JPH0411612A - High-refractive index optical resin - Google Patents

Abstract

PURPOSE:To obtain an optical resin having an excellent transparency and a high refractive index and being useful for plastic lenses for glasses, etc., by polymerizing a starting monomer containing a specified organosulfur compound. CONSTITUTION:A resin obtained by polymerizing a starting monomer containing an organosulfur compound of formula I [wherein R1 is H or methyl; and R2 is S or a group of formula II (wherein X is O or S; R3 is alkylene; and m is 0-3)]. The organosulfur compound can easily be obtained by, for example, coupling the corresponding diol compound with 2-chloroethyle acrylate or 2- chloroethyl methacrylate in a suitable solvent. The proportion of the organosulfur compound in the starting monomer is desirably in the range of 50-100wt.%. When the organo-sulfur compound is used in an amount of 1-30wt.%, the obtained resin can be used as a high-performance crosslinking agent having a high refractive index.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to an optical resin, and more specifically, to a high refractive index optical resin that has excellent transparency and a high refractive index, and is useful for plastic lenses for glasses. Regarding resin for use.

<Prior Art> In recent years, synthetic resin materials, which are lightweight, easy to mold, have excellent impact resistance, and dyeability, have been used as optical materials such as plastic lenses in place of inorganic glass. As the synthetic resin material, for example, polymethyl methacrylate, polydiethylene glycol bisallyl carbonate, polystyrene, and polycarbonate are known. However, although polymethyl methacrylate and polydiethylene glycol bisallyl carbonate are themselves lightweight and have excellent impact resistance, they have a low refractive index of about 1.49, so when used as lenses, they are difficult to use compared to inorganic glass. The drawback is that it requires a thick lens, making it unsuitable for high magnification and weight reduction. In addition, the refractive index of polystyrene and polycarbonate is 1.58 to 1.58.
Although it is high at around 1.59, since these are thermoplastic resins, they have the problem of being prone to optical distortion due to birefringence during injection molding, and have other drawbacks such as poor solvent resistance and scratch resistance. be.

Recently, various technical proposals have been made to improve these conventional drawbacks. For example, JP-A-53-7
No. 787 discloses a copolymer of diethylene glycol biscarbonate and diallylisophthalate,
No. 9-81318 discloses a copolymer of diallyl phthalate and unsaturated fatty acid alcohol benzoate, and JP-A-59-191708 discloses a di(meth)acrylate containing bisphenol A, diallyl isophthalate and diethylene glycol. Copolymers with bisallyl carbonate and the like are disclosed.

However, all of the optical resins proposed above have a problem in that they have a low refractive index of 1.52 to 1.56 and that unreacted allyl monomers tend to remain.

Further, in JP-A-57-28115, a copolymer of a styrene vinyl monomer and an unsaturated carboxylic acid heavy metal salt is disclosed, and in JP-A-60-55007, a halogen-substituted diallyl phthalate and a halogen-substituted Copolymers with allyl benzoate have been proposed, but although these have a high refractive index of about 1.58 to 1.60, the specific gravity of the polymer is large and has the disadvantage that it is impossible to reduce the weight of lenses etc. .

Further, in JP-A No. 55-13747, a copolymer of halogen-substituted styrene, di(meth)acrylate containing bisphenol A, benzyl methacrylate monomer, and phenol methacrylate monomer is disclosed in JP-A-59-133211. , hydroxyl (meth)acrylate having an aromatic ring, copolymers of diisocyanate compounds and styrene monomers have been proposed, but these resins have a refractive index of 1.6.
Although it is high, around 0, it has the disadvantages that it is difficult to control the polymerization reaction, the specific gravity of the polymer is large, and there are problems with weather resistance.

<Problems to be Solved by the Invention> An object of the present invention is to provide a resin that has desirable optical transparency as a resin for plastic lenses or other optical applications, has excellent weather resistance, solvent resistance, and impact resistance, and further has The object of the present invention is to provide a high refractive index optical resin having a low specific gravity.

<Means for Solving the Problems> According to the present invention, the following general formula (I) can be carried out, [wherein R□ represents a hydrogen atom or a methyl group, and R2 represents a sulfur atom or -8-( An organic sulfur compound represented by -R,X-)-, R35- (wherein, A high refractive index optical resin obtained by polymerizing a raw material monomer containing the following is provided.

The present invention will be explained in more detail below.

The high refractive index optical resin of the present invention is characterized by containing a specific organic sulfur compound as an essential raw material monomer, preferably exhibits a high refractive index of 1.60 or more, and has excellent physical properties. It is resin.

In the present invention, the organic sulfur compound used as an essential raw material monomer is represented by the following general formula (I), where R□ represents a hydrogen atom or a methyl group, and R2 represents a sulfur atom or -
1-R, If m exceeds 3, manufacturing is difficult. Examples of the organic sulfur compounds include the following, and they can be used alone or as a mixture.

The organic sulfur compound can be easily prepared by, for example, coupling a corresponding dithiol compound with 2-chloroethyl acrylate or 2-chloroethyl methacrylate in an appropriate solvent.

Further, the blending ratio of the organic sulfur compound in the raw material monomer is not particularly limited, but is preferably in the range of 1 to 100% by weight, particularly preferably 50 to 100% by weight, based on the entire raw material monomer. Furthermore, when the organic sulfur compound is blended in an amount of 1 to 30% by weight, it can also be used as a high-performance crosslinking agent having a high refractive index.

