JP5691601B2 - Composition for optical materials - Google Patents

Description

The present invention relates to a composition for an optical material and the like, and more particularly to an optical material such as a plastic lens, a prism, an optical fiber, an information recording substrate, and a filter, and more particularly a composition for an optical material suitable for a plastic lens. The present invention relates to a method for producing an optical material made of polyurethane resin having good optical properties by polymerizing a polymerizable composition comprising a polythiol compound and a polyiso (thio) cyanate compound.

Resin-made optical materials are lighter and harder to break than optical materials made of inorganic materials, and can be dyed. Therefore, in recent years, it has rapidly spread to optical materials such as eyeglass lenses and camera lenses.

There has been a demand for higher performance of resins for optical materials. Specifically, higher refractive index, higher Abbe number, lower specific gravity, higher heat resistance, etc. have been demanded. In response to such demands, various resins for optical materials have been developed and used so far.

Among them, proposals relating to polyurethane resins have been actively made. Among the polyurethane-based resins, the most typical resin includes a resin obtained by reacting a polythiol compound and a polyiso (thio) cyanate compound (see Patent Documents 1 and 2). This resin is colorless and transparent, and has excellent properties such as impact properties, dyeability and processability. In particular, the transparency of the resin is an essential property for lenses.

  However, when the resin for optical materials is produced, the resin and optical material obtained by polymerization sometimes turn yellow. Since it is an optical optical material application, if it changes color after curing, it will all become defective and a huge loss will occur. Accordingly, there has been a demand for a method that predicts whether or not yellow discoloration occurs after curing in a stage before curing, and enables determination of quality.

JP 7-252207 A Japanese Patent Laid-Open No. 9-110956

The problem to be solved by the present invention is to provide a composition for an optical material containing a polythiol capable of predicting and determining the occurrence of yellow discoloration after curing at the stage before polymerization curing, and determining whether it is good or bad. It is.

As a result of intensive studies in view of such a situation, the present inventors have found that a composition for optical materials comprising a polythiol having a total content of iron, chromium and nickel of 5.0 ppm or less and a polyiso (thio) cyanate compound. This problem has been solved by the object, and the present invention has been achieved.

That is, the present invention is as follows.
<1> An optical material composition comprising a polythiol compound having a total content of iron, chromium and nickel of 5.0 ppm or less and a polyiso (thio) cyanate compound.
<2> The polythiol compound is 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane, bis (mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol, pentaerythritol Selected from the group consisting of tetrakis (3-mercaptopropionate), bis (mercaptomethyl) sulfide, 1,3-bis (mercaptomethyl) benzene, and 1,1,3,3-tetrakis (mercaptomethylthio) propane The composition for optical materials according to <1>, wherein the composition is at least one compound.
<3> The polyiso (thio) cyanate compound is 2,5-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, 2,6-bis (isocyanatomethyl) -bicyclo [2.2.1]. ] Heptane, bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) benzene and α, α, α ', α'-tetramethylxylylene diisocyanate The composition for optical materials according to <1>, wherein the composition is at least one compound selected from the group consisting of:
<4> An optical material obtained by polymerizing the composition for optical materials according to <1>.
<5> The optical material according to <4>, wherein an annealing treatment is performed after the polymerization of the optical material composition.
<6> A method for producing a composition for optical materials, comprising a step of mixing a polythiol compound having a total content of iron, chromium and nickel of 5.0 ppm or less and a polyiso (thio) cyanate compound. It is.

According to the present invention, a composition for an optical material containing a polythiol compound that makes it possible to predict and determine the presence or absence of yellow discoloration after curing at the stage before polymerization curing, which has been difficult with the prior art, and to determine whether it is good or bad. Etc. can be provided.

The polythiol compound used in the present invention is not particularly limited as long as it is a compound having two or more thiol groups in one molecule.

Specific examples of the polythiol compound include methanedithiol, 1,2-ethanedithiol, 1,1-propanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 2,2-propanedithiol, 1,6- Hexanedithiol, 1,2,3-propanetrithiol, 1,1-cyclohexanedithiol, 1,2-cyclohexanedithiol, 2,2-dimethylpropane-1,3-dithiol, 3,4-dimethoxybutane-1,2 -Dithiol, 2-methylcyclohexane-2,3-dithiol, 1,1-bis (mercaptomethyl) cyclohexane, thiomalic acid bis (2-mercaptoethyl ester), 2,3-dimercapto-1-propanol (2-mercaptoacetate) ), 2,3-dimercapto-1-propanol 3-mercaptopropionate), diethylene glycol bis (2-mercaptoacetate), diethylene glycol bis (3-mercaptopropionate), 1,2-dimercaptopropyl methyl ether, 2,3-dimercaptopropyl methyl ether, 2, 2-bis (mercaptomethyl) -1,3-propanedithiol, bis (2-mercaptoethyl) ether, ethylene glycol bis (2-mercaptoacetate), ethylene glycol bis (3-mercaptopropionate), trimethylolpropane bis (2-mercaptoacetate), trimethylolpropane bis (3-mercaptopropionate), pentaerythritol tetrakis (2-mercaptoacetate, pentaerythritol tetrakis (3-mercaptotop Pioneto), tetrakis (mercaptomethyl) aliphatic polythiol compounds such as methane;

1,2-dimercaptobenzene, 1,3-dimercaptobenzene, 1,4-dimercaptobenzene, 1,2-bis (mercaptomethyl) benzene, 1,3-bis (mercaptomethyl) benzene, 1,4- Bis (mercaptomethyl) benzene, 1,2-bis (mercaptoethyl) benzene, 1,3-bis (mercaptoethyl) benzene, 1,4-bis (mercaptoethyl) benzene, 1,2,3-trimercaptobenzene, 1,2,4-trimercaptobenzene, 1,3,5-trimercaptobenzene, 1,2,3-tris (mercaptomethyl) benzene, 1,2,4-tris (mercaptomethyl) benzene, 1,3,3 5-tris (mercaptomethyl) benzene, 1,2,3-tris (mercaptoethyl) benzene, 1,2,4-tris (mer Puttoethyl) benzene, 1,3,5-tris (mercaptoethyl) benzene, 2,5-toluenedithiol, 3,4-toluenedithiol, 1,3-di (p-methoxyphenyl) propane-2,2-dithiol, Aromatic polythiol compounds such as 1,3-diphenylpropane-2,2-dithiol, phenylmethane-1,1-dithiol, 2,4-di (p-mercaptophenyl) pentane;

