JPH0360846B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an epoxy resin composition, and particularly to a composition suitable for casting electrical and electronic parts. (Background technology and prior art) In recent years, epoxy resin casting has been used for insulation treatment of ceramic capacitors, focus resistors, hybrid ICs, and simultaneous insulation treatment of bobbins, coils, ferrite cores, focus resistors, capacitors, diodes, etc. in flyback transformers. materials are used. However, because there is a difference in thermal expansion coefficient between the parts to be insulated and the casting material, peeling and cracking occur during cooling and cooling cycles during curing of the casting material, resulting in poor insulation. There is a problem. Conventionally, in an epoxy resin composition for obtaining a flexible cured product for the purpose of solving the above-mentioned problems, for example, dimer acid glycidyl ester, side chain type bisphenol A-based glycidyl ether, polypropylene glycol glycidyl Flexible epoxy resin (a) such as ether, polyamide amine, polyoxypropylene diamine,
A flexibility curing agent (b) such as a dibasic acid polyanhydride and a flexibility imparting agent (c) such as a polyol, phthalate ester, higher fatty acid, or reactive liquid rubber are blended singly or in combination. has been done. When such an epoxy resin composition is used as an insulating casting resin for electric or electronic parts, although the flexibility is satisfactory, there is a disadvantage that the moisture resistance is extremely poor. (Objective and Structure of the Invention) An object of the present invention is to provide an epoxy resin composition that provides a cured product with good flexibility and moisture resistance. The present invention consists of 100 parts by weight of epoxy resin (A), 50 to 250 parts by weight of alkenyl group-containing succinic anhydride (B), 5 to 50 parts by weight of castor oil polyol (C), and 1 to 20 parts by weight of silane coupling agent (D). It is an epoxy resin composition consisting of parts by weight. The epoxy resin as component (A) in the present invention is not limited in terms of properties, epoxy equivalent, molecular weight, molecular structure, etc., and various known epoxy resins can be used. Specifically, bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, hydrogenated bisphenol A epoxy resin, cycloaliphatic epoxy resin,
Examples include aromatic dicarboxylic acid glycidyl ester. One or more types of these can be used. Further, when the composition of the present invention is to be applied to the above-mentioned uses, it is preferable to use an epoxy resin that is liquid at room temperature from the viewpoint of workability. In the epoxy resin composition of the present invention, the epoxy resin as component (A) is 100 parts by weight based on the component content. When two or more types of epoxy resins are used in combination, there is no particular restriction on the amount. The alkenyl group-containing succinic anhydride as component (B) in the present invention has the following formula, for example: (In the formula, R is an alkenyl group). The alkenyl group represented by R includes various groups including a vinyl group.
Among these, preferred in the present invention are those having a large number of carbon atoms, specifically linear or branched alkenyl groups having 8 to 50 carbon atoms. If the alkenyl group has too few carbon atoms, the cured product obtained from the composition containing succinic anhydride to which the group is bonded will not have satisfactory flexibility; If it is too high, the cured product will have poor moisture resistance. Preferred examples of alkenyl groups are as follows.

