Solution composition and method for electroless deposition of coatings free of alkali metals
US6911067B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 2003 |
| Grant date | Jun 28, 2005 |
| Priority date | — |
| Expiry date | Mar 19, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C18/50
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An electroless deposition solution of the invention for forming an alkali-metal-free coating on a substrate comprises a first-metal ion source for producing first-metal ions, a pH adjuster in the form of a hydroxide for adjusting the pH of the solution, a reducing agent, which reduces the first-metal ions into the first metal on the substrate, a complexing agent for keeping the first-metal ions in the solution, and a source of ions of a second element for generation of second-metal ions that improve the corrosion resistance of the aforementioned coating. The method of the invention consists of the following steps: preparing hydroxides of a metal such as Ni and Co by means of a complexing reaction, in which solutions of hydroxides of Ni and Co are obtained by displacing hydroxyl ions OH− beyond the external boundary of ligands of mono- or polydental complexants; preparing a complex composition based on a tungsten oxide WO3 or a phosphorous tungstic acid, such as H3[P(W3O10)4], as well as on the use of tungsten compounds for improving anti-corrosive properties of the deposited films; mixing the aforementioned solutions of salts of Co, Ni, or W and maintaining under a temperatures wit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.