Method for dyeing keratin fibres comprising the application of an oxidative pre-treatment agent and a dyeing agent including chitosan and pigment

Abstract

The invention relates to a method for dyeing keratin fibres, in particular human hair, comprising the following steps: applying a pre-treatment agent (V) to the keratin fibres, wherein the pre-treatment agent (V-1) contains at least one oxidation agent; and applying a dyeing agent (F) to the keratin fibres, wherein the dyeing agent contains, in a cosmetic carrier, (F-1) at least one chitosan and / or a chitosan derivative, and (F-2) at least one pigment.

Description

[0001] A method for dyeing keratin fibers comprising the application of an oxidative pretreatment agent and a dye containing chitosan and pigment

[0002] The present application relates to a cosmetic method for coloring keratin fibers, in particular human hair, which comprises the application of at least two different agents (V) and (F). Agent (V) is a pretreatment agent containing at least one oxidizing agent in a cosmetic carrier. Colorant (F) contains at least one chitosan or a derivative thereof (F-1) and at least one pigment (F-2) in a cosmetic carrier.

[0003] Altering the shape and color of keratinous material, especially human hair, represents an important area of ​​modern cosmetics. Depending on the coloring requirements, hair coloring specialists are familiar with various coloring systems. For permanent, intense colorings with good fastness properties and good gray coverage, oxidation dyes are typically used. Such dyes contain oxidation dye precursors, so-called developer components, and coupler components, which, under the influence of oxidizing agents such as hydrogen peroxide, form the actual dyes. Oxidation dyes are characterized by very long-lasting coloring results.

[0004] When using direct dyes, the fully formed pigments diffuse from the dyeing agent into the hair fiber. Compared to oxidative hair coloring, the colors obtained with direct dyes are less durable and wash out more quickly. Colorations with direct dyes typically remain on the hair for between 5 and 20 washes.

[0005] The use of color pigments is known for temporary color changes on hair and / or skin. Color pigments are generally understood to be insoluble, color-imparting substances. These are present undissolved in the form of small particles in the coloring formulation and are deposited only externally on the hair fibers and / or the skin surface. Therefore, they can usually be removed without residue after several washes with surfactant-containing cleansers. Various products of this type are available on the market under the name hair mascara.

[0006] Coloring with pigments offers several key advantages. Because the pigments only attach to the keratin fibers, especially the hair fibers, from the outside, unwanted coloring can be removed quickly and easily without leaving any residue, thus offering the user the opportunity to return to their original hair color immediately and without much effort. This coloring process is therefore particularly attractive for consumers who do not want to recolor their hair regularly.

[0007] Despite these many advantages, the pigment-based coloring system still has several disadvantages, which are due to the pigments' limited penetration into the keratin material. Since the pigments do not diffuse into the keratin fibers, but rather merely deposit themselves on the outer surface of the fiber in the form of a shell or film, the washfastness of the colorations produced with this system still requires improvement. Various studies have attempted to bond the pigment(s) more permanently to the hair surface using film-forming materials, usually polymers.

[0008] For example, DE 19847883 A1 deals with the realization of pigment-based dyes using dyes containing at least one chitosan and one pigment. Combining the pigments with chitosan is intended to improve the abrasion resistance of the dyes. The major advantage of chitosans as film-forming materials is that they are based on biopolymers and therefore have improved ecological compatibility and degradability. As many users show increasing interest in products made from sustainable or renewable raw materials, the use of biopolymers is increasingly gaining attention. Nevertheless, dyes obtained with pigment and chitosan still have disadvantages with regard to their washfastness.Achieving even coloring over the entire length of the hair cannot yet be described as optimal, since the durability of the films varies on different sections of the hair, especially in the areas at the roots and tips.

[0009] WO 2021 / 190810 A1 describes dyes with pigments that are bonded to the hair surface via films of amino-functionalized silicone polymers. The washfastness of these dyes could be improved through oxidative pretreatment.

[0010] However, further work on WO 2021 / 190810 A1 revealed that the oxidative pretreatment, which was carried out here with the combination of hydrogen peroxide and peroxodisulfates, also resulted in hair lightening and damage. This can be particularly disadvantageous if the user resorts to pigment-based colorants because they want to avoid hair lightening and damage. Furthermore, the aminosilicones used in this case did not meet the requirements that an environmentally conscious user places on a product's ecological profile.

[0011] The objective of this application was therefore to find a pigment-based coloring process that would enable intensive coloring with improved washfastness. The coloring process should be carried out with the aid of biopolymers, and the hair should be lightened and damaged as little as possible by the coloring process. Ideally, the hair should not be damaged at all by the application of the colorant. Furthermore, a uniform color result should be achieved across the entire length of the keratin fiber, regardless of the degree of damage.

[0012] Surprisingly, it has now been found that the washfastness of dyed keratin fibers could be massively improved if the dyeing was carried out with a pigment and a chitosan and the keratin fibers were pretreated with at least one oxidizing agent before application of the dye.

[0013] A first object of the present invention is a process for dyeing keratin fibers, in particular human hair, comprising the following steps:

[0014] Application of a pretreatment agent (V) to the keratin fibers, wherein the pretreatment agent

[0015] (V-1) contains at least one oxidizing agent, and

[0016] - application of a coloring agent (F) to the keratin fibers, wherein the coloring agent is contained in a cosmetic carrier

[0017] (F-1) at least one chitosan and / or a chitosan derivative, and

[0018] (F-2) contains at least one pigment.

[0019] The work leading to this invention has shown that particularly intense and true-to-life color results can be achieved on hair by successively applying the two agents (V) and (F). Even after multiple washes, no undesirable or unattractive shift in shade occurred. The evenness of the color result was also significantly improved in this way.

[0020] Keratin fibers

[0021] Keratin fibers include hair, wool, and fur. Human hair is particularly preferred as keratin fibers.

[0022] Coloring agents

[0023] The term "coloring agent" is used in this invention to describe the coloring of keratin fibers, particularly hair, caused by the use of pigments. During this coloring, the pigments, as color-imparting compounds, are deposited in a homogeneous, uniform, and smooth film on the surface of the keratin material. The film is formed by the chitosan(s). Pretreatment agent (V)

[0024] Before applying the coloring agent (F), the pretreatment agent (V) is applied to the keratin fibers, in particular the hair, in the process according to the invention. The pretreatment agent described below is the ready-to-use pretreatment agent that can be applied directly to the keratin fibers or hair.

[0025] Oxidizing agent (V-1) or (V-2) in the pretreatment agent (V)

[0026] Oxidizing agents are substances with an oxidizing effect. Examples of oxidizing agents commonly used in cosmetics include hydrogen peroxide and / or at least one adduct thereof, particularly with inorganic or organic compounds, such as sodium perborate, sodium percarbonate, magnesium percarbonate, sodium percarbonate, polyvinylpyrrolidone n H2O2 (n is a positive integer greater than 0), urea peroxide, and melamine peroxide.

[0027] For use in the process according to the invention, the oxidizing agents from the group consisting of carbamide peroxide, potassium peroxodisulfate, ammonium peroxodisulfate and sodium peroxodisulfate have proven particularly suitable.

[0028] Carbamide peroxide is the adduct of hydrogen peroxide and urea, which is commercially available, for example, in the form of a white crystalline powder. It is a water-soluble crystalline adduct that can be formed by recrystallizing urea with a 30% hydrogen peroxide solution.

[0029] Carbamide peroxide is also referred to in the literature as urea hydrogen peroxide adduct, urea peroxide, perhydrite, percarbamide, or urea peroxide. Carbamide peroxide has the molecular formula CH6N2O3 and the CAS number 124-43-6.

[0030] Carbamide peroxide can be purchased commercially from Thermo Scientific, for example.

[0031] In a further embodiment, persulfates and / or their salts can also be used with particular preference as oxidizing agents in the pretreatment agent (V). The use of one or more persulfates from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate, and sodium peroxodisulfate is very particularly preferred.

[0032] Ammonium peroxodisulfate, which can also be called ammonium persulfate, is the persulfate with the molecular formula (NH4)2S2Oa.

[0033] Potassium peroxodisulfate, which can also be referred to as potassium persulfate, is the persulfate with the molecular formula K2S2O8. Sodium peroxodisulfate, which can also be referred to as sodium persulfate, is the persulfate with the molecular formula Na2S2O8.

[0034] In a particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains one or more oxidizing agents (V-1) from the group consisting of carbamide peroxide, potassium peroxodisulfate, ammonium peroxodisulfate and sodium peroxodisulfate.

[0035] During the experiments leading to this invention, it was found that a significant and effective improvement in washfastness could be achieved, particularly when a pretreatment agent (V) containing a combination of various oxidizing agents was used in the process according to the invention. Particularly good results were obtained when using a pretreatment agent (V) containing the combination of carbamide peroxide (V-1) and at least one peroxodisulfate (V-2) from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate, and sodium peroxodisulfate.

[0036] In a further particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains (V-1) carbamide peroxide and

[0037] (V-2) at least one peroxodisulfate selected from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate and sodium peroxodisulfate.

[0038] In a further particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains (V-1) carbamide peroxide and

[0039] (V-2) Ammonium peroxodisulfate.

[0040] In a further particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains (V-1) carbamide peroxide and (V-2) potassium peroxodisulfate.

[0041] Within the scope of a further particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains (V-1) carbamide peroxide and (V-2) sodium peroxodisulfate. Within the scope of a further particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains (V-1) carbamide peroxide and

[0042] (V-2) Ammonium peroxodisulfate and potassium peroxodisulfate.

[0043] In a further particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains (V-1) carbamide peroxide and

[0044] (V-2) Ammonium peroxodisulfate and sodium peroxodisulfate.

[0045] In a further particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains (V-1) carbamide peroxide and

[0046] (V-2) Potassium peroxodisulfate and sodium peroxodisulfate.

[0047] In a further particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains (V-1) carbamide peroxide and

[0048] (V-2) Ammonium peroxodisulfate, potassium peroxodisulfate and sodium peroxodisulfate.

[0049] According to the invention, the oxidative cosmetic pretreatment agent may additionally contain at least one catalyst as an optional ingredient that activates the oxidation of the substrate, such as the melanin present in the keratin material. Such catalysts include, for example, metal ions, iodides, quinones, or certain enzymes.

[0050] Suitable metal ions include Zn 2+ , Cu 2+ , Fe 2+ , Fe 3+ , Mn 2+ , Mn 4+ , Li + , Mg 2+ , Ca 2+ and Al 3+ Zn 2+ , Cu 2+ and Mn 2+ The metal ions can, in principle, be used in the form of any physiologically acceptable salt or in the form of a complex compound. Preferred salts are acetates, sulfates, halides, lactates, and tartrates.

