PRODUCTION OF CARBON FIBER, CARBON FIBER, PREPREG AND FORMED PRODUCT OF FIBER-REINFORCED COMPOSITE MATERIAL

摘要

PROBLEM TO BE SOLVED: To produce a carbon fiber that retains flexibility, when it is processed to a fiber-reinforced composite material with no occurrence of quality deterioration by bending. ;SOLUTION: Pitch fibers obtained from a mesophase pitch having a softening point of 200-400°C, a true density of 1.30-1.38 g/cm3 are subjected to a first infusibilization treatment at a temperature of 100-200°C in a mixed gas atmosphere containing 1-5 vol.% of nitrogen dioxide, 5-50 vol.% of oxygen and the rest of an inert gas such as nitrogen or steam, followed by a second infusibilization treatment at 200-350°C in a mixed gas atmosphere containing 1-5 vol.% of nitrogen dioxide, 5-40 vol.% of oxygen and the rest of an inert gas such as nitrogen or steam whereby the objective carbon fibers are produced.;COPYRIGHT: (C)2000,JPO