| 摘要 |
PROBLEM TO BE SOLVED: To provide a carbon fiber bundle which comprises >=24,000 monofilaments, can uniformly be subjected to an electrolytic oxidation treatment in the radial direction, to achieve the uniform and sufficient impregnability of a matrix resin and adhesivity to the matrix resin, and to provide a method for treating the surface of the carbon fiber bundle. SOLUTION: This method for treating the surface of the carbon fiber bundle, characterized by subjecting the carbon fiber bundle comprising >=24,000 monofilaments as an anode to an electrolytic oxidation treatment using a quantity of electricity of 7.5 to 45 C/g for >=4 sec. The obtained carbon fiber bundle has a surface oxygen concentration O/C of 0.05 to 0.15 measured by X-ray photoelectron spectroscopy, an irregularity of carbon fiber surface characteristic ipa of <=8% measured by Cyclic Voltammetry method, and a contact angle irregularity of <=10%. |
