Carbon fiber prepreg, and a production process thereof

A process for producing a carbon fiber prepreg comprising the steps of

• (a) preparing a sheet formed by a carbon fiber bundle comprising a plurality of continuous carbon filaments and having a hook drop value of 10 cm or more as the degree of fiber entanglement,
• (b) preparing a resin coated film in which a releasable film is coated with a matrix resin obtained by mixing a base resin mainly composed of a thermosetting resin and particles with a particle size of 150 .mu.m or less made of a thermoplastic resin in an amount corresponding to 20 wt % or less of the prepreg to be completed,
• (c) forming a laminated sheet in which the resin coated film is overlaid on the sheet formed by the carbon fiber bundle, in such a manner that the matrix resin contacts the surface of the sheet formed by the carbon fiber bundle, and
• (d) forming a formed resin impregnated product, in which the clearances between a plurality of carbon filaments of the carbon fiber bundle are impregnated with the base resin, by heating and pressing the laminated sheet.

A process for producing a carbon fiber prepreg comprising the steps of

• (a) preparing a sheet formed by a carbon fiber bundle comprising a plurality of continuous carbon filaments and having a hook drop value of 10 cm or more as the degree of fiber entanglement,
• (b) preparing a first resin coated film in which a first releasable film is coated with a base resin mainly composed of a thermosetting resin,
• (c) forming a first laminated sheet in which the first resin coated film is overlaid on the sheet formed by the carbon fiber bundle, in such a manner that the base resin contacts the surface of the sheet formed by the carbon fiber bundle,
• (d) forming a first formed resin impregnated product, in which the clearances between a plurality of carbon filaments of the carbon fiber bundle are impregnated with the base resin, by heating and pressing the laminated sheet,
• (e) preparing a second resin coated film in which a second releasable film is coated with a matrix resin obtained by mixing a base resin mainly composed of a thermosetting resin and particles with a particle size of 150 .mu.m or less made of a thermoplastic resin in an amount corresponding to 20 wt % or less of the prepreg to be completed,
• (f) forming a second laminated sheet in which the second resin coated film is overlaid on the first formed resin impregnated product, in such a manner that the matrix resin of the second resin coated film contacts the surface of the first formed resin impregnated product, and
• (g) heating and pressing the second laminated sheet, for forming the second formed resin impregnated product where the matrix resin and the base resin are integrated.