Epoxy resin composition, intermediate substrate, and fiber-reinforced composite material

Abstract

The purpose of the present invention is to provide an epoxy resin composition which exhibits a high level of deforming capacity and fracture toughness and from which a resin cured product maintaining heat resistance can be obtained. The epoxy resin composition according to the present invention satisfies condition 1 or condition 2 below, wherein the resin cured product obtained by reacting the epoxy resin composition at 150° C. for 60 minutes has a tensile elongation at break of 7% or more. Condition 1: including all the following components [A], [B], and [C], component [A]: a bifunctional aliphatic epoxy resin having a specific structure, component [B]: a terminal carboxy-modified acrylic rubber, and component [C]: a dicyandiamide. Condition 2: including the following components [D], [E], and [F] and satisfying conditions [a] and [b] below, component [D]: core-shell type rubber particles, component [E]: a boric ester compound, component [F]: a curing agent, condition [a]: including 9-18 parts by mass of component [D] with respect to 100 parts by mass of the total epoxy resin, and condition [b]: 0.003≤(the content of component [E]/the content of component [D])≤0.05.

Dependencies are inferred from the claim text.