1,2-bis (mercaptoethylthio) benzene, 1,3-bis (mercaptoethylthio) benzene, 1,4-bis (mercaptoethylthio) benzene, 1,2,3-tris (mercaptomethylthio) benzene, 1 , 2,4-Tris (mercaptomethylthio) benzene, 1,3,5-tris (mercaptomethylthio) benzene, 1,2,3-tris (mercaptoethylthio) benzene, 1,2,4-tris (mercaptoethylthio) ) Aromatic polythiol compounds containing sulfur atoms in addition to mercapto groups such as benzene, 1,3,5-tris (mercaptoethylthio) benzene, and their nuclear alkylates;

Bis (mercaptomethyl) sulfide, bis (mercaptomethyl) disulfide, bis (mercaptoethyl) sulfide, bis (mercaptoethyl) disulfide, bis (mercaptopropyl) sulfide, bis (mercaptomethylthio) methane, bis (2-mercaptoethylthio) Methane, bis (3-mercaptopropylthio) methane, 1,2-bis (mercaptomethylthio) ethane, 1,2-bis (2-mercaptoethylthio) ethane, 1,2-bis (3-mercaptopropyl) ethane, 1,3-bis (mercaptomethylthio) propane, 1,3-bis (2-mercaptoethylthio) propane, 1,3-bis (3-mercaptopropylthio) propane, 1,2,3-tris (mercaptomethylthio) Propane, 1,2,3-tris (2- Lucaptoethylthio) propane, 1,2,3-tris (3-mercaptopropylthio) propane, 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane, 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, bis (mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol, tetrakis (mercaptomethylthiomethyl) methane, tetrakis (2-mercaptoethyl) Thiomethyl) methane, tetrakis (3-mercaptopropylthiomethyl) methane, bis (2,3-dimer) Ptopropyl) sulfide, bis (1,3-dimercaptopropyl) sulfide, 2,5-dimercapto-1,4-dithiane, 2,5-dimercaptomethyl-1,4-dithiane, 2,5-dimercaptomethyl- Aliphatic polythiol compounds containing sulfur atoms other than mercapto groups such as 2,5-dimethyl-1,4-dithiane, bis (mercaptomethyl) disulfide, bis (mercaptoethyl) disulfide, bis (mercaptopropyl) disulfide, and the like Of thioglycolic acid and mercaptopropionic acid;

Hydroxymethyl sulfide bis (2-mercaptoacetate), hydroxymethyl sulfide bis (3-mercaptopropionate), hydroxyethyl sulfide bis (2-mercaptoacetate), hydroxyethyl sulfide bis (3-mercaptopropionate), hydroxypropyl Sulfide bis (2-mercaptoacetate), hydroxypropyl sulfide bis (3-mercaptopropionate), hydroxymethyl disulfide bis (2-mercaptoacetate), hydroxymethyl disulfide bis (3-mercaptopropionate), hydroxyethyl disulfide bis (2-mercaptoacetate), hydroxyethyl disulfide bis (3-mercaptopropionate), hydroxypropyl disulfide bis (2-mercaptoacetate), hydroxypropyl disulfide bis (3-mercaptopropionate), 2-mercaptoethyl ether bis (2-mercaptoacetate), 2-mercaptoethyl ether bis (3-mercaptopropionate), 1,4 Dithian-2,5-diol bis (2-mercaptoacetate), 1,4-dithian-2,5-diol bis (3-mercaptopropionate), thiodiglycolic acid bis (2-mercaptoethyl ester), thiodi Propionic acid bis (2-mercaptoethyl ester), 4,4-thiodibutyric acid bis (2-mercaptoethyl ester), dithiodiglycolic acid bis (2-mercaptoethyl ester), dithiodipropionic acid bis (2-mercaptoethyl ester) ), 4,4-dithio Dibutyl acid bis (2-mercaptoethyl ester), thiodiglycolic acid bis (2,3-dimercaptopropyl ester), thiodipropionic acid bis (2,3-dimercaptopropyl ester), dithioglycolic acid bis (2, 3-dimercaptopropyl ester), dithiodipropionic acid bis (2,3-dimercaptopropyl ester) and other mercapto groups, and other aliphatic polythiol compounds containing a sulfur atom and an ester bond;

A heterocyclic compound containing a sulfur atom in addition to a mercapto group such as 3,4-thiophenedithiol and 2,5-dimercapto-1,3,4-thiadiazole;

2-mercaptoethanol, 3-mercapto-1,2-propanediol, glycerol di (mercaptoacetate), 1-hydroxy-4-mercaptocyclohexane, 2,4-dimercaptophenol, 2-mercaptohydroquinone, 4-mercaptophenol, 3,4-dimercapto-2-propanol, 1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol, 1,2-dimercapto-1,3-butanediol, pentaerythritol tris (3-mercapto Propionate), pentaerythritol mono (3-mercaptopropionate), pentaerythritol bis (3-mercaptopropionate), pentaerythritol tris (thioglycolate), dipentaerythritol pentakis (3 Mercaptopropionate), hydroxymethyl - tris (mercaptoethylthiomethyl) methane, compounds containing 1-hydroxyethyl-thio-3-mercaptoethyl hydroxy group other than the mercapto group of thio benzene;

