Method for producing thiourethane resin raw material, method for producing polymerizable composition, and method for producing cured product

Abstract

To provide a method for producing a thiourethane resin raw material which enables production of a thiourethane resin by using a thiourethane resin as a starting material.SOLUTION: A method for producing a thiourethane resin raw material includes: a step 1 of reacting a thiourethane resin and an alcohol compound in the presence of an amine compound (XA) which is a tertiary amine compound to obtain a reaction liquid containing a polycarbamate composition (R) containing a polycarbamate compound, a polythiol composition (P) containing a polythiol compound (A1) having no ester bond in the molecule, and a polythiol composition (Q) containing a polythiol compound (A2) having at least one or more ester bonds in the molecule; and a step 2 of separating at least any one of the polycarbamate composition (R), the polythiol composition (P), a carboxylic acid (QC) having a mercapto group and polyalcohol (QA), using the reaction liquid obtained in the step 1.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a thiourethane resin raw material, a method for producing a polymerizable composition, and a method for producing a cured product. [Background technology]

[0002] 2. Description of the Related Art Plastic lenses, which are lenses containing resin, are lighter and less likely to break than inorganic lenses, and can be dyed, and therefore have rapidly become more widely used in recent years for applications such as eyeglass lenses and camera lenses. For example, various studies have been conducted on lenses containing thiourethane resins (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 63-46213 [Patent Document 2] Japanese Patent Application Publication No. 2-270859 [Patent Document 3] Japanese Patent Application Publication No. 7-252207 Summary of the Invention [Problem to be solved by the invention]

[0004] As raw materials for producing a thiourethane resin (hereinafter also referred to as "thiourethane resin raw materials"), a polythiol composition and a polyisocyanate composition are usually used. The polyisocyanate composition is produced, for example, from a polyamine compound. The polyamine compound, which is a raw material for the polyisocyanate composition, also corresponds to a thiourethane resin raw material (i.e., a raw material for producing a thiourethane resin).

[0005] A lens (for example, a spectacle lens) containing a thiourethane resin is produced by cutting a molded body containing a thiourethane resin. As a result, the lens manufacturing process may generate a large amount of cutting powder containing thiourethane resin as waste. Furthermore, in the process of producing a molded article containing a thiourethane resin, molded or processed articles may be produced. Additionally, used eyeglass lenses may be disposed of as waste by consumers. Conventionally, waste materials such as cutting chips, defective moldings, defective processing products, and used eyeglass lenses have been simply burned or buried as industrial waste, and have not been effectively utilized. However, from the viewpoint of effective use of materials (i.e., recycling), a technique for producing a thiourethane resin raw material using waste cutting powder containing thiourethane resin, or defective molding or processing products as a starting raw material is desired. The produced thiourethane resin raw material can be used as a raw material for producing thiourethane resin. Furthermore, there is a demand for a technique for producing a thiourethane resin raw material using a thiourethane resin as a starting material, not limited to using a thiourethane resin contained in cutting powder or defective molding or processing products as a starting material.

[0006] An object of the present disclosure is to provide a method for producing a thiourethane resin raw material, which can produce a thiourethane resin raw material using a thiourethane resin as a starting raw material, as well as a method for producing a polymerizable composition and a method for producing a cured product using the thiourethane resin raw material obtained by this production method. [Means for solving the problem]

[0007] Means for solving the above problems include the following aspects. <1> A step 1 of reacting a thiourethane resin obtained by curing a polymerizable composition including a polythiol composition including a polythiol compound having no ester bond in the molecule, a polythiol composition including a polythiol compound having at least one or more ester bonds in the molecule, and a polyisocyanate composition including a polyisocyanate compound with an alcohol compound in the presence of an amine compound (XA) which is a tertiary amine compound, to obtain a reaction liquid including a polycarbamate composition (R) including a polycarbamate compound, a polythiol composition (P) including a polythiol compound (A1) having no ester bond in the molecule, and a polythiol composition (Q) including a polythiol compound (A2) having at least one or more ester bonds in the molecule; a step 2 of separating at least one of the polycarbamate composition (R), the polythiol composition (P), a carboxylic acid (QC) having a mercapto group obtained by decomposing the polythiol compound (A2), and a polyalcohol (QA) obtained by decomposing the polythiol compound (A2) using the reaction liquid obtained in the step 1; A method for producing a thiourethane resin raw material comprising the steps of: <2> The step 2 includes a step 2a of adding an alkali metal-containing base and water to the reaction liquid obtained in the step 1 and performing extraction to separate an aqueous phase (S1) containing an alkali metal salt of the polythiol compound (A1), an alkali metal salt of a carboxylic acid having an alkali metal salt of a mercapto group obtained by decomposing the polythiol compound (A2), and the polyalcohol (QA) obtained by decomposing the polythiol compound (A2) from a polycarbamate composition (R). <1> A method for producing the thiourethane resin raw material described in claim 1. <3> The step 2 includes a step 2b of separating the aqueous phase (S2) containing the alkali metal salt of the carboxylic acid having a mercapto group and the polyalcohol (QA) from the polythiol composition (P) by adding an organic solvent and an acid to the aqueous phase (S1). <2> A method for producing the thiourethane resin raw material described in claim 1. <4> The step 2 includes a step 2c of adding an organic solvent and an acid to the aqueous phase (S2) to perform extraction, thereby separating the aqueous phase (S3) containing the polyalcohol (QA) and inorganic salt from the carboxylic acid (QC). <3> A method for producing the thiourethane resin raw material described in claim 1. <5> The step 2 includes a step 2d of isolating the polyalcohol (QA) from the aqueous phase (S3) by removing water and then separating the inorganic salts. <4> A method for producing the thiourethane resin raw material described in claim 1. <6> The method further includes a step 3, prior to the step 2, of adding an acid and water to the reaction solution obtained in the step 1 to separate the tertiary amine compound (XA) into an aqueous phase. <1> ~ <5> 13. A method for producing a thiourethane resin raw material according to claim 12. <7> The polythiol composition (P) is 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, At least one selected from the group consisting of <1> ~ <6> 13. A method for producing a thiourethane resin raw material according to claim 12. <8> The polythiol composition (Q) is Pentaerythritol tetrakis(3-mercaptopropionate), Pentaerythritol tetrakis(2-mercaptoacetate), Trimethylolpropane tris(3-mercaptopropionate) and Pentaerythritol tetrakis(3-mercaptobutyrate) At least one selected from the group consisting of <1> ~ <7> 13. A method for producing a thiourethane resin raw material according to claim 12. <9> The polyisocyanate composition includes at least one selected from the group consisting of pentamethylene diisocyanate, hexamethylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane, bis(isocyanatocyclohexyl)methane, 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and phenylene diisocyanate. <1> ~ <8> 13. A method for producing a thiourethane resin raw material according to claim 12. <10> The carboxylic acid (QC) is at least one selected from the group consisting of 3-mercaptopropionic acid, 2-mercaptoacetic acid, and 3-mercaptobutanoic acid. <1> ~ <9> 13. A method for producing a thiourethane resin raw material according to claim 12.

[0008] <11> The polyalcohol (QA) is at least one selected from the group consisting of pentaerythritol and trimethylolpropane. <1> ~ <10> 13. A method for producing a thiourethane resin raw material according to claim 12. <12> <1> ~ <11> A method for producing a polymerizable composition, comprising the step of producing a polymerizable composition using at least one of the polycarbamate composition (R), the polythiol composition (P), the carboxylic acid (QC), and the polyalcohol (QA), which are thiourethane resin raw materials obtained by the method for producing a thiourethane resin raw material described in any one of the above. <13> In the step of producing the polymerizable composition, the polymerizable composition is produced by mixing at least one of a polythiol composition containing a polythiol compound (A2) obtained by reacting the carboxylic acid (QC) and the polyalcohol (QA) and the polythiol composition (P) which is a raw material for the thiourethane resin, with a polyisocyanate composition. <12> A method for producing the polymerizable composition according to claim 1.

