Electroless nickel plating solution
US5306334A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1992 |
| Grant date | Apr 26, 1994 |
| Priority date | — |
| Expiry date | Jul 20, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C18/36
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Phosphorus-containing, crystalline, nickel-coated fabric, wherein said nickel contains 1 to 6 weight percent phosphorus, has crystallites greater than 3 nanometers and has a surface resistivity of less than 1 ohm/square is deposited onto a substrate a surface which is catalytic to electroless deposition of nickel by immersing the substrate into an electroless nickel plating solution consisting essentially of nickel salt, one or more organic acids, hypophosphite reducing agent, thiourea and ammonia and essentially no heavy metal, wherein the concentration of said thiourea is less than 1 ppm, maintained at a pH of 6.5 to 8.5 and a temperature less than 60.degree. C. Preferred plating solutions comprise essentially no lead or cadmium and have a molar ratio of nickel to hypophosphite in said solution is 0.4 to 0.55. Preferred organic acids are selected from the group consisting of lactic acid, acetic acid, propionic acid, pyruvic acid, aspartic acid and glycolic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.