For a fiber-reinforced composite material epoxy resin composition, preparation of the fiber-reinforced composite materials and fiber reinforced composite material

The present invention is, I. (1) at room temperature with an epoxy resin which is liquid, (2) an aromatic polyamine is a liquid at room temperature, (3) for a fiber-reinforced composite material epoxy resin composition which is diaminodiphenyl sulfone as an essential component, II. At least (4) trifunctional or more aromatic epoxy resins, (5) a bifunctional or trifunctional less aromatic epoxy resin, (6) an aromatic polyamine, between theoretical crosslinking points molecular weight of the cured product 250-350 g / a mol, and fiber-reinforced composite material epoxy resin composition for an initial viscosity at 80 ° C. is 1~500mPa / s, III. (7) polyglycidyl ethers of phenol aralkyl resin, according to the fiber-reinforced composite material epoxy resin composition comprising (8) a polyamine. The present invention provides a relatively low low viscosity at temperature, liquid epoxy resin composition which exhibits excellent performance reduction is small or the like of the glass transition temperature due to water absorption of the cured product.