CARBON FIBER FOR AQUEOUS PROCESS AND CHOPPED CARBON FIBER FOR AQUEOUS PROCESS

摘要

This invention provides a carbon fiber for an aqueous process which is excellent in convergence and opening properties. The carbon fiber for an aqueous process comprises a plurality of converged single fibers and satisfies (1) the surface oxygen index (O/C) of the single fibers as measured by X-ray photoelectron spectroscopy (ESCA) is not less than 0.03 and less than 0.12, and a sizing agent composed mainly of a surfactant is deposited on the single fibers, and the first contact angle with water as measured by a Wilhelmy method is not more than 75 degrees, (2) the surface oxygen index (O/C) of the single fibers as measured by X-ray photoelectron spectroscopy (ESCA) is not less than 0.12 and less than 0.20, and a sizing agent composed mainly of a surfactant is deposited on the single fibers, and the first contact angle with water as measured by a Wilhelmy method is not more than 65 degrees, and (3) the surface oxygen index (O/C) of the single fibers as measured by X-ray photoelectron spectroscopy (ESCA) is not less than 0.20 and not more than 0.30, and a sizing agent composed mainly of a surfactant is deposited on the single fibers, and the first contact angle with water as measured by a Wilhelmy method is not more than 55 degrees.