Blocked polyisocyanate composition, resin composition, resin film and laminate

Abstract

The blocked polyisocyanate composition of the present invention comprises a blocked polyisocyanate derived from one or more diisocyanates, an active hydrogen compound and a blocking agent comprising a malonic ester, wherein the active hydrogen compound has a number average molecular weight of 60 to 5000 and an average functional group number of 1.6 to 2.4.

Description

Technical Field

[0001] The present invention relates to a blocked polyisocyanate composition, a resin composition, a resin film and a laminate.

[0002] This application claims priority based on Japanese Patent Application No. 2020-085957 filed in Japan on May 15, 2020 and Japanese Patent Application No. 2020-189538 filed in Japan on November 13, 2020, and cites the contents thereof. Background Art

[0003] In the past, polyurethane resin coatings have very excellent wear resistance, chemical resistance and pollution resistance. In particular, polyurethane resin coatings using polyisocyanates obtained from aliphatic diisocyanates or alicyclic diisocyanates have better weather resistance, and their demand tends to increase. However, polyurethane resin coatings are usually two-component, so their use is extremely inconvenient. That is, the usual polyurethane resin coating contains two components, polyol and polyisocyanate, and it is necessary to store the polyol and polyisocyanate separately and mix the two during coating. In addition, once the two are mixed, the coating will gel in a short time and become unusable. Since polyurethane resin coatings have such problems, it is extremely difficult to use them for automatic coating in the field of production line coating such as automobile coating or weak electrical coating. In addition, since isocyanates easily react with water, it is impossible to use them in water-based coatings such as electrodeposition coatings. Furthermore, when using coatings containing isocyanates, it is necessary to fully clean the coating machine and the coating tank at the end of the operation, so the operating efficiency is significantly reduced.

[0004] In order to improve the above-mentioned problems, in the past, it has been proposed to use blocked polyisocyanates formed by blocking all active isocyanate groups with blocking agents. The blocked polyisocyanates do not react with polyols at room temperature. However, by heating, the blocking agent will dissociate and regenerate active isocyanate groups to react with polyols and cause crosslinking reactions, so the above-mentioned problems can be improved. Therefore, a lot of research on blocking agents is being carried out, and for example, phenol, methyl ethyl ketone oxime, etc. can be cited as representative blocking agents.

[0005] However, when using blocked polyisocyanates using these blocking agents, a high baking temperature of 140° C. or higher is generally required. The need for baking at a high temperature is not only energy-disadvantageous, but also requires the heat resistance of the substrate, which is a major factor limiting its use.

[0006] On the other hand, as low-temperature baking type blocked polyisocyanates, blocked polyisocyanates using active methylene compounds such as acetoacetate and malonate diesters are being studied. For example, Patent Documents 1 and 2 propose blocked polyisocyanate compositions that cure at 90°C.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2002-322238

[0010] Patent Document 2: Japanese Patent Application Publication No. 2006-335954 Summary of the invention

[0011] Problem that the invention aims to solve

[0012] However, in recent years, there has been a strong demand for a blocked polyisocyanate composition that cures at a temperature lower than 90° C. from the viewpoint of protecting the global environment and adapting to plastics with low heat resistance. Under such circumstances, there is no known blocked polyisocyanate composition that has good dispersibility when mixed with a polyvalent polyol (aqueous polyol, water-dispersible polyol) having a hydroxyl group, does not gel or excessively thicken during storage, does not reduce curability after storage, has good curability at 90° C. or lower or 80° C. or lower, and has excellent hardness and strength of a coating film obtained by curing at such a temperature.

[0013] The present invention has been made in view of the above-mentioned actual situation, and provides a blocked polyisocyanate composition which has good storage stability when formed into a resin composition, and has excellent curability, hardness, strength and solvent resistance at a low temperature of about 85°C or about 80°C when formed into a coating film, as well as a resin composition, a resin film and a laminate using the above-mentioned blocked polyisocyanate composition.

[0014] Solutions for solving problems

[0015] That is, the present invention includes the following aspects.

[0016] (1) A blocked polyisocyanate composition comprising: a blocked polyisocyanate derived from one or more diisocyanates, an active hydrogen compound, and a blocking agent comprising a malonic ester, wherein the active hydrogen compound has a number average molecular weight of 60 to 5000 and an average number of functional groups of 1.6 to 2.4.

[0017] (2) A blocked polyisocyanate composition comprising: a blocked polyisocyanate derived from an active hydrogen compound, a polyisocyanate, and a blocking agent comprising a malonic ester, wherein the active hydrogen compound has a number average molecular weight of 60 to 5000 and an average functional group number of 1.6 to 2.4.

[0018] (3) The blocked polyisocyanate composition according to (1) or (2), wherein the active hydrogen compound is polyol A.

[0019] (4) The blocked polyisocyanate composition according to (3), wherein the polyol A is one or more polyols selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanedimethanol, glycerol, and polycaprolactone polyols derived from these and ε-caprolactone.

[0020] (5) The blocked polyisocyanate composition according to any one of (2) to (4), wherein the content of the structural unit derived from the active hydrogen compound is 0.05 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the structural unit derived from the polyisocyanate.

[0021] (6) The blocked polyisocyanate composition according to any one of (2) to (5), wherein the polyisocyanate is a polyisocyanate having an average isocyanate group number of 3.5 or more, having an isocyanurate group, and derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

[0022] (7) The blocked polyisocyanate composition according to any one of (2) to (5), wherein the polyisocyanate is a polyisocyanate derived from a diisocyanate and a polyol B having an average functional group number of 2.9 or more and 8.0 or less.

[0023] (8) The blocked polyisocyanate composition according to any one of (2) to (7), wherein the blocked polyisocyanate comprises a structural unit represented by the general formula (I).

[0024]

[0025] In the above general formula (I), R 11 , R 12 and R 13 are each independently an alkyl group which may contain one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and R 11 , R 12 and R 13 The total number of carbon atoms is 3 or more and 20 or less, R 14 , R 15 and R 16 Each independently represents a hydrogen atom or an alkyl group which may have one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and a wavy line represents a connecting bond.

[0026] (9) The blocked polyisocyanate composition according to (8), wherein in the general formula (I), R 11 , R 12 and R 13The total carbon number of is 4 or more and 20 or less.

[0027] (10) The blocked polyisocyanate composition according to (8) or (9), wherein the structural unit represented by the general formula (I) comprises: 11 , R 12 and R 13 The total number of carbon atoms is 4 or more and 20 or less, R 16 A structural unit (I-1) represents a hydrogen atom.

[0028] (11) The blocked polyisocyanate composition according to any one of (8) to (10), wherein the structural unit represented by the general formula (I) comprises: 11 , R 12 and R 13 are each independently an unsubstituted alkyl group, R 14 , R 15 and R 16 Each is independently a hydrogen atom or an unsubstituted alkyl structural unit.

[0029] (12) The blocked polyisocyanate composition according to any one of (8) to (11), wherein the molar ratio of the hydroxyl group contained in the polyol A to the structural unit represented by the general formula (I) is 0.5 / 99.5 to 15 / 85.

[0030] (13) The blocked polyisocyanate composition according to any one of (1) to (12), wherein a portion of the blocked polyisocyanate has a structural unit derived from a hydrophilic compound.

[0031] (14) The blocked polyisocyanate composition according to (13), wherein the hydrophilic compound comprises one or more compounds selected from the group consisting of nonionic compounds and anionic compounds.

[0032] (15) The blocked polyisocyanate composition according to any one of (1) to (14), wherein the blocking agent comprises a malonic acid ester having a secondary alkyl group.

[0033] (16) A blocked polyisocyanate composition comprising a blocked polyisocyanate derived from a polyisocyanate and one or more blocking agents,

[0034] The blocked polyisocyanate comprises a structural unit represented by the general formula (I).

[0035]

[0036] In the above general formula (I), R 11 , R12 and R 13 are each independently an alkyl group which may contain one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and R 11 , R 12 and R 13 The total carbon number of R is 4 or more and 20 or less. 14 , R 15 and R 16 Each independently represents a hydrogen atom or an alkyl group which may contain one or more substituents selected from the group consisting of a hydroxyl group and an amino group. A wavy line represents a connecting bond.

[0037] (17) The blocked polyisocyanate composition according to (16), wherein the blocked polyisocyanate further comprises a structural unit represented by the general formula (II):

[0038] The molar ratio of the structural unit represented by the general formula (II) to the structural unit represented by the general formula (I) is 4 / 96 or more and 96 / 4 or less.

[0039]

[0040] In the above general formula (II), R 21 , R 22 , R 23 and R 24 Each independently represents a hydrogen atom or an alkyl group which may contain one or more substituents selected from the group consisting of a hydroxyl group and an amino group. A wavy line represents a connecting bond.

[0041] (18) The blocked polyisocyanate composition according to (16) or (17), wherein the structural unit represented by the general formula (I) comprises R 16 A structural unit (I-1) represents a hydrogen atom.

[0042] (19) The blocked polyisocyanate composition according to any one of (16) to (18), wherein in the general formula (I), R 11 , R 12 and R 13 Each is independently methyl or ethyl.

[0043] (20) The blocked polyisocyanate composition according to any one of (16) to (19), wherein a part of the isocyanate groups of the polyisocyanate is modified with a nonionic compound.

[0044] (21) The blocked polyisocyanate composition according to any one of (16) to (20), wherein the average number of isocyanate groups in the polyisocyanate is 2 or more.

[0045] (22) The blocked polyisocyanate composition according to any one of (16) to (21), wherein the polyisocyanate is a polyisocyanate derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

[0046] (23) The blocked polyisocyanate composition according to any one of (16) to (22), wherein the blocked polyisocyanate has an isocyanurate group.

[0047] (24) A resin composition comprising the blocked polyisocyanate composition according to any one of (1) to (23) above and a polyvalent hydroxy compound.

[0048] (25) A resin film obtained by curing the resin composition according to (24) above.

[0049] (26) A laminate comprising two or more layers of the resin film according to (25) having different compositions,

[0050] The average thickness per layer of the laminate is 1 μm or more and 50 μm or less.

[0051] (27) A method for producing a blocked polyisocyanate composition, which is the method for producing a blocked polyisocyanate composition according to any one of (1) to (15) above, comprising: a first step of reacting the polyisocyanate composition with a blocking agent containing a malonic ester, and a second step of reacting the blocked polyisocyanate composition obtained in the first step with an active hydrogen compound.

[0052] Effects of the Invention

[0053] According to the blocked polyisocyanate composition of the above embodiment, it is possible to provide a blocked polyisocyanate composition having good storage stability when formed into a resin composition, and having excellent curability, hardness and strength at a low temperature of about 80°C or about 85°C when formed into a coating. The resin composition of the above embodiment comprises the blocked polyisocyanate composition, has good storage stability, and has excellent curability, hardness and strength at a low temperature of about 80°C when formed into a coating. The resin film of the above embodiment is formed by curing the resin composition, and has excellent curability, hardness and strength at a low temperature of about 80°C. DETAILED DESCRIPTION

[0054] Hereinafter, a mode for implementing the present invention (hereinafter referred to as "this embodiment") will be described in detail. It should be noted that the present invention is not limited to the following this embodiment. The present invention can be implemented by appropriately changing it within the scope of the gist thereof.

[0055] In addition, in this specification, "polyol" means a compound having two or more hydroxyl groups (-OH).

[0056] In this specification, "polyisocyanate" refers to a reaction product in which a plurality of monomer compounds having one or more isocyanate groups (-NCO) are bonded to each other.

[0057] In this specification, "structural unit" refers to a structure derived from one molecule of monomer in the structure constituting a polyisocyanate or a blocked polyisocyanate. For example, a structural unit derived from malonate refers to a structure derived from one molecule of malonate in a blocked polyisocyanate. A structural unit may be a unit directly formed by a (co)polymerization reaction of a monomer, or a unit formed by treating a (co)polymer to convert a portion of the unit into another structure.

[0058] 《Blocked polyisocyanate composition according to the first embodiment》

[0059] The blocked polyisocyanate composition according to the first embodiment of the present invention includes a blocked polyisocyanate derived from one or more diisocyanates, an active hydrogen compound, and a blocking agent containing a malonic acid ester.

[0060] [Diisocyanate]

[0061] As the diisocyanate, a diisocyanate having 4 to 30 carbon atoms is preferred, and specific examples thereof include the following. These diisocyanates may be used alone or in combination of two or more.

[0062] (1) Aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate (MDI), 1,5-naphthalene diisocyanate, toluene diisocyanate (TDI), xylylene diisocyanate, and tetramethyl-m-xylylene diisocyanate (TMXDI).

[0063] (2) Aliphatic diisocyanates such as 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (hereinafter sometimes referred to as “HDI”), 2,2,4-trimethyl-1,6-diisocyanatohexane, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, 2-methylpentane-1,5-diisocyanate (MPDI), and lysine diisocyanate (hereinafter sometimes referred to as “LDI”).

[0064] (3) Alicyclic diisocyanates such as isophorone diisocyanate (hereinafter sometimes referred to as “IPDI”), 1,3-bis(diisocyanatomethyl)cyclohexane, 4,4′-dicyclohexylmethane diisocyanate, diisocyanate norbornane, and di(isocyanatomethyl)norbornane.

[0065] Among these, it is preferred to use at least one selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates. In addition, from the ease of industrial acquisition, HDI or IPDI is more preferably used. In addition, from the viewpoint of making the blocked polyisocyanate component low-viscosity, HDI is further preferably used.

[0066] In addition, as diisocyanate, it is preferable to use aliphatic diisocyanate and alicyclic diisocyanate in combination, and HDI and IPDI are particularly preferable. By using aliphatic diisocyanate and alicyclic diisocyanate in combination, the toughness and hardness of the coating film can be further improved.

[0067] When an aliphatic diisocyanate and an alicyclic diisocyanate are used in combination, the mass ratio of the structural unit derived from the aliphatic diisocyanate to the structural unit derived from the alicyclic diisocyanate is preferably 50 / 50 or more and 95 / 5 or less, more preferably 60 / 40 or more and 92 / 8 or less, and further preferably 65 / 35 or more and 90 / 10 or less.

[0068] By making the mass ratio of the structural unit derived from aliphatic diisocyanate to the structural unit derived from alicyclic diisocyanate above the above lower limit, the reduction in flexibility when formed into a coating film can be more effectively suppressed. On the other hand, by being below the above upper limit, the hardness when formed into a coating film can be further increased.

[0069] The mass ratio of the structural unit derived from aliphatic diisocyanate to the structural unit derived from alicyclic diisocyanate can be calculated, for example, using the following method. First, the mass of the unreacted diisocyanate after the reaction and the aliphatic diisocyanate concentration and the alicyclic diisocyanate concentration in the unreacted diisocyanate obtained by gas chromatography are used to calculate the mass of the unreacted aliphatic diisocyanate and the mass of the unreacted alicyclic diisocyanate. Then, from the mass of the aliphatic diisocyanate and the mass of the alicyclic diisocyanate put in, the mass of the unreacted aliphatic diisocyanate and the mass of the unreacted alicyclic diisocyanate calculated above are respectively subtracted, and the difference obtained is respectively used as the mass of the structural unit derived from aliphatic diisocyanate and the mass of the structural unit derived from alicyclic diisocyanate. Then, the mass of the structural unit derived from aliphatic diisocyanate is divided by the mass of the structural unit derived from alicyclic diisocyanate, thereby obtaining the mass ratio of the structural unit derived from aliphatic diisocyanate to the structural unit derived from alicyclic diisocyanate.

[0070] [Active hydrogen compounds]

[0071] The active hydrogen compound of the present embodiment is a compound containing a hydroxyl group and / or an amino group as an active hydrogen group.

[0072] The number average molecular weight Mn of the active hydrogen compound is 60 to 5000, preferably 100 to 4700, more preferably 300 to 4500, and further preferably 500 to 4000. When the number average molecular weight Mn of the active hydrogen compound is within the above range, the coating film has excellent curability and strength at a low temperature of about 80°C.

[0073] The number average molecular weight Mn of the active hydrogen compound is, for example, a polystyrene-standard number average molecular weight measured by gel permeation chromatography (GPC). Specifically, it can be measured using the method described in the Examples described below.

[0074] The average number of functional groups of the active hydrogen compound is 1.6 to 2.4, preferably 1.8 to 2.2, and more preferably 1.9 to 2.1. By setting the average number of functional groups of the active hydrogen compound within the above range, gelation during synthesis and storage of the blocked polyisocyanate can be suppressed, and high curability can be exhibited.

[0075] The average number of functional groups of the active hydrogen compound can be calculated using the following formula. It should be noted that, in the formula, "Mn" represents the number average molecular weight of the active hydrogen compound, "hydroxyl content" represents the content (mass %) of hydroxyl groups relative to 100 mass % of the solid content of the active hydrogen compound, "17" represents the molecular weight (g / mol) of hydroxyl groups, "amino content" represents the content (mass %) of amino groups relative to 100 mass % of the active hydrogen compound, and "15" represents the molecular weight (g / mol) of amino groups.

[0076] (Average number of functional groups in active hydrogen compounds) = {(Mn of active hydrogen compounds) × (hydroxyl group content) × 0.01} / 17 + {(Mn of active hydrogen compounds) × (amino group content) × 0.01} / 15

[0077] The content of the structural unit derived from the active hydrogen compound is preferably 0.05 parts by mass or more and 10 parts by mass or less, more preferably 0.1 parts by mass or more and 9 parts by mass or less, further preferably 0.25 parts by mass or more and 8 parts by mass or less, further preferably 0.3 parts by mass or more and 7 parts by mass or less, relative to 100 parts by mass of the structural unit derived from the diisocyanate. Alternatively, the content of the structural unit derived from the active hydrogen compound is more preferably 0.6 parts by mass or more and 9.5 parts by mass or less, relative to 100 parts by mass of the structural unit derived from the diisocyanate.

[0078] When the content of the structural unit derived from the active hydrogen compound is not less than the above lower limit relative to 100 parts by mass of the structural unit derived from the diisocyanate, the curing property, hardness and strength at a low temperature of about 80° C. when the coating film is prepared tend to be excellent. On the other hand, when the content of the structural unit derived from the active hydrogen compound is not more than the above upper limit relative to 100 parts by mass of the structural unit derived from the diisocyanate, gelation during synthesis of the blocked polyisocyanate composition can be suppressed, and the storage stability when prepared as a resin composition can be improved.

[0079] The content of the structural unit derived from the active hydrogen compound relative to 100 parts by mass of the structural unit derived from the diisocyanate can be calculated, for example, based on the blending ratio of the raw materials. Alternatively, the content of the structural unit derived from the active hydrogen compound relative to 100 parts by mass of the structural unit derived from the diisocyanate can also be obtained, for example, by nuclear magnetic resonance (NMR), infrared absorption spectroscopy (IR), gas chromatography (GC), mass spectrometry (MS), etc.

[0080] The active hydrogen compound containing an amino group is not particularly limited, and examples thereof include aliphatic diamine compounds such as ethylenediamine, trimethylenediamine, hexamethylenediamine, and octamethylenediamine; aromatic diamine compounds such as phenylenediamine and 4,4′-methylenebis(phenylamine); alicyclic diamine compounds such as cyclopentyldiamine, cyclohexyldiamine, 4,4′-diaminodicyclohexylmethane, 1,4-diaminocyclohexane, and isophoronediamine; and aspartic acid ester compounds.

[0081] The active hydrogen compound containing an amino group and a hydroxyl group is not particularly limited, and examples thereof include 1-amino-2-propanol and 5-amino-1-pentanol.

[0082] [Polyol A]

[0083] The active hydrogen compound of the present embodiment preferably contains only a hydroxyl group (hereinafter referred to as polyol A).

[0084] The number average molecular weight Mn of polyol A is 60 or more and 5000 or less, preferably 100 or more and 4700 or less, more preferably 300 or more and 4500 or less, and further preferably 500 or more and 4000 or less. By making the number average molecular weight Mn of polyol A within the above range, the curing property and strength at a low temperature of about 80° C. when the coating film is formed are excellent. The number average molecular weight Mn of polyol A is, for example, a number average molecular weight based on a polystyrene standard measured by gel permeation chromatography (GPC). Specifically, it can be measured using the method described in the examples described later.

[0085] The average number of functional groups of polyol A is 1.6 or more and 2.4 or less, preferably 1.8 or more and 2.2 or less, more preferably 1.9 or more and 2.1 or less. By making the average number of functional groups of polyol A within the above range, the gelation during the synthesis of blocked polyisocyanate and the gelation during storage can be suppressed, and high curability can be exhibited. The average number of functional groups of polyol A can be calculated using the following formula. It should be noted that, in the formula, "Mn" represents the number average molecular weight of polyol A, "hydroxyl content" represents the content (mass %) of hydroxyl groups relative to 100% by mass of the solid content of polyol A, and "17" represents the molecular weight (g / mol) of hydroxyl groups.

[0086] (Average number of functional groups of polyol A) = {(Mn of polyol A) × (hydroxyl content) × 0.01} / 17

[0087] Examples of the polyol A include 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanedimethanol, glycerol, and polycaprolactone polyols derived from these and ε-caprolactone, polyether polyols, polycarbonate polyols, and acrylic polyols. Among them, one or more diols selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanedimethanol and glycerol, or polycaprolactone diols derived from these diols and ε-caprolactone are preferred, and one or more diols selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol and 1,4-cyclohexanedimethanol, or polycaprolactone diols derived from these diols and ε-caprolactone are more preferred.

[0088] Examples of commercially available products of polycaprolactone diol include “PLACCEL 205UT” (number average molecular weight 530), “PLACCEL 220CPT” (number average molecular weight 2000), and “PLACCEL 240CP” (number average molecular weight 4000) from Daicel Corporation.

[0089] [Capping agent]

[0090] The end-capping agent includes a malonic ester. The malonic ester is not particularly limited, but preferably includes a malonic ester having a secondary alkyl group or a malonic ester having a primary alkyl group, and a malonic ester having a tertiary alkyl group, and more preferably includes a malonic ester having a secondary alkyl group and a malonic ester having a tertiary alkyl group. The end-capping agent may include one type each of a malonic ester having a secondary alkyl group, a malonic ester having a primary alkyl group, and a malonic ester having a tertiary alkyl group, or may include two or more types in combination.

[0091] The malonic acid ester having a primary alkyl group is not particularly limited, and examples thereof include dimethyl malonate, diethyl malonate, dipropyl malonate, dibutyl malonate, dicyclohexyl malonate, diphenyl malonate, etc. Among them, diethyl malonate is preferred as the malonic acid ester having a primary alkyl group.

[0092] The malonic acid ester having a secondary alkyl group is not particularly limited, and examples thereof include di-sec-butyl malonate, diisopropyl malonate, isopropyl ethyl malonate, etc. Among them, diisopropyl malonate is preferred as the malonic acid ester having a secondary alkyl group.

[0093] The malonic acid ester having a tertiary alkyl group is not particularly limited, and examples thereof include di-tert-butyl malonate, di(2-methyl-2-butyl) malonate, di(2-methyl-2-pentyl) malonate, (tert-butyl) ethyl malonate, (2-methyl-2-butyl) ethyl malonate, (2-methyl-2-butyl) isopropyl malonate, (2-methyl-2-pentyl) ethyl malonate, (2-methyl-2-pentyl) isopropyl malonate, (2-methyl-2-pentyl) isopropyl malonate, and (2-methyl-2-pentyl) hexyl isopropyl malonate. Among them, preferred are di(2-methyl-2-butyl) malonate, di(2-methyl-2-pentyl) malonate, (2-methyl-2-butyl) isopropyl malonate, (2-methyl-2-pentyl) ethyl malonate, (2-methyl-2-pentyl) isopropyl malonate, preferred are (2-methyl-2-butyl) ethyl malonate, (2-methyl-2-butyl) isopropyl malonate, (2-methyl-2-pentyl) ethyl malonate, (2-methyl-2-pentyl) hexyl isopropyl malonate, or preferred are tri-tert-butyl malonate, (2-methyl-2-butyl) isopropyl malonate, or (2-methyl-2-pentyl) isopropyl malonate.

[0094] As the malonic acid ester having a tertiary alkyl group, a commercially available one may be used, or one synthesized by the method of Reference 1 (Japanese Patent Application Laid-Open No. 11-130728) may be used.

[0095] The content of the malonic ester having a secondary alkyl group and the malonic ester having a tertiary alkyl group is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, particularly preferably 95 mol% or more, and most preferably 100 mol% relative to the total molar amount of all blocking agents used in the production of the blocked polyisocyanate.

[0096] By setting the content of the malonic acid ester having a secondary alkyl group and the malonic acid ester having a tertiary alkyl group to be within the above range, the low-temperature curability when formed into a resin film can be further improved.

[0097] (Other Capping Agents)

[0098] The blocking agent used in the production of the blocked polyisocyanate may contain other blocking agents in addition to the malonic acid ester having a secondary alkyl group and the malonic acid ester having a tertiary alkyl group, within a range that does not inhibit the storage stability of the resin composition and the low-temperature curing property of the resin film.

[0099] As other end-capping agents, for example, there can be mentioned 1) alcohol compounds, 2) alkylphenol compounds, 3) phenol compounds, 4) active methylene compounds other than malonic acid esters having secondary alkyl groups and malonic acid esters having tertiary alkyl groups, 5) thiol compounds, 6) acid amide compounds, 7) acid imide compounds, 8) imidazole compounds, 9) urea compounds, 10) oxime compounds, 11) amine compounds, 12) imide compounds, 13) bisulfites, 14) pyrazole compounds, 15) triazole compounds, etc. As end-capping agents, more specifically, there can be mentioned the following substances, etc.

[0100] 1) Alcohol compounds: methanol, ethanol, 2-propanol, n-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol and the like.

[0101] 2) Alkylphenol compounds: mono- and di-alkylphenols having an alkyl group having 4 or more carbon atoms as a substituent. Specific examples of the alkylphenol compounds include mono-alkylphenols such as n-propylphenol, iso-propylphenol, n-butylphenol, sec-butylphenol, tert-butylphenol, n-hexylphenol, 2-ethylhexylphenol, n-octylphenol, and n-nonylphenol; and di-alkylphenols such as di-n-propylphenol, diisopropylphenol, isopropylcresol, di-n-butylphenol, di-tert-butylphenol, di-sec-butylphenol, di-n-octylphenol, di(2-ethylhexyl)phenol, and di-n-nonylphenol.

