PURPOSE: To obtain the prepreg having a specific void content, excellent in adhesivity, flexibility, dynamically physical properties and durability, and useful for airplane structural materials, etc., by impregnating reinforcing fibers with a specified epoxy resin composition.
CONSTITUTION: This prepreg is produced by impregnating (B) reinforcing fibers with (A) an epoxy resin composition comprising an epoxy resin, a curing agent and a reactive group-containing solid butadiene-acrylonitrile copolymer rubber, and has a void content of ≤5.0%, the lowest viscosity of the component A being 80-1000 poises. The amount of the reactive group-containing solid butadiene-acrylonitrile copolymer rubber added to the component A is 3-10wt.% based on the whole weight of the component A. The prepreg is obtained e.g. by impregnating the component B with the component A and subsequently thermally treating the obtained prepreg at 10-70°C for 5-200hr.
MURAKI TOSHIO
AZUMA KUNIHIRO
