FR3117346A1 - Two-component oxidation powder hair color featuring a combination of thickeners - Google Patents

Abstract

The present invention is in the field of cosmetic hair coloring and relates to a kit for coloring keratinous fibers by oxidation, in particular human hair, comprising an anhydrous oxidation composition (OZ) containing sodium percarbonate or sodium and, separately from the oxidation composition (OZ), an anhydrous cosmetic coloring composition (FZ) containing precursors of oxidation dyes, a selected alkalizing agent based on sodium silicates or selected sodium metasilicates , at least one polysaccharide selected from sodium carboxymethylcellulose and xanthan gum, and mixtures thereof, as a first thickener, and further precipitated silica as an additional thickener, wherein an oxidative hair coloring agent can be prepared by mixing the components of the kit with water without the need to add additional hydrogen peroxide.

Description

Two-component oxidation powder hair color featuring a combination of thickeners

The present invention is in the field of cosmetic hair coloring and relates to a kit for coloring keratin fibers by oxidation, in particular human hair, comprising an anhydrous oxidation composition (OZ) containing sodium percarbonate or sodium and, separately from the oxidation composition (OZ), an anhydrous cosmetic coloring composition (FZ) containing precursors of oxidation dyes, a selected alkalizing agent based on sodium silicates or selected sodium metasilicates , at least one polysaccharide selected from sodium carboxymethylcellulose and xanthan gum, and mixtures thereof, as a first thickener, and further precipitated silica as an additional thickener, wherein an oxidative hair coloring agent can be prepared by mixing the components of the kit with water without the need to add additional hydrogen peroxide.

Another object of the present invention is a process for the oxidation dyeing of keratin fibers, in particular human hair, using the aforementioned anhydrous kit components and water.

The modification of the color of keratinous fibers, in particular hair, is an important field of modern cosmetics. Thus, the appearance of the hair can be adapted both to current fashion trends and to the special wishes of each person. When it comes to changing the color of the hair, there are various possibilities available to the specialist in the field.

Through the use of direct dyes, hair color can be changed temporarily. In this case, the ready-to-use dyes diffuse from the coloring agent into the hair fiber. Coloring with direct dyes causes little damage to the hair, but has a disadvantage, namely the low durability and rapid washout of the colors obtained with direct dyes.

If the consumer desires a long lasting color result or a shade lighter than their natural hair color, oxidative color modifying agents will generally be used. Oxidative coloring agents are used to obtain intense, permanent colorations with good color authenticity properties. These coloring agents usually contain precursors of oxidation dyes, called "developer constituents" and "coupler constituents" and which, under the action of oxidizing agents - generally hydrogen peroxide - interact to form the dyes themselves. Oxidative coloring agents are characterized by both excellent and long-lasting coloring results.

Oxidative color modifiers are generally marketed as two-component agents, in which two different preparations are packaged separately in two separate packages and are only mixed just before application. The first component of common coloring agent kits is an aqueous composition - acidic for stability reasons - containing as an oxidizing agent dissolved hydrogen peroxide at concentrations ranging from 1.5 to 24% by weight. These aqueous oxidizing agent compositions are frequently in the form of an emulsion or a dispersion and are generally offered in a plastic bottle with a resealable neck (developer bottle).

This oxidizing agent formulation of known coloring kits is mixed with a second preparation before application. This second preparation is an alkaline formulation which often comes in the form of a cream or gel and which also contains at least one oxidation dye precursor if a modification of the color is desired at the same time as the lightening. This second preparation is often packaged in a tube or in a plastic or glass container.

In the common application form described above, the second preparation, which contains the alkalizing agent and, if desired, the oxidation dye precursors, is transferred from the tube or container into the vial of developer, then mixed by stirring with the hydrogen peroxide preparation already present in the developer bottle. In this way, the mixture to be applied is prepared in the developer bottle. The application to the hair is then done via a small spout or neck provided at the top of the developer bottle. After shaking, the spout or neck is opened and the mixture to be applied can be extracted by squeezing the flexible developer bottle.

When preparing the mixture to be applied in a bowl, the two constituents - the first preparation containing the oxidizing agent and the second preparation containing an alkalizing agent and, if desired, precursors of oxidation dyes - are completely transferred to a bowl or similar container and then stirred using a brush, for example. The mixture to be applied is then extracted from the mixing bowl using the brush. In this form of application, the use of a bulky and expensive developer bottle is not necessary.

However, filling hydrogen peroxide solutions into such containers is associated with problems due to the reactivity of the hydrogen peroxide, which can gradually decompose to form oxygen (i.e. gas) depending on the storage conditions and possibly the presence of impurities having a decomposition action

As a general rule, developer bottles known from the state of the art only fill up with the oxidizing agent composition to only half, generally at the rate of only one third of their internal volume. As a rule, developer bottles are made of polyethylene. Since polyethylene is permeable to both water vapor and gases, there is no or very little overpressure in the developer bottle. In addition, developer bottles usually have thick, sturdy walls and a strong screw-on closure, so that the diffusion of water vapor or gas through the thickness of the walls is reduced and a very slight increase in pressure inside the vial has no negative effect.

As a result, the packaging is usually bulky, which is detrimental to sustainability and conservation of the environment and resources. The use of a solid as the oxidizing agent is advantageous, since the solid can be activated by the addition of water only without the need to also add hydrogen peroxide. Sodium percarbonate and sodium perborate are known as strong oxidizing agents for coloring preparations, for the activation of which the addition of water instead of hydrogen peroxide solution is sufficient. They are salts. However, the use of salts has a disadvantage for adjusting the viscosity of the ready-to-use hair coloring agent. Indeed, polyelectrolytes such as xanthan gum, which lose their viscosity-increasing effect as the salt(s) content increases, are often used as thickeners. If the ready-to-use hair coloring agent has too low a viscosity, it is more difficult to apply and may flow more easily from the hair during the exposure time, which is undesirable.

The objective of the present application is to provide a hair coloring agent comprising a solid oxidizing agent, which can be activated with water, the hair coloring agent not presenting any disadvantages in terms of handling, in particular in terms of viscosity of the ready-to-use hair coloring agent. In addition, hair color formulations should be packaged in a safe and space-saving manner to ensure high storage stability and to provide a coloring agent that is as resource-efficient as possible. In addition, the use of the coloring agent must be as safe as possible for the consumer.

The object of the invention is achieved by a kit for dyeing keratin fibers by oxidation, in particular human hair, comprising

(i) an anhydrous oxidation composition (OZ), containing at least one solid oxidizing agent, which can be activated with water, chosen from sodium percarbonate and sodium perborate, and containing no polysaccharide,

(ii) separately from (OZ), an anhydrous cosmetic coloring composition (FZ), containing

- at least one developer-type oxidation dye precursor and at least one coupler-type oxidation dye precursor, as well as

- at least one alkalizing agent chosen from sodium silicates and sodium metasilicates, each having a SiO ₂ /Na ₂ O molar ratio of 0.8 to 3.7, preferably of 1.0 to 3.6 , particularly preferably from 2.5 to 3.5, as well as

- at least one polysaccharide as thickener, chosen from sodium carboxymethylcellulose and xanthan gum and mixtures thereof,

the kit not comprising any constituent having a persulfate content,

characterized in that at least one of the compositions (FZ) or (OZ) contains precipitated silica.

