Means for coloring and decoloring of hair

The present invention is a decolorizing agent for fibers, a process for decolorization of fibers using this agent and a multi-component kit for coloring and subsequent decolorization of fibers, in particular of human hair, both the means for producing a stain on the Fiber and the effindungsgemäße means for decolorizing the fibers contains.

Oxidation colorants are outstandingly suitable for covering higher proportions of gray; in this case, the oxidation colorants used with a proportion of gray of up to 50% are generally referred to as oxidative tints, while those in the case of a gray content of up to 100% or <img file="EP0943316A2_D0001.tif" />Brightener "used oxidation dyes are usually referred to as so-called oxidative colors.

Direct dyes, especially nitro dyes, are widely used in non-oxidative colorants (so-called tints). They can penetrate into the hair due to their small size and it - at least in the outer areas - directly stain. Such tints are very gentle on the hair and usually survive several washes.

Direct dyes, especially nitro dyes, are also commonly used in oxidative dyes to create certain nuances or to intensify the color.

It is known that colored polymers produced oxidatively in the hair are generally very durable against external influences such as water, shampoo or light. Depending on the staining technique they are so firmly anchored that they generally remain in the hair until the next haircut. If removal of the coloration is desired, relatively aggressive chemicals such as formaldehyde sulfoxylates, hydrogen peroxide or hydrogen peroxide addition products must be used. Extensive decolorization is indeed possible, but is harmful to health or associated with hair damage.

A partial decolorization of non-oxidative tints is usually already possible by repeated hair washing, a targeted and complete immediate removal of the hair color is not possible in this way.

If a particular hair color is only to be worn for a short period of time, removal of the hair color under mild and gentle conditions is therefore an unsolved problem in both oxidative and non-oxidative dyeing.

According to the invention, this object is achieved by the use of a combination of a) at least one reductone, for example ascorbic acid, and / or a thiol and / or a sulfite and b) at least one α-oxocarboxylic acid or its physiologically acceptable salt.

The use of ascorbic acid in hair care products or hair dyes is known per se. In EP-PS 0 401 454, for example, it is proposed to remove residues of hydrogen peroxide, which remain after an oxidative treatment in human hair, with an aqueous solution of ascorbic acid. Suitable for this are ascorbic acid-containing effervescent tablets, which are dissolved in water immediately before use, which is then used for hair rinsing.

Furthermore, ascorbic acid is used in DE-OS 1 444 216 in a liquid hair dye to make the otherwise unstable liquid medium stable. The oxidation hair dye according to DE-OS 3 642 097 also contains ascorbic acid as stabilizer. It is all the more surprising that ascorbic acid can advantageously also be used for reducing the removal of oxidation colors from fibers, for example human hair.

The present invention is a multi-component kit for dyeing and later discoloring fibers, especially hair, which is characterized in that as component (I) it comprises agents for oxidative or non-oxidative dyeing of fibers, especially human hair, and as component (II) comprises means for reducing the removal of staining with a content of a) at least one reductone and / or a thiol and / or a sulfite and b) at least one α-oxocarboxylic acid or its physiologically acceptable salt.

From DE-OS 42 16 667 it is known to use α-ketodicarboxylic acids (for example α-ketoglutic acid) or their physiologically acceptable salts for the removal of hydrogen peroxide residues from the hair. Furthermore, it is known from JP-OS 63-101 307 to use as cell activator for hair growth, for example, an α-ketoglutaric acid.

The means for producing an oxidative dyeing (component (I)) contained in the multi-component kit according to the invention generally consist of a mixture of two components, namely a color carrier mass, which contains the dye precursors referred to as developer substance and coupler substance and optionally non-oxidative dyes, and an oxidizing agent, which is added immediately prior to use to form the oxidation dye, while the agents contained in the multi-component kit according to the invention for producing a non-oxidative dyeing (component (I)) are generally present in the form of a one-component preparation.

In the case of oxidative dyeing in the dye carrier mass, the multicomponent kit according to the invention contains as developer substance at least one dye precursor suitable for the formation of oxidation dyes. Particularly suitable for this purpose are 1,4-diaminobenzene (p-phenylenediamine), 1,4-diamino-2-methylbenzene (p-toluenediamine), 1,4-diamino-2,6-dimethyl-benzene, 1,4-diamino-2,5-dimethyl-benzene, 1,4-diamino-2,3-dimethyl-benzene, 2-chloro-1,4-diaminobenzene, 4-phenylamino-aniline, 4-dimethylamino-aniline, 4-diethylamino-aniline, 4- [di (2-hydroxyethyl) amino] aniline, 4 - [(2-methoxyethyl) amino] aniline, 4 - [(3-hydroxypropyl) amino] aniline, 1,4-diamino-2- (2-hydroxyethyl) benzene, 1,4-diamino-2- (1-methylethyl) benzene, 1,3-bis [(4-aminophenyl) (2-hydroxyethyl) amino] -2-propanol, 1,8-bis (2,5-diaminophenoxy) -3,6-dioxaoctane, 4-amino-phenol, 4-amino-3-methyl-phenol, 4-methylamino-phenol, 4-amino-2- (aminomethyl) -phenol, 4-Amino-2 - [(2-hydroxyethyl) amino] methyl-phenol, 4-amino-2- (methoxymethyl) phenol, 4-amino-2- (2-hydroxyethyl) -phenol, 5-amino-salicylic acid, 2,5-diamino-pyridine, 2,4,5,6-tetraamino pyrimidine, 2,5,6-triamino-4- (1H) -pyrimidone, 4,5-diamino-1- (2-hydroxyethyl) -1H-pyrazole, 4,5-diamino-1- (1-methylethyl) -1H-pyrazole, 4,5-diamino-1 - [(4-methylphenyl) methyl] -1H-pyrazole, 1 - [(4-chlorophenyl) methyl] -4,5-diamino-1H-pyrazol, 4,5-diamino-1-methyl-1H-pyrazole and 2-amino-phenol, 2-amino-6-methyl-phenol, 2-amino-5-methyl-phenol and / or salts thereof.

In addition, in the case of oxidative dyeing, the dye carrier mass contains at least one coupler substance suitable for forming an oxidation color. For this purpose, aromatic m-diamines, m-aminophenols, polyphenols or naphthols can be used. Particularly suitable are N- (3-dimethylamino-phenyl) -urea, 2,6-diaminopyridine, 2-Amino-4 - [(2-hydroxyethyl) amino] -anisole, 2,4-diamino-1-fluoro-5-methylbenzene, 2,4-diamino-1-methoxy-5-methylbenzene, 2,4-diamino-1-ethoxy-5-methylbenzene, 2,4-diamino-1- (2-hydroxyethoxy) -5-methylbenzene, 2,4-di [(2-hydroxyethyl) amino] -1,5-dimethoxy-benzene; 2,3-diamino-6-methoxy-pyridine, 3-Amino-6-methoxy-2- (methylamino) -pyridine, 2,6-diamino-3,5-dimethoxy-pyridine, 3,5-diamino-2,6-dimethoxy-pyridine, 1,3-diaminobenzene, 2,4-diamino-1- (2-hydroxyethoxy) benzene, 1- (2-aminoethoxy) -2,4-diaminobenzene, 2-Amino-1- (2-hydroxyethoxy) -4-methylamino-benzene, 2,4-diamino-phenoxy-acetic acid, 3- [di (2-hydroxyethyl) amino] aniline, 4-amino-2-di [(2-hydroxyethyl) amino] -1-ethoxybenzene, 5-methyl-2- (1-methylethyl) phenol, 3 - [(2-hydroxyethyl) amino] aniline, 3 - [(2-aminoethyl) amino] aniline, 1,3-di (2,4-diaminophenoxy) propane, Di (2,4-diaminophenoxy) methane, 1,3-diamino-2,4-dimethoxy-benzene; 2,6-bis (2-hydroxyethyl) amino-toluene, 4-hydroxyindole, 3-dimethylamino-phenol, 3-diethylamino-phenol, 5-amino-2-methyl-phenol, 5-Amino-4-fluoro-2-methyl-phenol, 5-amino-4-methoxy-2-methyl-phenol, 5-amino-4-ethoxy-2-methyl-phenol, 3-Amino-2,4-dichloro-phenol, 5-Amino-2,4-dichloro-phenol, 3-amino-2-methyl-phenol, 3-Amino-2-chloro-6-methyl-phenol, 3-amino-phenol, 2 - -acetamide [(3-hydroxyphenyl) amino] 5 - [(2-hydroxyethyl) amino] -2-methyl-phenol, 3 - [(2-hydroxyethyl) amino] -phenol, 3 - [(2-methoxyethyl) amino] -phenol, 5-amino-2-ethyl-phenol, 2- (4-amino-2-hydroxyphenoxy) ethanol, 5 - [(3-hydroxypropyl) amino] -2-methyl-phenol, 3 - [(2,3-dihydroxy-propyl) amino] -2-methyl-phenol, 3 - [(2-hydroxyethyl) amino] -2-methyl-phenol, 2-amino-3-hydroxy-pyridine, 5-Amino-4-chloro-2-methyl-phenol, 1-naphthol, 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,3-dihydroxy-naphthalene, 2,7-dihydroxy-naphthalene, 2-methyl-1-naphthol-acetate, 1,3-dihydroxybenzene, 1-chloro-2,4-dihydroxy-benzene, 2-chloro-1,3-dihydroxy-benzene, 1,2-dichloro-3,5-dihydroxy-4-methylbenzene, 1,5-dichloro-2,4-dihydroxy-benzene, 1,3-dihydroxy-2-methylbenzene, 3,4-methylenedioxy-phenol, 3,4-methylenedioxy-aniline, 5 - [(2-hydroxyethyl) amino] -1,3-benzodioxole, 6-bromo-1-hydroxy-3,4-methylenedioxy-benzene, 3,4-Diamino-benzoic acid, 3,4-dihydro-6-hydroxy-1,4 (2H) -benzoxazine, 6-amino-3,4-dihydro-1,4 (2H) -benzoxazine, 3-methyl-1-phenyl-5-pyrazolone, 5,6-dihydroxy-indole, 5,6-dihydroxy-indoline, 5-hydroxy-indole, 6-hydroxy-indol, 7-hydroxy-indol, 2,3-indolinedione and / or salts thereof.

The developer substances and coupler substances are contained in the color carrier mass in an amount of about 0.01 to 10 percent by weight, preferably 0.1 to 5 percent by weight.

