JPH0384021A - Thiocarbamic acid s-alkyl ester-based lens and its production - Google Patents

Abstract

PURPOSE:To obtain the title light-weight lens suitable as lens of glasses, etc., having excellent optical physical properties by adding a specific tertiary amine to a mixture of polyisocyanate and polythiol and subjecting to casting polymerization. CONSTITUTION:A polyisocyanate containing secondary or tertiary isocyanate and one or more sulfur atoms except mercapto group is blended with a polythiol such as mercapto compound containing hydroxyl group in the molar ratio of NCO/SH (functional group) of 0.5-3.0 5ppm-1% tertiary amine (e.g. dimethylaminoethyl acetate) is added to the blend, which is optionally mixed with a chain extender, a light stabilizer, a crosslinking agent, etc., are cast into a mold and polymerized at -20 to 200 deg.C for 0.5-72 hours to give the objective lens.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a thiocarbamic acid S-alkyl ester lens and a method for manufacturing the same. More specifically, by adding a tertiary amine having an electron-withdrawing group in the molecule to a mixture of polyisocyanate and polythiol,
The present invention relates to a method for producing a thiocarbamic acid S-alkyl ester lens characterized by cast polymerization, and a lens obtained by the method.

[Conventional technology]

Conventionally, when obtaining a urethane resin from a polyisocyanate and a polyol, a technique using a tertiary amine as a catalyst is known. The present inventors are conducting research to obtain a thiocarbamic acid S-alkyl ester lens from polyisocyanate and polythiol. Generally, plastic lenses are obtained by injecting a monomer into a mold made of a glass mold and a resin gasket and curing it by heating, but it takes 6 to 8 hours from monomer preparation to injection, during which time the monomer is injected. Possible viscosity must be maintained. Furthermore, the resin gasket used in the mold is made of thermoplastic resin, and its heat resistance is generally 120° C. or lower. Furthermore, from an economic standpoint, the time required for lens molding is generally considered to be within 24 hours, except for special cases. [Problems to be Solved by the Invention] The present inventors have conventionally used organic tin compounds as polymerization catalysts, but for example, in the case of the reaction between inphorone diisocyanate and pentaerythritol tetrakis (3-mercaptopropionate). The activity of organotin catalysts is low, and a temperature of 120° C. or more is required for gelation of the monomer, and the time required for polymerization is also 24 hours or more. Furthermore, when a tertiary amine such as triethylamine is used instead of an organic tin compound, the activity is high and the reaction proceeds explosively upon addition of the catalyst, making it impossible to inject the monomer mixture into the mold. [Means for Solving the Problems] In view of this situation, the present inventors conducted extensive studies and found that among tertiary amines, tertiary amines having an electron-withdrawing group in the molecule are similar to polyisocyanates. As a catalyst for obtaining thiocarbamic acid S-alkyl ester lenses from a mixture of polythiols, lenses can be produced within 24 hours at temperatures below 120°C while having appropriate activity, that is, sufficient pot life near room temperature. It was discovered that it has activity, leading to the present invention. That is, the present invention provides a method for producing a thiocarbamic acid S-alkyl ester lens, which comprises adding