JP2000336249A - Epoxy resin composition and high-voltage electricai and electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which is excellent in workability in injection and can retain black or dense navy blue without loss of color even when subjected to a long-term thermal history by mixing a component A comprising a blend of an acid anhydride, an inorganic filler and a cure accelerator with a component B comprising a blend of an epoxy resin, a coloring agent having an anthraquinone structure and a diazo dye. SOLUTION: The component A is prepared by blending 100 pts.wt. acid anhydride with 50-500 pts.wt. inorganic filler cornprising, e.g. a crystalline silica or talc, and 0.1-10 pts.wt. cure accelerator comprising, e.g. 2-ethyl-4-methylimidazole. The component B is prepared which contains an epoxy resin comprising, e.g. a bisphenol A epoxy resin having an epoxy equivalent of 100 to 4,000, in an amount of 70-100 pts.wt. based on 100 pts.wt. acid anhydride, and a coloring agent having an anthraquinone structure and a diazo dye at a weight ratio of the coloring agent to the dye of (30:70) to (70:30), with the total content of the coloring agent and the dye being 0.1-10 wt.%. The composition comprises a mixture of the component A and the component B. Examples of the acid anhydride used include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride and dodecenylphthalic anhydride.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition useful as a resin for filling electric equipment and a high-voltage electric / electronic component using the same.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a high-voltage electric / electronic component, a component is set in a case or a mold, and an acid anhydride and a curing accelerator thereof are mixed in a homogeneous mixture of an epoxy resin and an inorganic filler. A potting method of injecting and curing an epoxy resin composition under normal pressure or under vacuum is known.

However, in this method, the amount of the inorganic filler to be mixed is limited because the epoxy resin itself is highly viscous, and the epoxy resin composition undergoes volume shrinkage upon curing, so that the cured product has cracks. Peeling and cracking easily occur in the built-in coil and parts and case,
In addition, there is a problem that the temperature of the electric device becomes high due to poor heat conductivity, and the temperature used is limited. Furthermore, since the epoxy resin composition and the inorganic filler are mixed and defoamed under reduced pressure and then injected, the epoxy resin composition needs to have a long curing time, and the curing time after the injection is required. And there are limits to the rationalization of work processes and energy saving.

[0004] In addition, many other components are arranged in the place where these high-voltage electric / electronic parts are installed, and most of these components are of black or dark blue color. The epoxy resin composition used also needs to be colored black or dark blue.

[0005] Furthermore, carbon black pigments which have been used in black coloring of epoxy resin compositions have been used for high voltage electric and electronic parts since carbon is a conductive material. There is a tendency to refrain. On the other hand, it is considered as an alternative colorant for black or dark blue carbon. A compound having an azine bond or a compound having a diazo bond, when formed into an epoxy resin composition, has good initial color development, but when subjected to a long-term heat history at a high temperature of 130 ° C. or more, color loss is conspicuous, and black or dark blue Inability to retain color.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, has a low viscosity, is excellent in injection workability, and has a black-based cured product even when subjected to a long-term heat history at a high temperature. The present invention provides an epoxy resin composition capable of maintaining a black or dark blue color without color loss and a high-voltage electric / electronic component using the epoxy resin composition and having excellent insulation properties.

[0007]

The present invention relates to an acid anhydride-curable epoxy resin composition comprising a composition obtained by mixing an inorganic anhydride and a curing accelerator with an acid anhydride, and a composition comprising an A agent and an epoxy resin as a B agent. In addition, the present invention relates to an epoxy resin composition characterized in that a coloring agent having an anthraquinone structure and a diazo-based dye are blended in the B agent. The present invention also relates to a high-voltage electric / electronic component obtained by injecting and curing the epoxy resin composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the epoxy resin composition of the present invention, as described above, the agent A is a composition in which an inorganic filler and a curing accelerator are mixed with an acid anhydride. The acid anhydride that can be used is not particularly limited, but is preferably a liquid at room temperature, for example, methyltetrahydrophthalic anhydride,
Methylhexahydrophthalic anhydride, methylendomethylene phthalic anhydride, dodecenyl phthalic anhydride and the like are used. As a commercially available product, HN-2200 (Hitachi Chemical Industries, Ltd.)
(Trade name, manufactured by Nippon Zeon Co., Ltd.) and the like. These can be used alone or in combination of two or more.

As a curing accelerator for acid anhydrides, for example, 2
Imidazole such as -ethyl-4-methylimidazole, 1-cyanoethyl-4-methylimidazole, 1-benzyl-2-ethylimidazole and derivatives thereof, and tertiary amines such as trisdimethylaminophenol and benzyldimethylamine are used. Can be 2 for commercial products
E4MZ (trade name, manufactured by Shikoku Kasei Kogyo Co., Ltd.), BDMA (trade name, manufactured by Kao Corporation) and the like can be mentioned. The curing accelerator is used alone or in combination of two or more. The compounding amount of these curing accelerators is preferably from 0.1 to 10 parts by weight per 100 parts by weight of acid anhydride in view of reactivity, and from 0.1 to 10 parts by weight.
5 parts by weight is more preferable, and 0.1 to 3 parts by weight is particularly preferable.

