Method for producing isocyanate composition and isocyanate composition

Abstract

A method for producing an isocyanate composition comprising: a step (I) for reacting at least one selected from the group consisting of amino acids, amino acid hydrochlorides, and amino alcohol compounds with a carbonate ester to obtain a carbamate intermediate represented by formula (1); a step (II) for esterifying the carbamate intermediate represented by formula (1) to obtain a carbamate compound represented by formula (2); and a step (III) for thermally decomposing the carbamate compound represented by formula (2) to obtain an isocyanate compound represented by formula (3).

Description

Method for producing an isocyanate composition and isocyanate composition

[0001] The present invention relates to a method for producing an isocyanate composition and to an isocyanate composition. This application claims priority based on Japanese Patent Application No. 2025-019580, filed in Japan on February 7, 2025, the contents of which are incorporated herein by reference.

[0002] Isocyanates are widely used as raw materials in the manufacture of polyurethane foams, paints, adhesives, and other products. The main industrial method for producing isocyanates is the reaction of amine compounds with phosgene (phosgene process), and almost all of the world's production is carried out by this process. However, the phosgene process has many problems.

[0003] Firstly, the process uses large quantities of phosgene as a raw material. Phosgene is extremely toxic, requiring special care in handling to prevent exposure to employees, and necessitating special equipment for waste treatment. Secondly, the phosgene process produces large quantities of highly corrosive hydrogen chloride as a by-product, necessitating a process to remove this hydrogen chloride, and the resulting isocyanate often contains hydrolyzable chlorine. Therefore, using isocyanate produced by the phosgene process may adversely affect the weather resistance and heat resistance of polyurethane products.

[0004] Against this backdrop, there is a need for a method of producing isocyanate compounds without using phosgene. One proposed method for producing isocyanate compounds without using phosgene is the thermal decomposition of carbamic acid esters. It has long been known that isocyanates and hydroxy compounds can be obtained by the thermal decomposition of carbamate compounds (see, for example, Non-Patent Document 1). The basic reaction is illustrated by the following formula (A).

[0005] (In the formula, R represents an a-valent organic residue, R' represents a monovalent organic residue, and a represents an integer greater than or equal to 1.)

[0006] On the other hand, the thermal decomposition reaction of carbamate compounds is prone to various irreversible side reactions, such as undesirable thermal denaturation of the carbamate compound and condensation reactions of isocyanates produced by the thermal decomposition. Examples of side reactions include the formation of urea bonds represented by formula (B) below, the production of carbodiimides represented by formula (C) below, and the production of isocyanurates represented by formula (D) below (see Non-Patent Documents 1 and 2).

[0007]

[0008] These side reactions not only lead to a decrease in the yield and selectivity of the target isocyanate, but in particular, in the production of polyisocyanates, polymeric solids can precipitate, clogging the reactor and making long-term operation difficult.

[0009] Furthermore, various methods have been proposed for producing isocyanates using carbamate compounds as raw materials.

[0010] Patent Document 1 discloses a method for continuously producing polyisocyanates without a catalyst in the presence of a high-boiling point solvent by thermal decomposition of carbamate compounds. In the method disclosed in Patent Document 1, the isocyanate is recovered by evaporation, so harsh temperature conditions are required when producing high-boiling point isocyanates, and there are concerns about the formation of precipitates and polymeric substances in the reactor due to the above-mentioned side reactions.

[0011] Furthermore, Patent Document 2 discloses that monocarbamates can be decomposed in good yield at relatively low temperatures, preferably under reduced pressure, with or without the presence of a catalyst and / or stabilizer, and without the use of a solvent. The decomposition products (monoisocyanates and alcohols) are removed from the boiling reaction mixture by distillation and collected separately by fractional condensation. Methods for partially removing the reaction mixture to remove by-products formed by thermal decomposition are generally described. Thus, by-products can be removed from the bottom of the reactor, but the problem of adhesion to the reactor walls remains, and the challenges for long-term operation have not been solved.

[0012] Patent Document 3 reports a method for synthesizing relatively high molecular weight isocyanate group-containing polysiloxane compounds without adhesion to the apparatus by synthesizing aryl carbamates from amino group-containing polysiloxane compounds and performing thermal decomposition without a catalyst. However, the method for purification after thermal decomposition is not described, and the substrate is limited to isocyanate group-containing polysiloxane compounds.

[0013] Furthermore, when the carbamate compound used as a thermal decomposition raw material has an amino acid alkyl ester structure, a known method for producing amino acid aminoalkyl esters involves esterifying an amino acid with an amino alcohol in the presence of an acid catalyst and an organic solvent. In this reaction system, the reaction does not proceed in the later stages, resulting in a low reaction rate. Therefore, a method has been proposed in which hydrogen chloride gas is supplied to the reaction system, followed by the supply of an organic solvent to remove the water produced by the reaction (see, for example, Patent Document 4).

[0014] However, in the method described in Patent Document 4, since hydrogen chloride is used as a catalyst, hydrogen chloride gas is distilled off along with the water (water vapor) produced in the reaction, raising concerns that the reaction vessel and flow path may corrode.

[0015] Furthermore, when synthesizing carbamate compounds having an amino acid structure, since the amino group of the starting material is protected by an acid, a manufacturing method is disclosed, as shown in Patent Document 5, in which a carbonate ester is reacted with an amine having an amino acid skeleton in the presence of a base. However, organic bases are mainly used as the base, which are expensive and often difficult to separate after the reaction.

[0016] Japanese Unexamined Patent Publication No. 5-255227, U.S. Patent No. 4386033, Japanese Unexamined Patent Publication No. 2001-48855, Japanese Unexamined Patent Publication No. 2003-252840, Japanese Patent No. 6843977

[0017] Dritter Jahrgang, “186.AW Hofmann: Ueber die aromatischen Cyanate.”, Berichte der Deutschen Chemischen Gesellschaft, Vol. 3, pp. 653-658, 1870.Dyer E et al., “Thermal Degradation of Alkyl N-Phenylcarbamates.”, Journal of American Chemical Society, Vol. 81, pp. 2138-2143, 1959.

[0018] As mentioned above, various studies have been conducted on methods for producing isocyanates by thermal decomposition of carbamate compounds having an amino acid skeleton. However, in the synthesis of carbamates having an amino acid skeleton, as mentioned above, there are challenges such as the difficulty in efficiently removing the base after synthesizing the corresponding carbamate compound from amino acids using inexpensive bases and raw materials. Furthermore, the production of isocyanates by thermal decomposition of carbamate compounds presents challenges such as the generation of high-boiling point byproducts and the adhesion of these byproducts to the reactor, making it difficult to produce them continuously in high yield over long periods of time. As a result, this method is hardly carried out industrially.

[0019] The object of the present invention is to provide a method for producing isocyanates having an amino acid skeleton without using phosgene, without encountering the various problems seen in the prior art, and enabling the stable production of isocyanates in high yield over a long period of time.

[0020] Therefore, the inventors repeatedly investigated each step of the raw material amino acid process, including carbamate, esterification, thermal decomposition, and purification, and as a result discovered a synthetic route that enables the continuous production of isocyanate compositions in high yield, thus completing the present invention.

[0021] The present invention aims to provide a method for producing an isocyanate composition that can continuously produce an isocyanate composition having an amino acid skeleton in high yield, and an isocyanate composition having an amino acid skeleton.

[0022] In other words, the present invention includes the following embodiments: [1] A method for producing an isocyanate composition, comprising: (I) reacting at least one selected from the group consisting of amino acids, amino acid hydrochlorides, and amino alcohol compounds with a carbonate ester to obtain a carbamate intermediate represented by the following formula (1); (II) esterifying the carbamate intermediate represented by the following formula (1) to obtain a carbamate compound represented by the following formula (2); and (III) thermally decomposing the carbamate compound represented by the following formula (2) to obtain an isocyanate compound represented by the following formula (3). (In the formula, R １１ R represents an aliphatic hydrocarbon group having a valency of 2 to 4 and having 1 to 40 carbon atoms, or an aromatic group having a valency of 2 to 3 and having 6 to 40 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having a valency of 2 to 4 and having 1 to 40 carbon atoms and having one or more atoms selected from the group consisting of oxygen, nitrogen, and sulfur atoms. １２ (where n11 is a monovalent aliphatic group, aromatic group, or aralkyl group having 1 to 20 carbon atoms. n11 is an integer from 1 to 3. n12 is an integer from 1 to 3. n11 + n12 is 4 or less.) (In the formula, R ２１ R represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms and being monovalent or quadrivalent, or an aromatic group having 6 to 40 carbon atoms and being monovalent or trivalent, or an aliphatic hydrocarbon group or aromatic group having 1 to 4 carbon atoms and being monovalent or quadrivalent, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms. ２２ (where n21 is an integer from 1 to 4.) (In the formula, R ３１represents an aliphatic hydrocarbon group having a valence of 1 or more and 4 or less and a carbon number of 1 or more and 40 or less, or an aromatic group having a valence of 1 or more and 3 or less and a carbon number of 6 or more and 40 or less, or an aliphatic hydrocarbon group or an aromatic group having a valence of 1 or more and 4 or less and having one or more selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms and having a carbon number of 1 or more and 40 or less. n31 represents an integer of 1 to 4.) [2] A step (IV) of distilling and purifying the composition produced in the step (III) to obtain an isocyanate composition, wherein the isocyanate composition contains a carbonyl compound represented by the following formula (4), and the content ratio of the carbonyl compound to the total mass of the isocyanate composition is 2.0 mass ppm or more and 1.0×10 ５ mass ppm or less, the method for producing an isocyanate composition according to [1]. (In the formula, R ４１ is a divalent or higher and tetravalent or lower aliphatic hydrocarbon group having a carbon number of 1 or more and 40 or less, or a divalent or higher and tetravalent or lower aliphatic hydrocarbon group having a carbon number of 1 or more and 40 or less and having one or both of 1 to 4 ester groups and nitrogen atoms, R ４２ is an aliphatic group having a carbon number of 1 to 20, an aryl group having a carbon number of 6 to 20, or an aralkyl group having a carbon number of 7 to 20, which may contain oxygen, and X represents an oxygen atom or an NH group.) [3] The method for producing an isocyanate composition according to [1] or [2], wherein the solvent used in the step (I) is a mixed solvent of a hydroxy compound represented by the following formula (5) and water. (In formula (5), ring A ５１ is an aromatic hydrocarbon ring having a carbon number of 6 or more and 20 or less. R ５１ is a hydrogen atom, an alkyl group having a carbon number of 1 or more and 20 or less, an alkoxy group having a carbon number of 1 or more and 20 or less, an aryl group having a carbon number of 6 or more and 20 or less, an aryloxy group having a carbon number of 6 or more and 20 or less, an aralkyl group having a carbon number of 7 or more and 20 or less, an aralkyloxy group having a carbon number of 7 or more and 20 or less, or a hydroxy group. R[[ID=1​​It may combine with to form a ring structure. Also, n51 is an integer between 1 and 10.) [4] A method for producing an isocyanate composition according to any one of [1] to [3], wherein step (I) includes a step of reacting an amino acid or an amino acid hydrochloride with a carbonate ester in the presence of an inorganic base, and further a step of removing the remaining inorganic base or its salt by washing with water. [5] A method for producing an isocyanate according to any one of [1] to [4], wherein the isocyanate composition contains an isocyanate compound in an amount of 1% by mass or more and 99% by mass or less. [6] A method for producing an isocyanate composition according to any one of [1] to [5], wherein the thermal decomposition in step (III) is carried out in the presence of a solvent. [7] A method for producing an isocyanate composition according to any one of [1] to [6], wherein step (I) comprises, in this order, a step (X) of reacting the amino alcohol compound with a compound having a phenolic hydroxyl group to obtain a phenol salt of the amino alcohol compound, and a step (Y) of reacting a diester carbonate with the phenol salt of the amino alcohol compound to obtain the carbamate intermediate. [8] A method for producing an isocyanate composition according to [7], further comprising a step (Z) of purifying the carbamate intermediate by distillation. [9] A method for producing an isocyanate composition according to any one of [1] to [8], wherein the amino alcohol compound is a compound represented by the following formula (6). (In equation (6), R ６１ (where n61 is an n61+1 valent organic group, and n61 is an integer between 1 and 3.)

[10] A method for producing an isocyanate composition according to [7] or [8], wherein in step (I), the production ratio of at least one selected from the group consisting of a cyclic compound represented by the following general formula (7) and a carbamate carbonate compound represented by the following general formula (8) is 2 to 10 mol% with respect to the total amount of the carbamate intermediate. (In general formula (7), R ７１ is an n71+2 valent organic group, R ７１ R in equation (6) is ６１ It is the same organic group. n71 is a non-negative integer, and is the number obtained by subtracting 1 from n61 in equation (6). (In general formula (8), R８１ , R ８３ R is a monovalent organic group, and each is a residue obtained by independently removing one hydroxyl group from a hydroxyl compound. ８２ (where n81 is an n81 + n82 + 1-valent organic group, n81 is an integer of 1 or more, and n82 is an integer of 0 or more.)

[11] A method for producing an isocyanate composition according to any one of [1] to

[10] , comprising a step of subjecting the composition containing the carbamate compound produced in step (II) to a distillation step to purify the carbamate compound, wherein the composition containing the carbamate compound contains one or more compounds selected from the group consisting of alkyl carbamate compounds represented by the following general formula (9) and carbamate carbonate compounds represented by the following general formula (8). (In general formula (9), n91 is an integer between 1 and 4, inclusive. ９１ , R ９２ Each is at least one selected from the group consisting of a hydrogen atom or a group represented by the following general formula (10) and a group represented by the following general formula (11), and R in the formula ９１ , R ９２ At least one of them is a group represented by the following general formula (11): R ９３ (This is a residue obtained by removing n91 hydroxyl groups from an alcohol compound.) (In general formula (10), n101 is an integer of 0 or 1. R １０１ R is a divalent organic group having 1 to 30 carbon atoms, which may have substituents. １０２ (This is a monovalent organic group having 1 to 30 carbon atoms, which may have substituents.) (In general formula (11), n111 is an integer of 0 or 1. R １１１ R is a divalent organic group having 30 or fewer carbon atoms, which may have substituents. １１２ (This is a residue obtained by removing one hydroxyl group from an alcohol compound.) (In general formula (8), R ８１ , R ８３ R is a monovalent organic group, and each is a residue obtained by independently removing one hydroxyl group from a hydroxyl compound. ８２(where n81 is an n81 + n82 + 1-valent organic group, n81 is an integer of 1 or more, and n82 is an integer of 0 or more.)

[12] The method for producing an isocyanate composition according to [4], wherein the inorganic base is one or more selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[13] The method for producing an isocyanate composition according to any one of [1] to

[12] , wherein the carbonate ester is a compound represented by the following general formula (12). (R in general formula (12)) １２１ R represents a monovalent aliphatic group, aromatic group, or aralkyl group having 1 to 20 carbon atoms.)

[14] R in formula (1) １２１A method for producing an isocyanate composition according to any one of [1] to

[13] , wherein is an aryl group.

[15] The amino acid is one or more selected from the group consisting of lysine, glycine, alanine (each isomer), valine (each isomer), leucine (each isomer), aspartic acid (each isomer), glutamine, glutamic acid (each isomer), ornithine, lysine (each isomer), phenylalanine (each isomer), cystine (each isomer), methionine (each isomer), serine (each isomer), threonine (each isomer), and 2,6-diaminoheptanedione, wherein each isomer may be either an optical isomer or a positional isomer or both, and the positional isomer may be either an α-amino acid or a β-amino acid or both. A method for producing an isocyanate composition according to any one of [1] to

[14] .

[16] A method for producing an isocyanate composition according to any one of [1] to

[15] , further comprising step (V) of purifying the isocyanate compound from a liquid containing the isocyanate compound represented by formula (3) by either distillation or chromatographic separation or both.

[17] A method for producing an isocyanate composition according to

[16] , wherein the mobile phase used for the chromatographic separation is an organic solvent containing at least one compound that is inert to the isocyanate compound and does not have an aromatic ring.

[18] A method for producing an isocyanate composition according to

[16] , wherein the stationary phase used for the chromatographic separation step is a stationary phase that utilizes π-π interactions.

[19] The method for producing an isocyanate composition according to any one of

[16] to

[18] , wherein, in the case that step (V) is a chromatographic separation step, the impurities to be separated are at least one selected from the group consisting of compounds represented by the following general formula (13), compounds represented by the following general formula (4), compounds represented by the following general formula (14), and carbonate esters represented by the following general formula (12). (In general formula (13), n131 represents an integer between 1 and 8, inclusive. １３１ R is a divalent organic group with 1 to 30 carbon atoms. １３２ (This refers to a monovalent organic group having between 1 and 30 carbon atoms.) (In the formula, R ４１is an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, or an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, and having one or both of 1 to 4 ester groups and a nitrogen atom, and R ４２ (wherein X is an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen, and X represents an oxygen atom or an NH group.) (In general formula (14), n141 and n142 represent integers between 0 and 8, and the sum of n141 and n142 is n31 in formula (3). １４１ R represents an aliphatic hydrocarbon group having a valency of 1 to 40 carbon atoms and being divalent to 40 or less, or an aromatic group having a valency of 6 to 40 carbon atoms and being monovalent to 3 or less, or an aliphatic hydrocarbon group or aromatic group having a valency of 1 to 4 carbon atoms and being monovalent to 4 or less, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms. １４２ (This is a monovalent aromatic hydrocarbon group having 1 to 30 carbon atoms, which may have substituents.) (R in general formula (12)) １２１ (This represents a monovalent aliphatic group, an aromatic group, or an aralkyl group having 1 to 20 carbon atoms.)

[20] A method for producing an isocyanate composition according to

[18] , wherein the stationary phase is a synthetic resin having an aromatic ring.

[21] A method for producing an isocyanate composition according to

[16] , wherein step (V) is a chromatographic separation step, and the chromatographic separation is a pseudo-mobile bed chromatography method.

[22] A method for producing an isocyanate composition according to any one of

[16] to

[21] , wherein step (V) is a chromatographic separation step, further comprising a step of heating a liquid film of the isocyanate composition and performing distillation before the chromatographic separation step.

[23] An isocyanate composition containing an isocyanate and a carbonyl compound represented by the following general formula (4), wherein the content of the isocyanate relative to the total mass of the isocyanate composition is 90% by mass or more, and the content of the carbonyl compound relative to the total mass of the isocyanate composition is 2.0 ppm by mass or more and 1.0 × 10 ５ An isocyanate composition having a mass of ppm or less. (In the formula, R ４１ is an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, or an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, and having one or both of 1 to 4 ester groups and a nitrogen atom, and R ４２ (wherein is an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen, and X represents an oxygen atom or an NH group.)

[24] The isocyanate composition according to

[23] , wherein the isocyanate is an isocyanate compound represented by the following general formula (3). (In the formula, R ３１ R represents an aliphatic hydrocarbon group having a valency of 1 to 4 and having 1 to 40 carbon atoms, or an aromatic group having a valency of 1 to 3 and having 6 to 40 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having a valency of 1 to 4 and having 1 to 4 carbon atoms, and having one or more selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms. n31 represents an integer from 1 to 4.)

[25] R in formula (3) above ３１ The composition according to

[24] , wherein the amino acid skeleton is present.

[26] Furthermore, the composition contains either or both of the compound represented by the following formula (15) and the ether compound, and the content of each of the compound represented by the following formula (15) or the ether compound relative to the total mass of the isocyanate composition is 2.0 ppm by mass or more and 1.0 × 10 ５ An isocyanate composition according to any one of

[23] to

[25] , wherein the mass is ppm or less. (In the formula, R １５１ R represents a monovalent aliphatic hydrocarbon group having 1 to 40 carbon atoms, or a monovalent aromatic group having 6 to 40 carbon atoms, or a monovalent aliphatic hydrocarbon group or aromatic group having 1 to 40 carbon atoms and having one or both of 1 to 4 ester groups and a nitrogen atom. １５２ (wherein represents a monovalent aromatic group having 1 to 20 carbon atoms.)

[27] The isocyanate composition according to

[26] , wherein the compound represented by formula (15) is a carbamate group-containing compound, a carbonate ester, or an ester compound.

[0023] According to the present invention, it is possible to provide a method for producing an isocyanate composition having an amino acid skeleton in high yield and an isocyanate composition having an amino acid skeleton.

[0024] This is a schematic diagram illustrating the general structure of the apparatus used in the method for producing the isocyanate composition as used in the examples. This is a schematic diagram illustrating the general structure of the apparatus used in the method for producing the isocyanate composition as used in the examples. This is a schematic diagram illustrating the general structure of the apparatus used in the method for producing the isocyanate composition as used in the examples. This is a schematic diagram illustrating the general structure of the apparatus used in the method for producing the isocyanate composition as used in the examples. This is a schematic diagram illustrating the general structure of the apparatus used in the method for producing the isocyanate composition as used in the examples.

[0025] In this specification, when referring to the IUPAC rules and the IUPAC Nomenclature rules established thereafter (except when specifically referring to IUPAC recommendations, etc., from other years), it means the "Organic and Biochemical Nomenclature" (revised 2nd edition, published in 1992 by Nankodo Publishing, Japan), which is based on the edition that included all the rules for organic chemistry and biochemistry and the rules for transliteration into Japanese, published in 1980 as a supplement to "The Domain of Chemistry" based on Recommendations 1979, and incorporates all subsequent revisions and recommendations. "Organic" refers to the general group of compounds subject to the nomenclature disclosed in said nomenclature. This group may also include those listed in the 1993 recommendation. However, the "organic" compounds subject to the above Nomenclature also include organometallic compounds and metal complexes. In this embodiment, unless otherwise specified, terms such as “organic group” and “substituent” refer to a group composed of atoms that do not contain metal atoms and / or metalloids. Furthermore, in this embodiment, “organic compounds,” “organic groups,” or “substituents” composed of atoms selected from H (hydrogen atom), C (carbon atom), N (nitrogen atom), O (oxygen atom), S (sulfur atom), Cl (chlorine atom), Br (bromine atom), and I (iodine atom) are used.

[0026] The following explanation will make frequent use of the terms "aliphatic" and "aromatic." According to the IUPAC rules mentioned above, organic compounds are classified into aliphatic compounds and aromatic compounds. Aliphatic compounds are defined in accordance with the definition of aliphatic compounds based on the 1995 IUPAC Recommendation. This recommendation defines aliphatic compounds as "Acycloid or cycloid, saturated or unsaturated carbon compounds, excluding aromatic compounds." Furthermore, the term "aliphatic compound" used in the description of this embodiment refers to an "organic compound," "organic group," or "substituent" that contains both saturated and unsaturated compounds, and is linear and cyclic in shape, and is composed of atoms selected from the group consisting of the above-mentioned H (hydrogen atom), C (carbon atom), N (nitrogen atom), O (oxygen atom), S (sulfur atom), Si (silicon atom), Cl (chlorine atom), Br (bromine atom), or I (iodine atom) halogen atoms.

[0027] When an aromatic group such as an aralkyl group is bonded to an aliphatic group, it may be described as an "aliphatic group substituted with an aromatic group" or a "group consisting of an aliphatic group to which an aromatic group is bonded." This is based on the reactivity in this embodiment, as the reactive properties of groups like aralkyl groups are very similar to those of aliphatic groups, not aromatic groups. Furthermore, non-aromatic reactive groups that include aralkyl groups, alkyl groups, etc., may be described as an "aliphatic group which may be substituted with an aromatic group" or an "aliphatic group which may have an aromatic group bonded to it."

[0028] In this specification, when describing the general formulas of compounds, the definitions in accordance with the Nomenclature rules established by IUPAC mentioned above will be used. However, common names may be used for the names of specific groups and the names of example compounds. Furthermore, when the number of atoms, substituents, or quantities are mentioned in this specification, all of these represent integers.

[0029] The best mode for carrying out the present invention (hereinafter referred to as "this embodiment") will be described in detail below. However, the present invention is not limited to the following embodiment and can be implemented with various modifications within the scope of its gist.

[0030] <Method for Producing the Isocyanate Composition> The method for producing the isocyanate composition of the present invention comprises the steps of (I) obtaining a carbamate intermediate, (II) obtaining a carbamate compound, and (III) obtaining an isocyanate compound. Each step will be described below.

[0031] [Step (I)] Step (I) is a step of reacting at least one selected from the group consisting of amino acids, amino acid hydrochlorides, and amino alcohol compounds with a carbonate ester to obtain a carbamate intermediate represented by the following formula (1). Step (I) has a first embodiment in which at least one selected from the group consisting of amino acids and amino acid hydrochlorides is reacted with a carbonate ester to obtain a carbamate intermediate represented by the following formula (1), and a second embodiment in which an amino alcohol is reacted with a carbonate ester to obtain a carbamate intermediate.

[0032] (In the formula, R １１ R represents an aliphatic hydrocarbon group having a valency of 2 to 4 and having 1 to 40 carbon atoms, or an aromatic group having a valency of 2 to 3 and having 6 to 40 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having a valency of 2 to 4 and having 1 to 40 carbon atoms and having one or more atoms selected from the group consisting of oxygen, nitrogen, and sulfur atoms. １２ (where n11 is a monovalent aliphatic group, aromatic group, or aralkyl group having 1 to 20 carbon atoms. n11 is an integer from 1 to 3. n12 is an integer from 1 to 3. n11 + n12 is 4 or less.)

[0033] [Step (I): First Embodiment] First, the carbamate intermediate obtained in the first embodiment of Step (I) will be described.

[0034] {Carbamate intermediate obtained in the first embodiment of step (I)} The carbamate intermediate obtained in the first embodiment of step (I) has a structure represented by the general formula (1), where R １２ , R １１ n11 and n12 are carbamate intermediates with the structures shown below.

[0035] (R １２ ) In the first embodiment of step (I), in formula (1), R １２ R represents a monovalent aliphatic group, aromatic group, or aralkyl group having 1 to 20 carbon atoms. In one embodiment of the present invention, R １２ This represents an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen.

[0036] In the first embodiment of process (I), R in formula (1) １２ Examples include alkyl groups such as methyl, ethyl, propyl (each isomer), butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl. Examples of groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl; aryl groups such as phenyl, naphthyl, and anthryl; and aryl groups such as methylphenyl (various isomers), ethylphenyl (various isomers), propylphenyl (various isomers), butylphenyl (various isomers), pentylphenyl (various isomers), hexylphenyl (various isomers), α-cumylphenyl (various isomers), methoxyphenyl (various isomers), and ethoxyphenyl (various isomers).

[0037] From the standpoint of distillation separation from isocyanates, it is preferable that the compound represented by formula (1) has a higher boiling point than the isocyanate and is highly versatile. From this standpoint, R １２ The aryl group is preferred, and aryl groups such as phenyl group, naphthyl group, anthryl group, pyrenyl group, phenanthryl group, methylphenyl group (each isomer), ethylphenyl group (each isomer), propylphenyl group (each isomer), butylphenyl group (each isomer), pentylphenyl group (each isomer), hexylphenyl group (each isomer), α-cumylphenyl group (each isomer), methoxyphenyl group (each isomer), and ethoxyphenyl group (each isomer) are preferred, and among these, phenyl group, α-cumylphenyl group (each isomer), methoxyphenyl group (each isomer), and ethoxyphenyl group (each isomer) are more preferred.

[0038] (R １１ In the first embodiment of step (I), R １１ Preferably, the structure is represented by the following formulas (1-1) to (1-12), with (1-1), (1-2), (1-3), (1-4), (1-5), (1-6), (1-8), (1-9), and (1-10) being more preferred. In each formula, the wavy line indicates a bond with NH, and the dotted line indicates a bond with an OH group.

[0039]

[0040] (n11) In formula (1), n11 represents the number of carbamate groups, and in the first embodiment of step (I), n11 is an integer between 1 and 3.

[0041] (n12) In formula (1), n12 represents the number of hydroxyl groups, and in the first embodiment of step (I), n12 is between 1 and 2, and is a value such that n11 + n12 is 4 or less.

[0042] The method for producing the carbamate intermediate represented by formula (1) in the first embodiment of step (I) is not particularly limited other than reacting at least one selected from the group consisting of amino acids and amino acid hydrochlorides with a carbonate ester, but known methods can be used. For example, the carbamate intermediate may be produced by reacting a carbonate ester with an amino acid or amino acid hydrochloride. Alternatively, the carbamate intermediate may be produced by reacting an amino acid or amino acid hydrochloride with urea and an aliphatic alcohol or aromatic hydroxy compound.

[0043] In the first embodiment of step (I), it is preferable that the step involves reacting an amino acid or amino acid hydrochloride with a carbonate ester in the presence of an inorganic base. In this case, it is preferable that the step includes removing any remaining inorganic base or its salt by washing with water.

[0044] While the inorganic base is not particularly limited, lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, cesium hydroxide, calcium hydroxide, sodium carbonate, lithium carbonate, potassium carbonate, cesium carbonate, and calcium carbonate are preferred, and from the viewpoint of removal after the reaction, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate are more preferred.

[0045] In the reaction for synthesizing the carbamate intermediate represented by formula (1) in the first embodiment of step (I), a reactor that appropriately meets the conditions is selected. Specifically, conventionally known reactors such as stirred tanks, pressurized stirred tanks, vacuum stirred tanks, column reactors, distillation columns, packed columns, and thin-film distillers can be used in appropriate combinations. For example, various known methods can be used, such as a system using a reactor that includes a distillation column, a multi-stage distillation column, a multi-tube reactor, a continuous multi-stage distillation column, a packed column, a thin-film evaporator, a reactor with an internal support, a forced-circulation reactor, a drop film evaporator, or a drop evaporator, and a system combining these. From the viewpoint of quickly mixing amino acids, amino acid hydrochlorides, or amino alcohols with carbonate esters and a solvent, and distilling off low-boiling point components after the reaction, a method using a stirred tank equipped with a distillation column or a multi-stage stirred tank is preferred. The selection of reactors is the same for other steps, such as the second embodiment of step (I), step (II), step (III), etc.

[0046] There are no particular restrictions on the type of condenser provided in the reactor, and known condensers can be used. For example, conventionally known condensers such as multi-tube cylindrical condensers, double-tube condensers, single-tube condensers, and air-cooled condensers can be used in appropriate combinations. The condenser may be provided inside the reactor or outside the reactor and connected to the reactor by piping, and various forms can be adopted considering the type of reactor and condenser, the method of handling the condensate, etc. There are no particular restrictions on the material of the reactor and condenser, and known materials can be used as long as they do not adversely affect the carbamate or the products such as aromatic hydroxy compounds and isocyanates. For example, glass, stainless steel, carbon steel, Hastelloy®, or materials with a glass lining or Teflon® coating can be used. SUS304, SUS316, and SUS316L are inexpensive and preferably used. If necessary, instrumentation such as flow meters and thermometers, and known process equipment such as reboilers, pumps, and condensers may be added. Heating may be done by known methods such as steam or heaters, and cooling may be done by known methods such as natural cooling, cooling water, or brine. Additional processes may be added as necessary. The type of condenser provided in the reactor is the same for other processes such as process (II), process (III), etc.

[0047] For example, as a first embodiment of step (I), the following method can be exemplified for the production of a carbamate intermediate from a carbonate ester, an amino acid, and an amino acid hydrochloride.

[0048] Since the carbonate ester, amino acid, and amino acid hydrochloride are solids, the reaction may be carried out in the presence of a solvent.

[0049] Furthermore, since the amino group of amino acids and amino acid hydrochlorides is protonated by a carboxyl group or hydrochloric acid, reducing its reactivity, a base may be added for deprotonation.

[0050] {Amino Acids and Amino Acid Hydrochlorides} Amino acids that can be used in the first embodiment of step (I) include one or more selected from the group consisting of glycine, alanine (each isomer), arginine, asparagine, glutamine, glycine, lysine (each isomer), aspartic acid (each isomer), glutamine, glutamic acid (each isomer), ornithine, histidine, isoleucine, leucine (each isomer), cystine (each isomer), methionine (each isomer), phenylalanine (each isomer), tryptophan, valine (each isomer), serine (each isomer), threonine (each isomer), and 2,6-diaminoheptanedione. Each isomer may be either an optical isomer or a positional isomer, or both. The positional isomer may be either an α-amino acid or a β-amino acid, or both.

[0051] In particular, the amino acids that can be used in the first embodiment of step (I) are preferably glycine, alanine, valine, aspartic acid, lysine, glutamine, glutamic acid, methionine, ornithine, or leucine (including hydrochloride salts of various amino acids), and more preferably glycine, alanine, valine, aspartic acid, lysine, glutamine, glutamic acid, methionine, ornithine (including hydrochloride salts of various amino acids).

[0052] {Carbonate ester} The carbonate ester that can be used in the first embodiment of step (I) is not particularly limited, but compounds represented by the following formula (12) are preferred.

[0053] (R in equation (12)) １２１ (This indicates a monovalent aliphatic group, aromatic group, or aralkyl group having 1 to 20 carbon atoms.)

[0054] Examples of preferred carbonate esters represented by formula (12) include diphenyl carbonate, bis(2-methoxyphenyl) carbonate, bis(2-ethoxyphenyl) carbonate, and bis(α-cumylphenyl) carbonate (various isomers).

[0055] {Solvent} As the solvent that can be used in step (I), since amino acids are water-soluble, it is preferable to use a mixed solvent of a hydroxy compound represented by the following formula (5) and water.

[0056]

[0057] (In formula (5), ring A ５１ R is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. ５１ R is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, or a hydroxyl group. ５１ is ring A ５１ It may also be combined with other elements to form a ring structure. Furthermore, n51 is an integer between 1 and 10.

[0058] (R ５１ ) R ５１ Examples of alkyl groups having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group (each isomer), butyl group (each isomer), pentyl group (each isomer), hexyl group (each isomer), heptyl group (each isomer), octyl group (each isomer), nonyl group (each isomer), decyl group (each isomer), dodecyl group (each isomer), octadecyl group (each isomer), and so on.

