Azo dye reduction improvement of lignin
US4355996A · kind A · utility
20Cited by
9References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 4, 1981 |
| Grant date | Oct 26, 1982 |
| Priority date | — |
| Expiry date | Mar 4, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B67/0086
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Improved sulfonated lignin surfactants are provided for use as dispersants in dyestuffs. The process for providing the improved surfactants relates to using metals and borate salts to react with the azo dye reducing dihydroxy functions of the lignin molecule through chelation and ester formation mechanisms thereby inhibiting the lignin's azo dye reducing characteristics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.