Furthermore, this, colorant-containing, dye carrier mass may optionally additionally non-oxidative dyes (hereinafter <img file="EP0943316A2_D0002.tif" />direct dyes "), such as, for example, 1,4-bis [(2-hydroxyethyl) amino] -2-nitrobenzene, 1- (2-hydroxyethyl) amino-2-nitro-4- [di (2-hydroxyethyl) amino ] benzene (HC Blue No. 2), 1-amino-3-methyl-4 - [(2-hydroxyethyl) amino] -6-nitrobenzene (HC Violet no. 1), 4- [ethyl (2-hydroxyethyl) amino] -1 - [(2-hydroxyethyl) amino] -2-nitrobenzene hydrochloride (HC Blue No. 12), 4- [di (2-hydroxyethyl) amino] -1 - [(2-methoxyethyl) amino] -2-nitrobenzene (HC Blue no. 11), 1 - [(2,3-dihydroxypropyl) amino] -4- [methyl (2-hydroxyethyl) amino] -2-nitrobenzene (HC Blue No. 10), 1 - [(2,3-dihydroxypropyl) amino] -4- [ethyl (2-hydroxyethyl) amino] -2-nitrobenzene hydrochloride (HC Blue No. 9), 1- (3-hydroxypropylamino) -4- [di- (2-hydroxyethyl) amino] -2-nitrobenzene (HC Violet No. 2), 1-methylamino-4- [methyl- (2,3-dihydroxypropyl) amino] -2-nitrobenzene (HC Blue no. 6), 2 - ((4-amino-2-nitrophenyl) -amino) -5-dimethylaminobenzoic acid (HC Blue no. 13), 1-amino-4 - [(2-hydroxyethyl) amino] -2-nitrobenzene (HC Red no. 7), 2-amino-4,6-dinitrophenol, 4-amino-2-nitro-diphenylamine (HC Red no. 1), 1-amino-4- [di (2-hydroxyethyl) amino] -2-nitrobenzene hydrochloride (HC Red No. 13), 1-amino-5-chloro-4 - [(2-hydroxyethyl) amino] -2-nitrobenzene, 4-amino-1 - [(2-hydroxyethyl) amino] -2-nitrobenzene (HC Red no. 3), 4-amino-3-nitrophenol, 4 - [(2-hydroxyethyl) amino] -3-nitrophenol, 1 - [(2-aminoethyl) amino] -4- (2-hydroxyethoxy) -2-nitrobenzene (HC Orange No. 2), 4- (2,3-dihydroxy-propoxy) -1 - [(2-hydroxyethyl) amino] -2-nitrobenzene (HC Orange no. 3), 1-amino-5-chloro-4 - [(2,3-dihydroxypropyl) amino] -2-nitrobenzene (HC Red no. 10), 5-chloro-1,4- [di (2,3-dihydroxypropyl) amino] -2-nitrobenzene (HC Red no. 11), 2 - [(2-hydroxyethyl) amino] -4,6-dinitrophenol, 4-ethylamino-3-nitrobenzoic acid, 2 - [(4-amino-2-nitrophenyl) amino] benzoic acid, 2-chloro 6-ethylamino-4-nitrophenol, 2-amino-6-chloro-4-nitrophenol, 4 - [(3-hydroxypropyl) amino] -3-nitrophenol, 2,5-diamino-6-nitropyridine, 1,2, 3,4-Tetrahydro-6-nitroquinoxaline, 7-amino-3,4-dihydro-6-nitro-2H-1,4-benzoxazine (HC Red no. 14), 1-amino-2 - [(2-hydroxyethyl) amino] -5-nitrobenzene (HC Yellow No. 5), 1- (2-hydroxyethoxy) -2 - [(2-hydroxyethyl) amino] -5-nitrobenzene (HC Yellow No. 4), 1 - [(2-hydroxyethyl) amino] -2-nitrobenzene (HC Yellow No. 2), 2 - [(2-hydroxyethyl) amino] -1-methoxy-5-nitrobenzene, 2-amino-3-nitrophenol, 1- (2-hydroxyethoxy) -3-methylamino-4-nitrobenzene, 2,3- (Dihydroxypropoxy) -3-methylamino-4-nitrobenzene, 2 - [(2-hydroxyethyl) amino] -5-nitrophenol (HC Yellow No. 11), 3 - [(2-aminoethyl) amino] -1-methoxy-4-nitrobenzene hydrochloride (HC Yellow No.9), 1 - [(2-ureidoethyl) amino] -4-nitrobenzene, 4 - [( 2,3-dihydroxypropyl) amino] -3-nitro-1-trifluoromethylbenzene (HC Yellow No. 6), 1-chloro-2,4-bis [(2-hydroxyethyl) amino] -5-nitrobenzene (HC Yellow No. 10), 4 - [(2-hydroxyethyl) amino] -3-nitro-1-methylbenzene, 1-chloro-4 - [(2-hydroxyethyl) amino] -3-nitrobenzene (HC Yellow No. 12), 4 - [(2-hydroxyethyl) amino] -3-nitro-1-trifluoromethylbenzene (HC Yellow No. 13), 4 - [(2-hydroxyethyl) amino] -3-nitrobenzonitrile (HC Yellow No. 14), 4 - [(2-hydroxyethyl) amino] -3-nitrobenzamide (HC Yellow No. 15), 1,4-di [(2,3-dihydroxypropyl) amino] -9,10-anthraquinone, 1 - [(2-hydroxyethyl) amino] -4-methylamino-9,10-anthraquinone (CI61505, Disperse Blue No. 3), 2 - [(2-aminoethyl) amino] -9,10-anthraquinone (HC Orange no. 5), 1-hydroxy-4 - [(4-methyl-2-sulfophenyl) amino] -9,10-anthraquinone, 1 - [(3-aminopropyl) amino] -4-methylamino-9,10-anthraquinone (HC Blue No. 8), 1 - [(3-aminopropyl) amino] -9,10-anthraquinone (HC Red no. 8), 1,4-diamino-2-methoxy-9,10-anthraquinone (CI62015, Disperse Red no. 11, Solvent Violet No. 26), 1,4-dihydroxy-5,8-bis [(2-hydroxyethyl) amino] -9,10-anthraquinone (CI62500, Disperse Blue No. 7, Solvent Blue No. 69), 9- (dimethylamino) -benzo [a] phenoxazine-7-ium chloride (CI51175; 6), di [4- (diethylamino) phenyl] [4- (ethylamino) naphthyl] carbenium chloride (CI42595; 7), 3,7-di (dimethylamino) -phenothiazine-5-ium chloride (CI52015; 9), di [4- (dimethylamino) phenyl] [4- (phenylamino) naphthyl] carbenium chloride (CI44045; 26), 2 - [(4- (ethyl (2-hydroxyethyl) amino) phenyl) azo] -6-methoxy-3-methylbenzothiazolium methylsulfate (CI11154; 41), 8-amino-2-bromo-5-hydroxy-4-imino-6 - [(3- (trimethylammonio) phenyl) amino] -1 (4H) -naphthalenone chloride (CI56059; 99), bis [4- (dimethylamino) phenyl] [4- (methylamino) phenyl] carbenium chloride (CI42535; 1), tris [4- (dimethylamino) phenyl] carbenium chloride (CI42555; 3), 2- [3,6- (diethylamino) -dibenzopyranium-9-yl] -benzoic acid chloride (CI45170; 10), di (4-aminophenyl) (4-amino-3-methylphenyl) carbenium chloride (CI42510; 14), 1,3-bis [(2,4-diamino-5-methylphenyl) azo] -3-methylbenzene (CI21010; 4), 1 - [(4-aminophenyl) azo] -7- (trimethylammonio) -2-naphthol chloride (CI12250; 16), 1 - [(4-amino-2-nitrophenyl) azo] -7- (trimethylammonio) -2-naphthol chloride (Basic Brown no. 17), 1 - [(4-amino-3-nitrophenyl) azo] -7- (trimethyla ) -2-naphthol chloride (CI12251; 17), 3,7-diamino-2,8-dimethyl-5-phenyl-phenazinium chloride (CI 50240; 2), 1,4-dimethyl-5 - [(4- (dimethylamino) phenyl) azo] -1,2,4-triazolium chloride (CI11055; 22), 2-hydroxy-1 - [(2-methoxyphenyl) azo] -7- (trimethylammonio) naphthalene chloride (CI12245; 76), 2- [2 - ((2,4-dimethoxyphenyl) amino) ethenyl] -1,3,3-trimethyl-3H-indol-1-ium chloride (CI48055; 11), 3-methyl-1-phenyl-4 - [(3- (trimethylammonio) phenyl) -azo] -pyrazol-5-one chloride (CI12719; 57), bis [4- (diethylamino) phenyl] phenylcarbenium hydrogen sulfate (1: 1) (CI42040; 1), 1- [di (2-hydroxyethyl) amino] -3-methyl-4 - [(4-nitrophenyl) azo] benzene (CI11210, Disperse Red no. 17), 4 - [(4-aminophenyl) azo] -1- [di (2-hydroxyethyl) amino] -3-methylbenzene (HC Yellow No. 7), 2,6-diamino-3 - [(pyridin-3-yl) azo] -pyridine, 6-hydroxy-5 - [(4-sulfophenyl) azo] -2-naphthalenesulfonic acid disodium salt (CI15985; Food Yellow No. 3; FD &amp; C Yellow No. 6), 2,4-dinitro-1-naphthol-7-sulfonic acid disodium salt (CI10316; Acid Yellow no. 1; Food Yellow No. 1), 2- (indan-1,3-dion-2-yl) quinoline-x, x-sulfonic acid (mixture of mono- and disulfonic acid) (CI47005; 10; Food Yellow No. 13; Acid Yellow No. 3), 5-Hydroxy-1- (4-sulfophenyl) -4 - [(4-sulfophenyl) azo] pyrazole-3-carboxylic acid trisodium salt (CI19140; 4; Acid Yellow No. 23), 9- (2-carboxyphenyl) -6-hydroxy-3H-xanthen-3-one (CI45350; Acid Yellow no. 73; D &amp; C Yellow No. 8), 5 - [(2,4-dinitrophenyl) amino] -2-phenylamino-benzenesulfonic acid, sodium salt (CI10385; Acid Orange no. 3), 4 - [(2,4-dihydroxyphenyl) azo] -benzenesulfonic acid monosodium salt (CI14270; Acid Orange no. 6), 4 - [(2-hydroxynaphth-1-yl) azo] -benzenesulfonic acid, sodium salt (CI15510; Acid Orange no. 7), 4 - [(2,4-Dihydroxy-3 - [(2,4-dimethylphenyl) azo] -phenyl) azo] -benzenesulfonic acid, sodium salt (CI20170; 24), 4-hydroxy-3 - [(4-sulfonaphth-1-yl) azo] -1-naphthalenesulfonic acid disodium salt (CI14720; Acid Red No. 14), 6-hydroxy-5 - [(4-sulfonaphth-1-yl) azo] -2,4-naphthalenedisulfonic acid trisodium salt (CI16255; Ponceau 4R; Acid Red No. 18), 3-hydroxy-4 - [(4-sulfonaphth-1-yl) azo] -2,7-naphthalene-disulfonic acid trisodium salt (CI16185; Acid Red No. 27), 8-amino-1-hydroxy-2- (phenylazo) -3,6-naphthalenedisulfonic acid disodium salt (CI17200; Acid Red No. 33), 5- (acetylamino) -4-hydroxy-3 - [(2-methylphenyl) azo] -2,7-naphthalenedisulfonic acid disodium salt (CI 18065; 35), 2- (3-hydroxy-2,4,5,7-tetraiodo-dibenzopyran-6-one-9-yl) -benzoic acid disodium salt (CI45430; Acid Red No. 51), N- [6- (diethylamino) -9- (2,4-disulfophenyl) -3H-xanthen-3-ylidene] -N-ethyl-urethane-ammonium hydroxide, inner salt, sodium salt (CI45100; Acid Red no. 52), 8 - [(4- (phenylazo) phenyl) azo] -7-naphthol-1,3-disulfonic acid disodium salt (CI 27290; Acid Red No. 73), 2 ', 4', 5 ', 7'-tetrabromo-3', 6'-dihydroxyspiro [isobenzofuran-1 (3H), 9 '- [9H] xanthene] -3-one disodium salt (CI45380; Acid Red No. 87), 2 ', 4', 5 ', 7'-tetrabromo-4,5,6,7-tetrachloro-3', 6'-dihydroxyspiro [isobenzofuran-1 (3H), 9 '[9H] xanthene] - 3-one disodium salt (CI45410; Acid Red No. 92), 3 ', 6'-dihydroxy-4', 5'-diiodospiro- [isobenzofuran-1 (3H), 9 '(9H) -xanthene] -3-one disodium salt (CI45425; Acid Red no. 95), (2-sulfophenyl) di [4- (ethyl ((4-sulfophenyl) methyl) amino) phenyl] -carbenium disodium salt, betaine (CI42090; Acid Blue no. 9; FD &amp; C Blue No. 1), 1,4-bis [(2-sulfo-4-methylphenyl) amino] -9,10-anthraquinone disodium salt (CI 61570; Acid Green no. 25), bis [4- (dimethylamino) phenyl] - (3,7-disulfo-2-hydroxynaphth-1-yl) carbenium inner salt, monosodium salt (CI44090; 4; Acid Green No. 50), bis [4- (diethylamino) phenyl] (2,4-disulfophenyl) carbenium inner salt, sodium salt (2: 1) (CI42045; 3; Acid Blue No. 1), bis [4- (diethylamino) phenyl] (5-hydroxy-2,4-disulfophenyl) carbenium inner salt, calcium salt (2: 1) (CI42051; Acid Blue no. 3), 1-amino-4- (cyclohexylamino) -9,10-anthraquinone-2-sulfonic acid, sodium salt (CI62045; Acid Blue no. 62), 2- (1,3-dihydro-3-oxo-5-sulfo-2H-indol-2-ylidene) -2,3-dihydro-3-oxo-1H-indole-5-sulfonic acid disodium salt (CI73015 Acid Blue No. 74), 9- (2-Carboxyphenyl) -3 - [(2-methylphenyl) amino] -6 - [(2-methyl-4-sulfophenyl) amino] xanthylium inner salt, monosodium salt (CI45190; Acid Violet No. 9), 1-hydroxy-4 - [(4-methyl-2-sulfophenyl) amino] -9,10-anthraquinone, sodium salt (CI60730; D &amp; C Violet No. 1). 2; Acid Violet No. 43), bis [3-nitro-4 - [(4-phenylamino) -3-sulfophenylamino] -phenyl] -sulfone (CI10410; Acid Brown no. 13), 5-amino-4-hydroxy-6 - [(4-nitrophenyl) azo] -3- (phenylazo) -2,7-naphthalenedisulfonic acid disodium salt (CI20470; Acid Black no. 1), 3-hydroxy-4 - [(2-hydroxy-naphth-1-yl) azo] -7-nitro-1-naphthalenesulfonic acid-chromium complex (3: 2) (CI15711; Acid Black no. 52), 3 - [(2,4-dimethyl-5-sulfophenyl) azo] -4-hydroxy-1-naphthalenesulfonic acid disodium salt (CI14700; 1; Ponceau SX; FD &amp; C Red No. 4), 4- (acetylamino) -5-hydroxy-6 - [(7-sulfo-4 - [(4-sulfophenyl) azo] naphth-1-yl) azo] -1,7-naphthalenedisulfonic acid tetrasodium salt (CI28440; Food Black no. 1) and 3-hydroxy-4- (3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-ylazo) -naphthalene-1-sulfonic acid sodium salt, chromium complex (Acid Red No. 195), in particular 2,6-diamino-3- (pyridin-3-yl) azo-pyridine, 8-amino-2-bromo-5-hydroxy-4-imino-6 - [(3- (trimethylammonio) -phenyl) amino] -1 (4H) -naphthalenone chloride (CI56059; 99), or nitro dyes, for example, 1,4-bis [(2-hydroxyethyl) amino] -2-nitrobenzene, 1- (2-hydroxyethyl) amino-2-nitro-4- [di (2-hydroxyethyl) amino] - benzene (HC Blue no. 2), 1-amino-3-methyl-4 - [(2-hydroxyethyl) amino] -6-nitrobenzene (HC Violet no. 1), 4- [ethyl (2-hydroxyethyl) amino] -1 - [(2-hydroxyethyl) amino] -2-nitrobenzene hydrochloride (HC Blue No. 12), 4- [di (2-hydroxyethyl) amino] -1 - [(2-methoxyethyl) amino] -2-nitrobenzene (HC Blue no. 11), 1 - [(2,3-dihydroxypropyl) amino] -4- [methyl (2-hydroxyethyl) amino] -2-nitrobenzene (HC Blue No. 10), 1 - [(2,3-dihydroxypropyl) amino] -4- [ethyl (2-hydroxyethyl) amino] -2-nitrobenzene hydrochloride (HC Blue No. 9), 1- (3-hydroxypropylamino) -4- [di- (2-hydroxyethyl) amino] -2-nitrobenzene (HC Violet No. 2), 1-methylamino-4- [methyl- (2,3-dihydroxypropyl) amino] -2-nitrobenzene (HC Blue no. 6), 2 - ((4-amino-2-nitrophenyl) amino) -5-dimethylaminobenzoic acid (HC Blue No. 13), 1-amino-4 - [(2-hydroxyethyl) amino] -2-nitrobenzene (HC Red no. 7), 2-amino-4,6-dinitrophenol, 4-amino-2-nitro-diphenylamine (HC Red no. 1), 1-amino-4- [di (2-hydroxyethyl) amino] -2-nitrobenzene hydrochloride (HC Red No. 13), 1-amino-5-chloro-4 - [(2-hydroxyethyl) amino] -2-nitrobenzene, 4-amino-1 - [(2-hydroxyethyl) amino] -2-nitrobenzene (HC Red no. 3), 4-amino-3-nitrophenol, 4 - [(2-hydroxyethyl) amino] -3-nitrophenol, 1 - [(2-aminoethyl) amino] -4- (2-hydroxyethoxy) -2-nitrobenzene (HC Orange No. 2), 4- (2,3-dihydroxypropoxy) -1 - [(2-hydroxyethyl) amino] -2-nitrobenzene (HC Orange no. 3), 1-amino-5-chloro-4 - [(2,3-dihydroxypropyl) amino] -2-nitrobenzene (HC Red no. 10), 5-chloro-1,4- [di (2,3-dihydroxypropyl) amino] -2-nitrobenzene (HC Red No. 11), 2 - [(2-hydroxyethyl) amino] -4,6-dinitrophenol, 4-ethylamino-3-nitrobenzoic acid, 2 - [(4-amino-2-nitrophenyl) amino] benzoic acid, 2-chloro 6-ethylamino-4-nitrophenol, 2-amino-6-chloro-4-nitrophenol, 4 - [(3-hydroxypropyl) amino] -3-nitrophenol, 2,5-diamino-6-nitropyridine, 1,2,3 , 4-Tetrahydro-6-nitroquinoxaline, 7-amino-3,4-dihydro-6-nitro-2H-1,4-benzoxazine (HC Red no. 14), 1-amino-2 - [(2-hydroxyethyl) amino] -5-nitrobenzene (HC Yellow No. 5), 1- (2-hydroxyethoxy) -2 - [(2-hydroxyethyl) amino] -5-nitrobenzene (HC Yellow No. 4), 1 - [(2-hydroxyethyl) amino] -2-nitrobenzene (HC Yellow No. 2), 2 - [(2-hydroxyethyl) amino] -1-methoxy-5-nitrobenzene, 2-amino-3-nitrophenol, 1- (2-hydroxyethoxy) -3-methylamino-4-nitrobenzene, 2.3 - (dihydroxypropoxy) -3-methylamino-4-nitrobenzene, 2 - [(2-hydroxyethyl) amino] -5-nitrophenol (HC Yellow No. 11), 3 - [(2-aminoethyl) amino] -1-methoxy-4-nitrobenzene hydrochloride (HC Yellow No.9), 1 - [(2-ureidoethyl) amino] -4-nitrobenzene, 4 - [( 2,3-dihydroxypropyl) amino] -3-nitro-1-trifluoromethylbenzene (HC Yellow No. 6), 1-chloro-2,4-bis - [(2-hydroxyethyl) amino] -5-nitrobenzene (HC Yellow No. 10), 4 - [(2-hydroxyethyl) amino] -3-nitro-1-methylbenzene, 1-chloro-4 - [(2-hydroxyethyl) amino] -3-nitrobenzene (HC Yellow No. 12), 4 - [(2-hydroxyethyl) amino] -3-nitro-1-trifluoromethylbenzene (HC Yellow No. 13), 4 - [(2-hydroxyethyl) amino] -3-nitrobenzonitrile (HC Yellow No. 14), 4 - [(2-hydroxyethyl) amino] -3-nitrobenzamide (HC Yellow No. 15). Particularly preferred substantive dyes here are 4-amino-1 - [(2-hydroxyethyl) amino] -2-nitrobenzene (HC Red no. 3), 1-amino-4- [di (2-hydroxyethyl) amino] -2-nitrobenzene hydrochloride (HC Red No. 13), 8-amino-2-bromo-5-hydroxy-4-imino-6 - [(3- (trimethylammonio) -phenyl) amino] -1 (4H) -naphthalenone chloride (CI56059; 99), 4- [ethyl (2-hydroxyethyl) amino] -1 - [(2-hydroxyethyl) amino] -2-nitrobenzene hydrochloride (HC Blue No. 12), 1- (2-hydroxyethyl) amino-2-nitro-4- [di (2-hydroxyethyl) amino] benzene, 4- [ethyl (2-hydroxyethyl) amino] -1 - [(2 hydroxyethyl) amino] -2-nitrobenzene hydrochloride, 4-amino-3-nitro-phenol, 1-amino-4- [di (2-hydroxyethyl) amino] -2-nitrobenzene hydrochloride and / or 2-amino-6 -chloro-4-nitro-phenol and 2,6-diamino-3- (pyridin-3-yl) azo-pyridine.

