WO1998037114A1

WO1998037114A1 - Curable composition and optical material prepared therefrom

Info

Publication number: WO1998037114A1
Application number: PCT/JP1998/000643
Authority: WO
Inventors: Kouji Shimada; Katsumasa Yamamoto; Michio Suzuki; Takeo Ogihara; Yukio Ichikawa
Original assignee: Sumitomo Seika Chemicals Co., Ltd.
Priority date: 1997-02-19
Filing date: 1998-02-16
Publication date: 1998-08-27
Also published as: AU5881798A

Abstract

A curable composition comprising 5 to 90 % by weight of at least one mercapto compound selected from the group consisting of tetrakis(7-mercapto-2,5-dithiaheptyl)methane represented by the structural formula (I): C(CH2SCH2CH2SCH2CH2SH)4 and 2,3-bis[(2-mercaptoethyl)thioethylthio]-1-propanethiol of structural formula (II), and 10 to 95 % by weight of a compound copolymerizable with the mercapto compound. The curable composition is capable of forming a resin having an excellent handleability, a high refractive index and a low specific gravity and so is suitable for use as an optical material or the like.

Description

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Description Curable composition and optical material comprising the same

The present invention relates to a curable composition and an optical material comprising the same. More specifically, optical materials such as plastic lenses for eyeglasses, Fresnel lenses, lenticure lenses, optical disc substrates, plastic optical fibers, LCD prism sheets, light guide plates, and diffusion sheets, paints, adhesives, and seals The present invention relates to a curable composition useful as a raw material for materials. Background art

Conventionally, polystyrene resin, polymethyl methacrylate resin, polycarbonate resin, diethylene glycol diaryl carbonate resin, etc. have been widely used as resins for optical materials because they are lighter and easier to handle than glass. I have.

However, these resins for optical materials have the drawback that they have a low refractive index, a large birefringence and a large dispersing ability, and are inferior in heat resistance and impact resistance.

In recent years, as a resin having an improved refractive index, a resin in which halogen is introduced into an aromatic ring has been proposed (Japanese Patent Publication No. 5-4404). However, the refractive index of the resin is as high as 1.60, but the specific gravity is as large as 1.37. For example, when the resin is used for a plastic lens, the light weight required for the plastic lens is required. There is a disadvantage that the properties are not satisfied.

Also, in order to increase the refractive index of the resin, attempts have been made to increase the content of sulfur atoms having a high atomic refractive index in the monomer molecules of the resin (JP-A-2-27).

Japanese Unexamined Patent Application Publication No. 08-59, Japanese Unexamined Patent Publication (Kokai) No. 5-209589). High sulfur atom content -

It has been proposed to use low-molecular-weight mercapto compounds such as methanethiol, ethanethiol, and ethanedithiole as the monomer. However, when a low-molecular-weight mercapto compound is used, the low-molecular-weight mercapto compound emits a peculiar odor based on a mercapto group, and there is a problem with other raw material monomers used for curing a resin. There is a disadvantage that the amount used is limited due to the composition ratio.

In order to solve such a drawback, instead of the low-molecular-weight mercapto compound, trimethylolpropane tris- (thioglycolate), pen-erythritol tetratekis (thioglycolate) and the like are generally used as epoxy resin curing agents. It has been considered to use a polyfunctional mercapto compound having a large molecular weight. This mercapto compound has the advantage that it has a low molecular weight and therefore has a low odor and is easy to handle. However, since the content of sulfur atoms in the molecule of the mercapto compound is low, it is difficult to increase the content of sulfur atoms in the obtained resin and to obtain a resin having a desired refractive index. There are drawbacks. The present invention has been made in view of the prior art, and a first object of the present invention is to

It is another object of the present invention to provide a curable composition which gives a resin having a high refractive index and a low specific gravity and has excellent handleability.

