Separation method of thiourethane resin and its application

Abstract

To provide a separation method for a thiourethane resin and its application, which can separate a specific thiourethane resin from a composition containing two or more thiourethane resins.SOLUTION: A separation method for a thiourethane resin includes a separation step of contacting a composition X containing two or more thiourethane resins with an aqueous solution of an inorganic salt to separate a specific thiourethane resin from the composition X.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a method for separating thiourethane resins and applications thereof. [Background technology]

[0002] Plastic lenses, which are lenses containing resin, are lighter and less likely to break than inorganic lenses, and can be dyed, and so in recent years have rapidly become popular for use in eyeglass lenses, camera lenses, and the like. For example, various studies have been conducted on lenses containing thiourethane resins (see, for example, Patent Documents 1 to 3). Furthermore, Patent Document 4 discloses 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, and which includes a step of reacting a thiourethane resin with an active hydrogen compound to produce the thiourethane resin raw material. [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 [Patent Document 4] International Publication No. 2021 / 157701 Summary of the Invention [Problem to be solved by the invention]

[0004] The method for producing a thiourethane resin raw material described in Patent Document 4 is a method for producing a thiourethane resin raw material, which is a raw material for thiourethane resin, from a thiourethane resin as a starting material, taking into consideration the effective use (i.e., recycling) of thiourethane resin. In the above-mentioned production method, examples of the thiourethane resin raw material include a polythiol composition, a polyamine compound, and a polyisocyanate compound, and examples of the active hydrogen compound include an amine compound and an alcohol compound. More specifically, the starting material for the above manufacturing method may be, for example, cutting waste containing thiourethane resin recovered during at least one of the processes of manufacturing eyeglass lenses containing thiourethane resin, manufacturing eyeglasses using the eyeglass lenses, and disposing of the eyeglasses.

[0005] In carrying out the above-described production method, it is also envisioned that a composition containing two or more thiourethane resins may be used as a starting material for reasons such as ease of preparation of the starting material. In this case, it is considered desirable to separate a specific thiourethane resin from the composition containing two or more thiourethane resins and react the separated specific thiourethane resin with an active hydrogen compound.

[0006] An object of one embodiment of the present disclosure is to provide a method for separating a thiourethane resin, which can separate a specific thiourethane resin from a composition containing two or more types of thiourethane resins, and applications thereof. [Means for solving the problem]

[0007] The means for solving the above problems include the following aspects. <1> The method includes a separation step of contacting a composition X containing two or more types of thiourethane resins with an aqueous solution of an inorganic salt to separate a specific thiourethane resin from the composition X. Method for separating thiourethane resin. <2> The inorganic salt includes at least one selected from the group consisting of alkali metal halides and alkaline earth metal halides. <1> A method for separating a thiourethane resin according to claim 1. <3> The inorganic salt includes calcium chloride. <1> or <2> A method for separating a thiourethane resin according to claim 1. <4> The composition X is recovered during at least one of the processes of manufacturing eyeglass lenses, manufacturing eyeglasses, and disposing of eyeglasses. <1> ~ <3> 10. A method for separating a thiourethane resin according to any one of the above. <5> The composition X further contains at least one selected from the group consisting of a resin other than a thiourethane resin, a polymerization catalyst, a metal, an ultraviolet absorber, an internal mold release agent, a plasticizer, a dye, machine oil, and water. <1> ~ <4> 10. A method for separating a thiourethane resin according to any one of the above. <6> the specific thiourethane resin is thiourethane resin R1, The thiourethane resin R1 is a cured product of a polymerizable composition containing m-xylylene diisocyanate and a polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as a main component. <1> ~ <5> 10. A method for separating a thiourethane resin according to any one of the above. <7> the two or more thiourethane resins include the thiourethane resin R1 and the thiourethane resin R2, The thiourethane resin R2 is a cured product of a polymerizable composition including a polyisocyanate composition containing 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane and 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane as main components, a polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as a main component, and a polythiol composition containing pentaerythritol tetrakis(3-mercaptopropionate) as a main component. <6> A method for separating a thiourethane resin according to claim 1.

[0008] <8> <1> ~ <7> separating the specific thiourethane resin by any one of the methods for separating a thiourethane resin described in the above; a reaction step of reacting the specific thiourethane resin with an active hydrogen compound to produce a thiourethane resin raw material; A method for producing a thiourethane resin raw material, comprising: <9> The active hydrogen compound is at least one selected from the group consisting of an amine compound and an alcohol compound. <8> A method for producing the thiourethane resin raw material described in <10> <8> or <9> a step of producing a thiourethane resin raw material by the method for producing a thiourethane resin raw material described in producing a polymerizable composition using at least a portion of the thiourethane resin raw material as at least a portion of a raw material; A method for producing a polymerizable composition comprising: <11> <10> a step of producing a polymerizable composition by the method for producing a polymerizable composition according to the above item; curing the polymerizable composition to obtain a resin; A method for producing a resin comprising: <12> A method for producing a molded article containing a resin, comprising: <10> a step of producing a polymerizable composition by the method for producing a polymerizable composition according to the above item; a step of curing the polymerizable composition to obtain a molded article containing a resin; A method for producing a molded body comprising the steps of: <13> A method for producing an optical material including a molded article containing a resin, comprising: <10> a step of producing a polymerizable composition by the method for producing a polymerizable composition according to the above item; a step of curing the polymerizable composition to obtain a molded article containing a resin; A method for producing an optical material comprising the steps of: <14> A method for producing a lens including a molded article containing a resin, comprising: <10> a step of producing a polymerizable composition by the method for producing a polymerizable composition according to the above item; a step of curing the polymerizable composition to obtain a molded article containing a resin; A method for manufacturing a lens comprising: <15> <8> or <9> A polymerizable composition containing at least a portion of the thiourethane resin raw material obtained by the method for producing a thiourethane resin raw material described in 1. <16> <15> A resin which is a cured product of the polymerizable composition described in 1. <17> <16> A molded article comprising the resin described in 1. <18> <17> An optical material comprising the molded article according to claim 1. <19> <17> A lens comprising the molded article according to claim 1. <20> Contains thiourethane resin R1 and thiourethane resin R2, the ratio of the content of the thiourethane resin R2 to the total content of the thiourethane resin R1 and the thiourethane resin R2 is more than 0 mass% and 10 mass% or less, the thiourethane resin R1 is a cured product of a polymerizable composition containing m-xylylene diisocyanate and a polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as a main component, The thiourethane resin R2 is a cured product of a polymerizable composition including a polyisocyanate composition containing 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane and 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane as main components, a polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as a main component, and a polythiol composition containing pentaerythritol tetrakis(3-mercaptopropionate) as a main component. Resin composition. [Effects of the Invention]

[0009] According to one aspect of the present disclosure, there is provided a method for separating a thiourethane resin, which can separate a specific thiourethane resin from a composition containing two or more types of thiourethane resins, and applications thereof. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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 "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process 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 stages in this disclosure, 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. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples.

[0011] The method for separating a thiourethane resin according to the present disclosure (hereinafter also referred to as the separation method according to the present disclosure) includes a separation step of contacting a composition X containing two or more types of thiourethane resins with an aqueous solution of an inorganic salt to separate a specific thiourethane resin from the composition X. The separation method of the present disclosure may include other steps as needed.

[0012] The separation method of the present disclosure makes it possible to separate a specific thiourethane resin from composition X containing two or more types of thiourethane resins. The reason why such an effect is obtained is thought to be that, by contacting composition X with an aqueous solution of an inorganic salt in the separation step, the specific thiourethane resin and the thiourethane resin other than the specific thiourethane resin can be separated by taking advantage of the difference in specific gravity between them (i.e., by the principle of separation by difference in specific gravity).

[0013] In the present disclosure, the concept of "separating a specific thiourethane resin from composition X" encompasses not only separating only the specific thiourethane resin from composition X, but also separating composition XX containing the specific thiourethane resin from composition X. Here, the concentration of the specific thiourethane resin in composition XX is higher than the concentration of the specific thiourethane resin in composition X.

[0014] Each step that may be included in the separation method of the present disclosure will be described below.

[0015] <Separation process> The separation step is a step of separating a specific thiourethane resin from composition X by contacting composition X containing two or more types of thiourethane resins with an aqueous solution of an inorganic salt.

[0016] (Composition X) Composition X contains two or more types of thiourethane resins. Composition X may contain other components as necessary.

[0017] Composition X is preferably recovered during at least one of the processes of manufacturing eyeglass lenses, manufacturing eyeglasses, and disposing of eyeglasses. This embodiment allows for the recycling of thiourethane resins as materials for eyeglass lenses. where: The manufacturing process of eyeglass lenses means the process of producing resin by compounding monomers, which are resin raw materials, and then subjecting them to cast polymerization, and / or the process of cutting a resin molded body to obtain eyeglass lenses. The eyeglass manufacturing process refers to the process of combining eyeglass lenses with other components such as eyeglass frames to manufacture eyeglasses. 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, composition X containing thiourethane resin, which is a material for eyeglass lenses, and foreign matter may be generated as waste. In this embodiment, composition X produced in at least one of these processes is used as a starting material, and the thiourethane resin in composition X is reacted with an active hydrogen compound to obtain a thiourethane resin raw material, which is a decomposition product of the thiourethane resin.

