DE102023203836A1 - Solvent-free agent for dyeing keratin fibers, containing at least one chitosan and an organic coloring compound with acid group - Google Patents

Abstract

The present invention relates to an agent (F) for dyeing keratin fibers, in particular human hair, containing in a cosmetic carrier
(F-1) at least one chitosan and/or a chitosan derivative, and
(F-2) at least one organic coloring compound whose structure comprises at least one acid group, characterized in that the agent (F) is essentially free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol.

Description

The subject of the present application is a cosmetic agent for coloring keratin fibers, in particular human hair, which contains at least one chitosan and/or a chitosan derivative and at least one organic coloring compound whose structure comprises at least one acid group. The agent is further characterized in that it is essentially free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol.

A second subject matter of the present application is a method for dyeing keratin fibers, in particular human hair, in which the previously described dye is applied to the keratin fibers, allowed to act on the keratin fibers for a period of 1 to 60 minutes and then optionally rinsed out again.

Changing the shape and color of keratin material, especially human hair, is an important area of modern cosmetics. Depending on the coloring requirements, experts know of various coloring systems for changing hair color. Oxidation dyes are usually used for permanent, intensive coloring with good fastness properties and good gray coverage. Such dyes contain oxidation dye precursors, so-called developer components and coupler components, which form the actual dyes under the influence of oxidizing agents such as hydrogen peroxide. Oxidation dyes are characterized by very long-lasting coloring results.

When using direct dyes, the already fully formed dyes diffuse from the dye into the hair fiber. Compared to oxidative hair coloring, the colors obtained with direct dyes are less durable and wash out more quickly. Colors with direct dyes usually remain on the hair for a period of between 5 and 20 washes.

The use of color pigments is known for short-term color changes on the hair and/or skin. Color pigments are generally understood to be insoluble, color-giving substances. These are present undissolved in the form of small particles in the coloring formulation and are only deposited on the outside of the hair fibers and/or the surface of the skin. Therefore, they can usually be removed without residue by washing them a few times with detergents containing surfactants. Various products of this type are available on the market under the name hair mascara.

Coloring with pigments offers various significant advantages. Since the pigments only attach themselves to the keratin materials from the outside, especially to the hair fibers, 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 re-color their hair regularly.

In addition to these many advantages, the pigment-based coloring system still has some disadvantages, which are due to the low penetration depth of the pigments into the keratin material. Since the pigments do not diffuse into the keratin fiber, but are merely deposited in the form of a shell or film on the outside of the fiber, the washfastness of the colors produced with this system still needs to be improved. Various studies have attempted to bind the pigment(s) more permanently to the surface of the hair using film-forming materials, usually polymers.

For example, DE 19847883 A1 to create pigment-based colorings using colorants that contain at least one chitosan and one pigment. By combining the pigments with chitosan, the abrasion resistance of the colorings should be improved. The great 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 are showing increasing interest in products with sustainable or renewable raw materials, the use of biopolymers is increasingly coming into focus. Nevertheless, the colorings obtained with pigment and chitosan still have disadvantages in terms of their wash fastness. Achieving uniform colorings over the entire length of the hair cannot yet be described as optimal, as the durability of the films on different parts of the hair, especially at the roots and ends.

In further works published in JP2001089335 A described, hair was dyed with a combination of polysaccharides, chitosans and coloring compounds. In this case, the coloring compounds used were not pigments, but acid dyes. Acid dyes are usually used in combination with solvents to achieve a sufficiently high color intensity, as the solvents increase the penetration of the acid dyes into the hair fiber. However, acid dyes are also known to have a very strong skin coloring effect. In the presence of solvents, this skin coloring is often further intensified.

It was therefore the object of the present application to provide a dye which binds color-giving compounds to the surface of keratin fibers via a film and with which intensive colors with improved wash fastness can be achieved. The coloring should be carried out with the aid of biopolymers, and the keratin fibers or hair colored in this way should not feel coated or greasy, should have a well-groomed shine, and the bounce of the keratin fibers should not be negatively affected. At the same time, the dyes should have a reduced skin coloration.

Surprisingly, it has now been found that a solvent-free agent containing the combination of at least one chitosan (derivative) and an organic coloring compound with an acid group fully fulfills these tasks.

• (F-1) mindestens ein Chitosan und/oder ein Chitosanderivat, und
• (F-2) mindestens eine organische farbgebende Verbindung, deren Struktur mindestens eine Säuregruppe umfasst,

dadurch gekennzeichnet, dass das Mittel (F) im Wesentlichen frei ist von Lösungsmitteln aus der Gruppe aus Ethanol, Isopropanol, 1,2-Propylenglycol, 1,3-Propandiol, Glycerin, 1-Butanol, Phenoxyethanol und Benzylalkohol.A first subject of the present invention is an agent (F) for dyeing keratin fibers, in particular human hair, containing in a cosmetic carrier

• (F-1) at least one chitosan and/or a chitosan derivative, and
• (F-2) at least one organic coloring compound whose structure comprises at least one acid group,

characterized in that the agent (F) is essentially free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol.

