JPH078940B2 - Epoxy resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition for encapsulating an electronic component having excellent mechanical strength.

<Prior art> Epoxy resin containing an inorganic filler is widely used as a resin for encapsulating various electronic parts. The filler has mechanical properties, electrical properties, thermal properties, water resistance, and availability. Silica is mainly used because of its ease of use.

Silica is usually treated with a silane coupling agent,
It is kneaded with an epoxy resin and used. The treatment with the silane coupling agent contributes to the improvement of physical properties such as mechanical properties and electric properties of the epoxy resin composition. In particular, it has a great effect in preventing deterioration of physical properties due to moisture absorption and water absorption. There are various types of silane coupling agents, and an appropriate one is selected depending on the type of resin, the type of inorganic substance, the application, and the like.

It is known to use a plurality of silane coupling agents or silane compounds in combination (JP-B-59-43062, JP-A-59-8715, etc.).

<Problems to be Solved by the Invention> A composite mainly composed of an epoxy resin and silica absorbs water,
Due to moisture absorption, various physical properties such as mechanical strength are remarkably lowered. The use of the above-mentioned silane coupling agent can reduce the degree of this mechanical strength reduction, but it is not always sufficient.

The present invention is intended to provide an epoxy resin composition having improved physical properties due to water absorption and moisture absorption, particularly improved mechanical strength.

<Means for Solving Problems> In the present invention, in a composition containing at least a resin, a curing agent and silica, orthosilicate as silica and silica treated with a silane coupling agent having an epoxy group in the molecule are used. It is an epoxy resin composition characterized by the above.

The epoxy resin used in the present invention is not particularly limited as long as it is a compound having two or more epoxy groups in the molecule, and examples thereof include various bisphenol type epoxy resins, novolac type epoxy resins, alicyclic epoxy resins and the like. Any commercially available epoxy resin can be used.

Examples of the curing agent include phthalic anhydride, pyromellitic dianhydride, tetrahydrophthalic anhydride, acid anhydride curing agents such as succinic anhydride, dicyandiamide, diaminodiphenylmethane, diaminophenyl sulfone, amine curing agents such as metaphenylenediamine, A novolac-based curing agent such as phenol novolac or cresol novolac can be used.

The ratio of the epoxy resin and the curing agent used in the composition of the present invention is determined by the content of both functional groups. Usually, it is used so that the number of moles of functional groups in the curing agent is 0.8 to 1.2 with respect to 1 mole of epoxy groups in the epoxy resin.

In the present invention, it is important to use specially treated silica.

The silica used in the present invention includes crystalline one obtained from natural quartz, one obtained by melting it into an amorphous form, synthetic one obtained by hydrolyzing, condensing and firing various silicon compounds. It may be one.

The size is usually 0.1 to 500 μm, and silica of this size is preferably used from the viewpoint of fluidity when molding the composition. Any shape such as a crushed one obtained by crushing lumpy silica or a spherical one obtained by some method may be used.

The orthosilicate used in the present invention is also called tetraalkoxysilane, and silane having a lower alkoxy group is particularly preferable. Examples thereof include tetramethoxysilane (methyl orthosilicate), tetraethoxysilane (ethyl orthosilicate), tetrapropoxysilane (propyl orthosilicate), trimethoxyethoxysilane and dimethoxydiethoxysilane.

The silane coupling agent used in the present invention contains at least one epoxy group in its molecule, and preferably has one organic group containing an epoxy group bonded to a silicon atom via a carbon atom. A silane compound having the above and further having one or more hydrolyzable groups. Examples of the hydrolyzable group include a halogen atom,
There are an alkoxy group, an acyloxy group, an oximo group and the like, but an alkoxy group, particularly a lower alkoxy group is preferable.

Examples of such silane coupling agents include (γ-glycidyloxypropyl) trimethoxysilane, (γ-glycidyloxypropyl) triethoxysilane, (γ-glycidyloxypropyl) methyldimethoxysilane, and (γ-glycidylsilane). Roxypropyl) methyldiethoxysilane, (3,
4-epoxycyclohexyl) ethyltrimethoxysilane, [(3,4-epoxycyclohexyl) ethyl] methyldimethoxysilane and the like can be mentioned.

In the present invention, the ratio of the orthosilicate used for treating silica and the silane coupling agent having an epoxy group in the molecule is usually preferably in the range of 0.1 to 10 by weight.

The amount of the orthosilicate and the silane coupling agent having an epoxy group in the molecule varies depending on the average particle size of silica, the surface state, the specific surface area, etc., but usually it is used in the range of 0.1 to 10 wt% for each silica. preferable.

