| 摘要 |
PURPOSE:To form a fine film by galvanization without using NH4<+> ions, acetate ions or boric acid which causes a problem during the treatment of waste water by using an acidic galvanizing soln. contg. prescribed amounts of zinc ions, chlorine ions and aminocarboxylic acid or its salt. CONSTITUTION:To an acidic galvanizing soln. contg. >=10g/l zinc ions and >=50g/l chlorine ions is added >=10g/l aminocarboxylic acid or its salt, and galvanization is carried out using the resulting galvanizing soln. Though NH4<+> ions, acetate ions and boric acid are not present at all, satisfactory pH buffering action is produced. The uniformity of a formed film is made higher, and even a part exposed to high current density is hardly burned. Accordingly, a fine film is formed by galvanization.
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