Composition and optical materials and lenses using the same

Abstract

A composition is provided that yields an optical material having a high refractive index and excellent color tone. Formula (1): A composition comprising a compound (a) and a polythiol (b) represented by [wherein Ar represents an aromatic ring, m represents an integer from 2 to 8, and n represents an integer from 0 to 6, provided that m+n is less than or equal to the number of carbon atoms constituting the aromatic ring, and R1 each independently represents an alkylthio group, an epoxyalkylthio group, a thiol group, a halogen group, a hydroxyl group, a dialkylthiocarbamoyl group, or a dialkylcarbamoylthio group.]

Description

Technology Field

[0001] The present invention relates to a composition and an optical material and lens using the same. Background Technology

[0002] Optical materials, particularly those used for eyeglass lenses, require optical performance characteristics such as heat resistance, low specific gravity, high transparency, low yellowness, high refractive index, and high Abbe number. Recently, there has been a demand for additional high performance, with a particular need for optical materials possessing high refractive index and high Abbe number.

[0003] Polymerizable compositions for optical materials using episulfide compounds are attracting attention as materials for realizing high refractive index and high Abbe number. For example, Patent Document 1 describes an invention regarding a polymerizable composition containing a thioepoxy compound having one or more disulfide bonds within the molecule, such that the refractive index (nd) of the cured resin is 1.71 or higher. At this time, it is described that bis(2,3-epithiopropyl)disulfide is most preferred as the thioepoxy compound having one or more disulfide bonds within the molecule. Prior art literature

[0004] Japanese Patent Publication No. 2002-194083 The problem to be solved

[0005] According to the polymerizable composition described in Patent Document 1, an optical material with a high refractive index can be obtained. However, additional optical materials with a high refractive index are required. Furthermore, it has been found that as the refractive index of an optical material increases, the hue may deteriorate. Accordingly, the present invention provides a composition that enables the acquisition of an optical material with a high refractive index and excellent hue. means of solving the problem

[0006] The inventors have conducted diligent research to solve the above problem. As a result, they discovered that the above problem can be solved by combining an episulfide compound having an aromatic backbone and a polythiol compound, and thus completed the present invention. That is, the present invention is, for example, as follows.

[0007] [1] The following formula (1):

[0008] [Chemical Formula 1]

[0009]

[0010] [Among the above formulas,

[0011] Ar represents the directional ring,

[0012] m represents an integer from 2 to 8, and

[0013] n represents an integer from 0 to 6, and

[0014] However, m+n is less than or equal to the number of carbon atoms constituting the directional ring, and

[0015] R 1 Each represents, independently, an alkylthio group, an epoxyalkylthio group, a thiol group, a halogen group, a hydroxyl group, a dialkylthiocarbamoyl group, or a dialkylcarbamoylthio group.

[0016] A composition comprising a compound (a) and a polythiol (b) represented by

[0017] [2] The composition described in [1] above, in which Ar is an aromatic ring consisting of carbon and hydrogen.

[0018] [3] A composition described in [1] or [2] above, wherein m is 2 or 3.

[0019] [4] A composition described in any one of [1] to [3] above, wherein m+n is 2 to 6.

[0020] [5] A composition described in any one of [1] to [4], wherein the content of the above compound (a) is 5 to 95 mass% with respect to the total mass of the composition.

[0021] [6] The above polythiol(b) is 1,2,6,7-tetramercapto-4-thiaheptane, methanedithiol, (sulfanylmethyldisulfanyl)methanethiol, bis(2-mercaptoethyl)sulfide, 2,5-bis(mercaptomethyl)-1,4-dithiane, 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, A composition described in any one of [1] to [5] comprising at least one selected from the group consisting of tetramercaptopentaerythritol, 1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, and tyranmethanethiol.

[0022] [7] The following formula (2):

[0023] [Chemical Formula 2]

[0024]

[0025] [Among the above formulas,

[0026] p represents an integer from 0 to 4, and

[0027] q represents an integer between 0 and 2.

[0028] A composition described in any one of [1] to [6], further comprising a compound (c) represented by .

[0029] [8] A composition described in any one of [1] to [7] above, which additionally contains sulfur.

[0030] [9] A composition described in any one of [1] to [8], further comprising a prepolymerization catalyst.

[0031]

[10] The composition described in [9] comprises at least one of the prepolymerization catalysts selected from the group consisting of 2-mercapto-1-methylimidazole, 2-methyl-N-imidazole, and 1,2,2,6,6-pentamethylpiperidyl methacrylate.

[0032]

[11] A pre-cured product formed by pre-polymerizing any one of the compositions described in [1] to

[10] above.

[0033]

[12] An optical material formed by curing the composition described in any one of [1] to

[10] above or the pre-cured material described in

[11] above.

[0034]

[13] An optical lens comprising the optical material described in

[12] above. Effects of the invention

[0035] According to the present invention, a composition is provided that yields an optical material having a high refractive index and excellent color tone. Specific details for implementing the invention

[0036] The present invention is described in detail below by presenting embodiments and examples, but the present invention is not limited to the embodiments and examples shown below and may be implemented with arbitrary modifications within the scope that does not deviate from the gist of the present invention.

[0037] <Composition>

[0038] The composition according to the present invention comprises a compound (a) represented by formula (1) and a polythiol (b). In addition, it may further comprise a compound (c) represented by formula (2), sulfur, a polymerizable compound, a prepolymerization catalyst, a polymerization catalyst, a polymerization regulator, an additive, etc.

[0039] By including a compound (a) represented by formula (1), that is, an episulfide compound having an aromatic backbone, the refractive index of the resulting cured product (optical material) can be increased. Additionally, by including a polythiol (b) in the composition, the color tone of the resulting cured product (optical material) can be improved. By combining these, the refractive index and color tone of the resulting cured product (optical material) can be increased. For this reason, the above composition is preferably a composition for optical materials.

[0040] [Compound(a)]

[0041] Compound (a) is represented by the following formula (1).

[0042] [Chemical Formula 3]

[0043]

[0044] Ar represents an aromatic ring. Examples of the above aromatic rings include an aromatic ring composed of carbon and hydrogen, and a complex aromatic ring (an aromatic ring containing heteroatoms). Meanwhile, Ar has 2 or more carbon atoms, preferably 2 to 18, more preferably 2 to 12, and even more preferably 3 to 6. Additionally, Ar is preferably a 5-membered ring or a 6-membered ring, and more preferably a 6-membered ring.

