JP2006131554A - Cyclic polythiol for highly heat-resistant resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent resin material improved in heat resistance as a resin which is used for an optical element, and the like, having a high refractive index and a high Abbe's number. <P>SOLUTION: The transparent resin optical material is obtained by curing a composition for the transparent resin which contains a polythiol having a structure expressed by formula (1) or formula (2). Thus, a compound useful as a raw material for the new optical material in a field in which the high refractive index is required is obtained. Further, the resin obtained by polymerizing and curing the composition has very high optical characteristics and is improved in the heat resistance, so that the resin contributes to development of the optical element which requires the high heat resistance as a characteristic. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polythiol suitably used in resin fields such as optical materials and polyurethane resins that require high refractive index and high transparency, and resin additives such as vulcanizing agents for paints and synthetic resins. The composition further relates to a transparent resin produced using the polythiol.

In recent years, plastic lenses are rapidly spreading to optical elements such as spectacle lenses and camera lenses because they are lighter and harder to break than inorganic lenses and can be dyed.
The performance required for these plastic lenses is high refractive index and high Abbe number as optical performance, and high heat resistance and low specific gravity as physical properties.

  Currently, polythiourethane resins in which sulfur atoms are introduced into the resin are known as resins that satisfy these required performances to some extent. The polythiourethane resin is a resin having an excellent balance such as a high refractive index and good impact resistance (see, for example, Patent Document 1).

  However, there is a demand for higher refractive index and higher Abbe number, but on the other hand, both the refractive index and Abbe number are contradictory properties that the Abbe number decreases as the refractive index increases. It is very difficult to improve at the same time. In view of this, studies have been actively conducted to increase the refractive index while suppressing the decrease in the Abbe number.

The most representative proposal among these studies is a method using an episulfide compound. (For example, see Patent Document 2 and Patent Document 3)
However, although the resin obtained by the above method using an episulfide compound has very good optical properties, it has poor physical performance such as brittleness and low impact resistance, and is required for lenses. Not all physical properties are satisfied.

Under such circumstances, a new proposal has been made to increase the refractive index while using a polythiourethane resin, which is a balanced material in terms of optical and physical properties, while suppressing a decrease in the Abbe number. It was. (For example, see Patent Document 4)
JP-A-63-46213 WO-89 / 10575 publication Japanese Patent Laid-Open No. 9-110979 JP 2001-342172 A

  The optical material made of the resin proposed in Patent Document 4 has an excellent optical physical property such as having a very high refractive index and a balance between a high refractive index and a high Abbe number. However, the heat resistance is just over 100 ° C. In recent years, high heat resistance and weather resistance are required for resins used for optical elements and the like, and development of a high refractive index material having further high heat resistance is desired.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have succeeded in synthesizing a tetrafunctional polythiol compound having a 1,4-dithian skeleton, and curing the resin obtained by using the compound. It has been found that the heat resistance is improved and the weather resistance is excellent, and the present invention has been achieved.

That is, the present invention
[1] The present invention relates to a polythiol having a structure represented by the formula (1) or (2).

[2] to [7] are each one of preferred embodiments of the present invention.
[2] A composition for transparent resin containing at least one polythiol according to [1].
[3] A transparent resin obtained by curing the transparent resin composition according to [2].
[4] The composition for transparent resin according to [3], wherein the composition for transparent resin further contains one or more compounds selected from polyiso (thio) cyanate, polyepoxide, polyepisulfide, and olefin compounds, or a mixture thereof. Transparent resin.
[5] An optical material comprising the transparent resin according to [3] or [4]. Here, “consisting of” includes both the case where the entire optical material is made of the transparent resin and the case where a part of the optical material is made of the transparent resin. It is.
[6] A plastic lens made of the optical material according to [5]. Here, “consisting of” includes both the case where the entire plastic lens is made of the optical material and the case where a part of the plastic lens is made of the optical material. It is.
[7] A method for producing a transparent resin, comprising a step of obtaining the transparent resin according to the above [3] or [4] by cast polymerization.

  According to the present invention, a compound useful as a raw material for a novel optical material in the field of high refractive index is obtained, and the optical properties of a resin obtained by polymerization and curing are very high, and heat resistance is improved. Contributes to the development of optical elements that require heat resistance.

  Hereinafter, the present invention will be described in detail. First, the polythiol compound of the present invention will be described.

  The polythiol having the structure represented by the formula (1) or (2) according to the present invention is 1,4-dithian-2,5-bis (4,5-dimercapto-2-thiapentane) and 1,4- This refers to dithian-2,5-bis (5,6-dimercapto-2,3-dithiahexane).

  The polythiol compound having the structure represented by the formula (1) or (2) according to the present invention can be synthesized, for example, by the following method.

  Bifunctional polythiol compound 1,2-epithio-6,7-dimercapto-4-thiaheptane or 1,2-epithio-7,8-dimercapto-4 having a structure represented by formula (3) or (4), It is synthesized using 5-dithiaoctane as a raw material.

