SURFACE TREATED STEEL SHEET HAVING EXCELLENT WHITE RUST RESISTANCE, AND PRODUCTION METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a surface treated steel sheet which contains no chromium in a surface treatment film but still exhibits excellent corrosion resistance. SOLUTION: In the surface treated steel sheet, by realizing a reaction layer between a barrier layer and plating metal effective for corrosion inhibition not as a double layer but in a single layer film, corrosion resistance of a high degree can be obtained. The surface of a zinc base or aluminum base plated steel sheet is provided with a surface treatment film formed by applying a surface treatment composition containing (a) a water dispersible resin and/or or water soluble resin which is a reaction product between an epoxy group- containing resin and an active hydrogen-containing compound and in which part or the whole of the active hydrogen-containing compound is a hydrazine derivative containing active hydrogen, (b) a silane coupling agent, and (c) phoshoric acid and/or hexafluoro metal acid, and drying the same composition.