[0059] R ５１ Examples of alkoxy groups having 1 to 20 carbon atoms include methoxy, ethoxy, propoxy (each isomer), butyloxy (each isomer), pentyloxy (each isomer), hexyloxy (each isomer), heptyloxy (each isomer), octyloxy (each isomer), nonyloxy (each isomer), decyloxy (each isomer), dodecyloxy (each isomer), octadecyloxy (each isomer), and so on.

[0060] R ５１ Examples of aryl groups having 6 to 20 carbon atoms include phenyl groups and naphthyl groups.

[0061] R ５１Examples of aryl groups having an alkyl group as a substituent include methylphenyl group (various isomers), ethylphenyl group (various isomers), propylphenyl group (various isomers), butylphenyl group (various isomers), pentylphenyl group (various isomers), hexylphenyl group (various isomers), heptylphenyl group (various isomers), octylphenyl group (various isomers), nonylphenyl group (various isomers), decylphenyl group (various isomers), biphenyl group (various isomers), dimethylphenyl group (various isomers), diethylphenyl group (various isomers), dipropylphenyl group (various isomers), dibutylphenyl group (various isomers), dipentylphenyl group (various isomers), dihexylphenyl group (various isomers), diheptylphenyl group (various isomers), terphenyl group (various isomers), trimethylphenyl group (various isomers), triethylphenyl group (various isomers), tripropylphenyl group (various isomers), tributylphenyl group (various isomers), and the like.

[0062] R ５１ Examples of aryloxy groups having 6 to 20 carbon atoms include phenoxy group, methylphenoxy group (various isomers), ethylphenoxy group (various isomers), propylphenoxy group (various isomers), butylphenoxy group (various isomers), pentylphenoxy group (various isomers), hexylphenoxy group (various isomers), heptylphenoxy group (various isomers), octylphenoxy group (various isomers), nonylphenoxy group (various isomers), decylphenoxy group (various isomers), phenylphenoxy group (various isomers), Examples include dimethylphenoxy group (various isomers), diethylphenoxy group (various isomers), dipropylphenoxy group (various isomers), dibutylphenoxy group (various isomers), dipentylphenoxy group (various isomers), dihexylphenoxy group (various isomers), diheptylphenoxy group (various isomers), diphenylphenoxy group (various isomers), trimethylphenoxy group (various isomers), triethylphenoxy group (various isomers), tripropylphenoxy group (various isomers), tributylphenoxy group (various isomers), and so on.

[0063] R ５１Examples of aralkyl groups having 7 to 20 carbon atoms include phenylmethyl group, phenylethyl group (various isomers), phenylpropyl group (various isomers), phenylbutyl group (various isomers), phenylpentyl group (various isomers), phenylhexyl group (various isomers), phenylheptyl group (various isomers), phenyloctyl group (various isomers), and phenylnonyl group (various isomers).

[0064] R ５１ Examples of aralkyloxy groups having 7 to 20 carbon atoms include phenylmethoxy group, phenylethoxy group (various isomers), phenylpropyloxy group (various isomers), phenylbutyloxy group (various isomers), phenylpentyloxy group (various isomers), phenylhexyloxy group (various isomers), phenylheptyloxy group (various isomers), phenyloctyloxy group (various isomers), and phenylnonyloxy group (various isomers).

[0065] (Ring A ５１ ) Ring A ５１ This is an aromatic hydrocarbon ring with 6 to 20 carbon atoms. Ring A ５１ Ring A may be a monoring, polyring, or fused ring. ５１ Specifically, examples include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, naphthalene rings, chrysene rings, pyrene rings, triphenylene rings, pentalene rings, azulene rings, heptalene rings, indacene rings, biphenylene rings, acenaphthylene rings, aceantrylene rings, acephenanthrylene rings, etc. Among these, ring A ５１ The preferred rings are benzene rings, naphthalene rings, or anthracene rings, with benzene rings being more preferred. Furthermore, these rings are R ５１ It may have substituents other than R. ５１ Other substituents include R ５１ The same examples as those given in [reference] can be cited. ５１ and R ５１ Other substituents consist of different functional groups.

[0066] (n51) n51 is substituent R ５１ This indicates a number, which is an integer between 1 and 10 (inclusive).

[0067] In the formula (5), ring A ５１ Examples of the compound in which is a benzene ring include, for example, the compound represented by the following formula (5)-1.

[0068]

[0069] In formula (5)-1, R ５１１ to R ５１５ are each independently the same as the above R ５１ .

[0070] Among them, it is preferable that at least one of R ５１１ to R ５１５ is a hydrogen atom, and it is more preferable that all of R ５１１ to R ５１５ are hydrogen atoms.

[0071] Preferred hydroxy compounds include, for example, phenol, 2-ethylphenol, 2-propylphenol (each isomer), 2-butylphenol (each isomer), 2-pentylphenol (each isomer), 2-hexylphenol (each isomer), 2-heptylphenol (each isomer), 2-phenylphenol, 2,6-dimethylphenol, 2,4-diethylphenol, 2,6-diethylphenol, 2,4-dipropylphenol (each isomer), 2,6-dipropylphenol (each isomer), 2,4-dibutylphenol (each isomer), 2,4-dicumylphenol, α-cumylphenol (each isomer), methoxyphenol (each isomer), ethoxyphenol (each isomer), etc. Among these, phenol, methoxyphenol (each isomer), ethoxyphenol, and α-cumylphenol (each isomer) are preferred.

[0072] {Bases} The bases used for deprotonation are not particularly limited, but aniline, ammonia, triethylamine, pyridine, 4-dimethylaminopyridine, 4-dimethylaminopyridine, diazabicycloundecene, 1,8-bis(dimethylamino)naphthalene, imidazole, histidine, 1,4-diazabicycloundecene, lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, calcium hydroxide, sodium carbonate, lithium carbonate, potassium carbonate, cesium carbonate, calcium carbonate, and tetramethylammonium hydroxide are preferred, and from the viewpoint of removal after the reaction, ammonia, triethylamine, pyridine, imidazole, lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, calcium hydroxide, sodium carbonate, lithium carbonate, potassium carbonate, cesium carbonate, calcium carbonate, and tetramethylammonium hydroxide are more preferred.

[0073] {Reaction Temperature} The reaction temperature in the first embodiment of step (I) is not particularly limited, but is preferably 20°C to 120°C, and more preferably 40°C to 90°C. From the viewpoint of increasing the reaction rate, a reaction temperature of 40°C or higher is preferred, but if the reaction temperature is too high, a side reaction may occur in which the generated carbamate intermediate reacts with the starting amine compound, and the solvent may volatilize, so a temperature of 90°C or lower is preferred.

[0074] {Reaction Time} There are no particular restrictions on the reaction time of the first embodiment of step (I), but it is usually 0.001 hours or more and 100 hours or less, preferably 0.01 hours or more and 50 hours or less, and more preferably 0.1 hours or more and 20 hours or less.

[0075] {Amount of water} The amount of water used in the first embodiment of step (I) is not particularly limited, but it is preferably more than the amount required to dissolve the inorganic base and amino acid. The mixing ratio of water to hydroxy compound is not particularly limited, but it is preferably 0.1 to 100 times the mass of the hydroxy compound.

[0076] {Amount of hydroxy compound} There are no particular restrictions on the amount of hydroxy compound used in the first embodiment of step (I), but it is preferably greater than or equal to the amount that dissolves the carbonate ester, and preferably 0.1 times or more and 100 times or less by mass relative to the carbonate ester.

[0077] {Purification} In the first embodiment of step (I), the carbamate intermediate obtained may be purified. The method for purifying the carbamate intermediate represented by formula (1) is not particularly limited, but after the reaction, an organic solvent may be added and the organic phase may be washed with an acidic or neutral aqueous solution to remove any remaining bases or their salts. Alternatively, the remaining solvent and various raw materials may be removed by distillation, or the product may be purified by reprecipitation or recrystallization. Among these, from the viewpoint of efficiently purifying the carbamate compound, the method of washing the organic phase with an organic solvent followed by distillation purification is preferred.

[0078] {{Organic solvent during purification}} In the first embodiment of step (I), the organic solvent used to purify the obtained carbamate intermediate is not particularly limited, but toluene, xylene, cresol, phenol, guaiacol, cumylphenol (various isomers), chlorobenzene, dichlorobenzene (various isomers), chloroform, dichloroethane, cyclohexanone, methylcyclohexanone, methyl ethyl ketone, anisole, and toluene are preferably used.

[0079] [Process (I): Second Embodiment] A second embodiment of Process (I) will be described. The second embodiment of Process (I) includes the following steps (X) and (Y) in this order. Step (X): A step of reacting an amino alcohol compound with a compound having a phenolic hydroxyl group (hereinafter sometimes referred to as a "phenolic hydroxyl group-containing compound") to obtain a phenol salt of the amino alcohol compound. Step (Y): A step of reacting a diester carbonate with the phenol salt of the amino alcohol compound to obtain a carbamate intermediate.

[0080] Furthermore, the second embodiment of step (I) may include a step (Z) of purifying the carbamate intermediate by distillation.

[0081] In conventional reactions to obtain carbamates from amines and diester carbonates, in addition to the main reaction shown in the following reaction equation (101), the resulting carbamate reacts with the remaining amine in the starting material to form a urea bond, resulting in the side reaction shown in the following reaction equation (102). Therefore, in order to produce carbamates efficiently, it is necessary to suppress this side reaction.

[0082]

[0083] In the above reaction formulas (101) and (102), R, R', and R'' are each independently an alkyl group, an aryl group, or an aralkyl group.

[0084] In contrast, in the second embodiment of step (I), the inventors surprisingly found that by neutralizing the amino alcohol compound with a phenolic hydroxyl group-containing compound to obtain a phenol salt of the amino alcohol compound, and then reacting it with a diester carbonate, they could suppress the side reaction (102) that produces the compound having a urea bond and improve the selectivity of the reaction that produces the carbamate.

[0085] Although the reason for the above effects is not clear, as shown in the following reaction equations (104) and (105), the nucleophilicity of the amino alcohol compound is suppressed when it forms a salt with the phenolic hydroxyl group. This suppresses the progress of the side reaction (102) that forms a urea bond, which has a higher activation energy than carbamate, and thus increases the selectivity of the carbamate.

[0086] Furthermore, the inventors' investigations revealed that when the phenolic hydroxyl group-containing compound and the amino alcohol compound are mixed and reacted using only the phenolic hydroxyl group-containing compound as a solvent, without prior mixing of the phenolic hydroxyl group-containing compound and the amino alcohol compound, the formation of the phenol salt of the amino alcohol compound is insufficient, and the generation of a compound containing a urea bond occurs due to the localized high temperature caused by the heat of neutralization.

[0087]

[0088] In reaction equation (104), n11 is an integer greater than or equal to 1. １０１is an organic group having a valence of n11 + 1. R ３１ is a residue obtained by removing one of the hydroxy groups from an aromatic compound having one or more hydroxy groups directly bonded to an aromatic ring. In Reaction Scheme (105), n11 is an integer of 1 or more. R １０１ is an organic group having a valence of n11 + 1. R ３１ is a residue obtained by removing one of the hydroxy groups from an aromatic compound having one or more hydroxy groups directly bonded to an aromatic ring. R ２１ and R ２２ are each independently a residue obtained by removing one hydroxy group from a hydroxy compound. R ３１５ and R ２２５ are each independently a residue obtained by removing one hydroxy group from a hydroxy compound.

[0089] That is, in the second embodiment of step (I), by having the above configuration, it is possible to efficiently produce a carbamate of an amino alcohol while suppressing the generation of by-products containing a compound having a urea bond.

[0090] Next, each step of the second embodiment of step (I) will be described in detail below.

[0091] [Step (X)] Step (X) is a step of reacting an amino alcohol compound with a compound having a phenolic hydroxy group (hereinafter sometimes referred to as a "phenolic hydroxy group-containing compound") to obtain a phenol salt of the amino alcohol compound. The amino alcohol compound used in step (X) is preferably a compound represented by the following formula (6).

[0092]

[0093] In formula (6), R ６１ is an organic group having a valence of n61 + 1. n61 is an integer of 1 or more and 3 or less. ​In step (X), as shown in the following reaction equation (X)-1, the amino alcohol compound (6) is reacted with a phenolic hydroxyl group-containing compound (a compound represented by the following general formula (P1); hereafter sometimes referred to as "phenolic hydroxyl group-containing compound (P1)") to obtain the phenol salt of the compound (a compound represented by the following general formula (P2); hereafter sometimes referred to as "phenol salt of amino alcohol compound (P2)"). The reaction in step (X) is a neutralization reaction.

[0095]

[0096] In reaction equation (X)-1, n61 is an integer between 1 and 3 (inclusive). ６１ R is an organic group with n61+1 valency. Ｐ１１ This is a residue obtained by removing one hydroxyl group from an aromatic compound that has one or more hydroxyl groups directly bonded to an aromatic ring.

[0097] In step (X), the amount of phenolic hydroxyl group-containing compound (P1) used can be appropriately set depending on the type of amino alcohol compound (6) and phenolic hydroxyl group-containing compound (P1) used. However, from the viewpoint of maintaining the solubility of the resulting phenol salt (P2) of the amino alcohol compound, it is preferable that the amount is between 1 and 5 molar equivalents relative to the molar amount of amino groups in the amino alcohol compound (6). Furthermore, from the viewpoint of suppressing the amount of compounds other than the amino alcohol compound (6) and diester carbonate used in order to increase the final amount of carbamate produced, it is more preferable that the amount is between 1 and 2 molar equivalents.

[0098] In step (X), the phenolic hydroxyl group-containing compound (P1) used may be one type or a mixture of two or more phenolic hydroxyl group-containing compounds (P1).

[0099] In step (X), the amino alcohol compound (6) and the phenolic hydroxyl group-containing compound (P1) may be introduced into the reactor in either solid or liquid form. However, in order to expedite the neutralization reaction, it is preferable that at least one of them be introduced in a liquid state at a temperature above its melting point.

[0100] In step (X), the neutralization reaction between the amino alcohol compound (6) and the phenolic hydroxyl group-containing compound (P1) can be carried out at any reaction temperature, but it is preferably 0°C to 120°C, and more preferably 20°C to 80°C. A reaction temperature above the upper limit allows for a higher reaction rate, while a reaction temperature below the lower limit makes it easier to control the heat of neutralization generated. To maintain a constant reaction temperature, the reactor may be equipped with known cooling or heating devices.

[0101] In step (X), the reaction pressure can be appropriately set according to the type of amino alcohol compound (6) and phenolic hydroxyl group-containing compound (P1) used, and the reaction temperature. It may be under reduced pressure, atmospheric pressure, or under increased pressure, but is usually 20 Pa or more, 1 × 10⁻⁶ ６ It will be performed at or below Pa.

[0102] In step (X), the reaction time can be set appropriately according to the amount of raw materials used and the reaction time, but it is usually 0.001 hours or more and 50 hours or less, preferably 0.01 hours or more and 20 hours or less, and more preferably 0.1 hours or more and 10 hours or less.

[0103] In step (X), in order to prevent a decrease in manufacturing efficiency, it is preferable not to use any reaction solvent other than the amino alcohol compound (6) and the phenolic hydroxyl group-containing compound (P1), however, it is also possible to use a reaction solvent for the purpose of suppressing by-products. When a reaction solvent is used, it is preferable to use a phenolic hydroxyl group-containing compound (P1) with a relatively low melting point (approximately -150°C to 50°C), a compound that is inert to the amino alcohol compound and the phenolic salt of the resulting amino alcohol compound, or a mixture thereof, as the solvent.

[0104] A known tank reactor can be used as the reactor in process (X). The materials of the reactor and line can be any known material as long as they do not adversely affect the raw materials or products, but stainless steel such as SUS304, SUS316, and SUS316L are inexpensive and can be preferably used.

[0105] The phenol salt (P2) of the amino alcohol compound obtained in step (X) may be used as is in the subsequent step (Y), or it may be purified before being used in the subsequent step (Y). Examples of methods for purifying the phenol salt of the amino alcohol compound include the same method described in the "purification step" described later.

[0106] The structure of the phenol salt (P2) of an amino alcohol compound can be confirmed by known methods such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and infrared spectroscopy (IR).

[0107] [Step (Y)] In step (Y), as shown in the following reaction formula (Y)-1, a carbonate ester (a compound represented by the following general formula (Y2); hereafter sometimes referred to as "carbonate diester (Y2)") and a phenol salt (P2) of an amino alcohol compound are reacted to obtain a carbamate composition containing a carbamate (a compound represented by the following general formula (16); hereafter sometimes referred to as "carbamate (16)"), which is the carbamate intermediate (I) obtained in the second embodiment of step (I). Note that the reaction to obtain a carbamate from the phenol salt (P2) of an amino alcohol compound and a carbonate diester (Y2) is a substitution reaction. Furthermore, as shown in the reaction equation (Y)-1 below, the following by-products are produced: a compound represented by the general formula (Y4) below (phenolic hydroxyl group-containing compound (Y4)) and a compound represented by the general formula (Y5) below (this is the compound represented by the general formula (Y5) below; hereafter, it may be referred to as "hydroxyl group-containing compound (Y5)").

[0108]

[0109] In reaction equation (Y)-1, n61 is an integer greater than or equal to 1. ６１ R is an organic group with n61+1 valency. Ｐ１１ R is a residue obtained by removing one hydroxyl group from an aromatic compound that has one or more hydroxyl groups directly bonded to an aromatic ring. ２１ and R ２２ Each of these is independently a residue obtained by removing one hydroxyl group from a hydroxyl compound.

[0110] During step (Y)-1, a portion of the resulting carbamate (16) is converted into cyclic compound (7) and carbamate carbonate (8) through the reactions shown in formulas (Y)-2 and (Y)-3 below. At this time, as shown in the reaction formulas (Y)-2 and (Y)-3 below, a compound represented by the following general formula (VII) (hereinafter sometimes referred to as "hydroxyl group-containing compound (VII)") and a compound represented by the following general formula (IX) (hereinafter sometimes referred to as "hydroxyl group-containing compound (IX)") are produced as by-products.

[0111]

[0112] In reaction equation (Y)-2, n161 is an integer greater than or equal to 1. １６１ R is an organic group with n161+1 valency. １６２ R is a residue obtained by removing one hydroxyl group from a hydroxyl compound. ７１ is an n71+2 valent organic group, R ７１ = R １６１ Therefore, n71 is a non-negative integer, satisfying n71 = n161 - 1. In reaction equation (Y)-3, n161 is a non-negative integer. R １６１ R is an organic group with n161+1 valency. ２１ , R ２２ Each of these is independently a residue obtained by removing one hydroxyl group from a hydroxyl compound. ８１ , R ８３ is a monovalent organic group, R ２１ or R ２２ That is. R ８２ is an organic group with n81 + n82 + 1 valence, R ８２ = R １６１ Therefore, n81 is an integer greater than or equal to 1, satisfying n81 ≤ n161. n82 is an integer greater than or equal to 0, satisfying n82 = n161 - n81. ９１ Each of these is independently a residue obtained by removing one hydroxyl group from a hydroxy compound, and R ２１ or R ２２ That is the case.

[0113] Preferably, at least one selected from the group consisting of the cyclic compound (7) and carbamate carbonate (8) obtained in this manner is included in the carbamate composition in an amount of 2 mol% to 10 mol% relative to the carbamate (16) (the compound represented by formula (16) described later). Having the sum of the content of the cyclic compound (7) and carbamate carbonate (8) equal to or greater than the lower limit has the effect of suppressing the modification of the carbamate (16) during step (Z) described later. Furthermore, crystallization is suppressed even at high concentrations of carbamate (16), allowing the obtained component to be handled as a liquid, which tends to be advantageous for industrial implementation. Having the sum of the content of the cyclic compound (7) and carbamate carbonate (8) equal to or less than the upper limit suppresses a decrease in the yield of carbamate (16), further improving manufacturing efficiency.

[0114] In step (Y), the amount of diester carbonate (Y2) used can be appropriately set depending on the type of phenol salt (P2) of the amino alcohol compound and the diester carbonate (Y2) used. However, in order to avoid complicating the purification of the obtained carbamate (16), it is preferable that the amount is between 1 and 10 molar equivalents, and more preferably between 1 and 2 molar equivalents, relative to the molar amount of amino groups in the phenol salt (P2) of the amino alcohol compound.

[0115] In step (Y), the diester carbonate (Y2) used may be one type or a mixture of two or more diester carbonates.

[0116] In step (Y), it is preferable that the phenol salt (P2) of the amino alcohol compound be supplied to the reactor in a liquid state. To handle the phenol salt (P2) of the amino alcohol compound and the diester carbonate (Y2) in a liquid state, the same or a different phenolic hydroxyl group-containing compound used in step (X) may be used as a solvent. In particular, to prevent the purification of the resulting carbamate (16) from becoming complicated, it is preferable to use the same phenolic hydroxyl group-containing compound (P1) used in step (X) as the solvent. Alternatively, this can be done by heating the diester carbonate (Y2) charged in a tank reactor and dropping the phenol salt (P2) of the amino alcohol compound into the tank reactor.

[0117] In step (Y), reaction heat is generated during the reaction between the phenol salt (P2) of the amino alcohol compound and the diester carbonate (Y2). To facilitate control of the reaction temperature, step (Y) is carried out by continuously supplying the phenol salt (P2) of the amino alcohol compound to a reactor containing the diester carbonate (Y2), and it is preferable to control the supply rate of the phenol salt (P2) of the amino alcohol compound so that the temperature inside the reactor is within ±10°C of the set reaction temperature. The supply rate of the phenol salt (P2) of the amino alcohol compound is not particularly limited, but from the viewpoint of achieving both a reduction in reaction time and control of the reaction temperature in step (Y), it is preferable that the supply rate is such that the entire amount of the phenol salt (P2) of the amino alcohol compound can be added dropwise in 0.5 hours or more and 5 hours or less.

[0118] In step (Y), from the viewpoint of ensuring good mixing of the phenol salt (P2) of the amino alcohol compound and the diester carbonate (Y2), it is preferable that the diester carbonate (Y2) introduced into the reactor is heated to the reaction temperature before supplying the phenol salt (P2) of the amino alcohol compound.

[0119] In step (Y), regardless of the reaction temperature, the reaction to obtain a carbamate (16) from a phenol salt (P2) of an amino alcohol compound and a diester carbonate (Y2) can be carried out while suppressing the side reactions shown in the conventional reaction formula (102). In one embodiment of the present invention, the reaction temperature is preferably 30°C to 120°C, and more preferably 50°C to 90°C. A reaction temperature above the upper limit can further improve the reaction rate and increase the solubility of the raw materials and products, while a temperature below the lower limit can more effectively suppress the promotion of side reactions. To maintain a constant reaction temperature, the reactor may be equipped with known cooling or heating devices.

[0120] In step (Y), a catalyst may be used for purposes such as shortening the reaction time and lowering the reaction temperature. Examples of catalysts that can be used include organometallic compounds and inorganic metal compounds such as tin, lead, copper, and titanium; and basic catalysts such as alkali metal or alkaline earth metal alkoxides. Specific examples of alkali metal or alkaline earth metal alkoxides include methylates, ethylates, or butyrates of lithium, sodium, potassium, calcium, or barium.

[0121] In step (Y), it is preferable not to use any reaction solvent other than the phenol salt (P2) and diester carbonate (Y2) of the amino alcohol compound in order to prevent a decrease in manufacturing efficiency. However, it is also possible to use a reaction solvent to suppress by-products. When a reaction solvent is used, it is preferable to use a phenolic hydroxyl group-containing compound with a relatively low melting point (approximately -150°C to 100°C), a phenol salt of the amino alcohol compound, a diester carbonate, and a compound that is inert to the resulting carbamate, as well as mixtures thereof, as the solvent.

[0122] As the reactor in process (Y), known tank reactors, column reactors, distillation columns, etc., can be used. The material of the reactor and line can be any known material as long as it does not adversely affect the raw materials and products, but stainless steel such as SUS304, SUS316, and SUS316L is inexpensive and preferably used. From the viewpoint of suppressing side reactions caused by the mixing of the amino alcohol compound (6) that does not form a phenol salt and the diester carbonate (Y2), it is preferable that the reactor in process (X) and the reactor in process (Y) are different from each other, that is, that processes (X) and (Y) are carried out in different reaction systems.

[0123] [Purification Step] In the manufacturing method of this embodiment, after step (Y), the obtained carbamate (16) may be used for the production of esters etc. without performing a purification step. However, from the viewpoint of improving the yield of isocyanate, it is preferable to perform a purification step of carbamate (16).

[0124] In particular, in the purification process, known methods may be used to obtain carbamate (16), but it is preferable to include a step (Z) (hereinafter sometimes simply referred to as step (Z)) in which distillation is used to obtain carbamate (16) for the recovery and reuse of phenolic hydroxyl group-containing compounds (P1), hydroxyl group-containing compounds (VII) and (IX), and for the highly efficient purification of carbamate (16).

[0125] [Step (Z)] In step (Z), the carbamate composition obtained in step (Y) is heated, and the phenolic hydroxyl group-containing compound, hydroxyl group-containing compound, and residual carbonic acid diester are extracted as a gas phase to concentrate the carbamate, thereby obtaining a concentrated carbamate composition (concentrated carbamate solution).

[0126] Preferably, the carbamate composition obtained in step (Z) has a total content ratio of at least one selected from the group consisting of cyclic compounds (7) and carbamate carbonate (8) relative to the total amount of carbamate (16) of 2 mol% to 10 mol%. When the total content ratio of cyclic compounds (7) and carbamate carbonate (8) is above the lower limit, the carbamate (16) is less likely to denature when concentrated. Furthermore, it suppresses the crystallization of carbamate (16) during concentration and does not hinder the extraction of phenolic hydroxyl group-containing compounds, hydroxyl group-containing compounds, and residual carbonic acid diester as gas phase, thus enabling concentration to higher concentrations. On the other hand, when the total content ratio of cyclic compounds (7) and carbamate carbonate (8) is below the upper limit, a carbamate composition having high purity carbamate (16) is obtained, which is advantageous when the obtained carbamate (16) is used as a raw material in other steps.

[0127] The temperature during step (Z) depends on the boiling points of the phenolic hydroxyl group-containing compounds (P1), (VII), and (IX) to be recovered by distillation, as well as the thermal stability of the carbamate (16). However, it is desirable to perform the procedure at a temperature between 70°C and 140°C. A temperature above the lower limit allows for highly efficient removal of phenolic hydroxyl group-containing compounds and diester carbonates, while a temperature below the upper limit suppresses the denaturation of the carbamate (16).

[0128] The pressure used during process (Z) depends on the boiling points of the phenolic hydroxyl group-containing compounds (P1), (VII), and (IX) to be recovered by distillation, as well as the boiling point of the carbamate (16). However, it is desirable to use a pressure of 10 Pa or more and 10 kPa or less. A pressure above the lower limit can suppress flooding in the apparatus, and a pressure below the upper limit allows for highly efficient removal of phenolic hydroxyl group-containing compounds and diester carbonates.

[0129] The apparatus used for process (Z) can be of any type as long as it has the function of condensing and separating the gas phase. In addition to a standard batch reactor, packed columns, thin-film evaporators, reactors with internal supports, drop evaporators, and drop evaporators can be used.

[0130] In step (Z), if necessary, it is preferable to perform one or more further operations such as crystallization, reprecipitation, column chromatography, extraction, and stirring and washing of crystals with a solvent, either individually or in combination of two or more, in order to increase the purity of the carbamate (16) in the concentrated carbamate solution.

[0131] The structure of carbamate (16) can be confirmed by known methods such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and infrared spectroscopy (IR).

[0132] Next, the various raw materials used in the second embodiment of process (I) and the resulting carbamate intermediates, cyclic compounds, and carbamate carbonates will be described in detail below.

[0133] [Amino alcohol compounds] Any amino alcohol compound may have one or more amino groups and one or more hydroxyl groups, but it is preferable that it includes the compound represented by the following formula (6) (amino alcohol compound (6)).

[0134] (In formula (6), R ６１ (This is an organic group with n61+1 valency, where n61 is an integer greater than or equal to 1.)

[0135] (R ６１ ) In formula (6), R ６１ The group is an n61+1 valent organic group, preferably an organic group having 3 to 85 carbon atoms, and more preferably an organic group having 3 to 30 carbon atoms.

[0136] R ６１ The organic groups in this context are aliphatic hydrocarbon groups, aromatic hydrocarbon groups, or groups formed by the bonding of an aliphatic hydrocarbon group and an aromatic hydrocarbon group.

[0137] (n61) n61 is an integer greater than or equal to 1, preferably an integer between 1 and 10, and more preferably between 1 and 3.

[0138] Examples of amino alcohol compounds represented by formula (6) include aliphatic amino alcohol compounds having 1 to 30 carbon atoms, alicyclic amino alcohol compounds having 6 to 30 carbon atoms, and amino alcohol compounds containing aromatic groups having 6 to 30 carbon atoms.

[0139] Specifically, aliphatic amino alcohol compounds having 1 to 30 carbon atoms include ethanolamine, 3-amino-1-propanol, 4-amino-1-butanol, 4-amino-2-methyl-1-butanol, 6-amino-1-hexanol, (R Examples include )-3-amino-1-butanol, 3-amino-2,2-dimethyl-1-propanol, tris(hydroxymethyl)aminomethane, 2-amino-1-butanol, 1-amino-2-propanol, 2-amino-1-propanol, 2-amino-2-methyl-1-propanol, 1-amino-2-methyl-2-propanol, 1-amino-2-butanol, 3-amino-1,2-propanediol, 2-amino-1,3-propanediol, valinol, 2-aminopentan-1-ol, 2-amino-2-methyl-1,3-propanediol, 2-(2-aminoethoxy)ethanol, L-tert-leucinol, L-isoleucinol, and 2-amino-2-ethyl-1,3-propanediol.

[0140] Examples of alicyclic amino alcohol compounds with 6 to 30 carbon atoms include 2-aminocyclohexanol.

[0141] Examples of amino alcohol compounds containing aromatic groups with 6 to 30 carbon atoms include phenylglycinol and 2-amino-1-phenylethanol.

[0142] In addition, if structural isomers or stereoisomers exist for the amino alcohol compound in these formulas (6), those structural isomers and stereoisomers are also included in the above examples.

[0143] [Compounds containing phenolic hydroxyl groups] Any compound having one or more phenolic hydroxyl groups is acceptable as a compound containing phenolic hydroxyl groups, but it is preferable to include a compound represented by the following formula (P1) (phenolic hydroxyl group-containing compound (P1)).

[0144]

[0145] (R Ｐ１１ ) In formula (P1), R Ｐ１１ R is a residue obtained by removing one hydroxyl group from an aromatic compound that has one or more hydroxyl groups directly bonded to an aromatic ring. Ｐ１１ Preferably, it is an aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0146] This kind of R Ｐ１１ Examples include phenyl group, methylphenyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl, dimethylphenyl group, methoxyphenyl group, chlorophenyl group, nitrophenyl group, bromophenyl group, fluorophenyl group, nitrophenyl group, trifluoromethylphenyl group, and the like.

[0147] Preferred phenolic hydroxyl group-containing compounds (P1) include, for example, phenol, o-cresol, m-cresol, p-cresol, 4-ethylphenol, 4-propylphenol, 2-isopropylphenol, 2,6-dimethylphenol, 2-methoxyphenol, 3-tert-butylphenol, 4-butylphenol, 2-sec-butylphenol, 4-amylphenol, 4-hexylphenol, 4-heptylphenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2-bromophenol, 3-bromophenol, 2-fluorophenol, 3-fluorophenol, 4-fluorophenol, 2-nitrophenol, 2-hydroxybenzotrifluoride, and 4-hydroxybenzotrifluoride. If structural isomers or stereoisomers exist for these phenolic hydroxyl group-containing compounds, these are also included in the above examples.

[0148] [Diester carbonate] As diester carbonate, the diester carbonate represented by the above formula (12) can be used. Among them, as diester carbonate, R １２１ Preferably, each of these is an aromatic hydrocarbon group having 6 to 8 carbon atoms, which is a diaryl carbonate. Preferred diaryls include, for example, diphenyl carbonate, bis(2-methoxyphenyl) carbonate, bis(2-methylphenyl) carbonate, and bis(4-cumylphenyl) carbonate, with diphenyl carbonate being the most preferred. If structural isomers or stereoisomers exist for these diester carbonates, these are also included in the above examples.

[0149] The diester carbonate may contain metal atoms. The content of metal atoms relative to the total mass of the diester carbonate is preferably 0.001 ppm by mass or more and 10% by mass or less, more preferably 0.001 ppm by mass or more and 5% by mass or less, and even more preferably 0.002 ppm by mass or more and 3% by mass or less.

[0150] The above-mentioned metal atoms may exist as metal ions or as elemental metal atoms. Preferably, the metal atoms are those that can have a valence of 2 to 4, and more preferably, one or more metals selected from the group consisting of iron, cobalt, nickel, zinc, tin, copper, and titanium.

[0151] Known methods can be used to produce diester carbonates. For example, one method is described in International Publication No. 2009 / 139061 (Reference 1), which involves reacting an organotin compound having a tin-oxygen-carbon bond with carbon dioxide to produce a diester carbonate, and then producing a diaryl carbonate from the diester carbonate and an aromatic hydroxy compound.

[0152] [Carbamate intermediate obtained in the second embodiment of step (I)] The carbamate intermediate obtained in the second embodiment of step (I) is a compound represented by the following general formula (16) (hereinafter sometimes referred to as "carbamate (16)").

[0153]

[0154] In general formula (16), R １６１ This group is derived from the amino alcohol compound (6), and is a residue obtained by removing the amino group and hydroxyl group from the amino alcohol compound (6).