a tertiary amine having an electron-withdrawing group in the molecule to a mixture of polyisocyanate and polythiol, and performing cast polymerization. , and lenses obtained by cast polymerization. The tertiary amine having an electron exhausting group in the molecule used in the present invention is, for example, a compound having a group such as an ester group, carbonyl group, nitrile group, or nitro group in the molecule. , dimethylaminoethyl acetate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, N,N'-dimethylacetamide, dimethylamine acrylonitrile, diethylamine acrylonitrile, dimethylaminoacetone, 3-dimethylaminoacrolein, dimethylaminomethylenemalononitrile, diethylaminoacetone, diethylamino These are compounds such as acetonitrile, -diethylamine-3-butanone, and dimethylaminoacetonitrile. The amount of these tertiary amines added varies depending on the combination of monomers, but is generally 5 ppm to 1%. In the present invention, the polythiol used as a raw material includes a polythiol having at least one sulfur atom in addition to a mercapto group, a mercapto compound having a hydroxyl group, and a mercapto compound having a hydroxyl group and at least one sulfur atom in addition to a mercapto group. Compounds are also used. Specifically, examples of the polythiol include methanedithiol, 1,2-ethanedithiol, 1. l-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-dimethoxyphthane-1,2-dithiol, 2-methylcyclohexane-2
,3-dithiol,bicyclo[2,2,1]pebutere
xo-cis-2,3-dithiol, 1,1-bis(mercaptomethyl)cyclohexane, bis(thiomalate)
2-mercaptoethyl ester), 2.3-dimercaptosuccinic acid (2-mercaptoethyl ester), 2.3
-dimercapto-1-propatur (2-mercaptoacetate-1-), 2,3-dimercapto-1-propatur (3-mercaptopropionate), diethylene 1
1-Jl/)' 7 (')--11L-h"f
k7-h-y-k) S'>T tyrene 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)
, aliphatic polythiols such as pentaerythritol tetrakis (2-mercaptoacetate), pentaerythritol tetrakis (3-mercaptopropionate), and halogen-substituted compounds such as chlorine-substituted products and bromine-substituted products thereof, 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-bis(mercaptomethyleneoxy)benzene, 1.
3-bis(mercaptomethyleneoxy)benzene, 1.
4-bis(mercaptomethyleneoxy)benzene, 1.
2-bis(mercaptoethyleneoxy)benzene, 1,
3-bis(mercaptoethyleneoxy)benzene, 1.
4-bis(mercaptoethyleneoxy)benzene, 1.
2.3-trimercaptobenzene, 1.2.4-trimercaptobenzene, 1.3.5-trimercaptobenzene, 1,2.3-tris(mercaptomethyl)benzene, l, 2.4-tris(mercaptobenzene) methyl)benzene, 1.3.5-tris(mercaptomethyl)benzene, 1.2.3-)-lis(mercaptoethyl)benzene, l, 2.4-tris(mercaptoethyl)benzene, 1.3.5 - Tris(mercaptoethyl)benzene, 1.2.3-tris(mercaptomethyleneoxy)
Benzene, 1.2.4-tris(mercaptomethyleneoxy)benzene, 1.3.5-tris(mercaptomethyleneoxy)benzene, 1.2.3-tris(mercaptoethyleneoxy)benzene, 1.2.4- Tris (
Mercaptoethyleneoxy)benzene, 1.3.5-tris(mercaptoethyleneoxy)benzene, 1.2.
3.4-tetramercaptobenzene, 1.2.3.5-
Tetramercaptobenzene, 1.2.4.5-Tetramercaptobenzene, l, 2°3.4-tetrakis(mercaptomethyl)benzene, 1,2.3.5-tetrakis(mercaptomethyl)benzene, 1.2. 4.5-tetrakis(mercaptomethyl)benzene, l, 2.3.
4-tetrakis(mercaptoethyl)benzene, 1,2
, 3.5-tetrakis(mercaptoethyl)benzene,
1.2.4.5-tetrakis(mercaptoethyl)benzene, 1.2.3.4-tetrakis(mercaptomethyleneoxy)benzene, 1.2.3.5-tetrakis(mercaptomethyleneoxy)benzene, 1,2 ,4.5-
Tetrakis(mercaptomethyleneoxy)benzene, 1
．． 2.3.4-tetrakis(mercaptoethyleneoxy)benzene, 1, 2.3.5-tetrakis(mercaptoethyleneoxy)benzene, 1.2゜4.5-tetrakis(mercaptoethyleneoxy)benzene, 2.2
°-dimercaptobiphenyl, 4,4-dimercaptobiphenyl, 4,4°-dimercaptobenzene, 2.
