| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface treatment film capable of reducing the effect on the natural environment by limiting the elution of hexavalent chromium ions from the surface treatment film to a very low concentration. SOLUTION: The surface treatment film deposited on the surface of a zinc-based metal comprises trivalent chromium oxides, supporting salt or acid as the additive element of a surface treatment liquid, and hexavalent chromium oxides in which the concentration of the hexavalent chromium film to the total weight of the film including a zinc-based metal layer is regulated to≤100 ppm. COPYRIGHT: (C)2007,JPO&INPIT
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