Patent ID: 9121105
Filing Date: 2015-09-01
Classification: C25D,C25F,Y10T

Abstract:
1. A process for producing an environmentally friendly steel sheet for a container material, comprising: removing a tin oxide layer present on a tin-plated steel sheet by a cathodic electrolytic treatment in an aqueous solution containing sodium carbonate or sodium hydrogen carbonate, or by an immersion treatment in an aqueous sulfuric acid solution, so as to provide a thickness of from 0 mC/cm subsequently, forming a coating film by subjecting the tin-plated steel sheet to a cathodic electrolytic coating treatment in an aqueous solution of an alkali metal sulfate not containing a chromium compound, fluorine, or a nitrate nitrogen, but containing a zirconium compound, wherein said aqueous solution of an alkali metal sulfate has an electric conductivity of from 0.2 S/m to 6.0 S/m and a pH of from 1.5 to 2.5, and wherein the coating film has a film coating amount converted to zirconium of from 0.1 mg/m