[0018] -Thiourethane resin- Composition X contains two or more types of thiourethane resins. As the thiourethane resin, known thiourethane resins can be used, and for example, thiourethane resins described in known documents such as JP-A-63-46213, JP-A-2-270859, JP-A-7-252207, JP-A-60-199016, JP-A-60-217229, WO 2007 / 052329, and WO 2008 / 047626 can be used.

[0019] The content of the thiourethane resin in composition X (ie, the total content of two or more thiourethane resins) is preferably 80% by mass or more, and more preferably 90% by mass or more, based on the total amount of composition X.

[0020] The thiourethane resin typically contains a polymer of an isocyanate compound and a polythiol composition, that is, the thiourethane resin is typically produced using an isocyanate compound and a polythiol composition as raw materials.

[0021] -Isocyanate compounds as raw materials for thiourethane resins- The isocyanate compound used as a raw material for the thiourethane resin may be one type only, or two or more types. Examples of the isocyanate compound as a raw material for the thiourethane resin include known isocyanate compounds described in the above-mentioned known literature. The isocyanate compound as a raw material for the thiourethane resin preferably includes a polyisocyanate compound containing two or more isocyanato groups. Isocyanate compounds used as raw materials for thiourethane resins are: It is more preferable that the composition contains a diisocyanate compound containing two isocyanato groups, It is more preferable that the isocyanate component N contains at least one selected from the group consisting of pentamethylene diisocyanate, hexamethylene diisocyanate, m-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 (hereinafter also referred to as "isocyanate component N"); It is more preferable that the isocyanate component N is contained as the main component.

[0022] The isocyanate compound used as a raw material for the thiourethane resin has the following properties in terms of the performance of the thiourethane resin (for example, optical properties (for example, refractive index and / or Abbe number), heat resistance, specific gravity d, etc.): It is more preferable that the isocyanate component N1 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 (hereinafter also referred to as "isocyanate component N1"). It is more preferred that the isocyanate component N1 is contained as the main component.

[0023] -Polythiol composition as a raw material for thiourethane resin- The polythiol composition used as a raw material for the thiourethane resin may be of one type only, or may be of two or more types.

[0024] In this disclosure, a polythiol composition refers to a composition that contains at least one polythiol compound. Here, the polythiol compound is not particularly limited as long as it is a compound containing two or more thiol groups (also known as mercapto groups).

[0025] 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. 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 the 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.

[0026] Similarly, in the present disclosure, a composition "containing a certain component (hereinafter referred to as "component X") as a main component" 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.

[0027] The term "%" in the explanation of the above phrase "contains as a major 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.

[0028] Examples of the polythiol compound contained in the polythiol composition as a raw material for the thiourethane resin include known polythiol compounds described in the above-mentioned known literature.

[0029] The polythiol composition as a raw material for the thiourethane resin 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, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, pentaerythritol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), 2,5-dimercaptomethyl-1,4-dithiane, bis(mercaptoethyl) sulfide, and Diethylene glycol bis(mercaptopropionate) It is preferable that the polythiol component contains at least one selected from the group consisting of (hereinafter also referred to as "polythiol component A"). The polythiol composition more preferably contains polythiol component A as the main component. In this case, the polythiol composition may contain at least one component other than the polythiol component A (for example, another polythiol compound, a component other than a polythiol compound, etc.).

[0030] Other polythiol compounds include, for example, methanedithiol, 1,2-ethanedithiol, 1,2,3-propanetrithiol, 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, and 4,6-bis(mercaptomethylthio)-1,3-dithiane.

[0031] More specific embodiments of the polythiol composition as a raw material for the thiourethane resin include: An embodiment containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (hereinafter also referred to as "polythiol component A1") as the main component; an embodiment containing 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 (hereinafter, these three compounds are also collectively referred to as "polythiol component A2") as the main component; An embodiment containing pentaerythritol tetrakis(3-mercaptopropionate) (hereinafter also referred to as "polythiol component A3") as the main component; An embodiment containing polythiol component A1 and polythiol component A3 as main components; An embodiment containing polythiol component A2 and polythiol component A3 as main components; etc. The polythiol composition of each embodiment may contain at least one component other than the main component (for example, other polythiol compound, component other than polythiol compound, etc.).

[0032] -Specific thiourethane resin- In the separation step, the specific thiourethane resin is separated from composition X. The specific thiourethane resin to be separated can be appropriately selected from the thiourethane resins described above.

[0033] An example of a specific thiourethane resin is the following thiourethane resin R1. Thiourethane resin R1 is a cured product of a polymerizable composition containing m-xylylene diisocyanate and a polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (that is, polythiol component A1) as a main component.

[0034] A specific example of a case in which the two or more types of thiourethane resins include the above-mentioned thiourethane resin R1 as the specific thiourethane resin is a case in which the two or more types of thiourethane resins include the above-mentioned thiourethane resin R1 and the following thiourethane resin R2. Thiourethane resin R2 is a polyisocyanate composition containing 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane and 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane as main components; A polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (i.e., polythiol component A1) as a main component; a polythiol composition containing pentaerythritol tetrakis(3-mercaptopropionate) (i.e., polythiol component A3) as a main component; The cured product is a polymerizable composition comprising:

[0035] In this specific embodiment, the two or more thiourethane resins are A thiourethane resin R1 as a specific thiourethane resin (i.e., the target of separation in the separation step); Thiourethane resin R2 is a thiourethane resin of a specific thiourethane resin (i.e., not the target of separation in the separation step); This is an embodiment including the above. However, this specific embodiment is merely an example, and the thiourethane resin R2 may be applied as a specific thiourethane resin. Also, the thiourethane resin R1 does not have to be applied as a specific thiourethane resin.

[0036] -Ingredients other than thiourethane resin- Composition X may contain components other than the thiourethane resin (hereinafter also referred to as "foreign matter"). Composition X may contain, as a foreign matter, at least one selected from the group consisting of, for example, a resin other than a thiourethane resin, a polymerization catalyst, a metal, an ultraviolet absorber, an internal mold release agent, a plasticizer, a dye, machine oil, and water.

[0037] There are no particular limitations on the resins other than the thiourethane resin. for example; A hybrid material of a thiourethane resin and a urethane resin, produced by adding a polyol compound to the raw materials when producing a thiourethane resin; A hybrid material of thiourethane resin and urea resin, produced by adding a polyamine compound to the raw materials when producing the thiourethane resin; Also included in the scope of resin mixtures containing a thiourethane resin and a resin other than a thiourethane resin are the following.

[0038] The resin other than the thiourethane resin preferably includes at least one selected from the group consisting of a polycarbonate resin, a polyallyl carbonate resin, an acrylic resin, a urethane resin, and an episulfide resin. Like thiourethane resins, these resins can also be used as materials for eyeglass lenses.

[0039] In addition, resins other than thiourethane resin include: Polyolefin film for protecting the surface of resin molded bodies used in the manufacture of eyeglass lenses. A hard coat or primer coat for protecting the surface of a resin molded body for producing eyeglass lenses; Abrasives used when polishing resin molded bodies for producing eyeglass lenses; A resin material for fixing a resin molded body when cutting the resin molded body for producing eyeglass lenses; Tape or tape glue used to fix glass molds used when making resin molded bodies for making eyeglass lenses; Other examples include:

[0040] The polymerization catalyst may be the same as that used in forming the thiourethane resin (that is, in polymerizing the monomer). Examples of the polymerization catalyst include tertiary amine compounds, their inorganic or organic acid salts, metal compounds, quaternary ammonium salts, and organic sulfonic acids.

[0041] The metal may be a pure metal or an alloy. Specifically, metals include: Various pure metals such as Al, Ti, Zr, Au, Pt, Ag, Cu, Fe, Bi, Pb, Sn, In, and Ga; Alloys containing at least one pure metallic element (e.g., stainless steel); etc. Metals may be mixed into the thiourethane resin, for example, during at least one of the processes of manufacturing eyeglass lenses, manufacturing eyeglasses, and disposing of eyeglasses.

[0042] Each of the ultraviolet absorber, internal mold release agent, and dye can be added to, for example, a thiourethane resin for producing a lens (e.g., an eyeglass lens). Specific examples of these components can be found in the other components that can be contained in the polymerizable composition. The plasticizer can be contained in a gasket used to hold a molding mold when producing a molded article of a thiourethane resin by cast polymerization, for example. Machine oil and water are each used, for example, when grinding and / or polishing a molded body of thiourethane resin to produce a lens (e.g., an eyeglass lens), and may be mixed into thiourethane resin waste during this process.

[0043] The foreign matter may contain other components in addition to those mentioned above. For other components that may be contained, reference can be made to other components that may be contained in the polymerizable composition described below.

[0044] The content of foreign matter in composition X is preferably 0.001 parts by mass to 150 parts by mass, more preferably 0.001 parts by mass to 100 parts by mass, even more preferably 0.001 parts by mass to 10 parts by mass, even more preferably 0.01 parts by mass to 5 parts by mass, and even more preferably 0.01 parts by mass to 3 parts by mass, assuming that the total amount of the thiourethane resin in composition X is 100 parts by mass.

[0045] The total content of the thiourethane resin and foreign matter in composition X is preferably 80% by mass to 100% by mass, and more preferably 90% by mass to 100% by mass, based on the total amount of composition X.