[0045] The above-mentioned aromatic rings composed of carbon and hydrogen are not particularly limited, but examples include benzene rings, naphthalene rings, fluorene rings, anthracene rings, phenanthrene rings, etc. Among these, the aromatic ring composed of carbon and hydrogen is preferably a benzene ring.

[0046] The above complex aromatic rings are not particularly limited, but include furan rings, pyran rings, pyrrole rings, imidazole rings, pyrazol rings, oxazole rings, isooxazole rings, thiazole rings, isothiazol rings, triazole rings, thiadiazole rings, pyridine rings, pyrazine rings, pyrimidine rings, pyridazine rings, triazine rings, indole rings, isoindole rings, indazole rings, quinoline rings, isoquinoline rings, phthalazine rings, phenanthridine rings, acridine rings, etc. Among these, the complex aromatic ring is preferably a furan ring, pyran ring, pyrrole ring, imidazole ring, pyrazol ring, oxazole ring, isooxazole ring, thiazole ring, isothiazol ring, triazole ring, thiadiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, or triazine ring, more preferably a triazine ring or thiadiazole ring, and even more preferably a thiadiazole ring.

[0047] Among those described above, Ar is preferably an aromatic ring composed of carbon and hydrogen, and more preferably a benzene ring.

[0048] m represents an integer from 2 to 8, preferably 2, 3, or 6 in terms of tone and ease of synthesis, more preferably 2 or 3, and even more preferably 3.

[0049] n represents an integer from 0 to 6, preferably 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0050] m+n is less than or equal to the number of carbon atoms constituting the aromatic ring, preferably 2 to 6, more preferably 3 to 6, even more preferably 2 to 3, and particularly preferably 3. Meanwhile, "less than or equal to the number of carbon atoms constituting the aromatic ring" means not exceeding the number of carbon atoms having as an aromatic ring. For example, in the case of a benzene ring, which is an aromatic ring composed of carbon and hydrogen, m+n is 6 or less because the number of carbon atoms constituting the ring is 6. Also, in the case of a thiadiazole ring, which is a complex aromatic ring, m+n is 2 or less because the number of carbon atoms constituting the ring is 2.

[0051] R1 Each independently represents an alkyl thio group, an epoxyalkyl thio group, a thiol group, a halogen group, a hydroxyl group, a dialkyl thiocarbamoyl group, or a dialkylcarbamoyl thio group.

[0052] The above alkyl thio groups are not particularly limited, but examples include methyl thio groups, ethyl thio groups, propyl thio groups, butyl thio groups, isobutyl thio groups, sec-butyl thio groups, tert-butyl thio groups, pentyl thio groups, hexyl thio groups, etc.

[0053] The above epoxyalkylthio group is not particularly limited, but β-epoxypropylthio group may be used.

[0054] The above halogen groups are not particularly limited and may include fluorine (-F), chlorine (-Cl), bromine (-Br), iodine (-I), etc.

[0055] The above dialkylthiocarbamoyl group is not particularly limited, but examples include dimethylthiocarbamoyl group, diethylthiocarbamoyl group, ethylmethylthiocarbamoyl group, etc.

[0056] In addition, in one embodiment, compound (a) is represented by the following formula (1').

[0057] [Chemical Formula 4]

[0058]

[0059] In formula (1'), m represents an integer from 2 to 6, preferably 2, 3, or 6 in terms of tone and ease of synthesis, more preferably 2 or 3, and even more preferably 3.

[0060] In formula (1'), n represents an integer from 0 to 4, preferably from 0 to 2, more preferably from 0 or 1, and even more preferably from 0.

[0061] In formula (1'), m+n is 6 or less (m+n≤6), preferably 2 to 6, more preferably 3 to 6, and even more preferably 3.

[0062] In equation (1'), R 1 It is the same as the above formula (1).

[0063] Specific examples of compound (a) are not particularly limited to, but include bis(episulfide) compounds such as 1,3-bis(β-epithiopropylthio)benzene, 1,4-bis(β-epithiopropylthio)benzene; tris(episulfide) compounds such as 1,3,5-tris(β-epithiopropylthio)benzene, 1,2,4-tris(β-epithiopropylthio)benzene, 1,2,5-tris(β-epithiopropylthio)benzene; Alkylthio-substituted bis(episulfide) compounds such as 1-methyl-3,5-bis(β-epithiopropylthio)benzene, 1-methyl-2,4-bis(β-epithiopropylthio)benzene, 1-methyl-2,5-bis(β-epithiopropylthio)benzene, 1-ethyl-3,5-bis(β-epithiopropylthio)benzene, and 1-t-butylthio-3,5-bis(β-epithiopropylthio)benzene; Epoxyalkylthio-substituted bis(episulfide) compounds such as 1-(β-epoxypropylthio)-3,5-bis(β-epithiopropylthio)benzene, 1-(β-epoxypropylthio)-2,4-bis(β-epithiopropylthio)benzene, and 1-(β-epoxypropylthio)-2,5-bis(β-epithiopropylthio)benzene; thiol-substituted bis(episulfide) compounds such as 1-mercapto-3,5-bis(β-epithiopropylthio)benzene, 1-mercapto-2,4-bis(β-epithiopropylthio)benzene, and 1-mercapto-2,5-bis(β-epithiopropylthio)benzene; Halogen-substituted bis(episulfide) compounds such as 1-fluoro-3,5-bis(β-epithiopropylthio)benzene, 1-chloro-3,5-bis(β-epithiopropylthio)benzene, 1-bromo-3,5-bis(β-epithiopropylthio)benzene, 1-chloro-2,4-bis(β-epithiopropylthio)benzene, 1-chloro-2,5-bis(β-epithiopropylthio)benzene; hydroxyl-substituted bis(episulfide) compounds such as 1-hydroxy-3,5-bis(β-epithiopropylthio)benzene, 1-hydroxy-2,4-bis(β-epithiopropylthio)benzene, 1-hydroxy-2,5-bis(β-epithiopropylthio)benzene;Dialkylthiocarbamoyl group-substituted bis(episulfide) compounds such as 1-dimethylthiocarbamoyl-3,5-bis(β-epithiopropylthio)benzene, 1-emethylthiocarbamoyl-3,5-bis(β-epithiopropylthio)benzene, 1-emethylthiocarbamoyl-2,4-bis(β-epithiopropylthio)benzene, and 1-emethylthiocarbamoyl-2,5-bis(β-epithiopropylthio)benzene; Dialkylcarbamoylthio-substituted bis(episulfide) compounds such as 1-dimethylcarbamoylthio-3,5-bis(β-epithiopropylthio)benzene, 1-emethylcarbamoylthio-3,5-bis(β-epithiopropylthio)benzene, 1-dimethylcarbamoylthio-2,4-bis(β-epithiopropylthio)benzene, and 1-dimethylcarbamoylthio-2,5-bis(β-epithiopropylthio)benzene;Examples of heterocyclic compounds include 2,5-bis(β-epithiopropylthio)-1,3,4-thiadiazole, 3,4-bis(β-epithiopropylthio)-1,2,5-thiadiazole, and 2,4,6-tris(β-epithiopropylthio)-1,3,5-triazine. Among these, 1,3-bis(β-epithiopropylthio)benzene, 1,4-bis(β-epithiopropylthio)benzene, 1,3,5-tris(β-epithiopropylthio)benzene, 1-alkylthio-3,5-bis(β-epithiopropylthio)benzene, 1-epoxyalkylthio-3,5-bis(β-epithiopropylthio)benzene, 1-thio-3,5-bis(β-epithiopropylthio)benzene, 1-halo-3,5-bis(β-epithiopropylthio)benzene, 1-hydroxy-3,5-bis(β-epithiopropylthio)benzene, 1-dialkylthiocarbamoyl-3,5-bis(β-epithiopropylthio)benzene, It is preferable that it is 1-alkylcarbamoylthio-3,5-bis(β-epithiopropylthio)benzene, 2,5-bis(β-epithiopropylthio)-1,3,4-thiadiazole, 3,4-bis(β-epithiopropylthio)-1,2,5-thiadiazole, and 2,4,6-tris(β-epithiopropylthio)-1,3,5-triazine, and more preferably 1,3-bis(β-epithiopropylthio)benzene, 1,4-bis(β-epithiopropylthio)benzene, 1,3,5-tris(β-epithiopropylthio)benzene, 2,5-bis(β-epithiopropylthio)-1,3,4-thiadiazole, and 2,4,6-tris(β-epithiopropylthio)-1,3,5-triazine. It is preferable, and from the perspective of a higher refractive index, it is more preferable that it be 1,3,5-tris(β-epithiopropylthio)benzene. Meanwhile, the compound (a) described above may be used alone or in combination of two or more types.;

