Patent ID: 7378461

Claim:
A curable epoxy resin composition comprising: (A) a non-gelled amine-modified epoxy resin obtained by reacting an epoxy resin and a polyamine; and (B) at least one of boric acid and a borate ester, wherein a boron content (Y) is within the range of 4% to 30% by weight when a ratio (X) is less than 40%; (Y) is within the range of 3% to 25% by weight when (X) is within the range of 40% to 70%; (Y) is within the range of 5% to 20% by weight when (X) is over 70%; and (X) and (Y) satisfy a relationship defined by the formula (1): (X/2+Y)≦45, and the general formula (2): (X/20+Y)≧5, where the ratio (X) represents a ratio of an active hydrogen atom equivalent of the polyamine relative to an epoxy equivalent of the epoxy resin, and the boron content (Y) represents a boron content, expressed as a B 2 O 3 equivalent value, relative to a B 2 O 3 equivalent value of a total weight of (A) the amine-modified epoxy resin, and (B) the boric acid and the borate ester.