[0051] Suitable enzymes include peroxidases, which can significantly enhance the effect of small amounts of hydrogen peroxide. Furthermore, enzymes suitable for the invention are those that generate small amounts of hydrogen peroxide in situ with the aid of atmospheric oxygen and thus biocatalytically activate the oxidation of the dye precursors. Particularly suitable catalysts for the oxidation of dye precursors are the so-called 2-electron oxidoreductases in combination with the specific substrates, e.g.

[0052] Pyranose oxidase and e.g. D-glucose or galactose,

[0053] glucose oxidase and D-glucose,

[0054] Glycerol oxidase and glycerol, pyruvate oxidase and benzoic acid or their salts,

[0055] Alcohol oxidase and alcohol (MeOH, EtOH),

[0056] Lactate oxidase and lactic acid and their salts,

[0057] Tyrosinase oxidase and tyrosine,

[0058] Uricase and uric acid or their salts,

[0059] Choline oxidase and choline,

[0060] Amino acid oxidase and amino acids.

[0061] By selecting appropriate quantity ranges of oxidizing agent(s) (V-1) (or (V-1) and (V-2)) in the pretreatment agent (V), the extent of the influence that the pretreatment agent (V) has on the washfastness of the subsequently applied colorant (F) can be specifically controlled. In this context, it has been shown that the washfastness is better the higher the amount of oxidizing agent used in the pretreatment agent (V). On the other hand, however, the damage to the keratin material or the keratin fibers / hair also increases with increasing amounts of oxidizing agents. In order to find the optimal balance between these two effects, it has proven particularly preferable to use the oxidizing agent(s) in very specific quantity ranges in the pretreatment agent.

[0062] The pretreatment agent according to the invention preferably contains - based on the total weight of the pretreatment agent - 1.0 to 30.0 wt.%, preferably 3.0 to 20.0 wt.%, more preferably 6.0 to 15.0 wt.% and very particularly preferably 8.0 to 15.0 wt.% carbamide peroxide (V-1).

[0063] The pretreatment agent (V) according to the invention preferably contains - based on the total weight of the pretreatment agent - one or more persulfates (V-2) from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate and sodium peroxodisulfate in a total amount of 3.0 to 40.0 wt.%, preferably 3.0 to 30 wt.%, more preferably 6.0 to 20.0 wt.% and most preferably 9.0 to 17.0 wt.%.

[0064] In a further particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) - based on the total weight of the pretreatment agent (V) - contains

[0065] (V-1) 1.0 to 30.0 wt.%, preferably 3.0 to 20.0 wt.%, more preferably 6.0 to 15.0 wt.% and most preferably 8.0 to 15.0 wt.% carbamide peroxide, and

[0066] (V-2) one or more peroxodisulfates from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate and sodium peroxodisulfate in a total amount of 3.0 to 40.0 wt.%, preferably 3.0 to 30 wt.%, more preferably 6.0 to 20.0 wt.% and most preferably 9.0 to 17.0 wt.%.

[0067] Cosmetic carrier of the pretreatment agent (V) The oxidizing agent(s) (V-1) (or (V-1) and (V-2)) are contained in the pretreatment agent (V) in a cosmetic carrier. In principle, various carriers are conceivable as cosmetic carriers for the pretreatment agent (V), such as, for example, an aqueous, alcoholic, or aqueous-alcoholic carrier. The carrier can also be a cream, emulsion, a paste, or even a surfactant-containing foaming solution, such as, for example, a shampoo, foam aerosol, a foam formulation, or another preparation suitable for application to the hair. Water is the most common of all solvents in cosmetic products; therefore, in principle, water can also be used as the main ingredient as a cosmetic carrier.

[0068] However, the work leading to this invention has shown that the nature of the cosmetic carrier in the pretreatment agent (V) can have a major influence on the lightening and damage associated with the use of the oxidizing agent(s).

[0069] If, for example, the combination of carbamide peroxide (V-1) and peroxodisulfates (V-2) was used in pretreatment agents (V) with a very high water content, increased lightening and, associated with this, greater hair damage was observed. Although the washfastness of the pigment coloring was improved using the process according to the invention, the hair was also damaged more severely. Surprisingly, hair damage was massively reduced using a cosmetic carrier with a higher solvent content. It is assumed that the presence of the solvent either slows down the dissolution or decomposition of the carbamide peroxide or inhibits the reaction of carbamide peroxide with persulfates to such an extent that the inner part (i.e. the cortex) of the hair is less oxidatively changed, while the surface or cuticle is nevertheless modified so strongly that pigment-containing films can adhere better there.

[0070] Solvents from the group of glycerol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, ethanol, isopropanol, dipropylene glycol, diethylene glycol monoethyl ether, phenoxyethanol, benzyl alcohol, poly-Ci-Ce-alkylene glycols, dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate and glycerol carbonate have proven particularly suitable.

[0071] In a further preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains at least one solvent from the group consisting of glycerol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, ethanol, isopropanol, dipropylene glycol, diethylene glycol monoethyl ether, phenoxyethanol, benzyl alcohol, poly-Ci-Ce-alkylene glycols, dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, and glycerol carbonate. The solvent(s) in the pretreatment agent (V) are preferably used in amounts that are sufficiently high to slow the dissolution or interaction of the carbamide peroxide, but on the other hand are low enough that the product is not excessively polluted with solvents.The pretreatment agent (V) preferably contains - based on the total weight of the pretreatment agent (V) - one or more solvents from the group consisting of glycerol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, ethanol, isopropanol, dipropylene glycol, diethylene glycol monoethyl ether, phenoxyethanol, benzyl alcohol, poly-Ci-Ce-alkylene glycols, dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate and glycerol carbonate in a total amount of 3.0 to 80% by weight, preferably of 5.0 to 60.0% by weight, more preferably of 9.0 to 40.0% by weight and very particularly preferably of 12.0 to 25.0% by weight.

[0072] In a further very particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) - based on the total weight of the pretreatment agent (V) - contains one or more solvents from the group consisting of glycerol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, ethanol, isopropanol, dipropylene glycol, diethylene glycol monoethyl ether, phenoxyethanol, benzyl alcohol, poly-Ci-Ce-alkylene glycols, dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate and glycerol carbonate in a total amount of 3.0 to 80 wt.%, preferably from 5.0 to 60.0 wt.%, more preferably from 9.0 to 40.0 wt.% and very particularly preferably from 12.0 to 25.0 wt.%.

[0073] Most preferably, the pretreatment agent (V) contains glycerol and 1,2-propanediol.

[0074] Explicitly most preferably, the pretreatment agent (V) contains - based on the total weight of the pretreatment agent (V) - 12.0 to 25.0 wt.% glycerol and 1.0 to 7.0 wt.% 1,2-propanediol.

[0075] Instead of or in addition to the aforementioned solvents, the pretreatment agent (V) can also contain one or more polyalkylene glycols. The polyalkylene glycols reduce the polarity of the cosmetic carrier. Increasing the proportion of polyalkylene glycol(s) in the pretreatment agent (V) also resulted in a reduction in hair damage and lightening of the pretreated keratin fibers. In this way, the subsequent application of the colorant (F) improved the washfastness and uniformity of the colorings without excessively damaging the keratin fibers and without lightening their original hair color. In this context, it is suspected that the dissolution of the carbamide peroxide or its reaction with the persulfates is also reduced by the polyalkylene glycols, causing the oxidizing agents to react with a time delay or only with the surface of the keratin fibers.Polyalkylene glycols which are particularly suitable according to the invention are, for example, ethylene glycols of the formula (EG). where x is an integer from 1 to 10,000, preferably an integer from 2 to 500, more preferably an integer from 3 to 100 and most preferably an integer from 5 to 30.

[0076] The ethylene glycols of formula (EG) are protic substances with at least one hydroxyl group, which, due to their repeating unit -CH2-CH2-O-, can also be referred to as polyethylene glycols, provided x represents a value of at least 2. In the alkylene glycols of formula (EG), x represents an integer from 1 to 10,000.

[0077] Depending on their chain length, polyethylene glycols are liquid or solid, water-soluble polymers. Polyethylene glycols with a molecular weight between 200 g / mol and 400 g / mol are non-volatile liquids at room temperature. PEG 600 has a melting range of 17 to 22 °C and thus a paste-like consistency. With molecular weights above 3000 g / mol, PEGs are solid substances and are marketed as flakes or powders.

[0078] The use of low-molecular-weight alkylene glycols (or polyethylene glycols) has proven particularly suitable for achieving the object of the invention. For low-molecular-weight alkylene glycols (or polyethylene glycols) within the meaning of the present invention, x1 represents an integer from 1 to 100, preferably an integer from 1 to 80, more preferably an integer from 2 to 60, even more preferably an integer from 3 to 40, even more preferably an integer from 4 to 20, and most preferably an integer from 6 to 15.

[0079] A particularly preferred low-molecular-weight polyethylene glycol is PEG-8. PEG-8 contains an average of 8 ethylene glycol units (x1 = 8), has an average molecular weight of 400 g / mol, and bears the CAS number 25322-68-3. PEG-8 is also known as PEG 400 and is commercially available, for example, from APS.

[0080] Other suitable low-molecular-weight polyethylene glycols include PEG-6, PEG-7, PEG-9, and PEG-10. Another suitable polyethylene glycol is PEG-32. PEG-32 contains 32 ethylene glycol units (x1 = 32), has an average molecular weight of 1500 g / mol, and has the CAS number 25322-68-3. PEG-32 is also known as PEG 1500 and can be purchased commercially, for example, from Clariant.

[0081] The polyalkylene glycol(s), in particular the polyethylene glycols of formula (EG), are preferably used in the pretreatment agent (V) in amounts that are sufficiently high to slow the dissolution or interaction of the carbamide peroxide, but on the other hand are low enough that the product is not excessively polluted with solvents. The pretreatment agent (V) preferably contains - based on the total weight of the pretreatment agent (V) - one or more ethylene glycols of formula (EG) in a total amount of 1.0 to 80% by weight, preferably 1.5 to 60.0% by weight, more preferably 3.0 to 40.0% by weight, and most preferably 4.5 to 10.0% by weight.

[0082] In a further very particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) - based on the total weight of the pretreatment agent (V) - contains one or more ethylene glycols of the formula (EG) in a total amount of 1.0 to 80 wt.%, preferably 1.5 to 60.0 wt.%, more preferably 3.0 to 40.0 wt.% and very particularly preferably 4.5 to 10.0 wt.%, where x is an integer from 1 to 10,000, preferably an integer from 2 to 500, more preferably an integer from 3 to 100 and most preferably an integer from 5 to 30.

[0083] Most preferably, the pretreatment agent (V) contains at least one solvent from the group described above and at least one polyethylene glycol of the formula (EG).

