JPH02251528A - Resin composition for optical material - Google Patents

Abstract

PURPOSE:To obtain the subject composition of high refractive index, excellent in transparency, surface characteristics including surface hardness and heat resistance, thus useful for e.g. optical materials by copolymerization between a specific monomer and a second monomer having radical-polymerizable functional groups. CONSTITUTION:The objective composition can be obtained by copolymerization, in the presence of a radical polymerization initiator, of a mixture of (A) the first monomer of the formula (X is Cl, Br, methyl or ethyl; Y is CH3-C-CH3, SO2 or S; Z is H or CH3; (a) is 0 to 4; (b) is 0 or 1; (n) is 0 to 4) and (B) at least one of the second monomers having in the molecule two or more radical- polymerizable functional groups containing C=C so as to compose the total number of the OH groups in the component A fall between 0.1 and 0.99 times the total number of the functional groups in the component B. It is preferable that the functional groups in the component B be vinyl, (meth)acryl and/or allyl(carbonate).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a resin for lenses and other optical materials that is lightweight, has excellent transparency, heat resistance, surface hardness, impact resistance, and processability, and is easy to mold. It is used between compositions.

[Conventional technology]

Conventionally, various synthetic resins to replace inorganic glass have been researched and proposed, and have been put into practical use.For example, diethylene glycol bisallyl carbonate) (CR-39)
Recently, various allyl carbonates have been radically polymerized, or various (
Examples include products obtained by radical polymerization of meth)acrylic monomers, urethane or thiourethane resins obtained by reacting isocyanate compounds with polyols or polythiols, and resins obtained by combining them.

In addition, conventionally, compounds with OH groups have been used as intermediate raw materials for radically polymerizable compounds, such as acrylic monomers.
Alternatively, it is used as a raw material for urethane resin.

[Problem to be solved by the invention]

However, the physical properties of conventional resins do not necessarily satisfy all the properties. That is, allyl carbonate resins and (meth)acrylic resins are easy to mold, but they have drawbacks such as poor impact resistance and the need for many synthesis processes to obtain monomers.

Further, some urethane resins have good ffj impact resistance, but have a disadvantage of poor moldability during cast polymerization.

Means for Solving the C0 Problem] The present inventors have completed the present invention as a result of intensive research to improve the drawbacks of conventional resins.The present invention is based on the following general formula ( At least one type of monomer represented by 1) and at least one type of monomer having at least two radically polymerizable functional groups containing a carbon-carbon double bond in the molecule regardless of the type thereof. By polymerizing a monomer mixture comprising:

The present invention will be explained in detail below.

That is, the present invention is represented by the general formula (I) (wherein, X represents a chlorine atom, a bromine atom, a methyl group, an ethyl group, or another alkyl group, and Y represents a ,CH3
-C-CH2-CH3, (Is it possible to express the above in one way?) -502-5-, Z is Hl or CH3
, a represents an integer from O to 4, b represents O or 1, and n represents an integer from O to 4), and a carbon-carbon double in the molecule. At least one type of second monomer having at least two radically polymerizable functional groups containing a bond, and when the total number of OH groups in the first monomer is two or more types, 0.0 of the value of the total number of functional groups of This is a resin composition for optical materials, which is obtained by copolymerizing a mixture containing 1 to 0.99 times as much in the presence of a radical polymerization initiator.