The substantive dyes can be used in this color carrier mass in an amount of about 0.01 to 10 weight percent, preferably 0.1 to 5 weight percent.

In the multi-component kit is located separately from the color carrier mass and the oxidizing agent. The amount of hydrogen peroxide or hydrogen peroxide addition products or oxidizing enzymes contained in the multi-component kit is sized to be sufficient to quantitatively convert the mixture of dye precursors to the oxidation dye. In this case, the oxidizing agent can be present either in ready-to-use form or as a dry substance, which can be used after addition of a suitable solvent.

As the oxidizing agent which is also contained in the multi-component kit according to the invention, hydrogen peroxide or its addition compounds of urea, melamine or sodium bromate are generally used, with hydrogen peroxide being particularly preferred. In general, hydrogen peroxide or the hydrogen peroxide addition products are used to oxidize the dye precursors in a concentration of 1 to 12 weight percent.

Hair-friendly, however, is the enzymatic oxidation of the dye precursors with the aid of air or oxygen. It is characterized by particularly mild conditions. The pH is in the weakly acidic to slightly alkaline range and the enzyme proteins used do not attack the hair structure. In contrast to the use of peroxides, however, it is not possible to "whiten" the hair when using oxidizing enzymes.

For the oxidative generation of oxidation colors by means of air or oxygen in the presence of enzymes, single-stage or multi-stage enzymatic oxidation systems are available. In the single-stage enzyme systems, aromatic phenols and amines can be oxidized directly to the polymeric dye in a dye mixture with oxygen supply without addition of peroxide. For this purpose, phenol oxidases, preferably laccases, are suitable. In contrast, multistep enzymatic oxidation systems require several enzymes for dye production.

For a multi-stage enzymatic oxidation system for preparing the oxidation dye from the color precursors, a combination of an oxygen-oxidoreductase / substrate system and a peroxidase can be used. Examples of an oxygen-oxidoreductase / substrate system are as follows:<ul id="ul0001" list-style="none" compact="compact"><li>Glucose oxidase (EC 1.1.3.4) / D-glucose</li><li>Alcohol oxidase (EC 1.1.3.13) / ethanol</li><li>Pyruvate oxidase (EC 1.2.3.3) / pyruvate</li><li>Oxalate oxidase (EC 1.2.3.4) / oxalate</li><li>Cholesterol oxidase (EC 1.1.3.6) / cholesterol</li><li>Uricase (EC 1.7.3.3) / uric acid</li><li>Lactate oxidase / lactic acid</li><li>Xanthine oxidase (EC 1.1.3.22) / xanthine.</li></ul>

The classifications given for the enzymes in parentheses are in accordance with the "Classification of the International Union of Biochemistry on Nomenclature and Classification of Enzymes (1984)".

The preparation form for the dye carrier mass and for the ready-to-use oxidation colorant may be, for example, a solution, in particular an aqueous or aqueous-alcoholic solution. However, the particularly preferred preparation forms are a cream, a gel or an emulsion. Their composition is a mixture of the dye components with the usual additives for such preparations.

The non-oxidative dye-forming agent (component (I)) contained in the multi-component kit of the present invention contains, as dyes, the aforementioned substantive dyes, which dyes are contained in a total amount of about 0.01 to 10% by weight, preferably 0.1 to 5 weight percent, are used.

The non-oxidative colorant can be present, for example, in the form of a solution, in particular an aqueous or aqueous-alcoholic solution. However, the particularly preferred preparation forms are a cream, a gel, an aerosol foam or an emulsion. Their composition is a mixture of the dye components with the usual additives for such preparations.

Usual additives used in oxidative or non-oxidative coloring agents in solutions, creams, emulsions Gels or aerosol foams are, for example, solvents such as water, lower aliphatic alcohols, for example, ethanol, n-propanol and isopropanol or glycols such as glycerol and 1,2-propanediol, furthermore wetting agents or emulsifiers from the classes of anionic, cationic, amphoteric or nonionic surfactants such as fatty alcohol sulfates, ethoxylated fatty alcohol sulfates, alkylsulfonates, alkylbenzenesulfonates, alkyltrimethylammonium, alkylbetaines, ethoxylated fatty alcohols, ethoxylated nonylphenols, fatty acid, ethoxylated fatty alcohols, ethoxylated nonylphenols, fatty acid, ethoxylated fatty acid esters, also thickeners such as higher fatty alcohols, Starch or cellulose derivatives, perfumes, Hair pretreatment agents, conditioners, Hair swelling agents, Preservatives, still Vaseline, Paraffin oil and fatty acids as well as conditioners such as cationic resins, lanolin derivatives, Cholesterol, Pantothenic acid and betaine. The constituents mentioned are used in the quantities customary for such purposes, for example the wetting agents and emulsifiers in concentrations of about 0.5 to 30 percent by weight (based on the color carrier mass), the thickeners in an amount of about 0.1 to 25 percent by weight ( based on the color carrier mass) and the care substances in a concentration of about 0.1 to 5.0 percent by weight (based on the color carrier mass).

The pH of the ready-to-use oxidative or non-oxidative coloring agent is generally 3 to 11, preferably 5 to 9.

The pH of the ready-to-use oxidation colorant is adjusted to a pH value during the mixing of the preferably alkaline colorant mass with the usually acidic oxidant, which is influenced by the amounts of alkali in the color carrier mass and the amounts of acid in the oxidant and by the mixing ratio.

To adjust the pH suitable for the coloring, alkalizing agents such as alkanolamines, alkylamines, alkali hydroxides or ammonium hydroxide and alkali carbonates or ammonium carbonates, preferably ammonium hydroxide, or acids such as lactic acid, acetic acid, tartaric acid, phosphoric acid, hydrochloric acid, citric acid, ascorbic acid and boric acid can be used ,

Particularly in the case of enzymatically catalyzed oxidation, the use of a buffer system is recommended for controlling the pH. Citrate buffer, phosphate buffer or borate buffer can be used. Preferably, the use of a borate buffer (boric acid / NaOH) or a phosphate buffer (KH₂PO₄/ K₂HPO₄).

In the case of oxidative dyeing, immediately before the application of one of the abovementioned oxidizing agents, the color carrier mass containing the dye precursors and optionally substantive dyes and the other auxiliaries is mixed and applied to the hair. Depending on the desired color depth, this mixture is allowed to act for 5 to 60 minutes, preferably 15 to 30 minutes, at a temperature of 20 to 50 degrees Celsius, in particular at 30 to 40 degrees Celsius. The hair is then rinsed with water and optionally washed with a shampoo.

The color carrier mass and the oxidizing agent are mixed together in a weight ratio of 5: 1 to 1: 3, wherein a weight ratio of 1: 1 to 1: 2 is particularly preferred.

In the case of non-oxidative staining, the stain is applied to the hair. Depending on the desired color depth, this mixture is allowed to act for 5 to 60 minutes, preferably 15 to 30 minutes, at a temperature of 20 to 50 degrees Celsius, especially at 30 to 40 degrees Celsius. The hair is then rinsed with water and optionally washed with a shampoo.

Another essential constituent of the multicomponent kit according to the invention is the agent for reducing decolorization of the fibers of component (II) dyed with oxidation dyes and / or substantive dyes, which comprises a combination of a) at least one reductone and / or one thiol and / or one sulfite and b) at least one α-oxocarboxylic acid or physiologically acceptable salt thereof.

As reductones, for example, ascorbic acid or isoascorbic acid or their salts or esters, for example, 6-O-palmitoyl ascorbate, Hydroxypropanedial (triosereductone), 2,3-dihydroxy-2-cyclopenten-1-one (reductic acid) or mixtures of these compounds, preferably in an amount of 1 to 50% by weight, in particular from 2 to 10% by weight, be used wherein the use of ascorbic acid or isoascorbic acid and in particular of ascorbic acid is preferred. When using ascorbic acid salts or isoascorbic acid salts, the free acid can also be generated in situ from the salts, for example the alkali metal ascorbates or alkaline earth metal ascorbates or the alkali metal isoascorbates or alkaline earth metal isoascorbates, by adding an acid. This is advantageous because of the better solubility of the salts in water, especially at higher concentrations. Suitable ascorbic acid salts or isoascorbic acid salts are, in particular, the calcium salt, the magnesium salt and the sodium salt of ascorbic acid or isoascorbic acid.

As thiols, cysteine ​​or its salts, N-acetylcysteine, cysteamine or its salts, mercaptoacetaldehyde, penicillamine, glutathione, homocysteine ​​or its salts and / or calcium thioglycolate. can be used, with cysteine ​​and its salts are particularly preferred.

Furthermore, the decolorizing agent may contain sulfites, for example alkali metal sulfites or alkaline earth sulfites, in particular sodium sulfite, in order to prevent reoxidation of the dye precursors possibly remaining in the hair.

The amount of thiol used is 0.1 to 10% by weight, preferably 2 to 5% by weight, while the sulfite is used in an amount of 0.001 to 5% by weight, preferably in an amount of 0.01 to 0.5% by weight.

