produced by thermal decomposition is introduced into a distillation column to separate the blocking agent and the isocyanate compound in the distillation column.

[0458] In the thermal decomposition apparatus for a blocked isocyanate compound, the material of the portion that comes into contact with the composition containing the blocked isocyanate compound and the blocking agent, isocyanate compound, and other components that are generated during thermal decomposition may be any known material as long as it does not adversely affect the denaturation of the blocked isocyanate compound, the blocking agent, the isocyanate compound, and other components. Specific examples of such materials include steel, stainless steel, ceramic, carbon, and materials lined with these materials.

[0459] When a distillation apparatus is used, the type of the distillation apparatus is not particularly limited, and various known distillation apparatuses can be used, such as a batch distillation apparatus, a simple distillation apparatus, a multi-stage distillation column, a continuous multi-stage distillation column, or a packed column, or a distillation apparatus that combines these.

[0460] The distillation column used here can have two or more theoretical plates. However, if the number of theoretical plates is large, the multi-stage distillation column will become huge and may be difficult to implement industrially, so the number of theoretical plates is generally 500 or less.

[0461] Any type of distillation column can be used as long as it is typically used as a multi-stage distillation column, such as a plate column type using trays such as bubble trays, perforated trays, valve trays, and countercurrent trays, or a packed column type filled with various packings such as Raschig rings, Lessing rings, Paul rings, Berle saddles, Intalox saddles, Dixon packing, McMahon packing, Helipack, Sulzer packing, and Melapack. Furthermore, a mixed plate-packed column type having both tray sections and sections filled with packings is also preferably used.

[0462] Next, the raw materials used in the production method of the third embodiment and the resulting products will be described in detail below.

[0463] <Secondary amine compounds (I)> The secondary amine compound (I) is a compound represented by the following general formula (I).

[0464] [ka]

[0465] In general formula (I), R 11 and R 12 R is each independently a monovalent organic group. 11 and R 12 may be bonded to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 11 and R 12 At least one of the groups has an aromatic group.

[0466] It is known that compounds having an amino group directly bonded to an aromatic ring can become discolored by exposure to oxygen and other factors. However, it has been surprisingly found that secondary amine compound (I) exhibits a discoloration-reducing effect. While the cause of this effect is unclear, it is generally known that isocyanate compounds undergo thermal denaturation and discoloration upon heat treatment, and it is presumed that this is due to oxidation and degradation of the isocyanate compound or its derivatives. It is presumed that secondary amine compound (I) acts against oxidizing agents such as oxygen, functioning as an antioxidant that is oxidized instead of the isocyanate compound or its derivative, and is converted into a colorless or low-coloring substance upon heating. Furthermore, secondary amine compound (I) is an amine-based compound that is generally believed to promote the modification of isocyanate compounds, but the promotion of modification observed with common aliphatic amine compounds and heterocyclic amine compounds is either not observed or is only slight. This is presumably because secondary amine compound (I) has an aromatic group directly bonded to the nitrogen atom, resulting in low electron density on the nitrogen atom and poor nucleophilicity, and also because the substituent bonded to the nitrogen atom creates significant steric hindrance around the nitrogen atom.

[0467] Details of the secondary amine compound (I) are the same as those explained above in the "Method for producing a blocked isocyanate compound according to the first embodiment."

[0468] <Tertiary amine compounds (II)> The tertiary amine compound (II) is a compound represented by the following general formula (II).

[0469] [ka]

[0470] In general formula (II), R 21 , R 22 , and R 23 R is each independently a monovalent organic group. 21 and R 22 , R 22 and R23 , and R 23 and R 21 may each independently bond to each other to form a ring structure via a carbon-carbon bond, a carbon-oxygen-carbon bond, or a carbon-nitrogen-carbon bond. 21 , R 22 , and R 23 At least one of the groups has an aromatic group.

[0471] Compounds having an amino group directly bonded to an aromatic ring are known to discolor due to oxygen and other factors. However, it has been surprisingly found that tertiary amine compounds (II) exhibit a discoloration-reducing effect. While the cause of this effect is unclear, it is generally known that isocyanate compounds undergo thermal denaturation and discoloration upon heat treatment, and it is presumed that this is due to oxidation and degradation of the isocyanate compound or its derivatives. Tertiary amine compounds (II) act against oxidizing agents such as oxygen, functioning as antioxidants that are oxidized instead of isocyanate compounds or their derivatives, and are presumed to be transformed into colorless or low-coloring substances upon heating. Furthermore, tertiary amine compounds (II) are amine-based compounds that are generally known to promote the modification of isocyanate compounds, but the promotion of modification observed with common aliphatic amine compounds and heterocyclic amine compounds is either not observed or is only slight. This is presumably because the tertiary amine compound (II) has an aromatic group directly bonded to the nitrogen atom, resulting in low electron density on the nitrogen atom and poor nucleophilicity, and also because the substituent bonded to the nitrogen atom creates significant steric hindrance around the nitrogen atom.

[0472] Details of the tertiary amine compound (II) are the same as those explained above in the "Method for producing a blocked isocyanate compound according to the first embodiment."

[0473] <Phenol-based antioxidant> The phenolic antioxidant used in combination with the secondary amine compound (I) and the tertiary amine compound (II) is not particularly limited, and may be any compound having one or more hydroxy groups bonded to an aromatic ring in the molecule. Specific examples of the phenolic antioxidant include those exemplified in the above "Method for producing a blocked isocyanate compound according to the first embodiment."

[0474] <Blocked isocyanate compounds> The blocked isocyanate compound is a compound having a blocked isocyanate group that can be dissociated into a blocking agent and an isocyanate group by heat, as shown in the following reaction formula.

[0475] [ka]

[0476] In the above reaction formula, BL-H is a blocking agent, which is an organic compound having an active hydrogen group. a is n a is a valent organic group, and R 31 is the same as

[0477] The blocked isocyanate compound is not particularly limited, and may be a reaction product obtained by reacting an isocyanate compound with a blocking agent, as long as the compound has one or more isocyanate groups in the molecule blocked with a blocking agent. Here, "obtained by reacting an isocyanate compound with a blocking agent" means that the blocked isocyanate compound is obtained by the reaction shown in the above reaction formula, and the method for producing the blocked isocyanate compound is not particularly limited. Therefore, blocked isocyanate compounds produced by any method can be used, such as obtaining a blocked isocyanate compound from a blocking agent, a carbonic acid derivative, and an amine; obtaining a second blocked isocyanate compound by reacting a first blocked isocyanate compound with a second blocking agent via an addition-elimination reaction; obtaining a blocked isocyanate compound by reacting phosgene with an amine and then reacting it with a blocking agent; or obtaining a blocked isocyanate compound by reacting an isocyanate compound with a blocking agent.

