Metal surface-treating method
US6458219B2 · kind B2 · utility
8Cited by
2References
11Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | May 14, 2001 |
| Grant date | Oct 1, 2002 |
| Priority date | — |
| Expiry date | May 14, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C22/73
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
This invention provides a metal surface-treating method which comprises a chemical conversion step of dipping a substrate in an acidic aqueous zinc phosphate solution, and using an aqueous zinc nitrite solution as an accelerator, said aqueous zinc nitrite solution being substantially free of calcium ion and containing 0 to 6500 ppm of sodium ion and 0 to 20 ppm of sulfate ion in case of assuming the concentration of zinc nitrite [Zn(NO2)2] therein to be 10 weight % as NO2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.