[0102] 3) Phenolic compounds: phenol, cresol, ethylphenol, styrenated phenol, hydroxybenzoic acid esters, etc.

[0103] 4) Active methylene compounds: dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, methyl isobutyrylacetate, ethyl isobutyrylacetate, acetylacetone, etc.

[0104] 5) Mercaptan compounds: butyl mercaptan, dodecyl mercaptan, etc.

[0105] 6) Acid amide compounds: acetanilide, acetic acid amide, ε-caprolactam, δ-valerolactam, γ-butyrolactam, etc.

[0106] 7) Acid imide compounds: succinimide, maleic imide, etc.

[0107] 8) Imidazole compounds: imidazole, 2-methylimidazole, etc.

[0108] 9) Urea compounds: urea, thiourea, ethylene urea, etc.

[0109] 10) Oxime compounds: formaldehyde oxime, acetaldehyde oxime, propionoxime, methyl ethyl ketone oxime, cyclohexanone oxime, etc.

[0110] 11) Amine compounds: diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, isopropylethylamine, etc.

[0111] 12) Imine compounds: ethyleneimine, polyethyleneimine, etc.

[0112] 13) Bisulfite compounds: sodium bisulfite, etc.

[0113] 14) Pyrazole compounds: pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole, etc.

[0114] 15) Triazole compounds: 3,5-dimethyl-1,2,4-triazole, etc.

[0115] (Other components)

[0116] The blocked polyisocyanate composition of the present embodiment may further contain additives such as a solvent in addition to the above-mentioned blocked polyisocyanate.

[0117] Examples of the solvent include 1-methylpyrrolidone, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether (DPDM), propylene glycol dimethyl ether, methyl ethyl ketone, acetone, methyl Isobutyl ketone, propylene glycol monomethyl ether acetate, ethanol, methanol, isopropanol, 1-propanol, isobutanol, 1-butanol, tert-butanol, 2-ethylhexanol, cyclohexanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, ethyl acetate, isopropyl acetate, butyl acetate, toluene, xylene, pentane, isopentane, hexane, isohexane, cyclohexane, solvent naphtha, mineral spirit, etc. These solvents can be used alone or in combination of two or more. From the viewpoint of dispersibility in water, as a solvent, a solvent having a solubility in water of 5% by mass or more is preferred, and specifically, DPDM is preferred.

[0118] <Method for producing blocked polyisocyanate composition according to first embodiment>

[0119] The blocked polyisocyanate composition of the first embodiment is not particularly limited, and is obtained, for example, by reacting the above-mentioned diisocyanate, the above-mentioned active hydrogen compound and the above-mentioned blocking agent. The blocked polyisocyanate composition can be manufactured by reacting these compounds simultaneously. It is also possible to react the above-mentioned diisocyanate with the above-mentioned active hydrogen compound to generate an active hydrogen compound-modified polyisocyanate, and then react the active hydrogen compound-modified polyisocyanate with the blocking agent to manufacture the blocked polyisocyanate composition. Alternatively, the above-mentioned diisocyanate can be reacted with the above-mentioned blocking agent to generate a partially blocked polyisocyanate in which a part or all of the isocyanate groups of the polyisocyanate are blocked by the blocking agent, and then the partially blocked polyisocyanate is reacted with the above-mentioned active hydrogen compound to manufacture the blocked polyisocyanate composition.

[0120] The modification reaction of diisocyanate with an active hydrogen compound can be carried out regardless of the presence or absence of a solvent.

[0121] The amount of the active hydrogen compound added is preferably 0.05 mass parts or more and 10 mass parts or less, preferably 0.1 mass parts or more and 9 mass parts or less, more preferably 0.25 mass parts or more and 8 mass parts or less, and further preferably 0.3 mass parts or more and 7 mass parts or less relative to 100 mass parts of diisocyanate. Alternatively, the amount of the structural unit derived from the active hydrogen compound added is more preferably 0.6 mass parts or more and 9.5 mass parts or less relative to 100 mass parts of the structural unit derived from the diisocyanate. By making the amount of the active hydrogen compound added more than the above lower limit, it can be seen that the curing property, hardness and strength at a low temperature of about 80°C when the coating film is made are excellent. On the other hand, by making the amount of the active hydrogen compound added less than the above upper limit, the gelation during the synthesis of the blocked polyisocyanate composition can be suppressed, and the storage stability when the resin composition is made can be good.

[0122] When a solvent is used in the modification reaction of diisocyanate and the active hydrogen compound, a solvent inactive to isocyanate groups may be used.

[0123] The active hydrogen compound-modified polyisocyanate preferably contains an isocyanurate group, an allophanate group, a urethane group and / or a urea group.

[0124] Examples of the modification reaction between diisocyanate and active hydrogen compound will be described, but are not limited to the following.

[0125] First, the isocyanate group of the above-mentioned diisocyanate and the active hydrogen group of the active hydrogen compound are urethanized and / or ureidized. The reaction temperature at this time can be set to 20 to 200°C. The above-mentioned reaction temperature is preferably 50 to 150°C, more preferably 50 to 120°C, and further preferably 50 to 100°C. When it is 50°C or more, there is a tendency for the reaction to proceed easily, and when it is 200°C or less, there is a tendency for the coloring of the obtained polyisocyanate composition to decrease. The reaction time is preferably in the range of 0.5 hours to 24 hours, more preferably 0.5 hours to 10 hours, and further preferably 0.5 hours to 5 hours.

[0126] After a part or all of the active hydrogen groups of the active hydrogen compound react with the isocyanate groups of the diisocyanate, isocyanuration or allophanation reaction proceeds.

[0127] The urethanization reaction can be carried out after the allophanate reaction and the isocyanurate reaction, or can be carried out simultaneously with the allophanate reaction and the isocyanurate reaction, preferably after the urethanate bond is formed by the reaction of the isocyanate group of the diisocyanate and the hydroxyl group of the active hydrogen compound, the allophanate reaction is carried out simultaneously with the isocyanurate reaction. These reactions can be suitably carried out by the selection of isocyanurate reaction catalyst and reaction conditions.

[0128] When the reaction is carried out using a catalyst, the reaction temperature for isocyanurate conversion and allophanate conversion is 60 to 160° C., preferably 70 to 100° C. When the reaction temperature is 60° C. or higher, the allophanate reaction tends to proceed easily, and the molar ratio of allophanate group / (allophonate group+carbamate group) tends to increase. When the reaction temperature is 160° C. or lower, the coloring of the obtained polyisocyanate composition tends to become less.

[0129] The reaction time of isocyanurate conversion and allophanate conversion is preferably 1 to 10 hours, more preferably 1 to 7 hours, and further preferably 1 to 5 hours. When the reaction time is 1 hour or more, there is a tendency for the isocyanurate conversion rate and the allophanate conversion rate to increase. When the reaction time is 10 hours or less, there is a tendency for coloration to become less.

[0130] As the isocyanurate esterification and allophanate esterification catalyst that can be used in the above, there is no particular limitation, for example, it is preferably a catalyst with alkalinity. It is not limited to the following, for example, (i) hydroxides (hydroxides), acetic acid, organic weak acid salts such as capric acid of tetraalkylammonium such as tetramethylammonium and tetraethylammonium, (ii) hydroxides, acetic acid, organic weak acid salts such as capric acid of hydroxyalkylammonium such as trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, triethylhydroxyethylammonium, (iii) alkali metal salts such as tin, zinc, lead of alkylcarboxylic acids such as acetic acid, caproic acid, caprylic acid, myristic acid, (iv) metal alkoxides of sodium, potassium, (v) aminosilyl-containing compounds such as hexamethyldisilazane, (vi) Mannich bases, (vii) tertiary amines and epoxy compounds are used in combination, (viii) phosphorus compounds such as tributylphosphine, etc. It is preferred that the hydroxides and organic weak acid salts of tetraalkylammonium. These catalysts can be added once or continuously.

[0131] In order to terminate the reaction, the catalyst is deactivated. When the catalyst is neutralized and deactivated, an acidic substance such as phosphoric acid or acid phosphate is added. Alternatively, the catalyst may be deactivated by thermal decomposition or chemical decomposition. Furthermore, the catalyst may be deactivated by adsorbing the catalyst onto activated carbon, alumina, or the like and removing the catalyst from the system.

[0132] The yield of the polyisocyanate composition ((mass of the obtained polyisocyanate composition / total mass of the input raw materials)×100) is preferably 10 to 70% by mass, more preferably 30 to 60% by mass. By increasing the yield of the polyisocyanate composition, the molar ratio of the isocyanate group to the allophanate group and the carbamate group can be increased, and by reducing the yield of the polyisocyanate composition, the molar ratio of the isocyanate group to the allophanate group and the carbamate group can be reduced.

[0133] After the reaction is completed, unreacted diisocyanate monomers are removed by thin film evaporation, extraction, etc. The concentration of unreacted diisocyanate monomers in the obtained polyisocyanate composition is preferably 3% by mass or less, more preferably 1% by mass or less, further preferably 0.5% by mass or less, and further more preferably 0.3% by mass or less. When the concentration of unreacted diisocyanate monomers is 3% by mass or less, there is a tendency for the curability to become better.

[0134] At least a part of the active hydrogen compound-modified polyisocyanate may have a structural unit derived from a hydrophilic compound, that is, a hydrophilic group.

[0135] The blocking reaction between the diisocyanate (or active hydrogen compound-modified polyisocyanate) and the blocking agent is not particularly limited, and for example, the following two methods can be mentioned.

[0136] 1) A method of reacting the above-mentioned diisocyanate (or active hydrogen compound-modified polyisocyanate) with the above-mentioned malonic acid ester having a tertiary alkyl group, with the above-mentioned malonic acid ester having a secondary alkyl group, or with the above-mentioned malonic acid ester having a primary alkyl group.

[0137] 2) A method in which the above-mentioned diisocyanate (or active hydrogen compound-modified polyisocyanate) is reacted with at least one end-capping agent selected from the group consisting of the above-mentioned malonic ester having a tertiary alkyl group, the above-mentioned malonic ester having a secondary alkyl group and the above-mentioned malonic ester having a primary alkyl group, an alcohol having a chain alkyl group is added to the obtained reaction product, and an alkyl group derived from the above-mentioned alcohol is introduced by transesterification of the terminal ester portion of the above-mentioned reaction product.

[0138] The blocking reaction between diisocyanate (or active hydrogen compound modified polyisocyanate) and blocking agent can be carried out regardless of the presence or absence of solvent. It should be noted that the blocking agent can use one type each of a malonic ester having a primary alkyl group, a malonic ester having a secondary alkyl group, and a malonic ester having a tertiary alkyl group, or a combination of two or more types.

[0139] The amount of the blocking agent added may generally be 80 mol% to 200 mol%, preferably 90 mol% to 150 mol%, based on the total molar amount of the isocyanate groups.

[0140] In addition, in the case of using a malonate with a secondary alkyl group and a malonate with a tertiary alkyl group in the added end-capping agent, the molar ratio of the malonate with a secondary alkyl group to the malonate with a tertiary alkyl group (malonate with a secondary alkyl group / malonate with a tertiary alkyl group) is preferably more than 5 / 95 and less than 95 / 5, more preferably 7 / 93 or more and 93 / 7 or less, further preferably 10 / 90 or more and 93 / 7 or less, further preferably 20 / 80 or more and 93 / 7 or less, and particularly preferably 30 / 70 or more and 93 / 7 or less. By making the molar ratio above the lower limit, the storage stability when the resin composition is prepared can be good, and by being below the upper limit, the low-temperature curing property when the resin film is prepared can be good.

[0141] When a solvent is used in the blocking reaction, it is sufficient to use a solvent inactive to isocyanate groups.

[0142] When a solvent is used, the content of the nonvolatile component may be generally 10 to 95 parts by mass, preferably 20 to 80 parts by mass, and more preferably 30 to 75 parts by mass, based on 100 parts by mass of the blocked polyisocyanate composition.

[0143] In the blocking reaction, organic metal salts of tin, zinc, lead or the like, tertiary amine compounds, alkali metal alkoxides of sodium or the like, or the like can be used as a catalyst.

[0144] The amount of the catalyst added varies depending on the temperature of the blocking reaction, etc., but is usually 0.05 to 1.5 parts by mass, preferably 0.1 to 1.0 parts by mass, based on 100 parts by mass of the polyisocyanate.

[0145] The end-capping reaction can be generally carried out at a temperature of -20°C to 150°C, preferably 0°C to 100°C, and more preferably 10°C to 80°C. By setting the temperature of the end-capping reaction to be above the lower limit, the reaction rate can be further increased, and by setting it to be below the upper limit, the side reaction can be further suppressed.

[0146] After the end-capping reaction, neutralization treatment may be performed by adding an acidic compound or the like.

[0147] As the acidic compound, an inorganic acid or an organic acid may be used. Examples of the inorganic acid include hydrochloric acid, phosphorous acid, phosphoric acid, etc. Examples of the organic acid include methanesulfonic acid, p-toluenesulfonic acid, dioctyl phthalate, dibutyl phthalate, etc.

[0148] When the product is produced by the method 2) above, a transesterification reaction is carried out following the above-mentioned terminal blocking reaction.

[0149] The alcohol having a chain alkyl group used in the transesterification reaction of the method 2) is preferably a monohydric alcohol, for example, primary monohydric alcohols such as methanol, ethanol, propanol, butanol, hexanol, and 2-ethylhexanol; secondary monohydric alcohols such as isopropanol, 2-butanol, 2-pentanol, and 2-hexanol; tertiary monohydric alcohols such as tert-butanol, 2-methyl-2-butanol, 2-methyl-2-pentanol, 2-methyl-2-hexanol, 2-methyl-2-heptanol, 2-methyl-2-octanol, 3-methyl-3-pentanol, 3-ethyl-3-hexanol, and 3-ethyl-3-octanol, etc.

[0150] In addition, the chain alkyl group of the alcohol may be the same as that of the aforementioned end-capping agent or may be different. In the case of having a chain alkyl group different from that of the aforementioned end-capping agent, it is preferred to use a monohydric alcohol having a chain alkyl group having a different number of alkyl substitutions from that of the aforementioned end-capping agent. Specifically, for example, when using a single malonic acid ester having a secondary alkyl group as the end-capping agent, a monohydric alcohol having a tertiary alkyl group may be used.

[0151] When the alcohol is produced by the method 2), it is preferred to remove the generated alcohol or the residual portion of the added alcohol by distillation under normal pressure or reduced pressure during or after the transesterification reaction.

[0152] In order to efficiently carry out the transesterification reaction, it is preferred to remove the alcohol produced during the transesterification reaction by distillation or the like. In this case, in order to efficiently remove the alcohol component produced by the transesterification reaction, it is more preferred that the alcohol component added has a higher boiling point than the alcohol component produced.

[0153] The transesterification reaction can be generally performed at 0° C. to 150° C., preferably 30° C. to 120° C., and more preferably 50° C. to 100° C. By setting the temperature of the transesterification reaction to be above the lower limit, the reaction rate can be further increased, and by setting it to be below the upper limit, the side reaction can be further suppressed.

[0154] The amount of the alcohol component in the blocked polyisocyanate composition is preferably 0.05 to 41 parts by mass, more preferably 0.1 to 30 parts by mass, and further preferably 0.5 to 10 parts by mass relative to 100 parts by mass of the solid content of the blocked polyisocyanate composition. By making the amount of the alcohol component greater than the above lower limit, the storage stability of the coating becomes good, and by being less than the above upper limit, the thickening during the mixing of the water-based coating can be suppressed.

[0155] 《Blocked polyisocyanate composition according to the second embodiment》

[0156] The blocked polyisocyanate composition according to the second embodiment of the present invention contains a blocked polyisocyanate derived from an active hydrogen compound, a polyisocyanate, and a blocking agent containing a malonate.

[0157] Regarding the same configuration as that of the first embodiment described above, description thereof may be omitted.

[0158] The polyisocyanate preferably has an isocyanurate group and is derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

[0159] The average number of isocyanate groups of the polyisocyanate is 3.5 or more, preferably 4.0 or more, more preferably 4.5 or more, and further preferably 4.7 or more. By making the average number of isocyanate groups of the polyisocyanate be above the above lower limit, the curing property, hardness and strength at a low temperature of about 80° C. when the coating film is formed are excellent. On the other hand, the upper limit of the average number of isocyanate groups of the polyisocyanate is not limited, for example, it can be set to 20, can be set to 10, and can be set to 8.

[0160] The average number of isocyanate groups of the polyisocyanate can be determined, for example, by using the following formula from the number average molecular weight Mn and the isocyanate group content (NCO content) of the polyisocyanate.

[0161] Average number of isocyanate groups = (Mn of polyisocyanate × NCO content × 0.01) / 42

[0162] The number average molecular weight Mn of the polyisocyanate is, for example, a number average molecular weight based on polystyrene measured by GPC. Specifically, it can be measured using the method described in Examples described below.

[0163] The isocyanate group content (NCO content) can be measured by, for example, the method shown below.

[0164] Accurately weigh more than 2g and less than 3g (Wg) of polyisocyanate in a flask. Then, add 20mL of toluene to dissolve the polyisocyanate. Then, add 20mL of a toluene solution of 2 equivalents of di-n-butylamine, mix and leave at room temperature for 15 minutes. Then, add 70mL of isopropanol to mix. Then, titrate the liquid with 1 equivalent hydrochloric acid solution (factor F) in an indicator. Set the titration value obtained to V2mL. Then, set the titration value obtained in the absence of polyisocyanate to V1ml. Then, calculate the isocyanate group (NCO) content (mass %) of the polyisocyanate according to the following formula.

[0165] Isocyanate group (NCO) content (mass %) = (V1-V2) × F × 42 / (W × 1000) × 100

[0166] Alternatively, the polyisocyanate is preferably derived from the above-mentioned diisocyanate and a polyol B having an average functional group number of 2.9 or more and 8.0 or less. Thus, the average number of isocyanate groups of the obtained polyisocyanate can be further increased. In the polyisocyanate, a carbamate group is formed by the reaction of the hydroxyl group of the polyol B with the isocyanate group of the diisocyanate.

[0167] The average number of functional groups of polyol B is preferably 2.9 or more and 8.0 or less, more preferably 3 or more and 8 or less, more preferably 3 or more and 6 or less, further preferably 3 or more and 5 or less, and particularly preferably 3 or 4. The average number of functional groups of polyol B can be calculated, for example, using the following formula. It should be noted that, in the formula, "Mn" represents the number average molecular weight of polyol B, "hydroxyl content" represents the content (mass %) of hydroxyl groups relative to 100 mass % of the solid content of polyol B, and "17" represents the molecular weight (g / mol) of hydroxyl groups.

[0168] (Average number of functional groups of polyol B) = {(Mn of polyol B) × (hydroxyl content) × 0.01} / 17

[0169] The number average molecular weight Mn of the polyol B is preferably 100 to 1000, preferably 100 to 900, more preferably 100 to 800, further preferably 100 to 700, further preferably 100 to 500, further preferably 100 to 400, particularly preferably 100 to 350.

[0170] By setting the number average molecular weight Mn of the polyol within the above range, the blocked polyisocyanate composition has better low temperature curability when formed into a coating film, and has better hardness and strength. The number average molecular weight Mn of the polyol B is, for example, a polystyrene-based number average molecular weight measured by GPC.

[0171] The content of the structural unit derived from the active hydrogen compound is preferably 0.05 parts by mass or more and 10 parts by mass or less, more preferably 0.1 parts by mass or more and 9 parts by mass or less, further preferably 0.25 parts by mass or more and 8 parts by mass or less, further preferably 0.3 parts by mass or more and 7 parts by mass or less, relative to 100 parts by mass of the structural unit derived from the polyisocyanate. When the content of the structural unit derived from the active hydrogen compound is equal to or more than the lower limit value relative to 100 parts by mass of the structural unit derived from the polyisocyanate, a tendency is observed to show excellent curability, hardness and strength at a low temperature of about 80°C when the coating film is prepared. On the other hand, when the content of the structural unit derived from the active hydrogen compound is equal to or less than the upper limit value relative to 100 parts by mass of the structural unit derived from the polyisocyanate, gelation during synthesis of the blocked polyisocyanate composition can be suppressed, and storage stability when prepared as a resin composition can be improved.

[0172] The content of the structural unit derived from the active hydrogen compound relative to 100 parts by mass of the structural unit derived from the polyisocyanate can be calculated, for example, based on the blending ratio of the raw materials. Alternatively, the content of the structural unit derived from the active hydrogen compound relative to 100 parts by mass of the structural unit derived from the polyisocyanate can also be obtained, for example, by nuclear magnetic resonance (NMR), infrared absorption spectroscopy (IR), gas chromatography (GC), mass spectrometry (MS), etc.

[0173] The blocked polyisocyanate composition of the present embodiment can achieve both good storage stability when formed into a resin composition and excellent curability at a low temperature of about 80° C. when formed into a coating film by using a malonate as a blocking agent. Furthermore, part of the isocyanate groups of the blocked polyisocyanate are modified with an active hydrogen compound, thereby making it possible to further improve the storage stability when formed into a resin composition and the curability at a low temperature of about 80° C. when formed into a coating film, and to achieve excellent hardness and strength when formed into a coating film.

[0174] Hereinafter, each constituent component contained in the blocked polyisocyanate composition of the present embodiment will be described in more detail.

[0175] <Blocked Polyisocyanate>

[0176] The blocked polyisocyanate is a reaction product of an active hydrogen compound, a polyisocyanate and a blocking agent. That is, in the blocked polyisocyanate, at least a portion of the isocyanate groups in the polyisocyanate are modified with the active hydrogen compound, and at least a portion of the isocyanate groups in the polyisocyanate are blocked with the blocking agent.

[0177] [Structural unit (I)]

[0178] The blocked polyisocyanate preferably contains a structural unit represented by the following general formula (I) (hereinafter, sometimes referred to as structural unit (I)).

[0179]

[0180] In the above general formula (I), R 11 , R 12 and R 13 are each independently an alkyl group which may contain one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and R 11 , R 12 and R 13 The total number of carbon atoms is 3 or more and 20 or less, R 14 , R 15 and R 16 Each is independently a hydrogen atom or an alkyl group which may have one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and the wavy line indicates a bonding site to a residue after removing an isocyanate group from a polyisocyanate.

[0181] As R 11 , R 12 , R 13 , R 14 , R 15 and R 16 The alkyl group in the group preferably has 1 to 20 carbon atoms, more preferably 1 to 8 carbon atoms, further preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms.

[0182] Specific examples of the unsubstituted alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a n-butyl group, a tert-butyl group, a sec-butyl group, an isobutyl group, a n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a 1-methylbutyl group, a n-hexyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 2,2-dimethylbutyl group, a 2,3-dimethylbutyl group, an n-heptyl group, a 2-methylhexyl group, a 3-methylhexyl group, a 2,2-dimethylpentyl group, a 2,3-dimethylpentyl group, a 2,4-dimethylpentyl group, a 3,3-dimethylpentyl group, a 3-ethylpentyl group, a 2,2,3-trimethylbutyl group, an n-octyl group, an isooctyl group, a 2-ethylhexyl group, a nonyl group, and a decyl group.

[0183] In addition, R 11 , R 12 , R 13 , R 14 , R 15 and R 16 In the case of an alkyl group having a substituent, the substituent is a hydroxyl group or an amino group.

[0184] Examples of the alkyl group containing a hydroxyl group as a substituent include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.

[0185] Examples of the alkyl group containing an amino group as a substituent include an aminomethyl group, an aminoethyl group, an aminopropyl group, and an aminobutyl group.

[0186] Examples of the alkyl group having a hydroxyl group and an amino group as substituents include a hydroxyaminomethyl group, a hydroxyaminoethyl group, and a hydroxyaminopropyl group.

[0187] Among them, R 11 , R 12 and R 13 Each independently is preferably an unsubstituted alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group.

[0188] R 11 , R 12 and R 13 The total carbon number of is 3 or more and 20 or less, preferably 4 or more and 20 or less, more preferably 4 or more and 12 or less, further preferably 4 or more and 9 or less, further preferably 4 or more and 6 or less.

[0189] By making R 11 , R 12 and R 13 When the total carbon number of is greater than or equal to the above lower limit, storage stability can be exhibited when the aqueous resin composition is prepared. On the other hand, when it is less than or equal to the above upper limit, low temperature curing property can be exhibited.

[0190] In addition, R 14 , R 15 and R 16 Each independently represents a hydrogen atom or an alkyl group which may have one or more substituents selected from the group consisting of a hydroxyl group and an amino group (preferably an unsubstituted alkyl group having 1 to 4 carbon atoms).

[0191] Among them, R is preferred 14 , R 15 and R 16 At least one of them is a hydrogen atom, and more preferably only one of them is a hydrogen atom. 14 , R 15 and R 16 At least one of them is a hydrogen atom, thereby maintaining low temperature curing properties and further improving the storage stability when the water-based resin composition is prepared. That is, as the structural unit (I), it is more preferable to include a structural unit represented by the following general formula (I-1) (hereinafter, sometimes referred to as structural unit (I-1)).

[0192]

[0193] In the above general formula (I-1), R 11 , R 12 , R 13 , R 14 and R 15 As described in the above general formula (I). The wavy line indicates the bonding site with the residue after the isocyanate group of the polyisocyanate is removed.

[0194] The molar ratio of the structural unit (I-1) in the structural unit (I) (structural unit (I-1) / structural unit (I)) is more preferably 10 mol% or more, further preferably 30 mol% or more, further preferably 50 mol% or more, and most preferably 80 mol% or more.

[0195] [Polyisocyanate]

[0196] The polyisocyanate used in the production of the blocked polyisocyanate is a reaction product obtained by reacting a plurality of monomer compounds having one or more isocyanate groups (—NCO) (hereinafter, sometimes referred to as “isocyanate monomers”).

[0197] As the isocyanate monomer, an isocyanate monomer having a carbon number of 4 or more and 30 or less is preferred. As the isocyanate monomer, specifically, for example, the following substances can be exemplified. These isocyanate monomers may be used alone or in combination of two or more.

