Agent for treating keratin fibers, in particular human hair, containing at least one chitosan derivative obtained by reacting organic carboxylic acids with chitosan

Abstract

The present invention relates to an agent (M) for treating keratin fibers, in particular human hair, containing (M-1) at least one chitosan derivative, which comprises at least one structural unit of general formula (I), where R1 represents a saturated or unsaturated, linear or branched C2-C25 alkyl group, a saturated or unsaturated, linear or branched hydroxy C1-C21 alkyl group, an aryl C1-C6 alkyl group or a heteroaryl C1-C6 alkyl group.

Description

[0001] Henkel AG & Co. KGaA

[0002] 2024P00257WO

[0003] A preparation for treating keratinous fibers, especially human hair, containing at least one chitosan derivative obtained by reacting organic carboxylic acids with chitosan.

[0004] The present application relates to a cosmetic agent for treating keratinous fibers, in particular human hair, containing at least one chitosan derivative comprising at least one structural unit of general formula (I). The chitosan derivatives are obtained by reacting chitosan with at least one organic carboxylic acid.

[0005] Altering the shape and color of keratinous material, especially human hair, is an important area of ​​modern cosmetics. Depending on the desired color, professionals are familiar with various dyeing systems for changing hair color. For permanent, intense colorations with good colorfastness and gray coverage, oxidative dyes are typically used. These dyes contain oxidative dye precursors, so-called developer components and coupler components, which react with oxidizing agents such as hydrogen peroxide to form the actual dyes. Oxidative dyes are characterized by very long-lasting color results.

[0006] When using direct dyes, pre-formed pigments diffuse from the dye into the hair fiber. Compared to oxidative hair coloring, dyes produced with direct dyes are less durable and wash out more quickly. Dyes made with direct dyes typically remain on the hair for between 5 and 20 washes.

[0007] The use of color pigments is well-known for temporary color changes to hair and / or skin. Color pigments are generally understood to be insoluble, coloring substances. These are present in the coloring formulation in the form of small particles and are simply deposited on the hair fibers and / or skin surface. Therefore, they can usually be removed completely after a few washes with surfactant-containing cleansers. Various products of this type are available on the market under the name "hair mascara."

[0008] Dyeing with pigments offers several significant advantages. Since the pigments adhere only to the keratin material, particularly the hair fibers, unwanted colors can be removed quickly, easily, and completely, allowing users to return to their original hair color immediately and effortlessly. This makes the dyeing process especially attractive for consumers who don't want to regularly dye their hair.

[0009] Despite these many advantages, the pigment-based dyeing system still has some disadvantages, which stem from the limited penetration depth of the pigments into the keratinous material. Since the pigments do not diffuse into the keratin fiber but merely deposit on the outside of the fiber in the form of a coating or film, the wash fastness of dyes produced with this system still needs improvement. Various studies have attempted to bind the pigment(s) more permanently to the hair surface using film-forming materials, mostly polymers.

[0010] For example, German patent DE 19847883 A1 addresses the creation of pigment-based colorations using dyes containing at least one chitosan and one pigment. The combination of pigments with chitosan is intended to improve the abrasion resistance of the colorations. The major advantage of chitosan as a film-forming material lies in its biopolymer base, which offers improved environmental compatibility and biodegradability. As many users show increasing interest in products made with sustainable or renewable raw materials, the use of biopolymers is gaining prominence. Nevertheless, colorations achieved with pigment and chitosan still have drawbacks regarding their wash fastness. There remains a significant need for dyeing systems that utilize pigments and natural polymers to create the colorations and that have been further improved in terms of durability and wash fastness.

[0011] The objective of the present application was therefore to find a pigment-based dyeing process that would allow for intense colorations with improved wash fastness.

[0012] Surprisingly, it has now been found that this task can be solved if a dye containing a chitosan derivative is used for coloring, the amino group or amino groups of which are located in the C2 position of the D-glucosamine unit have been derivatized by reaction with an organic carboxylic acid.

[0013] A first object of the present invention is a means (M) for treating keratinous fibers, in particular human hair, comprising

[0014] (M-1) at least one chitosan derivative comprising at least one structural unit of general formula (I)

[0015] where

[0016] R1 represents a saturated or unsaturated, linear or branched C2-C25 alkyl group, a saturated or unsaturated, linear or branched hydroxy-Ci-C2i alkyl group, an aryl-Ci-Ce alkyl group, or a heteroaryl-Ci-Cs alkyl group.

[0017] The chitosan derivative(s) (M-1) formed a very stable film on the hair, which, due to the longer-chain alkyl or arylalkyl units bonded to the nitrogen atom, was more hydrophobic than non-derivatized chitosan and thus many times more resistant to washing. Such products have proven to be very suitable for styling hair as well as for shaping and / or styling. Particularly good results were observed when the product was formulated as a dye and contained at least one coloring compound in addition to the chitosan derivative(s) (M-1).

[0018] It was found that a dye containing at least one chitosan derivative (M-1) and a colorant (M-2) is able to color hair with the same intensity as a dye containing non-derivatized chitosan. Surprisingly, the wash fastness of the dyes was significantly improved with such a dye.

[0019] Keratinous fibers

[0020] Keratinous fibers include hair, wool, and fur. Human hair is particularly often considered a keratinous fiber.

[0021] Agents for the treatment of keratinous fibers

[0022] The term "agent for treating keratin fibers" is used in the application for all treatment methods in which the aim is to form a film that is as stable as possible on the keratin fibers. The agents according to the invention are also referred to as agents (M). These can be, for example, styling agents in which the film, due to its durability, lasts through several hair washes, thus achieving a particularly long-lasting styling effect. Agents for temporarily shaping the keratin fibers, agents for maintaining curls, and smoothing agents also fall into this category.

[0023] The treatment of keratin fibers according to the invention is particularly preferably a coloring process in which the agent contains, in addition to the chitosan derivative(s) (M-1), at least one coloring compound (M-2). The coloring compounds used are particularly preferably those dyes that adhere to the surface of the keratin fibers from the outside and are thus incorporated into the film formed by the chitosan derivative. These coloring compounds are therefore particularly preferably selected from the group consisting of pigments and / or direct dyes, and most preferably from the group consisting of pigments.

[0024] When the substance (M) is used as a dye, it can also be referred to as dye (F). The components (M-1), (M-2), (M-3), (M-4) and (M-5) described in more detail below can then also be referred to as components (F-1), (F-2), (F-3), (F-4) and (F-5).

[0025] Chitosans (M-1) on average (M)

[0026] As an essential component, the agent (M) according to the invention contains at least one chitosan derivative (M-1) comprising at least one structural unit of the general formula (I). where

[0027] R1 represents a saturated or unsaturated, linear or branched C2-C25 alkyl group, a saturated or unsaturated, linear or branched hydroxy-Ci-C2i alkyl group, an aryl-Ci-Ce alkyl group, or a heteroaryl-Ci-Cs alkyl group.

[0028] In the chitosan derivatives (M-1), chitosan is used as the starting material and reacted with at least one organic acid. The acids used in the reaction are C3-C26 alkyl carboxylic acids, hydroxy C2-C22 alkyl carboxylic acids, aryl C2-Cα alkyl carboxylic acids, and / or heteroaryl C2-C7 alkyl carboxylic acids. In this reaction, the amino group located at the C2 position of the D-glucosamine ring unit reacts with the carboxyl group of the organic acid to form an amide.