As the α-oxocarboxylic acid, both α-aldehyde acids and α-ketocarboxylic acids such as glyoxylic acid, pyruvic acid, oxaloacetic acid or α-ketoglutaric acid, and their alkali salts and alkaline earth salts can be used.

The amount of α-oxocarboxylic acid or physiologically acceptable salt used is 0.1 to 10 percent by weight, with an amount of from 0.5 to 5 percent by weight being preferred.

The corresponding α-oxocarboxylic esters do not improve the decolorizing reaction and can therefore only be used as α-oxocarboxylic acids after esterification (for example in situ).

In a particularly preferred embodiment, the decolorizing agent contains as component a) a combination of at least one reductone, preferably ascorbic acid and at least one thiol, preferably cysteine ​​and / or cysteine ​​hydrochloride, and as component b) an α-oxocarboxylic acid or its physiologically acceptable salt.

However, it is also possible to use for decolorizing an agent which is a reductone or a thiol or a sulfite alone, or a combination of a thiol and a sulfite or a combination of a reductone and a sulfite or a reductone and a thiol and a Sulfite and as component b) contains an α-oxocarboxylic acid or its physiologically acceptable salt.

The means for reducing decolorization of the fibers dyed with a combination of oxidation dyes and / or substantive dyes (hereinafter <img file="EP0943316A2_D0003.tif" />Decolorizing agent ") may be present as an aqueous or aqueous-alcoholic solution, as a gel, cream, emulsion or foam, wherein the decolorizing agent may be formulated both in the form of a one-component preparation and in the form of a multi-component preparation. In addition to the powder formulation, the decolorizing agent may also be formulated as a tablet, including effervescent tablets or granules, for protection against dust formation. From this, the decolorizing agent is then prepared before use with cold or warm water, optionally with the addition of one or more of the following aids. However, it is also possible that these aids (if they are in solid form) are already present in the decolorizing powder or decolorizing granules or the effervescent tablet. By wetting the powder with oils or waxes, it is additionally possible to reduce the formation of dust.

The decolorizing agent can be additional aids, such as solvents like water, lower aliphatic alcohols, for example, ethanol, n-propanol and isopropanol, Glycol ethers or glycols such as glycerol and in particular 1,2-propanediol, furthermore wetting agents or emulsifiers from the classes of anionic, cationic, amphoteric or nonionic surfactants such as fatty alcohol sulfates, ethoxylated fatty alcohol sulfates, alkylsulfonates, alkylbenzenesulfonates, alkyltrimethylammonium, alkylbetaines, ethoxylated fatty alcohols, ethoxylated nonylphenols, fatty acid, ethoxylated fatty alcohols, ethoxylated nonylphenols, fatty acid, ethoxylated fatty acid esters, also thickeners such as higher fatty alcohols, Starch or cellulose derivatives, perfumes, Hair pretreatment agents, conditioners, Hair swelling agents, Preservatives, Vaseline, Paraffin oil and fatty acids as well as conditioners such as cationic resins, lanolin derivatives, Cholesterol, Pantothenic acid and betaine, contain.

The pH of the decolorizing agent is about 1.8 to 6, especially 2.5 to 4. If necessary, the desired pH can be achieved by adding further acids, for example α-hydroxycarboxylic acids such as lactic acid, tartaric acid, citric acid or malic acid, phosphoric acid, acetic acid, glycolic acid salicylic acid, glutathione or gluconic acid lactone, or else alkalizing agents such as alkanolamines, alkylamines, alkali hydroxides, ammonium hydroxides, Alkali carbonates, ammonium carbonates or Alkaliphosphaten be adjusted.

Although it is particularly easy to add the α-oxocarboxylic acid directly to the decolorizing agent, it is also possible to degrade the α-oxocarboxylic acid separately from the decolorizing agent without deterioration of the decolorizing result and to use it in a separate after-treatment step subsequent to the decolorizing treatment.

It is likewise possible to use an α-oxocarboxylic acid or its physiologically acceptable salt both simultaneously in the decolorizing agent and in the after-treatment agent.

Surprisingly, it was found that the Entkärbeergebnis immediately after the Entfärbebehandlung Although both without α-Oxocarbonsäurezusatz (that is, when using only the component a)) and with α-Oxocarbonsäurezusatz is approximately equal; after some time, however, significant differences occur. Thus, the hair decolorized without α-Oxocarbonsäurezusatz discolored after a few hours or days due to the air oxidation again partially, while the decolored with α-Oxocarbonsäurezusatz hair remain unchanged. The α-Oxocarbonsäurezusatz thus causes a fixation of Entfärbeergebnisses and prevents the regression of the removed staining.

Depending on the dyeing and temperature to be decolored (about 20 to 50 degrees Celsius), the exposure time of the decolorizing agent is 5 to 60 minutes, in particular 15 to 30 minutes, whereby the decolorizing process can be accelerated by supplying heat. After completion of the exposure time of the decolorizer, the hair is rinsed with water, optionally washed with a shampoo.

If the decolorizing agent does not contain an α-oxocarboxylic acid, the hair is post-treated with a rinse containing an α-oxocarboxylic acid, preferably in the acidic pH range, following the decolorizing treatment, and then dried.

The application of the decolorizing agent of the component (II) according to the invention is, of course, not restricted to the decolorization of the dyeings produced by the component (I) of the multi-component kit according to the invention. Rather, the decolorizing preparation of component (II) can be used quite generally for decolorizing dyeings, even if these were not produced with the aid of the dyeing agent of component (I) according to the invention, but rather in a completely different and independent way. In addition, the decolorizing preparation of component (II) according to the invention is also suitable for decolorizing a variety of other natural or synthetic fibers, such as cotton, silk, viscose, nylon, cellulose acetate, if these have been dyed with oxidation dyes and / or substantive dyes, and is not limited to the decolorization of keratin fibers such as wool, furs or human hair.

The subject matter of the present application is therefore also an agent for the reduced decolorization of fibers dyed with oxidation dyes and / or substantive dyes, especially hair, which is a combination of a) at least one reductone, such as ascorbic acid or isoascorbic acid or their salts or esters, for example, 6-O-palmitoyl-ascorbic acid, Hydroxypropanedial (triosereductone), 2,3-dihydroxy-2-cyclopenten-1-one (reductic acid) or mixtures of these compounds, especially ascorbic acid, and / or at least one thiol, especially cysteine ​​or its salts, and / or at least one sulfite, especially sodium sulphite, and b) at least one α-oxocarboxylic acid or physiologically acceptable salt thereof, as well as the use of this decolorization agent for dyed fibers with oxidation dyes and / or substantive dyes, especially hair. Particularly preferred in this case is the use of a combination of a) at least one reductone, in particular ascorbic acid or isoascorbic acid or salts thereof, and at least one thiol, in particular cysteine ​​and / or cysteine ​​hydrochloride, and b) at least one α-oxocarboxylic acid or its physiologically acceptable salt ,

The decolorizing agent according to the invention enables a fast, gentle, uniform and durable decolorization of fibers dyed with oxidation dyes and / or substantive dyes without residual discoloration of the fiber.

The following examples are intended to explain the subject matter in more detail without restricting it to these examples.

Examples

Examples 1.1 to 1.14:

a. Oxidation hair

<tables id="tabl0001" num="0001"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Developer substance (s) (optionally with NH₃ (25% aqueous solution) or NaOH (10% aqueous solution))</entry><entry namest="col2" nameend="col2" align="left">Quantities according to Table 1</entry></row><row><entry namest="col1" nameend="col1" align="left">Coupler substance (s) (optionally with NH₃ (25% aqueous solution) or NaOH (10% aqueous solution))</entry><entry namest="col2" nameend="col2" align="left">Quantities according to Table 1</entry></row><row><entry namest="col1" nameend="col1" align="left">nitro dyes</entry><entry namest="col2" nameend="col2" align="left">Quantities according to Table 1</entry></row><row><entry namest="col1" nameend="col1" align="left">Disodium ethylenediaminetetraacetate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.30 g</entry></row><row><entry namest="col1" nameend="col1" align="left">sodium</entry><entry namest="col2" nameend="col2" align="char" char=",">0.40g</entry></row><row><entry namest="col1" nameend="col1" align="left">Sodium lauryl ether sulfate (28% aqueous solution)</entry><entry namest="col2" nameend="col2" align="char" char=",">10.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">isopropanol</entry><entry namest="col2" nameend="col2" align="char" char=",">10.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Ammonia (25% aqueous solution)</entry><entry namest="col2" nameend="col2" align="char" char=",">9,10 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Water, demineralized</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

5 g of the above color carrier mass are mixed with 5 g of a 4% hydrogen peroxide solution. The ready-to-use oxidation hair dye obtained is applied to the hair and spread evenly with a brush. After an exposure time of 30 minutes at 40 ° C, the hair is rinsed with lukewarm water and then dried.

b1. Entfärbegel:

<tables id="tabl0002" num="0002"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">ascorbic acid</entry><entry namest="col2" nameend="col2" align="char" char=",">5.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Methylhydroxyethylcellulose (Tylose MHB 10,000P from Hoechst / Germany)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">cysteine</entry><entry namest="col2" nameend="col2" align="char" char=",">2,00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Trisodium citrate dihydrate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.30 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

b2. Entfärbegel:

<tables id="tabl0003" num="0003"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">isoascorbic</entry><entry namest="col2" nameend="col2" align="char" char=",">5.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Methylhydroxyethylcellulose (Tylose MHB 10,000P from Hoechst / Germany)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">cysteine</entry><entry namest="col2" nameend="col2" align="char" char=",">2,00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">sodium</entry><entry namest="col2" nameend="col2" align="char" char=",">0.05 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Trisodium citrate dihydrate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.20 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

b3. Entfärbegel:

<tables id="tabl0004" num="0004"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">ascorbic acid</entry><entry namest="col2" nameend="col2" align="char" char=",">10.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">hydroxyethyl</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glutathione</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Trisodium citrate dihydrate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.90 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

b4. Entfärbegel:

<tables id="tabl0005" num="0005"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">sodium ascorbate</entry><entry namest="col2" nameend="col2" align="char" char=",">6.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">citric acid</entry><entry namest="col2" nameend="col2" align="char" char=",">6.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">hydroxyethyl</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

The pH of the decolorizing gel is between 2.5 and 3.5.

b5. Entfärbegel:

<tables id="tabl0006" num="0006"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">isoascorbic</entry><entry namest="col2" nameend="col2" align="char" char=",">6.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Methylhydroxyethylcellulose (Tylose MHB 10,000P from Hoechst / Germany)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">cysteine</entry><entry namest="col2" nameend="col2" align="char" char=",">2,00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">α-ketoglutaric acid</entry><entry namest="col2" nameend="col2" align="char" char=",">0.80 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

The pH is adjusted to 2.5 to 3.0 with trisodium citrate dihydrate.

b6. Entfärbegel:

<tables id="tabl0007" num="0007"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">sodium ascorbate</entry><entry namest="col2" nameend="col2" align="char" char=",">5.70 g</entry></row><row><entry namest="col1" nameend="col1" align="left">L-cysteine</entry><entry namest="col2" nameend="col2" align="char" char=",">2,00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">magnesium sulfate</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">citric acid</entry><entry namest="col2" nameend="col2" align="char" char=",">7.40 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Trisodium citrate dihydrate</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">hydroxyethyl</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">2-oxoglutarate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.80 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

b7. Entfärbegel:

<tables id="tabl0008" num="0008"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">sodium ascorbate</entry><entry namest="col2" nameend="col2" align="char" char=",">5.70 g</entry></row><row><entry namest="col1" nameend="col1" align="left">L-cysteine</entry><entry namest="col2" nameend="col2" align="char" char=",">2,00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">magnesium sulfate</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">citric acid</entry><entry namest="col2" nameend="col2" align="char" char=",">7.40 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Trisodium citrate dihydrate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.60 g</entry></row><row><entry namest="col1" nameend="col1" align="left">hydroxyethyl</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

b8. Entfärbegel:

<tables id="tabl0009" num="0009"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">sodium ascorbate</entry><entry namest="col2" nameend="col2" align="char" char=",">5.70 g</entry></row><row><entry namest="col1" nameend="col1" align="left">L-cysteine</entry><entry namest="col2" nameend="col2" align="char" char=",">2,00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">magnesium sulfate</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">citric acid</entry><entry namest="col2" nameend="col2" align="char" char=",">7.40 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Trisodium citrate dihydrate</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">hydroxyethyl</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Oxalessigsäure</entry><entry namest="col2" nameend="col2" align="char" char=",">0.70 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

The dyed hair described above is applied to the dyed hair and left for 30 minutes at 37 degrees Celsius (decolorizing agents b1 to b3) and 60 minutes at 40 degrees Celsius (decolorizing agents b4 and b5) and 20 to 60 minutes at 25 to 30 degrees, respectively Celsius (decolorizing agent b6) under a plastic cover, then washed thoroughly with water and a shampoo, optionally rinsed with water and then dried.

The result of this destaining treatment is summarized in Table 1.<tables id="tabl0010" num="0010"><img file="EP0943316A2_D0004.tif" /></tables><tables id="tabl0011" num="0011"><img file="EP0943316A2_D0005.tif" /></tables><tables id="tabl0012" num="0012"><img file="EP0943316A2_D0006.tif" /></tables><tables id="tabl0013" num="0013"><img file="EP0943316A2_D0007.tif" /></tables><tables id="tabl0014" num="0014"><img file="EP0943316A2_D0008.tif" /></tables><tables id="tabl0015" num="0015"><img file="EP0943316A2_D0009.tif" /></tables><tables id="tabl0016" num="0016"><img file="EP0943316A2_D0010.tif" /></tables><tables id="tabl0017" num="0017"><img file="EP0943316A2_D0011.tif" /></tables><tables id="tabl0018" num="0018"><img file="EP0943316A2_D0012.tif" /></tables><tables id="tabl0019" num="0019"><img file="EP0943316A2_D0013.tif" /></tables><tables id="tabl0020" num="0020"><img file="EP0943316A2_D0014.tif" /></tables><tables id="tabl0021" num="0021"><img file="EP0943316A2_D0015.tif" /></tables><tables id="tabl0022" num="0022"><img file="EP0943316A2_D0016.tif" /></tables><tables id="tabl0023" num="0023"><img file="EP0943316A2_D0017.tif" /></tables>

Examples 2.1 to 2.7:

The dyeing is carried out on bleached hair in the manner given in Example 1 (concentration of dye precursors: 0.05 mol / l).

The decolorization takes place with the Entfärbegelen <b>b1</b> or <b>b2</b>

On the dyed hair is applied to the above-described decolorizing agents and allowed to act for 20 or 30 minutes at 37 degrees Celsius under a plastic cover, then washed thoroughly with water and a shampoo, rinsed with water and then dried.

The results of the dyeing and deinking treatments are summarized in Table 2 below. <tables id="tabl0024" num="0024"><table frame="all"><title>Table 2</title><tgroup cols="6" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="26.25mm" /><colspec colnum="2" colname="col2" colwidth="26.25mm" /><colspec colnum="3" colname="col3" colwidth="26.25mm" /><colspec colnum="4" colname="col4" colwidth="26.25mm" /><colspec colnum="5" colname="col5" colwidth="26.25mm" /><colspec colnum="6" colname="col6" colwidth="26.25mm" /><thead valign="top"><row rowsep="1"><entry namest="col1" nameend="col6" align="center">Dyeing and decolouring results</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="center"><b>No.</b></entry><entry namest="col2" nameend="col2" align="left"><b>Developer / coupler combination</b></entry><entry namest="col3" nameend="col3" align="center"><b>Color after coloring</b></entry><entry namest="col4" nameend="col4" align="center"><b>bleach for</b></entry><entry namest="col5" nameend="col5" align="center"><b>Destaining time (minutes)</b></entry><entry namest="col6" nameend="col6" align="center"><b>Color after decolorization</b></entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" morerows="1" align="char" char="."><b>2.1</b></entry><entry namest="col2" nameend="col2" align="left">1,4-diamino-2-methyl-benzene-sulfate;</entry><entry namest="col3" nameend="col3" morerows="1" align="left">brown</entry><entry namest="col4" nameend="col4" morerows="1" align="left"><b>b1</b></entry><entry namest="col5" nameend="col5" morerows="1" align="right">30</entry><entry namest="col6" nameend="col6" morerows="1" align="left">beige</entry></row><row><entry namest="col2" nameend="col2" align="left">1,3-dihydroxybenzene</entry></row><row><entry namest="col1" nameend="col1" morerows="1" align="char" char="."><b>2.2</b></entry><entry namest="col2" nameend="col2" align="left">1,4-diamino-2-methylbenzene sulfate;</entry><entry namest="col3" nameend="col3" morerows="1" align="left">dark blue</entry><entry namest="col4" nameend="col4" morerows="1" align="left"><b>b2</b></entry><entry namest="col5" nameend="col5" morerows="1" align="right">30</entry><entry namest="col6" nameend="col6" morerows="1" align="left">Gray</entry></row><row><entry namest="col2" nameend="col2" align="left">1-naphthol</entry></row><row><entry namest="col1" nameend="col1" morerows="1" align="char" char="."><b>2.3</b></entry><entry namest="col2" nameend="col2" align="left">1,4-diamino-2-methyl-benzene-sulfate;</entry><entry namest="col3" nameend="col3" morerows="1" align="left">dark blue</entry><entry namest="col4" nameend="col4" morerows="1" align="left"><b>b1</b></entry><entry namest="col5" nameend="col5" morerows="1" align="right">30</entry><entry namest="col6" nameend="col6" morerows="1" align="left">brownish</entry></row><row><entry namest="col2" nameend="col2" align="left">3-Amino-6-methoxy-2- (methylamino) pyridine</entry></row><row><entry namest="col1" nameend="col1" morerows="1" align="char" char="."><b>2.4</b></entry><entry namest="col2" nameend="col2" align="left">4,5-diamino-1- (2-hydroxyethyl) -1H-pyrazole;</entry><entry namest="col3" nameend="col3" morerows="1" align="left">intense fuschia</entry><entry namest="col4" nameend="col4" morerows="1" align="left"><b>b1</b></entry><entry namest="col5" nameend="col5" morerows="1" align="right">30</entry><entry namest="col6" nameend="col6" morerows="1" align="left">pink</entry></row><row><entry namest="col2" nameend="col2" align="left">1-naphthol</entry></row><row><entry namest="col1" nameend="col1" morerows="1" align="char" char="."><b>2.5</b></entry><entry namest="col2" nameend="col2" align="left">1,4-diamino-2- (2-hydroxyethyl) benzene-sulfate;</entry><entry namest="col3" nameend="col3" morerows="1" align="left">intense violet</entry><entry namest="col4" nameend="col4" morerows="1" align="left"><b>b2</b></entry><entry namest="col5" nameend="col5" morerows="1" align="right">20</entry><entry namest="col6" nameend="col6" morerows="1" align="left">slightly yellowish</entry></row><row><entry namest="col2" nameend="col2" align="left">5-amino-2-methyl-phenol</entry></row><row><entry namest="col1" nameend="col1" morerows="1" align="char" char="."><b>2.6</b></entry><entry namest="col2" nameend="col2" align="left">4,5-diamino-1- (2-hydroxyethyl) -1H-pyrazole;</entry><entry namest="col3" nameend="col3" morerows="1" align="left">bordeaux-red</entry><entry namest="col4" nameend="col4" morerows="1" align="left"><b>b2</b></entry><entry namest="col5" nameend="col5" morerows="1" align="right">30</entry><entry namest="col6" nameend="col6" morerows="1" align="left">weak bordaux-red</entry></row><row><entry namest="col2" nameend="col2" align="left">2-Amino-4 - [(2-hydroxyethyl) amino] -anisole sulfate</entry></row><row><entry namest="col1" nameend="col1" morerows="2" rowsep="1" align="char" char="."><b>2.7</b></entry><entry namest="col2" nameend="col2" align="left">4-amino-3-methyl-phenol (0.06%);</entry><entry namest="col3" nameend="col3" morerows="2" rowsep="1" align="left">pink</entry><entry namest="col4" nameend="col4" morerows="2" rowsep="1" align="left"><b>b2</b></entry><entry namest="col5" nameend="col5" morerows="2" rowsep="1" align="right">20</entry><entry namest="col6" nameend="col6" morerows="2" rowsep="1" align="left">colorless</entry></row><row><entry namest="col2" nameend="col2" align="left">1-naphthol (0.04%);</entry></row><row rowsep="1"><entry namest="col2" nameend="col2" align="left">5-amino-2-methyl-phenol (0.03%)</entry></row></tbody></tgroup></table></tables>

Examples 2.8 to 2.33:

The dyeing is carried out on bleached hair in the manner given in Example 1 (unless otherwise stated, the concentration of dye precursors is 0.05 mol / l). The decolorization takes place with the Entfärbegel <b>B9.1.</b>

B9.1. Entfärbegel:

<tables id="tabl0025" num="0025"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">sodium ascorbate</entry><entry namest="col2" nameend="col2" align="char" char=",">5.60 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Methylhydroxyethylcellulose (Tylose MHB 10,000P from Hoechst / Germany)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Cysteine ​​hydrochloride</entry><entry namest="col2" nameend="col2" align="char" char=",">2.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">citric acid</entry><entry namest="col2" nameend="col2" align="char" char=",">5.00 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

The dyed hair described above is applied to the colored hair and allowed to act under a plastic cover for 20 or 30 minutes at 37 degrees Celsius, followed by thorough washing with water and a shampoo containing the glyoxylic acid-containing aftertreatment agent <b>B9.2</b> treated, rinsed with water and then dried.