1,1,3,3-tetrakis (mercaptomethylthio) propane, 1,1,2,2-tetrakis (mercaptomethylthio) ethane, 4,6-bis (mercaptomethylthio) -1,3-dithiacyclohexane, 1, 1,5,5-tetrakis (mercaptomethylthio) -3-thiapentane, 1,1,6,6-tetrakis (mercaptomethylthio) -3,4-dithiahexane, 2,2-bis (mercaptomethylthio) ethanethiol, 2- (4,5-Dimercapto-2-thiapentyl) -1,3-dithiacyclopentane, 2,2-bis (mercaptomethyl) -1,3-dithiacyclopentane, 2,5-bis (4,4- Bis (mercaptomethylthio) -2-thiabutyl) -1,4-dithiane, 2,2-bis (mercaptomethylthio) -1,3-propa Dithiol, 3-mercaptomethylthio-1,7-dimercapto-2,6-dithiaheptane, 3,6-bis (mercaptomethylthio) -1,9-dimercapto-2,5,8-trithianonane, 4,6-bis (mercapto) Methylthio) -1,9-dimercapto-2,5,8-trithianonane, 3-mercaptomethylthio-1,6-dimercapto-2,5-dithiahexane, 2- (2,2-bis (mercaptomethylthio) ethyl) -1 , 3-dithietane, 1,1,9,9-tetrakis (mercaptomethylthio) -5- (3,3-bis (mercaptomethylthio) -1-thiapropyl) 3,7-dithianonane, tris (2,2-bis ( Mercaptomethylthio) ethyl) methane, tris (4,4-bis (mercaptomethylthio) -2-thiabutyl) me , Tetrakis (2,2-bis (mercaptomethylthio) ethyl) methane, tetrakis (4,4-bis (mercaptomethylthio) -2-thiabutyl) methane, 3,5,9,11-tetrakis (mercaptomethylthio) -1 , 13-dimercapto-2,6,8,12-tetrathiatridecane, 3,5,9,11,15,17-hexakis (mercaptomethylthio) -1,19-dimercapto-2,6,8,12, 14,18-hexathiononadecane, 9- (2,2-bis (mercaptomethylthio) ethyl) -3,5,13,15-tetrakis (mercaptomethylthio) -1,17-dimercapto-2,6,8, 10,12,16-hexathiaheptadecane, 3,4,8,9-tetrakis (mercaptomethylthio) -1,11-dimercapto- 2,5,7,10-tetrathiaundecane, 3,4,8,9,13,14-hexakis (mercaptomethylthio) -1,16-dimercapto-2,5,7,10,12,15-hexathia Hexadecane, 8- {bis (mercaptomethylthio) methyl} -3,4,12,13-tetrakis (mercaptomethylthio) -1,15-dimercapto-2,5,7,9,11,14-hexathiapentadecane, 4 , 6-bis {3,5-bis (mercaptomethylthio) -7-mercapto-2,6-dithiaheptylthio} -1,3-dithiane, 4- {3,5-bis (mercaptomethylthio) -7- Mercapto-2,6-dithiaheptylthio} -6-mercaptomethylthio-1,3-dithiane, 1,1-bis {4- (6-mercaptomethylthio) -1,3-di Anilthio} -3,3 bis (mercaptomethylthio) propane, 1,3-bis {4- (6-mercaptomethylthio) -1,3-dithianylthio} -1,3-bis (mercaptomethylthio) propane, 1- {4 -(6-Mercaptomethylthio) -1,3-dithianylthio} -3- {2,2-bis (mercaptomethylthio) ethyl} -7,9-bis (mercaptomethylthio) -2,4,6,10-tetrathia Undecane, 1- {4- (6-mercaptomethylthio) -1,3-dithianylthio} -3- {2- (1,3-dithietanyl)} methyl-7,9-bis (mercaptomethylthio) -2,4 6,10-tetrathiaundecane, 1,5-bis {4- (6-mercaptomethylthio) -1,3-dithianylthio} -3- {2- (1,3-dithi Etanyl)} methyl-2,4-dithiapentane, 4,6-bis [3- {2- (1,3-dithietanyl)} methyl-5-mercapto-2,4-dithiapentylthio] -1,3- Dithiane, 4,6-bis {4- (6-mercaptomethylthio) -1,3-dithianylthio} -1,3-dithiane, 4- {4- (6-mercaptomethylthio) -1,3-dithianylthio} -6 -{4- (6-mercaptomethylthio) -1,3-dithianylthio} -1,3-dithiane, 3- {2- (1,3-dithietanyl)} methyl-7,9-bis (mercaptomethylthio) -1 , 11-dimercapto-2,4,6,10-tetrathiaundecane, 9- {2- (1,3-dithietanyl)} methyl-3,5,13,15-tetrakis (mercaptomethylthio) -1,17- Mercapto-2,6,8,10,12,16-hexathiaheptadecane, 3- {2- (1,3-dithietanyl)} methyl-7,9,13,15-tetrakis (mercaptomethylthio) -1, 17-dimercapto-2,4,6,10,12,16-hexathiaheptadecane, 3,7-bis {2- (1,3-dithietanyl)} methyl-1,9-dimercapto-2,4,6 , 8-tetrathianonane, 4- {3,4,8,9-tetrakis (mercaptomethylthio) -11-mercapto-2,5,7,10-tetrathiaundecyl} -5-mercaptomethylthio-1,3 -Dithiolane, 4,5-bis {3,4-bis (mercaptomethylthio) -6-mercapto-2,5-dithiahexylthio} -1,3-dithiolane, 4- {3,4-bis (mercapto) Tilthio) -6-mercapto-2,5-dithiahexylthio} -5-mercaptomethylthio-1,3-dithiolane, 4- {3-bis (mercaptomethylthio) methyl-5,6-bis (mercaptomethylthio)- 8-mercapto-2,4,7-trithiaoctyl} -5-mercaptomethylthio-1,3-dithiolane, 2- [bis {3,4-bis (mercaptomethylthio) -6-mercapto-2,5-di Thiahexylthio} methyl] -1,3-dithietane, 2- {3,4-bis (mercaptomethylthio) -6-mercapto-2,5-dithiahexylthio} mercaptomethylthiomethyl-1,3-dithietane, 2 -{3,4,8,9-tetrakis (mercaptomethylthio) -11-mercapto-2,5,7,10-tetrathiaundecylthio} Lucaptomethylthiomethyl-1,3-dithietane, 2- {3-bis (mercaptomethylthio) methyl-5,6-bis (mercaptomethylthio) -8-mercapto-2,4,7-trithiaoctyl} mercaptomethylthiomethyl -1,3-dithietane, 4,5-bis [1- {2- (1,3-dithietanyl)}-3-mercapto-2-thiapropylthio] -1,3-dithiolane, 4- [1- { 2- (1,3-dithietanyl)}-3-mercapto-2-thiapropylthio] -5- {1,2-bis (mercaptomethylthio) -4-mercapto-3-thiabutylthio} -1,3-dithiolane, 2- [bis {4- (5-mercaptomethylthio-1,3-dithiolanyl) thio}] methyl-1,3-dithietane, 4- {4- (5-mercaptomethylthio-1) 3-dithiolanyl) thio} -5- [1- {2- (1,3-dithietanyl)}-3-mercapto-2-thiapropylthio] -1,3-dithiolane, and dithioacetals such as these oligomers or A compound having a dithioketal skeleton;