[0064] The content of compound (a) is preferably 0.1 to 99.5 mass% with respect to the total mass of the composition, more preferably 5 to 95 mass%, even more preferably 10 to 95 mass%, and particularly preferably 10 to 85 mass%. If the content of compound (a) is within the above range, a sufficient color tone enhancement effect can be obtained. Meanwhile, in one embodiment, with respect to improving the color tone, the content of compound (a) is preferably 0.1 to 60 mass% with respect to the total mass of the composition, more preferably 1 to 55 mass%, and even more preferably 3 to 30 mass%.

[0065] [Polythiol(b)]

[0066] Polythiol (b) refers to a compound having two or more thiol groups (-SH) per molecule. In this case, the compound (a) (an episulfide compound having an aromatic backbone) is not included in polythiol (b).

[0067] Polythiols (b) are not particularly limited, but from the viewpoint of high color-improving effect, 1,2,6,7-tetramercapto-4-thiaheptane, methanedithiol, (sulfanylmethyldisulfanyl)methanethiol, bis(2-mercaptoethyl)sulfide, 2,5-bis(mercaptomethyl)-1,4-dithiane, 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, It is preferable that the polythiols are tetramercaptopentaerythritol, 1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, and tyranmethanethiol; more preferable that the polythiols are bis(2-mercaptoethyl)sulfide, 1,2,6,7-tetramercapto-4-thiaheptane, methanedithiol, (sulfanylmethyldisulfanyl)methanethiol, and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane; and even more preferable that the polythiols are bis(2-mercaptoethyl)sulfide, 1,2,6,7-tetramercapto-4-thiaheptane, and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane. Meanwhile, the polythiols (b) described above may be used alone or in combination of two or more types.

[0068] The content of polythiol (b) is preferably 0.1 to 30 mass% with respect to the total mass of the composition, more preferably 0.1 to 20 mass%, even more preferably 0.5 to 20 mass%, and particularly preferably 1 to 15 mass%. It is desirable for the content of polythiol (b) to be within the above range in that the balance between the color stabilization effect and heat resistance is improved. Meanwhile, in one embodiment, with respect to improving the color tone, the content of compound (b) is preferably 2 to 30 mass% with respect to the total mass of the composition, more preferably 4 to 30 mass%, and even more preferably 7.5 to 25 mass%.

[0069] [Compound(c)]

[0070] In one embodiment, the composition may additionally include compound (c). The compound (c) is represented by the following formula (2). Compound (c) is copolymerizable with compound (a) and, when used together with compound (a), has the effect of increasing curing reactivity.

[0071] [Chemical Formula 5]

[0072]

[0073] p represents an integer from 0 to 4, preferably from 0 to 2, and more preferably from 0 or 1.

[0074] q represents an integer from 0 to 2, preferably from 0 to 2, and more preferably from 0 to 1.

[0075] Specific examples of compound (c) are not particularly limited, but include bis(β-epithiopropyl)sulfide and bis(β-epithiopropyl)disulfide. Among these, bis(β-epithiopropyl)sulfide is preferred. The compound (c) described above may be used alone or in combination of two or more types. Meanwhile, bis(β-epithiopropyl)sulfide corresponds to a compound in which p=q=0 in the above formula (2), and bis(β-epithiopropyl)disulfide corresponds to a compound in which p=0 and q=1 in the above formula (2).

[0076] The content of compound (c) is 0 to 70 mass% with respect to the total mass of the composition, preferably 1 to 60 mass%, and more preferably 1 to 50 mass%. It is desirable for the content of compound (c) to be within the above range in that it can improve curing reactivity while ensuring heat resistance.

[0077] [sulfur]

[0078] In one embodiment, the composition may additionally include sulfur. By including sulfur, the refractive index of the resulting optical material can be improved.

[0079] The form of sulfur is not particularly limited and may be any form. Specific forms include fine sulfur, colloidal sulfur, precipitated sulfur, crystalline sulfur, sublimated sulfur, etc. Among these, fine sulfur is preferred from the perspective of dissolution rate.

[0080] The particle size (diameter) of sulfur is preferably smaller than 10 mesh (opening diameter 1.70 mm), more preferably smaller than 30 mesh (opening diameter 500 μm), and even more preferably smaller than 60 mesh (opening diameter 250 μm). It is preferable for the sulfur particle size to be smaller than 10 mesh because sulfur is easy to dissolve.