[0478] <Isocyanate compounds> As the isocyanate compound obtained by the production method of the third embodiment and serving as a raw material for the blocked isocyanate compound, a compound represented by the following general formula (VII) (hereinafter, sometimes referred to as "isocyanate compound (VII)") is preferably used.

[0479] [ka]

[0480] In general formula (VII), R 71 is an organic group having a valence of n71, where n71 is an integer of 1 or more and 12 or less.

[0481] [R 71 ] R 71 is an organic group with a valence of n71. That is, it is an organic group with a valence of 1 to 12. Among them, R 71The alkyl group is preferably an organic group consisting of carbon atoms, oxygen atoms, and hydrogen atoms, and more preferably an organic group having no active hydrogen atoms.

[0482] R 71 The aliphatic hydrocarbon group in is preferably an alkylene group or an alkanetriyl group, a cycloalkyl group, a cycloalkylene group or a cycloalkanetriyl group, or a group composed of the alkyl group, the alkylene group or the alkanetriyl group and the cycloalkyl group, the cycloalkylene group or the cycloalkanetriyl group, and more preferably a linear or branched alkylene group or an alkanetriyl group, a cycloalkylene group or a cycloalkanetriyl group, or a group composed of the alkylene group or the alkanetriyl group and the cycloalkyl group, the cycloalkylene group or the cycloalkanetriyl group.

[0483] Examples of the linear or branched alkylene group include a methylene group, an ethylene group, a propylene group, a trimethylene group, a pentylene group, an n-hexylene group, and a decamethylene group.

[0484] Examples of the cycloalkylene group include a cyclobutylene group, a cyclopentylene group, and a cyclohexylene group.

[0485] Examples of the linear or branched alkanetriyl group include a hexanetriyl group, a nonanetriyl group, and a decanetriyl group.

[0486] Examples of the cycloalkanetriyl group include a cyclopropanetriyl group, a cyclobutanetriyl group, a cyclopentanetriyl group, and a cyclohexanetriyl group.

[0487] R 71The aromatic hydrocarbon group in is preferably a substituted or unsubstituted group having an aromatic ring with 6 to 13 carbon atoms. Examples of the substituent include an alkyl group, an aryl group, and an aralkyl group. The aromatic ring may be an aromatic hydrocarbon ring or a heteroaromatic ring, and specific examples include a benzene ring, a naphthalene ring, and a pyridine ring.

[0488] Preferred isocyanate compounds (VII) include monofunctional isocyanate compounds, difunctional isocyanate compounds, and polyfunctional isocyanate compounds.

[0489] Examples of monofunctional isocyanate compounds include methyl isocyanate, ethyl isocyanate, propyl isocyanate (each isomer), butyl isocyanate (each isomer), pentyl isocyanate (each isomer), hexyl isocyanate (each isomer), octyl isocyanate (each isomer), nonyl isocyanate (each isomer), decyl isocyanate (each isomer), undecyl isocyanate (each isomer), dodecyl isocyanate (each isomer), tridecyl isocyanate (each isomer), tetra ... Isocyanate compounds with saturated hydrocarbon groups, such as tetradecyl isocyanate (each isomer), pentadecyl isocyanate (each isomer), hexadecyl isocyanate (each isomer), heptadecyl isocyanate (each isomer), octadecyl isocyanate (each isomer), nonadecyl isocyanate (each isomer), and eicosyl isocyanate (each isomer); 2-isocyanatomethyl acrylate, 2-isocyanatoethyl acrylate, 2-isocyanatopropyl acrylate (each isomer), and 2-isocyanatomethyl acrylate. Isocyanate compounds having unsaturated bonds, such as isocyanatobutyl (each isomer), 2-isocyanatomethyl methacrylate, 2-isocyanatoethyl methacrylate, 2-isocyanatopropyl methacrylate (each isomer), 2-isocyanatobutyl methacrylate (each isomer), phenyl isocyanate, benzyl isocyanate, etc.; (S)-2-isocyanato-3-tert-butoxymethyl propionate, (S)-2-isocyanato-3-tert-butoxyethyl propionate, (S)-2- Isocyanate compounds having an ether group, such as propyl isocyanato-3-tert-butoxypropionate (each isomer), butyl (S)-2-isocyanato-3-tert-butoxypropionate (each isomer), pentyl (S)-2-isocyanato-3-tert-butoxypropionate (each isomer), hexyl (S)-2-isocyanato-3-tert-butoxypropionate (each isomer), and dodecyl (S)-2-isocyanato-3-tert-butoxypropionate (each isomer);Isocyanate compounds having a halogen group, such as fluorophenyl isocyanate (each isomer), chlorophenyl isocyanate (each isomer), bromophenyl isocyanate (each isomer), and iodophenyl isocyanate (each isomer); glycine methyl ester isocyanate, glycine ethyl ester isocyanate, glycine propyl ester isocyanate (each isomer), glycine butyl ester isocyanate (each isomer), glycine pentyl ester isocyanate (each isomer), glycine hexyl ester isocyanate (each isomer), glycine dodecyl ester isocyanate (each isomer), leucine methyl ester isocyanate (Methyl 2-isocyanato-4-methyl pentanoate), leucine ethyl ester isocyanate (Ethyl 2-isocyanato-4-methyl pentanoate), leucine propyl ester isocyanate (each isomer), leucine butyl ester isocyanate (each isomer), leucine pentyl ester isocyanate (each isomer), leucine hexyl ester isocyanate (each isomer), leucine dodecyl ester isocyanate (each isomer), ethyl isocyanatoacetate, and other isocyanate compounds having a carbonyl group;