Another object of the present invention is a method for dyeing keratin fibers by oxidation, in particular human hair, comprising the following steps:

(i) supply of an anhydrous oxidation composition (OZ), containing at least one solid oxidizing agent, which can be activated with water, chosen from sodium percarbonate and sodium perborate, and containing no polysaccharide, and separately therefrom, supply of an anhydrous cosmetic coloring composition (FZ), the coloring composition (FZ) containing:

- at least one developer-type oxidation dye precursor and at least one coupler-type oxidation dye precursor, as well as

- at least one alkalizing agent chosen from sodium silicates and sodium metasilicates, each having a SiO ₂ /Na ₂ O molar ratio of 0.8 to 3.7, preferably of 1.0 to 3.6 , particularly preferably from 2.5 to 3.5, as well as

- at least one polysaccharide as thickener, chosen from sodium carboxymethylcellulose and xanthan gum and mixtures thereof,

(ii) mixing the composition (OZ), the cosmetic coloring composition (FZ) and water to form a ready-to-use coloring agent,

(iii) directly after step (ii), application of the ready-to-use coloring agent to the keratin fibres, in particular to human hair,

(iv) application of the ready-to-use coloring agent on the keratin fibres, in particular on human hair, for 5 to 60 minutes, preferably for 15 to 45 minutes, particularly preferably for 30 minutes,

(v) then rinsing the keratin fiber coloring agent with water, optionally washing the fibers with a cleaning agent containing a surfactant, conditioning the fibers with a conditioning agent and/or drying the fibers,

no persulphate being used in the process,

characterized in that the weight ratio between the sum of the weights of the compositions (OZ) and (FZ) and the weight of the amount of water used in step (ii), [(OZ)+(FZ)]/[ water], is in the range of 10:100 to 28:100, preferably 11:100 to 24:100, particularly preferably 12:100 to 22:100, most preferably 13:100 at 20:100, even more preferably from 14:100 to 19.6:100, exceptionally preferably from 16:100 to 18.1:100,

further characterized in that at least one of the compositions (FZ) or (OZ) contains precipitated silica as a thickener.

By “keratin fibers”, “keratin-based fibers” or “keratin fibers”, is meant fur, wool, feathers and in particular human hair. Although the agents according to the invention are suitable primarily for the lightening and coloring of keratin fibres, nothing in principle prevents their use in other contexts.

The kit according to the invention is a kit for modifying the color by oxidation of keratin fibers, that is to say a product which is applied to the human head after mixing with water in order to produce a coloring by oxidation or a toning of the hair. In this context, we speak of “toning” when the result is a color lighter than the original color of the hair. Throughout the present application, the term “cosmetic coloring composition (FZ)” is used as a synonym of the term “preparation (FZ)” or “colouring composition (FZ)”.

The kit according to the invention comprises, as first component, an anhydrous oxidation composition (OZ), containing at least one solid oxidizing agent, which can be activated with water, chosen from sodium percarbonate and sodium perborate, and containing no polysaccharides.

The compositions (OZ) and (FZ) designated as “anhydrous” of the coloring kits according to the invention and preferred according to the invention have a water content of 0 to 8% by weight, preferably of 0.1 to 5% by weight, particularly preferably from 0.5 to 2.5% by weight of water, in each case relative to the weight of the compositions (OZ) or (FZ). With the water contents mentioned in the range of 0 to 8% by weight, the compositions (OZ) and (FZ) are by definition considered as anhydrous within the meaning of the present application. These indications refer to the free water content. This does not take into account molecularly bound water content or water of crystallization, potentially associated with individual powder constituents. The water content can be measured with a moisture analyzer or a moisture meter, for example a moisture meter from Mettler, model Mettler HS 153, the loss on drying being determined at 105°C, stop criterion 50 seconds with a product weight from 1 to 1.5 grams.

In one embodiment of the invention, the anhydrous oxidation composition (OZ) of the coloring kit according to the invention and preferred according to the invention contains the solid oxidizing agent sodium percarbonate. By sodium percarbonate is meant an addition product of H₂O₂ of formula 2 Na₂CO₃3 hours₂O₂. When mixing with the coloring composition containing the alkalizing agent (FZ) and water, the ready-to-use coloring agent is obtained, in which sodium percarbonate develops its effect as an oxidizing agent.

The preferred coloring kits according to the invention and the preferred coloring methods according to the invention are characterized in that the sodium percarbonate is contained in the oxidation composition (OZ) in a total amount of 20 to 100% by weight , preferably from 40 to 90% by weight, preferably from 45 to 80% by weight, in particular from 55% to 70% by weight, relative to the weight of the oxidation composition (OZ).

It may exceptionally be preferred according to the invention for the sodium percarbonate to be contained in the oxidation composition (OZ) in a total amount of 100% by weight, relative to the weight of the oxidation composition (OZ).

In another preferred embodiment of the coloring kit according to the invention and of the coloring process according to the invention, the sodium percarbonate is present in coated form, preferably coated with at least one salt chosen from sodium carbonate , sodium hydrogencarbonate or sodium chloride and mixtures of these salts.

Another preferred embodiment of the coloring process according to the invention is characterized in that the ready-to-use coloring agent contains 1.0 to 7.0% by weight, preferably 1.5 to 6.0 % by weight, preferably 2.5 to 5.2 % by weight, in particular 2.7 to 4.7 % by weight, exceptionally preferably 3.0 to 3.6 % by weight of sodium percarbonate, in each case based on the weight of the ready-to-use coloring agent.

In another embodiment of the invention, the anhydrous oxidation composition (OZ) of the coloring kit according to the invention and preferred according to the invention contains the solid oxidizing agent sodium perborate. When mixing with the coloring composition containing the alkalizing agent (FZ) and water, the ready-to-use coloring agent is obtained, in which sodium perborate develops its effect as an oxidizing agent.

The preferred coloring kits according to the invention and the preferred coloring methods according to the invention are characterized in that the sodium perborate is contained in the oxidation composition (OZ) in a total amount of 20 to 100% by weight , preferably from 40 to 90% by weight, preferably from 45 to 80% by weight, in particular from 55% to 70% by weight, relative to the weight of the oxidation composition (OZ).

It may exceptionally be preferred according to the invention for the sodium perborate to be contained in the oxidation composition (OZ) in a total amount of 100% by weight, relative to the weight of the oxidation composition (OZ).

Another preferred embodiment of the coloring process according to the invention is characterized in that the ready-to-use coloring agent contains 1.0 to 7.0% by weight, preferably 1.5 to 6.0 % by weight, preferably 2.5 to 5.2 % by weight, in particular 2.7 to 4.7 % by weight, exceptionally preferably 3.0 to 3.6 % by weight of sodium perborate, in each case based on the weight of the ready-to-use coloring agent.