  Specifically, 1,2-epithio-6,7-dimercapto-4-thiaheptane and 1,2-epithio-7,8-dimercapto-4,5 represented by formula (3) or formula (4) -Compounds that can be ring-opening polymerization catalysts for episulfide compounds such as tertiary amines, phosphines, quaternary ammonium salts, and quaternary phosphonium salts are allowed to coexist in a polar or nonpolar solvent in which dithiaoctane is dissolved. The polythiol of the present invention can be synthesized by reacting with stirring at a predetermined temperature for a predetermined time.

  Here, usable solvents that can dissolve the compound represented by formula (3) or formula (4) include alcohol solvents such as methanol and ethanol, aliphatic hydrocarbon solvents such as hexane and heptane, benzene, and the like. , Aromatic hydrocarbon solvents such as toluene, aromatic halogenated hydrocarbon solvents such as chlorobenzene and dichlorobenzene, aliphatic halogenated hydrocarbon solvents such as dichloromethane and chloroform, and ester solvents such as ethyl acetate and butyl acetate In consideration of solubility, boiling point and the like, a mixture thereof may be used according to the purpose. The amount of the solvent used varies depending on the type of the solvent used, but if it is used in an amount equal to or greater than that of the raw material compound, the yield may be good. If the concentration of is reduced, the by-product may be suppressed.

  Next, compounds that can be used as a ring-opening polymerization catalyst for episulfide compounds that can be used will be described. Examples of the ring-opening polymerization catalyst in the present invention include tertiary amines, phosphines, quaternary ammonium salts, quaternary phosphonium salts, Lewis acids, radical polymerization catalysts, and cationic polymerization catalysts.

  Specific examples of the ring-opening polymerization catalyst include triethylamine, tri-n-butylamine, tri-n-hexylamine, N, N-diisopropylethylamine, triethylenediamine, triphenylamine, N, N-dimethylethanolamine, N, N. -Diethylethanolamine, N, N-dibutylethanolamine, N, N-dimethylbenzylamine, diethylbenzylamine, N, N-dimethylcyclohexylamine, N, N-diethylcyclohexylamine, N-methyldicyclohexylamine, N-methyl Morpholine, N-isopropylmorpholine, pyridine, N, N-dimethylaniline, β-picoline, N, N′-dimethylpiperazine, N-methylpiperidine, 2,2′-bipyridyl, hexamethylenetetramine, 1,8-diazabicyclo Tertiary amines such as 5,4,0) -7-undecene, trimethylphosphine, triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tribenzylphosphine, 1,2 -Phosphines such as bis (diphenylphosphino) ethane, 1,2-bis (dimethylphosphino) ethane, quaternary ammonium salts such as tetramethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetramethylphosphonium bromide , Quaternary phosphonium salts such as tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, dimethyltin dichloride, dibutyltin dichloride, dibutyltin dilaurate, tetrac Lorotin, dibutyltin oxide, diacetoxytetrabutyl distanoxane, zinc chloride, acetylacetone zinc, aluminum chloride, aluminum fluoride, triphenylaluminum, tetrachlorotitanium, calcium acetate and other Lewis acids, 2,2′-azobis ( 2-cyclopropylpropionitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), t-butylperoxy Radical polymerization catalysts such as 2-ethylhexanoate, n-butyl-4,4′-bis (t-butylperoxy) valerate, t-butylperoxybenzoate, diphenyliodonium hexafluorophosphoric acid, diphenyliodonium hexafluoroarsenic acid , Diphenyliodonium hexafluoroanti Emissions, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphate, cationic polymerization catalyst such as triphenylsulfonium hexafluoroarsenate. Among these, tertiary amines, phosphines, quaternary ammonium salts, and quaternary phosphonium salts are more preferable compounds for the reaction state and handling after completion of the reaction.

  The reaction temperature varies greatly depending on the level of the properties of the resulting compound, such as yield and hue, the type of catalyst used, the type of solvent, and the amount used. If it is performed at 20 ° C. to 120 ° C., the desired product can be obtained satisfactorily. It is more preferably −10 ° C. to 110 ° C., and further preferably 0 ° C. to 100 ° C. In such a temperature range, the higher the temperature is in the vicinity of 100 ° C., the shorter the reaction time, the better the yield and the quality of the compound obtained.

  After completion of the reaction, washing the reaction solution with a polar solvent such as water is preferable in terms of improving the quality of the resulting compound. At this time, the quality obtained may be further improved by washing using a thin acid or alkali aqueous solution. If the reaction solvent used after the washing is distilled off, a crude product of the target product can be obtained. The obtained crude product has a relatively high purity and can be used as a raw material by polymerization, but it can be further refined to improve the quality. The purification mentioned here includes distillation under ultra-high vacuum, chromatogram method using silica gel and activated carbon, a method by washing and extraction, and a method of removing insoluble matters such as filtration. The polythiol of the present invention obtained by purification is a colorless and transparent liquid.

  The polythiol having the structure represented by the formula (1) or (2) of the present invention thus obtained can be suitably used for an optical material made of a urethane-based resin. Moreover, it can also be suitably used for optical materials made of epoxide-based and / or episulfide-based resins and optical materials made of olefin-based resins. Furthermore, it can also be used as raw materials and additives such as raw materials for polyurethane resins, paint raw materials, and vulcanizing agents for synthetic resins.

