JPH02115217A - Resin composition for optical material - Google Patents

Abstract

PURPOSE:To obtain a resin composition for an optical material for optical disc bases excellent in transparency, heat resistance, humidity resistance and mechanical strengths and being optically homogeneous and lowly birefringent by curing an epoxy resin based on a compound having a specified polycyclic structure. CONSTITUTION:A resin composition for an optical material is produced by curing an epoxy resin based on a compound having a polycyclic structure of the formula. This resin composition is featured in that it is excellent in transparency, heat resistance, humidity resistance and mechanical strengths and is optically homogeneous and lowly birefringent. Therefore, it is very excellent as a resin for an optical material for optical discs. The above compound can be obtained by epoxidizing dicyclopentadiene with an oxidizing agent such as a peroxy acid (e.g., peroxyacetic acid) or a hydroperoxide.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a resin for optical materials, and particularly to digital audio discs and optical memory discs.

[Conventional technology] Note? , digital audio discs and optical discs that record and reproduce information on an information recording layer consisting of an A layer or a light reflective layer, and that reproduce information formed on an information recording layer;
Currently, inorganic glass and synthetic resins are used as substrate materials for magneto-optical disks. However, none of these materials completely satisfy the physical properties required for disks divided by materials, and performance is still not sufficient.

In other words, although inorganic glass has excellent optical properties, it has the drawbacks of being heavy, easily broken (and high manufacturing cost).In addition, as synthetic resins, polycarbonate resin, polymethyl methacrylate resin, and epoxy resin However, although polycarbonate resin has excellent heat resistance, moisture resistance, and impact resistance, it has poor fluidity during molding, so it suffers from anisotropy in density distribution due to molecular chain orientation and residual stress. This causes large birefringence to occur.As a result, it has the drawback of reducing the sensitivity of reading information recorded on the disc and making errors more likely.Polymethyl methacrylate resin is transparent. Although it has a high birefringence and low birefringence, it has high hygroscopicity and low heat resistance, making the disk difficult to use.On the other hand, bisphenol A1 bisphenol F1 is used as an epoxy resin for disk substrates.
By epoxidizing glycidyl ether type and cyclic olefins obtained from novolak resin etc. and epichlorohydrin? A cycloaliphatic type epoxy resin is used. Although these epoxy resins have excellent transparency, glycidyl ether type epoxy resins, which have a benzene ring as their main skeleton, have problems with birefringence, and alicyclic type epoxy resins have problems such as somewhat inferior heat resistance. It has points.

[Problems to be Solved by the Invention] In view of the above circumstances, the present invention provides transparency, heat resistance, moisture resistance,
An object of the present invention is to provide an epoxy resin composition for optical materials that has excellent mechanical strength, is optically homogeneous, and has low birefringence.

[Means for Solving the Problems] The present inventors have conducted extensive studies in order to solve the above problems.

As a result, we found that epoxy resins obtained from jepoxy compounds with specific polyalicyclic structures have excellent transparency, heat resistance, moisture resistance, and mechanical strength, as well as optical homogeneity and low birefringence. We have arrived at the present invention.

That is, the present invention relates to a resin composition for optical materials obtained by curing an epoxy resin containing a compound represented by the following general formula (1) as a main component.

The compound represented by the general formula (1) can be obtained by epoxidizing dicyclopentadiene with an oxidizing agent such as peracids or hydroperoxides. Peracids include performic acid, peracetic acid, perbenzoic acid, trifluoroperacetic acid, etc., hydroperoxides [i is hydrogen peroxide,
Tert-butyl hydroperoxide, cumene peroxide, etc. can be used.

A catalyst can be used if necessary during epoxidation, and in the case of peracids, an alkali such as sodium carbonate or lithium carbonate or an acid such as alpha acid is used. In the case of hydroperoxides, a mixture of molybdic acid or tungstic acid and sodium hydroxide or an organic acid is used for hydrogen peroxide, and a complex of molybdenum or vanadium is used for tertiary-butyl hydroperoxide.