The use of at least one solid oxidizing agent, which can be activated with water, chosen from sodium percarbonate and sodium perborate, makes it possible to eliminate the addition of a solution of hydrogen peroxide. The staining kits according to the invention are therefore more stable in storage and safer compared to staining kits comprising a solution of hydrogen peroxide. Persulfates, such as sodium persulfate, ammonium persulfate, and potassium persulfate, cannot be activated with water alone, but require the addition of a solution containing hydrogen peroxide. The staining kits and staining methods according to the invention are therefore free of persulfate.

“Solid” physical state refers to standard conditions of 20°C and 10 ⁵ Pa. Unless otherwise stated, all physical state statements refer to these standard conditions.

The oxidation composition according to the invention (OZ) is further characterized in that it does not contain any polysaccharide. It has surprisingly been found that the joint storage of an oxidizing agent, selected from sodium percarbonate and sodium perborate, with polysaccharides leads to disadvantages for both ingredients in terms of long-term stability.

One embodiment of the invention is characterized in that the oxidation composition according to the invention (OZ) contains precipitated silica as a thickener. The precipitated silica used according to the invention is in powder form. The preferred precipitated silica according to the invention has a tapped density in the range of 100 to 400 g/l, preferably in the range of 200 to 300 g/l, particularly preferably in the range of 230 to 260 g/l. l, preferably measured according to the DIN ISO 787-11 standard of October 1995. The preferred precipitated silica according to the invention is further characterized in that its suspension at 5% by weight reacts in a weakly acidic manner in water, i.e. it has a pH in the range of 6.0 to 6.9, preferably in the range of 6.3 to 6.7, most preferably 6.5, preferably measured according to DIN ISO 787-9 of September 2019.

The use of precipitated silica as a thickener produces a stable viscosity, independent of the salt content of the ready-to-use coloring agent obtained by mixing the oxidation composition (OZ) with the coloring composition (FZ) and water. This improves the application properties of the final product, as it allows the ready-to-use coloring agent to remain on the hair during the exposure time without running. Another advantage of precipitated silica as a thickener is its ecological balance: the raw material is based on natural raw materials and is not a microplastic.

Preferred staining kits and staining methods according to the invention are characterized in that the anhydrous oxidation composition (OZ) contains precipitated silica as a thickener at a concentration of 0.2 to 80.0% by weight, preferably 1.0 to 60% by weight, particularly preferably 5 to 25% by weight, exceptionally preferably 8 to 15% by weight, in each case based on the weight of the composition of oxidation (OZ).

A variant of the embodiment of the invention is characterized in that the coloring composition according to the invention (FZ) contains precipitated silica as a thickener. The precipitated silica to be used in (FZ) has the same characteristics as those described above in relation to (OZ).

Preferred staining kits and staining methods according to the invention are characterized in that the anhydrous staining composition (FZ) contains precipitated silica as a thickener at a concentration of 0.2 to 50.0% by weight , preferably 1.0 to 35% by weight, particularly preferably 5 to 10% by weight, in each case based on the weight of the coloring composition (FZ).

Other preferred staining kits and staining methods according to the invention are characterized in that the anhydrous staining composition (FZ) contains precipitated silica as a thickener at a concentration of 0.2 to 50.0% by weight, preferably 1.0 to 35% by weight, particularly preferably 5 to 10% by weight, in each case based on the weight of the coloring composition (FZ), and the anhydrous oxidizing composition (OZ) contains precipitated silica as a thickener at a concentration of 0.2 to 80.0% by weight, preferably 1.0 to 60% by weight, particularly preferably 5 to 25% by weight, exceptionally preferably 8 to 15% by weight, in each case based on the weight of the oxidation composition (OZ).

In another preferred embodiment of the coloring kit according to the invention and of the coloring process according to the invention, the oxidation composition (OZ) contains at least one adjuvant chosen from fillers, anti-caking agents and agents drying as well as mixtures of these adjuvants. These adjuvants are intended to prevent clumping or sticking of the powder components of the anhydrous (OZ) and (FZ) compositions.

The particularly preferred fillers are chosen from sodium sulphate and sodium chloride as well as their mixtures. Sodium chloride is particularly preferred because it can enhance the oxidizing effect of sodium percarbonate. This is particularly desirable for obtaining light shades.

The particularly preferred anti-caking agents are chosen from pyrogenic silicic acids, diatomaceous earth, calcium phosphate, calcium silicates, aluminum oxide, magnesium oxide, magnesium carbonate, zinc, stearates and mixtures thereof.

Particularly preferred drying agents are selected from sodium sulphate, sodium carbonate, magnesium sulphate, calcium chloride and fumed silicic acids and mixtures thereof.

The preferred coloring kits according to the invention and the preferred coloring methods according to the invention are characterized in that the oxidation composition (OZ) contains at least one adjuvant chosen from fillers, anti-caking agents and drying as well as mixtures of these adjuvants, in a total amount of 0.5 to 80% by weight, preferably 5 to 65% by weight, more preferably 10 to 55% by weight, in particular 20 to 35 % by weight, based on the weight of the oxidation composition (OZ).

The anhydrous coloring composition (FZ) of the coloring kit according to the invention and preferred according to the invention contains at least one developer-type oxidation dye precursor (developer component) and at least one oxidation dye precursor of coupler type (coupler component).

The developer constituents preferred according to the invention are chosen from the group formed by toluene-2,5-diamine, 2-methoxymethyl-p-phenylenediamine, 2-(2,5-diaminophenyl)ethanol, p- phenylenediamine, 2-(1,2-dihydroxyethyl)-p-phenylenediamine, N,N-bis-(2-hydroxyethyl)-p-phenylenediamine, 4,5-diamino-1-(2-hydroxyethyl) -1H-pyrazole, 4-aminophenol, 3-methyl-4-aminophenol, N-(4-amino-3-methylphenyl)-N-[3-(1H-imidazol-1-yl)propyl]amine , N,N'-bis-(2-hydroxyethyl)-N,N'-bis-(4-aminophenyl)-1,3-diamino-propan-2-ol, bis-(2-hydroxy-5- aminophenyl)methane, 1,3-bis-(2,5-diaminophenoxy)propan-2-ol, N,N'-bis-(4-aminophenyl)-1,4-diazacycloheptane, 1,10-bis -(2,5-diaminophenyl)-1,4,7,10-tetraoxadecane, 2,4,5,6-tetraaminopyrimidine, 4-hydroxy-2,5,6-triaminopyrimidine, 2-hydroxy -4,5,6-triaminopyrimidine, 2,3-diamino-6,7-dihydro-1H,5H-pyrazolo-[1,2-a]-pyrazol-1-one and their physiologically acceptable salts and their email angels.