As the inorganic filler, for example, crystalline silica, fused silica, hydrated alumina, alumina oxide, talc, calcium carbonate, glass beads, clay, magnesium oxide and the like are used. As this commercial product, CR
T-AA, CRT-D, RD-8 (trade name, manufactured by Tatsumori Co., Ltd.), COX-31 (trade name, manufactured by Micro Co., Ltd.), C-3
03H, C-315H, C-308 (Sumitomo Chemical Industries, Ltd.)
Trade name), SL-700 (trade name, manufactured by Takehara Chemical Industry Co., Ltd.) and the like. These inorganic fillers are used alone or in combination of two or more.

The amount of the inorganic filler is preferably from 50 to 500 parts by weight, more preferably from 80 to 4 parts by weight, per 100 parts by weight of the acid anhydride.
00 parts by weight is more preferable, and 100 to 300 parts by weight is more preferable. If the amount of the inorganic filler is too small, the thermal conductivity or the coefficient of linear expansion of the cured product is adversely affected, and if the amount of the inorganic filler is too large, the injection workability tends to be poor.

The B agent in the epoxy resin composition of the present invention contains an epoxy resin as an essential component. Epoxy resins that can be used in the present invention include:
Although a compound having at least two epoxy groups in the molecule is used, those having an epoxy equivalent of 100 to 4000 are preferable, those having an epoxy equivalent of 150 to 1000 are more preferable, and those having an epoxy equivalent of 170 to 500 are particularly preferable. Is preferred.

Examples of usable epoxy resins include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, polyglycidyl ether of polyhydric alcohol and the like. These resins are not particularly limited, but are preferably liquid at room temperature, and commercially available products are Epikote 828 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.),
GY-260 (trade name, manufactured by Ciba-Geigy), DER-33
1 (trade name of Dow Chemical Japan Co., Ltd.). These can be used alone or in combination.

When a low molecular weight epoxy resin serving as a reactive diluent such as polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether or butanediol diglycidyl ether is used as the epoxy resin, a higher molecular weight epoxy resin is used. It is preferable to use them together.

Further, the epoxy resin may contain an epoxy compound having only one epoxy group in one molecule. Such an epoxy compound is preferably used in the range of 0 to 40% by weight, more preferably in the range of 0 to 20% by weight, based on the total amount of the epoxy resin. Such epoxy compounds include n-butyl glycidyl ether, phenyl glycidyl ether,
Examples include dibromophenyl glycidyl ether and dibromocresyl glycidyl ether.

The amount of the epoxy resin is preferably 70 to 100 parts by weight, more preferably 90 to 150 parts by weight, more preferably 100 to 100 parts by weight, based on 100 parts by weight of the acid anhydride.
140 parts by weight is more preferred. If the amount of the epoxy resin is too small or too large, the balance between the acid anhydride and the epoxy resin is lost, and the curing does not proceed sufficiently.

The agent B of the epoxy resin composition of the present invention further contains a colorant having an anthraquinone structure and a diazo dye. The coloring agent having an anthraquinone structure is not particularly limited as long as it is an organic pigment or dye having an anthraquinone structure in its skeleton. General formula (I)

Embedded image Preferred are those having the following structure:
This is a blue-based fine powder. It is commercially available as Chromophtal Blue A3R (trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.).

Other colorants having an anthraquinone structure include anthraquinone violet RN,
And anthraquinone dyes such as RN and anthraquinone blue RXO (both are trade names manufactured by DuPont).

The diazo dye includes various known dyes, and is not particularly limited. This commercially available product is, for example, commercially available as Oil Black HBB (trade name, manufactured by Orient Chemical Industries, Ltd.).

The mixing ratio of the colorant having an anthraquinone structure to the diazo dye is 30/70 to 7 in terms of the weight ratio of the colorant having an anthraquinone structure / diazo dye.
It is preferable to use in the range of 0/30 from the viewpoint of coloring.
When the colorant having an anthraquinone structure is less than 30/70, the color loss of the epoxy resin composition is conspicuous when subjected to a long-term heat history at a high temperature, and when it is more than 70/30,
The blue color peculiar to the anthraquinone structure becomes conspicuous, and in any case, a black or dark blue hue cannot be maintained. The mixing ratio is more preferably in the range of 40/60 to 60/40, and particularly preferably in the range of 45/55 to 55/45.

The colorant having an anthraquinone structure and the colorant of a diazo dye are preferably used in the range of 0.1 to 10% by weight based on the total amount of the epoxy resin composition from the viewpoint of coloring. A range of 5% by weight is more preferable,
A range of 0.2 to 3% by weight is particularly preferred.

The epoxy resin composition of the present invention may further contain, if necessary, a flame retardant such as red phosphorus, hexabromobenzene and antimony trioxide, a silane coupling agent, and a defoaming agent such as a silicone agent. can do.