[0046] -Flake composition X containing two or more kinds of thiourethane resins- Composition X is preferably a crumb composition containing two or more types of thiourethane resins. That is, in the separation step, it is preferable to separate resin scraps of a specific thiourethane resin from the scrap composition X by contacting a scrap composition containing two or more types of thiourethane resins as the composition X (hereinafter also referred to as "scrap composition X") with an aqueous solution of an inorganic salt.

[0047] The scrap composition X is preferably cutting scrap (including the concept of polishing scrap; the same applies hereinafter) containing two or more types of thiourethane resins. Cutting chips are generated, for example, when an optical material (such as a lens) is manufactured by cutting a molded body containing a thiourethane resin.

[0048] In the present disclosure, the scrap composition, cutting scrap, polishing scrap, and resin scrap each include resin powder of thiourethane resin and resin pieces of thiourethane resin.

[0049] (aqueous solution of inorganic salts) In the separation step, the above-mentioned composition X is brought into contact with an aqueous solution of an inorganic salt to separate a specific thiourethane resin (for example, thiourethane resin R1) from composition X.

[0050] There are no particular limitations on the specific manner in which composition X is brought into contact with the aqueous solution of an inorganic salt. Specific embodiments include, for example: An embodiment in which composition X is placed in a container, an aqueous solution of an inorganic salt is added thereto, and the two are mixed; An embodiment in which an aqueous solution of an inorganic salt is placed in a container, and composition X is added thereto and mixed; A combination of these two aspects: etc.

[0051] Furthermore, when bringing composition X into contact with the aqueous solution of the inorganic salt, composition X and the aqueous solution of the inorganic salt may be mixed while blowing an inert gas such as nitrogen gas into the aqueous solution of the inorganic salt, thereby bringing the two into contact with each other.

[0052] In the separation step, composition X and an aqueous solution of an inorganic salt may be mixed and then allowed to stand. This allows the mixture of composition X and the aqueous solution of the inorganic salt to be separated into a composition with a high concentration of the specific thiourethane resin and a composition with a low concentration of the specific thiourethane resin via the aqueous solution of the inorganic salt. In this case, for example, by adjusting the density of the aqueous solution of inorganic salt, the difference in specific gravity between a composition having a high concentration of the specific thiourethane resin and a composition having a high concentration of a substance other than the specific thiourethane resin can be utilized to separate the two.

[0053] The density of the aqueous solution of inorganic salt is adjusted appropriately depending on the type of the specific thiourethane resin, the type of thiourethane resin other than the specific thiourethane resin, the mass ratio of the specific thiourethane resin to the thiourethane resin other than the specific thiourethane resin, etc. Therefore, the density of the aqueous solution of the inorganic salt is not particularly limited. For example, in an embodiment in which the two or more thiourethane resins include thiourethane resin R1 and thiourethane resin R2, the density of the aqueous solution of the inorganic salt is 1.268 g / cm 3 ~1.283g / cm 3 is preferred.

[0054] -Inorganic salts- The inorganic salt preferably contains at least one selected from the group consisting of alkali metal halides and alkaline earth metal halides. The alkali metal halide is preferably an alkali metal chloride, and more preferably sodium chloride, lithium chloride, potassium chloride, rubidium chloride, or cesium chloride. As the alkaline earth metal halide, an alkaline earth metal chloride is preferred, and calcium chloride, strontium chloride, or barium chloride is more preferred.

[0055] Preferably, the inorganic salt comprises calcium chloride.

[0056] The content of the inorganic salt in the aqueous solution of the inorganic salt is adjusted appropriately depending on the composition of composition X, the types of the two or more thiourethane resins, and the like. The content of the inorganic salt in the aqueous solution of the inorganic salt may be, for example, in the range of 5% by mass to 50% by mass, or 10% by mass to 40% by mass, relative to the total amount of the aqueous solution of the inorganic salt.

[0057] -water- The aqueous solution of the inorganic salt comprises water. The water content in the aqueous solution of the inorganic salt is preferably 50% by mass or more, more preferably 60% by mass or more.

[0058] -Other ingredients- The aqueous solution of the inorganic salt may contain other components in addition to water and the inorganic salt. Other components include surfactants (for example, anionic surfactants, cationic surfactants, nonionic surfactants, etc.).

[0059] [Resin composition] The resin composition according to one embodiment of the present disclosure comprises: Contains thiourethane resin R1 and thiourethane resin R2, the ratio of the content of thiourethane resin R2 to the total content of thiourethane resin R1 and thiourethane resin R2 is more than 0 mass% and 10 mass% or less, the thiourethane resin R1 is a cured product of a polymerizable composition containing m-xylylene diisocyanate and a polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as a main component, The thiourethane resin R2 is a cured product of a polymerizable composition including a polyisocyanate composition containing 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane and 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane as main components, a polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as a main component, and a polythiol composition containing pentaerythritol tetrakis(3-mercaptopropionate) as a main component. It is a resin composition.

[0060] The resin composition according to an embodiment of the present disclosure can be obtained, for example, by the decomposition method of the present disclosure described above. In this case, the thiourethane resin R1 corresponds to the specific thiourethane resin.

[0061] A resin composition according to one embodiment of the present disclosure contains a thiourethane resin R1 as a main component, and also contains a trace amount (that is, a content of more than 0 mass % and 10 mass % or less) of a thiourethane resin R2. By including a small amount of thiourethane resin R2, it is expected that industrial operability will be improved.

[0062] [Method for producing thiourethane resin raw material] The method for producing a thiourethane resin raw material according to the present disclosure includes: Separating the specific thiourethane resin by the separation method of the present disclosure; a reaction step of reacting the specific thiourethane resin with an active hydrogen compound to produce a thiourethane resin raw material; Includes: The method for producing a thiourethane resin raw material according to the present disclosure may include other steps as necessary.

[0063] According to the method for producing a thiourethane resin raw material of the present disclosure, a thiourethane resin raw material can be produced as a target product using a thiourethane resin as a starting material. This allows for the reuse (recycling) of materials. In particular, in the method for producing a thiourethane resin raw material of the present disclosure, the thiourethane resin raw material can be produced using the specific thiourethane resin separated by the aforementioned separation method of the present disclosure, making it easier to obtain the desired thiourethane resin raw material.

[0064] Hereinafter, each step that may be included in the method for producing a thiourethane resin raw material according to the present disclosure will be described.

[0065] <Process for separating specific thiourethane resin> For the step of separating a specific thiourethane resin, reference can be made to the description of the separation method of the present disclosure described above.

[0066] <Reaction process> The reaction step is a step in which a specific thiourethane resin is reacted with an active hydrogen compound to produce a thiourethane resin raw material.

[0067] The method for contacting the specific thiourethane resin with the active hydrogen compound is not particularly limited, and examples thereof include a method in which the specific thiourethane resin and the active hydrogen compound (and, if necessary, a reaction solvent) are placed in a reaction vessel and stirred. In this example, the order in which the specific thiourethane resin and the active hydrogen compound (and, if necessary, a reaction solvent) are placed in the reaction vessel is not particularly limited.

[0068] (Specific thiourethane resin) For specific thiourethane resins, reference can be made to the description of the separation method of the present disclosure above.

[0069] (active hydrogen compounds) In the reaction step, the active hydrogen compound functions as a decomposing agent for the specific thiourethane resin. From the viewpoint of the above-mentioned functions, the active hydrogen compound is preferably at least one selected from the group consisting of amine compounds and alcohol compounds.

[0070] -Amine compounds- As the amine compound, which is one of the preferred active hydrogen compounds, known amine compounds can be used without any particular limitation. The amine compound used in the reaction step may be one type only, or two or more types may be used.

[0071] From the viewpoint of further improving the reactivity between the thiourethane resin and the amine compound, the molecular weight of the amine compound is preferably 1,000 or less, more preferably 500 or less, even more preferably 300 or less, and still more preferably 200 or less. The lower limit of the molecular weight of the amine compound is, for example, 45 or more, preferably 59 or more, and more preferably 60 or more.

[0072] The amine compound is preferably an amine compound containing at least one of an amino group and a monoalkylamino group, and having a total of 1 to 6 (preferably 1 to 3, more preferably 1 or 2) amino groups and monoalkylamino groups.

[0073] Examples of preferred amine compounds include: Examples of such amine compounds include those containing at least one of an amino group and a monoalkylamino group, and having a total of 1 or 2 amino groups and monoalkylamino groups, and having a molecular weight of 300 or less.

[0074] Specific examples of the amine compound include alkylamines having 2 to 10 carbon atoms, aralkylamines having 7 to 10 carbon atoms (e.g., benzylamine), dialkylamines having 2 to 10 carbon atoms (e.g., di-n-butylamine), alkyldiamines having 2 to 10 carbon atoms (e.g., ethylenediamine, bis(2-aminoethyl)ether), alkyltriamines having 2 to 10 carbon atoms (e.g., bis(2-aminoethyl)amine), hydroxyalkylamines having 2 to 10 carbon atoms (e.g., monoethanolamine), bis(hydroxyalkyl)amines having 2 to 10 carbon atoms (e.g., bis(hydroxyethyl)amine), cyclic amines having 2 to 10 carbon atoms (e.g., morpholine), and secondary amines such as alkyl(hydroxyalkyl)amines having 2 to 10 carbon atoms (e.g., methylethanolamine, isopropylethanolamine). The amine compound is preferably benzylamine, di-n-butylamine, ethylenediamine, or monoethanolamine.