[0084] In a further particularly preferred embodiment, the pretreatment agent (V) according to the invention contains

[0085] - one or more solvents from the group consisting of glycerol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, ethanol, isopropanol, dipropylene glycol, diethylene glycol monoethyl ether, phenoxyethanol, benzyl alcohol, poly-Ci-Ce-alkylene glycols, dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate and glycerol carbonate, and

[0086] - one or more ethylene glycols of the formula (EG) described above. In order to inhibit the decomposition of the oxidizing agents, in particular the carbamide peroxide, or to stabilize the oxidizing agents, it has also proven particularly preferable to adjust the water content in the pretreatment agent to a medium to low range. Therefore, it is particularly advantageous if the pretreatment agent (V) contains, based on the total weight of the pretreatment agent (V), 5.0 to 70.0 wt.%, preferably 10.0 to 60.0 wt.%, more preferably 15.0 to 50.0 wt.%, and very particularly preferably 20.0 to 40.0 wt.% of water.

[0087] In a further very particularly preferred embodiment, a process according to the invention is characterized in that the pretreatment agent (V) contains - based on the total weight of the pretreatment agent (V) - 5.0 to 70.0 wt.%, preferably 10.0 to 60.0 wt.%, more preferably 15.0 to 50.0 wt.% and very particularly preferably 20.0 to 40.0 wt.% of water.

[0088] Dye (F)

[0089] Following the application of the pretreatment agent (V), the colorant (F) is then applied to the keratin material in the process according to the invention. The colorant (F) contains at least one chitosan and / or a chitosan derivative (F-1) and (F-2) at least one pigment in a cosmetic carrier.

[0090] Cosmetic carrier of the colorant (F)

[0091] As a cosmetic carrier for the colorant (F), for example, a suitable aqueous, alcoholic or aqueous-alcoholic carrier can be used. For the purpose of hair coloring, such carriers are, for example, creams, emulsions, gels, pastes or surfactant-containing foaming solutions, such as shampoos, foam aerosols, foam formulations or other preparations suitable for application to the hair. The cosmetic carrier for the colorant is particularly preferably a water-rich carrier, i.e. the colorant (F) preferably has a high water content. It has been found that colorants (F) which contain - based on the total weight of the pretreatment agent (V) - 50.0 to 99.0 wt. %, preferably 60.0 to 99.0 wt. %, more preferably 70.0 to 99.0 wt. % and very particularly preferably 80.0 to 99.0 wt. % water are particularly suitable for use in the process according to the invention.

[0092] In one embodiment, a process according to the invention is characterized in that the colorant (F) contains, based on the total weight of the colorant (F), 50.0 to 99.0 wt.%, preferably 60.0 to 99.0 wt.%, more preferably 70.0 to 99.0 wt.%, and most preferably 80.0 to 99.0 wt.% water. Chitosans (F-1) in the colorant (F)

[0093] Chitosan, also known as polyglusam, poly-D-glucosamine, or polyglucosamine, is a naturally occurring biopolymer derived from chitin, which is composed of ß-1,4-glycosidically linked N-acetylglucosamine residues (more precisely, 2-acetamido-2-deoxy-ß-D-glucopyranose residues), and is thus, like chitin, a polyaminosaccharide. To produce chitosan, chitin is deacetylated, so that the molecule ultimately consists of only approximately 2,000 linearly linked 2-amino-2-deoxy-ß-D-glucopyranose or glucosamine monomers. Chitosan has the CAS number 9012-76-4.

[0094] Chitosan is preferably produced from the chitin found in shellfish or crustaceans. Chitosan is industrially obtained from chitin by deacetylation. This can be achieved, for example, using (hot) sodium hydroxide solution or enzymatically. Both processes are used industrially, but the alkaline procedure is clearly the most widely used. The degree of resulting deacetylation can vary considerably: deacetylation can be complete or partial, resulting in a distribution of highly deacetylated regions alongside less deacetylated regions, or a homogeneous deacetylation distribution. At the same time, this chemical intervention can decrease the chain length of the polymer (depolymerization). The molecular weight of chitosan can vary over a wide range, for example, from 20,000 to approximately 5 million g / mol.

[0095] Chitosan derivatives are compounds with a chitosan base structure in which at least some of the functional groups present have been chemically modified. Chitosan derivatives are also based on a poly-D-glucosamine or polyglucosamine structure.

[0096] For example, a chitosan with a molecular weight of 20,000 to 800,000 g / mol, preferably 50,000 to 600,000 g / mol, more preferably 80,000 to 450,000 g / mol and most preferably 100,000 to 300,000 g / mol is very suitable.

[0097] In a further very particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least one chitosan and / or a chitosan derivative (F-1) with a molecular weight of 20,000 to 800,000 g / mol, preferably of 50,000 to 600,000 g / mol, more preferably of 80,000 to 450,000 g / mol and very particularly preferably of 100,000 to 300,000 g / mol.

[0098] In another particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least one chitosan (F-1) with a molecular weight of 20,000 to 800,000 g / mol, preferably 50,000 to 600,000 g / mol, more preferably 80,000 to 450,000 g / mol, and very particularly preferably 100,000 to 300,000 g / mol. A chitosan with a molecular weight of 100,000 to 300,000 g / mol can be purchased commercially, for example, from Sigma-Aldrich.

[0099] A chitosan with a lower molecular weight of 10,000 to 30,000 g / mol (or Dalton) can be purchased in pharmaceutical grade from BioLog Heppe (Kraeber), for example. The degree of deacetylation of this chitosan is 88-95%.

[0100] Chitosan in the form of its hydrochloride can be purchased as vegan chitosan from Sandream Impact. The chitosan hydrochloride is a chitosan derivative according to the invention.

[0101] Chitosan 027 is a suitable high molecular weight chitosan from Polymar, which has a molecular weight of 100,000 - 2,000,000 g / mol.

[0102] It has proven particularly advantageous if the colorant according to the invention contains the chitosan(s) and / or chitosan derivative(s) (F-1) in specific quantity ranges. Particularly good results were obtained when the colorant—based on the total weight of the colorant—contained one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 10.0 wt.%, preferably 0.2 to 8.0 wt.%, more preferably 0.5 to 6.0 wt.%, and most preferably 0.7 to 2.0 wt.%.

[0103] In a further particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) - based on the total weight of the colorant - contains one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 10.0 wt.%, preferably 0.2 to 8.0 wt.%, more preferably 0.5 to 6.0 wt.% and most preferably 0.7 to 2.0 wt.%.

[0104] In a further particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) - based on the total weight of the colorant - contains one or more chitosans in a total amount of 0.1 to 10.0 wt.%, preferably 0.2 to 8.0 wt.%, more preferably 0.5 to 6.0 wt.% and most preferably 0.7 to 2.0 wt.%.

[0105] Pigments (F-2) in the colorant (F)

[0106] As a second essential component of the invention, the colorant (F) used in the process according to the invention contains at least one pigment. Pigments within the meaning of the present invention are understood to mean color-imparting compounds which have a solubility in water at 25°C of less than 0.5 g / L, preferably less than 0.1 g / L, and even more preferably less than 0.05 g / L. The water solubility can be determined, for example, using the method described below: 0.5 g of the pigment is weighed into a beaker. A stir bar is added. Then, one liter of distilled water is added. This mixture is heated to 25°C for one hour while stirring on a magnetic stirrer. If undissolved components of the pigment are still visible in the mixture after this period, the solubility of the pigment is below 0.5 g / L.If the pigment-water mixture cannot be visually assessed due to the high intensity of the finely dispersed pigment, the mixture is filtered. If a portion of undissolved pigment remains on the filter paper, the pigment's solubility is below 0.5 g / L.

[0107] Suitable color pigments can be of inorganic and / or organic origin.

[0108] In a preferred embodiment, a colorant (F) according to the invention is characterized in that it contains at least one color-providing compound (F-2) from the group of inorganic and / or organic pigments.

[0109] In a preferred embodiment, a colorant (F) according to the invention is characterized in that it contains at least one inorganic and / or organic pigment (F-2).

[0110] Preferred color pigments are selected from synthetic or natural inorganic pigments. Inorganic color pigments of natural origin can be made from chalk, ochre, umber, green earth, burnt sienna, or graphite, for example. Other inorganic color pigments that can be used include black pigments such as iron oxide black, colored pigments such as ultramarine or iron oxide red, as well as fluorescent or phosphorescent pigments.

[0111] Particularly suitable are colored metal oxides, hydroxides, and oxide hydrates, mixed-phase pigments, sulfur-containing silicates, silicates, metal sulfides, complex metal cyanides, metal sulfates, chromates, and / or molybdates. Particularly preferred color pigments are black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and brown iron oxide (CI 77491), manganese violet (CI 77742), ultramarines (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), iron blue (ferric ferrocyanide, CI 77510), and / or carmine (cochineal).

[0112] Also particularly preferred color pigments according to the invention are colored pearlescent pigments. These are typically based on mica and / or mica and can be coated with one or more metal oxides. Mica belongs to the class of layered silicates. The most important representatives of these silicates are muscovite, phlogopite, paragonite, biotite, lepidolite, and margarite. To produce pearlescent pigments in combination with metal oxides, the mica, predominantly muscovite or phlogopite, is coated with a metal oxide.

[0113] As an alternative to natural mica, synthetic mica, optionally coated with one or more metal oxides, can also be used as a pearlescent pigment. Particularly preferred pearlescent pigments are based on natural or synthetic mica and coated with one or more of the aforementioned metal oxides. The color of the respective pigments can be varied by varying the layer thickness of the metal oxide(s).

[0114] In a further preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least inorganic pigment (F-2), which is preferably selected from the group of colored metal oxides, metal hydroxides, metal oxide hydrates, silicates, metal sulfides, complex metal cyanides, metal sulfates, bronze pigments and / or colored pigments based on mica or mica, which are coated with at least one metal oxide and / or one metal oxychloride.

[0115] In a further preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least one pigment which is selected from mica- or mica-based pigments coated with one or more metal oxides from the group consisting of titanium dioxide (CI 77891), black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and / or brown iron oxide (CI 77491, CI 77499), manganese violet (CI 77742), ultramarines (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), chromium oxide (CI 77288) and / or iron blue (ferric ferrocyanide, CI 77510).

[0116] Examples of particularly suitable color pigments are commercially available under the trade names Rona®, Colorona®, Xirona®, Dichrona® and Timiron® from Merck, Ariabel® and Unipure® from Sensient, Prestige® from Eckart Cosmetic Colors and Sunshine® from Sunstar.