Bromophenol represented by the general formula (I) used in the present invention, 2,4.6-tribromophenol, 4-
Chlorophenol, 2-chlorophenol, 2,4-dichlorophenol, 2,4.6-trichlorophenol, 2-bromo-4-chlorophenol, 4-bromo-2
-chlorophenol, 2-methylphenol, 4-methylphenol, 2,4-dimethylphenol, 2,4゜6-trimethylphenol, 2-ethylphenol, 4
-ethylphenol, 2.4-diethylphenol, 2
．． 4.6-) Diethylphenol, 2-isopropylphenol, 4-propylphenol, 4-bromo-2
-Methylphenol, 2-bromo-4-methylphenol, 4-chloro-2-methylphenol, 2-chloro-
4-methylphenol, 2-butylphenol, 4-pentylphenol, 2-ethyl-4-methylphenol, 4-ethyl-2-methylphenol, 4-phenylphenol, 2-phenylphenol, 2,4-diphenylphenol, 2 , 4.6-) diphenylphenol, 2-chloro-4-phenylphenol, 2-bromo-
Phenols and their derivatives such as 4-phenylphenol, 2-methyl-4-phenylphenol, benzyl alcohol, 4-chlorohensyl alcohol, 4-
Bromobenzyl alcohol, 2. dibromobenzyl alcohol, 2,4.6-)ribromobenzyl alcohol, 2,4-dichlorobenzyl alcohol, 2.4.6
-) dichlorobenzyl alcohol, 2-methylbenzyl alcohol, 2,4-dimethylbenzyl alcohol,
2-ethylbenzyl alcohol, 4-propylbenzyl alcohol, 4-bromo-2-methylbenzyl alcohol, 4-ethyl-2-methylbenzyl alcohol, 4-
Benzyl alcohol and its derivatives such as phenylbenzyl alcohol, 2-chloro-4-phenylbenzyl alcohol, thiophenol, 4-bromothiophenol, 2-bromothiophenol, 2,4-dibromothiophenol, 2,4.6 -) dibromothiophenol, 4-chlorothiophenol, 2-chlorothiophenol, 2,4-dichlorothiophenol, 2,4.6-
) dichlorothiophenol, 2-bromo-4-chlorothiophenol, 4-bromo-2-chlorothiophenol, 2-methylthiophenol, 4-methylthiophenol, 2,4-dimethylthiophenol, 2,4.6-
) dimethylthiophenol, 2-ethylthiophenol, 4-ethylthiophenol, 2.4-diethylthiophenol, 2,4.6-triethylthiophenol, 2
-isopropylthiophenol, 4-propylthiophenol, 4-bromo-2-methylthiophenol, 2-
Bromo-4-methylthiophenol, 4-chloro-2-
Methylthiophenol, 2-chloro-4-methylthiophenol, 2-butylthiophenol, 4-pentylthiophenol, 2-ethyl-4-methylthiophenol, 4-ethyl-2-methylthiophenol, 4-phenylthiophenol, 2- phenylthiophenol, 2,
4-diphenylthiophenol, 2,4.6-triphenylthiophenol, 2-chloro-4-phenylthiophenol, 2-bromo-4-phenylthiophenol,
Thiophenols and their derivatives such as 2-methyl-4-phenylthiophenol, benzyl mercaptan,
4-chlorobenzyl mercaptan, 4-bromobenzyl mercaptan, 2,4-dibromobenzyl mercaptan, 2°4.6-) dibromobenzyl mercaptan, 2,
4-dichlorobenzyl mercaptan, 2,4.6-)
dichlorobenzyl mercaptan, 2-methylbenzyl mercaptan, 2,4-dimethylbenzyl mercaptan,
2-ethylbenzylmercaptan, 4-probylbenzylmercaptan, 4-bromo-2-methylhensylmercaptan, 4-ethyl-2-methylbenzylmercaptan, 4-phenylbenzylmercaptan, 2-chloro-
Compounds such as benzyl mercaptan and derivatives thereof such as 4-phenylbenzyl mercaptan are included.