Keatin fibers

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

dyeing agents

The term "coloring agent" is used in the context of this invention for the coloring of keratin fibers, in particular hair, caused by the use of pigments or relatively poorly soluble organic coloring compounds. In this coloring, the pigments or coloring 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).

The agent (F) or colorant (F) is characterized by its content of at least one chitosan and/or a chitosan derivative (F-1) and at least one organic coloring compound (F-2) whose structure comprises at least one acid group.

Furthermore, the colorant (F) is characterized in that it is essentially free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol.

Chitosans (F-1) in the dye (F)

As a first essential component, the agent (F) according to the invention contains at least one chitosan or a derivative of chitosan (F-1).

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

Chitosan is preferably produced from the chitin contained in shellfish or crustaceans. Chitosan is obtained technically from chitin by deacetylation. This can be done, for example, using (hot) sodium hydroxide solution or enzymatically. Both processes are used technically, but the alkaline procedure is clearly the most used in terms of quantity. The degree of the resulting deacetylation can vary: deacetylation can be complete or partial, which can result in a distribution of strongly deacetylated areas next to slightly deacetylated areas or a homogeneous deacetylation distribution. At the same time, this chemical intervention can reduce the chain length of the polymer (depolymerization). The molecular weight of chitosan can be distributed over a wide spectrum, for example from 20,000 to around 5 million g/mol.

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

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.

In a further very particularly preferred embodiment, an agent according to the invention is characterized in that it 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 from 50,000 to 600,000 g/mol, more preferably from 80,000 to 450,000 g/mol and very particularly preferably from 100,000 to 300,000 g/mol.

In a further very particularly preferred embodiment, an agent according to the invention is characterized in that it 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.

A chitosan with a lower molecular weight of 10,000 to 30,000 g/mol (or Dalton) is available in pharmaceutical purity from the company BioLog Heppe (Kraeber), for example. The degree of deacetylation of this chitosan is 88 - 95%.

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

Chitosan O27 is a suitable, commercially available, high molecular weight chitosan from Polymar, which has a molecular weight of 100,000 - 2,000,000 g/mol.

It has been found to be particularly advantageous if the colorant according to the invention contains the chitosans and/or chitosan derivatives (F-1) in certain quantity ranges. Particularly good results were obtained if 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 2.5 wt.%.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains - based on the total weight of the agent (F) - one or more chitosans and/or chitosan derivatives (F-1) 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 2.5 wt.%.

In a further particularly preferred embodiment, a colorant (F) according to the invention is characterized in that it contains - based on the total weight of the colorant (F) - 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 2.5 wt. %.

organic coloring compound with acid group (F-2) in the dye (F)

As a second essential component, the colorant (F) according to the invention contains at least one organic coloring compound with an acid group. In the context of the invention, an acid group is understood to mean in particular an organic coloring compound with at least one carboxylic acid group, at least one sulfonic acid group and/or at least one sulfate group. The carboxylic acid group, sulfonic acid group and/or the sulfate group can also be present in the form of their salt(s).

These coloring compounds can, for example, be organic pigments with an acid group, or organic pigments with a carboxylic acid group, sulfonic acid group, sulfate group and/or salts thereof.

In principle, direct dyes from the group of acid dyes can also be used as coloring compounds; these are anionic direct dyes that contain a carboxylic acid group, a sulfonic acid group, a sulfate group and/or a salt thereof.

• (F-1) mindestens ein Chitosan und/oder ein Chitosanderivat, und
• (F-2) mindestens eine organische farbgebende Verbindung, deren Struktur mindestens eine Carbonsäuregruppe, eine Sulfonsäuregruppe, eine Sulfatgruppe und/oder ein Salz hiervon umfasst,

dadurch gekennzeichnet, dass das Mittel (F) im Wesentlichen frei ist von Alkoholen aus der Gruppe aus Ethanol, Isopropanol, 1,2-Propylenglycol, 1,3-Propandiol, Glycerin, 1-Butanol, Phenoxyethanol und Benzylalkohol.In one embodiment, therefore, particularly preferred is an agent (F) for dyeing keratin fibers, in particular human hair, containing in a cosmetic carrier

• (F-1) at least one chitosan and/or a chitosan derivative, and
• (F-2) at least one organic coloring compound whose structure comprises at least one carboxylic acid group, one sulfonic acid group, one sulfate group and/or a salt thereof,

characterized in that the agent (F) is essentially free of alcohols from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol.