[0198] (1) Aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate (MDI), 1,5-naphthalene diisocyanate, toluene diisocyanate (TDI), xylylene diisocyanate, and tetramethyl-m-xylylene diisocyanate (TMXDI).

[0199] (2) Aliphatic diisocyanates such as 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (hereinafter sometimes referred to as “HDI”), 2,2,4-trimethyl-1,6-diisocyanatohexane, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, 2-methylpentane-1,5-diisocyanate (MPDI), and lysine diisocyanate (hereinafter sometimes referred to as “LDI”).

[0200] (3) Alicyclic diisocyanates such as isophorone diisocyanate (hereinafter sometimes referred to as “IPDI”), 1,3-bis(diisocyanatomethyl)cyclohexane, 4,4′-dicyclohexylmethane diisocyanate, diisocyanate norbornane, and di(isocyanatomethyl)norbornane.

[0201] (4) Triisocyanates such as 4-isocyanatomethyl-1,8-octamethylene diisocyanate (hereinafter, sometimes referred to as “NTI”), 1,3,6-hexamethylene triisocyanate (hereinafter, sometimes referred to as “HTI”), bis(2-isocyanatoethyl) 2-isocyanatoglutarate (hereinafter, sometimes referred to as “GTI”), and lysine triisocyanate (hereinafter, sometimes referred to as “LTI”).

[0202] As the isocyanate monomer used in the manufacture of polyisocyanates, from the aspect of excellent weather resistance, it is preferred to select one or more diisocyanates from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates. In addition, diisocyanate monomers other than the above-mentioned aliphatic diisocyanates and alicyclic diisocyanates can also be used. In addition, as isocyanate monomers, from the ease of industrial acquisition, HDI or IPDI is more preferably used. In addition, as isocyanate monomers, from the viewpoint of making the blocked polyisocyanate component low-viscosity, HDI is further preferably used.

[0203] In addition, as the isocyanate monomer used in the manufacture of the polyisocyanate, any one of the aliphatic diisocyanate and the alicyclic diisocyanate may be used alone, or they may be used in combination, preferably aliphatic diisocyanate and alicyclic diisocyanate are used in combination, and HDI and IPDI are particularly preferred. By using aliphatic diisocyanate and alicyclic diisocyanate, the toughness and hardness of the coating film can be further improved.

[0204] In the polyisocyanate, the mass ratio of the structural unit derived from the aliphatic diisocyanate to the structural unit derived from the alicyclic diisocyanate is preferably 50 / 50 to 95 / 5, more preferably 60 / 40 to 92 / 8, further preferably 65 / 35 to 90 / 10.

[0205] By making the mass ratio of the structural unit derived from aliphatic diisocyanate to the structural unit derived from alicyclic diisocyanate above the above lower limit, the reduction in flexibility when formed into a coating film can be more effectively suppressed. On the other hand, by being below the above upper limit, the hardness when formed into a coating film can be further increased.

[0206] The mass ratio of the structural unit derived from the aliphatic diisocyanate to the structural unit derived from the alicyclic diisocyanate can be calculated using, for example, the method described in the first embodiment.

[0207] The polyisocyanate preferably has an isocyanurate group, and may have one or more functional groups selected from the group consisting of an allophanate group, a uretdione group, an iminooxadiazinedione group, an isocyanurate group, a carbamate group, and a biuret group in addition to the isocyanurate group.

[0208] (Polyol B)

[0209] Examples of the polyol B include trimethylolpropane, glycerol, a trivalent or higher polyol, and polycaprolactone polyol derived from ε-caprolactone.

[0210] Examples of commercially available polycaprolactone polyols include “PLACCEL 303” (number average molecular weight 300), “PLACCEL 305” (number average molecular weight 550), “PLACCEL 308” (number average molecular weight 850), and “PLACCEL 309” (number average molecular weight 900) from Daicel Corporation.

[0211] (Method for producing polyisocyanate)

[0212] The details of the method for producing the polyisocyanate will be described below.

[0213] For example, polyisocyanates can be prepared by allophanate reaction to form allophanate groups, uretdione reaction to form uretdione groups, iminooxadiazinedione reaction to form iminooxadiazinedione groups, isocyanurate reaction to form isocyanurate groups, carbamate reaction to form carbamate groups, and biuret reaction to form biuret groups in the presence of excess isocyanate monomers, and then removing unreacted isocyanate monomers after the reaction is completed. That is, the polyisocyanates obtained by the above reaction are those formed by bonding a plurality of the above isocyanate monomers, and are reaction products having one or more selected from the group consisting of allophanate groups, uretdione groups, iminooxadiazinedione groups, isocyanurate groups, carbamate groups, and biuret groups.

[0214] Alternatively, the above reactions may be performed separately and the polyisocyanates obtained from the separate reactions may be mixed at a specific ratio.

[0215] From the viewpoint of simplicity of production, it is preferred to conduct the above-mentioned reactions at once to obtain a polyisocyanate, and from the viewpoint of freely adjusting the molar ratio of each functional group, it is preferred to produce them separately and then mix them.

[0216] (1) Method for producing allophanate-containing polyisocyanate

[0217] The allophanate group-containing polyisocyanate is obtained by adding an alcohol to an isocyanate monomer and using an allophanate-forming reaction catalyst.

[0218] The alcohol used for forming the allophanate group is preferably an alcohol consisting only of carbon, hydrogen and oxygen.

[0219] Specific examples of the alcohol include, but are not limited to, monohydric alcohols and diols. These alcohols may be used alone or in combination of two or more.

[0220] Examples of the monohydric alcohol include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, and nonanol.

[0221] Examples of the diol include ethylene glycol, 1,3-butanediol, neopentyl glycol, and 2-ethylhexanediol.

[0222] Among them, as the alcohol, monohydric alcohol is preferred, and monohydric alcohol having a molecular weight of 200 or less is more preferred.

[0223] Examples of the allophanation reaction catalyst include, but are not limited to, alkyl carboxylates of tin, lead, zinc, bismuth, zirconium, zirconyl, and the like.

[0224] Examples of tin alkyl carboxylates (organotin compounds) include tin 2-ethylhexanoate and dibutyltin dilaurate.

[0225] Examples of the lead alkyl carboxylate (organolead compound) include lead 2-ethylhexanoate.

[0226] Examples of zinc alkyl carboxylates (organic zinc compounds) include zinc 2-ethylhexanoate and the like.

[0227] Examples of the bismuth alkyl carboxylate include bismuth 2-ethylhexanoate and the like.

[0228] Examples of zirconium alkyl carboxylates include zirconium 2-ethylhexanoate and the like.

[0229] Examples of zirconyl alkyl carboxylates include zirconyl 2-ethylhexanoate, etc. These catalysts may be used alone or in combination of two or more.

[0230] In addition, the isocyanurate reaction catalyst described below can also be used as the allophanate reaction catalyst. When the allophanate reaction is carried out using the isocyanurate reaction catalyst described below, of course, a polyisocyanate containing an isocyanurate group (hereinafter sometimes referred to as "isocyanurate-type polyisocyanate") is also produced.

[0231] Among them, it is preferred in terms of economical production to carry out the allophanation reaction and the isocyanuration reaction using an isocyanuration reaction catalyst described later as an allophanation reaction catalyst.

[0232] The lower limit of the amount of the allophanation reaction catalyst used is preferably 10 mass ppm, more preferably 20 mass ppm, further preferably 40 mass ppm, and particularly preferably 80 mass ppm, based on the mass of the charged isocyanate monomer.

[0233] The upper limit of the amount of the allophanation reaction catalyst used is preferably 1000 mass ppm, more preferably 800 mass ppm, further preferably 600 mass ppm, particularly preferably 500 mass ppm, based on the mass of the charged isocyanate monomer.

[0234] That is, the amount of the allophanate reaction catalyst used relative to the mass of the isocyanate monomer added is preferably 10 mass ppm or more and 1000 mass ppm or less, more preferably 20 mass ppm or more and 800 mass ppm or less, further preferably 40 mass ppm or more and 600 mass ppm or less, and particularly preferably 80 mass ppm or more and 500 mass ppm or less.

[0235] Moreover, as a lower limit of the allophanation reaction temperature, 40 degreeC is preferable, 60 degreeC is more preferable, 80 degreeC is further preferable, and 100 degreeC is especially preferable.

[0236] Moreover, as an upper limit of the allophanation reaction temperature, 180 degreeC is preferable, 160 degreeC is more preferable, and 140 degreeC is still more preferable.

[0237] That is, the allophanation reaction temperature is preferably 40°C to 180°C, more preferably 60°C to 160°C, further preferably 80°C to 140°C, particularly preferably 100°C to 140°C.

[0238] By making the allophanation reaction temperature not less than the above lower limit, the reaction rate can be further increased. By making the allophanation reaction temperature not more than the above upper limit, there is a tendency that the coloring of the polyisocyanate can be more effectively suppressed.

[0239] (2) Method for producing uretdione group-containing polyisocyanate

[0240] When a polyisocyanate having a uretdione group is derived from an isocyanate monomer, it can be produced by, for example, polymerizing the isocyanate monomer using a uretdione reaction catalyst or by heat.

[0241] The uretdione reaction catalyst is not particularly limited, and examples thereof include tertiary phosphines such as trialkylphosphines, tri(dialkylamino)phosphines, and cycloalkylphosphines, and Lewis acids.

[0242] Examples of the trialkylphosphine include tri-n-butylphosphine and tri-n-octylphosphine.

[0243] Examples of the tri(dialkylamino)phosphine include tri(dimethylamino)phosphine and the like.

[0244] Examples of the cycloalkylphosphine include cyclohexyldi-n-hexylphosphine and the like.

[0245] Examples of the Lewis acid include boron trifluoride and zinc chloride.

[0246] Most uretdione reaction catalysts can also promote isocyanurate reaction.

[0247] When a uretdione reaction catalyst is used, it is preferred to add a deactivator for the uretdione reaction catalyst such as phosphoric acid or methyl p-toluenesulfonate to stop the uretdione reaction when a desired yield is achieved.

[0248] In addition, when a polyisocyanate having a uretdione group is obtained by heating one or more diisocyanates selected from the group consisting of the above-mentioned aliphatic diisocyanates and the above-mentioned alicyclic diisocyanates without using a uretdione reaction catalyst, the heating temperature is preferably 120° C. or more, more preferably 150° C. or more and 170° C. or less. In addition, the heating time is preferably 1 hour or more and 4 hours or less.

[0249] (3) Method for producing polyisocyanate containing iminooxadiazinedione group

[0250] When deriving the iminooxadiazinedione group-containing polyisocyanate from an isocyanate monomer, an iminooxadiazinedione reaction catalyst is generally used.

[0251] Examples of the iminooxadiazinedionization catalyst include those shown in the following 1) or 2).

[0252] 1) (Poly)hydrogen fluoride represented by the general formula M[Fn] or the general formula M[Fn(HF)m] (wherein m and n are integers satisfying the relationship m / n>0. M is an n-charged cation (mixture) or one or more free radicals having a total valence of n.)

[0253] 2) From the general formula R 1 -CR' 2 -C(O)O- or general formula R 2 = A compound represented by CR'-C(O)O- and a quaternary ammonium cation or a quaternary phosphonium cation (wherein R 1 and R 2 Each is independently a linear, branched or cyclic, saturated or unsaturated perfluoroalkyl group having 1 to 30 carbon atoms. Each of the multiple R's is independently a hydrogen atom, or an alkyl or aryl group having 1 to 20 carbon atoms, which may contain a heteroatom.

[0254] Specific examples of the compound 1) ((poly)hydrogen fluoride) include tetramethylammonium fluoride hydrate and tetraethylammonium fluoride.

[0255] Specific examples of the compound 2) include 3,3,3-trifluorocarboxylic acid, 4,4,4,3,3-pentafluorobutanoic acid, 5,5,5,4,4,3,3-heptafluoropentanoic acid, and 3,3-difluoroprop-2-enoic acid.

[0256] Among them, as the iminooxadiazinedionization reaction catalyst, 1) is preferred from the viewpoint of easy availability, and 2) is preferred from the viewpoint of safety.

[0257] The lower limit of the amount of the iminooxadiazinedionization catalyst used is not particularly limited, but is preferably 5 ppm, more preferably 10 ppm, and even more preferably 20 ppm in terms of mass ratio relative to the isocyanate monomer such as HDI as a raw material from the viewpoint of reactivity.

[0258] The upper limit of the amount of the iminooxadiazinedionization catalyst used is preferably 5000 ppm, more preferably 2000 ppm, and even more preferably 500 ppm by mass ratio relative to the isocyanate monomer such as HDI as a raw material, from the viewpoint of suppressing coloration and discoloration of the product and controlling the reaction.

[0259] That is, the amount of the iminooxadiazinedionization catalyst used is preferably 5 ppm to 5000 ppm, more preferably 10 ppm to 2000 ppm, and further preferably 20 ppm to 500 ppm, based on the mass ratio of the isocyanate monomer such as HDI as the raw material.

[0260] The lower limit of the reaction temperature for iminooxadiazinedionization is not particularly limited, but is preferably 40°C, more preferably 50°C, and even more preferably 60°C from the viewpoint of reaction rate.

[0261] The upper limit of the reaction temperature for iminooxadiazinedionization is preferably 150° C., more preferably 120° C., and even more preferably 110° C. from the viewpoint of suppressing coloration and discoloration of the product.

[0262] That is, the reaction temperature of the iminooxadiazinedionization is preferably 40°C to 150°C, more preferably 50°C to 120°C, and further preferably 60°C to 110°C.

[0263] For the imino-oxadiazinedionization reaction, the imino-oxadiazinedionization reaction can be stopped at the time when the desired imino-oxadiazinedione content is reached. The imino-oxadiazinedionization reaction can be stopped, for example, by adding an acidic compound to the reaction solution. As the acidic compound, for example, phosphoric acid, acidic phosphates, sulfuric acid, hydrochloric acid, sulfonic acid compounds, etc. can be cited. Thus, the imino-oxadiazinedionization catalyst is neutralized or deactivated by thermal decomposition or chemical decomposition. After the reaction is stopped, filtration is performed as needed.

[0264] (4) Method for producing isocyanurate group-containing polyisocyanate

[0265] Examples of the catalyst for deriving the isocyanurate group-containing polyisocyanate from the isocyanate monomer include commonly used isocyanurate formation reaction catalysts.

[0266] The isocyanurate reaction catalyst is not particularly limited, but is generally preferably a basic isocyanurate reaction catalyst. Specific examples of the isocyanurate reaction catalyst include the following.

[0267] 1) Hydroxides of tetraalkylammonium such as tetramethylammonium, tetraethylammonium, tetrabutylammonium, and organic weak acid salts such as acetates, propionates, octanoates, decanoates, myristates, and benzoates of the above tetraalkylammonium.

[0268] 2) Hydroxides of aryltrialkylammonium such as benzyltrimethylammonium and trimethylphenylammonium, and organic weak acid salts such as acetates, propionates, octanoates, decanoates, myristates, and benzoates of the above aryltrialkylammonium.

[0269] 3) Hydroxides of hydroxyalkylammonium such as trimethylhydroxyethylammonium, trimethylhydroxypropylammonium, triethylhydroxyethylammonium, triethylhydroxypropylammonium, and organic weak acid salts such as acetates, propionates, caprylates, caprates, myristates, and benzoates of the above hydroxyalkylammonium.

[0270] 4) Metal salts of tin, zinc, lead or the like of alkyl carboxylic acids such as acetic acid, propionic acid, caproic acid, caprylic acid, capric acid, myristic acid or the like.

[0271] 5) Metal alkoxides such as sodium and potassium.

[0272] 6) Aminosilyl-containing compounds such as hexamethylenedisilazane.

[0273] 7) Mannich bases.

[0274] 8) A mixture of tertiary amines and epoxy compounds.

[0275] 9) Phosphorus compounds such as tributylphosphine.

[0276] Among them, from the viewpoint of being less likely to generate unwanted by-products, the isocyanurate reaction catalyst is preferably a quaternary ammonium hydroxide or a quaternary ammonium weak organic acid salt, and more preferably a tetraalkylammonium hydroxide, a tetraalkylammonium weak organic acid salt, an aryltrialkylammonium hydroxide, or an aryltrialkylammonium weak organic acid salt.

[0277] The upper limit of the amount of the isocyanuration reaction catalyst used is preferably 1000 mass ppm, more preferably 500 mass ppm, and even more preferably 100 mass ppm, based on the mass of the charged isocyanate monomer.

[0278] On the other hand, the lower limit of the amount of the isocyanuration reaction catalyst used is not particularly limited, and may be, for example, 10 mass ppm.

[0279] The isocyanurate reaction temperature is preferably 50° C. to 120° C., more preferably 60° C. to 90° C. When the isocyanurate reaction temperature is below the upper limit, coloration of the polyisocyanate tends to be more effectively suppressed.

[0280] When the desired conversion rate (ratio of the mass of the polyisocyanate produced by the isocyanuration reaction to the mass of the isocyanate monomer fed) is reached, the isocyanuration reaction is stopped by adding an acidic compound (e.g., phosphoric acid, acidic phosphate, etc.).

[0281] It should be noted that in order to obtain polyisocyanates, it is necessary to stop the reaction at the initial stage. However, since the reaction rate of the isocyanurate reaction is very fast at the initial stage, it is difficult to stop the reaction at the initial stage, and the reaction conditions, especially the amount and method of adding the catalyst, need to be carefully selected. For example, a method of adding the catalyst in batches at regular intervals can be recommended as a suitable addition method.

[0282] Therefore, the conversion rate of the isocyanuration reaction for obtaining the polyisocyanate is preferably 10% to 60%, more preferably 15% to 55%, and even more preferably 20% to 50%.

[0283] By making the conversion rate of the isocyanurate reaction below the upper limit, the blocked polyisocyanate component can have a lower viscosity. In addition, by making the conversion rate of the isocyanurate reaction above the lower limit, the reaction termination operation can be performed more easily.

[0284] When deriving an isocyanurate group-containing polyisocyanate, an alcohol having a valence of more than one valence and less than or equal to six valence may be used in addition to the above-mentioned isocyanate monomer.

[0285] As the alcohol having a valence of more than 1 and less than 6 that can be used, for example, non-polymerizable alcohol and polymerizable alcohol can be mentioned. The "non-polymerizable alcohol" mentioned here refers to an alcohol having no polymerizable group. On the other hand, the "polymerizable alcohol" refers to an alcohol obtained by polymerizing a monomer having a polymerizable group and a hydroxyl group.

[0286] Examples of the non-polymerizable alcohol include polyols such as monools, diols, triols, and tetraols.

[0287] Examples of the monohydric alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, n-pentanol, n-hexanol, n-octanol, n-nonanol, 2-ethylbutanol, 2,2-dimethylhexanol, 2-ethylhexanol, cyclohexanol, methylcyclohexanol, and ethylcyclohexanol.

[0288] Examples of the glycols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,3-butylene glycol, 2-methyl-1,2-propylene glycol, 1,5-pentanediol, 2-methyl-2,3-butylene glycol, 1,6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butylene glycol, 2-ethylhexanediol, 1,2-octanediol, 1,2-decanediol, 2,2,4-trimethylpentanediol, 2-butyl-2-ethyl-1,3-propylene glycol, and 2,2-diethyl-1,3-propylene glycol.

[0289] Examples of the triols include glycerol and trimethylolpropane.

[0290] Examples of the tetraols include pentaerythritol and the like.

[0291] The polymerizable alcohol is not particularly limited, and examples thereof include polyester polyols, polyether polyols, acrylic polyols, polyolefin polyols, and the like.

[0292] The polyester polyols are not particularly limited, and examples thereof include products obtained by condensation reaction of a dibasic acid alone or in mixture with a polyol alone or in mixture.

[0293] The dibasic acid is not particularly limited, and examples thereof include at least one dibasic acid selected from the group consisting of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, and terephthalic acid.

[0294] The polyol is not particularly limited, and examples thereof include at least one polyol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, and glycerol.

[0295] Examples of the polyester polyols include polycaprolactones obtained by ring-opening polymerization of ε-caprolactone using the above-mentioned polyols.

[0296] The polyether polyols are not particularly limited, and examples thereof include polyether polyols obtained by adding alkylene oxides alone or in mixture to polyols alone or in mixture using alkali metal hydroxides or strong alkaline catalysts, polyether polyols obtained by reacting alkylene oxides with polyamine compounds, and so-called polymer polyols obtained by polymerizing acrylamide or the like using the above-mentioned polyethers as a medium.

[0297] Examples of the alkali metal include lithium, sodium, and potassium.

[0298] Examples of the strong basic catalyst include alkoxides and alkylamines.

[0299] Examples of the polyol include the same ones as those exemplified in the above-mentioned polyester polyols.

[0300] Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.

[0301] Examples of the polyamine compound include ethylenediamines and the like.

[0302] The acrylic polyols are not particularly limited, and examples thereof include those obtained by copolymerizing a monomer containing an ethylenically unsaturated bond having a hydroxyl group, either alone or in mixture, and another monomer containing an ethylenically unsaturated bond copolymerizable therewith, either alone or in mixture.

[0303] The ethylenically unsaturated bond-containing monomer having a hydroxyl group is not particularly limited, and examples thereof include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxybutyl methacrylate.

[0304] The other ethylenically unsaturated bond-containing monomer copolymerizable with the ethylenically unsaturated bond-containing monomer having a hydroxyl group is not particularly limited, and examples thereof include acrylic acid esters, methacrylic acid esters, unsaturated carboxylic acids, unsaturated amides, vinyl monomers, and vinyl monomers having a hydrolyzable silyl group.

[0305] Examples of the acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, benzyl acrylate, and phenyl acrylate.

[0306] Examples of the methacrylate include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, benzyl methacrylate, and phenyl methacrylate.

[0307] Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, and itaconic acid.

[0308] Examples of the unsaturated amide include acrylamide, methacrylamide, N,N-methylenebisacrylamide, diacetone acrylamide, diacetone methacrylamide, maleic acid amide, and maleimide.

[0309] Examples of the vinyl monomer include glycidyl methacrylate, styrene, vinyltoluene, vinyl acetate, acrylonitrile, and dibutyl fumarate.

[0310] Examples of the vinyl monomer having a hydrolyzable silyl group include vinyltrimethoxysilane, vinylmethyldimethoxysilane, and γ-(meth)acryloxypropyltrimethoxysilane.

[0311] Examples of the polyolefin polyols include terminal hydroxylated polybutadiene and hydrogenated products thereof.

[0312] (5) Method for producing polyisocyanate containing carbamate group

[0313] When the urethane group-containing polyisocyanate is derived from an isocyanate monomer, it can be produced by, for example, mixing an excess amount of the isocyanate monomer, the polyol B, and an alcohol other than the polyol B as needed, and adding a urethanization reaction catalyst as needed.

[0314] Examples of the alcohol include those exemplified as the "alcohol having a valence of not less than one valence and not more than six valence" except for the polyol B described above.

[0315] The urethanization reaction catalyst is not particularly limited, and examples thereof include tin compounds, zinc compounds, and amine compounds.

[0316] The urethanization reaction temperature is preferably 50°C or higher and 160°C or lower, and more preferably 60°C or higher and 120°C or lower.

[0317] When the urethanization reaction temperature is not more than the above upper limit, coloration of the polyisocyanate tends to be more effectively suppressed.

[0318] The urethanization reaction time is preferably 30 minutes to 4 hours, more preferably 1 hour to 3 hours, and even more preferably 1 hour to 2 hours.

[0319] The ratio of the molar amount of the isocyanate group of the isocyanate monomer to the molar amount of the hydroxyl group of the polyol B (and the alcohol other than the polyol B used as required) is preferably 2 / 1 or more and 50 / 1 or less. By making the molar ratio above the above lower limit, the polyisocyanate can be made to have a lower viscosity. By making the molar ratio below the above upper limit, the yield of the polyisocyanate containing carbamate group can be further improved.

[0320] (6) Method for producing biuret group-containing polyisocyanate

[0321] The biuret-forming agent for deriving the biuret group-containing polyisocyanate from the isocyanate monomer is not particularly limited, and examples thereof include water, monovalent tertiary alcohols, formic acid, organic primary monoamines, and organic primary diamines.

[0322] The isocyanate group is preferably set to 6 mol or more, more preferably 10 mol or more, and further preferably 10 mol or more and 80 mol or less relative to 1 mol of the biuretizing agent. When the molar amount of the isocyanate group is above the above lower limit relative to 1 mol of the biuretizing agent, the viscosity of the polyisocyanate becomes sufficiently low, and when it is below the above upper limit, the low temperature curing property when made into a resin film is further improved.

[0323] In addition, a solvent may be used during the biuret reaction. The solvent may be any solvent as long as it can dissolve the isocyanate monomer and the biuret-forming agent such as water and form a uniform phase under the reaction conditions.

[0324] Specific examples of the solvent include ethylene glycol-based solvents and phosphoric acid-based solvents.

[0325] Examples of the ethylene glycol solvent include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, ethylene glycol mono-isopropyl ether acetate, ethylene glycol mono-n-butyl ether acetate, ethylene glycol diacetate, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol di-n-propyl ether, ethylene glycol diisopropyl ether, ethylene glycol di-n-butyl ether, ethylene glycol methyl ethyl ether, ethylene glycol methyl isopropyl ether, ethylene glycol methyl n-butyl ether, ethylene glycol ethyl n-propyl ether, ethylene glycol ethyl isopropyl ether, ethylene glycol ethyl n-butyl ether, ethylene glycol n-propyl n-butyl ether, ethylene glycol isopropyl n-butyl ether, diethylene glycol monomethyl ether ethyl Acid ester, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-propyl ether acetate, diethylene glycol monoisopropyl ether acetate, diethylene glycol mono-n-butyl ether acetate, diethylene glycol diacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol diisopropyl ether, diethylene glycol di-n-butyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl isopropyl ether, diethylene glycol methyl n-propyl ether, diethylene glycol methyl n-butyl ether, diethylene glycol ethyl isopropyl ether, diethylene glycol ethyl n-propyl ether, diethylene glycol ethyl n-butyl ether, diethylene glycol n-propyl n-butyl ether, diethylene glycol isopropyl n-butyl ether, and the like.

