| 摘要 |
PROBLEM TO BE SOLVED: To stably obtain color tones of orange, yellow, purple, gray and green systems by subjecting a film to an anodic oxidation treatment, then subjecting the films further to an AC constant voltage electrolytic treatment for a prescribed time after electrolytic current stabilizes and subjecting the film to an electrolytic coloration treatment in an aqueous sulfuric acid solution containing a metal salt. SOLUTION: The anodically oxidized film of a prescribed film thickness is subjected to chemical conversion by the conventional method using the aqueous sulfuric acid solution and if an AC constant voltage electrolysis of about 2 to 5 V is effected thereafter, just the slight currents flows in an initial period but the current increase gradually and attains a peak, following which the current begins to decrease gradually and stabilizes at a specified current value when a specified time elapses. The time until the stable current value is attained varies largely with anodically oxidized film chemical conversion conditions and the color tones of extremely high reproducibility may be obtained if the lapse time after the stable current value is attained is kept constant. The coloration voltage at this time is preferably specified to <=10 V, by which the color reproducibility of the color tones may be assured.
|