[0117] Particularly preferred color pigments with the trade name Colorona® are, for example:

[0118] Colorona Copper, Merck, MICA, CI 77491 (IRON OXIDES)

[0119] Colorona Passion Orange, Merck, Mica, CI 77491 (Iron Oxides), Alumina

[0120] Colorona Patina Silver, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE) Colorona RY, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 75470 (CARMINE)

[0121] Colorona Oriental Beige, Merck, MICA, CI 77891 (TITANIUM DIOXIDE), CI 77491 (IRON OXIDES) Colorona Dark Blue, Merck, MICA, TITANIUM DIOXIDE, FERRIC FERROCYANIDE

[0122] Colorona Chameleon, Merck, CI 77491 (IRON OXIDES), MICA Colorona Aborigine Amber, Merck, MICA, Cl 77499 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE)

[0123] Colorona Blackstar Blue, Merck, Cl 77499 (IRON OXIDES), MICA

[0124] Colorona Patagonian Purple, Merck, MICA, Cl 77491 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE), Cl 77510 (FERRIC FERROCYANIDE)

[0125] Colorona Red Brown, Merck, MICA, Cl 77491 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE)

[0126] Colorona Russet, Merck, Cl 77491 (TITANIUM DIOXIDE), MICA, Cl 77891 (IRON OXIDES)

[0127] Colorona Imperial Red, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), D&C RED NO. 30 (Cl 73360)

[0128] Colorona Majestic Green, Merck, Cl 77891 (TITANIUM DIOXIDE), MICA, Cl 77288 (CHROMIUM OXIDE GREENS)

[0129] Colorona Light Blue, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), FERRIC FERROCYANIDE (Cl 77510)

[0130] Colorona Red Gold, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0131] Colorona Gold Plus MP 25, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), IRON OXIDES (Cl 77491)

[0132] Colorona Carmine Red, Merck, MICA, TITANIUM DIOXIDE, CARMINE

[0133] Colorona Blackstar Green, Merck, MICA, Cl 77499 (IRON OXIDES)

[0134] Colorona Bordeaux, Merck, MICA, Cl 77491 (IRON OXIDES)

[0135] Colorona Bronze, Merck, MICA, Cl 77491 (IRON OXIDES)

[0136] Colorona Bronze Fine, Merck, MICA, Cl 77491 (IRON OXIDES)

[0137] Colorona Fine Gold MP 20, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0138] Colorona Sienna Fine, Merck, Cl 77491 (IRON OXIDES), MICA

[0139] Colorona Sienna, Merck, MICA, Cl 77491 (IRON OXIDES)

[0140] Colorona Precious Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Silica, Cl 77491 (Iron oxides), Tin oxide

[0141] Colorona Sun Gold Sparkle MP 29, Merck, MICA, TITANIUM DIOXIDE, IRON OXIDES, MICA, Cl 77891 , Cl 77491 (EU)

[0142] Colorona Mica Black, Merck, Cl 77499 (Iron oxides), Mica, Cl 77891 (Titanium dioxide)

[0143] Colorona Bright Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Cl 77491 (Iron oxides)

[0144] Colorona Blackstar Gold, Merck, MICA, Cl 77499 (IRON OXIDES)

[0145] Weiterhin besonders bevorzugte Farbpigmente mit der Handelsbezeichnung Xirona® sind beispielsweise:

[0146] Xirona Golden Sky, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0147] Xirona Caribbean Blue, Merck, Mica, CI 77891 (Titanium Dioxide), Silica, Tin Oxide

[0148] Xirona Kiwi Rose, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0149] Xirona Magie Mauve, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide. Other particularly preferred color pigments with the trade name Unipure® include:

[0150] Unipure Red LC 381 EM, Sensient CI 77491 (Iron Oxides), Silica

[0151] Unipure Black LC 989 EM, Sensient, CI 77499 (Iron Oxides), Silica

[0152] Unipure Yellow LC 182 EM, Sensient, CI 77492 (Iron Oxides), Silica

[0153] In a further embodiment, the pretreatment agent (V) according to the invention may also contain one or more organic pigments

[0154] The organic pigments according to the invention are correspondingly insoluble, organic dyes or lakes which can be selected, for example, from the group of nitroso, nitro-azo, xanthene, anthraquinone, isoindolinone, isoindoline, quinacridone, perinone, perylene, diketopyrrolopyorrole, indigo, thioindido, dioxazine and / or triarylmethane compounds.

[0155] Particularly suitable organic pigments are, for example, carmine, quinacridone, phthalocyanine, sorghum, blue pigments with the color index numbers CI 42090, CI 69800, CI 69825, CI 73000, CI 74100, CI 74160, yellow pigments with the color index numbers CI 11680, CI 11710, CI 15985, CI 19140, CI 20040, CI 21100, CI 21108, CI 47000, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, CI 74260, orange pigments with the color index numbers CI 1 1725, CI 15510, CI 45370, CI 71105, red pigments with the color index numbers CI 12085, CI 12120, CI 12370, CI 12420, CI 12490, CI 14700, CI 15525, CI 15580, CI 15620, CI 15630, CI 15800, CI 15850, CI 15865, CI 15880, CI 17200, CI 26100, CI 45380, CI 45410, CI 58000, CI 73360, CI 73915 and / or CI 75470.

[0156] In a further particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least one organic pigment (F-2), which is preferably selected from the group consisting of carmine, quinacridone, phthalocyanine, sorghum, blue pigments with the color index numbers CI 42090, CI 69800, CI 69825, CI 73000, CI 74100, CI 74160, yellow pigments with the color index numbers CI 1 1680, CI 11710, CI 15985, CI 19140, CI 20040, CI 21100, CI 21108, CI 47000, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, CI 74260, orange pigments with the color index numbers C1 11725, CI 15510, CI 45370, CI 71 105, red pigments with the color index numbers CI 12085, CI 12120, CI 12370, CI 12420, CI 12490, CI 14700, CI 15525, CI 15580, CI 15620, CI 15630, CI 15800, CI 15850, CI 15865, CI 15880, CI 17200, CI 26100, CI 45380, CI 45410, CI 58000, CI 73360, CI 73915 and / or CI 75470.

[0157] The organic pigment can also be a colored lake. For the purposes of the invention, the term colored lake refers to particles comprising a layer of absorbed dyes, the particle-dye unit being insoluble under the aforementioned conditions. The particles can be, for example, inorganic substrates, which can be aluminum, silica, calcium borosilicate, calcium aluminum borosilicate, or even aluminum.

[0158] Alizarin lake, for example, can be used as a colored varnish.

[0159] Due to their excellent light and temperature stability, the use of the aforementioned pigments in the colorant (F) of the process according to the invention is very particularly preferred. Furthermore, it is preferred if the pigments used have a specific particle size. It is therefore advantageous according to the invention if the at least one pigment has an average particle size D50 of 1.0 to 50 pm, preferably of 5.0 to 45 pm, more preferably of 10 to 40 pm, in particular of 14 to 30 pm. The average particle size D50 can be determined, for example, using dynamic light scattering (DLS).

[0160] Pigments with a specific shape can also be used to color the keratin fibers. For example, a pigment based on a lamellar and / or lenticular substrate plate can be used. Furthermore, coloring based on a substrate plate containing a vacuum-metallized pigment is also possible.

[0161] In a further preferred embodiment, an agent according to the invention is characterized in that it contains at least one pigment (a2) which is selected from the group of pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

[0162] The substrate platelets of this type have an average thickness of at most 50 nm, preferably less than 30 nm, more preferably at most 25 nm, for example at most 20 nm. The average thickness of the substrate platelets is at least 1 nm, preferably at least 2.5 nm, more preferably at least 5 nm, for example at least 10 nm. Preferred ranges for the thickness of the substrate platelets are 2.5 to 50 nm, 5 to 50 nm, 10 to 50 nm; 2.5 to 30 nm, 5 to 30 nm, 10 to 30 nm; 2.5 to 25 nm, 5 to 25 nm, 10 to 25 nm, 2.5 to 20 nm, 5 to 20 nm and 10 to 20 nm. Each substrate platelet preferably has a thickness that is as uniform as possible. Due to the low thickness of the substrate platelets, the pigment has particularly high hiding power.

[0163] The substrate platelets are preferably monolithic in structure. Monolithic in this context means consisting of a single, closed unit without fractures, stratification, or inclusions, although structural changes may occur within the substrate platelets. The substrate platelets are preferably homogeneous in structure, meaning that no concentration gradient occurs within the platelets. In particular, the substrate platelets are not layered and do not contain any particles or particles distributed within them.

[0164] The size of the substrate platelet can be tailored to the specific application, especially the desired effect on the keratin material. Typically, the substrate platelets have an average diameter of approximately 2 to 200 pm, particularly approximately 5 to 100 pm.

[0165] In a preferred embodiment, the aspect ratio, expressed as the ratio of the average size to the average thickness, is at least 80, preferably at least 200, more preferably at least 500, and particularly preferably more than 750. The average size of the uncoated substrate platelets is understood to be the d50 value of the uncoated substrate platelets. Unless otherwise stated, the d50 value was determined using a Sympatec Heios device with Quixel wet dispersion. For sample preparation, the sample to be tested was predispersed in isopropanol for 3 minutes.

[0166] The substrate platelets can be made of any material that can be formed into platelets.

[0167] They can be of natural origin or synthetically produced. Materials from which the substrate platelets can be constructed include metals and metal alloys, metal oxides, preferably aluminum oxide, inorganic compounds and minerals such as mica and (semi-)precious stones, as well as plastics. The substrate platelets are preferably made of metal (or metal alloys).

[0168] Any metal suitable for metallic luster pigments can be considered. Such metals include iron and steel, as well as all air- and water-resistant (semi)metals such as platinum, zinc, chromium, molybdenum, and silicon, as well as their alloys such as aluminum bronze and brass. Preferred metals are aluminum, copper, silver, and gold. Preferred substrate platelets are aluminum platelets and brass platelets, with aluminum platelets being particularly preferred.

[0169] Lamellar substrate platelets are characterized by an irregularly structured edge and are also called "cornflakes" due to their appearance.

[0170] Due to their irregular structure, pigments based on lamellar substrate platelets generate a high degree of scattered light. Furthermore, pigments based on lamellar substrate platelets do not completely cover the existing color of a keratinous material, and effects similar to natural graying can be achieved, for example.

[0171] Lenticular (= lens-shaped) substrate platelets have a generally regular, round edge and are also called "silver dollars" due to their appearance. Due to their regular structure, the proportion of reflected light predominates in pigments based on lenticular substrate platelets.

[0172] Vacuum metallized pigments (VMPs) can be obtained, for example, by releasing metals, metal alloys, or metal oxides from appropriately coated foils. They are characterized by a particularly thin substrate platelet thickness in the range of 5 to 50 nm and a particularly smooth surface with increased reflectivity. Substrate platelets comprising a vacuum-metallized pigment are also referred to as VMP substrate platelets in this application. VMP substrate platelets made of aluminum can be obtained, for example, by releasing aluminum from metallized foils.

[0173] The substrate plates made of metal or metal alloy can be passivated, for example by anodizing (oxide layer) or chromating.

[0174] Uncoated lamellar, lenticular, and / or VPM substrate plates, especially those made of metal or metal alloy, reflect incident light to a high degree and produce a light-dark flop. These have proven particularly preferred for use in the colorant.

[0175] Suitable pigments based on a lamellar substrate platelet include, for example, the pigments of the VISIONAIRE series from Eckart.

[0176] Pigments based on a lenticular substrate platelet are available, for example, under the name Alegrace® Gorgeous from Schlenk Metallic Pigments GmbH.