[0326] Examples of the phosphoric acid-based solvent include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, and tributyl phosphate.

[0327] These solvents can be used alone or in combination of two or more.

[0328] Among them, as the ethylene glycol-based solvent, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol diacetate or diethylene glycol dimethyl ether is preferred.

[0329] In addition, as the phosphoric acid-based solvent, trimethyl phosphate or triethyl phosphate is preferred.

[0330] The biuret reaction temperature is preferably 70° C. to 200° C., more preferably 90° C. to 180° C. When the temperature is at most the upper limit, coloration of the polyisocyanate tends to be more effectively prevented.

[0331] The allophanation reaction, uretdione reaction, iminooxadiazinedionation reaction, isocyanuration reaction, urethanation reaction, and biuretation reaction described above may be performed successively, or several reactions may be performed simultaneously.

[0332] The polyisocyanate can be obtained by removing the unreacted isocyanate monomer from the reaction liquid after the reaction is completed by thin film distillation, extraction or the like.

[0333] Furthermore, an antioxidant or an ultraviolet absorber may be added to the obtained polyisocyanate for the purpose of suppressing coloration during storage, for example.

[0334] As antioxidants, for example, hindered phenols such as 2,6-di-tert-butyl-p-cresol can be mentioned. As ultraviolet absorbers, for example, benzotriazole, benzophenone, etc. can be mentioned. These antioxidants and ultraviolet absorbers can be used alone or in combination of two or more. Their addition amount is preferably 10 mass ppm or more and 500 mass ppm or less relative to the mass of the polyisocyanate.

[0335] [Active hydrogen compounds]

[0336] The active hydrogen compound of this embodiment is the same as the active hydrogen compound of the first embodiment.

[0337] [Polyol A]

[0338] As the active hydrogen compound in the present embodiment, polyol A is also preferred.

[0339] In the blocked polyisocyanate molecule, the hydroxyl group of polyol A and the isocyanate group of polyisocyanate form a urethane bond, and the structural unit derived from polyol A is bonded to the polyisocyanate. Alternatively, the hydroxyl group of polyol A and the ester group of blocked polyisocyanate are bonded by an ester exchange reaction.

[0340] Examples of such polyol A include 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanedimethanol, glycerol, polycaprolactone polyols derived from these and ε-caprolactone, polyether polyols, polycarbonate polyols, and acrylic polyols. Among them, one or more diols selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanedimethanol and glycerol, or polycaprolactone diols derived from these diols and ε-caprolactone are preferred; one or more diols selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol and 1,4-cyclohexanedimethanol, or polycaprolactone diols derived from these diols and ε-caprolactone are more preferred; and 1,4-butanediol or polycaprolactone diol is further preferred.

[0341] Examples of commercially available products of polycaprolactone diol include those described in the first embodiment.

[0342] The molar ratio of the hydroxyl group contained in the polyol A to the structural unit (I) (OH / structural unit (I)) is preferably 0.5 / 99.5 to 15 / 85, and more preferably 6 / 94 to 15 / 85. When the molar ratio (OH / structural unit (I)) is within the above range, the blocked polyisocyanate composition has a highly flexible structure, and a crosslinking structure is more easily formed when mixed with a main agent, so that the curing property at low temperature, hardness, strength and solvent resistance when formed into a coating film tend to be improved.

[0343] The content (molar) of the hydroxyl group contained in the polyol A is calculated from the blending amounts of the polyol A and the end-capping agent, or measured by gas chromatography / mass spectrometry (GC / MS method), and the content (molar) of the structural unit (I) is determined by 13 The measurement was performed by C-NMR.

[0344] [Capping agent]

[0345] The capping agent comprises a malonate ester.

[0346] (Malonate having tertiary alkyl group)

[0347] The terminal blocking agent preferably contains a malonic acid ester having a tertiary alkyl group. The terminal blocking agent may contain one type of malonic acid ester having a tertiary alkyl group, or may contain two or more types.

[0348] The malonic acid ester having a tertiary alkyl group is not particularly limited, and the same malonic acid ester as that in the first embodiment can be used.

[0349] (Malonate having secondary alkyl group)

[0350] The terminal blocking agent preferably contains a malonic acid ester having a secondary alkyl group. The terminal blocking agent may contain one type of malonic acid ester having a secondary alkyl group, or may contain two or more types.

[0351] The malonic acid ester having a secondary alkyl group is not particularly limited, and the same malonic acid ester as that in the first embodiment can be used.

[0352] Among them, as the end-capping agent, it is preferred to contain diisopropyl malonate as the malonic acid ester having a secondary alkyl group, and to contain di-tert-butyl malonate and (2-methyl-2-butyl)isopropyl malonate as the malonic acid ester having a tertiary alkyl group.

[0353] (Other Capping Agents)

[0354] The end-capping agent used in the manufacture of the blocked polyisocyanate may include, in addition to the malonate having a secondary alkyl group and the malonate having a tertiary alkyl group, other end-capping agents within the range that does not hinder the storage stability when the resin composition is made and the low-temperature curing property when the resin film is made. As other end-capping agents, the same substances as those in the first embodiment can be used.

[0355] The content of the malonic ester having a secondary alkyl group and the malonic ester having a tertiary alkyl group is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, particularly preferably 95 mol% or more, and most preferably 100 mol% relative to the total molar amount of all blocking agents used in the production of the blocked polyisocyanate.

[0356] By setting the content of the malonic acid ester having a secondary alkyl group and the malonic acid ester having a tertiary alkyl group to be within the above range, the low-temperature curability when formed into a resin film can be further improved.

[0357] [Hydrophilic compounds]

[0358] At least a part of the blocked polyisocyanate may have a structural unit derived from a hydrophilic compound, that is, a hydrophilic group.

[0359] The hydrophilic compound is a compound having a hydrophilic group. In addition to the hydrophilic group, the hydrophilic compound preferably has one or more active hydrogen groups for reacting with at least one isocyanate group of the polyisocyanate per molecule of the hydrophilic compound. Specifically, the active hydrogen group includes a hydroxyl group, a mercapto group, a carboxylic acid group, an amino group, and a thiol group.

[0360] As the hydrophilic compound, nonionic compounds, cationic compounds, and anionic compounds can be cited. These hydrophilic compounds can be used alone or in combination of two or more. Among them, as the hydrophilic compound, nonionic compounds are preferred from the viewpoint of easy availability and not susceptible to electrical interaction with the compound, and anionic compounds are preferred from the viewpoint of suppressing the reduction in hardness of the obtained resin film.

[0361] (Non-ionic compound)

[0362] As nonionic compounds, specifically, compounds formed by adding ethylene oxide to the hydroxyl group of monohydric alcohols and alcohols can be cited. As monohydric alcohols, for example, methanol, ethanol, butanol, etc. can be cited. As compounds formed by adding ethylene oxide to the hydroxyl group of alcohols, for example, ethylene glycol, diethylene glycol, polyethylene glycol, etc. can be cited. These nonionic compounds also have active hydrogen groups that react with isocyanate groups.

[0363] Among them, as the nonionic compound, polyethylene glycol monoalkyl ethers obtained by adding ethylene oxide to the hydroxyl group of a monohydric alcohol are preferred because the water dispersibility of the blocked polyisocyanate composition can be improved with a small amount of use.

[0364] The number of addition of ethylene oxide as the compound to which ethylene oxide is added is preferably 4 or more and 30 or less, and more preferably 4 or more and 25 or less. When the number of addition of ethylene oxide is equal to or greater than the above lower limit, there is a tendency that water dispersibility can be more effectively imparted to the blocked polyisocyanate composition, and when the number of addition of ethylene oxide is equal to or less than the above upper limit, there is a tendency that precipitates of the blocked polyisocyanate composition are less likely to be generated during low-temperature storage.

[0365] The lower limit of the amount of the nonionic hydrophilic group added to the blocked polyisocyanate (hereinafter sometimes referred to as "the content of the nonionic hydrophilic group") is preferably 0.1% by mass, more preferably 0.15% by mass, further preferably 0.20% by mass, and particularly preferably 0.25% by mass, relative to the mass of the solid content of the hydrophilic polyisocyanate composition, from the viewpoint of the water dispersion stability of the blocked polyisocyanate composition.

[0366] The upper limit of the content of the nonionic hydrophilic group is preferably 55% by mass, more preferably 50% by mass, further preferably 48% by mass, and particularly preferably 44% by mass, relative to the mass of the solid content of the blocked polyisocyanate composition, from the viewpoint of water resistance of the obtained resin film.

[0367] That is, the content of the nonionic hydrophilic group is preferably 0.1% by mass to 55% by mass, more preferably 0.15% by mass to 50% by mass, further preferably 0.20% by mass to 48% by mass, particularly preferably 0.25% by mass to 44% by mass, relative to the mass of the solid content of the blocked polyisocyanate composition.

[0368] When the content of the nonionic hydrophilic group is within the above range, the blocked polyisocyanate composition tends to be further dispersed in water, thereby obtaining a homogeneous film.

[0369] When the amount of the nonionic hydrophilic group added to the blocked polyisocyanate is expressed as a molar ratio, it is preferably 0.05 mol% to 8 mol%, more preferably 0.10 mol% to 5 mol%, further preferably 0.15 mol% to 4 mol%, particularly preferably 0.15 mol% to 3 mol%, and most preferably 0.15 mol% to 2 mol%, relative to 100 mol% of the isocyanate group of the raw material polyisocyanate.

[0370] (Cationic Compound)

[0371] As the cationic compound, specifically, a compound having both a cationic hydrophilic group and an active hydrogen group can be cited. In addition, a compound having an active hydrogen group such as a glycidyl group and a compound having a cationic hydrophilic group such as a sulfide, a phosphine, etc. can also be used as a hydrophilic compound. In this case, a compound having an isocyanate group is reacted with a compound having an active hydrogen group in advance, and functional groups such as a glycidyl group are added, and then compounds such as a sulfide, a phosphine, etc. are reacted. From the viewpoint of ease of manufacture, a compound having both a cationic hydrophilic group and an active hydrogen group is preferred.

[0372] Specific examples of the compound having both a cationic hydrophilic group and an active hydrogen group include dimethylethanolamine, diethylethanolamine, diethanolamine, methyldiethanolamine, etc. In addition, the tertiary amino group formed by addition of these compounds can also be quaternized using, for example, dimethyl sulfate or diethyl sulfate.

[0373] The reaction between the cationic compound and the alicyclic polyisocyanate may be carried out in the presence of a solvent. In this case, the solvent preferably does not contain an active hydrogen group, and specific examples thereof include ethyl acetate, propylene glycol monomethyl ether acetate, and dipropylene glycol dimethyl ether.

[0374] The cationic hydrophilic group added to the blocked polyisocyanate is preferably neutralized with a compound having an anionic group. Specific examples of the anionic group include a carboxyl group, a sulfonic acid group, a phosphoric acid group, a halogen group, and a sulfate group.

[0375] Specific examples of the compound having a carboxyl group include formic acid, acetic acid, propionic acid, butyric acid, and lactic acid.

[0376] Specific examples of the compound having a sulfonic acid group include ethanesulfonic acid and the like.

[0377] Specific examples of the compound having a phosphoric acid group include phosphoric acid and acidic phosphoric acid esters.

[0378] Specific examples of the compound having a halogen group include hydrochloric acid and the like.

[0379] Specific examples of the compound having a sulfate group include sulfuric acid and the like.

[0380] Among them, as the compound having an anionic group, a compound having a carboxyl group is preferred, and acetic acid, propionic acid, or butyric acid is more preferred.

[0381] (Anionic compound)

[0382] Specific examples of the anionic hydrophilic group include a carboxyl group, a sulfonic acid group, a phosphoric acid group, a halogen group, and a sulfate group.

[0383] Specific examples of the anionic compound include compounds having both an anionic group and an active hydrogen group, and more specific examples include compounds having a carboxyl group of a monohydroxycarboxylic acid or a polyhydroxycarboxylic acid as an anionic group.

[0384] Examples of the monohydroxycarboxylic acid include 1-hydroxyacetic acid, 3-hydroxypropanoic acid, 12-hydroxy-9-octadecanoic acid, hydroxypivalic acid, and lactic acid.

[0385] Examples of the compound having a carboxyl group of a polyhydroxycarboxylic acid as an anionic group include dimethylolacetic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolpentanoic acid, dihydroxysuccinic acid, and dimethylolpropionic acid.

[0386] In addition, compounds having both a sulfonic acid group and an active hydrogen group may also be mentioned, and more specific examples thereof include isethionic acid and the like.

[0387] Among them, as the compound having both an anionic group and an active hydrogen group, hydroxypivalic acid or dimethylolpropionic acid is preferred.

[0388] The anionic hydrophilic group added to the blocked polyisocyanate is preferably neutralized with an amine compound which is a basic substance.

[0389] Specific examples of the amine compound include ammonia and water-soluble amino compounds.

[0390] As the water-soluble amino compound, specifically, for example, monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, triethanolamine, butylamine, dibutylamine, 2-ethylhexylamine, ethylenediamine, propylenediamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, etc. can be mentioned. In addition, tertiary amines such as triethylamine and dimethylethanolamine can also be mentioned, and these can also be used. These amine compounds can be used alone or in combination of two or more.

[0391] <Other components>

[0392] The blocked polyisocyanate composition of the present embodiment may further contain additives such as a solvent in addition to the above-mentioned blocked polyisocyanate.

[0393] As the solvent, the same solvent as that in the first embodiment can be used.

[0394] <Method for producing blocked polyisocyanate composition>

[0395] The blocked polyisocyanate composition is not particularly limited, and can be obtained, for example, by reacting the above-mentioned polyisocyanate, the above-mentioned active hydrogen compound and the above-mentioned blocking agent. The blocked polyisocyanate composition can be manufactured by reacting these compounds simultaneously. The above-mentioned polyisocyanate can also be reacted with the above-mentioned active hydrogen compound to generate an active hydrogen compound-modified polyisocyanate, and then the active hydrogen compound-modified polyisocyanate is reacted with the blocking agent to manufacture the blocked polyisocyanate composition. Alternatively, the above-mentioned polyisocyanate can also be reacted with the above-mentioned blocking agent to generate a partially blocked polyisocyanate in which a part or all of the isocyanate groups of the polyisocyanate are blocked by the blocking agent, and then the partially blocked polyisocyanate is reacted with the above-mentioned active hydrogen compound to manufacture the blocked polyisocyanate composition.

[0396] The modification reaction of the polyisocyanate (or partially blocked polyisocyanate) with the active hydrogen compound can be carried out in the presence or absence of a solvent.

[0397] The amount of the active hydrogen compound added is preferably 0.05 parts by mass or more and 10 parts by mass or less, more preferably 0.1 parts by mass or more and 9 parts by mass or less, further preferably 0.25 parts by mass or more and 8 parts by mass or less, further preferably 0.3 parts by mass or more and 7 parts by mass or less, relative to 100 parts by mass of the polyisocyanate. By making the amount of the active hydrogen compound added equal to or greater than the above lower limit, it is possible to see a tendency for excellent curability, hardness, and strength at a low temperature of about 80° C. when the coating is formed. On the other hand, by making the amount of the active hydrogen compound added equal to or less than the above upper limit, gelation during the synthesis of the blocked polyisocyanate composition can be suppressed, and the storage stability when the resin composition is formed can be improved.

[0398] When a solvent is used in the modification reaction of the polyisocyanate (or partially blocked polyisocyanate) and the active hydrogen compound, a solvent inactive to isocyanate groups may be used.

[0399] The reaction temperature of the polyisocyanate (or partially blocked polyisocyanate) and the active hydrogen compound is preferably 50°C or higher and 160°C or lower, more preferably 60°C or higher and 120°C or lower.

[0400] When the reaction temperature is set to be above the lower limit, the reactivity tends to be further improved. In addition, when the reaction temperature is set to be below the upper limit, the coloration, gelation, etc. of the polyisocyanate tends to be more effectively suppressed.

[0401] The blocking reaction between the polyisocyanate (or active hydrogen compound-modified polyisocyanate) and the blocking agent is not particularly limited and is similar to the blocking reaction between the diisocyanate and the blocking agent in the first embodiment. For example, the following two methods can be mentioned.

[0402] 1) A method of reacting the above-mentioned polyisocyanate (or active hydrogen compound-modified polyisocyanate) with the above-mentioned malonic acid ester having a tertiary alkyl group, with the above-mentioned malonic acid ester having a secondary alkyl group, or with the above-mentioned malonic acid ester having a primary alkyl group.

[0403] 2) A method in which the polyisocyanate (or active hydrogen compound-modified polyisocyanate) is reacted with at least one end-capping agent selected from the group consisting of the malonic ester having a tertiary alkyl group, the malonic ester having a secondary alkyl group, and the malonic ester having a primary alkyl group, an alcohol having a chain alkyl group is added to the obtained reaction product, and an alkyl group derived from the alcohol is introduced by transesterification of the terminal ester portion of the reaction product.

[0404] The blocking reaction between the polyisocyanate (or active hydrogen compound-modified polyisocyanate) and the blocking agent can be carried out in the presence or absence of a solvent.

[0405] The amount of the blocking agent added may generally be 80 mol% or more and 200 mol% or less, and preferably 90 mol% or more and 150 mol% or less, relative to the total molar amount of the isocyanate groups.

[0406] In addition, in the case of using a malonate with a secondary alkyl group and a malonate with a tertiary alkyl group in the added end-capping agent, the molar ratio of the malonate with a secondary alkyl group to the malonate with a tertiary alkyl group (malonate with a secondary alkyl group / malonate with a tertiary alkyl group) exceeds 5 / 95 and is less than 95 / 5, preferably 7 / 93 or more and 93 / 7 or less, more preferably 10 / 90 or more and 93 / 7 or less, further preferably 20 / 80 or more and 93 / 7 or less, and particularly preferably 30 / 70 or more and 93 / 7 or less. By making the molar ratio above the above lower limit, the storage stability when the resin composition is made can be good, and by being below the above upper limit, the low temperature curing property when the resin film is made can be good.

[0407] When a solvent is used in the blocking reaction, it is sufficient to use a solvent inactive to isocyanate groups.

[0408] When a solvent is used, the content of the solvent (non-volatile component) may be generally 10 parts by mass or more and 95 parts by mass or less, preferably 20 parts by mass or more and 80 parts by mass or less, and more preferably 30 parts by mass or more and 75 parts by mass or less, based on 100 parts by mass of the blocked polyisocyanate composition.

[0409] In the blocking reaction, organic metal salts of tin, zinc, lead or the like, tertiary amine compounds, alkali metal alkoxides of sodium or the like, or the like can be used as a catalyst.

[0410] The amount of the catalyst added varies depending on the temperature of the blocking reaction, etc., but is usually 0.05 to 1.5 parts by mass, preferably 0.1 to 1.0 parts by mass, based on 100 parts by mass of the polyisocyanate.

[0411] The end-capping reaction can be generally carried out at a temperature of -20°C to 150°C, preferably 0°C to 100°C, and more preferably 10°C to 80°C. By setting the temperature of the end-capping reaction to be above the lower limit, the reaction rate can be further increased, and by setting it to be below the upper limit, the side reaction can be further suppressed.

[0412] After the end-capping reaction, neutralization treatment may be performed by adding an acidic compound or the like.

[0413] As the acidic compound, those described in the first embodiment can be used.

[0414] When the product is produced by the method 2) above, a transesterification reaction is carried out following the above-mentioned terminal blocking reaction.

[0415] As the alcohol having a chain alkyl group used in the transesterification reaction of the method 2), the same alcohol as that in the first embodiment can be used.

[0416] In addition, the chain alkyl group of the alcohol may be the same as that of the aforementioned end-capping agent or may be different. In the case of having a chain alkyl group different from that of the aforementioned end-capping agent, it is preferred to use a monohydric alcohol having a chain alkyl group having a different number of alkyl substitutions from that of the aforementioned end-capping agent. Specifically, for example, when using a single malonic acid ester having a secondary alkyl group as the end-capping agent, a monohydric alcohol having a tertiary alkyl group may be used.

[0417] When the alcohol is produced by the method 2), it is preferred to remove the generated alcohol or the residual portion of the added alcohol by distillation under normal pressure or reduced pressure during or after the transesterification reaction.

[0418] In order to efficiently carry out the transesterification reaction, it is preferred to remove the alcohol produced during the transesterification reaction by distillation or the like. In this case, in order to efficiently remove the alcohol component produced by the transesterification reaction, it is more preferred that the alcohol component added has a higher boiling point than the alcohol component produced.

[0419] The transesterification reaction can be generally performed at 0° C. to 150° C., preferably 30° C. to 120° C., and more preferably 50° C. to 100° C. By setting the temperature of the transesterification reaction to be above the lower limit, the reaction rate can be further increased, and by setting it to be below the upper limit, the side reaction can be further suppressed.

[0420] The amount of the alcohol component in the blocked polyisocyanate composition is preferably 0.05 to 41 parts by mass, more preferably 0.1 to 30 parts by mass, and further preferably 0.5 to 10 parts by mass relative to 100 parts by mass of the solid content of the blocked polyisocyanate composition. By making the amount of the alcohol component greater than the above lower limit, the storage stability of the coating becomes good, and by being less than the above upper limit, the thickening during the mixing of the water-based coating can be suppressed.

[0421] When a hydrophilic compound is used, the polyisocyanate, the active hydrogen compound, the blocking agent, and the hydrophilic compound may be reacted.

[0422] The reaction of the polyisocyanate with the active hydrogen compound, the reaction of the polyisocyanate with the hydrophilic compound, and the reaction of the polyisocyanate with the blocking agent may also be carried out simultaneously, or the second and subsequent reactions may be carried out after any reaction is carried out in advance. Among them, it is preferred to first carry out the reaction of the polyisocyanate with the hydrophilic compound, obtain the hydrophilic compound-modified polyisocyanate modified with the hydrophilic compound, and then carry out the reaction of the obtained hydrophilic compound-modified polyisocyanate with the active hydrogen compound or the blocking agent simultaneously or separately. The reaction of the hydrophilic compound-modified polyisocyanate with the active hydrogen compound and the reaction of the hydrophilic compound-modified polyisocyanate with the blocking agent may all be carried out first.

[0423] The reaction between the polyisocyanate and the hydrophilic compound can use an organic metal salt, a tertiary amine compound, or an alkali metal alkoxide as a catalyst. Examples of the metal constituting the organic metal salt include tin, zinc, and lead. Examples of the alkali metal include sodium.

[0424] The reaction temperature of the polyisocyanate and the hydrophilic compound is preferably -20°C or higher and 150°C or lower, more preferably 30°C or higher and 130°C or lower. By setting the reaction temperature to be above the lower limit, there is a tendency to further improve the reactivity. In addition, by setting the reaction temperature to be below the upper limit, there is a tendency to more effectively suppress side reactions.

[0425] It is preferred that the hydrophilic compound is completely reacted with the polyisocyanate without remaining in an unreacted state. By preventing the hydrophilic compound from remaining in an unreacted state, it tends to more effectively suppress the reduction in the water dispersion stability of the blocked polyisocyanate composition and the low-temperature curing property when formed into a resin film.

[0426] The reaction of the hydrophilic compound-modified polyisocyanate with the active hydrogen compound and the reaction of the hydrophilic compound-modified polyisocyanate with the blocking agent can use the methods described as the above-mentioned active hydrogen compound modification reaction and the above-mentioned blocking reaction.

[0427] <Characteristics of Blocked Polyisocyanate Composition>

[0428] [Weight average molecular weight Mw]

[0429] The weight average molecular weight Mw of the blocked polyisocyanate composition of this embodiment is preferably 3.0×10 3 More preferably 3.0×10 3 Above and 2.0×10 5 Below, more preferably 4.0×10 3 Above and 1.5×10 5 Below, most preferably 4.0×10 3 Above and 7.0×10 4By setting the weight average molecular weight Mw within the above range, the viscosity of the blocked polyisocyanate composition can be maintained more favorably. The weight average molecular weight Mw can be measured, for example, by gel permeation chromatography (hereinafter, sometimes abbreviated to "GPC").

[0430] 《Blocked polyisocyanate composition according to the third embodiment》

[0431] The blocked polyisocyanate composition according to the third embodiment of the present invention comprises a blocked polyisocyanate derived from a polyisocyanate and one or more blocking agents, wherein the blocked polyisocyanate comprises the structural unit (I).

[0432] In this embodiment, description of the same configuration as that of the first embodiment or the second embodiment may be omitted.

[0433] [Blocked polyisocyanate]

[0434] [Structural unit (I)]

[0435] The blocked polyisocyanate contained in the blocked polyisocyanate composition of the present embodiment contains a structural unit (I) represented by the following general formula (I) in the molecule.

[0436]

[0437] In the above general formula (I), R 11 , R 12 and R 13 are each independently an alkyl group which may contain one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and R 11 , R 12 and R 13 The total carbon number of R is 4 or more and 20 or less. 14 , R 15 and R 16 Each is independently a hydrogen atom or an alkyl group which may have one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and the wavy line indicates a bonding site to a residue after removing an isocyanate group from a polyisocyanate.

[0438] As R 11 , R 12 , R 13 , R 14 , R 15 and R 16 The alkyl group in the group preferably has 1 to 20 carbon atoms, more preferably 1 to 8 carbon atoms, further preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms.

[0439] Examples of the unsubstituted alkyl group include the same groups as those in the second embodiment.

[0440] Examples of the alkyl group containing a hydroxyl group as a substituent, the alkyl group containing an amino group as a substituent, and the alkyl group containing a hydroxyl group and an amino group as substituents include the same groups as those in the second embodiment.

[0441] Among them, R 11 , R 12 and R 13 Each independently is preferably an unsubstituted alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and at least one of them is preferably an ethyl group.

[0442] R 11 , R 12 and R 13 The total carbon number of is 4 or more and 20 or less, more preferably 4 or more and 12 or less, further preferably 4 or more and 9 or less, further preferably 4 or more and 6 or less.

[0443] By making R 11 , R 12 and R 13 The total carbon number of is greater than the above lower limit, thereby being able to exhibit storage stability when made into a water-based resin composition. On the other hand, by being less than the above upper limit, low temperature curing properties can be exhibited. In addition, from the viewpoint of solvent resistance when made into a coating film, R 11 , R 12 and R 13 The total carbon number of is more preferably 4.