[0155] In general formula (16), R １６２ This is a group derived from diester carbonate (12), -COO-R １２１ These are the residues excluding [the specified residue].

[0156] In general formula (16), n161 is the same number as the valence of the hydroxyl group of the amino alcohol compound (6), and is an integer of 1 or more.

[0157] Examples of carbamates represented by general formula (16) include R １６１ Carbamates with 4 to 60 carbon atoms, where the aliphatic hydrocarbon group is R １６１ Carbamates with 8 to 60 carbon atoms, where the alicyclic hydrocarbon group is R １１ Examples include carbamates with 8 to 60 carbon atoms, where the aromatic hydrocarbon group is the carbon atom.

[0158] In general formula (16), R １６１Carbamates with 4 to 60 carbon atoms and an aliphatic hydrocarbon group include, specifically, methyl (2-hydroxyethyl) carbamate, methyl (3-hydroxypropyl) carbamate, methyl (4-hydroxybutyl) carbamate, methyl (4-hydroxy-3-methylbutyl) carbamate, methyl (6-hydroxyhexyl) carbamate, methyl-(4-hydroxybutan-2-yl) carbamate, methyl (3-hydroxy-2,2-dimethylpropyl) carbamate, and methyl (1,3-dihydroxy-2-(hydroxymethyl)propane Methyl(1-hydroxybutan-2-yl) carbamate, methyl(2-hydroxypropyl) carbamate, methyl(1-hydroxypropan-2-yl) carbamate, methyl(1-hydroxy-2-methylpropan-2-yl) carbamate, methyl(2-hydroxy-2-methylpropyl) carbamate, methyl(2-hydroxybutyl) carbamate, methyl(2,3-dihydroxypropyl) carbonate, methyl(1,3-dihydroxypropan-2-yl) carbonate, methyl(S)-(1-hydroxypropyl) (C-3-methylbutan-2-yl) carbamate, methyl(1-hydroxypentan-2-yl) carbamate, methyl(1,3-dihydroxy-2-methylpropane-2-yl) carbonate, methyl(2-(2-hydroxyethoxy)ethyl) carbamate, methyl(S)-(1-hydroxy-3,3-dimethylbutan-2-yl) carbamate, methyl((2S,3S)-1-hydroxy-3-methylpentan-2-yl) carbamate, methyl(1-hydroxy-2-(hydroxymethyl)pentan-2-yl) carbamate, ethyl(2-H Examples include hydroxyethyl carbamate, ethyl (3-hydroxypropyl) carbamate, ethyl (4-hydroxybutyl) carbamate, ethyl (4-hydroxy-3-methylbutyl) carbamate, ethyl (6-hydroxyhexyl) carbamate, ethyl-(4-hydroxybutan-2-yl) carbamate, ethyl (3-hydroxy-2,2-dimethylpropyl) carbamate, ethyl (1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl) carbamate, and ethyl (1-hydroxybutan-2-yl) carbamate.

[0159] In general formula (16), R １６１Carbamates having 4 to 60 carbon atoms and being an aliphatic hydrocarbon group include, specifically, ethyl (2-hydroxypropyl) carbamate, ethyl (1-hydroxypropan-2-yl) carbamate, ethyl (1-hydroxy-2-methylpropan-2-yl) carbamate, ethyl (2-hydroxy-2-methylpropyl) carbamate, ethyl (2-hydroxybutyl) carbamate, ethyl (2,3-dihydroxypropyl) carbamate, and ethyl (1,3-dihydroxypropan-2-yl) carbamate. Ethyl-(S)-(1-hydroxy-3-methylbutan-2-yl) carbamate, ethyl(1-hydroxypentan-2-yl) carbamate, ethyl(1,3-dihydroxy-2-methylpropane-2-yl) carbamate, ethyl(2-(2-hydroxyethyl)ethyl) carbamate, ethyl-(S)-(1-hydroxy-3,3-dimethylbutan-2-yl) carbamate, ethyl-(2S,3S)-1-hydroxy-3-methylpentan-2-yl) carbamate, ethyl(1-hydroxy-2 -(hydroxymethyl)pentan-2-yl) carbamate, phenyl(2-hydroxyethyl) carbamate, phenyl(3-hydroxypropyl) carbamate, phenyl(4-hydroxybutyl) carbamate, phenyl(4-hydroxy-3-methylbutyl) carbamate, phenyl(6-hydroxyhexyl) carbamate, phenyl-(4-hydroxybutan-2-yl) carbamate, phenyl(3-hydroxy-2,2-dimethylpropyl) carbamate, phenyl(1,3-dihydroxy-2 -(hydroxymethyl)propan-2-yl) carbamate, phenyl(1-hydroxybutan-2-yl) carbamate, phenyl(2-hydroxypropyl) carbamate, phenyl(1-hydroxypropan-2-yl) carbamate, phenyl(1-hydroxy-2-methylpropan-2-yl) carbamate, phenyl(2-hydroxy-2-methylpropyl) carbamate, phenyl(2-hydroxybutyl) carbamate, phenyl(2,3-dihydroxypropyl) carbonate, phenyl(1,3-dihydroxypropane-2-yl) carbonate, phenyl(S)-(1-hydroxy-3-methylbutan-2-yl) carbamate, phenyl(1-hydroxypentan-2-yl) carbamate, phenyl(1,3-dihydroxy-2-methylpropane-2-yl) carbonate, phenyl(2-(2-hydroxyethoxy)ethyl) carbamate, phenyl(S)-(1-hydroxy-3,3-dimethylbutan-2-yl) carbamate, phenyl((2S,3S)-1-hydroxy-3-methylpentan-2-yl) carbamate, phenyl(1-hydroxy-2-(hydroxymethyl)pentan-2-yl) carbamate, ortho-tolyl(2-hydroxyethyl) carbamate, ortho-tolyl(3-hydroxypropyl) carbamate, ortho-tolyl(4-hydroxybutyl) carbamate, Examples include ortho-tolyl(4-hydroxy-3-methylbutyl) carbamate, ortho-tolyl(6-hydroxyhexyl) carbamate, ortho-tolyl-(4-hydroxybutan-2-yl) carbamate, ortho-tolyl(3-hydroxy-2,2-dimethylpropyl) carbamate, ortho-tolyl(1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl) carbamate, ortho-tolyl(1-hydroxybutan-2-yl) carbamate, ortho-tolyl(2-hydroxypropyl) carbamate, ortho-tolyl(1-hydroxypropan-2-yl) carbamate, ortho-tolyl(1-hydroxy-2-methylpropan-2-yl) carbamate, ortho-tolyl(2-hydroxy-2-methylpropyl) carbamate, and ortho-tolyl(2-hydroxybutyl) carbamate.

[0160] In general formula (16), R １６１Carbamates with 4 to 60 carbon atoms and an aliphatic hydrocarbon group include, specifically, ortho-tolyl(2,3-dihydroxypropyl)carbamate, ortho-tolyl(1,3-dihydroxypropan-2-yl)carbamate, ortho-tolyl-(S)-(1-hydroxy-3-methylbutan-2-yl)carbamate, ortho-tolyl(1-hydroxypentan-2-yl)carbamate, ortho-tolyl(1,3-dihydroxy-2-methylpropan-2-yl)carbamate, and ortho-tolyl(2-(2-hydroxyethyl)ethyl)carbamate. Carbamate, ortho-tolyl-(S)-(1-hydroxy-3,3-dimethylbutan-2-yl) carbamate, ortho-tolyl-(2S,3S)-1-hydroxy-3-methylpentan-2-yl) carbamate, ortho-tolyl(1-hydroxy-2-(hydroxymethyl)pentan-2-yl) carbamate, methoxyphenyl(2-hydroxyethyl) carbamate, methoxyphenyl(3-hydroxypropyl) carbamate, methoxyphenyl(4-hydroxybutyl) carbamate, methoxyphenyl(4-hydroxy-3-methylbutyl) carbamate Carbamate, Methoxyphenyl (6-hydroxyhexyl) carbamate, Methoxyphenyl-(4-hydroxybutan-2-yl) carbamate, Methoxyphenyl (3-hydroxy-2,2-dimethylpropyl) carbamate, Methoxyphenyl (1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl) carbamate, Methoxyphenyl (1-hydroxybutan-2-yl) carbamate, Methoxyphenyl (2-hydroxypropyl) carbamate, Methoxyphenyl (1-hydroxypropan-2-yl) carbamate, Methoxy Phenyl(1-hydroxy-2-methylpropan-2-yl) carbamate, methoxyphenyl(2-hydroxy-2-methylpropyl) carbamate, methoxyphenyl(2-hydroxybutyl) carbamate, methoxyphenyl(2,3-dihydroxypropyl) carbamate, methoxyphenyl(1,3-dihydroxypropan-2-yl) carbamate, methoxyphenyl-(S)-(1-hydroxy-3-methylbutan-2-yl) carbamate, methoxyphenyl(1-hydroxypentan-2-yl) carbamate, methoxyphenyl(1,3-dihydroxy-2-methylpropan-2-yl) carbamate, methoxyphenyl (2-(2-hydroxyethyl)ethyl) carbamate, methoxyphenyl-(S)-(1-hydroxy-3,3-dimethylbutan-2-yl) carbamate, methoxyphenyl-(2S,3S)-1-hydroxy-3-methylpentan-2-yl) carbamate, methoxyphenyl (1-hydroxy-2-(hydroxymethyl)pentan-2-yl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(2-hydroxy Ethyl carbamate, 4-(2-phenylpropan-2-yl)phenyl(3-hydroxypropyl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(4-hydroxybutyl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(4-hydroxy-3-methylbutyl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(6-hydroxyhexyl) carbamate, 4-(2-phenylpropan-2-yl)phenyl-(4-hydroxybutan-2-yl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(3-hydroxy-2,2-dimethylpropyl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(1-hydroxybutan-2-yl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(2-hydroxypropyl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(1-hydroxy(hydroxypropyl))carbamate Xypropan-2-yl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(1-hydroxy-2-methylpropan-2-yl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(2-hydroxy-2-methylpropyl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(2-hydroxybutyl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(2,3-dihydroxypropyl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(1,3-dihydroxypropan-2-yl)carbamate, 4-(2-phenylpropan-2-yl)phenyl-(S)-(1-hydroxy-3-methylbutan-2-yl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(1-hydroxypentan-2-yl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(1,3-dihydroxy-2-methylpropan-2-yl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(2- Examples include (2-hydroxyethyl)ethyl)carbamate, 4-(2-phenylpropan-2-yl)phenyl-(S)-(1-hydroxy-3,3-dimethylbutan-2-yl)carbamate, 4-(2-phenylpropan-2-yl)phenyl-(2S,3S)-1-hydroxy-3-methylpentan-2-yl)carbamate, and 4-(2-phenylpropan-2-yl)phenyl(1-hydroxy-2-(hydroxymethyl)pentan-2-yl)carbamate.

[0161] In general formula (16), R １６１ Examples of alicyclic carbamates having 8 to 60 carbon atoms and being an alicyclic hydrocarbon group include methyl(2-hydroxycyclohexyl)carbamate, ethyl(2-hydroxycyclohexyl)carbamate, phenyl(2-hydroxycyclohexyl)carbamate, ortho-tolyl(2-hydroxycyclohexyl)carbamate, methoxyphenyl(2-hydroxycyclohexyl)carbamate, and 4-(2-phenylpropan-2-yl)phenyl(2-hydroxycyclohexyl)carbamate.

[0162] In general formula (16), R １６１Carbamates containing an aromatic group having 8 to 60 carbon atoms, which is an aromatic hydrocarbon group, include methyl (2-hydroxy-1-phenylethyl) carbamate, methyl (2-hydroxy-2-phenylethyl) carbamate, ethyl (2-hydroxy-2-phenylethyl) carbamate, phenyl (2-hydroxy-1-phenylethyl) carbamate, phenyl (2-hydroxy-2-phenylethyl) carbamate, ortho-tolyl (2- Examples include hydroxy-1-phenylethyl) carbamate, ortho-tolyl(2-hydroxy-2-phenylethyl) carbamate, methoxyphenyl(2-hydroxy-1-phenylethyl) carbamate, methoxyphenyl(2-hydroxy-2-phenylethyl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(2-hydroxy-1-phenylethyl) carbamate, and 4-(2-phenylpropan-2-yl)phenyl(2-hydroxy-2-phenylethyl) carbamate.

[0163] Furthermore, if structural isomers or stereoisomers exist for these carbamates, those structural isomers and stereoisomers are also included in the above examples.

[0164] [Cyclic Compounds] Cyclic compounds are compounds represented by the following formula (7) (hereinafter sometimes referred to as "cyclic compounds (7)").

[0165] (In formula (7), R ７１ is an n71+2 valent organic group, R ７１ R in equation (6) is ６１ It is the same organic group. n71 is a non-negative integer, and is the number obtained by subtracting 1 from n61 in equation (6).

[0166] In formula (7), R ７１ This group is derived from the amino alcohol compound (6), and is a residue obtained by removing the amino group and hydroxyl group from the amino alcohol compound (6).

[0167] In formula (7), n71 is the same number as the number obtained by subtracting 1 from the valence of the hydroxyl group of the amino alcohol compound (6), and is a non-negative integer.

[0168] As the cyclic compound represented by the general formula (7), for example, R ７１ is a cyclic compound having 2 to 20 carbon atoms and being an aliphatic hydrocarbon group, R ７１ is a cyclic compound having 6 to 20 carbon atoms and being an alicyclic hydrocarbon group, R ７１ is a cyclic compound having 6 to 20 carbon atoms and being an aromatic hydrocarbon group, and the like can be mentioned.

[0169] In the general formula (7), R ７１ As the cyclic compound having 2 to 20 carbon atoms and being an aliphatic hydrocarbon group, specifically, 2-oxazolidone, 1,3-oxadiane-2-one, 1,3-oxazepan-2-one, 6-methyl-1,3-oxazepan-2-one, 1,3-oxazonan-2-one, (R)-4-methyl-1,3-oxazinane-2-one, 5,5-dimethyl-1,3-oxazinane-2-one, 4-(1,3-dihydroxypropan-2-yl)-1,3-oxazinane-2-one, 4-ethyloxazolidine-2-one, 5-methyloxazolidine-2-one, 4-methyloxazolidine-2-one, 4,4-dimethyloxazolidine-2-one, 5,5-dimethyloxazolidine-2-one, 5-ethyloxazolidine-2-one, 5-(hydroxymethyl)oxazolidine-2-one, 4-(hydroxymethyl)oxazolidine-2-one, (S)-4-isopropyloxazolidine-2-one, 4-propyloxazolidine-2-one, 4-(hydroxymethyl)-4-methyloxazolidine-2-one, 1,6,3-dioxazocan-2-one, (S)-4-(tert-butyl)oxazolidine-2-one, (S)-4-((S)-sec-butyl)oxazolidine-2-one, 4-(hydroxymethyl)-4-propyloxazolidine-2-one, and the like can be mentioned.

[0170] In the general formula (7), R ７１ As the cyclic compound having 6 to 20 carbon atoms and being an alicyclic hydrocarbon group, specifically, hexahydrobenzo[d]oxazol-2(3H)-one and the like can be mentioned.

[0171] In the general formula (7), R ７１Examples of the cyclic compound having 6 to 20 carbon atoms which is an aromatic hydrocarbon group include, specifically, 4-phenyloxazolidin-2-one, 5-phenyloxazolidin-2-one and the like.

[0172] In addition, when there are structural isomers or stereoisomers in these cyclic compounds, those structural isomers or stereoisomers are also included in the above exemplification.

[0173] [Carbamate carbonate] Carbamate carbonate is a compound represented by the following general formula (8) (hereinafter, may be referred to as "carbamate carbonate (8)").

[0174]

[0175] In general formula (8), R ８１ and R ８３ are monovalent organic groups, and are each independently a residue obtained by removing one hydroxy group from a hydroxy compound. R ８２ is an n81 + n82 + monovalent organic group. n81 is an integer of 1 or more. n82 is an integer of 0 or more.

[0176] In general formula (8), R ８１ and R ８３ are each a group derived from carbonate ester (12), and are a residue obtained by removing -COO-R １２１ from carbonate ester (12). R ８２ is a group derived from amino alcohol compound (6), and is a residue obtained by removing an amino group and a hydroxy group from amino alcohol compound (6).

[0177] In general formula (8), n81 and n81 are integers of 0 or more, and n81 + n82 takes a value such that it is the same number as the valence of the hydroxy group of amino alcohol compound (6).

[0178] Examples of the carbamate carbonate represented by general formula (8) include, for example, carbamate carbonate having 10 to 66 carbon atoms in which R ８２ is an aliphatic hydrocarbon group, carbamate carbonate having 14 to 66 carbon atoms in which R ８２ is an alicyclic hydrocarbon group, R [[ID=Examples include carbamate carbonates, which have 14 to 66 carbon atoms and are aromatic hydrocarbon groups.

[0179] In general formula (8), R ８２Carbamate carbonates having 10 to 66 carbon atoms and being an aliphatic hydrocarbon group include, specifically, methyl (2-((methoxycarbonyl)oxy)ethyl) carbamate, methyl (3-((methoxycarbonyl)oxy)propyl) carbamate, methyl (4-((methoxycarbonyl)oxy)butyl) carbamate, methyl (3-methyl-4-((methoxycarbonyl)oxy)butyl) carbamate, methyl (6-((methoxycarbonyl)oxy)hexyl) carbamate, methyl-(4-((methoxycarbonyl)oxy)butan-2-yl) carbamate, methyl (2,2-dimethyl-3-((methoxycarbonyl)oxy)propyl) carbamate, methyl (1,3-dihydroxy-2-(((methoxycarbonyl)oxy)methyl)propan-2-yl) carbamate, methyl (1-((methoxycarbonyl)oxy)butan-2-yl) carbamate, methyl (2-((methoxycarbonyl)oxy)propyl) carbamate, methyl (1-((methoxycarbonyl)oxy)propan-2-yl) carbamate, methyl (2-methyl-1-((methoxycarbonyl)oxy)propan-2-yl) carbamate, methyl (2-methyl-2- ((methoxycarbonyl)oxy)propyl)carbamate, methyl (2-((methoxycarbonyl)oxy)butyl)carbamate, methyl (3-hydroxy-2-((methoxycarbonyl)oxy)propyl)carbamate, methyl (1-hydroxy-3-((methoxycarbonyl)oxy)propan-2-yl)carbamate, methyl(S)-(3-methyl-1-((methoxycarbonyl)oxy)butan-2-yl)carbamate Methyl(1-((methoxycarbonyl)oxy)pentan-2-yl) carbamate, methyl(1-hydroxy-2-methyl-3-((methoxycarbonyl)oxy)propan-2-yl) carbamate, methyl(2-(2-((methoxycarbonyl)oxy)ethoxy)ethyl) carbamate, methyl(S)-(3,3-dimethyl-1-((methoxycarbonyl)oxy)butan-2-yl) carbamate, methyl((2S,3S)-3-methyl-1-((methoxycarbonyl)oxy)pentan-2-yl)carbamate, methyl(1-hydroxy-2-(((methoxycarbonyl)oxy)methyl)pentan-2-yl)carbamate, ethyl(2-((ethoxycarbonyl)oxy)ethyl)carbamate, ethyl(3-((ethoxycarbonyl)oxy)propyl)carbamate, ethyl(4-((ethoxycarbonyl)oxy)butyl)carbamate, ethyl(3-methyl-4-((ethoxycarbonyl)oxy)butyl)carbamate, ethyl(6-((ethoxycarbonyl)oxy)hexyl)carbamate, ethyl-(4-((ethoxycarbonyl (L)oxy)butan-2-yl)carbamate, ethyl (2,2-dimethyl-3-((ethoxycarbonyl)oxy)propyl)carbamate, ethyl (1,3-dihydroxy-2-(((ethoxycarbonyl)oxy)methyl)propan-2-yl)carbamate, ethyl (1-((ethoxycarbonyl)oxy)butan-2-yl)carbamate, ethyl (2-((ethoxycarbonyl)oxy)propyl)carbamate, ethyl (1-((ethoxycarbonyl)oxy)propan-2-yl)carbamate, ethyl (2-methyl-1-((ethoxycarbonyl)oxy)propan-2-yl)carbamate, ethyl (2-methyl-2- Examples include ((ethoxycarbonyl)oxy)propyl) carbamate, ethyl (2-((ethoxycarbonyl)oxy)butyl) carbamate, ethyl (3-hydroxy-2-((ethoxycarbonyl)oxy)propyl) carbamate, ethyl (1-hydroxy-3-((ethoxycarbonyl)oxy)propan-2-yl) carbamate, ethyl (S)-(3-methyl-1-((ethoxycarbonyl)oxy)butan-2-yl) carbamate, ethyl (1-((ethoxycarbonyl)oxy)pentan-2-yl) carbamate, and ethyl (1-hydroxy-2-methyl-3-((ethoxycarbonyl)oxy)propan-2-yl) carbamate.

[0180] In general formula (8), R ８２Carbamate carbonates having 10 to 66 carbon atoms and being an aliphatic hydrocarbon group include, specifically, ethyl (2-(2-((ethoxycarbonyl)oxy)ethoxy)ethyl)carbamate, ethyl(S)-(3,3-dimethyl-1-((ethoxycarbonyl)oxy)butan-2-yl)carbamate, ethyl((2S,3S)-3-methyl-1-((ethoxycarbonyl)oxy)pentan-2-yl)carbamate, ethyl (1-hydroxy-2-(((ethoxycarbonyl)oxy)methyl)pentan-2-yl)carbamate, and phenyl(2-((phenoxy) Phenyl(oxy)ethyl)carbamate, phenyl(3-((phenoxycarbonyl)oxy)propyl)carbamate, phenyl(4-((phenoxycarbonyl)oxy)butyl)carbamate, phenyl(3-methyl-4-((phenoxycarbonyl)oxy)butyl)carbamate, phenyl(6-((phenoxycarbonyl)oxy)hexyl)carbamate, phenyl-(4-((phenoxycarbonyl)oxy)butan-2-yl)carbamate, phenyl(2,2-dimethyl-3-((phenoxycarbonyl)oxy)propyl)carbamate, phenyl(1,3-Dihydroxy-2-(((phenoxycarbonyl)oxy)methyl)propan-2-yl)carbamate, phenyl(1-((phenoxycarbonyl)oxy)butan-2-yl)carbamate, phenyl(2-((phenoxycarbonyl)oxy)propyl)carbamate, phenyl(1-((phenoxycarbonyl)oxy)propan-2-yl)carbamate, phenyl(2-methyl-1-((phenoxycarbonyl)oxy)propan-2-yl)carbamate, phenyl(2-methyl-2- ((phenoxycarbonyl)oxy)propyl) carbamate, phenyl (2-((phenoxycarbonyl)oxy)butyl) carbamate, phenyl (3-hydroxy-2-((phenoxycarbonyl)oxy)propyl) carbamate, phenyl (1-hydroxy-3-((phenoxycarbonyl)oxy)propan-2-yl) carbamate, phenyl(S)-(3-methyl-1-((phenoxycarbonyl)oxy)butan-2-yl) carbamate Phenyl(1-((phenoxycarbonyl)oxy)pentan-2-yl) carbamate, phenyl(1-hydroxy-2-methyl-3-((phenoxycarbonyl)oxy)propane-2-yl) carbamate, phenyl(2-(2-((phenoxycarbonyl)oxy)ethoxy)ethyl) carbamate, phenyl(S)-(3,3-dimethyl-1-((phenoxycarbonyl)oxy)butan-2-yl) carbamate, phenyl((2S,3S)-3-methyl-1-((phenoxycarbonyl)oxy)pentan-2-yl)carbamate, phenyl(1-hydroxy-2-(((phenoxycarbonyl)oxy)methyl)pentan-2-yl)carbamate, ortho-tolyl(2-(((ortho-triloxy)carbonyl)oxy)ethyl)carbamate, ortho-tolyl(3-(((ortho-triloxy)carbonyl)oxy)propyl)carbamate, ortho-tolyl(4-(((ortho-triloxy)carbonyl)oxy )Butyl)Carbamate, ortho-tolyl(3-methyl-4-(((ortho-triloxy)carbonyl)oxy)butyl)Carbamate, ortho-tolyl(6-(((ortho-triloxy)carbonyl)oxy)hexyl)Carbamate, ortho-tolyl-(4-(((ortho-triloxy)carbonyl)oxy)butan-2-yl)Carbamate, ortho-tolyl(2,2-dimethyl-3-(((ortho-triloxy)carbonyl)oxy)propyl)Carbamate, ortho-tolyl(1,3-Dihydroxy-2-((((ortho-triloxy)carbonyl)oxy)methyl)propan-2-yl)carbamate, ortho-tolyl(1-(((ortho-triloxy)carbonyl)oxy)butan-2-yl)carbamate, ortho-tolyl(2-(((ortho-triloxy)carbonyl)oxy)propyl)carbamate, ortho-tolyl(1-(((ortho-triloxy)carbonyl)oxy)propan-2-yl)carbamate, ortho-tolyl(2-methyl-2- (((ortho-triloxy)carbonyl)oxy)propyl)carbamate, ortho-tolyl(2-(((ortho-triloxy)carbonyl)oxy)butyl)carbamate, ortho-tolyl(3-hydroxy-2-(((ortho-triloxy)carbonyl)oxy)propyl)carbamate, ortho-tolyl(1-hydroxy-3-(((ortho-triloxy)carbonyl)oxy)propan-2-yl)carbamate, ortho-tolyl(S)-(3-methyl-1-(((ortho-triloxy)carbonyl)oxy)butan-2-yl)carbamate, ortho-tolyl(1-(((ortho-triloxy)carbonyl)oxy)pentan-2-yl)carbamate, ortho-tolyl(1-hydroxy-2-methyl-3-(((ortho-triloxy)carbonyl)oxy)propan- Examples include 2-yl) carbamate, ortho-tolyl(2-(2-(((ortho-triloxy)carbonyl)oxy)ethoxy)ethyl) carbamate, ortho-tolyl(S)-(3,3-dimethyl-1-(((ortho-triloxy)carbonyl)oxy)butan-2-yl) carbamate, ortho-tolyl((2S,3S)-3-methyl-1-(((ortho-triloxy)carbonyl)oxy)pentan-2-yl) carbamate, ortho-tolyl(1-hydroxy-2-((((ortho-triloxy)carbonyl)oxy)methyl)pentan-2-yl) carbamate, methoxyphenyl(2-(((methoxyphenoxy)carbonyl)oxy)ethyl) carbamate, and methoxyphenyl(3-(((methoxyphenoxy)carbonyl)oxy)propyl) carbamate.

[0181] In general formula (8), R ８２Carbamate carbonates having 10 to 66 carbon atoms and being an aliphatic hydrocarbon group include, specifically, methoxyphenyl (4-(((methoxyphenoxy)carbonyl)oxy)butyl) carbamate, methoxyphenyl (3-methyl-4-(((methoxyphenoxy)carbonyl)oxy)butyl) carbamate, methoxyphenyl (6-(((methoxyphenoxy)carbonyl)oxy)hexyl) carbamate, methoxyphenyl-(4-(((methoxyphenoxy)carbonyl)oxy)butan-2-yl) carbamate, and methoxyphenyl (2,2-dimethyl-3-(((methoxyphenoxy)carbonyl)oxy)propyl) carbamate. Methoxyphenyl (1,3-dihydroxy-2-((((methoxyphenoxy)carbonyl)oxy)methyl)propan-2-yl) carbamate, Methoxyphenyl (1-(((methoxyphenoxy)carbonyl)oxy)butan-2-yl) carbamate, Methoxyphenyl (2-(((methoxyphenoxy)carbonyl)oxy)propyl) carbamate, Methoxyphenyl (1-(((methoxyphenoxy)carbonyl)oxy)propan-2-yl) carbamate, Methoxyphenyl (2-methyl-1-(((methoxyphenoxy)carbonyl)oxy)propan-2-yl) carbamate, Methoxyphenyl (2-methyl-2- (((Methoxyphenoxy)carbonyl)oxy)propyl)carbamate, Methoxyphenyl (2-(((Methoxyphenoxy)carbonyl)oxy)butyl)carbamate, Methoxyphenyl (3-hydroxy-2-(((Methoxyphenoxy)carbonyl)oxy)propyl)carbamate, Methoxyphenyl (1-hydroxy-3-(((Methoxyphenoxy)carbonyl)oxy)propan-2-yl)carbamate, Methoxyphenyl (S)-(3-methyl-1-(((Methoxyphenoxy)carbonyl)oxy)butan-2-yl)carbamate, Methoxyphenyl (1-(((Methoxyphenoxy)carbonyl)oxy)pentan-2-yl)carbamate, Methoxyphenyl (1-hydroxy-2-methyl-3-(((Methoxyphenoxy)carbonyl)oxy)propan-2-yl)carbamate,Methoxyphenyl (2-(2-(((methoxyphenoxy)carbonyl)oxy)ethoxy)ethyl) carbamate, Methoxyphenyl (S)-(3,3-dimethyl-1-(((methoxyphenoxy)carbonyl)oxy)butan-2-yl) carbamate, Methoxyphenyl ((2S,3S)-3-methyl-1-(((methoxyphenoxy)carbonyl)oxy)pentan-2-yl) carbamate, Methoxyphenyl (1-hydroxy-2-((((methoxyphenoxy)carbonyl)oxy)methyl)pentan-2-yl) carbamate 4-(2-phenylpropane-2-yl)phenyl(2-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)ethyl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(3-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)propyl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(4-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)butyl)carbamate, 4-(2-phenylpropane- 2-yl)phenyl(3-methyl-4-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)butyl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(6-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)hexyl)carbamate, 4-(2-phenylpropane-2-yl)phenyl-(4-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)butan-2-yl)carbamate, 4-(2-phenylpropane-2-yl) Phenyl(2,2-dimethyl-3-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)propyl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(1,3-dihydroxy-2-((((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)methyl)propane-2-yl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(1-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)butan-2-yl)carbamate,4-(2-phenylpropan-2-yl)phenyl(2-(((4-(2-phenylpropan-2-yl)phenoxy)carbonyl)oxy)propyl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(1-(((4-(2-phenylpropan-2-yl)phenoxy)carbonyl)oxy)propan-2-yl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(2-methyl-1-(((4-(2-phenylpropan-2-yl)phenoxy)carbonyl)oxy)propan-2-yl)carbamate, 4-(2-phenylpropan-2-yl)phenyl(2-methyl-2- (((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)propyl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(2-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)butyl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(3-hydroxy-2-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)propyl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(1-hydroxy-3-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)propane-2-yl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(S )-(3-methyl-1-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)butan-2-yl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(1-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)pentan-2-yl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(1-hydroxy-2-methyl-3-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)propane-2-yl)carbamate, 4-(2-phenylpropane-2-yl)phenyl(2-(2-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)ethoxy)ethyl)carbamate,Examples include 4-(2-phenylpropane-2-yl)phenyl(S)-(3,3-dimethyl-1-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)butan-2-yl)carbamate, 4-(2-phenylpropane-2-yl)phenyl((2S,3S)-3-methyl-1-(((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)pentan-2-yl)carbamate, and 4-(2-phenylpropane-2-yl)phenyl(1-hydroxy-2-((((4-(2-phenylpropane-2-yl)phenoxy)carbonyl)oxy)methyl)pentan-2-yl)carbamate.

[0182] In general formula (8), R ８２ Carbamate carbonates having 14 to 66 carbon atoms and having an alicyclic hydrocarbon group include, specifically, methyl (2-((methoxycarbonyl)oxy)cyclohexyl) carbamate, ethyl (2-((ethoxycarbonyl)oxy)cyclohexyl) carbamate, phenyl (2-((phenoxycarbonyl)oxy)cyclohexyl) carbamate, ortho-tolyl (2-(((ortho-triloxy)carbonyl)oxy)cyclohexyl) carbamate, methoxyphenyl (2-(((methoxyphenoxy)carbonyl)oxy)cyclohexyl) carbamate, and 4-(2-phenylpropan-2-yl)phenyl (2-(((4-(2-phenylpropan-2-yl)phenoxy)carbonyl)oxy)cyclohexyl) carbamate.

[0183] In general formula (8), R ８２Carbamate carbonates with 14 to 66 carbon atoms and an aromatic hydrocarbon group include, specifically, methyl (1-phenyl-2-((methoxycarbonyl)oxy)ethyl) carbamate, methyl (2-phenyl-2-((methoxycarbonyl)oxy)ethyl) carbamate, ethyl (1-phenyl-2-((ethoxycarbonyl)oxy)ethyl) carbamate, ethyl (2-phenyl-2-((ethoxycarbonyl)oxy)ethyl) carbamate, phenyl (2-((phenoxycarbonyl)oxy)-1-phenylethyl) carbamate, phenyl (2-((phenoxycarbonyl)oxy)-2-phenylethyl) carbamate, and ortho-tolyl (1-phenyl-2-(((ortho-triloxy)carbonyl)oxy) ethyl Examples include ) carbamates, ortho-tolyl(2-phenyl-2-(((ortho-triloxy)carbonyl)oxy)ethyl) carbamate, methoxyphenyl(1-phenyl-2-(((methoxyphenoxy)carbonyl)oxy)ethyl) carbamate, methoxyphenyl(2-phenyl-2-(((methoxyphenoxy)carbonyl)oxy)ethyl) carbamate, 4-(2-phenylpropan-2-yl)phenyl(1-phenyl-2-(((4-(2-phenylpropan-2-yl)phenoxy)carbonyl)oxy)ethyl) carbamate, and 4-(2-phenylpropan-2-yl)phenyl(2-phenyl-2-(((4-(2-phenylpropan-2-yl)phenoxy)carbonyl)oxy)ethyl) carbamate.