When using this dye, the coloring is achieved primarily by the color-giving compounds not diffusing into the keratin fiber, but depositing themselves on the surface of the fiber in a film formed from the chitosans.

The penetration of the dyes into the keratin fiber can be prevented primarily by the relatively poor solubility of the color-giving compounds.

For this reason, it has been found to be particularly preferred if an organic pigment is used as the organic coloring compound.

Pigments in the sense of the present invention are understood to mean 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, 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 are weighed in 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 pigment, which may be finely dispersed, the mixture is filtered. If a portion of undissolved pigments remains on the filter paper, the solubility of the pigment is below 0.5 g/L.

In a preferred embodiment, a colorant (F) according to the invention is characterized in that it contains, as organic coloring compound (F-2), at least one organic pigment which has a solubility in water at 25 °C of less than 0.5 g/L, preferably less than 0.1 g/L, even more preferably less than 0.05 g/L.

The organic pigments according to the invention are correspondingly insoluble, organic dyes or colored 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.

Particularly suitable organic pigments include carmine, the blue pigment with the color index numbers CI 42090, yellow pigments with the color index numbers CI 15985, CI 19140, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, orange pigments with the color index numbers CI 15510, CI 45370, red pigments with the color index numbers CI 14700, CI 15525, CI 15580, CI 15620, CI 15630, CI 15800, CI 15850, CI 15865, CI 15880 and/or CI 45410.

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains, as organic coloring compound (F-2), at least one organic pigment selected from the group consisting of carmine, the blue pigment with the color index number CI 42090, yellow pigments with the color index numbers CI 15985, CI 19140, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, orange pigments with the color index numbers CI 15510, CI 45370, red pigments with the color index numbers CI 14700, CI 15525, CI 15580, CI 15620, CI 15630, CI 15800, CI 15850, CI 15865, CI 15880 and CI 45410.

Unipure Red LC 3079, for example, is a monoazo pigment that is in the form of a calcium salt and is called calcium 3-hydroxy-4-[(4-methyl-2-sulfonatophenyl)azo]-2-naphthoate. Unipure Red LC 3079 has the CI number 15850. The pigment has both a carboxylic acid group and a sulfonic acid group and is practically insoluble in water.

Pigment Yellow 100 is a yellow organic pigment with the CI number 19140, which has two sulfonic acid groups and one carboxylic acid group and can exist in the form of its aluminum salt or trisodium salt. The aluminum salt of Pigment Yellow 100 is called 1H-pyrazole-3-carboxylic acid, 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-4-[(4-sulfophenyl)azo]-, aluminum complex and has the CAS number 12225-21-7. The pigment can be purchased commercially, for example, under the trade name Unipure Yellow LC 125 from the company Sensient. Pigment Yellow 100 is practically insoluble in water.

Due to their excellent light and temperature resistance, the use of the aforementioned pigments in the colorant (F) of the process according to the invention is very particularly preferred. It is also preferred if the pigments used have a certain particle size. It is therefore advantageous according to the invention if the at least one pigment has an average particle size D ₅₀ of 1.0 to 50 µm, preferably from 5.0 to 45 µm, preferably from 10 to 40 µm, in particular from 14 to 30 µm. The average particle size D ₅₀ can be determined, for example, using dynamic light scattering (DLS).

In principle, direct dyes from the group of acid dyes can also be used as organic coloring compounds with an acid group (F-2).

Direct dyes are dyes that are absorbed directly into the hair and do not require an oxidative process to form the color. Direct dyes are usually nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinones, triarylmethane dyes or indophenols. According to the invention, these dyes carry at least one acid group, in particular at least one carboxylic acid group, a sulfonic acid group, a sulfate group and/or a salt thereof.

Anionic direct dyes are also known as acid dyes. Acid dyes are direct dyes that have at least one carboxylic acid group (-COOH) and/or one sulfonic acid group (-SO ₃ H) and/or one sulfate group (-OSO ₃ H). Depending on the pH value, the protonated forms (-COOH, -SO ₃ H) of the carboxylic acid or sulfonic acid groups are in equilibrium with their deprotonated forms (-COO ^- , -SO ₃ ^- or -OSO ₃ ^- ). As the pH value decreases, the proportion of protonated forms increases. If direct dyes are used in the form of their salts, the carboxylic acid groups or sulfonic acid groups are 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.

The alkaline earth salts (such as calcium salts and magnesium salts) or aluminum salts of acid dyes often have a poorer 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 dye.

An essential feature of acid dyes is their ability to form anionic charges, whereby the carboxylic acid or sulfonic acid groups responsible for this are usually 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.