[0490] Examples of bifunctional isocyanate compounds include dimethylene diisocyanate, trimethylene diisocyanate (each isomer), tetramethylene diisocyanate (each isomer), pentamethylene diisocyanate (each isomer), hexamethylene diisocyanate (each isomer), heptamethylene diisocyanate (each isomer), octamethylene diisocyanate (each isomer), diisocyanatocyclohexane (each isomer), bisisocyanatomethylcyclohexane (each isomer), isophorone diisocyanate (each isomer), dicyclohexylmethylcyclohexane (each isomer), diisocyanate ... Diisocyanatodimethylpropane (each isomer), diisocyanatodimethylpentane (each isomer), diisocyanatodimethylhexane (each isomer), diisocyanatodimethylheptane (each isomer), diisocyanatodimethyloctane (each isomer), diisocyanatodimethylnonane (each isomer), diisocyanatodimethyldecane (each isomer), diisocyanatomethylethylpropane (each isomer), diisocyanatomethylethylbutane (each isomer), diisocyanatomethylethylpentane (each isomer), diisocyanatomethylethylpropane (each isomer), diisocyanatomethylethylbutane (each isomer), diisocyanatomethylethylpentane (each isomer), Isocyanate compounds having saturated hydrocarbon groups, such as isocyanatomethylethylhexane (each isomer), diisocyanatomethylethylheptane (each isomer), diisocyanatomethylethyloctane (each isomer), diisocyanatodiethylpropane (each isomer), diisocyanatodiethylpentane (each isomer), diisocyanatodiethylhexane (each isomer), diisocyanatodiethylheptane (each isomer), diisocyanatodiethyloctane (each isomer), and diisocyanatodiethylnonane (each isomer); diphenylmethane diisocyanate isocyanate compounds having an unsaturated hydrocarbon group, such as methyl methyl ether (each isomer), tolylene diisocyanate (each isomer), naphthalene diisocyanate (each isomer), xylylene diisocyanate (each isomer), tetramethylxylylene diisocyanate (each isomer), methylenebis(diisoamyl-phenylene) diisocyanate (each isomer), oxybis(phenylene diisocyanate) (each isomer), carbonylbis(phenylene) diisocyanate (each isomer), butene diisocyanate (each isomer), and butynylene diisocyanate;Examples of the isocyanate compounds include ester group-containing isocyanate compounds such as lysine methyl ester isocyanate, lysine ethyl ester isocyanate, lysine propyl ester isocyanate (each isomer), lysine butyl ester isocyanate (each isomer), lysine pentyl ester isocyanate (each isomer), and lysine hexyl ester isocyanate (each isomer);

[0491] Examples of polyfunctional isocyanates include isopropane triisocyanate, butane triisocyanate (each isomer), pentane triisocyanate (each isomer), hexane triisocyanate (each isomer), heptane triisocyanate (each isomer), octane triisocyanate (each isomer), nonane triisocyanate (each isomer), decane triisocyanate (each isomer), undecane triisocyanate (each isomer), dodecane triisocyanate (each isomer), tridecane triisocyanate (each isomer), tetradecane triisocyanate (each isomer), pentadecane triisocyanate (each isomer), hexadecane triisocyanate (each isomer), heptadecane triisocyanate (each isomer), and octadecane triisocyanate. Examples of suitable isocyanate compounds include isocyanate compounds having saturated hydrocarbon groups such as methyl methyl ether (each isomer), nonadecane triisocyanate (each isomer), and icosane triisocyanate (each isomer); isocyanate compounds having unsaturated hydrocarbon groups such as polymeric MDI (each isomer); isocyanate compounds having ester groups such as 2-isocyanatoethyl 2,6-diisocyanatohexanoate; and other isocyanate compounds having bifunctional or higher functionality with an isocyanurate group, isocyanate compounds having biuret or higher functionality with an allophanate group, and isocyanate compounds obtained by crosslinking an isocyanate compound having bifunctional or higher functionality with a compound having a bifunctional or higher functionality of active hydrogen.

[0492] <Blocking agent> The blocking agent, which is a by-product of the production method of the third embodiment and is a raw material for the blocked isocyanate compound, may be any compound that has an active hydrogen group, reacts with an isocyanate group to form a bond, and decomposes into an isocyanate compound and a blocking agent upon thermal decomposition. Examples of such blocking agents include alcohol-based, phenol-based (hereinafter, alcohol-based and phenol-based blocking agents may be collectively referred to as "hydroxy compound"), thiol-based, amine and ammonia-based, oxime-based, hydroxylamine-based, and active methylene-based blocking agents. Among these, hydroxyl compound-based, amine and ammonia-based, and hydroxylamine-based blocking agents are preferred from the viewpoint of the stability of the blocking agent upon thermal decomposition. Phenol-based, amine-based, or hydroxylamine-based blocking agents, or ammonia, are more preferred because they cause less denaturation of the isocyanate compound upon thermal decomposition. Phenol-based blocking agents are even more preferred because they are particularly stable upon thermal decomposition and cause less denaturation of the isocyanate compound upon thermal decomposition.

[0493] [Phenol-based blocking agent] The phenol-based blocking agent is not particularly limited as long as it is a compound having a hydroxyl group bonded to an aromatic ring, but a blocking agent having a phenol group or a naphthol group is preferred due to its ease of availability. It may be a compound having a hydroxyl group bonded to one aromatic ring in the molecule, or a compound having hydroxyl groups bonded to two or more aromatic rings in the molecule. When a compound having hydroxyl groups bonded to two or more aromatic rings in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the compound having hydroxyl groups bonded to the aromatic ring. Therefore, it is preferable to use a compound having a hydroxyl group bonded to one aromatic ring in the molecule as a phenol-based blocking agent.

[0494] Preferred phenol-based blocking agents include those exemplified above in the "Method for producing a blocked isocyanate compound according to the first embodiment."

[0495] [Alcohol-based blocking agent] The alcohol-based blocking agent is not particularly limited as long as it is an aliphatic compound having a hydroxyl group, and may be an aliphatic compound having one hydroxyl group in the molecule or two or more hydroxyl groups in the molecule. When an aliphatic compound having two or more hydroxyl groups in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the aliphatic compound having a hydroxyl group. Therefore, it is more preferable to use an aliphatic compound having one hydroxyl group in the molecule.

[0496] Preferred examples of the alcohol-based blocking agent include the same as those exemplified in the above "Method for producing a blocked isocyanate compound according to the first embodiment."

[0497] [Amine and ammonia-based blocking agents] As the amine and ammonia-based blocking agent, an amine compound having a primary or secondary amino group as the active hydrogen group or ammonia can be used. When a primary amine compound or ammonia is used as the blocking agent, the urea bond formed by the reaction of the primary amine compound or ammonia with an isocyanate compound has two possible cleavage directions during thermal decomposition, so that an isocyanate compound is formed on the primary amine compound used as the blocking agent, making it difficult to obtain the desired isocyanate compound. Therefore, it is preferable to use an amine compound having a secondary amino group.

[0498] The amine and ammonia-based blocking agent may be an amine compound having one amino group in the molecule, or may be an amine compound having two or more amino groups in the molecule. When an amine compound having two or more amino groups in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the amine compound. Therefore, it is preferable to use an amine compound having one amino group in the molecule as the amine and ammonia-based blocking agent.

[0499] Preferred amine and ammonia-based blocking agents include those exemplified above in the "Method for producing a blocked isocyanate compound according to the first embodiment."