[0184] Furthermore, if structural isomers or stereoisomers exist for these carbamates, those structural isomers and stereoisomers are also included in the above examples.

[0185] In the second embodiment of step (I), the production ratio of at least one selected from the group consisting of the cyclic compound represented by formula (7) and the carbamate carbonate compound represented by formula (8) is preferably 2 to 10 mol% relative to the total amount of carbamate (16).

[0186] [Step (II)] Step (II) is a step in which the carbamate intermediate obtained in Step (I) above is esterified to obtain a carbamate compound represented by the following formula (2) (hereinafter sometimes referred to as "carbamate compound (2)"). First, the obtained carbamate compound will be explained.

[0187] [Carbamate Compound (2)] The carbamate compound obtained in step (II) is a compound represented by the following formula (2).

[0188] In the formula, R ２１ R represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms and being monovalent or quadrivalent, or an aromatic group having 6 to 40 carbon atoms and being monovalent or trivalent, or an aliphatic hydrocarbon group or aromatic group having 1 to 4 carbon atoms and being monovalent or quadrivalent, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms. ２２ represents a monovalent aliphatic group, aromatic group, or aralkyl group having 1 to 20 carbon atoms. n21 represents an integer from 1 to 4.

[0189] (R ２１ ) In formula (2), R ２１ This refers to an aliphatic hydrocarbon group having 1 to 40 carbon atoms with a valency of 1 to 4, an aromatic group having 6 to 40 carbon atoms with a valency of 1 to 3, or an aliphatic hydrocarbon group or aromatic group having 1 to 40 carbon atoms with a valency of 1 to 4, and having 1 to 4 ester groups and / or nitrogen atoms.

[0190] Pay particular attention ２１ Preferably, the structure is one of the structures represented by the following general formulas (17) to (20).

[0191]

[0192] In formula (17), R １７１ R is divalent and represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having 1 to 20 carbon atoms having one or more selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom. １７２This represents a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having 1 to 20 carbon atoms having one or more atoms selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom. The dashed line indicates a bond with the N atom.

[0193] In formula (18), R １８１ R is monovalent and represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having 1 to 20 carbon atoms having one or more selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom. １８２ n181 represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having 1 to 20 carbon atoms having one or more atoms selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom. n182 represents an integer from 1 to 3. The dashed line indicates a bond with the N atom.

[0194] In formula (19), R １９１ R is divalent and represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having 1 to 20 carbon atoms having one or more selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom. １９２ This represents a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having 1 to 20 carbon atoms having one or more atoms selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom. The carbon number waveline indicates a bond with the N atom.

[0195] In formula (20), R ２０１ R is monovalent and represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having 1 to 20 carbon atoms having one or more selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom. ２０２n₂O₁+1 valence represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having 1 to 20 carbon atoms having one or more atoms selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom. n₂O₂ represents an integer from 1 to 3. The dashed line indicates a bond with the N atom.

[0196] Pay particular attention ２１ Preferably, the structure is represented by the following formulas (2-1) to (2-34). In each formula, the wavy line indicates a bond with the N atom.

[0197]

[0198]

[0199] (R ２２ ) In formula (2), R ２２ This represents one or more groups selected from the group consisting of aliphatic groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, and aralkyl groups having 7 to 20 carbon atoms, which may contain oxygen.

[0200] R in formula (2) ２２Examples of the group represented by R¹⁰ include an alkyl group such as methyl, ethyl, propyl (each isomer), butyl (each isomer), pentyl (each isomer), hexyl (each isomer), heptyl (each isomer), octyl (each isomer), nonyl (each isomer), decyl (each isomer), undecyl (each isomer), dodecyl (each isomer), tridecyl (each isomer), tetradecyl (each isomer), pentadecyl (each isomer), hexadecyl (each isomer), heptadecyl (each isomer), octadecyl (each isomer), nonadecyl (each isomer), eicosyl (each isomer); a cycloalkyl group such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl; an aryl group such as phenyl, naphthyl, anthryl; and an aryl group such as methylphenyl (each isomer), ethylphenyl (each isomer), propylphenyl (each isomer), butylphenyl (each isomer), pentylphenyl (each isomer), hexylphenyl (each isomer), α-cumylphenyl (each isomer), methoxyphenyl (each isomer), ethoxyphenyl (each isomer).

[0201] From the viewpoint of distillation separation from isocyanate, it is preferable that the boiling point of the compound represented by the formula (2) is higher than that of isocyanate and the versatility is high. From this viewpoint, aryl groups such as phenyl, naphthyl, anthryl, pyrenyl, phenanthryl, methylphenyl (each isomer), ethylphenyl (each isomer), propylphenyl (each isomer), butylphenyl (each isomer), pentylphenyl (each isomer), hexylphenyl (each isomer), α-cumylphenyl (each isomer), methoxyphenyl (each isomer), ethoxyphenyl (each isomer) are preferable, and among these, phenyl, α-cumylphenyl (each isomer), methoxyphenyl (each isomer), ethoxyphenyl (each isomer) are more preferable.

[0202] (n21) In the formula (2), n21 represents an integer of 1 to 4.

[0203] Next, the conditions of the step (II) will be described.

[0204] {Raw Materials} In step (II), an esterification reaction is carried out between a raw material having a carboxyl group and a raw material having a hydroxyl group in order to obtain the carbamate compound (2). As the raw material having a carboxyl group, the carbamate intermediate (1) obtained in the first embodiment of step (I) can be used, and as the raw material having a hydroxyl group, the carbamate intermediate (1) obtained in the second embodiment of step (II), i.e., carbamate (16), can be used, or an aliphatic alcohol can be used as the raw material having a hydroxyl group.

[0205] When using an aliphatic alcohol as a raw material having a hydroxyl group, methanol, ethanol, propanol (various isomers), butanol (various isomers), pentanol (various isomers), hexanol (various isomers), heptanol (various isomers), octanol (various isomers), cyclohexanol, benzyl alcohol, phenethyl alcohol, ethylene glycol, glycerol, trimethylolethane, and trimethylolpropane are preferably used, and more preferably methanol, ethanol, butanol, isobutanol, glycerol, and trimethylolpropane.

[0206] In step (II), from the viewpoint of shifting the chemical equilibrium between the raw material and the ester, it is desirable that the amount of hydroxyl groups in the raw material having hydroxyl groups be in excess of the carboxyl groups in the raw material having carboxyl groups.

[0207] In step (II), if the carbamate intermediate (1) obtained in the first embodiment of step (I) is used as the raw material having carboxyl groups, and carbamate (16) is used as the raw material having hydroxyl groups, the amount of carbamate (16) used is preferably such that the amount of hydroxyl groups in carbamate (16) is 1.2 times or more and 5 times or less the amount of carboxyl groups in carbamate intermediate (1) obtained in the first embodiment of step (I), and more preferably 1.2 times or more and 2 times the amount of hydroxyl groups in carbamate (16) is used to prevent the remaining carbamate (16) from causing side reactions and worsening the yield of carbamate compound (2).

[0208] In step (II), if the carbamate intermediate (1) obtained in the first embodiment of step (I) is used as the raw material having the carboxyl group, and an aliphatic alcohol is used as the raw material having the hydroxyl group, it is preferable that the amount of aliphatic alcohol used is such that the amount of hydroxyl groups in the carbamate (16) is 1.2 times or more molar equivalent to the amount of carboxyl groups in the carbamate intermediate (1) obtained in the first embodiment of step (I) and is 100 times or less molar equivalent.

[0209] {Catalyst} In step (II), the carbamate compound (2) may be synthesized using an acid catalyst. In this case, the acid catalyst used should have a standard boiling point of 0°C or higher. The standard boiling point of the acid catalyst is 0°C or higher, preferably 10°C or higher, more preferably 30°C or higher, and even more preferably 50°C or higher. By having a standard boiling point of the acid catalyst above the above lower limit, it can be used in a liquid state under the reaction conditions, and the distillation of the acid can be suppressed more effectively. The monoacid catalyst may be an organic acid or an inorganic acid. Examples of organic acids include aliphatic sulfonic acid, aromatic sulfonic acid, alkyl phosphoric acid, alkyl sulfuric acid, aromatic sulfuric acid, etc. Specific examples of aliphatic sulfonic acid include methanesulfonic acid. Specific examples of aromatic sulfonic acid include p-toluenesulfonic acid (standard boiling point: 140°C) and trifluoromethanesulfonic acid. Specific examples of alkyl phosphoric acid include dimethyl phosphate and diethyl phosphate. Examples of alkyl sulfates include dimethyl sulfate, diethyl sulfate, and lauryl sulfate. Examples of aromatic sulfate esters include phenyl sulfate and phenyl fluoride sulfate. Examples of inorganic acids include sulfuric acid, phosphoric acid, nitric acid, and boric acid. These acids may be used individually or in combination of two or more.

[0210] Among the acid catalysts mentioned above, aliphatic sulfonic acid, aliphatic sulfonic acid, or inorganic acid is preferred as the acid catalyst, and methanesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, sulfuric acid, or phosphoric acid, or a combination thereof is more preferred.

[0211] The amount of acid catalyst used in step (II) is preferably 0.01 molar equivalents or more and 2 molar equivalents or less relative to the carboxyl groups in the raw material having carboxyl groups, from the viewpoint of promoting the reaction.

[0212] {Solvent} The reaction to obtain the carbamate compound (2) in step (II) may be carried out in the presence of a solvent. If the starting material having a hydroxyl group is a liquid at the reaction temperature, it may be used as the solvent, or an organic solvent may be used separately.

[0213] When using an organic solvent separately, a preferred organic solvent is one or more compounds selected from the group consisting of ethers, ketones, and esters, due to the high solubility of the raw material carbamate intermediate (I) and the product carbamate compound (II).

[0214] The one or more compounds selected from the group consisting of ethers, ketones, and esters are preferably compounds in which a species selected from the group consisting of aliphatic hydrocarbon groups having 1 to 30 carbon atoms and aromatic hydrocarbon groups having 6 to 30 carbon atoms are bonded by an ether group, a ketone group, and an ester group.

[0215] One or more compounds selected from the group consisting of ethers, ketones, and esters are particularly preferred, such as dibutyl ether, anisole, veratrol, 1,2,3-trimethoxybenzene, diphenyl ether, diethoxybenzene, 1,2-methylenedioxybenzene, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, triglime, cyclohexanone, cyclopentanone, methyl ethyl ketone, acetophenone, diethylene glycol monoethyl ether acetate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, γ-butyrolactone, and γ-valerolactone.

[0216] Furthermore, anisole, veratrol, 1,2,3-trimethoxybenzene, diethoxybenzene, dibutyl ether, diphenyl ether, 1,2-methylenedioxybenzene, cyclohexanone, and cyclopentanone are more preferable in order to separate from water and remove the acid catalyst in the washing process described later.

[0217] The organic solvent may contain an azeotropic solvent compound to remove water by utilizing the azeotropic effect. Any azeotropic solvent that can form an azeotrope with water and is inert with the raw material or carbamate compound (2) can be used, and examples include aliphatic compounds, alicyclic compounds, aromatic compounds which may have substituents, unsubstituted hydrocarbons, or mixtures thereof.

[0218] Examples of azeotropic solvent compounds include alkanes, aromatic hydrocarbons and alkyl-substituted aromatic hydrocarbons, aromatic compounds substituted with nitro groups or halogens, polycyclic hydrocarbon compounds, and alicyclic hydrocarbons.

[0219] Examples of alkanes include hexane, heptane, octane, nonane, decane, n-hexadecane, n-octadecane, eicosane, and squalane.

[0220] Examples of aromatic hydrocarbons and alkyl-substituted aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, triethylbenzene, cumene, diisopropylbenzene, dibutylbenzene, naphthalene, mesitylene, lower alkyl-substituted naphthalene, and dodecylbenzene. Examples of aromatic compounds substituted with nitro groups or halogens include chlorobenzene, 4-methylbenzyl chloride, p-dichlorobenzene, brombenzene, dibrombenzene, chlornaphthalene, bromnaphthalene, nitrobenzene, and nitronaphthalene.

[0221] Examples of polycyclic hydrocarbon compounds include diphenyl, substituted diphenyl, diphenylmethane, terphenyl, anthracene, phenanthrene, benzyltoluene, isomers of benzyltoluene, and triphenylmethane. Examples of alicyclic hydrocarbons include cyclohexane and ethylcyclohexane.

[0222] Among these, aromatic hydrocarbons and alkyl-substituted aromatic hydrocarbons or aromatic compounds substituted with nitro groups or halogens are preferred as inert solvents, alkyl-substituted aromatic hydrocarbons or aromatic compounds substituted with halogens are more preferred, and toluene, xylene, mesitylene or p-dichlorobenzene are even more preferred.

[0223] When using an azeotropic solvent compound, depending on the type of azeotropic solvent compound and the solubility of the raw materials used, it is preferable that the amount of the azeotropic solvent compound is between 0.2 and 5 weight equivalents relative to the organic solvent that is not an azeotropic solvent compound. Having the amount of the azeotropic solvent compound above the lower limit allows for highly efficient extraction of water, as described later, while having it below the upper limit does not impair the solubility of the product.

[0224] {Reaction Conditions} In step (II), the raw materials, solvent, and acid catalyst may be introduced into the reactor in either solid or liquid form. However, in order to quickly dissolve the raw materials, it is preferable that at least one of them be introduced in a liquid state at a temperature above its melting point.

[0225] In step (II), the acid catalyst may be introduced simultaneously with the introduction of the raw materials and the organic solvent, or the carboxyl group-containing raw material and the hydroxyl group-containing raw material may be dissolved in the organic solvent, allowed to dissolve, and then introduced. However, the latter method is preferable because it can suppress side reactions that occur under high-temperature conditions when dissolving the quantities.

[0226] In step (II), if the raw materials are dissolved in advance before introducing the acid catalyst, the temperature conditions are preferably 30°C or higher from the viewpoint of rapid dissolution, and 90°C or lower from the viewpoint of suppressing side reactions.

[0227] In step (II), the temperature conditions for esterification after adding the acid catalyst are preferably 30°C to 120°C, and more preferably 40°C to 90°C. A reaction temperature above the upper limit allows for a higher reaction rate, while a temperature below the lower limit suppresses side reactions.

[0228] In step (II), there are no particular restrictions on the reaction time, but it is usually between 0.001 hours and 100 hours, preferably between 0.01 hours and 50 hours, and more preferably between 0.1 hours and 10 hours.

[0229] In step (II), it is preferable to perform the reaction under reduced pressure and distill off water and organic solvents from the liquid and gas phases. This shifts the chemical equilibrium in the esterification reaction towards the product side, enabling a highly efficient reaction.

[0230] In step (II), it is preferable to continuously add the organic solvent so that the volume of the reaction solution does not change even if water and the organic solvent are removed. This operation may also be performed by phase separation of the removed water and organic solvent, and by returning a portion of the organic phase to the reaction apparatus using a Dean-Stark apparatus or the like.

[0231] {Purification} In one embodiment of the present invention, the method for purifying the carbamate compound (2) produced in step (II) is not particularly limited, but it is preferable to remove any remaining acid catalyst, solvent, and various raw materials by a water washing step, a distillation purification step, or a combination of both.

[0232] {{Water Washing Process}} In process (II), for the purpose of purifying the carbamate compound (2), water may be added to the composition containing the obtained carbamate compound (2) to remove residual raw materials, by-products, and the acid catalyst, and the aqueous phase may be removed.

[0233] In the washing process, it is preferable to preheat the components obtained in step (II) to a liquid state. In this case, the temperature should preferably be between 50°C and 90°C. Setting the temperature above the lower limit prevents compound precipitation and enables good phase separation, as well as improving the solubility of the acid catalyst in the aqueous phase, allowing for highly efficient washing. Setting the temperature below the upper limit suppresses side reactions during washing, enabling highly efficient washing.

[0234] In the washing process, the amount of water used per wash is preferably 0.25 weight equivalents or more and 1 weight equivalent or less relative to the total amount of the liquid phase containing the carbamate compound (2) obtained in step (II). Being within this range prevents the aqueous and organic phases from becoming an emulsion and making separation impossible, thereby achieving good separation.

[0235] In the washing step, after adding water to the liquid phase containing the carbamate compound (2) obtained in step (2), the stirring time is preferably 10 seconds to 5 hours. Setting the time above the lower limit allows the acid catalyst to be extracted into the aqueous phase through good contact between the aqueous phase and the organic phase, while setting the time below the upper limit suppresses the hydrolysis of the carbamate compound (2).

[0236] In the washing step, water is added to the liquid phase containing the carbamate compound (2) obtained in step (2), and after stirring, it is preferable to allow it to stand for 5 minutes to 1 hour to separate the aqueous phase from the organic phase. Setting the time above the lower limit ensures good separation of the aqueous phase from the organic phase, while setting the time below the upper limit suppresses hydrolysis of the carbamate compound (2) in the liquid phase.

[0237] In the water washing step, when adding water to the liquid phase containing the carbamate compound (2) obtained in step (2), one or more of the solvents deemed preferable in step (2), which are organic solvents that dissolve the organic phase and separate from water, may also be used to promote the subsequent phase separation into the aqueous phase and the organic phase.

[0238] In the washing process, after phase separation, whether to extract the aqueous phase from the upper or lower layer depends on the density of the organic solvent used, the amount of dissolved compounds, and the density of the solvent. However, it is preferable to extract the aqueous phase as the upper layer, as this reduces the amount of organic solvent and allows for the acquisition of a high-concentration organic phase.

[0239] In the washing process, the number of times water is added, stirred, allowed to stand, and the drained water washing operation can be performed any number of times as long as the acid catalyst is removed, but it is preferable that it be performed between 1 and 10 times. Setting it above the lower limit ensures that the acid catalyst is removed efficiently, while setting it below the upper limit helps to suppress the hydrolysis of the carbamate compound (2) and contributes to improving the recovery rate of the raw material in the distillation purification process described later.

[0240] In the washing process, a reactor that appropriately meets the conditions is selected. Specifically, conventionally known reactors such as stirring tanks, pressurized stirring tanks, vacuum stirring tanks, column reactors, distillation columns, packed columns, and thin-film distillers can be used in appropriate combinations. For example, various known methods can be used, such as using a reactor that includes a distillation column, multi-stage distillation column, multi-tube reactor, continuous multi-stage distillation column, packed column, thin-film evaporator, reactor with an internal support, forced-circulation reactor, drop film evaporator, or drop evaporator, or a combination thereof. From the viewpoint of quickly mixing the raw materials, separating the phases, and extracting the liquid phase, and from the viewpoint of performing the "pre-concentration process" described later after the washing process, a method using a stirring tank or multi-stage stirring tank equipped with an extraction line and a distillation column is preferred.

[0241] There are no particular restrictions on the type of condenser provided in the reactor, and known condensers can be used. For example, conventionally known condensers such as multi-tube cylindrical condensers, double-tube condensers, single-tube condensers, and air-cooled condensers can be used in appropriate combinations. The condenser may be provided inside the reactor or outside the reactor and connected to the reactor by piping, and various forms can be adopted considering the type of reactor and condenser, the method of handling the condensate, etc. There are no particular restrictions on the material of the reactor and condenser, and known materials can be used as long as they do not adversely affect the carbamate compounds, etc. For example, glass, stainless steel, carbon steel, Hastelloy®, or materials with a glass lining or Teflon® coating can be used. SUS304, SUS316, and SUS316L are inexpensive and preferably used. Instrumentation equipment such as flow meters and thermometers, and known process equipment such as reboilers, pumps, and condensers may be added as needed. Heating may be done by known methods such as steam or heaters, and cooling may be done by known methods such as natural cooling, cooling water, or brine. Additional processes may be added as needed.

[0242] {Distillation Purification Step} For the purpose of purifying the carbamate compound (2) produced in step (II), it is preferable to remove any remaining solvent and various raw materials by distillation. If the water washing step was performed before the distillation purification step, it is preferable to perform purification by distillation in order to remove any remaining water in the liquid phase.

[0243] In the distillation purification process, a reactor that appropriately matches the conditions is selected. Specifically, conventionally known reactors such as stirred tanks, pressurized stirred tanks, vacuum stirred tanks, column reactors, distillation columns, packed columns, and thin-film distillers can be used in appropriate combinations. For example, various known methods are used, such as a system using a reactor that includes a distillation column, multi-stage distillation column, multi-tube reactor, continuous multi-stage distillation column, packed column, thin-film evaporator, reactor with an internal support, forced-circulation reactor, drop film evaporator, or drop evaporator, and a system combining these. If the objective is to efficiently remove low-boiling components such as solvents, a stirred tank equipped with a distillation column or a multi-stage stirred tank is preferred, and if the objective is to improve the recovery rate of the remaining carbamate intermediate (1) with a relatively high boiling point, a distillation column, multi-stage distillation column, packed column, thin-film evaporator, drop film evaporator, or drop evaporator is more preferred.

[0244] There are no particular restrictions on the type of condenser provided in the reactor, and known condensers can be used. For example, conventionally known condensers such as multi-tube cylindrical condensers, double-tube condensers, single-tube condensers, and air-cooled condensers can be used in appropriate combinations. The condenser may be provided inside the reactor or outside the reactor and connected to the reactor by piping, and various forms can be adopted considering the type of reactor and condenser, the method of handling the condensate, etc. There are no particular restrictions on the material of the reactor and condenser, and known materials can be used as long as they do not adversely affect the carbamate compounds, etc. For example, glass, stainless steel, carbon steel, Hastelloy®, or materials with a glass lining or Teflon® coating can be used. SUS304, SUS316, and SUS316L are inexpensive and preferably used. Instrumentation equipment such as flow meters and thermometers, and known process equipment such as reboilers, pumps, and condensers may be added as needed. Heating may be done by known methods such as steam or heaters, and cooling may be done by known methods such as natural cooling, cooling water, or brine. Additional processes may be added as needed.

[0245] In the distillation purification process, the temperature conditions during implementation depend on the type of raw material, solvent, and acid catalyst to be removed. However, when removing the remaining solvent other than the carbamate intermediate (1), a temperature of 30°C to 120°C is preferred, and when removing the remaining raw material, the carbamate intermediate (1), a temperature of 100°C to 250°C is preferred.

[0246] In the distillation and purification process, the pressure used is usually between 20 Pa and 1 × 10⁶ Pa, although this depends on the type of compound being removed.

[0247] In the distillation purification process, the carbamate compound (2) to be purified has a structure represented by formula (19) or formula (20) R ２１ If the carbamate compound (2) is one of the carbamate compounds (2) present in step (2), the composition containing the carbamate compound (2) after step (2) (hereinafter sometimes referred to as the carbamate composition) contains one or more compounds selected from the group consisting of alkyl carbamate compounds represented by formula (9) and carbamate carbonate compounds represented by formula (8), which are different from the carbamate compound (2).

[0248] Alkylcarbamate compounds are by-products produced during the synthesis of carbamate compound (2) in step (II). Carbamate carbonate compound (8) is a compound that is present as an impurity in the amino alcohol carbamate used in the synthesis of the carbamate compounds described later.

[0249] When the carbamate composition described above is used, the denaturation of the carbamate compound (2) is suppressed during the distillation purification process of the carbamate compound (2). The reason for this effect is not clear, but it is thought that the alkyl carbamate compound (9) and the carbamate carbonate compound (8) have high boiling points and function as good solvents for the carbamate compound (2), thereby suppressing denaturation. In addition, it is thought that they suppress denaturation by forming hydrogen bonds between the protons in the carbamate structure of the alkyl carbamate compound (9) or the carbamate carbonate compound (8) and the carbonyl moiety in the carbamate compound (2), contributing to the stabilization of the ester moiety and carbamateization in the carbamate compound (2).

[0250] In the carbamate composition of this embodiment, the content of alkylcarbamate compound (9) and carbamate carbonate compound (8) is preferably such that their total mass is 3% by mass or more and 20% by mass or less in weight ratio with respect to carbamate compound (2). If the above value is above the lower limit, the denaturation of carbamate compound (2) can be suppressed in the distillation purification process of carbamate compound (2), and the yield of carbamate compound (2) can be improved. If the above value is below the upper limit, carbamate compound (2) can be concentrated to a high concentration in distillation purification, which improves the yield when used in subsequent thermal decomposition for isocyanate synthesis, and reduces raw material costs.

[0251] The content of the alkylcarbamate compound (9) and the carbamate carbonate compound (8) and the content of the carbamate compound (2) are as follows: １ The analysis can be performed by quantifying each compound using a combination of H-NMR, liquid chromatography, and gas chromatography. The detailed conditions for the above analysis can be those described in the examples.

[0252] The carbamate composition used in the method of implementation of this embodiment has the above configuration, which suppresses the denaturation of the carbamate compound (2) when distillation purification is used in the production of the carbamate compound (2), and improves the yield of the carbamate compound (2).

[0253] (Alkylcarbamate compound (9)) Alkylcarbamate compound (9) is a compound represented by the following formula (9).

[0254]

[0255] In equation (9), n91 is an integer between 1 and 4 (inclusive). ９１ , R ９２ Each is at least one selected from the group consisting of a hydrogen atom or a group represented by the following formula (10) and a group represented by the following formula (11), where R in the formula ９１ , R ９２ At least one of them is a group represented by the following formula (11): R９３ This is a residue obtained by removing n91 hydroxyl groups from an alcohol compound.

[0256]

[0257] In equation (10), n101 is an integer of 0 or 1. １０１ R is a divalent organic group having 1 to 30 carbon atoms, which may have substituents. １０２ This is a monovalent organic group having 1 to 30 carbon atoms, which may have substituents.

[0258]

[0259] In general formula (11), n111 is an integer of 0 or 1. １１１ R is a divalent organic group having 30 or fewer carbon atoms, which may have substituents. １１２ This is a residue obtained by removing one hydroxyl group from an alcohol compound.

[0260] [R ９１ , R ９２ In the above formula (9), R ９１ , R ９２ R is at least one selected from the group consisting of a hydrogen atom or a group represented by the general formula (10) or a group represented by the general formula (11). ９１ , R ９２ At least one of these is a group represented by the general formula (11).

[0261] [n101, n111] In the general formula (10), n101 is an integer of 0 or 1. When n101 is 0, the base represented by the general formula (10) is R in the general formula (9). ９１ or R ９２ The residues excluding the one shown bond to the nitrogen atom described in general formula (10). In general formula (11), n111 is an integer of 0 or 1. When n111 is 0, the group represented by general formula (11) is the R in general formula (9). ９１ or R ９２ The residues excluding the one shown bond to the nitrogen atom described in general formula (11).

[0262] In the above general formula (9), R ９１ , R ９２At least one of them is a group represented by the general formula (10) where n101 is 0, or a group represented by the general formula (11) where n111 is 0.

[0263] [R １０１ , R １１１ ] In the above general formula (10), R １０１ R is a divalent organic group having 1 to 30 carbon atoms, which may have substituents. In the general formula (11), １１１ This is a divalent organic group having 1 to 30 carbon atoms, which may have substituents.

[0264] R １０１ and R １１１ The organic groups in this context are aliphatic hydrocarbon groups, aromatic hydrocarbon groups, or groups formed by the bonding of an aliphatic hydrocarbon group and an aromatic hydrocarbon group. Specific R １０１ and R １１１ Examples of these include cyclic hydrocarbon groups, acyclic hydrocarbon groups, groups formed by bonding an acyclic hydrocarbon group with one or more cyclic groups, and groups in which these groups are covalently bonded to a specific nonmetallic atom. Examples of the cyclic groups include cyclic hydrocarbon groups, heterocyclic groups, heterocyclic spiro groups, and heterobridged cyclic groups. Examples of the cyclic hydrocarbon groups include monocyclic hydrocarbon groups, condensed polycyclic hydrocarbon groups, bridged cyclic hydrocarbon groups, spiro hydrocarbon groups, ring-aggregated hydrocarbon groups, and cyclic hydrocarbon groups with side chains. Examples of the nonmetallic atoms include carbon, oxygen, nitrogen, sulfur, and silicon.

[0265] Furthermore, "covalently bonded with a specific nonmetal atom" means, for example, that the group exemplified above is covalently bonded with the group represented by the following formulas (21-1) to (21-14).

[0266]

[0267] Among them, R １０１ and R １１１The organic group in this is preferably a cyclic hydrocarbon group, an acyclic hydrocarbon group, a group formed by bonding an acyclic hydrocarbon group with one or more cyclic groups, or a group in which these groups are covalently bonded with a group represented by formula (21-1), formula (21-2), formula (21-3), formula (21-4), formula (21-5), formula (21-8), formula (21-9), formula (21-10), or formula (21-12).

[0268] Examples of cyclic hydrocarbon groups include cyclopentyl groups, cyclohexyl groups, phenyl groups, naphthyl groups, anthryl groups, and pyrenyl groups.

[0269] Examples of acyclic hydrocarbon groups include methyl, ethyl, propyl (various isomers), butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, and octadecyl groups.

[0270] R １０１ and R １１１ Substituents in this group include halogeno groups, thioalkyl groups, amide groups, and carbamide groups (-NHCONH ２ ) and the like are preferred.

[0271] [R １０２ ] R １０２ This is a monovalent organic group having 1 to 30 carbon atoms, which may have substituents. Preferably, it is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms.

[0272] R １０２ The aliphatic hydrocarbon group having 1 to 30 carbon atoms may be linear or branched. In particular, R １０２ In R, the aliphatic hydrocarbon group having 1 to 30 carbon atoms is preferably an alkyl group. １０２ The number of carbon atoms in the linear alkyl group is preferably 1 to 5, more preferably 1 to 4, and even more preferably 1 or 2. ２２Examples of linear alkyl groups in this context include methyl, ethyl, n-propyl, n-butyl, and n-pentyl groups. １０２ The number of carbon atoms in the branched alkyl group is preferably 3 to 10, and more preferably 3 to 5. １０２ Examples of branched alkyl groups in this context include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, and 2,2-dimethylbutyl group.

[0273] R １０２ The alicyclic hydrocarbon group having 3 to 30 carbon atoms may be monocyclic or polycyclic. Specific examples of monocyclic alicyclic hydrocarbon groups include cyclopentyl and cyclohexyl groups. Specific examples of polycyclic alicyclic hydrocarbon groups include adamantyl, norbornyl, isobornyl, tricyclodecyl, and tetracyclododecyl groups.

[0274] R １０２ In this context, aromatic hydrocarbon groups having 6 to 30 carbon atoms are preferred, and aromatic hydrocarbon groups having 6 to 12 carbon atoms are preferred. Examples of such aromatic hydrocarbon groups include phenyl groups, methylphenyl groups, methoxyphenyl groups, ethoxyphenyl groups, cumylphenyl groups, and the like.

[0275] Among them, R １０２ Preferably, the group is an aromatic hydrocarbon group having 6 to 30 carbon atoms, more preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms, even more preferably an aromatic hydrocarbon group having 6 to 8 carbon atoms, and particularly preferably a phenyl group or a methoxyphenyl group.

[0276] Among the alkylcarbamate compounds (9) mentioned above, preferred compounds are, for example, those represented by the following general formulas (9-1) to (9-8).

[0277]

[0278] In general formulas (9-1) to (9-8), n91 is an integer between 1 and 4 (inclusive).９３ X is a residue obtained by removing n91 hydroxyl groups from an alcohol compound. １１ or X １２ Each is independently a phenyl group, a methylphenyl group, and R １１２ It is one of the following types, and X in the formula １１ or X １２ At least one of them is R １１２ That is the case.

[0279] [n91] In the general formulas (9) and (9-1) to (9-8) above, n91 is an integer between 1 and 4.

[0280] [R ９３ , R １１２ ] R ９３ This is a residue obtained by removing n91 or more hydroxyl groups from an alcohol compound. ９３ As such, an organic group having 1 to 50 carbon atoms is preferred. １１２ This is a residue obtained by removing one hydroxyl group from an alcohol compound. １１２ As such, a monovalent organic group having 1 to 50 carbon atoms is preferred.

[0281] R ９３ and R １１２ R is an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a group formed by the bonding of an aliphatic hydrocarbon group and an aromatic hydrocarbon group. ９３ and R １１２ Examples of these include cyclic hydrocarbon groups, acyclic hydrocarbon groups, groups formed by bonding an acyclic hydrocarbon group with one or more cyclic groups, and groups in which these groups are covalently bonded to a specific nonmetallic atom. Examples of the cyclic groups include cyclic hydrocarbon groups, heterocyclic groups, heterocyclic spiro groups, and heterobridged cyclic groups. Examples of the cyclic hydrocarbon groups include monocyclic hydrocarbon groups, condensed polycyclic hydrocarbon groups, bridged cyclic hydrocarbon groups, spiro hydrocarbon groups, ring-aggregated hydrocarbon groups, and cyclic hydrocarbon groups with side chains. Examples of the nonmetallic atoms include carbon, oxygen, nitrogen, sulfur, and silicon.

[0282] Furthermore, "covalently bonded with a specific nonmetal atom" means, for example, that the group exemplified above is covalently bonded with the group represented by formulas (21-1) to (21-14).

[0283] Among them, R ９３ and R １１２ Preferably, the group is a cyclic hydrocarbon group, an acyclic hydrocarbon group, or a group formed by bonding an acyclic hydrocarbon group to one or more cyclic groups, or a group in which these groups are covalently bonded to a group represented by formula (21-1), formula (21-2), formula (21-3), formula (21-4), formula (21-5), formula (21-8), formula (21-9), or formula (21-12), and more preferably, an organic group represented by the following general formula (22).

[0284] (In general formula (22), n221 is an integer between 1 and 4, and is equal to n11. R ２２１ R is an n221+1 valent organic group having 1 to 30 carbon atoms, which may have substituents. ２２２ (This is a monovalent organic group having 1 to 30 carbon atoms, which may have substituents.)

[0285] [R ２２１ In general formula (22), R ２２１ This is an n221+1 valent organic group having 1 to 30 carbon atoms, which may have substituents.

