Thermally conductive composite silicone rubber sheet

Abstract

A thermally conductive composite silicone rubber sheet including a thermally conductive silicone rubber sheet and a thermosoftening silicone resin layer provided on one side or both sides of the thermally conductive silicone rubber sheet and having a thickness of 0.5 to 10 μm and an absolute viscosity of 10 to 700 Pa·s at 70° C. The thermosoftening silicone resin layer includes (A) 75 to 95% by mass of a thermosoftening silicone resin in which the proportion of phenyl groups to the number of all substituents directly bonded to silicon atoms is 20 mol % or more, and (B) 5 to 25% by mass of a diphenylsiloxy group-containing organopolysiloxane represented by the following formula (1): wherein m is an integer of 3 to 5, and n is an integer of 5 to 12. Thus, a thermally conductive composite silicone rubber sheet can develop adhesiveness on instantaneous contact while suppressing oil bleed.

Dependencies are inferred from the claim text.