Composition and process for treating metal
US5769967A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 2, 1996 |
| Grant date | Jun 23, 1998 |
| Priority date | — |
| Expiry date | Jul 2, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C22/37
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Heating an aqueous mixture of a fluoroacid such as H.sub.2 TiF.sub.6 and an oxide, hydroxide, and/or carbonate such as silica produces a clear mixture with long term stability against settling of any solid phase, even when the oxide, hydroxide, or carbonate phase before heating was a dispersed solid with sufficiently large particles to scatter light and make the mixture before heating cloudy. The clear mixture produced by heating can be mixed with soluble hexavalent and/or trivalent chromium, and preferably also nitrate and chloride ions to produce a composition that provides a conversion coating with good protection against corrosion while requiring substantially less chromium than previous coatings of equal corrosion protective quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.