Tris (mercaptomethylthio) methane, tris (mercaptoethylthio) methane, 1,1,5,5-tetrakis (mercaptomethylthio) -2,4-dithiapentane, bis (4,4-bis (mercaptomethylthio) -1,3 Dithiabutyl (mercaptomethylthio) methane, tris (4,4-bis (mercaptomethylthio) -1,3-dithiabutyl) methane, 2,4,6-tris (mercaptomethylthio) -1,3,5-trithiacyclohexane, 2,4-bis (mercaptomethylthio) -1,3,5-trithiacyclohexane, 1,1,3,3-tetrakis (mercaptomethylthio) -2-thiapropane, bis (mercaptomethyl) methylthio-1,3,5 -Trithiacyclohexane, tris ((4-mercaptomethyl-2,5-dithia Cyclohexyl-1-yl) methylthio) methane, 2,4-bis (mercaptomethylthio) -1,3-dithiacyclopentane, 2-mercaptoethylthio-4-mercaptomethyl-1,3-dithiacyclopentane, 2 -(2,3-dimercaptopropylthio) -1,3-dithiacyclopentane, 4-mercaptomethyl-2- (2,3-dimercaptopropylthio) -1,3-dithiacyclopentane, 4- Mercaptomethyl-2- (1,3-dimercapto-2-propylthio) -1,3-dithiacyclopentane, tris (2,2-bis (mercaptomethylthio) -1-thiaethyl) methane, tris (3,3- Bis (mercaptomethylthio) -2-thiapropyl) methane, tris (4,4-bis (mercaptomethylthio) -3-thiabutyl) meta 2,4,6-tris (3,3-bis (mercaptomethylthio) -2-thiapropyl) -1,3,5-trithiacyclohexane, tetrakis (3,3-bis (mercaptomethylthio) -2-thiapropyl ) Compounds having ortho-trithioformate skeleton such as methane and further oligomers thereof;

3,3′-di (mercaptomethylthio) -1,5-dimercapto-2,4-dithiapentane, 2,2′-di (mercaptomethylthio) -1,3-dithiacyclopentane, 2,7-di (mercapto) Methyl) -1,4,5,9-tetrathiaspiro [4.4] nonane, 3,9-dimercapto-1,5,7,11-tetrathiaspiro [5.5] undecane, and oligomers thereof. And compounds having an orthotetrathiocarbonate skeleton.

However, the polythiol compound is not limited to the above exemplary compounds. Each of the above exemplary compounds may be used alone or in combination of two or more.

Among the above exemplified compounds, preferred compounds are 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane, bis (mercaptomethyl) -3,6,9-trithia-1,11-undecane. Dithiol, pentaerythritol tetrakis (3-mercaptopropionate), bis (mercaptomethyl) sulfide, 1,3-bis (mercaptomethyl) benzene, 1,1,3,3-tetrakis (mercaptomethylthio) propane.

The total content of iron, chromium, and nickel in the polythiol may be any measuring method as long as the total content of iron, chromium, and nickel can be measured, but is preferably measured using an ICP emission spectrometer. To do. The measurement is performed after pretreatment of polythiol with an acid such as sulfuric acid or nitric acid according to a conventional method. These measurements are performed, and a polythiol having a total content of iron, chromium, and nickel of 5.0 ppm or less is used. Preferably it is 2.0 ppm or less, More preferably, it is 1.0 ppm or less, More preferably, it is 0.5 ppm or less, Most preferably, it is 0.3 ppm or less.

  When the total content of iron, chromium and nickel exceeds 5.0 ppm, these polythiol-containing compositions turn yellow and become unusable when polymerized and cured. Therefore, by measuring the total content of iron, chromium, and nickel, it is possible to predict and determine the occurrence of discoloration to yellow without polymerization and curing, and to determine the quality of the polythiol.

When the total content of iron, chromium, and nickel exceeds 5.0 ppm, it is an effective technique to set the content to 5.0 ppm or less through a purification process. It is also an effective technique to obtain a more preferable, more preferable, and most preferable state by further purification. Examples of the purification method include water washing, distillation, column separation operation, adsorbent treatment, ion exchange resin treatment, and the like, but water washing and distillation are preferred.

  Washing with water may or may not use a solvent, but is usually used. Any solvent may be used as long as it dissolves the polythiol, but ether, toluene, benzene, preferably toluene, which are easily separated from water, are preferably used. Therefore, washing with water is usually performed in a state dissolved in toluene, and toluene is removed after completion.

  The conditions for distillation vary depending on the polythiol used, but any conditions may be used as long as the polythiol can be distilled. It is preferably under reduced pressure, more preferably 0.01 to 100 Torr. Although distillation temperature should just be a temperature which does not decompose | disassemble, Preferably it is 20-200 degreeC, More preferably, it is 50 to 150 degreeC.

In the present invention, a polyurethane resin for an optical material is produced by polymerizing a polymerizable composition comprising a polythiol compound and a polyiso (thio) cyanate compound.