[0500] [Hydroxylamine blocking agent] The hydroxylamine-based blocking agent is not particularly limited, and may be a hydroxylamine compound having one hydroxylamine structure in the molecule, or a hydroxylamine compound having two or more hydroxylamine structures in the molecule. When a hydroxylamine compound having two or more hydroxylamine structures in the molecule is used as a blocking agent, it is more difficult to separate the isocyanate compound from the hydroxylamine compound. Therefore, it is preferable to use a hydroxylamine compound having one hydroxylamine structure in the molecule as a hydroxylamine-based blocking agent.

[0501] Examples of the hydroxylamine compound having one hydroxylamine structure in the molecule include the same compounds as those exemplified in the above "Method for producing a blocked isocyanate compound according to the first embodiment."

[0502] <<Method for producing isocyanate compound according to fourth and fifth embodiments>> The method for producing an isocyanate compound of this embodiment (hereinafter, sometimes simply referred to as the "production method of the fourth embodiment") includes the following steps: a first reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound (I) and a tertiary amine compound (II) to obtain a blocked isocyanate compound; a second reaction step of thermally decomposing the blocked polyisocyanate compound into an isocyanate compound and the first blocking agent in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound (I) and a tertiary amine compound (II) to obtain the isocyanate compound; Includes:

[0503] Alternatively, the method for producing an isocyanate compound of this embodiment (hereinafter, may be simply referred to as the "production method of the fifth embodiment") may include: a first reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound (I) and a tertiary amine compound (II) to obtain a blocked isocyanate compound; an addition-elimination reaction step of reacting the first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound (I) and a tertiary amine compound (II) to obtain a second blocked isocyanate compound; a second reaction step in which the second blocked isocyanate compound is decomposed into a second blocking agent and an isocyanate compound by heat treatment in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound (I) and a tertiary amine compound (II), thereby obtaining the isocyanate compound; Includes:

[0504] The second blocking agent is a compound different from the first blocking agent and the third blocking agent derived from a carbonic acid derivative, which is the same as the compound derived from a carbonic acid derivative described above.

[0505] The first blocked isocyanate compound and the second blocked isocyanate compound have different structures.

[0506] As described above, the blocked isocyanate used in the method for producing an isocyanate compound according to the third embodiment can be a blocked isocyanate compound produced by any method, such as obtaining a blocked isocyanate compound from a blocking agent, a carbonic acid derivative, and an amine, reacting phosgene with an amine and then reacting the resulting mixture with a blocking agent to obtain a blocked isocyanate compound, or reacting an isocyanate compound with a blocking agent to obtain a blocked isocyanate compound.

[0507] Among these, a method in which a blocked isocyanate compound is produced from a blocking agent, a carbonic acid derivative, and an amine, and a blocked isocyanate composition containing the obtained blocked isocyanate compound is used as a raw material in the second reaction step, i.e., the production method of the fourth embodiment, and a method in which a blocked isocyanate compound is produced from a blocking agent, a carbonic acid derivative, and an amine, a second blocking agent is added to the resulting blocked isocyanate composition containing the blocked isocyanate compound, a second blocked isocyanate compound is produced by an addition-elimination reaction, and the resulting blocked isocyanate composition containing the second blocked isocyanate compound is used as a raw material in the second reaction step, i.e., the production method of the fifth embodiment, are useful production methods in that they do not use highly toxic phosgene or expensive reagents.

[0508] When the blocked isocyanate composition containing the first blocked isocyanate compound obtained in the first reaction step is used as a raw material in the second reaction step, the first blocked isocyanate compound may contain a blocked isocyanate group in which a third blocking agent derived from a carbonic acid derivative is bonded to an isocyanate group.

[0509] In particular, the carbonic acid derivative is a compound represented by the general formula (VI-1), R 611 and R 612 is a hydrogen atom, and among the compounds represented by the general formula (VI-2), R 611 and R 612When a compound in which R is a hydrogen atom is heated in the presence of a blocking agent, ammonia is produced. 611 and R 612 is a hydrogen atom, and / or among the compounds represented by the general formula (VI-2), R 621 and R 622 When a blocked isocyanate compound is produced from a compound in which α is a hydrogen atom and an amine, the resulting first blocked isocyanate compound may contain a blocked isocyanate group (hereinafter referred to as a ureido group) obtained by the reaction of ammonia with an isocyanate group. A blocked isocyanate compound containing a ureido group may produce a polymer component having a crosslinkable functional group such as a ureylene group (-NHCONH-) upon thermal modification. Therefore, it is preferable to reduce the amount of blocked isocyanate containing the ureido group present in the raw materials in the second reaction step. Furthermore, it is more preferable to carry out the thermal decomposition reaction in the presence of one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II), since this can reduce thermal modification. One possible reason for this is that a compound containing a ureido group can decompose into an amine and isocyanic acid upon thermal dissociation, but isocyanic acid or cyanic acid in equilibrium with isocyanic acid is an acidic substance and may function as an acid catalyst, promoting the modification of the isocyanate group. Therefore, it is presumed that the presence of one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) reduces the acidity in the reaction system, which increases due to the presence of these acid components, and suppresses denaturation through a neutralization reaction with isocyanic acid or cyanic acid in equilibrium with isocyanic acid.

[0510] When a blocked isocyanate composition containing a second blocked isocyanate compound obtained through the first reaction step and the addition-elimination reaction step is used as a raw material in an isocyanate production step, the first blocked isocyanate compound from the addition-elimination reaction step may contain a blocked isocyanate group in which a third blocking agent derived from a carbonic acid derivative is bonded to an isocyanate group.

[0511] In particular, the carbonic acid derivative is a compound represented by the general formula (VI-1), R 611 and R 612 is a hydrogen atom, and among the compounds represented by the general formula (VI-2), R 611 and R 612 When a compound in which R is a hydrogen atom is heated in the presence of a blocking agent, ammonia is produced. 611 and R 612 is a hydrogen atom, and / or among the compounds represented by the general formula (VI-2), R 621 and R 622 When a first blocked isocyanate compound is produced from a compound in which ⁢ ⁢ ⁢ (I) ⁢ ⁢ (II) ... Therefore, it is presumed that the presence of one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) reduces the acidity in the reaction system, which increases due to the presence of these acid components, and suppresses denaturation through a neutralization reaction with isocyanic acid or cyanic acid in equilibrium with isocyanic acid. [Example]

[0512] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. All of the reagents used as raw materials were purified products. In the following, Examples 2-14, 2-22, 2-30, 2-38, 2-46, 2-53, 2-61, 2-69, 2-77, and 2-85 are referred to as reference examples.