A second object of the present invention is to provide an optical material comprising the curable composition. Disclosure of the invention

According to the present invention,

[1] Equation (I) _:

_{_{_{C (CH 2 SCH 2 CH 2}}} SCH 2 CH 2 SH) 4 tetrakis one represented by (I) (7 - mercapto one 2, heptyl to 5 dithia) methane and formula (U): (II)

2,3-bis [(2-mercaptoethyl) thioethylthio] —11 at least one mercapto compound selected from the group consisting of propanethiols, 5 to 90% by weight, and copolymerizable with the mercapto compound Curable composition comprising 10 to 95% by weight of a novel compound; and

(2) An optical material obtained by copolymerizing the curable composition

Is provided. BEST MODE FOR CARRYING OUT THE INVENTION

As described above, the curable composition of the present invention has the formula (I):

Tetrakis (7-mercapto-1,2,5-dithiaheptyl) methane represented by C (CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SH) 4 (I) and the formula (Π):

(II)

2,3-bis [(2-mercaptoethyl) thioethylthio] represented by the formula: 5-90% by weight of at least one mercapto compound selected from the group consisting of propanethiol (hereinafter simply referred to as mercapto compound) And 10 to 95% by weight of a compound copolymerizable with the mercapto compound.

The tetrakis (7-mercapto-2,5-dithiaheptyl) methane used in the present invention is prepared, for example, by the method described in JP-A-9-263575. _

Can be That is, the tetrakis- (7-mercapto-2,5-dithiaheptyl) methane is, for example, bis- (2-mercaptoethyl) sulfite and pentaerythrityltetrabromide such as pentaerythrityltetrabromide. A halide and a quaternary ammonium salt or a quaternary phosphonium salt such as tetra-n-butylammonium bromide, if necessary, in the presence of a base such as sodium hydroxide and the like, as a catalyst. Can be. The reaction of bis- (2-mercaptoethyl) sulphite and phenol erythrityl tetrahalide can be carried out by mixing both and stirring the mixture under heating while adding the base. The reaction temperature at this time is usually preferably set to 30 to 120 ° C. The ratio of bis (2-mercaptoethyl) sulfite to pentaerythrityl tetrahalide is at least 4 times the molar ratio of bis- (2-mercaptoethyl) sulfite to pentaerythrityl tetrahalide. Is preferably set, and more preferably 4 to 50 times the molar amount. The amount of the base used is usually preferably set to 4 to 6 times the molar amount of erythrityl tetrahalide. Usually, the amount of the catalyst used is preferably set to 0.01 to 0.1 times the molar amount of erythrityl tetrahalide.

The above-mentioned 2,3-bis [(2-mercaptoethyl) thioethylthio] 111 propanthiol can be produced by the method described in Japanese Patent Application Laid-Open No. 9-287672. That is, the 2,3-bis [(2-mercaptoethyl) thioethylthio] 1-1-propanethiol is, for example, ephalohydrin or 1,3-dihalogeno-1-propanol and 2-[(2-mercaptoethyl) 1,3-bis [(2-hydroxyethyl) thioethylthio] —2-propanol was produced by reacting ethanol with ethanol in the presence of a base, and the resulting 1,3-bis [(2-hydroxy [Ethyl) thioethylthio] A reaction product is obtained by reacting 12-propanol with thiourea in the presence of a mineral acid. Can be. The content of the mercapto compound in the curable composition of the present invention is 5% by weight or more, preferably 10% by weight or more, from the viewpoint of increasing the refractive index of a cured product obtained by using the curable composition of the present invention. From the viewpoint of enhancing the polymerizability of the curable composition of the present invention, that is, the curing reaction, the content is 90% by weight or less, preferably 80% by weight or less, and more preferably 75% by weight or less.

Representative examples of the compound copolymerizable with the mercapto compound include, for example,

(1) at least one selected from the group consisting of a polyisocyanate compound, a polyisothiocyanate compound, and an isothiocyanate compound having an isocyanate group (hereinafter, referred to as a first embodiment);

(2) a monomer having a polymerizable unsaturated bond (hereinafter, referred to as a second embodiment);

(3) Epoxy compound (hereinafter referred to as third embodiment)

(4) Epicio compound (hereinafter referred to as a fourth embodiment)

And so on.

In any of the first to fourth embodiments, each compound may be used alone or in combination of two or more.

First, the first embodiment will be described.

In the first embodiment, as described above, the compound copolymerizable with the mercapto compound is selected from the group consisting of a polyisocyanate compound, a polyisothiocyanate compound, and an isothiocyanate compound having an isocyanate group. At least one selected may be used.

Specific examples of the polyisocyanate compound include, for example, aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic polyisocyanate, and sulfur-containing polyisocyanate. These polyisocyanate compounds can be used alone or in combination of two or more.

Representative examples of the aliphatic polyisocyanate include, for example, ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, and hexane. Examples include samethylene diisocyanate, xylylene diisocyanate, bis (isocyanatoethyl) benzene, bis (isocyanatopropyl) benzene, bis (isocyanatobutyl) benzene, and bis (isocyanatomethyl) naphthalene. Of these, hexamethylene diisocyanate, xylylene diisocyanate and bis (isocyanatoethyl) benzene, particularly xylylene diisocyanate, can be suitably used in the present invention.