[0286] [n221] In general formula (22), n221 is an integer between 1 and 4, and is equal to n11.

[0287] R ２２１The structure is preferably one with one primary amino group and n221 hydroxyl groups removed from the amino alcohol compound. Specifically, the amino alcohol compounds referred to here are ethanolamine, 3-amino-1-propanol, 4-amino-1-butanol, 4-amino-2-methyl-1-butanol, 6-amino-1-hexanol, (R Examples include 3-amino-1-butanol, 3-amino-2,2-dimethyl-1-propanol, tris(hydroxymethyl)aminomethane, 2-amino-1-butanol, 1-amino-2-propanol, 2-amino-1-propanol, 2-amino-2-methyl-1-propanol, 1-amino-2-methyl-2-propanol, 1-amino-2-butanol, 3-amino-1,2-propanediol, 2-amino-1,3-propanediol, valinol, 2-aminopentan-1-ol, 2-amino-2-methyl-1,3-propanediol, 2-(2-aminoethoxy)ethanol, L-tert-leucinol, L-isoleucinol, 2-amino-2-ethyl-1,3-propanediol, 2-aminocyclohexanol, phenylglycinol, and 2-amino-1-phenylethanol.

[0288] [R ２２２ In general formula (22), R ２２２ This residue is obtained by removing one hydroxyl group from a hydroxy compound, and is preferably an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms.

[0289] R ２２２ The aliphatic hydrocarbon group having 1 to 30 carbon atoms in R may be linear or branched. ２２２ In R, the aliphatic hydrocarbon group having 1 to 30 carbon atoms is preferably an alkyl group. ２２２ The number of carbon atoms in the linear alkyl group is preferably 1 to 5, more preferably 1 to 4, and even more preferably 1 or 2. ２２２Examples of linear alkyl groups in this context include methyl, ethyl, n-propyl, n-butyl, and n-pentyl groups. ２２２ The number of carbon atoms in the branched alkyl group is preferably 3 to 10, and more preferably 3 to 5. ２２２ Examples of branched alkyl groups in this context include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, and 2,2-dimethylbutyl group.

[0290] R ２２２ The alicyclic hydrocarbon group having 3 to 30 carbon atoms may be monocyclic or polycyclic. Specific examples of monocyclic alicyclic hydrocarbon groups include cyclopentyl and cyclohexyl groups. Specific examples of polycyclic alicyclic hydrocarbon groups include adamantyl, norbornyl, isobornyl, tricyclodecyl, and tetracyclododecyl groups.

[0291] R ２２２ In this context, aromatic hydrocarbon groups having 6 to 30 carbon atoms are preferred, and aromatic hydrocarbon groups having 6 to 15 carbon atoms are preferred. Examples of such aromatic hydrocarbon groups include phenyl groups, methylphenyl groups, methoxyphenyl groups, ethoxyphenyl groups, cumylphenyl groups, and the like.

[0292] Among them, R ２２２ Each of these groups is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms, more preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms, even more preferably an aromatic hydrocarbon group having 6 to 8 carbon atoms, and particularly preferably a phenyl group or a methoxyphenyl group.

[0293] A preferred structure of general formula (22) is, for example, a group represented by any of the following general formulas (22-1) to (22-26).

[0294]

[0295] In general formulas (22-1) to (22-26), X is a phenyl group or a methylphenyl group.

[0296] <Carbamate carbonate compound (8)> Carbamate carbonate compound (8) is the same compound as the compound shown in the general formula (8) above.

[0297] [Step (III)] Step (III) is a step in which the carbamate compound obtained in Step (II) above is thermally decomposed to obtain an isocyanate compound represented by the following formula (3). Hereafter, the isocyanate compound represented by formula (3) may be referred to as "isocyanate compound (3) represented by formula (3)".

[0298]

[0299] In the formula, R ３１ n31 represents an aliphatic hydrocarbon group having a valency of 1 to 4 and 1 to 40 carbon atoms, or an aromatic group having a valency of 1 to 3 and 6 to 40 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having a valency of 1 to 4 and 1 to 4 carbon atoms, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms.

[0300] R ３１However, if at least one of the above aliphatic hydrocarbon group and aromatic group is bonded via an ester group, forming a group with 1 to 20 carbon atoms, then compound (3) specifically includes, for example, 2-isocyanatoethyl-2-isocyanatoacetate, 2-isocyanatoethyl-2-isocyanatopropanoate, 2-isocyanatoethyl-2-isocyanato-3-methylbutanoate, 2-isocyanatoethyl-2,5-diisocyanato-5-oxopentanoate, and bis(2-isocyanatoethyl)-2-isocyanatopentanediole 2-Isocyanatoethyl-2-Isocyanato-4-(methylthio)butanoate, 2-Isocyanatoethyl-2,6-diisocyanatohexanoate, 2-Isocyanatoethyl-2,5-diisocyanatopentanoate, bis(2-Isocyanatoethyl)-2-Isocyanatosuccinate, 3-Isocyanatopropyl-2,6-diisocyanatohexanoate, 4-Isocyanatobutyl-2,6-diisocyanatohexanoate, 6-Isocyanatohexyl-2,6-diisocyanatohexanoate, 2-(2-Isocyanatoethoxy C)ethyl-2,6-diisocyanatohexanoate, 2-isocyanatocyclohexyl-2,6-diisocyanatohexanoate, 2-isocyanato-2-((2-isocyanatoacetoxy)methyl)propane-1,3-diyl-bis(2-isocyanatoacetate), 2-isocyanato-2-(((2-isocyanatopropanoyl)oxy)methyl)propane-1,3-diyl-bis(2-isocyanatopropanoate), 2-isocyanato-2-(((2-isocyanato-3-methylbutanoyl)oxy)methyl)propane-1, 3-Diyl-bis(2-isocyanato-3-methylbutanoate), 2-isocyanato-2-(((2-isocyanato-4-(methylthio)butanoyl)oxy)methyl)propane-1,3-Diyl-bis(2-isocyanato-4-(methylthio)butanoate), Methyl-2,6-diisocyanatohexanoate, Ethyl-2,6-diisocyanatohexanoate, Butyl-2,6-diisocyanatohexanoate, Isobutyl-2,6-diisocyanatohexanoate, 2-((2-isocyanatoacetoxy)methyl)propane-1,3-Diyl-bis(2-isocyanatoacetate), 2-ethyl-2-((2-isocyanatoacetoxy)methyl)propane-1,3-diyl-bis(2-isocyanatoacetate), 2-(((2-isocyanatopropanoyl)oxy)methyl)propane-1,3-diyl-bis(2-isocyanatopropanoate), 2-ethyl-2-(((2-isocyanatopropanoyl)oxy)methyl)propane-1,3-diyl-bis(2-isocyanatopropanoate), 2-(((2-isocyanato-3-methylbutanoyl)oxy)methyl)propane-1,3-diyl-bis(2-isocyanatoacetate) Examples include anato-3-methylbutanoate, 2-ethyl-2-(((2-isocyanato-3-methylbutanoyl)oxy)methyl)propane-1,3-diyl-bis(2-isocyanato-3-methylbutanoate), 2-(((2-isocyanato-4-(methylthio)butanoyl)oxy)methyl)propane-1,3-diyl-bis(2-isocyanato-4-(methylthio)butanoate), 2-ethyl-2-(((2-isocyanato-4-(methylthio)butanoyl)oxy)methyl)propane-1,3-diyl-bis(2-isocyanato-4-(methylthio)butanoate), etc.

[0301] (n31) In the general formula (3) above, n31 represents the number of isocyanate groups and is an integer between 1 and 4. Preferably, n31 is between 2 and 4. Generally, polymers can be obtained by reacting an isocyanate with n31 or more with a dihydroxy compound or diamine compound having active hydrogen. The larger the value of n31, the more crosslinking sites (isocyanate groups) there are per isocyanate molecule, so the crosslinking density when polymerized increases, which can shorten the curing time and improve the hardness of the polymer. Higher crosslinking density means that the average molecular chain length between crosslinking sites decreases. When there are three or more isocyanate groups in the isocyanate molecule (a is 3 or more), linear polymers can be further bonded together, which tends to increase the molecular weight of the polymer, so a significant reduction in curing time and a dramatic improvement in polymer properties such as hardness can be expected. On the other hand, in isocyanate production, heating highly reactive isocyanate compounds can trigger a denaturation reaction, leading to adhesion and clogging of the equipment. Therefore, it is preferable that the isocyanate compound has four or fewer isocyanate groups (n31).

[0302] Among these, R in equation (3) ３１ The structure is preferably represented by the above formulas (2-1) to (2-34), and among these, (2-1) to (2-19) are more preferred. In each formula, the wavy line indicates a coupling.

[0303] The isocyanate compound of formula (3) is obtained by carrying out a thermal decomposition reaction of the carbamate compound of formula (2) in the presence of a solvent.

[0304] The thermal decomposition reaction involves the formation of a hydroxy compound R from the carbamate compound of formula (2) above. ２ This reaction yields the isocyanate of formula (3) above through the partial elimination of OH groups.

[0305] The materials used for the reactors and lines where the thermal decomposition and purification processes are carried out may be any known material, as long as it does not adversely affect the carbamate compound, the resulting hydroxy compound and isocyanate, or the solvent. However, SUS304, SUS316, SUS316L, etc., are inexpensive and preferably used.

[0306] From the viewpoint of separating the generated hydroxy compounds and isocyanates, a method using a distillation column, a stirred tank equipped with a distillation column, or a multi-stage stirred tank is preferred, and a structure with a large gas-liquid contact area that allows the generated low-boiling point components to be quickly moved into the gas phase is also preferred.

[0307] Preferably, the reactor includes a line for supplying the carbamate compound, a line for removing the gaseous component containing the hydroxy compound produced by the thermal decomposition reaction, and a line for removing a mixture containing the compound that was not removed as a gaseous component, as well as the unreacted carbamate compound and the hydroxy compound. It is particularly preferable that the line for removing the gaseous component containing the hydroxy compound is located in a position that allows for the removal of the gaseous component from the reactor, and that there is also a line for removing the mixture containing the compound that was not removed as a gaseous component, as well as the unreacted carbamate compound and the hydroxy compound.

[0308] Additionally, a separate line may be installed to supply one or more substances selected from the group consisting of inert gases and liquid inert solvents from below the reactor. Each line may be equipped with facilities for heating, cooling, or insulating to prevent clogging, etc.

[0309] {Solvent} The thermal decomposition reaction of carbamate compounds is preferably carried out in the presence of a solvent from the viewpoint of suppressing isocyanate modification. From the viewpoint of preventing the raw material carbamate compound from becoming locally highly concentrated, the solvent is preferably supplied to the reactor in which the thermal decomposition reaction is carried out as a mixture with the carbamate compound.

[0310] It is preferable to use one or more compounds selected from the group consisting of carbonate esters, ethers, hydrocarbons, and ketones as the solvent. The solvent may be supplied to the reactor before the start of the reaction (or during the supply process), during the reaction, or at both timings. In any case, from the viewpoint of preventing localized high concentrations of the carbamate compound in the reactor, it is preferable to supply the solvent to the reactor as a mixture with the carbamate compound.

[0311] While a larger amount of solvent is preferable to suppress side reactions, considering the size of the reactor, the amount of solvent used is preferably 0.001 to 100 times the carbamate compound in terms of stoichiometric molar ratio, more preferably 2 to 80 times, and even more preferably 0.1 to 50 times. Furthermore, if a carbonate derivative is contained in the product containing the carbamate compound during its production, the carbonate derivative may be used as is, or a new carbonate derivative may be added to the carbamate compound.

[0312] The carbonate ester used as the solvent is preferably the compound represented by formula (12).

[0313] Among them, R １２１ Preferred are substituted or unsubstituted aryl groups. Also preferred are aryl groups such as phenyl, naphthyl, anthryl, pyrenyl, phenanthryl, methylphenyl (each isomer), ethylphenyl (each isomer), propylphenyl (each isomer), butylphenyl (each isomer), pentylphenyl (each isomer), hexylphenyl (each isomer), α-cumylphenyl (each isomer), methoxyphenyl (each isomer), and ethoxyphenyl (each isomer). Among these, phenyl, α-cumylphenyl (each isomer), methoxyphenyl (each isomer), and ethoxyphenyl (each isomer) are more preferred.

[0314] The ether used as a solvent is not particularly limited, but compounds represented by the following formula (300) are preferably used.

[0315]

[0316] (In general formula (300), R ３０１ and R ３０３ Each of these is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. ３０２c is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, an arylene group having 7 to 20 carbon atoms, or an aralkylene group having 7 to 20 carbon atoms. c is an integer between 0 and 20.

[0317] (R ３０１ and R ３０３ ) R ３０１ and R ３０３ Examples of alkyl groups having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group (each isomer), butyl group (each isomer), pentyl group (each isomer), hexyl group (each isomer), heptyl group (each isomer), octyl group (each isomer), nonyl group (each isomer), decyl group (each isomer), dodecyl group (each isomer), octadecyl group (each isomer), and so on.

[0318] R ３０１ and R ３０３ Examples of aryl groups having 6 to 20 carbon atoms include phenyl groups and naphthyl groups.

[0319] R ３０１ and R ３０３ Examples of aralkyl groups having 7 to 20 carbon atoms include phenylmethyl group, phenylethyl group (various isomers), phenylpropyl group (various isomers), phenylbutyl group (various isomers), phenylpentyl group (various isomers), phenylhexyl group (various isomers), phenylheptyl group (various isomers), phenyloctyl group (various isomers), and phenylnonyl group (various isomers).

[0320] Substituents of alkyl groups include aryl groups, halogen groups, and nitrile groups. Examples of aryl groups include those mentioned above. Examples of halogen groups include fluoro groups, chloro groups, bromo groups, and iodo groups. Substituents of aryl and aralkyl groups include alkyl groups, halogen groups, and nitrile groups. Examples of alkyl and halogen groups include those mentioned above.

[0321] (R ３０２ ) R ３０２Examples of alkylene groups having 1 to 20 carbon atoms include methylene groups, ethylene groups, and propylene groups. ３０２ Examples of arylene groups with 7 to 20 carbon atoms in R include phenylene groups and naphthylene groups. ３０２ Examples of aralkylene groups having 7 to 20 carbon atoms include phenylenemethylene groups and methylenephenylenemethylene groups.

[0322] Substituents on alkylene groups include aryl groups, alkoxy groups, halogen groups, and nitrile groups. Examples of alkoxy groups include methoxy groups, ethoxy groups, propyloxy groups (each isomer), butoxy groups (each isomer), and hexyloxy groups (each isomer). Examples of aryl groups and halogen groups include those mentioned above. Substituents on arylene groups and aralkylene groups include alkyl groups, alkoxy groups, halogen groups, and nitrile groups. Examples of alkyl groups, alkoxy groups, and halogen groups include those mentioned above.

[0323] Examples of preferred ethers (300) include compounds represented by the following formulas (300-1) to (300-23).

[0324]

[0325]

[0326]

[0327] The hydrocarbons used as solvents can include aliphatic hydrocarbons, alicyclic hydrocarbons, aliphatic or alicyclic hydrocarbons having unsaturated bonds such as alkenes and alkynes, and substituted or unsubstituted aromatic hydrocarbons.

[0328] Preferred hydrocarbons include, for example, aliphatic hydrocarbons and alicyclic hydrocarbons such as pentane, cyclopentanehexane, hexane, 1-hexene, cyclohexene, heptane, octane, nonane, decane, n-hexadecane, n-octadecane, 2,2,4-trimethylpentane, dodecane, 1-dodecene, pentadecane, dimethylpentane, 2,2-dimethylhexane, paraffin, eicosane, squalane, and aliphatic or alicyclic hydrocarbons having unsaturated bonds such as alkenes and alkynes; benzene, toluene, xylene, ethylbenzene, cumene, diisopropylbenzene, di Examples include aromatic hydrocarbons such as butylbenzene, naphthalene, lower alkyl-substituted naphthalene, dodecylbenzene, and mesitylene; aromatic compounds substituted with nitro groups or halogens such as chlorobenzene, dichlorobenzene, brombenzene, dibrombenzene, chlornaphthalene, bromnaphthalene, nitrobenzene, and nitronaphthalene; and polycyclic hydrocarbon compounds such as diphenyl, substituted diphenyl, diphenylmethane, terphenyl, anthracene, phenanthrene, benzyltoluene, isomers of benzyltoluene, dibenzyltoluene, dibenzyltoluene, fluorene, and triphenylmethane.

[0329] The ketone used as a solvent is not particularly limited, but compounds represented by the following formula (400) are preferably used.

[0330]

[0331] In general formula (400), R ４０１ and R ４０２ Each of these is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms.

[0332] R ４０１ and R ４０２ Examples of alkyl groups, aryl groups, and aralkyl groups in the above-mentioned "ether (300)" are the same as those exemplified above.

[0333] Preferred ketones (400) include, for example, compounds represented by the following formulas (400-1) to (400-10).

[0334]

[0335] {Reaction Conditions} The reaction temperature is usually in the range of 100°C to 400°C. Higher temperatures are preferable to increase the reaction rate, but at high temperatures, side reactions as described above may occur due to at least one of the carbamate compound and the isocyanate product. Therefore, a range of 130°C to 300°C is preferable, and a range of 150°C to 280°C is more preferable. Known cooling and heating devices may be installed in the reactor to keep the reaction temperature constant.

[0336] The reaction pressure varies depending on the type of compound used and the reaction temperature, but it can be reduced pressure, atmospheric pressure, or pressurized pressure, and is usually carried out in the range of 20 Pa to 1 × 10⁶ Pa. There are no particular restrictions on the reaction time (residence time in the case of the continuous method), but it is usually 0.001 hours to 100 hours, preferably 0.01 hours to 50 hours, and more preferably 0.1 hours to 10 hours.

[0337] A catalyst can be used in the pyrolysis reaction, and the amount of catalyst used is preferably 0.01% to 30% by mass relative to the mass of the carbamate, and more preferably 0.5% to 20% by mass. Suitable catalysts include organometallic catalysts such as dibutyltin dilaurate, lead octoate, and stanaoctoate; and amines such as 1,4-diazabicyclo[2,2,2]octane, triethylenediamine, and triethylamine. Among these, organometallic catalysts such as dibutyltin dilaurate, lead octoate, and stanaoctoate are particularly preferred. These compounds may be used individually or as a mixture of two or more.

[0338] To suppress the formation of 1-nylon structures from isocyanates, stabilizers may be added to the pyrolysis process. These stabilizers may be added to the reaction vessel as raw materials beforehand, added through a line during the pyrolysis reaction, or added after the pyrolysis process. It is preferable to add the stabilizers after the pyrolysis process to prevent them from denatured during the pyrolysis reaction. The amount of stabilizer used is preferably 10 ppm to 5% relative to the mass of the isocyanate compound (II), and more preferably 50 ppm to 1% to improve long-term storage stability. As stabilizers, sulfate esters such as benzenesulfonic acid, vinylsulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, monomethyl sulfate, monoethyl sulfate, mono-n-propyl sulfate, etc., as well as phosphate monoesters, phosphate diesters, and phosphate triesters such as methyl phosphate, dimethyl phosphate, butyl phosphate, dibutyl phosphate, isodecyl phosphate, diisodecyl phosphate, 2-ethylhexyl phosphate, di-2-ethylhexyl phosphate, lauryl phosphate, dilauryl phosphate, stearyl phosphate, distearyl phosphate, dioleyl phosphate, and phenylphosphonic acid, as well as sulfuric acid and phosphoric acid can be used, and multiple combinations of these may also be used.

[0339] [Step (IV)] In one embodiment of the present invention, it is preferable to include step (IV) of distillation purification of the composition produced in step (III) to obtain an isocyanate composition. The isocyanate composition obtained after step (IV) preferably contains a carbonyl compound represented by the following formula (4), and the content ratio of the carbonyl compound to the total mass of the isocyanate composition is 2.0 ppm by mass or more, or 1.0 × 10⁻⁶. ５ It is preferable that the mass be ppm or less.

[0340] By keeping the value above the lower limit, the adhesion of by-products to the equipment during the isocyanate purification process can be prevented, thereby improving the yield of the isocyanate compound (3). On the other hand, by keeping the value below the upper limit, the amount of carbonyl compound used can be reduced, thereby lowering raw material costs.

[0341] The above values ​​are, １The carbonyl compounds and isocyanates can be quantified by combining H-NMR, liquid chromatography, and gas chromatography. The detailed conditions for the above analysis can be those described in the examples.

[0342] The carbonyl compound represented by the following formula (4) will be explained.

[0343] (In the formula, R ４１ is an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, or an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, and having one or both of 1 to 4 ester groups and a nitrogen atom, and R ４２ (wherein X is an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen, and X represents an oxygen atom or an NH group.)

[0344] (R ４１ ) In formula (4), R ４１ is an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, or an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, and having one or both of 1 to 4 ester groups and a nitrogen atom. Also, R ４１ This may be an aliphatic hydrocarbon group having 1 to 40 carbon atoms and being divalent or tetravalent or less, and having 1 to 4 sulfur atoms.

[0345] R ４１ If R is an aliphatic hydrocarbon group, ４１Preferably, the group is a linear or branched alkyl group, alkylene group or alkanetriyl group, a cycloalkyl group, a cycloalkylene group or cycloalkanetriyl group, or a group composed of the alkyl group, alkylene group or alkanetriyl group and the cycloalkyl group, cycloalkylene group or cycloalkanetriyl group; more preferably, the group is a linear or branched alkylene group or alkanetriyl group, a cycloalkylene group or cycloalkanetriyl group, or a group composed of the alkylene group or alkanetriyl group and the cycloalkyl group, cycloalkylene group or cycloalkanetriyl group.

[0346] R ４１ Examples of linear or branched alkylene groups include methylene, ethylene, propylene, trimethylene, pentylene, n-hexylene, and decamethylene groups. Examples of cycloalkylene groups include cyclobutylene and cyclohexylene groups. Examples of linear or branched alkanetriyl groups include hexanetriyl, nonanetriyl, and decantriyl groups. Examples of cycloalkanetriyl groups include cyclopropanetriyl, cyclobutanetriyl, cyclopentanetriyl, and cyclohexanetriyl groups.

[0347] R ４１When the above-mentioned aliphatic hydrocarbon group has 1 to 20 carbon atoms, is divalent to quadrivalent, and has 1 to 4 ester groups, a skeleton having an ester group obtained by reacting the carboxyl group of an amino acid with a hydroxy compound by known methods, with the amino group removed, or a skeleton having a glycerol skeleton, or a skeleton having a trimethylolpropane skeleton is preferred. Specific examples of amine compounds having an ester group include lysine methyl ester diamine, lysine ethyl ester diamine, lysine butyl ester diamine, lysine isobutyl ester diamine, 2-aminoethyl-2,5-diaminopentanoate, 2-aminoethyl-2,6-diaminohexanoate, 2-(2-aminoethoxy)ethyl-2,6-diaminohexanoate, 2-aminocyclohexyl-2,6-diaminohexanoate, 3-aminopropyl-2,6-diaminohexanoate, 4-aminobutyl-2,6-diaminohexanoate, 6-aminohexyl-2,6-diaminohexanoate, bis(2-aminoethyl)-2-aminobutanediate, bis(2-aminoethyl)-2-aminopentanediate, tris(2-aminoethyl)hexane-1,3,6-tricarboxylate, and the like.

[0348] Among these, R in equation (4) ４１ The structure is preferably represented by the following formulas (4-1) to (4-33), with (4-1), (4-2), (4-5), (4-6), (4-7), (4-11), (4-12), (4-13), (4-14), (4-15), (4-16), (4-17), and (4-20) being more preferred. In each formula, the dashed line indicates a coupling.

[0349]

[0350] (R ４２ ) In the above formula (4), R ４２ This refers to an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen.

[0351] R ４２Examples include alkyl groups such as methyl, ethyl, propyl (each isomer), butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl. Examples of groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl; aryl groups such as phenyl, naphthyl, and anthryl; and aryl groups such as methylphenyl (various isomers), ethylphenyl (various isomers), propylphenyl (various isomers), butylphenyl (various isomers), pentylphenyl (various isomers), hexylphenyl (various isomers), α-cumylphenyl (various isomers), methoxyphenyl (various isomers), and ethoxyphenyl (various isomers).

[0352] From the perspective of distillation separation from isocyanates, it is preferable that the compound represented by formula (4) has a higher boiling point than isocyanates and is highly versatile. From this perspective, aryl groups such as phenyl group, naphthyl group, anthryl group, pyrenyl group, phenanthryl group, methylphenyl group (each isomer), ethylphenyl group (each isomer), propylphenyl group (each isomer), butylphenyl group (each isomer), pentylphenyl group (each isomer), hexylphenyl group (each isomer), α-cumylphenyl group (each isomer), methoxyphenyl group (each isomer), and ethoxyphenyl group (each isomer) are preferred, and among these, phenyl group, α-cumylphenyl group (each isomer), methoxyphenyl group (each isomer), and ethoxyphenyl group (each isomer) are more preferred.

[0353] For the reasons stated above, the carbonyl compound is preferably structured as shown in the following formulas (4-1') to (4-33'), and among these, (4-1'), (4-2'), (4-5'), (4-6'), (4-7'), (4-11'), (4-12'), (4-13'), (4-14'), (4-15'), (4-16'), (4-17'), and (4-20') are more preferred.

[0354]

[0355] The carbonyl compound represented by formula (4) is presumed to be produced by the reaction mechanism represented by the following formulas (E) or (F). In formula (E), the carbonyl compound is given by the intramolecular reaction of the isocyanate group and the carbamate group during the thermal decomposition reaction of the carbamate compound of formula (2). On the other hand, in formula (F), the carbonyl compound is given by the intramolecular cyclization reaction of the hydroxyl group that is produced during the thermal decomposition reaction of the carbamate compound having an ester group, which reacts with the carbonate ester solvent during the thermal decomposition reaction of the ester group.

[0356]

[0357] In formulas (E) and (F), R is a divalent organic group which may have substituents, and R', R'', and R''' are monovalent organic groups which may have substituents.

[0358] In step (IV), a distillation apparatus that appropriately matches the conditions is selected. Specifically, conventionally known distillation apparatuses such as stirred tanks, pressurized stirred tanks, vacuum stirred tanks, column reactors, distillation columns, packed columns, and thin-film distillation apparatuses can be used in appropriate combinations. For example, various known methods can be used, such as a system using a distillation apparatus that includes a distillation column, multi-stage distillation column, multi-tube reactor, continuous multi-stage distillation column, packed column, thin-film evaporator, reactor with an internal support, forced-circulation reactor, drop film evaporator, or drip evaporator, and a system combining these. Distillation columns, multi-stage distillation columns, packed columns, thin-film evaporators, drop film evaporators, and drip evaporators are more preferable, as they promote distillation by forming a liquid film and performing distillation, thereby shortening the time required for distillation, with the intention of suppressing the denaturation of the isocyanate compound (3).

[0359] Different or the same type of distillation apparatus may be used in the light-boiling separation process and the high-boiling separation process, which will be described later. The same apparatus may be used repeatedly in the light-boiling separation process and the high-boiling separation process.

[0360] Furthermore, the light-boiling separation process and the high-boiling separation process, described later, may each be performed multiple times, or one of the light-boiling separation process and the high-boiling separation process may be performed before or after the other.

[0361] [Light Boiling Separation Process] In the light boiling separation process, the solvent and hydroxyl compounds are obtained as gas phase components and the isocyanate compound (3) as a liquid phase component by distillation, thereby separating the solvent and hydroxyl compounds from the isocyanate compound (3).

[0362] (Reaction conditions) The temperature at which the light boiling separation step is carried out is usually in the range of 80°C to 200°C. Higher temperatures are preferable for efficient separation of the light boiling components. However, at high temperatures, the isocyanate compound (3) may be removed as a gaseous component, and the yield of the isocyanate compound (3) obtained as a liquid-phase component may decrease. Therefore, a temperature of 90°C to 180°C is preferable, and 100°C to 160°C is more preferable.

[0363] The pressure used during distillation varies depending on the type of compound used and the temperature at the time of the reaction, but is usually in the range of 20 Pa to 10,000 Pa. There are no particular restrictions on the reaction time (residence time in the case of a continuous method), but it is usually between 0.001 hours and 100 hours, preferably between 0.01 hours and 50 hours, and more preferably between 0.1 hours and 10 hours, in order to suppress the denaturation of the isocyanate compound (3).

[0364] It is preferable to add a stabilizer similar to the one used in the thermal decomposition step before and after the light boiling separation step. This stabilizer may be added as a raw material beforehand, added during the light boiling separation step via the line, or added after the light boiling separation step. It is preferable to add the stabilizer to the liquid phase component after the light boiling separation step so that it does not denature during the light boiling separation step. The amount of stabilizer used is preferably 10 ppm to 5% of the mass of the isocyanate compound (3), and more preferably 50 ppm to 1% to improve long-term storage stability. As stabilizers, sulfate esters such as benzenesulfonic acid, vinylsulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, monomethyl sulfate, monoethyl sulfate, mono-n-propyl sulfate, etc., as well as phosphate monoesters, phosphate diesters, and phosphate triesters such as methyl phosphate, dimethyl phosphate, butyl phosphate, dibutyl phosphate, isodecyl phosphate, diisodecyl phosphate, 2-ethylhexyl phosphate, di-2-ethylhexyl phosphate, lauryl phosphate, dilauryl phosphate, stearyl phosphate, distearyl phosphate, dioleyl phosphate, and phenylphosphonic acid, as well as sulfuric acid and phosphoric acid can be used, and multiple combinations of these may also be used.

[0365] The light boiling separation process may be used to decompose the remaining carbamate groups of the compounds contained in the liquid phase component, thereby partially obtaining the isocyanate compound (3). In this case, the same temperature and pressure conditions as those for the thermal decomposition process described above should be adopted.

[0366] [High-boiling separation process] In the high-boiling separation process, the isocyanate compound (3) is obtained as a gas phase component and the high-boiling component as a liquid phase component by distillation, thereby separating the high-boiling component from the isocyanate compound (3).

[0367] (Reaction conditions) The temperature at which the high-boiling separation process is carried out is usually in the range of 110°C to 280°C. Higher temperatures are preferable for efficient separation of high-boiling components. However, at high temperatures, decomposition of carbamate groups remaining in the high-boiling components occurs, and the resulting hydroxy compounds are added to the gas phase components and react with isocyanate compounds, leading to a decrease in yield. Therefore, temperatures of 120°C to 240°C are preferable, and 130°C to 200°C are more preferable.

[0368] The pressure used during distillation varies depending on the type of compound used and the temperature at the time of the reaction, but is usually in the range of 20 Pa to 10,000 Pa. There are no particular restrictions on the reaction time (residence time in the case of a continuous reaction), but it is usually between 0.001 hours and 100 hours, preferably between 0.01 hours and 50 hours, and more preferably between 0.1 hours and 10 hours, in order to suppress the denaturation of the isocyanate compound.

[0369] It is preferable to add a stabilizer similar to the one used in the thermal decomposition step before and after the high-boiling separation step. This stabilizer may be added as a raw material beforehand, added through the line during the high-boiling separation step, or added after the high-boiling separation step. To prevent the stabilizer from denatured during the high-boiling separation step, and considering the possibility that the stabilizer may not be distilled off into the gas phase component depending on the conditions, it is preferable to add it through the line to the condensed gas phase component during the high-boiling separation step, or to the condensed gas phase component after the high-boiling separation step. The amount of stabilizer used is preferably 10 ppm to 5% of the mass of the isocyanate compound (3), and more preferably 50 ppm to 1% to improve long-term storage stability. As stabilizers, sulfate esters such as benzenesulfonic acid, vinylsulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, monomethyl sulfate, monoethyl sulfate, mono-n-propyl sulfate, etc., as well as phosphate monoesters, phosphate diesters, and phosphate triesters such as methyl phosphate, dimethyl phosphate, butyl phosphate, dibutyl phosphate, isodecyl phosphate, diisodecyl phosphate, 2-ethylhexyl phosphate, di-2-ethylhexyl phosphate, lauryl phosphate, dilauryl phosphate, stearyl phosphate, distearyl phosphate, dioleyl phosphate, and phenylphosphonic acid, as well as sulfuric acid and phosphoric acid can be used, and multiple combinations of these may also be used.

[0370] [Step (V)] In one embodiment of the present invention, for the purpose of obtaining a higher purity isocyanate compound (3), the present invention may include step (V) of purifying the isocyanate compound (3) from the reaction solution containing the isocyanate compound (3) by chromatographic separation, or by distillation and chromatographic separation. Step (V) reduces at least one of the group consisting of the compound (13) described later, the carbonyl compound (4), the compound (14) described later, and the carbonate ester, which are contained as impurities in the reaction solution containing the isocyanate compound (3) obtained in step (III), thereby obtaining a high purity isocyanate compound (3).

[0371] In step (V), with the intention of improving the separation efficiency and yield in the chromatographic separation step described later, it is preferable to purify the reaction solution containing the isocyanate compound obtained by the thermal decomposition reaction in step (III) by distillation before chromatographic separation to obtain an isocyanate composition in which the isocyanate compound (3) is concentrated (hereinafter sometimes simply referred to as "concentrated isocyanate composition"). This distillation purification step mainly consists of a light-boiling separation step that removes solvents and hydroxy compounds by distillation, and a high-boiling separation step that separates high-boiling components present after the thermal decomposition reaction.

