Thermally-curable heat-conductive silicone grease composition

摘要

Provided is a thermally-curable heat-conductive silicone grease composition which has a high shape-retaining property in an early stage even when the viscosity of the composition is low (i.e., the composition is easy to apply) in the early stage, and which becomes soft (has low hardness) after being cured. A thermally-curable heat-conductive silicone grease composition comprising, as essential components:
(A) an organopolysiloxane having a viscosity of 100 to 100,000 mPa·s at 25° C. and containing at least one alkenyl group per molecule;(B) an organopolysiloxane represented by general formula (1);
(wherein R1 represents a monovalent hydrocarbon group; R2 represents an alkyl group, an alkoxyalkyl group, an alkenyl group or an acyl group; n represents 2 to 100; and a represents 1 to 3);
(C) an organohydrogenpolysiloxane containing at least two hydrogen atoms each directly bound to a silicon atom per molecule;(D) a catalyst selected from the group consisting of platinum and platinum compounds;(F) a heat-conductive filler having a heat conductivity of 10 W/m·° C. or more; and(G) a silica micropowder.

主权项

1. A heat-curable, heat-conductive silicone grease composition comprising, as essential components,
(A) 100 parts by weight of an organopolysiloxane having a viscosity of 100 to 100,000 mPa·s at 25° C. and containing at least one alkenyl group per molecule, (B) based on the weight of component (A), 10 to 900 parts by weight of an organopolysiloxane having the general formula (1):wherein R1 is independently a substituted or unsubstituted monovalent hydrocarbon group, R2 is independently an alkyl, alkoxyalkyl, alkenyl or acyl group, n is an integer of 2 to 100, and a is an integer of 1 to 3,
(C) an organohydrogenpolysiloxane containing at least two silicon-bonded hydrogen atoms per molecule in such an amount that the number of Si—H groups divided by the number of alkenyl groups in components (A) and (B) may fall in the range from 0.1 to 10.0, (D) a catalyst selected from the group consisting of platinum and platinum compounds in such an amount as to provide 0.1 to 500 ppm of platinum atom based on the weight of component (A), (F) based on the weight of component (A), 100 to 20,000 parts by weight of a heat-conductive filler having a thermal conductivity of at least 10 W/m·° C., (G) based on the weight of component (A), 0.1 to 100 parts by weight of finely divided silica, said finely divided silica being surface-treated fumed silica, and (H) based on the weight of component (A), 0.1 to 20 parts by weight of a silane coupling agent having one of the following three structural formulas:in which formulas the symbol Me designates a methyl group.