JPS6445868A - Electrolytic oxidizing treatment of carbon fiber - Google Patents

Abstract

PURPOSE: To accomplish a uniform and stable surface treatment of carbon fiber without damaging it by electrolytic oxidation treatment of the carbon fiber in an acidic electrolyte followed by an alkaline electrolyte successively with itself as anode. CONSTITUTION: The subject electrolytic oxidation treatment is carried out as follows: using carbon fiber as anode and pref. a platinum plate as cathode, the carbon fiber is subjected to electrolytic treatment in an acidic electrolyte containing an inorganic acid such as phosphoric, sulfuric or nitric acid or an organic acid, the resulting carbon fiber being washed with water and then dried, immediately followed by further electrolytic treatment of the resulting carbon fiber in an alkaline electrolyte containing sodium hydroxide, ammonia or the like, thereby obtaining the aimed carbon fiber with the surface subjected to electrolytic oxidation. According to the above electrolytic oxidation process, high-quality carbon fiber can be afforded through easy, stable and uniform treatment; the carbon fiber thus obtained is highly effective as a composite reinforcing material through compounding in a variety of matrix resins.