[0029] Chitosan, also known as polyglucosamine or poly-D-glucosamine, is used as a starting material in the synthesis of the chitosan derivative (M-1). It is a naturally occurring biopolymer derived from chitin, which is composed of β-1,4-glycosidically linked N-acetylglucosamine residues (specifically, 2-acetamido-2-deoxy-β-D-glucopyranose residues). Like chitin, it is a polyaminosaccharide. Chitosan is produced by deacetylating chitin, resulting in a molecule consisting of approximately 2000 linearly linked 2-amino-2-deoxy-β-D-glucopyranose or glucosamine monomers. Chitosan has the CAS number 9012-76-4.

[0030] Chitosan is preferably produced from chitin, which is found in shellfish or crustaceans. Industrially, chitosan is obtained from chitin through deacetylation. This can be achieved, for example, using (hot) sodium hydroxide or enzymatically. Both processes are used industrially, but the alkaline method is clearly the most prevalent in terms of volume.

[0031] The degree of deacetylation can vary considerably: Deacetylation can be complete or partial, resulting in a distribution of strongly deacetylated areas alongside weakly deacetylated areas, or a homogeneous deacetylation distribution. Simultaneously, this chemical intervention can decrease the polymer chain length (depolymerization). The molecular weight of chitosan can be distributed over a wide range, for example, from 20,000 to approximately 5 million g / mol.

[0032] Theoretically, complete deacetylation of chitosan gives it a structure of the formula (Chitosan-I) (Chitosan-I) where n is determined by the molecular weight of the chitosan and is preferably an integer from 1 to 10,000, more preferably from 10 to 5,000, and most particularly preferably from 50 to 3,000. Partially deacetylated chitosans have an idealized structure of the formula (Chitosan-II).

[0033] (Chitosan-ll) where the remainder R stands for a grouping COCH3.

[0034] The index number n is again determined by the molecular weight of the chitosan and preferably represents an integer from 1 to 10,000, more preferably from 10 to 5,000 and most particularly preferably from 50 to 3,000.

[0035] The structure of the formula (Chitosan-II) is intended to illustrate that chitosan comprises both D-glucosamine units and N-acetyl-D-glucosamine units. The structure is idealized; that is, in partially deacetylated chitosan, the deacetylated and acetylated units do not necessarily have to alternate strictly. Therefore, a D-glucosamine unit does not always have to be directly adjacent to an N-acetyl-D-glucosamine unit. In partially deacetylated chitosan, for example, several D-glucosamine units can follow one another until one or more N-acetylglucosamine units are attached.

[0036] The chitosan derivative (M1) comprises at least one structural unit of formula (I).

[0037] Since the chitosan derivative (M-1) according to the invention is a polymer, it preferably comprises several structural units of formula (I), particularly preferably at least 3, more preferably at least 5, and most preferably at least 10 structural units of formula (I). The number of structural units of formula (I) in the chitosan derivative (M-1) can be adjusted by the molar ratio in which chitosan and the organic carboxylic acids R1-COOH are reacted together.

[0038] The structural unit of formula (I) represents an N-acyl-glucosamine unit. The dashed line extending from the oxygen atom at position 1 represents the bonding site to the carbon atom of the adjacent N-acyl-glucosamine unit or glucosamine unit to the right. This bond is formed via a β-1,4-glycosidic linkage. If the structural unit of formula (I) is located at the right end of the chitosan derivative polymer chain, the dashed line extending from the oxygen atom at position 1 can also lead to a hydrogen atom.

[0039] The dashed line extending from the carbon atom at position 4 in formula (I) represents the bonding site to the oxygen atom at position 1 of the N-acyl-glucosamine unit or glucosamine unit to its left. If the structural unit of formula (I) is located at the left end of the polymer chain of the chitosan derivative, the dashed line extending from the carbon atom at position 4 can also lead to a hydroxyl group.

[0040] The residue R1 represents a saturated or unsaturated, linear or branched C2-C25 alkyl group, a saturated or unsaturated, linear or branched hydroxy-Ci-C2i alkyl group, an aryl-Ci-Ce alkyl group, or a heteroaryl-Ci-Cs alkyl group.

[0041] Examples of a saturated, linear C2-C25 alkyl group are the ethyl group, the propyl group, the n-butyl group, the n-pentyl group, the n-hexyl group, the n-heptyl group, the n-octyl group, the n-nonyl group, the n-decyl group, the n-undecyl group, the n-dodecyl group, the n-undecyl group, the n-dodecyl group, the n-tridecyl group, the n-tetradecyl group, the n-pentadecyl group, the n-hexadecyl group, the n-heptadecyl group and the n-octadecyl group.

[0042] The C2-C25 alkyl group can also be monounsaturated.

[0043] Examples of a monounsaturated, linear C2-C25 alkyl group include ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexydecenyl, heptadecenyl, and octadecenyl. The double bonds can be located at different positions along the alkyl chain. With a chain length of four or more carbon atoms, the C4-C25 alkyl group can also be polyunsaturated.

[0044] Examples of a polyunsaturated, linear C4-C25 alkyl group include a butadienyl group, a pentadienyl group, a hexadienyl group, a heptadienyl group, an octadienyl group, a nonadienyl group, a decadienyl group, an undecadienyl group, a dodecydienyl group, a tridecadienyl group, a tetradecadienyl group, a pentadecadienyl group, a hexadecadienyl group, a heptadecydienyl group, and an octadecadienyl group. The double bonds can be located at different positions along the alkyl chain.

[0045] From a chain length of 3 carbon atoms, the R1 group can also represent a saturated, branched C3-C25 alkyl group. Examples include the isopropyl group, the methylpropyl group, the ethylpropyl group, the methylbutyl group, the ethylbutyl group, the methylpentyl group, the ethylpentyl group, the methylhexyl group, the ethylhexyl group, the methylheptyl group, the ethylheptyl group, the methyloctyl group, and the ethyloctyl group. The alkyl groups (in this case, the methyl and ethyl groups) that represent the branches can be located at different positions along the alkyl chain.

[0046] Examples of suitable hydroxy-Ci-Ce alkyl groups include the 2-hydroxyethyl group, the 3-hydroxypropyl group, and the 2-hydroxypropyl group.

[0047] Examples of saturated, linear hydroxy-Ci-C2i alkyl groups include the hydroxymethyl group, the hydroxyethyl group, the hydroxypropyl group, the hydroxybutyl group, the hydroxypentyl group, the hydroxyhexyl group, the hydroxyheptyl group, the hydroxyoctyl group, the hydroxynonyl group, the hydroxyoxydecyl group, the hydroxyundecyl group, the hydroxydodecyl group, the hydroxytridecyl group, the hydroxytetradecyl group, the hydroxypentadecyl group, the hydroxyhexadecyl group, the hydroxyheptadecyl group, and the hydroxyoctadecyl group. The hydroxy group can be located at various positions along the alkyl chain.

[0048] The R1 group can also represent an aryl-Ci-Ce alkyl group or a heteroaryl-Ci-Cs alkyl group. Examples include a phenylmethyl group, a phenylethyl group, a phenylpropyl group, and a phenylbutyl group.

[0049] Particularly good improvements in wash fastness were obtained when at least one chitosan derivative (M-1) was used in the agent (M) for the treatment of the keratin fibers, comprising at least one structural unit of formula (I), where R1 represents a saturated linear C5-C23 alkyl group, preferably a saturated linear Cg-C2i alkyl group, more preferably a saturated linear Cn-C2i alkyl group, and most preferably a saturated linear C-Cig alkyl group.

