Bilayer oxide film and process for producing same
US5178967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 1990 |
| Grant date | Jan 12, 1993 |
| Priority date | — |
| Expiry date | Feb 8, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S206/819
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A bilayer oxide film which comprises a preferably porous layer containing aluminum oxide and a non-porous layer comprising an oxide of a valve metal, e.g. tantalum. The layers are integral. The film is produced by forming a coating of aluminium or an anodizable aluminum alloy on a valve metal (or alloy), anodizing the resulting structure in an electrolyte (preferably one capable of converting the aluminum (or alloy) to a porous oxide film) in the presence of an adhesion-reducing agent (e.g. fluoride ions) that makes the resulting anodized bilayer film easily detachable from the remaining valve metal. The bilayer film is then detached from the valve metal, e.g. by adhering a flexible plastic film to the bilayer and using the film to peel off the bilayer from the valve metal. The resulting bilayer can be used for a variety of purposes, e.g. as a vapor or oxygen barrier useful for packaging, or as a coating containing magnetic particles used to make a magnetic recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.