5-Toluenedithiol, 3.4-Toluenedithiol, 1, 4-naphthalenedithiol, 1.5-naphthalenedithiol, 2.6-naphthalenedithiol, 2.7-
Naphthalene dithiol, 2,4-dimethylbenzene-1
, 3-dithiol, 4,5-dimethylbenzene-1,3
-dithiol, 9. lO-anthracene dimethanethiol, 1,3-di(p-methoxyphenyl)propane-2
, 2-dithiol, 1,3-diphenylpropane-2,
Aromatic polythiols such as 2-dithiol, phenylmethane-1,1-dithiol, 2,4-di(p-mercaptophenyl)pentane, and 2,5-dichlorobenzene-
1,3-dithiol, 1,3-di(p-chlorophenyl)propane-2,2-dithiol, 3.4.5-tribromo-1,2-dimercaptobenzene, 2.3.4.6
halogen-substituted aromatic polythiols such as chlorine-substituted products such as -tetrachloro-1,5-bis(mercaptomethyl)benzene, bromine-substituted products, and 2-methylamino-4,6-
Cithio-sym-) riazine, 2-ethylamino-
4,6-sithio-sym-) liazine, 2-amino-4,6-sithio-sym=triazine, 2-morpholino-4,6-sithio-sym-triazine, 2
-cyclohexylamino-4,6-sithio-sym
-triazine, 2-methoxy-4,6-sithiorus
ym-triazine, 2-phenoxy-4,6-sithio-sym-triazine, 2-thiobenzeneoxy-4
, 6-sithio-sym-)-lyazine, 2-thiobutyloxy-4,6-sithio-sym-triazine, etc., and halogen-substituted compounds such as chlorine-substituted products and bromine-substituted products thereof. . Examples of difunctional or higher-functional polythiols containing at least one sulfur atom in addition to a mercapto group include, for example, 1,2
-bis(mercaptomethylthio)benzene, 1,3-bis(mercaptomethylthio)benzene, 1,4-bis(
Mercaptomethylthio)benzene, 1,2-bis(mercaptoethylthio)benzene, 1,3-bis(mercaptoethylthio)benzene, 1,4-bis(mercaptoethylthio)benzene, l, 2.3-tris(mercapto Methylthio)benzene, 1.2.4- Tris(mercaptomethylthio)benzene, 1.3.5- Tris(mercaptomethylthio)benzene, I, 2.3-Tris(mercaptoethylthio)benzene, 1.2.4-
Tris(mercaptoethylthio)benzene, 1.3.5
- tris(mercaptoethylthio)benzene, 1.2
．． 3.4-tetrakis(mercaptomethylthio)benzene, 1.2.3.5-tetrakis(mercaptomethylthio)benzene, 1.2.4.5-tetrakis(mercaptomethylthio)benzene, 1.2,3.4-tetrakis (mercaptoethylthio)benzene, 1.2.3.5-
Tetrakis(mercaptoethylthio)benzene, l,
2.4.5-Tetrakis(mercaptoethylthio)benzene, etc., and aromatic polythiols such as their nuclear alkyl compounds, bis(mercaptomethyl) sulfide, bis(mercaptoethyl) sulfide, 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-mercaptopropylthio)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-Mercaptoethylthio)propane, 1,2.3-
tris(3-mercaptopropylthio)propane, tetrakis(mercaptomethylthiomethyl)methane, tetrakis(2-mercaptoethylthiomethyl)methane, tetrakis(3-mercaptopropylthiomethyl)methane,
Bis(2,3-dimercaptopropyl) sulfide, 2
, 5-dimercapto-1,4-dithiane, bis(mercaptomethyl) disulfide, bis(mercaptoethyl)
Disulfide, bis(mercaptopropyl) disulfide, etc., and their esters 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), Hydroxypropylsulfide bis(2-mercaptoacetate), Hydroxypropylsulfide 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-mercaptopropionate) mercaptoacetate), hydroxypropyl disulfide bis(3-mercaptopropionate), 2-mercaptoethyl ether bis(2-mercapto7cetate), 2
-mercaptoethyl ether bis(3-mercaptopropionate), 1,4-dithiane-2,5-diol bis(2-mercaptoacetate)-), 1,4-dithiane-2,5-diol bis(3-mercapto propionate), thiodiglycolic acid bis(2-mercaptoethyl ester), thiodipropionate bis(2-mercaptoethyl ester), 4,4-thiodibutylic acid bis(
2-mercaptoethyl ester), dithioglycolic acid bis(2-mercaptoethyl ester), dithiodipropionic acid bis(2-mercaptoethyl ester), 4.