[0075] -Amount of amine compound- When an amine compound is used as the active hydrogen compound, the charge mass ratio of the amine compound to the thiourethane resin (i.e., charge mass ratio [amine compound / thiourethane resin]) can be adjusted appropriately, but is preferably 0.10 or more and less than 1.0. When the charge mass ratio [amine compound / thiourethane resin] is 0.10 or more, the production of the polythiol composition is further promoted. When the charge mass ratio [amine compound / thiourethane resin] is less than 1.0, the amine compound remaining in the reaction mixture can be further suppressed. The charge mass ratio [amine compound / thiourethane resin] is preferably 0.15 to 0.95, and more preferably 0.20 to 0.90.

[0076] When an amine compound is used as the active hydrogen compound, the number of millimoles of the amine compound charged per 1 g of thiourethane resin is preferably 1.0 mmol / g to 30 mmol / g, more preferably 2.0 mmol / g to 20 mmol / g, and even more preferably 3.0 mmol / g to 10.0 mmol / g.

[0077] When an amine compound is used as the active hydrogen compound, the charge equivalent of the amine compound relative to the thiourethane resin (charge equivalent [amine compound / thiourethane resin]) is preferably 1.0 to 2.0, more preferably more than 1.0 and 1.8 or less, and even more preferably more than 1.0 and 1.6 or less. When the charge equivalent [amine compound / thiourethane resin] is 1.0 or more, the production of the polythiol composition is further promoted. When the charge equivalent [amine compound / thiourethane resin] is 2.0 or less, the amount of the amine compound remaining in the reaction mixture can be further reduced. Here, the charge equivalent of the amine compound relative to the thiourethane resin (charge equivalent [amine compound / thiourethane resin]) means the ratio of the total number of amino groups and monoalkylamino groups in the charged amine compound to the total number of thiourethane bonds in the charged thiourethane resin.

[0078] -Alcohol compounds- The alcohol compound, which is one of the preferred active hydrogen compounds, may be a monoalcohol compound containing only one hydroxy group, or a polyol compound containing two or more hydroxy groups.

[0079] From the viewpoint of further improving the reactivity with the thiourethane resin, the molecular weight of the alcohol compound is preferably 1000 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.

[0080] 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").

[0081] In this disclosure, boiling point means the boiling point at 1 atmosphere (101325 Pa).

[0082] The proportion of alcohol compound A in the total amount of alcohol compounds is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, and even more preferably 80% by mass to 100% by mass.

[0083] As an alcohol compound, 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 preferably, it is benzyl alcohol, phenethyl alcohol, 1-decanol, 1-nonanol, 1-octanol, 1-heptanol, 1-hexanol, 1-pentanol, propylene glycol, or ethylene glycol; More preferred are benzyl alcohol, phenethyl alcohol, 2-octanol, 1-octanol, 1-heptanol, 1-hexanol, 1-pentanol, and propylene glycol.

[0084] The preferred range of the amount of the alcohol compound charged when an alcohol compound is used as the active hydrogen compound is the same as the preferred range of the amount of the amine compound charged when an amine compound is used as the active hydrogen compound.

[0085] When an amine compound and an alcohol compound are used as the active hydrogen compound, the preferred range of the total amount of the amine compound and the alcohol compound to be charged is the same as the preferred range of the amount of the amine compound to be charged when an amine compound is used as the active hydrogen compound, as described above.

[0086] (Reaction solvent) In the reaction step, it is preferable to bring the specific thiourethane resin into contact with the active hydrogen compound in the presence of a reaction solvent. The reaction solvent is preferably an organic solvent, and more preferably a hydrocarbon compound having 5 to 12 carbon atoms (preferably 6 to 10, more preferably 7 to 9). The hydrocarbon compound is preferably hexane, heptane, octane, nonane, decane, xylene, mesitylene, or toluene, more preferably heptane, octane, nonane, xylene, mesitylene, or toluene, and particularly preferably xylene or toluene. The reaction solvent may be one type only, or two or more types.

[0087] (Reaction temperature) The reaction temperature between the specific thiourethane resin and the active hydrogen compound in the reaction step can be adjusted as appropriate. In the reaction step, the specific thiourethane resin is preferably contacted with the active hydrogen compound under temperature conditions (i.e., reaction temperature) of 50°C to 150°C (more preferably 60°C to 145°C, and even more preferably 70°C to 140°C). For example, in a mode of obtaining a polythiol composition as a target product, when the reaction temperature is 50°C to 150°C, the purity of the polythiol component as a main component in the polythiol composition as a target product (i.e., the content of the main component relative to the total amount of the polythiol composition) can be further improved.

[0088] (Reaction time) The reaction time between the specific thiourethane resin and the active hydrogen compound in the reaction step can be adjusted as appropriate, but is preferably 0.1 to 20 hours, more preferably 0.5 to 16 hours, and even more preferably 1 to 10 hours.

[0089] (Thiourethane resin raw material as target product) In the reaction step, the thiourethane resin is reacted with an active hydrogen compound to produce a thiourethane resin raw material as a decomposition product of the thiourethane resin and also as a target product. The target thiourethane resin raw material is a material (i.e., a compound or composition; the same applies below) obtained as a decomposition product of a thiourethane resin, and is also a material that can be used as a raw material for producing a new thiourethane resin. The thiourethane resin raw material as the target product and the thiourethane resin raw material as the starting material for the specific thiourethane resin do not need to be completely identical. Hereinafter, preferred embodiments of the thiourethane resin raw material as the target of the production method of the present disclosure will be described.

[0090] The target thiourethane resin raw material preferably contains at least one compound selected from the group consisting of a polythiol composition, a polyurea compound, a polycarbamate compound, a polyamine compound, a polyisocyanate compound, and a polyurethane compound.

[0091] -Polythiol composition as target product, polyisocyanate compound as target product- Among the target thiourethane resin raw materials, the polythiol composition and the polyisocyanate compound are direct raw materials for producing the thiourethane resin. That is, the thiourethane resin can be produced by reacting the polythiol composition with the polyisocyanate compound. For the polythiol composition and the polyisocyanate compound, known literature on thiourethane resins can be referred to as appropriate. The preferred embodiments of the polyisocyanate compound as the target product are the same as the preferred embodiments of the isocyanate compound as the raw material of the thiourethane resin described above. The preferred embodiments of the polythiol composition as the target product are the same as the preferred embodiments of the polythiol composition as the raw material for the thiourethane resin described above.

[0092] The polythiol composition as the target product and the polythiol composition as the starting material for the specific thiourethane resin do not need to be completely identical. However, from the viewpoint of the performance of the thiourethane resin produced from the polythiol composition as the target product, it is preferable that the type of polythiol component as the main component in the polythiol composition as the target product and the type of polythiol component as the main component in the polythiol composition as the raw material are the same. In this case, for example, an optical material B having performance comparable to that of optical material A can be produced using cutting chips generated during the production of optical material A as the raw material.

[0093] -Polyamine compounds as target substances- The target polyamine compound is a compound that can be used as a raw material for a polyisocyanate compound. Specifically, the polyamine compound can be produced by reacting the polyamine compound with phosgene (i.e., carbonyl dichloride). The target polyamine compound can be produced, for example, by reacting a polyurea compound described below with an amine compound. The target polyamine compound can be produced, for example, by reacting a polycarbamate compound described below with an amine compound.

[0094] -Polyurea compounds as the target product- The polyurea compound as the target product is a compound that can be used as a raw material for a polyamine compound. Specifically, a polyamine compound can be produced by reacting a polyurea compound with an amine compound. The target polyurea compound can be produced, for example, by decomposing the thiourethane resin through a reaction between the thiourethane resin and an amine compound. Specifically, the thiourethane resin can be decomposed into a polythiol composition and a polyurea compound by reacting the thiourethane resin with an amine compound (aminolysis).

[0095] -Polycarbamate compounds as target products- The target polycarbamate compound is a compound that can be used as a raw material for a polyamine compound. Specifically, a polyamine compound can be produced by reacting a polycarbamate compound with an amine compound. The target polycarbamate compound can be produced, for example, by decomposing a thiourethane resin through a reaction between the thiourethane resin and an alcohol compound. Specifically, the thiourethane resin can be decomposed into a polythiol composition and a polycarbamate compound by reacting the thiourethane resin with an alcohol compound (alcoholysis).

[0096] There are no particular limitations on the use of the thiourethane resin raw material as the target product. Specific applications of the target thiourethane resin raw material include a thiourethane resin raw material for producing optical materials (for example, lenses, preferably eyeglass lenses). In other words, a specific example of the method for producing a thiourethane resin raw material according to the present disclosure is a method for producing a thiourethane resin raw material for use in producing optical materials. In this specific example, when cutting chips containing thiourethane resin generated during the production of optical materials are used as the specific thiourethane resin starting material, effective utilization (i.e., recycling) of the materials (thiourethane resin and its raw material, the thiourethane resin raw material) can be effectively realized.

