JPS6279220A - Novel epoxy resin composition for optical use - Google Patents

Abstract

PURPOSE:To provide the titled novel epoxy resin composition for optical use, composed of an epoxy resin, an organic polybasic acid anhydride and a specific cure accelerator, having high ultraviolet ray transmittance and especially suitable as an optical disk base, lens, prism, etc. CONSTITUTION:The objective composition can be produced by compounding (A) a solid or liquid epoxy resin with (B) an organic polybasic acid anhydride (e.g. hexahydrophthalic anhydride) as a curing agent and (C) a compound containing the structural unit of formula (A1, A2 and A3 are saturated or unsaturated C; A4 is saturated C or H) in the molecule as a cure accelerator. Preferably, the amount of the component B is 50-140pts.(wt.) per 100pts. of the component A and that of the component C is 0.001-0.3pts. per 100pts. of the whole composition.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to optical materials, particularly substrates for optical disks, lenses,
This invention relates to an epoxy resin optical composition suitable for prisms and the like.

[Conventional technology]

Conventionally, epoxy resin compositions used as optical materials have been known to use liquid epoxy resins, acid anhydrides as curing agents, and tertiary amines, imidazoles, carboxyl metal salts, etc. as curing accelerators. (Special Publication Sho!9-2224q
No., Japanese Patent Application Publication No. Sho J'9-/997/J).

However, when these general epoxy resins and curing accelerators are used, the molded product becomes extremely discolored, especially! 00nm~
The light transmittance at 300 rtm was extremely low, making it unsuitable as an optical material. In particular, when used as an optical disk substrate for coating an ultraviolet curable resin layer to provide guide grooves on an epoxy casting plate, 3 A j of the bright lines of the mercury lamp used to cure the ultraviolet curable resin Although it is necessary to have a high transmittance of ultraviolet light in the vicinity of nm, conventional epoxy resin molded products have a low transmittance of light in the vicinity of 36srtn, making them unsuitable as substrates for optical disks.

[Problem that the invention seeks to solve]

An object of the present invention is to provide an epoxy resin molded article that does not have the above-mentioned problems and has high light transmittance in a short wavelength range. That is, the object of the present invention is to have a light transmittance of 60 cm or more per thickness/fl at a wavelength of 3Ajnm, and
An object of the present invention is to provide a cured epoxy resin having a light transmittance of 90% or more per 7W thickness over a wavelength range of oo nm = 900 nm.

[Means to solve all problems]

As a result of intensive studies to solve the above problems, the present inventors found that
We have arrived at the present invention.

That is, in the present invention, a solid epoxy resin or a liquid epoxy resin is mixed with an organic polybasic acid anhydride as a curing agent and a compound having the following structural unit in its molecule as a curing accelerator.
This relates to an optical epoxy resin composition characterized in that the above structural unit is used in an amount of /~2% by weight (in the formula, A++Az+As is saturated or unsaturated carbon, and A4 is saturated carbon or hydrogen). Among the compounds having a curing accelerator, those having a total molecular weight of 300 or less are preferred from the viewpoint of solubility in the epoxy resin and curability of the epoxy resin.

Examples of such compounds include /, ♂-diazabicyclo (s, !A, o) 7-unzoseshi, otsuj-
Examples include diazabi/chloroC''+310)s-nonene, benzylimidazole, /-ethyl λ-methylimidazole, 4-cordimethylimidazole, /~methylimidazole, and the like.

As a curing agent, phthalic anhydride, maleic anhydride, dodecylsuccinic anhydride, hexahydrophthalic anhydride, μ anhydride
Organic polybasic acid anhydrides such as m-methylcyclohexane, 42-dicarboxylic acid, tetrahydrophthalic anhydride, methylnasic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic anhydride are preferably used alone or in combination. Generally, amine curing agents are strongly colored and their use is not preferred.

It is preferable to use the curing agent in an amount of JO to 1170 parts by weight per 100 parts by weight of the epoxy resin from the viewpoint of heat resistance and mechanical strength of the cured product.

