INTERMEDIATE TREATMENT IN ELECTROLYTIC COLORATION OF ALUMINUM ANODICALLY OXIDIZED FILM

摘要

PURPOSE:To obtain a colored material having uniformity and even colored depth by treating a oxidized film with aqueous soln. contg. chelating agent to Al ion before electrolytically coloring Al anodic oxidized film. CONSTITUTION:Before coloring electrolytically Al, the anodically oxidized film formed by a conventional method, the oxidized film is treated by aqueous soln. contg. chelating agent to Al ion, to activate the surface of oxidezed film. Dibasic acid, e.g. oxalic acid, maloic acid, tartaric acid, etc. is used to chelating agent, and pH of aqueous soln. contg. said agent is adjusted within 2-10pH range. The temp. of soln. is regulated to the room temp. -60 deg.C in the treatment.