EPOXY RESIN COMPOSITION FOR ELECTRIC INSULATION

PROBLEM TO BE SOLVED: To make an epoxy resin composition for electric insulation excellent in electric breakdown characteristic also at a high temperature and to suitably use the composition for an insulating member of an electrical equipment and an epoxy unit part of a PJ type power cable connecting part by constituting the composition of at least epoxy resin, curing agent and molten silica and making the rates of impurity elements in molten silica as specified wt.%. SOLUTION: Epoxy resin is preferably bisphenol epoxy resin having epoxy equivalent of 350 to 450. Curing agent is acid anhydride curing agent such as phthalic anhydride and hydrogenated phthalic anhydride. In molten silica as filler, the rates of impurity elements in molten silica are made 0.25 wt.% or below, preferably 0.1 wt.% or below. Concretely, AL, Fe, Na, K, Ca, Mg, Cr as impurity elements adversely affecting an electric breakdown characteristic are included in molten silica. The rates of these impurity elements are made 0.25 wt.% or below for the whole quantity of molten silica.