In the present invention, as a method of treating silica with a silane coupling agent having an orthosilicate and an epoxy group in the molecule, for example, those obtained by dissolving each of these in water or an organic solvent are mixed with silica, and after standing for a while, Ordinary methods such as a method of drying, a method of distilling off the solvent by heating or reducing pressure, a method of drying or a method of directly contacting and mixing an orthosilicate and a silane coupling agent having an epoxy group in the molecule with silica without using a solvent Can be done at.

Further, when treating silica, a method of simultaneously treating silica by mixing an orthosilicate and a silane coupling agent having an epoxy group in the molecule, after treating silica with an orthosilicate, a silane coupling agent having an epoxy group Or a method of treating silica with a silane coupling agent having an epoxy group and then treating with orthosilicate is also applicable.

The silica thus treated can be used in any ratio with respect to the above-mentioned epoxy resin and curing agent. Although the ratio varies depending on the use, it is usually selected from the range of 10 to 500 parts by weight based on 100 parts by weight of the total amount of the epoxy resin and the curing agent.

These treated silka, epoxy resin, and curing agent can be uniformly kneaded by a dry kneading method, a melt kneading method, a solution method, or the like with a roll, a kneader, an extruder, or the like to form a composition.

In the composition of the present invention, if necessary, a curing accelerator, a release agent,
A colorant or the like can be added.

<Examples> Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 200 g of fused silica (“RD-8”, manufactured by Tatsumori Co., Ltd.) was added to a solution prepared by dissolving 0.5 g of methyl orthosilicate and 0.5 g of γ-glycidyloxypropyltrimethoxysilane in 200 ml of methanol and stirred well. did. Methanol was evaporated with stirring at 50-60 ° C under normal pressure, and then heated at 100 ° C for 2 hours.

150 g of the treated silica and 33.3 g of an orthocresol novolac epoxy resin having an epoxy value of 220, 16.7 g of a phenol novolac resin having an OH value of 110, and 1,8-
Diazabicyclo (5,4,0) undecene-70.25g and carnauba wax 0.2g were added and melt-kneaded at 100 ° C for 5 minutes.

Use a mold to make this 100 mm × 100 mm × 1 mm at 130 ° C for 15
After molding at 70 kg / cm ² for minutes, it was cured at 180 ° C. for 5 hours.

The cured product was cut into a size of 80 mm × 10 mm × 1 mm, and as it was (before water absorption) and after boiling in water for 10 hours (after water absorption), the tensile strength and the elongation were measured using a tensilon meter. The results are shown in Table 1.

Example 2 In Example 1, 0.5 g of methyl orthosilicate and γ
-A composition was obtained in the same manner except that 0.3 g of methyl orthosilicate and 0.7 g of γ-glycidyloxypropyltrimethoxysilane were used instead of 0.5 g of glycidyloxypropyltrimethoxysilane. The results of measuring the tensile strength and the elongation are shown in Table 1.

Example 3 200 g of fused silica (“RD-8”, manufactured by Tatsumori Corporation) was added to a solution of 0.3 g of methyl orthosilicate in 200 ml of methanol and stirred well. Methanol was evaporated under normal pressure at 50 to 60 ° C. with stirring, and then heated at 100 ° C. for 2 hours for orthosilicate treatment. Then, orthosilicate treated silica, was added to a solution of 0.7 g of γ-glycidyloxypropyltrimethoxysilane dissolved in 200 ml of methanol, and methanol was evaporated under stirring at 50-60 ° C. under normal pressure, and then 100 ° C. It was heated for 2 hours and treated with a silane coupling agent.

Thereafter, melt kneading, molding and curing were carried out in the same manner as in Example 1, and the tensile strength and elongation before and after water absorption were measured. The results are shown in Table 1.

Comparative Examples 1-3 Silica not treated with silane and 1 g of γ-glycidyloxypropyltrimethoxysilane in Example 1
A composition similar to that of Example 1 was obtained using silica treated only with silane coupling agent and silica treated with orthosilicate only with 1 g of methyl orthosilicate to obtain tensile strength and elongation. Was measured. The results are summarized in Table 1.

<Effects of the Invention> The epoxy resin cured product of the present invention exhibits excellent mechanical properties, particularly mechanical properties after water absorption, and is useful as a resin for sealing various electronic components.

 ─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-60-245664 (JP, A) JP-A-57-162747 (JP, A) JP-A-61-296020 (JP, A) JP-A-61- 113642 (JP, A) JP-A-62-149743 (JP, A)

Claims (1)

[Claims] 1. An epoxy resin composition comprising at least an epoxy resin, a curing agent and silica, wherein orthosilicate and silica treated with a silane coupling agent having an epoxy group in the molecule are used as silica. object.