| 摘要 |
PROBLEM TO BE SOLVED: To provide a black steel sheet excellent in flaw resistance and fingerprint resistance, in which a composition not containing chromium is used so as to obviate a particular waste water treatment required for disposal of haxavalent chromium in the treatment process of a steel sheet or during the use of a surface treated steel sheet produced, which is also excellent in corrosion resistance and is free from the change of a color tone such as a whitening and low glossiness. SOLUTION: The surface of a Zn-Ni plated steel sheet subjected to a blackening treatment is coated with a metallic surface treating composition containing a metal ion, a water dispersible organic resin that is (a) glass transition temperature: 10 to 80 deg.C, (b) solubility parameter: less than 9.8, (c) refractive index: less than 1.55, and acid to deposit a skin layer for the black steel sheet.
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