[0009] <14> <12> or <13> A step of producing a polymerizable composition by the method for producing a polymerizable composition according to the above-mentioned item 1, a step of obtaining a cured product by curing the polymerizable composition; A method for producing a cured product comprising the steps of: Effect of the Invention

[0010] According to the present disclosure, there is provided a method for producing a thiourethane resin raw material, which can produce a thiourethane resin raw material using a thiourethane resin as a starting raw material, as well as a method for producing a polymerizable composition using the thiourethane resin raw material obtained by this production method, and a method for producing a cured product. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a diagram showing each step of producing a thiourethane resin raw material from thiourethane resin powder R1 in Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In the present disclosure, the term "step" refers not only to an independent step, but also to a step that cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved. In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component contained in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified. In the numerical ranges described in the present disclosure in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples.

[0013] [Method for producing thiourethane resin raw material] The method for producing a thiourethane resin raw material according to the present disclosure includes: A step 1 of reacting a thiourethane resin obtained by curing a polymerizable composition including a polythiol composition including a polythiol compound having no ester bond in the molecule, a polythiol composition including a polythiol compound having at least one or more ester bonds in the molecule, and a polyisocyanate composition including a polyisocyanate compound with an alcohol compound in the presence of an amine compound (XA) which is a tertiary amine compound, to obtain a reaction liquid including a polycarbamate composition (R) including a polycarbamate compound, a polythiol composition (P) including a polythiol compound (A1) having no ester bond in the molecule, and a polythiol composition (Q) including a polythiol compound (A2) having at least one or more ester bonds in the molecule; a step 2 of separating at least one of the polycarbamate composition (R), the polythiol composition (P), a carboxylic acid (QC) having a mercapto group obtained by decomposing the polythiol compound (A2), and a polyalcohol (QA) obtained by decomposing the polythiol compound (A2) using the reaction liquid obtained in the step 1; The method includes:

[0014] According to the manufacturing method of the present disclosure, a thiourethane resin raw material can be manufactured using a thiourethane resin as a starting material. The reason why such an effect is achieved is presumed to be as follows. In the production method of the present disclosure, it is believed that by reacting a thiourethane resin with an alcohol compound in the presence of an amine compound (XA), which is a tertiary amine compound, the thiourethane resin is chemically decomposed, and a thiourethane resin raw material is obtained as a decomposition product of the thiourethane resin.

[0015] In the present disclosure, the term "thiourethane resin raw material" refers to a raw material for producing a thiourethane resin. The thiourethane resin raw material includes not only raw materials capable of producing a thiourethane resin by reacting themselves, such as the polythiol composition (P), but also compounds such as the carboxylic acid (QC), polyalcohol (QA), and polycarbamate composition (R) that are further reacted as necessary and then used as a reactant for synthesizing a thiourethane resin.

[0016] In the manufacturing method of the present disclosure, the thiourethane resin and the alcohol compound are reacted in the presence of an amine compound (XA) which is a tertiary amine compound, thereby making it possible to suppress the generation of by-products due to unintended side reactions. Therefore, the purity of the thiourethane resin raw material separated in step 2 tends to be high. For example, the polythiol compound (A2) having at least one or more ester bonds in the molecule obtained in step 1 is prone to side reactions, but the alcohol compound and tertiary amine compound used in step 1 tend not to react easily with the polythiol compound (A2). This makes it possible to separate carboxylic acid (QC) and polyalcohol (QA) with high purity in step 2.

[0017] [Process 1] The manufacturing method of the present disclosure includes a step 1 in which a thiourethane resin obtained by curing a polymerizable composition including a polythiol composition (hereinafter also referred to as a "first polythiol composition") including a polythiol compound having no ester bonds in its molecule, a polythiol composition (hereinafter also referred to as a "second polythiol composition") including a polythiol compound having at least one or more ester bonds in its molecule, and a polyisocyanate composition including a polyisocyanate compound is reacted with an alcohol compound in the presence of an amine compound (XA) that is a tertiary amine compound to obtain a reaction liquid including a polycarbamate composition (R) including a polycarbamate compound, a polythiol composition (P) including a polythiol compound (A1) having no ester bonds in its molecule, and a polythiol composition (Q) including a polythiol compound (A2) having at least one or more ester bonds in its molecule.

[0018] In the present disclosure, the polythiol composition may contain components other than the polythiol compound as impurities. The polythiol composition preferably contains at least one polythiol compound as a main component. For example, the first polythiol composition preferably contains a polythiol compound having no ester bond in the molecule as a main component, and the second polythiol composition preferably contains a polythiol compound having at least one ester bond in the molecule as a main component. The polythiol composition (P) preferably contains a polythiol compound (A1) as a main component, and the polythiol composition (Q) preferably contains a polythiol compound (A2) as a main component.

[0019] Here, "the polythiol composition contains at least one polythiol compound as a main component" means that the total content of the at least one polythiol compound relative to the total amount of the polythiol composition is 50% or more. The total content of at least one polythiol compound relative to the total amount of the polythiol composition is preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more.

[0020] In the present disclosure, a composition "contains as a main component" a certain component (hereinafter referred to as "component X") means that the content of component X (when component X consists of two or more compounds, the total content of the two or more compounds) is 50% or more of the total amount of the composition. The content of the main component, component X, is preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more, based on the total amount of the composition.

[0021] The "%" in the explanation of the above term "contains as a main component" means the ratio (area %) of the total area of ​​all peaks of component X (e.g., at least one polythiol compound) to the total area of ​​all peaks of the composition (e.g., a polythiol composition) determined by high performance liquid chromatography.

[0022] (Thiourethane resin) The thiourethane resin is a starting material in the manufacturing method of the present disclosure. The thiourethane resin is a reaction product obtained by curing a polymerizable composition including a first polythiol composition, a second polythiol composition, and a polyisocyanate composition.

[0023] <First polythiol composition> The first polythiol composition is a polythiol composition containing a polythiol compound that does not have an ester bond in the molecule.The polythiol compound that does not have an ester bond in the molecule is not particularly limited as long as it does not have an ester bond in the molecule and has two or more mercapto groups.

[0024] Examples of polythiol compounds having no ester bond in the molecule include 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 2,5-dimercaptomethyl-1,4-dithiane, bis(2-mercaptoethyl)sulfide, methanedithiol, 1,2-ethanedithiol, 1,2 ,3-propane trithiol, tetrakis(mercaptomethylthiomethyl)methane, tetrakis(2-mercaptoethylthiomethyl)methane, tetrakis(3-mercaptopropylthiomethyl)methane, bis(2,3-dimercaptopropyl)sulfide, 2,5-dimercapto-1,4-dithiane, 2,5-dimercaptomethyl-2,5-dimethyl-1,4-dithiane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, etc. The polythiol compound having no ester bond in the molecule may be one type alone or two or more types in combination.

[0025] A polythiol compound having no ester bond in the molecule is 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, It is preferable that the composition contains at least one selected from the group consisting of:

[0026] <Second Polythiol Composition> The second polythiol composition is a polythiol composition containing a polythiol compound having at least one or more ester bonds in the molecule. The polythiol compound having at least one or more ester bonds in the molecule is not particularly limited as long as it has one or more ester bonds in the molecule and two or more mercapto groups.

[0027] A polythiol compound having at least one ester bond in the molecule is Pentaerythritol tetrakis(3-mercaptopropionate), Pentaerythritol tetrakis(2-mercaptoacetate), Trimethylolpropane tris(3-mercaptopropionate), Pentaerythritol tetrakis(3-mercaptobutyrate) and Diethylene glycol bis(3-mercaptopropionate) It is preferable that the composition contains at least one selected from the group consisting of Pentaerythritol tetrakis(3-mercaptopropionate), Pentaerythritol tetrakis(2-mercaptoacetate), Trimethylolpropane tris(3-mercaptopropionate) and Pentaerythritol tetrakis(3-mercaptobutyrate) It is more preferable that the composition contains at least one selected from the group consisting of:

[0028] In the present disclosure, a polythiol composition containing a polythiol compound that does not have an ester bond in the molecule and a polythiol compound that has an ester bond in the molecule is classified as a second polythiol composition.

[0029] <Polyisocyanate composition> The polyisocyanate composition contains a polyisocyanate compound. The polyisocyanate compound is not particularly limited as long as it is a compound containing two or more isocyanate groups. The polyisocyanate composition preferably contains a polyisocyanate compound as a main component. The polyisocyanate composition may be, for example, one type of polyisocyanate compound, a mixture of two or more types of polyisocyanate compounds, or a mixture of one or more types of polyisocyanate compounds and other components. The polyisocyanate composition preferably contains at least one selected from the group consisting of pentamethylene diisocyanate, hexamethylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane, bis(isocyanatocyclohexyl)methane, 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and phenylene diisocyanate.

