Dyed trivalent chromium conversion coatings and methods of using same
US12173408B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 2019 |
| Grant date | Dec 24, 2024 |
| Priority date | — |
| Expiry date | May 17, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C2222/10
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An aqueous conversion coating solution comprises a trivalent chromium compound, a zirconate compound, and a dye compound. The trivalent chromium compound can comprise trivalent chromium compounds such as trivalent chromium sulfate. The dye compound can comprise an azo dye, a chromium complex dye, an anthraquinoid dye, and/or a methine dye. The zirconate compound can comprise alkali metal hexafluorozirconate compounds. The conversion coating solution can comprise a phosphorous compound such as an organic amino-phosphonic acid compound. The conversion coating solution can be formed by mixing a dye additive containing the dye with a trivalent chromium conversion coating solution that does not contain a dye. The conversion coating solution can be used to treat metal substrates comprising aluminum, magnesium, and/or zinc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.