  Next, the composition for transparent resin of the present invention will be described. The transparent resin composition of the present invention containing at least one polythiol having a structure represented by the formula (1) or (2) produces a transparent resin having a high refractive index, a high Abbe number, and a high heat resistance. Useful for. The composition for transparent resin of the present invention only needs to contain at least one polythiol having a structure represented by the formula (1) or (2), and the other components are not particularly limited. From the viewpoint of obtaining the above, it is preferable to further contain polyiso (thio) cyanate. Although there is no restriction | limiting in particular in content of the polythiol which has a structure represented by Formula (1) or (2) in the transparent resin composition of this invention, When the weight of the whole transparent resin composition is 100 weight part The amount is usually 0.1 to 80 parts by weight, preferably 1 to 75 parts by weight. When the content of the polythiol is within the above range, it is preferable in that the heat resistance of the obtained resin is improved.

  Next, it describes about the transparent resin of this invention. Here, “transparent resin” refers to a resin having a property of transmitting light.

Resins that can be used for light transmission such as various lenses such as eyeglass lenses and camera lenses, light guide plates, display element substrates, and the like correspond to the “transparent resin” herein. Although there is no restriction | limiting in particular in the transmittance | permeability of transparent resin, From a viewpoint of utilizing light effectively, it is preferable that the light transmittance of thickness 1mm conversion in a use wavelength is 80% or more. The wavelength used is determined in relation to the application. Usually, the wavelength used is in the visible light region, but is not necessarily limited to this, and depending on the application, the wavelength used may be in the ultraviolet or infrared region.

A transparent resin can be produced by reacting a polythiol having a structure represented by the formula (1) or (2) of the present invention with a polyiso (thio) cyanate. The polyiso (thio) cyanate here means a compound having two or more iso (thio) cyanate groups in the molecule, and can be appropriately selected from known polyiso (thio) cyanates.

Specific examples of preferable compounds having two or more iso (thio) cyanate groups in the molecule include hexamethylene diisocyanate, 2,2-dimethylpentane diisocyanate, and 2,2,4-trimethyl. Hexane diisocyanate, butene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,6,11-undecatriisocyanate, 1, 3,6-hexamethylene triisocyanate, 1,8-diisocyanato-4-isocyanatomethyloctane, bis (isocyanatoethyl) carbonate, bis (isocyanatoethyl) ether, lysine diisocyanatomethyl ester, lysine triisocyanate , Xylylene diisocyanate, bis (isocyanate Toethyl) benzene, bis (isocyanatopropyl) benzene, α, α, α ′, α′-tetramethylxylylene diisocyanate, bis (isocyanatobutyl) benzene, bis (isocyanatomethyl) naphthalene, bis (isocyanatomethyl) ) Aliphatic polyisocyanates such as diphenyl ether, bis (isocyanatoethyl) phthalate, mesityrylene triisocyanate, 2,6-di (isocyanatomethyl) furan,
Isophorone diisocyanate, bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, dicyclohexyldimethylmethane diisocyanate, 2,2-dimethyldicyclohexylmethane diisocyanate, 2, 5-bis (isocyanatomethyl) bicyclo- [2,2,1] -heptane, 2,6-bis (isocyanatomethyl) bicyclo- [2,2,1] -heptane, 3,8-bis (isocyanato Fats such as methyl) tricyclodecane, 3,9-bis (isocyanatomethyl) tricyclodecane, 4,8-bis (isocyanatomethyl) tricyclodecane, 4,9-bis (isocyanatomethyl) tricyclodecane Cyclic polyisocyanates,
Phenylene diisocyanate, tolylene diisocyanate, ethylphenylene diisocyanate, isopropylphenylene diisocyanate, dimethylphenylene diisocyanate, diethylphenylene diisocyanate, diisopropylphenylene diisocyanate, trimethylbenzene triisocyanate, benzene triisocyanate , Biphenyl diisocyanate, toluidine diisocyanate, 4,4-diphenylmethane diisocyanate, 3,3-dimethyldiphenylmethane-4,4-diisocyanate, bibenzyl-4,4-diisocyanate, bis (isocyanatophenyl ) Ethylene, 3,3-dimethoxybiphenyl-4,4-diisocyanate, phenylisocyanatoethyl isocyanate, hexahydrobenzene diiso Annatto, aromatic polyisocyanates such as hexahydroterephthalic diphenylmethane-4,4-diisocyanate,
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 (isocyanatoethylthio) ethane, bis (isocyanatomethylthio) ethane, 1, Sulfur-containing aliphatic isocyanates such as 5-diisocyanato-2-isocyanatomethyl-3-thiapentane,
Diphenyl sulfide-2,4-diisocyanate, diphenyl sulfide-4,4-diisocyanate, 3,3-dimethoxy-4,4-diisocyanatodibenzylthioether, bis (4-isocyanatomethylbenzene) sulfide, Aromatic sulfide isocyanates such as 4,4-methoxybenzenethioethylene glycol-3,3-diisocyanate,
Diphenyl disulfide-4,4-diisocyanate, 2,2-dimethyldiphenyl disulfide-5,5-diisocyanate, 3,3-dimethyldiphenyl disulfide-5,5-diisocyanate, 3,3-dimethyldiphenyl disulfide 6,6-diisocyanate, 4,4-dimethyldiphenyl disulfide-5,5-diisocyanate, 3,3-dimethoxydiphenyl disulfide-4,4-diisocyanate, 4,4-dimethoxydiphenyl disulfide-3 Sulfur-containing heterocyclic compounds such as aromatic disulfide isocyanates such as 1,3-diisocyanate, 2,5-diisocyanatothiophene, 2,5-bis (isocyanatomethyl) thiophene,
In addition, 2,5-diisocyanatotetrahydrothiophene, 2,5-bis (isocyanatomethyl) tetrahydrothiophene, 3,4-bis (isocyanatomethyl) tetrahydrothiophene, 2,5-diisocyanato-1,4- Dithiane, 2,5-bis (isocyanatomethyl) -1,4-dithiane, 4,5-diisocyanato-1,3-dithiolane, 4,5-bis (isocyanatomethyl) -1,3-dithiolane, 4, Isocyanate compounds such as 5-bis (isocyanatomethyl) -2-methyl-1,3-dithiolane. Examples of the isothiocyanate compound include a compound obtained by converting a part or all of the isocyanate group of the isocyanate compound into an isothiocyanate group. However, these compounds are not limited to the exemplified compounds. 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, and burette-modified products. Bodies, dimerization or trimerization reaction products, and the like can also be used.