[0030] The polyisocyanate composition more preferably contains at least one selected from the group consisting of m-xylylene diisocyanate, 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, and 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane.

[0031] The thiourethane resin used in the manufacturing method of the present disclosure is preferably recovered during at least one of the processes of manufacturing eyeglass lenses, manufacturing eyeglasses, and disposing of eyeglasses. This embodiment realizes recycling of the thiourethane resin, which is a material for eyeglass lenses. Where: The manufacturing process of eyeglass lenses means the process of producing resin by mixing monomers, which are resin raw materials, and casting polymerization, and / or the process of cutting a resin molded body to obtain eyeglass lenses. The eyeglass manufacturing process refers to the process of manufacturing eyeglasses by combining eyeglass lenses with other components such as eyeglass frames. The eyeglasses disposal process refers to the process of disposing of eyeglasses that have been manufactured but are no longer needed, used eyeglasses, etc. In either process, thiourethane resin, a material used in eyeglass lenses, can be generated as waste.

[0032] The thiourethane resin used in the manufacturing method of the present disclosure may be a powder containing a thiourethane resin (hereinafter also referred to as "thiourethane resin powder").

[0033] The thiourethane resin powder is not particularly limited, and may be, for example, cutting powder of a molded body containing a thiourethane resin and / or the above cutting powder that has been sieved. The cutting dust of a molded body containing a thiourethane resin is generated, for example, when a molded body containing a thiourethane resin is cut to produce an optical material (for example, a lens). The thiourethane resin powder may also be a lump powder obtained by crushing and / or pulverizing a molded body containing a thiourethane resin.

[0034] (Alcohol compounds) The alcohol compound functions as a decomposing agent for the thiourethane resin, which is the starting material. The alcohol compound may be a monoalcohol compound containing only one hydroxy group, or a polyol compound containing two or more hydroxy groups.

[0035] From the viewpoint of further improving the reactivity with the thiourethane resin, the molecular weight of the alcohol compound is preferably 1,000 or less, more preferably 500 or less, even more preferably 300 or less, and even more preferably 200 or less. The lower limit of the molecular weight of the alcohol compound is, for example, 40 or more, preferably 50 or more, and more preferably 60 or more.

[0036] The alcohol compound preferably includes an alcohol compound having a boiling point of 135° C. to 250° C. (hereinafter, also referred to as "alcohol compound A"). In this disclosure, boiling point means the boiling point at 1 atmosphere (101325 Pa).

[0037] The proportion of the alcohol compound A in the total amount of the alcohol compounds is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, and further preferably 80% by mass to 100% by mass.

[0038] From the viewpoint of performance such as reactivity as a decomposition agent for thiourethane resin, the alcohol compound is preferably an alcohol compound having one hydroxy group. As an alcohol compound having one hydroxyl group, Preferred are benzyl alcohol, phenethyl alcohol, 2-octanol, 2-ethyl-1-hexanol, 1-decanol, 1-nonanol, 1-octanol, 1-heptanol, 1-hexanol, 1-pentanol, propylene glycol, and ethylene glycol; More preferred are benzyl alcohol, phenethyl alcohol, 1-decanol, 1-nonanol, 1-octanol, 1-heptanol, 1-hexanol and 1-pentanol.

[0039] -Amount of alcohol compound- The charge mass ratio of the alcohol compound to the thiourethane resin (that is, the charge mass ratio [alcohol compound / thiourethane resin]) can be appropriately adjusted, and is preferably 0.10 to 20. When the charge mass ratio [alcohol compound / thiourethane resin] is 0.10 or more, the production of the polythiol composition is further promoted. When the charge mass ratio [alcohol compound / thiourethane resin] is 20 or less, the alcohol compound can be further prevented from remaining in the reaction mixture. The charge mass ratio [alcohol compound / thiourethane resin] is more preferably 0.30 to 15, further preferably 0.40 to 10, and further preferably 2.7 to 4.1.

[0040] The number of millimoles of the alcohol compound charged per 1 g of the thiourethane resin is preferably 1.0 mmol / g to 100 mmol / g, more preferably 2.0 mmol / g to 80 mmol / g, even more preferably 5.0 mmol / g to 60 mmol / g, and still more preferably 25 mmol / g to 37.5 mmol / g.

[0041] The charge equivalent of the alcohol compound relative to the thiourethane resin (charge equivalent [alcohol compound / thiourethane resin]) is preferably 1-25, more preferably 1.2-20, further preferably 1.5-15, and further preferably 10-15. When the charge equivalent [alcohol compound / thiourethane resin] is 1 or more, the production of the polythiol composition is further promoted. When the charge equivalent [alcohol compound / thiourethane resin] is 50 or less, the alcohol compound can be further prevented from remaining in the reaction mixture. Here, the charge equivalent of the alcohol compound relative to the thiourethane resin (charge equivalent [alcohol compound / thiourethane resin]) means the ratio of the number of hydroxy groups in the charged alcohol compound to the total number of thiourethane bonds in the charged thiourethane resin.

[0042] (Amine Compound (XA)) In the production method of the present disclosure, a thiourethane resin is reacted with an alcohol compound in the presence of an amine compound (XA) that is a tertiary amine compound. The tertiary amine compound is believed to function as a decomposition assistant. The tertiary amine compound is not particularly limited. The tertiary amine compound may be a chain amine compound or a cyclic amine compound. The tertiary amine compound may be one type or a combination of two or more types.

[0043] The molecular weight of the tertiary amine compound is preferably 1,000 or less, more preferably 500 or less, even more preferably 300 or less, and even more preferably 200 or less. The lower limit of the molecular weight of the tertiary amine compound is, for example, 59 or more, and preferably 70 or more.

[0044] Tertiary amine compounds are Preferred are N,N-dimethylethanolamine, N,N-dimethylaminopropanol, N,N-diethylaminoethanol, N-methyldiethanolamine, diisopropylethylamine, triethylamine, triisopropylamine, triisobutylamine, N,N-dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, dimethylpiperazine, 1-ethylpiperidine, 4-(2-hydroxyethyl)morpholine, 1,4-diazabicyclo[2,2,2]octane (abbreviation: DABCO), diazabicyclononene, and diazabicycloundecene; More preferably, it is N,N-dimethylethanolamine, N,N-diethylaminoethanol, N-methyldiethanolamine, diisopropylethylamine, triisopropylamine, triisobutylamine, N,N-dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, dimethylpiperazine, 1-ethylpiperidine, 1,4-diazabicyclo[2,2,2]octane, diazabicyclononene, or diazabicycloundecene; More preferred are N,N-dimethylethanolamine, diisopropylethylamine, N,N-dimethylcyclohexylamine, N-ethylmorpholine, and 1,4-diazabicyclo[2,2,2]octane.

[0045] The charged mass ratio of the tertiary amine compound to the alcohol compound (that is, the charged mass ratio [tertiary amine compound / alcohol compound]) can be appropriately adjusted and is, for example, preferably 0.001 to 2.00. The charged mass ratio [tertiary amine compound / alcohol compound] is more preferably 0.002 to 1.50, and further preferably 0.004 to 1.20.

[0046] The molar ratio of the tertiary amine compound to the alcohol compound (that is, the molar ratio of the tertiary amine compound / alcohol compound) can be appropriately adjusted and is, for example, preferably 0.001 to 3.00. The charging molar ratio [tertiary amine compound / alcohol compound] is more preferably 0.002 to 2.50, further preferably 0.003 to 2.00, further preferably 0.004 to 1.50, and further preferably 0.004 to 1.00.

[0047] -Reaction temperature- The reaction temperature between the thiourethane resin and the alcohol compound can be appropriately adjusted. It is preferable to react the thiourethane resin with the alcohol compound under temperature conditions (i.e., reaction temperature) of 70°C to 200°C (more preferably 90°C to 180°C, even more preferably 100°C to 170°C, and even more preferably 140°C to 160°C). When the reaction temperature is 70° C. to 200° C., the purity of the polythiol component as the main component in the target polythiol composition (that is, the content of the main component relative to the total amount of the polythiol composition) can be further improved. The reaction between the thiourethane resin and the alcohol compound may be carried out under pressurized conditions. When the reaction is carried out under pressurized conditions, the reaction time may be shortened.