The functional groups of the second monomer used in the present invention, which have at least two radically polymerizable functional groups containing a carbon-carbon double bond in the molecule regardless of their type, include vinyl groups,
Mention may be made of (meth)acrylic, allyl and allyl carbonate groups, among which the vinyl group 1.
A (meth)acrylic group and an allyl group are preferred. Specifically, the second monomer is a polyvalent vinyl compound such as divinylbenzene or divinylnaphthalene as a monomer having a vinyl group; and as a monomer having a methacrylic group. , 4-diacryloxybenzene, 1,4-dimethacryloxybenzene, 1,4-diacryloxyethoxybenzene, 1,4-dimethacryloxyethoxybenzene, and other benzene derivatives, 1,5-diacryloxy naphthalene, 1,5-dimethacryloxinaphthalene, l, 5
-bis(β-acryloxyethoxy)naphthalene, 1,
Naphthalene derivatives such as 5-bis(β-dimethacrylokijetoxy)naphthalene, biphenyl derivatives such as 2゜2'-bisacryloxybiphenyl, 2.2'-bismethacryloxybiphenyl, 2.2'-bis (β-acryloxyethoxy)biphenyl, 2,2′-bis(β
-dimethacrylokijetoxy)biphenyl, 2.2'-
Bis(4-acryloxyphenyl)propane, 2.2'
-bis(4-methacryloxyphenyl)propane, 2,
2'-bis(4-acryloxyethoxyphenyl)propane, 2,2'-bis(4-methacryloxyethoxyphenyl)propane, 2.2'-bis(4-acryloxypolyethoxyphenyl)propane, 2.2 '-Bis (4
-methacryloxypolyethoxyphenyl)propane, 2
, 2'-bis(4-7cryloxy-3,5-dibromophenyl)propane, 2,21-bis(4-methacryloxy-3,5-dibromophenyl)propane, 2,2''-
Bis(4-acryloxyethoxy-3,5-dibromophenyl)propane, 2,2'-bis(4-methacryloxyethoxy-3°5-dibromophenyl)propane,
2.2'-bis(4-acryloxypolyethoxy-3
,5-dibromophenyl)propane, 2,2'-bis(
4-methacryloxypolyethoxy-3,5-dibromophenyl)propane, 2,2'-bis(4-acryloxy-3,5-dichlorophenyl)propane, 2,2'-bis(4-methacryloxy-3,5- Dichlorophenyl
Propane, 2,2'-bis(4-acryloxyethoxy-3,5-dichlorophenyl)propane, 2,2'-bis(4-methacryloxyethoxy-3,5-dichlorophenyl)propane, 2,2'-bis (4-acryloxypolyethoxy-3,5-dichlorophenyl)propane,
2,2'-bis(4-methacryloxypolyethoxy-3
, 5-dichlorophenyl)propane, bisphenol A derivatives such as 2.2'-bis(4-7cryloxyphenyl)sulfone, 2゜2'-bis(4-methacryloxyphenyl)sulfone, 2.2'- Bis(4-acryloxyethoxyphenyl)sulfone, 2,2'-bis(4-
methacryloxyethoxyphenyl) sulfone, 2.2'
-bis(4-acryloxypolyethoxyphenyl)sulfone, 2,2'-bis(4-methacryloxypolyethoxyphenyl)sulfone, 2,2'-bis(4-acryloxy-3,5-dibromophenyl)sulfone, 2,2'
-bis(4-methacryloxy-3,5-dibromophenyl)sulfone, 2゜2'-bis(4-acryloxyethoxy-3,5-dibromophenyl)sulfone, 2.2'
-bis(4-methacryloxyethoxy-3,5-dibromophenyl)sulfone, 2,2'-bis(4-acryloxypolyethoxy-3,5-dibromophenyl)sulfone, 2,2'-bis(4- Methacryloxypolyethoxy-3,5-dibromophenyl) sulfone, 2,2'-bis(4-acryloxy-3,5-dichlorophenyl)sulfone, 2,2'-bis(tomethacryloxy 3,5-
dichlorophenyl) sulfone, 2,2'-bis(4-acryloxyethoxy-3,5-dichlorophenyl)sulfone, 2,2'-bis(4-methacryloxyethoxy-
3,5-dichlorophenyl) sulfone, 2.2'-bis(4-acryloxypolyethoxy-3,5-dichlorophenyl) sulfone, 2゜2'-bis(4-methacryloxypolyethoxy-3,5-dichlorophenyl) Bisphenol S derivatives such as sulfone, bis(4-7cryloxyphenyl) sulfide, bis(4-methacryloxyphenyl) sulfide, bis(4-acryloxyethoxyphenyl) sulfide, bis(4-methacryloxyethoxyphenyl) Sulfide, bis(4-acryloxypolyethoxyphenyl) sulfide, bis(4-methacryloxyboriethoxyphenyl) sulfide, bis(
4-acryloxy-3,5-dibromophenyl) sulfide, bis(4-methacryloxy-3,5-dibromophenyl) sulfide, bis(4-acryloxyethoxy-3,5-dibromophenyl) sulfide, bis(4-
(methacryloxyethoxy-3,5-dibromophenyl)
Sulfide, bis(4-acryloxypolyethoxy-3
,5-dibromophenyl) sulfide, bis(4-methacryloxypolyethoxy-3,5-dibromophenyl)
Sulfite, bis(4-7cryloxy-3,5-dichlorophenyl) sulfide, bis(4-methacryloxy-
3,5-dichlorophenyl) sulfide, bis(4-acryloxyethoxy-3°5-dichlorophenyl) sulfite, bis(4-methacryloxyethoxy-3,5-
dichlorophenyl) sulfide, bis(4-acryloxypolyethoxy-3,5-dichlorophenyl) sulfide, bis(4-methacryloxypolyethoxy-3,5-
(dichlorophenyl) sulfide, thiodiphenol derivatives such as ethyl rangel glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, nano ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene Glycol dimethacrylate, tetraethylene glycol dimethacrylate, nano ethylene glycol dimethacrylate, 1.4
-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate,
1,6-hexanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate,! , lO-decanediol diacrylate, 1
．． 10-decanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate,
aliphatic alcohol derivatives such as; monomers having an allyl group include bisallyl terephthalate, bisallyl isophthalate, triallyl trimellitate, bisallyl diphenate, bis(allyloxycarbonylmethyl terephthalate); ) ester, 5゜5'-dimethylbiphenyl-3,3'-dicarboxylic acid allyl ester, 1,9-dimethoxynaphthalene-3,7
-dicarboxylic acid allyl ester, 1,1'-dimethyldiphenylmethane-3,3'-dicarboxylic acid allyl ester, polyvalent allyl ester of nato; monomers having an allyl carbonate group include 1,3-benzene allyl carbonate , 1.4-naphthalene bisallyl carbonate, 1.5-naphthalene bisallyl carbonate, 1.6
-Naphthalene bisallyl carbonate, 1,7-naphthalene bisallyl carbonate, 2,6-naphthalene bisallyl carbonate, 2,7-naphthalene bisallyl carbonate, 4,4'-diphenylpropane bisallyl carbonate, 4,4'-diphenyl Examples include compounds such as polyvalent allyl carbonates such as sulfone bisallyl carbonate and diethylene glycol bisallyl carbonate.