[0081] The purity of sulfur is not particularly limited, but it is desirable to be 98% or higher, more desirable to be 99.0% or higher, even more desirable to be 99.5% or higher, and particularly desirable to be 99.9% or higher. It is desirable that the purity of sulfur be 98% or higher in that the color tone of the resulting optical material is further improved.

[0082] The sulfur content is preferably 0 to 20 mass% with respect to the total mass of the composition, more preferably 0.1 to 18 mass%, and even more preferably 1 to 15 mass%. A sulfur content within the above range is desirable in that it provides an excellent balance between the refractive index improvement effect and solubility.

[0083] [Polymerizable Compounds]

[0084] In one embodiment, the composition may additionally include a polymerizable compound. By including the polymerizable compound, the physical properties of the optical material can be adjusted. Meanwhile, "polymerizable compound" means a compound capable of copolymerizing with compound (a).

[0085] The above polymerizable compound is not particularly limited as long as it is a compound copolymerizable with compound (a), and examples include episulfide compounds, vinyl compounds, methacrylic compounds, acrylic compounds, allyl compounds, etc. other than compounds (a) and (c). These compounds may be used individually or in combination of two or more types.

[0086] The amount of polymerizable compound added is not particularly limited as long as it is within a range that does not impede the effects of the present invention, for example, it is preferably 0 to 30 mass% with respect to the total mass of the composition, more preferably 1 to 30 mass%, and even more preferably 1 to 20 mass%.

[0087] [Prepolymerization Catalyst]

[0088] In one embodiment, the composition may further include a prepolymerization catalyst. By including the prepolymerization catalyst, the pre-cured product described below can be manufactured effectively.

[0089] The prepolymerization catalyst is not particularly limited, but may include imidazoles, phosphines, thioureas, quaternary ammonium salts, quaternary phosphonium salts, tertiary sulfonium salts, secondary iodonium salts, hindered amines, etc. Among these, imidazoles and hindered amines are preferred from the viewpoint of good compatibility with the composition.

[0090] The above imidazoles are not particularly limited, but examples include N-benzylimidazole, 4-methylimidazole, 4-ethylimidazole, 1-phenylimidazole, 2-methyl-N-methylimidazole, etc.

[0091] The above hindered amines are not particularly limited, but examples include hindered amines such as 1,2,2,6,6-pentamethylpiperidyl methacrylate, 1,2,2,6,6-pentamethylpiperidyl acrylate, and 1,2,2,6,6-pentamethylpiperidyl-4-vinylbenzoate.

[0092] Among these, the prepolymerization catalyst preferably comprises at least one selected from the group consisting of 2-mercapto-1-methylimidazole, 2-methyl-N-imidazole, and 1,2,2,6,6-pentamethylpiperidyl methacrylate. Meanwhile, the prepolymerization catalyst described above may be used alone or in combination of two or more types.

[0093] The amount of prepolymerization catalyst added is not determined uniformly as it varies depending on the composition, mixing ratio, and polymerization curing method; however, it is generally preferable to have an amount of 0.0001% to 10% by weight, and more preferable to have an amount of 0.003% to 3.0% by weight, based on 100% by weight of the total of compound (a), polythiol (b), compound (c), and sulfur. An amount of 0.0001% or more of the prepolymerization catalyst added is desirable in that the prepolymerization reaction proceeds well. On the other hand, an amount of 10% or less of the prepolymerization catalyst added is desirable in that oxidation resistance is increased.

[0094] [Polymerization Catalyst]

[0095] In one embodiment, the composition may additionally include a polymerization catalyst. By including the polymerization catalyst, the composition can be polymerized effectively to produce an optical material.

[0096] The polymerization catalyst is not particularly limited, but may include amines, phosphines, quaternary ammonium salts, quaternary phosphonium salts, tertiary sulfonium salts, secondary iodonium salts, inorganic acids, Lewis acids, organic acids, silicic acids, tetrafluoric boric acids, peroxides, azo compounds, condensates of aldehydes and ammonia compounds, guanidines, thioureas, thiazoles, sulfenamides, thiurams, dithiocarbamates, xantogenates, acidic phosphate esters, etc. Among these, it is preferable that the catalyst be an amine, a phosphine, a quaternary ammonium salt, or a quaternary phosphonium salt. Meanwhile, these polymerization catalysts may be used alone or in combination of two or more types.

[0097] The amount of polymerization catalyst added is preferably 0.0001 to 10 mass% with respect to the total mass of the composition, and more preferably 0.01 to 3 mass%.

[0098] [Polymerization Adjuster]

[0099] In one embodiment, the composition may additionally include a polymerization modifier.

[0100] Polymerization regulators are not particularly limited, but examples include halides of groups 13 to 16 of the long periodic table. Among these, halides of silicon, germanium, tin, and antimony are preferred, and chlorides of germanium, tin, and antimony having alkyl groups are even more preferred. These polymerization regulators may be used alone or in combination of two or more types.

[0101] The amount of polymerization regulator added is preferably 0.0001 to 5.0 mass% with respect to the total mass of the composition, and more preferably 0.01 to 2 mass%.

[0102] [Additives]

[0103] In one embodiment, the composition may additionally include additives. The additives are not particularly limited, but may include antioxidants, bluing agents, UV absorbers, deodorizing agents, adhesion improvers, mold release improvers, radical polymerization initiators, etc. These additives may be used alone or in combination of two or more.

[0104] The content of the additive is preferably 0 to 10 mass% with respect to the total mass of the composition, and more preferably 0.5 to 10 mass%.

[0105] [Composition of the composition]

[0106] In one embodiment, the composition has the following composition. That is, with respect to the total amount of the composition, the composition,

[0107] Compound (a): 5 to 95 mass%, preferably 10 to 95 mass%;

[0108] Polythiol (b): 0.1 to 30 mass%, preferably 0.5 to 20 mass%;

[0109] Compound (c): 0 to 85 mass%, preferably 0 to 80 mass%;

[0110] Sulfur: 0~20 mass%, preferably 0~15 mass%;

[0111] Prepolymerization catalyst: 0 to 5 mass%, preferably 0 to 3 mass%;

[0112] Polymerization catalyst: 0 to 5 mass%, preferably 0.0001 to 3 mass%; and

[0113] Polymerization modifier: 0~5 mass%, preferably 0.0001~3 mass%;

[0114] Includes

[0115] <Method for manufacturing the composition>

[0116] The composition described above is not particularly limited and can be prepared by known methods. Specifically, it can be prepared by mixing compound (a) and polythiol (b), and, if necessary, compound (c), sulfur, etc.