B9.2. aftertreatment agent

<tables id="tabl0026" num="0026"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Cetrimonium chloride (50%)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Glyoxylic acid (50%)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">hydroxyethyl</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Trisodium citrate dihydrate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.30 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

The results of the dyeing and decolorizing treatments are summarized in Table 2a below.<tables id="tabl0027" num="0027"><img file="EP0943316A2_D0018.tif" /></tables><tables id="tabl0028" num="0028"><img file="EP0943316A2_D0019.tif" /></tables><tables id="tabl0029" num="0029"><img file="EP0943316A2_D0020.tif" /></tables><tables id="tabl0030" num="0030"><img file="EP0943316A2_D0021.tif" /></tables><tables id="tabl0031" num="0031"><img file="EP0943316A2_D0022.tif" /></tables><tables id="tabl0032" num="0032"><img file="EP0943316A2_D0023.tif" /></tables><tables id="tabl0033" num="0033"><img file="EP0943316A2_D0024.tif" /></tables><tables id="tabl0034" num="0034"><img file="EP0943316A2_D0025.tif" /></tables><tables id="tabl0035" num="0035"><img file="EP0943316A2_D0026.tif" /></tables><tables id="tabl0036" num="0036"><img file="EP0943316A2_D0027.tif" /></tables><tables id="tabl0037" num="0037"><img file="EP0943316A2_D0028.tif" /></tables>

Examples 2.34 to 2.36:

The dyeing is carried out on bleached hair in the manner given in Example 1 (unless otherwise stated, the concentration of dye precursors is 0.05 mol / l).

The decolorization takes place with those in the examples <b>1.1 to 1.14</b> described Entfärbegelen <b>b6, b7 or b8.</b> For the post-treatment, a glyoxylic acid-containing agent according to <b>B9.2</b> from example <b>2.8 to 2.33</b> used.

On the dyed hair is in each case the above-described decolorizing agent <b>b6, b7 or b8</b> applied. After an exposure time of 30 minutes at 37 degrees Celsius under a plastic cover, the hair is rinsed thoroughly with water for 5 minutes with the glyoxylic acid-containing aftertreatment agent<b>B9.2</b> treated, rinsed with water and then dried.

The results of the dyeing treatments and decolorizing treatments are summarized in Table 2b below. <tables id="tabl0038" num="0038"><table frame="all"><title>Table 2b:</title><tgroup cols="7" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="22.50mm" /><colspec colnum="2" colname="col2" colwidth="22.50mm" /><colspec colnum="3" colname="col3" colwidth="22.50mm" /><colspec colnum="4" colname="col4" colwidth="22.50mm" /><colspec colnum="5" colname="col5" colwidth="22.50mm" /><colspec colnum="6" colname="col6" colwidth="22.50mm" /><colspec colnum="7" colname="col7" colwidth="22.50mm" /><thead valign="top"><row rowsep="1"><entry namest="col1" nameend="col7" align="center">Dyeing and decolouring results</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" rowsep="0" align="left"><b>No.</b></entry><entry namest="col2" nameend="col2" rowsep="0" align="left"><b>Developer / coupler combination</b></entry><entry namest="col3" nameend="col3" rowsep="0" align="center"><b>Color after coloring</b></entry><entry namest="col4" nameend="col6" align="left"><b>color values</b></entry><entry namest="col7" nameend="col7" rowsep="0" align="center"><b>decolorizing%</b></entry></row><row rowsep="1"><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" /><entry namest="col3" nameend="col3" /><entry namest="col4" nameend="col4" align="left"><b>L</b></entry><entry namest="col5" nameend="col5" align="center"><b>a</b></entry><entry namest="col6" nameend="col6" align="center"><b>b</b></entry><entry namest="col7" nameend="col7" /></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" morerows="5" align="char" char="."><b>2:34</b></entry><entry namest="col2" nameend="col2" morerows="1" align="left">1,4-diamino-2-methylbenzene sulfate: 1.10 g</entry><entry namest="col3" nameend="col3" morerows="5" align="left">blue black</entry><entry namest="col4" nameend="col6" align="left">untreated hair:</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col4" nameend="col4" align="char" char=",">31.9;</entry><entry namest="col5" nameend="col5" align="char" char=",">+7.0;</entry><entry namest="col6" nameend="col6" align="char" char=",">+11.7</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col2" nameend="col2" align="left">1,4-diamino-2- (2-hydroxyethyl) benzene sulfate: 1.25 g</entry><entry namest="col4" nameend="col6" align="left">After dyeing:</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col2" nameend="col2" align="left">5-amino-2-methyl-phenol: 0.25 g</entry><entry namest="col4" nameend="col4" align="char" char=",">20.4;</entry><entry namest="col5" nameend="col5" align="char" char=",">+0.8;</entry><entry namest="col6" nameend="col6" align="char" char=",">-1.3</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col2" nameend="col2" morerows="1" align="left">1,3-di (2,4-diaminophenoxy) -propane: 1.74g</entry><entry namest="col4" nameend="col6" align="left">after 1x decolorization with <b>b6</b> and 5 minutes post-treatment with <b>B9.2:</b></entry><entry namest="col7" nameend="col7" morerows="1" align="right">84</entry></row><row><entry namest="col4" nameend="col4" align="char" char=",">33.5;</entry><entry namest="col5" nameend="col5" align="char" char=",">+9.0;</entry><entry namest="col6" nameend="col6" align="char" char=",">+13.2</entry></row><row><entry namest="col1" nameend="col1" morerows="5" align="char" char="."><b>2:35</b></entry><entry namest="col2" nameend="col2" morerows="1" align="left">1,4-diamino-2-methylbenzene sulfate: blue-black 1.10g</entry><entry namest="col3" nameend="col3" morerows="5" /><entry namest="col4" nameend="col6" align="left">untreated hair:</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col4" nameend="col4" align="char" char=",">32.1;</entry><entry namest="col5" nameend="col5" align="char" char=",">+6.7;</entry><entry namest="col6" nameend="col6" align="char" char=",">+11.2</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col2" nameend="col2" align="left">1,4-diamino-2- (2-hydroxyethyl) benzene sulfate: 1.25 g</entry><entry namest="col4" nameend="col6" align="left">After dyeing:</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col2" nameend="col2" align="left">5-amino-2-methyl-phenol: 0.25 g</entry><entry namest="col4" nameend="col4" align="char" char=",">18.9;</entry><entry namest="col5" nameend="col5" align="char" char=",">+0.6;</entry><entry namest="col6" nameend="col6" align="char" char=",">-1.1</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col2" nameend="col2" morerows="1" align="left">1,3-di (2,4-diaminophenoxy) -propane: 1.74g</entry><entry namest="col4" nameend="col6" align="left">after 1x decolorization with <b>b7</b> and 5 minutes post-treatment with <b>B9.2:</b></entry><entry namest="col7" nameend="col7" morerows="1" align="right">89</entry></row><row><entry namest="col4" nameend="col4" align="char" char=",">33.9;</entry><entry namest="col5" nameend="col5" align="char" char=",">+8.0;</entry><entry namest="col6" nameend="col6" align="char" char=",">+11.1</entry></row><row><entry namest="col1" nameend="col1" morerows="5" rowsep="1" align="char" char="."><b>2:36</b></entry><entry namest="col2" nameend="col2" morerows="1" align="left">1,4-diamino-2-methylbenzene sulfate: 1.10 g</entry><entry namest="col3" nameend="col3" morerows="5" rowsep="1" align="left">blue black</entry><entry namest="col4" nameend="col6" align="left">untreated hair:</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col4" nameend="col4" align="char" char=",">30.6;</entry><entry namest="col5" nameend="col5" align="char" char=",">+6.8;</entry><entry namest="col6" nameend="col6" align="char" char=",">+10.9</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col2" nameend="col2" align="left">1,4-diamino-2- (2-hydroxyethyl) benzene sulfate: 1.25 g</entry><entry namest="col4" nameend="col6" align="left">After dyeing:</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col2" nameend="col2" align="left">5-amino-2-methyl-phenol: 0.25 g</entry><entry namest="col4" nameend="col4" align="char" char=",">19.5;</entry><entry namest="col5" nameend="col5" align="char" char=",">+0.8;</entry><entry namest="col6" nameend="col6" align="char" char=",">-1.0</entry><entry namest="col7" nameend="col7" /></row><row><entry namest="col2" nameend="col2" morerows="1" rowsep="1" align="left">1,3-di (2,4-diaminophenoxy) -propane: 1.74g</entry><entry namest="col4" nameend="col6" align="left">after 1x decolorization with <b>b8</b> and 5 minutes post-treatment with <b>B9.2:</b></entry><entry namest="col7" nameend="col7" morerows="1" rowsep="1" align="right">82</entry></row><row rowsep="1"><entry namest="col4" nameend="col4" align="char" char=",">32.0;</entry><entry namest="col5" nameend="col5" align="char" char=",">+8.9;</entry><entry namest="col6" nameend="col6" align="char" char=",">+12.8</entry></row></tbody></tgroup></table></tables>

Examples 3.1 to 3.32:

The dyeing is carried out on bleached hair in the manner given in Example 1 (concentration of dye precursors: 0.05 mol / l).