[0050] In a particularly preferred embodiment, a composition according to the invention is characterized in that it contains at least one chitosan derivative (M-1) wherein

[0051] R1 represents a saturated linear C5-C23 alkyl group, preferably a saturated linear C9-C2i alkyl group, more preferably a saturated linear Cn-C2i alkyl group and most preferably a saturated linear Ci3-Ci9 alkyl group.

[0052] In a particularly preferred embodiment, a means according to the invention is characterized in that it contains at least one chitosan derivative (M-1) comprising at least one structural unit of the general formula (I), wherein

[0053] R1 represents a saturated linear C5-C23 alkyl group, preferably a saturated linear C9-C2i alkyl group, more preferably a saturated linear Cn-C2i alkyl group and most preferably a saturated linear Ci3-Ci9 alkyl group.

[0054] The most preferred substituent is R1, which represents a saturated, linear C-alkyl group.

[0055] Production of chitosan derivatives (M-1)

[0056] The chitosan derivative (M-1) is produced by reacting chitosan with an organic carboxylic acid R1-COOH.

[0057] The residue R1 here represents the same substituents that it also represents in the structural unit of formula (1), i.e. R1 represents a saturated or unsaturated, linear or branched C2-C25 alkyl group, a saturated or unsaturated, linear or branched hydroxy-Ci-C2i alkyl group, an aryl-Ci-Ce alkyl group or a heteroaryl-Ci-Cs alkyl group.

[0058] Examples of the aforementioned groups and preferred and especially preferred structural units, for which the remainder R1 stands, have already been mentioned.

[0059] The reaction of the acid R1-COOH with chitosan derives the amino group located at the 2-position of a glucosamine unit of the chitosan and converts it into the corresponding amide. Preferably, several amino groups at the 2-position of the glucosamine units are converted into the corresponding amides by this reaction.

[0060] This reaction can be carried out, for example, in a solvent such as water, ethanol, or a mixture of water and ethanol. The amide formation from the amino group of chitosane and the carboxyl group of acid R1-COOH can also be performed in the presence of reactive agents such as dicyclohexylcarbodiimide or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide. The aforementioned carbodiimides are known, for example, to enable amide formation under very mild conditions.

[0061] In a further preferred embodiment, a composition (M) according to the invention is characterized in that it contains at least one chitosan derivative (M-1) obtained by reaction of chitosan with an acid R1-COOH, wherein

[0062] R1 represents a saturated or unsaturated, linear or branched C2-C25 alkyl group, a saturated or unsaturated, linear or branched hydroxy-Ci-C2i alkyl group, an aryl-Ci-Ce alkyl group, or a heteroaryl-Ci-Cs alkyl group.

[0063] R1 particularly favorably represents a saturated or unsaturated, linear or branched C2-C25 alkyl group. The corresponding acid, R1-COOH, is therefore a saturated or unsaturated, linear or branched C3-C26 alkylcarboxylic acid.

[0064] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains at least one chitosan derivative (M-1) obtained by reaction of chitosan with a saturated or unsaturated, linear or branched C3-C26 alkylcarboxylic acid.

[0065] Particularly suitable acids include, for example, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid and octadecanoic acid.

[0066] Tetradecanoic acid, hexadecanoic acid and octadecanoic acid are particularly preferred.

[0067] The most preferred form is octadecanoic acid, which is also known as stearic acid and has the CAS number 57-11-4.

[0068] In the conversion to the chitosan derivative (M-1), a chitosan with a specific molecular weight is preferably used. For example, a chitosan with a molecular weight of 20,000 to 800,000 g / mol is very suitable, 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.

[0069] Accordingly, the chitosan derivative (M-1) also has a molecular weight of this order of magnitude. In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains at least one chitosan derivative (M-1) having 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.

[0070] Chitosan with a molecular weight of 100,000 to 300,000 g / mol can be purchased commercially, for example, from the company Sigma Aldrich. This can be derivatized as described in the example.

[0071] A chitosan with a lower molecular weight of 10,000 to 30,000 g / mol (or Daltons) is, for example, commercially available in pharmaceutical purity from BioLog Heppe (Kraeber). The degree of deacetylation of this chitosan is 88–95%.

[0072] Chitosan 027 is a suitable, commercially available, high-molecular-weight chitosan from the company Polymar, which has a molecular weight of 100,000 - 2,000,000 g / mol.

[0073] Furthermore, it has proven particularly advantageous if the dye according to the invention contains the chitosan derivative(s) (M-1) in certain quantity ranges. Particularly good results were obtained when the agent (M) – based on the total weight of the agent (M) – contained one or more chitosan derivatives (M-1) in a total amount of 0.01 to 20.0 wt.%, preferably 0.1 to 8.0 wt.%, more preferably 0.2 to 4.0 wt.%, and most preferably 0.3 to 2.0 wt.%.

[0074] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains – based on the total weight of the composition (M) – one or more chitosan derivatives (M-1) in a total amount of 0.01 to 20.0 wt.%, preferably 0.1 to 8.0 wt.%, more preferably 0.2 to 4.0 wt.%, and most preferably 0.3 to 2.0 wt.%. Coloring compounds (M-2) in the composition

[0075] As already described, the composition (M) according to the invention is in particular a composition for dyeing keratinous fibers. As a dyeing agent (F), the composition in particular additionally contains at least one coloring compound (M-2).

[0076] The colorant compound(s) are deposited on the surface of the keratin fibers and incorporated into the film formed by the chitosan derivative(s) (M-1). The films thus formed exhibit improved resistance to treatments with water and shampooing, so that the dyes obtained in this way are also characterized by improved wash fastness.

[0077] In a further particularly preferred embodiment, a means according to the invention is characterized in that it is a means for dyeing the keratinous fibers, which contains at least one coloring compound (M-2) which is preferably selected from the group of pigments and direct dyes, and most preferably selected from the group of pigments.

[0078] In a particularly preferred embodiment, the composition (M) according to the invention contains at least one pigment as the coloring compound (M-2). For the purposes of this invention, pigments are understood to be coloring 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, by the method described below: 0.5 g of the pigment is weighed into a beaker. A magnetic 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 potentially finely dispersed pigment, the mixture is filtered. If a proportion of undissolved pigment remains on the filter paper, the pigment's solubility is below 0.5 g / L.

[0079] Suitable color pigments can be of inorganic and / or organic origin.

[0080] In a preferred embodiment, a means (M) according to the invention is characterized in that it contains at least one color-imparting compound (F-2) from the group of inorganic and / or organic pigments.

[0081] Inorganic pigments generally have a higher refractive index than organic pigments, therefore scattering a greater proportion of light and offering greater opacity. When particularly opaque colorations are desired, the use of one or more inorganic pigments has proven especially advantageous.

[0082] Preferred color pigments are selected from synthetic or natural inorganic pigments. Inorganic color pigments of natural origin can be produced, for example, from chalk, ochre, umber, green earth, burnt sienna, or graphite. Furthermore, black pigments such as iron oxide black, colored pigments such as ultramarine or iron oxide red, as well as fluorescent or phosphorescent pigments can be used as inorganic color pigments.

[0083] 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. Especially 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), ultramarine (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), iron blue (ferric ferrocyanide, CI 77510) and / or carmine (cochineal).

[0084] Colored pearlescent pigments are also particularly preferred according to the invention. These are typically mica- and / or micaceous and can be coated with one or more metal oxides. Mica belongs to the layered silicates. The most important representatives of these silicates are muscovite, phlogopite, paragonite, biotite, lepidolite, and margarite. To produce the pearlescent pigments in combination with metal oxides, the mica, predominantly muscovite or phlogopite, is coated with a metal oxide.

