Stability additive for trivalent chrome conversion coating bath solutions
US6648986B1 · kind B1 · utility
11Cited by
8References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 13, 2002 |
| Grant date | Nov 18, 2003 |
| Priority date | — |
| Expiry date | May 13, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C2222/10
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An acidic aqueous solution containing a water soluble trivalent chromium compound is provided with a solution stability additive for reducing precipitation of trivalent chromium over time. The concentration of the solution stability additive varies based on the complexing capability of the additive. Suitable additives for use as solution stability additives in accordance with the present invention are selected from the group consisting of acetic acid, glycolic acid, and mixtures thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.