| 摘要 |
PROBLEM TO BE SOLVED: To improve rust-preventive performance with minimal change in the appearance of a metal plated layer by laminating a lower plated layer and a gold plated layer onto the surface of a resin base material and then coating the surface of the gold-plated layer with a chromate coating. SOLUTION: A resin base material 1 obtained by injection molding is made electroconductive by cleaning its surface to remove dust and stains, then roughening the resulting surface by a chemical etching method, imparting a catalyst such as Pd or the like and depositing a metal such as Cu, Ni or the like on the surface. A lower plated layer 2 such as Cu+Ni coating or the like is formed on the resin base material by an electroplating method, and a gold plated layer 3, e.g. having a thickness of about 0.15μm is laminated on the surface of the lower plated layer 2 by electrically depositing. Further, a chromate coating is deposited on the gold-plated layer 3 by immersing the resin base material 1 into a chromate treating liquid containing hexavalent chromium only for a specified time. Thereby, the pin holes formed in the gold-plated layer 3 can be covered, and the corrosion, caused by moisture or the like invaded from the pin holes, of the lower plated layer 2 can be inhibited.
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