  Among these compounds, more preferable are the hexamethylene diisocyanate, isophorone diisocyanate, bis (isocyanatomethyl) cyclohexane, xylylene diisocyanate, dicyclohexylmethane dihydrate, taking into account the requirements of the optical properties of the present invention. Isocyanate, 2,5-bis (isocyanatomethyl) bicyclo- [2,2,1] -heptane, 2,6-bis (isocyanatomethyl) bicyclo- [2,2,1] -heptane, bis (isocyanate Natomethyl) sulfide, bis (isocyanatomethyl) sulfide, bis (isocyanatomethyl) disulfide, bis (isocyanatoethyl) disulfide, bis (isocyanatomethylthio) methane, bis (isocyanatoethylthio) methane, 2,5- Diisocyanato-1,4-dithiane, 2 5-bis (isocyanatomethyl) -1,4-dithiane, 4,5-diisocyanato-1,3-dithiolane, 4,5-bis (isocyanatomethyl) -1,3-dithiolane, 4,5-bis ( Isocyanatomethyl) -2-methyl-1,3-dithiolane, 2,5-diisocyanatothiophene, 2,5-bis (isocyanatomethyl) thiophene, and 2,4-tolylene diisocyanate At least one selected compound.

  Since the polythiol having the structure represented by the formula (1) or (2) according to the present invention is polyfunctional, when the above bifunctional or higher isocyanate is used, its three-dimensional crosslinkability is very high. The resin obtained by the polymerization has very high heat resistance and is very suitable for the resin field where high heat resistance is a required physical property. However, depending on the application, the heat resistance may be too high, in which case various known thiol compounds may be used depending on the purpose in order to lower the three-dimensional crosslinkability or to modify other resin properties. It is also possible to add. The thiol compound here means a thiol compound other than the polythiol of the present invention. In particular, if the purpose is not to significantly impair the three-dimensional crosslinkability, a compound having two or more mercapto groups in the molecule, or one mercapto group, and an isocyanate group It is appropriate to select and add a compound having at least one active hydrogen group capable of reacting, or a compound having at least two active hydrogen groups capable of reacting with an isocyanate group without having a mercapto group. is there.

  Here, specific examples of thiol compounds that can be added to modify the performance of the resin include monofunctional thiol compounds such as methyl mercaptan, ethyl mercaptan, propyl mercaptan, butyl mercaptan, octyl mercaptan, dodecyl mercaptan, tert-dodecyl. Aliphatic mercaptan compounds such as mercaptan, hexadecyl mercaptan, octadecyl mercaptan, cyclohexyl mercaptan, benzyl mercaptan, ethylphenyl mercaptan, 2-mercaptomethyl-1,3-dithiolane, 2-mercaptomethyl-1,4-dithiane, thiophenol, Examples include aromatic mercaptan compounds such as mercaptotoluene, but are not limited thereto.