[0513] <First Test> [Physical Properties 1-1] (Amino group content) The amino group content (mol%) in the resulting blocked isocyanate composition was determined by titrating the amino groups in the resulting blocked isocyanate composition as a measurement sample with 1 N hydrochloric acid. In this titration, the secondary amine compound (I), tertiary amine compound (II), and blocking agent contained in the blocked isocyanate composition were previously removed by distillation under reduced pressure.

[0514] [Physical Properties 1-2] (Blocked isocyanate group content) The content (mol%) of blocked isocyanate groups in the obtained blocked isocyanate composition (hereinafter sometimes abbreviated as "NCO-BL mol%") was determined according to the following formula from the molar amount of amino groups in the primary amine compound contained in the reaction mixture containing the primary amine compound, carbonic acid derivative, and blocking agent before the reaction, which is calculated from the amount of the primary amine compound charged, and the molar amount of blocked isocyanate groups formed after the reaction. The molar amount of blocked isocyanate groups was determined from the concentration of blocked isocyanate groups determined from the NMR spectrum and the total mass of the obtained blocked isocyanate composition.

[0515] "NCO-BL mol%" = (molar amount of blocked isocyanate groups) × 100 / (molar amount of amino groups of primary amine compound)

[0516] [Physical Properties 1-3] (Content of isocyanate groups bonded to secondary amine compound (I)) The content (mol%) of isocyanate groups bonded to secondary amine compound (I) in the obtained blocked isocyanate composition (hereinafter sometimes abbreviated as "NCO-(compound (I)) mol%") was calculated from the molar amount of amino groups of the primary amine compound contained in the reaction mixture containing the organic primary amine, carbonic acid derivative, and blocking agent before the reaction, calculated from the amount of the primary amine compound charged, and the molar amount of NCO-(compound (I)) remaining after thermal decomposition, according to the following formula. The molar amount of NCO-(compound (I)) was calculated from the concentration of NCO-(compound (I)) determined from the NMR spectrum and the total mass of the obtained blocked isocyanate composition. "NCO-(Compound (I)) mol%" = (molar amount of NCO-(compound (I))) × 100 / (molar amount of amino groups in the primary amine compound)

[0517] [Physical Properties 1-4] (oxygen concentration) Synthesis gas to be supplied to the reactor was generated from a nitrogen cylinder and an oxygen cylinder, and the oxygen concentration (volume %) of the synthesis gas was measured using a galvanic cell oxygen concentration meter.

[0518] [Rating 1-1] (Mass Balance) The sum of the amino group content (mol%), NCO-BL mol%, and NCO-(compound (I)) mol% contained in the obtained blocked isocyanate composition was calculated as the mass balance (hereinafter sometimes abbreviated as "MB mol%)."

[0519] [Rating 1-2] (Hazen color number) The Hazen color index was measured by dissolving 1 g of a blocked isocyanate composition in 2 g of benzyltoluene after distilling off the free compounds (I), (II), and blocking agent contained in the resulting reaction solution, and the value was then measured using a Hazen meter. The result was ranked according to the following criteria.

[0520] (Evaluation criteria) Rank 1: APHA 0 or more and less than 5 Rank 2: APHA 5 or above but less than 10 Rank 3: APHA 10 or above but less than 15 Rank 4: APHA 15 or above but less than 20 Rank 5: APHA 20 or above but less than 25 Rank 6: APHA 25 or above but less than 30 Rank 7: APHA 30 or above but less than 35 Rank 8: APHA 35 or above but less than 40 Rank 9: APHA 40 to 45 Rank 10: APHA 45 or above but less than 50

[0521] [Example 1-1] A 500 mL SUS pressure vessel equipped with a filler-filled condenser tube (the condensate from the condenser tube enters the 500 mL SUS pressure vessel) and an ammonia trap was charged with 10 parts by mass of hexamethylenediamine (HDA), 15.5 parts by mass of urea, 90 parts by mass of phenol, and 1 part by mass of N-methylaniline (NMA). The internal temperature of the 500 mL pressure vessel was set to 240 °C, and the temperature of the condenser tube was set to 60 °C. Synthetic gas was generated from a nitrogen cylinder and an oxygen cylinder. After confirming with an oxygen concentration meter that the oxygen concentration in the synthetic gas was 0.1 vol%, the synthetic gas was supplied to the 500 mL SUS pressure vessel and adjusted to an absolute pressure of 405 kPa. The reaction was then allowed to proceed for 2 hours. As a result, 103.3 parts by mass of the reaction solution was obtained in the 500 mL SUS pressure vessel. The urea, free phenol, and free N-methylaniline contained in the resulting reaction solution were distilled off under reduced pressure to obtain a blocked isocyanate composition. Analysis revealed that the amino group content was 0 mol%, 1 The NCO-BL mol% was 84 mol%, the NCO-(compound I) mol% was 5 mol%, and the MB mol% was 89 mol% as determined from the integrated value of H NMR. 1 g of the resulting blocked isocyanate composition was dissolved in 2 g of benzyltoluene, and the Hazen color index was determined, which was found to correspond to rank 3.

[0522] [Examples 1-2 to 1-125 and Comparative Examples 1-1 to 1-11] For Examples 1-2 to 1-125 and Comparative Examples 1-1 to 1-11, blocked isocyanate compounds were produced in the same manner as in Example 1-1, except that the conditions were as shown in the following table.

[0523] In the following table, the abbreviations represent the following compounds.

[0524] (blocking agent) PhOH: Phenol o-cresol: o-cresol m-cresol: m-cresol p-cresol: p-cresol OCP: o-chlorophenol n-BuOH: normal butanol DBA: Dibutylamine

[0525] (Secondary amine compound (I)) NMA: N-methyl-aniline NEA: N-ethyl-aniline NBA: N-butyl-aniline DPA: N,N-diphenylamine

[0526] (Tertiary amine compound (II)) NNDMA: N,N-dimethylaniline NNDEA: N,N-diethylaniline NMDPA: N-methyl-N,N-diphenylamine TPA: Triphenylamine

[0527] (Primary amine compounds) HDA: 1,6-hexamethylenediamine IPDA: Isophoronediamine (mixture of isomers) BMCA: 4,4'-methylenebis(cyclohexylamine) (mixture of isomers) DAT: Diaminotoluene (mixture of isomers) DPM: 4,4'-diphenylmethanediamine

[0528] (Other compounds) BL-NCO: Blocked isocyanate

[0529] [Table 1-1]

[0530] [Table 1-2]

[0531] [Table 1-3]

[0532] [Table 1-4]

[0533] [Table 1-5]

[0534] [Table 1-6]

[0535] [Table 1-7]

[0536] [Table 1-8]

[0537] [Table 1-9]

[0538] [Table 1-10]

[0539] [Table 1-11]

[0540] [Table 1-12]

[0541] As can be seen from the above table, the blocked isocyanate compositions produced by adding one or more compounds selected from the group consisting of secondary amine compounds (I) and tertiary amine compounds (II) had Hazen color scale (APHA) ranks of 7 or less, which were good.

