Bleaching and dyeing; fluid treatment and chemical modification – Dyeing involving animal-derived natural fiber material ,... – Hair dyeing
Reexamination Certificate
2003-01-24
2004-11-16
Einsmann, Margaret (Department: 1751)
Bleaching and dyeing; fluid treatment and chemical modification
Dyeing involving animal-derived natural fiber material ,...
Hair dyeing
C008S405000, C008S406000, C008S407000, C008S408000, C008S423000
Reexamination Certificate
active
06818023
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to formulations for coloring keratin fibers, more particularly human hair, which contain special dye precursors of the indole or indoline type and a component for intensifying and/or shading the color, to the use of this component for intensifying and/or shading colors and to corresponding coloring processes.
Among the various products available for the cosmetic treatment of the human body, formulations for modifying or shading the color of the hair occupy a prominent position. Disregarding blonding preparations which lighten the hair oxidatively by degrading the natural hair dyes, two types of colorants have long been of importance in the coloring of hair.
So-called oxidation colorants are used for permanent, intensive colors with corresponding fastness properties. Oxidation colorants normally contain oxidation dye precursors, so-called primary intermediates and secondary intermediates. The primary intermediates form the actual dyes with one another or by coupling with one or more secondary intermediates under the influence of oxidizing agents or atmospheric oxygen. Although oxidation colorants are distinguished by excellent coloring results, they can also be attended by disadvantages for certain narrow circles of people. Thus certain dye precursors can cause unwanted skin irritation in so called “para-allergics”. In addition, oxidation dyes are generally developed with oxidizing agents, more particularly hydrogen peroxide. In the event of frequent application by people with sensitive hair, this can cause harm or even damage to the hair structure which has to be repaired with special hair-care products. It is also important not to underestimate the number of people who, in the context of the popular “natural versus chemical” debate, avoid using chemical products wherever possible because of their personal feelings.
Colorants or tints containing substantive dyes as their coloring component are normally used for temporary colors. Substantive dyes are based on dye molecules which are directly absorbed onto the hair and do not require an oxidative process for developing the color. Dyes such as these include, for example, henna which has been used since ancient times for coloring the body and hair.
However, since in the eyes of many consumers both coloring processes are tainted by a hint of the “artificial” with its negative associations, a new coloring process has recently attracted considerable attention. In this process, precursors of the natural hair dye melanin are applied to the hair and, through oxidative processes in the hair, form near-natural dyes. A corresponding process using 5,6-dihydroxyindoline as dye precursor is described in EP-B1 530 229. By application and, more particularly, frequent application of formulations containing 5,6-dihydroxyindoline, grey hair can be restored to its natural color. The color can be developed with atmospheric oxygen as sole oxidizing agent so that there is no need to use other oxidizing agents.
Under the described conditions, however, satisfactory results can only be achieved in people who, before “going grey”, had medium blond to dark brown hair. Accordingly, there has been no shortage of attempts to modify this known coloring process in such a way that even originally red and, above all, dark to black hair can be restored to its original color.
One method of obtaining dark to black color tones, particularly those described by experts as “flat”, is the subject of German patent application 197 32 975.6 to which reference is expressly made, particularly in regard to the prior art literature cited therein. The solution proposed in this patent application is to add conventional secondary intermediates. Although the color can be developed with atmospheric oxygen alone, the use of at least one other oxidizing agent is recommended as a preferred alternative.
However, in view of the above-mentioned reservations of many consumers, there is still a need for a formulation which restores grey hair to its natural color, even in people with originally dark to black hair, without any need for purely synthetic dye components or to use other oxidizing agents than atmospheric oxygen.
It has now surprisingly been found that the problem stated above can be solved by application of a formulation which, besides known dye precursors of the indole or indoline type, contains at least one amino acid or oligopeptide.
DESCRIPTION OF THE INVENTION
Accordingly, the present invention relates to formulations for coloring keratin fibers, more particularly human hair, containing a dye precursor selected from the group consisting of indoline derivatives and indole derivatives, characterized in that it additionally contains at least one amino acid or oligopeptide.
Amino acids in the context of the invention are substances which contain at least one amino group and at least one —COOH or —SO
3
H group.
Preferred amino acids are aminocarboxylic acids, more particularly &agr;-aminocarboxylic acids and &ohgr;-aminocarboxylic acids. Among the &agr;-aminocarboxylic acids, arginine, lysine, ornithine and histidine are particularly preferred.
The amino acids are preferably added to the formulations according to the invention in free form. However, the amino acids may also be used in salt form. Preferred salts are the compounds containing hydrohalic acids, more particularly hydrochlorides and hydrobromides.
A particularly preferred amino acid is arginine used in particular in free form but also as the hydrochloride.
The present invention does of course also encompass formulations containing two or more amino acids or oligopeptides. In this case, combinations of arginine with another amino acid or oligopeptide are preferred.
In addition, the amino acids may also be used in the form of oligopeptides and protein hydrolyzates providing steps are taken to ensure that the necessary quantities of compounds conforming to the definition of amino acids according to the invention are present. Reference is expressly made in this connection to the disclosure of DE-OS 22 15 303.
The formulations according to the invention contain the amino acid or oligopeptide in quantities of preferably 0.1 to 10% by weight and more preferably 1 to 4% by weight, based on the formulation as a whole.
Hair colorants, more particularly those where the color is developed oxidatively with atmospheric oxygen or other oxidizing agents, such as hydrogen peroxide, are normally adjusted to a mildly acidic or alkaline pH value, i.e. to a pH value in the range from about 5 to 11. To this end, the colorants contain alkalizing agents, normally alkali metal or alkaline earth metal hydroxides, ammonia or organic amines.
In one special embodiment of the present invention, the amino acid or the oligopeptide is used not only to promote color development, but also at least partly as an alkalizing agent. Accordingly, amino acids and oligopeptides of which 2.5% by weight solutions in water have a pH value of 9 or higher are preferably used in this embodiment. One such amino acid is the preferred arginine. In this particular embodiment, the other alkalizing agent is selected from the group consisting of monoethanolamine, monoisopropanolamine, 2-amino-2-methylpropanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methylbutanol and triethanolamine and alkali metal and alkaline earth metal hydroxides. Within this group, monoethanolamine, triethanolamine and 2-amino-2-methylpropanol and 2-amino-2-methyl-1,3-propanediol are particularly preferred. &ohgr;-Amino acids, such as &ohgr;-aminocaproic acid, are also preferably used as alkalizing agents in this embodiment of the invention.
Particularly advantageous properties are exhibited by formulations in which the amino acid or the oligopeptide and the other alkalizing agent are present in a ratio by weight of 1:5 to 5:1. Quantity ratios of 1:2 to 2:1 have proved to be particularly suitable.
The formulations according to the invention contain a dye precursor of the indole or indoline type as another compulsor
Hoeffkes Horst
Neuhaus Winifried
Schumann Klaus
Einsmann Margaret
Harper Stephen D.
Henkel Kommanditgesellschaft auf Aktien
Hill Gregory M.
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