4-dithiodibutyric 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),
Aliphatic polythiols such as dithiodipropionate bis(2,3-dimercaptopropyl ester), heterocyclic compounds such as 3,4-thiophenedithiol, bismuthiol, 2,5-dimercapto-1,3,4-thiadiazole, etc. can be mentioned. Furthermore, halogen-substituted products such as chlorine-substituted products and bromine-substituted products may also be used. Further, examples of mercapto compounds having a hydroxyl group include 2-mercaptoethanol, 3-mercapto-1,2-propanediol, glycerin di(mercaptoacetate), 1-hydroxy-4-mercaptocyclohexane, 2,4-mercapto-1,2-propanediol, dimercaptophenol, 2-
Mercaptohydroquinone, 4-mercaptophenol, 1.2-dimercapto-3-propatol, 1.3-
dimercapto-2-propatur, 2,3-dimercapto-1-propatur, 1,2-dimercapto-1,3
-butanediol, pentaerythritol tris (3-
mercaptopropionate), pentaerythritol mono(3-mercaptopropionate), pentaerythritol bis(3-mercaptopropionate), pentaerythritol tris(thioglycolate), pentaerythritol bis(thioglycolate), etc. It will be done. Furthermore, halogen-substituted products such as chlorine-substituted products and bromine-substituted products may also be used. Examples of mercapto compounds having a hydroxyl group and at least one sulfur atom in addition to the mercapto group include hydroxymethyltris(mercaptoethylthiomethyl)methane, l-hydroxyethylthio-3-
Mercaptoethylthiobenzene, 4-hydroxy-4°
-Mercaptodiphenylsulfone, 2-(2-mercaptoethylthio)ethanol, dihydroxyethylsulfide mono(3-mercaptopropionate), dimercaptoethane mono(salicylate), hydroxyethylthiomethyltris(mercaptoethylthiomethyl)methane, etc. can be mentioned. Further, halogen-substituted polythiols such as chlorine-substituted polythiols and bromine-substituted polythiols may be used.These polythiols may be used alone or in combination of two or more. Examples of the polyisocyanate used as a raw material in the present invention include ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, 2,2°-dimethylbencune diisocyanate, 2.
2.4- Trimethylhexane diisocyanate, decamethylene diisocyanate, butene diisocyanate,
1.3-butadiene-1,4-diisocyanate, 2.