[0372] For the distillation purification in step (V), an appropriate distiller is selected to suit the conditions. Specifically, conventionally known distillers such as stirred tanks, pressurized stirred tanks, vacuum stirred tanks, column reactors, distillation columns, packed columns, and thin-film distillers can be used in appropriate combinations. For example, various known methods can be used, such as a system using a distiller that includes a distillation column, multi-stage distillation column, multi-tube reactor, continuous multi-stage distillation column, packed column, thin-film evaporator, reactor with an internal support, forced-circulation reactor, drop film evaporator, or drip evaporator, or a system combining these. Distillation columns, multi-stage distillation columns, packed columns, thin-film evaporators, drop film evaporators, and drip evaporators are more preferred, as they promote distillation by forming a liquid film and performing distillation, thereby shortening the time required for distillation, with the intention of suppressing the denaturation of the isocyanate compound (3).

[0373] There are no particular restrictions on the type of condenser provided in the apparatus, and known condensers can be used. For example, conventionally known condensers such as multi-tube cylindrical condensers, double-tube condensers, single-tube condensers, and air-cooled condensers can be used in appropriate combinations. The condenser may be provided inside the distiller or outside the distiller and connected to the distiller by piping, and various forms can be adopted considering the type of distiller and condenser, the method of handling the condensate, etc. There are no particular restrictions on the material of the distiller and condenser, and known materials can be used as long as they do not adversely affect the isocyanate compound (3) above. For example, glass, stainless steel, carbon steel, Hastelloy®, or materials with a glass lining or Teflon® coating can be used. SUS304, SUS316, and SUS316L are inexpensive and preferably used. Instrumentation equipment such as flow meters and thermometers, and known process equipment such as reboilers, pumps, and condensers may be added as needed. Heating may be done by known methods such as steam or heaters, and cooling may be done by known methods such as natural cooling, cooling water, or brine. Additional processes may be added as needed.

[0374] Different or the same type of distillation apparatus may be used in the light-boiling separation process and the high-boiling separation process, which will be described later. The same apparatus may be used repeatedly in the light-boiling separation process and the high-boiling separation process.

[0375] Furthermore, the light-boiling separation process and the high-boiling separation process, described later, may each be performed multiple times, or one of the light-boiling separation process and the high-boiling separation process may be performed before or after the other.

[0376] [Light Boiling Separation Process] In the light boiling separation process, the solvent and hydroxyl compounds are obtained as gas phase components and the isocyanate compound (3) as a liquid phase component by distillation, thereby separating the solvent and hydroxyl compounds from the isocyanate compound (3).

[0377] (Reaction conditions) The temperature at which the light boiling separation step is carried out is usually in the range of 80°C to 200°C. Higher temperatures are preferable for efficient separation of the light boiling components. However, at high temperatures, the isocyanate compound (3) may be removed as a gaseous component, and the yield of the isocyanate compound (3) obtained as a liquid-phase component may decrease. Therefore, a temperature of 90°C to 180°C is preferable, and 100°C to 160°C is more preferable.

[0378] The pressure used during distillation varies depending on the type of compound used and the temperature at the time of the reaction, but is usually in the range of 20 Pa to 10,000 Pa. There are no particular restrictions on the reaction time (residence time in the case of a continuous method), but it is usually between 0.001 hours and 100 hours, preferably between 0.01 hours and 50 hours, and more preferably between 0.1 hours and 10 hours, in order to suppress the denaturation of the isocyanate compound (3).

[0379] It is preferable to add a stabilizer similar to the one used in the thermal decomposition step before and after the light boiling separation step. This stabilizer may be added as a raw material beforehand, added during the light boiling separation step via the line, or added after the light boiling separation step. It is preferable to add the stabilizer to the liquid phase component after the light boiling separation step so that it does not denature during the light boiling separation step. The amount of stabilizer used is preferably 10 ppm to 5% of the mass of the isocyanate compound (3), and more preferably 50 ppm to 1% to improve long-term storage stability. As stabilizers, sulfate esters such as benzenesulfonic acid, vinylsulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, monomethyl sulfate, monoethyl sulfate, mono-n-propyl sulfate, etc., as well as phosphate monoesters, phosphate diesters, and phosphate triesters such as methyl phosphate, dimethyl phosphate, butyl phosphate, dibutyl phosphate, isodecyl phosphate, diisodecyl phosphate, 2-ethylhexyl phosphate, di-2-ethylhexyl phosphate, lauryl phosphate, dilauryl phosphate, stearyl phosphate, distearyl phosphate, dioleyl phosphate, and phenylphosphonic acid, as well as sulfuric acid and phosphoric acid can be used, and multiple combinations of these may also be used.

[0380] The light boiling separation process may be used to decompose the remaining carbamate groups of the compounds contained in the liquid phase component, thereby partially obtaining the isocyanate compound (3). In this case, the same temperature and pressure conditions as those for the thermal decomposition process described above should be adopted.

[0381] [High-boiling separation process] In the high-boiling separation process, the isocyanate compound (3) is obtained as a gas phase component and the high-boiling component as a liquid phase component by distillation, thereby separating the high-boiling component from the isocyanate compound (3).

[0382] (Reaction conditions) The temperature at which the high-boiling separation process is carried out is usually in the range of 110°C to 280°C. Higher temperatures are preferable for efficient separation of high-boiling components. However, at high temperatures, decomposition of carbamate groups remaining in the high-boiling components occurs, and the resulting hydroxy compounds are added to the gas phase components and react with isocyanate compounds, leading to a decrease in yield. Therefore, temperatures of 120°C to 240°C are preferable, and 130°C to 200°C are more preferable.

[0383] The pressure used during distillation varies depending on the type of compound used and the temperature at the time of the reaction, but is usually in the range of 20 Pa to 10,000 Pa. There are no particular restrictions on the reaction time (residence time in the case of a continuous reaction), but it is usually between 0.001 hours and 100 hours, preferably between 0.01 hours and 50 hours, and more preferably between 0.1 hours and 10 hours, in order to suppress the denaturation of the isocyanate compound.

[0384] It is preferable to add a stabilizer similar to the one used in the thermal decomposition step before and after the high-boiling separation step. This stabilizer may be added as a raw material beforehand, added through the line during the high-boiling separation step, or added after the high-boiling separation step. To prevent the stabilizer from denatured during the high-boiling separation step, and considering the possibility that the stabilizer may not be distilled off into the gas phase component depending on the conditions, it is preferable to add it through the line to the condensed gas phase component during the high-boiling separation step, or to the condensed gas phase component after the high-boiling separation step. The amount of stabilizer used is preferably 10 ppm to 5% of the mass of the isocyanate compound (3), and more preferably 50 ppm to 1% to improve long-term storage stability. As stabilizers, sulfate esters such as benzenesulfonic acid, vinylsulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, monomethyl sulfate, monoethyl sulfate, mono-n-propyl sulfate, etc., as well as phosphate monoesters, phosphate diesters, and phosphate triesters such as methyl phosphate, dimethyl phosphate, butyl phosphate, dibutyl phosphate, isodecyl phosphate, diisodecyl phosphate, 2-ethylhexyl phosphate, di-2-ethylhexyl phosphate, lauryl phosphate, dilauryl phosphate, stearyl phosphate, distearyl phosphate, dioleyl phosphate, and phenylphosphonic acid, as well as sulfuric acid and phosphoric acid can be used, and multiple combinations of these may also be used.

[0385] After the distillation purification process described above, a purification process other than distillation separation or chromatographic separation may be performed before the chromatographic separation process described later.

[0386] [Chromatographic Separation Process] In the chromatographic separation process, the concentrated isocyanate composition obtained in the above distillation purification process is diluted with a mobile phase described later, and passed through a column packed with a stationary phase. This separates the isocyanate compound (3) from the concentrated isocyanate composition and compounds that have boiling points close to those of the isocyanate compound (3) and are difficult to separate by distillation, thereby obtaining a high-purity isocyanate compound (3).

[0387] In the case of isocyanate compounds with low thermal stability, chromatographic separation is more advantageous than distillation separation for removing trace amounts of aromatic compounds, as it does not denature the isocyanate compound (3). In particular, the authors found that using a synthetic adsorbent utilizing π-π interactions as the stationary phase in the chromatographic separation process suppresses the denature of isocyanate compounds compared to commonly used adsorbents such as silica gel and activated clay. This is thought to be because many common adsorbents have hydroxyl groups on their surface, and these hydroxyl groups are responsible for their adsorption capacity. Furthermore, when isocyanates are the target of separation, the reaction between these hydroxyl groups and the isocyanates causes the isocyanates to denature.

[0388] Furthermore, by employing a pseudo-moving bed method for chromatographic separation in this system, highly efficient separation is possible even in systems with small differences in π-π interactions, thereby achieving a method that contributes to the high purity of isocyanate compounds.

[0389] The chromatographic separation and chromatographic separation using a pseudo-mobile phase in the present invention are also useful in the purification of isocyanate compounds obtained by means other than the above reaction, in that they allow for the high-purity isocyanate compound with byproducts removed to be obtained in high yield. Examples of isocyanate compounds obtained by means other than the above phosgene method include isocyanate compounds obtained using the phosgene method.

[0390] [Concentrated isocyanate composition used for chromatographic separation] The amount of isocyanate compound (3) contained in the concentrated isocyanate composition is preferably 1% by mass or more and 99.9% by mass or less relative to the total mass of the concentrated isocyanate composition, preferably 5% by mass or more and 99.5% by mass or less, and more preferably 10% by mass or more and 99% by mass or less, in order to increase the concentration of isocyanate compound (3) in the liquid phase component obtained after chromatographic separation and to reduce the number of steps required to remove the mobile phase.

[0391] In the chromatographic separation process, the concentrated isocyanate composition used is preferably one obtained through the thermal decomposition or distillation purification process, but compositions with similar compositions obtained by other methods can also be separated effectively.

[0392] It is preferable that the organic solvent used in the thermal decomposition step, which is included in the concentrated isocyanate composition, has an aromatic ring. It is preferable that any organic solvent without an aromatic ring is thoroughly removed in the distillation purification step.

[0393] [Stationary Phase] The adsorbent used as the stationary phase in the chromatographic separation step is preferably an adsorbent that utilizes π-π interactions, does not have hydroxyl groups in principle, and does not contain active hydrogen. That is, synthetic resins that have aromatic rings without hydroxyl groups as constituent units are preferred, and specifically include polystyrene, styrene-divinylbenzene copolymer, and modified polystyrene. Modified polystyrenes include polystyrene in which bromine is partially loaded into the structure. The particle size of the adsorbent depends on the target to be separated, the required manufacturing rate, and the pressure resistance of the system, but is generally 1 to 500 μm.

[0394] [Mobile Phase] In one aspect of the present invention, the mobile phase used for chromatographic separation is preferably an organic solvent containing at least one compound that is inert to the isocyanate compound (3) and does not have an aromatic ring. The mobile phase is preferably an organic solvent that dissolves the isocyanate composition and does not have active hydrogen groups such as hydroxyl groups in order not to react with the isocyanate. In addition, it is preferable that the organic solvent does not have an aromatic ring. By not having an aromatic ring, it does not inhibit the π-π interaction between the adsorbent surface and the compound in the isocyanate composition to be separated, and functions well as a solvent.

[0395] Specific examples of organic solvents include alkanes, alicyclic hydrocarbons, nitriles, ketones, esters, ethers and thioethers, sulfoxides, sulfones, and amides.

[0396] Examples of alkanes include hexane, heptane, octane, nonane, decane, n-hexadecane, n-octadecane, eicosane, and squalane.

[0397] Examples of alicyclic hydrocarbons include cyclohexane and ethylcyclohexane. Examples of ketones include acetone and methyl ethyl ketone.

[0398] Examples of nitriles include acetonitrile, propionitrile, dimethylacetamide, butyronitrile, valeronitrile, and hexanonitrile.

[0399] Examples of esters include dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, γ-butyrolactone, and γ-valerolactone.

[0400] Examples of ethers include ethylene glycol monobutyl ether (also known as butyl cellosolve), diethyl ether, and tetrahydrofuran.

[0401] Examples of sulfoxides include dimethyl sulfoxide, and examples of sulfones include dimethyl sulfone, diethyl sulfone, and sulfolane.

[0402] Examples of amides include dimethylacetamide, dimethylformamide, and N-methyl-2-pyrrolidone.

[0403] The mobile phase may be a mixture of two or more of the organic solvents.

[0404] [Implementation Conditions] The temperature used when performing chromatographic separation is usually 15°C to 80°C, and more preferably 25°C to 50°C, although this depends on the mobile phase and the material to be separated.

[0405] Chromatographic separation apparatuses include fixed-bed, circulating, mobile-bed, and pseudo-mobile-bed systems, but for the reasons mentioned above, the pseudo-mobile-bed system is the most preferred.

[0406] There are no particular restrictions on the material of the apparatus used for chromatographic separation; known materials can be used as long as they do not adversely affect the isocyanate compound (3) mentioned above. For example, glass, stainless steel, carbon steel, Hastelloy®, or materials with a glass lining or Teflon® coating can be used. SUS304, SUS316, and SUS316L are inexpensive and preferably used. Instrumentation equipment such as flow meters and thermometers, and known process equipment such as pumps may be added as needed. Heating can be done by known methods such as steam or heaters, and cooling can be done by known methods such as natural cooling, cooling water, or brine. Additional processes may be added as needed.

[0407] [Chromatographic Separation by Pseudo-Mobile Bed Method] The preferred method for the chromatographic separation step in step (V) is the pseudo-mobile bed chromatography method. In the pseudo-mobile bed chromatography method, four or more column vessels are connected in a single or circulating flow, and at four connection points between some of the column vessels, a total of four liquid outlets are connected in this order along the direction of mobile phase flow: a mobile phase inlet, an extract (described later) outlet, a raw material liquid inlet, and a raffinate (described later) outlet. These liquid inlets and outlets are switched to move at regular intervals along the direction of mobile phase flow to the connection points between adjacent column vessels using a multi-port valve or the like, thereby creating a state similar to countercurrent contact between the developing solvent and adsorbent in mobile bed chromatography. By using this method, even when the difference in interaction between the two target substances with the adsorbent is small, high purity and high yield separation is possible. In the apparatus, the liquid to be separated is separated into a raffinate component, which has little interaction with the adsorbent, and an extract component, which has a large interaction with the adsorbent.

[0408] In this embodiment, by employing a pseudo-mobilization bed method, the separation efficiency utilizing the π-π interaction described above is improved, and high-purity, high-yield purification is achieved by obtaining an isocyanate compound as the raffinate component and other components as the extract component.

[0409] In this embodiment, in chromatographic separation using the pseudo-mobile phase method, at least four, preferably eight, and more preferably twelve column apparatuses are used, each packed with the stationary phase by a dry or wet packing method. It is preferable that all columns are connected in a circulating manner. The four liquid inlets and outlets—the mobile phase inlet, the extract outlet (described later), the raw material liquid inlet, and the raffinate outlet (described later)—may be connected at equal or unequal intervals, as long as they are connected between any of the column apparatuses along the direction of mobile phase flow.

[0410] Regarding the operation method of the pseudo-mobile bed method, any method is acceptable as long as it can separate the isocyanate compound from other components. For example, a three-zone pseudo-mobile bed apparatus with reduced eluent recovery, an intermittent sample supply type pseudo-mobile bed apparatus with a process that stops the supply of raw material liquid and mobile phase and the extraction of raffinate and extract for a certain period of time, and only performs circulation, an intermittent sample supply / recovery type pseudo-mobile bed that intermittently supplies mobile phase and recovers raffinate, and supplies raw material liquid and mobile phase and recovers extract during the normal column switching time, and a multi-component pseudo-mobile bed method that attempts to obtain compounds other than isocyanate compounds as active ingredients may be used.

[0411] Any known material can be used for the column apparatus, as long as it does not adversely affect the isocyanate compound. For example, glass, stainless steel, carbon steel, Hastelloy®, or materials with a glass lining or Teflon® coating can be used. SUS304, SUS316, and SUS316L are inexpensive and preferably used. Temperature sensors, UV detectors, and RI detectors may be installed at each liquid inlet / outlet and in the column apparatus for monitoring.

[0412] As the raw material liquid, the concentrated isocyanate composition obtained in the distillation and purification process may be diluted with the mobile phase. In this case, it is preferable to dilute the liquid so that the mass of the concentrated isocyanate composition is between 1% and 90% by mass relative to the total mass of the diluted raw material liquid. The switching time at each liquid inlet and outlet connection depends on the separation target and operating conditions, but is generally between 1 second and 300 minutes.

[0413] The obtained raffinate may be subjected to a chromatographic separation step using a pseudo-mobile bed method, followed by a purification operation to remove the mobile phase as appropriate, in order to obtain an isocyanate compound. In this process, the light-boiling separation step or the high-boiling separation step may be used, and the obtained mobile phase may be reused for the chromatographic separation step.

[0414] Next, we will describe the impurities separated from the reaction solution containing the isocyanate compound (3) in step (V). At least one of the following compounds (13), carbonyl compound (4), compound (14), and carbonate ester can be reduced by step (V).

[0415] If the catalyst described above was used in any of the multiple steps taken to obtain a reaction solution containing the isocyanate compound (3), step (V) can be used to remove those catalysts from the reaction solution containing the isocyanate compound (3). Furthermore, step (V) can be used to remove other impurities from isocyanate compounds obtained by means other than those of the present invention. Examples of other impurities include metal complexes, ionic liquids, and chlorine-containing compounds. Examples of chlorine-containing compounds include compounds containing chloride ions as salts and compounds containing chlorine atoms in their structure by covalent bonds.

[0416] [Compound (13)] Examples of impurities that can be removed in step (V) include compounds represented by the following general formula (13).

[0417]

[0418] In general formula (13), n131 represents an integer between 1 and 8, inclusive.１３１ R is a divalent organic group with 1 to 30 carbon atoms. １３２ This is a monovalent organic group having 1 to 30 carbon atoms.

[0419] Compound (13) is presumed to be produced by the reaction mechanisms represented by the following formulas (G) and (H). In formula (G), during the thermal decomposition reaction of the aryl carbamate compound, the hydroxy compound removed from the carbamate group reacts with the carbamate having an ester group in its molecule and the compound obtained by the thermal decomposition of the carbamate, after which the thermal decomposition reaction proceeds. In formula (H), it is obtained by reaction with an isocyanate having an ester group in its molecule.

[0420]

[0421] In equations (G) and (H), R and R'' are monovalent organic groups, and R' is a b-valent organic group. a and b are integers greater than or equal to 1, and a can be less than or equal to b.

[0422] (R １３２ ) R in equation (13) １３２ R is a monovalent organic group having 1 to 30 carbon atoms. １３２ Examples of organic groups include cyclic hydrocarbon groups, acyclic hydrocarbon groups, groups formed by bonding an acyclic hydrocarbon group with one or more cyclic groups, and groups in which these groups are covalently bonded to a specific nonmetallic atom. Examples of the cyclic groups include cyclic hydrocarbon groups, heterocyclic groups, heterocyclic spiro groups, and heterobridged cyclic groups. Examples of the cyclic hydrocarbon groups include monocyclic hydrocarbon groups, condensed polycyclic hydrocarbon groups, bridged cyclic hydrocarbon groups, spiro hydrocarbon groups, ring aggregated hydrocarbon groups, and cyclic hydrocarbon groups with side chains. Examples of the nonmetallic atoms include carbon, oxygen, nitrogen, sulfur, and silicon.

[0423] Furthermore, "covalently bonded with a specific nonmetal atom" means, for example, that the group exemplified above is covalently bonded with one or more groups represented by formulas (21-1) to (21-14).

[0424] Among them, R １３２The organic group in this is preferably a cyclic hydrocarbon group, an acyclic hydrocarbon group, a group formed by bonding an acyclic hydrocarbon group with one or more cyclic groups, or a group in which these groups are covalently bonded with one or more groups represented by formulas (21-1), (21-2), (21-3), (21-4), (21-5), or (21-12).

[0425] Examples of cyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl groups.

[0426] Examples of acyclic hydrocarbon groups include methyl, ethyl, propyl (various isomers), butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, and octadecyl groups.

[0427] Also, R １３２ An example is a monovalent aromatic hydrocarbon group having 1 to 30 carbon atoms, which may have substituents. In step (V), from the viewpoint of separating isocyanate and distillation before the chromatographic separation step, it is preferable that the boiling point of the compound represented by formula (13) is higher than that of the isocyanate and that it is highly versatile. From this viewpoint, R in formula (13) １３２ More preferably, the phenyl group, methylphenyl group (each isomer), methoxyphenyl group (each isomer), and cumylphenyl group (each isomer) are used.

[0428] (R １３１ ) R １３１ R is a divalent organic group with 1 to 30 carbon atoms. １３１ The structure is preferably represented by the following formulas (13-1) to (13-9). In each formula, the dashed line indicates a bond with NCO, and the dotted line indicates a bond with CO group.

[0429]

[0430] [Compound (14)] Examples of impurities that can be removed in step (V) include compounds represented by the following general formula (14).

[0431] In general formula (14), n141 and n142 represent integers between 0 and 8, and the sum of n141 and n142 is n31 in formula (3). １４１ R represents an aliphatic hydrocarbon group having a valency of 1 to 40 carbon atoms and being divalent to 40 or less, or an aromatic group having a valency of 6 to 40 carbon atoms and being monovalent to 3 or less, or an aliphatic hydrocarbon group or aromatic group having a valency of 1 to 4 carbon atoms and being monovalent to 4 or less, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms. １４２ This is a monovalent aromatic hydrocarbon group having 1 to 30 carbon atoms, which may have substituents.

[0432] Compound (14) is presumed to be produced by a reaction mechanism represented by the following formulas (J) or (K). In formula (J), some carbamate groups remain after the thermal decomposition reaction of the carbamate compound of formula (2), giving compound (14). On the other hand, in formula (K), during the thermal decomposition step, the isocyanate compound reacts with hydroxy compounds produced by the thermal decomposition of other carbamate compounds and high-boiling components to give compound (14).

[0433]

[0434] In equations (J) and (K), n141 and n142 are integers between 0 and 8, and n141 + n142 = n1 and n141 + n142 = n2. ａ R is an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 1 to 4, or an aliphatic hydrocarbon group or aromatic group having 1 to 40 carbon atoms, a valency of 1 to 4, and having one or more selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom. ａ１ This is a monovalent aromatic hydrocarbon group having 1 to 30 carbon atoms, which may have substituents.

[0435] (R １４１ ) In the above general formula (14), R １４１This refers to an aliphatic hydrocarbon group having a valency of 2 to 4 and 1 to 40 carbon atoms, or an aromatic group having a valency of 1 to 3 and 6 to 40 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having a valency of 1 to 4 and 1 to 4 carbon atoms, having one or more selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, and a sulfur atom.

[0436] Pay particular attention １４１ Preferably, the structure is represented by the above formulas (2-1) to (2-34).

[0437] (R １４２ ) In the above general formula (14), R １４２ This refers to a monovalent aromatic hydrocarbon group having 1 to 30 carbon atoms, which may have substituents.

[0438] From the standpoint of distillation separation from isocyanates, it is preferable that the boiling point of the compound represented by formula (14) is higher than that of the isocyanate and that it is highly versatile. From this standpoint, R in formula (14) is preferable. １４２ More preferably, the phenyl group, methylphenyl group (each isomer), methoxyphenyl group (each isomer), and cumylphenyl group (each isomer) are used.

[0439] (n141, n142) In the general formula (14), n141 represents the number of isocyanate groups and is an integer between 0 and 8. In the general formula (14), n142 represents the number of carbamate groups and is an integer between 0 and 8. Compound (14) is a by-product produced in the process of thermally decomposing carbamate compound (2) to obtain isocyanate compound (3), as described above, and has at least one isocyanate group, so it is preferable that n141 is 1 or more. In the general formula (14), the sum of n141 and n142 is equal to n31.

[0440] <Isocyanate Composition> One aspect of the present invention is an isocyanate composition containing an isocyanate and a carbonyl compound represented by the above formula (4). The isocyanate composition may be a composition obtained in step (IV) or (V). In one aspect of the present invention, the content of isocyanate relative to the total mass of the isocyanate composition is 90% by mass or more. The content of the carbonyl compound relative to the total mass of the isocyanate composition is 2.0 ppm by mass or more, or 1.0 × 10 ５ Mass ppm or less (0.0002 mass % or more and 10 mass % or less).

[0441] Generally, compounds containing unsaturated bonds tend to be easily oxidized, and unsaturated compounds as impurities are likely to cause discoloration. However, the compound represented by formula (4) acts effectively during the storage of isocyanate compositions, improving the stability of isocyanate compounds without discoloring the compositions. This effect is presumed to be achieved because the carbonyl group of the compound represented by formula (4) is reactive with water and oxygen, suppressing the denaturation reaction of isocyanate compounds caused by water and oxygen. Furthermore, the compound represented by formula (4) has many carbon-oxygen unsaturated bonds, which tends to enhance this effect.

[0442] The above values ​​are, １ The carbonyl compound, the unsaturated compound, and the isocyanate can be calculated by combining H-NMR, liquid chromatography, and gas chromatography. The detailed conditions for the above analysis can be those described in the examples.

[0443] In one embodiment of the present invention, the isocyanate is preferably an isocyanate represented by formula (3) above. In this case, R in formula (3) above ３１ It is preferable that it has an amino acid skeleton.

[0444] Furthermore, in one embodiment of the present invention, the isocyanate composition may further contain, based on the total mass of the isocyanate composition, in an amount of 2.0 ppm by mass or more and 1.0 × 10⁵ ppm by mass or less (0.0002% by mass or more and 10% by mass or less), one or both of a compound having at least one unsaturated bond represented by the following formula (15) (hereinafter sometimes simply referred to as "unsaturated bond compound") and an ether compound.

[0445]

[0446] In the formula, R １５１ R represents a monovalent aliphatic hydrocarbon group having 1 to 40 carbon atoms, or a monovalent aromatic group having 6 to 40 carbon atoms, or a monovalent aliphatic hydrocarbon group or aromatic group having 1 to 40 carbon atoms and having one or both of 1 to 4 ester groups and a nitrogen atom. １５２ This represents a monovalent aromatic group with 1 to 20 carbon atoms.

[0447] Examples of the unsaturated compound of formula (15) include carbamate group-containing compounds, carbonate esters, and ester compounds.

[0448] {Carbamate group-containing compound} Preferably, either or both of the compound represented by formula (14) and the compound represented by formula (23) below, which does not have an isocyanate group, are used as the carbamate group-containing compound.

[0449] (In the formula, R ２３２ R in formula (4) above ４２ Showing something similar to R ２３１ (wherein n231 represents an integer from 1 to 8.)

[0450] {R ２３１} In the above general formula (23), R ２３１Preferably, the structure is represented by the following formulas (23-1) to (23-30), and among these, (23-1), (23-2), (23-3), (23-4), (23-5), (23-6), (23-7), (23-8), (23-9), (23-10), (23-11), (23-12), (23-13), (23-14), (23-15), (23-16), (23-25), and (23-26) are more preferred. In each formula, the dashed line indicates a coupling.

[0451]

[0452]

[0453] {{R ２３２ In the above general formula (23), R ２３２ This refers to an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen.

[0454] R in equation (23) above ２３２ Examples include alkyl groups such as methyl, ethyl, propyl (each isomer), butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl. Examples of groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl; aryl groups such as phenyl, naphthyl, and anthryl; and aryl groups such as methylphenyl (various isomers), ethylphenyl (various isomers), propylphenyl (various isomers), butylphenyl (various isomers), pentylphenyl (various isomers), hexylphenyl (various isomers), α-cumylphenyl (various isomers), methoxyphenyl (various isomers), and ethoxyphenyl (various isomers).

[0455] As for compound (23), among the structures described above, it is preferable that it be a structure represented by the following formulas (23-1') to (23-46').

[0456]

[0457]

[0458]

[0459]

[0460]

[0461] {Carbonate ester} As the carbonate ester, the carbonate ester represented by the above formula (12) is preferred.

[0462] {Ester Compounds} As ester compounds, compounds represented by the following formula (24) (hereinafter sometimes referred to as "compound (24)") are preferred.

[0463] (In the formula, R ２４２ R is in equation (4) above. ４２ It is similar to R ２４１ This represents an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 1 to 4, or an aliphatic hydrocarbon group or aromatic group having 1 to 40 carbon atoms, a valency of 1 to 4, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, a nitrogen atom, an oxygen atom, and a sulfur atom.

[0464] (R ２４１ ) In the above general formula (24), R ２４１ Preferably, the structure is represented by the following formulas (24-1) to (24-9), with (24-1) and (24-2) being more preferred. In each formula, the wavy line indicates a coupling.

[0465]

[0466] (R ２４２ ) In general formula (24), R ２４２ This refers to an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen.

[0467] R in equation (24) above ２４２ Examples include alkyl groups such as methyl, ethyl, propyl (each isomer), butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl. Examples of groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl; aryl groups such as phenyl, naphthyl, and anthryl; and aryl groups such as methylphenyl (various isomers), ethylphenyl (various isomers), propylphenyl (various isomers), butylphenyl (various isomers), pentylphenyl (various isomers), hexylphenyl (various isomers), α-cumylphenyl (various isomers), methoxyphenyl (various isomers), and ethoxyphenyl (various isomers).

[0468] Among these, aryl groups such as phenyl group, naphthyl group, anthryl group, pyrenyl group, phenanthryl group, methylphenyl group (each isomer), ethylphenyl group (each isomer), propylphenyl group (each isomer), butylphenyl group (each isomer), pentylphenyl group (each isomer), hexylphenyl group (each isomer), α-cumylphenyl group (each isomer), methoxyphenyl group (each isomer), and ethoxyphenyl group (each isomer) are preferred, and among these, phenyl group, α-cumylphenyl group (each isomer), methoxyphenyl group (each isomer), and ethoxyphenyl group (each isomer) are more preferred.

[0469] Among these, the ester compound is more preferably one with a structure represented by the following formulas (24-1') to (24-16').

[0470]

[0471] {Ether Compounds} The ether compounds are not particularly limited, but compounds represented by the following formula (25) are preferably used.

[0472]

[0473] In general formula (25), R ２５１ and R ２５３ Each of these is independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. ２５２ n251 is an integer between 0 and 20.

[0474] (R ２５１ and R ２５３ ) R ２５１ and R ２５３ Examples of alkyl groups having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group (each isomer), butyl group (each isomer), pentyl group (each isomer), hexyl group (each isomer), heptyl group (each isomer), octyl group (each isomer), nonyl group (each isomer), decyl group (each isomer), dodecyl group (each isomer), octadecyl group (each isomer), and so on.

[0475] R ２５１ and R ２５３ Examples of aryl groups having 6 to 20 carbon atoms include phenyl groups and naphthyl groups.

[0476] R ２５１ and R ２５３ Examples of aralkyl groups having 7 to 20 carbon atoms include phenylmethyl group, phenylethyl group (various isomers), phenylpropyl group (various isomers), phenylbutyl group (various isomers), phenylpentyl group (various isomers), phenylhexyl group (various isomers), phenylheptyl group (various isomers), phenyloctyl group (various isomers), and phenylnonyl group (various isomers).

[0477] Substituents of alkyl groups include aryl groups, halogen groups, and nitrile groups. Examples of aryl groups include those mentioned above. Examples of halogen groups include fluoro groups, chloro groups, bromo groups, and iodo groups. Substituents of aryl and aralkyl groups include alkyl groups, halogen groups, and nitrile groups. Examples of alkyl and halogen groups include those mentioned above.

[0478] (R ２５２ ) R ２５２ Examples of alkylene groups having 1 to 20 carbon atoms include methylene groups, ethylene groups, and propylene groups. ２５２ Examples of arylene groups with 7 to 20 carbon atoms in R include phenylene groups and naphthylene groups. ２５２ Examples of aralkylene groups having 7 to 20 carbon atoms include phenylenemethylene groups and methylenephenylenemethylene groups.

[0479] Substituents on alkylene groups include aryl groups, alkoxy groups, halogen groups, and nitrile groups. Examples of alkoxy groups include methoxy groups, ethoxy groups, propyloxy groups (each isomer), butoxy groups (each isomer), and hexyloxy groups (each isomer). Examples of aryl groups and halogen groups include those mentioned above. Substituents on arylene groups and aralkylene groups include alkyl groups, alkoxy groups, halogen groups, and nitrile groups. Examples of alkyl groups, alkoxy groups, and halogen groups include those mentioned above.

[0480] Examples of preferred ether compounds (25) include compounds represented by any of the following formulas (25-1) to (25-23).

[0481]

[0482]

[0483]

[0484] The present invention will be described in detail below based on examples, but the scope of the present invention is not limited to these examples.

[0485] <Analysis method> (1) １ As the H-NMR analysis apparatus, we used the JNM-A400 FT-NMR system manufactured by JEOL Ltd. １ H-NMR analysis was performed.

[0486] (1-1) １ 0.3 g of the prepared sample solution for H-NMR analysis was weighed, and 0.7 g of deuterated chloroform and 0.05 g of dimethyldiphenylsilane as an internal standard were added and the mixture was homogenized to obtain the NMR analysis sample.

[0487] (1-2) Quantitative analysis: Analysis was performed on each standard substance, and quantitative analysis of the analytical sample solution was carried out based on the calibration curve created.

[0488] (2) Gas chromatography analysis method The analysis was performed under the following conditions.

[0489] (Measurement conditions) Equipment: Shimadzu Corporation, GC-2010 Column: DB-1, diameter 0.25 mm, length 30 m, film thickness 1.0 μm Column temperature: 60°C to 300°C Inlet temperature: 300°C Carrier gas: Helium Carrier gas flow rate: 40 mL / min Detector: FID (Flame Ionization Detector)

[0490] (2-1) Preparation of gas chromatography analysis sample: 1.0 g of the sample solution was weighed, 10 g of acetonitrile and 0.1 g of anisole as an internal standard were added, and the mixture was homogenized to obtain the gas chromatography analysis sample.

[0491] (3) Liquid chromatography analysis method The analysis was performed under the following conditions.

