JPH09137042A - Epoxy resin composition and electric machinery and apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the above low-viscosity composition, comprising an epoxy resin, an acid anhydride, a curing accelerator and a spherical silica having a specific grain diameter, having low expansivity, excellent in cracking resis tance and suitable for providing electric machineries and apparatuses excellent in heat cycling resistance and reliability. SOLUTION: This epoxy resin composition comprises (A) an epoxy resin, (B) an acid anhydride such as methyltetrahydrophthalic anhydride, methylendomethylenephthalic anhydride or dodecenylphthalic anhydride, (C) a curing accelerator such as imidazole (derivative) (e.g. 2-ethyl-4- methylimidazole), tertiary amines (e.g. trisdimethylaminophenol) and (D) a spherical silica having <=5μm average grain diameter. The component (D) is contained in an amount of preferably 5-50 pts. by wt. based on 100 pts. by wt. component (A) and, as necessary, (E) an inorganic filler other than the component (D) is further contained in an amount of preferably 100-495 pts. by wt. based on 100 pts. by wt. component (A).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition and an electric device using the same.

[0002]

2. Description of the Related Art Conventionally, epoxy resin compositions have excellent insulating and mechanical properties and are widely used as various electrical insulating materials. In recent years, however, electrical equipment has become smaller and lighter and operating temperature has risen. Therefore, the epoxy resin composition is required to have improved injection workability and crack resistance. In order to improve the crack resistance, a method of increasing the compounding amount of the filler and decreasing the coefficient of thermal expansion is used, but the viscosity of the epoxy resin composition remarkably increases, so that the injection workability decreases. .

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The inventions of claims 1 and 2 provide an epoxy resin composition having a low viscosity and a low expansion. The invention of claim 3 provides an electric device excellent in crack resistance.

[0004]

According to the present invention, there are provided (A) an epoxy resin, (B) an acid anhydride, (C) a curing accelerator and (D) a curing accelerator.
The present invention relates to an epoxy resin composition containing spherical silica having an average particle diameter of 5 μm or less. In the epoxy resin composition of the present invention, 5 to 50 parts by weight of (D) spherical silica having an average particle diameter of 5 μm or less is contained as an inorganic filler in 100 parts by weight of (A) epoxy resin, and (E) etc. The present invention relates to an epoxy resin composition containing 100 to 495 parts by weight of the inorganic filler. The present invention also relates to an electric device using the above epoxy resin composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin as the component (A) used in the present invention is not particularly limited and has at least one epoxy group in one molecule. For example, bisphenol A type epoxy resin, bisphenol. Examples thereof include F-type epoxy resin, bisphenol AD-type epoxy resin, polyglycidyl ester of polyhydric alcohol, and alicyclic epoxy resin. These resins are preferably liquid at room temperature, and commercially available products are Epicoat 828 (Shell Chemical Co., Ltd. trade name), GY-260 (Ciba Geigy Co., Ltd. trade name), DER-331 (Dow Chemical Co., Ltd. trade name). , ERLE-4221 (trade name of Union Carbide Co., Ltd.) and the like. These may be used in combination.

The acid anhydride as the component (B) used in the present invention is not particularly limited, but a liquid at room temperature is preferable,
For example, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylendomethylenephthalic anhydride, dodecenylphthalic anhydride and the like are used. These are preferably used as a mixture of isomers. As commercial products, HN-2200, HN-2000S, HN-550
0 (trade name of Hitachi Chemical Co., Ltd.), QH-200
(Trade name of Nippon Zeon Co., Ltd.), PH-5000 (trade name of Tonen Co., Ltd.) and the like. These may be used in combination.

Examples of the (C) component curing accelerator used in the present invention include 2-ethyl-4-methylimidazole, 1-cyanoethyl-4-methylimidazole and 1-
Imidazole and its derivatives such as benzyl-2-ethylimidazole, and tertiary amines such as trisdimethylaminophenol and benzenmethylamine are used. Commercially available products are 1B2MZ, 2E4MZ-CN, 2
PHZ, 2E4MZ (trade name of Shikoku Kasei Co., Ltd.), B
DMA (trade name, manufactured by Kao Corporation), IS-130 (trade name, manufactured by Dainippon Color Materials Industry Co., Ltd.) and the like.

