Epoxy resin composition, prepreg, fiber-reinforced resin molded body, and integrated product

An epoxy resin composition comprising an epoxy resin (A) that has a polycyclic aromatic hydrocarbon skeleton or a biphenyl skeleton and has an epoxy equivalent weight of 220 g/eq or more and 290 g/eq or less and a polyamine compound having an average active hydrogen equivalent weight of 55 g/eq or more and 100 g/eq or less wherein the average epoxy equivalent weight over all epoxy resins present is 160 g/eq or more and 255 g/eq or less,

• wherein the epoxy resin composition satisfying at least one of the following features (i) or (ii):
• feature (i):
• the epoxy resin (A) has a weight average molecular weight of 500 g/mol or more and 1,000 g/mol or less:
• feature (ii):
• the epoxy resin (A) has a structure represented by formula (1) or (2):
• wherein in the formula (1),
• X is selected from an ether bond, a sulfide bond, and a biphenyl bond;
• R1 and R2 are each independently selected from a hydrogen atom, an aliphatic hydrocarbon group with a carbon number of 1 to 4, an alicyclic hydrocarbon group with a carbon number of 4 or less, a halogen atom, a glycidyl ether group, and a glycidyl amine group;
• Ar is selected from naphthalene, anthracene, pyrene, and tetracene;
• and
• n is an integer of 2 or more;
• wherein in the formula (2),
• X1 and X2 are each independently selected from an ether bond, a sulfide bond, and a biphenyl bond;
• R1 to R6 are each independently selected from a hydrogen atom, an aliphatic hydrocarbon group with a carbon number of 1 to 4, an alicyclic hydrocarbon group with a carbon number of 4 or less, a halogen atom, a glycidyl ether group, and a glycidyl amine group;
• Ar1 to Ar3 are each independently selected from phenylene, naphthylene, anthracene, pyrene, and tetracene;
• and
• at least one or more of Ar1 to Ar3 are selected from the above group excluding phenylene.