[0085] As an alternative to natural mica, synthetic mica coated with one or more metal oxides can also be used as a pearlescent pigment. Particularly favored 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 changing the thickness of the metal oxide layer(s).

[0086] In a further preferred embodiment, a method according to the invention is characterized in that the agent (M) contains at least inorganic pigment (M-2), which is preferably selected from the group consisting 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 micaceous oxide, which are coated with at least one metal oxide and / or one metal oxychloride.

[0087] In a further preferred embodiment, a composition (M) according to the invention is characterized in that it contains at least one pigment selected from mica- or micaceous-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), ultramarine (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). Examples of particularly suitable color pigments are available commercially 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.

[0088] Please be sure to drink the color pigments with the Handelsbezeichnung Colorona® and beispielsweise:

[0089] Colorona Copper, Merck, MICA, CI 77491 (IRON OXIDES)

[0090] Colorona Passion Orange, Merck, Mica, CI 77491 (Iron Oxides), Alumina

[0091] Colorona Patina Silver, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0092] Colorona RY, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 75470 (CARMINE)

[0093] Colorona Oriental Beige, Merck, MICA, CI 77891 (TITANIUM DIOXIDE), CI 77491 (IRON OXIDES) Colorona Dark Blue, Merck, MICA, TITANIUM DIOXIDE, FERRIC FERROCYANIDE

[0094] Colorona Chameleon, Merck, CI 77491 (IRON OXIDES), MICA

[0095] Colorona Aborigine Amber, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0096] Colorona Blackstar Blue, Merck, CI 77499 (IRON OXIDES), MICA

[0097] Colorona Patagonian Purple, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE), CI 77510 (FERRIC FERROCYANIDE)

[0098] Colorona Red Brown, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0099] Colorona Russet, Merck, CI 77491 (TITANIUM DIOXIDE), MICA, CI 77891 (IRON OXIDES)

[0100] Colorona Imperial Red, Merck, MICA, TITANIUM DIOXIDE (CI 77891), D&C RED NO. 30 (CI 73360)

[0101] Colorona Majestic Green, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 77288 (CHROMIUM OXIDE GREENS)

[0102] Colorona Light Blue, Merck, MICA, TITANIUM DIOXIDE (CI 77891), FERRIC FERROCYANIDE (Cl 77510)

[0103] Colorona Red Gold, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0104] Colorona Gold Plus MP 25, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), IRON OXIDES (Cl 77491)

[0105] Colorona Carmine Red, Merck, MICA, TITANIUM DIOXIDE, CARMINE

[0106] Colorona Blackstar Green, Merck, MICA, Cl 77499 (IRON OXIDES)

[0107] Colorona Bordeaux, Merck, MICA, Cl 77491 (IRON OXIDES)

[0108] Colorona Bronze, Merck, MICA, Cl 77491 (IRON OXIDES)

[0109] Colorona Bronze Fine, Merck, MICA, Cl 77491 (IRON OXIDES)

[0110] Colorona Fine Gold MP 20, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0111] Colorona Sienna Fine, Merck, Cl 77491 (IRON OXIDES), MICA

[0112] Colorona Sienna, Merck, MICA, Cl 77491 (IRON OXIDES) Colorona Precious Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Silica, Cl 77491 (Iron oxides), Tin oxide

[0113] Colorona Sun Gold Sparkle MP 29, Merck, MICA, TITANIUM DIOXIDE, IRON OXIDES, MICA, Cl 77891 , Cl 77491 (EU)

[0114] Colorona Mica Black, Merck, Cl 77499 (Iron oxides), Mica, Cl 77891 (Titanium dioxide) Colorona Bright Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Cl 77491 (Iron oxides) Colorona Blackstar Gold, Merck, MICA, Cl 77499 (IRON OXIDES)

[0115] Other particularly preferred color pigments with the trade name Xirona® include, for example:

[0116] Xirona Golden Sky, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0117] Xirona Caribbean Blue, Merck, Mica, CI 77891 (Titanium Dioxide), Silica, Tin Oxide

[0118] Xirona Kiwi Rose, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0119] Xirona Magic Mauve, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide.

[0120] In addition, particularly preferred color pigments with the trade name Unipure® include, for example:

[0121] Unipure Red LC 381 EM, Sensient CI 77491 (Iron Oxides), Silica

[0122] Unipure Black LC 989 EM, Sensient, CI 77499 (Iron Oxides), Silica

[0123] Unipure Yellow LC 182 EM, Sensient, CI 77492 (Iron Oxides), Silica

[0124] In a further embodiment, the agent (M) according to the invention can also contain one or more organic pigments. Organic pigments typically do not have as good an opacity as inorganic pigments, but are often more brilliant and produce particularly vibrant shades. Therefore, if the keratinous fibers are to be colored in particularly vibrant shades, the use of at least one organic pigment is especially preferred.

[0125] The organic pigments according to the invention are correspondingly insoluble organic dyes or color lakes, which may be selected, for example, from the group of nitroso, nitro-azo, xanthene, anthraquinone, isoindolinone, isoindolin, quinacridone, perinone, perylene, diketopyrrolopyorrole, indigo, thioindido, dioxazine, and / or triarylmethane compounds.

[0126] Particularly suitable organic pigments include, 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 11725, CI 15510, CI 45370, CI 71105, and red pigments. with the color index numbers Cl 12085, Cl 12120, Cl 12370, Cl 12420, Cl 12490, Cl 14700, Cl 15525, Cl 15580, Cl 15620, Cl 15630, Cl 15800, Cl 15850, Cl 15865, Cl 15880, Cl 17200, Cl 26100, Cl 45380, Cl 45410, Cl 58000, Cl 73360, Cl 73915 and / or Cl 75470.

[0127] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains at least one organic pigment (M-2) 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, and 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.

[0128] The organic pigment can also be a paint lake. For the purposes of the invention, the term "paint lake" refers to particles comprising a layer of absorbed dyes, wherein the particle-dye unit is insoluble under the aforementioned conditions. The particles can be, for example, inorganic substrates such as aluminum, silica, calcium borosilicate, calcium aluminum borosilicate, or even aluminum.

[0129] For example, alizarin lacquer can be used as a colored lacquer.

[0130] Due to their excellent light and temperature resistance, the use of the aforementioned pigments in the composition (M) is particularly preferred. Furthermore, it is preferred if the pigments used have a specific particle size. Therefore, according to the invention, it is advantageous if the at least one pigment has a mean particle size D50 of 1.0 to 50 pm, preferably of 5.0 to 45 pm, more preferably of 10 to 40 pm, and particularly of 14 to 30 pm. The mean particle size D50 can be determined, for example, using dynamic light scattering (DLS).

[0131] Pigments with a specific shape can also be used to color the keratin fibers. For example, a pigment based on a lamellar and / or a lenticular substrate platelet can be used. Furthermore, coloring based on a substrate platelet comprising a vacuum-metallized pigment is also possible. In another preferred embodiment, a composition according to the invention is characterized in that it contains at least one pigment selected from the group consisting of pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet, and vacuum-metallized pigments.

[0132] The substrate platelets of this type have an average thickness of at most 50 nm, preferably less than 30 nm, particularly 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, particularly preferably at least 5 nm, for example at least 10 nm. Preferred thickness ranges for 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. Preferably, each substrate platelet has as uniform a thickness as possible. Due to the small thickness of the substrate platelets, the pigment exhibits particularly high opacity.

[0133] The substrate platelets are preferably monolithic. In this context, monolithic means consisting of a single, closed unit without fractures, layering, or inclusions, although structural changes may occur within the substrate platelets. The substrate platelets are preferably homogeneous, meaning that no concentration gradient exists within the platelets. In particular, the substrate platelets are not layered and do not contain any particles or other distributed particles.