[0444] In addition, R 14 , R 15 and R 16 Each independently represents a hydrogen atom or an alkyl group which may have one or more substituents selected from the group consisting of a hydroxyl group and an amino group (preferably an unsubstituted alkyl group having 1 to 4 carbon atoms).

[0445] Among them, R 14 , R 15 and R 16 Among them, preferably at least one is a hydrogen atom, and more preferably only one is a hydrogen atom. 14 , R 15 and R 16 At least one of them is a hydrogen atom, thereby maintaining low temperature curing properties and further improving the storage stability when the water-based resin composition is prepared. That is, as the structural unit (I), it is more preferable to include a structural unit represented by the following general formula (I-1) (hereinafter, sometimes referred to as structural unit (I-1)).

[0446]

[0447] In the above general formula (I-1), R 11 , R 12 , R 13 , R 14 and R 15 As described in the above general formula (I), the wavy line indicates the bonding site with the residue after the isocyanate group of the polyisocyanate is removed.

[0448] The molar ratio of the structural unit (I-1) in the aforementioned structural unit (I) (structural unit (I-1) / structural unit (I)) is more preferably 10 mol% or more, further preferably 30 mol% or more, further preferably 50 mol% or more, further preferably 80 mol% or more, further preferably 90 mol% or more.

[0449] [Structural unit (II)]

[0450] It is preferred that the blocked polyisocyanate contained in the blocked polyisocyanate composition of the present embodiment further contains a structural unit represented by the following general formula (II) (hereinafter, sometimes referred to as structural unit (II)) in the molecule.

[0451]

[0452] In the above general formula (II), R 21 , R 22 , R 23 and R 24 Each is independently a hydrogen atom or an alkyl group which may have one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and the wavy line indicates a bonding site to a residue after removing an isocyanate group from a polyisocyanate.

[0453] As R 21 , R 22 , R 23 and R 24 The alkyl group optionally containing one or more substituents selected from the group consisting of a hydroxyl group and an amino group may be exemplified by the above-mentioned “R 11 , R 12 , R 13 , R 14 , R 15 and R 16 The same groups as those exemplified in "

[0454] Among them, as R 21 , R 22 , R 23 and R 24From the perspective of excellent storage stability when the water-based resin composition is prepared, a hydrogen atom or an unsubstituted alkyl group having 1 to 4 carbon atoms is preferred, and a hydrogen atom, a methyl group or an ethyl group is more preferred. From the perspective of excellent low-temperature curing properties, a methyl group or an ethyl group is further preferred.

[0455] R 21 , R 22 , R 23 and R 24 When all of them are methyl groups, the two ester sites of the malonic acid ester of the structural unit (II) are both isopropyl groups. 21 and R 22 Any one of them is a hydrogen atom, the other is a methyl group, and R 23 and R 24 When any one of them is a hydrogen atom and the other is a methyl group, both ester sites of the malonic acid ester of the structural unit (II) are ethyl groups. 21 , R 22 , R 23 and R 24 All of them are methyl groups, that is, both of the two ester sites of the malonic acid ester of the structural unit (II) are isopropyl groups.

[0456] The molar ratio of the structural unit represented by the general formula (II) to the structural unit represented by the general formula (I) (structural unit (II) / structural unit (I)) is preferably 4 / 96 or more and 96 / 4 or less, more preferably 5 / 95 or more and 95 / 5 or less, further preferably 7 / 93 or more and 93 / 7 or less, further more preferably 10 / 90 or more and 90 / 10 or less, further preferably 20 / 80 or more and 85 / 15 or less, further preferably 30 / 70 or more and 85 / 15 or less, further preferably 35 / 65 or more and 85 / 15 or less, further preferably 50 / 50 or more and 70 / 30 or less. By making the molar ratio above the lower limit, the storage stability when made into a resin composition can be made better, and by making it below the upper limit, the low temperature curing property when made into a resin film can be made better.

[0457] For the molar ratio, for example, 1 H-NMR and 13 The composition ratio of the structural unit (II) to the structural unit (I) of the blocked polyisocyanate composition was measured by C-NMR, and the molar ratio of the structural unit (II) to the structural unit (I) was calculated therefrom.

[0458] It is known that R 11 , R 12 and R 13Blocked polyisocyanates that are all methyl groups, i.e., at least one ester group in the diester portion is a tert-butyl group, have excellent curing properties with polyhydroxy compounds at low temperatures of around 85°C, but have high reactivity with water in water-based resin compositions. When mixed with water-based resin compositions and stored in the form of water-based resin compositions containing polyhydroxy compounds, a curing agent and water, they tend to increase viscosity and gel.

[0459] On the other hand, the blocked polyisocyanate composition of the present embodiment has R 11 , R 12 and R 13 The total carbon number of the polyol is 4 or more and 20 or less, so that even when it is mixed into a water-based resin composition, the viscosity increase and gelation of the mixed solution of the polyol compound, the curing agent, and water can be effectively suppressed during storage, and good storage stability can be exerted. At the same time, a resin film with excellent curability at a low temperature of about 85°C is obtained.

[0460] The blocked polyisocyanate composition of the present embodiment may be a blocked polyisocyanate in which at least a portion of the isocyanate groups in the molecule are blocked with a malonate having a secondary alkyl group or a malonate having a primary alkyl group, or a malonate having a tertiary alkyl group. Alternatively, the blocked polyisocyanate composition may be a mixture of a blocked polyisocyanate in which at least a portion of the isocyanate groups in the polyisocyanate are blocked with a malonate having a secondary alkyl group, a blocked polyisocyanate in which at least a portion of the isocyanate groups in the polyisocyanate are blocked with a malonate having a primary alkyl group, and a blocked polyisocyanate in which at least a portion of the isocyanate groups in the polyisocyanate are blocked with a malonate having a tertiary alkyl group.

[0461] [Other functional groups]

[0462] The blocked polyisocyanate may have one or more functional groups selected from the group consisting of an allophanate group, a uretdione group, an iminooxadiazinedione group, an isocyanurate group, a carbamate group, and a biuret group. Among them, it is preferred to have an isocyanurate group from the viewpoint of excellent weather resistance.

[0463] The blocked polyisocyanate contained in the blocked polyisocyanate composition of the present embodiment is derived from a polyisocyanate obtained by the same method using the same isocyanate as in the second embodiment described above, and at least one blocking agent.

[0464] [Polyisocyanate]

[0465] (isocyanate)

[0466] As the isocyanate monomer used in the manufacture of the polyisocyanate, similarly to the second embodiment, from the aspect of excellent weather resistance, it is preferred to use one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates. In addition, from the perspective of ease of industrial acquisition, HDI or IPDI is more preferably used. In addition, from the perspective of making the blocked polyisocyanate component low in viscosity, HDI is further preferably used.

[0467] As the isocyanate monomer used in the manufacture of the polyisocyanate, any of aliphatic diisocyanate and alicyclic diisocyanate can be used alone or in combination. Preferably, aliphatic diisocyanate and alicyclic diisocyanate are used in combination, and HDI and IPDI are particularly preferred. By using aliphatic diisocyanate and alicyclic diisocyanate, the toughness and hardness of the coating film can be further improved.

[0468] In the polyisocyanate, from the viewpoint of improving the hardness and strength of the coating film, the mass ratio of the structural unit derived from the aliphatic diisocyanate to the structural unit derived from the alicyclic diisocyanate (structural unit derived from the aliphatic diisocyanate / structural unit derived from the alicyclic diisocyanate) is preferably 50 / 50 or more and 95 / 5 or less, more preferably 55 / 45 or more and 93 / 7 or less, further preferably 60 / 40 or more and 91 / 9 or less, and further preferably 65 / 35 or more and 90 / 10 or less.

[0469] By making the mass ratio of the structural unit derived from aliphatic diisocyanate to the structural unit derived from alicyclic diisocyanate above the above lower limit, the reduction in flexibility when formed into a coating film can be more effectively suppressed. On the other hand, by being below the above upper limit, the hardness when formed into a coating film can be further increased.

[0470] (Polyol)

[0471] The polyisocyanate is preferably derived from the above-mentioned diisocyanate and a polyol (preferably the above-mentioned polyol B) having an average functional group number of 3.0 or more and 8.0 or less. This can further increase the average number of isocyanate groups in the polyisocyanate. In the polyisocyanate, carbamate groups are formed by the reaction of the hydroxyl groups of the polyol and the isocyanate groups of the diisocyanate monomer.

[0472] The average number of functional groups of the polyol is preferably 3.0 to 8.0, more preferably 3 to 6, further preferably 3 to 5, particularly preferably 3 or 4. The average number of functional groups of the polyol referred to here is the number of hydroxyl groups present in one molecule of the polyol.

[0473] The number average molecular weight of the polyol is preferably 100 to 1000, preferably 100 to 900, more preferably 100 to 600, more preferably 100 to 570, further preferably 100 to 500, further preferably 100 to 400, particularly preferably 100 to 350, and most preferably 100 to 250, from the viewpoint of improving the hardness and strength of the coating film.

[0474] By setting the number average molecular weight of the polyol within the above range, the blocked polyisocyanate composition has better low temperature curability when formed into a coating film, and particularly better hardness and strength. The number average molecular weight Mn of the polyol is, for example, a polystyrene-standard number average molecular weight measured by GPC.

[0475] Examples of such a polyol include trimethylolpropane, glycerol, a trivalent or higher polyol, and polycaprolactone polyol derived from ε-caprolactone.

[0476] Examples of commercially available products of polycaprolactone polyol include those similar to those described in the second embodiment.

[0477] (Manufacture of polyisocyanates)

[0478] The polyisocyanate can be produced in the same manner as in the second embodiment described above.

[0479] In addition, for example, an antioxidant or ultraviolet light absorber may be added to the obtained polyisocyanate for the purpose of suppressing coloration during storage. As the antioxidant or ultraviolet light absorber, one of the aforementioned second embodiment may be used alone or two or more may be used in combination. The amount thereof added is preferably 10 mass ppm or more and 500 mass ppm or less relative to the mass of the polyisocyanate.

[0480] (Average number of isocyanate groups in polyisocyanates)

[0481] The average number of isocyanate groups of the polyisocyanate is preferably 2 or more from the perspective of improving the low-temperature curing property when the resin film is formed, and is more preferably 3 or more and 20 or less, further preferably 3.2 or more and 10 or less, particularly preferably 3.5 or more and 8 or less, and most preferably 4.2 or more and 6 or less from the perspective of taking into account both the low-temperature curing property when the resin film is formed and the compatibility with the polyhydroxy compound.

[0482] The average number of isocyanate groups in the polyisocyanate can be determined by the method described in the second embodiment.

[0483] [Capping agent]

[0484] The blocking agent used in the production of the blocked polyisocyanate preferably contains a malonic acid ester having a secondary alkyl group or a malonic acid ester having a primary alkyl group, and contains a malonic acid ester having a tertiary alkyl group, and more preferably contains a malonic acid ester having a secondary alkyl group and a malonic acid ester having a tertiary alkyl group. The blocking agent may contain one kind each of a malonic acid ester having a secondary alkyl group, a malonic acid ester having a primary alkyl group, and a malonic acid ester having a tertiary alkyl group, or may contain two or more kinds in combination.

[0485] The malonic acid ester having a primary alkyl group, the malonic acid ester having a secondary alkyl group, and the malonic acid ester having a tertiary alkyl group are not particularly limited, and the same malonic acid esters as those in the first embodiment can be used.

[0486] (Other Capping Agents)

[0487] The end-capping agent used in the manufacture of the blocked polyisocyanate may include, in addition to the malonate having a secondary alkyl group and the malonate having a tertiary alkyl group, other end-capping agents within the range that does not hinder the storage stability when the resin composition is prepared and the low-temperature curing property when the resin film is prepared. As other end-capping agents, the substances described in the first embodiment can be used.

[0488] (Content of malonate ester having secondary alkyl group and malonate ester having tertiary alkyl group)

[0489] The content of the malonic ester having a secondary alkyl group and the malonic ester having a tertiary alkyl group is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, particularly preferably 95 mol% or more, and most preferably 100 mol% relative to the total molar amount of all blocking agents used in the production of the blocked polyisocyanate.

[0490] By setting the content of the malonic acid ester having a secondary alkyl group and the malonic acid ester having a tertiary alkyl group to be within the above range, the low-temperature curability when formed into a resin film can be further improved.

[0491] [Nonionic compounds]

[0492] In the blocked polyisocyanate composition of the present embodiment, a part of the isocyanate groups may be modified with a nonionic compound. That is, a structural unit derived from a nonionic compound may be introduced into a part of the isocyanate groups of the blocked polyisocyanate.

[0493] As the nonionic compound, the same compounds as those in the second embodiment described above can be used.

[0494] The lower limit of the amount of the structural unit derived from the nonionic compound added to the blocked polyisocyanate (hereinafter sometimes referred to as "the content of the nonionic compound") is preferably 0.1% by mass, more preferably 0.15% by mass, further preferably 0.2% by mass, and particularly preferably 0.25% by mass, relative to the mass of the solid content of the blocked polyisocyanate composition, from the viewpoint of the water dispersion stability of the blocked polyisocyanate composition.

[0495] The upper limit of the content of the nonionic compound is preferably 55% by mass, more preferably 50% by mass, further preferably 48% by mass, and particularly preferably 44% by mass, relative to the mass of the solid content of the blocked polyisocyanate composition, from the viewpoint of water resistance of the obtained resin film.

[0496] That is, the content of the nonionic compound is preferably 0.1% by mass to 55% by mass, more preferably 0.15% by mass to 50% by mass, further preferably 0.20% by mass to 48% by mass, particularly preferably 0.25% by mass to 44% by mass, relative to the mass of the solid content of the blocked polyisocyanate composition.

[0497] When the content of the nonionic compound is within the above range, the blocked polyisocyanate composition is further dispersed in water, and a homogeneous film tends to be obtained.

[0498] From the viewpoint of suppressing the decrease in the hardness and strength of the obtained resin film, when the amount of the nonionic compound added to the blocked polyisocyanate is expressed by molar ratio, relative to 100 mol% of the isocyanate group of the raw material polyisocyanate, it is preferably 0.05 mol% or more and 15 mol% or less, more preferably 0.10 mol% or more and 12 mol% or less, further preferably 0.10 mol% or more and 9 mol% or less, further preferably 0.10 mol% or more and 6 mol% or less, and most preferably 0.15 mol% or more and 4 mol% or less.

[0499] [Other hydrophilic compounds]

[0500] At least a part of the blocked polyisocyanate may have a structural unit derived from a hydrophilic compound other than a nonionic compound, that is, a hydrophilic group other than a nonionic hydrophilic group.

[0501] The other hydrophilic compound is a compound having a hydrophilic group other than a nonionic hydrophilic group. The other hydrophilic compound preferably has, in addition to the hydrophilic group other than the nonionic hydrophilic group, one or more active hydrogen groups for reacting with at least one isocyanate group of the polyisocyanate per molecule of the other hydrophilic compound. Specifically, the active hydrogen group includes a hydroxyl group, a mercapto group, a carboxylic acid group, an amino group, and a thiol group.

[0502] Other hydrophilic compounds include cationic compounds and anionic compounds. These hydrophilic compounds may be used alone or in combination of two or more. Among them, as other hydrophilic compounds, anionic compounds are preferred from the viewpoint of suppressing the hardness and strength of the obtained resin film and the viewpoint of improving emulsification.

[0503] As the cationic compound and the anionic compound, those described in the second embodiment can be used.

[0504] <Other components>

[0505] The blocked polyisocyanate composition of the present embodiment may contain additives such as a solvent in addition to the above-mentioned blocked polyisocyanate. As the solvent, the substances described in the above-mentioned first embodiment can be used.

[0506] <Method for producing blocked polyisocyanate composition>

[0507] The method for producing the blocked polyisocyanate composition of the present embodiment is not particularly limited, and similarly to the blocking reaction of the polyisocyanate and the blocking agent in the second embodiment, the following two methods can be mentioned.

[0508] 1) A method of reacting the polyisocyanate with the malonic acid ester having a tertiary alkyl group, the malonic acid ester having a secondary alkyl group, or the malonic acid ester having a primary alkyl group.

[0509] 2) A method in which the polyisocyanate is reacted with at least one end-capping agent selected from the group consisting of the malonic ester having a tertiary alkyl group, the malonic ester having a secondary alkyl group, and the malonic ester having a primary alkyl group, an alcohol having a chain alkyl group is added to the obtained reaction product, and an alkyl group derived from the alcohol is introduced by transesterification of the terminal ester portion of the reaction product.

[0510] Of the above two methods, method 2) is preferred in view of the ease of the process and the ease of controlling the molar ratio of structural unit (II) / structural unit (I).

[0511] The blocking reaction between the polyisocyanate and the blocking agent can be carried out in the presence or absence of a solvent to obtain a blocked polyisocyanate.

[0512] The end-capping agent may include one type each of a malonic acid ester having a primary alkyl group, a malonic acid ester having a secondary alkyl group, and a malonic acid ester having a tertiary alkyl group, or may include two or more types in combination.

[0513] The amount of the blocking agent added may generally be 80 mol% to 200 mol%, preferably 90 mol% to 150 mol%, based on the total molar amount of the isocyanate groups.

[0514] In addition, in the added end-capping agent, the molar ratio of the structural unit derived from the malonic acid ester having a secondary alkyl group to the structural unit derived from the malonic acid ester having a tertiary alkyl group [(malonic acid ester having a secondary alkyl group) / (malonic acid ester having a tertiary alkyl group)], and the molar ratio of the structural unit derived from the malonic acid ester having a primary alkyl group to the structural unit derived from the malonic acid ester having a tertiary alkyl group [(malonic acid ester having a primary alkyl group) / (malonic acid ester having a tertiary alkyl group)] are 4 / 96 or more and 96 / 4 or less, preferably 5 / 95 or more and 95 / 5 or less, more preferably 7 / 93 or more and 93 / 7 or less, further more preferably 10 / 90 or more and 90 / 10 or less, further preferably 20 / 80 or more and 85 / 15 or less, particularly preferably 30 / 70 or more and 85 / 15 or less, and most preferably 35 / 65 or more and 85 / 15. When the molar ratio is equal to or higher than the above lower limit, the storage stability when formed into a water-based resin composition can be improved, and when it is equal to or lower than the above upper limit, the low-temperature curing property when formed into a resin film can be improved.

[0515] When a solvent is used, it is sufficient to use a solvent that is inactive to isocyanate groups.

[0516] When a solvent is used, the content of the nonvolatile component derived from the polyisocyanate and the blocking agent is as described in the above-mentioned second embodiment based on 100 parts by mass of the blocked polyisocyanate composition.

[0517] In the blocking reaction, organic metal salts of tin, zinc, lead or the like, tertiary amine compounds, alkali metal alkoxides of sodium or the like, or the like can be used as a catalyst.

[0518] The amount of the catalyst added and the end-capping reaction temperature are the same as those described in the second embodiment.

[0519] After the terminalization reaction, neutralization treatment may be performed by adding an acidic compound or the like. As the acidic compound, the same compounds as those in the first or second embodiment may be used.

[0520] When a hydrophilic compound including a nonionic compound is used, the polyisocyanate, the blocking agent, and the hydrophilic compound are reacted to obtain the hydrophilic compound.

[0521] The reaction of the polyisocyanate with the hydrophilic compound containing the nonionic compound and the reaction of the polyisocyanate with the blocking agent may be carried out simultaneously, or the second and subsequent reactions may be carried out after any one of the reactions is carried out in advance. Among them, it is preferred to first carry out the reaction of the polyisocyanate with the hydrophilic compound to obtain a hydrophilic compound-modified polyisocyanate modified with the hydrophilic compound, and then carry out the reaction of the obtained hydrophilic compound-modified polyisocyanate with the blocking agent.

[0522] The reaction between the polyisocyanate and the hydrophilic compound can be carried out in the same manner as in the second embodiment described above.

[0523] The reaction between the hydrophilic compound-modified polyisocyanate and the blocking agent can be carried out by the same method as the blocking reaction between the polyisocyanate and the blocking agent described above.

[0524] When the product is produced by the method 2) above, a transesterification reaction is carried out following the above-mentioned terminal blocking reaction.

[0525] As the alcohol having a chain alkyl group used in the transesterification reaction of the method 2), the same alcohol as that in the first embodiment can be used.

[0526] In addition, the chain alkyl group of the alcohol may be the same as that of the aforementioned end-capping agent or may be different. In the case of having a chain alkyl group different from that of the aforementioned end-capping agent, it is preferred to use a monohydric alcohol having a chain alkyl group having a different number of alkyl substitutions from that of the aforementioned end-capping agent. Specifically, for example, when using a single malonic acid ester having a secondary alkyl group as the end-capping agent, a monohydric alcohol having a tertiary alkyl group may be used.

[0527] When the alcohol is produced by the method 2), it is preferred to remove the generated alcohol or the residual portion of the added alcohol by distillation under normal pressure or reduced pressure during or after the transesterification reaction.

[0528] In order to efficiently carry out the transesterification reaction, it is preferred to remove the alcohol produced during the transesterification reaction by distillation or the like. In this case, in order to efficiently remove the alcohol component produced by the transesterification reaction, it is more preferred that the alcohol component added has a higher boiling point than the alcohol component produced.

[0529] The transesterification reaction can be generally performed at 0° C. to 150° C., preferably 30° C. to 120° C., and more preferably 50° C. to 100° C. By setting the temperature of the transesterification reaction to be above the lower limit, the reaction rate can be further increased, and by setting it to be below the upper limit, the side reaction can be further suppressed.

[0530] The molar ratio of the structural unit (II) to the structural unit (I) can be controlled by adjusting the molar ratio of the alcohol added to the blocked isocyanate group, the transesterification reaction temperature and the transesterification reaction time, and the distillation removal of the generated alcohol.

[0531] The amount of the alcohol component in the blocked polyisocyanate composition is preferably 0.05 to 41 parts by mass, more preferably 0.1 to 30 parts by mass, and further preferably 0.5 to 10 parts by mass relative to 100 parts by mass of the solid content of the blocked polyisocyanate composition. By making the amount of the alcohol component greater than the above lower limit, the storage stability of the coating becomes good, and by being less than the above upper limit, the thickening during the mixing of the water-based coating can be suppressed.

[0532] <Characteristics of Blocked Polyisocyanate Composition>

[0533] [Weight average molecular weight Mw]

[0534] The weight average molecular weight Mw of the blocked polyisocyanate composition of the present embodiment is the same as that of the second embodiment described above.

[0535] 《Resin composition》

[0536] The resin composition of the present embodiment includes the blocked polyisocyanate composition of the first, second or third embodiment and a polyvalent hydroxy compound. The resin composition of the present embodiment may also be a one-component resin composition including a curing agent component and a main agent component.

[0537] The resin composition of the present embodiment has good storage stability, and is excellent in curability at a low temperature of about 80° C., hardness, and strength when formed into a coating film.

[0538] Furthermore, the resin composition of the present embodiment is excellent in storage stability when used as a water-based resin composition, and therefore is particularly suitable for use as a water-based resin composition.

[0539] The constituent components of the resin composition of the present embodiment will be described in detail below.

[0540] <Polyhydroxy Compounds>

[0541] In this specification, the "polyhydroxy compound" refers to a compound having at least two hydroxyl groups (hydroxy) in one molecule, and is also called a "polyol".

[0542] Specific examples of the polyvalent hydroxy compound include aliphatic hydrocarbon polyols, polyether polyols, polyester polyols, epoxy resins, fluorine-containing polyols, and acrylic polyols.

[0543] Among them, the polyhydroxy compound is preferably polyester polyols, fluorine-containing polyols or acrylic polyols.

[0544] [Aliphatic hydrocarbon polyols]

[0545] Examples of the aliphatic hydrocarbon polyols include terminal hydroxylated polybutadiene and hydrogenated products thereof.

[0546] [Polyether polyols]

[0547] Examples of the polyether polyols include polyether polyols obtained by any of the following methods (1) to (3).

[0548] (1) Polyether polyols or polytetramethylene glycols obtained by adding alkylene oxides alone or in mixture to polyols alone or in mixture.

[0549] (2) Polyether polyols obtained by reacting a polyfunctional compound with an alkylene oxide.

[0550] (3) So-called polymer polyols obtained by polymerizing acrylamide or the like using the polyether polyols obtained in (1) or (2) as a medium.

[0551] Examples of the polyol include glycerol and propylene glycol.

[0552] Examples of the alkylene oxide include ethylene oxide and propylene oxide.

[0553] Examples of the polyfunctional compound include ethylenediamine and ethanolamines.

[0554] [Polyester polyols]

[0555] Examples of the polyester polyols include any of the following (1) and (2).

[0556] (1) Polyester polyol resins obtained by condensation reaction of a dibasic acid alone or a mixture of two or more thereof and a polyol alone or a mixture of two or more thereof.

[0557] (2) Polycaprolactones obtained by ring-opening polymerization of ε-caprolactone using a polyol.

[0558] Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.

[0559] Examples of the polyol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerol, pentaerythritol, 2-methylolpropanediol, and ethoxylated trimethylolpropane.

[0560] [Epoxy resin]

[0561] Examples of the epoxy resins include novolac epoxy resins, β-methylepichlorohydrin epoxy resins, oxirane epoxy resins, glycidyl ether epoxy resins, glycol ether epoxy resins, epoxy aliphatic unsaturated compounds, epoxidized fatty acid esters, ester polycarboxylic acids, aminoglycidyl epoxy resins, halogenated epoxy resins, resorcinol epoxy resins, and epoxy resins modified with amino compounds, polyamide compounds, and the like.

[0562] [Fluorinated polyols]

[0563] Examples of the fluorine-containing polyols include copolymers of fluoroolefins, cyclohexyl vinyl ether, hydroxyalkyl vinyl ether, monocarboxylic acid vinyl esters, and the like disclosed in Reference 1 (Japanese Patent Application Laid-Open No. 57-34107) and Reference 2 (Japanese Patent Application Laid-Open No. 61-275311).