[0097] Furthermore, when a polythiol composition is obtained by reacting a thiourethane resin with an active hydrogen compound in the reaction step, a polythiol composition having a high purity of the polythiol component as the main component can be obtained compared to known methods (e.g., a method of obtaining a polythiol composition by reacting a thiourethane resin with sodium hydroxide). Therefore, even when the polythiol composition as the target product is used in the production of an optical material (for example, a lens), an optical material having good performance can be obtained. The performance of the optical material includes optical properties (for example, refractive index and / or Abbe number), heat resistance, specific gravity d, and the like.

[0098] (Reaction mixture containing thiourethane resin raw material) The reaction step may be a step of contacting composition X with an active hydrogen compound in the presence of a reaction solvent (preferably an organic solvent, more preferably a hydrocarbon compound having 5 to 12 carbon atoms) to react the thiourethane resin in composition X with the active hydrogen compound, thereby obtaining a reaction mixture containing the target thiourethane resin raw material. The reaction mixture may contain the thiourethane resin raw material as a main product produced by decomposition, and other components other than the thiourethane resin raw material. Other components include by-products produced by decomposition, reaction solvents, residues of raw materials, impurities contained in the raw materials, and the like.

[0099] <Target separation process> The method for producing a thiourethane resin raw material according to the present disclosure may include a target product separation step of separating the target thiourethane resin raw material from the reaction mixture containing the thiourethane resin raw material. The separation method in the target product separation step is not particularly limited, and known methods can be applied. Examples of the separation method in the target product separation step include filtration, decantation, extraction, distillation, drying (including drying under reduced pressure), purification (for example, column chromatography), etc. A plurality of separation methods may be used in combination.

[0100] When the thiourethane resin raw material contains a polythiol composition, the target product separation step preferably includes filtering the reaction mixture containing the thiourethane resin raw material obtained in the reaction step to obtain a filtrate containing the polythiol composition. According to this embodiment, it is easier to remove solids contained in the reaction mixture (for example, solids containing by-products). The solid content includes, for example, a polyurea compound and / or a polycarbamate compound. As described above, the polyurea compound and the polycarbamate compound can also be used as raw materials for the thiourethane resin.

[0101] In one preferred embodiment when the target substance separation step includes obtaining a filtrate containing a polythiol composition, The target substance separation step obtaining a filtrate containing a polythiol composition by filtering a reaction mixture containing a thiourethane resin raw material; acid washing the filtrate containing the polythiol composition; Separating the polythiol composition from the acid-washed filtrate; (hereinafter referred to as Separation Mode A). According to Separation Mode A, alkaline components (for example, residues of active hydrogen compounds) can be easily removed from the filtrate by acid washing, so a polythiol composition having a higher purity of the polythiol component as the main component can be obtained. In the separation mode A, a water wash may be added after the acid wash, and the polythiol composition may be separated from the filtrate after the water wash.

[0102] In Separation Mode A, examples of the acid used for acid washing include hydrochloric acid, carbonic acid, nitric acid, sulfuric acid, acetic acid, formic acid, and oxalic acid.

[0103] Another preferred embodiment of the target substance separation step includes obtaining a filtrate containing a polythiol composition, The target substance separation step obtaining a filtrate containing a polythiol composition by filtering a reaction mixture containing a thiourethane resin raw material; adding a base containing an alkali metal to the filtrate containing the polythiol composition, and then adding water to perform extraction, thereby obtaining a water extract containing an alkali metal salt of the polythiol composition; Adding an acid to the aqueous extract containing the alkali metal salt of the polythiol composition to obtain an aqueous liquid containing the polythiol composition; adding an extraction solvent (preferably an organic solvent, more preferably a hydrocarbon compound having 5 to 12 carbon atoms) to an aqueous liquid containing the polythiol composition and performing extraction, thereby obtaining an extract containing the polythiol composition; Separating the polythiol composition from the extract containing the polythiol composition; (hereinafter referred to as Separation Mode B).

[0104] In separation mode B, first, the polythiol composition in the filtrate containing the polythiol composition is converted to an alkali metal salt, and then extracted with water to obtain an aqueous extract containing the alkali metal salt of the polythiol composition. Next, an acid is added to the aqueous extract to return the alkali metal salt of the polythiol composition to the polythiol composition. The polythiol composition is extracted from the resulting aqueous liquid containing the polythiol composition with a reaction solvent to obtain an extract containing the polythiol composition. The polythiol composition is separated from the resulting extract containing the polythiol composition. According to Separation Mode B, even when the filtrate containing the polythiol composition contains a large amount of components other than the polythiol composition, a polythiol composition having a high purity of the polythiol component as the main component can be obtained. In particular, even if foreign matter is contained in the filtrate containing the polythiol composition, the inclusion of the foreign matter in the finally obtained polythiol composition can be prevented.

[0105] In Separation Mode B, the alkali metal in the alkali metal-containing base is preferably sodium, potassium or lithium, more preferably sodium or potassium. Examples of the base containing an alkali metal include sodium methoxide, sodium ethoxide, sodium propoxide, sodium hydroxide, potassium hydroxide, and lithium hydroxide. The base containing an alkali metal can be added to the filtrate in the form of an alcohol solution (methanol solution, ethanol solution, etc.) if necessary.

[0106] In Separation Mode B, examples of the acid added to the aqueous extract containing the alkali metal salt of the polythiol composition include hydrochloric acid, carbonic acid, nitric acid, sulfuric acid, acetic acid, formic acid, and oxalic acid.

[0107] In Separation Mode B, the hydrocarbon compound used as the extraction solvent may be one kind or two or more kinds. In Separation Mode B, the preferred embodiments of the hydrocarbon compound as the extraction solvent are the same as the preferred embodiments of the hydrocarbon compound as the reaction solvent described above. However, the reaction solvent and the extraction solvent may be the same or different.

[0108] In the separation mode B, when separating the polythiol composition from the extract containing the polythiol composition, it is particularly preferable to first filter the extract and then separate the polythiol composition from the filtered extract. This makes it possible to remove components insoluble in the extraction solvent (e.g., oligomer components such as incomplete decomposition products and oxidized products) from the extract, thereby obtaining a polythiol composition having a higher purity of the polythiol component as the main component.

[0109] <Sieving process> The method for producing a thiourethane resin raw material according to the present disclosure may further include a sieving step, prior to the reaction step, of sieving cutting chips as resin chips containing the specific thiourethane resin. When the method for producing a polythiol composition of the present disclosure includes a sieving step, the resin waste (e.g., resin powder) that has passed through a sieve made of particles with small particle sizes is brought into contact with an active hydrogen compound in the reaction step, thereby further improving the reaction efficiency between the thiourethane resin and the active hydrogen compound.

[0110] There are no particular limitations on the sieve. The nominal mesh size of the sieve as defined by JIS Z-8801-1:2019 is, for example, 0.1 mm to 2 mm, preferably 0.3 mm to 2 mm, and more preferably 0.5 mm to 1.5 mm.

[0111] <Cleaning process> The method for producing a thiourethane resin raw material according to the present disclosure may further include a washing step, prior to the reaction step, in which the resin waste containing the specific thiourethane resin is washed with a washing solvent (preferably an organic solvent, more preferably a hydrocarbon compound having 5 to 12 carbon atoms). In this case, in the reaction step, the thiourethane resin in the resin waste washed in the washing step is reacted with an active hydrogen compound. This results in a polythiol composition having a higher purity of the polythiol component as the main component. In particular, in the method for producing a polythiol composition of the present disclosure, when cutting chips as resin chips containing a specific thiourethane resin are used as the starting material, the above-mentioned cleaning step can effectively remove oil derived from the cutting machine that adheres to the cutting chips, thereby obtaining a polythiol composition having a higher purity of the polythiol component as the main component.

[0112] The organic solvent used as the washing solvent may be one kind or two or more kinds. The preferred embodiments of the organic solvent as the washing solvent are the same as the preferred embodiments of the organic solvent as the reaction solvent described above. However, the reaction solvent and the washing solvent may be the same or different.

[0113] There are no particular limitations on the washing method used in the washing step, and known methods can be used, such as a method in which the above-mentioned washing solvent is added to and mixed with resin waste containing a specific thiourethane resin.

[0114] When the method for producing a thiourethane resin raw material according to the present disclosure includes the sieving step and the washing step, the sieving step and the washing step are preferably performed in this order, which eliminates the need to wash away the cutting chips that did not pass through the sieve, thereby further reducing the amount of washing solvent used.

[0115] Furthermore, when the resin waste containing the specific thiourethane resin contains moisture, a drying step may be included for the purpose of removing moisture before the reaction step.

[0116] [Method for producing polymerizable composition] The method for producing a polymerizable composition of the present disclosure includes: A step of producing a thiourethane resin raw material by the method for producing a thiourethane resin raw material of the present disclosure; obtaining a polymerizable composition using at least a portion of the thiourethane resin raw material as at least a portion of a raw material; Includes: The method for producing the polymerizable composition of the present disclosure may include other steps as necessary.

[0117] In the method for producing a polymerizable composition of the present disclosure, In a step of producing a polythiol composition, a thiourethane resin raw material is produced using a specific thiourethane resin as a starting material, In the step of obtaining a polymerizable composition, at least a portion of the thiourethane resin raw material produced above is used as at least a portion of the raw material to produce a polymerizable composition. The resulting polymerizable composition can be reused to produce a thiourethane resin. In this way, the method for producing a polymerizable composition of the present disclosure realizes effective utilization (i.e., recycling) of materials (i.e., thiourethane resin and its raw materials).