[0492] (Measurement conditions) Apparatus: Shimadzu Corporation, LC-10AT Column: Inertsil ODS Particle size 5 μm, inner diameter 2.1 mm, length 250 mm Column temperature: 40°C Developing solvent: Water / acetonitrile = 90 / 10 Developing solvent flow rate: 1 mL / min Detector: Photodiode array detector

[0493] (3-1) Preparation of liquid chromatography analysis sample: 1.0 g of the sample solution was weighed, and 10 g of acetic acid was added and mixed uniformly to obtain the liquid chromatography analysis sample.

[0494] (3-2) Quantitative analysis: Analysis was performed on each standard substance, and quantitative analysis of the analytical sample solution was carried out based on the calibration curve created.

[0495] <Hazen Color Count> The Hazen color count is the value obtained by measuring with a Hazen meter.

[0496] <Operation of the Simulated Mobile Bed Apparatus> The apparatus shown in Figure 5 is used for chromatographic separation using a simulated mobile bed. Column: Amberlite XAD 2000 Column packing method: After packing by dry packing, the developing solvent is passed through the column. Column porosity: Average 0.32 Column length: 30 cm Column changeover time: 5 minutes Developing solvent: Acetonitrile

[0497] Operating procedure: Flow the developing solvent from 510 to fill each line and column with the developing solvent. Open the solenoid valves A1, B1, C1, D1 (collectively referred to as solenoid valve group 1) and close the other solenoid valves. After the raw material liquid begins to flow from the raw material tank 500 through the line to 101, and after a predetermined column switching time has elapsed, open A2, B2, C2, D2 (referred to as solenoid valve group 2) and close solenoid valve group 1. After another predetermined column switching time has elapsed, open A3, B3, C3, D3 (referred to as solenoid valve group 3) and close solenoid valve group 2. After another predetermined column switching time has elapsed, open A4, B4, C4, D4 (referred to as solenoid valve group 4) and close solenoid valve group 3. After another predetermined column switching time has elapsed, open A5, B5, C5, D5 (referred to as solenoid valve group 5) and close solenoid valve group 4. Furthermore, after a predetermined column switching time has elapsed, A6, B6, C6, D6 (referred to as solenoid valve group 6) are opened and solenoid valve group 5 is closed. After another predetermined column switching time has elapsed, A7, B7, C7, D7 (referred to as solenoid valve group 7) are opened and solenoid valve group 6 is closed. After another predetermined column switching time has elapsed, A8, B8, C8, D8 (referred to as solenoid valve group 8) are opened and solenoid valve group 7 is closed. After another predetermined column switching time has elapsed, solenoid valve group 1 is opened and solenoid valve group 8 is closed. By continuing this cycle from the initial state where solenoid valve group 1 is open during operation, a pseudo-stationary phase movement is achieved, and chromatographic separation is performed in a pseudo-mobilization phase. If the raw material liquid in the raw material tank 500 becomes empty, the developing solvent is supplied and the operation is continued until the entire column and line are replaced with the developing solvent. In Figure 5, 504 is the extract tank.

[0498] [Example 1] Step (A1): Production of a carbamate intermediate from lysine monohydrochloride The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, a mixture of 30 kg (164 mol) of lysine monohydrochloride and 103 kg (500 mol) of sodium hydroxide aqueous solution was supplied from storage tank 101 through line 11 to baffled SUS reactor 104. Next, with line 16 closed, 217 kg (2306 mol) of phenol was supplied from storage tank 102 through line 15 to baffled SUS reactor 105, and 217 kg (1013 mol) of diphenyl carbonate was supplied from storage tank 103 through line 13 to the reactor 105. The liquid temperature in reactor 105 was adjusted to 50°C and homogenized by stirring. Then, a mixture of lysine monohydrochloride and sodium hydroxide was supplied to reactor 105 from reactor 104 via line 14. After stirring continued for 7 hours, 125 kg of 2.5 M hydrochloric acid aqueous solution was supplied to reactor 105 from storage tank 101 via line 11, reactor 104, and line 14, and then stirred. 100 kg of anisole was supplied to reactor 105 from storage tank 102 via line 12, and then stirred. After standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing with 2.5 M hydrochloric acid aqueous solution was performed three times. Then, 200 kg of water was added to reactor 105 in the same manner as the supply method of the 2.5 M hydrochloric acid aqueous solution described above, stirred, and after standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. The reaction mixture was then heated to 80°C, and the internal pressure was reduced to approximately 1 kPa, allowing the anisole solvent and other components to be withdrawn to storage tank 107 via line 17 and condenser A11. Subsequently, 458 kg of the liquid from reactor 105 was withdrawn to storage tank 106 via line 16.

[0499] The reaction solution from storage tank 106 was transferred to storage tank 205 as shown in Figure 2, and the carbamate intermediate was purified using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 120°C, and the internal pressure was set to 2.5 kPa. The reaction solution from storage tank 205 was supplied to the top of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate the phenol and the carbamate intermediate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. 227 kg of liquid was recovered from storage tank 203 via line 23. The reaction solution recovered in storage tank 203 was transferred back to 205, and the thin-film distillation apparatus 201 was heated to 140°C, and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate diphenyl carbonate and carbamate compounds. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (A1)") was 65 kg.

[0500] Analysis of the reaction solution (A1) by liquid chromatography revealed that N is the carbamate intermediate corresponding to lysine monohydrochloride. ２ , N ６ -Bis(phenoxycarbonyl)lysine was obtained in a yield of 84% by mass compared to the theoretical yield expected from the lysine monohydrochloride used in the preparation.

[0501] Process (B1): Carbamate compound production. The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, 221 kg (6898 mol) of methanol and 1.4 kg (14 mol) of sulfuric acid were supplied from storage tanks 101 and 102 to reactor 104 via lines 11 and 12, respectively, and stirred. Next, with line 16 closed, the entire volume of the mixture in reactor 104 was transferred from reactor 104 to reactor 105 via line 14, and 65 kg of reaction solution A1 (carbamate intermediate: 138 mol) was supplied from storage tank 103 to reactor 105 via line 13. The liquid temperature in reactor 105 was adjusted to 65°C and stirred for 1 hour. 53 kg of diphenyl ether was transferred from storage tank 103 to reactor 105 via line 13. The reaction solution was then adjusted to 50°C, and the internal pressure was reduced to approximately 3 kPa, allowing methanol solvent and other components to be withdrawn to storage tank 107 via line 17 and condenser A11. The temperature was then raised to 80°C, and 100 kg of water was transferred from storage tank 103 to reactor 105 via line 13 and stirred. After stopping the stirring and allowing it to stand for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing operation was repeated a total of three times. Subsequently, the internal pressure was reduced to 3 kPa at 80°C to remove any remaining water from the organic phase. Then, 120 kg of the liquid from reactor 105 (hereinafter referred to as "reaction solution (B1)") was withdrawn to storage tank 106 via line 16.

[0502] Analysis of the reaction solution (B1) by liquid chromatography revealed that methyl-N was present as a carbamate compound. ２ , N ６ -Bis(phenoxycarbonyl)lignate in the reaction solution (A1) used ２ , N ６ - The yield was 92% by mass, compared to the theoretical yield expected from bis(phenoxycarbonyl)lysine. The carbamate compound was present in reaction solution (B1) at 42 wt%.

[0503] Process (C1): Pyrolysis of Carbamate Compounds The reaction was carried out using the apparatus shown in Figure 3. With line 34 closed, 53 kg of diphenyl ether was supplied from storage tank 301 to baffled SUS reactor 303 via line 31. The temperature of the multi-stage distillation column 304 was raised to 195°C, the jacket temperature of reactor 303 was heated to 245°C, and the pressure was reduced to 50-60 kPa. 47 kg of reaction solution (B1) recovered in process (B1) was heated to 120°C and supplied to reactor 303 via line 31 in about 14 minutes to perform pyrolysis of the carbamate compound. The phenol produced by pyrolysis was separated from diphenyl ether and the product methyl-2,6-diisocyanatohexanoate in distillation column 304 and recovered in storage tank 305 via line 33 and condenser A31. After all of the reaction solution (B1) had been transferred, the extraction of phenol was continued at an internal temperature of 245°C. The reaction was terminated 3 hours after all of the reaction solution (B1) had been transferred. The mass of the reaction solution in reactor 303 was 62 kg. ¹H-NMR and gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (C1)") revealed that methyl-2,6-diisocyanatohexanoate was produced in a yield of 80% by mass relative to the theoretical yield expected from the amount of carbamate compound used in step (C1). The concentration of methyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (C1) was 14% by mass.

[0504] Process (D1): Light Boiling Separation Process 1 After performing Process (C1), light boiling separation was carried out immediately. The temperature of the multi-stage distillation column 304 was set to 90°C, the jacket temperature of the reactor 303 was set to 130°C, and the pressure was reduced to 0.1 kPa. In the distillation column 304, diphenyl ether was separated from methyl-2,6-diisocyanatohexanoate and recovered in the storage tank 305 via line 33 and condenser A31. After distilling off the diphenyl ether for 5 hours, the distillation was terminated. The mass of the reaction solution in reactor 303 was 40 kg. Gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (D1)") revealed that the recovery rate of methyl-2,6-diisocyanatohexanoate was 95% by mass relative to the theoretical yield expected from the amount of isocyanate compound obtained in step (C1), and the concentration of methyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (D1) was 20% by mass.

[0505] Process (E1): Light boiling separation process 2 The reaction solution (D1) was transferred to the storage tank 205 shown in Figure 2, and light boiling cut-off was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 150°C and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to remove diphenyl ether. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (E1)") was 27 kg.

[0506] Gas chromatography analysis of the reaction solution (E1) revealed that the recovery rate of methyl-2,6-diisocyanatohexanoate was 95% by mass, relative to the theoretical yield expected from the amount of isocyanate compound in the reaction solution (D1) used in step (E1). Furthermore, the concentration of methyl-2,6-diisocyanatohexanoate relative to the total mass of the reaction solution (E1) was 28% by mass.

[0507] Process (F1): High-boiling separation process 2 The reaction solution (E1) was transferred to the storage tank 205 shown in Figure 2, and high-boiling cut was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 160°C and the internal pressure was set to 0.1 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to recover methyl-2,6-diisocyanatohexanoate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 202 (hereinafter referred to as "reaction solution (F1)") was 19 kg.

[0508] ¹H-NMR, gas chromatography, and liquid chromatography analysis of reaction solution (F1) revealed that the recovery rate of methyl-2,6-diisocyanatohexanoate was 100% by mass, relative to the theoretical yield expected from the isocyanate compound in the reaction solution (E1), and the solution contained 88 wt% methyl-2,6-diisocyanatohexanoate.

[0509] 26.1 g of reaction solution (F1) and 104.4 g of acetonitrile (four times the weight of reaction solution (F1)) were added to a 200 mL flask and stirred to obtain a homogeneous solution. The solution in the flask was supplied to the raw material tank 500 of the pseudo-mobile bed chromatograph shown in Figure 5, and the raw material tank 500 was maintained under a nitrogen atmosphere. In addition, a sufficient amount of acetonitrile was supplied as an eluent to the eluent tank 510. The pseudo-mobile bed chromatograph was operated while supplying liquid from the raw material tank 500 at a rate of 1.8 g / min and from the eluent tank 510 at a rate of 7.2 g / min, and withdrawing the liquid to the raffinate tank 503 at a rate of 3.5 g / min and to the extract tank 504 at a rate of 5.5 g / min. After the procedure, all solenoid valves were closed, the liquid in the raffinate tank 503 was heated to 80°C, and the developing solvent was removed by distillation under reduced pressure to 0.1 kPa, and the mixture was thoroughly removed to the storage tank 501 via line 21 and condenser E1. As a result, 21.2 g of the purified isocyanate composition obtained as the liquid phase component was transferred to the storage tank 502 via line 52. A portion of this was sampled and analyzed by 1H-NMR and gas chromatography. The results showed that methyl-2,6-diisocyanatohexanoate was present at a concentration of 98.6% by mass, and the yield was 91.5% by weight compared to the theoretical yield expected from the isocyanate compound in the reaction solution (F1) used.

[0510] [Example 2] Step (A2): Production of a carbamate intermediate from lysine monohydrochloride The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, a mixture of 30 kg (164 mol) of lysine monohydrochloride and 103 kg (500 mol) of aqueous sodium hydroxide solution was supplied from storage tank 101 through line 11 to baffled SUS reactor 104. Next, with line 16 closed, 217 kg (2306 mol) of phenol was supplied from storage tank 102 through line 15 to baffled SUS reactor 105, and 217 kg (1013 mol) of diphenyl carbonate was supplied from storage tank 103 through line 13 to the reactor 105. The liquid temperature in reactor 105 was adjusted to 50°C and homogenized by stirring. Then, a mixture of lysine monohydrochloride and sodium hydroxide was supplied to reactor 105 from reactor 104 via line 14. After stirring continued for 7 hours, 125 kg of 2.5 M hydrochloric acid aqueous solution was supplied to reactor 105 from storage tank 101 via line 11, reactor 104, and line 14, and then stirred. 100 kg of anisole was supplied to reactor 105 from storage tank 102 via line 12, and then stirred. After standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing with 2.5 M hydrochloric acid aqueous solution was performed three times. Then, in the same manner as the supply method of 2.5 M hydrochloric acid aqueous solution described above, 200 kg of water was added to reactor 105, stirred, and after standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. The reaction mixture was then heated to 80°C, and the internal pressure was reduced to approximately 1 kPa, allowing the anisole solvent and other components to be withdrawn to storage tank 107 via line 17 and condenser A11. Subsequently, 458 kg of the liquid from reactor 105 was withdrawn to storage tank 106 via line 16.

[0511] The reaction solution from storage tank 106 was transferred to storage tank 205 as shown in Figure 2, and the carbamate intermediate was purified using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 120°C, and the internal pressure was set to 2.5 kPa. The reaction solution from storage tank 205 was supplied to the top of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate the phenol and the carbamate intermediate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 203 was 227 kg. The reaction solution recovered in storage tank 203 was transferred back to 205, and the thin-film distillation apparatus 201 was heated to 140°C, and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate diphenyl carbonate and carbamate compounds. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (A2)") was 65 kg.

[0512] Analysis of the reaction solution (A2) by liquid chromatography revealed that N is the carbamate intermediate corresponding to lysine monohydrochloride. ２ , N ６ -Bis(phenoxycarbonyl)lysine was obtained in a yield of 84% by mass compared to the theoretical yield expected from the lysine monohydrochloride used in the preparation.

[0513] Process (B2): Carbamate compound production. The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, 318 kg (6898 mol) of ethanol and 1.4 kg (14 mol) of sulfuric acid were supplied from storage tanks 101 and 102 to reactor 104 via lines 11 and 12, respectively, and stirred. Next, with line 16 closed, the entire volume of the mixture in reactor 104 was transferred from reactor 104 to reactor 105 via line 14, and 65 kg of reaction solution (A2) (carbamate intermediate: 138 mol) was supplied from storage tank 103 to reactor 105 via line 13. The liquid temperature in reactor 105 was adjusted to 65°C and stirred for 1 hour. 53 kg of diphenyl ether was transferred from storage tank 103 to reactor 105 via line 13. The reaction solution was then adjusted to 50°C, and the internal pressure was reduced to approximately 3 kPa, allowing the ethanol solvent and other components to be withdrawn to storage tank 107 via line 17 and condenser A11. The temperature was then raised to 80°C, and 100 kg of water was transferred from storage tank 103 to reactor 105 via line 13 and stirred. After stopping the stirring and allowing it to stand for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing operation was repeated a total of three times. Subsequently, the internal pressure was reduced to 3 kPa at 80°C to remove any remaining water from the organic phase. Then, 122 kg of the liquid from reactor 105 (hereinafter referred to as "reaction solution (B2)") was withdrawn to storage tank 106 via line 16.

[0514] Analysis of the reaction solution (B2) by liquid chromatography revealed that ethyl-N was present as a carbamate compound. ２ , N ６ -Bis(phenoxycarbonyl)lignate in reaction solution A2 used ２ , N ６ - The yield was 96% by mass compared to the theoretical yield expected from bis(phenoxycarbonyl)lysine. The carbamate compound was present in reaction solution (B2) at 45 wt%.

[0515] Process (C2): Pyrolysis of Carbamate Compounds The reaction was carried out using the apparatus shown in Figure 3. With line 34 closed, 56 kg of diphenyl ether was supplied from storage tank 301 to baffled SUS reactor 303 via line 32. The temperature of the multistage distillation column 304 was raised to 195°C, the jacket temperature of reactor 303 was heated to 245°C, and the pressure was reduced to 50-60 kPa. 44 kg of reaction solution (B2) recovered in process (B2) was heated to 120°C and supplied to reactor 303 via line 31 in about 14 minutes to perform pyrolysis of the carbamate compound. The phenol produced by pyrolysis was separated from diphenyl ether and the product ethyl-2,6-diisocyanatohexanoate in distillation column 304 and recovered in storage tank 305 via line 33 and condenser A31. After all of the reaction solution (B2) had been transferred, the extraction of phenol was continued at an internal temperature of 245°C. The reaction was terminated 3 hours after all of the reaction solution (B2) had been transferred. The mass of the reaction solution in reactor 303 was 60 kg. ¹H-NMR and gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (C2)") revealed that ethyl-2,6-diisocyanatohexanoate was produced in a yield of 80% by mass relative to the theoretical yield expected from the amount of carbamate compound used in step (C1). The concentration of ethyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (C2) was 15% by mass.

[0516] Process (D2): Light Boiling Separation Process 1 After performing Process (C2), light boiling separation was carried out immediately. The temperature of the multi-stage distillation column 304 was set to 90°C, the jacket temperature of the reactor 303 was set to 130°C, and the pressure was reduced to 0.1 kPa. In the distillation column 304, diphenyl ether was separated from ethyl-2,6-diisocyanatohexanoate and recovered in the storage tank 305 via line 33 and condenser A31. After distilling off the diphenyl ether for 5 hours, the distillation was terminated. The mass of the reaction solution in reactor 303 was 39 kg. Gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (D2)") revealed that the recovery rate of ethyl-2,6-diisocyanatohexanoate was 95% by mass relative to the theoretical yield expected from the amount of isocyanate compound obtained in step (C1), and the concentration of ethyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (D2) was 21% by mass.

[0517] Process (E2): Light Boiling Separation Process 2 The reaction solution (D2) was transferred to the storage tank 205 shown in Figure 2, and light boiling cut-off was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 150°C and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to remove diphenyl ether. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (E2)") was 25 kg.

[0518] Gas chromatography analysis of the reaction solution (E2) revealed that the recovery rate of ethyl-2,6-diisocyanatohexanoate was 95% by mass, relative to the theoretical yield expected from the amount of isocyanate compound in the reaction solution (D1) used in step (E1). Furthermore, the concentration of ethyl-2,6-diisocyanatohexanoate relative to the total mass of the reaction solution (E2) was 31% by mass.

[0519] Process (F2): High-boiling separation process 2 The reaction solution (E2) was transferred to the storage tank 205 shown in Figure 2, and high-boiling cut was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 160°C and the internal pressure was set to 0.1 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to recover ethyl-2,6-diisocyanatohexanoate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 202 (hereinafter referred to as "reaction solution (F2)") was 17 kg.

[0520] ¹H-NMR, gas chromatography, and liquid chromatography analysis of the reaction solution (F2) revealed that the recovery rate of ethyl-2,6-diisocyanatohexanoate was 100% by mass, relative to the theoretical yield expected from the isocyanate compound in the reaction solution (E1), and the solution contained 91 wt% ethyl-2,6-diisocyanatohexanoate. 48.2 g of reaction solution (F2) and 192.8 g of acetonitrile (four times the weight of reaction solution (F2)) were added to a 200 mL flask and stirred to obtain a homogeneous solution. The solution from the flask was supplied to the raw material tank 500 of the pseudo-mobilization chromatograph shown in Figure 5, and the raw material tank 500 was maintained under a nitrogen atmosphere. In addition, a sufficient amount of acetonitrile was supplied to the eluent tank 510 as an eluent. The simulated mobile phase apparatus was operated while supplying liquid at a rate of 2.4 g / min from the raw material tank 500 and 7.4 g / min from the eluent tank 510, and withdrawing the liquid at a rate of 3.9 g / min to the raffinate tank 503 and 5.9 g / min to the extract tank 504. After operation, all solenoid valves were closed, the liquid in the raffinate tank 503 was heated to 80°C, and the developing solvent was removed by distillation by reducing the pressure to 0.1 kPa, and the liquid was thoroughly removed to the storage tank 501 via line 51 and condenser E1. As a result, the 41.0 g of purified isocyanate composition obtained as the liquid phase component was transferred to the storage tank 502 via line 52. A portion of the sample was sampled and analyzed by 1H-NMR and gas chromatography. The results showed that ethyl-2,6-diisocyanatohexanoate was present at a concentration of 98.8% by mass, and the yield was 92.4% by weight compared to the theoretical yield expected from the isocyanate compound in the reaction solution (F1) used.

[0521] [Example 3] Step (A3): Production of carbamate intermediate from lysine monohydrochloride The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, a mixture of 30 kg (164 mol) of lysine monohydrochloride and 103 kg (500 mol) of aqueous sodium hydroxide solution was supplied from storage tank 101 through line 11 to baffled SUS reactor 104. Next, with line 16 closed, 217 kg (2306 mol) of phenol was supplied from storage tank 102 through line 15 to baffled SUS reactor 105, and 217 kg (1013 mol) of diphenyl carbonate was supplied from storage tank 103 through line 13 to the reactor 105. The liquid temperature in reactor 105 was adjusted to 50°C and homogenized by stirring, after which a mixture of lysine monohydrochloride and sodium hydroxide was supplied from reactor 104 through line 14. After stirring for 7 hours, 125 kg of 2.5 M hydrochloric acid solution was supplied from storage tank 101 to reactor 105 via line 11, reactor 104, and line 14, and then stirred. 100 kg of anisole was supplied from storage tank 102 to reactor 105 via line 12, and then stirred. After standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing with 2.5 M hydrochloric acid solution was performed three times. Then, 200 kg of water was added to reactor 105 in the same manner as the supply method of the 2.5 M hydrochloric acid solution described above, stirred, and after standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. The reaction solution was then heated to 80°C, and the internal pressure was reduced to approximately 1 kPa, allowing the anisole solvent, etc., to be removed to storage tank 107 via line 17 and condenser A11. Finally, 458 kg of the liquid from reactor 105 was removed to storage tank 106 via line 16.

[0522] The reaction solution from storage tank 106 was transferred to storage tank 205 as shown in Figure 2, and the carbamate intermediate was purified using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 120°C, and the internal pressure was set to 2.5 kPa. The reaction solution from storage tank 205 was supplied to the top of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate the phenol and the carbamate intermediate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 203 was 227 kg. The reaction solution recovered in storage tank 203 was transferred back to 205, and the thin-film distillation apparatus 201 was heated to 140°C, and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate diphenyl carbonate and carbamate compounds. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (A3)") was 65 kg.

[0523] Analysis of the reaction solution (A3) by liquid chromatography revealed that N is the carbamate intermediate corresponding to lysine monohydrochloride. ２ , N ６ -Bis(phenoxycarbonyl)lysine was obtained in a yield of 84% by mass compared to the theoretical yield expected from the lysine monohydrochloride used in the preparation.

[0524] Process (B3): Carbamate compound production. The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, 511 kg (6898 mol) of isobutanol and 1.4 kg (14 mol) of sulfuric acid were supplied from storage tanks 101 and 102 to reactor 104 via lines 11 and 12, respectively, and stirred. Next, with line 16 closed, the entire volume of the mixture in reactor 104 was transferred from reactor 104 to reactor 105 via line 14, and 65 kg of reaction solution A5 (carbamate intermediate: 138 mol) was supplied from storage tank 103 to reactor 105 via line 13. The liquid temperature in reactor 105 was adjusted to 65°C and stirred for 1 hour. 53 kg of diphenyl ether was transferred from storage tank 103 to reactor 105 via line 13. The reaction solution was then adjusted to 50°C, and the internal pressure was reduced to approximately 3 kPa, allowing the isobutanol solvent and other components to be withdrawn to storage tank 107 via line 17 and condenser A11. The temperature was then raised to 80°C, and 100 kg of water was transferred from storage tank 103 to reactor 105 via line 13 and stirred. After stopping the stirring and allowing it to stand for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing operation was repeated a total of three times. Subsequently, the internal pressure was reduced to 3 kPa at 80°C to remove any remaining water from the organic phase. Then, 126 kg of the liquid from reactor 105 (hereinafter referred to as "reaction solution (B3)") was withdrawn to storage tank 106 via line 16.

[0525] Analysis of the reaction solution (B3) by liquid chromatography revealed that the carbamate compound was isobutyl-N ２ , N ６ -Bis(phenoxycarbonyl)lignate in the reaction solution (A2) used, ２ , N ６ - The compound was obtained in 96% by mass, exceeding the theoretical yield expected from bis(phenoxycarbonyl)lysine. The carbamate compound was present in reaction solution (B3) at 47 wt%.

[0526] Process (C3): Pyrolysis of Carbamate Compounds The reaction was carried out using the apparatus shown in Figure 3. With line 34 closed, 56 kg of diphenyl ether was supplied from storage tank 301 to baffled SUS reactor 303 via line 32. The temperature of the multistage distillation column 304 was raised to 195°C, the jacket temperature of reactor 303 was heated to 245°C, and the pressure was reduced to 50-60 kPa. 44 kg of reaction solution (B3) recovered in process (B3) was heated to 120°C and supplied to reactor 303 via line 31 in about 14 minutes to perform pyrolysis of the carbamate compound. The phenol produced by pyrolysis was separated from diphenyl ether and the product isobutyl-2,6-diisocyanatohexanoate in distillation column 304 and recovered in storage tank 305 via line 33 and condenser A31. After all of the reaction solution (B3) had been transferred, the extraction of phenol was continued at an internal temperature of 245°C. The reaction was terminated 3 hours after all of the reaction solution (B3) had been transferred. The mass of the reaction solution in reactor 303 was 60 kg. ¹H-NMR and gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (C3)") revealed that isobutyl-2,6-diisocyanatohexanoate was produced in a yield of 80% by mass relative to the theoretical yield expected from the amount of carbamate compound used in step (C3). The concentration of isobutyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (C3) was 15% by mass.

[0527] Process (D3): Light Boiling Separation Process 1 After performing Process (C3), light boiling separation was carried out immediately. The temperature of the multistage distillation column 304 was set to 90°C, the jacket temperature of the reactor 303 was set to 130°C, and the pressure was reduced to 0.1 kPa. In the distillation column 304, diphenyl ether was separated from isobutyl-2,6-diisocyanatohexanoate and recovered in the storage tank 305 via line 33 and condenser A31. After distilling off the diphenyl ether for 5 hours, the distillation was terminated. The mass of the reaction solution in reactor 303 was 39 kg. Gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (D3)") revealed that the recovery rate of isobutyl-2,6-diisocyanatohexanoate was 95% by mass relative to the theoretical yield expected from the amount of isocyanate compound obtained in step (C3), and the concentration of isobutyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (D3) was 22% by mass.

[0528] Process (E3): Light Boiling Separation Process 2 The reaction solution (D3) was transferred to the storage tank 205 shown in Figure 2, and light boiling cut-off was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 150°C and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to remove diphenyl ether. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (E3)") was 26 kg.

[0529] Gas chromatography analysis of the reaction solution (E3) revealed that the recovery rate of isobutyl-2,6-diisocyanatohexanoate was 95% by mass, relative to the theoretical yield expected from the amount of isocyanate compound in the reaction solution (D1) used in step (E3). Furthermore, the concentration of isobutyl-2,6-diisocyanatohexanoate relative to the total mass of the reaction solution (E3) was 32% by mass.

[0530] Process (F3): High-boiling separation process 2 The reaction solution (E3) was transferred to the storage tank 205 shown in Figure 2, and high-boiling cut-off was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 160°C and the internal pressure was set to 0.1 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to recover isobutyl-2,6-diisocyanatohexanoate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 202 (hereinafter referred to as "reaction solution (F3)") was 18 kg.

[0531] ¹H-NMR, gas chromatography, and liquid chromatography analysis of the reaction solution (F3) revealed that the recovery rate of isobutyl-2,6-diisocyanatohexanoate was 100% by mass, relative to the theoretical yield expected from the isocyanate compound in the reaction solution (E3). The solution contained 81 wt% isobutyl-2,6-diisocyanatohexanoate. 48.2 g of reaction solution (F3) and 192.8 g of acetonitrile (four times the weight of reaction solution (F3)) were added to a 200 mL flask and stirred to obtain a homogeneous solution. The solution in the flask was supplied to the raw material tank 500 of the pseudo-mobilization chromatograph shown in Figure 5, and the raw material tank 500 was maintained under a nitrogen atmosphere. In addition, a sufficient amount of acetonitrile was supplied to the eluent tank 510 as an eluent. The simulated mobile phase apparatus was operated while supplying liquid at a rate of 2.4 g / min from the raw material tank 500 and 7.4 g / min from the eluent tank 510, and withdrawing the liquid at a rate of 3.9 g / min to the raffinate tank 503 and 5.9 g / min to the extract tank 504. After operation, all solenoid valves were closed, the liquid in the raffinate tank 503 was heated to 80°C, and the developing solvent was removed by distillation by reducing the pressure to 0.1 kPa, and the liquid was thoroughly removed to the storage tank 501 via line 51 and condenser E1. As a result, the 41.0 g of purified isocyanate composition obtained as the liquid phase component was transferred to the storage tank 502 via line 52. A portion of the sample was sampled and analyzed by 1H-NMR and gas chromatography. The results showed that isobutyl-2,6-diisocyanatohexanoate was present at a concentration of 98.8% by mass, and the yield was 92.4% by weight compared to the theoretical yield expected from the isocyanate compound in the reaction solution (F3) used.

[0532] [Example 4] Step (A4): Production of carbamate intermediate from lysine monohydrochloride The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, a mixture of 30 kg (164 mol) of lysine monohydrochloride and 103 kg (500 mol) of aqueous sodium hydroxide solution was supplied from storage tank 101 through line 11 to baffled SUS reactor 104. Next, with line 16 closed, 217 kg (2306 mol) of phenol was supplied from storage tank 102 through line 15 to baffled SUS reactor 105, and 217 kg (1013 mol) of diphenyl carbonate was supplied from storage tank 103 through line 13 to the reactor 105. The liquid temperature in reactor 105 was adjusted to 50°C and homogenized by stirring, after which a mixture of lysine monohydrochloride and sodium hydroxide was supplied from reactor 104 through line 14. After stirring for 7 hours, 125 kg of 2.5 M hydrochloric acid solution was supplied from storage tank 101 to reactor 105 via line 11, reactor 104, and line 14, and then stirred. 100 kg of anisole was supplied from storage tank 102 to reactor 105 via line 12, and then stirred. After standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing with 2.5 M hydrochloric acid solution was performed three times. Then, 200 kg of water was added to reactor 105 in the same manner as the supply method of the 2.5 M hydrochloric acid solution described above, stirred, and after standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. The reaction solution was then heated to 80°C, and the internal pressure was reduced to approximately 1 kPa, allowing the anisole solvent, etc., to be removed to storage tank 107 via line 17 and condenser A11. Finally, 458 kg of the liquid from reactor 105 was removed to storage tank 106 via line 16.

[0533] The reaction solution from storage tank 106 was transferred to storage tank 205 as shown in Figure 2, and the carbamate intermediate was purified using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 120°C, and the internal pressure was set to 2.5 kPa. The reaction solution from storage tank 205 was supplied to the top of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate the phenol and the carbamate intermediate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 203 was 227 kg. The reaction solution recovered in storage tank 203 was transferred back to 205, and the thin-film distillation apparatus 201 was heated to 140°C, and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate diphenyl carbonate and carbamate compounds. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (A4)") was 65 kg.

[0534] Analysis of the reaction solution (A4) by liquid chromatography revealed that N is the carbamate intermediate corresponding to lysine monohydrochloride. ２ , N ６ -Bis(phenoxycarbonyl)lysine was obtained in a yield of 84% by mass compared to the theoretical yield expected from the lysine monohydrochloride used in the preparation.

[0535] Process (B4): Carbamate compound production. The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, 511 kg (6898 mol) of 1-butanol and 1.4 kg (14 mol) of sulfuric acid were supplied from storage tanks 101 and 102 to reactor 104 via lines 11 and 12, respectively, and stirred. Next, with line 16 closed, the entire volume of the mixture in reactor 104 was transferred from reactor 104 to reactor 105 via line 14, and 65 kg of reaction solution A5 (carbamate intermediate: 138 mol) was supplied from storage tank 103 to reactor 105 via line 13. The liquid temperature in reactor 105 was adjusted to 65°C and stirred for 1 hour. 53 kg of diphenyl ether was transferred from storage tank 103 to reactor 105 via line 13. The reaction solution was then adjusted to 50°C, and the internal pressure was reduced to approximately 3 kPa, allowing the 1-butanol solvent and other components to be withdrawn to storage tank 107 via line 17 and condenser A11. The temperature was then raised to 80°C, and 100 kg of water was transferred from storage tank 103 to reactor 105 via line 13 and stirred. After stopping the stirring and allowing it to stand for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing operation was repeated a total of three times. Subsequently, the internal pressure was reduced to 3 kPa at 80°C to remove any remaining water from the organic phase. Then, 126 kg of the liquid from reactor 105 (hereinafter referred to as "reaction solution (B4)") was withdrawn to storage tank 106 via line 16.

[0536] Analysis of the reaction solution (B4) by liquid chromatography revealed that the carbamate compound was butyl-N ２ , N ６ -Bis(phenoxycarbonyl)lignate in the reaction solution (A4) used ２ , N ６ - The yield was 96% by mass compared to the theoretical yield expected from bis(phenoxycarbonyl)lysine. The carbamate compound was present in reaction solution (B4) at 47 wt%.