The polyiso (thio) cyanate compound used in the present invention is not particularly limited as long as it is a compound having two or more iso (thio) cyanate groups in one molecule. The term “iso (thio) cyanate” means “isocyanate or isothiocyanate”.

Specific examples of the polyiso (thio) cyanate compound include hexamethylene diisocyanate, 2,2-dimethylpentane diisocyanate, 2,2,4-trimethylhexane diisocyanate, butene diisocyanate, and 1,3-butadiene. -1,4-diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8-di Aliphatic polyisocyanate compounds such as isocyanate-4-isocyanatomethyloctane, bis (isocyanatoethyl) carbonate, bis (isocyanatoethyl) ether, lysine diisocyanatomethyl ester, lysine triisocyanate;

2,5-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, 2,6-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, bis (isocyanatomethyl) cyclohexane, Alicyclic polyisocyanate compounds such as dicyclohexylmethane diisocyanate and isophorone diisocyanate;

1,2-diisocyanatobenzene, 1,3-diisocyanatobenzene, 1,4-diisocyanatobenzene, 2,4-diisocyanatotoluene, ethylphenylene diisocyanate, isopropylphenylene diisocyanate, dimethylpheny Range isocyanate, diethyl phenylene diisocyanate, diisopropyl phenylene diisocyanate, trimethylbenzene triisocyanate, benzene triisocyanate, biphenyl diisocyanate, toluidine diisocyanate, 4,4'-methylenebis (phenyl isocyanate), 4 , 4′-methylenebis (2-methylphenylisocyanate), bibenzyl-4,4′-diisocyanate, bis (isocyanatophenyl) ethylene, 1,2-bis (isocyanatomethyl) benze 1,3-bis (isocyanatomethyl) benzene, 1,4-bis (isocyanatomethyl) benzene, 1,2-bis (isocyanatoethyl) benzene, 1,3-bis (isocyanatoethyl) benzene, , 4-bis (isocyanatoethyl) benzene, 1,2-bis (isocyanatopropyl) benzene, 1,3-bis (isocyanatopropyl) benzene, 1,4-bis (isocyanatopropyl) benzene, α, α , Α ′, α′-tetramethylxylylene diisocyanate, bis (isocyanatobutyl) benzene, bis (isocyanatomethyl) naphthalene, bis (isocyanatomethylphenyl) ether, bis (isocyanatoethyl) phthalate, 2,6 A polyisocyanate compound having an aromatic ring compound such as di (isocyanatomethyl) furan;

Bis (isocyanatomethyl) sulfide, bis (isocyanatoethyl) sulfide, bis (isocyanatopropyl) sulfide, bis (isocyanatohexyl) sulfide, bis (isocyanatomethyl) sulfone, bis (isocyanatomethyl) disulfide, bis ( Isocyanatoethyl) disulfide, bis (isocyanatopropyl) disulfide, bis (isocyanatomethylthio) methane, bis (isocyanatoethylthio) methane, bis (isocyanatomethylthio) ethane, bis (isocyanatomethylthio) ethane, 1, 5-diisocyanato-2-isocyanatomethyl-3-thiapentane, 1,2,3-tris (isocyanatomethylthio) propane, 1,2,3-tris (isocyanatoethylthio) propane, 3,5-dithia-1 , 2,6 , 7-heptanetetraisocyanate, 2,6-diisocyanatomethyl-3,5-dithia-1,7-heptanediisocyanate, 2,5-diisocyanatomethylthiophene, isocyanatoethylthio-2,6 A sulfur-containing aliphatic polyisocyanate compound such as dithia-1,8-octane diisocyanate;

Aromatic sulfide polyisocyanate compounds such as 2-isocyanatophenyl-4-isocyanatophenyl sulfide, bis (4-isocyanatophenyl) sulfide, bis (4-isocyanatomethylphenyl) sulfide;

Bis (4-isocyanatophenyl) disulfide, bis (2-methyl-5-isocyanatophenyl) disulfide, bis (3-methyl-5-isocyanatophenyl) disulfide, bis (3-methyl-6-isocyanatophenyl) Aromatic disulfide polyisocyanate compounds such as disulfide, bis (4-methyl-5-isocyanatophenyl) disulfide, bis (4-methoxy-3-isocyanatophenyl) disulfide;

2,5-diisocyanatotetrahydrothiophene, 2,5-diisocyanatomethyltetrahydrothiophene, 3,4-diisocyanatomethyltetrahydrothiophene, 2,5-diisocyanato-1,4-dithiane, 2,5-diisocyanate Natomethyl-1,4-dithiane, 4,5-diisocyanato-1,3-dithiolane, 4,5-bis (isocyanatomethyl) -1,3-dithiolane, 4,5-diisocyanatomethyl-2-methyl A sulfur-containing alicyclic polyisocyanate compound such as -1,3-dithiolane;

Aliphatic polyisothiocyanate compounds such as 1,2-diisothiocyanatoethane and 1,6-diisothiocyanatohexane; Alicyclic polyisothiocyanate compounds such as cyclohexanediisothiocyanate; 1,2-di Isothiocyanatobenzene, 1,3-diisothiocyanatobenzene, 1,4-diisothiocyanatobenzene, 2,4-diisothiocyanatotoluene, 2,5-diisothiocyanato-m-xylene, 4, 4'-methylenebis (phenylisothiocyanate), 4,4'-methylenebis (2-methylphenylisothiocyanate), 4,4'-methylenebis (3-methylphenylisothiocyanate), 4,4'-diisothi Oceanatobenzophenone, 4,4′-diisothiocyanato-3,3′-dimethylbenzophenone, bis ( - isothiocyanatophenyl) aromatic poly isothiocyanate compounds such as ether;

Further, carbonyl polyisothiocyanate such as 1,3-benzenedicarbonyldiisothiocyanate, 1,4-benzenedicarbonyldiisothiocyanate, (2,2-pyridine) -4,4-dicarbonyldiisothiocyanate, and the like. Isocyanate compounds; sulfur-containing aliphatic polyisothiocyanate compounds such as thiobis (3-isothiocyanatopropane), thiobis (2-isothiocyanatoethane), dithiobis (2-isothiocyanatoethane);

