Process for the manufacture of cyano azo dyes
US4257944A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1979 |
| Grant date | Mar 24, 1981 |
| Priority date | — |
| Expiry date | Mar 26, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B43/42
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Process for disperse azo dyes having a cyano radical ortho to the azo group by reacting the corresponding halogeno dye with a covalent non-metallic nitrile in the presence of a copper catalyst and an acid acceptor. Previous processes have used a metal cyanide as the cyanide source. The present process does, however, contemplate the use of a non-metallic nitrile, even in small amounts, in combination with a metal cyanide for which advantages are to be gained in terms of reduced copper usage. The non-metallic nitrile is preferably a cyanohydrin which may be prepared in situ by reacting an aldehyde or ketone with a metal cyanide. The metal cyanide may itself provide the copper catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.