Thermally conductive silicone potting composition and its cured product

Abstract

To provide a thermally conductive silicone potting composition that, despite containing a large amount of thermally conductive filler, has low viscosity and high flowability, can flow into minute spaces, and has a desired thermal conductivity after curing. [Solution] (A) Organopolysiloxanes having an average of 0.5 or more alkenyl groups bonded to silicon atoms per molecule, and 0.02 or more hydroxyl groups bonded to silicon atoms per molecule. (B) Thermally conductive filler, (C)Organohydrogensiloxane having at least two SiH groups in one molecule, and (D) A thermally conductive silicone potting composition containing a hydrosilylation reaction catalyst.

Claims

1. (A) Organopolysiloxane having an average of 0.5 or more alkenyl groups bonded to silicon atoms per molecule, and 0.02 or more hydroxyl groups bonded to silicon atoms per molecule. (B) Thermally conductive filler, (C) Organohydrogensiloxane having at least two SiH groups in one molecule, and (D) Hydrosilylation reaction catalyst Includes, The aforementioned component (A) is a dimethylpolysiloxane whose terminals are sealed with a group selected from the group consisting of a dimethylvinylsilyl group, a trimethylsilyl group, a dimethylhydroxysilyl group, and a group represented by the following formula (1) (wherein, on average 0.5 to 1.8 of the terminals per molecule are dimethylvinylsilyl groups, and on average 0.02 to 0.1 are one or more selected from the group consisting of a dimethylhydroxysilyl group and a group represented by the following formula (1)), A thermally conductive silicone potting composition comprising (B) a thermally conductive filler in an amount of 500 to 2,000 parts by mass per 100 parts by mass of component (A). 【Chemistry 1】 (In the formula, m is an integer between 0 and 5, and the dashed line represents a connection.)

2. The thermally conductive silicone potting composition according to Claim 1, wherein the (B) thermally conductive filler is contained in an amount of 800 to 1,500 parts by mass per 100 parts by mass of the (A) component.

3. The thermally conductive silicone potting composition according to claim 1, wherein the viscosity of component (A) at 25°C, as measured by a type B rotational viscometer, is 10 to 1,000 mPa·s.

4. (E) The thermally conductive silicone potting composition according to claim 1, comprising one or more selected from the group consisting of a silane compound represented by the following general formula (2) and an organopolysiloxane represented by the following general formula (3). 【Chemistry 2】 (In the formula, R 1 (where n represents a monovalent hydrocarbon group that does not independently possess an aliphatic unsaturated bond, and n represents an integer from 0 to 30.)

5. The thermally conductive silicone potting composition according to claim 4, wherein the thermally conductive filler (B) is surface-treated with component (E).

6. (F) The thermally conductive silicone potting composition according to claim 1, comprising an organopolysiloxane represented by the following general formula (4). 【Transformation 3】 (In the formula, R 2 These represent monovalent hydrocarbon groups independently of each other, and R 3 (Each of the elements independently represents an alkyl group, alkoxyalkyl group, alkenyl group, or acyl group, where p is an integer between 2 and 100, and a is an integer between 1 and 3.)

7. The thermally conductive silicone potting composition according to claim 1, wherein the viscosity at 25°C is 100 Pa·s or less.

8. A cured product obtained by curing the thermally conductive silicone potting composition according to any one of claims 1 to 7.

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