| 摘要 |
PROBLEM TO BE SOLVED: To prepare a chemical conversion treatment solution which enables the deposition of a chemical conversion film which exhibits adhesion for a coating film and corrosion resistance equal to those of a chromate film, and to provide a chemical conversion treated steel sheet. SOLUTION: The chemical conversion treatment solution for treatment to coating consists of titanium hydrofluoride, zirconium hydrofluoride, silica, tannic acid and a water dispersible organic resin, The mass ratio of the tannic acid to the water dispersible organic resin is 100:0.5 to 15, and the mass ratio of inorganic matters to the total content of the tannic acid and water dispersible organic resin expressed in terms of dry mass is 1:0.5 to 2. The titanium hydrofluoride, zirconium hydrofluoride and silica are preferably blended so that, by metallic element ratio, the content of Ti is controlled to >=70 mass%, Zr to <=20 mass%, and Si to 3 to 20 mass%. The chemical conversion treatment solution is applied to a coating original sheet, and is heated and dried, so that the chemical conversion film containing Ti, Zr and Si can be deposited thereon.
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