Representative examples of alicyclic polyisocyanates include, for example, isophorone diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, bis (isocyanatomethyl) cyclohexane, dicyclohexane Xylmethane diisocyanate, 2,2'-dimethyldicyclohexylmethane diisocyanate, dicyclohexyldimethylmethane diisocyanate, and the like. Among them, isophorone diisocyanate, cyclohexane diisocyanate and bis (isocyanatomethyl) cyclohexane can be suitably used in the present invention.

Representative examples of aromatic polyisocyanates include, for example, tolylene diisocyanate, phenylene diisocyanate, dimethyl phenylene diisocyanate, ethyl phenylene diisocyanate, Zentri isocyanate, trimethylbenzene triisocyanate, naphthalene diisocyanate, biphenyl diisocyanate, 4,4 'diphenylmethane diisocyanate, toluidine diisocyanate and the like. Among these, tolylene diisocyanate can be suitably used in the present invention.

Representative examples of the sulfur-containing polyisocyanate include, for example, thiogetyl diisocyanate, dithiogetyl diisocyanate, thiodipropyl diisocyanate, dithiodibutyl pill diisocyanate, diphenyl sulfide 4,4 'diisocyanate, diphenyl sulphide 2,4'-diisocyanate, bis (4 —Isocyanatomethylbenzene) sulfide, 1,4-dithiane-1,2,5-diisocyanate, diphenyldisulfide-1,4,4′-diisocyanate. Among these, diphenyl sulfide-1,4,4'-diisocyanate can be suitably used in the present invention.

Specific examples of the polyisothiocyanate compound include, for example, aliphatic or alicyclic polyisothiocyanate, aromatic polyisocyanate, and sulfur-containing polyisothiocyanate.

Representative examples of the aliphatic or cycloaliphatic polyisothiocyanate include, for example, 1,2-dithithiocyanatopropane, 1,3-diisothiocyanatopropane, 1,4-diisothiocyanatobutane, p-phenyl Examples thereof include di-diisopropylidene diisothiocyanate and cyclohexanediisothiocyanate. Representative examples of aromatic polyisocyanates include, for example, 1,2-diisothiocyanatobenzene, 1,3-diisothiocyanatobenzene, 1,4-diisothiocyanatobenzene, 2,4-diisothiocyanate Examples include natotoluene, 2,5-diisothiocyanate-m-xylene, 4,4'-diisothiocyanato 1,1'-biphenyl, 1, -methylenebis (4-isothiocyanato-benzene), and the like. Among them, 1,2-diisothiocyanatobenzene, 1,3-diisothiocyanatobenzene and 1,4-diisothiocyanatobenzene can be suitably used in the present invention.

Representative examples of sulfur-containing polyisothiocyanates include, for example, Tiobis (2-dithiocyanatoethane), dithiobis (2-isothiocyanatoethane), thiopis (3-itithiocyanatopropane), and Tiobis (4-isothiocyanatobenzene) and sulfonylbis (4-isothiocyanatobenzene).

Specific examples of the above isocyanate compound having an isocyanate group include, for example, aliphatic or alicyclic compounds, aromatic compounds, and sulfur-containing compounds. .

It is.

Representative examples of the aliphatic or alicyclic compounds include, for example, 1-isocyanato-to- 3-isothiocyanato-propane, 1-isocyanato-to-6-isothiocyanato-to-hexane, 1-isocyanato-to- 4-itthocyanato-to-cyclo Hexane and the like.

Representative examples of the aromatic compound include, for example, 1-isocyanato- 4-isothiocyanato-benzene, 4-methyl-3-isocyanato-to 1-isothiocyanato-benzene, and the like.

Representative examples of the sulfur-containing compound include, for example, 4-isocyanato-to 4'-isothiocyanato-todiphenyl sulfide.

Next, the second embodiment will be described.

In the second embodiment, as described above, a monomer having a polymerizable unsaturated bond can be used as the compound copolymerizable with the mercapto compound.

Specific examples of the monomer having a polymerizable unsaturated bond include, for example, an aromatic vinyl compound, an alicyclic vinyl compound, (meth) acrylic acid, a monofunctional (meth) atalylic acid derivative, a polyfunctional (meth) And acrylic acid derivatives. Here, “(meth) acryl” means both “acryl” and “methacryl” (hereinafter the same). These monomers having a polymerizable unsaturated bond can be used alone or in combination of two or more.