【formula】

[Formula] C ₁₅ H ₃₁ −CH=CH−CH ₂ −,

[Formula] In the formula, R′ and R″ are each a monovalent hydrocarbon group. However, the total number of carbon atoms of R′ and R″ is
9, 13 or 15. Examples of the succinic anhydride containing such an alkenyl group include those illustrated below. (1) Octenyl succinic anhydride (1 of 2) Octenyl succinic anhydride (2) Dodecenyl succinic anhydride (manufactured by Sanyo Chemical Co., Ltd., trade name DDSA) In the formula, R ¹ and R ² are monovalent hydrocarbon groups, and R ₁ and R ₂
The sum of the number of carbon atoms is 9. (3) Octadecenyl succinic anhydride (manufactured by CHEMICALS, trade name MILLIKEN) (4) Substituted succinic anhydride (manufactured by Toho Chemical Co., Ltd., trade name
ASA 168P) In the formula, R ³ and R ⁴ are monovalent hydrocarbon groups, and R ³ and
The sum of the number of carbon atoms in R ⁴ is 13 or 15. The content of these alkenyl group-containing succinic anhydrides is 50 to 250 parts by weight, preferably 100 to 170 parts by weight, based on 100 parts by weight of the epoxy resin. If the content is less than 50 parts by weight, sufficient flexibility cannot be imparted to the cured product, and if the content exceeds 250 parts by weight, there will be no problem with flexibility, but the cured product will be Mechanical strength becomes inferior. The castor oil polyol as component (C) in the present invention imparts moisture resistance to the cured product obtained from the composition of the present invention. In the present invention, the polyol must be castor oil-based, and the purpose cannot be achieved even if other polyols are used. Examples of this castor oil polyol include
URIC-47 (trade name, manufactured by Ito Oil Co., Ltd.) can be mentioned. The content of castor oil polyol is 5 to 50 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of epoxy resin.
It is 20 to 30 parts by weight. If it is less than 5 parts by weight, the effect of imparting flexibility to the cured product will not be sufficient, and if it exceeds 50 parts by weight, the moisture resistance and heat resistance of the cured product will decrease. Examples of the silane coupling agent (D) in the present invention include 3-glycidoxypropyltrimethoxysilane, N-(2-aminoethyl)-3-
Aminopropyltrimethoxysilane, 2-(3,
Examples include 4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and 3-methacryloxypropyltrimethoxysilane. The content of this silane coupling agent is in the range of 1 to 20 parts by weight per 100 parts by weight of the epoxy resin. The composition of the present invention may contain other components such as a curing accelerator, an inorganic filler, a diluent, a flame retardant, an antifoaming agent, a coloring agent, etc., as long as they do not impede the purpose of the present invention. Good too. As curing accelerators, tertiary amine compounds and their salts, DBU [1.8-diazabicyclo(5,4,
0) undecene-7] and its salts, imidazole compounds, quaternary ammonium salts, organic metal salts, etc., and examples of inorganic fillers include silica, alumina, aluminum hydroxide, magnesium oxide, and calcium carbonate. , talc, mica, clay, etc. The composition of the present invention is prepared by uniformly mixing the above-mentioned components (A) to (D) and optional components. (Effects of the Invention) When the epoxy resin composition of the present invention having the composition described above is applied to the insulation treatment of electrical and electronic parts, the insulation can be maintained even when cooling after heat curing or when the insulation treatment parts are subjected to cooling and heating cycles. The treated film does not peel or crack, it firmly adheres to parts, and has excellent moisture resistance. Examples 1 to 3 and Comparative Examples 1 to 9 The hardness, crack resistance, weight increase rate, and volume resistivity values described below for the cured products obtained from the epoxy resin compositions having the compositions shown in the table below In order to investigate this, a cured product (test sample) suitable for measurement of each physical property was prepared using an epoxy resin composition. The curing conditions for producing the cured product are as in Example 1.
-3, 110 for Comparative Examples 1-4 and 7-9
Heating for 5 hours at °C, 60 °C for comparative examples 5-6
It was heated for 5 hours. Hardness: Measured using a Shore hardness meter (D type). Cracking resistance: Create 5 test pieces according to JIS C2105 (solvent-free liquid range test method for electrical insulation), measure the cycle in which cracks occur for each test piece, and calculate the average value of this cycle. did. Weight increase rate (after pressure test): The test piece was humidified at 120℃ and 1.2 atm for 24 hours.
The weight of the test piece after humidification was measured, and the percentage with respect to the weight of the test piece before humidification was calculated. Volume resistivity value (after pressure test) The test piece was humidified at 120°C and 1.2 atm for 24 hours, and the volume resistivity value after this humidification was measured.

【table】

【table】

[Table] Among the ingredients in Table 1, the chemical names and manufacturing company names of the components listed by trade name are as follows.

【table】

【table】

Claims (1)

[Scope of Claims] 1. 100 parts by weight of epoxy resin (A), 50 to 250 parts by weight of alkenyl group-containing succinic anhydride (B), 5 to 50 parts by weight of castor oil polyol (C), and silane coupling agent (D). An epoxy resin composition comprising 1 to 20 parts by weight. 2. The epoxy resin is selected from bisphenol A epoxy resins, bisphenol F epoxy resins, phenol novolak epoxy resins, hydrogenated bisphenol epoxy resins, cycloaliphatic epoxy resins, and aromatic dicarboxylic acid epoxy resins. The epoxy resin composition according to claim 1, which is one or more types. 3 Alkenyl group-containing succinic anhydride has the formula (In the formula, R represents an alkenyl group.) The epoxy resin composition according to claim 1, wherein R represents an alkenyl group. 4 The alkenyl group in the alkenyl group-containing succinic anhydride is C ₁₅ H ₃₁ −CH=CH−CH ₂ − (Here, R′ and R″ are monovalent hydrocarbon groups, but R′ and
The total number of carbons in R″ is 9, 13 or 15)
The epoxy resin composition according to claim 1, which is represented by: 5 The silane coupling agent is 3-glycidoxypropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane,
Claim 1 which is 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, 3-methacryloxypropyltrimethoxysilane The epoxy resin composition described in . 6. The epoxy resin composition according to claim 1, which contains a curing accelerator. 7. The epoxy resin composition according to claim 1, which contains an inorganic filler.