Examples of acid dyes that can be mentioned are: 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 (CI 18965), Acid Yellow 23 (COLIPA n° C 29, Covacap Jaune W 1100 (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, CI 15510, D&C Orange 4, COLIPA n° C015), Acid Orange 10 (C.I. 16230; Orange G sodium salt), Acid Orange 11 (CI 45370), Acid Orange 15 (CI 50120), Acid Orange 20 (CI 14600), Acid Orange 24 (BROWN 1;CI20170;KATSU201;nosodium salt;Brown No.201;RESORCIN BROWN;ACID ORANGE 24;Japan Brown 201;D & C Brown No.1), Acid Red 14 (C.I.14720), Acid Red 18 (E124, Red 18; CI 16255), Acid Red 27 (E 123, CI 16185, C-Red 46, Real Red D, FD&C Red No.2, Food Red 9, Naphthol Red S), Acid Red 33 (Red 33, Fuchsia Red, D&C Red 33, CI 17200), Acid Red 35 (CI C.I.18065) , Acid Red 51 (CI 45430, Pyrosin B, Tetraiodofluorescein, Eosin J, lodeosin), Acid Red 52 (CI 45100, Food Red 106, Solar Rhodamine B, Acid Rhodamine B, Red n° 106 Pontacyl Brilliant Pink), Acid Red 73 (CI CI 27290), Acid Red 87 (Eosin, CI 45380), Acid Red 92 (COLIPA n° C53, CI 45410), Acid Red 95 (CI 45425, Erythtosine,Simacid Erythrosine Y), Acid Red 184 (CI 15685), Acid Red 195, Acid Violet 43 (Jarocol Violet 43, Ext. D&C Violet n° 2, C.I. 60730, COLIPA n° C063), Acid Violet 49 (CI 42640), Acid Violet 50 (CI 50325), Acid Blue 1 (Patent Blue, CI 42045), Acid Blue 3 (Patent Blue V, CI 42051), Acid Blue 7 (CI 42080), Acid Blue 104 (CI 42735), Acid Blue 9 (E 133, Patent Blue AE, Amido Blue AE, Erioglaucine A, CI 42090, C.I. Food Blue 2), Acid Blue 62 (CI 62045), Acid Blue 74 ( E 132, CI 73015), Acid Blue 80 (CI 61585), Acid Green 3 (CI 42085, Foodgreen1), Acid Green 5 (CI 42095), Acid Green 9 (C.I.42100), Acid Green 22 (C.I.42170), Acid Green 25 (CI 61570, Japan Green 201, D&C Green No. 5), Acid Green 50 (brilliant acid green BS, C.I. 44090, Acid Brilliant Green BS, E 142), Acid Black 1 (Black n° 401, Naphthalene Black 10B, Amido Black 10B, CI 20 470, COLIPA n° B15), Acid Black 52 (CI 15711), Food Yellow 8 (CI 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 1st

In a further embodiment, an agent according to the invention is therefore characterized in that it contains, as organic coloring compound (F-2), at least one acid dye selected from the group consisting of Acid Yellow 1, Acid Yellow 3, Acid Yellow 9, Acid Yellow 17, Acid Yellow 23, Acid Yellow 36, Acid Yellow 121, Acid Orange 6, Acid Orange 7, Acid Orange 10, Acid Orange 11, Acid Orange 15, Acid Orange 20, Acid Orange 24, Acid Red 14, Acid Red 18, Acid Red 27, Acid Red 33, Acid Red 35, Acid Red 51, Acid Red 52, Acid Red 73, Acid Red 87, Acid Red 95, Acid Red 184, Acid Red 195, Acid Violet 43, Acid Violet 49, Acid Violet 50, Acid Blue 1, Acid Blue 3, Acid Blue 7, Acid Blue 104, Acid Blue 9, Acid Blue 62, Acid Blue 74, Acid Blue 80, Acid Green 3, Acid Green 5, Acid Green 9, Acid Green 22, Acid Green 25, Acid Green 50, Acid Black 1, Acid Black 52, Food Yellow 8, 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.

Since the alkaline earth metal salts (such as calcium salts and magnesium salts) or aluminum salts of acid dyes are less soluble than the corresponding alkali metal salts, an organic dye that is considered an acid dye in the form of its alkali metal salt can also be present in the form of a pigment if the counterion for the acid group(s) is not an alkali metal ion but an alkaline earth metal ion or an analogous, correspondingly more highly charged counterion. If the solubility of these salts is below 0.5 g/L (25 °C, 760 mmHg), the compounds do not fall under the definition of a direct dye.

As already described above, these acid dyes should not diffuse into the keratin fibers, but rather be embedded in the chitosan film on the surface of the keratin fibers. For this reason, acid dyes are particularly preferred, the solubility of which is so high that they can no longer be assigned to the group of organic pigments, but which nevertheless have relatively poor solubility.