[0177] Pigments based on a substrate platelet comprising a vacuum metallized pigment are available, for example, under the name Alegrace® Marvelous or Alegrace® Aurous from Schlenk Metallic Pigments GmbH.

[0178] The pigment(s) (F-2) represent(s) the second essential constituent of the colorant (F) according to the invention and are preferably used in the composition in specific quantity ranges. Particularly good results were obtained when the colorant—based on the total weight of the colorant—contained one or more pigments (F-2) in a total amount of 0.01 to 10.0 wt. %, preferably 0.1 to 5.0 wt. %, more preferably 0.2 to 2.5 wt. %, and most preferably 0.25 to 1.5 wt. %.

[0179] In a further very particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) - based on the total weight of the colorant - contains one or more pigments (F-2) in a total amount of 0.01 to 10.0 wt.%, preferably 0.1 to 5.0 wt.%, more preferably from 0.2 to 2.5 wt.% and very particularly preferably from 0.25 to 1.5 wt.%.

[0180] Direct dyes in the dyeing agent (F)

[0181] In principle, the coloring agents (F) used in the process according to the invention can also contain one or more direct dyes as optional components. Direct dyes are dyes that are absorbed directly onto the hair and do not require an oxidative process to develop the color. Direct dyes are typically nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinones, triarylmethane dyes, or indophenols.

[0182] The direct dyes according to the present invention have a solubility in water (760 mmHg) at 25°C of more than 0.5 g / L and are therefore not considered pigments. Preferably, the direct dyes according to the present invention have a solubility in water (760 mmHg) at 25°C of more than 1.0 g / L.

[0183] The essential advantage of the process according to the invention, however, is that the colorations achievable with the pigment-based colorant (F) are, on the one hand, very wash-stable, but, on the other hand, also possess very high shade stability. This means that fading of the color, if it occurs to a lesser extent after several washes of the keratin material, occurs while maintaining the color shade without any visible color shift. This shade stability can be observed even when the colorant (F) contains a mixture of pigments (F-2) of different colors.

[0184] Without being committed to this theory, it is suspected in this context that the reason for the high stability of the color nuance is that all pigments are deposited in the form of a film on the surface of the keratin material. Unlike direct dyes, the pigments cannot diffuse into the keratin material, and also unlike direct dyes, the size or structure of a pigment cannot influence its depth of penetration into the keratin material.

[0185] If a mixture of different colored direct dyes is applied to the keratin material, these different dyes are generally based on different chromophoric structures and molecules of different sizes. Due to their structural differences, these different dyes can diffuse to different depths into the keratin material and are also washed out of the keratin material to varying degrees during washing. Particularly with natural-toned colorations, which are created, for example, using a mixture of a yellow, a red, and a blue direct dye, a color shift from brown to yellowish, reddish, or bluish can be observed over the course of several washes or shampoos.

[0186] The colors produced using the process according to the invention are based on a pigment-silicone film located on the surface of the keratin material. Washing tests have now shown that although repeated washing leads to a slight reduction in color intensity, there is no shift in the shade. The dissolution of different colored pigments from the film during a hair wash is therefore much more uniform.

[0187] The fact that this color shift does not occur when using the process according to the invention is a significant advantage over a dyeing system based on direct dyes. For this reason, it is particularly preferred if the dyeing agent (F) contains no direct dyes or contains them in only very small amounts.

[0188] In a further, very particularly preferred embodiment, a process according to the invention is characterized in that the total amount of the direct dyes contained in the colorant (F) - based on the total weight of the colorant (F) - is below 0.1% by weight, preferably below 0.05% by weight, more preferably below 0.01% by weight and very particularly preferably below 0.001% by weight.

[0189] In other words, in a further very particularly preferred embodiment, a process according to the invention is characterized in that the total amount of the direct dyes contained in the colorant (F) - based on the total weight of the colorant (F) - is below 0.1 wt.%, preferably below 0.05 wt.%, more preferably below 0.01 wt.% and very particularly preferably below 0.001 wt.%, wherein the direct dyes are characterized in that they have a solubility in water (760 mmHg) at 25 °C of more than 0.5 g / L.

[0190] In a further, very particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) is free of direct dyes. Direct dyes can be divided into anionic, cationic, and nonionic direct dyes.

[0191] Kationische direktziehende Farbstoffe sind beispielsweise Basic Blue 7, Basic Blue 26, HC Blue 16, Basic Violet 2 und Basic Violet 14, Basic Yellow 57, Basic Red 76, Basic Blue 16, Basic Blue 347 (Cationic Blue 347 / Dystar), HC Blue No. 16, Basic Blue 99, Basic Brown 16, Basic Brown 17, Basic Yellow 57, Basic Yellow 87, Basic Orange 31 , Basic Red 51 Basic Red 76.

[0192] Examples of non-ionic direct dyes include non-ionic nitro and quinone dyes and neutral azo dyes. Examples of non-ionic direct dyes are those known under the international designations "N" and "N" respectively.Handelsnamen 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 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, Disperse Black 9 bekannten Verbindungen, sowie 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-dinitro- phenol, 4-[(2-Hydroxyethyl)amino]-3-nitro-1 -methylbenzol, 1-Amino-4-(2-hydroxyethyl)-amino-5- chlor-2-nitrobenzol, 4-Amino-3-nitrophenol, 1-(2'-Ureidoethyl)amino-4-nitrobenzol, 2-[(4-Amino-2- nitrophenyl)amino]-benzoesäure, 6-Nitro-1 ,2,3,4-tetrahydrochinoxalin, 2-Hydroxy-1 ,4-naphtho- chinon, Pikraminsäure und deren Salze, 2-Amino-6-chloro-4-nitrophenol, 4-Ethylamino-3-nitro- benzoesäure und 2-Chlor-6-ethylamino-4-nitrophenol.

[0193] Anionic direct dyes are also known as acid dyes. Acid dyes are defined as direct dyes that contain at least one carboxylic acid group (-COOH) and / or one sulfonic acid group (-SO3H). Depending on the pH, the profaned forms (-COOH, -SO3H) of the carboxylic acid or sulfonic acid groups exist in equilibrium with their deprotonated forms (-COO-, -SOs). As the pH decreases, the proportion of profaned forms increases. If direct dyes are used in the form of their salts, the carboxylic acid or sulfonic acid groups are present in deprotonated form and are neutralized with corresponding stoichiometric equivalents of cations to maintain electroneutrality. Acid dyes according to the invention can also be used in the form of their sodium salts and / or their potassium salts.

[0194] The acid dyes within the meaning of the present invention have a solubility in water (760 mmHg) at 25°C of more than 0.5 g / L and are therefore not considered pigments. The acid dyes within the meaning of the present invention preferably have a solubility in water (760 mmHg) at 25°C of more than 1.0 g / L. The alkaline earth metal salts (such as calcium salts and magnesium salts) or aluminum salts of acid dyes often have poorer solubility than the corresponding alkali metal salts. If the solubility of these salts is below 0.5 g / L (25°C, 760 mmHg), they do not fall under the definition of a direct dye.

[0195] A key feature of acid dyes is their ability to form anionic charges, with the carboxylic acid or sulfonic acid groups responsible for this being typically linked to various chromophoric systems. Suitable chromophoric systems can be found, for example, in the structures of nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinone dyes, triarylmethane dyes, xanthene dyes, rhodamine dyes, oxazine dyes, and / or indophenol dyes.

[0196] Als Beispiele für Säurefarbstoffe können können genannt werden: Acid Yellow 1 (D&C Yellow 7, Citronin A, Ext. D&C Yellow No. 7, Japan Yellow 403, CI 10316, COLIPA n° B001), Acid Yellow 3 (COLIPA n° : C 54, D&C Yellow N° 10, Quinoline Yellow, E104, Food Yellow 13), Acid Yellow 9 (CI 13015), Acid Yellow 17 (C1 18965), Acid Yellow 23 (COLIPA n° C 29, Covacap Jaune W 1 100 (LCW), Sicovit Tartrazine 85 E 102 (BASF), Tartrazine, Food Yellow 4, Japan Yellow 4, FD&C Yellow No. 5), Acid Yellow 36 (CI 13065), Acid Yellow 121 (CI 18690), Acid Orange 6 (CI 14270), Acid Orange 7 (2-Naphthol orange, Orange II, C1 15510, D&C Orange 4, COLIPA n° C015), Acid Orange 10 (C.l. 16230; Orange G sodium salt), Acid Orange 11 (Cl 45370), Acid Orange 15 (Cl 50120), Acid Orange 20 (Cl 14600), Acid Orange 24 (BROWN 1 ;CI20170;KATSU201 ;nosodiumsalt;Brown No.201 ;RESORCIN BROWN;ACID ORANGE 24;Japan Brown 201 ;D & C Brown No.1), Acid Red 14 (C.1.14720), Acid Red 18 (E124, Red 18; Cl 16255), Acid Red 27 (E 123, Cl 16185, C-Rot 46, Echtrot D, FD&C Red Nr.2, Food Red 9, Naphtholrot S), Acid Red 33 (Red 33, Fuchsia Red, D&C Red 33, Cl 17200), Acid Red 35 (Cl C.l.18065), Acid Red 51 (Cl 45430, Pyrosin B, Tetraiodfluorescein, Eosin J, lodeosin), Acid Red 52 (Cl 45100, Food Red 106, Solar Rhodamine B, Acid Rhodamine B, Red n° 106 Pontacyl Brilliant Pink), Acid Red 73 (Cl Cl 27290), Acid Red 87 (Eosin, Cl 45380), Acid Red 92 (COLIPA n° C53, Cl 45410), Acid Red 95 (Cl 45425, Erythtosine.Simacid Erythrosine Y), Acid Red 184 (Cl 15685), Acid Red 195, Acid Violet 43 (Jarocol Violet 43, Ext. D&C Violet n° 2, C.l. 60730, COLIPA n° C063), Acid Violet 49 (Cl 42640), Acid Violet 50 (Cl 50325), Acid Blue 1 (Patent Blue, Cl 42045), Acid Blue 3 (Patent Blau V, Cl 42051), Acid Blue 7 (Cl 42080), Acid Blue 104 (Cl 42735), Acid Blue 9 (E 133, Patentblau AE, Amidoblau AE, Erioglaucin A, Cl 42090, C.l.Food Blue 2), Acid Blue 62 (Cl 62045), Acid Blue 74 (E 132, Cl 73015), Acid Blue 80 (Cl 61585), Acid Green 3 (Cl 42085, Foodgreenl), Acid Green 5 (Cl 42095), Acid Green 9 (C.1.42100), Acid Green 22 (C.1.42170), Acid Green 25 (Cl 61570, Japan Green 201, D&C Green No. 5), Acid Green 50 (Brilliant Green BS, Cl 44090, Acid Brilliant Green BS, E 142), Acid Black 1 (Black n° 401, Naphthalene Black 10B, Amido Black 10B, Cl 20 470, COLIPA n° B15), Acid Black 52 (Cl 15711), Food Yellow 8 (Cl 14270), Food Blue 5, D&C Yellow 8, D&C Green 5, D&C Orange 10, D&C Orange 11, D&C Red 21, D&C Red 27, D&C Red 33, D&C Violet 2 and / or D&C Brown 1. The water solubility of the anionic substantive dyes can be determined, for example, in the following way. 0.1 g of the anionic substantive dye is placed in a beaker. A stir bar is added. Then 100 ml of water is added.This mixture is heated to 25 °C on a magnetic stirrer while stirring. It is stirred for 60 minutes. The aqueous mixture is then visually assessed. If undissolved residues are still present, the amount of water is increased - for example, in steps of 10 ml. Water is added until the used amount of dye has completely dissolved. If the dye-water mixture cannot be assessed visually due to the high intensity of the dye, the mixture is filtered. If a portion of undissolved dye remains on the filter paper, the solubility test is repeated using a larger amount of water. If 0.1 g of the anionic direct dye dissolves in 100 ml of water at 25 °C, the solubility of the dye is 1.0 g / L.

[0197] Acid Yellow 1 is called 8-hydroxy-5,7-dinitro-2-naphthalenesulfonic acid disodium salt and has a solubility in water of at least 40 g / L (25°C).

[0198] Acid Yellow 3 is a mixture of the sodium salts of mono- and disulfonic acids of 2-(2-quinolyl)-1H-indene-1,3(2H)-dione and has a water solubility of 20 g / L (25 °C).

[0199] Acid Yellow 9 is the disodium salt of 8-hydroxy-5,7-dinitro-2-naphthalenesulfonic acid, its water solubility is above 40 g / L (25 °C).

[0200] Acid Yellow 23 is the trisodium salt of 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-4-((4-sulfophenyl)azo)- 1 H-pyrazole-3-carboxylic acid and is readily soluble in water at 25 °C.

[0201] Acid Orange 7 is the sodium salt of 4-[(2-hydroxy-1-naphthyl)azo]benzenesulfonate. Its water solubility is greater than 7 g / L (25 °C).

[0202] Acid Red 18 is the trisodium salt of 7-hydroxy-8-[(E)-(4-sulfonato-1-naphthyl)-diazenyl)]-1,3-naphthalenedisulfonate and has a very high water solubility of more than 20 wt%.

[0203] Acid Red 33 is the disodium salt of 5-amino-4-hydroxy-3-(phenylazo)-naphthalene-2,7-disulfonate; its water solubility is 2.5 g / L (25 °C).

[0204] Acid Red 92 is the disodium salt of 3,4,5,6-tetrachloro-2-(1,4,5,8-tetrabromo-6-hydroxy-3-oxoxanthen-9-yl)benzoic acid, whose water solubility is stated to be greater than 10 g / L (25 °C).

[0205] Acid Blue 9 is the disodium salt of 2-({4-[N-ethyl(3-sulfonatobenzyl]amino]phenyl}{4-[(N-ethyl(3-sulfonatobenzyl)imino]-2,5-cyclohexadien-1-ylidene}methyl)-benzenesulfonate and has a water solubility of more than 20 wt.% (25 °C). Other optional ingredients in the agents (V) and / or (F)

[0206] In addition to the components already described as essential to the invention, the pretreatment agent (V) and / or the coloring agent (F) may also contain further optional ingredients. Thus, the agents may also contain further active ingredients, auxiliaries, and additives, such as, for example, solvents; fatty components such as, for example, Cs-Cs fatty alcohols, Cs-Cs fatty acid triglycerides, Cs-Cs fatty acid monoglycerides, Cs-Cs fatty acid diglycerides, and / or hydrocarbons; polymers; structuring agents such as glucose, maleic acid, and lactic acid; hair-conditioning compounds such as phospholipids, for example, lecithin and cephalins; perfume oils, dimethyl isosorbide, and cyclodextrins; fiber-structure-improving agents, in particular mono-, di-, and oligosaccharides such as, for example, glucose, galactose, fructose, fructose, and lactose; dyes for coloring the agent; Anti-dandruff agents such as Piroctone Olamine, Zinc Omadine and Climbazole;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, where appropriate, anionically or cationically modified derivatives; vegetable oils; sunscreens and UV blockers; active ingredients such as panthenol, pantothenic acid, pantolactone, allantoin, pyrrolidinonecarboxylic acids and their salts, and bisabolol; polyphenols, in particular hydroxycinnamic acids, 6,7-dihydroxycoumarins, hydroxybenzoic acids, catechins, tannins, leucoanthocyanidins, anthocyanidins, flavanones, flavones, and flavonols; ceramides or pseudoceramides; vitamins, provitamins, and vitamin precursors; plant extracts; fats and waxes such as fatty alcohols, beeswax, montan wax, and paraffins; Swelling and penetrating agents such as glycerin, propylene glycol monoethyl ether, carbonates, bicarbonates, guanidines, ureas, and primary, secondary, and tertiary phosphates; opacifiers such as latex, styrene / PVP, and styrene / acrylamide copolymers;Pearlescent agents such as ethylene glycol mono- and distearate and PEG-3 distearate; as well as propellants such as propane-butane mixtures, N2O, dimethyl ether, CO2 and air.

[0207] The expert will select these additional substances based on the desired properties of the product. Regarding further optional components and the amounts of these components used, reference is expressly made to the relevant manuals known to the expert. The additional active ingredients and excipients are preferably used in the preparations according to the invention in amounts of 0.0001 to 25 wt.%, in particular 0.0005 to 15 wt.%, based on the total weight of the respective product. pH of pretreatment agent (V) and / or colorant (F)

[0208] The pH values ​​of the agents (V) and (F) according to the invention can be adjusted to a slightly acidic to alkaline pH value.

[0209] Within the scope of one embodiment, the pretreatment agent (V) has a pH of 6.0 to 12.0, preferably from 7.0 to 11.5, more preferably from 7.5 to 11.0 and very particularly preferably from 9.0 to 11.0. If pretreatment agents (V) with these pH values ​​were used in the process according to the invention, dyeings with particularly good fastness properties could be achieved. Within the scope of a further embodiment, a process according to the invention is characterized in that the pretreatment agent (V) has a pH of 6.0 to 12.0, preferably from 7.0 to 11.5, more preferably from 7.5 to 11.0 and very particularly preferably from 9.0 to 11.0.

[0210] The pH of the colorant (F) according to the invention can be adjusted to a slightly acidic to alkaline pH. The colorant (F) most preferably has a pH in the range from 3.0 to 10.0, preferably from 3.0 to 8.5, more preferably from 3.0 to 7.0, and most preferably from 3.0 to 6.0.

[0211] To adjust the desired pH values, alkalizing and acidifying agents known to those skilled in the art can be used. The pH values ​​used in the present invention are pH values ​​measured at a temperature of 22°C.

[0212] As alkalizing agents, the agents can contain, for example, ammonia, alkanolamines and / or basic amino acids.

[0213] The alkanolamines usable in the agent according to the invention are preferably selected from primary amines with a C2-C6 alkyl parent structure carrying at least one hydroxyl group. Preferred alkanolamines are selected from the group consisting of 2-aminoethane-

[0214] 1-ol (monoethanolamine), 3-aminopropan-1-ol, 4-aminobutan-1-ol, 5-aminopentan-1-ol, 1-aminopropan-2-ol, 1-aminobutan-2-ol, 1-aminopentan-2-ol, 1-aminopentan-3-ol, 1 -aminopentan-4-ol, 3-Amino-2-methylpropan-1-ol, 1-amino-2-methylpropan-2-ol, 3-aminopropan-1,2-diol, 2-amino-

[0215] 2-methylpropane-1,3-diol.

[0216] Particularly preferred alkanolamines according to the invention are selected from 2-aminoethane-1-ol and / or 2-amino-2-methylpropane-1-ol. A particularly preferred embodiment is therefore characterized in that the agent according to the invention contains an alkanolamine selected from 2-aminoethane-1-ol and / or 2-amino-2-methylpropane-1-ol as an alkalizing agent.

[0217] An amino acid within the meaning of the invention is an organic compound that contains at least one protonatable amino group and at least one -COOH or -SO 5 H group in its structure. Preferred amino acids are aminocarboxylic acids, in particular α-(alpha)-aminocarboxylic acids and α-aminocarboxylic acids, with α-aminocarboxylic acids being particularly preferred.

[0218] For the purposes of the invention, basic amino acids are those amino acids that have an isoelectric point pI greater than 7.0. Basic α-aminocarboxylic acids contain at least one asymmetric carbon atom. Within the scope of the present invention, both possible enantiomers can be used equally as a specific compound or as mixtures thereof, in particular as racemates. However, it is particularly advantageous to use the naturally occurring isomer form, usually in the L-configuration.

[0219] The basic amino acids are preferably selected from the group consisting of arginine, lysine, ornithine, and histidine, particularly preferably arginine and lysine. In another particularly preferred embodiment, an agent according to the invention is characterized in that the alkalizing agent is a basic amino acid from the group consisting of arginine, lysine, ornithine, and / or histidine.

[0220] In addition, the agent may contain other alkalizing agents, particularly inorganic alkalizing agents. Inorganic alkalizing agents usable according to the invention are preferably selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, sodium phosphate, potassium phosphate, sodium silicate, sodium metasilicate, potassium silicate, sodium carbonate, and potassium carbonate.

[0221] Also in accordance with the invention is the adjustment of the desired pH value using a buffer system. A buffer or buffer system is usually understood to be a mixture of a weak or medium-strength acid (e.g., acetic acid) with a virtually completely dissociated neutral salt of the same acid (e.g., sodium acetate). If a small amount of base or acid is added, the pH hardly changes (buffering). The effect of the buffer substances contained in a buffer solution is based on the capture reaction of hydrogen or hydroxide ions with the formation of weak acids or bases due to their dissociation equilibrium. A buffer system can be formed from a mixture of an inorganic or organic acid and a corresponding salt of this acid. Acids can be buffered by all salts of weak acids and strong bases, and bases by salts of strong acids and weak bases. Strong (fully dissociated into ions) hydrochloric acid, for example, can be used.buffered by adding sodium acetate. According to equilibrium. Hydrochloric acid is converted by sodium acetate to weak acetic acid, forming sodium chloride. Acetic acid dissociates only to a very small extent in the presence of an excess of sodium acetate. Buffers that act against both acids and bases are mixtures of weak acids and their salts.

[0222] Examples of buffer systems known from the literature include acetic acid / sodium acetate, boric acid / sodium borate, phosphoric acid / sodium phosphate, and bicarbonate / soda. The pH of the agent according to the invention can be adjusted, for example, by adding an inorganic or organic buffer system. For the purposes of the present invention, an inorganic buffer system is understood to be a mixture of an inorganic acid and its conjugate corresponding inorganic base.