In addition, solvents can also be used, for example in the case of peracetic acid, aromatic compounds, ether compounds, ester compounds,
Ketone compounds etc. can be used.

The reaction temperature is carried out below the decomposition temperature of the epoxidizing agent used, and may be 0 to 70°C for peracetic acid and 20 to 150°C for tert-butyl hydroperoxide/molybdenum dioxide diacetylacetonate system.

Note that the above-described synthesis method is merely an example, and is not necessarily limited to this method.

In the present invention, the resin is cured by light or heat with the addition of an epoxy curing catalyst, curing agent, curing accelerator, etc.

Examples of photocuring catalysts include onium salt compounds of Lewis acid anions, and complexes of photocleavable nranol derivatives and aluminum chelates. Onium salts of Lewis acid anions include aromatic halonium salts such as diaryliodonium salts and diarylbromonium salts.・
Aromatic chalconium salts such as realylsulfonium salts and triarylselenium salts, diazonium salts, and other substances that can be efficiently photocleaved are used. Lewis acids that form salts with onium ions, such as ClO4-, B
There are F4-, PF6-, AsF65bF6-, etc.

Photocleavable silanol derivative-aluminum chelate)
(In the combined compound, silanol is derivatized with 0-nitrobenzyl alcohol, trialkylmethane hydroperoxide, etc. as a photocleavable silanol derivative.
-Nitrobenzylsilyl ether, trialkylmethanesilyl peroxide, etc. are used. As the aluminum chelate, aluminum tris acetoacetate chelate such as aluminum tris ethyl acetoacetate, aluminum tris-0-carbonylphenol chelate such as aluminum tris salicylaldehydate, aluminum tris acetylacetone chelate, etc. are used.

The amount of the photocuring catalyst used is 0.01 to 5 parts by weight, preferably 0.01 to 1 part by weight, per 100 parts by weight of the epoxy compound.In addition, a photosensitizer, a stabilizer, etc. may be added as necessary. Additives may also be used.

Although the light used during curing varies depending on the curing catalyst used, it is usually 180 to 700 nm, and ultraviolet light is particularly effective. Examples of the light source include a low-pressure mercury lamp, a high-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a hydrogen discharge tube, a tungsten lamp, a halogen lamp, a sodium discharge tube, a neon discharge tube, a He-Ne laser A laser, and the like. Irradiation time is 1 second ~
About 5 minutes is good.

Epoxy curing agents used during heat curing include amines such as aliphatic polyamines, aromatic polyamines, secondary and tertiary amines, fatty acids, condensates of fatty acids and aliphatic polyamines such as dimer acids and trimer acids. Polyamide resins such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride,
Acid anhydrides such as benzophenone tetracarboxylic anhydride, chlorendic anhydride, dodecyl succinic anhydride, methyltetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, boron trifluoride and monoethylamine,
Examples include complexes with piperidine, aniline, butylamine, triethanolamine, etc. Hardening agent is epoxy compound 1
5 to 20'0 parts by weight per 00 parts by weight.

As curing accelerators, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylethanolamine, dimethylaminoethanol, tri(dimethylaminomethyl)phenol, 2-methylimidazole, 2-phenylimidazole, 2- Imidazoles such as phenyl-4-methylimidazole and 2-heptadecylimidazole, organic phosphines such as tributylphosphine, methyldiphenylphosphine, diphenylphosphine, triphenylphosphine, and phenylphosphine, tetraphenolphosphonium tetraphenylborate, 2-ethyl- Examples include tetraphenylboron salts such as 4-methylimidazoletetraphenylborate.

The curing accelerator is 0.01 to 10 parts by weight, preferably 0.05 parts by weight, based on 100 parts by weight of the epoxy compound and curing agent.
~5 parts by weight are used.

Thermal curing is usually from 0 to 200°C, preferably from 20 to 130°C.
Performed at °C.

