Preparation of a concentrated solution of an anionic azo dye containing a sulfonic acid group
US4058517A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 21, 1973 |
| Grant date | Nov 15, 1977 |
| Priority date | — |
| Expiry date | Feb 21, 1993 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B41/002
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Process of preparing a concentrated solution of a water-soluble anionic azo dye containing 1 to 4 sulfonic acid groups by diazotization and coupling of a diazo and coupling component, respectively, in the solvent or solvent mixture required for the concentrated solution which should have as essential solvents water and/or water-soluble or water-miscible organic solvents other than carboxylic acids. Diazotization is carried out with a nitrous acid ester of a hydroxy-substituted aliphatic hydrocarbon, e.g., an alkyl nitrite. The process provides highly stable concentrated or stock solutions of unlimited miscibility with water for use in continuous dyeing methods.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.