Process for improving the storage stability of indole dyestuffs
US4208183A · kind A · utility
24Cited by
2References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 9, 1978 |
| Grant date | Jun 17, 1980 |
| Priority date | — |
| Expiry date | May 9, 1998 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61Q5/10
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The invention relates to storage-stable dyestuff solutions which can be mixed at the time of use with appropriate carriers. These solutions comprise at least one dihydroxyindole of the formula: ##STR1## in which R.sub.1 and R.sub.2 independently of one another denote hydrogen or methyl, or a cosmetically acceptable salt thereof, in an anhydrous solvent chosen from amongst ethyl, isopropyl and tert.-butyl alcohol, ethylene glycol monomethyl, monoethyl and monobutyl ethers and the acetate of ethylene glycol monoethyl ether.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.