Composition and process for treating metals
US5449415A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 2, 1994 |
| Grant date | Sep 12, 1995 |
| Priority date | — |
| Expiry date | Sep 2, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C22/44
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A chromium free conversion coating at least equivalent in corrosion protective quality to conventional chromate conversion coatings can be formed on metals, particularly cold rolled steel, by a dry-in-place aqueous acidic liquid comprising: PA0 (A) a component of anions, each of said anions consisting of (i) at least four fluorine atoms and (ii) at least one atom of an element selected from the group consisting of titanium, zirconium, hafnium, silicon, and boron, and, optionally, (iii) ionizable hydrogen atoms, and, optionally, (iv) one or more oxygen atoms; PA0 (B) a component of cations of elements selected from the group consisting of cobalt, magnesium, manganese, zinc, nickel, tin, zirconium, iron, and copper; the ratio of the total number of cations of this component to the total number of anions of component (A) being at least 1:5; PA0 (C) sufficient free acid to give the composition a pH in the range from 0.5 to 5.0; PA0 (D) a component selected from the group consisting of phosphorus-containing inorganic oxyanions and phosphonate anions; and PA0 (E) a component selected from the group consisting of water-soluble and water-dispersible organic polymers and polymer-forming res…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.