[0134] The size of the substrate platelet can be tailored to the specific application, particularly the desired effect on the keratinous material. Typically, the substrate platelets have a mean maximum diameter of approximately 2 to 200 pm, especially approximately 5 to 100 pm.

[0135] In a preferred embodiment, the aspect ratio, expressed as the ratio of the mean size to the mean thickness, is at least 80, preferably at least 200, more preferably at least 500, and particularly preferably more than 750. The mean size of the uncoated substrate platelets is defined as the d50 value of the uncoated substrate platelets. Unless otherwise specified, the d50 value was determined using a Sympatec Heios instrument with Quixel wet dispersion. For sample preparation, the sample to be tested was pre-dispersed in isopropanol for 3 minutes.

[0136] The substrate plates can be made from any material that can be formed into platelets. They can be of natural origin or synthetically produced. Materials from which the substrate plates can be made include, for example, metals and metal alloys, metal oxides, preferably aluminum oxide, inorganic compounds and minerals such as mica and (semi-)precious stones, as well as plastics. Preferably, the substrate plates are made of metal alloys.

[0137] Any metal suitable for metallic luster pigments can be used. Such metals include iron and steel, as well as all air- and water-resistant (semi-)metals such as platinum, zinc, chromium, molybdenum, and silicon, and their alloys such as aluminum bronzes and brass. Preferred metals are aluminum, copper, silver, and gold. Preferred substrate platelets are aluminum and brass platelets, with aluminum platelets being particularly preferred.

[0138] Platelet-shaped pigments adhere particularly flat to the fibers. When made of metal, they form a reflective surface that makes the keratin fibers shine exceptionally brightly.

[0139] Lamellar substrate platelets are characterized by an irregularly structured edge and are also referred to as "cornflakes" due to their appearance.

[0140] Due to their irregular structure, pigments based on lamellar substrate platelets produce a high proportion of scattered light. Furthermore, these pigments do not completely mask the existing color of a keratinous material, and effects similar to natural graying can be achieved.

[0141] Lenticular (lens-shaped) substrate platelets have a generally regular, rounded edge and are also referred to as "silver dollars" due to their appearance. Because of their regular structure, pigments based on lenticular substrate platelets have a high proportion of reflected light.

[0142] 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, ranging from 5 to 50 nm, and by a particularly smooth surface with increased reflectivity. Substrate platelets comprising a vacuum metallized pigment are also referred to as VMP substrate platelets within the scope of this application. Aluminum VMP substrate platelets can be obtained, for example, by releasing aluminum from metallized foils. The metal or metal alloy substrate platelets can be passivated, for example, by anodizing (oxide layer) or chromating.

[0143] Uncoated lamellar, lenticular and / or VPM substrate platelets, especially those made of metal or metal alloy, reflect the incident light to a high degree and produce a light-dark flop. These have proven particularly advantageous for use in dyes.

[0144] Suitable pigments based on a lamellar substrate platelet include, for example, the VISIONAIRE series pigments from Eckart.

[0145] Pigments based on a lenticular substrate platelet are available, for example, under the name Alegrace® Gorgeous from the company Schlenk Metallic Pigments GmbH.

[0146] 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.

[0147] The pigment(s) (M-2) are preferably used in specific quantity ranges in the average. Particularly good results were obtained when the compound (M) – based on the total weight of the compound (M) – contained one or more pigments (M-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.%.

[0148] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains - based on the total weight of the composition (M) - one or more pigments (M-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.%.

[0149] The product (M) may also contain one or more direct dyes as coloring compounds. Direct dyes are dyes that adhere directly to the hair and do not require an oxidative process to develop their color. Typical direct dyes are nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinones, triarylmethane dyes, or indophenols.

[0150] The direct-acting 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 to be considered pigments. Preferably, the direct-acting dyes according to the present invention have a solubility in water (760 mmHg) at 25 °C of more than 1.0 g / L.

[0151] However, it may be preferable if the agent (M) does not contain any direct dyes.

[0152] Direct-drawing dyes can be divided into anionic, cationic, and nonionic direct-drawing dyes.

[0153] Cationic direct dyes include Basic Blue 7, Basic Blue 26, HC Blue 16, Basic Violet 2 and 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.

[0154] Examples of nonionic direct-drawing dyes include nonionic nitro and quinone dyes and neutral azo dyes. Examples of nonionic direct-drawing dyes are those known by their international names, or...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.

[0155] Anionic direct-drawing dyes are also known as acid dyes. Acid dyes are defined as direct-drawing dyes that possess at least one carboxylic acid group (-COOH) and / or one sulfonic acid group (-SO3H). Depending on the pH, the rudimentary forms (-COOH, -SO3H) of the carboxylic acid or sulfonic acid groups exist in equilibrium with their deprotonated forms (-COO-, -SOs). The proportion of rudimentary forms increases with decreasing pH. When direct-drawing dyes are used in the form of their salts, the carboxylic acid or sulfonic acid groups exist 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 potassium salts.The acid 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 to be considered pigments. Preferably, the acid dyes according to the present invention have a solubility in water (760 mmHg) at 25 °C of more than 1.0 g / L.

[0156] Alkaline earth salts (such as calcium and magnesium salts) and aluminum salts of acid dyes often have lower solubility than the corresponding alkali 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-drawing dye.

[0157] A key characteristic of acid dyes is their ability to form anionic charges, with the carboxylic acid or sulfonic acid groups responsible for this typically being 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.

[0158] 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 (Brillantsäuregrün BS, C.l. 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 und / oder D&C Brown 1 .

[0159] The water solubility of anionic direct-acting dyes can be determined, for example, using the following method. Place 0.1 g of the anionic direct-acting dye into a beaker. Add a magnetic stir bar. Then add 100 ml of water. Heat this mixture to 25 °C on a magnetic stirrer while stirring. Stir for 60 minutes. Afterward, visually inspect the aqueous mixture. If undissolved dye remains, increase the amount of water—for example, in 10 ml increments. Continue adding water until the dye is completely dissolved. If the dye-water mixture cannot be visually assessed due to the high intensity of the dye, filter the mixture. If some undissolved dye remains on the filter paper, repeat the solubility test with a larger amount of water.If 0.1 g of the anionic direct-drawing dye dissolves in 100 ml of water at 25 °C, the solubility of the dye is 1.0 g / L.

[0160] 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).

[0161] Acid Yellow 3 is a mixture of the sodium salts of mono- and disulfonic acids of 2-(2-quinolyl)- 1 H-indene-1 ,3(2H)-dione and has a water solubility of 20 g / L (25 °C).

[0162] 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).

[0163] Acid Yellow 23 is the trisodium salt of 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-4-((4-sulfophenyl)azo)-1H-pyrazole-3-carboxylic acid and is readily soluble in water at 25 °C.

[0164] 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).

[0165] 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.%.

[0166] 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).

[0167] 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 given as greater than 10 g / L (25 °C).

[0168] 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). In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains – based on the total weight of the composition – one or more direct dyes (M-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%.

[0169] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains – based on the total weight of the composition – one or more coloring compounds (M-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.%. organic and / or inorganic acids (M-3)

[0170] As a further optional component, the agent (M) according to the invention may contain at least one organic and / or inorganic acid (M-3).