[0542] On the other hand, the Hazen color rank of the blocked isocyanate composition produced without adding either the secondary amine compound (I) or the tertiar...

Claims

1. The method includes a reaction step of reacting a primary amine compound, a carbonic acid derivative, and a blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I), the following general formula (I-2), or the following general formula (I-3), and a tertiary amine compound represented by the following general formula (II), the following general formula (II-2), or the following general formula (II-3), to obtain a blocked isocyanate compound, The method for producing a blocked isocyanate compound, wherein the blocking agent comprises one or more compounds selected from the group consisting of hydroxy compounds, amine compounds, and ammonia. 【Chemical 1】 (In general formula (I), R １１ and R １２ are each independently a monovalent organic group. １１ and R １２ At least one of the groups has an aromatic group. 【Chemistry 2】 (In general formula (I-2), R １２１ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １２２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n121 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 3】 (In general formula (I-3), R １３１ is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １３１ is —O—, —NH—, or —C(═O)—. １３２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group. n131 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 4】 (In general formula (II), R ２１ , R ２２ , and R ２３ are each independently a monovalent organic group. ２１ , R ２２ , and R ２３ At least one of the groups has an aromatic group. 【Chemistry 5】 (In general formula (II-2), R ２２１ is a monovalent organic group. ２２２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２２１ and R ２２２ may be bonded to each other to form a carbon-carbon bond. ２２３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n221 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 6】 (In general formula (II-3), R ２３１ is a monovalent organic group. ２３２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２３１ and R ２３２ may be bonded to each other to form a carbon-carbon bond. ２３１ is —O—, —NH—, or —C(═O)—. ２３３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n231 represents the number of substituents and is an integer of 0 to 4.

2. 2. The method for producing a blocked isocyanate compound according to claim 1, wherein the primary amine compound is an amine compound represented by the following general formula (III): 【Chemistry 7】 (In general formula (III), R ３１ is an n31-valent organic group, where n31 is an integer of 1 or more and 12 or less.

3. The method for producing a blocked isocyanate compound according to claim 1 or 2, wherein the blocking agent is an aromatic hydroxy compound represented by the following general formula (IV-1): 【Chemistry 8】 (In general formula (IV-1), ring A ４１ is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. ４１ is a hydrogen atom, a halogen atom, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkyloxycarbonyl group having from 1 to 20 carbon atoms, an alkylcarbonyloxy group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aryloxy group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or an aralkyloxy group having from 7 to 20 carbon atoms. ４１ is ring A ４１ may bond to form a ring structure. n41 is an integer of 1 or more and 10 or less.

4. The method for producing a blocked isocyanate compound according to claim 1 or 2, wherein the blocking agent is an aliphatic hydroxy compound represented by the following general formula (IV-2): 【Chemistry 9】 (In general formula (IV-2), R ４２ represents a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 24 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

5. The method for producing a blocked isocyanate compound according to claim 1 or 2, wherein the blocking agent is a secondary amine compound represented by the following general formula (V), the general formula (I-2), or the general formula (I-3): 【Chemistry 10】 (In general formula (V), R ５１ and R ５２ are each independently a monovalent organic group.

6. 3. The method for producing a blocked isocyanate compound according to claim 1, wherein the carbonic acid derivative is a compound represented by the following general formula (VI): 【Chemistry 11】 (In general formula (VI), R ６１ and R ６２ are each independently an amino group, a substituted or unsubstituted alkoxy group having from 1 to 20 carbon atoms, or an aryloxy group having from 6 to 20 carbon atoms, or a substituted or unsubstituted alkylamino group having from 1 to 20 carbon atoms, or an arylamino group having from 6 to 20 carbon atoms.

7. 3. The method for producing a blocked isocyanate compound according to claim 1, wherein the oxygen concentration in the gas supplied in the reaction step is 21% by volume or less, based on the total volume of the gas.

8. 3. The method for producing a blocked isocyanate compound according to claim 1 or 2, wherein in the reaction step, the amount of one or more compounds selected from the group consisting of secondary amine compounds represented by general formula (I), general formula (I-2), or general formula (I-3) and tertiary amine compounds represented by general formula (II), general formula (II-2), or general formula (II-3) is 1 ppm by mass or more relative to the total mass of the primary amine compound and the blocking agent.

9. The method for producing a blocked isocyanate compound according to claim 1 or 2, wherein the reaction step simultaneously contains a secondary amine compound represented by general formula (I), general formula (I-2), or general formula (I-3) and a tertiary amine compound represented by general formula (II), general formula (II-2), or general formula (II-3).

10. The method includes a reaction step of decomposing a blocked isocyanate compound into a blocking agent and an isocyanate compound by heat treatment in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I), the following general formula (I-2), or the following general formula (I-3), and a tertiary amine compound represented by the following general formula (II), the following general formula (II-2), or the following general formula (II-3), thereby obtaining the isocyanate compound, the blocking agent comprises one or more compounds selected from the group consisting of a hydroxy compound, an amine compound, and ammonia; In the reaction step, the amount of one or more compounds selected from the group consisting of secondary amine compounds represented by general formula (I), general formula (I-2), or general formula (I-3) and tertiary amine compounds represented by general formula (II), general formula (II-2), or general formula (II-3) is 1 mass ppm or more relative to the reaction liquid. 【Chemistry 12】 (In general formula (I), R １１ and R １２ are each independently a monovalent organic group. １１ and R １２ At least one of the groups has an aromatic group. 【Chemistry 13】 (In general formula (I-2), R １２１ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １２２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n121 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 14】 (In general formula (I-3), R １３１ is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １３１ is —O—, —NH—, or —C(═O)—. １３２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group. n131 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 15】 (In general formula (II), R ２１ , R ２２ , and R ２３ are each independently a monovalent organic group. ２１ , R ２２ , and R ２３ At least one of the groups has an aromatic group. 【Chemistry 16】 (In general formula (II-2), R ２２１ is a monovalent organic group. ２２２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２２１ and R ２２２ may be bonded to each other to form a carbon-carbon bond. ２２３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n221 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 17】 (In general formula (II-3), R ２３１ is a monovalent organic group. ２３２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２３１ and R ２３２ may be bonded to each other to form a carbon-carbon bond. ２３１ is —O—, —NH—, or —C(═O)—. ２３３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n231 represents the number of substituents and is an integer of 0 to 4.