The decolorization takes place with the following means:

A: decolorizing gel (corresponding to b4 from example 1):

<tables id="tabl0039" num="0039"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">sodium ascorbate</entry><entry namest="col2" nameend="col2" align="char" char=",">6.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">citric acid</entry><entry namest="col2" nameend="col2" align="char" char=",">6.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">hydroxyethyl</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

The pH of the decolorizing gel is between 2.5 and 3.5.

B: decolorizing solution:

<tables id="tabl0040" num="0040"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">ascorbic acid</entry><entry namest="col2" nameend="col2" align="char" char=",">10 G</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.5 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Water, demineralized</entry><entry namest="col2" nameend="col2" align="char" char=","><u>90 G</u></entry></row><row rowsep="1"><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="char" char=",">100 G</entry></row></tbody></tgroup></table></tables>

C: decolorizing balm:

<tables id="tabl0041" num="0041"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Cetylstearylalkohol</entry><entry namest="col2" nameend="col2" align="char" char=",">4.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">cetyl lactate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Dimethicone</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">cetyltrimethylammonium</entry><entry namest="col2" nameend="col2" align="char" char=",">0.65 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">ascorbic acid</entry><entry namest="col2" nameend="col2" align="char" char=",">6.00 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Water, demineralized</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

The pH of the decolorizing balsam is adjusted to 2.5 with a 2% aqueous NaOH solution.

D: defoaming foam:

<tables id="tabl0042" num="0042"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Cetylstearylalkohol</entry><entry namest="col2" nameend="col2" align="char" char=",">1.30 g</entry></row><row><entry namest="col1" nameend="col1" align="left">PEG-35 castor oil</entry><entry namest="col2" nameend="col2" align="char" char=",">0.47 g</entry></row><row><entry namest="col1" nameend="col1" align="left">cetyltrimethylammonium</entry><entry namest="col2" nameend="col2" align="char" char=",">0.94 g</entry></row><row><entry namest="col1" nameend="col1" align="left">ascorbic acid</entry><entry namest="col2" nameend="col2" align="char" char=",">6.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Water, demineralized</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Propane / butane (5 bar)</entry><entry namest="col2" nameend="col2" align="char" char=",">6.00 g</entry></row></tbody></tgroup></table></tables>

The pH of the decolorizing foam is adjusted to 2.5 with trisodium citrate dihydrate.

The hair is treated at 40 ° C for 20 to 60 minutes with the decolorizing agent, then washed thoroughly with water and a shampoo and then dried.

The results of the dyeing and deinking treatments are summarized in Table 3 below.<tables id="tabl0043" num="0043"><img file="EP0943316A2_D0029.tif" /></tables><tables id="tabl0044" num="0044"><img file="EP0943316A2_D0030.tif" /></tables><tables id="tabl0045" num="0045"><img file="EP0943316A2_D0031.tif" /></tables><tables id="tabl0046" num="0046"><img file="EP0943316A2_D0032.tif" /></tables><tables id="tabl0047" num="0047"><img file="EP0943316A2_D0033.tif" /></tables><tables id="tabl0048" num="0048"><img file="EP0943316A2_D0034.tif" /></tables><tables id="tabl0049" num="0049"><img file="EP0943316A2_D0035.tif" /></tables><tables id="tabl0050" num="0050"><img file="EP0943316A2_D0036.tif" /></tables><tables id="tabl0051" num="0051"><img file="EP0943316A2_D0037.tif" /></tables><tables id="tabl0052" num="0052"><img file="EP0943316A2_D0038.tif" /></tables><tables id="tabl0053" num="0053"><img file="EP0943316A2_D0039.tif" /></tables><tables id="tabl0054" num="0054"><img file="EP0943316A2_D0040.tif" /></tables>

Example 4:

Enzymatically oxidized hair color (a)

<tables id="tabl0055" num="0055"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Stearyl alcohol polyglycol ether (= Steareth 20)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.40 g</entry></row><row><entry namest="col1" nameend="col1" align="left">sodium</entry><entry namest="col2" nameend="col2" align="char" char=",">0.10 g</entry></row><row><entry namest="col1" nameend="col1" align="left"><i>di</i>Sodium ethylenediaminetetraacetate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.30 g</entry></row><row><entry namest="col1" nameend="col1" align="left">D-glucose</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glycerin</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">isopropanol</entry><entry namest="col2" nameend="col2" align="char" char=",">5.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">1,2-propanediol</entry><entry namest="col2" nameend="col2" align="char" char=",">2,00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">1,4-diamino-2-methylbenzene sulfate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.025 M</entry></row><row><entry namest="col1" nameend="col1" align="left">5-amino-2-methylphenol</entry><entry namest="col2" nameend="col2" align="char" char=",">0.025 M</entry></row><row><entry namest="col1" nameend="col1" align="left">Glucose oxidase (EC 1.1.3.4)</entry><entry namest="col2" nameend="col2" align="char" char=",">400 units</entry></row><row><entry namest="col1" nameend="col1" align="left">Peroxidase (EC 1.11.1.7)</entry><entry namest="col2" nameend="col2" align="char" char=",">400 units</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">0.1 M borate buffer (pH 8.5)</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

Decolorizing gel (according to b9.1)

<tables id="tabl0056" num="0056"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">sodium ascorbate</entry><entry namest="col2" nameend="col2" align="char" char=",">5.60 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Methylhydroxyethylcellulose (Tylose MHB 10,000P from Hoechst / Germany)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Cysteine ​​hydrochloride</entry><entry namest="col2" nameend="col2" align="char" char=",">2.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">citric acid</entry><entry namest="col2" nameend="col2" align="char" char=",">5.00 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

Aftertreatment agent (according to b9.2)

<tables id="tabl0057" num="0057"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Cetrimonium chloride (50%)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Glyoxylic acid (50%)</entry><entry namest="col2" nameend="col2" align="char" char=",">1.00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">hydroxyethyl</entry><entry namest="col2" nameend="col2" align="char" char=",">1.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Trisodium citrate dihydrate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.30 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">water</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 100.00 g</entry></row></tbody></tgroup></table></tables>

The hair dye described above <b>(A)</b> is applied to bleached hair. After a contact time of 60 minutes at room temperature (25 degrees Celsius), the hair is washed and dried.

The deep purple colored hair is then 20 minutes at 40 ° C with the decolorizing gel <b>B9.1</b> and 2 to 3 minutes with the post-treatment agent <b>B9.2</b> treated.

The hair is then washed thoroughly and dried. The hair gets almost its original color back.

Example 5: Two-component decolorizing emulsion

Component 1:

<tables id="tabl0058" num="0058"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Cetylstearylalkohol</entry><entry namest="col2" nameend="col2" align="char" char=",">4,50g</entry></row><row><entry namest="col1" nameend="col1" align="left">cetyl lactate</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Dimethicone</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row><entry namest="col1" nameend="col1" align="left">cetyltrimethylammonium</entry><entry namest="col2" nameend="col2" align="char" char=",">0.65 g</entry></row><row><entry namest="col1" nameend="col1" align="left">glyoxylic</entry><entry namest="col2" nameend="col2" align="char" char=",">0.50 g</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Water, demineralized</entry><entry namest="col2" nameend="col2" align="char" char=",">ad 92.00 g</entry></row></tbody></tgroup></table></tables>

Component 2:

<tables id="tabl0059" num="0059"><table frame="all"><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">L-cysteine</entry><entry namest="col2" nameend="col2" align="char" char=",">2,00 g</entry></row><row><entry namest="col1" nameend="col1" align="left">Ascorbic acid (powdered)</entry><entry namest="col2" nameend="col2" align="char" char=","><u>6.00 g</u></entry></row><row rowsep="1"><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="char" char=",">100.00 g</entry></row></tbody></tgroup></table></tables>

Component 1 is mixed with component 2 immediately prior to use and the pH of the ready-to-use decolorizing preparation thus obtained is adjusted to 2.5 with trisodium citrate dihydrate.

Example 6: Decolorizing gel

<dl id="dl0001" compact="compact"><dt>8.00 g</dt><dd>ascorbic acid</dd><dt>2,00 g</dt><dd>L-cysteine</dd><dt>0.08 g</dt><dd>a-ketoglutaric</dd><dt>2,00 g</dt><dd>hydroxyethyl</dd><dt>0.50 g</dt><dd>silica</dd></dl>

The pH is adjusted to 2.5 to 3.0 with trisodium citrate dihydrate. The mixture is mixed before use with 89.34 g of warm water and mixed well. The decolorizing gel thus obtained may be used to decolorize fibers or hair colored with oxidative dyes.

The L * a * b * colorimetric data given in the present examples were determined using a colorimeter from Minolta, type Chromameter II.

Here, the L value stands for the brightness (that is, the lower the L value is, the greater the color intensity), while the a value is a measure of the red component (that is, the larger the a value is, the more larger is the red portion). The b value is a measure of the blue component of the color, the blue component being greater, the more negative the b value is.

The value D indicates the color difference that exists between the untreated and the dyed or bleached streaks. It is determined as follows:<maths id="math0001" num=""><math display="block"><mrow><mtext>D = √</mtext><msqrt><msub><mrow><mtext>(L</mtext></mrow><mrow><mtext>i</mtext></mrow></msub><msub><mrow><mtext>-L</mtext></mrow><mrow><mtext>0</mtext></mrow></msub><msup><mrow><mtext>)</mtext></mrow><mrow><mtext>2</mtext></mrow></msup><msub><mrow><mtext> + (a</mtext></mrow><mrow><mtext>i</mtext></mrow></msub><msub><mrow><mtext>-a</mtext></mrow><mrow><mtext>0</mtext></mrow></msub><msup><mrow><mtext>)</mtext></mrow><mrow><mtext>2</mtext></mrow></msup><msub><mrow><mtext> + (b</mtext></mrow><mrow><mtext>i</mtext></mrow></msub><msub><mrow><mtext>-b</mtext></mrow><mrow><mtext>O</mtext></mrow></msub><msup><mrow><mtext>)</mtext></mrow><mrow><mtext>2</mtext></mrow></msup></msqrt></mrow></math><img file="EP0943316A2_D0041.tif" /></maths> where L₀, a₀ and b₀ the colorimetry of untreated hair and L_i, a_i and b_i represent the values ​​of the treated hair. The percent decolorization rate was determined as follows:<maths id="math0002" num=""><math display="block"><mrow><mtext>Decolorizing% = [1 - (D after decolorization / D after staining)] × 100.</mtext></mrow></math><img file="EP0943316A2_D0042.tif" /></maths>

All percentages stated in the present application are percentages by weight unless stated otherwise.