Patent ID: 9284657
Filing Date: 2016-03-15
CPC Classification: C25D

Claim Text:
1. A replenisher for use in supplying zirconium ions to a metal surface treatment solution which contains zirconium ions and fluorine ions and which is used to form, on a surface of a steel sheet, a zirconium-containing chemical conversion coating through electrolytic treatment, comprising: (A) hexafluorozirconic acid or a salt thereof; and/or (B) hydrofluoric acid or a salt thereof; and (C) a fluorine-free zirconium compound, wherein a total concentration (g/L) of the zirconium ions derived from the hexafluorozirconic acid or a salt thereof (A) and the fluorine-free zirconium compound (C) is at least 20, wherein a ratio (M