| 摘要 |
PURPOSE:To provide a titled electroplating bath which yields a smooth and good zinc-lead plating film by incorporating an adequate amt. of bivalent lead ion having a suitable concn. and a the nonionic surface active agent expressed by the specific general formula as a levelling agent in a chloride bath, etc. of bivalent zinc ion. CONSTITUTION:A smooth and good zinc-lead co-deposited plating film having excellent corrosion preventiveness is obtd. by an acidic zinc-lead co-deposition electroplating bath contg. bivalent lead ion having the conc. of <=1/50 the concn. of zinc ion in a molar ratio and contg. further the nonionic surface active agent expressed by the general formula ( I ) (where R1; 1-4 C alkyl group or phenyl group, R2 and R3; hydrogen or methyl group, m and n; 1-30 interger), (II) (where R; 1-18C alkyl group, m; 2-20 interger) in the range of 0.1-30g/l as a levelling agent in a chloride bath of bivalent zinc ion, borofluoride bath, silicofluoride bath or a mixed bath of chloride and borofluoride or silicofluoride.
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