Examples of the bifunctional or higher polythiol compound include 1,1-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, bis (2-mercaptoethyl ester) thiomalate, 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 ( - mercaptopropionate), tetrakis (mercaptomethyl) aliphatic such as methane polythiol compound,
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 polythiols 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 alkylated products,
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-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-mercaptoethyl) Thio) propane, 1,2,3-tris (3-mercaptopropylthio) ) Propane, 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane, 4,8-dimercaptomethyl-1,11-mercapto-3,6,9-trithiaundecane, 4,7 Dimercaptomethyl-1,11-mercapto-3,6,9-trithiaundecane, 5,7-dimercaptomethyl-1,11-mercapto-3,6,9-trithiaundecane, tetrakis (mercaptomethylthiomethyl) ) Methane, tetrakis (2-mercaptoethylthiomethyl) methane, tetrakis (3-mercaptopropylthiomethyl) methane, bis (2,3-dimercaptopropyl) sulfide, bis (1,3-dimercaptopropyl) sulfide, 2 , 5-dimercapto-1,4-dithiane, 2,5-dimercaptomethyl-1,4-dithiane, , 5-dimercaptomethyl-2,5-dimethyl-1,4-dithiane, bis (mercaptomethyl) disulfide, bis (mercaptoethyl) disulfide, bis (mercaptopropyl) disulfide, and other sulfur atoms in addition to the mercapto group Aliphatic polythiol compounds, and esters of these thioglycolic and mercaptopropionic acids,
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, aliphatic polythiol compounds containing a sulfur atom and an ester bond, and 3,4-thiophenedithiol A heterocyclic compound containing a sulfur atom in addition to a mercapto group such as 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, and compounds having a dithioacetal or dithioketal skeleton such as oligomers thereof,
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-dithi 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] me 2,4,6-tris [3,3-bis (mercaptomethylthio) -2-thiapropyl] -1,3,5-trithiacyclohexane, tetrakis [3,3-bis (mercaptomethylthio) -2-thiapropyl ] Compounds having an orthocarboxylic acid trithioester 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. Examples include compounds having an ortho-carbonic acid tetrathioester skeleton, but are not limited to these exemplified compounds.

  These exemplified compounds may be used alone or in combination of two or more. Of these compounds, it is preferable to select an aliphatic polythiol compound rather than an aromatic one in consideration of the optical properties of the resulting resin, particularly the Abbe number. Further, in view of optical properties, particularly refractive index requirements, it is more preferable to select a compound having a sulfur atom in addition to a thiol group such as a sulfide bond and / or a disulfide bond, and a dithioacetal skeleton, a dithioketal skeleton, an orthocarboxylic acid tricarboxylic acid, It is more preferable to select a compound having a thioester skeleton and an orthocarbonic acid tetrathioester skeleton.

  In addition, a known episulfide compound, epoxy compound, olefin compound or the like can be added for the purpose of modifying the performance of the resin.

Here, specific examples of episulfide compounds that can be added include bis (β-epithiopropyl) sulfide, bis (β-epithiopropyl) disulfide, bis (β-epithiopropylthio) methane, and 1,2-bis. (Β-epithiopropylthio) ethane, 1,2-bis (β-epithiopropylthio) propane, 1,3-bis (β-epithiopropylthio) propane, 1,3-bis (β-epithio) Propylthio) -2-methylpropane, 1,4-bis (β-epithiopropylthio) butane, 1,4-bis (β-epithiopropylthio) -2-methylbutane, 1,3-bis (β- Epithiopropylthio) butane, 1,5-bis (β-epithiopropylthio) pentane, 1,5-bis (β-epithiopropylthio) -2-methylpentane, 1,5-bis (β- Pithiopropylthio) -3-thiapentane, 1,6-bis (β-epithiopropylthio) hexane, 1,6-bis (β-epithiopropylthio) -2-methylhexane, 3,8-bis ( β-epithiopropylthio) -3,6-dithiaoctane, 1,2,3-tris (β-epithiopropylthio) propane, 2,2-bis (β-epithiopropylthio) -1,3-bis (Β-epithiopropylthiomethyl) propane, 2,2-bis (β-epithiopropylthiomethyl) -1- (β-epithiopropylthio) butane, 1,5-bis (β-epithiopropylthio) ) -2- (β-epithiopropylthiomethyl) -3-thiapentane, 1,5-bis (β-epithiopropylthio) -2,4-bis (β-epithiopropylthiomethyl) -3-thiapentane , 1- ( β-epithiopropylthio) -2,2-bis (β-epithiopropylthiomethyl) -4-thiahexane, 1,5,6-tris (β-epithiopropylthio) -4- (β-epithio Propylthiomethyl) -3-thiahexane, 1,8-bis (β-epithiopropylthio) -4- (β-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (β-epi Thiopropylthio) -4,5-bis (β-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (β-epithiopropylthio) -4,4-bis (β-epithio) Propylthiomethyl) -3,6-dithiaoctane, 1,8-bis (β-epithiopropylthio) -2,5-bis (β-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8- Bis (β-epithio Lopyrthio) -2,4,5-tris (β-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,1,1-tris [[2- (β-epithiopropylthio) ethyl] thiomethyl]- 2- (β-epithiopropylthio) ethane, 1,1,2,2-tetrakis [[2- (β-epithiopropylthio) ethyl] thiomethyl] ethane, 1,11-bis (β-epithiopropyl) Thio) -4,8-bis (β-epithiopropylthiomethyl) -3,6,9-trithiaundecane, 1,11-bis (β-epithiopropylthio) -4,7-bis (β- Epithiopropylthiomethyl) -3,6,9-trithiaundecane, 1,11-bis (β-epithiopropylthio) -5,7-bis (β-epithiopropylthiomethyl) -3,6 Such as 9-trithiaundecane Jo aliphatic β- epithiopropylthio compounds, and,
1,3-bis (β-epithiopropylthio) cyclohexane, 1,4-bis (β-epithiopropylthio) cyclohexane, 1,3-bis (β-epithiopropylthiomethyl) cyclohexane, 1,4- Bis (β-epithiopropylthiomethyl) cyclohexane, 2,5-bis (β-epithiopropylthiomethyl) -1,4-dithiane, 2,5-bis [[2- (β-epithiopropylthio) Cycloaliphatic β-epithiopropylthio compounds such as ethyl] thiomethyl] -1,4-dithiane, 2,5-bis (β-epithiopropylthiomethyl) -2,5-dimethyl-1,4-dithiane ,as well as,
1,2-bis (β-epithiopropylthio) benzene, 1,3-bis (β-epithiopropylthio) benzene, 1,4-bis (β-epithiopropylthio) benzene, 1,2-bis (Β-epithiopropylthiomethyl) benzene, 1,3-bis (β-epithiopropylthiomethyl) benzene, 1,4-bis (β-epithiopropylthiomethyl) benzene, bis [4- (β- Epithiopropylthio) phenyl] methane, 2,2-bis [4- (β-epithiopropylthio) phenyl] propane, bis [4- (β-epithiopropylthio) phenyl] sulfide, bis [4- ( aromatic β-epithiopropylthio compounds such as β-epithiopropylthio) phenyl] sulfone and 4,4′-bis (β-epithiopropylthio) biphenyl, It is not limited only to these exemplary compounds. Among these exemplified compounds, more preferred compounds are bis (β-epithiopropyl) sulfide and bis (β-epithiopropyl) disulfide, and more preferred compounds are bis (β-epithiopropyl) disulfide. .