Sulfur-containing fragrances such as 1-isothiocyanato-4-[(2-isothiocyanato) sulfonyl] benzene, thiobis (4-isothiocyanatobenzene), sulfonyl (4-isothiocyanatobenzene), dithiobis (4-isothiocyanatobenzene) Group polyisothiocyanate compounds; sulfur-containing alicyclic polyisothiocyanate compounds such as 2,5-diisothiocyanatothiophene and 2,5-diisothiocyanato-1,4-dithiane;

1-isocyanato-6-isothiocyanatohexane, 1-isocyanato-4-isothiocyanatocyclohexane, 1-isocyanato-4-isothiocyanatobenzene, 4-methyl-3-isocyanato-1-isothiocyanatobenzene, 2- Isocyanato groups such as isocyanato-4,6-diisothiocyanato-1,3,5-triazine, 4-isocyanatophenyl-4-isothiocyanatophenyl sulfide, 2-isocyanatoethyl-2-isothiocyanatoethyl disulfide And a polyiso (thio) cyanate compound having an isothiocyanato group.

Furthermore, halogen-substituted products such as chlorine-substituted products and bromine-substituted products, alkyl-substituted products, alkoxy-substituted products, nitro-substituted products and prepolymer-modified products with polyhydric alcohols, carbodiimide-modified products, urea-modified products, and burette-modified products. Bodies, dimerization or trimerization reaction products and the like can also be used.

However, the polyiso (thio) cyanate compound is not limited to the above exemplary compounds. Moreover, each above-mentioned exemplary compound may be used individually, and may mix and use 2 or more types.

Among the above exemplified compounds, preferred compounds are 2,5-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, 2,6-bis (isocyanatomethyl) -bicyclo [2.2.1]. ] Heptane, bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) benzene and α, α, α ', α'-tetramethylxylylene diisocyanate It is.

The use ratio of the polythiol compound and the polyiso (thio) cyanate compound is usually SH group / NCO (NCS) group = 0.5 to 3.0, preferably 0.6 to 2.0, more preferably 0.8 to Within the range of 1.3.

The composition for optical materials of the present invention is a composition comprising a polythiol compound and a polyiso (thio) cyanate compound as main components. In addition to this, it is of course possible to further improve the practicality of the resulting material by adding optional components such as a catalyst, an internal mold release agent, an ultraviolet absorber, and a bluing agent as necessary.
For example, a polyurethane-based lens can be produced by injecting a polythiol compound, a polyiso (thio) cyanate compound and, if necessary, optional components into a lens mold and polymerizing them.

As the catalyst for polymerizing and curing the composition for optical materials of the present invention, a known urethanization catalyst is used. The addition amount of the polymerization catalyst varies depending on the components of the composition, the mixing ratio and the polymerization curing method, but is not generally determined, but is usually 0.001 wt% or more and 5 wt% or less with respect to the total amount of the optical material composition, Preferably, 0.01 wt% or more and 1 wt% or less is used, and most preferably 0.01 wt% or more and 0.5 wt% or less is used. When the addition amount of the polymerization catalyst is more than 5 wt%, the refractive index and heat resistance of the cured product may be lowered and coloring may occur. On the other hand, if it is less than 0.001 wt%, it may not be cured sufficiently and heat resistance may be insufficient.

Preferable examples of the ultraviolet light inhibitor include benzotriazole compounds. Among these, specific examples of preferred compounds are 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole, 5-chloro-2- (3,5-di-tert-butyl-2-hydroxyphenyl) -2H. -Benzotriazole, 2- (3-tert-butyl-2-hydroxy-5-methylphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-tert-pentyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (2-hydroxy-4-octyloxyphenyl) -2H-benzotriazole, 2 -(2-Hydroxy-5-tert-octylphenyl) -2H benzotriazole. Preferable examples of the bluing agent include anthraquinone compounds.

When the composition for optical materials of the present invention is difficult to peel off from the mold after polymerization, a known external and / or internal mold release agent is used or added to improve the mold release from the mold of the resulting cured product. It is also possible to squeeze. Release agents include fluorine-based nonionic surfactants, silicon-based nonionic surfactants, phosphate esters, acidic phosphate esters, oxyalkylene-type acidic phosphate esters, alkali metal salts of acidic phosphate esters, and alkalis of oxyalkylene-type acidic phosphate esters. Examples include metal salts, alkali metal salts of higher fatty acids, higher fatty acid esters, paraffins, waxes, higher aliphatic amides, higher aliphatic alcohols, polysiloxanes, aliphatic amine ethylene oxide adducts, and these can be used alone or in two types. A mixture of the above may be used. The addition amount is usually 0.0001 to 5 wt% with respect to the total amount of the composition for optical materials.

In addition to the polythiol compound and the iso (thio) cyanate compound forming the urethane resin, for the purpose of improving various physical properties, operability and polymerization reactivity of the polyurethane resin, an active hydrogen compound typified by an amine or the like, You may add 1 or more types of compounds other than urethane formation raw materials, such as an epoxy compound, an olefin compound, a carbonate compound, and an ester compound.

An optical material made of a polyurethane resin is usually produced by cast polymerization. Specifically, a polythiol compound and a polyiso (thio) cyanate compound are mixed. This mixed solution (polymerizable composition) is defoamed by an appropriate method as necessary, and then poured into a mold for optical material, and is usually gradually heated from a low temperature to a high temperature for polymerization. Thereafter, the optical material is obtained by demolding.

In this invention, it is preferable to deaerate with respect to the composition for optical materials previously. The deaeration treatment is performed under reduced pressure before, during or after mixing the compound capable of reacting with some or all of the composition components, the polymerization catalyst, and the additive. Preferably, it is performed under reduced pressure during or after mixing. The treatment conditions are 0 to 100 ° C. under reduced pressure of 0.001 to 50 torr for 1 minute to 24 hours. The degree of decompression is preferably 0.005 to 25 torr, more preferably 0.01 to 10 torr, and the degree of decompression may be varied within these ranges. The deaeration time is preferably 5 minutes to 18 hours, more preferably 10 minutes to 12 hours. The temperature at the time of deaeration is preferably 5 ° C. to 80 ° C., more preferably 10 ° C. to 60 ° C., and the temperature may be varied within these ranges. In the degassing treatment, renewing the interface of the resin composition by stirring, blowing of gas, vibration by ultrasonic waves or the like is a preferable operation for enhancing the degassing effect.

