COMPOSITION FOR SURFACE TREATMENT, TREATMENT LIQUID FOR SURFACE TREATMENT, SURFACE TREATMENT METHOD, AND PRODUCT COMPRISING METAL MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide composition for surface treatment which is, e.g., formed on the surface of a metal material such as iron, zinc, zinc-containing plating, aluminum, an aluminum alloy, magnesium, a magnesium alloy or the like, has improved corrosion resistance even in an uncoated state or after coating, further, in a conventionally used phosphate treatment stage, and also, without improving a treatment apparatus, further can reduce the consumption of a chemical, and can be obtained at a low cost. SOLUTION: The composition for surface treatment comprises zinc, phosphoric acid and an aromatic nitro compound. The concentration of the zinc [Zn] (the unit is mol/L), the concentration of the phosphoric acid [PO4] (the unit is mol/L), and the concentration of the aromatic nitrocompound [NO2] (the unit is mol/L) satisfy the relation of 100≤ä[Zn]/[PO4]}/[NO2]≤700. COPYRIGHT: (C)2004,JPO