JPH051116A - Resin for optics - Google Patents

Abstract

PURPOSE:To obtain the resin useful for lenses, etc., having high refractive index and Abbe's number, excellent transparency, heat resistance and impact resistance by polymerizing and curing an addition reaction product of p-vinylbenzyl acrylate, etc., and 4,4'-thiobenzenethiol. CONSTITUTION:p-Vinylbenzyl acrylate, etc., is made to react with 4,4' thiobenzenethiol, etc., in the presence of a basic catalyst such as triethylamine in a solvent such as toluene under heating to give an unsaturated molecular weight sulfur compound shown by the formula [R is CH2, CH2CH or CH(CH3) CH2]. Then, this compound is used alone or mixed with divinylbenzene, etc., and tertiary butylperoxybenzoate as a radical polymerization initiator to give a polymerizable composition, which is fed to a space between two sheets of glass molds, polymerized and cured under heating at 80 deg.C for 6 hours or at 100 deg.C for 3 hours to give the objective resin for optics having >=1.55 refractive index, high Abbe's number and small optical strain.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical resin, and more particularly to an optical resin having excellent optical properties such as refractive index and transparency and various mechanical properties.

[0002]

2. Description of the Related Art In recent years, synthetic resin materials excellent in light weight, moldability, impact resistance and dyeability have been used as lens materials instead of inorganic glass. Known examples of the synthetic resin material include polymethyl methacrylate, polydiethylene glycol bisallyl carbonate, polystyrene, and polycarbonate. However, although the polymethylmethacrylate and polydiethyleneglycolbisallylcarbonate are excellent in lightness and impact resistance, they have a low refractive index of about 1.49, so that when used as a lens, a thicker lens than inorganic glass is required. However, it is not suitable for high magnification and light weight. Further, although the polystyrene and polycarbonate have a high refractive index of about 1.58 to 1.59, they are thermoplastic resins and therefore have a problem that optical distortion due to birefringence is likely to occur during injection molding. There are drawbacks such as lack of solvent resistance and scratch resistance.

Therefore, recently, some technical proposals have been made to improve the above-mentioned conventional drawbacks with a high refractive index. For example, in JP-A-53-7787, a copolymer of diethylene glycol biscarbonate and diallyl isophthalate is disclosed in JP-A-59-8131.
No. 8 discloses a copolymer of diallyl phthalate and unsaturated fatty acid alcohol benzoate.
Japanese Patent No. 191708 proposes a copolymer of di (meth) acrylate having bisphenol A and diallyl isophthalate with diethylene glycol bisallyl carbonate, and the like. Has a low refractive index of 1.52 to 1.56, and has a problem that unreacted allyl monomer is likely to remain due to the difference in copolymerizability.

Further, JP-A-57-28115 discloses that
As a copolymer of a styrene derivative and a heavy metal salt of unsaturated carboxylic acid, JP-A-60-55007 proposes a copolymer of a nuclear halogen-substituted diallyl phthalate and a nuclear halogen-substituted allyl benzoate. However, the above-mentioned copolymer has a high refractive index of 1.58 to 1.60, but since it uses a monomer containing a heavy metal salt or a halogen, it has a large specific gravity, which makes the lens heavy and the lens lightweight. There is a problem that it is difficult to make it.

Further, in JP-A-55-13747, nuclear halogen-substituted styrene, di (meth) acrylate having bisphenol A, benzyl methacrylate monomer, and phenol methacrylate monomer. And the like is a copolymer of hydroxydi (meth) acryl having an aromatic ring in JP-A-59-133211.
A copolymer of a diisocyanate-based monomer and a styrene-based monomer has been proposed. In this copolymer, although the refractive index is as high as 1.60, it is difficult to control the polymerization reaction, It has poor weather resistance and high specific gravity.

[0006]

Therefore, an object of the present invention is to have a desirable refractive index, transparency, etc. for plastic lenses or other optical resins, and to have excellent weather resistance, solvent resistance, impact resistance, etc. Another object is to provide an optical resin having a low specific gravity.

[0007]

According to the present invention, an optical product obtained by polymerizing and curing a polymerizable composition containing an organic sulfur compound represented by the following general formula 2 (hereinafter referred to as organic sulfur compound A) A resin is provided.

[0008]

[Chemical 2]

The present invention will be described in more detail below.

The optical resin of the present invention is characterized by containing a specific organic sulfur compound as an essential raw material monomer as a polymerizable composition to be polymerized and cured.

The specific organic sulfur compound used in the optical resin of the present invention is the organic sulfur compound A represented by the general formula 2.

Specific examples of the organic sulfur compound A are compounds represented by the following chemical formulas (3), (4), (5), (6), (7) and (8), and they may be used alone or as a mixture. You can

[0013]

[Chemical 3]

[0014]

[Chemical 4]

[0015]

[Chemical 5]

[0016]

[Chemical 6]

[0017]

[Chemical 7]

[0018]

[Chemical 8]

To prepare the organic sulfur compound A, for example, P-vinylbenzyl acrylate and 4,4'-thiobenzenethiol are combined with a base such as triethylamine, trimethylamine, sodium methylate, etc. It can be easily obtained by reacting at 0 to 80 ° C. for 30 minutes to 48 hours in the absence of a solvent or in a solvent such as benzene or toluene in the presence of a strong catalyst.

The blending ratio of the organic sulfur compound A in the polymerizable composition is not particularly limited,
It is preferably in the range of 20 to 100% by weight. If the blending ratio is less than 20% by weight, a sufficient refractive index cannot be obtained, which is not preferable.

Further, in the present invention, examples of the raw material monomer other than the organic sulfur compound A which can be used as the raw material component of the polymerizable composition include, for example, styrene, p-methylstyrene, p-chlorostyrene and o-chloro. Styrene, p-bromostyrene, o-bromostyrene, α-methylstyrene, vinyl acetate, vinyl propionate, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, phenyl acrylate, phenyl methacrylate, benzyl acrylate,
Benzyl methacrylate, bromphenyl methacrylate, acrylonitrile, methacrylonitrile, 2,2-
Bis (4- (meth) acryloyloxyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxypolyethoxyphenyl) propane, 2,2-bis (4-2'-hydroxy-3 '-( (Meth) acryloxypropoxyphenyl) propane, diethyleneglyco-
Rubisallyl carbonate, diallyl tetrachlorophthalate, diallyl phthalate, p-divinylbenzene, m
-Divinylbenzene, divinylbiphenyl, ethylene glycol bis (meth) acrylate, diethylene glycol bis (meth) acrylate, polyethylene glyco-
Rubis (meth) acrylate, dipropylene glycol bis methacrylate, triethylene glycol bis acrylate, tetraethylene glycol bis (meth) acrylate, bisphenol A bis (meth) acrylate
, Diallyl isophthalate, allyl methacrylate,
Preferable examples include propylene glycol bisacrylate and the like.

The high refractive index optical resin of the present invention can be prepared, for example, by heat-polymerizing or copolymerizing each of the raw material monomers in the presence of a radical polymerization initiator. As the radical polymerization initiator, an organic peroxide or an azo compound having a 10-hour half-life temperature of 160 ° C. or lower can be used, and specific examples thereof include benzoyl peroxide, diisopropyl peroxydicarbonate, and tert-butyl. Peroxy-2-ethylhexanoate, tert-butyl peroxypivalate, tert-butyl peroxydiisobutyrate, lauroyl peroxide, tert-butyl-peroxyacetate, tert-butyl peroxyoctoate, tert-butyl peroxybenzoate, Azobisisobutyronitrile and the like can be mentioned, and when used, they can be used alone or as a mixture. The amount of the radical polymerization initiator used is preferably 1 based on 100 parts by weight of the total charged polymerizable composition.
It is 0 part by weight or less, particularly preferably 5 parts by weight or less.

In order to carry out the heat polymerization or copolymerization, for example, the polymerizable composition and the radical polymerization initiator are directly charged in a desired mold, preferably 0 to 200 ° C., 1 to 4
It can be polymerized by heating for 8 hours. At this time, the polymerization system is preferably carried out in an atmosphere of an inert gas such as nitrogen, carbon dioxide or helium. In addition, before the polymerization, the polymerizable composition is, for example, 0 to 20.
After prepolymerization at 0 ° C. for 0.5 to 48 hours, it is possible to charge in a desired mold and post-polymerize.

Further, additives such as UV absorbers, anti-coloring agents and dyeing accelerators may be added to the polymerizable composition as required. Further, for the purpose of improving the surface properties of the cured product, various surface treatments can be performed after the curing.

[0025]

INDUSTRIAL APPLICABILITY The optical resin of the present invention has a refractive index of 1.55 or more and a high Abbe number, has a small optical strain, and has optical transparency, heat resistance, solvent resistance and impact resistance. Is also excellent, and further, the specific gravity is small and the weight can be reduced.
Further, since reaction control and molding at the time of curing and polymerization are easy, it is useful as a plastic lens such as a lens for glasses, a camera lens, an optical material, or other optical resin material.

[0026]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[0027]

Example 1 To 9 g of the organic sulfur compound shown in Table 1 and 1 g of divinylbenzene, 0.05 g of tertiary butyl peroxybenzoate was added and mixed to obtain a polymerizable composition.
Then, after charging the polymerizable composition into two glass molds, the composition was placed in a thermostat at 80 ° C., heated at a curing temperature of 80 ° C. for 6 hours, and further heated to 100 ° C. in 3 hours, Finally, it 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 the refractive index, Abbe number, b *
The value and heat resistance were measured according to the following methods. The results are shown in Table 1.

Refractive index and Abbe number: An Abbe refractometer (manufactured by Atago Co., Ltd.) was used, and measurement was carried out using a methyl iodide saturated solution as an intermediate solution.

B * value (yellowness): measured using a photometer model 1001 manufactured by Nippon Denshoku Industries Co., Ltd. The smaller this value, the smaller the yellowness and the better.

Heat resistance: A sample having no deformation or discoloration in an oil bath at 130 ° C. was evaluated as ◯, and a sample having deformation or discoloration was evaluated as x.

[0031]

Examples 2 to 4 Cured resins were prepared in the same manner as in Example 1 except that the polymerizable compositions shown in Table 1 were used, and each measurement was performed. The results are shown in Table 1.

[0032]

[Table 1]

[0033]

Comparative Examples 1 to 3 Cured resins were prepared in the same manner as in Example 1 except that the compounds shown in Table 2 were used as raw material monomers, and each measurement was performed. The results are shown in Table 2.

[0034]

[Table 2]

Claims (1)

1. An optical resin obtained by polymerizing and curing a polymerizable composition containing an organic sulfur compound represented by the following general formula 1. [Chemical 1]