| 摘要 |
PURPOSE:To obtain a discoloration preventing film which is excellent in adhesiveness, maintains a silver color, and has fine luster, by a method wherein a film of the complex compound salt of Cr and P and a clear coating are applied in this sequence on the surface of an outer casing component for a timepiece, which is formed of silver, silver alloy or plating formed thereof. CONSTITUTION:By using an electrolyte containing sodium tripoly phosphate of 80g/l-85g/l, sodium chromate of 20g/l-25g/l and a surfactant of 0.2-0.3%, silver-plating 3 is applied on a dialplate blank having, for instance, a pattern 4 of a dial plate 5 of a clock, and further thereon a discoloration preventing film of a complex compound salt containing Cr and P is applied. Next, a mixed coating liquid of thinner (a mixture of five kinds of solvents of ester, ketone, ether, hydrocarbon and alcohol) of 5 weight parts, and of a coating composition of 6pts.wt. being composed of the resin of three kind of acryl, vinyl and cellulose and of the above thinner, is applied on the film 2 and dried, and thereby a clear coating film 1 is formed. By this constitution, an outer casing whose silver color is maintained and which has fine luster can be obtained. |