[0537] Process (C4): Pyrolysis of Carbamate Compounds The reaction was carried out using the apparatus shown in Figure 3. With line 34 closed, 56 kg of diphenyl ether was supplied from storage tank 301 to baffled SUS reactor 303 via line 32. The temperature of the multistage distillation column 304 was raised to 195°C, the jacket temperature of reactor 303 was heated to 245°C, and the pressure was reduced to 50-60 kPa. 44 kg of reaction solution (B4) recovered in process (B4) was heated to 120°C and supplied to reactor 303 via line 31 in about 14 minutes to perform pyrolysis of the carbamate compound. The phenol produced by pyrolysis was separated from diphenyl ether and the product isobutyl-2,6-diisocyanatohexanoate in distillation column 304 and recovered in storage tank 305 via line 33 and condenser A31. After all of the reaction solution (B4) had been transferred, the extraction of phenol was continued at an internal temperature of 245°C. The reaction was terminated 3 hours after all of the reaction solution (B4) had been transferred. The mass of the reaction solution in reactor 303 was 60 kg. ¹H-NMR and gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (C4)") revealed that butyl-2,6-diisocyanatohexanoate was produced in a yield of 80% by mass relative to the theoretical yield expected from the amount of carbamate compound used in step (C4). The concentration of butyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (C4) was 15% by mass.

[0538] Process (D4): Light Boiling Separation Process 1 After performing Process (C4), light boiling separation was carried out immediately. The temperature of the multistage distillation column 304 was set to 90°C, the jacket temperature of the reactor 303 was set to 130°C, and the pressure was reduced to 0.1 kPa. In the distillation column 304, diphenyl ether was separated from butyl-2,6-diisocyanatohexanoate and recovered in the storage tank 305 via line 33 and condenser A31. After distilling off the diphenyl ether for 5 hours, the distillation was terminated. The mass of the reaction solution in reactor 303 was 39 kg. Gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (D4)") revealed that the recovery rate of butyl-2,6-diisocyanatohexanoate was 95% by mass relative to the theoretical yield expected from the amount of isocyanate compound obtained in step (C4), and the concentration of butyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (D4) was 22% by mass.

[0539] Process (E4): Light Boiling Separation Process 2 The reaction solution (D4) was transferred to the storage tank 205 shown in Figure 2, and light boiling cut-off was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 150°C and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to remove diphenyl ether. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (E4)") was 26 kg.

[0540] Gas chromatography analysis of the reaction solution (E4) revealed that the recovery rate of butyl-2,6-diisocyanatohexanoate was 95% by mass, relative to the theoretical yield expected from the amount of isocyanate compound in the reaction solution (D1) used in step (E4). Furthermore, the concentration of butyl-2,6-diisocyanatohexanoate relative to the total mass of the reaction solution (E4) was 32% by mass.

[0541] Process (F4): High-boiling separation process 2 The reaction solution (E4) was transferred to the storage tank 205 shown in Figure 2, and high-boiling cut was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 160°C and the internal pressure was set to 0.1 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to recover butyl-2,6-diisocyanatohexanoate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 202 (hereinafter referred to as "reaction solution (F4)") was 18 kg.

[0542] ¹H-NMR, gas chromatography, and liquid chromatography analysis of the reaction solution (F4) revealed that the recovery rate of butyl-2,6-diisocyanatohexanoate was 100% by mass, relative to the theoretical yield expected from the isocyanate compound in the reaction solution (E4). The solution contained 81 wt% butyl-2,6-diisocyanatohexanoate. 48.2 g of reaction solution (F4) and 192.8 g of acetonitrile (four times the weight of reaction solution (F4)) were added to a 200 mL flask and stirred to obtain a homogeneous solution. The solution from the flask was supplied to the raw material tank 500 of the pseudo-mobilization chromatograph shown in Figure 5, and the raw material tank 500 was maintained under a nitrogen atmosphere. In addition, a sufficient amount of acetonitrile was supplied to the eluent tank 510 as an eluent. The simulated mobile phase apparatus was operated while supplying liquid at a rate of 2.4 g / min from the raw material tank 500 and 7.4 g / min from the eluent tank 510, and withdrawing the liquid at a rate of 3.9 g / min to the raffinate tank 503 and 5.9 g / min to the extract tank 504. After operation, all solenoid valves were closed, the liquid in the raffinate tank 503 was heated to 80°C, and the developing solvent was removed by distillation by reducing the pressure to 0.1 kPa, and the liquid was thoroughly removed to the storage tank 501 via line 51 and condenser E1. As a result, the 41.0 g of purified isocyanate composition obtained as the liquid phase component was transferred to the storage tank 502 via line 52. A portion of the sample was sampled and analyzed by 1H-NMR and gas chromatography. The results showed that butyl-2,6-diisocyanatohexanoate was present at a concentration of 98.8% by mass, and the yield was 92.4% by weight compared to the theoretical yield expected from the isocyanate compound in the reaction solution (F4) used.

[0543] [Example 5] Step (A5): Production of carbamate intermediate from lysine monohydrochloride The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, a mixture of 30 kg (164 mol) of lysine monohydrochloride and 103 kg (500 mol) of aqueous sodium hydroxide solution was supplied from storage tank 101 through line 11 to baffled SUS reactor 104. Next, with line 16 closed, 217 kg (2306 mol) of phenol was supplied from storage tank 102 through line 15 to baffled SUS reactor 105, and 217 kg (1013 mol) of diphenyl carbonate was supplied from storage tank 103 through line 13 to the reactor 105. The liquid temperature in reactor 105 was adjusted to 50°C and homogenized by stirring, after which a mixture of lysine monohydrochloride and sodium hydroxide was supplied from reactor 104 through line 14. After stirring for 7 hours, 125 kg of 2.5 M hydrochloric acid solution was supplied from storage tank 101 to reactor 105 via line 11, reactor 104, and line 14, and then stirred. 100 kg of anisole was supplied from storage tank 102 to reactor 105 via line 12, and then stirred. After standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing with 2.5 M hydrochloric acid solution was performed three times. Then, 200 kg of water was added to reactor 105 in the same manner as the supply method of the 2.5 M hydrochloric acid solution described above, stirred, and after standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. The reaction solution was then heated to 80°C, and the internal pressure was reduced to approximately 1 kPa, allowing the anisole solvent, etc., to be removed to storage tank 107 via line 17 and condenser A11. Finally, 458 kg of the liquid from reactor 105 was removed to storage tank 106 via line 16.

[0544] The reaction solution from storage tank 106 was transferred to storage tank 205 as shown in Figure 2, and the carbamate intermediate was purified using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 120°C, and the internal pressure was set to 2.5 kPa. The reaction solution from storage tank 205 was supplied to the top of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate the phenol and the carbamate intermediate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 203 was 227 kg. The reaction solution recovered in storage tank 203 was transferred back to 205, and the thin-film distillation apparatus 201 was heated to 140°C, and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to separate diphenyl carbonate and carbamate compounds. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (A5)") was 65 kg.

[0545] Analysis of the reaction solution (A5) by liquid chromatography revealed that N is the carbamate intermediate corresponding to lysine monohydrochloride. ２ , N ６ -Bis(phenoxycarbonyl)lysine was obtained in a yield of 84% by mass compared to the theoretical yield expected from the lysine monohydrochloride used in the preparation.

[0546] Process (G5): Production of carbamate intermediate from 2-aminoethanol. The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, 20 kg (327 mol) of 2-aminoethanol and 31 kg (327 mol) of phenol were supplied from storage tanks 101 and 102 via line 11 to baffled SUS reactor 104, respectively. Next, with line 16 closed, 92 kg (982 mol) of phenol was supplied from storage tank 102 via line 15 to baffled SUS reactor 105, and 105 kg (491 mol) of diphenyl carbonate was supplied from storage tank 103 via line 13 to reactor 105. The liquid temperature in reactor 105 was adjusted to 50°C and homogenized by stirring. Then, a mixture of 2-aminoethanol and phenol was supplied from reactor 104 via line 14 to reactor 105 over a period of 1.5 hours. After stirring was continued for 4 hours, the reaction solution was then heated to 80°C and the internal pressure was reduced to approximately 0.1 kPa, allowing the phenol to be withdrawn into storage tank 107 via line 17 and condenser A11. Subsequently, 100 kg of the liquid from reactor 105 (hereinafter referred to as "reaction solution (G5)") was withdrawn into storage tank 106 via line 16.

[0547] Analysis of the reaction solution (G5) by liquid chromatography revealed that phenyl(2-hydroxyethyl)carbamate, the carbamate intermediate corresponding to 2-aminoethanol, was obtained in a yield of 84% by mass, compared to the theoretical yield expected from the initial 2-aminoethanol.

[0548] Process (B5): Carbamate Compound Production The reaction was carried out using the apparatus shown in Figure 4. With line 45 closed, a mixture of 223 kg of anisole, 55 kg of toluene, and 6.6 kg (69 mol) of methanesulfonic acid was supplied from storage tank 401 to reactor 404 via line 41. Next, 100 kg of reaction solution (G6) (carbamate intermediate: 276 mol) and 65 kg of reaction solution (A6) (carbamate intermediate: 138 mol) were supplied from storage tanks 402 and 403 to reactor 404 via lines 42 and 43, respectively, and stirred to homogenize. The temperature of condenser A41 was set to 5°C, the liquid temperature of reactor 404 was set to 50°C, and the internal pressure was adjusted to 5 to 15 kPa to extract the water produced as a by-product along with the solvent into storage tank 405, and the reaction was carried out by returning only the upper layer of solvent to reactor 404 via line 44. After continuing the reaction for 12 hours, line 44 was closed and the internal pressure was adjusted to 3 kPa to distill off the toluene into storage tank 404. Then, at 50°C, 343 kg of water was transferred from storage tank 401 to reactor 404 via line 41 and stirred. After stopping the stirring and letting it stand for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing operation was performed a total of five times. Then, at 80°C, the internal pressure was reduced to 0.1 kPa and the solvent was removed into storage tank 401 via line 41. Subsequently, 145 kg of the liquid from reactor 404 was removed into storage tank 406 via line 45.

[0549] The reaction solution from storage tank 406 was transferred to storage tank 205 in Figure 2, and the carbamate compound was purified using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 80°C and the internal pressure was set to 0.1 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1.0 kg / hour via line 21 to separate the raw material from the carbamate compound. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (B5)") was 81 kg.

[0550] Analysis of the reaction solution (B5) by liquid chromatography revealed that the carbamate compound was 2-((phenoxycarbonyl)amino)ethyl-N ２ , N ６-Bis(phenoxycarbonyl)lignate in the reaction solution (A6) used ２ , N ６ - The yield was 90% by mass, relative to the theoretical yield expected from bis(phenoxycarbonyl)lysine. The carbamate compound was present in reaction solution (B5) at 84 wt%.

[0551] Process (C5): Pyrolysis of Carbamate Compounds The reaction was carried out using the apparatus shown in Figure 3. With line 34 closed, 89 kg of diphenyl carbonate was supplied from storage tank 301 to baffled SUS reactor 303 via line 32. The temperature of the multistage distillation column 304 was raised to 180°C, the jacket temperature of reactor 303 was heated to 230°C, and the pressure was reduced to 11-16 kPa. 11 kg of reaction solution (B5) recovered in process (B5) was heated to 120°C and supplied to reactor 303 via line 31 in about 12 minutes to perform pyrolysis of the carbamate compound. The phenol produced by pyrolysis was separated from diphenyl carbonate and the product 2-isocyanatoethyl-2,6-diisocyanatohexanoate in distillation column 304 and recovered in storage tank 305 via line 33 and condenser A31. After all of the reaction solution (B5) had been transferred, the extraction of phenol was continued at an internal temperature of 230°C. The reaction was terminated 3 hours after all of the reaction solution (B5) had been transferred. The mass of the reaction solution in reactor 303 was 42 kg. ¹H-NMR and gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (C5)") revealed that 2-isocyanatoethyl-2,6-diisocyanatohexanoate was produced in a yield of 84% by mass relative to the theoretical yield expected from the amount of carbamate compound used in step (C5). The concentration of 2-isocyanatoethyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (C5) was 5% by mass.

[0552] Process (D5): Light Boiling Separation Process 1 After performing Process (C5), light boiling separation was carried out immediately. The temperature of the multi-stage distillation column 304 was set to 90°C, the jacket temperature of the reactor 303 was set to 130°C, and the pressure was reduced to 0.1 kPa. In the distillation column 304, diphenyl carbonate was separated from 2-isocyanatoethyl-2,6-diisocyanatohexanoate and recovered in the storage tank 305 via line 33 and condenser A31. After distilling off the diphenyl carbonate for 5 hours, the distillation was terminated. The mass of the reaction solution in reactor 303 was 27.3 kg. Gas chromatography analysis of this reaction solution (hereinafter referred to as "reaction solution (D5)") revealed that the recovery rate of 2-isocyanatoethyl-2,6-diisocyanatohexanoate was 95% by mass compared to the theoretical yield expected from the amount of isocyanate compound obtained in step (C5), and the concentration of 2-isocyanatoethyl-2,6-diisocyanatohexanoate relative to the total mass of reaction solution (D5) was 7% by mass.

[0553] Process (E5): Light Boiling Separation Process 2 The reaction solution (D5) was transferred to the storage tank 205 shown in Figure 2, and light boiling cut-off was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 150°C and the internal pressure was set to 0.3 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to remove diphenyl carbonate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The liquid recovered from storage tank 203 (hereinafter referred to as "reaction solution (E5)") was 6 kg.

[0554] Gas chromatography analysis of the reaction solution (E5) revealed that the recovery rate of 2-isocyanatoethyl-2,6-diisocyanatohexanoate was 95% by mass, relative to the theoretical yield expected from the amount of isocyanate compound in the reaction solution (D5) used in step (E1). Furthermore, the concentration of 2-isocyanatoethyl-2,6-diisocyanatohexanoate relative to the total mass of the reaction solution (E5) was 30% by mass.

[0555] Process (F5): High-boiling separation process 2 The reaction solution (E5) was transferred to the storage tank 205 shown in Figure 2, and high-boiling cut was performed using the apparatus shown in Figure 2. The thin-film distillation apparatus 201 (manufactured by Kobe Steel Environmental Solutions Co., Ltd., Japan) was heated to 160°C and the internal pressure was set to 0.1 kPa. The reaction solution from storage tank 205 was supplied to the upper part of the thin-film distillation apparatus 201 at a rate of approximately 1 kg / hour via line 21 to recover 2-isocyanatoethyl-2,6-diisocyanatohexanoate. The generated gaseous components were transferred to storage tank 202 via line 22 and condenser A21. The amount of liquid recovered from storage tank 202 (hereinafter referred to as "reaction solution (F5)") was 4.3 kg.

[0556] ¹H-NMR, gas chromatography, and liquid chromatography analysis of reaction solution (F5) revealed that the recovery rate of 2-isocyanatoethyl-2,6-diisocyanatohexanoate was 100% by mass, relative to the theoretical yield expected from the isocyanate compound in the reaction solution (E1) used. The solution contained 83 wt% 2-isocyanatoethyl-2,6-diisocyanatohexanoate. 54.3 g of reaction solution (F5) and 217.2 g of acetonitrile (four times the weight of reaction solution (F5)) were added to a 200 mL flask and stirred to obtain a homogeneous solution. The solution in the flask was supplied to the raw material tank 500 of the pseudo-mobilization chromatograph shown in Figure 5, and the raw material tank 500 was maintained under a nitrogen atmosphere. In addition, a sufficient amount of acetonitrile was supplied to the eluent tank 510 as an eluent. The simulated mobile phase apparatus was operated while supplying liquid at a rate of 2.4 g / min from the raw material tank 500 and 7.4 g / min from the eluent tank 510, and withdrawing the liquid at a rate of 4.0 g / min to the raffinate tank 503 and 5.8 g / min to the extract tank 504. After operation, all solenoid valves were closed, the liquid in the raffinate tank 503 was heated to 80°C, and the developing solvent was removed by distillation under reduced pressure to 0.1 kPa, and the mixture was thoroughly removed to the storage tank 501 via line 51 and condenser E1. As a result, 42.4 g of the purified isocyanate composition obtained as the liquid phase component was transferred to the storage tank 502 via line 52. A portion of the mixture was sampled and analyzed by 1H-NMR and gas chromatography. The results showed that 2-isocyanatoethyl-2,6-diisocyanatohexanoate was present at a concentration of 97.9% by mass relative to the theoretical yield expected from the isocyanate compound in the reaction solution (F1), resulting in a yield of 92.4% by weight.

[0557] [Example 6] Step (A6): Production of carbamate intermediate from lysine monohydrochloride The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, a mixture of 30 kg (164 mol) of lysine monohydrochloride and 96 kg (triethylamine: 950 mol) was supplied from storage tank 101 through line 11 to baffled SUS reactor 104. Next, with line 16 closed, 217 kg (2306 mol) of phenol was supplied from storage tank 102 through line 15 to baffled SUS reactor 105, and 217 kg (1013 mol) of diphenyl carbonate was supplied from storage tank 103 through line 13 to the reactor 105. The liquid temperature in reactor 105 was adjusted to 50°C and homogenized by stirring, after which a mixture of lysine monohydrochloride and triethylamine was supplied from reactor 104 through line 14. After stirring for 7 hours, 125 kg of 2.5 M hydrochloric acid solution was supplied from storage tank 101 to reactor 105 via line 11, reactor 104, and line 14, and then stirred. 100 kg of anisole was supplied from storage tank 102 to reactor 105 via line 12, and then stirred. After standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing with 2.5 M hydrochloric acid solution was performed three times. Then, 200 kg of water was added to reactor 105 in the same manner as the supply method of the 2.5 M hydrochloric acid solution described above, stirred, and after standing for 15 minutes, the upper aqueous phase was removed using a dip nozzle. The reaction solution was then heated to 80°C, and the internal pressure was reduced to approximately 1 kPa, allowing the anisole solvent, etc., to be removed to storage tank 107 via line 17 and condenser A11. Then, 458 kg of toluene was added to reactor 105 via line 13, and reprecipitation purification was performed. Subsequently, the liquid phase was withdrawn from line 16, and 458 kg of toluene was added again to wash the solid. This process of withdrawing the liquid phase from line 16 was repeated twice. The reactor was then heated to 80°C, and the internal pressure was increased to approximately 1 kPa to dry the solid, and 62 kg of solid (hereinafter referred to as "solid (A6)") was recovered from the stirring tank 105.

[0558] Analysis of the solid (A6) by liquid chromatography revealed that N is the carbamate intermediate corresponding to lysine monohydrochloride. ２ , N ６-Bis(phenoxycarbonyl)lysine was obtained in a yield of 60% by mass, exceeding the theoretical yield expected from the lysine monohydrochloride used in the preparation. ¹H-NMR and liquid chromatography analysis of the solid (A6) revealed a carbamate intermediate content of 77 wt%.

[0559] Process (G6): Production of carbamate intermediate from 2-aminoethanol. The reaction was carried out using the apparatus shown in Figure 1. With line 14 closed, 20 kg (327 mol) of 2-aminoethanol and 31 kg (327 mol) of phenol were supplied from storage tanks 101 and 102 via line 11 to baffled SUS reactor 104, respectively. Next, with line 16 closed, 92 kg (982 mol) of phenol was supplied from storage tank 102 via line 15 to baffled SUS reactor 105, and 105 kg (491 mol) of diphenyl carbonate was supplied from storage tank 103 via line 13 to reactor 105. The liquid temperature in reactor 105 was adjusted to 50°C and homogenized by stirring. Then, a mixture of 2-aminoethanol and phenol was supplied from reactor 104 via line 14 to reactor 105 over a period of 1.5 hours. After stirring was continued for 4 hours, the reaction solution was then heated to 80°C and the internal pressure was reduced to approximately 0.1 kPa, allowing the phenol to be extracted into storage tank 107 via line 17 and condenser A11. Subsequently, 100 kg of the liquid from reactor 105 (hereinafter referred to as "reaction solution (G6)") was extracted into storage tank 106 via line 16.

[0560] Analysis of the reaction solution (G6) by liquid chromatography revealed that phenyl(2-hydroxyethyl)carbamate, the carbamate intermediate corresponding to 2-aminoethanol, was obtained in a yield of 84% by mass, compared to the theoretical yield expected from the initial 2-aminoethanol.

[0561] Process (B6): Carbamate Compound Production The reaction was carried out using the apparatus shown in Figure 4. With line 45 closed, a mixture of 200 kg of anisole, 49 kg of toluene, and 5.9 kg (62 mol) of methanesulfonic acid was supplied from storage tank 401 to reactor 404 via line 41. Next, 89 kg of reaction solution G6 (carbamate intermediate: 246 mol) and 62 kg of solid (A6) (carbamate intermediate: 123 mol) were supplied from storage tanks 402 and 403 to reactor 404 via lines 42 and 43, respectively, and stirred to homogenize. The temperature of condenser A41 was set to 5°C, the liquid temperature of reactor 404 to 50°C, and the internal pressure was adjusted to 5 to 15 kPa to extract the water produced as a by-product along with the solvent into storage tank 405, and the reaction was carried out by returning only the upper layer of solvent to reactor 404 via line 44. After continuing the reaction for 12 hours, line 44 was closed and the internal pressure was adjusted to 3 kPa to distill off the toluene into storage tank 404. Then, at 50°C, 343 kg of water was transferred from storage tank 401 to reactor 404 via line 41 and stirred. After stopping the stirring and letting it stand for 15 minutes, the upper aqueous phase was removed using a dip nozzle. This washing operation was performed a total of five times. Then, at 80°C, the internal pressure was reduced to 0.1 kPa to remove the solvent into storage tan...

Claims

1. A method for producing an isocyanate composition, comprising: (I) reacting at least one selected from the group consisting of amino acids, amino acid hydrochlorides, and amino alcohol compounds with a carbonate ester to obtain a carbamate intermediate represented by the following formula (1); (II) esterifying the carbamate intermediate represented by the following formula (1) to obtain a carbamate compound represented by the following formula (2); and (III) thermally decomposing the carbamate compound represented by the following formula (2) to obtain an isocyanate compound represented by the following formula (3). (In the formula, R １１ R represents an aliphatic hydrocarbon group having a valency of 2 to 4 and having 1 to 40 carbon atoms, or an aromatic group having a valency of 2 to 3 and having 6 to 40 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having a valency of 2 to 4 and having 1 to 40 carbon atoms and having one or more atoms selected from the group consisting of oxygen, nitrogen, and sulfur atoms. １２ (where n11 is a monovalent aliphatic group, aromatic group, or aralkyl group having 1 to 20 carbon atoms. n11 is an integer from 1 to 3. n12 is an integer from 1 to 3. n11 + n12 is 4 or less.) (In the formula, R ２１ R represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms and being monovalent or quadrivalent, or an aromatic group having 6 to 40 carbon atoms and being monovalent or trivalent, or an aliphatic hydrocarbon group or aromatic group having 1 to 4 carbon atoms and being monovalent or quadrivalent, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms. ２２ (where n21 is an integer from 1 to 4.) (In the formula, R ３１ n31 represents an aliphatic hydrocarbon group having a valency of 1 to 4 and 1 to 40 carbon atoms, or an aromatic group having a valency of 1 to 3 and 6 to 40 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having a valency of 1 to 4 and 1 to 4 carbon atoms, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms.

2. The process includes a step (IV) of distilling and purifying the composition produced in step (III) above to obtain an isocyanate composition, wherein the isocyanate composition contains a carbonyl compound represented by the following formula (4), and the content ratio of the carbonyl compound to the total mass of the isocyanate composition is 2.0 ppm by mass or more, or 1.0 × 10⁻⁶. ５ A method for producing the isocyanate composition according to claim 1, wherein the mass is ppm or less. (In the formula, R ４１ is an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, or an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, and having one or both of 1 to 4 ester groups and a nitrogen atom, and R ４２ (wherein X is an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen, and X represents an oxygen atom or an NH group.) 3. The method for producing an isocyanate composition according to claim 1 or 2, wherein the solvent used in the step (I) is a mixed solvent of a hydroxy compound represented by the following formula (5) and water. (In formula (5), ring A ５１ is an aromatic hydrocarbon ring having 6 to 20 carbon atoms. R ５１ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, or a hydroxy group. R ５１ may be bonded to ring A ５１ to form a ring structure. Further, n51 is an integer of 1 or more and 10 or less.) 4. A method for producing an isocyanate composition according to claim 1 or 2, wherein step (I) includes a step of reacting an amino acid or amino acid hydrochloride with a carbonate ester in the presence of an inorganic base, and further comprises a step of removing any remaining inorganic base or salt thereof by washing with water.

5. The method for producing the isocyanate composition according to claim 1 or 2, wherein the isocyanate composition contains an isocyanate compound in an amount of 1% by mass or more and 99% by mass or less.

6. A method for producing an isocyanate composition according to claim 1 or 2, wherein the thermal decomposition in step (III) is carried out in the presence of a solvent.

7. A method for producing an isocyanate composition according to claim 1 or 2, wherein step (I) comprises, in this order, a step (X) of reacting the amino alcohol compound with a compound having a phenolic hydroxyl group to obtain a phenol salt of the amino alcohol compound, and a step (Y) of reacting a diester carbonate with the phenol salt of the amino alcohol compound to obtain the carbamate intermediate.

8. A method for producing an isocyanate composition according to claim 7, further comprising the step (Z) of purifying the carbamate intermediate by distillation.

9. The method for producing the isocyanate composition according to claim 1 or 2, wherein the amino alcohol compound is a compound represented by the following formula (6). (In equation (6), R ６１ (where n61 is an n61+1 valent organic group, and n61 is an integer between 1 and 3.) 10. The method for producing an isocyanate composition according to claim 7, wherein in step (I), the production ratio of at least one selected from the group consisting of a cyclic compound represented by the following general formula (7) and a carbamate carbonate compound represented by the following general formula (8) is 2 to 10 mol% with respect to the total amount of the carbamate intermediate. (In general formula (7), R ７１ is an n71+2 valent organic group, R ７１ R in equation (6) is ６１ It is the same organic group. n71 is a non-negative integer, and is the number obtained by subtracting 1 from n61 in equation (6). (In general formula (8), R ８１ , R ８３ R is a monovalent organic group, and each is a residue obtained by independently removing one hydroxyl group from a hydroxyl compound. ８２ (where n81 + n82 + 1-valent organic group, n81 is a non-negative integer, and n82 is a non-negative integer.) 11. A method for producing an isocyanate composition according to claim 1 or 2, comprising a step of subjecting the composition containing the carbamate compound produced in step (II) to a distillation step to purify the carbamate compound, wherein the composition containing the carbamate compound contains one or more compounds selected from the group consisting of alkyl carbamate compounds represented by the following general formula (9) and carbamate carbonate compounds represented by the following general formula (8). (In general formula (9), n91 is an integer between 1 and 4, inclusive. ９１ , R ９２ Each is at least one selected from the group consisting of a hydrogen atom or a group represented by the following general formula (10) and a group represented by the following general formula (11), and R in the formula ９１ , R ９２ At least one of them is a group represented by the following general formula (11): R ９３ (This is a residue obtained by removing n91 hydroxyl groups from an alcohol compound.) (In general formula (10), n101 is an integer of 0 or 1. R １０１ R is a divalent organic group having 1 to 30 carbon atoms, which may have substituents. １０２ (This is a monovalent organic group having 1 to 30 carbon atoms, which may have substituents.) (In general formula (11), n111 is an integer of 0 or 1. R １１１ R is a divalent organic group having 30 or fewer carbon atoms, which may have substituents. １１２ (This is a residue obtained by removing one hydroxyl group from an alcohol compound.) (In general formula (8), R ８１ , R ８３ R is a monovalent organic group, and each is a residue obtained by independently removing one hydroxyl group from a hydroxyl compound. ８２ (where n81 + n82 + 1-valent organic group, n81 is a non-negative integer, and n82 is a non-negative integer.) 12. The method for producing an isocyanate composition according to claim 4, wherein the inorganic base is one or more selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

13. A method for producing an isocyanate composition according to claim 1 or 2, wherein the carbonate ester is a compound represented by the following general formula (12). (R in general formula (12)) １２１ (This indicates a monovalent aliphatic group, aromatic group, or aralkyl group having 1 to 20 carbon atoms.) 14. R in equation (1) above １２１ A method for producing an isocyanate composition according to claim 1 or 2, wherein is an aryl group.

15. The method for producing an isocyanate composition according to claim 1 or 2, wherein the amino acid is one or more selected from the group consisting of lysine, glycine, alanine (each isomer), valine (each isomer), leucine (each isomer), aspartic acid (each isomer), glutamine, glutamic acid (each isomer), ornithine, lysine (each isomer), phenylalanine (each isomer), cystine (each isomer), methionine (each isomer), serine (each isomer), threonine (each isomer), and 2,6-diaminoheptanedione, and each isomer may be either an optical isomer or a positional isomer or both, and the positional isomer may be either an α-amino acid or a β-amino acid or both.

16. A method for producing an isocyanate composition according to claim 1 or 2, further comprising step (V) of purifying the isocyanate compound from a liquid containing the isocyanate compound represented by formula (3) by distillation and / or chromatographic separation.

17. The method for producing an isocyanate composition according to claim 16, wherein the mobile phase used for chromatographic separation is an organic solvent containing at least one compound that is inert to the isocyanate compound and does not have an aromatic ring.

18. The method for producing an isocyanate composition according to claim 16, wherein the stationary phase used for chromatographic separation is a stationary phase that utilizes π-π interactions.

19. The method for producing an isocyanate composition according to claim 16, wherein, in the case where step (V) is a chromatographic separation step, the impurities to be separated are at least one selected from the group consisting of compounds represented by the following general formula (13), compounds represented by the following general formula (4), compounds represented by the following general formula (14), and carbonate esters represented by the following general formula (12). (In general formula (13), n131 represents an integer between 1 and 8, inclusive. １３１ R is a divalent organic group with 1 to 30 carbon atoms. １３２ (This refers to a monovalent organic group having between 1 and 30 carbon atoms.) (In the formula, R ４１ is an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, or an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, and having one or both of 1 to 4 ester groups and a nitrogen atom, and R ４２ (wherein X is an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen, and X represents an oxygen atom or an NH group.) (In general formula (14), n141 and n142 represent integers between 0 and 8, and the sum of n141 and n142 is n31 in formula (3). １４１ R represents an aliphatic hydrocarbon group having a valency of 1 to 40 carbon atoms and being divalent to 40 or less, or an aromatic group having a valency of 6 to 40 carbon atoms and being monovalent to 3 or less, or an aliphatic hydrocarbon group or aromatic group having a valency of 1 to 4 carbon atoms and being monovalent to 4 or less, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms. １４２ (This is a monovalent aromatic hydrocarbon group having 1 to 30 carbon atoms, which may have substituents.) (R in general formula (12)) １２１ (This indicates a monovalent aliphatic group, aromatic group, or aralkyl group having 1 to 20 carbon atoms.) 20. A method for producing an isocyanate composition according to claim 18, wherein the stationary phase is a synthetic resin having an aromatic ring.

21. The method for producing an isocyanate composition according to claim 16, wherein, when step (V) is a chromatographic separation step, the chromatographic separation is a pseudo-mobility-bed chromatography method.

22. The method for producing an isocyanate composition according to claim 16, wherein, if step (V) is a chromatographic separation step, the method further includes a step of heating a liquid film of the isocyanate composition and performing distillation before the chromatographic separation step.

23. An isocyanate composition containing an isocyanate and a carbonyl compound represented by the following general formula (4), wherein the content of the isocyanate relative to the total mass of the isocyanate composition is 90% by mass or more, and the content of the carbonyl compound relative to the total mass of the isocyanate composition is 2.0 ppm by mass or more, or 1.0 × 10 ５ An isocyanate composition having a mass of ppm or less. (In the formula, R ４１ is an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, or an aliphatic hydrocarbon group having 1 to 40 carbon atoms, with a valency of 2 to 4, and having one or both of 1 to 4 ester groups and a nitrogen atom, and R ４２ (wherein X is an aliphatic group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may contain oxygen, and X represents an oxygen atom or an NH group.) 24. The isocyanate composition according to claim 23, wherein the isocyanate is an isocyanate compound represented by the following general formula (3). (In the formula, R ３１ n31 represents an aliphatic hydrocarbon group having a valency of 1 to 4 and 1 to 40 carbon atoms, or an aromatic group having a valency of 1 to 3 and 6 to 40 carbon atoms, or an aliphatic hydrocarbon group or aromatic group having a valency of 1 to 4 and 1 to 4 carbon atoms, and having one or more atoms selected from the group consisting of 1 to 4 ester groups, nitrogen atoms, and sulfur atoms.

25. R in equation (3) above ３１ The composition according to claim 24, wherein the amino acid backbone is present.

26. Furthermore, the composition contains either or both of the compound represented by formula (15) below and the ether compound, and the respective content of the compound represented by formula (15) below or the ether compound relative to the total mass of the isocyanate composition is 2.0 ppm by mass or more, or 1.0 × 10⁻⁶. ５ The isocyanate composition according to claim 23, wherein the mass is ppm or less. (In the formula, R １５１ R represents a monovalent aliphatic hydrocarbon group having 1 to 40 carbon atoms, or a monovalent aromatic group having 6 to 40 carbon atoms, or a monovalent aliphatic hydrocarbon group or aromatic group having 1 to 40 carbon atoms and having one or both of 1 to 4 ester groups and a nitrogen atom. １５２ (This indicates a monovalent aromatic group with 1 to 20 carbon atoms.) 27. The isocyanate composition according to claim 26, wherein the compound represented by formula (15) is a carbamate group-containing compound, a carbonate ester, or an ester compound.

Images