Preferred physiologically acceptable salts of the precursors of oxidation dyes which contain one or more amine groups are in particular the hydrochlorides (monohydrochloride x HCl, or dihydrochloride x 2 HCl), the sulphate (x H ₂ SO _{4 )} and the hydrobromide ( monohydrobromide x HBr or dihydrobromide x 2 HBr) of the compound.

The preferred coloring kits according to the invention and the preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains at least one developer constituent chosen from toluene-2,5-diamine, 2 -methoxymethyl-p-phenylenediamine, 2-(2,5-diaminophenyl)ethanol, p-phenylenediamine, 2-(1,2-dihydroxyethyl)-p-phenylenediamine, N,N-bis-(2-hydroxyethyl )-p-phenylenediamine, 4,5-diamino-1-(2-hydroxyethyl)-1H-pyrazole, 4-aminophenol, 3-methyl-4-aminophenol, N-(4-amino-3-methylphenyl )-N-[3-(1H-imidazol-1-yl)propyl]amine, N,N'-bis-(2-hydroxyethyl)-N,N'-bis-(4-aminophenyl)-1,3 -diamino-propan-2-ol, bis-(2-hydroxy-5-aminophenyl)methane, 1,3-bis-(2,5-diaminophenoxy)propan-2-ol, N,N'-bis -(4-aminophenyl)-1,4-diazacycloheptane, 1,10-bis-(2,5-diaminophenyl)-1,4,7,10-tetraoxadecane, 2,4,5,6-tetraaminopyrimidine, 4-hydroxy-2,5,6-triaminopyrimidine, 2-hydroxy-4,5,6-triaminopyrimidine, 2,3-diamino-6,7- dihydro-1H,5H-pyrazolo-[1,2-a]-pyrazol-1-one and their physiologically acceptable salts and mixtures thereof, in a total amount of 0.1 to 40% by weight, preferably 1 to 30 % by weight, particularly preferably 5 to 25 % by weight, exceptionally preferably 10 to 20 % by weight, in each case based on the weight of the anhydrous coloring composition (FZ).

The preferred coupler-type oxidation dye precursors according to the invention are chosen from the group consisting of 5-amino-2-methylphenol, 3-amino-2-chloro-6-methylphenol, 2-hydroxy-4- aminophenoxyethanol, 5-amino-4-chloro-2-methylphenol, 5-(2-hydroxyethyl)-amino-2-methylphenol, 2,4-dichloro-3-aminophenol, 2-aminophenol, 3- phenylenediamine, 2-(2,4-diaminophenoxy)ethanol, 1,3-bis(2,4-diaminophenoxy)propane, 1-methoxy-2-amino-4-(2-hydroxyethylamino)benzene, 1, 3-bis(2,4-diaminophenyl)propane, 2,6-bis(2'-hydroxyethylamino)-1-methylbenzene, 2-({3-[(2-hydroxyethyl)amino]-4-methoxy-5 -methylphenyl}amino)ethanol, 2-({3-[(2-hydroxyethyl)amino]-2-methoxy-5-methylphenyl}amino)ethanol, 2-({3-[(2-hydroxyethyl)amino] -4,5-dimethylphenyl}amino)ethanol, 2-[3-morpholino-4-ylphenyl)amino]ethanol, 3-amino-4-(2-methoxyethoxy)-5-methylphenylamine, 1-amino- 3-bis-(2-hydroxyethyl)aminobenzene, resorcinol, 2-methylresorcinol, 4-chloro resorcinol, 1,2,4-trihydroxybenzene, 2-amino-3-hydroxypyridine, 3-amino-2-methylamino-6-methoxypyridine, 2,6-dihydroxy-3,4-dimethylpyridine, 3,5-diamino-2,6-dimethoxypyridine, 1-phenyl-3-methylpyrazol-5-one, 1-naphthol, 1,5-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,7 -dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 4-hydroxyindole, 6-hydroxyindole, 7-hydroxyindole, 4-hydroxyindoline, 6-hydroxyindoline, 7-hydroxyindoline or mixtures of these compounds or their physiologically acceptable salts.

The preferred coloring kits according to the invention and the preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains at least one coupler constituent, chosen from the group consisting of 5-amino-2- methylphenol, 3-amino-2-chloro-6-methylphenol, 2-hydroxy-4-aminophenoxyethanol, 5-amino-4-chloro-2-methylphenol, 5-(2-hydroxyethyl)-amino-2- methylphenol, 2,4-dichloro-3-aminophenol, 2-aminophenol, 3-phenylenediamine, 2-(2,4-diaminophenoxy)ethanol, 1,3-bis(2,4-diaminophenoxy)propane, 1-methoxy-2-amino-4-(2-hydroxyethylamino)benzene, 1,3-bis(2,4-diaminophenyl)propane, 2,6-bis(2'-hydroxyethylamino)-1-methylbenzene, 2-({3-[(2-hydroxyethyl)amino]-4-methoxy-5-methylphenyl}amino)ethanol, 2-({3-[(2-hydroxyethyl)amino]-2-methoxy-5- methylphenyl}amino)ethanol, 2-({3-[(2-hydroxyethyl)amino]-4,5-dimethylphenyl}amino)ethanol, 2-[3-morpholino-4-ylphenyl)amino]ethanol, 3-amino-4-(2-methoxyethoxy) -5-methylphenylamine, 1-amino-3-bis-(2-hydroxyethyl)aminobenzene, resorcinol, 2-methylresorcinol, 4-chlororesorcinol, 1,2,4-trihydroxybenzene, 2-amino-3 -hydroxypyridine, 3-amino-2-methylamino-6-methoxypyridine, 2,6-dihydroxy-3,4-dimethylpyridine, 3,5-diamino-2,6-dimethoxypyridine, 1-phenyl -3-methylpyrazol-5-one, 1-naphthol, 1,5-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 4-hydroxyindole, 6- hydroxyindole, 7-hydroxyindole, 4-hydroxyindoline, 6-hydroxyindoline, 7-hydroxyindoline or mixtures of these compounds or their physiologically acceptable salts, in a total amount of 0.1 to 40% by weight , preferably 1 to 20% by weight, particularly preferably 5 to 15% by weight, exceptionally preferably 6 to 10% by weight, in each case based on the weight of the anhydrous coloring composition (FZ) .

