Patent ID: 7153348

Claim:
A hexavalent chromium-free surface treating agent for Sn-based or Al-based plated steel sheet, comprising a trivalent chromium compound (A), a water-dispersible silica (B), a lubricity imparting component (C) of one or more of polyolefin wax, fluorine-containing wax and paraffin wax, and water, the mass ratio on a solid content basis, of the water-dispersible silica (B) to the lubricity imparting component (C), (B)/(C), being within a range from 5/95 to 95/5, and a metal nitrate (D), with the metal in the metal nitrate being at least one selected from the group consisting of alkali earth metals, Co, Ni, Fe, Zr and Ti, wherein said surface treating agent is hexavalent chromium-free.