Further, the present invention further provides a third monomer having one radically polymerizable functional group containing a carbon-carbon double bond in the molecule regardless of its type, in the transparent resin composition for optical materials. The third monomer, which may be contained in an amount of up to 30% by weight, is suitably used, for example, when it is desired to adjust the refractive index of the resin or to improve the impact resistance and heat resistance of the resin.

Specifically, the third monomer compound is styrene, 4-
Chlorostyrene, dichlorostyrene, bromostyrene,
Monomers with vinyl groups such as dipromostyrene, N
- maleimide derivatives such as phenylmaleimide, N-(2-chlorophenylmaleimide), N-cyclohexylmaleimide, N-diethylphenylmaleimide, N-dimethylphenylmaleimide, phenyl acrylate,
Phenyl methacrylate, chlorophenyl acrylate, chlorophenyl methacrylate, dichlorophenyl acrylate, dichlorophenyl methacrylate, trichlorophenyl acrylate, trichlorophenyl methacrylate, bromophenyl acrylate, bromophenyl methacrylate, dibromophenyl acrylate, dibromophenyl methacrylate, tribromophenyl acrylate, tribromophenyl methacrylate, a
Lophenoxyethyl acrylate, dichlorophenoxyethyl acrylate, trichlorophenoxyethyl acrylate, chlorophenoxyethyl methacrylate, dichlorophenoxyethyl methacrylate, tricumylophenoxyethyl methacrylate, bromophenoxyethyl acrylate, dibromophenoxyethyl acrylate, tribromophenoxyethyl acrylate, bromophenoxy Methacrylate derivatives with aromatic rings such as ethyl methacrylate, dibromophenoxyethyl methacrylate, tribromophenoxyethyl methacrylate, benzyl acrylate, benzyl methacrylate, bromobenzyl acrylate, dibromobenzyl acrylate, bromobenzyl methacrylate, dibromobenzyl methacrylate, methyl acrylate, methyl Methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, pentyl acrylate, penty methacrylate, octyl acrylate, octyl methacrylate, dodecyl acrylate, dodecyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, aliphatic methacrylate derivatives such as cyclohexyl acrylate, cyclohexyl methacrylate, bornyl acrylate, bornyl methacrylate, dicyclopentenyl acrylate, dicyclopentenyl methacrylate, alicyclic compound derivatives, allyl benzoate, Examples include allyl naphthalenecarboxylate, phenyl acrylic carbonate, and benzyl allyl carbonate.

In the present invention, at least one type of first monomer represented by the above general formula (1) and at least two radically polymerizable functional groups containing a carbon-carbon double bond in the molecule, regardless of their types, are used. at least one type selected from the second monomers having the following properties, and optionally a third monomer having one radically polymerizable functional group containing a carbon-carbon double bond in the molecule regardless of its type. A monomer mixture containing at least one selected monomer at a specific ratio is polymerized in the presence of a polymerization initiator.