[0048] -Reaction time- The reaction time between the thiourethane resin and the alcohol compound can be appropriately adjusted and is preferably 0.1 to 50 hours, more preferably 0.5 to 30 hours, even more preferably 1 to 20 hours, and still more preferably 4 to 7 hours.

[0049] (Reaction solution) In the production method of the present disclosure, a reaction liquid is obtained by reacting a thiourethane resin with an alcohol compound in the presence of an amine compound (XA) that is a tertiary amine compound. The resulting reaction solution is A polycarbamate composition (R) containing a polycarbamate compound; A polythiol composition (P) containing a polythiol compound (A1) having no ester bond in the molecule, and Polythiol composition (Q) containing a polythiol compound (A2) having at least one ester bond in the molecule Includes.

[0050] <Polycarbamate composition (R)> The polycarbamate composition (R) contains a polycarbamate compound which is an alcoholysis product of a thiourethane resin, produced by the reaction of a thiourethane resin with an alcohol compound (i.e., alcoholysis). A polycarbamate compound is a compound (ie, a polyurethane compound) that contains two or more carbamate bonds (ie, urethane bonds). The polycarbamate compound is, for example, a polycarbamate compound (i.e., a polyurethane compound) having a structure in which all isocyanato groups in a polyisocyanate compound, which is one of the raw materials of a thiourethane resin, react with hydroxyl groups in an alcohol compound to form carbamate bonds (i.e., urethane bonds). The polycarbamate composition (R) preferably contains a polycarbamate compound as a main component. The polycarbamate composition (R) may be, for example, one type of polycarbamate compound, a mixture of two or more types of polycarbamate compounds, or a mixture of one or more types of polycarbamate compounds and by-products generated by alcoholysis.

[0051] The polycarbamate compound is not particularly limited as long as it is a compound containing a residue obtained by removing all of the isocyanato groups from the above-mentioned polyisocyanate compound and two or more carbamate bonds.

[0052] <Polythiol Composition (P)> The polythiol composition (P) is an alcoholysis product of a thiourethane resin produced by the reaction (i.e., alcoholysis) of a thiourethane resin with an alcohol compound. The polythiol composition (P) contains a polythiol compound (A1) that does not have an ester bond in the molecule. Specific examples of the polythiol compound (A1) that does not have an ester bond in the molecule are the same as the polythiol compound that does not have an ester bond in the molecule contained in the first polythiol composition described above.

[0053] <Polythiol Composition (Q)> The polythiol composition (Q) is an alcoholysis product of a thiourethane resin produced by the reaction (i.e., alcoholysis) of a thiourethane resin with an alcohol compound. The polythiol composition (Q) contains a polythiol compound (A2) having at least one ester bond in the molecule. Specific examples of the polythiol compound (A2) having at least one ester bond in the molecule are the same as the polythiol compound having at least one ester bond in the molecule contained in the second polythiol composition described above.

[0054] In step 1, at least a portion of the polythiol compound (A2) contained in the polythiol composition (Q) may be decomposed. For example, a portion of the ester groups (e.g., one ester group) of the polythiol compound (A2) may undergo an ester exchange reaction with an alcohol compound serving as a decomposition agent to produce an ester compound produced by a reaction between a carboxylic acid (QC) having a mercapto group (described later) and the alcohol compound serving as a decomposition agent.

[0055] [Process 2] The manufacturing method of the present disclosure includes step 2, in which the reaction liquid obtained in step 1 is used to separate at least one of the polycarbamate composition (R), the polythiol composition (P), the carboxylic acid (QC) having a mercapto group obtained by decomposing the polythiol compound (A2), and the polyalcohol (QA) obtained by decomposing the polythiol compound (A2).

[0056] In step 2, it is sufficient to separate any one of the polycarbamate composition (R), the polythiol composition (P), the carboxylic acid (QC), and the polyalcohol (QA), and it is preferable to separate all of them. By separating these compositions or compounds from the reaction solution, the separated compositions or compounds can be used as raw materials for producing a thiourethane resin (i.e., polythiourethane resin raw material).

[0057] There is no particular limitation on the method for separating the above-mentioned composition or compound from the reaction solution, and any known method can be applied. Examples of the separation method include filtration, decantation, extraction, distillation, dissolution, drying (including drying under reduced pressure), purification (for example, column chromatography), etc. A plurality of separation methods may be used in combination.

[0058] For example, the polycarbamate composition (R), the polythiol composition (P), the carboxylic acid (QC), and the polyalcohol (QA) can be separated by extracting them with an organic solvent or an inorganic solvent capable of dissolving these compositions or compounds. In addition, an acid, a base, or the like may be used when extracting them with an organic solvent or an inorganic solvent. As a method for purifying these compositions or compounds, a general purification method such as column purification, distillation purification, recrystallization purification, salt extraction, etc. is used.

[0059] Since the polythiol compound (A2) has at least one ester bond in the molecule, it is easily decomposed when the composition or compound is separated from the reaction solution, for example, the ester bond is easily hydrolyzed in the presence of an acid or a base. Therefore, the ester bond in the polythiol compound (A2) is decomposed to form a carboxylic acid (QC) having a mercapto group or a salt thereof, a polyalcohol (QA), etc. In step 2, the carboxylic acid (QC) having a mercapto group, the polyalcohol (QA), etc. obtained by decomposing the polythiol compound (A2) may be separated.

[0060] <Carboxylic Acid (QC)> The carboxylic acid (QC) is derived from the polythiol compound (A2) and is not particularly limited as long as it is a carboxylic acid having a mercapto group. The carboxylic acid (QC) is a compound having one or more carboxy groups that form an ester bond in the molecule of the polythiol compound (A2) by reacting with the hydroxy group of the polyalcohol (QA), and is preferably a compound having one carboxy group that forms an ester bond in the molecule of the polythiol compound (A2).

[0061] The carboxylic acid (QC) is preferably at least one selected from the group consisting of 3-mercaptopropionic acid, 2-mercaptoacetic acid, and 3-mercaptobutanoic acid, and more preferably at least one selected from the group consisting of 3-mercaptopropionic acid and 2-mercaptoacetic acid.

[0062] <Polyalcohol (QA)> The polyalcohol (QA) is not particularly limited as long as it is derived from the polythiol compound (A2) and has two or more hydroxyl groups. The polyalcohol (QA) is a compound having two or more hydroxyl groups that react with the carboxyl group of the carboxylic acid (QC) to form an ester bond in the molecule of the polythiol compound (A2). The number of hydroxyl groups in the polyalcohol (QA) is preferably the same as the number of ester bonds in the polythiol compound (A2). Specifically, the number of hydroxyl groups in the polyalcohol (QA) is preferably 2 to 6, and more preferably 3 or 4.

[0063] The polyalcohol (QA) is preferably at least one selected from the group consisting of pentaerythritol and trimethylolpropane, and more preferably pentaerythritol.

[0064] [Process 3] The manufacturing method of the present disclosure may further include step 3, prior to step 2, in which an acid and water are added to the reaction liquid obtained in step 1 to separate an amine compound (XA), which is a tertiary amine compound, into an aqueous phase. This allows the amine compound (XA) used in step 1 to be separated from the reaction liquid. The acid is not particularly limited, and examples thereof include carbonic acid, nitric acid, sulfuric acid, acetic acid, formic acid, oxalic acid, and hydrogen chloride. The acid may be an acid alone or an aqueous solution of an acid such as hydrochloric acid. When the acid and water are added to the reaction liquid, the acid and water may be added to the reaction liquid in any order, or an aqueous solution of an acid may be added to the reaction liquid.

[0065] In step 3, a solvent may be added to the reaction solution obtained in step 1 before the acid and water are added to the reaction solution. This solvent can function as a co-solvent for separating the amine compound (XA) into the aqueous phase.

