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

An object of the present invention is to provide an epoxy resin composition that can be preferably used for prepreg and fiber reinforced composite material applications and is excellent in elastic modulus, strength, and pot life.The present invention is the epoxy resin composition including the following components [A] to [C] and satisfying the following conditions (1) to (3):[A]: epoxy resin[B]: polyamine curing agent, and[C]: a compound having a boiling point of 130°C or more and a molecular weight m of 50 or more and 250 or less, the compound having no epoxy group in the molecule and having substantially no curing ability of an epoxy resin, and(1): at least a part of the component [C] has two or more alcoholic hydroxyl groups in the molecule.(2): the ratio C/E of the amount by mole, E, for epoxy groups of the component [A] to the amount by mole, C, of the component [C] satisfying the condition (1) is 0.01 or more and 0.20 or less.(3): the viscosity at 70°C for 2 hours is 5.0 times or less the initial viscosity at 70°C.