11. The method for producing an isocyanate compound according to claim 10, wherein the isocyanate compound is an isocyanate compound represented by the following general formula (VII): 【Chemistry 18】 (In general formula (VII), R ７１ is an n71-valent organic group, where n71 is an integer of 1 or more and 12 or less.

12. The method for producing an isocyanate compound according to claim 10 or 11, wherein the blocking agent is an aromatic hydroxy compound represented by the following general formula (IV-1): 【Chemistry 19】 (In general formula (IV-1), ring A ４１ is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. ４１ is a hydrogen atom, a halogen atom, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkyloxycarbonyl group having from 1 to 20 carbon atoms, an alkylcarbonyloxy group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aryloxy group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or an aralkyloxy group having from 7 to 20 carbon atoms. ４１ is ring A ４１ may bond to form a ring structure. n41 is an integer of 1 or more and 10 or less.

13. The method for producing an isocyanate compound according to claim 10 or 11, wherein the blocking agent is an aliphatic hydroxy compound represented by the following general formula (IV-2): 【Chemistry 20】 (In general formula (IV-2), R ４２ represents a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 24 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

14. The method for producing an isocyanate compound according to claim 10 or 11, wherein the blocking agent is a secondary amine compound represented by the following general formula (V), the general formula (I-2), or the general formula (I-3): 【Chemical 21】 (In general formula (V), R ５１ and R ５２ are each independently a monovalent organic group.

15. 12. The method for producing an isocyanate compound according to claim 10, wherein in the reaction step, the oxygen concentration in the gas supplied is 21% by volume or less relative to the total volume of the gas.

16. The method for producing an isocyanate compound according to claim 10 or 11, wherein the reaction step simultaneously contains a secondary amine compound represented by the general formula (I), the general formula (I-2), or the general formula (I-3) and a tertiary amine compound represented by the general formula (II), the general formula (II-2), or the general formula (II-3).

17. a first reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I), the following general formula (I-2), or the following general formula (I-3), and a tertiary amine compound represented by the following general formula (II), the following general formula (II-2), or the following general formula (II-3), to obtain a blocked isocyanate compound; a reaction step of decomposing the blocked isocyanate compound into the first blocking agent and an isocyanate compound by heat treatment in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound represented by the general formula (I), the general formula (I-2), or the general formula (I-3) and a tertiary amine compound represented by the general formula (II), the general formula (II-2), or the general formula (II-3), thereby obtaining the isocyanate compound; Including, The method for producing an isocyanate compound, wherein the first blocking agent comprises one or more compounds selected from the group consisting of a hydroxy compound, an amine compound, and ammonia. 【Chemical 22】 (In general formula (I), R １１ and R １２ are each independently a monovalent organic group. １１ and R １２ At least one of the groups has an aromatic group. 【Chemical 23】 (In general formula (I-2), R １２１ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １２２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n121 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 24】 (In general formula (I-3), R １３１ is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １３１ is —O—, —NH—, or —C(═O)—. １３２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group. n131 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 25】 (In general formula (II), R ２１ , R ２２ , and R ２３ are each independently a monovalent organic group. ２１ , R ２２ , and R ２３ At least one of the groups has an aromatic group. 【Chemical 26】 (In general formula (II-2), R ２２１ is a monovalent organic group. ２２２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２２１ and R ２２２ may be bonded to each other to form a carbon-carbon bond. ２２３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n221 represents the number of substituents and is an integer of 0 to 4. 【Chemical 27】 (In general formula (II-3), R ２３１ is a monovalent organic group. ２３２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２３１ and R ２３２ may be bonded to each other to form a carbon-carbon bond. ２３１ is —O—, —NH—, or —C(═O)—. ２３３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n231 represents the number of substituents and is an integer of 0 to 4.

18. The method includes an addition-elimination reaction step of reacting a first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I), the following general formula (I-2), or the following general formula (I-3), and a tertiary amine compound represented by the following general formula (II), the following general formula (II-2), or the following general formula (II-3), to obtain a second blocked isocyanate compound, the second blocking agent is a compound different from the first blocking agent that blocks the isocyanate group of the first blocked isocyanate compound, the first blocked isocyanate compound and the second blocked isocyanate compound have different structures, The method for producing a blocked isocyanate compound, wherein the first blocking agent comprises one or more compounds selected from the group consisting of hydroxy compounds, amine compounds, and ammonia. 【Chemical Formula 28】 (In general formula (I), R １１ and R １２ are each independently a monovalent organic group. １１ and R １２ At least one of the groups has an aromatic group. 【Chemical Formula 29】 (In general formula (I-2), R １２１ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １２２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n121 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 30】 (In general formula (I-3), R １３１ is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １３１ is —O—, —NH—, or —C(═O)—. １３２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group. n131 represents the number of substituents and is an integer of 0 to 4. 【Chemical 31】 (In general formula (II), R ２１ , R ２２ , and R ２３ are each independently a monovalent organic group. ２１ , R ２２ , and R ２３ At least one of the groups has an aromatic group. 【Chemical 32】 (In general formula (II-2), R ２２１ is a monovalent organic group. ２２２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２２１ and R ２２２ may be bonded to each other to form a carbon-carbon bond. ２２３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n221 represents the number of substituents and is an integer of 0 to 4. 【Chemical 33】 (In general formula (II-3), R ２３１ is a monovalent organic group. ２３２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２３１ and R ２３２ may be bonded to each other to form a carbon-carbon bond. ２３１ is —O—, —NH—, or —C(═O)—. ２３３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n231 represents the number of substituents and is an integer of 0 to 4.

19. 19. The method for producing a blocked isocyanate compound according to claim 18, wherein the isocyanate compound used in producing the first blocked isocyanate compound comprises an isocyanate compound represented by the following general formula (VII): 【Chemical 34】 (In general formula (VII), R ７１ is an n71-valent organic group, where n71 is an integer of 1 or more and 12 or less.

20. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein the first blocking agent comprises an aromatic hydroxy compound represented by the following general formula (IV-1): 【Chemistry 35】 (In general formula (IV-1), ring A ４１ is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. ４１ is a hydrogen atom, a halogen atom, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkyloxycarbonyl group having from 1 to 20 carbon atoms, an alkylcarbonyloxy group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aryloxy group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or an aralkyloxy group having from 7 to 20 carbon atoms. ４１ is ring A ４１ may bond to form a ring structure. n41 is an integer of 1 or more and 10 or less.

21. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein the first blocking agent comprises an aliphatic hydroxy compound represented by the following general formula (IV-2): 【Chemical 36】 (In general formula (IV-2), R ４２ represents a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 24 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

22. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein the first blocking agent comprises a secondary amine compound represented by the following general formula (V), the general formula (I-2), or the general formula (I-3): 【Chemical 37】 (In general formula (V), R ５１ and R ５２ are each independently a monovalent organic group.