[0066] Examples of the solvent that can be added in step 3 include organic solvents such as hydrocarbon compounds having 5 to 12 carbon atoms (preferably 6 to 10, and more preferably 7 to 9), ether compounds having 4 to 12 carbon atoms, ketone compounds having 3 to 12 carbon atoms, ester compounds having 4 to 12 carbon atoms, alcohol compounds having 2 to 12 carbon atoms, and nitrile compounds having 2 to 12 carbon atoms. The hydrocarbon compounds include hexane, heptane, octane, nonane, decane, xylene, mesitylene, and toluene. The ether compounds include diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, dimethoxyethane, and 1,4-dioxane. The ketone compounds include acetone, methyl ethyl ketone, methyl isobutyl ketone, and 2-octanone. The ester compounds include ethyl acetate, butyl acetate, and pentyl acetate. The alcohol compounds include ethanol, 1-propanol, isopropanol, 1-butanol, 1-octanol, 2-octanol, benzyl alcohol, phenethyl alcohol, ethylene glycol, propylene glycol and methyl cellosolve. The nitrile compounds include acetonitrile and propionitrile. The solvent that can be added in step 3 may be only one type, or two or more types.

[0067] When the production method of the present disclosure includes step 3, the amine compound (XA), which is a tertiary amine compound, is separated from the reaction liquid into an aqueous phase, and the reaction liquid is obtained as an organic phase containing the polycarbamate composition (R), the polythiol composition (P), and the polythiol composition (Q).

[0068] In step 3, at least a portion of the polythiol compound (A2) contained in the polythiol composition (Q) may be decomposed, for example, into a carboxylic acid (QC) and a polyalcohol (QA).

[0069] <Step 2a> Step 2 preferably includes step 2a in which an alkali metal-containing base and water are added to the reaction solution obtained in step 1 to perform extraction. This step 2a separates an aqueous phase (S1) containing an alkali metal salt of a polythiol compound (A1), an alkali metal salt of a carboxylic acid having an alkali metal salt of a mercapto group obtained by decomposing the polythiol compound (A2), and a polyalcohol (QA) obtained by decomposing the polythiol compound (A2), from a polycarbamate composition (R). In this step, the polycarbamate composition (R) can be selectively separated.

[0070] The alkali metal salt of the polythiol compound (A1) is a compound in which the hydrogen atom of the mercapto group in the polythiol compound (A1) is substituted with an alkali metal. The alkali metal salt of a carboxylic acid having an alkali metal salt of a mercapto group is a compound in which the polythiol compound (A2) is decomposed (more specifically, decomposed in the presence of a base) so that the hydrogen atoms of the mercapto groups are substituted with alkali metals and the hydrogen atoms of the carboxy groups are substituted with alkali metals.

[0071] The alkali metal in the base containing an alkali metal is preferably sodium, potassium or lithium, and more preferably sodium or potassium. Examples of the base containing an alkali metal include sodium methoxide, sodium ethoxide, sodium propoxide, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. The base containing an alkali metal may be a base alone or an aqueous solution of a base.

[0072] In step 2a, water is added to the reaction solution to perform extraction. In this case, an aqueous solution of the base obtained by previously mixing the base containing an alkali metal salt with the water used for extraction may be used for extraction. In step 2a, the base may be added to the reaction solution and then water may be added, or water may be added to the reaction solution and then the base may be added.

[0073] In step 2a, the aqueous phase (S1) which is an aqueous extract containing an alkali metal salt of the polythiol compound (A1), an alkali metal salt of a carboxylic acid having an alkali metal salt of a mercapto group, and a polyalcohol (QA) is separated from the polycarbamate composition (R). The polycarbamate composition (R) separated may be contained in the organic phase, the polycarbamate composition (R) separated and the alcohol compound used in step 1 may be contained in the organic phase, and the polycarbamate composition (R) separated and the alcohol compound used in step 1 and the organic solvent which may be used in step 3 may be contained in the organic phase. The polycarbamate composition (R) contained in the organic phase may be isolated from the organic phase by appropriate operations such as washing, filtration, decantation, extraction, distillation, dissolution, drying (including drying under reduced pressure), and purification.

[0074] The separated polycarbamate composition (R) may be used as a raw material for a thiourethane resin, or may be used for something other than a raw material for a thiourethane resin. For example, the polycarbamate compound contained in the polycarbamate composition (R) may be reacted with an amine compound to form a polyamine, or the amino group of the polyamine may be isocyanated to form a polyisocyanate compound, or a polyisocyanate composition containing the polyisocyanate compound may be used as a thiourethane resin raw material.

[0075] <Process 2b> Step 2 preferably includes step 2b of separating the aqueous phase (S2) containing the alkali metal salt of the carboxylic acid having a mercapto group and the polyalcohol (QA) from the polythiol composition (P) by adding an organic solvent and an acid to the aqueous phase (S1). In this step, the polythiol composition (P) can be selectively separated.

[0076] Examples of the organic solvent used in step 2b include the organic solvents listed as the solvent that can be added in step 3. The acid used in step 2b may be an acid alone or an aqueous solution of an acid, etc. The acid is not particularly limited, and examples thereof include hydrogen chloride, carbonic acid, nitric acid, sulfuric acid, acetic acid, formic acid, and oxalic acid.

[0077] In step 2b, it is preferable to adjust the pH by adding an acid. For example, it is preferable to adjust the pH to a weak base. Specifically, it is preferable to adjust the pH to 7.0 to 11.0 at 25° C., and more preferably to 8.0 to 10.0. When the aqueous phase (S1) contains an alkali metal salt of a carboxylic acid having an alkali metal salt of a mercapto group or a sodium salt of 3-mercaptopropionic acid having a sodium salt of a mercapto group, it is more preferable to adjust the pH to 9.5.

[0078] In step 2b, an alkali metal salt of a carboxylic acid having a mercapto group is obtained from the alkali metal salt of a carboxylic acid having an alkali metal salt of a mercapto group by adding an acid to the aqueous phase (S1). Furthermore, a polythiol compound (A1) is obtained from the alkali metal salt of the polythiol compound (A1), and as a result, a polythiol composition (P) containing the polythiol compound (A1) is obtained.

[0079] In step 2b, the aqueous phase (S2) containing the alkali metal salt of a carboxylic acid having a mercapto group and the polyalcohol (QA) is separated from the polythiol composition (P). The separated polythiol composition (P) may be contained in the organic phase. The polythiol composition (P) contained in the organic phase may be isolated from the organic phase by appropriate operations such as washing, filtration, decantation, extraction, distillation, dissolution, drying (including drying under reduced pressure), and purification. In addition, an acid may be further added to the aqueous phase (S2) to adjust the pH, thereby converting the alkali metal salt of the carboxylic acid having a mercapto group into the carboxylic acid (QC) having a mercapto group. The esterification reaction may be carried out in a state where the carboxylic acid (QC) having a mercapto group and the polyalcohol (QA) are allowed to coexist in the aqueous phase (S2) without separating the carboxylic acid (QC) having a mercapto group and the polyalcohol (QA) from the aqueous phase (S2). This makes it possible to produce a polythiol composition (Q) containing the polythiol compound (A2) as a main component.

[0080] <Process 2c> Step 2 preferably includes step 2c, in which an organic solvent and an acid are added to the aqueous phase (S2) to perform extraction to separate the aqueous phase (S3) containing the polyalcohol (QA) and inorganic salts from the carboxylic acid (QC). In this step, the carboxylic acid (QC) can be selectively separated.

[0081] In step 2c, a carboxylic acid (QC) and an inorganic salt are obtained from the alkali metal salt of a carboxylic acid having a mercapto group by adding an acid to the aqueous phase (S2).

[0082] In step 2c, the aqueous phase (S3) containing the polyalcohol (QA) and inorganic salts is separated from the carboxylic acid (QC). The separated carboxylic acid (QC) may be contained in the organic phase. The carboxylic acid (QC) contained in the organic phase may be isolated from the organic phase by appropriate procedures such as washing, filtration, decantation, extraction, distillation, dissolution, drying (including drying under reduced pressure), and purification.

[0083] <Process 2d> Step 2 preferably includes step 2d of isolating polyalcohol (QA) from the aqueous phase (S3) by removing water and then separating inorganic salts. For example, polyalcohol (QA) may be isolated by appropriately performing operations such as washing, filtration, decantation, extraction, distillation, dissolution, drying (including drying under reduced pressure) and purification after distilling water from the aqueous phase (S3).