  Moreover, the compound which replaced the epithiopropylthio group of the said episulfide compound with the epithiopropyloxy group can also be mentioned. Moreover, it is not limited only to said exemplary compound, These may be used individually or in mixture of 2 or more types.

  Furthermore, specific examples of the epoxy compound that can be added include compounds in which the epithio group of the episulfide compound is replaced with an epoxy group. Moreover, it is not limited only to said exemplary compound, These may be used individually or in mixture of 2 or more types.

  Specific examples of olefin compounds that can be added include ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, and tetraethylene glycol. Dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, ethylene glycol bisglycidyl acrylate, ethylene glycol bisglycidyl methacrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, 2 2-bis (4-acryloxyethoxyphenyl) propane, 2,2-bis (4-methacryloxyethoxyphenyl) propane, 2,2-bis (4-acryloxydiethoxyphenyl) propane, 2,2-bis ( 4-methacryloxydiethoxyphenyl) propane, bisphenol F diacrylate, bisphenol F dimethacrylate, 1,1-bis (4-acryloxyethoxyphenyl) methane, 1,1-bis (4-methacryloxyethoxyphenyl) methane, 1,1-bis (4-acryloxydiethoxyphenyl) methane, 1,1-bis (4-methacryloxydiethoxyphenyl) methane, dimethyloltricyclodecane diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri Methacrylate, glycerol diacri Glycerol dimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, methylthioacrylate, methylthiomethacrylate, phenylthioacrylate, benzylthiomethacrylate, xylylenedithioldiacrylate, xylylenedithioldimethacrylate, mercaptoethyl (Meth) acrylate compounds such as sulfide diacrylate and mercaptoethylsulfide dimethacrylate, allyl compounds such as allyl glycidyl ether, diallyl phthalate, diallyl terephthalate, diallyl isophthalate, diallyl carbonate, diethylene glycol bisallyl carbonate, styrene, chlorostyrene, methylstyrene , Bromostyrene, dibromostyrene, divinylbenzene, vinyl compounds such as 3,9-divinylspirobi (m-dioxane), and diisopropenylbenzene, but are not limited to the exemplified compounds.

  Any of these olefin compounds may be used alone or in admixture of two or more as long as the required physical properties can be satisfied.

  As the curing catalyst used in the present invention, tertiary amines, phosphines, quaternary ammonium salts, quaternary phosphonium salts, Lewis acids, radical polymerization catalysts, cationic polymerization catalysts and the like are usually used.

  Specific examples of the curing catalyst include compounds used when synthesizing a polythiol having a structure represented by the above formula (1) or (2).

  Among these exemplified compounds, preferred are organic tin compounds such as dimethyltin dichloride, dibutyltin dichloride, dibutyltin dilaurate, tetrachlorotin, dibutyltin oxide, diacetoxytetrabutyldistanoxane and the like.

  Although the said curing catalyst may be used individually or in mixture of 2 or more types, when the 2 or more types of curing catalyst from which activity differs is used together, the hue and optical distortion (pulse separation) of the resin obtained may become favorable. .

  The addition amount of the curing catalyst is used in the range of 0.001 to 1 wt% with respect to the total weight of the composition containing the polythiol compound having the structure represented by the formula (1) or (2) according to the present invention. It is more preferable to use in the range of 0.005 to 0.5 wt%. When the addition amount of the curing catalyst is 0.001 to 1 wt%, the polymerizability is good, which is preferable in terms of pot life at the time of preparation, transparency of the resin obtained, optical physical properties, or weather resistance.