During curing, other epoxy resins may be mixed as long as the properties of the resin for optical materials of the present invention are not impaired. Any other epoxy resin may be used as long as it is transparent and liquid, but examples include bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, alicyclic epoxy resin, hydrogenated bisphenol A Examples include type epoxy resins, aliphatic epoxy resins, glycidyl ether type epoxy resins, and the like.

When curing the resin of the present invention, an antioxidant, an antistatic agent, an ultraviolet absorber, a mold release agent, etc. may be added as necessary.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited only to these examples.

The various physical properties obtained in the Examples were measured by the following test methods.

(1) Light transmittance 2. Measure the light transmittance at 500 nm with a spectrophotometer. (2) Birefringence: [1. (3) Heat distortion temperature: Measured with a heat distortion tester according to ASTM-D-648 (4) Hardness: Measured with a pencil hardness tester according to JIS-6911 (5) Water absorption rate: ASTM -Measurement according to D-570 Production Example 1 132 g of dicyclopentadiene, 201 g of ethyl acetate in a 1 liter flask with a crystallinity of 1.1 and a dropping funnel of 1. ) g and at 30°C 89 g of peracetic acid l'1
Ethyl monoacid solution is added dropwise over 3 hours. After dripping, 50'
Keep at C for 2 hours. After the reaction is complete, pour the reaction mixture into distilled water.
After washing twice, the ethyl acetate layer was crimped to obtain 160 g of the target product, jepoxydicyclopentadiene.

Example 1 Jepoxydicyclopentadiene 1 prepared in Production Example
After adding 1 g of 4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate to 00 g and vacuum degassing this composition, a mold consisting of a glass plate with a diameter of 120 mm and a spacer with a thickness of 1.2 mm was prepared. Inject UV light (80W/cm, distance 20cm) into the
It was irradiated for 0 seconds and cured.

Take out the cured product from the mold and make it with a thickness of 1.2 mm and a diameter of 12 mm.
A 0 mm disc was obtained.

The results of the optical transmittance, birefringence, heat distortion temperature, pencil hardness, and water absorption of the obtained disk substrate are shown in Table 1. Example 2 In the production example, i'? 60 g of phthalic anhydride and 1 g of 2-methylimidazole were added to 100 g of prepared jepoxydicyclopentadiene, and the composition was degassed under vacuum, and then prepared using a glass plate with a diameter of 120 mm and a spacer with a thickness of 1°2 mm. The mixture was injected into a mold made of , and kept at 100°C for 3 hours to harden.

The hardened material was taken out of the mold and had a thickness of 1.2 mm.

A disk with a diameter of 120 mm was obtained.

Table 1 shows the results of the optical transmittance, birefringence, heat distortion temperature, pencil hardness, and water absorption of the illuminated disk substrate.

Comparative Example 1 A disk group was obtained in the same manner as in Example 1 using bisphenol A diglycidyl ether as the epoxy resin.

? Light transmittance, birefringence, and thermal degree of smooth disk substrate 11
Table 1 shows the results of temperature, pencil hardness, and water absorption.

Comparative Example 2 Using bisphenol A diglycidyl ether as the epoxy resin, a disk substrate B was prepared in the same manner as in Example 2.
7t.

? 11. What is the light transmittance of the disk substrate? The results of U refraction, heat distortion temperature, pencil hardness and water absorption are shown in Table 1.

Table 1 [Effects of the Invention] The resin of the present invention prepared in this way has polyalicyclic (
Because it has a 1'11 structure, it has excellent transparency, heat resistance, moisture resistance, and mechanical strength, and is optically homogeneous. j2! ++ has the characteristic of having a small fold. Therefore, it is an extremely excellent resin for optical materials for substrates of optical discs.

Claims (1)

[Claims] 1) A resin for optical materials obtained by curing an epoxy resin whose main component is a compound represented by the following general formula (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) Composition.