[0117] Pre-cured material

[0118] According to one embodiment of the present invention, a pre-cured material is provided. The pre-cured material is formed by pre-polymerizing the composition described above. By using a pre-cured material, it is desirable from the viewpoint that the rate of viscosity increase can be reduced, the transparency of the optical material is improved, and handling becomes easier. Meanwhile, in this specification, "pre-cured material" refers to a liquid with a viscosity of 5,000 mps or less and includes a polymer, a partial polymer, an oligomer, etc. formed by a polymerization reaction of at least one of compound (a), polythiol (b), compound (c), sulfur, and a polymerizable compound. Meanwhile, in this specification, "viscosity" is adopted as a value measured by the following method.

[0119] [Viscosity Measurement Method]

[0120] The viscosity of the pre-cured product at 30°C is measured using a cone-plate type viscometer DV2THA CP (manufactured by Brookfield AMETEK).

[0121] Method for manufacturing a pre-cured material

[0122] According to one embodiment of the present invention, a method for manufacturing a pre-cured product is provided. The method for manufacturing the pre-cured product includes a prepolymerization process for prepolymerizing a composition.

[0123] [Pre-polymerization process]

[0124] The prepolymerization process is a process of prepolymerizing a composition.

[0125] The composition described above is used. The composition preferably includes a prepolymerization catalyst.

[0126] Preferably, the prepolymerization process is performed by molding into a mold or similar structure, with the view that the polymerization process described below is carried out subsequently after the prepolymerization. At this time, it is desirable to filter and remove impurities using a filter with a hole diameter of about 0.1 to 5 μm before molding, with the view that this improves the quality of the optical material.

[0127] The temperature of the above prepolymerization is preferably -10 to 160°C, more preferably 0 to 100°C, and even more preferably 20 to 80°C.

[0128] The time of the above prepolymerization is preferably 0.1 to 480 minutes, more preferably 0.1 to 420 minutes, and even more preferably 0.1 to 360 minutes.

[0129] In one embodiment, the prepolymerization is preferably carried out at -10 to 160°C for 0.1 to 480 minutes, more preferably at 0 to 100°C for 0.1 to 420 minutes, and even more preferably at 20 to 80°C for 0.1 to 360 minutes.

[0130] Pre-polymerization may be carried out at atmospheric pressure, under high pressure, or under reduced pressure. When pre-polymerization is carried out under reduced pressure, the reaction proceeds more gently compared to when carried out at atmospheric pressure because hydrogen sulfide, which promotes the reaction, is removed. On the other hand, when carried out at atmospheric pressure, it may be carried out in the atmosphere or in an inert gas.

[0131] In a prepolymerization process, it is desirable to detect the progress of the prepolymerization reaction. The detection method is not particularly limited and may include liquid chromatography, viscosity measurement, specific gravity measurement, and refractive index measurement. Among these, it is desirable to perform refractive index measurement because it is simple. Meanwhile, these detection methods may be used individually or in combination of two or more types.

[0132] It is preferable to detect the progress of the prepolymerization reaction in-line. In particular, when prepolymerization is performed under high pressure or reduced pressure, it is more preferable to perform detection in-line, as this eliminates the need to release the pressure or reduced pressure to acquire a measurement sample. When performing detection in-line, for example, when measuring the refractive index, the detection unit of the refractive index meter can be immersed in the composition before prepolymerization and the reaction solution of the prepolymerization to detect the increase in the refractive index accompanying the progress of the reaction and to control the progress of the reaction. On the other hand, in the case of a detection method where the measured value, such as the refractive index, changes with temperature, it is preferable to predetermine the relationship between the temperature of the detection unit and the refractive index by performing multiple regression analysis on the measurement temperature, the refractive index, and the refractive index at a reference temperature. Specifically, it is preferable to use a refractive index meter equipped with a temperature compensation function capable of automatically converting to the refractive index at a reference temperature. Examples of inline refractive indices include a method that uses a light-emitting diode as a light source to identify the angle of prism-reflected light using a CCD cell.

[0133] Optical Materials

[0134] According to one embodiment of the present invention, an optical material is provided. The optical material is formed by curing the composition described above or the pre-cured material described above. That is, the optical material is a cured product of the composition or pre-cured material.

[0135] The optical material according to this form has a high refractive index and excellent color tone.

[0136] Specifically, the refractive index of the optical material is preferably 1.70 or higher, more preferably 1.72 or higher, even more preferably 1.73 or higher, and particularly preferably 1.75 or higher. That is, the composition described above has a refractive index of the optical material obtained that is preferably 1.70 or higher, more preferably 1.72 or higher, even more preferably 1.73 or higher, and particularly preferably 1.75 or higher. Meanwhile, the value of the "refractive index" is measured by the method described in the example.

[0137] In addition, regarding the color tone of the optical material, it is preferable that the YI value is 5 or less, more preferable that it is 4 or less, even more preferable that it is 3 or less, and particularly preferable that it is 2 or less. That is, the composition described above has a YI value of the resulting optical material that is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2 or less. Meanwhile, in this specification, the "YI value" is measured by the method described in the examples.

[0138] Since the optical material according to the present form has a high refractive index and excellent color tone, it is possible to incorporate various comonomers into the composition and increase the amount of such comonomers, thereby enabling the design of optical materials with a wide range of physical properties.

[0139] Method for manufacturing optical materials

[0140] According to one embodiment of the present invention, a method for manufacturing an optical material is provided. The manufacturing method comprises a polymerization process for polymerizing the composition described above or the pre-cured material described above.

[0141] [Polymerization Process]

[0142] The polymerization process is a process of polymerizing the composition described above or the pre-cured material described above.

[0143] The polymerization process is typically carried out by molding a composition or a pre-cured material into a mold or similar structure and polymerizing it. When using a composition, it is desirable to filter out and remove impurities using a filter with a hole diameter of about 0.1 to 5 μm before molding, from the perspective of improving the quality of the optical material.

[0144] In one embodiment, the polymerization process includes a process of raising the temperature to the polymerization temperature, a process of maintaining the temperature at the polymerization temperature, and a process of lowering the temperature.