The high-voltage electric / electronic component of the present invention is obtained by injecting and curing an epoxy resin composition obtained by mixing the above-mentioned agent A and agent B. Specifically, agent A and B
An epoxy resin composition is mixed by mixing the epoxy resin composition, which is preferably preheated to 30 to 70 ° C., defoamed under reduced pressure (preferably 1 Torr or less), and then placed in a case or a mold on which high-voltage electric and electronic components are mounted. Injection and heating and curing are preferably performed at 60 to 170 ° C. (particularly preferably 80 to 160 ° C.) for 1 to 8 hours, and when a mold is used, it is removed from the mold after curing. Parts are obtained.
Further, each of the A agent and the B agent is preferably 30 to 70 ° C.
After pre-heating and defoaming under reduced pressure (preferably 1 Torr or less), the mixture is mixed so that air does not enter to obtain an epoxy resin composition, and then molded as described above to produce high-voltage electrical and electronic components. be able to.

Examples of the high-voltage electrical and electronic parts to be insulated by using the epoxy resin composition of the present invention include transformers, flyback transformers, neon transformers, and the like in which the parts are housed in a plastic or metal case or mold. Examples include an ignition coil and a caseless type transformer thereof.

[0025]

Next, the present invention will be described more specifically with reference to examples. Example 1 and Comparative Examples 1 to 3 An epoxy resin composition having the composition shown in Table 1 was heated to 60 ° C., defoamed at 0.5 Torr for 5 minutes, and then injected under a reduced pressure of 10 Torr. After curing at 135 ° C. for 2 hours, test pieces for various evaluations were obtained.

The substances used in Examples and Comparative Examples were as follows:
These are: [Agent A] Acid anhydride: methyltetrahydrophthalic anhydride (trade name: HN-2200, manufactured by Hitachi Chemical Co., Ltd.) Curing accelerator: 2-ethyl-4-methylimidazole (trade name: 2E4MZ, manufactured by Shikoku Chemical Industry Co., Ltd.) Filler: crystalline silica having an average particle size of 7 μm (trade name: CRT-AA, manufactured by Tatsumori Co., Ltd.)

[Agent B] Epoxy resin: Bisphenol A type EP (Epicoat 828, manufactured by Yuka Shell Co., Ltd.) Anthraquinone colorant: Chromophthal Blue A3R
(Ciba Specialty Chemicals Co., Ltd., trade name) Diazo dye: Oil Black HBB (Orient Chemical Co., Ltd., trade name)

[0028]

[Table 1]

The test pieces were evaluated by the following methods. (1) Change in Hue of Cured Product A test piece after curing the epoxy resin composition having the composition shown in Table 1 was put into a thermostat at 150 ° C., and the hue change of the test piece after standing for a prescribed time was visually determined. (2) Dielectric breakdown strength In a mold of 50 mm x 100 mm x 2 mm, a test piece was made to have a diameter of 20 mm in an oil bath using a BDV measuring machine (manufactured by Meiwa Denki Co., Ltd.).
Was set between a spherical electrode and a disc electrode having a diameter of 20 mm, and the breakdown voltage was measured to determine the strength of the breakdown.

(3) Model impregnation rate A glass bead (average particle size: 80 μm) dried at 100 ° C. for 1 hour was filled into a polypropylene test tube having a diameter of 15 mm so as to be about 60 mm in height while vibrating. After weighing, the weight (W ₀ g) of the glass beads was measured. Next, the resin composition was poured into a polypropylene test tube filled with glass beads so as to have a height of about 60 mm, left under reduced pressure of 10 mmHg for 10 minutes, and thermally cured under specified conditions. Thereafter, the glass beads separated from the cured product without being impregnated were collected and their weight (W ₁ g) was measured. The model impregnation rate was calculated from the following equation.

(Equation 1)

From the results shown in Table 1, when the epoxy resin composition of the present invention was used, unlike the case where only a diazo dye was used (Comparative Example 1), even when subjected to heat history at a high temperature. It was found that there was no color loss of the test piece, and unlike the case where only the organic pigment having an anthraquinone structure was used (Comparative Example 2), the hue of the test piece could be colored dark blue.

Further, when the epoxy resin composition of the present invention was used, a high value was obtained also in the strength of dielectric breakdown, so that it was equivalent to the non-colored epoxy resin composition of the prior art shown in Comparative Example 3. It turned out that the characteristic of was obtained. Further, when the epoxy resin composition of the present invention containing a coloring agent having an anthraquinone structure and a diazo dye is used, the coloring is also a black hue, and the same hue as other components is obtained. Can meet the requirements of

[0033]

EFFECT OF THE INVENTION The epoxy resin composition of the present invention has a low viscosity and excellent workability for injection, and has high insulation properties.
It is possible to provide a black or dark blue high-voltage electric / electronic component that does not lose color of a black cured product even when subjected to a heat history for a long time at a high temperature and can maintain black or dark blue.

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Claims (2)

[Claims] An acid anhydride-curable epoxy resin composition comprising a composition obtained by blending an inorganic anhydride and a curing accelerator with an acid anhydride, and an epoxy resin composition comprising an epoxy resin as a B agent, wherein the B agent has an anthraquinone structure. An epoxy resin composition comprising a colorant having the formula (I) and a diazo dye. 2. A high-voltage electric / electronic component obtained by injecting and curing the epoxy resin composition according to claim 1.