Patent ID: 7652104

Claim:
An epoxy resin composition comprising (A) an epoxy resin (B) a curing agent, and (C) an epoxidized polyisoprene (c-1) that contains an epoxy group at 0.15 to 2 meq/g in the epoxidized polyisoprene and has a number-average molecular weight of 15,000 to 200,000 or an epoxidized polybutadiene (c-2) that contains an epoxy group at 0.15 to 2 meq/g in the epoxidized polybutadiene and has a number-average molecular weight of 20,000 to 200,000, wherein the polybutadiene (c-2), before being epoxidized, is formed by polymerizing butadiene, wherein the polybutadiene (c-2) before being epoxidized, consists of butadiene units, wherein the polyisoprene (c-1), before being epoxidized, is formed by polymerizing isoprene, and wherein the polyisoprene (c-1), before being epoxidized, consists of isoprene units.