In the present invention, the total number of OH groups (number of moles
2) is 0.0 of the value of the total number of functional groups (number of moles x number of functional groups) of the second monomer. It is suitable to set it as 1 to 0.99 times, preferably to set it as 0.2 to 0.8 times.

The OH group of the first monomer undergoes an addition reaction with the functional group of the second monomer in the presence of a radical polymerization initiator. Furthermore, the remaining OH
Polymerization continues by addition of the group to the functional group of another molecule.

However, if the number of OH groups in the first monomer is more than 0.99 times the total number of functional groups in the second monomer, the radical polyaddition reaction will not proceed efficiently, and only those with low molecular weight will be used. On the other hand, if the total number of OH groups in the first monomer is less than 0.1 times the total number of functional groups in the second monomer, the content of the first monomer will be small and the present invention will not be obtained. It would be off topic.

Further, the mixture of the present invention may contain at least one type of third monomer in a total amount of 0 to 30% by weight, as described above, and the content of the third monomer exceeds 30% by weight. In this case, the crosslinking density of the resin obtained by polymerization becomes low, making it impossible to achieve the object of the present invention.

The method of polymerizing the resin composition of the present invention is not particularly limited, and any known polymerization method can be employed. For example, the composition can be produced by heating the mixed solution in the presence of a polymerization initiator between molds held by gaskets or spacers, but the composition can also be produced by photopolymerization or radiation polymerization.

Moreover, it can also be produced by a reaction injection molding method (RIM) by selecting the type and type of polymerization initiator, and is not limited to a specific polymerization method.

The polymerization initiator used here is not particularly limited, and known ones can be used. Examples of the polymerization initiator used during thermosetting include 2.2'-azobis(4-
methoxy-2,4-dimethylvaleronitrile), 2.2
'-Azobis(2-cyclobutavirpropionitrile)
, 2.2'-azobis(2,4-dimethylvaleronitrile), 2.2'-azobis(2-methylpropionitrile), 2,2'-azobis(2-methylbutyronitrile), 1,1゛-azobis(cyclohexane-1-carbonitrile), 2-phenyrazoq-methoxy-2,4
-dimethylvaleronitrile), 2,21-azobis(2
, 4,4-trimethylpentane), 2,2'-azobis(2-methylpropane), dimethyl 2,2'-azobis(2-methylpropionate), or t-butylperoxyisopropionate. building carbonate,
cumyl peroxyoctoate, t-butylperoxyisobutyrate, t-butylperoxypivalate, t
- Peroxy esters such as butyl peroxy (2-ethylhexanoate), peroxy dicarbonates such as diisopropyl peroxy dicarbonate, similystyl peroxy dicarbonate, benzoyl peroxide, 3.3,5-) Diacyl peroxides such as ethylhexanoyl peroxide and isobutyryl peroxide, dialkyl peroxides such as dicumyl peroxide and di-t-butyl peroxide, dipropylbenzene hydroperoxide, and t-butyl hydroperoxide. Hydroperoxides such as oxides, 1,1. Examples include peroxyketals such as -bis(t-butylperoxy)cyclohexane, ketone peroxides such as cyclohexanone peroxide and methyl ethyl ketone peroxide, and other peroxides. Furthermore, it is preferable to use an azo compound as the polymerization initiator used for thermosetting from the viewpoint of coloring the resin, and when curing with ultraviolet rays,
Examples of the initiator include, but are not limited to, benzoin isopropyl ether, benzophenone, benzoin isobutyl ether, acetophenone, and the like.

Furthermore, known cationic polymerization initiators, anionic polymerization initiators, etc. other than radical polymerization initiators can also be used.

The amount of the polymerization initiator is usually 0.001 based on the monomer.
~10% by weight, preferably 0.01~5% by weight.

The type and concentration of the polymerization initiator used are determined in consideration of the composition of the monomer mixture, reactivity, reaction rate control, etc.

In addition, the resin composition of the present invention may contain an ultraviolet absorber of 0.01 to improve its light resistance and weather resistance, if necessary.
It is desirable to contain up to 3.0% by weight. If the concentration of ultraviolet absorber is less than 0°01!1%, the light resistance will be extremely low.
It has almost no effect on improving weather resistance, and if it exceeds 3.0%, yellow coloring becomes noticeable and the commercial value tends to decrease.

