JPS5857425A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin composition of good adhesive strength which is excellent in storage stability at around room temperature and which cures rapidly, upon heating, by adding an imidazole azine derivative and tetrahydrophthalic anhydride as a curing agent. CONSTITUTION:To an epoxy resin, epoxy eq. weight of about 400-1,000 and MW of about 800-2,500 (e.g., ''Epikote 1002 '', Shell Co.) are added (B) about 0.5-10pts.wt. per 100pts.wt. epoxy resin, imidazole azine derivative of the formula (wherein R1-R5 are each H, a (cyclo)alkyl, (cyclo)alkenyl, acyl, allyl, aryl, aldehyde, amino, or cyano) (e.g., ''Curazole 2MZ-AZINE '', Shikoku Kasei Co.) and (C) 0.05-0.2 eq. per eq. of epoxy group of component A, of phthalic anhydride and/or tetrahydrophthalic anhydride.

Description

[Detailed description of the invention] The present invention relates to epoxy resin compositions.

Epoxy resins are widely used in electrical insulation materials, adhesives, molding materials, etc. because they provide cured products with excellent mechanical, electrical, and chemical properties when cured with acid anhydrides or amines.

However, when an acid anhydride curing agent is blended, the epoxy resin composition is relatively stable at room temperature, but has the disadvantage of requiring heating at a considerably high temperature for a long time during curing. Therefore, a curing accelerator such as a tertiary amine, a quaternary ammonium compound, or an organic metal complex salt is used in combination to shorten the curing time. However, the addition of these curing accelerators improves curability but has the disadvantage that storage stability is significantly impaired.

Therefore, there is a strong demand for a curing agent having so-called latent properties, which exhibits excellent storage stability as the composition hardly reacts at around room temperature, and which reacts rapidly even at relatively low temperatures when heated.

By the way, as latent curing agents, several types of boron-tin compound curing agents have been commercially available, but they have the disadvantage of having a negative effect on the properties of cured products due to their high hygroscopicity. It was also insufficient in some respects.

The present invention was made in view of the above points, and its purpose is to rapidly accelerate the curing reaction only when heated without accelerating curing near room temperature, and to improve adhesive properties, especially good adhesive strength. An object of the present invention is to provide an epoxy resin composition.

That is, the present invention is characterized by containing an epoxy resin, an azine derivative of imidazoles, and 0.05 to 0.2 equivalents of phthalic anhydride and/or tetrahydrophthalic anhydride per equivalent of the epoxy group of the epoxy resin. This invention relates to an epoxy resin composition.

Epoxy resins used in the present invention include bisphenol-type epoxy resins, resorcinol-type epoxy resins, novolac-type epoxy resins, halogenated epoxy resins thereof, hydantoin-type epoxy resins, epoxy resins having heterocycles such as triazine rings, and isocyanurate rings. can be mentioned.

In addition, these epoxy resins have an epoxy equivalent of 400
~1,000 and a molecular weight of about 800 to 2,500 is generally used.

The azine derivative of imidazole used in the present invention is generally represented by the following formula.

In the above general formula, R1''-R1 is a hydrogen atom, an alkyl group, an alkenyl group, an acyl group, an allyl group, an aryl group, a cycloalkyl group, a cycloalkenyl group, an aldehyde group, an amino group, a cyano group, etc. They may be the same or different.

More specifically, imidazoles, such as imidazole, 2-methylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1-
Benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2
-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, etc.
] can be mentioned. The amount of the azine derivative of imidazoles added is preferably 0.5 to 10 parts by weight per 100 parts by weight of the epoxy resin.

The reason why the amount of phthalic anhydride and/or tetrahydrophthalic anhydride used in the present invention is limited to Q, 05-0.2 equivalents per equivalent of epoxy group in the epoxy resin is that if the amount is 0.05 equivalent or less, almost no This is because the effect of improving storage stability is not observed, and on the other hand, if the amount is 0.2 equivalent or more, it has the disadvantage that it takes a long time to completely cure.

The composition of the present invention can be produced by uniformly heating and mixing the above three components and cooling the mixture.

When heating and mixing the three components, inorganic fillers,
Pigments, deterioration inhibitors, etc. may be added.

The composition of the present invention described above has excellent storage stability at room temperature and cures in a relatively short time.

The present invention will be specifically explained below using examples.

Note that parts in the examples are parts by weight.

Example 1 Epoxy resin (Epicor manufactured by Shell Co., Ltd. 1002) 1
00 parts, 2.0 parts of an azine derivative of imidazoles (manufactured by Shikoku Kasei Co., Ltd. +-ysol 2MZ-AZINg), and 3.0 parts of phthalic anhydride were kneaded for 5 minutes with heated rolls at 70°C, and then cooled to form a lump. This material was ground to obtain epoxy resin composition powder of 30 mesh passes.

Its properties are shown in Table 1 below.

Example 2 100 parts of Ebiko) 1002 (supra), 5 parts of Kitamazole 2 MZ-AZINg (supra), and 10 parts of detrahydrophthalic anhydride were treated in the same manner as in Example 1 to give 30 mesh passes. An epoxy resin composition powder was obtained.

Its properties are shown in Table 1 below.

Comparative Example: 100 parts of Ebiko)'#1002 (mentioned above) and Kiou Azo
/I/ 2 MZ-kZINE was treated in the same manner as in Example 1 to obtain an epoxy resin composition powder of 200 messier passes.

IKI at 120°C for 30 minutes to bond the minium boards together.
7. , l conditions), and the shear adhesive strength of the obtained test piece is shown.

Table 1 Patent Applicant Nitto Electric Industry Co., Ltd. Representative Upper Third Division Amendment (Voluntary) April 28, 1980 Haruhashi Shimada, Commissioner of the Patent Office 1, Indication of Case 1982 Patent Application No. 156486 2 , Name of the invention Epoxy A1 Resin Assemble Paramono 3, Relationship with the person making the amendment Patent applicant name (396) Nitto Electric Industry Co., Ltd. Electric 0726 [Phase] 2981-94 Date 5, Subject of amendment ( 1) The general formula at the bottom of page 3 of the specification is corrected as follows.

" ” that's all

Claims (1)

[Claims] Epoxy resins, azine derivatives of imidazoles, and 0.05 to 1 equivalent of poquin group of the epoxy resins.
An epoxy resin composition comprising 0.2 equivalents of phthalic anhydride and/or tetrahydrophthalic anhydride.