Method of operating process for anodizing valve metals
US6235181A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1999 |
| Grant date | May 22, 2001 |
| Priority date | — |
| Expiry date | Mar 10, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D11/26
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method of anodizing a metal comprising immersing a metal substrate into an a glycerine-based electrolytic solution and applying a constant current to produce a uniform film. The electrolytic solution additionally comprises at least one acidic organic salt, inorganic salt, or mixtures thereof. Suitable salts include dibasic potassium phosphate, P-toluene sulfonate, potassium hydrogen sulfate and monobasic potassium tartrate. The electrolytic solution may be prepared by mixing glycerine and the salt or salts, and then heating the solution to about 150 to 180.degree. C. for about 1 to 12 hours. The prepared solution preferably has a water content of less than 0.1 wt %. Anodizing may be performed in the electrolytic solution at temperatures above about 150.degree. C. to achieve non-thickness-limited film growth. Temperature fluctuations within the solution are reduced by the use of impellers or ultrasonic agitation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.