| 摘要 |
PROBLEM TO BE SOLVED: To form an anodically oxidized composite film which is free of water drop traces and has an excellent adhesion property on the surface of aluminum material by suppressing the hydration reaction of the anodically oxidized film. SOLUTION: Aluminum or aluminum alloy is subjected to an anodic oxidation treatment then to a pickling treatment with hot water added with lower carboxylic acid or lower carboxylate followed by electrodeposition coating. One or >=1 kind of tartaric acid, maleic acid, citric acid, etc., are used as the lower carboxylic acid and an alkaline metal salt, ammonium salt, etc., are used as the lower carboxylate. The hot water is managed preferably to a range of a pH 5 to 8.
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