For this reason, acid dyes which have a solubility in water at 25 °C of less than 20 g/L, preferably less than 18 g/L, even more preferably less than 15 g/L and most preferably less than 12 g/L are particularly preferably used as organic coloring compounds (F-2).

In a further very particularly preferred embodiment, an agent according to the invention is therefore characterized in that it contains, as organic coloring compound (F-2), at least one acid dye which has a solubility in water at 25 °C of less than 20 g/L, preferably less than 18 g/L, even more preferably less than 15 g/L and very particularly preferably less than 12 g/L.

The water solubility of the anionic direct dyes can be determined in the following way, for example. 0.1 g of the anionic direct 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 assessed visually. If there are still undissolved residues, the amount of water is increased - for example in steps of 10 ml. Water is added until the amount of dye used 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 with a higher 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.

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).

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).

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).

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

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

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

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).

Brilliant Blue FCF, alternatively also known as Food Blue 2 or Acid Blue 9, is called disodium salt disodium 2-[(Z)-{4-[ethyl(3-sulfonatobenzyl)amino]phenyl}{(4Z)-4-[ethyl(3-sulfonatobenzyl)iminio]-2,5-cyclohexadien-1-ylidene}methyl]benzenesulfonate and has the CAS number 3844-45-9. The disodium salt of Acid Blue 9 has a water solubility of more than 20 wt.% (25 °C).

Acid Blue 74 is alternatively known as indigo carmine, Food Blue 1 or FD&C Blue 2 and has the chemical name indigo-5,5'-disulfonic acid, disodium salt or disodium 5,5'-(2-(1,3-dihydro-3-oxo-2H-indazol-2-ylidene)-1,2-dihydro-3H-indol-3-one)disulfonate. Acid Blue 74 in the form of the disodium salt has a solubility in water of 10 g/L at 25 °C.

The coloring compound(s) (F-2) represent the second essential component of the coloring agent (F) according to the invention and are preferably used in the composition in certain quantity ranges. Particularly good results were obtained when the coloring agent (F) - based on the total weight of the coloring agent - contained one or more coloring compounds (F-2) in a total amount of 0.01 to 10.0% by weight, preferably 0.1 to 5.0% by weight, more preferably 0.2 to 2.5% by weight and very particularly preferably 0.25 to 1.5% by weight.

In a further very particularly preferred embodiment, an agent (F) according to the invention is characterized in that it contains - based on the total weight of the agent (F) - one or more organic coloring compounds (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 very particularly preferably 0.25 to 1.5 wt. %.

Solvent-free dye (F)

The agent according to the invention is characterized in that it is essentially free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol. This means that none of the solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol are intentionally added to the agent.

Some raw materials may contain one or more of the above solvents in small amounts as a minor component, so that when this raw material is to be used, marginal amounts of this solvent are introduced. However, it has been found that the presence of such small amounts of solvent does not unduly increase skin discoloration.

In summary, an agent which is essentially free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol is understood to mean an agent which - based on its total weight - contains the above-mentioned solvents in a total amount of less than 0.2% by weight, preferably less than 0.1% by weight, even more preferably less than 0.05% by weight and most preferably less than 0.01% by weight.

Most preferably, the colorant (F) is free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol, i.e. the agent contains these solvents in a total amount of 0% by weight.

organic and/or inorganic acids (F-3) in the dye

As an optional component, the agent according to the invention or the colorant (F) may contain at least one organic and/or inorganic acid (F-3).

By using one or more acids, the pH value of the dye (F) can be lowered, whereby the chitosan is fully or partially protonated and dissolves better. Macroscopically, the protonation of the chitosan in water is perceived as swelling, from which a particularly even and thin film is deposited on the keratin fibers such as hair when the preferred or particularly preferred pH value is set. It has been shown that the durability of the film is better the more even the film forms on the hair. By forming a particularly even film, dyes with particularly good wash fastness could also be obtained. In addition, the presence of the acid(s) (F-3) in the dye also means that the chitosan can form a particularly thin film on the hair. Comparative studies have shown that a uniformly thin film has better resistance to external mechanical influences.

Particularly suitable organic acids include acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid.

Formic acid and propanoic acid are also suitable as organic acids.

In a further particularly preferred embodiment, an agent according to the invention is therefore characterized in that it contains at least one organic acid (F-3), which is preferably selected from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid.

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

Within the scope of a further explicitly particularly preferred embodiment, an agent (F) according to the invention is therefore characterized in that it contains acetic acid (F-3).

By using the acid(s) in the appropriate amounts, the pH value of the dye can be adjusted to the desired pH range.