2.4-Trimethylhexamethylene diisocyanate, 1,6.11-undecatriisocyanate, 1.3
．． 6-hexamethylene triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane,
2.5.7-drimethyl-1.8-diisocyanate-
5-Isocyanate methyl octane, bis(isocyanate ethyl) carbonate, bis(isocyanate ethyl) ether, 1,4-butylene glycol dipropyl ether-w, w'-diisocyanate, lysine diisocyanate methyl ester, lysine triisocyanate, 2-isocyanate ethyl -2,6-diucyanate hexanoate, 2-isocyanate propyl-2,
6-diitsocyanatehexanoate, xylylene diisocyanate, bis(isocyanateethyl)benzene, bis(isocyanatepropyl)benzene, α, α,
α°, α゛-Tetramethylxylylene diisocyanate, bis(isocyanatobutyl)benzene, bis(isocyanethyl)diphenyl ether, bis(isocyanateethyl)phthalate, mesitylylene triisocyanate, 2,6-di(incyanatemethyl) aliphatic polyisocyanates such as furan, isophorone diisocyanate, bis(incyanate methyl)cyclohexane,
Dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, dicyclohexylmethylmethane diisocyanate, 2.2°-dimethyldicyclohexylmethane diisocyanate, bis(4-isocyanate-n-butylidene)pentaerythritol, dimic acid diisocyanate, 2-methyl isocyanate-3- (3-Incyanatopropyl)-5-Isocyanatemethyl-bicyclo-[2,2,1]-hebutane, 2-Isocyanatemethyl-3-(3-Isocyanatepropyl)-6-Incyanatomethyl-bicyclo[2 ,2,1]-hebutane, 2-isocyanatomethyl-2-(3-isocyanatopropyl)-5-isocyanatemethyl-bicyclo-
[2,2,11-heptane, 2-isocyanatomethyl-2-(3-isocyanatopropyl)-6-indianatemethyl-bicyclo[2,2,1]-hebutane,
2-Isocyanatemethyl-3-(3-isocyanatepropyl)-5-(2-isocyanateethyl)-bicyclo-[2,2',1]-hebutane, 2-isocyanatemethyl-3-(3-isocyanatepropyl) -6
-(2-Incyanatoethyl)-bicyclo-[2,2
, 11-hebutane, 2-isocyanatomethyl-2-(
3-isocyanatopropyl)-5-(2-isocyanatoethyl)-bicyclo-[2,2,1]-heptane,
Alicyclic polyisocyanates such as 2-isocyanatemethyl-2-(3-isocyanatepropyl)-6-(2-isocyanateethyl)-bicyclo-[2,2,1]-hebutane, phenylene diisocyanate, tolylene diisocyanate, Ethylphenylene diisocyanate, isopropylphenylene diisocyanate, dimethylphenylene diisocyanate, diethylphenylene diisocyanate, diisopropylphenylene diisocyanate, trimethylbenzene triisocyanate, benzene triisocyanate, naphthalene diisocyanate, methylnaphthalene diisocyanate, biphenyl diisocyanate, toridine diisocyanate, 4.4゛-diphenylmethane diisocyanate cyanate, 3,3°-dimethyldiphenylmethane-4,4°-diisocyanate, bibenzyl-4,4°-diisocyanate, bis(isocyanate phenyl)ethylene, 3,3°-dimethoxybiphenyl-4,4°-diisocyanate, triphenylmethane triisocyanate , polymeric MDI, naphthalene triisocyanate, diphenylmethane-2,4,4°
-Triisocyanate, 3-methyldiphenylmethane-
4,6,4°-triisocyanate, 4-methyldiphenylmethane-3,5,2°, 4°. 6'-pentaisocyanate, phenyl isocyanate methyl isocyanate, phenyl isocyanate ethyl isocyanate, tetrahydronaphthylene diisocyanate, hexahydrobenzene diisocyanate, hexahydrodiphenylmethane-4,4°-diisocyanate, diphenyl ether diisocyanate, ethylene glycol diphenyl ether diisocyanate, 1,3-