[0564] [Acrylic polyols]

[0565] The acrylic polyols can be obtained, for example, by polymerizing a polymerizable monomer having one or more active hydrogen atoms in one molecule, or by copolymerizing a polymerizable monomer having one or more active hydrogen atoms in one molecule with another monomer copolymerizable with the polymerizable monomer, if necessary.

[0566] Examples of the polymerizable monomer having one or more active hydrogen atoms in one molecule include the following (i) to (iii). These may be used alone or in combination of two or more.

[0567] (i) Acrylic acid esters having active hydrogen, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate.

[0568] (ii) Methacrylic acid esters having active hydrogen, such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxybutyl methacrylate.

[0569] (iii) (meth)acrylates having polyvalent active hydrogen such as glycerol monoacrylate or methacrylate, trimethylolpropane monoacrylate or methacrylate.

[0570] Examples of other monomers copolymerizable with the polymerizable monomer include the following (i) to (v). These may be used alone or in combination of two or more.

[0571] (i) Acrylates such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate.

[0572] (ii) Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate and glycidyl methacrylate.

[0573] (iii) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid.

[0574] (iv) Unsaturated amides such as acrylamide, N-methylol acrylamide and diacetone acrylamide.

[0575] (v) Styrene, vinyl toluene, vinyl acetate, acrylonitrile, etc.

[0576] In addition, acrylic polyols obtained by copolymerizing polymerizable ultraviolet stable monomers disclosed in Reference 3 (Japanese Patent Application Laid-Open No. 1-261409) and Reference 4 (Japanese Patent Application Laid-Open No. 3-006273) and the like can be cited.

[0577] Specific examples of the polymerizable UV-stable monomer include 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonyl-4-crotonyloxy-2,2,6,6-tetramethylpiperidine, and 2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropoxy)benzophenone.

[0578] For example, the acrylic polyol can be obtained by subjecting the above-mentioned monomer components to solution polymerization in the presence of a known radical polymerization initiator such as a peroxide or an azo compound, and diluting the mixture with an organic solvent or the like as necessary.

[0579] When obtaining a water-based acrylic polyol, it can be produced by a known method such as a method of subjecting an olefinic unsaturated compound to solution polymerization and conversion to an aqueous layer, emulsion polymerization, etc. In this case, water solubility or water dispersibility can be imparted by neutralizing the acidic part of a carboxylic acid-containing monomer such as acrylic acid or methacrylic acid, or a sulfonic acid-containing monomer, etc., with amines or ammonia.

[0580] [Hydroxy value and acid value of polyhydroxy compounds]

[0581] The hydroxyl value of the polyhydroxy compound contained in the resin composition of the present embodiment is preferably 5 mgKOH / g or more and 300 mgKOH / g or less, more preferably 10 mgKOH / g or more and 280 mgKOH / g or less, and further preferably 30 mgKOH / g or more and 250 mgKOH / g or less. By making the hydroxyl value of the polyhydroxy compound within the above range, a resin film having various physical properties such as tensile strength and the like can be obtained that are more excellent. Specifically, by making the hydroxyl of the polyhydroxy compound above the above lower limit, the cross-linking density of the carbamate based on the reaction with polyisocyanate is further increased, and it is easier to play the function of carbamate bond. On the other hand, by making the hydroxyl of the polyhydroxy compound below the above upper limit, the mechanical properties of the resin film are made better under the state where the cross-linking density is not excessively increased. The hydroxyl value of the polyhydroxy compound is measured, for example, by potentiometric titration, and is calculated in the form of a value relative to the solid content in the polyhydroxy compound.

[0582] [Glass transition temperature Tg of polyhydroxy compound]

[0583] The glass transition temperature Tg of the polyhydroxy compound contained in the resin composition of the present embodiment is preferably 0°C or more and 100°C or less, more preferably 0°C or more and 90°C or less, further preferably 0°C or more and 80°C or less, and particularly preferably 5°C or more and 70°C or less. By making the glass transition temperature of the polyhydroxy compound within the above range, a resin film having better tensile strength can be obtained. The glass transition temperature of the polyhydroxy compound can be measured, for example, using the method described in the examples described later.

[0584] [Weight average molecular weight Mw of polyhydroxy compound]

[0585] The weight average molecular weight Mw of the polyhydroxy compound is preferably 5.0×10 3 Above and 2.0×10 5 Less than, more preferably 5.0×10 3 Above and 1.5×10 5 Below, more preferably 5.0×10 3 Above and 1.0×10 5 When the weight average molecular weight Mw of the polyvalent hydroxy compound is within the above range, a resin film having more excellent physical properties such as tensile strength can be obtained. The weight average molecular weight Mw of the polyvalent hydroxy compound can be measured by the method described in the examples described below, for example.

[0586] [NCO / OH]

[0587] The molar equivalent ratio (NCO / OH) of the isocyanate groups of the blocked polyisocyanate composition contained in the resin composition of the present embodiment to the hydroxyl groups of the polyvalent hydroxy compound is determined according to the desired physical properties of the resin film, and is usually 0.01 to 22.5.

[0588] [Content of blocked polyisocyanate composition]

[0589] In the resin composition of the present embodiment, for the content of blocked polyisocyanate, as long as the molar equivalent ratio of the isocyanate group of the blocked polyisocyanate to the hydroxyl group of the polyol compound is within the above range, for example, relative to 100 parts by mass of the polyol compound, preferably 1 part by mass or more and 200 parts by mass or less, more preferably 5 parts by mass or more and 180 parts by mass or less, further preferably 10 parts by mass or more and 150 parts by mass or less. By making the content of blocked polyisocyanate within the above range, a resin film having various physical properties such as tensile strength can be obtained that are more excellent. The content of blocked polyisocyanate can also be calculated according to, for example, the amount of compounding, or can also be identified and quantitatively calculated using nuclear magnetic resonance (NMR) method and gas chromatography / mass spectrometry (GC / MS method).

[0590] <Other additives>

[0591] The resin composition of the present embodiment may further contain other additives.

[0592] As other additives, for example, curing agents that can react with the crosslinking functional groups in the polyhydroxy compound, curing catalysts, solvents, pigments (extender pigments, coloring pigments, metallic pigments, etc.), ultraviolet absorbers, light stabilizers, free radical stabilizers, anti-yellowing agents that suppress coloring during the baking process, coating surface regulators, flow regulators, pigment dispersants, defoamers, thickeners, film-forming aids, etc. can be cited.

[0593] Examples of the curing agent include melamine resins, urea resins, epoxy group-containing compounds or resins, carboxyl group-containing compounds or resins, acid anhydrides, alkoxysilane-containing compounds or resins, and hydrazide compounds.

[0594] The curing catalyst may be a basic compound or a Lewis acid compound.

[0595] Examples of the basic compound include metal hydroxides, metal alkoxides, metal carboxylates, metal acetylacetonates, hydroxides of onium salts, onium carboxylates, halides of onium salts, metal salts of active methylene compounds, onium salts of active methylene compounds, aminosilanes, amines, phosphines, etc. As the onium salt, ammonium salts, phosphonium salts or sulfonium salts are suitable.

[0596] Examples of the Lewis acidic compound include organic tin compounds, organic zinc compounds, organic titanium compounds, and organic zirconium compounds.

[0597] Examples of the solvent include the same solvents as those exemplified in the above-mentioned blocked polyisocyanate composition.

[0598] In addition, as pigments (extender pigments, coloring pigments, metallic pigments, etc.), ultraviolet absorbers, light stabilizers, free radical stabilizers, anti-yellowing agents for suppressing coloration during the baking process, coating surface regulators, flow regulators, pigment dispersants, defoamers, thickeners and film-forming aids, known substances can be appropriately selected and used.

[0599] <Method for producing resin composition>

[0600] The resin composition of the present embodiment can be used in any of a solvent-based and an aqueous-based composition, and is preferably used in the form of an aqueous-based resin composition.

[0601] In the case of the resin combination (water-based resin combination) of manufacturing water-based matrix, first, in polyhydroxy compound or its aqueous dispersion or water-soluble, as required, add the curing agent, curing catalyst, solvent, pigment (body pigment, coloring pigment, metallic pigment etc.), ultraviolet light absorber, light stabilizer, free radical stabilizer, the anti-yellowing agent of the coloring during the inhibition baking process, coating surface regulator, flow regulator, pigment dispersant, defoamer, thickener, film-making aid etc. that can react with the crosslinking functional group in polyhydroxy compound.Then, add the above-mentioned blocked polyisocyanate composition or its aqueous dispersion as curing agent, and then add water, solvent as required to adjust viscosity.Then, utilize stirring machine to carry out forced stirring, thus can obtain the resin combination (water-based resin combination) of water-based matrix.

[0602] In the case of manufacturing a solvent-based resin composition, first, in a polyhydroxy compound or its solvent dilution, a curing agent, a curing catalyst, a solvent, pigments (body pigments, coloring pigments, metallic pigments, etc.), a UV absorber, a light stabilizer, a free radical stabilizer, an anti-yellowing agent for suppressing the coloring during the baking process, a coating surface regulator, a flow regulator, a pigment dispersant, a defoamer, a thickener, an additive such as a film-making aid that can react with the crosslinking functional group in the polyhydroxy compound are added as needed. Then, the above-mentioned blocked polyisocyanate composition is added as a curing agent, and as needed, a solvent is further added to adjust the viscosity. Then, by stirring manually or using a stirring machine such as mazelar, a solvent-based resin composition can be obtained.

[0603] Resin film

[0604] The resin film of the present embodiment is obtained by curing the above-mentioned resin composition. The resin film of the present embodiment is excellent in curability at a low temperature of about 80°C, hardness, and strength.

[0605] The resin film of the present embodiment is obtained by applying the above-mentioned resin composition to a substrate using a known method such as roll coating, curtain flow coating, spray coating, rotary cup coating, or electrostatic coating, and then heating and curing the resin composition.

[0606] The heating temperature is preferably about 70°C to 120°C, more preferably about 70°C to 110°C, and even more preferably about 75°C to 100°C, from the viewpoint of energy saving and heat resistance of the substrate.

[0607] The heating time is preferably about 1 minute to about 60 minutes, more preferably about 2 minutes to about 40 minutes, from the viewpoint of energy saving and heat resistance of the substrate.

[0608] The substrate is not particularly limited, and examples thereof include outer panels of automobile bodies such as passenger cars, trucks, motorcycles, and buses; automobile parts such as bumpers; outer panels of home appliances such as mobile phones and audio equipment; various films, etc. Among them, outer panels or automobile parts of automobile bodies are preferred.

[0609] The material of the substrate is not particularly limited, and examples thereof include metal materials such as iron, aluminum, brass, copper, tinplate, stainless steel, galvanized steel, zinc alloy (Zn-Al, Zn-Ni, Zn-Fe, etc.) plated steel; resins such as polyethylene resin, polypropylene resin, acrylonitrile-butadiene-styrene (ABS) resin, polyamide resin, acrylic resin, vinylidene chloride resin, polycarbonate resin, polyurethane resin, epoxy resin, and various FRP and other plastic materials; inorganic materials such as glass, cement, and concrete; wood; fiber materials such as paper and cloth, etc., among which metal materials or plastic materials are preferred.

[0610] The substrate may be a surface treatment such as phosphate treatment, chromate treatment, composite oxide treatment, etc., on the surface of the above-mentioned metal material, or the metal surface of the vehicle body formed by the above-mentioned metal material, and a coating film may be formed thereon. As a substrate with a coating film formed thereon, a surface treatment may be performed as needed and a primer coating film may be formed thereon, for example, a vehicle body with a primer coating film formed thereon using an electro-deposition coating. The substrate may be a surface treatment of the above-mentioned plastic material, or the plastic surface of the automobile parts formed by the above-mentioned metal material, etc., which is formed by a desired surface treatment. In addition, the substrate may be a combination of a plastic material and a metal material.

[0611] The resin film of the present embodiment is as shown in the examples described later, and the resin film with a film thickness of 40 μm formed by heating the above-mentioned resin composition at 80°C for 30 minutes to solidify it is preferably 82% by mass or more, more preferably 83% by mass or more, further more preferably 84% by mass or more, further preferably 85% by mass or more, and further preferably 86% by mass or more when the gel fraction is immersed in acetone at 23°C for 24 hours after being stored at 23°C for 1 week. By making the gel fraction above the above lower limit, low temperature curing can be made better. On the other hand, the upper limit of the gel fraction is not particularly limited, for example, it can be set to 100% by mass. The specific determination method of the gel fraction can be, for example, the method shown in the examples described later.

[0612] The resin film of the present embodiment is as shown in the examples described later, and the Konig hardness of the resin film with a film thickness of 40 μm formed by heating the above-mentioned resin composition on glass at 80°C for 30 minutes to solidify it at 23°C is preferably 40 times or more, more preferably 45 times or more, further more preferably 50 times or more, further preferably 55 times or more, and further preferably 60 times or more. By making the Konig hardness above the above lower limit, a resin film with better hardness can be formed. On the other hand, the upper limit of the Konig hardness is not particularly limited, for example, it can be set to 160 times. The specific determination method of the Konig hardness can use the method shown in the examples described later, for example.

[0613] The resin film of the present embodiment is as shown in the examples described later. The resin film having a film thickness of 40 μm obtained by heating the above-mentioned resin composition at 80° C. for 30 minutes to solidify it preferably has a tensile maximum stress of 10.0 MPa or more, more preferably 15 MPa or more, further preferably 20 MPa or more, and particularly preferably 25 MPa or more at 23° C. By making the tensile maximum stress at 23° C. be above the above-mentioned lower limit, a resin film with better strength can be made. On the other hand, the upper limit of the tensile maximum stress at 23° C. is not particularly limited, and can be set to 100 MPa, for example. The specific method for measuring the tensile maximum stress at 23° C. can use, for example, the method shown in the examples described later.

[0614] The resin film of the present embodiment is excellent in low-temperature curing properties and therefore can be suitably used as a coating film for products in various fields requiring energy conservation or for materials with low heat resistance.

[0615] Layered

[0616] The laminate of the present embodiment includes two or more layers of the above-mentioned resin film having different compositions. The average thickness of each layer of the resin film is 1 μm to 50 μm. The laminate of the present embodiment includes the above-mentioned resin film, and thus has excellent low-temperature curing properties.

[0617] The laminated body of the present embodiment may include two or more layers of the above-mentioned resin films having the same composition.

[0618] In addition, the laminated body of the present embodiment is obtained by laminating various coating films including the above-mentioned resin film on an adherend.

[0619] Examples of adherends include glass, various metals, porous members, members coated with various coatings, cured sealants, rubbers, leathers, fibers, nonwoven fabrics, resin films and plates, ultraviolet curing acrylic resin layers, and layers formed from inks.

[0620] Examples of the various metals include aluminum, iron, zinc steel, copper, and stainless steel.

[0621] Examples of the porous member include wood, paper, mortar, and stone.

[0622] Examples of the various coatings include fluorine coating, urethane coating, acrylic urethane coating, and the like.

[0623] Examples of the sealant cured product include silicone-based, modified silicone-based, and urethane-based products. Examples of the rubbers include natural rubber and synthetic rubber.

[0624] Examples of the leather include natural leather and artificial leather.

[0625] Examples of the fibers include plant fibers, animal fibers, carbon fibers, and glass fibers.

[0626] Examples of resins used as raw materials for the resin films and sheets include polyvinyl chloride, polyester, acrylic, polycarbonate, triacetyl cellulose, and polyolefin.

[0627] Examples of the inks include printing inks and UV inks.

[0628] The laminate of the present embodiment is obtained by applying the above-mentioned resin compositions of different compositions to the adherends respectively and heating them to cure them using a known method such as roller coating, curtain flow coating, spray coating, rotary cup coating, electrostatic coating, etc., or by heating all the layers together after coating to cure them.

[0629] The laminated body of the present embodiment may further include, in addition to the above-mentioned resin film, layers formed of other well-known components such as a primer layer, an adhesive layer, and a decorative layer.

[0630] Example

[0631] Hereinafter, the present embodiment will be described in more detail based on examples and comparative examples, but the present embodiment is not limited to the following examples at all.

[0632] <Test Items>

[0633] The blocked polyisocyanate compositions obtained in Examples and Comparative Examples were subjected to measurement of various physical properties and evaluations by the methods shown below.

[0634] [Physical properties 1]

[0635] (Isocyanate group (NCO) content)

[0636] In order to measure the NCO content of the polyisocyanate, the polyisocyanate before being blocked with a blocking agent is used as a measurement sample.

[0637] First, accurately weigh more than 2g and less than 3g (Wg) of the test sample in a flask. Then, add 20mL of toluene to dissolve the test sample. Then, add 20mL of a toluene solution of 2 equivalents of di-n-butylamine, mix, and leave at room temperature for 15 minutes. Then, add 70mL of isopropanol to mix. Then, titrate the liquid with 1 equivalent hydrochloric acid solution (factor F) in an indicator. Set the obtained titration value to V2mL. Next, set the titration value obtained in the absence of a polyisocyanate sample to V1ml. Next, calculate the isocyanate group (NCO) content (mass %) of the polyisocyanate according to the following formula.

[0638] Isocyanate group (NCO) content (mass %) = (V1-V2) × F × 42 / (W × 1000) × 100

[0639] [Physical Properties 2]

[0640] (Number average molecular weight and weight average molecular weight)

[0641] The number average molecular weight and the weight average molecular weight are based on polystyrene standards measured by gel permeation chromatography (GPC) using the following apparatus.

[0642] In order to measure the number average molecular weight of the polyisocyanate, the polyisocyanate before being blocked with a blocking agent is used as a measurement sample.

[0643] Regarding the weight average molecular weight, the blocked polyisocyanate composition or the polyvalent hydroxy compound is used as a measurement sample as it is. The measurement conditions are shown below.

[0644] (Measurement conditions)

[0645] Device: Made by Tosoh Corporation, HLC-802A

[0646] Column: Made by Tosoh Corporation, G1000HXL×1

[0647] G2000HXL×1

[0648] G3000HXL×1

[0649] Carrier: Tetrahydrofuran

[0650] Detection method: Differential refractometer

[0651] [Physical Properties 3]

[0652] (Average number of isocyanate groups)

[0653] The average number of isocyanate groups (average number of NCO) of the polyisocyanate is calculated by the following formula. It should be noted that, in the formula, "Mn" is the number average molecular weight of the polyisocyanate before the blocking agent, and the value measured in the above "Physical Property 2" is used. "NCO content" is the isocyanate group content of the polyisocyanate measured before the blocking agent, and the value calculated in the above "Physical Property 1" is used.

[0654] Average number of isocyanate groups = (Mn × NCO content × 0.01) / 42

[0655] [Physical Properties 4]

[0656] (Solid Content of Blocked Polyisocyanate Composition)

[0657] The solid content of the blocked polyisocyanate composition is determined as follows.

[0658] First, accurately weigh an aluminum dish with a bottom diameter of 38 mm. Then, accurately weigh about 1 g (W1) of the blocked polyisocyanate composition manufactured in the embodiments and comparative examples on the aluminum dish. Next, adjust the blocked polyisocyanate composition to a uniform thickness. Next, keep the blocked polyisocyanate composition placed on the aluminum dish in an oven at 105°C for 1 hour. Next, after the aluminum dish becomes room temperature, accurately weigh the blocked polyisocyanate composition (W2) remaining on the aluminum dish. Next, calculate the solid content (mass %) of the blocked polyisocyanate composition according to the following formula.

[0659] Solid content of blocked polyisocyanate composition (mass %) = W2 / W1×100

[0660] [Property 5]

[0661] (Hydroxy value)

[0662] The hydroxyl value of the polyvalent hydroxy compound is measured and calculated by potentiometric titration. In addition, the hydroxyl value is a value relative to the solid content in the polyvalent hydroxy compound.

[0663] [Physical Properties 6]

[0664] (Glass transition temperature Tg)

[0665] The glass transition temperature of the polyhydroxy compound is determined by dispersing the organic solvent and water in the polyhydroxy compound solution under reduced pressure and then vacuum drying the solution. The resulting substance is measured using a differential scanning calorimeter (DSC) at a heating rate of 5°C / min, and the resulting value is used as the glass transition temperature.

[0666] [Properties 7]

[0667] (Molar ratio of hydroxyl groups contained in polyol A to structural unit (I) (OH / structural unit (I))

[0668] The molar ratio of the content (molar) of the hydroxyl group contained in the polyol A in the blocked polyisocyanate composition to the structural unit (I) is calculated from the blending amounts of the polyol A and the blocking agent.

[0669] Alternatively, the content (molar) of the hydroxyl groups contained in the polyol A is measured by gas chromatography / mass spectrometry (GC / MS method), and the content (molar) of the structural unit (I) is measured by 13 The molar amount was calculated by C-NMR measurement, and the molar ratio was determined.

[0670] (Measurement conditions)

[0671] (Content of hydroxyl groups contained in polyol A (mol))

[0672] After adding 2-ethylhexanol in an amount of 5 times the molar amount of effective isocyanate groups in the blocked polyisocyanate composition to the blocked polyisocyanate composition, the mixture was heated at 120° C. for 5 hours. The generated polyol A component was measured by gas chromatography / mass spectrometry (GC / MS) for the heated reaction liquid, thereby calculating the content (molar) of hydroxyl groups contained in the polyol A in the blocked polyisocyanate composition.

[0673] Device: Agilent Technologies Japan, Ltd. "Agilent7890, 5977"

[0674] Column: Agilent Technologies Japan, Ltd. "HP-5MS" (L30m, I.D0.250mm, Film0.25um)

[0675] Carrier gas: Helium

[0676] Detector: MSD

[0677] Ionization method: EI

[0678] Inlet temperature: 320℃

[0679] Transfer temperature: 320℃

[0680] Oven temperature: 40°C (hold for 5 minutes) → (heating at 20°C / min) → 320°C (hold for 10 minutes)

[0681] Split ratio: 1 / 1000

[0682] Mass range: m / z 10~800

[0683] Injection volume: 0.5 μL

[0684] (Content of structural unit (I) (mol))

[0685] The content of the structural unit (I) in the blocked polyisocyanate composition is determined by 13 C-NMR.

[0686] Device: JEOL-ECZ500 (SC) (trade name)

[0687] Solvent: deuterated chloroform

[0688] Cumulative times: 5120 times

[0689] Sample concentration: 50wt / vol%

[0690] Chemical shift standard: deuterated chloroform was set to 77.0 ppm.

[0691] [Physical Property 8] Molar Ratio of Structural Unit (I-1) in Structural Unit (I)

[0692] The molar ratio of the structural unit (I-1) to the structural unit (I) in the blocked polyisocyanate composition (structural unit (I-1) / structural unit (I)) was calculated using the method shown below.

[0693] Specifically, by using "JEOL-ECZ500 (SC)" (trade name) manufactured by JEOL 13 The total molar amount of the structural unit (I) (including the structural unit (I-1)) and the molar amount of the structural unit (I-1) were calculated by C-NMR measurement, and the molar ratio thereof was determined.

[0694] (Measurement conditions)

[0695] Device: JEOL-ECZ500 (SC) (trade name)

[0696] Solvent: deuterated chloroform

[0697] Cumulative times: 5120 times

[0698] Sample concentration: 50wt / vol%

[0699] Chemical shift standard: deuterated chloroform was set to 77.0 ppm.

[0700] [Physical Properties 9]

[0701] (Molar ratio of structural unit (II) / structural unit (I))

[0702] The blocked polyisocyanate composition was prepared by drying under reduced pressure at 50° C. or less by evaporating the solvent and other components with an evaporator at a molar ratio of the structural unit (II) to the structural unit (I) (structural unit (II) / structural unit (I)). 13 C-NMR was used to measure the composition ratio of the structural unit (II) to the structural unit (I), and the molar ratio of the structural unit (II) to the structural unit (I) was calculated.

[0703] (Measurement conditions)

[0704] Device: JEOL-ECZ500 (SC) (trade name)

[0705] Solvent: deuterated chloroform

[0706] Cumulative times: 5120 times

[0707] Sample concentration: 50wt / vol%

[0708] Chemical shift standard: deuterated chloroform was set to 77.0 ppm.

[0709] [Properties 10]

[0710] (Amount of monool in blocked polyisocyanate)

[0711] The amount (mass %) of the monool in the blocked polyisocyanate composition was quantitatively determined by gas chromatography.

[0712] Installation: GC-2014 by SHIMADZU

[0713] Column: AgilentJ&WDB-1 (L30m, I.D0.25mm, Film1.00um)

[0714] Carrier gas: Helium

[0715] Detector: FID

[0716] Inlet temperature: 100℃

[0717] Detector temperature: 220°C

[0718] Oven temperature: 40°C (hold for 5 minutes) → (heating at 10°C / min) → 150°C (hold for 5 minutes)

[0719] Injection volume: 0.3μL

[0720] [Manufacturing of resin composition 1-1]

[0721] The polyvalent hydroxy compound OHP1 and each blocked isocyanate composition were mixed so that the ratio of the molar amount of isocyanate group to the molar amount of hydroxyl group (isocyanate group / hydroxyl group) was 1, and 2-propanol was further mixed so that the solid content was 35% by mass to obtain a resin composition.

[0722] [Manufacturing of resin composition 1-2]

[0723] The polyvalent hydroxy compound OHP1 and each blocked isocyanate composition were mixed so that the ratio of the molar amount of isocyanate group to the molar amount of hydroxyl group (isocyanate group / hydroxyl group) was 1, and butyl acetate was further mixed so that the solid content was 35% by mass to obtain a resin composition.

[0724] [Evaluation 1-1]

[0725] (Storage stability)

[0726] The resin composition obtained in the above "Manufacture of resin composition 1-1" was measured for initial viscosity and viscosity after storage at 40°C for 10 days (viscometer: RE-85R manufactured by Toki Sangyo Co., Ltd.). Next, the ratio of the viscosity after storage to the initial viscosity was calculated. Based on the calculated ratio of the viscosity after storage to the initial viscosity, the storage stability was evaluated according to the following evaluation criteria.

