| abstract |
The present invention provides a metal material given a chrome-free surface treatment satisfying all of the requirements of corrosion resistance, heat resistance, fingermark resistance, conductivity, coatability, and blackening resistance at the time of working, which was difficult to achieve with conventional chromate-free technology. The chromate-free surface treated metal material of the present invention is comprised of a metal material on the surface of which is coated and dried an aqueous metal surface treatment agent comprising an organic silicon compound (W), obtained by blending a silane coupling agent (A) containing one amino group in its molecule and a silane coupling agent (B) containing one glycidyl group in its molecule in a solid weight ratio [(A)/(B)] of 0.5 to 1.7, at least one type of fluorocompound (X) selected from fluorotitanic acid or fluorozirconic acid, phosphoric acid (Y), and a vanadium compound (Z) so as to form a composite coating containing the different ingredients. |