Aromatic polyisocyanates such as propylene glycol diphenyl ether diisocyanate, benzophenone diisocyanate, diethylene glycol diphenyl ether diisocyanate, dibenzofuran diisocyanate, carbazole diisocyanate, ethyl carbazole diisocyanate, dichlorocarbazole diisocyanate, thiodiethyl diisocyanate, thiodipropyl diisocyanate, thiodihexyl diisocyanate , dimethylsulfone diisocyanate, dithio dimethyl diisocyanate, dithiodiethyl diisocyanate,
Fused aliphatic isocyanates such as dithiodipropyl diisocyanate, diphenylsulfide-2,4°-diisocyanate, diphenylsulfide-4,4°-diisocyanate, 3,3°-dimethoxy-4,4°-diisocyanate dibenzylthioether, bis( 4-Isocyanate methylbenzene) sulfide, 1,2-bis(
Aromatic sulfide isocyanates such as 4-methoxy-3-isocyanate phenylthio)ethane, diphenyldisulfibid 4,4°-diisocyanate, 2.2
゛-Dimethyldiphenyldisulfide-5,5°-diisocyanate, 3.3°-dimethyldiphenyldisulfide-5,5°-diisocyanate, 3.3°-dimethyldiphenyldisulfide-6,6°-diisocyanate, 4,4°- dimethyldiphenyldisulfide-5,
5°-diisocyanate, 3.3°-dimethoxydiphenyl disulfide-4,4°-diisocyanate, 4,
4°-Dimethoxydiphenyl disulfide-3,3°-
Aromatic disulfide isocyanates such as diisocyanate, diphenylsulfone-4,4°-diisocyanate, diphenylsulfone-3,3°-diisocyanate, benzidine sulfone-4,4°-diisocyanate, diphenylmethanesulfone-4,4°-diisocyanate, 4-methyldiphenylsulfone-2,4°-diisocyanate, 4.4゛-dimethoxydiphenylsulfone-3,3-diisocyanate, 3,3°-dimethoxy-4,4-diisocyanate dibenzylsulfone, 4
, 4°-dimethyldiphenylsulfone-3,3°-diisocyanate, 4.4°-di-tart-butyldiphenylsulfone-3,3°-diisocyanate, 1.2-
Aromatic sulfonic isocyanates such as bis(4-methoxy-3-isocyanatophenylsulfonyl)ethane, 4.4°-dichlorodiphenylsulfone-3,3°-diisocyanate, 4-methyl-3-isocyanatebenzenesulfonyl-4°- Isocyanate phenol ester, sulfonic acid ester isocyanate such as 4-methoxy-3-isocyanatebenzenesulfonyl-4'-isocyanatephenol ester, 4-methyl-3-isocyanatebenzenesulfonylanilide-3
°-Methyl-4°-isocyanatebenzene, dibenzenesulfonylethylenedi7mine-4,4°-diisocyanate, N,N'-bis(4-methoxy-3-isocyanatebenzenesulfonyl)ethylenediamine, 4-methyl-3-, Aromatic sulfonic acid amide isocyanates such as isocyanate benzenesulfonylanilide-4°-methyl-3°-isocyanate benzene, fused heterocyclic compounds such as thiophene-2,5-diisocyanate,
Other examples include 1,4-dithiane-2,5-diisocyanate. In addition, halogen substituted products such as chlorine substituted products, bromine substituted products, alkyl substituted products, alkoxy substituted products, nitro substituted products, prepolymer modified products with polyhydric alcohols, carbodiimide modified products, urea modified products, biuret modified products Dimerization, dimerization or trimerization reaction products can also be used. Among these polyisocyanates, polyisocyanates having secondary and/or tertiary isocyanate groups generally have lower reactivity than polyisocyanates having only primary isocyanate groups. This is particularly effective when using isocyanates with low reactivity. Further, the above polyisocyanates may be used alone or in combination of two or more types. The ratio of polyisocyanate and polythiol used in the present invention is such that the NCO/SH (functional group) molar ratio is usually 0.5.
