Composition and process for pickling and removing rust from metal
US4400289A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 1982 |
| Grant date | Aug 23, 1983 |
| Priority date | — |
| Expiry date | Feb 5, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23G1/025
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A pickling and rust-removing paste composition suitable for cleaning metal surfaces, including surfaces of steel and aluminum. The composition contains fluoride ions and a mixture of calcium compounds and tervalent iron and/or aluminum compounds and has an acidity corresponding to at least 10% by weight of free acid, calculated at 100% HF. The composition also most preferably contains at least one anion selected from nitrate, sulfate, phosphate and chloride and has an acidity corresponding to from about 15 to 30% by weight of free acid, calculated as 100% HF. The composition is applied to that portion of the metal surface, such as steel or aluminum, to be treated and is retained in contact with the surface for a period of time sufficient to effect the desired pickling and/or removal of rust on the surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.