JPH1171503A - Epoxy resin composition and insulation treatment of electric instrument using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition of two-pack type showing excellent casting workability, slight in filler precipitation in storage, capable of developing excellent nonconductivity, useful for insulating electric instruments, by using a component prepared by mixing a specific acid anhydride with a prescribed inorganic filler and a curing promoter. SOLUTION: This epoxy resin composition of two-pack type comprises (A) a component obtained by mixing an acid anhydride (A1 ) containing methyltetrahydrophthalic anhydride (A1 ') and methylhexahydrophthalic anhydride (A1 ") as essential components with an inorganic filler (A2 ) containing a spherical silica having <=2 μm average particle diameter (A2 ') as an essential component and a curing promoter (A3 ) and (B) an epoxy resin. Preferably, the component A comprises 10-90 pts.wt. of the component A1 " based on 50 pts.wt. of the component A1 ' and 50-500 pts.wt. of the component A2 and 0.1-10 pts.wt. of the component A3 based on 100 pts.wt. of the component A1 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an epoxy resin composition and a method for insulating electrical equipment using the same.

[0002]

2. Description of the Related Art Conventionally, as an insulation treatment method for electric equipment, a potting method in which a coil or a part is set in a case and a uniform mixture of a resin and an inorganic filler is injected under normal pressure or vacuum and cured. It has been known. However, in this method, the amount of the inorganic filler to be mixed is limited from the viewpoint of workability, and volume shrinkage occurs upon curing, which causes cracks in the cured product and peels off the built-in coils and components. And a crack is easily generated, and the cast product has a large linear expansion coefficient, so that the heat cycle property is poor. In addition, since the thermal conductivity is small, there is a problem that the temperature of the device becomes high and the temperature used is limited. Furthermore, since the injection operation is performed after the resin composition and the inorganic filler are mixed and defoamed under vacuum, it is necessary to use a resin composition having a long pot life, and therefore, the curing time after the injection. And there are limits to the rationalization of work processes and energy saving.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and is an epoxy resin which is excellent in casting workability, has less sedimentation of inorganic filler during storage, and is excellent in insulation. An object of the present invention is to provide a composition and a method for insulating an electric device using the composition to obtain an electric device having excellent insulating properties and thermal conductivity.

[0004]

SUMMARY OF THE INVENTION The present invention provides an inorganic filler containing methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride as essential components, and an inorganic filler containing spherical silica having an average particle diameter of 2 μm or less as essential components. The present invention relates to a two-pack type epoxy resin composition in which a mixture of an agent and a curing accelerator is used as agent A and an epoxy resin is used as agent B, and an insulation treatment method for electrical equipment, characterized by using this composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the two-pack type epoxy resin composition of the present invention comprises an A agent containing an acid anhydride, an inorganic filler and a curing accelerator and a B agent comprising an epoxy resin. Things. The acid anhydride in the agent A contains methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride as essential components. These commercial products include HN
-2000, HN-5500 (manufactured by Hitachi Chemical Co., Ltd., trade name), QH-200 (manufactured by Zeon Corporation, trade name),
PH-5000 (trade name, manufactured by Tonen Petrochemical Industry Co., Ltd.). As the acid anhydride, besides the above-mentioned essential components, methylhymic anhydride, dodecenyl phthalic anhydride and the like can also be used. The amount of these acid anhydrides is preferably in the range of 0 to 100 parts by weight based on 100 parts by weight of the essential components.

The amount of methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride used is preferably 10 to 90 parts by weight of methylhexahydrophthalic anhydride and 50 parts by weight of methyltetrahydrophthalic anhydride.
-85 parts by weight is more preferable, and 30-70 parts by weight is particularly preferable. If the content of methyltetrahydrophthalic anhydride is greater than this range and the content of methylhexahydrophthalic anhydride is less, the glass transition temperature decreases, and if the content is opposite, the viscosity increases and the casting workability decreases.

Examples of the acid anhydride curing accelerator include imidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-4-methylimidazole, and 1-benzyl-2.
Imidazole derivatives such as -ethylimidazole; tertiary amines such as trisdimethylaminophenol and benzyldimethylamine; and the like, and these can be used alone or in combination of two or more. As commercially available products, 2E4MZ, 2E4MZ-CN (Shikoku Chemical Industry)
(Trade name, manufactured by Kao Corporation) and BDMA (trade name, manufactured by Kao Corporation). The compounding amount of the curing accelerator is acid anhydride 10
0.1 to 10 parts by weight per 0 parts by weight, preferably 0.1 to 10 parts by weight.
-5 parts by weight is more preferable, and 0.1-3 parts by weight is particularly preferable.

