Replenisher and method for producing surface-treated steel sheet
US9284657B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 2011 |
| Grant date | Mar 15, 2016 |
| Priority date | — |
| Expiry date | Nov 30, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D21/18
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A replenisher which is capable of supplying Zr ions to a metal surface treatment solution, while suppressing an increase in the HF concentration in the metal surface treatment solution, so that a chemical conversion coating film can be continuously formed on a steel sheet by electrolysis and contains (A) zirconium hydrofluoric acid or a salt thereof and/or (B) hydrofluoric acid or a salt thereof and (C) a fluorine-free zirconium compound. The total concentration (g/l) of zirconium ions derived from the components (A) and (C) is 20 or more, and the ratio of the total molar amount (MF) of the fluorine ions derived from the components (A) and (B) relative to the total molar amount (MZr) of the zirconium ions derived from the components (A) and (C), namely MF/MZr is 0.01 or more but less than 4.00.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.