Ultra-black coating due to surface morphology
US4233107A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 20, 1979 |
| Grant date | Nov 11, 1980 |
| Priority date | — |
| Expiry date | Apr 20, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S126/908
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention provides a method of producing an ultra-black surface coating, having an extremely high light absorption capacity, on a substrate, such as a metal, ceramic, glass, or plastic, the blackness being associated with a unique surface morphology consisting of a dense array of microscopic pores etched into the surface, as well as the resulting coated substrate. The method involves preparing the substrate for plating with a nickel-phosphorus alloy, as by cleaning and/or activating it, immersing the thus-prepared substrate in an electroless plating bath containing nickel and hypophosphite ions in solution until an electroless nickel-phosphorus alloy coating has been deposited on the substrate, and then removing the substrate, coated with the electroless nickel-phosphorus alloy, from the plating bath and washing and drying it. The dried substrate, coated with the electroless nickel-phosphorus alloy, is then immersed in an etchant bath consisting of an aqueous solution of nitric acid, wherein the nitric acid concentration ranges from a 1:5 ratio with distilled or de-ionized water to concentrated, until the coated surface of the substrate develops ultra-blackness, the blackness b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.