| abstract |
(57) [Summary] [Constitution] Epoxy resin, curing agent and silica fine powder are essential components, and the content of silica fine powder is 60 to 80% by weight of the total amount of epoxy resin, curing agent and silica fine powder. . The silica fine powder is surface-treated with 3-methacryloxypropylmethoxysilane and has an average particle size of 0.5 to 10% of cumulative weight% of 5.2 μm and particle size 0.2 μm or less And a cumulative weight% of less than 12.0 μm and a particle size of less than 12.0 μm is 90% or more. [Effect] Before curing, the fine silica powder does not settle, the silica fine powder can be contained in a high amount, and refrigerated storage is possible. Since the viscosity before curing is low, workability such as coating work is good. Further, since the fine silica powder is contained in a high content and the fine silica powder before curing does not settle and the fine silica powder is always uniformly contained, the cured product shows good thermal conductivity evenly. Particularly, it is useful as an insulating adhesive layer for a high heat dissipation wiring board. |