[0118] Furthermore, as described above, the method for producing a thiourethane resin raw material according to the present disclosure produces a polythiol composition having a high purity of the polythiol component as the main component, compared to known methods (e.g., a method for producing a polythiol composition by reacting a thiourethane resin with sodium hydroxide). In the method for producing a polymerizable composition of the present disclosure, such a polythiol composition is used. Therefore, the polymerizable composition obtained by the method for producing a polymerizable composition of the present disclosure can produce a resin having excellent properties (e.g., optical properties (e.g., refractive index and / or Abbe number), heat resistance, specific gravity d, etc.). Therefore, 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.

[0119] <Process for producing thiourethane resin raw material> For the process for producing a thiourethane resin raw material, the above-described method for producing a thiourethane resin raw material of the present disclosure can be referred to as appropriate.

[0120] <Step of Obtaining Polymerizable Composition> In the step of obtaining a polymerizable composition, at least a portion of the thiourethane resin raw material obtained in the step of producing a thiourethane resin raw material is used as at least a portion of the raw material to obtain the polymerizable composition.

[0121] In the step of obtaining the polymerizable composition, at least a portion of the thiourethane resin raw material obtained in the step of producing the thiourethane resin raw material is used, and if necessary, this at least a portion may be mixed with other components.

[0122] The other components include thiourethane resin raw materials (for example, new thiourethane resin raw materials) other than the thiourethane resin raw material obtained in the process of producing the thiourethane resin raw material (that is, the recycled thiourethane resin raw material).

[0123] The polymerizable composition preferably contains a polythiol composition and a polyisocyanate compound as monomers. In this case, the polythiol composition preferably includes a polythiol composition that is a recycled product.

[0124] Examples of other components include a polymerization catalyst, an internal mold release agent, a resin modifier, a chain extender, a crosslinking agent, a radical scavenger, a light stabilizer, an ultraviolet absorber, an antioxidant, an oil-soluble dye, a filler, an adhesion improver, an antibacterial agent, an antistatic agent, a dye, a fluorescent brightener, a fluorescent pigment, and an inorganic pigment.

[0125] Examples of the polymerization catalyst include tertiary amine compounds, their inorganic or organic acid salts, metal compounds, quaternary ammonium salts, and organic sulfonic acids. The internal mold release agent may be an acidic phosphate ester, such as a monophosphate ester or a diphosphate ester, which may be used alone or in combination of two or more. 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. Examples of the ultraviolet absorber include triazine-based ultraviolet absorbers and benzotriazole-based ultraviolet absorbers.

[0126] [Method for producing resin] The method for producing a resin according to the present disclosure includes: a step of producing a polymerizable composition by the method for producing a polymerizable composition according to the present disclosure; a step of curing the polymerizable composition to obtain a resin; Includes: The method for producing a resin according to the present disclosure may include other steps as necessary. According to the method for producing a resin of the present disclosure, the same effects as those of the method for producing a polymerizable composition of the present disclosure described above can be achieved.

[0127] The resin produced by the resin production method of the present disclosure and the resins of the present disclosure described below are both thiourethane resins, but in this disclosure they will be simply referred to as "resins" to distinguish them from the thiourethane resin that is one of the starting materials for the thiourethane resin raw material.

[0128] In the step of obtaining a resin, the polymerizable composition is cured to obtain a resin. The polymerizable composition can be cured by polymerizing the monomers in the polymerizable composition (for example, a polythiol composition and a polyisocyanate compound; the same applies hereinafter). As a pretreatment for polymerization, the polymerizable composition may be subjected to treatments such as filtration and 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 monomers 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.

[0129] In the step of obtaining the resin, the polymer obtained by polymerizing the monomer may be subjected to a treatment such as annealing to obtain the resin. The annealing temperature is preferably 50°C to 150°C, more preferably 90°C to 140°C, and even more preferably 100°C to 130°C.

[0130] [Method for producing molded body] The method for producing a molded article according to the present disclosure is a method for producing a molded article containing a resin, comprising: a step of producing a polymerizable composition by the method for producing a polymerizable composition according to the present disclosure; a step of curing the polymerizable composition to obtain a molded article containing a resin; Includes: The method for producing a molded article according to the present disclosure may include other steps as necessary. According to the method for producing a molded article of the present disclosure, the same effects as those of the method for producing a polymerizable composition of the present disclosure described above can be achieved.

[0131] In the step of obtaining a molded article containing a resin, the polymerizable composition is cured to obtain a molded article containing a resin. For preferable conditions for curing the polymerizable composition, i.e., for polymerizing the monomers in the polymerizable composition, the section "Method for producing resin" can be referred to as appropriate.

[0132] An example of the polymerization in this step is cast polymerization. In cast polymerization, the polymerizable composition is first poured into a mold held by a gasket or tape, etc. At this time, degassing treatment, filtration treatment, etc. may be carried out as necessary. Next, the monomer in the polymerizable composition injected between the molds is polymerized to cure the composition between the molds, and the cured product is then removed from the molds to obtain a molded article containing the resin. The polymerization of the monomer may be carried out by heating the polymerizable composition, for example, using a heating device equipped with a mechanism for heating an object to be heated in an oven, water, or the like.

[0133] [Methods for manufacturing optical materials and lenses] The method for producing an optical material (e.g., a lens) according to the present disclosure is a method for producing an optical material (e.g., a lens) including a molded body containing a resin, the method comprising: a step of producing a polymerizable composition by the method for producing a polymerizable composition according to the present disclosure; a step of curing the polymerizable composition to obtain a molded article containing a resin; Includes: The method for producing an optical material (for example, a lens; the same applies hereinafter) of the present disclosure may include other steps as necessary. According to the method for producing an optical material of the present disclosure, the same effects as those of the method for producing a polymerizable composition of the present disclosure described above can be achieved.

[0134] The method for producing an optical material according to the present disclosure is an application of the method for producing a molded article according to the present disclosure. For example, in the method for producing a molded article according to the present disclosure, by appropriately selecting the shape of the mold used in the above-described cast polymerization, a molded article applicable to optical materials (for example, lenses) can be obtained.

[0135] Examples of optical materials include lenses (for example, eyeglass lenses, camera lenses, and polarized lenses), light-emitting diodes (LEDs), and the like.

[0136] The method for producing an optical material (for example, a lens) according to the present disclosure may include a step of forming a coating layer on one or both sides of a molded article containing a resin.

[0137] Specific examples of the coating layer include a primer layer, a hard coat layer, an anti-reflection layer, an anti-fogging coat layer, an anti-fouling layer, and a water-repellent layer. These coating layers may be formed individually or in a multi-layer structure of multiple coating layers. When coating layers are formed on both sides, the same coating layer may be formed on each side, or different coating layers may be formed on each side.

[0138] The components of the coating layer can be appropriately selected depending on the purpose. Examples of components of the coating layer include resins (e.g., urethane resins, epoxy resins, polyester resins, melamine resins, polyvinyl acetal resins, etc.), infrared absorbers, light stabilizers, antioxidants, photochromic compounds, dyes, pigments, and antistatic agents.

[0139] For details about eyeglass lenses and coating layers, reference can be made as appropriate to the descriptions in publicly known documents such as JP 2002-194083 A and WO 2017 / 047745 A.

[0140] [Polymerizable composition] The polymerizable composition of the present disclosure contains at least a portion of the thiourethane resin raw material obtained by the above-described method for producing a thiourethane resin raw material of the present disclosure. The polymerizable composition of the present disclosure can be produced by the method for producing a polymerizable composition of the present disclosure described above. According to the polymerizable composition of the present disclosure, the same effects as those of the method for producing the polymerizable composition of the present disclosure described above can be achieved. For preferred embodiments of the polymerizable composition of the present disclosure, the above-described method for producing the polymerizable composition of the present disclosure can be referred to as appropriate.

[0141] [Resins, molded products, optical materials (e.g. lenses)] The resin of the present disclosure is a cured product of the polymerizable composition of the present disclosure described above. The molded article of the present disclosure is a molded article containing the resin of the present disclosure described above. The optical material (for example, a lens) of the present disclosure is an optical material (for example, a lens) containing the resin of the present disclosure described above. The resin, molded article, and optical material (for example, lens) of the present disclosure exhibit the same effects as those of the method for producing a polymerizable composition of the present disclosure described above.

[0142] The resin of the present disclosure, the molded article of the present disclosure, and the optical material (e.g., a lens) of the present disclosure can be produced by the above-mentioned method for producing the resin of the present disclosure, the method for producing the molded article of the present disclosure, and the method for producing the optical material (e.g., a lens) of the present disclosure, respectively. For preferred aspects of the resin of the present disclosure, the molded article of the present disclosure, and the optical material (e.g., a lens) of the present disclosure, reference can be made to the preferred aspects of the method for producing the resin of the present disclosure, the method for producing the molded article of the present disclosure, and the method for producing the optical material (e.g., a lens) of the present disclosure, respectively.

[0143] <Preferable properties of resin or molded product> From the viewpoint of heat resistance, the glass transition temperature Tg of the resin (or molded article) of the present disclosure is preferably 80° C. or higher, and more preferably 85° C. or higher. The glass transition temperature Tg may be 105°C or lower, or may be 100°C or lower.