The spherical silica as the component (D) used in the present invention is commercially available, for example, S-O (trade name of Micron Co., Ltd.) ES-03 (trade name of Tokai Mineral Co., Ltd.), SO-25R ( Tatsumori Co., Ltd. product name) can be used. In the present invention, as the inorganic filler (E) component other than the component (D), crystalline silica, fused silica, spherical silica having an average particle size of more than 5 μm, hydrated alumina, alumina oxide, talc, calcium carbonate, mica,
Glass beads, magnesium hydroxide, clay, etc. are used. This commercially available product is CRT-C66, CRT
-AA, CRT-D, RD-8 (manufactured by Tatsumorisha), EC-3
0, EC-100 (trade name of Tokai Mineral Co., Ltd.),
C-303H, C-315H, C-308 (manufactured by Sumitomo Chemical Co., Ltd.), SL-700 (manufactured by Takehara Chemical Co., Ltd.), COX31 (trade name by Micron Co., Ltd.) and the like may be used together with the component (D). These are used alone or in combination of two or more.

In the present invention, it is preferable to add 50 to 150 parts by weight of the component (B) to 100 parts by weight of the component (A), and 70 to 1 to 100 parts by weight of the component (A).
More preferably, it is 10 parts by weight. If the amount of component (B) is too small or too large, the glass transition temperature upon curing tends to be low and the mechanical strength tends to be weak. The blending amount of the component (C) in the present invention is preferably 0.05 to 3.0 parts by weight, more preferably 0.1 to 2.0 parts by weight, based on 100 parts by weight of the component (A). If the component (C) is too small, the curing time will be long, and if it is too large, the reactivity will be high and the pot life will be shortened.

In the present invention, the component (D) is used to prevent the filler from settling during curing as much as possible, and to eliminate or reduce the drawback that the linear expansion coefficient differs between the upper and lower parts of the cured product. The blending amount of the component (D) is the component 1 of the component (A).
5 to 50 parts by weight is preferable with respect to 00 parts by weight, and 10 to
30 parts by weight is more preferred. If the blending amount is too small, the intended purpose cannot be achieved and the crack resistance tends to be poor. If the blending amount exceeds 50 parts by weight, the mixing becomes incomplete or the viscosity is high even if the mixing is possible. Workability tends to be poor. The average particle size of the component (D) is 5 μm or less, but if the average particle size exceeds 5 μm, the filler tends to settle during curing, and the coefficient of linear expansion tends to differ between the upper and lower parts of the cured product.

When the component (E) is used in the present invention, the compounding amount thereof is 10 per 100 parts by weight of the component (A).
0 to 495 parts by weight is preferable, and 130 to 345 parts by weight is more preferable. If this blending amount is too small, the effect of reducing the linear expansion coefficient and the occurrence of cracks is small, and if it is too large, the mixing tends to be incomplete, or even if mixing is possible, the viscosity is high and the workability tends to be poor.

In the epoxy resin composition of the present invention, a flame retardant such as red phosphorus, hexabromobenzene, dibromophenyl glycidyl ether, dibromocresyl grindyl ether, antimony trioxide, red iron oxide, and ferric oxide may be added, if necessary. , Carbon, a coloring agent such as titanium white, a silane coupling agent, a defoaming agent such as a silicone agent, and the like can be added.

The above-described resin composition of the present invention is used for insulation of electric equipment and is generally cast and cured.
As an electric device, it can be used for a high voltage transformer, a circuit component, a sensor, a module, an IC regulator, an electrical component, a heat radiation component, a condenser and the like.

[0014]

The present invention will be described below with reference to examples. The average particle size of the packing material was measured and various performances were evaluated by the following methods. (1) Average particle size of filler: SEDIGRAPH 5000E
Using P (trade name of Shimadzu Corporation), a filler is added to an aqueous solution of 0.1% by weight of sodium hexametaphosphate, ultrasonic dispersion is performed for 2 minutes as a preliminary dispersion, and the particle size distribution is measured, and the cumulative weight% is 50% by weight. The particle diameter when it became% was taken as the average particle diameter. (2) Viscosity: The viscosity of the epoxy resin composition in a constant temperature bath at 25 ° C. according to JIS C 2105, manufactured by Tokyo Keiki Co., Ltd. B
It was measured using a rotational viscometer. (3) Coefficient of linear expansion: After curing the epoxy resin composition under predetermined conditions, a test piece of 5 mm × 5 mm × 5 mm was cut out, and T
The measurement was performed using a MA tester (manufactured by Rigaku Corporation).

