JPH07126491A - Heat-resistant resin composition - Google Patents

Abstract

PURPOSE:To provide a resin composition excellent in heat resistance and storage stability, and causing no separating of a bismaleimide compound contained therein, essentially comprising the bismaleimide compound, an epoxy resin of specified melting point and a triazine ring-contg. epoxy resin having specific structure. CONSTITUTION:The objective composition essentially comprising (A) a bismaleimide compound (e.g. N,N'-ethylenebismaleimide), (B) an epoxy resin <=70 deg.C in melting point (e.g. bisphenol A-type epoxy resin) and (C) pref. 2-20wt.%, based on the whole composition, of a triazine ring-contg. epoxy resin of the formula (R<3> is CH2 or C2H4). This composition may also be incorporated with a curing agent such as an acid anhydride.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant resin composition which is a material used for impregnation of electric equipment and has excellent heat resistance and storage stability.

[0002]

2. Description of the Related Art A bismaleimide compound / epoxy compound / epoxy compound / using a bismaleimide compound synthesized from a diamine such as diaminodiphenylmethane and maleic anhydride has been used as a heat-resistant impregnating material of class H class for insulation of electrical equipment. Acid anhydride resin compositions are often used.

However, since this impregnated material has a relatively high viscosity at room temperature, it has the drawback that it must be heated to lower its viscosity before it is used. Since the heating is repeated for each operation, the impregnated material gradually thickens and eventually becomes unusable. In addition, the bismaleimide compound has a poor solubility in the above-mentioned resin system, and therefore has a defect that crystals are deposited with the lapse of time. Further, if the amount of the bismaleimide compound is increased for the purpose of improving the heat resistance, there is a drawback that the storage stability of the composition deteriorates. As described above, the conventional bismaleimide compound / epoxy compound / acid anhydride resin composition had a short pot life and large material loss economically.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve the above-mentioned drawbacks, and is excellent in heat resistance and storage stability, has good solubility of the bismaleimide compound, does not cause precipitation, and causes no material loss. The present invention is intended to provide a heat resistant resin composition having a low content.

[0005]

As a result of intensive studies aimed at achieving the above object, the present inventor has found that the composition described below can achieve the above object and completed the present invention. .

That is, the present invention provides (A) a bismaleimide compound, (B) an epoxy resin having a melting point of 70 ° C. or lower, and (C).
Epoxy resin having a triazine ring represented by the following general formula

[0007]

[Chemical 2] (However, wherein ^R 3 is _{-CH 2 -, - C 2 H} 4 - represents a)
The heat-resistant resin composition is characterized by comprising as an essential component.

The present invention will be described in detail below.

The (A) bismaleimide compound used in the present invention is represented by the following general formula.

[0010]

[Chemical 3] (However, in the formula, R ¹ is a hydrogen atom or an alkyl group, and R ² is
Divalent alkyl group or

[0011]

[Chemical 4] Examples of specific compounds (representing an aromatic group such as N, N'-ethylene bismaleimide, N, N'-hexamethylene bismaleimide, N, N'-m-phenylene bismaleimide, N, N) Examples include ′-(4,4′-diphenylmethane) bismaleimide, N, N ′-(4,4′-diphenylether) bismaleimide, N, N′-methylenebis (3-chloro-p-phenylene) bismaleimide and the like. These can be used alone or in combination of two or more.

As the epoxy resin (B) having a melting point of 70 ° C. or lower used in the present invention, a compound having two or more epoxy groups in one molecule and a melting point of 70 ° C. or lower can be widely used. When the melting point exceeds 70 ° C, the bismaleimide compound is difficult to dissolve and the viscosity becomes high, which is not preferable. Specific examples include a bisphenol A type epoxy resin obtained by reacting bisphenol A with epichlorohydrin, a bisphenol F type epoxy resin obtained by reacting bisphenol F with epichlorohydrin, an alicyclic epoxy resin, and the like. Can be used alone or in combination of two or more.

