JPH04173813A - Resin for optical science - Google Patents

Abstract

PURPOSE:To obtain the title resin useful for lens for glasses, having high refractive index (>=1.55), small chromatic aberration, small optical strain, excellent in optical transparency, solvent resistance, impact resistance with small specific gravity by polymerizing a raw material monomer containing a specific organic sulfur compound. CONSTITUTION:A raw material monomer containing preferably 60-90wt.% organic sulfur compound shown by the formula is polymerized to give the objective resin. Styrene, vinyl acetate, methyl methacrylate, phenyl acrylate or acrylonitrile may be cited as the raw material monomer except the organic sulfur compound.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an optical resin, and more particularly to an optical resin that is excellent in optical properties such as refractive index, chromatic aberration, and transparency, and various mechanical properties.

<Prior Art> In recent years, synthetic resin materials that are lightweight, easy to mold, have excellent impact resistance, dyeability, etc. have been used as lens materials instead of inorganic glass. As the synthetic resin material, for example, polymethyl methacrylate, polydiethylene glycol bisallyl carbonate, polystyrene, and polycarbonate are known. Although the polymethyl methacrylate and polydiethylene glycol bisallyl carbonate have excellent lightness and impact resistance, their refractive index is as low as about 1.49, so when used as a lens, a thicker lens is required compared to inorganic glass. The drawback is that it is not suitable for high magnification and weight reduction.

In addition, although polystyrene and polycarbonate have a high refractive index of about 1.58 to 1.59, since they are thermoplastic resins, they have the problem of easily causing optical distortion due to birefringence during injection molding. It has drawbacks such as poor solvent resistance and scratch resistance.

Recently, several technical proposals have been made to improve these conventional drawbacks with high refractive index. For example, JP-A-1-309002 discloses a plastic lens made by curing a distyryl-type organic sulfur compound and a trivalent or tetravalent thiol compound; Furthermore, a sulfur-containing plastic lens is produced by mixing and curing a compound having 1.3 or more vinyl groups on a molar average and a compound having 1.1 or more thiol groups on a molar average in a specific ratio. JP-A No. 2-58001 proposes a high refractive index optical resin obtained by reacting a dimercaptobenzene nuclear substitute with a compound having at least two reactive unsaturated groups per molecule. .

<Problems to be Solved by the Invention> However, although the above-mentioned optical resins have a high refractive index, they have problems in terms of chromatic aberration, and furthermore, the thiol compounds used as raw materials have a strong odor and are poor in handling.
There are also problems with the working environment.

Therefore, an object of the present invention is to create a resin that has desirable refractive index, chromatic aberration, transparency, etc. as a resin for plastic lenses or other optical applications, has excellent various mechanical properties, is low odor, and has excellent handling properties during curing. The object of the present invention is to provide a resin for optical use.

<Means for Solving the Problems> According to the present invention, there is provided an optical resin obtained by polymerizing a raw material monomer containing an organic sulfur compound represented by the following structural formula.

The present invention will be explained in more detail below.

The optical resin of the present invention is characterized by containing an organic sulfur compound represented by the following structural formula as an essential raw material monomer.

To prepare the organic sulfur compound 1 For example, 2 molar equivalents of divinylbenzene and 1 molar equivalent of 4,4'-thiobisbenzenethiol are used, preferably benzene, toluene, etc. as a solvent, preferably at a reaction temperature of -20°C. ～+
It can be easily obtained by reacting at 100°C, preferably for 30 minutes to 48 hours.

In the present invention, the blending ratio of the organic sulfur compound is preferably 1 to 90% by weight based on the entire raw material monomer, and particularly preferably, a sufficient refractive index of 1.60 or more can be obtained. A desirable range is 60 to 90% by weight. When the blending ratio of the organic sulfur compound is less than 1% by weight, optical effects such as refractive index and Atsube's number are lowered, and when it exceeds 90% by weight, mechanical strength is lowered, which is not preferable. Further, the organic sulfur compound is
When used in a range of 30% by weight, it can also be used as a high-performance crosslinking agent with a high refractive index.

In addition, in the present invention, specific examples of compounds that can be used as raw material monomers other than the organic sulfur compounds include styrene, p-methylstyrene, p-methylstyrene, and p-methylstyrene.
- Chlorstyrene, 0-chlorstyrene, p-bromstyrene, 0-bromstyrene, vinyl acetate, vinyl propionate, methyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, phenyl methacrylate, phenyl acrylate, benzyl methacrylate, benzyl acrylate, 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,
m-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 Preferred examples include isophthalate, allyl methacrylate, propylene glycol bisacrylate, hexaethylene glycol bisacrylate, octaethylene glycol bisacrylate, and decaneethylene glycol bisacrylate.