  A typical polymerization method for obtaining the resin (for example, plastic lens) of the present invention includes cast polymerization. That is, a composition containing a polythiol compound having a structure represented by the formula (1) or (2) according to the present invention containing a curing catalyst is injected between molding molds held by a gasket or a tape. At this time, there is no problem even if processing such as defoaming processing under reduced pressure or filtration processing such as pressurization or decompression is performed as necessary.

  Then, it can be cured by heating in a heatable apparatus such as an oven or water, and the resin can be taken out.

  The kind and amount of the curing catalyst and the like for obtaining the transparent resin of the present invention, and the kind and ratio of the monomer vary depending on the composition of the composition to be polymerized, and therefore cannot be generally limited.

  The heating polymerization conditions of the composition of the present invention injected into the molding mold are the composition of the composition containing the polythiol compound having the structure represented by the formula (1) or (2) of the present invention, the type of the curing catalyst, Although the conditions are largely different depending on the shape of the mold and the like, it is not possible to limit the conditions.

In some cases, it is preferable to hold or gradually raise the temperature in the temperature range of 10 ° C. to 150 ° C. and polymerize in 1 to 80 hours.
Furthermore, the composition of the present invention may be able to shorten the polymerization time by irradiation with ultraviolet rays. In this case, a curing catalyst such as a radical polymerization catalyst may be required.
In the resin molding of the present invention, a stabilizer, a resin modifier, a chain extender, a cross-linking agent, a light stabilizer typified by a HALS system, benzotriazole, as in a known molding method depending on the purpose UV absorbers typified by the system, antioxidants typified by the hindered phenols, colorants, dyes typified by the anthraquinone disperse dyes, fillers, external mold release agents typified by the silicones You may add various substances, such as a mold release agent and an adhesive improvement agent.

Examples of the internal release agent used in the present invention may be any as long as they have a release effect and do not impair physical properties such as transparency of the resin, but preferably a surfactant. Is used. Surfactants that are preferably used as mold release agents are broadly classified into ionic surfactants and nonionic surfactants, and ionic surfactants are classified into anionic surfactants and cationic surfactants. The Examples of the anionic surfactant include sulfate ester, sulfonate ester, and phosphate ester. Among these, phosphate ester surfactants are preferable, and acidic phosphate ester anionic surfactants are particularly preferable. Is preferred. Some of the compounds described as the above-mentioned catalysts such as quaternary ammonium salts and quaternary phosphonium salts can also be used as internal mold release agents as long as they exhibit a mold release effect. These internal release agents may be used alone or in combination of two or more. These are appropriately selected from the monomer combination, polymerization conditions, economy, and ease of handling. The amount of the internal mold release agent used is usually in the range of 1 to 10,000 ppm based on the total weight of the gun composition, either alone or as a mixture of two or more. When the addition amount is 1 ppm or more, the release ability is good, and when it is 10000 ppm or less, release from the mold during the casting polymerization is suppressed, and deterioration of surface accuracy of the lens surface and white turbidity of the obtained lens are prevented. Can do.
The addition amount of various additives other than the internal mold release agent that enables the above addition varies depending on the type, structure, and effect of each additive and cannot be generally limited. It is used in the range of 0.001 to 10 wt% with respect to the weight, but is preferably used in the range of 0.01 to 5 wt%. The dye is preferably used in the range of 1 ppb to 100 ppm instead of this range. Within these ranges, a well cured resin can be produced, and a resin having good transparency and optical properties may be obtained.

  Further, the taken out resin may be subjected to a treatment such as annealing as necessary. The annealing temperature is usually 50 ° C. to 200 ° C., preferably 90 ° C. to 150 ° C. If it is 100 to 130 degreeC, it is more preferable.

  A transparent resin obtained by curing a composition containing a polythiol having a structure represented by the formula (1) or (2) according to the present invention has a good hue, a very high refractive index, and a high refractive index and Abbe. The resin has a good balance of numbers and is very excellent in transparency without optical distortion, has particularly improved heat resistance, and is particularly excellent in a conventional high refractive index material. The transparent resin of the present invention can be obtained as molded articles of various shapes by changing the mold during casting polymerization, and requires a high refractive index and transparency, and requires an eyeglass lens, a camera lens, a light emitting diode ( It can be used for various applications as an optical resin such as LED). In particular, it is suitable as an optical material and an optical element such as a camera lens and a light emitting diode.

