Process for separating multivalent metal Ions from autodeposition compositions and process for regenerating ion exchange resins useful therewith
US5945170A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 1997 |
| Grant date | Aug 31, 1999 |
| Priority date | — |
| Expiry date | Nov 17, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB05D7/142
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The use of selected cation exchange resins to remove dissolved multivalent cations ions such as iron, zinc, and chromium from used autodeposition compositions permits reuse of the autodeposition compositions without the need for added surfactant and without developing any undesirable graininess or other texture in the coatings formed. Iminodiacetate cation exchange resins are very effective for removing iron ions when they are the only multivalent ions to be removed, and can be efficiently regenerated with 0.5 to 4% by weight aqueous hydrofluoric acid. By proper choice of other cation exchange resins and operating conditions, zinc can be selectively extracted from autodeposition baths containing both iron and zinc, and either iron or zinc can be selectively displaced from the loaded ion exchange resin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.