[0171] The use of one or more acids can lower the pH of the agent (M), thereby protonating the chitosan completely or partially, thus improving its solubility. Macroscopically, the protonation of chitosan in water is observed as swelling, from which, when the preferred or highly preferred pH is established, a particularly uniform and thin film is deposited on the keratin fibers, such as hair. It has been shown that the more uniformly the film forms on the hair, the better its durability. The formation of a particularly uniform film has also resulted in dyes with exceptionally good wash fastness. Furthermore, the presence of the acid(s) (M-3) in the dye also enables the chitosan to form a particularly thin film on the hair.Comparative studies have shown that a uniformly thin film has better resistance to external mechanical influences.

[0172] Particularly suitable organic acids include, for example, acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid, methyllactic acid, glucuronic acid, glycolic acid, pyruvic acid, 2-hydroxybutanoic acid, 2-hydroxypentanoic acid, gluconic acid, mandelic acid, phenyllactic acid, gluconic acid, galacturonic acid, aleuric acid, ribonic acid, fumaric acid; salts and mixtures thereof.

[0173] Formic acid and propanoic acid are also suitable acids (M-3).

[0174] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains at least one organic acid (M-3) from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid, methyllactic acid, glucuronic acid, glycolic acid, pyruvic acid, 2-hydroxybutanoic acid, 2-hydroxypentanoic acid, gluconic acid, mandelic acid, phenyllactic acid, gluconic acid, galacturonic acid, aleuric acid, ribonic acid, fumaric acid; salts and mixtures thereof, in particular acetic acid and / or a salt of acetic acid.

[0175] Acetic acid dissolves chitosan particularly well and leads to very thin and uniform films; therefore, a dye (F) containing acetic acid is particularly preferred.

[0176] In a further explicitly preferred embodiment, a means according to the invention is therefore characterized in that it contains acetic acid (M-3).

[0177] By using the acid(s) in suitable quantities, the pH of the dye can be adjusted to the desired pH range. Particularly thin and uniform films were obtained when the dye (M) was adjusted to a pH in the range of 2.0 to 7.5, preferably 3.0 to 7.0, more preferably 3.5 to 6.5, and most preferably 4.0 to 6.0.

[0178] In a further particularly preferred embodiment, a means according to the invention is therefore characterized in that it has a pH value of 2.0 to 7.5, preferably of 3.0 to 7.0, more preferably of 3.5 to 6.5 and most preferably of 4.0 to 6.0.

[0179] Furthermore, particularly good results were obtained when the composition (M) contained water and acids in a specific weight ratio. It proved especially advantageous to adjust the weight ratio of the water (M-4) to the acids (M-3) contained in the composition (M), i.e., the weight ratio (F-4) / (F-3), to a value of 1000 to 10, preferably 500 to 40, more preferably 200 to 60, and most preferably 150 to 85.

[0180] In a further particularly preferred embodiment, a composition according to the invention is therefore characterized in that the weight ratio of the water (M-4) contained in the composition (M) to the acids (M-3), i.e. the weight ratio (M-4) / (M-3), is in a value of 1000 to 10, preferably from 500 to 40, more preferably from 200 to 60 and most preferably from 150 to 85.

[0181] Average water content (M-4)

[0182] The chitosan derivative(s) (M-1) are particularly preferably incorporated into a cosmetic carrier. The cosmetic carrier is particularly preferably a mixture of organic solvents (M-5) and water (M-4). Ethanol is the most preferred organic solvent, so the cosmetic carrier is most preferably a mixture of ethanol and water.

[0183] Since the concentration of the organic solvent(s) is preferably chosen to be relatively high, it is advantageous to reduce the water content accordingly. The composition (M) therefore preferably contains 10 to 50 wt.%, more preferably 15 to 45 wt.%, further preferably 20 to 40 wt.%, and most preferably 25 to 35 wt.% water (M-4). The quantities of water given here are based on the total weight of the composition.

[0184] In a further particularly preferred embodiment, a means (M) according to the invention is characterized in that it contains - based on the total weight of the means (M) - 10 to 50 wt.%, preferably 15 to 45 wt.%, more preferably 20 to 40 wt.% and most preferably 25 to 35 wt.% water (M-4).

[0185] Solvent (M-5) on average (M)

[0186] Furthermore, it has also proven advantageous to add one or more solvents other than water to the agent (M). Suitable organic solvents include, for example, ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol, 1-hexanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, phenoxyethanol, benzyl alcohol, and / or polyethylene glycols.

[0187] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains at least one organic solvent (M-5) from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol, 1-hexanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, 1-butanol, phenoxyethanol, benzyl alcohol and / or polyethylene glycols.

[0188] Ethanol has the Cas number 64-17-5.

[0189] Isopropanol is also alternatively called 2-propanol and has the CAS number 67-63-0.

[0190] 1,2-Propylene glycol is also alternatively referred to as 1,2-propanediol and bears the CAS numbers 57-55-6 [(RS)-1,2-Dihydroxypropane], 4254-14-2 [(R)-1,2-Dihydroxypropane] and 4254-15-3 [(S)-1,2-Dihydroxypropane],

[0191] 1,3-Propanediol or 1,3-Dihydroxypropane has the CAS number 504-63-2.

[0192] Glycerin is also alternatively known as 1,2,3-propanetriol and has the CAS number 56-81-5. 1-Butanol can also be called n-butanol or butyl alcohol and has the CAS number 71-36-3.

[0193] Phenoxyethanol has the Cas number 122-99-6.

[0194] Benzyl alcohol is also known as phenylmethanol and bears the CAS number 100-51-6. Polyethylene glycols according to the present invention are polymers with the general formula C₂nH₄n+2O that are liquid at room temperature (25 °C). n +i. The repeating unit of the linearly structured polymer is (-CH2-CH2-O-), with a molar mass of approximately 44 g-mol. -1 Chemically, it is a polyether. Polyethylene glycols are therefore understood to be ethylene glycols of the formula (EG). where x represents an integer from 2 to 10000.

[0195] Particularly uniform and resistant colorations could be achieved when the agent (M) - based on the total weight of the agent (M) - contained one or more organic solvents (M-5) in a total amount of 40 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

[0196] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains - based on the total weight of the composition (M) - one or more organic solvents (M-5) in a total amount of 40 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

[0197] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that it contains - based on the total weight of the composition (M) - one or more organic solvents (M-5) from the group consisting of ethanol, 1-propanol and isopropanol in a total amount of 40 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

[0198] Explicitly and especially preferred is an agent (M) which contains - based on the total weight of the agent (M) - 40 to 95 wt.%, preferably 50 to 90 wt.%, further preferably 55 to 85 wt.% and most preferably 60 to 80 wt.% ethanol (M-5).

[0199] Average proportion of components (M-1), (M-2), (M-3), (M-4) and (M-5) (M)

[0200] During the work leading to this invention, microscopic images were taken which showed that a thin, uniform film on the keratin fibers possesses particularly good resistance to external influences such as mechanical friction or hair washing. The smoother and more continuous the film, the less surface area it offers to external forces. Once the film is broken in one place, it can be completely removed very quickly by the constant movement of the keratin fibers.

[0201] It was found that the films produced with the agent (M) or with the dye (F) were particularly thin, uniform, and stable when the dye consisted largely of components (M-1), (M-2), (M-3), (M-4), and (M-5). It is suspected that other components could disrupt the uniformity of the film because they could become embedded in the film, weaken it at that point, or create a point of attack for external forces. For this reason, it is especially preferred that components (M-1), (M-2), (M-3), (M-4), and (M-5) are present together in the dye (F) in a proportion of at least 90.0 wt.%, preferably at least 93 wt.%, more preferably at least 96 wt.%, and most preferably at least 99 wt.%.