[0008] The inorganic filler compounded in the agent A has an average particle size of 2
It contains spherical silica having an average particle diameter of 0.05 μm or less, preferably 0.05 to 2 μm, as an essential component. Examples of this commercially available product include Admafine SO-25R (trade name, manufactured by Admatechs Co., Ltd.). The average particle size is 2 μm
The compounding amount of the following spherical silica is preferably 1 to 40% by weight, more preferably 1 to 30% by weight, and particularly preferably 2 to 20% by weight based on the total amount of the inorganic filler to be compounded. If the amount of the spherical silica having an average particle diameter of 2 μm or less is less than 1% by weight, the effect of suppressing sedimentation of the inorganic filler during storage will not be exhibited, and if it exceeds 40% by weight, the viscosity will increase and casting workability will increase. descend.

As the inorganic filler other than the spherical silica having an average particle diameter of 2 μm or less, an inorganic filler having an average particle diameter of 8 to 10 μm is preferable. For example, crystalline silica, fused silica, hydrated alumina, alumina oxide, talc, carbonate Calcium, mica, glass fiber, glass beads, magnesium hydroxide,
Clay or the like is used. As this commercial product, CRT
-AA, CRT-D, RD-8 (trade name, manufactured by Tatsumori Corporation), COX-31 (trade name, manufactured by Micron Corporation,
C-303H, C-315H, C-308 (trade name, manufactured by Sumitomo Chemical Co., Ltd.), SL-700 (trade name, manufactured by Takehara Chemical Co., Ltd.) and the like. These inorganic fillers can be used alone or in combination of two or more.

The total amount of the inorganic filler is 10
50 to 500 parts by weight to 0 parts by weight is preferable, and 80 parts by weight
The content is more preferably from 400 to 400 parts by weight, particularly preferably from 100 to 300 parts by weight. If the amount of the inorganic filler is less than 50 parts by weight, the thermal conductivity or the coefficient of linear expansion of the cured product is adversely affected. If the amount is more than 500 parts by weight, the amount of the inorganic filler is too large, resulting in poor injection operability.

Examples of the epoxy resin include 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 include Epicoat 828 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) and GY-260 (trade name, manufactured by Ciba Geigy Co., Ltd.) Name), DER-331 (trade name, manufactured by Dow Chemical Japan Co., Ltd.) and the like. These can be used in combination. As epoxy resin,
It is preferable to use a low molecular weight epoxy resin as a reactive diluent such as polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, or butanediol diglycidyl ether in combination with a higher molecular weight epoxy resin. The low molecular weight epoxy resin is preferably used in an amount of 40% by weight or less based on the total amount of the epoxy resin.

The epoxy resin of the present invention 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. Examples of such epoxy compounds include n-butyl glycidyl ether, phenyl glycidyl ether, dibromophenyl glycidyl ether, dibromocresyl glycidyl ether, and the like. The mixing amount of these epoxy resins is 70 to 100 parts by weight of the acid anhydride.
It is preferably 170 parts by weight, more preferably 90 to 150 parts by weight, and particularly preferably 100 to 140 parts by weight. If the amount of the epoxy resin is less than 70 parts by weight or more than 150 parts by weight, the balance between the acid anhydride and the epoxy resin is lost, and the curing does not proceed sufficiently.

The epoxy resin composition of the present invention may further comprise, if necessary, a flame retardant such as red phosphorus, hexabromobenzene, antimony trioxide and the like, and a coloring agent such as red iron oxide, ferric oxide, carbon and titanium white. And an antifoaming agent such as a silane coupling agent and a silicone agent. These are preferably blended with the agent B.

In order to insulate electrical equipment using the epoxy resin composition of the present invention, the above-mentioned A agent and B agent are uniformly mixed, and then preheated preferably at 30 to 70 ° C., preferably 1 Torr or less. After defoaming under reduced pressure, the mixture is poured into a case or a mold on which electric / electronic parts are mounted, preferably 60 to 1
What is necessary is just to heat-harden at 70 degreeC (especially preferably 80-160 degreeC) for 1 to 8 hours, and just remove from a metal mold after hardening, when using a metal mold. Examples of the electrical equipment to be subjected to the insulation treatment method of the present invention include, for example, a transformer or a flyback transformer, a neon transformer, an ignition coil, or a caseless type of a transformer in which components are contained in a plastic or metal case or a mold. And a transformer.