Preferred coloring kits according to the invention and preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains one or more direct-acting dyes. Preferred nonionic direct acting dyes are selected from the group consisting of HC Yellow 2, HC Yellow 4, HC Yellow 5, HC Yellow 6, HC Yellow 12, HC Orange 1, Disperse Orange 3, HC Red 1, HC Red 3, HC Red 7, HC Red 10, HC Red 11, HC Red 13, HC Red BN, HC Blue 2, HC Blue 11, HC Blue 12, Disperse Blue 3, HC Violet 1, Disperse Violet 1, Disperse Violet 4 and Disperse Black 9, as well as 1,4-diamino-2-nitrobenzol, 2-amino-4-nitrophenol, 1,4 -bis-(2-hydroxyethyl)-amino-2-nitrobenzol, 3-nitro-4-(2-hydroxyethyl)aminophenol, 2-(2-hydroxyethyl)amino-4,6-dinitrophenol, 4-[( 2-hydroxyethyl)amino]-3-nitro-1-methylbenzol, 1-amino-4-(2-hydroxyethyl)amino-5-chloro-2-nitrobenzol, 4-amino-3-nitrophenol, 1-( 2'-ureidoethyl)amino-4-nitrobenzol, 2-[(4-amino-2-nitrophenyl)amino]-benzoic acid, 4-[(3-hydroxypropyl)amino]-3-nitrophenol, 4-nitro-o-phenylenediamine, 6-nitro-1,2,3,4-tetrahydr oquinoxaline, 2-hydroxy-1,4-naphthoquinone, picramic acid and its salts, 2-amino-6-chloro-4-nitrophenol, 4-ethylamino-3-nitrobenzoic acid and 2-chloro-6-ethylamino-4-nitrophenol.

Preferred anionic direct-acting dyes are selected from the group consisting of Acid Yellow 1, Yellow 10, Acid Yellow 23, Acid Yellow 36, Acid Orange 7, Acid Red 33, Acid Red 52, Pigment Red 57:1, Acid Blue 7, Acid Green 50, Acid Violet 43, Acid Black 1, Acid Black 52, Bromophenol Blue and Tetrabromophenol Blue.

Suitable cationic direct-acting dyes are cationic dyes based on triphenylmethane, such as, for example, Basic Blue 7, Basic Blue 26, Basic Violet 2 and Basic Violet 14; aromatic systems substituted by a quaternary nitrogen group, for example Basic Yellow 57, Basic Red 76, Basic Blue 99, Basic Brown 16 and Basic Brown 17; cationic anthraquinone dyes such as HC Blue 16 (Bluequat B); as well as direct dyes containing a heterocycle having at least one quaternary nitrogen atom, in particular Basic Yellow 87, Basic Orange 31 and Basic Red 51. The cationic direct-acting dyes marketed under the Arianor brand are also suitable cationic direct dyes according to the invention.

The coloring composition according to the invention (FZ) is further characterized in that it contains at least one alkalizing agent chosen from sodium silicates and sodium metasilicates, each having a SiO ₂ /Na ₂ molar ratio O from 0.8 to 3.7, preferably from 1.0 to 3.6, particularly preferably from 2.5 to 3.5. Solid alkalizing agents can be incorporated into the anhydrous coloring composition (FZ) as appropriate. Upon dissolving the coloring composition (FZ) in water, these alkalizing agents produce the alkaline pH needed to activate the sodium percarbonate.

The preferred coloring kits according to the invention and the preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains at least one alkalizing agent chosen from sodium silicates and sodium metasilicates , each having a SiO ₂ /Na ₂ O molar ratio of 0.8 to 3.7, preferably 1.0 to 3.6, particularly preferably 2.5 to 3.5, in a total amount of 5 to 50% by weight, preferably 8 to 40% by weight, particularly preferably 10 to 35% by weight, exceptionally preferably 15 to 25% by weight, in each case based on the weight of the anhydrous coloring composition (FZ).

Another preferred embodiment of the coloring process according to the invention is characterized in that the ready-to-use coloring agent contains at least one alkalizing agent chosen from sodium silicates and sodium metasilicates, having each an SiO ₂ /Na ₂ O molar ratio of 0.8 to 3.7, preferably 1.0 to 3.6, particularly preferably 2.5 to 3.5, in a total amount of 0, 8 to 5.0% by weight, preferably 1.0 to 4.0% by weight, particularly preferably 1.2 to 3.5% by weight, in each case based on the weight of the agent ready-to-use coloring.

Other preferred coloring kits according to the invention and preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains as secondary alkalizing agent basic magnesium carbonate (hydroxide of magnesium carbonate ). Basic magnesium carbonate (hydroxide of magnesium carbonate) has several advantages in the context of the invention: it has a weaker alkaline effect than sodium silicates and metasilicates, which each have a SiO ₂ /Na ₂ O from 0.8 to 3.7, preferably from 1.0 to 3.6, particularly preferably from 2.5 to 3.5, and thus buffers the alkalinity of the ready-to-use coloring agent . The preferred pH adjustment according to the invention of the ready-to-use coloring agent with only one of the aforementioned sodium (meta)silicates can produce an undesirable foam during the preparation of the application mixture. This phenomenon is limited by the addition of basic magnesium carbonate (hydroxide of magnesium carbonate). In addition, basic magnesium carbonate (magnesium carbonate hydroxide) has very good adsorption properties. These can be used to extract dust from the anhydrous (FZ) coloring composition with an oil. The adsorption of an oil added for dust extraction binds the fine powder particles of the individual components of the coloring composition (FZ), so that a low dust or dust free powder is obtained. In addition, the ready-to-use coloring agent forms a fine creamy mass in the presence of basic magnesium carbonate (magnesium carbonate hydroxide).

The preferred coloring kits according to the invention and the preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains 5 to 16% by weight, preferably 6 to 14% by weight, so particularly preferred 8 to 11% by weight of basic magnesium carbonate (hydroxide of magnesium carbonate), in each case based on the weight of the anhydrous coloring composition (FZ).

Another preferred embodiment of the coloring process according to the invention is characterized in that the ready-to-use coloring agent contains 0.5 to 2.0% by weight, preferably 0.6 to 1.2 % by weight, particularly preferably 0.7 to 1.0 % by weight, of basic magnesium carbonate (hydroxide of magnesium carbonate), in each case based on the weight of the ready-to-use coloring agent .

The anhydrous coloring composition (FZ) of the coloring kit according to the invention and preferred according to the invention also contains at least one polysaccharide as thickener, chosen from sodium carboxymethylcellulose and xanthan gum and mixtures thereof.

The preferred coloring kits according to the invention and the preferred coloring methods according to the invention are characterized in that the anhydrous cosmetic coloring composition (FZ) and the anhydrous composition (OZ) containing sodium percarbonate are present in a ratio weight of [FZ]/[OZ] in the range 1:1 to 6:1, preferably 1.1:1 to 4:1, particularly preferably 1.5:1 to 3:1.

The combination of the thickener and the alkalizing agent used according to the invention leads to easier handling of the ready-to-use coloring agent which can be prepared from the kit according to the invention and to 'water.

When mixing the anhydrous components of the kit according to the invention (OZ) and (FZ) with water, the mixture remains of low viscosity during the first seconds of mixing, so that mixing can be carried out easily and quickly. The viscosity then increases and the ready-to-use coloring agent can be easily applied to the keratin fibers due to the higher viscosity. After the usual time required for mixing and application, a maximum viscosity is reached. The already applied mixture does not flow from the hair. As the combination of thickener and alkalizing agent used according to the invention gradually develops the viscosity of the ready-to-use agent, the ready-to-use coloring agent which can be prepared from the kit according to the invention is easier to handle.

According to the invention, by “xanthanes” is meant natural polysaccharides which can be obtained from sugary substrates using bacteria of the genus Xanthomonas. Preferably, the xanthan d-glucose, d-mannose, d-glucuronic acid, acetate and pyruvate used according to the invention contains a molar ratio of 28:30:20:17:5.1-6.3, the main chain being made up of glucose units linked to the β-1,4 (also called the cellulose chain). The xanthans used in a particularly preferred manner in the context of the present invention have the CAS number 11138-66-2 and the following structural formula

Xanthan gum is a polyelectrolyte due to the presence of carboxylate groups.

In the context of the present invention, the use of xanthans, of which at least 95% by weight have a particle diameter of less than 0.180 mm in powder form and of which the 1% solution by weight in a 1% aqueous solution by weight of KCl (potassium chloride) has a viscosity of 1400-1600 mPa s (measured with Brookfield LVTD, spindle 3, 60 rpm, 25°C), has proven particularly advantageous. Such xanthans are commercially available, for example, under the trade name Keltrol CG-SFT from CP Kelco.

Sodium carboxymethylcellulose thickener (INCI: Cellulose Gum) is commercially available, for example, under the trade name "Cekol 50000".

The preferred coloring kits according to the invention and the preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains, in each case relative to its weight, 5 to 25% by weight, of preferably 10 to 22% by weight, particularly preferably 12 to 19% by weight, exceptionally preferably 13 to 18% by weight of sodium carboxymethylcellulose.

Other preferred coloring kits according to the invention and preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains, in each case relative to its weight, 2 to 10% by weight, preferably 3 to 8% by weight, particularly preferably 4 to 7% by weight, exceptionally preferably 5.5 to 6% by weight xanthan gum.

Other preferred coloring kits according to the invention and preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains, in each case relative to its weight, 5 to 25% by weight, preferably 10 to 22% by weight, particularly preferably 12 to 19% by weight, exceptionally preferably 13 to 18% by weight sodium carboxymethylcellulose and 2 to 10% by weight, preferably 3 to 8% by weight , particularly preferably 4 to 7% by weight, exceptionally preferably 5.5 to 6% by weight of xanthan gum.

Other preferred coloring kits according to the invention and other preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains as thickener a mixture of sodium carboxymethylcellulose and xanthan gum, weight ratio of sodium carboxymethylcellulose to xanthan gum being in the range of 2.5:1 to 5:1, preferably 3:1 to 4.3:1.

Another preferred embodiment of the coloring process according to the invention is characterized in that the ready-to-use coloring agent contains 0.4 to 3.0% by weight, preferably 0.8 to 2.6 % by weight, particularly preferably 1.2 to 2.2 % by weight, of sodium carboxymethylcellulose, in each case based on the weight of the ready-to-use coloring agent.

Another preferred embodiment of the coloring process according to the invention is characterized in that the ready-to-use coloring agent contains 0.1 to 1.2% by weight, preferably 0.3 to 1.0 % by weight, particularly preferably 0.4 to 0.6 % by weight, of xanthan gum, in each case based on the weight of the ready-to-use coloring agent.

Another preferred embodiment of the coloring process according to the invention is characterized in that the ready-to-use coloring agent contains 0.4 to 3.0% by weight, preferably 0.8 to 2.6 % by weight, particularly preferably 1.2 to 2.2 % by weight sodium carboxymethylcellulose and 0.1 to 1.2 % by weight, preferably 0.3 to 1.0 % by weight, particularly preferably 0.4 to 0.6% by weight of xanthan gum, in each case based on the weight of the ready-to-use coloring agent.

Other preferred staining kits according to the invention and preferred staining methods according to the invention are characterized in that no ammonium salt is present.

Other preferred coloring kits according to the invention and preferred coloring methods according to the invention are characterized in that no polymer or copolymer with monomers containing acrylate, methacrylate or vinyl and no polyurethane is here.

The preferred anhydrous (OZ) oxidation compositions according to the invention and the preferred anhydrous (FZ) coloring compositions according to the invention each have a bulk density in the range from 450 to 1000 g/l (grams per liter ), preferably from 500 to 950 g/l, and particularly preferably from 550 to 900 g/l. The determination of the apparent density is preferably carried out according to standard EN ISO 60, January 2000 version.

Unless otherwise stated, all temperature indications are given on the basis of a pressure of 1013 mbar.

Another preferred embodiment of the coloring process according to the invention is characterized in that the ready-to-use coloring agent has a viscosity in the range of 10 to 100 Pa s, preferably 20 to 85 Pa s , particularly preferably 40 to 80 Pa s, exceptionally preferably 60 to 75 Pa s, in each case measured at 20°C with a Brookfield rotational viscometer, model LVDVII+, spindle 5, 4 revolutions per minute (r/ min).

The coloring process according to the invention is characterized in that the weight ratio between the sum of the weights of the compositions (OZ) and (FZ) and the weight of the quantity of water used to prepare the coloring agent ready for use according to the invention, [(OZ)+(FZ)]/[water], is in the range from 10:100 to 28:100, preferably from 11:100 to 24:100, particularly preferably from 12:100 to 22:100, very particularly preferably from 13:100 to 20:100, even more preferably from 14:100 to 19.6:100, exceptionally preferably from 16:100 to 18, 1:100.

Other preferred coloring kits according to the invention and preferred coloring methods according to the invention are characterized in that the anhydrous oxidation composition (OZ) and/or the anhydrous coloring composition (FZ) additionally contain an agent dust remover that prevents the formation of dust in powdery components. In particular, oils can be used as dedusting agents, in particular oils chosen from paraffin oil, silicone oil or ester oil as well as mixtures of these oils, paraffin oil being particularly favourite.

Other preferred coloring kits according to the invention and preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains, in each case relative to its weight, at least one oil in an amount total from 0.1 to 10.0% by weight, preferably from 1.0 to 6.0% by weight, particularly preferably from 2.0 to 3.0% by weight.

Other preferred coloring kits according to the invention and preferred coloring methods according to the invention are characterized in that the coloring composition (FZ) contains, in each case relative to its weight, a paraffin oil in an amount total from 0.1 to 10.0% by weight, preferably from 1.0 to 6.0% by weight, particularly preferably from 2.0 to 3.0% by weight.

Other preferred staining kits according to the invention and preferred staining methods according to the invention are characterized in that the anhydrous staining composition (FZ) contains one or more acids which are present in solid form under standard conditions. Such an acid, in combination with the alkalizing agent, allows better buffering of the pH of the ready-to-use coloring agent. It is therefore preferred in the context of the present invention for the anhydrous coloring composition (FZ) to additionally contain at least one acid chosen from the group consisting of succinic acid, dipicolinic acid, citric acid, malic acid, maleic acid and/or tartaric acid.

Oxidative coloring processes on keratin fibers generally take place in an alkaline medium. However, in order to preserve the keratin fibers and the skin as much as possible, it is not desirable to set a pH that is too high. It is therefore preferred that the pH of the ready-to-use coloring agent which can be prepared from the kit according to the invention or preferred according to the invention be comprised in the range from 7 to 11, preferably in the range from 8 to 11.0, particularly preferably in the range of 9 to 10.5, exceptionally preferably in the range of 9.3 to 10.0, in each case measured at a temperature of 20°C.

The anhydrous coloring composition (FZ) may additionally contain additional active substances, adjuvants and additives. Thus, one or more fatty constituents from the group of C ₁₂ to C ₃₀ fatty alcohols, triglycerides of C ₁₂ to C ₃₀ fatty acids, monoglycerides of C ₁₂ to C ₃₀ fatty acids, diglycerides of C ₁₂ to C ₃₀ fatty acids and/or hydrocarbons may for example be present.

Preferably, the anhydrous coloring composition (FZ) may also contain a surfactant substance, these surfactant substances being called surfactants or emulsifiers, depending on the field of application: they are preferably chosen from anionic, zwitterionic, amphoteric surfactants and emulsifiers and non-ionic.

In addition, the anhydrous coloring composition (FZ) may contain other active substances, adjuvants and additives, such as nonionic polymers, for example polyethylene glycols solid under standard conditions, quaternized cellulose ethers, conditioning compounds hair such as phospholipids, for example lecithin; perfume oils, active principles improving the fibrous structure, in particular mono-, di- and oligosaccharides such as glucose, galactose, fructose and lactose; dyes for coloring the agent; amino acids and oligopeptides; protein hydrolysates of animal and/or plant origin, as well as in the form of their fatty acid condensation products or their optionally anionically or cationically modified derivatives; fatty substances and vegetable oils; active ingredients such as panthenol, pantothenic acid, pantolactone, pyrrolidinonecarboxylic acids and their salts; ceramides or pseudoceramides; vitamins, provitamins and vitamin precursors; plant extracts; fats and waxes such as fatty alcohols, beeswax, montan wax and paraffins.

Concerning other preferred embodiments of the coloring methods according to the invention and preferred according to the invention, what has been explained on the coloring kits according to the invention and preferred according to the invention applies mutatis mutandis.

Another object of the present invention is the use of precipitated silica in the coloring kits according to the invention and preferred according to the invention and the coloring methods according to the invention and preferred according to the invention as a thickener. What has been explained on the preferred embodiments of the precipitated silica applies mutatis mutandis for the preferred uses according to the invention as a thickener.

The following examples illustrate the present invention, without however limiting it:

Examples: (all the quantities indicated are expressed in grams)

Example 1 Example 2 Example 3 Example 4 Composition of ' oxidation (OZ) 6,000 6,000 9,500 13,000 sodium percarbonate 4,000 4,000 2,000 6,000 sodium sulphate 2,000 sodium chloride 2,000 2,000 4,000 Sipernat 22 (INCI: Silica, precipitated silica) 5,500 3,000 Coloring composition (FZ) 10,000 10,000 12,500 15,000 Magnesium carbonate basic (magnesium carbonate hydroxide) heavy, pharm. 400g/l 1,000 1,000 0.900 1,000 Sipernat 22 0.500 0.500 0.035 5,100 Aeroperl 300/30 (INCI: Silica, pyrogenic silicic acid) 0.040 0.040 0.040 0.040 p-Tolylenediamine sulfate 1,970 1,970 1,970 1,970 2,4-diaminophenoxyethanol 2HCl 0.160 0.160 0.160 0.160 Resorcinol 0.260 0.260 0.260 0.260 m-aminophenol 0.660 0.660 0.660 0.660 sodium sulphate 1,245 1,235 2,100 1,535 Anhydrous sodium metasilicate* - - - - Britesil C 265 * 1,600 1,600 4,100 1,600 Sodium carboxymethylcellulose (INCI: Cellulose Gum; Cekol 50000) 1,800 1,800 1,700 1,900 Xanthan 0.600 0.600 0.400 0.600 Succinic acid - 0.010 0.010 0.010 Liquid paraffin 0.165 0.165 0.165 0.165 municipal water 100 100 100 100 Ready-to-use coloring agent (AWF) 116 116 122 128 pH 9.5 9.5 9.3 9.5 Viscosity [Pa s] (Brookfield LVDVII+, #5, 4 rpm, 20°C) 74.6 71.2 73.1 70.2

* Britesil C 265: Hydrated sodium silicate, Akzo PQ Silica, SiO ₂ /Na ₂ O molar ratio: 2.65

*Fine anhydrous sodium metasilicate: Silmaco FE powder, SiO ₂ /Na ₂ O molar ratio: 0.91 - 1.01

The anhydrous oxidizing composition (OZ) and the anhydrous coloring composition (FZ) remained packaged separately from each other, for example in a sachet packaging, until the preparation of the ready coloring agent to work.

Just before application to the hair, the anhydrous oxidation composition (OZ) and the anhydrous coloring composition (FZ) were mixed with the amount of water (municipal water, tap water) indicated in the table below. above and mixed to form a homogeneous mass, the ready-to-use coloring agent.

Directly after its preparation, the ready-to-use coloring agent was applied to human hair.

After an exposure time of 30 minutes, the coloring agent was rinsed off thoroughly with water.

Optionally, the hair was then cleaned with a shampoo containing a surfactant and conditioned with a conditioner. After rinsing out the conditioner, the hair was first towel-dried and then hair-dried at approximately 85°C.

The hair has been colored bluish black.

Examples: (all the quantities indicated are expressed in % by weight)

Example 5 Example 6 Coloring composition (FZ) 10,000 10,000 Magnesium carbonate basic (magnesium carbonate hydroxide) heavy, pharm. 400g/l 8,500 8,500 Sipernat 22 8,000 - Aeroperl 300/30 (INCI: Silica, pyrogenic silicic acid) 0.300 0.300 sodium sulphate 47,591 55,591 Sodium carboxymethylcellulose (INCI: Cellulose Gum; Cekol 50000) 19,000 19,000 Xanthan 5,500 5,500 Succinic acid 0.300 0.300 p-Tolylenediamine sulfate 5,441 5,441 4-chlororesorcinol 0.418 0.418 2-methylresorcinol 0.223 0.223 Resorcinol 1,809 1,809 m-aminophenol 0.418 0.418 Liquid paraffin 2,500 2,500 Total 100,000 100,000 Maximum Viscosity (20°C) [Pa s] 17.1 14.9 Average viscosity (20°C) [Pa s] 14.1 12.7

The coloring compositions (FZ) of example 5 (according to the invention) and of example 6 (comparative example) were each mixed with water according to a weight ratio (FZ) to water of 10:100 to form a homogeneous cream. The viscosity of the two creams was determined using a Haake iQ viscometer (2400 seconds with CCB25 bucket and CC25 coaxial cylinder, shear rate: 4.0/s ⁻¹ ).

The addition of precipitated silica results in a higher maximum viscosity as well as a higher average viscosity.

