Patent ID: 7250193
Filing Date: 2007-07-31
Classification: C23C

Abstract:
1. A pretreatment method for subsequent coating comprising pretreating a surface with a chemical conversion coating agent to form a chemical conversion coat, wherein the chemical conversion coating agent comprises fluorine and at least one member selected from the group consisting of zirconium, titanium and hafnium, the chemical conversion coat has a fluorine concentration of 10% or less on an atom ratio basis of the chemical conversion coat, and at least a part of the surface is an iron material; and wherein the chemical conversion coating agent further contains an amino group-containing-silane coupling agent; and further contains at least one member selected from the group consisting of a water-borne resin containing an isocyanate group or a melamine group or both (i) and a water-soluble resin having a constituent unit expressed by the chemical formula (1): or the chemical formula (2): or both in at least a part thereof (iii); and wherein said chemical conversion coating agent substantially contains no phosphate ions.