[0144] From the viewpoint of application to optical materials, the refractive index (ne) of the resin (or molded article) of the present disclosure is preferably 1.550 or more, more preferably 1.600 or more, and even more preferably 1.650 or more. There is no particular upper limit to the refractive index (ne), but the upper limit is, for example, 1.700.

[0145] The Abbe number of the resin (or molded article) of the present disclosure is preferably 28 or more, and more preferably 30 or more, from the viewpoint of application to optical materials. There is no particular upper limit to the Abbe number, but the upper limit is, for example, 40, and preferably 35.

[0146] From the viewpoint of application to optical materials, the specific gravity d of the resin (or molded article) of the present disclosure is preferably 1.00 or more. There is no particular upper limit to the specific gravity d, but from the viewpoint of application to optical materials, the upper limit is, for example, 1.50, and preferably 1.40. [Example]

[0147] Examples of the present disclosure will be described below, but the present disclosure is not limited to the following examples. Hereinafter, unless otherwise specified, "%" means "mass %," and "room temperature" means 25°C.

[0148] Hereinafter, the purity (mass%) of polythiol component A1 in the polythiol composition means the content (mass%) of polythiol component A1 relative to the total amount of the polythiol composition, and more specifically, means the content (mass%) of polythiol component A1 relative to the total amount of the polythiol composition, measured by high performance liquid chromatography under the following conditions and determined using an internal standard substance.

[0149] (High performance liquid chromatography conditions) Column: YMC-Pack ODS-A (particle size S: 5 μm, 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: 160 mg of sample and 150 mg of internal standard (1,2,4-trimethylbenzene) are dissolved and mixed in 10 ml of acetonitrile. Injection volume: 2μL

[0150] <Measurement of the purity of the target substance contained in resin waste> The purity (ratio) of the target substance contained in the resin waste, including resin pieces and resin powder, can be determined by FT-IR measurement based on the following method.

[0151] (FT-IR conditions) Shimadzu IRSpirit

[0152] (FT-IR measurement method) 100 resin pieces are randomly selected from the resin waste containing resin pieces and resin powder, and each piece is analyzed by FT-IR. The FT-IR chart of each resin piece was compared with the FT-IR charts of several types of eyeglass lenses measured in advance, and it was confirmed which eyeglass lens peak matched the peak of the FT-IR chart of each resin piece. Based on the confirmed results, the content ratio (mass%) of the target substance contained in 100 resin pieces was calculated, and the obtained content ratio (mass%) was taken as the purity (mass%) of the target substance contained in the resin scraps. For example, thiourethane resin has a viscosity of 1640 cm -1 A characteristic peak of a thiourethane bond is observed around 1736 cm. In addition, a method for distinguishing between thiourethane resin R1 and thiourethane resin R2 is to look for the peak (1736 cm) of an ester bond derived from a polythiol composition containing pentaerythritol tetrakis(3-mercaptopropionate) (i.e., polythiol component A2) as the main component, which is contained only in thiourethane resin R2. -1 They can be distinguished by the presence or absence of a

[0153] [Reference production example 1] <Production of Molded Body 1 Containing Thiourethane Resin R1> In a flask equipped with a stirrer, Dimethyltin dichloride (trade name: Nestin P, manufactured by Honjo Chemical Co., Ltd.) as a polymerization catalyst (100 ppm by mass based on the total amount of the polyisocyanate compound described below and the polythiol composition T1 described below), Zelec-UN (manufactured by Stepan; acidic phosphate ester) as a release agent (1000 ppm by mass based on the total amount of the polyisocyanate compound described below and the polythiol composition T1 described below), m-xylylene diisocyanate (XDI) (52 parts by mass), which is a polyisocyanate compound; A polythiol composition T1 (48 parts by mass) containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (i.e., polythiol component A1) as a main component, The mixture was stirred and mixed at room temperature for 1 hour to obtain a polymerizable composition which was a transparent homogeneous solution.

[0154] Next, the polymerizable composition was filtered under reduced pressure using a PTFE (polytetrafluoroethylene) filter and then thoroughly degassed under a reduced pressure of 600 Pa until no more foaming was observed. The degassed polymerizable composition was poured between a pair of glass molds secured with tape. The pair of glass molds were then placed in an oven, with the oven temperature set to 10°C. The oven temperature was then raised from 10°C to 120°C over 38 hours. Through the above process, the monomers (polyisocyanate compound and polythiol composition T1) in the degassed polymerizable composition were polymerized, and a molded product 1 containing a thiourethane resin R1 (i.e., a cured product of a polymerizable composition containing m-xylylene diisocyanate and a polythiol composition T1 mainly composed of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane) was formed between the pair of glass molds. Subsequently, the inside of the oven was cooled, and after cooling, the pair of glass molds was taken out of the oven, and then the molded body 1 was removed from the pair of glass molds, thereby obtaining the molded body 1.

[0155] <Production of thiourethane resin scrap R1> A lens was manufactured by cutting the molded body 1 obtained above. Cutting waste generated during this process was collected to obtain thiourethane resin waste R1 (that is, resin waste containing thiourethane resin R1). The thiourethane resin scraps R1 (ie, cutting scraps) contain resin pieces and resin powder (the same applies to the thiourethane resin scraps R2 described below).

[0156] [Reference production example 2] <Production of Molded Body 2 Containing Thiourethane Resin R2> In a flask equipped with a stirrer, Dibutyltin dichloride as a polymerization catalyst (600 ppm by mass relative to the total amount of the polyisocyanate compound shown below, the polythiol composition T1 shown below, and the polythiol composition T2 shown below), Zelec-UN (Stepan; acidic phosphate ester) as a release agent (1200 ppm by mass based on the total amount of the polymerizable composition obtained), a polyisocyanate composition (50.6 parts by mass) based on 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane and 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane; A polythiol composition T1 (25.6 parts by mass) containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (i.e., polythiol component A1) as a main component, A polythiol composition T2 (23.9 parts by mass) containing pentaerythritol tetrakis(3-mercaptopropionate) (i.e., polythiol component A2) as a main component, The mixture was stirred and mixed at room temperature (25°C) for 1 hour to obtain a polymerizable composition which was a transparent homogeneous solution. A molded body 2 containing thiourethane resin R2 was produced in the same manner as in the production of molded body 1 containing thiourethane resin R1 and the production of thiourethane resin scraps R1, except that the obtained polymerizable composition was used. Here, thiourethane resin R2 is a cured product of a polymerizable composition containing a polyisocyanate composition containing 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane and 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane as main components, a polythiol composition T1 containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as a main component, and a polythiol composition T2 containing pentaerythritol tetrakis(3-mercaptopropionate) as a main component.

[0157] <Production of thiourethane resin scrap R2> A lens was manufactured by cutting the molded body 2 obtained above. Cutting waste generated during this process was collected to obtain thiourethane resin waste R2 (that is, resin waste containing thiourethane resin R2).

[0158] Example 1 <Production of composition X containing two or more types of thiourethane resins (composition X1)> The thiourethane resin scrap R1 obtained in Reference Manufacturing Example 1 and the thiourethane resin scrap R2 obtained in Reference Manufacturing Example 2 were mixed in a ratio such that the ratio of the mass of the thiourethane resin scrap R1 to the mass of the thiourethane resin scrap R2 (hereinafter also referred to as the mass ratio [R1 / R2]) was 3 / 7, thereby obtaining a composition X1 containing two types of thiourethane resins (i.e., thiourethane resin R1 and thiourethane resin R2).

[0159] <Separation of thiourethane resin> Example 1 shows an example in which thiourethane resin R1 was separated from composition X containing two or more types of thiourethane resins. Details will be explained below.

[0160] (Preparation of calcium chloride aqueous solution) By mixing calcium chloride decahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and pure water in a 20 L tank, a calcium chloride solution with a concentration of 31.0% and a density of 1.283 g / cm3 was obtained. 3 An aqueous calcium chloride solution was obtained.

[0161] (separation process) Composition X1 (500 g) was added to the above aqueous calcium chloride solution (volume: 15 L) adjusted to a temperature of 20° C., and mixed for 10 minutes while blowing nitrogen gas into the mixture. The resulting mixture was allowed to stand for 30 minutes, whereby the resin waste RL, which has a lower density than the calcium chloride aqueous solution, floated to the surface by specific gravity separation, and the resin waste RH, which has a higher density than the calcium chloride aqueous solution, settled, thereby separating the two (this is the separation process).

[0162] Next, the resin waste RL and the resin waste RH were collected separately. The separated and collected resin waste RL and resin waste RH were washed with pure water, and then dried in a vacuum drying oven at 90°C for 3 hours to remove moisture. The resin waste RH was analyzed by FT-IR, and the mass ratio [R1 / R2] (that is, the ratio of the mass of resin waste R1 to the mass of resin waste R2) in the resin waste RH was measured and found to be 9 / 1.

[0163] As described above, by the separation step of contacting composition X1 containing resin scraps R1 and R2 in a mass ratio [R1 / R2] of 3 / 7 with an aqueous solution of calcium chloride, which is an aqueous solution of inorganic salts, resin scraps RH containing resin scraps R1 and R2 in a mass ratio [R1 / R2] of 9 / 1 was obtained. That is, by the separation step, resin scraps R1 could be separated from composition X1.

