Process for dyeing keratinous fibres, at acid pH using 6- or 7-monohydroxyindoles and the compositions employed
US5207798A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1991 |
| Grant date | May 4, 1993 |
| Priority date | — |
| Expiry date | Mar 7, 2011 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61K8/492
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Process for dyeing keratinous fibres, in particular human keratinous fibres such as hair, characterized in that there is applied to these fibres a composition containing, in a suitable dyeing mixture, at least one indole-based coupler, of the formula: ##STR1## in which R.sub.1 designates a hydrogen atom or a C.sub.1 -C.sub.4 alkyl radical; R.sub.2 and R.sub.3, which may be identical or different, designate a hydrogen atom, a C.sub.1 -C.sub.4 lower alkyl radical, a carboxyl radical or an alkoxycarbonyl radical; X designates a hydrogen atom, a C.sub.1 -C.sub.4 lower alkyl radical, a C.sub.1 -C.sub.18 alkoxy radical, a halogen atom, a C.sub.2 -C.sub.20 acyloxy radical or an acetylamino group; the OH group occupying the 6- or 7- positions of the aromatic ring; as well as the salts of these compounds; PA0 one oxidation dye precursor; PA0 one oxidising agent; PA0 the pH of the composition applied to the fibres being less than 7.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.