Patent ID: 6960878

Claim:
An epoxy resin composition comprising: an epoxy resin comprising an alicyclic epoxy resin in an amount of 65% by weight or more of the epoxy resin, an acid anhydride represented by the general formula (1) or dicarboxylic acid represented by the general formula (2) in an amount of 0.005 to 1.5 mol based on an epoxy equivalent of the epoxy resin, and a cation curing agent in an amount of 0.0001 to 0.01 mol based on an epoxy equivalent of said epoxy resin wherein R 1 represents a cyclic or aliphatic alkyl, or a cyclic or aliphatic aryl, said R 1 having 0 to 12 carbon atoms and R 2 represents an alkyl or aryl, said R 2 having 0 to 12 carbon atoms.