Representative examples of the aromatic vinyl compound include, for example, styrene, permethylstyrene, vinyltoluene, chlorostyrene, bromostyrene, chloromethylstyrene, methoxystyrene, butylthiostyrene, divinylbenzene, and the like. Among them, styrene and divinylbenzene can be suitably used in the present invention.

Representative examples of the alicyclic vinyl compound include, for example, cyclohexene, 4-vinylcyclohexene, 1,5-cyclooctadiene, 5-vinylbicyclo [2,2, _

1] Heptow 2 -en.

Representative examples of monofunctional (meth) acrylic acid derivatives include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) ) Acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, vol (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, Phenyl (meth) acrylate, benzyl (meth) acrylate, 1-naphthyl (meth) acrylate, black phenyl (meth) acrylate, bromophenyl (meth) acrylate, tribromof Sulfonyl (meth) § click Relate, main Tokishifueniru (meth) Akurireto, Shianofuweniru (meth) § acrylate, chloromethyl (meth) Akurireto, Buromoechiru (meth) Akuri rate, 2-hydroxy-E chill (meth) Akurireto, 2-hydroxypropyl

Examples include (meth) acrylate, polyethylene glycol (meth) acrylate, N, N-dimethyl (meth) acrylamide, and N, N-getyl (meth) acrylamide. Among them, methyl (meth) acrylate, cyclohexyl (meth) acrylate and phenyl (meth) acrylate can be suitably used in the present invention.

Representative examples of polyfunctional (meth) acrylic acid derivatives include, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol diacrylate.

(Meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4 Tandiol di (meth) acrylate, 1,5—pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl W-

Glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and other polyols (meth) acrylate; bis (4-methacryloylthiolate) And polythiol poly (meth) acrylates such as (phenyl) sulfide. Among these, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and bis (meth) acrylate (4-Methacryloylthiooffenyl) sulfide can be suitably used in the present invention.

Next, the third embodiment will be described.

In the third embodiment, as described above, an epoxy compound can be used as a compound copolymerizable with a mercapto compound.

Specific examples of the epoxy compound include a monomer having an epoxy group and an oligomer having an epoxy group. These epoxy compounds can be used alone or in combination of two or more.

Representative examples of monomers having an epoxy group and oligomers having an epoxy group include, for example, aryl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, 2-ethylhexyl glycidyl ether, sec-butyl Monofunctional glycidyl ethers such as tert-butyl glycidyl ether, tert-butyl phenyl glycidyl ether, and 2-methyloctyl glycidyl ether; 1,6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, neopentyl Glycol diglycidyl ether, glycerol diglycidyl ether, glyceryl triglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glyco Polyfunctional glycidyl ethers such as -

Bis [4- (2,3-epoxypropylthio) phenyl] sulfide, 1,4-di (2,3-epoxypropylthio) benzene and other polyfunctional glycidyl thioethers; glycidyl (meth) acrylate, Glycidyl esters such as glycidyl phthalate, diglycidylhexahydrophthalate, diglycidyltetrahydrophthalate, dimethyldiglycidylhexahydrophthalate; bisphenol A glycidyl ether, bisphenol F glycidyl ether, brominated bisphenol A glycidyl ether, Biphenyl glycidyl ether, tetramethyl biphenol glycidyl ether, resorcin glycidyl ether, hydroquinone glycidyl ether, dihydroxynaphthylene glycidyl ether, bisphen Glycidyl ethers such as glycidyl ether of phenolic novolak resin, glycidyl ether of phenol novolak resin, glycidyl ether of cresol novolak resin, glycidyl ether of dicyclopentadienephenol resin, glycidyl ether of terpene phenol resin and glycidyl ether of naphthol novolak resin; 4-Epoxycyclohexylmethyl-3,4-epoxycyclo mouth carboxylate, 3,4-epoxycyclohexylethyl-3,4 epoxycyclohexanecarboxylate, vinylcyclohexenedioxide, arylcyclohexenedioxide, 3,4-epoxy — 4-Methylcyclohexyl 2-propylene oxide, 2- (3,4-epoxycyclohexyl 5,5-spiro-1,3,4-epoxy) Rohexane 1 m-dioxane, bis (3,4-epoxycyclohexyl) adipate, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxycyclohexyl) ether, bis ( Alicyclic epoxy resins such as 3,4-epoxycyclohexylmethyl) ether and bis (3,4-epoxycyclohexyl) getylsiloxane. These epoxy compounds can be used alone or in combination of two or more.