To prepare the high refractive index optical resin of the present invention, for example,
It can be obtained by heating or copolymerizing each of the raw material monomers in the presence of a radical polymerization initiator.

The radical polymerization initiator has a 10-hour half-life temperature of 16
Organic peroxides or azo compounds having a temperature of 0°C or lower can be used, and specifically, for example, benzoyl peroxide, diisopropyl peroxydicarbonate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy Examples include pivalate, tert-butyl peroxydiisobutyrate, lauroyl peroxide, t-butyl peroxy acetate, tert-peroxy octoate, t-butyl peroxybenzoate, azobisisobutyronitrile, etc. When used alone or Can be used as a mixture. The amount of the radical polymerization initiator used is 10 parts by weight or less, particularly preferably 5 parts by weight or less, based on 100 parts by weight of the total monomers charged.

In order to carry out the thermal polymerization or copolymerization, for example, each of the monomers and a radical polymerization initiator may be directly charged into a desired mold and polymerized by heating preferably at 0 to 200°C for 1 to 48 hours. can. At this time, the polymerization system is
For example, it is desirable to carry out under an inert gas atmosphere such as nitrogen, carbon dioxide, or helium. In addition, before the polymerization, the raw material monomers are heated at 0 to 200°C and 0.5 to 48°C.
After prepolymerizing for a period of time, it can be charged into a desired mold and post-polymerized.

Moreover, additives such as a UV absorber and a coloring inhibitor can be added to these raw material monomers as necessary.

Furthermore, various surface treatments can be performed after curing in order to improve the surface properties of the cured product.

<Effects of the Invention> The optical resin of the present invention has a refractive index of 1.55 or more,
Moreover, it has small chromatic aberration and optical distortion, and is excellent in optical transparency, heat resistance, solvent resistance, and impact resistance, and furthermore, it has a small specific gravity and can be lightweight. Furthermore, there is no bad odor characteristic of sulfur compounds when the monomer composition is charged or cured.

Because the monomer composition has low viscosity, it has excellent handling properties, and reaction control during curing polymerization and molding are easy, so it is suitable for plastic lenses such as eyeglass lenses, camera lenses, optical materials, and other optical applications. Useful as a resin material.

<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.

Divinylbenzene (meta form: para form = 6: 4) 26
0 g (2 moles) and 250 thiobisbenzenethiol
g (1 mol) and 500 g of toluene as a solvent were charged into a reaction vessel and reacted for 24 hours under water cooling. Next, the solvent was removed under reduced pressure to obtain an organic sulfur compound represented by the following structural formula in a yield of 98%.

Organic sulfur compound obtained in the synthesis example (hereinafter referred to as TBT)
3 g of tert-butyl peroxybenzoate was added to the raw material monomers consisting of 3 g and 7 g of methyl methacrylate.
．． 05 g of a monomer composition was obtained. Then 2
After charging the monomer composition into a glass mold,
℃ in a constant temperature bath, heated at a curing temperature of 80℃ for 6 hours, and then raised the temperature to 100℃ in 3 hours, and finally to 100℃.
It was heated for 3 hours. Finally, 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, 5-point value, and heat resistance were measured according to the following methods. The results are shown in Table 1.

-Refractive index and Atsube number: Measurements were performed using an Atsube refractometer (manufactured by Atago Co., Ltd.) and a saturated methyl iodide solution as an intermediate solution.

- 5-point value (yellowness): Measured using Photometer Model 1001 manufactured by Nippon Denshoku Industries Co., Ltd. Note that the smaller this value is, the lower the degree of yellowness is, and the better.

・Heat resistance: Those with no deformation or discoloration in an oil bath at 130°C were rated O1. Those with deformation or discoloration were rated ×.

A cured resin was prepared in the same manner as in Example 1, except that the raw material monomers shown in Table 1 were used each time, and each measurement was performed. The results are shown in Table 1.

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

The results are shown in Table 2.

Claims (1)

[Claims] An optical resin obtained by polymerizing a raw material monomer containing an organic sulfur compound represented by the following structural formula ▲ Numerical formula, chemical formula, table, etc. ▼.