As the epoxy resin, either a solid epoxy resin or an epoxy resin can be used, such as bisphenol A, pyrocatechol, resorcinol, hydroquinone, etc. , 4L-dihydroxydiphenylmethane, g
, g-dimethyl-diphenylmethane, μll-dihydroxy-diphenyl-dimethylmethane, ≠-dihydroxy-diphenyl-methylmethane, g, <<-2hydroxy-diphenyl-cyclohexane, μ, Hiro-dihydroxy-3,3-dimethane Roudiphenylpropane, 1L,
4! -dihydroxy-diphenyl, ≠-dihydroquine-diphenylsulfone, tris-(nuhydroxyphenyl)-methane or halogenated products of these diphenols, or novolaks or cresol novolaks, or obtained from aromatic hydroxycarboxylic acids Polyglycidyl ethers of polyphenols such as diphenols can be used.

Furthermore, the use of the following is also preferred.

Polyvalent aromatic, aliphatic and alicyclic glycidyl esters, such as adipate glycidyl esters, glycidyl esters of polyhydric alcohols, triglycidyl isocyanurates, compounds and copolymers containing epoxidizable double bonds, such as , a polymer based on polybutadiene, cyclopentadiene epoxidized with peroxide.

As the solid resin, one having a melting point≠O-♂0°C is preferable because of its ease of handling.

The curing accelerator is preferably used in a range of 0.00/-λ, preferably Q, 001 to 03% by weight in the entire composition. If the amount of the curing accelerator exceeds 2%, it is not preferable because the heat distortion temperature of the cured product decreases.

When a solid epoxy resin is used, the amount of curing accelerator can be reduced, and in order to improve the light transmittance in the short wavelength range of 300 to 1,000 nm, K is used to reduce the amount of curing accelerator. It is preferable to do less.

Such an optical epoxy resin composition is molded by a plastic molding method. Casting is the most suitable plastic molding method, and transfer molding and injection molding are also possible. The molding temperature is important in this molding, and lower temperatures are preferred.

It is usually carried out at a temperature of 750°C or lower.

[For production]

The molded product obtained from the epoxy resin composition of the present invention is
It has excellent mechanical properties and thermal properties, and has high light transmittance from the ultraviolet to the near-infrared, making it ideal as an optical material.

C Example] Next, examples will be shown. Parts represent parts by weight.

Example 1 An epoxy resin composition having the following composition was prepared.

Epoxy resin (AER-JJ/, manufactured by Asahi Kasei ■) 10
0 parts, curing agent (hexahydrophthalic anhydride) lrO parts,
Curing accelerator (4g-diazapin o (,g,<t,0
) 7,105 parts of 7-undece was injected into a glass mold that had been subjected to a gold mold release treatment, and cured at 100°C for 2 hours and then at 1iro°C for 1 hour. 3 of the epoxy plate (thickness/, j sll ) molded in Figure 1
For comparison, a light transmittance curve is shown in which benzyldimethylamine is used as a curing accelerator, showing the light transmittance over a range of 00°C to 900°C.

Example 2 A solid epoxy resin composition having the following composition was prepared.

Solid epoxy resin AER-200″) too parts by weight (e) Asahi Kasei epoxy: Bisphenol 1M epoxy resin, epoxy weight part
2°C above the melting point (method for measuring the melting point by the mercury method of Durr & H). To prepare the composition, first add 700% of the epoxy resin.
Warm to ℃ and dissolve. Dissolve in this in advance,
Add the reserved HHPA and stir until a homogeneous solution is obtained. The resulting composition was poured into a glass mold equipped with a spacer, and the resin was cured by heating at 160° C. for 5 hours.

After this, remove it from the mold and get the thickness /, JI + II
A positive transparent substrate was obtained.

The light transmittance of the obtained epoxy substrate was as follows.

Wavelength Light transmittance 1.00 to 900℃m 9/, O
N 9/, 5% 3 & jny11 71!
blood

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows light transmittance curves of epoxy plates obtained in Examples and Comparative Examples.

Claims (1)

[Claims] (1) A solid epoxy resin or a liquid epoxy resin containing an organic polybasic acid anhydride as a curing agent and 0.001 to 2% by weight of a compound having the following structural unit in the molecule as a curing accelerator. Characteristic optical epoxy resin composition. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, A_1, A_2, A_3 are saturated or unsaturated carbons, and A_4 is saturated carbon or hydrogen.)