Epoxy resin composition for fiber-reinforced composite material, prepreg, and fiber-reinforced composite material

An epoxy resin composition for fiber reinforced composite materials comprising:

• [A]:
• an epoxy resin having a structure as represented by general formula (1):
• where each R1 and R2 independently denotes one selected from the group consisting of an aliphatic hydrocarbon group with a carbon number of 1 to 4, an alicyclic hydrocarbon group with a carbon number of 3 to 6, an aromatic hydrocarbon group with a carbon number of 6 to 10, a halogen atom, an acyl group, a trifluoromethyl group, and a nitro group;
• n represents an integer of 0 to 4;
• m represents an integer of 0 to 5;
• and X is one selected from the group consisting of −O—, —S—, —CO—, —C(═O)O—, and —SO2—;
• [B] a tri or more-functional epoxy resin having three or more epoxy groups per molecule;
• an optional epoxy resin other than [A] and [B];
• and
• [C] a curing agent;
• wherein [A] accounts for 5 to 60 mas % of all epoxy resin present in the composition;
• and
• wherein [B] accounts for 40 to 80 mass % of all epoxy resin present in the composition.