[0202] If components (M-1), (M-2), (M-3), (M-4) and (M-5) together constitute at least 90.0 wt.% in the mixture (M), then the mixture (M) consists – based on its total weight – of at least 90 wt.% of components (M-1), (M-2), (M-3), (M-4) and (M-5). In other words, in this case, other substances or ingredients different from (M-1) to (M-5) are present in the dye (F) only in a maximum wt.%, but preferably in even smaller proportions.

[0203] In a further particularly preferred embodiment, a composition (M) according to the invention is characterized in that the components (M-1), (M-2), (M-3), (M-4) and (M-5) are together contained in the composition (M) in a quantity of at least 90.0 wt.%, preferably at least 93 wt.%, more preferably at least 96 wt.% and most preferably at least 99 wt.%.

[0204] Methods for dyeing keratinous fibers

[0205] The agent (M) is used in processes for treating keratinous fibers, especially human hair. It is particularly well-suited as a dye.

[0206] A second subject matter of the present application is therefore a method for treating keratinous fibers, in particular human hair, in which an agent (M), which has already been disclosed in detail in the description of the first subject matter of the invention, is applied to the keratinous fibers and optionally rinsed off after an exposure time.

[0207] Particularly preferably, the second object of the present invention is a method for dyeing keratinous fibers, especially human hair, in which the agent (M), which has already been disclosed in detail in the description of the first object of the invention, is applied to the keratinous fibers and optionally rinsed off after an exposure time.

[0208] The dye can be applied to the keratin fibers, for example, with a gloved hand or using a brush or applicator. After application, the dye can be spread over the keratin fibers and, if necessary, gently massaged in.

[0209] In one embodiment, the agent is rinsed off using a rinse-off method and, after a contact time, is rinsed off with water or with water and the aid of shampoo. Suitable contact times are, for example, 5 to 60 minutes, preferably 5 to 45 minutes, more preferably 5 to 30 minutes, and most preferably 5 to 15 minutes.

[0210] The uniformity of the color and its wash fastness were particularly outstanding when the product was applied as a "leave-on" treatment. In this case, the product was not rinsed off; instead, the keratin fibers still coated with the product were dried. Drying of the keratin fibers can be carried out at room temperature in the open air, or the fibers still coated with the product can be heated to accelerate the drying process.

[0211] A method for treating keratinous fibers, especially human hair, is therefore particularly preferred, comprising

[0212] - the application of an agent, as disclosed in detail in the description of the first subject matter of the invention, to the keratinous fibers, and

[0213] - the drying of the keratinous fibers covered with the agent (M), wherein the drying preferably takes place at a temperature of 40 °C to 210 °C, preferably from 40 °C to 190 °C, more preferably from 45 °C to 170 °C, even more preferably from 45 °C to 100 °C and most preferably from 45 °C to 70 °C.

[0214] Heating or heat treatment refers to the process of bringing the keratin fibers into contact with a heated device, or applying this heated device to or on the keratin fibers. Furthermore, the keratin material can also be exposed to warm / hot air for heat treatment. Examples of devices used include a hairdryer, a heat cap, a flat iron, a curling iron, or an infrared lamp.

[0215] In a particularly preferred embodiment, a method according to the invention is characterized by drying the keratinous fibers covered with the agent (M), wherein the drying preferably takes place at a temperature of 40 °C to 210 °C, more preferably from 40 °C to 190 °C, more preferably from 45 °C to 170 °C, even more preferably from 45 °C to 100 °C and most preferably from 45 °C to 70 °C.

[0216] The duration of the heat treatment can be adjusted to the selected temperature range. For example, 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.

[0217] In the process according to the invention, the keratin fibers can be completely subjected to heat treatment during drying, but the heat treatment of partial areas of the keratin fibers can also be included. Complete heat treatment of the keratin fibers is preferred, i.e., preferably all keratin fibers to which the dye (F) has also been applied are heat treated.

[0218] For example, the keratin fibers or hair can be treated with a hairdryer, possibly under combs or brushes, blowing warm or hot air onto the fibers. This air is particularly preferred at a temperature of 40 to 70 °C. Alternatively, the keratin material or hair can be held under an infrared lamp, preferably set to a temperature of 40 to 70 °C.

[0219] In a further particularly preferred embodiment, a method according to the invention is characterized in that the heat treatment is carried out by using a hairdryer, a hair dryer, a heat cap, a flat iron, a curling iron or an infrared lamp.

[0220] During heat treatment or heating, the keratin fibers can also be combed or brushed.

[0221] For example, if the hair is combed continuously or occasionally during blow-drying, the individual fibers can be separated particularly well from each other, and the feel of the dyed hair was particularly good and uncoated.

[0222] In a further particularly preferred embodiment, the method according to the invention is therefore characterized in that the keratin fibers or the hair are combed or brushed during the heat treatment.

[0223] Regarding the other preferred embodiments of the methods according to the invention, what has been said about the means according to the invention applies mutatis mutantis. Examples

[0224] 1. Synthesis of the reaction product (M-1) from chitosan and stearic acid

[0225] The amino group located at the C2 atom of chitosan was derivatized by amide formation with stearic acid. The reaction proceeded according to the following reaction scheme, where chitosan is idealized in this scheme:

[0226] 0.40 g of stearic acid and 2.1 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) were dissolved in 80 ml of ethanol. This mixture was dissolved in an ultrasonic bath for 15 minutes. The mixture was then stirred for one hour at 60 °C (300 rpm).

[0227] 1.0 g of chitosan (mW = 100,000–300,000 g / mol, Sigma Aldrich) was dissolved in 120 ml of water and heated to 60 °C. The mixture with stearic acid was added dropwise to the chitosan solution. This reaction mixture was stirred at 80 °C (300 rpm) for 4 hours and then allowed to cool to room temperature. To separate the byproducts, the mixture was dialyzed for 48 hours using a dialysis membrane (molecular weight 3.5 kDa, Spectrum Laboratories, Laguna Hills, CA) and against distilled water. The reaction mixture was then freeze-dried and washed with 100 ml of ethanol.

[0228] 2. Spectroscopic investigation of the reaction product (M-1)

[0229] The reaction product obtained in this way (M-1) was investigated by IR spectroscopy.

[0230] The IR spectra of the starting materials chitosan and stearic acid, as well as of the stearoyl-derivatized chitosan (M-1) at the nitrogen atom, are shown in Figure 1. The synthesis product (M-1) exhibited intense absorption bands at 1638 cm⁻¹ and 1565 cm⁻¹. These bands indicate the presence of a secondary amide (R-NH-R). The solid-state 13C CP-MAS NMR spectra of chitosan and the reaction product of chitosan are shown in Figure 2.

[0231] The NMR spectrum of the stearic acid-modified chitosane (B) showed significantly more signals in the high field than the reference spectrum of the unmodified chitosane (A).

[0232] This indicates an increase in CH2 and CH3 groups. The reason for this is the implemented alkyl chain of stearic acid.

[0233] 3. Solubility tests of chitosan, stearic acid and the reaction product (M-1) of chitosan and stearic acid

[0234] Solubility tests were performed to demonstrate that the stearic acid, which reacted with the amino groups of the chitosan, is not cleaved off once the modified chitosan is dissolved in acidic water for the color formulation. Three approaches were compared for this purpose:

[0235] - 0.18 g chitosan

[0236] - 0.252 g reaction product (M-1) of chitosan with stearic acid (SA chitosan)

[0237] - Mixture of 0.18 g chitosan and 0.072 g stearic acid (chitosan + SA)

[0238] For each reaction, the specified amount of chitosan was first dissolved in 5.7 g of deionized water with 0.12 g of acetic acid, stirring continuously at 60 °C for several hours. Then, 13.92 g of ethanol were added to this solution. These mixtures were documented with photographs. The photographs are shown in Figure 3.

