CHROMIUM-FREE CONVERSION COATING

摘要

A composition comprising a conducting polymer dispersion, at least one silane, at least one zirconium salt and at least one cerium nitrate salt, wherein the pH value of the composition is between 1.0 and 6Ø Furthermore, a process for treatment of a metallic surface, the process comprising the steps of: a) pretreating the metallic surface; b) coating the metallic surface with a conversion coating by contacting such metallic surface with the above described composition; and c) drying the coated metallic surface. As well as the conversion coating applied on the metallic surface by the process of the invention, the use of such conversion coating to protect against corrosion and promote adherence, and the metallic surface coated with the conversion coating obtained by such process.