(4) Crack resistance: A 1/2 inch iron spring washer was set on a metal dish having a diameter of 60 mm, and the epoxy resin composition was injected to the upper end of the washer and cured to obtain a test piece. After that, the metal dish was removed, and a heat cycle test was performed according to the heat cycle conditions of JIS C 2105 (shown in Table 1) to observe the crack generation state, and the number of cycles in which cracks occurred was shown.

[0016]

[Table 1]

(5) Sedimentability of filler during curing: inner diameter 1
An epoxy resin composition having a height of 10 cm was poured into a 6 mm test tube, cured, and 10 mm each at the upper part and the lower part were cut out to obtain test pieces. The ash content (%) remaining after burning the test piece was determined, and the difference between the upper part and the lower part was taken. The larger the difference, the greater the sedimentation property. (6) Model impregnation rate: A polyethylene test tube having a diameter of 16 mm was filled with glass beads and then weighed to obtain the weight (W ₀ g). Next, the resin composition was injected and the pressure was reduced to 1 at a reduced pressure of 10 Torr.
It was left for 0 minutes and cured at 80 ° C. under normal pressure for 3 hours. Then, the cured product was taken out from the polyethylene test tube, and the weight (W ₁ g) of the glass beads separated from the cured product without being impregnated with the lower resin composition was calculated, and the model impregnation rate was calculated from the following equation.

[0018]

(Equation 1) The model impregnation rate is to determine the rate of impregnation of the resin composition into the filler, and shows that the model impregnation rate is high and the impregnation property is excellent when the filler in the unimpregnated portion is small.

Examples 1 to 7 and Comparative Examples 1 to 8 Fillers shown in Table 2 were used, and epoxy resin compositions having the formulations shown in Tables 3 and 4 were used. The results are shown in Tables 3 and 4.

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

From Tables 3 and 4, it is shown that Examples 1 to 7 are all excellent in low viscosity, low expansion, crack resistance and sedimentation of the filler. In addition, Comparative Examples 1 to 3
Without using spherical silica of 5 μm or less in the filler,
Although it is a mixture using hydrated alumina of 5 μm or less, alumina, and crystalline silica, all of them have high viscosity and poor workability,
Comparative Example 4 is a composition in which spherical silica having a particle size of 18 μm is used in the packing material, but the sedimentation property of the packing material is poor and the crack resistance is also poor, and Comparative Example 5 is spherical silica of 5 μm or less in the packing material. Is more than 50 parts by weight, but the viscosity is high and the workability is inferior. In Comparative Example 6, the filler contains less than 5 parts by weight of spherical silica of 5 μm or less, but the viscosity is high and Settling is poor, and Comparative Example 7 has a filler content of less than 150 parts by weight, but has a large linear expansion coefficient and poor crack resistance, and Comparative Example 8 has a filler content of more than 500 parts by weight. The filler was too much to mix.

[0024]

The epoxy resin composition according to claims 1 and 2 has low viscosity, low expansion, excellent crack resistance, and excellent settling property of the filler, so that it can be used for electrical equipment such as high-voltage transformers, sensors and modules. Suitable for The electric device according to the third aspect is excellent in heat cycle resistance and is suitable for the requirement of high reliability.

Claims (3)

[Claims] (1) an epoxy resin, (B) an acid anhydride,
An epoxy resin composition comprising (C) a curing accelerator and (D) spherical silica having an average particle size of 5 μm or less. 2. (A) 100 parts by weight of an epoxy resin, 5 to 50 parts by weight of (D) spherical silica having an average particle size of 5 μm or less is contained as an inorganic filler, and (E) 100 to 100 parts of another inorganic filler. The epoxy resin composition according to claim 1, comprising 495 parts by weight. 3. An electric device using the epoxy resin composition according to claim 1.