As the epoxy resin having a triazine ring (C) used in the present invention, any epoxy resin having the general formula of Chemical formula 2, in which the bismaleimide compound is easily dissolved and which is reactive, may be used. It is desirable that the epoxy resin having a triazine ring be blended in an amount of 2 to 20% by weight based on the total resin composition. Compounding amount is 2
If it is less than 10% by weight, it does not contribute to the stability of dissolution of the bismaleimide compound, and if it exceeds 20% by weight, the viscosity becomes high, and it becomes a hard and brittle cured product, which is not preferable.

The above-mentioned bismaleimide compound, melting point 70 ° C.
Curing agents such as acid anhydrides, amine compounds, imidazole compounds and organic peroxides can be used for the following epoxy resin and epoxy resin systems having a triazine ring. These curing agents can be used alone or in combination of two or more. Further, as a diluent, triallyl isocyanurate, diallyl phthalate or the like can be added and blended in an amount of 15% by weight or less.

The heat-resistant resin composition of the present invention contains the above-mentioned bismaleimide compound, an epoxy resin having a melting point of 70 ° C. or less, and an epoxy resin having a triazine ring as essential components, but within the range not deviating from the object of the present invention, Further, if necessary, for example, a colorant, a flame retardant, a filler, and other components can be added and blended.

The heat-resistant resin composition of the present invention contains the above-mentioned bismaleimide compound, an epoxy resin having a melting point of 70 ° C. or less, an epoxy resin having a triazine ring, and other components, which are mixed by heating, followed by cooling, followed by curing and curing. It can be manufactured by adding an accelerator.

[0017]

The heat-resistant resin composition of the present invention can achieve the object by using a bismaleimide compound, an epoxy resin having a melting point of 70 ° C. or less, and an epoxy resin having a triazine ring as essential components. That is, the heat resistance is improved by increasing the amount of the bismaleimide compound, and by introducing an epoxy resin having a triazine ring, the bismaleimide compound is dissolved without impairing the heat resistance, crystal precipitation is suppressed, and storage stability is improved. Is an improvement of.

[0018]

EXAMPLES Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In the following examples and comparative examples, "part" means "part by weight".

Example 1 40 parts of N, N '-(4,4'-diphenylmethane) bismaleimide, an epoxy resin TEPIC having a triazine ring
(Nissan Chemical Co., Ltd., trade name) 15 parts, 45 parts of bisphenol F type epoxy resin (epoxy equivalent 170) having a melting point of 70 ° C or lower is put in a flask, heated and stirred at 180 ° C for 2 hours to make a uniform liquid, and then cooled. Then, 60 parts of methyltetrahydrophthalic anhydride as a curing agent and 0.1 part of dicumyl peroxide as a curing accelerator were added and mixed well to produce a brown heat resistant resin composition.

Examples 2 to 3 Using the composition shown in Table 1, a brownish heat resistant resin composition was produced in the same manner as in Example 1.

Comparative Example A brown-colored heat-resistant resin composition having the composition shown in Table 1 was produced in the same manner as in Example 1.

The viscosity and storage stability of the heat-resistant resin compositions produced in Examples 1 to 3 and the comparative example, and the volume resistivity, the weight loss on heating, and the heat loss of the cast plates prepared by using the compositions. The heat distortion temperature was tested, and the results are shown in Table 1. All of the present inventions showed excellent results, and the effects of the present invention could be confirmed.

[0023]

[Table 1] * 1: Epoxy resin with triazine ring (Nissan Chemical Co., Ltd., trade name). * 2: ○: Good, ×: Crystal precipitation.

[0024]

As is clear from the above description and Table 1, the heat-resistant resin composition of the present invention is excellent in heat resistance and storage stability, has no precipitation of the bismaleimide compound, and has a long pot life. It has good workability and is suitable as an insulating material of Class H class for electrical equipment.

Claims (1)

[Claims] 1. An (A) bismaleimide compound, (B) an epoxy resin having a melting point of 70 ° C. or lower, and (C) an epoxy resin having a triazine ring represented by the following general formula: (However, wherein R ³ is _{-CH 2 -, - C 2 H} 4 - represents a)
A heat-resistant resin composition, comprising: