Process for producing hair dyes

Abstract

The invention relates to a process for the preparation of a coloring cream for bleaching or coloring keratin fibers in which a pre-mix is introduced in any of its. process step Said pre-mix comprises a suspension of Xanthan gum in at least one non-ionic emulsifier of the formula CH3-(CH2)11-[O-CH2-CH2]n-OH, (I) or CH3-(CH2)7-C2H2-(CH2)8-[O-CH2-CH2]m-OH, (II) with n = 2 to 9, preferably n = 2 to 4, and m = 2 to 5 and that at least one fatty alcohol with an alkyl chain featuring 12 to 30 C-atoms is added before or together with the pre-mix or in any other step of the process.

Description

[0001] Process for producing hair dyes

[0002] The invention relates to a process for preparing a coloring cream for bleaching or coloring keratin fibers by introducing a novel Xanthan gum suspension as a pre-mix at any process step. Further, a Xanthan gum suspension for use in the process, a cosmetic composition comprising the Xanthan gum suspension, a kit for dyeing or bleaching keratin fibers and a ready-to-use mixture obtainable by mixing the kit components are described.

[0003] Hair dyeing and bleaching have seen a significant rise in popularity in recent years. Not only do people seek to change their natural hair color for a more fashionable look, but many also use dyeing products to conceal gray hair. There are two main coloring processes in this context: oxidative (or permanent) dyeing and direct (or semi-permanent) dyeing.

[0004] Oxidative dyes comprise one or more precursors of oxidative dyes, so-called primary intermediates, and one or more color coupling agents to obtain the desired shades. These compounds are small aromatic molecules being able to diffuse in the hair shaft where, once activated by atmospheric oxygen or an oxidizing agent, they further react with other precursors to form larger colored molecules.

[0005] Compositions comprising primary intermediates and couplers are normally activated by mixing with an oxidant, commonly referred to as a "developer" or "activator." Hydrogen peroxide is the most commonly used activator these days. The thus-obtained ready-to-use compositions are subsequently applied to the keratin fibers for a certain period of time, during which the dye(s) is (are) formed. An important group of these specific cosmetic compositions are present in a cream-like state at the temperature of application (this is typically between 20 - 35°C). The primary intermediates employed in these cosmetic compositions are usually derivatives of benzene, e.g. p-phenylenediamines, o- and p- aminophenols or heterocyclic compounds such as 4,5-diamino pyrazoles or pyrimidines. Primary intermediates which are combined with color coupling agents open the way for realizing a broad color spectrum. Preferred color coupling agents are resorcinols, m-aminophenols, m-phenylenediamines, 1- naphthols, and di-, tri- and tetra-substituted pyridines.

[0006] The cosmetic compositions based on oxidative dyes are usually manufactured and provided as two component kits, wherein one kit component has a basic pH and comprises the primary intermediates and the color coupling agents. The second kit component comprises a hydrogen peroxide composition which is usually stabilized by an amount of phosphoric acid. Usually, both kit components are preferentially provided in cream- or gel-like form. Prior to use, a ready- to-use compositions is produced by mixing both kit components either by stirring in a bowl or by shaking in a container, e.g. a bottle or a jar.

[0007] The ready-to-use mixture is then applied to the hair by means of a brush or another applicator tool. Preferably, coloring mixtures have a certain higher viscosity in order to prevent dripping during the treatment of the hair.

[0008] Optimum results in the oxidative coloring of hair are normally achieved by ready- to-use mixtures which are adjusted to a pH in the range of from 9.0 to 10.5. Usually, the kit components are mixed directly prior to application to the hair in a ratio of from 1 :1 to 1 :3 by weight. The resulting mixture is then applied to the hair by means of a brush or another applicator tool. A common configuration of cosmetic compositions in a cream-like form comprises at least long chain fatty alcohols, water and one or more emulsifiers to achieve thus cream-like consistency. Thereby, the choice of the emulsifier system strongly determines the properties of the creams.

[0009] In the past, conventional cream-like compositions, especially nonionic compositions based on fatty alcohols and nonionic oil-in-water emulsifiers, have been useful for formulating primary intermediates and couplers which have been available as free bases. As soon as primary intermediates or couplers were adducts with an acid, for instance sulfuric acid or hydrochloric acid such as Toluene-2,5-diamine Sulfate, Hydroxyethyl-p-phenylenediamine Sulfate, 1- Hydroxyethyl-4,5-diamino pyrazole Sulfate, 2,4-Diaminophenoxyethanol Sulfate or the corresponding (di)Hydrochloride; stability of cream compositions often decreased and, as consequence of the high salt load, separated into an oil phase and a water phase.

[0010] In order to improve the stability and the salt tolerance of cream bases it was found that the combination of nonionic with anionic emulsifiers has contributed to meet the general requirements of the color creams, for instance Sodium Cocoyl Isethionate, Sodium Lauryl Sulfate or Sodium Laureth Sulfate as illustrated by the examples of EP594811 B1 contributed to improving consistency and storage stability of the compositions.

[0011] Based on this, modem cream-like compositions, which are particularly salt tolerant, comprise for instance combinations of long-chain C12 to C30 fatty alcohols and phosphate ester emulsifiers. The emulsifiers are for instance: i) monoester phosphates of alkoxylated fatty alcohols, wherein the alkox- ylated fatty alcohols are composed of C12 to C22 fatty alcohols alkoxylated with from 1 to 50 moles of an alkylene oxide, wherein the number of moles of alkylene oxide is with respect to the moles of fatty alcohol; ii) diester phosphates of non-alkoxylated fatty alcohols, wherein the non- alkoxylated fatty alcohols are composed of C12-C22 fatty alcohols; iii) organic phosphate ester compound selected from mono- and diacyl or alkyl substituted polyglycerol derivatives of phosphoric acid as mentioned below.

[0012] Best known combinations of phosphate ester emulsifiers are for instance Dicetyl Phosphate and Ceteth-10 Phosphate as described by US 6, 117,915A. Commercial are blends of both emulsifiers and Cetearyl Alcohol, called Crodafos CES (available from Croda GmbH, 41334 Nettetal, Germany).

[0013] Further useful phosphate ester emulsifiers are Oleth-5 Phosphate (and) Dioleyl Phosphate called Crodafos HCE, Potassium Cetyl Phosphate (available from local distributors DSM and Croda), as well as Polyglyceryl-3 Rice Branate Phosphate, Polyglyceryl-4 Stearate Phosphate (available from Socri, via Majocchi, 13 / B, 27020 Torre d’Isola, Italy), Polyglyceryl-3 Oleyl Ether Phosphate, and Polyglyceryl-4 Sorbity I Ether Olivate Phosphate.

[0014] Compositions comprising a combination of dicetylphosphate, ceteth-10 phosphate and fatty alcohols were found to be able to absorb a wide range of ingredients such as polymers, salts and oils, even all at once, without necessarily tending towards instability.

[0015] To further stabilize and prevent syneresis these complex and salt loaded cosmetic compositions often comprise Xanthan gum and propylene glycol.

[0016] While the use of propylene glycol is approved for different applications such as solvent or plasticizer in household products, as food additive or as ingredient of personal care products and pharmaceutical preparations, there are reports that skin exposure may cause skin-sensitizing and irritations (see Lessmann, H.; Schnuch, A.; Geier, J.; liter, W.; "Skin-sensitizing and irritant properties of propylene glycol", Contact Dermatitis, 2005, 53, 247-259 or Al Jasser, M.; Mebuke, N.; de Gannes, G.; “Propylene glycol: an often unrecognized cause of allergic contact dermatitis in patients using topical corticosteroids”, Skin Therapy Lett., 2011 16(5), 5-7).

[0017] In case the presence of Propylene glycol has to be avoided or it is unwished in modem cosmetic products, the number of organic solvents useful for dispersing Xanthan gum is limited. This, however, gave reason to further explore new liquids for color cosmetic applications.

[0018] In principle, it is possible to replace the propylene glycol with water, but the slow addition of powdery Xanthan gum, which is a polysaccharide comprising (3-1 ,4- bonded D-glucose units as backbone, to a stirred or otherwise agitated aqueous composition leads to inhomogeneous suspensions since as conventional agitators give rise to several problems:

[0019] - Xanthan gum as most of the gums begins to hydrate nearly as soon as it is added to water and sometimes hydration occurs before the gum is fully suspended. This results in the formation of gum balls and lumps that still have dry gum powder on the inside, since the water could not fully penetrate gum ball or lump. Such agglomerates are commonly termed “fisheyes”.

[0020] - Agitators such as the widely used impeller agitator do not produce sufficient shear to rapidly break agglomerates down.

[0021] - The increase in viscosity adds to this problem, so that sufficient agitation of the solution becomes increasingly difficult.

[0022] - Long mixing times are often necessary to complete suspen- sion / hydration of Xanthan, leading to long batch times and delays in production. - Anhydrous Xanthan gum gradually hydrates during storage or subsequent processing, leading to undesired changes in product viscosity.

[0023] - Dissolving of Xanthan Gum in water takes relatively long time, usually several hours.

[0024] Therefore, a number of different mechanical suspension and hydration methods have been applied in an attempt to try to overcome these issues. Methods may vary according to the type of composition and the scale of production.

[0025] For example, special equipment such as high shear mixers may improve the homogenization in processes relying on the direct addition of powdery Xanthan gum to water or aqueous compositions. However, such equipment is more expensive in the acquisition and more complex to handle in comparison to standard stirrers.

[0026] Alternatively, Xanthan Gum may be added in a premixed form to the other components. The use of aqueous premixes of Xanthan gum for hair cosmetic composition is described in EP 2 979 683 B1. However, in consideration of the limited amount of water present in a hair color cream, aqueous concentrates of Xanthan gum are not convenient considering that these mixtures are extremely viscous and therefore hardly manageable.

[0027] To overcome these technical disadvantages, amongst others Xanthan gum premixes are used. Another advantage is that the Xanthan gum / propylene glycol mixtures do not thicken as rapidly as, e.g., Xanthan gum / glycerol mixtures. However, this does not completely eliminate the disadvantages of using propylene glycol.

[0028] Therefore, it is the object of the present invention to provide a convenient process for manufacturing a cosmetic composition comprising Xanthan gum as stabilizer without having to rely on complex blending procedures as well as the use of propylene glycol-based suspensions.

[0029] This object is solved by a process with the features of claim 1 . The process for preparing a coloring cream for bleaching or coloring keratin fibers wherein a premix is admixed at any step in the manufacture of this cream. This pre-mix is a suspension of Xanthan gum in at least one non-ionic emulsifier of the formula

[0030] CH3-(CH2)n-[O-CH2-CH2]n-OH, (I) or

[0031] CH3-(CH2)7-C2H2-(CH2)8-[O-CH2-CH2]m-OH, (II) with n = 2 to 9 and m = 2 to 5.

[0032] Surprisingly, it was found that these suspensions of Xanthan gum in at least one non-ionic emulsifier of formula (I) or formula (II) allowed the preparation of stable cosmetic compositions for bleaching or coloring keratin fibers such as human hair using Xanthan gum as stabilizing agent and thickener, particularly for a coloring cream.

[0033] Basically, the coloring cream contains further at least one fatty alcohol with an alkyl chain featuring 12 to 30 C-atoms. While fatty alcohols provide thickening and stabilization, xanthan gum increases the viscosity of the aqueous phase and contributes to preventing the coalescence of droplets. The non-ionic emulsifiers improve the formation and stability of the emulsion. The combination of fatty alcohol, xanthan gum, and a non-ionic emulsifier results in a synergistic effect for a stable and viscous emulsion with enhanced texture and increased shelf life. This effect is particularly high when the fatty alcohol is already added to the premix as it stabilizes the pre-mix and prevents clumping. Preferably, the fatty alcohol is added in an amount of 3 to 50 wt.-%, which leads to a particularly high stability of the suspension.

[0034] It is an essential advantage that these previously produced and storable Xan- than gum suspensions may be added at any technically adequate point. This renders the preparation process facile and highly convenient since neither sophisticated equipment is required.

[0035] The non-ionic emulsifiers of formula (I) are so-called polyethylene glycol lauryl ethers featuring up to 9 ethyleneoxy units. These emulsifiers are commercially available as Laureth-2, Laureth-3, Laureth-4, Laureth-5, Laureth-6, Laureth-7, Laureth-8, and Laureth-9 (INCI names). Among these Laureth-2, Laureth-3 and Laureth-4 (n = 2 to 4) are preferred, most preferred are Laureth-2 and Laureth-3 (n = 2 or 3).

[0036] The non-ionic emulsifiers of formula (II) are so-called polyethylene glycol oleyl ethers featuring up to 5 ethyleneoxy units. These emulsifiers are commercially available as Oleth-2, Oleth-3, Oleth-4 and Oleth-5 (INCI names). Among these, Oleth-2 and Oleth-3 (n = 2 or 3) are preferred.

[0037] The non-ionic emulsifiers of formula (I) and formula (II) are liquid at 20 to 25°C, which allows easy suspending Xanthan gum at ambient temperature. Surprisingly, it was found that according to Griffin’s HLB scale (hydrophilic-lipophilic balance) these non-ionic emulsifiers fall in the general range of between 6.0 and 10.0 and thus, are pronounced water-in-oil emulsifiers (W / O-emulsifiers) or wetting agents. However, such water-in-oil emulsifiers are not obvious coemulsifiers of oil-in-water compositions such as cosmetic hair compositions, especially when the latter are based on phosphate ester emulsifiers. Particular suitable suspensions are obtained with non-ionic emulsifiers of formula (I) and / or (II) having an HLB value between 6.0 and 8.0.

[0038] In a preferred embodiment, the Xanthan gum suspension is prepared by addition of Xanthan gum to the at least one non-ionic emulsifier under stirring. Preferably, the suspension is prepared at ambient temperature. Therefore, only readily available low-cost equipment and a minimum of effort are required to obtain the Xanthan gum suspension. The suspension may not only be prepared immediately prior to the preparation of the cosmetic composition but also multiple hours or days in advance since the suspension's properties were found to remain unchanged even after storing periods of up to a week and longer.

[0039] It Further the coloring cream comprises preferably a non-ionic emulsifier selected from polyoxyethylene alkyl ethers with an alkyl chain featuring 14 to 30 C- atoms and at least 20, preferably 20 to 100 ethylene oxide units and / or one or more anionic emulsifiers. These additional emulsifiers further improve the resulting cosmetic composition's properties such as salt tolerance or consistency.

[0040] Preferably, the one or more anionic emulsifiers are selected from alkoxylated fatty alcohol phosphate monoesters, wherein the alkoxylated fatty alcohols are composed of fatty alcohols featuring an alkyl chain of 12 to 22 C-atoms and are alkoxylated with 1 to 50 units of an alkylene oxide, non-alkoxylated fatty alcohol phosphate diesters, wherein the non-alkoxylated fatty alcohols are composed of fatty alcohols featuring an alkyl chain of 12 to 22 C-atoms, organic phosphate ester compounds selected from mono- and diacyl or -alkyl substituted polyglycerol derivatives of phosphoric acid or mixtures thereof. Particularly stable cosmetic compositions, that may comprise a broad variety of different neutral or ionic, hydrophilc or lipophilic compounds without being prone to syneresis, are obtained in combination with the inventive Xanthan gum suspension. Particularly preferred organic phosphate ester compounds are oleth-5 phosphate (and) dioleyl phosphate referred to as "Crodafos HCE", potassium cetyl phosphate (available from local distributors DSM and Croda GmbH), as well as plyglyceryl-3 rice branate phosphate, plyglyceryl-4 stearate phosphate (available from Socri, via Majocchi, 13 / B, 27020 Torre d’Isola, Italy), polyglyceryl-3 oleyl ether phosphate, and polyglyceryl-4 sorbityl ether olivate phosphate among others.

[0041] Further compounds may be added in the preparation process either as individual components or together with other compounds. If multiple compounds are mixed and added in form of a component, it is preferred that hydrophilic compounds are included in (overall) hydrophilic components and lipophilic compounds in (overall) lipophilic components.

[0042] In a preferred embodiment, an aqueous solution comprising a buffering agent and / or a base is admixed in any order. Thus, the pH value of the resulting cosmetic composition can be adapted to a desired value since the composition's (coloration) performance greatly depends on its pH value. Furthermore, the charge state of other constituents and consequently their solubility may be changed by adapting the pH value accordingly.

[0043] The ratio of the individual components is selected such that the concentration of the individual compounds falls into the respective concentration ranges provided below.

[0044] It is preferred that the pre-mix is admixed with water in a first process step. Thereby, the aqueous component, which may account for the major constituent of the resulting cosmetic composition in terms of weight, may be present as base to which the further components are consecutively added. This creates a particularly good mixing. However, the early addition of the Xanthan suspension may facilitate the admixing of the further components, despite a beginning increase in viscosity due to the hydration of Xanthan in presence of water. In this aspect it was surprisingly found that the sequence of admixing the Xanthan suspension to other cream components does not significantly affect the properties of the final cosmetic composition, emphasizing that components may be mixed in any order. In this context, it should be emphasized that this effect does not generally occur with the addition as a Xanthan mixture, but specifically with the addition as a suspension.

[0045] In a preferred embodiment of the process, the introduction of the pre-mix occurs at a temperature between 35 and 95 °C, preferably between 65 to 85 °C, particularly preferred 70 to 80 °C, with stirring. It was found that elevated temperatures facilitate homogenization of the mixture. Thereby, higher temperatures, especially the respective preferred temperature ranges, are particularly suited.

[0046] If volatile compounds are to be added in the process, the temperature should be adjusted such that evaporation is prevented or limited during the mixing of the components. Therefore, individual components may be added at different temperatures. In this aspect, it is particularly preferred to add an aqueous ammonia solution, preferably at a temperature range between 25 and 50°C to avoid excessive evaporation. Additionally or alternatively, evaporation may be reduced or prevented by using a closed and / or pressurized reaction system.

[0047] Homogenization of the mixture is greatly accelerated by stirring. In principle, stirring may be effected by any suitable means in dependency of respective reaction system used. Suitable stirrers may be for example propeller stirrers, discoidal stirrers, impeller stirrers, rigid paddle or rigid blade stirrers. Homogeni- zation may further be improved by utilizing ultrasonic waves or high-shear mixers.

[0048] In a preferred embodiment of the preparation process, the pre-mix is admixed sequentially, and the resulting mixture is further homogenized by stirring for an additional 1 to 20 minutes depending on the batch size, preferably 5 to 10 minutes after each sequential mixing step. In terms of the invention, a mixing step ends once a component has been fully added to the mixture. Further homogenization improves the cosmetic composition's quality since locally high concentrations of individual components in the composition are avoided. Moreover, the temperature of the (intermediate) mixture or cosmetic composition, respectively, may be adjusted to the desired range during this homogenization period.

[0049] In a further embodiment of the invention, the process is conducted batchwise. A batchwise preparation greatly facilitates the process control, in particular homogenization. Depending on the process scale, any suitable mixing vessel may be employed. Preferably, the mixing vessel comprises means for heating and cooling, stirring and homogenizing to improve the process control as described above.

[0050] The invention further relates to a suspension comprising Xanthan gum and at least one non-ionic emulsifier of the formula

[0051] CH3-(CH2)ii-[O-CH2-CH2]n-OH, (I) or

[0052] CH3-(CH2)7-C2H2-(CH2)8-[O-CH2-CH2]m-OH, (H) with n = 2 to 9and m = 2 to 5. Surprisingly, it was found that these suspensions can be used as replacement for conventional propylene glycol-based Xanthan gum suspensions without affecting the obtained cosmetic composition's properties. Another particular advantage of using non-ionic emulsifiers of formula (I) or (II) as suspension medium for Xanthan gum is in the increased storage stability of the suspension. As such, the suspension may be prepared at the beginning of a production campaign and used for the preparation of an entire series of shades, since the inventive suspensions do not substantially thicken over a period of at least 5 to 7 days. In contrast, such an approach is hardly possible when using propylene glycol-based Xanthan gum suspensions as these noticeably thicken over the course of 24 hours. A similar effect is observed for similar gum suspensions in propylene glycol. The time advantage is considerable as it is not necessary to prepare a fresh batch prior to the production of a shade. The Xanthan gum suspension may be prepared as described above.

[0053] The Xanthan gum suspension may not only comprise a single non-ionic emulsifier of formula (I) or (II) as suspension medium but also a mixture of the non- ionic emulsifiers of formula (I) and / or (II).

[0054] In a preferred embodiment, the Xanthan gum suspension consists solely of Xanthan gum and the respective non-ionic emulsifier or mixture of non-ionic emulsifiers of formula (I) and / or (II), i.e. , the suspension comprises no further constituents, in particularly not propylene glycol or other glycols. The suspensions were found to be most convenient in terms of mid- to long-term stability.

[0055] The Xanthan gum amount in the suspension may be 10 to 50 wt.-%, preferably 20 to 30 wt.-% based on the total weight of the suspension. Within this concentration range useful suspensions are obtained. If the suspended Xanthan gum settles over time, the settled particles may simply be resuspended by stirring and / or shaking prior to use. The invention further relates to a cosmetic composition comprising water, at least one fatty alcohol with an alkyl chain featuring 12 to 30 C-atoms that further comprises a previously formed suspension of Xanthan gum and at least one non-ionic emulsifier of the formula

[0056] CH3-(CH2)n-[O-CH2-CH2]n-OH, (I) or

[0057] CH3-(CH2)7-C2H2-(CH2)8-[O-CH2-CH2]m-OH, (II) with n = 2 to 9, and m = 2 to 5.

[0058] Moreover, said composition further contains at least one fatty alcohol with an alkyl chain featuring 12 to 30 C-atoms.

[0059] It is preferred that Xanthan gum is present in a concentration between 0.1 to 5.0 wt.-%, preferably 0.5 to 2.5 wt.-% based on the total weight of the cosmetic composition. Xanthan gum not only allows adjusting the cosmetic composition's consistency but also prevents efficiently from syneresis.

[0060] It is further preferred that the at least one non-ionic emulsifier according to the formula (I) or formula (II) is present in a concentration between 0.1 to 5.0 wt.-%, 1 .0 to 3.0 wt.-% based on the total weight of the cosmetic composition.

[0061] Although the above-mentioned non-ionic emulsifiers of formula (I) or formula (II) according to the current invention replace propylene glycol as suspension medium in the Xanthan gum suspension, propylene glycol and other glycols may be present as further constituents of the cosmetic composition for bleaching or coloring keratin fibers in a preferred embodiment in a concentration of 0.1 to 10 wt.-%, preferably 0.5 to 2.5 wt.-%, of the total weight of the cosmetic composition.

[0062] In a further embodiment, the cosmetic composition comprises a non-ionic emulsifier selected from polyoxyethylene alkyl ethers with an alkyl chain featuring 14 to 30 C-atoms and at least 20, preferably 20 to 100 ethylene oxide units and / or one or more anionic emulsifiers as described above.

[0063] Typically, the at least one fatty alcohol with an alkyl chain featuring 12 to 30 C- atoms accounts for 3 to 50 wt.-%, preferably 5 to 25 wt.-% of the total weight of cosmetic composition. If further emulsifiers such as a non-ionic emulsifier selected from polyoxyethylene alkyl ethers with an alkyl chain featuring 14 to 30 C- atoms and at least 20 and / or one or more anionic emulsifiers are present, the given concentration ranges apply to the sum of the emulsifiers. Thereby, particularly stable cosmetic compositions are obtained.

[0064] Preferably, water is present in a concentration of between 10 to 90 wt.-%, preferably between 30 to 80 wt.-%, most preferably 50 to 70 wt.-% of the total weight of the cosmetic composition.

[0065] A cosmetic composition of the current invention optionally comprises at least one oxidative dye precursor and / or at least one direct dye.

[0066] Suitable primary intermediates for use in hair dyeing compositions include, but are not limited to: toluene-2,5-diamine, p-phenylenediamine, N-phenyl-p- phenylenediamine, N,N-bis(2-hydroxyethyl)-p-phenylenediamine, 2- hydroxyethyl-p-phenylenediamine, hydroxypropyl-bis-(N-hydroxyethyl-p- phenylenediamine), 2-methoxymethyl-p-phenylenediamine, 2-(1 ,2- dihydroxyethyl)-p-phenylenediamine, 2,2’-(2-(4- aminophenylamino)ethylazanediyl)diethanol, 2-(2,5-diamino-4- methoxyphenyl)propane-1 ,3-diol, 2-(7-amino-2H-benzo[b][1 ,4]oxazin-4(3H)- yl)ethanol,2-chloro-p-phenylenediamine, p-aminophenol, p-

[0067] (methylamino)phenol, 4-amino-m-cresol, 2-methoxy-p-phenylenediamine, 2,2’- methylenebis-4-aminophenol,2,4,5,6-tetraminopyrimidine, 2,5,6-triamino-4- pyrimidinol, 1 -hydroxyethyl-4,5-diami-nopyrazole sulfate, 4,5-diamino-1- methylpyrazole, 4,5-diamino-1-ethylpyrazole, 4,5-diamino-1-isopropylpyrazole, 4,5-diamino-1 -butylpyrazole, 4,5-diamino-1 -pentylpyrazole, 4,5-diamino-1 - benzylpyrazole, 2,3-diamino-6,7-dihydropyrazolo[1 ,2-a]pyrazol-1 (5H)-one dimethosulfonate, physiologically compatible water-soluble salts thereof and mixtures thereof.

[0068] Suitable couplers are selected from the group consisting of; resorcinol, 4- chlororesorcinol, 2-chlororesorcinol, 2-methylresorcinol, 4,6-dichlorobenzene- 1 ,3-diol, 2, 4-dimethylbenzene-1 ,3-diol, m-aminophenol, 4-amino-2- hydroxytoluene, 2-methyl-5-hydroxyethylaminophenol, 3-amino-2,6- dimethylphenol, 3-amino-2,4-dichlorophenol, 5-amino-6-chloro-o-cresol, 5- amino-4-chloro-o-cresol, 6-hydroxybenzomorpholine, 2-amino-5-phenylphenol, 2-amino-5-methylphenol, 2-amino-6-methylphenol, 2-amino-5-ethoxyphenol, 5- methyl-2-(methylamino)phenol, 2,4-diaminophenoxyethanol, 2-amino-4- hydroxyethylaminoanisole, 1 ,3-bis-(2,4-diaminophenoxy)-propane, 2,2’-(2- methyl-1 ,3-phenylene)bis(azanediyl)diethanol,benzene-1 ,3-diamine, 2,2’-(4,6- diamino-1 ,3-phenylene)bis(oxy)diethanol, 3-(pyrrolidin-1 -yl)aniline, 1 -(3-

[0069] (dimethylamino)phenyl)urea, 1 -(3-aminophenyl)urea, 1 -naphthol, 2-methyl-1 - naphthol, 1 ,5-naphthalenediol, 2,7-naphthalenediol, 1 -acetoxy-2- methylnaphthalene, 4-chloro-2-methylnaphthalen-1 -ol, 4-methoxy-2- methylnaphthalen-1 -ol, 2,6-dihydroxy-3,4-dimethylpyridine, 2,6-dimethoxy-3,5- pyridinediamine, 3-amino-2-methylamino-6-methoxypyridine, 2-amino-3- hydroxypyridine, 2,6-diaminopyridine, pyridine-2,6-diol, 5,6-dihydroxyindole, 6- hydroxyindole, 5,6-dihydroxyindoline, 3-methyl-1 -phenyl-1 H-pyrazol-5(4H)-one, 1 ,2,4-trihydroxybenzene, hydroxyethyl-3,4-methylenedioxyaniline, physiologically compatible water-soluble salts thereof and mixtures thereof.

[0070] In a preferred embodiment, these cosmetic compositions for the oxidative dyeing of keratin fibers comprise primary intermediates and couplers from 0.1 to 10.0 wt.-%, preferably from 0.3 to 6.0 wt.-%, more preferably from 0.5 to 4.0 wt.- % by weight. The stated quantities refer to the total amount of primary intermediates and couplers,

[0071] The hair dyeing compositions of the present invention may also comprise compatible direct dyes, in an amount sufficient to provide additional coloring, particularly with regard to intensity. Typically, such an amount in the cosmetic compositions will range from 0.05 to 4 wt.-%, by weight of the direct dyes relative to the total weight of the composition.

[0072] The following direct dyes and combinations thereof are preferably used:

[0073] Acid dyes such as Acid Yellow 1 , Acid Orange 3, Acid Black 1 , Acid Black 52, Acid Orange 7, Acid Red 33, Acid Yellow 23, Acid Blue 9, Acid Violet 43, HC Blue 16, Acid Blue 62, Acid Blue 25, Acid Red 4;Basic Dyes such as Basic Brown 17, Basic Red 118, Basic Orange 69, Basic Red 76, Basic Brown 16, Basic Yellow 57, Basic Violet 14, Basic Blue 7, Basic Blue 26, Basic Red 2, Basic Blue 99, Basic Yellow 29, Basic Red 51 , Basic Orange 31 , Basic Yellow 87, 4-(3-(4-am ino-9, 10-dioxo-9, 10-dihydroanthracen-1 -ylam ino)propyl)-4- methylmorpholin-4-ium-methylsulfate, (E)-1 -(2-(4-(4,5-dimethylthiazol-2- yl)diazenyl)phenyl)(ethyl)amino)ethyl)-3-methyl-1 H-imidazol-3-iumchloride, (E)- 4-(2-(4-(dimethylamino)phenyl)diazenyl)-1 -methyl-1 H-imidazo1 -3-ium-3- yl)butane-1 -sulfonate, (E)-4-(4-(2-methyl-2-phenylhydrazono)methyl)pyridinium- 1 -yl)butane-1 -sulfonate, N, N-dimethyl-3-(4-(methylamino)-9, 10-dioxo-

[0074] 4a,9,9a,10-tetrahydroanthracen-1-ylamino)-N-propylpropan-1 -aminiumbromide; Disperse Dyes such as Disperse Red 17, Disperse Violet 1 , Disperse Red 15, Disperse Black 9, Disperse Blue 3, Disperse Blue 23, Disperse Blue 377;

[0075] Nitro Dyes such as 1 -(2-(4-nitrophenylamino)ethyl)urea, 2-(4-methyl-2- nitrophenylamino)ethanol, 4-nitrobenzene-1 ,2-diamine, 2-nitrobenzene-1 ,4- diamine, Picramic acid, HC Red No. 13, 2,2’-(2-nitro-1 ,4- phenylene)bis(azanediyl)diethanol, HC Yellow No. 5, HC Red No. 7, HC Blue No.2, HC Yellow No. 4, HC Yellow No. 2, HC Orange No. 1 , HC Red No. 1 , 2-(4- amino-2-chloro-5-nitrophenylamino)ethanol, HC Red No. 3, 4-amino-3- nitrophenol,4-(2-hydroxyethylamino)-3-nitrophenol,2-amino-3-nitrophenol,2-(3- (methylamino)-4-nitrophenoxy)ethanol, 3-(3-amino-4-nitrophenyl)propane-1 ,2- diol, HC Yellow No. 11 , HC Violet No. 1 , HC Orange No. 2, HC Orange No. 3, HC Yellow No. 9, HC Red No. 10, HC Red No. 11 , 2-(2-hydroxyethylamino)-4,6- dinitrophenol, HC Blue No. 12, HC Yellow No. 6, HC Yellow No. 12, HC Blue No. 10, HC Yellow No. 7, HC Yellow No. 10, HC Blue No. 9, 2-chloro-6- (ethylamino)-4-nitrophenol, 6-nitropyridine-2,5-diamine, HC Violet No. 2, 2- amino-6-chloro-4-nitrophenol, 4-(3-hydroxypropylamino)-3-nitrophenol, HC Yellow No. 13, 6-nitro-1 ,2,3,4-tetrahydroquinoxaline, HC Red No. 14, HC Yellow No. 15, HC Yellow No. 14, N2-methyl-6-nitropyridine-2,5-diamine, N1 -allyl-2- nitrobenzene-1 ,4-diamine, HC Red No. 8, HC Green No.1 , HC Blue No. 14, and / or natural dyes such as Annato, Anthocyanins, Beetroot, Carotene, Capsanthin, Lycopene, Chlorophyll, Henna, Indigo and Cochineal.

[0076] Optionally, the cosmetic compositions according to the current invention comprise at least one further compound selected from the group of pH modifiers, buffering agents, chelants, thickeners and conditioning agents. These compounds may be used to further adapt the cosmetic composition to the respective purpose.

[0077] The pH modifier and / or buffering agent may be present in an amount that is sufficiently effective to adjust the pH of the cosmetic composition to fall within a range from 3 to 13, preferably from 6 to 12, more preferably from 9 to 11. For dyeing compositions best coloration results are achieved under alkaline conditions, i.e. , at a pH value of 8 to 12, preferably 9 to 11 .

[0078] In principle, any alkalizing agent known in the art may be used as pH modifier and / or buffering agent. Preferred compounds are ammonia, alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, 2-amino-2-methyl-1 ,3-propanediol, 2-amino- 2-methyl-1 -propanol, and 2-amino-2-hydroxymethyl-1 ,3-propanediol, amino acids and salts thereof, guanidinium salts, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal and ammonium carbonates, and mixtures thereof. Particularly preferred are ammonia and / or alkanolamines as well as alkali salts of amino acids.

[0079] Typically, the cosmetic compositions, in particular cosmetic compositions for oxidative dyeing of keratin fibers, comprise from 0.1 to 10 wt.-%, preferably from 0.5 to 6 wt.-%, more preferably from 1.0 to 4.0 wt.-% of the total weight of the cosmetic composition.

[0080] In addition to Xanthan gum, one or more thickeners may be present in an amount sufficient to provide the cosmetic composition with a viscosity so that it can be readily applied to the hair without unduly dripping off the hair and causing mess. Typically, such an amount will be at least 0.05 wt.-%, preferably at least 0.5 wt.-%, more preferably at least 0.75 wt.-% of the total weight of the composition. Preferred upper limits may be 5.0 wt.-%, preferably 2.0 wt.-%, more preferably 1 .0 wt.-% of the total weight of the composition. When the composition is obtained by mixing several components, the thickener may be present in any of the components. Preferred are salt tolerant thickeners, including but not limited to: guar, hydroxypropyl guar, scleroglucan, methylcellulose, ethylcellulose (available as AQUACOTE™), hydroxyethyl cellulose (available as NATROSOL™), carboxymethyl cellulose, hydroxypropylmethyl cellulose, microcrystalline cellulose, hydroxybutylmethyl cellulose, hydroxypropyl cellulose (available as KLUCEL™), hydroxyethyl ethyl cellulose, cetyl hydroxyethyl cellulose (available as NATROSOL™ Plus 330), N-vinylpyrollidone (available as POVIDONE™), acrylates / Ceteth-20 Itaconate copolymer (available as STRUCTURE™ 3001 ), hydroxypropyl starch phosphate (available as STRUCTURE™ ZEA), polyethoxylated urethanes or polycarbamyl polyglycol ester (e.g. PEG-150 / Decyl / SMDI copolymer (available as ACULYN™ 44), PEG-150 / Stearyl / SMDI copolymer available as ACULYN™ 46), acrylatesBeheneth-25 Methacrylate Copolymer (available as ACULYN™ 28), acrylates / vinyl neodecanoatecrosspolymer (available as ACULYN™ 38), acrylates / Steareth-20 methacrylate crosspolymer (available as ACULYN™ 88), PEG-150 Distearate (available as ACULYN™ 60), trihydroxystearin (available as THIXCIN™), acrylates copolymer (e.g. available as ACULYN™ 33) or hydro- phobically modified acrylate copolymers (e.g. Acrylates / Steareth-20 Methacrylate Copolymer (available as ACULYN™ 22), non-ionic amphophilic polymers comprising at least one fatty chain and at least one hydrophilic unit selected from polyether urethanes comprising at least one fatty chain.

[0081] Preferably, the cosmetic compositions are present in a gel-like, cream-like or foam-like state at the temperature of application, which is typically between 20 to 35°C.

[0082] Typical cream-like compositions, in particular freshly produced and highly salt- loaded cream compositions, have a viscosity below the target viscosity. Upon standing, the viscosity gradually increases until reaching a certain plateau corresponding to the desired target viscosity. This process takes normally up to a few days depending on the specific composition and salt load. The cosmetic compositions of the present invention may comprise chelants in an amount sufficient to reduce the amount of metal ions available to interact with other formulation components.

[0083] Suitable chelants for use herein include but are not limited to: etylenediaminetet- raacetic acid (EDTA), diethylenetriamine-N,N’,N"-polyacids, diethylenetriaminepentaacetic acid (DTPA), diethylenetriaminepenta(methylene phosphonic acid) (DTPMP), diamine-N,N’-dipolyacid, monoaminemonoamide-N,N’-dipolyacid, and N,N’-bis(2-hydroxybenzyl)ethylenediamine-N,N’-diacetic acid chelants (EDDS (ethylenediaminedisuccinic acid)), carboxylic acids (preferably aminocarboxylic acids), phosphonic acids (preferably aminophosphonic acids) and polyphosphoric acids, their salts and derivatives.

[0084] Preferably, chelants are present in a concentration between 0.15 to 2.0 wt.-%, preferably at least 0.25 to 1 .0 wt.-% of the total weight of the composition.

[0085] In a preferred embodiment, the cosmetic composition comprises at least one conditioning agent. Suitable conditioning agents are preferably selected from silicone materials, aminosilicones, polymeric resins, polyol carboxylic acid esters, cationic polymers such as compounds being commercially available under the name “Polyquaternium”, cationic surfactants such as compounds being commercially available under the name “Quaternium” as well as quaternary surfactants such as Behentrimonium chloride and / or Behentrimonium methosulfate, Cetrimonium chloride, Stearalkonium chloride, insoluble oils and oil derived materials and mixtures thereof. Additional materials include mineral oils and other oils such as squalane and squalene, glycerin and sorbitol. Preferred conditioning agents are cationic polymers. Alternatively, the cosmetic compositions are used in combination with a composition comprising at least on conditioning agent, i.e. , without admixing the conditioning agent to the cosmetic composition during its preparation process.

[0086] The conditioning agent may be present in a concentration of between 0.05 to 20.0 wt.-%, preferably of between 0.1 to 15.0 wt.-%, more preferably of between 0.2 to 10.0 wt.-%, most preferably of between 0.2 to 2.0 wt.-% of the total weight of the composition.

[0087] The invention further relates to a kit for dyeing or bleaching keratin fibers, comprising at least two separate kit components, wherein the first kit component comprises a cosmetic composition as described above and the second kit component comprises an oxidizing agent.

[0088] The separate provision of a cosmetic composition based on oxidative dyes as a first kit component and a second kit component comprising an oxidizing agent, i.e., the activator or developer, is required to prevent a premature formation of the final dye due to a reaction oxidative dye precursors in presence of an oxidant.

[0089] Preferably, the second kit component comprises an aqueous solution of hydrogen peroxide or its addition compounds of urea, melamine, sodium borate or sodium carbonate as oxidant. In a particularly preferred embodiment, the concentration of respective oxidant is between 2 to 12 wt.-%, preferably 6 to 9 wt.-% of the total weight of the second kit component. Thereby, a second kit component comprising hydrogen peroxide as oxidant is preferably stabilized by phosphoric acid.

[0090] The kit may further comprise at least one conditioning agent as described above as a separate third kit component. The conditioning agent may be present in a concentration of between 0.05 to 20.0 wt.-%, preferably of between 0.1 to 15.0wt.-%, more preferably of between 0.2 to 10.0 wt.-%, most preferably of between 0.2 to 2.0 wt.-% of the total weight of the third kit component.

[0091] The present invention also relates to a ready-to-use composition obtainable by mixing the at least the first and second kit component. Thereby, the oxidant comprised in the second kit component activates the oxidative dye precursors in the first component such that the corresponding dye is formed.

[0092] Preferably, the ready-to-use composition comprises the first and second kit component in a ratio of between 1 :1 and 1 :3 by weight.

[0093] In a further embodiment, the ready-to-use composition has a pH value of 8.0 to 11.0, preferably of 9.0 to 10.5, since optimum results in the oxidative coloring of keratin fibers are achieved in this pH range.

[0094] According to the present invention, the oxidant is present in the ready-to-use compositionin a concentration of between 0.1 to 12 wt.-%, preferably of between 0.5 to 10.0wt.-%, more preferably of between 1 .0 to 8.0 wt.-% of the total weight of the ready-to-use composition.

[0095] The ready-to-use composition may further comprise at least one conditioning agent in an effective concentration. Said conditioning agent may be comprised in the first kit component and / or the third kit component. Preferably, the at least one conditioning agent is present in the ready-to-use composition in a concentration of between 0.05 to 20.0 wt.-%, preferably of between 0.1 to 15.0 wt.-%, more preferably of between 0.2 to 10.0 wt.-%, most preferably of between 0.2 to 2.0 wt.-% of the total weight of the ready-to-use composition. Alternatively, a third kit component comprising at least one conditioning agent may be used separately from the ready-to-use composition, i.e., in a step preceding and / or following the application of the ready-to-use composition.

[0096] The invention further relates to a process for coloring or bleaching keratin fibers, comprising the steps of providing keratin fibers and applying the ready-to-use composition as described above on the keratin fibers.

[0097] Preferably, the ready-to-use composition is prepared immediately before use, i.e., its application to the keratin fibers, by mixing of at least the first and second kit component.

[0098] The keratin fibers may be rinsed with water and / or shampooed prior and / after the application of the ready-to-use composition.

[0099] In a preferred embodiment, the ready-to-use composition is applied to the hair in an amount that is sufficient for e.g. the hair dyeing treatment, preferably in an amount of between about 60 to 200 grams.

[0100] It is further preferred to apply the ready-to-use composition at a temperature of 20 to 35 °C. The application time may be chosen such that the dyeing result is sufficient, i.e., between 2 to 90 min, preferably between 30 to 45 min.

[0101] Optionally, the third kit component comprising at least one conditioning agent is applied after the application of the ready-to-use composition, preferably after an intermediate rinsing and / or shampooing step.