[0164] Next, the calcium chloride concentration in the aqueous calcium chloride solution was changed in various ways to change the density, and the same operation as in the above separation step was carried out. As a result, the density of the calcium chloride solution was 1.268 g / cm 3 ~1.283g / cm 3 It was confirmed that when the specific gravity difference is within this range, the resin waste RL and the resin waste RH can be separated in the same manner as in the above separation step (that is, the resin waste R1 can be separated from the composition X1 by separation based on the difference in specific gravity).

[0165] Example 101 <Production of thiourethane resin raw material (polythiol composition)> Example 101 shows an example in which a polythiol composition, which is a thiourethane resin raw material, was produced by reacting the thiourethane resin R1 in the resin waste RH obtained in Example 1 (i.e., the resin waste RH containing the resin waste R1 and the resin waste R2 in a mass ratio [R1 / R2] = 9 / 1) with monoethanolamine as an active hydrogen compound. Details are explained below.

[0166] (Reaction step) The resin waste RH obtained in Example 1 (i.e., resin waste RH containing resin waste R1 and resin waste R2 in a mass ratio [R1 / R2] = 9 / 1) (100 g) was placed in a 500 mL flask equipped with a condenser, and monoethanolamine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (40.5 g; 0.663 mol) and toluene (193 g) were added thereto. The mixture was heated and stirred at 90°C for 5 hours to obtain a reaction mixture containing a polythiol composition (this is the reaction process).

[0167] (Separation of Polythiol Composition from Reaction Mixture) The reaction mixture obtained in the reaction step was subjected to a separation operation including extraction according to the above-described separation mode B, whereby the polythiol composition was separated from the reaction mixture. Details are described below. The reaction mixture obtained in the reaction step was cooled to 60°C, and then solids were removed by filtration. 23 g of 35% hydrochloric acid was added to the obtained filtrate and washed at 40°C, followed by 75 g of water and washing at 40°C. Next, 59 g of 31% aqueous sodium hydroxide solution was added and stirred at 40°C. 75 g of water was added to this and the soluble components were extracted at 40°C, and the resulting aqueous extract was washed twice with 100 g of toluene at 40°C. Next, 105 g of 35% hydrochloric acid was added to the obtained aqueous extract and stirred. The soluble components were extracted from the obtained aqueous liquid with 150 g of toluene at 40°C to obtain a toluene extract. This toluene extract was washed three times with 75 g of water at 40°C to obtain a toluene solution of a polythiol composition. The toluene was removed from the resulting toluene solution using a rotary evaporator. The resulting mixture was subjected to removal of low-boiling components using a vacuum pump and filtration through a 1-micron PTFE membrane filter, yielding 35.05 g of polythiol composition T101, primarily composed of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (i.e., polythiol component A1).

[0168] <Measurement> The following measurements were carried out on the obtained polythiol composition T101. The results are shown in Table 1.

[0169] -Purity of polythiol component A1 (mass%)- The purity (mass %) of the polythiol component A1 in the polythiol composition was measured by high performance liquid chromatography under the conditions described above.

[0170] -SH value (mmol / g)- Using a potentiometric automatic titrator manufactured by Kyoto Electronics Manufacturing Co., Ltd. and a 0.05 mol / L iodine solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), the SH value (mmol / g) of polythiol composition T101 (i.e., the number of millimoles of thiol groups per 1 g of polythiol composition; the same applies below) was measured.

[0171] -Refractive index- The refractive index of the polythiol composition T101 was measured using a refractometer RA-600 manufactured by Kyoto Electronics Manufacturing Co., Ltd.

[0172] -YI (yellowness index), L*, a*, and b*- For the polythiol composition T101, the YI (yellowness index) and L*, a*, and b* in the CIE1976 (L*, a*, b*) color system were measured using a spectrophotometer (CM-5 manufactured by Konica Minolta) with a cell length of 1 cm.

[0173] [Table 1]

[0174] As described above, by reacting the thiourethane resin R1 in the resin waste RH obtained in Example 1 (i.e., resin waste RH containing resin waste R1 and resin waste R2 in a mass ratio [R1 / R2] = 9 / 1) with monoethanolamine as an active hydrogen compound, it was possible to produce polythiol composition T101, a thiourethane resin raw material. The obtained polythiol composition T101 has excellent purity of the contained polythiol component A1, and good SH value and optical properties (specifically, refractive index, YI, a * , b * , and L *) could be prepared.

[0175] Example 201 (Production of molded body 201 containing thiourethane resin) A molded body 201 containing a thiourethane resin was obtained by the same procedure as in the production of molded body 1 in Reference Production Example 1, except that the polythiol composition T1 (48 parts by mass) in Reference Production Example 1 was changed to the polythiol composition T101 (48 parts by mass) obtained in Example 101. The obtained molded article had good transparency, was free from distortion, and had a good appearance.

[0176] The molded article obtained above was subjected to a performance test. The results are shown in Table 2. The performance test items were optical properties (refractive index and Abbe number), heat resistance, and color hue. Each test was carried out using the following test methods. Refractive index (ne), Abbe number (νe): Using a Pulfrich refractometer KPR-30 manufactured by Shimadzu Corporation, the refractive indices (ne, nF', nC') were measured at wavelengths of 546.1 nm (mercury e-line), 480.0 nm (Cd F'-line), and 643.9 nm (Cd C'-line), respectively, and the refractive index (ne) and Abbe number (νe) were calculated. ·Heat resistance: The glass transition temperature (Tg) was measured using a thermomechanical analyzer TMA-60 manufactured by Shimadzu Corporation by the TMA penetration method (50 g load, pin tip 0.5 mmφ, heating rate 10°C / min) and used as an index of heat resistance. ·Yellowness (YI): Using a spectrophotometer (CM-5 manufactured by Konica Minolta), the yellowness index (YI) was measured on a 9 mm thick flat plate, and used as an index of the hue of the optical material.

[0177] [Table 2]

[0178] As shown in Table 2, a molded body 201 containing a thiourethane resin could be produced using the polythiol composition T101 produced from the resin waste RH. The obtained molded body 201 was excellent in optical properties, heat resistance, and color.

Claims

1. a separation step of contacting a composition X containing two or more thiourethane resins with an aqueous solution of an inorganic salt to separate a specific thiourethane resin from the composition X; Method for separating thiourethane resin.

2. 2. The method for separating a thiourethane resin according to claim 1, wherein the inorganic salt comprises at least one selected from the group consisting of alkali metal halides and alkaline earth metal halides.

3. The method for separating a thiourethane resin according to claim 1 or claim 2, wherein the inorganic salt includes calcium chloride.

4. The method for separating a thiourethane resin according to any one of claims 1 to 3, wherein the composition X is recovered during at least one of a process for manufacturing eyeglass lenses, a process for manufacturing eyeglasses, and a process for disposing of eyeglasses.

5. The method for separating a thiourethane resin according to any one of claims 1 to 4, wherein composition X further contains at least one selected from the group consisting of a resin other than a thiourethane resin, a polymerization catalyst, a metal, an ultraviolet absorber, an internal mold release agent, a plasticizer, a dye, machine oil, and water.

6. the specific thiourethane resin is thiourethane resin R1, The thiourethane resin R1 is a cured product of a polymerizable composition containing m-xylylene diisocyanate and a polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as a main component. The method for separating a thiourethane resin according to any one of claims 1 to 5.

7. The two or more types of thiourethane resins include the thiourethane resin R1 and the thiourethane resin R2, the thiourethane resin R2 is a cured product of a polymerizable composition containing a polyisocyanate composition containing 2,5-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane and 2,6-bis(isocyanatomethyl)bicyclo-[2.2.1]-heptane as main components, a polythiol composition containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as a main component, and a polythiol composition containing pentaerythritol tetrakis(3-mercaptopropionate) as a main component; The method for separating a thiourethane resin according to claim 6.

8. A step of separating the specific thiourethane resin by the method for separating a thiourethane resin according to any one of claims 1 to 7; a reaction step of reacting the specific thiourethane resin with an active hydrogen compound to produce a thiourethane resin raw material; A method for producing a thiourethane resin raw material, comprising:

9. 9. The method for producing a thiourethane resin raw material according to claim 8, wherein the active hydrogen compound is at least one selected from the group consisting of an amine compound and an alcohol compound.

10. A step of producing a thiourethane resin raw material by the method for producing a thiourethane resin raw material according to claim 8 or 9; producing a polymerizable composition using at least a portion of the thiourethane resin raw material as at least a portion of a raw material; A method for producing a polymerizable composition comprising:

11. A step of producing a polymerizable composition by the method for producing a polymerizable composition according to claim 10; curing the polymerizable composition to obtain a resin; A method for producing a resin comprising:

12. A method for producing a molded article containing a resin, comprising: A step of producing a polymerizable composition by the method for producing a polymerizable composition according to claim 10; a step of curing the polymerizable composition to obtain a molded article containing a resin; A method for producing a molded body comprising the steps of:

13. A method for producing an optical material including a molded article containing a resin, comprising: A step of producing a polymerizable composition by the method for producing a polymerizable composition according to claim 10; a step of curing the polymerizable composition to obtain a molded article containing a resin; A method for producing an optical material comprising the steps of:

14. A method for producing a lens including a molded article containing a resin, comprising: A step of producing a polymerizable composition by the method for producing a polymerizable composition according to claim 10; a step of curing the polymerizable composition to obtain a molded article containing a resin; A method for manufacturing a lens comprising:

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