SILICA FILLER AND EPOXY RESIN COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain a silica filler fully improved in adhesion to a resin through a silane coupling agent by providing silanol group on its surface at a specific amount and performing surface treatment with the silane coupling agent. SOLUTION: This silica filler is obtained by providing >=6μmol/g of silanol group on its surface and performing surface treatment on the surface with a silane coupling agent. The silanol group on the silica filler can be easily adjusted by the burning temperature of silica gel. It is preferable that this silica filler is spherical and has a mean particle diameter of 2-10μm and a geometrical standard deviation a of <=1.5 in a particle size distribution shown by the formulaσ=(D1/D2)0.5 [D1 is a particle diameter in the case of an accumulation of 84 wt.%; D2 is a particle diameter in the case of an accumulation of 16 wt.%; wherein D1 and D2 are each the particle diameter at a point of accumulation from the beginning of a particle diameter of 0μm in the result of the particle size distribution measurement]. This silica filler thus obtained can be used preferably in epoxy resin compositions.