[0239] The photos show that chitosan itself dissolves readily in the mixture of water and ethanol in the presence of acetic acid. The reaction product (M-1) of chitosan and stearic acid also dissolves very well under these reaction conditions. Both samples formed a slightly viscous, yellowish, clear liquid.

[0240] In contrast, the sample containing a mixture of chitosan and stearic acid showed solid components in the form of white particles. This solid formation is due to the insolubility of stearic acid in the mixture of acetic acid, water, and ethanol. Had the stearic acid been cleaved during the preparation of the dye with the reaction product (M-1), insoluble stearic acid fragments should also have been visible in the sample of reaction product (M-1, chitosan SA). Since these did not form, it can be assumed that the stearic acid is not cleaved when the reaction product (M-1) is incorporated into the formulation. The reaction product (M-1) is therefore formulation-stable.

[0241] 4. Production and application of dyes

[0242] The following dyes were produced. Unless otherwise stated, all values ​​are given as weight percent.

[0243] The dyes were applied to strands of hair (Kerling brand, Euronaturhaar white, 5 cm long). For this, 2.0 g of dye (F) per gram of hair strand was massaged in and left to act for 1 minute. The strands, still coated with dye, were then dried with a standard hairdryer. The dyed strands were visually assessed by a trained person under a daylight lamp.

[0244] The color intensity was assessed according to the school grading system (1 = very high color intensity; 6 = very low color intensity).

[0245] The color intensities of the hair strands dyed with formulations F1 and F2 were comparable.

[0246] 5. Measuring wash fastness

[0247] Following the coloring process described in point 4, each colored strand of hair (Kerling brand, Euronaturhaar white, 5 cm long) underwent five manual washes. For each wash, the strand was moistened, then a standard shampoo (Schwarzkopf, Schauma 7 Herbs) was massaged into the strand for 15 seconds (0.25 g of shampoo per gram of hair). The strand was then rinsed with lukewarm tap water for 30 seconds and dried.

[0248] After each hair wash, the respective strand was measured using colorimetric methods (measurement of the L*a*b* values ​​with Mach5 HD).

[0249] The AE value used to assess wash fastness is derived from the L*a*b* color measurement values ​​measured on the respective strand as follows:

[0250] AE = [ (Li - Lo) 2 + (ai - ao) 2 + (bi - bo) 2 ] 1 / 2

[0251] Lo, ao and bo = measured values ​​of the dyed, unwashed hair strand

[0252] Li, ai and bi = measured values ​​of the dyed and washed hair strand

[0253] A low AE value indicates a minimal color difference between dyed, unwashed hair and dyed, washed hair. In other words, the lower the specific AE value, the better the color stability of the dye.

[0254] Aa = Difference in a-values ​​before and after washing (color change in the red-green range) Ab = Difference in b-values ​​before and after washing (color change in the yellow-blue range) AL = Difference in L-values ​​before and after washing (change in brightness)

[0255] HW = Hair wash

[0256] Chitosan-SA = reaction product (M-1) of chitosan and stearic acid

[0257] All difference values, especially the Aa values ​​and the AE values, were greater in the hair dyed with F1 than in the strands dyed with the stearic acid-modified derivative of chitosan (formulation F2).

[0258] The hair dyed with F2 showed much better wash fastness than the hair dyed with F1.

Claims

Patent claims 1. Agent (M) for treating keratinous fibers, especially human hair, containing (M-1) at least one chitosan derivative comprising at least one structural unit of general formula (I) where R1 represents a saturated or unsaturated, linear or branched C2-C25 alkyl group, a saturated or unsaturated, linear or branched hydroxy-Ci-C2i alkyl group, an aryl-Ci-Ce alkyl group, or a heteroaryl-Ci-Cs alkyl group.

2. Composition (M) according to claim 1, characterized in that it contains at least one chitosan derivative (M-1) wherein R1 represents a saturated linear C5-C23 alkyl group, preferably a saturated linear C9-C2i alkyl group, more preferably a saturated linear Cn-C2i alkyl group and most preferably a saturated linear C-Cig alkyl group.

3. Composition (M) according to one of claims 1 to 2, characterized in that it contains at least one chitosan derivative (M-1) obtained by reaction of chitosan with a saturated or unsaturated, linear or branched C3-C26 alkylcarboxylic acid.

4. Composition (M) according to any one of claims 1 to 3, characterized in that it contains at least one chitosan derivative (M-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.

5. Composition (M) according to any one of claims 1 to 4, characterized in that it comprises - based on the total weight of the composition (M) - one or more chitosan derivatives (M-1) in a The total amount contains 0.01 to 20.0 wt.%, preferably 0.1 to 8.0 wt.%, more preferably 0.2 to 4.0 wt.% and most preferably 0.3 to 2.0 wt.%.

6. Composition (M) according to any one of claims 1 to 5, characterized in that it is a composition for dyeing the keratinous fibers, which contains at least one coloring compound (M-2) which is preferably selected from the group consisting of pigments and direct dyes, and most preferably selected from the group consisting of pigments.

7. Composition (M) according to one of claims 1 to 6, characterized in that it contains - based on the total weight of the composition - one or more coloring compounds (M-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.%.

8. Composition (M) according to any one of claims 1 to 7, characterized in that it contains at least one organic acid (M-3) from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid, methyllactic acid, glucuronic acid, glycolic acid, pyruvic acid, 2-hydroxybutanoic acid, 2-hydroxypentanoic acid, gluconic acid, mandelic acid, phenyllactic acid, gluconic acid, galacturonic acid, aleuric acid, ribonic acid, fumaric acid; salts and mixtures thereof, in particular acetic acid and / or a salt of acetic acid.

9. Composition (M) according to any one of claims 1 to 8, characterized in that it has a pH value of 2.0 to 7.5, preferably of 3.0 to 7.0, more preferably of 3.5 to 6.5 and most preferably of 4.0 to 6.

0.

10. Composition (M) according to any one of claims 1 to 9, characterized in that it contains - based on the total weight of the composition - 10 to 50 wt.%, preferably 15 to 45 wt.%, more preferably 20 to 40 wt.% and most preferably 25 to 35 wt.% water (M-4).

11. Composition (M) according to any one of claims 1 to 10, characterized in that it contains at least one organic solvent (M-5) from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol, 1-hexanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, 1-butanol, phenoxyethanol, benzyl alcohol and / or polyethylene glycols.

12. Composition (M) according to one of claims 1 to 11, characterized in that it contains - based on the total weight of the composition - one or more organic solvents (M-5) in a total amount of 40 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

13. Composition (M) according to any one of claims 1 to 12, characterized in that the components (M-1), (M-2), (M-3), (M-4) and (M-5) together are contained in the composition (M) in a quantity of at least 90.0 wt.%, preferably at least 93 wt.%, more preferably at least 96 wt.% and most preferably at least 99 wt.%.

14. Method for treating keratinous fibers, in particular human hair, in which an agent (M) according to one of claims 1 to 13 is applied to the keratinous fibers and optionally rinsed off after an exposure time.

15. Method according to claim 14, characterized by drying the keratinous fibers covered with the agent (M), wherein the drying preferably takes place at a temperature of 40 °C to 210 °C, preferably from 40 °C to 190 °C, more preferably from 45 °C to 170 °C, even more preferably from 45 °C to 100 °C and most preferably from 45 °C to 70 °C.

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