1. Field of the invention
This invention relates to polymeric dyes obtained by condensation of cationic biopolymers with dyes, to a process for their production, to formulations containing these dyes for dyeing fibers, to processes for dyeing fibers using the polymeric dyes and to their use for dyeing fibers.
2. Discussion of the Related Art
So-called substantive dyes or oxidation dyes are normally used for coloring keratin fibers, preferably human hair. Oxidation dyes consist of a primary intermediate and a secondary intermediate and are formed on the hair itself under the effect of oxidizing agents or atmospheric oxygen.
However, there is a need on the market for coloring products which enable the color of hair to be rapidly changed, i.e. which can be quickly and completely washed out. The hair normally has to be washed 5 to 6 times to remove known products, something which many consumers find unsatisfactory.
Another disadvantage of known hair coloring or hair tinting formulations is that the products always penetrate into the keratin fibers and, hence, cause damage--albeit normally slight--to the hair structure. Since the formulations do not act selectively on keratin fibers, the treated scalp is generally colored at the same time which consumers also find undesirable.
Accordingly, the problem addressed by the present invention was to provide new formulations for the temporary coloring of keratin fibers which would not have any of the disadvantages mentioned above.