[0084] In the above, a method for isolating each of the thiourethane resin raw materials is described, in which the polycarbamate composition (R) is isolated in step 2a, the polythiol composition (P) containing the polythiol compound (A1) is isolated in step 2b, the carboxylic acid (QC) is isolated in step 2c, and the polyalcohol (QA) is isolated in step 2d. However, the present invention is not limited thereto, and any component in the polycarbamate composition (R), the polythiol composition (P), the carboxylic acid (QC), and the polyalcohol (QA) may be selectively isolated, and each component may be isolated in any order.

[0085] In the production method of the present disclosure, the polythiol composition (P) contained in the reaction solution in step 1 and the polythiol composition (P) separated in step 2 do not need to be completely identical, and may differ in the content of polythiol compound (A1), the content of other components, etc. The polythiol composition as the target product and the polythiol composition as the raw material for the thiourethane resin do not need to be completely the same.

[0086] The use of the thiourethane resin raw material obtained by the production method of the present disclosure is not particularly limited. For example, the thiourethane resin raw material obtained by the production method of the present disclosure may be used for preparing a polymerizable composition, or may be used for producing optical materials (e.g., eyeglass lenses) and other molded articles.

[0087] [Method for producing polymerizable composition] The method for producing a polymerizable composition of the present disclosure includes a step of producing a polymerizable composition using at least one of the thiourethane resin raw materials obtained by the method for producing a thiourethane resin raw material of the present disclosure, which are a polycarbamate composition (R), a polythiol composition (P), a carboxylic acid (QC), and a polyalcohol (QA). The obtained polymerizable composition may be reused for the production of a thiourethane resin, or may be used for another purpose.

[0088] In the method for producing a polymerizable composition of the present disclosure, a high-purity thiourethane resin raw material obtained by the method for producing a thiourethane resin raw material of the present disclosure is used. As a result, the polymerizable composition obtained by the method for producing a polymerizable composition of the present disclosure tends to produce a cured product excellent in various properties (e.g., optical properties (e.g., refractive index and / or Abbe number), heat resistance, specific gravity d, etc.). For this reason, the polymerizable composition obtained by the method for producing a polymerizable composition according to the present disclosure is particularly suitable as a composition for producing a thiourethane resin for optical materials.

[0089] In the step of producing a polymerizable composition, at least one of a polythiol composition containing a polythiol compound (A2) obtained by reacting a carboxylic acid (QC) and a polyalcohol (QA) and a polythiol composition (P) which is a raw material for a thiourethane resin is mixed with a polyisocyanate composition to produce a polymerizable composition.

[0090] The mixing ratio of the polythiol component containing at least one of the polythiol composition containing the polythiol compound (A2) and the polythiol composition (P) and the polyisocyanate composition is not particularly limited. The ratio of the charged mass of the polythiol component to the charged mass of the polyisocyanate composition (i.e., charged mass [polythiol component / polyisocyanate composition]) is preferably 0.10 to 10.0, more preferably 0.20 to 5.00, even more preferably 0.50 to 1.50, and still more preferably 0.70 to 1.30. Furthermore, the molar ratio of mercapto groups contained in the polythiol component to isocyanato groups in the polyisocyanate composition (mercapto groups / isocyanato groups) is preferably 0.5 to 3.0, more preferably 0.6 to 2.0, and even more preferably 0.8 to 1.3.

[0091] The total mass of the polythiol component and the polyisocyanate composition is not particularly limited. For example, the total mass of the polythiol component and the polyisocyanate composition is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, based on the total amount of the polymerizable composition produced.

[0092] The polythiol component may contain a polythiol compound other than the polythiol composition containing the polythiol compound (A2) and the polythiol composition (P). Examples of the other polythiol compounds include the polythiol compounds exemplified in the first polythiol composition and the second polythiol composition.

[0093] The polyisocyanate composition used in the production of the polymerizable composition is not particularly limited, and may be a polyisocyanate composition derived from the polycarbamate composition (R) separated in the production method of the thiourethane resin raw material of the present disclosure, or may be a separately prepared polyisocyanate composition. The separately prepared polyisocyanate composition is not particularly limited as long as it is a composition containing a compound containing two or more isocyanate groups, and examples thereof include the above-mentioned polyisocyanate compositions.

[0094] When mixing the polythiol component and the polyisocyanate composition, the polythiol component and the polyisocyanate composition may be mixed with other components, if necessary. After mixing at least the polythiol component and the polyisocyanate composition, other components may be added to the mixture. These other components include polymerization catalysts, internal release agents, resin modifiers, chain extenders, crosslinking agents, radical scavengers, light stabilizers, ultraviolet absorbers, antioxidants, oil-soluble dyes, fillers, adhesion improvers, antibacterial agents, antistatic agents, dyes, fluorescent brightening agents, fluorescent pigments, inorganic pigments, and the like.

[0095] Examples of the polymerization catalyst include tertiary amine compounds, their inorganic or organic acid salts, metal compounds, quaternary ammonium salts, and organic sulfonic acids.

[0096] As the internal mold release agent, an acidic phosphate ester can be used. Examples of the acidic phosphate ester include a phosphate monoester and a phosphate diester, and each of them can be used alone or in combination of two or more kinds.

[0097] Examples of the resin modifier include episulfide compounds, alcohol compounds, amine compounds, epoxy compounds, organic acids, anhydrides of organic acids, olefin compounds including (meth)acrylate compounds, etc. Here, the (meth)acrylate compound means at least one of an acrylate compound and a methacrylate compound.

[0098] The above-mentioned components can be mixed in a conventional manner, and the method of mixing is not particularly limited.

[0099] [Method for producing the cured product] The method for producing a cured product of the present disclosure includes the steps of producing a polymerizable composition by the method for producing a polymerizable composition of the present disclosure, and curing the polymerizable composition to obtain a cured product.

[0100] In the step of obtaining a cured product, the polymerizable composition is cured to obtain a cured product. The curing of the polymerizable composition can be carried out by polymerizing the monomers in the polymerizable composition (for example, the polythiol component and the polyisocyanate composition). As a pretreatment for polymerization, the polymerizable composition may be subjected to a treatment such as filtration or degassing. The polymerization conditions (e.g., polymerization temperature, polymerization time, etc.) for polymerizing the monomers in the polymerizable composition are appropriately set in consideration of the composition of the composition, the type and amount of the monomer in the composition, the type and amount of the polymerization catalyst in the composition, and the properties of the mold when a mold described below is used. The polymerization temperature may be, for example, from -50°C to 150°C, or from 10°C to 150°C. The polymerization time may be, for example, 1 hour to 200 hours, or 1 hour to 80 hours.

[0101] In the step of obtaining a cured product, a polymer obtained by polymerization of a monomer may be subjected to a treatment such as annealing to obtain a cured product. The annealing temperature may be 50°C to 150°C, 90°C to 140°C, 100°C to 130°C, or the like.

[0102] Applications of the cured product are not particularly limited, and examples thereof include optical materials such as lenses, and molded articles other than optical materials. EXAMPLES

[0103] Examples of the present disclosure will be described below, but the present disclosure is not limited to the following examples. Hereinafter, "room temperature" means 25°C unless otherwise specified.

