Solution for chemical conversion treatment

Abstract

Abstract PURPOSE:To obtain a soln. for chemical conversion treatment capable of forming a film having high corrosion resistance and a fine appearance on the surface of a metal such as a zinc film formed by galvanizing without causing environmental pollution by adding tervalent Cr ions, a silicate, a fluoride and an acid. CONSTITUTION:This soln. for chemical conversion treatment contains 0.1-10g/l tervalent Cr ions from a feeding source such as Cr2(SO4)3 or CrCl3, 0.1-20g/l (expressed in terms of silicate ions) silicate such as sodium metasilicate or sodium orthosilicate, 0.1-10g/l (expressed in terms of fluorine ions) fluoride such as hydrofluoric acid or borofluoric acid and 0.5-20g/l acid such as nitric acid or sulfuric acid. The soln. is preferably adjusted to about 0.1-2.5pH. A dye can be added to the soln. so as to provide a desired color tone to a film formed by chemical conversion treatment. An acid mordant dye or a mordant dye is preferably added as the dye at 0.05-2g/l concn.

Inventors

• 👤 Motonobu Kubo
• 👤 久保　元伸
• 👤 Mitsuyasu Kubo
• 👤 久保　光康

Bibliographic Details