| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a carbon fiber that contributes to improvement in interlaminar fracture toughness of composite material. <P>SOLUTION: The method for producing a carbon fiber includes, when a carbon fiber strand to which 0.3-5.0 wt.%, based on the fiber weight, of a sizing agent comprising an epoxy resin as a main component is attached, performing a dry heat-treatment at 200-250°C until the epoxy equivalent of the sizing agent after the treatment is 2.0-4.0 times as much as the epoxy equivalent of the sizing agent before the attachment. A carbon fiber for a composite material, having excellent composite performance, especially excellent interlaminar fracture toughness to be an index of interlayer brittleness, is obtained. <P>COPYRIGHT: (C)2011,JPO&INPIT |