[0145] The above polymerization may be carried out in multiple stages. That is, there may be two or more processes for maintaining the polymerization temperature. In one embodiment, the polymerization process includes a process of raising the temperature to a first polymerization temperature, a process of maintaining the temperature at the first polymerization temperature, a process of raising the temperature to a second polymerization temperature, a process of maintaining the temperature at the second polymerization temperature, and a process of lowering the temperature. In this case, the first polymerization temperature is lower than the second polymerization temperature. Also, in another embodiment, the polymerization process includes a process of raising the temperature to a first polymerization temperature, a process of maintaining the temperature at the first polymerization temperature, a process of lowering the temperature to a second polymerization temperature, a process of maintaining the temperature at the second polymerization temperature, and a process of lowering the temperature. In this case, the first polymerization temperature is higher than the second polymerization temperature.

[0146] It is preferable that the heating rate of the process for raising the temperature be 0.1℃ to 100℃ / h. In addition, it is preferable that the cooling rate of the process for lowering the temperature be 0.1℃ to 100℃ / h.

[0147] The polymerization temperature is typically -10℃ to 140℃, and preferably 0℃ to 140℃.

[0148] The polymerization time is typically 1 to 100 hours, and preferably 1 to 72 hours. Meanwhile, in this specification, "polymerization time" means the time including the time for the process of raising the temperature and the process of lowering the temperature.

[0149] Meanwhile, it is preferable to anneale the obtained optical material after polymerization. By annealing, deformation of the optical material can be prevented or suppressed. Meanwhile, the annealing temperature is preferably 50 to 150°C. In addition, the annealing time is preferably 10 minutes to 5 hours.

[0150] For the obtained optical material, surface treatments such as dyeing, hard coating, impact-resistant coating, anti-reflective, and anti-fog properties may be performed as needed.

[0151] Uses of Optical Materials

[0152] The optical materials described above are useful for various purposes, such as optical components, mechanical parts, electrical and electronic parts, automotive parts, civil engineering and construction materials, molding materials, as well as materials for paints and adhesives. Among these, optical materials are suitable for optical applications such as transparent glass or cover glass, such as eyeglass lenses, imaging lenses for (digital) cameras, light beam focusing lenses, light diffusion lenses, encapsulating materials for LEDs, optical adhesives, bonding materials for light transmission, optical fibers, prisms, filters, diffraction gratings, watch glass, and cover glass for display devices; and for display device applications such as substrates for display elements like LCDs, organic ELs, or PDPs, substrates for color filters, substrates for touch panels, information recording substrates, display backlights, light guide plates, display protective films, anti-reflective films, anti-fog films, etc. The above optical material is preferably used for purposes such as optical lenses, prisms, optical fibers, information recording substrates, and filters, and is more preferably used for optical lenses. That is, in one embodiment, an optical lens comprising the optical material described above is provided.

[0153] The optical lens obtained from the composition according to the present invention is highly useful because it exhibits excellent stability, color, and transparency, and can be utilized in fields where expensive high-refractive-index glass lenses have traditionally been used, such as telescopes, binoculars, and TV projectors. If necessary, it is preferable to use it in the form of an aspherical lens.

[0154] Examples

[0155] The present invention will be specifically described below by way of examples, but the embodiments may be modified appropriately as long as they demonstrate the effects of the present invention.

[0156] The analysis and evaluation of optical materials were performed using the following methods.

[0157] [Refractive index of optical materials]

[0158] Using a digital precision refractive index meter KPR-2000 (manufactured by Shimadzu Corporation), the refractive index of an optical material at 25°C for the e-line (546.1 nm) was measured.

[0159] [Color Evaluation of Optical Materials]

[0160] The YI value of an optical material with a thickness of 2.6 mm at 25°C was measured using a spectrophotometer CM-5 (manufactured by Konica Minolta Japan Co., Ltd.).

[0161] [Synthesization Example 1: Synthesis of 1,3,5-Trimercaptobenzene (hereinafter referred to as TMB)]

[0162] [Chemical Formula 6]

[0163]

[0164] It was synthesized with reference to Beilstein Journal of Organic Chemistry, 8, 461-471, No. 53; 2012. Specifically, it is as follows.

[0165] That is, a 4-neck flask equipped with a thermometer and a dropping funnel was nitrogen-extruded. Then, 400 g of N-methylpyrrolidone and 82.7 g (2067 mmol) of sodium hydroxide were added and stirred at 5°C. Subsequently, 186.4 g (2067 mmol) of t-butylthiol was added dropwise and stirred at 5°C for 3 hours. Furthermore, 50.0 g (275.56 mmol) of 1,3,5-trichlorobenzene was added, the temperature was raised to 120°C, and the mixture was stirred for 24 hours. Next, the reaction solution was cooled to 25°C, 400g of toluene was added, and then washed three times with 400g of water and the solvent was removed to obtain 45.3g (132.3mmol) of crude product of 1,3,5-tris(t-butylthio)benzene (TTBB).

[0166] 45.3 g (132.3 mmol) of the obtained crude product of TTBB was placed in a 3-neck flask equipped with a thermometer, and the reaction vessel was nitrogen-submerged. Then, 436 g of toluene was added and stirred at 20°C. Subsequently, 19.4 g (145.4 mmol) of aluminum chloride was added and stirred for 3 hours. 225 g of 20% sulfuric acid was added to wash the toluene layer three times, and the solvent was removed to obtain 16.1 g (92.4 mmol) of crude product of TMB.

[0167] By purifying the obtained crude TMB product using a silica gel column, a fraction of TMB1 (TMB purity 100%) (TMB fraction 1) and two fractions containing TMB2 and TMB3 (TMB fractions 2 and 3) were obtained. The results obtained are shown in Table 1 below.

[0168] [Synthesis Example 2: Synthesis of TMB]

[0169] [Chemical Formula 7]

[0170]

[0171] It was synthesized with reference to Bulletin de la Societe Chimique de France, (2), 302-8; 1987. Specifically, it is as follows.

[0172] Specifically, 30.0 g (238 mmol) of phloroglucinol and 375 g of N,N-dimethylformamide were added to a 3-neck flask equipped with a thermometer. Subsequently, the reaction mixture was cooled to 5°C, 133.4 g (1189 mmol) of 1,4-diazabicyclo[2.2.2]octane and 147.0 g (1189 mmol) of dimethylthiocarbamoyl chloride were added, and the mixture was stirred for 24 hours. Then, 300 g of chloroform was added, followed by washing three times with 300 g of 10% NaOH aqueous solution and removing the solvent to obtain 73.8 g (190 mmol) of crude product of 1,3,5-tris(dimethylthiocarbamoyl)benzene.

