| 摘要 |
PROBLEM TO BE SOLVED: To obtain a silver-plated film having a uniform, beautiful and glossy appearance by preventing discoloration and the unevenness of a color tone in a displacement-silver-plating process. SOLUTION: A displacement-silver-plating bath containing a soluble silver salt and a complexing agent formed of a sulfur-containing compound such as thiourea further includes at least one of a chlorine-containing compound and a bromine-containing compound. The chlorine-containing compound contained in the displacement-silver-plating bath effectively prevents the discoloration of the silver film. The displacement-silver-plating bath also includes lactic acid, formic acid, a compound containing an amino group such as aspartic acid, and a compound containing a carboxyl group, which prevent the discoloration of the film, improve the unevenness of the plated film, and contribute to providing the plated film with a uniform, glossy and silver-white appearance. COPYRIGHT: (C)2007,JPO&INPIT
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