[0727] (Evaluation Criteria)

[0728] A: The ratio of the viscosity after storage to the initial viscosity is 2.0 or less

[0729] B: The ratio of the viscosity after storage to the initial viscosity is more than 2.0 and less than 3.0

[0730] C: Gelation

[0731] [Evaluation 1-2]

[0732] (Low temperature curing property: gel fraction)

[0733] The resin composition obtained in the above-mentioned "Manufacture of resin composition 1-2" was applied to a polypropylene (PP) plate in a manner such that the dry film thickness was 40 μm, and then heated and dried at 80°C for 30 minutes to obtain a resin film. The obtained resin film was stored at room temperature (23°C) for 1 week, and the gel fraction was measured. The gel fraction was calculated as a percentage (mass %) of the value obtained by dividing the mass of the undissolved portion of the resin film when it was immersed in acetone at 23°C for 24 hours by the mass before immersion. It should be noted that a gel fraction of 82% by mass or more was evaluated as good.

[0734] [Evaluation 1-3]

[0735] (Koenig hardness)

[0736] The resin composition obtained in the above "Manufacturing of resin composition 1-2" was applied to a glass plate in a manner such that the dry film thickness was 40 μm, and then heated and dried at 80° C. for 30 minutes to obtain a resin film. The obtained resin film was measured for Koenig hardness (times) under 23° C. using a Koenig hardness tester (BYK Gardner Pendulum hardness tester). It should be noted that a Koenig hardness of 40 times or more was evaluated as good.

[0737] [Evaluation 1-4]

[0738] (Strength: Maximum tensile stress)

[0739] The resin composition obtained in the above-mentioned "Manufacturing of resin composition 1-2" was applied to a polypropylene (PP) plate in a manner that the dry film thickness became 40 μm, and then heated and dried at 80°C for 30 minutes to obtain a resin film. The obtained resin film was cut into a width of 10 mm and a length of 40 mm, and the distance between the chucks was set to 20 mm. The tensile test was performed at a speed of 20 mm / min under a 23°C environment. The maximum point stress at this time was taken as the maximum tensile stress. It should be noted that the maximum tensile stress of 10.0 MPa or more was evaluated as good.

[0740] [Evaluation 1-5]

[0741] (Solvent resistance (xylene friction test))

[0742] The obtained water-based resin composition was applied to a glass plate in a manner such that the dry film thickness was 40 μm, and then heated and dried at 85°C for 30 minutes to obtain a resin film. The obtained resin film was stored at room temperature (23°C) for 1 day, and a cotton swab impregnated with xylene was rubbed back and forth 20 times at a length of 3 cm at 23°C to observe the state of the resin film. The solvent resistance was evaluated according to the state of the resin film and the following evaluation criteria. The evaluation result of B or above was evaluated as good solvent resistance.

[0743] A: Almost no degradation was observed

[0744] B: Streaks are observed locally at the friction part

[0745] C: Streaks were observed at the friction part, and filming was observed.

[0746] D: The area where the resin film of the friction part is completely dissolved

[0747] <Synthesis of Polyisocyanate>

[0748] [Synthesis Example 1-1]

[0749] (Synthesis of polyisocyanate P1-1)

[0750] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of HDI and 5.3 parts by mass of a polyester polyol (polycaprolactone triol) derived from a triol and ε-caprolactone ("PLACCEL 303" (trade name), average number of functional groups: 3, number average molecular weight 300) derived from a triol and ε-caprolactone were added under a nitrogen stream, and the temperature in the reactor was kept at 89° C. for 1 hour under stirring to carry out a urethanization reaction. Thereafter, the temperature in the reactor was kept at 63° C., an isocyanurate-forming catalyst tetramethylammonium octanoate was added, and phosphoric acid was added at a point in time when the yield was 52% by mass to stop the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain an isocyanurate-type polyisocyanate (hereinafter, sometimes referred to as "polyisocyanate P1-1").

[0751] The obtained polyisocyanate P1-1 had an NCO content of 18.6% by mass, a number average molecular weight of 1220, and an average number of isocyanate groups of 5.4. 1 H-NMR analysis confirmed the presence of an isocyanurate group.

[0752] [Synthesis Example 1-2]

[0753] (Synthesis of polyisocyanate P1-2)

[0754] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 81 parts by mass of HDI, 19 parts by mass of IPDI, and 3.35 parts by mass of trimethylolpropane (average number of functional groups: 3, molecular weight: 134) as a triol were added under a nitrogen stream, and the temperature in the reactor was kept at 88°C for 1 hour under stirring to carry out a urethanization reaction. Thereafter, the temperature in the reactor was kept at 78°C, 0.012 parts by mass of tetramethylammonium octanoate as an isocyanurate catalyst was added, and phosphoric acid was added at a point in time when the yield was 44% by mass to stop the reaction. After filtering the reaction liquid, unreacted HDI and IPDI were removed using a thin film evaporator to obtain an isocyanurate type polyisocyanate (hereinafter sometimes referred to as "polyisocyanate P1-2"). The obtained polyisocyanate P1-2 had an NCO content of 19.0% by mass, a number average molecular weight of 1170, and an average number of isocyanate groups of 5.3. In addition, the obtained polyisocyanate P1-2 is subjected to 1 H-NMR analysis confirmed the presence of an isocyanurate group.

[0755] [Synthesis Example 1-3]

[0756] (Synthesis of polyisocyanate P1-3)

[0757] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 70 parts by mass of HDI, 30 parts by mass of IPDI, and 2.9 parts by mass of trimethylolpropane (average number of functional groups: 3, molecular weight: 134) as a triol were added under a nitrogen stream, and the temperature in the reactor was kept at 88°C for 1 hour under stirring to carry out a urethanization reaction. Thereafter, the temperature in the reactor was kept at 78°C, 0.012 parts by mass of tetramethylammonium octanoate as an isocyanurate catalyst was added, and phosphoric acid was added at a point in time when the yield was 44% by mass to stop the reaction. After filtering the reaction liquid, unreacted HDI and IPDI were removed using a thin film evaporator to obtain an isocyanurate type polyisocyanate (hereinafter sometimes referred to as "polyisocyanate P1-3"). The obtained polyisocyanate P1-3 had an NCO content of 18.9% by mass, a number average molecular weight of 1130, and an average number of isocyanate groups of 5.1. In addition, the obtained polyisocyanate P1-3 is subjected to 1 H-NMR analysis confirmed the presence of an isocyanurate group.

[0758] [Synthesis Example 1-4]

[0759] (Synthesis of polyisocyanate P1-4)

[0760] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of HDI were added under a nitrogen flow, the temperature in the reactor was maintained at 60°C under stirring, 0.095 parts by mass of trimethylbenzylammonium hydroxide was added, and after 4.5 hours, 0.02 parts by mass of phosphoric acid was added when the conversion rate reached 40% by mass to stop the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain an isocyanurate-type polyisocyanate (hereinafter sometimes referred to as "polyisocyanate P1-4"). The NCO content of the obtained polyisocyanate P1-4 was 22.0% by mass, the number average molecular weight was 655, and the average number of isocyanate groups was 3.43. In addition, the obtained polyisocyanate P1-4 was subjected to 1 H-NMR analysis confirmed the presence of an isocyanurate group.

[0761] [Synthesis Example 1-5]

[0762] (Synthesis of polyisocyanate P1-5)

[0763] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 600 parts by mass of HDI and 10.8 parts of 1,3-butanediol as a diol were added under a nitrogen flow, and the temperature in the reactor was maintained at 90°C for 1 hour under stirring to carry out a urethane reaction. Thereafter, the temperature in the reactor was maintained at 80°C, 0.03 parts of tetramethylammonium octanoate was added as an isocyanurate catalyst, the refractive index of the reaction solution was measured, and phosphoric acid was added to stop the reaction when the yield was 55%. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain an isocyanurate-type polyisocyanate (hereinafter sometimes referred to as "polyisocyanate P1-5"). The NCO content of the obtained polyisocyanate P1-5 was 19.3% by mass, the number average molecular weight was 970, and the average number of isocyanate groups was 4.4. In addition, the obtained polyisocyanate P1-5 was subjected to 1 H-NMR analysis confirmed the presence of an isocyanurate group.

[0764] <Manufacturing of Blocked Polyisocyanate Composition>

[0765] [Example 1-1]

[0766] (Production of Blocked Polyisocyanate Composition BL-a1-1)

[0767] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P1-1 obtained in Synthesis Example 1-1, 0.59 parts by mass of polycaprolactone diol (hereinafter sometimes referred to as "C1") (manufactured by Daicel Corporation, "PLACCEL 205UT" (trade name), number average molecular weight 530, average number of functional groups 2) (0.50 mol% relative to 100 mol% of isocyanate groups), 0.008 parts by mass of 2-ethylhexyl acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., "JP-508T" (trade name)), and 54.2 parts by mass of dipropylene glycol dimethyl ether (DPDM) were mixed under a nitrogen stream and reacted at 80°C for 3 hours. The reaction solution was cooled to 40°C, and diisopropyl malonate (hereinafter sometimes referred to as "B1") in an amount of 50 mol% relative to 100 mol% of the isocyanate group, and di-tert-butyl malonate (hereinafter sometimes referred to as "B2") in an amount of 50 mol% relative to 100 mol% of the isocyanate group were added, and further, dipropylene glycol dimethyl ether (DPDM) was added to prepare the solid content in a manner of 60 mass%. Next, a methanol solution containing sodium methoxide (28 mass% relative to the total mass of the solution) was added dropwise while stirring: 1.1 parts by mass, and the external bath was adjusted so that the solution temperature became 47°C, and a blocking reaction was performed at 47°C for more than 6 hours. After confirming the disappearance of the peak of the isocyanate group by infrared spectroscopy (IR), a blocked polyisocyanate composition BL-a1-1 was obtained. For the obtained blocked polyisocyanate composition BL-a1-1, the solid content was 60.0 mass% and the weight average molecular weight was 2.1×10 4 .

[0768] [Examples 1-2 to 1-14, 1-17 to 1-21, 1-23, 1-26 and Comparative Examples 1-1 to 1-2] (Manufacturing of blocked polyisocyanate compositions BL-a1-2 to BL-a1-14, BL-a1-17 to BL-a1-21, BL-a1-23, BL-a1-26, and BL-b1-1 to BL-b1-2)

[0769] Each blocked polyisocyanate composition was produced by the same method as in Example 1-1 except that the types and blending amounts of the polyisocyanate, the polyol, and the blocking agent were as shown in Tables 1 to 6.

[0770] [Examples 1-15]

[0771] (Production of Blocked Polyisocyanate Composition BL-a1-15)

[0772] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P1-1 obtained in Synthesis Example 1-1, 50 parts by mass of diisopropyl malonate (B1) with respect to 100 parts by mass of isocyanate groups, and 50 parts by mass of di-tert-butyl malonate (B2) with respect to 100 parts by mass of isocyanate groups were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added so that the solid content became 60 parts by mass. Then, 1.1 parts by mass of a methanol solution containing sodium methoxide (28 parts by mass with respect to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature became 47° C., and a blocking reaction was performed at 47° C. for more than 6 hours. Next, 0.59 parts by mass of polycaprolactone diol (C1) (manufactured by Daicel Corporation, "PLACCEL 205UT" (trade name), number average molecular weight 530, average number of functional groups 2) was added, and the external bath was adjusted so that the solution temperature became 80° C., and the reaction was carried out for 2 hours to obtain a blocked polyisocyanate composition BL-a1-15. The obtained blocked polyisocyanate composition BL-a1-15 had a solid content of 60.1% by mass and a weight average molecular weight of 1.8×10 4 .

[0773] [Examples 1-16]

[0774] (Manufacture of Blocked Polyisocyanate Composition BL-a1-16)

[0775] In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux condenser, 100 parts by mass of the polyisocyanate P1-2 obtained in Synthesis Example 1-2 and polycaprolactone diol (C1) (manufactured by Daicel Corporation, "PLACCEL 205UT" (trade name), number average molecular weight 530, average number of functional groups 2): 0.59 mass parts (0.50 mol% relative to 100 mol% of isocyanate groups), methoxy polyethylene glycol (MPG-081, ethylene oxide repeating unit: 15, manufactured by Nippon Emulsifier Co., Ltd.) in an amount of 0.5 mol% relative to 100 mol% of isocyanate groups of polyisocyanate P1-2, 2-ethylhexyl acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., "JP-508T" (trade name)): 0.008 mass parts, and dipropylene glycol dimethyl ether (DPDM): 54.2 mass parts were mixed and reacted at 80°C for 4 hours. The reaction solution was cooled to 40°C, and 70 mol% of diisopropyl malonate (B1) relative to 100 mol% of isocyanate groups and 30 mol% of di-tert-butyl malonate (B2) relative to 100 mol% of isocyanate groups were added, and then dipropylene glycol dimethyl ether (DPDM) was added to prepare the solid content to 60% by mass. Next, a methanol solution containing sodium methoxide (28% by mass relative to the total mass of the solution) was added dropwise while stirring: 1.1 parts by mass, and the external bath was adjusted so that the solution temperature became 47°C, and the blocking reaction was carried out at 47°C for more than 6 hours. After confirming the disappearance of the peak of the isocyanate group by infrared spectroscopy (IR), a blocked polyisocyanate composition BL-a1-16 was obtained. For the obtained blocked polyisocyanate composition BL-a1-16, the solid content was 60.0% by mass and the weight average molecular weight was 2.0×10 4 .

[0776] [Examples 1-22]

[0777] (Production of Blocked Polyisocyanate Composition BL-a1-22)

[0778] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P1-1 obtained in Synthesis Example 1-1, 5.9 parts by mass of polycaprolactone diol (C1) (manufactured by Daicel Corporation, "PLACCEL 205UT" (trade name), number average molecular weight 530, average number of functional groups 2) (0.50 mol% relative to 100 mol% of isocyanate groups), 0.008 parts by mass of 2-ethylhexyl acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., "JP-508T" (trade name)), and 57.0 parts by mass of dipropylene glycol dimethyl ether (DPDM) were mixed under a nitrogen stream and reacted at 80°C for 3 hours. The reaction solution was cooled to 40°C, and diisopropyl malonate (B1) was added in an equimolar manner to the isocyanate group, and further, dipropylene glycol dimethyl ether (DPDM) was added to prepare the solid content to 60% by mass. Then, a methanol solution containing sodium methoxide (28% by mass relative to the total mass of the solution) was added dropwise while stirring: 1.1 parts by mass, and the external bath was adjusted so that the solution temperature became 47°C, and a blocking reaction was carried out at 47°C for more than 6 hours to obtain a blocked polyisocyanate composition intermediate. Thereafter, 200% by mole of tert-butyl alcohol was added relative to the blocked isocyanate group, and the generated isopropyl alcohol was removed by distillation under normal pressure while reacting at 80°C for 3 hours. Thereafter, isopropyl alcohol and tert-butyl alcohol were further distilled off under reduced pressure (50 kPa) at 60°C, and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-a1-22. The blocked polyisocyanate composition BL-a1-22 obtained had a solid content of 60.0% by mass and a weight average molecular weight of 9.0×10 3 .

[0779] [Example 1-24]

[0780] (Production of Blocked Polyisocyanate Composition BL-a1-24)

[0781] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P1-1 obtained in Synthesis Example 1-1, 5.9 parts by mass of polycaprolactone diol (C1) (manufactured by Daicel Corporation, "PLACCEL 205UT" (trade name), number average molecular weight 530, average number of functional groups 2) (0.50 mol% relative to 100 mol% of isocyanate groups), 0.008 parts by mass of 2-ethylhexyl acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., "JP-508T" (trade name)), and 57.0 parts by mass of dipropylene glycol dimethyl ether (DPDM) were mixed under a nitrogen stream and reacted at 80°C for 3 hours. The reaction solution was cooled to 40°C, and diisopropyl malonate (B1) was added in an equimolar amount to the isocyanate group, and further, dipropylene glycol dimethyl ether (DPDM) was added to prepare the solid content to 60% by mass. Then, a methanol solution containing sodium methoxide (28% by mass relative to the total mass of the solution) was added dropwise while stirring: 1.1 parts by mass, and the external bath was adjusted so that the solution temperature became 47°C, and a blocking reaction was carried out at 47°C for more than 6 hours to obtain a blocked polyisocyanate composition intermediate. Thereafter, 200 mol% of 2-methyl-2-butanol was added relative to the blocked isocyanate group, and the generated isopropanol was removed by distillation under normal pressure while reacting at 110°C for 5 hours. Thereafter, isopropanol and 2-methyl-2-butanol were distilled off at 60° C. under reduced pressure (50 kPa), and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-a1-24. The blocked polyisocyanate composition BL-a1-24 had a solid content of 60.0% by mass and a weight average molecular weight of 9.0×10 3 .

[0782] [Example 1-25]

[0783] (Production of Blocked Polyisocyanate Composition BL-a1-25)

[0784] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P1-1 obtained in Synthesis Example 1-1 and diisopropyl malonate (B1) in an equimolar amount with the isocyanate group were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added so that the solid content was 60% by mass. Then, 1.1 parts by mass of a methanol solution containing sodium methoxide (28% by mass relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 47°C, and a terminalization reaction was performed at 47°C for more than 6 hours. Then, 5.9 parts by mass of polycaprolactone diol (C1) (manufactured by Daicel Corporation, "PLACCEL 205UT" (trade name), number average molecular weight 530, average number of functional groups 2) was added, and the external bath was adjusted so that the solution temperature was 80°C, and the reaction was performed for 2 hours. Thereafter, 200 mol% of 2-methyl-2-butanol was added relative to the blocked isocyanate group, and the reaction was carried out at 110°C for 5 hours while removing the generated isopropyl alcohol by distillation under normal pressure. Thereafter, the isopropyl alcohol and 2-methyl-2-butanol were further distilled off under reduced pressure (50 kPa) at 60°C, and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass, thereby obtaining a blocked polyisocyanate composition BL-a1-25. The obtained blocked polyisocyanate composition BL-a1-25 had a solid content of 60.0% by mass and a weight average molecular weight of 9.0×10 3 .

[0785] <Manufacturing of polyhydric hydroxy compounds>

[0786] [Production Example 1]

[0787] (Manufacture of polyhydroxy compound OHP1)

[0788] In a four-necked flask equipped with a stirring device, a thermometer, a condenser, and a nitrogen inlet, 29 parts by mass of propylene glycol monomethyl ether were added, and the temperature was raised to 110°C under nitrogen aeration. After reaching 110°C, the nitrogen aeration was stopped, and a mixture containing 22.3 parts by mass of 2-hydroxyethyl methacrylate, 8.0 parts by mass of methyl methacrylate, 26.1 parts by mass of butyl acrylate, 42.3 parts by mass of styrene, 1.3 parts by mass of acrylic acid, and 1.9 parts by mass of 2,2'-azobis(isobutyronitrile) was added dropwise over 5.5 hours. Then, after stirring for 3 hours while blowing nitrogen at 115°C, the mixture was cooled to 30°C, and then the solvent was removed by an evaporator. Next, butyl acetate was added to obtain a solution of a polyhydroxy compound OHP1, which is an acrylic polyol resin, having a solid content of 60% by mass. For the polyhydroxy compound OHP1, the weight average molecular weight is Mw2.73×10 4, the hydroxyl value is 139 mgKOH / g, and the glass transition temperature Tg is 29.8°C.

[0789] In the following Tables 1 to 6, the following compounds are represented by abbreviations.

[0790] (Polyol A)

[0791] C1: polycaprolactone diol (manufactured by Daicel Corporation, "PLACCEL 205UT" (trade name), number average molecular weight 530, average number of functional groups 2)

[0792] C2: polycaprolactone diol (manufactured by Daicel Corporation, "PLACCEL 220CPT" (trade name), number average molecular weight 2000, average number of functional groups 2)

[0793] C3: polycaprolactone diol (manufactured by Daicel Corporation, "PLACCEL 240CP" (trade name), number average molecular weight 4000, average number of functional groups 2)

[0794] C4: 1,4-butanediol (molecular weight 90.12, number of hydroxyl groups 2)

[0795] C5: 1,3-Butanediol (molecular weight 90.12, number of hydroxyl groups 2)

[0796] (Capping agent)

[0797] B1: Diisopropyl Malonate

[0798] B2: Di-tert-butyl malonate

[0799] B3: Di(2-methyl-2-butyl)malonate

[0800] [Table 1]

[0801]

[0802] [Table 2]

[0803]

[0804] [Table 3]

[0805]

[0806] [Table 4]

[0807]

[0808] [Table 5]

[0809]

[0810] [Table 6]

[0811]

[0812] [Table 7]

[0813]

[0814] [Table 8]

[0815]

[0816] [Table 9]

[0817]

[0818] [Table 10]

[0819]

[0820] [Table 11]

[0821]

[0822] [Table 12]

[0823]

[0824] According to the above table, the blocked polyisocyanate compositions BL-a1-1 to BL-a1-16 (Examples 1-1 to 1-16) have good storage stability when prepared as resin compositions, and are excellent in curability at a low temperature of about 80° C., hardness, and strength when prepared as coating films.

[0825] In comparison of blocked polyisocyanate compositions BL-a1-1 to BL-a1-4 (Examples 1-1 to 1-4) having different amounts of polyol A, it can be seen that the smaller the amount of polyol A is, the more excellent the curability, hardness and strength at a low temperature of about 80°C when the coating film is formed are.

[0826] In comparison of blocked polyisocyanate compositions BL-a1-2, BL-a1-11 and BL-a1-12 (Examples 1-2, 1-11 and 1-12) having different molar ratios of blocking agent B1 to blocking agent B2, it can be seen that those with B1 / B2 of 70 / 30 or less have better curing properties and hardness at a low temperature of about 80°C when the coating film is formed, and those with B1 / B2 of 50 / 50 have particularly excellent strength when the coating film is formed.

[0827] In comparison of blocked polyisocyanate compositions BL-a1-11, BL-a1-13 and BL-a1-14 (Examples 1-11, 1-13 and 1-14) using different types of polyisocyanates, it can be seen that the smaller the average isocyanate group number of the polyisocyanate, the better the hardness of the coating film. On the other hand, it can be seen that the larger the average isocyanate group number of the polyisocyanate, the better the curing property at a low temperature of about 80°C.

[0828] The blocked polyisocyanate compositions BL-b1-1 to BL-b1-2 (Comparative Examples 1-1 and 1-2) that were not modified based on polyol A had good storage stability when made into resin compositions, but had poor curability, hardness, strength, and solvent resistance at a low temperature of about 80°C when made into coating films.

[0829] [Preparation of water-based resin composition]

[0830] A water-based main agent acrylic polyol (manufactured by Nuplex, "Setaqua (registered trademark) 6515" (trade name), OH (mol%) (on solids) = 3.3, acid value (mgKOH / g) = 9.9, solid content 45% by mass) and each blocked polyisocyanate composition were mixed in such a manner that the ratio of the molar amount of isocyanate groups to the molar amount of hydroxyl groups (isocyanate groups / hydroxyl groups) was 0.80. Ion exchange water was further mixed, and a trace amount of dimethylaminoethanol was added to prepare the solution in such a manner that the pH was between 8.0 and 8.5 and the solid content was 45% by mass. Next, the solution was stirred at 1000 rpm for 15 minutes using a homodispersor, and after degassing, a water-based resin composition was obtained.

[0831] [Evaluation 2-1]

[0832] (Low temperature curing)

[0833] The obtained resin composition is applied to a polypropylene (PP) plate in a manner that the dry film thickness becomes 40 μm, and then heated and dried at 85°C for 30 minutes to obtain a resin film. The obtained resin film is stored at room temperature (23°C) for 1 week, and the gel fraction is measured. The gel fraction is calculated as the percentage (mass %) of the value obtained by dividing the mass of the undissolved portion of the resin film when it is immersed in acetone at 23°C for 24 hours by the mass before immersion. The low-temperature curing property is evaluated according to the following evaluation criteria based on the obtained gel fraction. Those with an evaluation result of C or above are evaluated as having good low-temperature curing property.

[0834] (Evaluation Criteria)

[0835] A: Initial gel fraction is 85% by mass or more

[0836] B: Initial gel fraction is 82% by mass or more and less than 85% by mass

[0837] C: Initial gel fraction is 78% by mass or more and less than 82% by mass

[0838] D: Initial gel fraction is 70% by mass or more and less than 78% by mass

[0839] E: Initial gel fraction less than 70% by mass

[0840] [Evaluation 2-2]

[0841] (Storage stability)

[0842] 20 g of the obtained water-based resin composition was stored at 40°C for 3 days, and the water-based resin composition after storage was used to measure the gel fraction before storage (initial gel fraction) and the gel fraction after storage. The gel fraction was determined by the method described in "Evaluation 2-1". The gel fraction retention rate was calculated using the following formula.

[0843] Gel fraction retention rate (%) = (gel fraction after storage) / (initial gel fraction) × 100

[0844] Storage stability was evaluated based on the obtained gel fraction retention rate according to the following evaluation criteria. The storage stability was evaluated to be good when the evaluation result was D or higher.

[0845] (Evaluation Criteria)

[0846] A: Gel rate retention rate is more than 90%

[0847] B: Gel fraction retention rate is 80% or more and less than 90%

[0848] C: Gel fraction retention rate is 73% or more and less than 80%

[0849] D: Gel fraction retention rate is 67% or more and less than 73%

[0850] E: Gel fraction retention rate is 60% or more and less than 67%

[0851] F: Gel rate retention rate is more than 60%

[0852] [Evaluation 2-3]

[0853] (Koenig hardness)

[0854] A resin film was obtained on a glass plate using the same method as in the above-mentioned "Evaluation 2-1". The obtained resin film was measured for Koenig hardness (times) at 23°C using a Koenig hardness tester (BYK Gardner Pendulum hardness tester). Based on the Koenig hardness value, the Koenig hardness was evaluated according to the following evaluation criteria. The Koenig hardness was evaluated as good if the evaluation result was B or above.

[0855] (Evaluation Criteria)

[0856] A: More than 30 times

[0857] B: 25 or more times but less than 29 times

[0858] C: 20 or more times but less than 24 times

[0859] D: Less than 19 times

[0860] [Evaluation 2-4]

[0861] (Solvent resistance (ethanol friction test))

[0862] The obtained water-based resin composition was applied to a glass plate in a manner such that the dry film thickness was 40 μm, and then heated and dried at 85°C for 30 minutes to obtain a resin film. The obtained resin film was stored at room temperature (23°C) for 1 day, and the obtained resin film was rubbed back and forth 20 times with a cotton swab impregnated with ethanol at a length of 3 cm at 23°C to observe the state of the resin film. The solvent resistance was evaluated according to the state of the resin film and the following evaluation criteria. The evaluation results of B or above were evaluated as good solvent resistance.