[0223] For the purposes of the present invention, an organic buffer system is understood to be a mixture of an organic acid and its corresponding conjugate base. Due to the organic acid residue, the corresponding conjugate base of the organic acid is also organic. The cation present to neutralize the charge of the acid anion can be inorganic or organic.

[0224] Examples of inorganic acids are sulfuric acid, hydrochloric acid, and phosphoric acid (H3PO4). Phosphoric acid is a medium-strength acid and is particularly preferred.

[0225] A particularly suitable inorganic acid is potassium dihydrogen phosphate

[0226] Potassium dihydrogen phosphate has the molecular formula KH2PO4 and the CAS number 7778-77-0. Potassium dihydrogen phosphate has a molar mass of 136.09 g / mol. It is highly soluble in water (222 g / l at 20 °C) and has an acidic reaction in water. A 5% solution of potassium dihydrogen phosphate in water has a pH of 4.4.

[0227] Another particularly suitable inorganic acid is sodium dihydrogen phosphate. Sodium dihydrogen phosphate has the molecular formula NaH2PO4 and the CAS numbers 7558-80-7 (anhydrate), 10049-21-5 (monohydrate), and 13472-35-0 (dihydrate). Anhydrous sodium dihydrogen phosphate has a molar mass of 119.98 g / mol. Sodium dihydrogen phosphate reacts acidically in aqueous solution.

[0228] Dipotassium hydrogen phosphate is particularly preferred as the corresponding salt of the two aforementioned acids. Dipotassium hydrogen phosphate has the molecular formula K2HPO4 and bears the CAS numbers 7758-11-4 (anhydrous) and 16788-57-1 (trihydrate). Anhydrous dipotassium hydrogen phosphate has a molar mass of 174.18 g / mol. Dipotassium hydrogen phosphate reacts alkalinely in aqueous solution.

[0229] Disodium hydrogen phosphate is also particularly preferred as a corresponding salt of the two aforementioned acids. Disodium hydrogen phosphate has the molecular formula N32HPO4 and bears the CAS numbers 7558-79-4 (anhydrous), 10028-24-7 (dihydrate), 7782-85-6 (heptahydrate), and 10039-32-4 (dodecahydrate). The anhydrous disodium hydrogen phosphate has a molar mass of 141.96 g / mol. Disodium hydrogen phosphate reacts alkalinely in aqueous solution. The desired pH can also be adjusted using an inorganic and / or organic acid. Examples of organic acids are acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, acetic acid, malic acid, malonic acid, and maleic acid.

[0230] Examples of the corresponding salts of these organic acids are the sodium and potassium salts of citric acid, the sodium and potassium salts of succinic acid, the sodium and potassium salts of tartaric acid, the sodium and potassium salts of lactic acid, the sodium and potassium salts of acetic acid, the sodium and potassium salts of malic acid, the sodium and potassium salts of malonic acid and the sodium and potassium salts of maleic acid.

[0231] Sequence of procedural steps

[0232] As previously described, the pretreatment agent (V) is applied before the application of the colorant (F). In this context, it has proven particularly preferable to apply the pretreatment agent (V) to the keratin material, allow it to act for a certain period of time, and then rinse it off with water.

[0233] Particularly preferred is therefore a process for coloring keratin fibers, in particular human hair, comprising the following steps in the given order:

[0234] (1) Applying the pretreatment agent (V) to the keratin fibers,

[0235] (2) allowing the pretreatment agent applied in step (1) to act on the keratin fibres for a period of 2 to 45 minutes, preferably from 2 to 30 minutes and particularly preferably from 2 to 20 minutes,

[0236] (3) Rinsing the pretreatment agent (V) with water,

[0237] (4) Applying the colorant (F) to the keratin fibers, and

[0238] (5) Exposing the colorant applied in step (4) to the keratin fibers for a period of time from 15 seconds to 45 minutes, preferably from 30 seconds to 30 minutes and particularly preferably from 1 to 15 minutes.

[0239] In step (1) of the method according to the invention, a pretreatment agent (V) containing at least one oxidizing agent is applied to the hair.

[0240] In the next step, the previously applied pretreatment agent (V) is allowed to act on the keratin fibers. Various exposure times are possible, ranging from 2 to 45 minutes, preferably from 2 to 30 minutes, and particularly preferably from 2 to 20 minutes.

[0241] After the pretreatment agent (V) has been applied to the keratin fibers, it is finally rinsed out with water in step (3). The pretreatment agent (V) can either be washed out with water alone, i.e., without the aid of a shampoo, or the wash-out process can be assisted by the use of a shampoo.

[0242] In principle, the user can now freely choose the period between the application of the two agents (V) and (F).

[0243] However, it may be preferable that no further products, such as other conditioners or styling products, are applied between the application of the two products (V) and (F). In this way, the maximum period between the application of the two products (V) and (F) is preferably limited to a maximum of 24 hours.

[0244] It has been found to be preferable if there is a period of maximum 24 hours, preferably maximum 12 hours, more preferably maximum 6 hours and most preferably maximum 3 hours between rinsing out the pretreatment agent (V) with water and applying a colorant (F) to the keratin fibers.

[0245] In a further preferred embodiment, a process according to the invention is characterized in that between steps (3) and (4) there is a period of a maximum of 24 hours, preferably a maximum of 12 hours, more preferably a maximum of 6 hours and most preferably a maximum of 3 hours.

[0246] In a further preferred embodiment, a process according to the invention is characterized in that step (4) takes place directly after step (3). Step (4) involves the application of the colorant.

[0247] The action of the colorant (F) on the keratin fibers in step (5) can, for example, take place for a period of 15 seconds to 30 minutes, preferably for a period of 30 seconds to 15 minutes, particularly preferably for a period of 1 to 15 minutes.

[0248] Preparation of the ready-to-use pretreatment agent by mixing two separately prepared preparations

[0249] The pretreatment agent according to the invention described above is the ready-to-use pretreatment agent (V), which, in the form in which it is present, can be applied directly to the keratin fibers or hair. As previously described, the pretreatment agent is characterized by its content of at least one oxidizing agent (V-1) and particularly preferably by its content of a combination of carbamide peroxide (V-1) and at least one persulfate (V-2) from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate, and sodium peroxodisulfate. In principle, both oxidizing agents from groups (V-1) and (V-2) can be formulated together in one agent and made available to the user in this form.However, for reasons of storage stability, it has proven particularly preferable if the carbamide peroxide (V-1) and the persulfates (V-2) are packaged in separate products, so that the user has to mix these two products together shortly before use and in this way prepare the ready-to-use pretreatment product (V).

[0250] A method according to the invention comprising the following steps is therefore particularly preferred:

[0251] (1) Providing a first agent containing carbamide peroxide

[0252] (2) Providing a second agent which contains one or more peroxodisulfates from the group consisting of potassium peroxodisulfate, ammonium peroxodisulfate and sodium peroxodisulfate,

[0253] (3) Mixing the first and second agents to produce a ready-to-use pretreatment agent (V),

[0254] (4) Applying the pretreatment agent (V) prepared in step (3) to the keratin fibers,

[0255] (5) allowing the pretreatment agent (V) applied in step (4) to act on the keratin fibres for a period of 2 to 45 minutes, preferably from 2 to 30 minutes and particularly preferably from 2 to 20 minutes,

[0256] (6) Rinsing the pretreatment agent (V) with water, and

[0257] (7) Applying the colorant (F) to the keratin fibers.

[0258] The first agent, which contains carbamide peroxide (V-1), is particularly preferably a liquid or flowable agent, most preferably a gel, containing the previously described solvents and / or polyalkylene glycols. The second agent, which contains the peroxodisulfate(s) (V-2), is particularly preferably solid or paste-like.

[0259] The previously described embodiments and preferred or particularly preferred embodiments apply to the sequence of process steps.

[0260] In a further preferred embodiment, a process according to the invention is characterized in that there is a period of maximum 24 hours, preferably maximum 12 hours, more preferably maximum 6 hours and most preferably maximum 3 hours between the application of the pretreatment agent (V) and the application of the colorant (F).

[0261] Applying the colorant as a rinse-off or leave-on application. After applying the colorant, or after it has been applied and allowed to take effect, it can be rinsed out again in a subsequent step. Rinsing can be done with or without the aid of a shampoo or conditioner, for example.

[0262] Particularly good results were obtained, however, when the inventive coloring process was designed as a leave-on process. This means that in this case, the colorant (F) was not rinsed out immediately after application, but rather the hair was dried while still coated with the colorant (F). The drying of the keratin fibers can take place at room temperature or be assisted by an external heat source.

[0263] Heat treatment involves bringing the keratin material into contact with a heated device, or applying this heated device to or on the keratin material. Furthermore, the keratin material can also be exposed to warm / hot air for heat treatment. Devices such as a hairdryer, a blow dryer, a thermal cap, a flat iron, a curling iron, or an infrared lamp can be used.

[0264] It has been found that it is preferred if the treatment temperature during the heat treatment is between 40°C and 210°C, preferably from 50°C to 190°C, more preferably from 50°C to 170°C, even more preferably from 50°C to 150°C, and most preferably from 50°C to 100°C. In other words, it has proven particularly preferred if the heat treatment is carried out using a device that is heated to a temperature of 40°C to 210°C, preferably from 50°C to 190°C, more preferably from 50°C to 170°C, even more preferably from 50°C to 150°C, and most preferably from 50°C to 100°C.

[0265] In a particularly preferred embodiment, a method according to the invention is characterized in that the heat treatment is carried out using a device which is heated to a temperature of 40 °C to 210 °C, preferably from 50 °C to 190 °C, more preferably from 50 °C to 170 °C, even more preferably from 40 °C to 100 °C and most preferably from 40 °C to 80 °C.

[0266] Within the scope of a particularly preferred embodiment, a method according to the invention is characterized by drying the keratin fibers still coated with the colorant (F), preferably drying the keratin fibers still coated with the colorant (F) under the action of heat at a temperature of 40°C to 210°C, preferably from 40°C to 190°C, more preferably from 40°C to 170°C, even more preferably from 40°C to 100°C and most preferably from 40°C to 80°C. For example, the keratin material or the hair can be treated with a hairdryer that blows warm or hot air onto the keratin material. This air is particularly preferably 40 to 100°C or most preferably 40 AC to 80 °C. Alternatively, the keratin material or the hair is held under an infrared lamp, which is preferably set to a temperature of 40 to 100 °C. For heat treatment, hair can also be pressed between two appropriately heated plates of a straightening iron, with the plates simultaneously moving along the fiber. The straightening iron plates, for example, can be set to a temperature of up to 210 °C.

[0267] The duration of the heat treatment can be adapted to the selected temperature range. For example, a heat treatment can be carried out for a duration of 5 seconds to 60 minutes, preferably from 15 seconds to 45 minutes, more preferably from 15 seconds to 30 minutes, and most preferably from 15 seconds to 15 minutes.

[0268] Examples

[0269] 1 . Formulations

[0270] The following formulations were prepared (all data in wt.% unless otherwise stated):

[0271]

[0272] 2. Application to strands

[0273] The first ready-to-use pretreatment agent (V) was prepared by mixing 2 parts by weight of carbamide peroxide gel (agent (1-1)) and 1 part by weight of persulfate bleaching powder (agent (2)). This agent is referred to below as agent (V1).

[0274] The second ready-to-use pretreatment agent (V) was prepared by mixing 2 parts by weight of the aqueous hydrogen peroxide solution (agent (1-2)) and 1 part by weight of persulfate bleaching powder (agent (2)). This agent is referred to below as agent (V2).

[0275] The resulting ready-to-use pretreatment agent (V) was applied to strands of hair (Kerling). 4.0 g of pretreatment agent (V) per gram of hair was applied to the strands, massaged in, and left to work at room temperature for 30 minutes. The strands were then rinsed with water. The colorant (F) was then applied directly to the still-damp hair. 2.0 g of colorant (F) per gram of hair strand was massaged in and left to work for 1 minute. The strands, still coated with the colorant, were then dried with a standard hairdryer. The colored strands were visually assessed by a trained person under a daylight lamp.

[0276] Reference strands were treated directly with the respective colorant (F) without the use of the pretreatment agent (V). Before applying the colorant (F), the reference strand was moistened only with water, then the colorant was applied according to the procedure described above. These strands were also visually assessed by a trained person under a daylight lamp.

[0277] Following the coloring process, each colored strand underwent five manual hair washes. For each wash, the strand was moistened, then a commercially available shampoo (Schwarzkopf, Schauma 7 Kräuter) was massaged into the strand for 25 seconds (0.25 g of shampoo per gram of hair). The strand was then rinsed with lukewarm tap water for 30 seconds and dried.

[0278] After each hair wash, the respective strand was again visually assessed under the daylight lamp.

[0279] The hair strands were assessed for their color intensity using a scale from 1 (very low color intensity) to 5 (very high color intensity). The evenness of the coloring was also assessed using a scale from 1 (very uneven coloring) to 5 (very even coloring).

[0280] Comparison = staining without pretreatment

[0281] Invention = successive application of pretreatment agent (V-1) or (V-2) and dye (F) 0 HW = color result directly after dyeing

[0282] 5 = high intensity 1 = low intensity = very even coloring 1 = uneven coloring = high intensity 1 = low intensity = very even coloring 1 = uneven coloring The strands dyed with the process according to the invention (V1) / (F1), (V2) / (F1), (V1) / (F2) and (V2) / (F2) showed improved washfastness and a more even color result compared to the corresponding coloring without pretreatment (V).

[0283] 3. Measurement of hair damage

[0284] To measure the hair damage associated with pretreatment, the respective pretreatment agent (V1) or (V2) was applied to hair strands (Kerling). For this purpose, 4.0 g of pretreatment agent (V) per gram of hair was applied to the strands, massaged in, and left to act at room temperature for 30 minutes. The strands were then rinsed with water and dried.

[0285] The amount of cysteic acid present in the hair strand was then determined using quantitative NIR spectroscopy.

[0286] The spectra were recorded with an MPA™FT -NIR spectrometer from Bruker Optik GmbH. The infrared range covers the wavenumber range of 12500 cm -1 up to 4000 cm -1 and is characteristic of overtone and combination vibrations of, for example, CH, OH and NH groups.

[0287] The measurements were carried out using the integrating sphere module at six different sample positions in diffuse reflection. For the analysis of the measured NIR spectra, the wavenumber range of 7300 cm -1 up to 4020 cm -1 chosen.

[0288] The NIR spectra of cystine show in the wavenumber range of 6200 cm -1 up to 5500 cnr 1 characteristic absorption bands. If the hair changes due to more severe damage (ie the cysteic acid content in the hair increases), this affects the bands in the NIR spectrum that are characteristic of cysteic acid at 5020 cm -1 up to 4020 cm -1The quantitative analysis of the NIR spectra was carried out using computer-aided methods.

[0289] The NIR analysis value provides the amount of mol of cysteic acid per 100 mol of amino acid. The higher this cysteic acid value, the more severe the hair damage:

[0290] Pretreatment with pretreatment agent (V1) was associated with reduced hair damage compared to pretreatment with (V2).

Claims

Patent claims 1. A process for dyeing keratin fibers, in particular human hair, comprising the following steps: - application of a pretreatment agent (V) to the keratin fibers, wherein the pretreatment agent (V-1) contains at least one oxidizing agent, and - application of a coloring agent (F) to the keratin fibers, wherein the coloring agent is contained in a cosmetic carrier (F-1) at least one chitosan and / or a chitosan derivative, and (F-2) contains at least one pigment.

2. Process according to claim 1, characterized in that the pretreatment agent (V) contains one or more oxidizing agents (V-1) from the group consisting of carbamide peroxide, potassium peroxodisulfate, ammonium peroxodisulfate and sodium peroxodisulfate.

3. Method according to one of claims 1 to 2, characterized in that the pretreatment agent (V) - based on the total weight of the pretreatment agent (V) - contains (V-1) 1.0 to 30.0 wt.%, preferably 3.0 to 20.0 wt.%, more preferably 6.0 to 15.0 wt.% and most preferably 8.0 to 15.0 wt.% carbamid peroxide, and (V-2) one or more peroxodisulfates from the group consisting of ammonium peroxodisulfate, potassium peroxodisulfate and sodium peroxodisulfate in a total amount of 3.0 to 40.0 wt.%, preferably 3.0 to 30 wt.%, more preferably 6.0 to 20.0 wt.% and most preferably 9.0 to 17.0 wt.%.

4. Method according to one of claims 1 to 3, characterized in that the pretreatment agent (V) - based on the total weight of the pretreatment agent (V) - one or more solvents from the group consisting of glycerol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, ethanol, isopropanol, dipropylene glycol, diethylene glycol monoethyl ether, phenoxyethanol, benzyl alcohol, poly-Ci-Ce-alkylene glycols, dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate and glycerol carbonate in a total amount of 3.0 to 80% by weight, preferably 5.0 to 60.0% by weight, more preferably 9.0 to 40.0% by weight and most preferably 12.0 to 25.0% by weight.

5. Process according to one of claims 1 to 4, characterized in that the pretreatment agent (V) - based on the total weight of the pretreatment agent - contains one or more ethylene glycols of the formula (EG) in a total amount of 1.0 to 80.0 wt.%, preferably 1.5 to 60.0 wt.%, more preferably 3.0 to 40.0 wt.% and most preferably 4.5 to 10.0 wt.%, where x is an integer from 1 to 10,000, preferably an integer from 2 to 500, more preferably an integer from 3 to 100 and most preferably an integer from 5 to 30.

6. The method according to any one of claims 1 to 5, characterized in that the pretreatment agent (V) - based on the total weight of the pretreatment agent (V) - contains 5.0 to 70.0 wt.%, preferably 10.0 to 60.0 wt.%, more preferably 15.0 to 50.0 wt.% and most preferably 20.0 to 40.0 wt.% water.

7. The method according to any one of claims 1 to 6, characterized in that the colorant (F) contains at least one chitosan and / or one chitosan derivative (F-1) having a molecular weight of 20,000 to 800,000 g / mol, preferably of 50,000 to 600,000 g / mol, more preferably of 80,000 to 450,000 g / mol and most preferably of 100,000 to 300,000 g / mol.

8. The method according to any one of claims 1 to 7, characterized in that the colorant (F) - based on the total weight of the colorant (F) - contains one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 10.0 wt.%, preferably 0.2 to 8.0 wt.%, more preferably 0.5 to 6.0 wt.% and most preferably 0.7 to 2.0 wt.%.

9. The method according to any one of claims 1 to 8, characterized in that the colorant (F) contains at least one inorganic pigment (F-2), which is preferably selected from the group of colored metal oxides, metal hydroxides, metal oxide hydrates, silicates, metal sulfides, complex metal cyanides, metal sulfates, bronze pigments and / or colored pigments based on mica or mica, which are coated with at least one metal oxide and / or one metal oxychloride.

10. The method according to any one of claims 1 to 9, characterized in that the colorant (F) contains at least one organic pigment (F-2), which is preferably selected from the group consisting of carmine, quinacridone, phthalocyanine, sorghum, blue pigments with the color index numbers CI 42090, CI 69800, CI 69825, CI 73000, CI 74100, CI 74160, yellow pigments with the color index numbers CI 11680, CI 11710, CI 15985, CI 19140, CI 20040, CI 21100, CI 21108, CI 47000, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, CI 74260, orange pigments with the color index Numbers CI 11725, CI 15510, CI 45370, CI 71105, red pigments with the Color Index numbers CI 12085, CI 12120, CI 12370, CI 12420, CI 12490, CI 14700, CI 15525, CI 15580, CI 15620, CI 15630, CI 15800, CI 15850, CI 15865, CI 15880, CI 17200, CI 26100, CI 45380, CI 45410, CI 58000, CI 73360, CI 73915 and / or CI 75470.

11. Process according to one of claims 1 to 10, characterized in that the colorant (F) contains at least one pigment (F-2) selected from the group of pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

12. The method according to any one of claims 1 to 11, characterized in that the colorant (F) - based on the total weight of the colorant - contains one or more pigments (F-2) in a total amount of 0.01 to 10.0 wt.%, preferably 0.1 to 5.0 wt.%, more preferably 0.2 to 2.5 wt.% and most preferably 0.25 to 1.5 wt.%.

13. Method according to one of claims 1 to 12, comprising the following steps: (1) Providing a first agent containing carbamide peroxide (2) Providing a second agent which contains one or more peroxodisulfates from the group consisting of potassium peroxodisulfate, ammonium peroxodisulfate and sodium peroxodisulfate, (3) Mixing the first and second agents to produce a ready-to-use pretreatment agent (V), (4) Applying the pretreatment agent (V) prepared in step (3) to the keratin fibers, (5) allowing the pretreatment agent (V) applied in step (4) to act on the keratin fibres for a period of 2 to 45 minutes, preferably from 2 to 30 minutes and particularly preferably from 2 to 20 minutes, (6) Rinsing the pretreatment agent (V) with water, and (7) Applying the colorant (F) to the keratin fibers.

14. The method according to any one of claims 1 to 13, characterized in that between the application of the pretreatment agent (V) and the application of the colorant (F) there is a period of maximum 24 hours, preferably of maximum 12 hours, more preferably of maximum 6 hours and most preferably of maximum 3 hours.

15. The method according to any one of claims 1 to 14, characterized by drying the keratin fibers still coated with the colorant (F), preferably drying the hair still coated with the colorant (F), under the action of heat at a temperature of 40 °C to 210 °C, preferably from 40 °C to 190 °C, more preferably from 40 °C to 170 °C, even more preferably from 40 °C to 100 °C and most preferably from 40 °C to 80 °C.

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