[0104] Hereinafter, the purity (%) of the polythiol compound A1 in the polythiol composition X1 means the content (%) of the polythiol compound A1 relative to the total amount of the polythiol composition, and more specifically, means the ratio (area %) of the total area of ​​the peaks of the polythiol compound A1 to the total area of ​​all peaks of the polythiol composition, as measured by high performance liquid chromatography under the following conditions: (High performance liquid chromatography conditions) Column: YMC-Pack ODS-A (particle size S: 5 μm, pore size: 12 nm, column shape: Φ6 mm × 150 mm) Mobile phase: acetonitrile / 0.01 mol potassium dihydrogen phosphate aqueous solution = 60 / 40 (vol / vol) Column temperature: 40℃ Flow rate: 1.0ml / min Detector: UV detector, wavelength 230 nm Preparation of measurement solution: Dissolve and mix 160 mg of sample in 10 ml of acetonitrile. Injection volume: 2μL

[0105] [Reference production example 1] (Production of Molded Body R1 Containing Thiourethane Resin and UV Absorber) In a flask equipped with a stirrer, Dibutyltin dichloride as a polymerization catalyst (amount added: 600 ppm by mass based on the total amount of the polyisocyanate composition described below, the polythiol composition X1 described below, and the polythiol composition Y described below), Tinuvin 329 (manufactured by BASF Japan Ltd., 2-(2H-benzotriazol-2-yl)-4-tert-octylphenol) is a UV absorber (amount added: 500 ppm by mass based on the total amount of the polyisocyanate composition described below, the polythiol composition X1 described below, and the polythiol composition Y described below), Zelec-UN (manufactured by Stephan Co.; acidic phosphate ester) as a release agent (amount added: 1000 ppm by mass based on the total amount of the polyisocyanate composition described below, the polythiol composition X1 described below, and the polythiol composition Y described below), A mixture of 2,5-bis(isothiocyanatomethyl)bicyclo-[2.2.1]-heptane and 2,6-bis(isothiocyanatomethyl)bicyclo-[2.2.1]-heptane (amount added: 50.6 parts by mass) which is a polyisocyanate composition, A polythiol composition X1 (addition amount: 25.6 parts by mass) mainly composed of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (i.e., polythiol compound A1), A polythiol composition Y (addition amount: 23.8 parts by mass) mainly composed of pentaerythritol tetrakis(3-mercaptopropionate) (i.e., polythiol compound A2) The mixture was stirred and mixed at room temperature (25° C.) for 1 hour to obtain a transparent homogeneous solution that was a polymerizable composition.

[0106] Next, the polymerizable composition was filtered under reduced pressure with a PTFE (polytetrafluoroethylene) filter, and then degassed sufficiently under a reduced pressure of 600 Pa until foaming was no longer observed. The degassed polymerizable composition was poured between a pair of glass molds fixed with tape, and then the pair of glass molds were placed in an oven, and the temperature inside the oven was set to 10°C. Next, the temperature inside the oven was raised from 10°C to 120°C over 38 hours. Through the above process, the monomers (polyisocyanate composition and polythiol composition) in the degassed polymerizable composition were polymerized, and a molded body containing the thiourethane resin R1 (i.e., a cured product of the polymerizable composition) was formed between the pair of glass molds. Next, the inside of the oven was cooled, and after cooling, the pair of glass molds were removed from the oven, and then the molded body was removed from the pair of glass molds to obtain a molded body.

[0107] (Production of thiourethane resin powder R1) The molded article obtained above was cut to produce a lens. The cutting powder generated during the process was collected to obtain thiourethane resin powder R1 (i.e., powder containing thiourethane resin R1).

[0108] Example 1 (Decomposition of thiourethane resin powder R1 by alcohol compounds) -Reaction process- The entire amount of the thiourethane resin powder R1 (210 g) obtained in Reference Production Example 1 was charged into a 2 L flask equipped with a cooling tube. Benzyl alcohol (FUJIFILM Wako Pure Chemical Industries, Ltd.) (557 g; 5.15 mol) and 1,4-diazabicyclo-[2.2.2]-octane [abbreviation; DABCO] (FUJIFILM Wako Pure Chemical Industries, Ltd.) (5.80 g; 51.7 mmol) were added thereto, and the mixture was heated and stirred at 150°C for 5 hours to obtain a reaction liquid containing a polycarbamate composition, polythiol compound A1, and polythiol compound A2 (reaction process).

[0109] -Separation process 1- The reaction liquid obtained in the above reaction step was cooled to 60°C, and 500g of 2-octanol was added to the reaction liquid as an auxiliary solvent for separation. The obtained liquid was washed once with 10.5g of 35% hydrochloric acid to remove 1,4-diazabicyclo-[2.2.2]-octane, and then washed with 200mL of water. 30.8% aqueous sodium hydroxide solution (188g; 1.45mol) was added to the washed liquid and stirred. 300mL of water was added thereto to perform a liquid separation operation, and an alcohol solution containing a polycarbamate composition and an aqueous solution containing a polythiol compound A1 intermediate and a polythiol compound A2 intermediate were separated. The polythiol compound A1 intermediate contains the sodium salt of polythiol compound A1, and the polythiol compound A2 intermediate contains 3-mercaptopropionic acid sodium salt having a sodium salt of a mercapto group and pentaerythritol, which are obtained by decomposing polythiol compound A2. Then, 150 g of 2-octanol was added to the aqueous solution to wash once. 200 g of toluene was added to the resulting aqueous extract, and 86 g of 35% hydrochloric acid was added. The pH of the aqueous solution at this time was 9.50. Then, a separation operation was performed to separate a toluene solution containing polythiol compound A1 from an aqueous solution containing sodium salt of 3-mercaptopropionic acid and pentaerythritol obtained by decomposition of polythiol compound A2. The resulting toluene solution was washed once with 100 mL of water, and then washed once with 106 g of 35% hydrochloric acid, followed by washing and separation twice with 100 mL of water to obtain a toluene solution containing polythiol compound A1. The toluene was removed from the obtained toluene solution by a rotary evaporator, and low boiling point components were removed by a vacuum pump. Then, the solution was filtered through a 3-micron PTFE membrane filter to obtain 36.8 g of a polythiol composition P mainly composed of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (i.e., polythiol compound A1). Here, the purity of the polythiol compound A1 in the polythiol composition P (ie, the content of the polythiol compound A1 relative to the total amount of the polythiol composition P) is 92.8% (above, separation step 1).

[0110] -Separation process 2- 350g of methyl isobutyl ketone was added as an extraction solvent to the aqueous solution containing the sodium salt of 3-mercaptopropionic acid and pentaerythritol obtained in the above separation step 1, and 106g of 35% hydrochloric acid was added and stirred. A separation operation was then performed to obtain a methyl isobutyl ketone solution containing 3-mercaptopropionic acid. 250g of methyl isobutyl ketone was added again to the aqueous solution obtained at this time, and a separation extraction was performed to obtain a methyl isobutyl ketone solution containing 3-mercaptopropionic acid. At this time, the aqueous solution containing pentaerythritol was also collected. The solvent was removed from the resulting methyl isobutyl ketone solution using a rotary evaporator, and 24.7 g of 3-mercaptopropionic acid was obtained by vacuum distillation. This compound is a raw material for synthesizing pentaerythritol tetrakis(3-mercaptopropionate), which is the polythiol compound A2 (separation step 2).

[0111] -Purification process 1- The alcohol solution containing the polycarbamate composition obtained in the separation step 1 was heated and decompressed to distill off benzyl alcohol and 2-octanol. As a result, 181.0 g of a yellow solid polycarbamate composition was obtained. The polycarbamate compound contained in this composition is a raw material for synthesizing a polyamine compound that can be derived into a polyisocyanate compound (refining step 1).

[0112] -Purification process 2- Water was removed from the aqueous solution containing pentaerythritol obtained in the above separation step 2 using a rotary evaporator to obtain a white solid. Then, 200 g of acetonitrile was added and filtered under reduced pressure to obtain a white solid containing pentaerythritol and sodium chloride. The white solid was then added to 500 g of ethanol and ultrasonically dissolved at 60°C. The white solid, which was mainly composed of sodium chloride, was removed by filtration to obtain an ethanol solution containing pentaerythritol. After removing ethanol from the obtained ethanol solution using a rotary evaporator, the obtained white solid was dried under reduced pressure with heating to obtain 7.90 g of pentaerythritol. This compound is a raw material for the synthesis of pentaerythritol tetrakis(3-mercaptopropionate), which is polythiol compound A2 (refining step 2).

[0113] In Example 1, each step of producing a thiourethane resin raw material from thiourethane resin powder R1 is shown in Figure 1. As shown in Figure 1, a polycarbamate composition, a polythiol compound A1, 3-mercaptopropionic acid, and pentaerythritol can be separated by Example 1. The correspondence between each step of Example 1 and the above-mentioned step 1, step 2, steps 2a to 2d, and step 3 is also shown in Figure 1.