In the present invention, monomers other than the organic sulfur compound that can be used as raw material monomer components include, for example, styrene, P-methylstyrene, p-chlorostyrene, 0-chlorostyrene, p-bromstyrene, 0-
Bromstyrene, vinyl acetate, vinyl propionate, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, phenyl methacrylate, phenyl acrylate, benzyl acrylate,
Benzyl methacrylate, bromphenyl methacrylate, acrylonitrile, methacrylate trile, 2,2-
Bis(4-methacryloyloxyethoxyphenyl)propane, 2,2-bis(4-acryloyloxyethoxyphenyl)propane, diethylene glycol bisallyl carbonate, diallyl tetrachlorophthalate, diallyl phthalate, P-divinylbenzene, □-divinylbenzene, Divinylbiphenyl, ethylene glycol bis methacrylate, diethylene glycol bis methacrylate, ethylene glycol bis acrylate, diethylene bis acrylate, dipropylene glycol bis methacrylate, triethylene glycol bis acrylate, tetraethylene glycol bis acrylate, bisphenol A bis methacrylate, diallyl tetrachlorphthalate, Preferred examples include diallyl isophthalate, allyl methacrylate, propylene glycol bisacrylate, hexaethylene glycol bisacrylate, octaethylene glycol bisacrylate, and decaneethylene glycol bisacrylate.

The high refractive index optical resin of the present invention can be prepared, for example, by heating or copolymerizing the raw material monomers described above in the presence of a radical polymerization initiator. The radical polymerization initiator has a 10-hour half-life temperature of 160° C.
Organic peroxides or azo compounds having a temperature of 0.degree. Barate, tert-butyl peroxydiisobutyrate, lauroyl peroxide, t-butyl peroxy acetate, tert-peroxy octoate, tert-butyl peroxybenzoate, azobisisobutyronitrile, etc. may be used alone or as a mixture. It can be used as The amount of the radical polymerization initiator used is preferably 10 parts by weight or less, particularly preferably 5 parts by weight or less, based on 100 parts by weight of the raw material.

In order to carry out the thermal polymerization or copolymerization, for example, the raw materials and the radical polymerization initiator are directly charged into a desired mold, and polymerized by heating preferably at 0 to 200°C for 1 to 48 hours. I can do it. At this time, the polymerization is preferably carried out under an atmosphere of an inert gas such as nitrogen, carbon dioxide, or helium. Moreover, before the polymerization,
It is also possible to prepolymerize the raw material monomers, for example, at 0 to 200°C for 0.5 to 48 hours, and then charge them into a desired mold for post-polymerization.

In addition, additives such as UV absorbers and anti-coloring agents can be added to these raw material monomers as necessary, and various surface treatments can be applied after curing to improve the surface properties of the cured product. It can also be applied.

<Effects of the Invention> The high refractive index optical resin of the present invention has a high refractive index of 1.60 or more, low optical distortion, optical transparency, heat resistance, and solvent resistance. It has excellent impact resistance, and has a low specific gravity, allowing for weight reduction. In addition, since reaction control during curing and polymerization and molding are easy, it is useful as a resin material for plastic lenses such as eyeglass lenses, camera lenses, and optical materials, or for other optical applications.

<Examples> Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

1"L 0.05g of tert-butyl peroxybenzoate was mixed with a raw material monomer consisting of compound (I) shown by the following structural formula and 6g of styrene,
A monomer composition was prepared.

Next, the monomer composition was placed in two glass molds, placed in a constant temperature bath at 80°C, heated at a curing temperature of 80°C for 6 hours, and then raised to 100°C in 3 hours to finalize. The mixture was heated at 100°C for 3 hours. Finally, an annealing treatment was performed at 100° C. for 2 hours to obtain a cured resin. The obtained cured resin was taken out from the mold, and its refractive index, Abe's number, and transparency were measured according to the following methods. The results are shown in Table 1.

・Refractive index and Atsbe number: Measured using an Atsbe refractometer (manufactured by Atago Co., Ltd.) ・Transparency: When observed with the naked eye, those that are transparent are rated O, and those that are slightly cloudy are rated △. did.

1. Instead of the raw material monomer of Example 1, a raw material monomer (Example 4) consisting of 80 parts by weight of compound (2) shown by the following structural formula and 10 parts by weight of benzyl methacrylate,
A raw material monomer (Example 5) consisting of 80 parts by weight of compound (5) represented by the following structural formula and 20 parts by weight of methyl methacrylate was mixed with compound (6) represented by the following structural formula.
A raw material monomer (Example 2) consisting of 80 parts by weight and...(2) 20 parts by weight of P-chlorostyrene was converted into compound (3) 8 shown by the following structural formula.
A raw material (Example 6) consisting of 0 parts by weight and 20 parts by weight of methyl methacrylate was converted into a compound (7) represented by the following structural formula.
A raw material monomer (Example 3) consisting of 100 parts by weight and 20 parts by weight of p-chlorostyrene was converted into a compound (4) 9 represented by the following structural formula.
0 parts by weight and O C) I2 sum HCOCH, CH β 2 CH2
0CH, C12 Father H2CH, 0 Engineering H=CH2...(4
) A cured resin was prepared in the same manner as in Example 1, except that the raw material monomers (Example 7) consisting of the following were used, and each measurement was performed. The results are shown in Table 1.

Comparative Examples 1 and 2 A cured resin was prepared in the same manner as in Example 1, except that the raw material monomers shown in Table 2 were used, and each measurement was performed.

The results are shown in Table 2.

(Margin below)

Claims (1)

[Claims] The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, R_1 represents a hydrogen atom or a methyl group, and R_1 represents a hydrogen atom or a methyl group;
2 is a sulfur atom or ▲There are mathematical formulas, chemical formulas, tables, etc.▼
(where X represents an oxygen atom or a sulfur atom, R_3 represents an alkylene group, and m represents an integer of 0 to 3)] obtained by polymerizing a raw material monomer containing an organic sulfur compound represented by High refractive index optical resin.