Among these epoxy compounds, ethylene glycol diglycidyl ether _

Bis (4- (2,3-epoxypropylthio) phenyl) sulfide, glycidyl (meth) acrylate, bisphenol A glycidyl ether, brominated bisphenol A glycidyl ether and 3,4-epoxycyclohexylme Tyl-3,4-epoxycyclohexanecarboxylate can be suitably used in the present invention.

Next, a fourth embodiment will be described.

In the fourth embodiment, as described above, an epitio compound can be used as a compound copolymerizable with a mercapto compound.

Specific examples of the above-mentioned epitio compound include, for example, bis [4- (2,3-epipiopropylthio) phenyl] sulfide, bis [4-1 (2,3-epipiopropylthio) -13-methylphenyl] sulfide, bis [ 4-(2,3-Epithiopropylthio) -1,3,5-dimethylphenyl] sulfide and other polyfunctional thioglycidyl thioethers. These epipic compounds can be used alone or in combination of two or more.

Among these epitio compounds, bis [4- (2,3-epiciopropylthio) phenyl] sulfide can be suitably used in the present invention. In the curable composition of the present invention, the content of the compound copolymerizable with the mercapto compound, represented by the first to fourth embodiments, is the balance of the mercapto compound. That is, the content of the compound copolymerizable with the mercapto compound is 95% by weight or less, preferably 90% by weight or less from the viewpoint of increasing the refractive index of a cured product obtained by using the curable composition of the present invention. Further, from the viewpoint of enhancing the polymerizability of the curable composition of the present invention, that is, the curing reaction, it is preferably at least 10% by weight, preferably at least 20% by weight, and more preferably at least 25% by weight. Is done.

The curable composition of the present invention contains a mercapto compound and a compound copolymerizable with the mercapto compound, but other copolymerization is possible as long as the object of the present invention is not impaired. A compound may be contained. ―

In addition, the curable composition of the present invention may optionally include, for example, a light stabilizer, an ultraviolet absorber, an antioxidant, a coloring inhibitor, a polymerization inhibitor, a release agent, an antifoaming agent, a bluing agent, An additive such as a fluorescent dye may be appropriately compounded.

The curable composition of the present invention thus obtained gives a resin having a high refractive index and a low specific gravity, and is excellent in handleability.

Accordingly, the curable composition of the present invention can be used for optical materials such as plastic lenses for eyeglasses, Fresnel lenses, lenticure lenses, optical disk substrates, plastic optical fibers, prism sheets for LCDs, light guide plates, and diffusion sheets, paints, and adhesives. It can be suitably used as a raw material for agents, sealing materials and the like. In particular, the curable composition of the present invention can be suitably used for an optical material.

The optical material of the present invention is obtained by copolymerizing the curable composition. As a method of copolymerizing the curable composition, the curable composition of the present invention may be an optical material that requires transparency. Considering the use, for example, a solution polymerization method and a bulk polymerization method are suitable.

The polymerization of the curable composition can be carried out, for example, by heating, irradiation with a light beam such as ultraviolet rays, or the like, if necessary, using a polymerization initiator according to a generally employed method.

For example, when the compound of the first embodiment or the compound of the fourth embodiment is used as a compound copolymerizable with a mercapto compound, the curable composition is heated to a temperature of about 60 to 150 ° C. Is heated to effect copolymerization. When the compound of the second embodiment is used as the copolymerizable compound, the copolymerization is carried out using a radical polymerization initiator such as 2,2′-azobis (2,4-dimethylvaleronitrile). be able to. Further, when the copolymerizable compound of the third embodiment is used, for example, boron trifluoride.getyl ether complex, boron trifluoride.amine complex, aluminum chloride, titanium tetrachloride, -

The copolymerization can be carried out using a Lewis acid such as tin chloride, iron chloride (III), zinc chloride and the like; and a cationic polymerization initiator such as an ammonium salt, a sulfonium salt, an oxonium salt and a phosphonium salt.