[0114] Example 2 (Production of Molded Body 1 Containing Thiourethane Resin) In a flask equipped with a stirrer, Dibutyltin dichloride as a polymerization catalyst (amount added: 100 ppm by mass based on the total amount of the polyisocyanate composition and the polythiol composition P described below), Zelec-UN (Stepan Chemical Company; acidic phosphate ester) as a release agent (amount added: 1000 ppm by mass based on the total amount of the polymerizable composition obtained), A composition containing 99% by mass or more of m-xylylene diisocyanate (XDI), which is a polyisocyanate composition (addition amount: 52 parts by mass), A polythiol composition P (addition amount: 48 parts by mass) recovered in the separation step 1, which contains 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (i.e., polythiol compound A1) as a main component; The mixture was stirred and mixed at room temperature (25° C.) for 1 hour to obtain a transparent homogeneous solution that was a polymerizable composition.

[0115] Next, the polymerizable composition was filtered under reduced pressure with a PTFE (polytetrafluoroethylene) filter, and then degassed sufficiently under a reduced pressure of 600 Pa until no foaming was observed. The degassed polymerizable composition was poured between a pair of glass molds fixed with tape, and then the pair of glass molds were placed in an oven, and the temperature inside the oven was set to 10°C. Next, the temperature inside the oven was raised from 10°C to 120°C over 38 hours. Through the above process, the monomers (polyisocyanate composition and polythiol composition) in the degassed polymerizable composition were polymerized, and a molded body containing the thiourethane resin 2 (i.e., a cured product of the polymerizable composition) was formed between the pair of glass molds. Next, the inside of the oven was cooled, and after cooling, the pair of glass molds were removed from the oven, and then the molded body was removed from the pair of glass molds to obtain a molded body. The obtained molded article had good transparency, was free of distortion, and had a good appearance.

[0116] [Reference production example 2] A molded article was obtained in the same manner as in Example 2, except that the polythiol composition P recovered in the separation step 1 in Example 2 was changed to the polythiol composition X1 used in Reference Production Example 1.

[0117] The molded articles obtained in Reference Production Example 2 and Example 2 were subjected to performance tests. The results are shown in Table 1. The performance test items were optical properties (refractive index and Abbe number), heat resistance, and specific gravity d. Each test was carried out according to the following test methods. Refractive index (ne), Abbe number (νe): Using a Shimadzu Pulfrich refractometer KPR-30, the refractive indexes (ne, nF', nC') at wavelengths of 546.1 nm (mercury e-line), 480.0 nm (Cd F'-line), and 643.9 nm (Cd C'-line) were measured at 20°C, and the refractive index (ne) and Abbe number (νe) were calculated based on the measurement results. Heat resistance: Using a Shimadzu Corporation thermomechanical analyzer TMA-60, the glass transition temperature (Tg) was measured by the TMA penetration method (50g load, pin tip 0.5mmφ, heating rate 10℃ / min) and used as an index of heat resistance. Specific gravity d: Measured by Archimedes' method at 20℃.

[0118] [Table 1]

[0119] As shown in Table 1, the molded article of Example 2 produced using the polythiol composition X1 recovered in Example 1 had performance comparable to that of the molded article of Reference Production Example 2.

[0120] [Examples 3 to 5] Instead of the benzyl alcohol used in decomposing the thiourethane resin powder R1 in Example 1, 1-octanol, 1-pentanol or 2-octanol was used, and the reaction conditions were appropriately changed in consideration of Example 1, and the same operation as in Example 1 was carried out. As a result, the polythiol composition X1 mainly composed of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (i.e., polythiol compound A1), 3-mercaptopropionic acid, pentaerythritol and polycarbamate composition were each obtained separately.

Claims

1. A step 1 of reacting a thiourethane resin obtained by curing a polymerizable composition including a polythiol composition including a polythiol compound having no ester bond in the molecule, a polythiol composition including a polythiol compound having at least one or more ester bonds in the molecule, and a polyisocyanate composition including a polyisocyanate compound with an alcohol compound in the presence of an amine compound (XA) which is a tertiary amine compound, to obtain a reaction liquid including a polycarbamate composition (R) including a polycarbamate compound, a polythiol composition (P) including a polythiol compound (A1) having no ester bond in the molecule, and a polythiol composition (Q) including a polythiol compound (A2) having at least one or more ester bonds in the molecule; a step 2 of separating at least one of the polycarbamate composition (R), the polythiol composition (P), a carboxylic acid (QC) having a mercapto group obtained by decomposing the polythiol compound (A2), and a polyalcohol (QA) obtained by decomposing the polythiol compound (A2) using the reaction liquid obtained in the step 1; A method for producing a thiourethane resin raw material comprising the steps of:

2. The process 2 includes a step 2a of adding an alkali metal-containing base and water to the reaction liquid obtained in the process 1 and performing extraction to separate an aqueous phase (S1) containing the alkali metal salt of the polythiol compound (A1), the alkali metal salt of a carboxylic acid having an alkali metal salt of a mercapto group obtained by decomposing the polythiol compound (A2), and the polyalcohol (QA) obtained by decomposing the polythiol compound (A2) from a polycarbamate composition (R). The process for producing a thiourethane resin raw material according to claim 1.

3. The method for producing a thiourethane resin raw material according to claim 2, wherein the step 2 includes a step 2b of separating an aqueous phase (S2) containing the alkali metal salt of a carboxylic acid having a mercapto group and the polyalcohol (QA) from the polythiol composition (P) by adding an organic solvent and an acid to the aqueous phase (S1).

4. The method for producing a thiourethane resin raw material according to claim 3, wherein the step 2 includes a step 2c of adding an organic solvent and an acid to the aqueous phase (S2) and performing extraction to separate an aqueous phase (S3) containing the polyalcohol (QA) and an inorganic salt from the carboxylic acid (QC).

5. The method for producing a thiourethane resin raw material according to claim 4, wherein the step 2 includes a step 2d of isolating the polyalcohol (QA) by removing water from the aqueous phase (S3) and then separating the inorganic salt.

6. The method for producing a thiourethane resin raw material according to any one of claims 1 to 5, further comprising a step 3, prior to the step 2, of adding an acid and water to the reaction liquid obtained in the step 1 to separate the amine compound (XA), which is a tertiary amine compound, into an aqueous phase.

7. The polythiol composition (P) is 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, The method for producing a thiourethane resin raw material according to any one of claims 1 to 6, comprising at least one selected from the group consisting of:

8. The polythiol composition (Q) is Pentaerythritol tetrakis(3-mercaptopropionate), Pentaerythritol tetrakis(2-mercaptoacetate), Trimethylolpropane tris(3-mercaptopropionate) and Pentaerythritol tetrakis(3-mercaptobutyrate) The method for producing a thiourethane resin raw material according to any one of claims 1 to 7, comprising at least one selected from the group consisting of:

9. The polyisocyanate composition includes at least one selected from the group consisting of pentamethylene diisocyanate, hexamethylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane, bis(isocyanatocyclohexyl)methane, 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and phenylene diisocyanate. The method for producing a thiourethane resin raw material according to any one of claims 1 to 8.

10. The method for producing a thiourethane resin raw material according to any one of claims 1 to 9, wherein the carboxylic acid (QC) is at least one selected from the group consisting of 3-mercaptopropionic acid, 2-mercaptoacetic acid, and 3-mercaptobutanoic acid.

11. The method for producing a thiourethane resin raw material according to any one of claims 1 to 10, wherein the polyalcohol (QA) is at least one selected from the group consisting of pentaerythritol and trimethylolpropane.

12. A method for producing a polymerizable composition, comprising a step of producing a polymerizable composition using at least one of the polycarbamate composition (R), the polythiol composition (P), the carboxylic acid (QC), and the polyalcohol (QA), which are thiourethane resin raw materials obtained by the method for producing a thiourethane resin raw material according to any one of claims 1 to 11.

13. 13. The method for producing a polymerizable composition according to claim 12, wherein in the step of producing the polymerizable composition, the polymerizable composition is produced by mixing at least one of a polythiol composition containing a polythiol compound (A2) obtained by reacting the carboxylic acid (QC) and the polyalcohol (QA) and the polythiol composition (P) which is the thiourethane resin raw material, and a polyisocyanate composition.

14. A step of producing a polymerizable composition by the method for producing a polymerizable composition according to claim 12 or 13; a step of obtaining a cured product by curing the polymerizable composition; A method for producing a cured product comprising the steps of:

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