Method for electrodepositing zinc and zinc alloy coatings from an alkaline coating bath with reduced depletion of organic bath additives
US11339492B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 2018 |
| Grant date | May 24, 2022 |
| Priority date | — |
| Expiry date | Feb 5, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D21/18
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The present invention relates to a method for the galvanic deposition of zinc and zinc alloy coatings from an alkaline coating bath with a reduced degradation of organic bath additives. An electrode that contains metallic manganese and/or manganese oxide and is insoluble in the bath is hereby used as an anode. The electrode is produced from metallic manganese or an alloy comprising at least 5% by weight of manganese, or from an electrically conductive substrate and a metallic manganese and/or manganese oxide-containing coating applied thereto, or from a composite material, wherein the coating and the composite material comprise at least 5% by weight of manganese. The method according to the invention is particularly suitable for the galvanic deposition of zinc-nickel alloy coatings from alkaline zinc-nickel baths since the formation of cyanides can be very effectively inhibited.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.