Prepreg, fiber-reinforced composite material, method for producing same, and epoxy resin composition

A prepreg, comprising:

• a reinforcing fiber;
• and
• an epoxy resin composition comprising a component (A), a component (B), a component (D), and a component (C) as an optional component,
• wherein:
• the component (A) is an epoxy resin that does not include a sulfur atom in the molecule:
• the component (B) is an imidazole compound represented by formula (1):
• R1 represents a straight-chain or branched-chain alkyl group or hydroxymethyl group having 1-5 carbon atoms;
• R2 represents a hydrogen atom or a straight-chain or branched-chain alkyl group having 1-5 carbon atoms;
• the component (C) is an imidazole compound represented by formula (2):
• R3 represents an organic group containing at least one carbon atom, and R4˜R6 represent a hydrogen atom, a methyl group or an ethyl group;
• the component (D) is an epoxy resin that includes at least one sulfur atom in its molecule;
• and
• an amount of the component (B) in the epoxy resin composition is 2˜40 parts by mass based on the total 100 parts by mass of the component (A) and the component (D),
• provided that a curing agent other than the components (A) to (D) is not included in the epoxy resin composition.