Universal aqueous coating compositions for pretreating metal surfaces
US6805756B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 2002 |
| Grant date | Oct 19, 2004 |
| Priority date | — |
| Expiry date | Sep 1, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C2222/20
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A universal aqueous composition and a process for using such a composition for pretreating metal substrates is provided. The aqueous composition includes a hydroxy functional cyclic compound, such as a tannin, in an amount of at least about 500 ppm, phosphate ions, an oxidizer-accelerator, and at least one Group IVB metal compound capable of converting to a metal oxide upon application to the metal substrate, such as a fluorozirconate or fluorotitanate. The composition may further contain fluoride ions and/or iron. The composition is particularly useful for corrosion resistance with a variety of metals such as iron, steel, zinc-coated surfaces, aluminum, and alloys thereof. A disaccharide may further be provided to prolong the useful life of the composition, particularly when used in spray applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.