EPOXY RESIN COMPOSITION, PREPREG, AND CARBON FIBER-REINFORCED COMPOSITE MATERIAL

An epoxy resin composition including [A1] a hardener represented by Formula (1), and [B] an aromatic epoxy resin having tri- or higher functionality, wherein a carbon nuclear relaxation time T 1 C corresponding to a benzene ring carbon atom in the main backbone of Formula (1) assigned to 130 ppm in a solid-state 13 C-NMR spectrum is 42 seconds or longer, and a prepreg and a carbon fiber-reinforced composite material obtained using the epoxy resin composition: wherein X represents any one selected from -CH 2 -, -O-, -CO-, -C(=O)O-, -S-, -SO 2 -, and -NHC(=O)-; n represents 1 to 5; and R 1 to R 6 each represent at least one selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 4 or less carbon atoms, and an a halogen atom, wherein when X is -C(=O)O- or -NHC(=O)-, X may be in either direction. Provided are an epoxy resin composition that provides a carbon fiber-reinforced composite material excellent in tensile strength and compression strength and suitable as a structural material, a prepreg, and a carbon fiber-reinforced composite material.