Composition and process for forming a solid adherent protective coating on metal surfaces
US5948178A · kind A · utility
0Cited by
9References
20Claims
0Family size
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Key dates
| Filing date | Jun 16, 1995 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Jun 16, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C22/56
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An aqueous liquid chromate free composition for forming a protective coating on metals, particularly aluminum, is made by reacting cobalt(II) cations, carboxylate anions, at least one other type of coordinate complexing agent for cobalt(III) cations, and an oxidizing agent in an aqueous solution in which the molar ratio of carboxylate anions to cobalt(II) cations is from 0.10 to 6.8 and the aqueous solution contains no more than 1% of each of ammonia, ammonium ions, and nitrite ions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.