[0102] Further objectives, features, advantages and possible applications of the invention can also be taken from the description of the following examples. All features described form the subject matter of the invention per se or in any combination, independent of their inclusion in the claims or their back references. Examples

[0103] Viscosity data provided below was determined by means of a Brookfield viscometer, spindle B-LV-64 with "rpm 1" for ready-to-use compositions and "rpm 2" for cosmetic (tint) compositions at a temperature of 21 °C. The measurements were conducted as per the standard manufacturer's instructions.

[0104] Example 1 : Storage and usability of Xanthan gum suspensions Suspensions of Xanthan gum were prepared by addition of Xanthan gum (6.0 g) to respective suspension medium (20.0 g) under stirring (see Tables 1.1 and 1.2)

[0105] Table 1.1 :Comparative Xanthan gum suspensions

[0106] Table 1.2: Inventive Xanthan gum suspensions

[0107] The use of water as suspension medium is excluded in practice due to the spontaneous lump formation. Propylene glycol-based suspensions exhibited good initial properties but stirrability and thus, usability deteriorated over during extended storage periods such as 24h or longer.

[0108] In contrast, Xanthan gum suspensions on basis of a non-ionic emulsifier of formula (I) or (II) exhibit excellent short- and long-term properties, whereby no significant differences were observed within the series of the inventive compositions. Even after standing for a day at room temperature, after which the suspension in propylene glycol had already become very viscous and difficult to handle, the inventive suspensions were still easily stirrable allowing to obtain a homogeneous suspension for further use.

[0109] In conclusion, Xanthan gum suspensions in propylene glycol are not suitable for extended storage times and have to be prepared immediately prior to a production batch. In contrast, the inventive suspensions can be used for at least one week after preparation, during which the suspensions do not noticeably thicken and can be easily stirred to obtain homogeneous suspensions before adding the required amounts to new production batches.

[0110] Example 2: Preparation of a cosmetic composition - Addition of the Xanthan gum suspension to the initial manufacturing step

[0111] Step 1 :

[0112] With stirring, Xanthan gum (6.0 g) is added to

[0113] - propylene glycol (20.0 g) (comparative) or

[0114] - the liquid Laureth (20.0 g) or Oleth (20.0 g) emulsifier (inventive) as indicated in Table 4.1 below.

[0115] The obtained suspension is used in Step 2 (see below). Total weight: 26.0 g.

[0116] Step 2: Water (250.0 g) is placed in a separate beaker. With stirring, the Xanthan gum suspension (26.0 g) from Step 1 is added followed by the addition of Crodafos CES (60.0 g), Ceteareth-25 (2.0 g), Stearyl alcohol (20.0 g), Cetearyl alcohol 50:50 (30.0 g), a 1 :1 mixture of Lauryl alcohol and Myristyl alcohol (40.0 g) and an aqueous sodium hydroxide solution (30% in water, 10.0 g). Then the mixture is heated to 75-80°C, homogenized for 2 min and allowed to cool to 50°C. Total weight: 438.0 g.

[0117] Step 3:

[0118] In a separate beaker water (250.0g) and glycerin (25.0 g) are placed. Stirring is started and tris(hydroxymethyl)aminomethane (17.5 g), glycine (80.0 g) and an aqueous sodium hydroxide solution (30% in water, 149.5 g), disodium EDTA (2.0 g), ascorbic acid (4.0 g), sodium sulfite (2.0 g), sodium hydrosulfite (2.0 g) is added, whereby a clear solution is obtained. Total weight: 532.0 g.

[0119] If the composition contains one or more dyes and / or additional non-coloring ingredients, their weight is compensated by reducing the amount of water. Total weight eight: 532.0 g

[0120] Step 4:

[0121] While stirring, the solution from Step 3 is added to the dispersion of Step 2. The obtained mixture is maintained at 40°C for 10 minutes, then an aqueous Ammonia solution (28% in water, 30.0 g) is carefully added, followed by homogenization to obtain the final tint composition. Total weight: 1000 g.

[0122] Example 3: Manufacturing process - Addition of the Xanthan gum suspension to the last manufacturing step Step 1 :

[0123] With stirring, Xanthan gum (6.0 g) is added to

[0124] - propylene glycol (20.0 g) (comparative) or

[0125] - the liquid Laureth (20.0 g) or Oleth (20.0 g) emulsifier (inventive) as indicated in Table 4.1 below.

[0126] The obtained suspension is used in Step 4 (see below). Total weight: 26.0 g.

[0127] Step 2:

[0128] Water (250.0 g) is placed in a separate beaker. With stirring, Crodafos CES (60.0 g), Ceteareth-25 (2.0 g), Stearyl alcohol (20.0 g), Cetearyl alcohol 50:50 (30.0 g), and a mixture of Lauryl alcohol and Myristyl alcohol 50:50 (40.0 g) are added, followed by the addition of an aqueous sodium hydroxide solution (30% in water, 10.0 g). Then the mixture is heated to 75-80°C, homogenized by stirring for 2 min and allowed to cool to 50°C. Total weight: 412.0 g.

[0129] Step 3:

[0130] In a separate beaker water (250.0 g) and glycerin (25.0 g) are placed. Stirring is started and tris(hydroxymethyl)aminomethane (17.5 g), glycine (80.0 g),an aqueous sodium hydroxide solution (30% in water, 149.5 g), disodium EDTA (2.0 g), ascorbic acid (4.0 g), sodium sulfite (2.0 g), sodium hydrosulfite (2.0 g) are added, whereby a clear solution is obtained. Total weight: 532.0 g.

[0131] If the composition contains one or more dyes and / or additional non-coloring ingredients, their weight is compensated for by reducing the amount of water. Total weight: 532.0 g. Step 4:

[0132] While stirring, the solution from Step 3 is added to the mixture of Step 2. The obtained mixture is maintained at 40°C for 10 minutes, while the Xanthan gum suspension (26.0 g) from Step 1 and aqueous Ammonia solution (28% in water, 30.0 g) is added. After homogenizing by stirring for 10 minutes the tint composition is obtained. Total weight: 1000 g.

[0133] Example 4: Tint compositions I Compositions based on cetearyl alcohol, di-cetyl phosphate and ceteth-10 phosphate have been selected as model compositions as these are able to absorb various hydrophilic and lipophilic substances and thus, are particularly prone to syneresis if not stabilized by Xanthan gum. Table 4.1 : Tint compositions

[0134] Table 4.2: Viscosities of the tint compositions

[0135] A suspension of Xanthan gum in propylene glycol was used in comparative Example 4.0, which defines the reference value. In the inventive Examples 4.1 to 4.4, propylene glycol was replaced by the respective non-ionic emulsifiers of formula (I) or (II) as indicated in Table 4.1 , namely Laureth-3, Laureth-9, Oleth-3 and Oleth-5.

[0136] The viscosity values of Table 4.2 were measured for compositions prepared according to the method of Example 2. Tint compositions prepared according to the method of Example 3, i.e. , addition of the suspension in the final step exhibit similar initial as well as final viscosities emphasizing, that the individual components may be mixed together in any order.

