BLACKENING TREATMENT SOLUTION FOR BLACK Cr-Co ALLOY PLATING FILM
AssigneeOkuno Chemical Industries Co., Ltd.
InventorsJunichi Katayama, Shingo Nagamine, Ryuichi Tamura
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Abstract
The present invention provides a blackening treatment method for a black Cr—Co alloy plating film, the method comprising bringing a black Cr—Co alloy plating film having a Cr content of 1 to 15 wt. % into contact with a blackening treatment solution comprising an aqueous solution with a pH value of −1 to 5. According to the present invention, the blackish color of a less blackish plating film formed from a plating bath containing trivalent chromium is enhanced to further improve decorativeness. Furthermore, the corrosion resistance of the film can be more improved by performing electrolytic chromate treatment after blackening treatment.
Claims9
A blackening treatment method for a black Cr—Co alloy plating film, the method comprising bringing a black Cr—Co alloy plating film having a Cr content of 1 to 15 wt. % into contact with a blackening treatment solution comprising an aqueous solution with a pH value of −1 to 5.
A blackening treatment solution for a black Cr—Co alloy plating film, the solution comprising an aqueous solution with a pH value of −1 to 5.
Dependencies are inferred from the claim text.