-3.0, preferably 0.5-1.5. The plastic lens of the present invention has thiocarbamic acid S-
It is made from alkyl ester resin, and thiocarbamic acid S-
Although it is mainly composed of alkyl ester bonds, depending on the purpose, it may contain allophanate bonds, urea bonds, biuret bonds, etc. in addition to thiocarbamic acid S-alkyl ester bonds. For example, increasing the crosslinking density by further reacting the thiocarbamic acid S-alkyl ester bond with an isocyanate group often gives favorable results.In this case, the reaction temperature is raised to at least 100°C and the isocyanate Use many ingredients. Alternatively, a urea bond or a biuret bond may be utilized by partially using an amine or the like. As described above, when using something other than a mercapto compound that reacts with an isocyanate compound, special attention must be paid to coloring. In addition, depending on the purpose, various substances such as chain extenders, crosslinking agents, light stabilizers, ultraviolet absorbers, antioxidants, oil-soluble dyes, fillers, and mold release agents may be added, as in known molding methods. May be added. To adjust the desired reaction rate, thiocarbamate S
- Other known reaction catalysts used in the production of alkyl esters, such as organotin compounds, may also be used in combination. The thiocarbamic acid S-alkyl ester lens of the present invention is usually obtained by cast polymerization. Specifically, polythiol, polyisocyanate, and a catalyst are mixed, poured into a mold, and polymerized. Polymerization temperature and time vary depending on the type of monomer and additives such as catalysts, but are usually -20 to 200°C, 0.5 to
It is 72 hours. Further, the polymerized lens may be annealed if necessary. [Effect of the invention] Thiocarbamic acid S- of the present invention obtained in this way
Alkyl ester lenses have excellent optical properties,
It is lightweight and has excellent impact resistance, making it suitable for use as eyeglass lenses and camera lenses. In addition, the thiocarbamic acid S-alkyl ester lens of the present invention can be improved as necessary to provide antireflection, high hardness, improved abrasion resistance, improved chemical resistance, antifogging properties, or fashionability. Therefore, surface polishing, antistatic treatment, hard coat treatment, anti-reflection coating treatment, dyeing treatment,
Physical and chemical treatments such as light control treatment can be performed. [Examples and Comparative Examples] The present invention will be specifically explained below using Examples and Comparative Examples. In addition, among the performance tests of the obtained lenses, the refractive index, number of cracks, pot life, polymerizability, and appearance were evaluated by the following test methods. Refractive index, Atsube number: Measured at 20'C using a Pulfrich refractometer. Pot life: After monomer preparation and after defoaming at room temperature for 8 hours, those that could be injected into a mold under normal pressure conditions were rated as (○), and those that were impossible were rated as (×). Polymerization property: Those that gelled within 12 hours at 90°C were rated as (○), and those that did not gelled as (×). Appearance: Visually observed. Example 1 Isophorone diisocyanate 44 g 1 Pentaerythritol tetrakis (3-mercaptopropionate) 48
g, dibutyltin dilaurate 0.1 g, dimethylaminoethyl acetate 0.02 g, and internal mold release agent 0.1 g were mixed and defoamed at room temperature for 8 hours. Thereafter, the mixture was poured into a mold made of a glass mold and a resin gasket, and heated at 90° C. for 12 hours, resulting in gelation. 1 more
After raising the temperature to 50°C, the lens was taken out. At this time,
The gasket was melted. The lenses thus obtained were colorless and transparent, had a refractive index no" = 1.55, and an Atsube number ν.■ = 47. Examples 2 to 7. Comparative Examples 1 to 5 Same as Example 1. Lenses were formed using the compositions shown in Table 1, and the results are shown in Table 1.

Claims (1)

[Claims] 1) A thiocarbamic acid S-alkyl ester lens characterized by adding a tertiary amine having an electron-withdrawing group in the molecule to a mixture of polyisocyanate and polythiol and performing cast polymerization. manufacturing method. 2) The polyisocyanate is secondary and/or tertiary
2. The method for producing a thiocarbamic acid S-alkyl ester lens according to claim 1, wherein the polyisocyanate is a polyisocyanate having a class isocyanate group. 3) A thiocarbamic acid S-alkyl ester lens obtained by adding a tertiary amine having an electron-withdrawing group in the molecule to a mixture of polyisocyanate and polythiol and performing cast polymerization. 4) The polyisocyanate is secondary and/or tertiary
The thiocarbamic acid S-alkyl ester lens according to claim 3, which is a polyisocyanate having a class isocyanate group.