[0863] (Evaluation Criteria)

[0864] A: Almost no degradation

[0865] B: Streaks are observed locally at the friction part

[0866] C: Streaks were observed at the friction part, and filming was observed.

[0867] D: The area where the resin film of the friction part is completely dissolved

[0868] <Synthesis of Polyisocyanate>

[0869] [Synthesis example 2-1]

[0870] (Synthesis of polyisocyanate P2-1)

[0871] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of HDI and 5.2 parts by mass of a polyester polyol derived from a triol and ε-caprolactone ("PLACCEL303" (trade name), average number of functional groups: 3, number average molecular weight 300, manufactured by Daicel Chemical Co., Ltd.) were added under a nitrogen stream, and the temperature in the reactor was maintained at 88°C for 1 hour under stirring to carry out a urethanization reaction. Thereafter, the temperature in the reactor was maintained at 62°C, an isocyanurate-forming catalyst tetramethylammonium octanoate was added, and phosphoric acid was added at a point in time when the yield was 51% by mass to stop the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain an isocyanurate-type polyisocyanate (hereinafter, sometimes referred to as "polyisocyanate P2-1"). The obtained polyisocyanate P2-1 had an NCO content of 18.8% by mass, a number average molecular weight of 1180, and an average number of isocyanate groups of 5.3. In addition, the obtained polyisocyanate P2-1 was subjected to 1 H-NMR analysis confirmed the presence of an isocyanurate group.

[0872] [Synthesis example 2-2]

[0873] (Synthesis of polyisocyanate P2-2)

[0874] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of HDI were added under a nitrogen flow, the temperature in the reactor was maintained at 60°C, and an isocyanurate-forming catalyst, tetramethylammonium octanoate, was added. When the yield reached 38% by mass, phosphoric acid was added to stop the reaction. After filtering the reaction solution, unreacted HDI was removed using a thin film evaporator to obtain an isocyanurate-type polyisocyanate (hereinafter sometimes referred to as "polyisocyanate P2-2"). The NCO content of the obtained polyisocyanate P2-2 was 22.2% by mass, the number average molecular weight was 650, and the average number of isocyanate groups was 3.4. In addition, the obtained polyisocyanate P2-2 was subjected to 1 H-NMR analysis confirmed the presence of an isocyanurate group.

[0875] [Synthesis example 2-3]

[0876] (Synthesis of polyisocyanate P2-3)

[0877] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of polyisocyanate P2-1, 13 parts by mass of dipropylene glycol dimethyl ether (DPDM), 15 parts by mass of methoxy polyethylene glycol (MPG-081, ethylene oxide repeating unit: 15, manufactured by Nippon Emulsifier Co., Ltd.) (5 mol% relative to 100 mol% of the isocyanate group of polyisocyanate P2-1), 0.08 parts by mass of 2-ethylhexyl acid phosphate (JP-508T, manufactured by Johoku Chemical Industry Co., Ltd.), and dipropylene glycol dimethyl ether (DPDM) were mixed under a nitrogen stream and stirred at 120° C. for 2 hours to obtain polyisocyanate P2-3. The obtained polyisocyanate P2-3 had an NCO content of 14.0% by mass and an average number of isocyanate groups of 5.0.

[0878] [Synthesis example 2-4]

[0879] (Synthesis of polyisocyanate P2-4)

[0880] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of polyisocyanate P2-2, 13 parts by mass of dipropylene glycol dimethyl ether (DPDM), 18 parts by mass of methoxy polyethylene glycol (MPG-081, ethylene oxide repeating unit: 15, manufactured by Nippon Emulsifier Co., Ltd.) (5 mol% relative to 100 mol% of the isocyanate group of polyisocyanate P2-2), 0.08 parts by mass of 2-ethylhexyl acid phosphate (JP-508T, manufactured by Johoku Chemical Industry Co., Ltd.), and dipropylene glycol dimethyl ether (DPDM) were mixed under a nitrogen stream and stirred at 120° C. for 2 hours to obtain polyisocyanate P2-4. The obtained polyisocyanate P2-4 had an NCO content of 16.2% by mass and an average number of isocyanate groups of 3.2.

[0881] <Manufacturing of Blocked Polyisocyanate Composition>

[0882] [Example 2-1]

[0883] (Production of Blocked Polyisocyanate Composition BL-a2-1)

[0884] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3, 43.9 parts by mass of diisopropyl malonate (70 mol % relative to 100 mol % of NCO groups), and 23.0 parts by mass of (2-methyl-2-pentyl) isopropyl malonate (30 mol % relative to 100 mol % of NCO groups) were placed under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added so that the solid content became 60 mol %. Subsequently, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 mol % relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature became 55° C., and a blocking reaction was performed at 55° C. for 5 hours to obtain a blocked polyisocyanate composition BL-a2-1 having a solid content of 60 wt %.

[0885] [Example 2-2]

[0886] (Production of Blocked Polyisocyanate Composition BL-a2-2)

[0887] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3, 43.9 parts by mass of diisopropyl malonate (70 mol % relative to 100 mol % of NCO groups), and 21.6 parts by mass of (2-methyl-2-butyl) isopropyl malonate (30 mol % relative to 100 mol % of NCO groups) were placed under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added so that the solid content became 60 mol %. Subsequently, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 mol % relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature became 55° C., and a blocking reaction was performed at 55° C. for 5 hours to obtain a blocked polyisocyanate composition BL-a2-2 having a solid content of 60 wt %.

[0888] [Example 2-3]

[0889] (Production of Blocked Polyisocyanate Composition BL-a2-3)

[0890] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 63.9 parts by mass of diisopropyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the solid content to 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition intermediate having a solid content of 60 wt%. Thereafter, 30 parts by mass of 2-methyl-2-butanol (100 mol% relative to the blocked isocyanate groups) was added, and the reaction was carried out at 80°C for 3 hours while removing the generated isopropanol by distillation under normal pressure. Thereafter, isopropyl alcohol and 2-methyl-2-butanol were further distilled off at 60° C. under reduced pressure (50 kPa), and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-a2-3.

[0891] [Examples 2-4]

[0892] (Production of Blocked Polyisocyanate Composition BL-a2-4)

[0893] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 63.9 parts by mass of diisopropyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the solid content to 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition intermediate with a solid content of 60 wt%. Thereafter, 15 parts by mass of 2-methyl-2-butanol (50 mol% relative to the blocked isocyanate group) was added, and the reaction was carried out at 80°C for 3 hours while removing the generated isopropanol by distillation under normal pressure. Thereafter, isopropyl alcohol and 2-methyl-2-butanol were further distilled off at 60° C. under reduced pressure (50 kPa), and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-a2-4.

[0894] [Example 2-5]

[0895] (Production of Blocked Polyisocyanate Composition BL-a2-5)

[0896] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3, 31.3 parts by mass of diisopropyl malonate (50 mol% relative to 100 mol% of NCO groups), and 34.0 parts by mass of (2-methyl-2-butyl) isopropyl malonate (50 mol% relative to 100 mol% of NCO groups) were placed under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added so that the solid content became 60 mol%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 mol% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature became 55° C., and a blocking reaction was performed at 55° C. for 5 hours to obtain a blocked polyisocyanate composition BL-a2-5 having a solid content of 60 wt%.

[0897] [Example 2-6]

[0898] (Production of Blocked Polyisocyanate Composition BL-a2-6)

[0899] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3, 60.2 parts by mass of diisopropyl malonate (96 mol% relative to 100 mol% of NCO groups), and 2.9 parts by mass of (2-methyl-2-butyl) isopropyl malonate (4 mol% relative to 100 mol% of NCO groups) were placed under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added so that the solid content became 60 wt%. Subsequently, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature became 55° C., and a blocking reaction was performed at 55° C. for 5 hours to obtain a blocked polyisocyanate composition BL-a2-6 having a solid content of 60 wt%.

[0900] [Example 2-7]

[0901] (Production of Blocked Polyisocyanate Composition BL-a2-7)

[0902] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 54.4 parts by mass of diethyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the mixture so that the solid content was 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition intermediate having a solid content of 60 wt%. Thereafter, 30 parts by mass of 2-methyl-2-butanol (100 mol% relative to the blocked isocyanate groups) was added, and the reaction was carried out at 80°C for 5 hours while removing the generated ethanol by distillation under normal pressure. Thereafter, ethanol and 2-methyl-2-butanol were further distilled off at 60° C. under reduced pressure (50 kPa), and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-a2-7.

[0903] [Example 2-8]

[0904] (Production of Blocked Polyisocyanate Composition BL-a2-8)

[0905] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 63.9 parts by mass of diisopropyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the solid content to 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition intermediate having a solid content of 60 wt%. Thereafter, 3-methyl-3-pentanol: 34.8 parts by mass (100 mol% relative to the blocked isocyanate group) was added, and the reaction was carried out at 80°C for 3 hours while removing the generated isopropanol by distillation under normal pressure. Thereafter, isopropyl alcohol and 3-methyl-3-pentanol were further distilled off at 60° C. under reduced pressure (50 kPa), and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-a2-8.

[0906] [Example 2-9]

[0907] (Production of Blocked Polyisocyanate Composition BL-a2-9)

[0908] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-4 obtained in Synthesis Example 2-4, 73.9 parts by mass of diisopropyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added so that the solid content was 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition intermediate having a solid content of 60 wt%. Thereafter, 40.2 parts by mass of 3-methyl-3-pentanol (100 mol% relative to the blocked isocyanate groups) was added, and the reaction was carried out at 80°C for 3 hours while removing the generated isopropanol by distillation under normal pressure. Thereafter, isopropyl alcohol and 3-methyl-3-pentanol were further distilled off at 60° C. under reduced pressure (50 kPa), and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-a2-9.

[0909] [Example 2-10]

[0910] (Manufacture of Blocked Polyisocyanate Composition BL-a2-10)

[0911] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 63.9 parts by mass of diisopropyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the solid content to 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature became 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition intermediate having a solid content of 60 wt%. Thereafter, 43.3 parts by mass of 3-ethyl-3-hexanol (100 mol% relative to the blocked isocyanate groups) was added, and the reaction was carried out at 80°C for 3 hours while removing the generated isopropyl alcohol by distillation under normal pressure. Thereafter, isopropyl alcohol and 3-ethyl-3-hexanol were further distilled off at 60° C. under reduced pressure (30 kPa), and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-a2-10.

[0912] [Example 2-11]

[0913] (Manufacture of Blocked Polyisocyanate Composition BL-a2-11)

[0914] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3, 12.5 parts by mass of diisopropyl malonate (20 mol% relative to 100 mol% of NCO groups), and 57.5 parts by mass of (2-methyl-2-butyl) isopropyl malonate (80 mol% relative to 100 mol% of NCO groups) were placed under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added so that the solid content became 60 mol%. Subsequently, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 mol% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature became 55° C., and a blocking reaction was performed at 55° C. for 5 hours to obtain a blocked polyisocyanate composition BL-a2-11 having a solid content of 60 wt%.

[0915] [Example 2-12]

[0916] (Production of Blocked Polyisocyanate Composition BL-a2-12)

[0917] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 63.9 parts by mass of diisopropyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the solid content to 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 mol% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition intermediate having a solid content of 60 wt%. Thereafter, 75 parts by mass of 2-methyl-2-butanol (250 mol% relative to the blocked isocyanate groups) was added, and the reaction was carried out at 80°C for 3 hours while removing the generated isopropanol by distillation under normal pressure. Thereafter, isopropyl alcohol and 2-methyl-2-butanol were further distilled off at 60° C. under reduced pressure (50 kPa), and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-a2-12.

[0918] [Example 2-13]

[0919] (Manufacture of Blocked Polyisocyanate Composition BL-a2-13)

[0920] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3, 43.9 parts by mass of diisopropyl malonate (70 mol % relative to 100 mol % of NCO groups), and 24.4 parts by mass of di(2-methyl-2-butyl) malonate (30 mol % relative to 100 mol % of NCO groups) were placed under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added so that the solid content became 60 mol %. Subsequently, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 mol % relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature became 55° C., and a blocking reaction was performed at 55° C. for 5 hours to obtain a blocked polyisocyanate composition BL-a2-13 having a solid content of 60 wt %.

[0921] [Comparative Example 2-1]

[0922] (Manufacture of Blocked Polyisocyanate Composition BL-b2-1)

[0923] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3, 43.9 parts by mass of diisopropyl malonate (70 mol % relative to 100 mol % of NCO groups), and 50.5 parts by mass of di-tert-butyl malonate (30 mol % relative to 100 mol % of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare a solid content of 60 wt %. Subsequently, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt % relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature became 55° C., and a blocking reaction was performed at 55° C. for 5 hours to obtain a blocked polyisocyanate composition BL-b2-1 having a solid content of 60 wt %.

[0924] [Comparative Example 2-2]

[0925] (Manufacture of Blocked Polyisocyanate Composition BL-b2-2)

[0926] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 63.9 parts by mass of diisopropyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the mixture so that the solid content was 60 wt%. Subsequently, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition BL-b2-2 having a solid content of 60 wt%.

[0927] [Comparative Example 2-3]

[0928] (Manufacture of Blocked Polyisocyanate Composition BL-b2-3)

[0929] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 54.3 parts by mass of diethyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the mixture so that the solid content was 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition BL-b2-3 having a solid content of 60 wt%.

[0930] [Comparative Examples 2-4]

[0931] (Manufacture of Blocked Polyisocyanate Composition BL-b2-4)

[0932] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 63.9 parts by mass of diisopropyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the mixture so that the solid content was 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 mol% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition intermediate having a solid content of 60 wt%. Thereafter, 49.3 parts by mass of tert-butyl alcohol (150 mol% relative to the blocked isocyanate groups) was added, and the mixture was reacted at 80°C for 5 hours under reflux. Thereafter, isopropyl alcohol and tert-butyl alcohol were further distilled off at 60° C. under reduced pressure (50 kPa), and finally, dipropylene glycol dimethyl ether (DPDM) was added to adjust the solid content to 60% by mass to obtain a blocked polyisocyanate composition BL-b2-4.

[0933] [Comparative Example 2-5]

[0934] (Manufacture of Blocked Polyisocyanate Composition BL-b2-5)

[0935] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate P2-3 obtained in Synthesis Example 2-3 and 73.4 parts by mass of di-tert-butyl malonate (102 mol% relative to 100 mol% of NCO groups) were added under a nitrogen stream, and dipropylene glycol dimethyl ether (DPDM) was further added to prepare the mixture so that the solid content was 60 wt%. Then, 1.0 parts by mass of a methanol solution containing sodium methoxide (28 wt% relative to the total mass of the solution) was added dropwise while stirring, and the external bath was adjusted so that the solution temperature was 55°C, and a blocking reaction was carried out at 55°C for 5 hours to obtain a blocked polyisocyanate composition BL-b2-5 having a solid content of 60 wt%.

[0936] The measurement results of the physical properties of each blocked polyisocyanate composition obtained in Examples and Comparative Examples and the evaluation results obtained by the methods described above are shown in the following table.

[0937] [Table 13]

[0938]

[0939] [Table 14]

[0940]

[0941] [Table 15]

[0942]

[0943] [Table 16]

[0944]

[0945] [Table 17]

[0946]

[0947] [Table 18]

[0948]

[0949] [Table 19]

[0950]

[0951] [Table 20]

[0952]

[0953] According to the above Tables 13 to 20, for R in the structural unit (I) 11 , R 12 and R 13 The blocked polyisocyanate compositions BL-a2-1 to BL-a2-10 (Examples 2-1 to 2-10) having a total carbon number of 4 or more have particularly good storage stability when made into resin compositions and good solvent resistance when made into resin films.

[0954] In addition, for the blocked polyisocyanate compositions BL-a2-2 to BL-a2-6 (Examples 2-2 to 2-6) having different molar ratios of structural unit (II) / structural unit (I), it can be seen that the smaller the molar ratio of structural unit (II) / structural unit (I), the better the low-temperature curing property and Koenig hardness when the resin film is prepared. On the other hand, it can be seen that the larger the molar ratio of structural unit (II) / structural unit (I), the better the storage stability.

[0955] For R in the structural unit (I) 11 , R 12 and R 13 The blocked polyisocyanate compositions BL-a2-3 and BL-a2-10 (Examples 2-3 and 2-10) with different alkyl groups show that R 11 , R 12 and R 13 The blocked polyisocyanate composition BL-a2-3 having a total carbon number of 4 tends to have better low-temperature curing property, Koenig hardness, and solvent resistance when formed into a resin film.

[0956] In addition, for the blocked polyisocyanate compositions BL-a2-3 and BL-a2-7 (Examples 2-3 and 2-7) having different types of blocking agents as the source of the structural unit (II), it can be seen that BL-a2-3 using diisopropyl malonate tends to have better low-temperature curing properties and Koenig hardness when formed into a resin film than BL-a2-7 using diethyl malonate.

[0957] In addition, for the blocked polyisocyanate compositions BL-a2-8 and BL-a2-9 (Examples 2-8 and 2-9) using different types of polyisocyanates for the blocking reaction, it can be seen that the blocked polyisocyanate composition BL-a2-8 using a polyisocyanate with a larger average number of isocyanate groups tends to have better low-temperature curing properties and Koenig hardness when formed into a resin film.

[0958] On the other hand, for R in the structural unit (I) 11 , R 12 and R 13 The blocked polyisocyanate compositions BL-b2-1 (Comparison Example 2-1), BL-b2-4 (Comparison Example 2-4) and BL-b2-5 (Comparison Example 2-5), each having a total carbon number of 3, can maintain good low-temperature curing properties, Koenig hardness and solubility when made into resin films, but have poor storage stability when made into water-based resin compositions.

[0959] In addition, for the blocked polyisocyanate composition BL-b2-2 (Comparative Example 2-2) and the blocked polyisocyanate BL-b2-3 (Comparative Example 2-3) not containing the structural unit (I), although the storage stability when made into a water-based resin composition can be maintained good, the low-temperature curing property, Koenig hardness, and solvent resistance when made into a resin film are poor.

[0960] Industrial Applicability

[0961] The blocked polyisocyanate composition of this embodiment can provide a blocked polyisocyanate composition having good storage stability when formed into a resin composition and excellent curability at a low temperature of about 80° C., hardness, and strength when formed into a coating film.

Claims

1. A blocked polyisocyanate composition, comprising: a blocked polyisocyanate derived from an active hydrogen compound, a polyisocyanate, and a blocking agent containing a malonate, wherein the active hydrogen compound has a number average molecular weight of 60 or more and 5000 or less, and an average number of functional groups of 1.6 or more and 2.4 or less, the active hydrogen compound is a polyol A, and the polyol A is one or more polyols selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanedimethanol, glycerol, and polycaprolactone polyols derived from these and ε-caprolactone, in, The blocked polyisocyanate composition is prepared by reacting the polyisocyanate with the active hydrogen compound to generate an active hydrogen compound-modified polyisocyanate, and then reacting the active hydrogen compound-modified polyisocyanate with a blocking agent. Wherein, the blocked polyisocyanate comprises a structural unit represented by general formula (I), In the general formula (I), R 11 , R 12 and R 13 are each independently an alkyl group which may contain one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and R 11 , R 12 and R 13 The total number of carbon atoms is 3 or more and 20 or less, R 14 , R 15 and R 16 Each independently represents a hydrogen atom or an alkyl group optionally containing one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and the wavy line represents a connecting bond, Wherein, as the structural unit represented by the general formula (I), it includes R 11 , R 12 and R 13 The total number of carbon atoms is 4 or more and 20 or less, R 16 A structural unit (I-1) represents a hydrogen atom.

2. The blocked polyisocyanate composition according to claim 1, in, The active hydrogen compound has a number average molecular weight of 100 or more and 4700 or less.

3. The blocked polyisocyanate composition according to claim 2, in, The active hydrogen compound has a number average molecular weight of 500 or more and 4000 or less.

4. The blocked polyisocyanate composition according to claim 1, in, The active hydrogen compound has an average functional group number of 1.9 or more and 2.1 or less.

5. The blocked polyisocyanate composition according to claim 1, in, The content of the structural unit derived from the active hydrogen compound is 0.05 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the structural unit derived from the polyisocyanate.

6. The blocked polyisocyanate composition according to claim 1, in, The polyisocyanate is a polyisocyanate having an average isocyanate group number of 3.5 or more, having an isocyanurate group, and derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

7. The blocked polyisocyanate composition according to claim 1, in, The polyisocyanate is a polyisocyanate derived from a diisocyanate and a polyol B having an average functional group number of 2.9 or more and 8.0 or less.

8. The blocked polyisocyanate composition according to claim 7, in, The number average molecular weight of the polyol B is 100 or more and 1000 or less.

9. The blocked polyisocyanate composition according to claim 1, in, In the general formula (I), R 11 , R 12 and R 13 The total carbon number of is 4 or more and 20 or less.

10. The blocked polyisocyanate composition according to claim 1, in, The molar ratio of the structural unit (I-1) in the structural unit (I) (structural unit (I-1) / structural unit (I)) is 10 mol% or more.

11. The blocked polyisocyanate composition according to claim 10, in, The molar ratio of the structural unit (I-1) in the structural unit (I) (structural unit (I-1) / structural unit (I)) is 80 mol% or more.

12. The blocked polyisocyanate composition according to claim 1 or 9, in, As the structural unit represented by the general formula (I), it includes R 11 , R 12 and R 13 are each independently an unsubstituted alkyl group, R 14 , R 15 and R 16 Each of the structural units is independently a hydrogen atom or an unsubstituted alkyl group.

13. The blocked polyisocyanate composition according to claim 1 or 9, in, The molar ratio of the hydroxyl group contained in the polyol A to the structural unit represented by the general formula (I) is 0.5 / 99.5 to 15 / 85.

14. The blocked polyisocyanate composition according to claim 13, in, The molar ratio of the hydroxyl group contained in the polyol A to the structural unit represented by the general formula (I) is 6 / 94 to 15 / 85.

15. The blocked polyisocyanate composition according to claim 1, in, A portion of the blocked polyisocyanate has a structural unit derived from a hydrophilic compound.

16. The blocked polyisocyanate composition according to claim 15, in, The hydrophilic compound includes one or more compounds selected from the group consisting of nonionic compounds and anionic compounds.

17. The blocked polyisocyanate composition according to claim 1, in, The capping agent includes a malonate ester having a secondary alkyl group.

18. The blocked polyisocyanate composition according to claim 17, in, The end-capping agent includes a malonate having a secondary alkyl group and a malonate having a tertiary alkyl group.

19. The blocked polyisocyanate composition according to claim 18, in, The molar ratio of the malonic acid ester having a secondary alkyl group to the malonic acid ester having a tertiary alkyl group (malonic acid ester having a secondary alkyl group / malonic acid ester having a tertiary alkyl group) is more than 5 / 95 and less than 95 / 5.

20. The blocked polyisocyanate composition according to claim 19, in, The molar ratio of the malonic acid ester having a secondary alkyl group to the malonic acid ester having a tertiary alkyl group (malonic acid ester having a secondary alkyl group / malonic acid ester having a tertiary alkyl group) is 30 / 70 or more and 93 / 7 or less.

21. A blocked polyisocyanate composition comprising a blocked polyisocyanate derived from a polyisocyanate and one or more blocking agents, The blocked polyisocyanate comprises a structural unit represented by general formula (I), In the general formula (I), R 11 , R 12 and R 13 are each independently an alkyl group which may contain one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and R 11 , R 12 and R 13 The total carbon number of R is 4 or more and 20 or less. 14 , R 15 and R 16 Each independently represents a hydrogen atom or an alkyl group optionally containing one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and the wavy line represents a connecting bond, in, As the structural unit represented by the general formula (I), R 16 A structural unit (I-1) representing a hydrogen atom, Wherein, the blocked polyisocyanate further comprises a structural unit represented by general formula (II), The molar ratio of the structural unit represented by the general formula (II) to the structural unit represented by the general formula (I) is 30 / 70 or more and 96 / 4 or less, In the general formula (II), R 21 , R 22 , R 23 and R 24 Each independently represents a hydrogen atom or an alkyl group which may have one or more substituents selected from the group consisting of a hydroxyl group and an amino group, and a wavy line represents a connecting bond.

22. The blocked polyisocyanate composition according to claim 21, in, The molar ratio of the structural unit represented by the general formula (II) to the structural unit represented by the general formula (I) is 50 / 50 or more and 70 / 30 or less.

23. The blocked polyisocyanate composition according to claim 21, in, The molar ratio of the structural unit (I-1) in the structural unit (I) (structural unit (I-1) / structural unit (I)) is 10 mol% or more.

24. The blocked polyisocyanate composition according to claim 23, in, The molar ratio of the structural unit (I-1) in the structural unit (I) (structural unit (I-1) / structural unit (I)) is 80 mol% or more.

25. The blocked polyisocyanate composition according to claim 24, in, The molar ratio of the structural unit (I-1) in the structural unit (I) (structural unit (I-1) / structural unit (I)) is 90 mol% or more.

26. The blocked polyisocyanate composition according to claim 21, in, In the general formula (I), R 11 , R 12 and R 13 Each is independently methyl or ethyl.

27. The blocked polyisocyanate composition according to claim 21, in, A part of the isocyanate groups of the polyisocyanate is modified with a nonionic compound.

28. The blocked polyisocyanate composition according to claim 21, in, The polyisocyanate has an average isocyanate group number of 2 or more.

29. The blocked polyisocyanate composition according to claim 21, in, The polyisocyanate is a polyisocyanate derived from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

30. The blocked polyisocyanate composition according to claim 21, in, The blocked polyisocyanate has an isocyanurate group. 31 . A resin composition comprising the blocked polyisocyanate composition according to claim 1 and a polyhydroxy compound.

32. A resin film obtained by curing the resin composition according to claim 31.

33. A laminate comprising two or more layers of the resin film according to claim 32 having different compositions, The average thickness per layer of the laminate is 1 μm or more and 50 μm or less.

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