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

To provide a carbon fiber-reinforced composite material which can activate tensile strength of carbon fibers at a high utilization rate, has both excellent compressive strength and impact resistance, and has high tensile strength, and a prepreg which enables manufacture of the same.SOLUTION: A carbon fiber-reinforced composite material contains the following components [A] carbon fibers 1, [BCDc] a matrix resin and [Ec] thermoplastic resin particles 4, and is formed by stacking a carbon fiber layer containing the bundles of [A] and [BCDc] for fixing the bundles, wherein in a distribution curve obtained from a free volume radius obtained by a position annihilation lifetime measuring method and its presence probability, a difference between a maximum value and a minimum value of a pore radius is 0.09 nm or more, in a cross section obtained by cutting at an arbitrary position in a thickness direction, [Ec] is observed so that a ratio of a major axis to a minor axis at 30% or more thereof on a number basis is 1.1 or more, and 90 area% or more thereof on an area basis is contained between layers 3 between the carbon fiber layer and the carbon fiber layer.SELECTED DRAWING: Figure 7 【課題】炭素繊維の持つ引張強度を高い利用率で活用でき、優れた圧縮強度と耐衝撃性を兼ね備え、高い引張強度を有する炭素繊維強化複合材料およびそれを製造できるプリプレグを提供する。【解決手段】次の構成要素［Ａ］炭素繊維１、［ＢＣＤｃ］マトリックス樹脂および［Ｅｃ］熱可塑性樹脂粒子４を含み、［Ａ］の束とそれを固定する［ＢＣＤｃ］とを含む炭素繊維層が積層された炭素繊維強化複合材料であって、陽電子消滅寿命測定法で得られる自由体積半径とその存在確率から得られる分布曲線において、孔半径の最大値と最小値の差が０．０９ｎｍ以上であり、任意の位置で厚み方向に切断して得られる断面において、［Ｅｃ］は、その個数基準での３０％以上において長径と短径の比が１．１以上として観測され、かつ、その面積基準での９０面積％以上が炭素繊維層と炭素繊維層の層間３に含有されている、炭素繊維強化複合材料。【選択図】図７