PREPREG AND FIBER-REINFORCED COMPOSITE MATERIAL

摘要

Provided is a prepreg for obtaining a fiber-reinforced composite material which combines stable impact resistance and interlaminar toughness with compressive strength under wet heat conditions. The prepreg comprises an epoxy resin, reinforcing fibers, and polymer particles [C] which are insoluble in the epoxy resin and are either [Cx] or [Cy], wherein 90% or more of [C] are present in the range of from one or each surface of the prepreg to a depth corresponding to 20% of the thickness of the prepreg. [Cx] Polymer particles giving a particle diameter distribution chart (x-i) which has at least two peaks and (x-ii) in which the particle diameter ratio between the two highest peaks is in the range of 1.5-7 and (x-iii) in which the peak, of the two highest peaks, that is located on the larger-particle-diameter side has a half-value width in the range of 1.1-3. [Cy] Polymer particles (y-i) which have an average particle diameter which is 1-18 µm or is larger than 12 µm but not larger than 50 µm, (y-ii) which have a degree of sphericity of 90-100, and (y-iii) which have a glass transition temperature of 80-155ºC.