CHEMICAL FILM FINISHING AGENT AND METHOD FOR PRODUCING SAME

摘要

The following two means are provided for a finishing agent for a chemical conversion coating wherein the finishing agent is capable of forming a finishing coating having an excellent corrosion resistance and excellent appearance as well as being suppressed in the elution of trivalent chromium: (A) the ratio of the chromium equivalent molar concentration of a water-soluble trivalent chromium-containing substance contained in the finishing agent relative to the phosphorus equivalent molar concentration of a water-soluble phosphoric acid-based compound contained in the finishing agent is 0.5 or more; and (B) a water-soluble aluminum-containing substance and/or a water-soluble zirconium-containing substance are contained in the finishing agent such that the ratio of the total of the chromium equivalent molar concentration of the water-soluble trivalent chromium-containing substance, the aluminum equivalent molar concentration of the water-soluble aluminum-containing substance, and the zirconium equivalent molar concentration of the water-soluble zirconium-containing substance relative to the phosphorus equivalent molar concentration of the water-soluble phosphoric acid-based compound is 0.5 or more.