The polymerization temperature and the polymerization time when the curable composition is polymerized vary depending on the composition of the curable composition, the application, the type of the polymerization initiator used, the amount used, and the like, and cannot be unconditionally specified. . Usually, the polymerization temperature may be about 0 to 200 ° C, preferably about 20 to 150 ° C. In the first and fourth embodiments, as described above, the polymerization temperature is preferably about 60 to 150 ° C. It is desirable that the polymerization time is about 0.2 to 100 hours, preferably about 1 to 72 hours.

The optical material of the present invention was obtained by a method other than the above method as long as the optical material had the same structure as the optical material obtained by the above method, that is, the curable composition used in the present invention as a repeating unit. It may be something.

The optical material of the present invention thus obtained has excellent properties such as a high refractive index and a low specific gravity.

Therefore, the optical material of the present invention can be suitably used such as a plastic lens for eyeglasses, a Fresnel lens, a lenticule lens, an optical disk substrate, a plastic optical fiber, a prism sheet for LCD, a light guide plate, and a diffusion sheet. Next, the present invention will be described in more detail based on examples, but the present invention is not limited to only these examples. Production Example 1

Prepare a 100-OmL four-necked flask equipped with a stirrer, thermometer, and condenser, and add 600 g (3.9 mol) of bis (2-mercaptoethyl) sulfite to it. And 50 g (0.129 mole) of erythrityl tetrabromide W098 / 37114-

4.1 g (0.0127 mol) of tetra-n-butylammonium bromide as a medium was added. Next, this was heated to 80 to 100 ° C., and 21.9 g (0.53 mol) of a 10% aqueous sodium hydroxide solution was added dropwise under a nitrogen atmosphere. Thereafter, the mixture was stirred for 3 hours while maintaining the temperature at 80 to 100 ° C.

Next, the reaction solution was cooled to 50 ° C., separated, washed twice with water, and then the organic layer was concentrated under reduced pressure. This concentrate was separated using silica gel column chromatography to obtain 72.6 g (0.107 mol) of tetrakis (7-mercapto-1,2,5-dithiheptyl) methane represented by the formula (I). Was done. Example 1

Mixture of tetrakis (7-mercapto-1,2,5-dithiaheptyl) methane 11.6 g (64% by weight) and m-xylylene diisocyanate 6.4 g (36% by weight) Thus, a curable composition was obtained.

After sufficiently degassing the curable composition, it is poured into a glass mold having a diameter of 5 cm and a thickness of 3 cm, heated at 60 ° C for 5 hours, and then heated to 100 ° C over 15 hours. The temperature was raised and the temperature was kept at 100 ° C. for 3 hours and then at 120 ° C. for 3 hours, and then the mold was released. The obtained optical material was uniform and colorless and transparent. Each physical property of the obtained optical material was evaluated by the following methods. The results are shown in Table 1.

(1) Refractive index and Abbe number

The refractive index and Abbe number at 20 ° C were measured using an Abbe refractometer (manufactured by Adago Co., Ltd., type 4T).

(2) Specific gravity

The measurement was performed according to JI SK 6911. The abbreviations shown in Tables 1 and 2 below indicate the following. -

① H I S 4: Tetrakisseux (7-mercapto-2,5-dithiaheptyl) methane

② H I S 3: 2,3-bis [(2-mercaptoethyl) thioethylthio]

1—Propane ol

③ mXD I: m_xylylene diisocyanate

④ DVB: divinylbenzene (purity: 80

⑤ MPS MA: bis (4-methacryloylthiophenyl) sulfide

⑥ St: Styrene

⑦ MPG: bis [4- (2,3-epoxypropylthio) phenyl] sulfide,

⑧ TD I: Tolylene diisocyanate

⑨ DMDS: Bis (2-mercaptoethyl) sulfite

⑩ MPT: bis- [4- (2,3-epitithiopropylthio) phenyl] sulfide Example 2

To 100 parts by weight of the curable composition having the composition shown in Table 1, 2,2′-azobis (2,4-dimethylvaleronitrile) (a product name of Wako Pure Chemical Industries, Ltd.) was added as a radical polymerization initiator. : V-65) 0.8 parts by weight was added and uniformly dissolved.

Next, the curable composition was sufficiently degassed, poured into a glass mold having a diameter of 5 cm and a thickness of 0.3 cm, heated at 36 ° C for 7 hours, and then heated at 80 ° C for 7 hours. The temperature was raised to 80 ° C for 1 hour, and then the mold was released. The obtained optical material was uniform and colorless and transparent. Each physical property was evaluated in the same manner as in Example 1. The results are shown in Table 1

Example 3 -An optical material was prepared in the same manner as in Example 2 except that a curable composition having the composition shown in Table 1 was used, and each physical property was evaluated. The results are shown in Table 1. Example 4

To 100 parts by weight of the curable composition shown in Table 1, 0.5 part by weight of 2-ethyl-4-imidimidazole (manufactured by Wako Pure Chemical Industries, Ltd.) was added as a curing accelerator, and the mixture was uniformly mixed. Dissolved.