In this context, it has also proven particularly preferred to adjust the pH of the agent (F) to an acidic or low range of 1.0 to 6.0, preferably 1.1 to 5.0, more preferably 1.2 to 4.0, even more preferably 1.3 to 3.0 and most preferably 1.3 to 2.5. So that the pH of the agent (F) can be measured, the agent additionally contains water (F-4).

It is assumed that by lowering the pH value, the equilibrium reaction of the acid groups present on the coloring compounds (F-2) is shifted more towards the protonated acid, which further reduces the solubility of the acid dyes and allows the coloring compounds to integrate even better into the chitosan film. Therefore, the lower the pH value of the dye, the better the color absorption and wash fastness of the dyes. However, for reasons of skin compatibility, the pH value should not be lowered too much. In particular, the pH range from 1.3 to 2.5 produced very good dyeing results with acceptable skin compatibility.

In a further particularly preferred embodiment, an agent according to the invention is therefore characterized in that it contains water (F-4) and has a pH value of 1.0 to 6.0, preferably 1.1 to 5.0, more preferably 1.2 to 4.0, even more preferably 1.3 to 3.0 and most preferably 1.3 to 2.5.

pH values can be measured with a commercially available glass electrode at 22 °C.

Amount of components (F-1), (F-2), (F-3) and (F-4) in the dye

As part of the work leading to this invention, microscopic images were taken which showed that a thin, even film on the keratin fibers has a particularly good resistance to external influences such as mechanical friction or washing the hair. The smoother and more closed the film is, the less surface area it has to be attacked by external forces. Once the film has broken open in one place, it is completely detached very quickly due to the constant movement of the keratin fibers.

It was found that the films produced with the colorant (F) were particularly thin, uniform and stable when the colorant consisted to a large extent of the components (F-1), (F-2), (F-3) and (F-4). It is assumed that other components could disrupt the uniformity of the film because they could become embedded in the film, weaken the film at this point or form a surface for external forces to act on. For this reason, it is particularly preferred if the components (F-1), (F-2), (F-3) and (F-4) are contained together in the colorant (F) in a proportion of at least 90.0% by weight, preferably at least 93% by weight, more preferably at least 96% by weight and very particularly preferably at least 99% by weight.

If the components (F-1), (F-2), (F-3) and (F-4) are contained together in a proportion of at least 90.0% by weight in the colorant, then the colorant consists - based on its total weight - of at least 90% by weight of the components (F-1), (F-2), (F-3) and (F-4). In other words, in this case, other substances or ingredients that are different from (F-1) to (F-4) are only contained in the colorant (F) in a proportion of a maximum of 10% by weight, but preferably in even smaller proportions.

• (F-1) Chitosan und/oder Chitosanderivat,
• (F-2) organische farbgebende Verbindung mit Säuregruppe,
• (F-3) organische Säure, und
• (F-4) Wasser,

zusammen in einen Mengenanteil von mindestens 90,0 Gew.-%, bevorzugt von mindestens 93 Gew.-%, weiter bevorzugt von mindestens 96 Gew.-% und ganz besonders bevorzugt von mindestens 99 Gew.-% enthält.In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains the components

• (F-1) Chitosan and/or chitosan derivative,
• (F-2) organic coloring compound with acid group,
• (F-3) organic acid, and
• (F-4) Water,

together 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.%.

• (F-1) Chitosan,
• (F-2) organische farbgebende Verbindung mit Säuregruppe,
• (F-3) organische Säure, und
• (F-4) Wasser,

zusammen in einen Mengenanteil von mindestens 90,0 Gew.-%, bevorzugt von mindestens 93 Gew.-%, weiter bevorzugt von mindestens 96 Gew.-% und ganz besonders bevorzugt von mindestens 99 Gew.-% enthält.In a further particularly preferred embodiment, an agent according to the invention is characterized in that it contains the components

• (F-1) Chitosan,
• (F-2) organic coloring compound with acid group,
• (F-3) organic acid, and
• (F-4) Water,

together 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.%.

viscosity of the dye (F)

The work carried out within the scope of this application has shown that particularly thin films could be formed even when the agent or colorant (F) was inherently thin and spread quickly and with good spreading effect on the keratin material. It is therefore further preferred if the colorant (F) has a viscosity of 1 to 10,000 mPas, preferably 10 to 5,000 mPas, more preferably 10 to 3,000 mPas and very particularly preferably 10 to 2,000 mPas (22 °C / Brookfield viscometer / spindle 3 / 30 rpm = revolutions per minute).

In a further particularly preferred embodiment, an agent according to the invention is characterized in that it has a viscosity of 1 to 10,000 mPas, preferably 10 to 5,000 mPas, more preferably 10 to 3,000 mPas and very particularly preferably 10 to 2,000 mPas (22 °C / Brookfield viscometer / spindle 3 / 30 rpm).

