| 摘要 |
PURPOSE:To raise resistance to liquid-leakage by chemically polishing a negative collector, which is made of copper and has a gold plating on it, with a special polishing-agent, and thereby forming a film of a benzotriazole compound on the surface of the contact between the negative collector and a gasket. CONSTITUTION:A positive-electrode can 5 is packed with a positive mixture, on which a separator 2 is placed. A negative terminal plate 6 which works as a negative collector is packed with a negative mixture 4 of zinc, which is placed on the separator 2. Next, an annular gasket 7 is interposed between the negative terminal plate 6 and the positive-electrode can 5, thus constituting a button-type battery which is hermetically sealed. The negative terminal plate 6 is formed of a clad plate which consists of, for example, a copper plate 8, a nickel layer 9 on the outer surface of the plate 8, and a layer 10 of either copper or copper alloy on the inner surface of the plate 8. After a gold layer 12 is formed on the layer 10 by plating, the layer 12 is subjected to chemical polishing with a polishing agent of a hydrogen peroxide-sulfuric acid system. Furthermore, a film 14 which mainly contains a benzotriazole compound is formed on the surface of the contact between the gasket 7 and the glod layer 12. |