[0137] As shown in Table 4.2, the viscosity of the creams is relatively low immediately after production and increases upon standing. After 3 to 5 days the final viscosity is achieved in all example formulations, i.e., the viscosity remains essentially constant and in a range suitable for the subsequent application. The inventive Examples 4.1 to 4.4 exhibit similar initial and final viscosity values as compara- tive Example 4.0. This demonstrates that the non-ionic emulsifiers of formula (I) or (II) are suitable drop-in replacements for propylene glycol without causing any inconveniences. Example 5: Ready-to-use compositions I

[0138] Table 5.1 : Standard developer composition with hydrogen peroxide as oxidation agent The resulting pH value of both developer compositions is 3.0.

[0139] The tint compositions as according to Example 4.0 (comparative) and the Examples 4.1 to 4.4 (see Table 4.1 ) were mixed in a ratio of 1 :1.5 with the developer composition of Example 5.11. The viscosities of the thus-obtained ready- to-use compositions were measured immediately after their preparation.

[0140] Table 5.2: Viscosities of the ready-to-use compositions

[0141] As shown in Table 5.2, the viscosities of the inventive Examples 5.1 to 5.4 are in the same order of magnitude as the reference value Example 5.0, whereby nonionic emulsifiers of formula (I) or (II) featuring longer chains lead to alower the final viscosity.

[0142] The obtained ready-to-use compositions are applied onto light-blond human hair. After remaining on the hair for 30 minutes, the hair was rinsed with lukewarm water and dried. The comparative compositions with propylene glycol and the inventive compositions gave identical dark blonde results. The obtained perfect shade match demonstrates that Xanthan gum propylene glycol suspensions may be readily replaced by Xanthan gum suspension on basis of the inventive non-ionic emulsifier of formula (I) or formula (II) without affecting the resulting coloration.

[0143] Example 6: Tint compositions II

[0144] Table 6.1 :Tint compositions of the shade "Very light blond".

[0145] The above shade examples were prepared according to the method of Example 2. In comparison to the tint compositions of Example 4, the different dye composition is used, while the dye base itself was kept constant. The remainder to 100 % was water.

[0146] Table 6.2: Viscosities of the tint compositions

[0147] Example 7: Ready-to-use compositions II

[0148] The ready-to-use compositions are obtained by mixing the tints of Example 6 (see Table 6.1 ) in a ratio of 1 :1.5 with the developer composition of Example 5.12. The viscosities of the thus-obtained ready-to-use compositions were measured immediately after their preparation.

[0149] The viscosities of the respective compositions were found to be similar to the value obtained for comparative Example 7.0. The tendency of non-ionic emulsifiers of formula (I) or (II) featuring longer chains to form lower viscosityready-to- use compositions was also observed for Examples 7.1 to 7.4.

[0150] Table 5.2: Viscosities of the ready-to-use compositions

[0151]

[0152] The ready-to-use compositions were then applied onto 50% human grey hair. After remaining on the hair for 30 minutes, the hair was rinsed with lukewarm water and dried. The comparative composition with propylene glycol and the inventive comprising a non-ionic emulsifier of formula (I) or (II) gave identical dark blonde results, confirming that the inventive compositions do not cause a variation in the obtained coloration.

[0153] In summary, a performance tests as well as viscosity data taken from tints and ready-to-use compositions confirm that the novel Xanthan gum dispersions do not negatively impact the overall properties of the compositions compared to compositions comprising propylene glycol.

Claims

Claims1. Process for the preparation of a coloring cream for bleaching or coloring keratin fibers in which a pre-mix is introduced in any process step of the preparation process, characterized in that the pre-mix comprises a suspension of Xanthan gum in at least one non-ionic emulsifier of the formulaCH3-(CH2)ii-[O-CH2-CH2]n-OH, (I) orCH3-(CH2)7-C2H2-(CH2)8-[O-CH2-CH2]m-OH, (II) with n = 2 to 9, preferably n = 2 to 4, and m = 2 to 5 and that at least one fatty alcohol with an alkyl chain featuring 12 to 30 C-atoms is added before or together with the pre-mix or in any other step of the process.

2. Process according to claim 1 , characterized in that the premix is prepared by addition of Xanthan gum to the at least one non-ionic emulsifier of the formula (I) or (II) under stirring.

3. Process according to claim 1 or 2, characterized in that the coloring cream further comprises water, a nonionic emulsifier selected from polyoxyethylene alkyl ethers with an alkyl chain featuring 14 to 30 C-atoms and at least 20 ethylene oxide units and / or one or more anionic emulsifiers.

4. Process according to any of the previous claims, characterized in that the at least one fatty alcohol with an alkyl chain featuring 12 to 30 C-atoms is used in an amount of 3 to 50 wt.-%.

5. Process according to any of the previous claims, characterized in that an aqueous solution comprising a buffering agent and / or a base is admixed in any process step.

6. Process according to any of the previous claims, characterized in that the pre-mix is mixed with water as a first process step or that the pre-mix is mixed with non-aqueous components prior to the introduction in any process step.

7. Process according to any of the claims, characterized in that the mixing occurs at a temperature between 35°C and 95 °C and / or with stirring.

8. Process according to any of the previous claims, characterized in that the pre-mix is introduced sequentially, and a resulting mixture is further homogenized by stirring for between 1 to 20 min after each sequential mixing step.

9. Process according to any of the previous claims, characterized in that the process is conducted batchwise.

10. A suspension for use in a process according to any of claims 1 to 9 comprising Xanthan gum and at least one non-ionic emulsifier of the formulaCH3-(CH2)ii-[O-CH2-CH2]n-OH, (I) orCH3-(CH2)7-C2H2-(CH2)8-[O-CH2-CH2]m-OH, (II) with n = 2 to 9, preferably n = 2 to 4, and m = 2 to 5.

11. Suspension according to claim 10, characterized in that the Xanthan gum is present in an amount of 10 to 50 wt.-% based on the total weight of the suspension.

12. A cosmetic composition comprising water, at least one fatty alcohol with an alkyl chain featuring 12 to 30 C-atoms, characterized in that the cosmetic composition further comprises a previously formed suspension of Xanthan gum and at least one non-ionic emulsifier of the formulaCH3-(CH2)ii-[O-CH2-CH2]n-OH, (I) orCH3-(CH2)7-C2H2-(CH2)8-[O-CH2-CH2]m-OH, (II) with n = 2 to 9, preferably n = 2 to 4, and m = 2 to 5 wherein the at least one fatty alcohol with an alkyl chain featuring 12 to 30 C-atoms is present before the addition of the pre-mix or it is added together with the pre-mix or is added in any subsequent step of the process.

13. A cosmetic composition according to claim 12, characterized in that Xanthan gum is present in a concentration between 0.1 to 5.0 wt-% based on the total weight of the cosmetic composition.

14. A cosmetic composition according to claim 12 or 13 characterized in that the at least one nonionic emulsifier according to the formula (I) or formula (II) is present in a concentration between 0.1 to 5.0 wt.-% based on the total weight of the cosmetic composition.

15. Cosmetic composition according to any of claims 12 to 14, characterized in that it comprises at least one oxidative dye precursor and / or at least one direct dye.

16. Cosmetic composition according to any of claims 12 to 15, characterized in that it comprises at least one further compound selected from the group of pH modifiers, buffering agents, chelants, thickeners and conditioning agents.

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