Process for dyeing keratin fibers

The agent described above is intended to be used for coloring keratin fibers, especially hair.

A second subject matter of the present invention is therefore a method for dyeing keratin fibers, in particular human hair, in which an agent (F), as disclosed in detail in the description of the first subject matter of the invention, is applied to the keratin fibers, allowed to act on the keratin fibers for a period of 1 to 60 minutes, preferably 30 to 45 minutes, and then optionally rinsed out again.

In this context, it has been found to be particularly preferred to apply the dye (F) to the keratin fibers, leave it to act for a certain period of time and then rinse it off with water.

1. (1) Applizieren des Mittels (F) auf die keratinischen Fasern,
2. (2) Einwirken des in Schritt (1) applizierten Mittels (F) auf die keratinischen Fasern für einen Zeitraum von 2 bis 60 Minuten, bevorzugt von 2 bis 45 Minuten und besonders bevorzugt von 30 bis 45 Minuten, und
3. (3) Ausspülen des Mittels (F) mit Wasser.

Particularly preferred is therefore a method for dyeing keratin fibers, in particular human hair, comprising the following steps in the order given:

1. (1) Applying the agent (F) to the keratin fibers,
2. (2) allowing the agent (F) applied in step (1) to act on the keratin fibers for a period of 2 to 60 minutes, preferably 2 to 45 minutes and particularly preferably 30 to 45 minutes, and
3. (3) Rinse the agent (F) with water.

The action in step (2) can also be supported by increased temperatures, such as placing a cap or a heat cap on the hair covered with the dye (F). In this way, the hair covered with the cap can heat up to 40 to 50 °C, for example.

With regard to the further preferred embodiments of the method according to the invention, what has been said about the agent according to the invention applies mutatis mutantis.

examples

1. Formulations

The following dyes (F) were prepared (all data in wt.% unless otherwise stated): dye (F) F1 (wt.%) F2 (wt.%) F3 (wt.%) Chitosan (MW = 100,000 - 300,000 g/mol, Sigma Aldrich) 1.0 - 1.0 Unipure Red LC 3079 (Pigment Red 7, Cas No. 5281-04-9 (CI 15850) 1.0 1.0 - Acid Red 33 - - 1.0 acetic acid ad pH 2.0 ad pH 2.0 ad pH 2.0 water (distilled) ad 100 ad 100 ad 100 dye (F) F4 (wt.%) F5 (wt.%) F6 (wt.%) Chitosan (MW = 100,000 - 300,000 g/mol, Sigma Aldrich) 1.0 - 1.0 Indigo carmine (Acid Blue 74) (disodium salt) 1.0 1.0 - Acid Blue 9 (disodium salt) - - 1.0 acetic acid ad pH 2.0 ad pH 2.0 ad pH 2.0 water (distilled) ad 100 ad 100 ad 100 Dye (F) with pigment without acid group F7 (wt.%) F8 (wt.%) F9 (wt.%) Chitosan (MW = 100,000 - 300,000 g/mol, Sigma Aldrich) 2.0 2.0 2.0 Pigment Yellow 1 (CI 11680, CAS number 2512-29-0) 2-[(4-Methyl-2-nitrophenyl)-azo]-3-oxo-N-phenylbutyramide 0.4 0.4 0.4 acetic acid ad pH 1.4 ad pH 2.1 ad pH 3.3 water (distilled) ad 100 ad 100 ad 100 Dye (F) with pigment with acid group F10 (wt.%) F11 (wt.%) F12 (wt.%) Chitosan (MW = 100,000 - 300,000 g/mol, Sigma Aldrich) 2.0 2.0 2.0 Pigment Yellow 100 (Unipure Yellow LC 123, CI 19140, CAS number 12225-21-7, 1H-pyrazole-3-carboxylic acid, 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-4-[(4-sulfophenyl)azo]-, aluminum complex 0.4 0.4 0.4 acetic acid ad pH 1.4 ad pH 2.1 ad pH 3.3 water (distilled) ad 100 ad 100 ad 100

2. Application to strands

The dyes were applied to strands of hair (Kerling company). 4.0 g of dye (F) was massaged into each gram of hair strand and left to work for 35 minutes. The strands were then washed out with water and dried with a hairdryer.

3. Measurement of wash fastness

After coloring, each colored strand was subjected to ten 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 shampoo per gram of hair). The strand was then rinsed with lukewarm tap water for 30 seconds and dried. After each wash, the respective strand was again visually assessed under the daylight lamp.

The hair strands were assessed for their colour intensity using a scale from 1 (very low colour intensity) to 5 (very high colour intensity). An uncoloured hair strand was rated 0.