Claims (14)

1. Kit for dyeing keratin fibers by oxidation, in particular human hair, comprising
(i) an anhydrous oxidation composition (OZ), containing at least one solid oxidizing agent, which can be activated with water, chosen from sodium percarbonate and sodium perborate, and containing no polysaccharide,
(ii) separately from (OZ), an anhydrous cosmetic coloring composition (FZ), containing
- at least one developer-type oxidation dye precursor and at least one coupler-type oxidation dye precursor, as well as
- at least one alkalizing agent chosen from sodium silicates and sodium metasilicates, each having a SiO ₂ /Na ₂ O molar ratio of 0.8 to 3.7, preferably of 1.0 to 3.6 , particularly preferably from 2.5 to 3.5, as well as
- at least one polysaccharide as thickener, chosen from sodium carboxymethylcellulose and xanthan gum and mixtures thereof,
the kit not comprising any constituent having a persulfate content,
characterized in that at least one of the compositions (FZ) or (OZ) contains precipitated silica. Process for dyeing keratin fibers by oxidation, in particular human hair, comprising the following steps:
(i) supply of an anhydrous oxidation composition (OZ), containing at least one solid oxidizing agent, which can be activated with water, chosen from sodium percarbonate and sodium perborate, and containing no polysaccharide, and separately therefrom, supply of an anhydrous cosmetic coloring composition (FZ), the coloring composition (FZ) containing:
- at least one developer-type oxidation dye precursor and at least one coupler-type oxidation dye precursor, as well as
- at least one alkalizing agent chosen from sodium silicates and sodium metasilicates, each having a SiO ₂ /Na ₂ O molar ratio of 0.8 to 3.7, preferably of 1.0 to 3.6 , particularly preferably from 2.5 to 3.5, as well as
- at least one polysaccharide as thickener, chosen from sodium carboxymethylcellulose and xanthan gum and mixtures thereof,
(ii) mixing the composition (OZ), the cosmetic coloring composition (FZ) and water to form a ready-to-use coloring agent,
(iii) directly after step (ii), application of the ready-to-use coloring agent to the keratin fibres, in particular to human hair,
(iv) laying the ready-to-use coloring agent on the keratin fibres, in particular on human hair, for 5 to 60 minutes, preferably for 15 to 45 minutes, particularly preferably for 30 minutes,
(v) then rinsing the keratin fiber coloring agent with water, optionally washing the fibers with a cleaning agent containing a surfactant, conditioning the fibers with a conditioning agent and/or drying the fibers,
no persulfate being used in the process,
characterized in that the weight ratio between the sum of the weights of the compositions (OZ) and (FZ) and the weight of the amount of water used in step (ii), [(OZ)+(FZ)]/[ water], is in the range of 10:100 to 28:100, preferably 11:100 to 24:100, particularly preferably 12:100 to 22:100, most preferably 13:100 at 20:100, even more preferably from 14:100 to 19.6:100, exceptionally preferably from 16:100 to 18.1:100,
further characterized in that at least one of the compositions (FZ) or (OZ) contains precipitated silica as a thickener. Coloring kit according to Claim 1 or coloring process according to Claim 2, characterized in that the composition (FZ) contains, in each case relative to its weight, 5 to 25% by weight, preferably 10 to 22% by weight, particularly preferably 12 to 19% by weight, exceptionally preferably 13 to 18% by weight sodium carboxymethylcellulose and/or 2 to 10% by weight, preferably 3 to 8% by weight, particularly preferably 4 to 7% by weight, exceptionally preferably 5.5 to 6% by weight of xanthan gum. Coloring kit according to Claim 1 or 3 and coloring process according to Claim 2 or 3, characterized in that a mixture of sodium carboxymethylcellulose and xanthan gum is present as thickener, in which the weight ratio between the sodium carboxymethylcellulose and xanthan gum is in the range of 2.5:1 to 5:1, preferably 3:1 to 4.3:1. Coloring kit according to Claim 1, 3 or 4 and coloring process according to one of Claims 2 to 4, characterized in that the anhydrous cosmetic coloring composition (FZ) additionally contains basic magnesium carbonate (carbonate hydroxide of magnesium). Coloring kit according to one of Claims 1 or 3 to 5 and coloring process according to one of Claims 2 to 5, characterized in that no ammonium salt is present. Coloring kit according to one of Claims 1 or 3 to 6 and coloring process according to one of Claims 2 to 6, characterized in that no polymer or copolymer with monomers containing acrylate, methacrylate or vinyl and no polyurethane are present. Coloring kit according to one of Claims 1 or 3 to 7 and coloring process according to one of Claims 2 to 7, characterized in that at least one solid oxidizing agent, which can be activated with water, chosen from sodium percarbonate and sodium perborate, is contained in the composition (OZ) in a total amount of 20 to 100% by weight, preferably 40 to 90% by weight, preferably 45 to 80% by weight, in particular from 55% to 70% by weight, relative to the weight of the composition (OZ). Coloring kit according to one of Claims 1 or 3 to 8 and coloring process according to one of Claims 2 to 8, characterized in that the anhydrous cosmetic coloring composition (FZ) and the anhydrous composition (OZ) are present in a weight ratio of [FZ]/[OZ] in the range from 1:1 to 6:1, preferably from 1.1:1 to 4:1, particularly preferably from 1.5:1 to 3: 1. Coloring kit according to one of Claims 1 or 3 to 9 and coloring process according to one of Claims 2 to 9, characterized in that the anhydrous coloring composition (FZ) contains precipitated silica as thickener at a concentration of 0.2 to 50.0% by weight, preferably 1.0 to 35% by weight, particularly preferably 5 to 10% by weight, in each case based on the weight of the composition of coloring (FZ). Coloring kit according to one of Claims 1 or 3 to 10 and coloring process according to one of Claims 2 to 10, characterized in that the anhydrous oxidation composition (OZ) contains precipitated silica as thickener at a concentration of 0.2 to 80.0% by weight, preferably 1.0 to 60% by weight, particularly preferably 5 to 25% by weight, exceptionally preferably 8 to 15% by weight, in each case relative to the weight of the oxidation composition (OZ). Coloring process according to one of Claims 2 to 11, characterized in that the ready-to-use coloring agent contains 1.0 to 7.0% by weight, preferably 1.5 to 6.0% by weight, preferably 2.5 to 5.2% by weight, in particular 2.7 to 4.7% by weight, exceptionally preferably 3.0 to 3.6% by weight of sodium percarbonate, in each case relative to the weight of the ready-to-use coloring agent. Coloring process according to one of Claims 2 to 12, characterized in that the ready-to-use coloring agent contains 1.0 to 7.0% by weight, preferably 1.5 to 6.0% by weight, preferably 2.5 to 5.2% by weight, in particular 2.7 to 4.7% by weight, exceptionally preferably 3.0 to 3.6% by weight of sodium perborate, in each case relative to the weight of the ready-to-use coloring agent. Use of precipitated silica in a coloring kit according to one of Claims 1 or 3 to 11 or in a coloring process according to one of Claims 2 to 13 as a thickener.