| 摘要 |
PURPOSE:To improve the corrosion resistance of a steel sheet as a base for coating after phosphating by blending halogenated hydrocarbon as a medium with specified amts. of phosphoric acid, water, a soluble solvent, an org. compd. contg. nitrogen, an aprotic polar org. compd. and polyphenol resin, and coating a steel sheet with the resultant composition. CONSTITUTION:A compsn. for phosphating a steel sheet is composed of 100pts. wt. halogenated hydrocarbon as a medium, 0.1-7pts.wt. phosphoric acid, >=0.2pt.wt. water, <=110pts.wt. soluble solvent, 0-22pts.wt. org. compd. contg. nitrogen, 0-33pts.wt. aprotic polar org. compd. and >=0.1pt.wt. polyphenol resin. The max. amt. of the water used is so limited as to form a uniform phase and that of the polyphenol resin is so limited as to give viscosity at which work is enabled. When the treating soln. is applied to a steel sheet or the sheet is dipped in the soln., an iron phosphate coating film having corrosion resistance comparable to that of a zinc phosphate coating film is formed on the surface of the sheet. |
