| 摘要 |
PURPOSE: To obtain a carbon fiber specifically excellent in mechanical strength especially in compressive strength at a high temperature and a high humidity and suitable for a fiber reinforced composite material by imparting a sizing agent of a specific compound after an electrolytic surface treatment of the fiber. CONSTITUTION: This carbon fiber is produced by electrolytic surface treating the carbon fiber in the aqueous solution of an ammonium salt so as to make <=0.20 surface oxygen concentration O/C and >=0.20 surface nitrogen concentration N/C measured by a X-ray photoelectron spectroscopy, and imparting any one of a epoxy, polyester, polyimide, bismaleimide or polyurethane compound containing bromine, fluorine or a condensed polycyclic aromatic ring, a mixture thereof or an epoxy compound having <=2.0% moisture absorption ratio to the surface treated carbon fiber as a sizing agent. |