[0173] 73.8 g of the obtained crude product of 1,3,5-tris(dimethylthiocarbamoyl)benzene was placed in a 3-neck flask equipped with a thermometer and stirred at 240°C for 7 hours. Afterwards, by cooling to 25°C, 73.8 g (190 mmol) of crude product of 1,3,5-tris(dimethylcarbamoylthio)benzene was obtained.

[0174] 73.8 g of the obtained crude product of 1,3,5-tris(dimethylcarbamoylthio)benzene was placed in a three-necked flask equipped with a thermometer. Subsequently, 826 g of diethylene glycol, 89.1 g of water, and 53.4 g (952 mmol) of potassium hydroxide were added, and the mixture was stirred at 95°C for 10 hours. Afterward, the mixture was cooled to 25°C, and 370 g of 20% sulfuric acid and 740 g of chloroform were added. The organic layer was washed three times with water, and the solvent was removed to obtain 15.9 g (91 mmol) of crude product of TMB.

[0175] By purifying the obtained crude TMB product using a silica gel column, a fraction of TMB1 (TMB purity 100%) (TMB fraction 4) and three fractions (TMB fractions 5–7) including TMB4, TMB5, and TMB6 were obtained. The results obtained are shown in Table 1 below.

[0176] [Chemical Formula 8]

[0177]

[0178] [Table 1]

[0179]

[0180] [Synthesization Example 3: Synthesis of Episulfide Compounds]

[0181] 15.0 g (86.1 mmol) of TMB fraction 1 was added to a 4-neck flask equipped with a thermometer and a dropping funnel, and the reaction vessel was nitrogen-submerged. Subsequently, a solution of 0.72 g of 24% sodium hydroxide aqueous solution dissolved in 59.4 g of methanol and 65.0 g of toluene were added to the reaction vessel, and the mixture was stirred while cooling to 5°C. Next, 24.7 g (266.8 mmol) of epichlorohydrin was added dropwise while maintaining the liquid temperature at 5–15°C. After the dropwise addition was completed, stirring was performed again at 5°C for 3 hours to obtain 1,3,5-tris(3-chloro-2-hydroxypropylthio)benzene.

[0182] Next, 64.6 g (387.3 mmol) of a 24% aqueous sodium hydroxide solution was added dropwise while maintaining the liquid temperature at 5–15°C. After the addition was finished, the liquid temperature was raised to 15°C and aged for 17 hours. After washing the organic layer three times with 150 g of water, the solvent was removed to obtain 29.0 g of 1,3,5-tris(β-epoxypropylthio)benzene (total yield 98%).

[0183] To 29.0 g (84.7 mmol) of the obtained 1,3,5-tris(β-epoxypropylthio)benzene, 145 mL of toluene, 145 mL of methanol, 1.56 g (15.2 mmol) of acetic anhydride, and 38.7 g (508.0 mmol) of thiourea were added, and stirring was performed at 20°C for 24 hours. 145 g of 20% sulfuric acid was added, the toluene layer was washed three times with water, and the solvent was removed to obtain 23.1 g of crude product of 1,3,5-tris(β-epoxypropylthio)benzene (hereinafter referred to as Compound 1). By purifying the crude product with a silica gel column, fraction (a-1) of compound 1 with 100% purity and two fractions (a-2 and a-3) containing compound 2 (1-mercapto-3,5-bis(β-epithiopropylthio)benzene) and compound 3 (1-(β-epoxypropylthio)-3,5-bis(β-epithiopropylthio)benzene) were obtained. The results obtained are shown in Table 2 below.

[0184] [Synthesization Example 4: Synthesis of Episulfide Compounds]

[0185] A crude product of Compound 1 was obtained by the same method as in Synthesis Example 3, except that TMB fraction 2 was used instead of TMB fraction 1. By purifying the crude product with a silica gel column, a fraction (a-1) of Compound 1 with 100% purity and a fraction (a-4) containing Compound 4 (1-chloro-3,5-bis(β-epithiopropylthio)benzene) were obtained. The results obtained are shown in Table 2 below.

[0186] [Synthesization Example 5: Synthesis of Episulfide Compounds]

[0187] A crude product of Compound 1 was obtained by the same method as in Synthesis Example 3, except that TMB fraction 3 was used instead of TMB fraction 1. By purifying the crude product with a silica gel column, a fraction (a-1) of Compound 1 with 100% purity and a fraction (a-5) containing Compound 5 (1-t-butylthio-3,5-bis(β-epithiopropylthio)benzene) were obtained. The results obtained are shown in Table 2 below.

[0188] [Synthesization Example 6: Synthesis of Episulfide Compounds]

[0189] A crude product of Compound 1 was obtained by the same method as in Synthesis Example 3, except that TMB fraction 5 was used instead of TMB fraction 1. By purifying the crude product with a silica gel column, a fraction (a-1) of Compound 1 with 100% purity and a fraction (a-6) containing Compound 6 (1-hydroxy-3,5-bis(β-epithiopropylthio)benzene) were obtained. The results obtained are shown in Table 2 below.

[0190] [Synthesization Example 7: Synthesis of Episulfide Compounds]

[0191] A crude product of Compound 1 was obtained by the same method as in Synthesis Example 3, except that TMB fraction 6 was used instead of TMB fraction 1. By purifying the crude product with a silica gel column, a fraction (a-1) of Compound 1 with 100% purity and a fraction (a-7) containing Compound 7 (1-dimethylthiocarbamoyl-3,5-bis(β-epithiopropylthio)benzene) were obtained. The results obtained are shown in Table 2 below.

[0192] [Synthesization Example 8: Synthesis of Episulfide Compounds]

[0193] A crude product of Compound 1 was obtained by the same method as in Synthesis Example 3, except that TMB fraction 7 was used instead of TMB fraction 1. By purifying the crude product with a silica gel column, a fraction (a-1) of Compound 1 with 100% purity and a fraction (a-8) containing Compound 8 (1-dimethylcarbamoylthio-3,5-bis(β-epithiopropylthio)benzene) were obtained. The results obtained are shown in Table 2 below.

[0194] [Synthesization Example 9: Synthesis of Episulfide Compounds]

[0195] A crude product of Compound 9 (1,3-bis(β-epithiopropylthio)benzene) was obtained by the same method as in Synthesis Example 3, except that 1,3-dimercaptobenzene (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used instead of TMB fraction 1. By purifying the crude product with a silica gel column, a fraction (a-9) of Compound 9 with a purity of 100% was obtained. The results obtained are shown in Table 2 below.