Furthermore, in the lens using the transparent resin of the present invention, if necessary, antireflection, imparting high hardness, improving wear resistance, improving chemical resistance, imparting antifogging, or surface polishing, antistatic treatment, hard coat Physical or chemical treatment such as treatment, non-reflective coating treatment, and dyeing treatment can be performed.
[Example]
Hereinafter, the present invention will be specifically described by way of examples. Of the performance tests of the obtained resin, the refractive index, heat resistance, and weather resistance were evaluated by the following test methods.
Refractive index (nd): Measured at 20 ° C. using a Purfrich refractometer.
Heat resistance: Tg in the TMA penetration method (50 g load, pin tip 0.5 mmφ) was regarded as heat resistance.
-Weather resistance: Irradiated with a carbon arc fade meter for 20 hours, the resin having a large discoloration was evaluated as x, the resin having a slight discoloration was evaluated as Δ, and the resin having almost no discoloration was evaluated as ○.
[Example 1]
In a reactor equipped with a stirrer, thermometer and Dimroth, 42.4 g (0.2 mol) of 1,2-epithio-6,7-dimercapto-4-thiaheptane and 200 g of toluene were charged and mixed. After adding 0.04 g of butylammonium bromide and raising the temperature to 40 ° C., aging was similarly performed at 50 ° C. for 24 hours. After completion of the reaction, the reaction solution was cooled to room temperature, charged with 200 g of an aqueous hydrochloric acid solution, washed with the toluene layer, removed the aqueous layer, and then washed with performance of taking 4 times with 200 g of water. The obtained toluene layer was colorless and transparent. The toluene layer was dehydrated with anhydrous magnesium sulfate, filtered, and further concentrated with an evaporator. The concentrated residue was 40.9 g. As a result of IR analysis of the concentrated residue, absorption of a mercapto group was confirmed at 2548 cm ⁻¹ . The obtained residue was passed through a silica gel column using hexane and ethyl acetate as developing solvents for purification, and the main component was taken out. The extracted component was 21.4 g and was colorless and transparent. The recovered main component was 1,4-dithian-2,5-bis (4,5-dimercapto-2-thiapentane) as a result of analysis. The obtained compound is hereinafter referred to as compound (A).

  Identification data for the compound (A) is shown below.

[Example 2]
Instead of 42.4 g (0.2 mol) of 1,2-epithio-6,7-dimercapto-4-thiaheptane, 48.8 g (0.2 mol) of 1,2-epithio-7,8-dimercapto-4,5-dithiaoctane The reaction and removal were conducted in the same manner as in Example 1 except that 0.03 g of triethylamine was used instead of 0.04 g of tetrabutylammonium bromide. As a result, the recovered main component was 1,4-dithian-2,5-bis (5,6-dimercapto-2,3-dithiahexane) as a result of analysis. The obtained compound is hereinafter referred to as “compound (B)”.

  Identification data for the compound (B) is shown below.

[Example 3]
In order to confirm the performance of the compound (A), polymerization was performed with polyisocyanate. 21.2 g of compound (A) and 44.4 g of isophorone diisocyanate (hereinafter referred to as compound (C)) as a polyisocyanate, 200 ppm of dibutyltin dichloride as a catalyst, acidic phosphate ester as an internal mold release agent (trade name) ZelecUN) was added to 1000 ppm and mixed and dissolved, followed by filtration to obtain a transparent solution. The obtained transparent solution was deaerated at 600 Pa for 1 hour. After degassing, the mixed solution was poured into a mold composed of a glass mold and a tape. The mold was put into an oven, gradually heated from 10 ° C. to 120 ° C., and polymerized in 24 hours. After completion of the polymerization, the mold was taken out from the oven and released to obtain a resin. The obtained resin was further annealed at 120 ° C. for 3 hours. The obtained resin was colorless and transparent and was good. Table 3 shows optical properties, heat resistance, and weather resistance of the obtained resin.
[Example 4]
In order to confirm the performance of the compound (B), polymerization was performed with polyisocyanate. Compound (B) 24.4 g and 2,5-bis (isocyanatomethyl) bicyclo- [2,2,1] -heptane, 2,6-bis (isocyanatomethyl) bicyclo- [2,2 as polyisocyanate , 1] -heptane (hereinafter referred to as Compound (D)) 41.2 g was mixed and dissolved by adding 200 ppm of dibutyltin dichloride as a catalyst and 1000 ppm of acidic phosphate ester (trade name ZelecUN) as an internal mold release agent. After mixing with the product, it was filtered to make a clear solution. The obtained transparent solution was deaerated at 600 Pa for 1 hour. After degassing, the mixed solution was poured into a mold composed of a glass mold and a tape. The mold was put into an oven, gradually heated from 10 ° C. to 120 ° C., and polymerized in 24 hours. After completion of the polymerization, the mold was taken out from the oven and released to obtain a resin. The obtained resin was further annealed at 120 ° C. for 3 hours. The obtained resin was colorless and transparent and was good. Table 3 shows optical properties, heat resistance, and weather resistance of the obtained resin.
[Comparative Example 1]
Instead of compound (A), 34.7 g of 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane (hereinafter referred to as compound (E)) and polyisocyanate were used as compound (D) 41. A resin was prepared in the same manner as in Example 4 except that 2 g was used. The obtained resin was colorless and transparent. Table 3 shows optical properties, heat resistance, and weather resistance of the obtained resin.

Claims (7)

A polythiol having a structure represented by formula (1) or (2).

A transparent resin composition comprising at least one polythiol according to claim 1. A transparent resin obtained by curing the transparent resin composition according to claim 2. The transparent resin according to claim 3, wherein the composition for transparent resin further contains one or more compounds selected from polyiso (thio) cyanate, polyepoxide, polyepisulfide, and olefin compound, or a mixture thereof. An optical material comprising the transparent resin according to claim 3. A plastic lens comprising the optical material according to claim 5. The manufacturing method of transparent resin including the process of obtaining the transparent resin of Claim 3 or 4 by cast polymerization.