[0015]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

The evaluation of various characteristics was performed by the following methods. Viscosity The viscosity of the epoxy resin composition was measured according to JIS in a thermostat at 25 ° C.
It was measured using a B-type rotary viscometer manufactured by Tokyo Keiki Co., Ltd. according to -C2105. Storage and sedimentation of inorganic filler A measuring device shown in Fig. 1 was prepared. 110mm in diameter, 1 height
A glass tube 2 having a diameter of 8 mm was attached to a lid of a 30 mm metal cylindrical can 1 as shown in FIG.
g of weight 3 was placed. A mark 4 is attached to the glass tube 2,
When the inorganic filler had not settled, the same height as the lid of the can 1 was marked. A in the can 1 of this measuring device
When the inorganic filler settles when the agent is stored in a can at 1500 g and stored at 25 ° C., as shown in FIG. 2, when a settling layer 5 is formed, the position of the glass tube 2 is shifted by the height of the settling layer. And the position of the mark 4 also rises. Therefore, the height (h) from the surface of the lid of the can 1 to the mark 4 was measured, and this was defined as the height of the sedimentary layer.

Glass transition temperature and linear expansion coefficient The epoxy resin composition is heated to 60 ° C.
After defoaming for 2 minutes, it is cured at 80 ° C. for 2 hours and at 135 ° C. for 2 hours. After that, a 5 × 5 × 5 mm test piece was cut out,
The glass transition temperature and the coefficient of linear expansion were measured using a TMA thermophysical tester (manufactured by Rigaku Corporation). Thermal conductivity Cured in a disk-shaped mold 50 mm in diameter and 10 mm thick in the same manner as described above. The obtained disk was taken out and measured using a thermal conductivity measuring device (Cymatech manufactured by Dynatech Co., Ltd.).

Examples 1 to 3 and Comparative Examples 1 to 3 Epoxy resin compositions having the formulations shown in Table 1 were prepared, and the evaluation results of various properties are shown in Table 1. The substances described in Table 1 are as follows.

Agent A Acid anhydride HN-2000 (methyl tetrahydrophthalic anhydride, manufactured by Hitachi Chemical Co., Ltd.) HN-5000 (methyl hexahydrophthalic anhydride, manufactured by Hitachi Chemical Co., Ltd.) Inorganic filler CRT-AA ( Crystalline silica having an average particle diameter of 7 μm, manufactured by Tatsumori Co., Ltd. SO-25R (spherical silica having an average particle diameter of 0.5 μm, manufactured by Admatics Co., Ltd.) Curing accelerator 2E4MZ-CN (1-cyanoethyl-4-methyl-) 2
-Ethyl imidazole, manufactured by Shikoku Chemicals Co., Ltd. B agent Epoxy resin Epicoat 828 (bisphenol A type epoxy resin,
Yuka Shell Co., Ltd.)

[0020]

[Table 1]

Various properties of the epoxy resin composition having the composition shown in Table 1 were evaluated by the above-mentioned methods. As a result, the compositions of Examples 1 to 3 showed that despite the large amount of the inorganic filler,
In addition to low viscosity, excellent casting workability, less sedimentation of inorganic filler during storage, high glass transition temperature, excellent heat resistance, low linear expansion coefficient, heat Excellent cycleability. Since the inorganic fillers of Comparative Examples 1 to 3 have more settling of the inorganic filler during storage than those of Examples 1 to 3, it is necessary to redisperse the inorganic filler before use. Is significantly inferior.

[0022]

The epoxy resin composition according to the present invention has a low sedimentation of the inorganic filler during storage, has a low viscosity, has excellent workability for injection, has a low coefficient of linear expansion, has excellent heat cycle resistance, and Since the glass transition temperature is high and the thermal conductivity is high, an electric device with excellent heat resistance can be provided. In addition, an electric device manufactured by injecting the epoxy resin composition according to the present invention has excellent insulation and heat conductivity, and has high reliability.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a measuring device for storage and settling of inorganic filler.

FIG. 2 is an explanatory view of the measuring device of FIG. 1 in a state where a sedimentation layer of an inorganic filler is formed.

[Explanation of symbols]

 1 can 2 glass tube 3 weight 4 mark 5 sedimentation layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01F 41/12 H01F 41/12 B // C08G 59/42 C08G 59/42 B29K 63:00

Claims (2)

[Claims] 1. An acid anhydride containing methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride as essential components, an inorganic filler containing spherical silica having an average particle diameter of 2 μm or less as an essential component, and a curing accelerator. A two-pack type epoxy resin composition in which the compounded material is used as an agent A and the epoxy resin is used as an agent B. 2. A method for insulating electrical equipment, comprising using the two-part epoxy resin composition according to claim 1.