The UV absorbers used in the present invention include a wide range of UV absorbers such as benzotriazole, benzophenone, salicylic acid, and cyanoacrylate, as well as hindered amine, Ni complex, and benzoate UV stabilizers.

Furthermore, during polymerization, mold release agents, antioxidants,
Additives such as antistatic agents and various stabilizers, and bluing agents may be contained.

Furthermore, the surface of the resin molded article of the present invention can be coated in order to improve its optical and mechanical stability.

[Effect]

The resin composition obtained by the present invention has transparency, surface properties,
It has excellent surface hardness, heat resistance, impact resistance, and processability, and also has a higher refractive index than CR-39, making it extremely excellent as a resin for optical materials.

Examples of the optical materials include so-called lens necks such as eyeglass lenses and camera materials, prisms, disks such as video disks, mirrors such as concave mirrors and polygons, and optical fibers.

〔Example〕

Next, the present invention will be described in detail, but the present invention is not limited thereto.The test methods for each characteristic were performed as follows.

Transparency: Visually observed high transparency was rated as good (0), slightly good was rated as fair (△), and poor was rated as poor (x).

Refractive index and Atsube number: Measured using an Atsube refractometer.

Processability: Those with a good polished surface after grinding with a beading machine for eyeglass lens processing were rated as good (0), those with a slightly good surface were rated as slightly good (Δ), and those with poor surfaces were rated as poor (X).

Impact resistance: A steel ball drop test was performed on a concave material with a center thickness of 2 mII+ according to the FDAM rating, and those with no cracks were rated Good (○), those with slight cracks were rated Fair (Δ), and those with cracks were rated Poor (X). ).

hardness: Measured by pencil hardness.

Example 1 30 parts by weight of 2,2'-bis(4-hydroxyphenyl)propane as the first monomer, 70 parts by weight of tetraethylene glycol dimethacrylate as the second monomer, and as a radical polymerization initiator, A mixed solution consisting of 1.5 parts by weight of dimethyl 2,2'-azobis(2-methylpropionate) was poured into a mold assembled with a glass mold, ethylene-vinegar, and a copolymer gasket, and was heated for 20 hours. It was heated from 40°C to 90°C. The lens thus obtained was transparent and had good processability, impact resistance, and surface hardness as shown in Table 1.

Examples 2 to 7 Polymerization was carried out in exactly the same manner as in Example 1 to obtain transparent lenses of various compositions. The results are shown in Table 1.

Comparative Example 1 A mixed solution consisting of 30 parts of diethylene glycol, 7 oam parts of tetraethylene glycol dimethacrylate, and 1.5 parts by weight of dimethyl 2,2''-azobis(2-methylpropionate) as a radical polymerization initiator, The lens was poured into a mold prepared in the morning using a glass mold and an ethylene-vinyl acetate copolymer gasket, and heated from 40° C. to 90° C. over 20 hours.The lens thus obtained was milky white.

Claims (4)

[Claims] (1) General formula (I) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X represents a chlorine atom, bromine atom, methyl group, ethyl group, or other alkyl group, and Y represents a CH CH
3, -SO2-, -S-, Z is H or CH
3, a represents an integer from 0 to 4, and b represents 0 or 1.
and n represents an integer of 0 to 4), and a second monomer having at least two radically polymerizable functional groups containing a carbon-carbon double bond in the molecule. a mixture containing at least one type of OH groups in the first monomer such that the total number of OH groups in the first monomer is 0.1 to 0.99 times the value of the total number of functional groups in the second monomer. , a resin composition for optical materials which is copolymerized in the presence of a radical polymerization initiator. (2) The functional group of the second monomer is a vinyl group, (meth)
The resin composition for optical materials according to claim 1, which is an acrylic group, an allyl group, or an allyl carbonate group. (3) The mixture further contains at least one type of third monomer having one radically polymerizable functional group containing a carbon-carbon double bond in the molecule regardless of its type. A resin composition for optical materials according to item 1. (4) The functional group of the third monomer is a vinyl group, (meth)
4. The resin composition for optical materials according to claim 3, which is an acrylic group, an allyl group, or an allyl carbonate group, and the mixture contains 0 to 30% by weight of a third monomer.