| 摘要 |
PROBLEM TO BE SOLVED: To prepare a pretreatment solution with which a coated steel sheet having excellent adhesiveness of a coating film and corrosion resistance can be obtained without incorporating chromium. SOLUTION: The pretreatment solution for coating for a coated steel sheet consists of polyvinyl alcohol, tannic acid, titanium hydrofluoride, zirconium hydrofluoride and silica. Tannic acid is contained in 2 to 15 pts.mass to 100 pts.mass of polyvinyl alcohol. Further, an inorganic matter of 1.6 to 1.8 times the total content of polyvinyl alcohol and tannic acid expressed in terms of dry mass is contained in the solution.
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