23. 20. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein the second blocking agent comprises one or more compounds selected from the group consisting of hydroxy compounds and amine compounds.

24. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein the second blocking agent comprises an aromatic hydroxy compound represented by the following general formula (IV-1): 【Chemical 38】 (In general formula (IV-1), ring A ４１ is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. ４１ is a hydrogen atom, a halogen atom, a carboxy group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkyloxycarbonyl group having from 1 to 20 carbon atoms, an alkylcarbonyloxy group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, an aryloxy group having from 6 to 20 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms, or an aralkyloxy group having from 7 to 20 carbon atoms. ４１ is ring A ４１ may bond to form a ring structure. n41 is an integer of 1 or more and 10 or less.

25. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein the second blocking agent comprises an aliphatic hydroxy compound represented by the following general formula (IV-2): 【Chemical 39】 (In general formula (IV-2), R ４２ represents a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 24 carbon atoms, which may have an ether group, a carbonyl group, or an ester group.

26. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein the second blocking agent comprises a secondary amine compound represented by the following general formula (V), the general formula (I-2), or the general formula (I-3): 【Chemistry 40】 (In general formula (V), R ５１ and R ５２ are each independently a monovalent organic group.

27. 20. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein in the addition-elimination reaction step, the oxygen concentration in the gas supplied is 21 volume % or less, based on the total volume of the gas.

28. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein in the addition-elimination reaction step, the amount of one or more compounds selected from the group consisting of secondary amine compounds represented by general formula (I), general formula (I-2), or general formula (I-3) and tertiary amine compounds represented by general formula (II), general formula (II-2), or general formula (II-3) is 1 ppm by mass or more relative to the reaction solution.

29. The method for producing a blocked isocyanate compound according to claim 18 or 19, wherein the addition-elimination reaction step simultaneously contains a secondary amine compound represented by general formula (I), general formula (I-2), or general formula (I-3) and a tertiary amine compound represented by general formula (II), general formula (II-2), or general formula (II-3).

30. a reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I), the following general formula (I-2), or the following general formula (I-3), and a tertiary amine compound represented by the following general formula (II), the following general formula (II-2), or the following general formula (II-3), to obtain a first blocked isocyanate compound; an addition-elimination reaction step of reacting the first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound represented by general formula (I), general formula (I-2), or general formula (I-3) and a tertiary amine compound represented by general formula (II), general formula (II-2), or general formula (II-3), to obtain a second blocked isocyanate compound; Including, the second blocking agent is a compound different from the first blocking agent and the third blocking agent derived from the carbonic acid derivative, The method for producing a blocked isocyanate compound, wherein the first blocked isocyanate compound and the second blocked isocyanate compound have different structures. 【Chemistry 41】 (In general formula (I), R １１ and R １２ are each independently a monovalent organic group. １１ and R １２ At least one of the groups has an aromatic group. 【Chemistry 42】 (In general formula (I-2), R １２１ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １２２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n121 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 43】 (In general formula (I-3), R １３１ is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １３１ is —O—, —NH—, or —C(═O)—. １３２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group. n131 represents the number of substituents and is an integer of 0 to 4. 【Chemical Formula 44】 (In general formula (II), R ２１ , R ２２ , and R ２３ are each independently a monovalent organic group. ２１ , R ２２ , and R ２３ At least one of the groups has an aromatic group. 【Chemistry 45】 (In general formula (II-2), R ２２１ is a monovalent organic group. ２２２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２２１ and R ２２２ may be bonded to each other to form a carbon-carbon bond. ２２３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n221 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 46】 (In general formula (II-3), R ２３１ is a monovalent organic group. ２３２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２３１ and R ２３２ may be bonded to each other to form a carbon-carbon bond. ２３１ is —O—, —NH—, or —C(═O)—. ２３３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n231 represents the number of substituents and is an integer of 0 to 4.

31. a first reaction step of reacting a primary amine compound, a carbonic acid derivative, and a first blocking agent by heat treatment in the presence of one or more compounds selected from the group consisting of a secondary amine compound represented by the following general formula (I), the following general formula (I-2), or the following general formula (I-3), and a tertiary amine compound represented by the following general formula (II), the following general formula (II-2), or the following general formula (II-3), to obtain a first blocked isocyanate compound; an addition-elimination reaction step of reacting the first blocked isocyanate compound with a second blocking agent by an addition-elimination reaction in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound represented by general formula (I), general formula (I-2), or general formula (I-3) and a tertiary amine compound represented by general formula (II), general formula (II-2), or general formula (II-3), to obtain a second blocked isocyanate compound; a second reaction step of decomposing the second blocked isocyanate compound into a second blocking agent and an isocyanate compound by heat treatment in the presence or absence of one or more compounds selected from the group consisting of a secondary amine compound represented by the general formula (I), the general formula (I-2), or the general formula (I-3) and a tertiary amine compound represented by the general formula (II), the general formula (II-2), or the general formula (II-3), thereby obtaining the isocyanate compound; Including, the second blocking agent is a compound different from the first blocking agent and the third blocking agent derived from the carbonic acid derivative, The method for producing an isocyanate compound, wherein the first blocked isocyanate compound and the second blocked isocyanate compound have different structures. 【Chemistry 47】 (In general formula (I), R １１ and R １２ are each independently a monovalent organic group. １１ and R １２ At least one of the groups has an aromatic group. 【Chemistry 48】 (In general formula (I-2), R １２１ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １２２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n121 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 49】 (In general formula (I-3), R １３１ is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. １３１ is —O—, —NH—, or —C(═O)—. １３２ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group. n131 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 50】 (In general formula (II), R ２１ , R ２２ , and R ２３ are each independently a monovalent organic group. ２１ , R ２２ , and R ２３ At least one of the groups has an aromatic group. 【Chemistry 51】 (In general formula (II-2), R ２２１ is a monovalent organic group. ２２２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２２１ and R ２２２ may be bonded to each other to form a carbon-carbon bond. ２２３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n221 represents the number of substituents and is an integer of 0 to 4. 【Chemistry 52】 (In general formula (II-3), R ２３１ is a monovalent organic group. ２３２ R is a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. ２３１ and R ２３２ may be bonded to each other to form a carbon-carbon bond. ２３１ is —O—, —NH—, or —C(═O)—. ２３３ represents a substituent on the benzene ring, and is a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, which may have an ether group, a carbonyl group, or an ester group. n231 represents the number of substituents and is an integer of 0 to 4.

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