Coloring agent comprising transition metals

Details Coloring agent comprising transition metals Coloring agent comprising transition metals

2001-09-25

2003-11-18

Gupta, Yogendra N. (Department: 1751)

Bleaching and dyeing; fluid treatment and chemical modification

Dyeing involving animal-derived natural fiber material ,...

Hair dyeing

C008S406000, C008S408000, C008S621000, C008S623000, C008S624000, C008S627000, C008S628000, C008S631000

Reexamination Certificate

active

06648925

ABSTRACT:

CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national stage application under 35 U.S.C. §371 of international application PCT/EP99/09903 filed on Dec. 14, 1999, the international application not being published in English. This application also claims priority under 35 U.S.C. §119 to DE 198 59 681.2, filed on Dec. 23, 1998.
FIELD OF THE INVENTION
This invention relates to colorants containing transition metal complexes included in clathrate compounds as oxidation catalysts and to the use of these compositions for coloring keratin-containing fibers.
BACKGROUND OF THE INVENTION
In general, keratin-containing fibers, for example wool, pelts and in particular human hair, are colored either with substantive dyes or with oxidation dyes which are formed by oxidative coupling of one or more primary intermediates with one another or with one or more secondary intermediates.
Substantive dyes are applied under moderate conditions. Unfortunately, their disadvantage is that the colors obtained often have inadequate fastness properties. Although intensive colors with good fastness properties can be obtained with oxidation dyes, the color is generally developed under the effect of H
2
O
2
or H
2
O
2
adducts, which can result in damage to the fibers.
Oxidation colorants using atmospheric oxygen as a very mild oxidizing agent have also been proposed. However, oxidation with atmospheric oxygen is generally incomplete. In oxidation hair colorants in particular, which are generally applied in a cream-like cosmetic carrier, the atmospheric oxygen comes up against considerable diffusion barriers. In addition, it has been proposed, for example in EP-B1 0 548 620, to limit the hydrogen peroxide content of the oxidation colorants to 1% by weight or less, but at the same time to add special enzymes, peroxidases, to the colorant for activation. Unfortunately, none of these proposals has yet produced a significant breakthrough in terms of a competitive market product.
Accordingly, there is still a need for oxidation colorants which, by virtue of their relatively low content of oxidizing agents or by oxidation with atmospheric oxygen, enable coloring to be carried out under more moderate conditions without adversely affecting the final coloring result. In addition, it is highly desirable to reduce the pH of the colorants to a value around the neutral point in order to prevent possible damage to the fibers through the normally strong alkalinity of the colorants.
The use of transition metal complexes in connection with the oxidative coloring of hair is known in principle. For example, it was proposed in European patent application EP-A2-507 448 to treat the hair before the actual coloring process with a transition metal complex containing the ligands 2,2′-dipyridyl or o-phenanthroline in order to stabilize the hair against oxidative degradation of the cysteine. In addition, it was proposed in German patent DE-C1-195 34 214 to use transition metal complexes as oxidation catalysts in hair colorants containing derivatives of 4-(2,5-diaminophenoxymethyl)-1,3-dioxolane as primary intermediates. Finally, it was proposed in German patent application 197 57 510.2 to use transition metal complexes with ligands of the salen type as oxidation catalysts. In all these coloring preparations, the transition metal cations are present in free form and, potentially, may accumulate on or in the hair. However, this may be regarded as in no way optimal in terms of minimizing the damage potential of the colorants. Accordingly, there was a need to develop oxidation catalysts for hair colorants which would only lead to a very low concentration of free transition metal cations in the preparation to be applied.
SUMMARY OF THE INVENTION
It has now been found that, by using transition metal complexes included in cavities of clathrate compounds in oxidation colorants,
the quantity of oxidizing agent can be greatly reduced and/or
coloring can be carried out with atmospheric oxygen as sole oxidizing agent or
coloring can be carried out in the neutral pH range.
The compositions according to the invention are further distinguished by the low concentration of free transition metal cations in the preparation to be applied.
In a first embodiment, therefore, the present invention relates to compositions for coloring keratin fibers, more particularly human hair, which contain at least one dye precursor and 0.0001 to 1.0% by weight of a transition metal cation with at least two stable oxidation stages included in cavities of clathrate compounds which is complexed with at least one multidentate ligand.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, multidentate ligands are molecules which have two or more electron donor centers.
Preferred transition metals are iron, cobalt, copper, manganese, molybdenum, ruthenium and/or vanadium; complexes with iron and, more particularly, with copper or ruthenium as transition metal have proved to be particularly suitable for the purposes of the invention.
Preferred clathrate compounds in which the transition metal complexes are included are inter alia zeolites of type A, K, L, P-L, O, T, X, Y and &OHgr; and mixtures thereof, the choice of the suitable clathrate compound being determined by the size of the transition metal complex to be included. It is crucial that, in the production of the included complexes, both the transition metal ion and the ligands necessary for complexing are able to enter the cavity of the clathrate compound whereas the complex in the process of formation may no longer pass through the opening of the cavity in order to guarantee stable inclusion of the complex. The sizes of the cavities of the various zeolites are known in principle to the expert. For example, the zeolite Y preferred for the purposes of the invention has cavities with diameters of ca. 1.3 nm of which the openings have a diameter of 0.74 nm. By “stable inclusion” is meant that no quantities of free complex influencing the oxidation catalysis can be detected under in-use conditions, i.e. in the hair treatment preparation. The transition metal complexes being formed in, and then included in, the cavities of the clathrate compounds are far more stable and hence effective over a longer period than the same transition metal complexes which have been applied to the surface of carrier materials even though these carrier materials are the same clathrate compounds.
Ligands which may be used in the transition metal complexes suitable for use in accordance with the invention are typical inorganic and organic substances. Besides carboxylates, organic ligands in such complexes include in particular compounds containing primary, secondary and/or tertiary amine and/or alcohol functions, such as pyridine, pyridazine, pyrimidine, pyrazine, imidazole, pyrazole, triazole, 2,2′-bispyridylamine, tris-(2-pyridylmethyl)amine, 1,4,7-triazacyclononane, 1,4,7-trimethyl-1,4,7-triazacyclononane, 1,5,9-trimethyl-1,5,9-triazacyclododecane, (bis-((1-methylimidazol-2-yl)-methyl))-(2-pyridylmethyl)-amine, N,N′-(bis-(1-methylimidazol-2-yl)-methyl)-ethylenediamine, N-bis-(2-benzimidazolyl-methyl)-aminoethanol, 2,6-bis-(bis-(2-benzimidazolylmethyl)aminomethyl)-4-methylphenol, N,N,N′,N′-tetrakis-(2-benzimidazolylmethyl)-2-hydroxy-1,3-diaminopropane, 2,6-bis-(bis-(2-pyridylmethyl)-aminomethyl)-4-methyl-phenol, 1,3-bis-(bis-(2-benzimidazolylmethyl)aminomethyl)-benzene, sorbitol, mannitol, erythritol, adonitol, inositol, lactose and optionally substituted salens, porphines and porphyrines. Inorganic neutral ligands include, in particular, ammonia and water. The presence of at least one ammonia ligand is preferred, above all in the Co(III) complexes where the central atom is normally present with the coordination number 6. Unless all the coordination sites of the transition metal central atom are occupied by neutral ligands, a complex to be used in accordance with the invention contains other, preferably anionic ligands, more particularly mono- or bidentate ligands. These include, in particul

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