Furthermore, by purifying the composition for optical material and / or each raw material before mixing with a filter having a pore size of about 0.05 to 10 μm to purify impurities, the quality of the optical material of the present invention is further improved. It is also preferable from the viewpoint of increasing.

The composition for optical material subjected to the above reaction and treatment is poured into a glass or metal mold, and after the polymerization and curing reaction is advanced by irradiation with active energy rays such as heating or ultraviolet rays, the composition is removed from the mold. . In this way, an optical material is manufactured. The composition for optical material is preferably polymerized and cured by heating to produce an optical material. In this case, the curing time is 0.1 to 200 hours, usually 1 to 100 hours, and the curing temperature is −10 to 160 ° C., usually −10 to 140 ° C. The polymerization can be carried out by holding at a predetermined polymerization temperature for a predetermined time, raising the temperature by 0.1 ° C. to 100 ° C./hour, lowering the temperature by 0.1 ° C. to 100 ° C./hour, and combinations thereof. In addition, in the method for producing an optical material of the present invention, it is preferable to anneal the cured product at a temperature of 50 to 150 ° C. for about 10 minutes to 5 hours after the completion of polymerization in order to remove distortion of the optical material. It is processing.

The polyurethane-based resin produced by the method of the present invention has features that are lightweight and excellent in impact resistance, and also has a good hue. Therefore, this resin is suitable for applications of optical materials such as lenses and prisms. In particular, it is very suitable for the use of lenses such as spectacle lenses and camera lenses.

In addition, the optical material is surface-polished, antistatic treatment, for the purpose of improving the antireflection, high hardness, wear resistance, chemical resistance, cloud resistance, or fashionability, if necessary. Physical and chemical treatments such as hard coat treatment, non-reflective coat treatment, dyeing treatment, and light control treatment can be performed.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Evaluation was performed by the following method.
Total content of iron, chromium and nickel: The total content of iron, chromium and nickel of polythiol was measured using ICP emission analyzer SPS5520 manufactured by SII Nanotechnology.
Measurement of yellow: A flat plate having a thickness of 5 mm was prepared by the following polymerization methods A to D, and the YI value was measured using a color techno JS555.
The YI value was compared with a flat plate prepared using a polythiol having a total content of iron, chromium and nickel of the detection limit (0.1 ppm) or less, and the difference (ΔYI) was 0.1 or less. 0.3 was set as (circle), 0.3-0.5 was set as (triangle | delta), and 0.5 or more was set as x. The thing above △ is a pass.

(Create blank)
1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane (hereinafter referred to as Compound A), bis, whose total content of iron, chromium and nickel was below the detection limit (0.1 ppm) (Mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol (hereinafter referred to as Compound B), pentaerythritol tetrakis (mercaptopropionate) (hereinafter referred to as Compound C) A flat plate having a thickness of 5 mm was prepared according to Preparations 1 to 4.

Examples 1-3
Using 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane (compound A) having a total content of iron, chromium, and nickel shown in Table 1, according to the following production method 1, An optical material composition and an optical material were prepared, and ΔYI was determined by comparing with a blank. The results are summarized in Table 1.

Examples 4-6
According to the following production method 2 using bis (mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol (compound B) having a total content of iron, chromium and nickel shown in Table 1, the present invention A composition for optical material and an optical material were prepared, and ΔYI was determined by comparing with the blank. The results are summarized in Table 1.

Examples 7-9
1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane (compound A) having a total content of iron, chromium and nickel shown in Table 1, and iron, chromium and nickel contents shown in Table 1 The composition for optical materials and the optical material of the present invention were prepared according to the following production method 3 using pentaerythritol tetrakis (mercaptopropionate) (compound C), and ΔYI was obtained by comparing with the blank. The results are summarized in Table 1.

Examples 10-12
Bis (mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol (compound B) having a total content of iron, chromium and nickel shown in Table 1 and iron, chromium and nickel shown in Table 1 Using the amount of pentaerythritol tetrakis (mercaptopropionate) (compound C), the composition for optical material and the optical material of the present invention were prepared according to the following production method 4, and ΔYI was obtained by comparing with the blank. The results are summarized in Table 1.

Comparative Example 1
Using 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane (compound A) having a total content of iron, chromium, and nickel shown in Table 1, according to the following production method 1, An optical material composition and an optical material were prepared, and ΔYI was determined by comparing with a blank. The results are summarized in Table 1.

Comparative Example 2
According to the following production method 2 using bis (mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol (compound B) having a total content of iron, chromium and nickel shown in Table 1, the present invention A composition for optical material and an optical material were prepared, and ΔYI was determined by comparing with the blank. The results are summarized in Table 1.

Comparative Example 3
1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane (compound A) having a total content of iron, chromium and nickel shown in Table 1, and iron, chromium and nickel contents shown in Table 1 In accordance with the following manufacturing method 3, the composition for optical materials of this invention and an optical material were produced, and (DELTA) YI was calculated | required using the following pentaerythritol tetrakis (mercaptopropionate) (compound C). The results are summarized in Table 1.

Comparative Example 4
Bis (mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol (compound B) having a total content of iron, chromium and nickel shown in Table 1, and iron, chromium and nickel contained in Table 1 Using the amount of pentaerythritol tetrakis (mercaptopropionate) (compound C), the composition for optical materials and the optical material of the present invention were prepared according to the following production method 4, and ΔYI was determined. The results are summarized in Table 1.

