METHOD FOR ELECTROLYTICALLY COLORING ALUMINUM MATERIAL TO GIVE PRIMARY COLOR

摘要

PURPOSE:To obtain an electrolytically colored film having superior stripping resistance by alternately subjecting an Al material to DC anodic electrolysis and AC electrolysis plural times in a sulfuric acid bath to form a multilayered oxide film and by electrolytically coloring the pretreated Al material in an aqueous metallic salt soln. CONSTITUTION:An Al material is alternately subjected to DC anodic electrolysis and AC electrolysis plural times in a sulfuric acid bath to form a multilayered oxide film of 0.5-30mum thickness. The thickness of each of the DC and AC layers in the film is 0.001-0.1mum. The pretreated Al material is electrolytically colored in an aqueous metallic salt soln.