Next, after sufficiently degassing the curable composition, it was poured into a glass mold having a diameter of 5 cm and a thickness of 0.3 cm, and heated at 50 ° C for 2 hours. The temperature was raised to 100 ° C., kept at 80 ° C. for 5 hours, then raised to 100 ° C. over 3 hours, kept at 100 ° C. for 10 hours, and then demolded. The obtained optical material was uniform and colorless and transparent. Each physical property was evaluated in the same manner as in Example 1. The results are shown in Table 1. Example 5

To 100 parts by weight of the curable composition shown in Table 1, as a radical polymerization initiator, t-butylbutyloxy-2-ethylhexanoate (manufactured by NOF CORPORATION, trade name: perbutyl 0) 1. 0 parts by weight was added and uniformly dissolved.

Next, after sufficiently degassing the curable composition, it was poured into a glass mold having a diameter of 5 cm and a thickness of 3 cm, heated at 55 ° C for 7 hours, and then heated at 90 ° C for 4 hours. The temperature was raised to 90 ° C. for 2 hours, then raised to 130 ° C. over 1 hour, and kept at 130 ° C. for 1 hour, followed by demolding. The obtained optical material was uniform and colorless and transparent. Each physical property was evaluated in the same manner as in Example 1. The results are shown in Table 1. Example 6

An optical material was prepared in the same manner as in Example 1 except that a curable composition having the composition shown in Table 1 was used, and each physical property was evaluated. The results are shown in Table 1. table 1

From the results shown in Table 1, the optical materials obtained in Examples 1 to 6 were all higher than the conventional excellent optical materials (refractive index: 1.60, specific gravity: 1.37). It can be seen that it has a refractive index and a low specific gravity. Production Example 2

A 500 ml four-necked flask equipped with a stirrer, thermometer and condenser was prepared. To this, 360 g (0.45 mol) of a 5% aqueous sodium hydroxide solution was added, and under a nitrogen atmosphere, 2—C (2-mercaptoethyl) thio] ethanol 62.1 g (0.4 (5 mol) was added dropwise to obtain a homogeneous solution.

Next, 20.3 g (0.22 mol) of epichlorohydrin was dropped into the flask at 20 to 40 ° C over 1 hour, and further heated at 40 to 50 ° C for 1 hour. Stirred. Then, the reaction solution was cooled to 20 ° C, filtered, and dried. .

70.8 g of 1,3-bis [(2-hydroxyethyl) thioethylthio] -12-propanol were obtained.

Next, 70.8 g of the obtained 1,3-bis [(2-hydroxyethyl) thioethylthio] -2-propanol was dissolved in 166.9 g (1.6 mol) of 35% hydrochloric acid. To the mixture was added 9.12 g (1.2 mol) of thiourea, and the mixture was stirred at 100 to 110 ° C for 5 hours.

Thereafter, the reaction solution was cooled to room temperature, and then 10.9.3 g (1.8 mol) of 28% aqueous ammonia was added at 20 to 40 ° C to make the reaction solution alkaline. Stirred for hours.

After completion of the stirring, the reaction solution was cooled to room temperature, 250 ml of toluene was added for extraction, and the toluene layer was separated. The toluene layer was washed with 100 ml of a 5% hydrochloric acid aqueous solution, further washed twice with 100 ml of water, and dried by adding 2 Og of magnesium sulfate.

Next, the toluene was distilled off under reduced pressure and concentrated, and the obtained concentrated solution was separated by silica gel column chromatography. As a result, 2,3-bis [(2-mercapto) represented by the formula (Π) was obtained. (Ethyl) thioethylthio] -1-propanethiol 61.6 g (0.162 g) was obtained. Example 7

2,3-Bis [(2-mercaptoethyl) thioethylthio] -1 1-propanethiol 12.4 g (61 weight) and m-xylylene diisocyanate 8.0 g (39 weight%) Was uniformly mixed to obtain a curable composition.