In addition, the detail of the manufacturing method used by the said Example and comparative example is as follows.
Manufacturing method 1
To 52 parts by weight of 1,3-bis (isocyanatomethyl) benzene (hereinafter referred to as Compound X), 0.05 parts by weight of dibutyltin dichloride as a curing catalyst and 0.10 parts by weight of dioctyl phosphate are added at 10 to 15 ° C. And dissolved. Furthermore, 48 parts by weight of 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane (Compound A) was mixed to obtain a uniform solution. This mixed homogeneous liquid is defoamed at 600 Pa for 1 hour, filtered through a 1 μm PTFE filter, poured into a 70 mm diameter + 5D mold, and polymerized from 40 ° C. to 130 ° C. over 24 hours. It was. Thereafter, the mold was removed to obtain an optical material.

Manufacturing method 2
Mixing 1 part by weight of 1,3-bis (isocyanatomethyl) benzene 5 (compound X) with 0.05 part by weight of dibutyltin dichloride and 0.10 part by weight of dioctyl phosphate as a curing catalyst at 10 to 15 ° C. Dissolved. Further, 49 parts by weight of bis (mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol (Compound B) was mixed to obtain a uniform solution. This mixed homogeneous liquid is defoamed at 600 Pa for 1 hour, filtered through a 1 μm PTFE filter, poured into a 70 mm diameter + 5D mold, and polymerized from 40 ° C. to 130 ° C. over 24 hours. It was. Thereafter, the mold was removed to obtain an optical material.

Manufacturing method 3
2,5-bis (isocyanatomethyl-bicyclo [2.2.1] heptane and 2,6-bis (isocyanatomethyl-bicyclo [2.2.1] heptane mixture (hereinafter referred to as compound Y)) 50 In 6 parts by weight, 0.06 part by weight of dibutyltin dichloride and 0.12 part by weight of dioctyl phosphate as a curing catalyst were mixed and dissolved at 10 to 15 ° C. Further, 1,2-bis [(2- Mercaptoethyl) thio] -3-mercaptopropane (compound A) 25.5 parts by weight and pentaerythritol tetrakis (mercaptopropionate) (compound C) 23.9 parts by weight were mixed to obtain a uniform solution. The solution was defoamed at 600 Pa for 1 hour, filtered through a 1 μm PTFE filter, poured into a mold having a diameter of 70 mm and + 5D, from 40 ° C. to 130 ° C. Was polymerized for 24 hours. Then demolded to obtain an optical material.

Manufacturing method 4
Mixture of 2,5-bis (isocyanatomethyl-bicyclo [2.2.1] heptane and 2,6-bis (isocyanatomethyl-bicyclo [2.2.1] heptane (Compound Y) 50.6 parts by weight In addition, 0.06 parts by weight of dibutyltin dichloride and 0.12 parts by weight of dioctyl phosphate were mixed and dissolved as a curing catalyst at 10 to 15 ° C. Furthermore, bis (mercaptomethyl) -3,6,9-trithia. -25.5 parts by weight of 1,11-undecanedithiol (compound B) and 23.9 parts by weight of pentaerythritol tetrakis (mercaptopropionate) (compound C) were mixed to obtain a uniform solution. After defoaming at 600 Pa for 1 hour, the mixture was filtered through a 1 μm PTFE filter, poured into a mold with a diameter of 70 mm and + 5D, from 40 ° C. to 130 ° C. For 24 hours, and then demolded to obtain an optical material.

In the above embodiment, yellowing after curing is prevented by polymerizing the composition for optical material using polythiol that satisfies the condition that the total content of iron, chromium and nickel is 0.5 ppm or less. I was able to. Therefore, according to the present invention, prior to the polymerization reaction, it is possible to preliminarily predict the presence or absence of yellowing after polymerization and to judge whether it is good or not, and to selectively produce only an optical material with good properties. For this reason, both effective utilization of the composition for optical materials and manufacture of an excellent optical material are possible.

Claims (6)

A method for obtaining a polythiol compound raw material for an optical material composition containing a polythiol compound and a polyiso (thio) cyanate compound, wherein the total content of iron, chromium and nickel in the polythiol compound is measured. A method of obtaining a polythiol compound raw material for a composition for optical materials by selecting a polythiol compound having a total content of iron, chromium and nickel of 2.0 ppm or less. The polythiol compound is 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane, bis (mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol, pentaerythritol tetrakis (3 -Mercaptopropionate), bis (mercaptomethyl) sulfide, 1,3-bis (mercaptomethyl) benzene, and at least one selected from the group consisting of 1,1,3,3-tetrakis (mercaptomethylthio) propane The method of obtaining the polythiol compound raw material for the composition for optical materials of Claim 1 which is a compound of these. The polyiso (thio) cyanate compound is 2,5-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, 2,6-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, Consists of bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) benzene, and α, α, α ′, α′-tetramethylxylylene diisocyanate The method for obtaining a polythiol compound raw material for an optical material composition according to claim 1, which is at least one compound selected from the group. A method for producing a composition for optical materials comprising a polythiol compound and a polyiso (thio) cyanate compound, comprising the following steps (1) and (2): .
Step (1): The total content of iron, chromium and nickel in the polythiol compound is measured. As a result, a polythiol compound having a total content of iron, chromium and nickel of 2.0 ppm or less is selected and used for optical materials. The process of obtaining the polythiol compound raw material for compositions.
Step (2): A step of mixing the polythiol compound raw material obtained in step (1) and the polyiso (thio) cyanate compound. The polythiol compound is 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane, bis (mercaptomethyl) -3,6,9-trithia-1,11-undecanedithiol, pentaerythritol tetrakis (3 -Mercaptopropionate), bis (mercaptomethyl) sulfide, 1,3-bis (mercaptomethyl) benzene, and at least one selected from the group consisting of 1,1,3,3-tetrakis (mercaptomethylthio) propane The method for producing a composition for an optical material according to claim 4, wherein The polyiso (thio) cyanate compound is 2,5-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, 2,6-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, Consists of bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) benzene, and α, α, α ′, α′-tetramethylxylylene diisocyanate The manufacturing method of the composition for optical materials of Claim 4 which is at least 1 sort (s) of compound chosen from the group.