[0196] [Synthesization Example 10: Synthesis of Episulfide Compounds]

[0197] A crude product of Compound 10 (2,5-bis(β-epithiopropylthio)-1,3,4-thiadiazole) was obtained by the same method as in Synthesis Example 3, except that bismuthiool (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used instead of TMB fraction 1. By purifying the crude product with a silica gel column, a fraction (a-10) of Compound 10 with a purity of 100% was obtained. The results obtained are shown in Table 2 below.

[0198] [Synthesization Example 11: Synthesis of Episulfide Compounds]

[0199] A crude product of Compound 11 (2,4,6-tris(β-epithiopropylthio)-1,3,5-triazine) was obtained by the same method as in Synthesis Example 3, except that thiocyanuric acid (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used instead of TMB fraction 1. By purifying the crude product with a silica gel column, a fraction (a-11) of Compound 11 with a purity of 100% was obtained. The results obtained are shown in Table 2 below.

[0200] Compound 1: 1,3,5-Tris(β-epithiopropylthio)benzene

[0201] Compound 2: 1-Mercapto-3,5-bis(β-epithiopropylthio)benzene

[0202] Compound 3: 1-(β-epoxypropylthio)-3,5-bis(β-epithiopropylthio)benzene

[0203] Compound 4: 1-chloro-3,5-bis(β-epithiopropylthio)benzene

[0204] Compound 5: 1-t-butylthio-3,5-bis(β-epithiopropylthio)benzene

[0205] Compound 6: 1-hydroxy-3,5-bis(β-epithiopropylthio)benzene

[0206] Compound 7: 1-Dimethylthiocarbamoyl-3,5-bis(β-epithiopropylthio)benzene

[0207] Compound 8: 1-Dimethylcarbamoylthio-3,5-bis(β-epithiopropylthio)benzene

[0208] Compound 9: 1,3-Bis(β-epithiopropylthio)benzene

[0209] Compound 10: 2,5-bis(β-epithiopropylthio)-1,3,4-thiadiazole

[0210] Compound 11: 2,4,6-Tris(β-epithiopropylthio)-1,3,5-triazine

[0211] [Chemical Formula 9]

[0212]

[0213] [Table 2]

[0214]

[0215] [raw material]

[0216] As polythiols (b), the following compounds b-1 to b-3 were prepared.

[0217] b-1: 1,2,6,7-tetramercapto-4-thiaheptane

[0218] b-2: Bis(2-mercaptoethyl)sulfide

[0219] b-3: 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane

[0220] [Chemical Formula 10]

[0221]

[0222] In addition, as compound (c), the following compounds c-1 to c-2 were prepared.

[0223] c-1: Bis(β-epithiopropyl)sulfide

[0224] c-2: Bis(β-epithiopropyl)disulfide

[0225] [Chemical Formula 11]

[0226]

[0227] [Example 1]

[0228] A composition was prepared by mixing 80 parts by mass of oil fraction a-1, 20 parts by mass of compound b-1, 0.02 parts by mass of tetra-n-butylphosphonium bromide as a polymerization catalyst, and 0.05 parts by mass of di-n-butyltin dichloride as a polymerization modifier while performing vacuum degassing.

[0229] [Examples 2–18, Comparative Examples 1–3]

[0230] A composition was prepared in the same manner as in Example 1, except that the composition was changed to the one shown in Table 3.

[0231] [evaluation]

[0232] The compositions prepared in Examples 1 to 18 and Comparative Examples 1 to 3 were heated at 30°C for 10 hours, then heated to 100°C over 10 hours, and finally heated at 100°C for 5 hours to polymerize and cure. After cooling, an annealing treatment was performed at 120°C for 30 minutes to produce an optical material.

[0233] The results of the refractive index and color tone evaluation of the manufactured optical material are shown in Table 3 below.

[0234] [Table 3]

[0235]

[0236] As is evident from the results in Table 3, the cured product (optical material) formed by curing the compositions of Examples 1 to 18 has a high refractive index and excellent color tone.

[0237] Meanwhile, in Comparative Example 1, the color tone was insufficient as a result of not including polythiol (b).

[0238] In addition, in Comparative Example 2 according to the prior art using compound c-1 (bis(β-epithiopropyl)sulfide), it can be seen that the refractive index is insufficient.

[0239] Furthermore, Comparative Example 3 shows that when sulfur is added to increase the refractive index, the hue is reduced.

Claims

Claim 1 The following formula (1): [In the above formula, Ar represents an aromatic ring, m represents 2 or 3, n represents an integer from 0 to 4, m+n is 3 to 6, provided that m+n is less than or equal to the number of carbon atoms constituting the aromatic ring, and R 1 A composition comprising a compound (a) and a polythiol (b) represented by [each independently represents an alkyl thio group, an epoxyalkyl thio group, a thiol group, a halogen group, a hydroxyl group, a dialkyl thiocarbamoyl group, or a dialkylcarbamoyl thio group]. Claim 2 A composition according to claim 1, wherein Ar is an aromatic ring consisting of carbon and hydrogen. Claim 3 delete Claim 4 delete Claim 5 A composition according to claim 1, wherein the content of the compound (a) is 5 to 95 mass% with respect to the total mass of the composition. Claim 6 In claim 1, the polythiol (b) is 1,2,6,7-tetramercapto-4-thiaheptane, methanedithiol, (sulfanylmethyldisulfanyl)methanethiol, bis(2-mercaptoethyl)sulfide, 2,5-bis(mercaptomethyl)-1,4-dithiane, 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithioundecane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, A composition comprising at least one selected from the group consisting of tetramercaptopentaerythritol, 1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, and tyranmethanethiol. Claim 7 In paragraph 1, the following formula (2): A composition further comprising a compound (c) represented by [wherein p represents an integer from 0 to 4 and q represents an integer from 0 to 2]. Claim 8 A composition according to claim 1, further comprising sulfur. Claim 9 A composition according to claim 1, further comprising a prepolymerization catalyst. Claim 10 A composition according to claim 9, wherein the prepolymerization catalyst comprises at least one selected from the group consisting of 2-mercapto-1-methylimidazole, 2-methyl-N-imidazole, and 1,2,2,6,6-pentamethylpiperidyl methacrylate. Claim 11 A pre-cured product formed by pre-polymerizing a composition described in any one of claims 1, 2 and 5 through 10. Claim 12 A composition described in any one of claims 1, 2 and 5 to 10; or an optical material formed by curing a pre-cured product formed by pre-polymerizing the composition. Claim 13 An optical lens comprising the optical material described in paragraph 12.

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