After sufficiently degassing the curable composition, it was poured into a glass mold having a diameter of 5 cm and a thickness of 0.3 cm. Next, this mold was heated at 60 ° C for 5 hours, heated to 100 ° C over 15 hours, and kept at 100 ° C for 3 hours and then at 120 ° C for 3 hours. After that, the mold was removed to obtain an optical material. The obtained optical material was uniform and colorless and transparent. .

As physical properties of the obtained optical material, a refractive index, an Abbe number, and a specific gravity were evaluated in the same manner as in Example 1. The results are shown in Table 2. Example 8

To 100 parts by weight of the curable composition having the composition shown in Table 2, 2,2′-abbis (2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a radical polymerization initiator. Trade name: V-6 5) 0.8 part by weight was added and uniformly dissolved.

Next, after sufficiently degassing the curable composition, it was poured into a glass mold having a diameter of 5 cm and a thickness of 0.3 cm. After heating at 70 ° C. for 7 hours, the temperature was raised to 80 ° C. over 7 hours, kept at 80 ° C. for 1 hour, and demolded to obtain an optical material.

The obtained optical material was uniform and colorless and transparent.

The physical properties of the obtained optical material were evaluated in the same manner as in Example 1. The results are shown in Table 2. Example 9

An optical material was obtained in the same manner as in Example 7, except that the curable composition having the composition shown in Table 2 was used.

The obtained optical material was uniform and colorless and transparent.

The physical properties of the obtained optical material were evaluated in the same manner as in Example 1. The results are shown in Table 2. Example 10

To 100 parts by weight of the curable composition having the composition shown in Table 2, 0.5 parts by weight of 2-ethyl-4-methylimidazole as a curing accelerator was added and uniformly dissolved. Next, the curable composition was sufficiently degassed, and then poured into a glass mold having a diameter of 5 cm and a thickness of 0.3 cm. Subsequently, the mold was heated at 50 ° C for 2 hours, heated to 80 ° C over 3 hours, kept at 80 ° C for 5 hours, and then heated to 100 ° C over 3 hours. After the temperature was raised and kept at 100 ° C. for 10 hours, it was released from the mold to obtain an optical material.

The obtained optical material was uniform and colorless and transparent.

The physical properties of the obtained optical material were examined in the same manner as in Example 1. The results are shown in Table 2. Example 1 1

An optical material was prepared in the same manner as in Example 7 except that a curable composition having a composition shown in Table 2 was used, and each physical property was evaluated. The results are shown in Table 2.

Table 2

From the results shown in Table 2, the optical materials obtained in Examples 7 to 11 were all superior to the conventional excellent optical materials (refractive index: 1.60, specific gravity: 1.37). It can be seen that it has a high refractive index and a low specific gravity. Industrial applicability

The curable composition of the present invention provides a resin having a high refractive index, a low specific gravity, and excellent handleability.

Therefore, the curable composition of the present invention comprises a plastic lens for spectacles, a Fresnel lens, a lenticule lens, an optical disc substrate, a plastic optical fiber,

It can be suitably used as a raw material for optical materials such as prism sheets for LCDs, light guide plates and diffusion sheets, paints, adhesives and sealing materials. Equivalent

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described in detail herein. Such equivalents are intended to be encompassed by the following claims.

Claims

The scope of the claims

1. Formula (I):

Tetrakis (7-mercapto-1,2,5-dithiaheptyl) methane represented by C (CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SH) ₄ (I) and formula (II):

CH ₂ SH

CHSCH ₂ CH ₂ SCH ₂ CH ₂ SH (II)

I

2,3-bis [(2-mercaptoethyl) thioethylthio] represented by CH2S, H2, H2S, H2, H2SH At least one mercapto compound selected from the group consisting of propanethiol 5-90 A curable composition comprising, by weight, 10 to 95% by weight of a compound copolymerizable with the mercapto compound.

2. The compound copolymerizable with the mercapto compound is at least one selected from the group consisting of a polyisocyanate compound, a polyisothiocyanate compound, and an isothiocyanate compound having an isocyanate group. The curable composition according to the above.

3. The curable composition according to claim 1, wherein the compound copolymerizable with the mercapto compound is a monomer having a polymerizable unsaturated bond.

4. The curable composition according to claim 1, wherein the compound copolymerizable with the mercapto compound is an epoxy compound.

5. The curable composition according to claim 1, wherein the compound copolymerizable with the mercapto compound is an epithio compound.

6. An optical material obtained by copolymerizing the curable composition according to any one of claims 1 to 5.