0 HW = Color result directly after coloring shade: red Number of washes (HW), color intensity 0 HW 10 HW F1, red Unipure Red LC 3079 + chitosan, pH 2 5 2 F2, red Unipure Red LC 3079, pH 2 4 0 F3, violet red Acid Red 33 + chitosan, pH 2 5 3 5 = high intensity 1 = low intensity 0 = uncolored shade: blue Number of washes (HW), color intensity 0 HW 10 HW F4, brewery blue Acid Blue 74 + chitosan, pH 2 4 2 F5, grey-blue Acid Blue 74, pH 2 3 1 F6, medium blue Acid Blue 9 + Chitosan, pH 2 4 0-1 5 = high intensity 1 = low intensity 0 = uncolored shade: yellow Number of washes (HW), color intensity 0 HW 10 HW F7 Pigment Yellow 1 + chitosan, pH 1.4 4 1 F8 Pigment Yellow 1, chitosan, pH 2.1 4 1 F9 Pigment Yellow 1, chitosan, pH 3.3 4 1 F10, Pigmen Yellow 100, chitosan, pH 1.4 5 5 F11 Pigment Yellow 100, chitosan, pH 2.1 5 5 F12 Pigment Yellow 100, chitosan, pH 3.3 4 2 5 = high intensity 1 = low intensity 0 = uncolored

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 19847883 A1 [0008]
• JP 2001089335 A [0009]

Claims (13)

Agent (F) for coloring keratin fibers, in particular human hair, containing in a cosmetic carrier (F-1) at least one chitosan and/or a chitosan derivative, and (F-2) at least one organic coloring compound whose structure comprises at least one acid group, characterized in that the agent (F) is essentially free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, phenoxyethanol and benzyl alcohol. means after claim 1 , characterized in that it 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 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. Remedy according to one of the Claims 1 until 2 , characterized in that it contains - based on the total weight of the agent (F) - one or more chitosans and/or chitosan derivatives (F-1) 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 2.5 wt.%. Remedy according to one of the Claims 1 until 3 , characterized in that it contains as organic coloring compound (F-2) at least one organic pigment which has a solubility in water at 25 °C of less than 0.5 g/L, preferably less than 0.1 g/L, even more preferably less than 0.05 g/L. Remedy according to one of the Claims 1 until 4 , characterized in that it contains as organic coloring compound (F-2) at least one organic pigment selected from the group consisting of carmine, a blue pigment with the color index numbers CI 42090, yellow pigments with the color index numbers CI 15985, CI 19140, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, orange pigments with the color index numbers CI 15510, CI 45370, red pigments with the color index numbers CI 14700, CI 15525, CI 15580, CI 15620, CI 15630, CI 15800, CI 15850, CI 15865, CI 15880 and CI 45410. Remedy according to one of the Claims 1 until 5 , characterized in that it contains, as the organic coloring compound (F-2), at least one acid dye selected from the group consisting of Acid Yellow 1, Acid Yellow 3, Acid Yellow 9, Acid Yellow 17, Acid Yellow 23, Acid Yellow 36, Acid Yellow 121, Acid Orange 6, Acid Orange 7, Acid Orange 10, Acid Orange 11, Acid Orange 15, Acid Orange 20, Acid Orange 24, Acid Red 14, Acid Red 18, Acid Red 27, Acid Red 33, Acid Red 35, Acid Red 51, Acid Red 52, Acid Red 73, Acid Red 87, Acid Red 95, Acid Red 184, Acid Red 195, Acid Violet 43, Acid Violet 49, Acid Violet 50, Acid Blue 1, Acid Blue 3, Acid Blue 7, Acid Blue 104, Acid Blue 9, Acid Blue 62, Acid Blue 74, Acid Blue 80, Acid Green 3, Acid Green 5, Acid Green 9, Acid Green 22, Acid Green 25, Acid Green 50, Acid Black 1, Acid Black 52, Food Yellow 8, 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. Remedy according to one of the Claims 1 until 6 , characterized in that it contains as organic coloring compound (F-2) at least one acid dye which has a solubility in water at 25 °C of less than 20 g/L, preferably less than 18 g/L, even more preferably less than 15 g/L and most preferably less than 12 g/L. Remedy according to one of the Claims 1 until 7 , characterized in that it contains - based on the total weight of the agent (F) - one or more organic coloring compounds (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. %. Remedy according to one of the Claims 1 until 8 , characterized in that it contains at least one organic acid (F-3), which is preferably selected from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid. Remedy according to one of the Claims 1 until 9 , characterized in that it contains water (F-4) and has a pH of 1.0 to 6.0, preferably 1.1 to 5.0, more preferably 1.2 to 4.0, even more preferably 1.3 to 3.0 and most preferably 1.3 to 2.5. Remedy according to one of the Claims 1 until 10 , characterized in that it contains the components (F-1) chitosan and/or chitosan derivative, (F-2) organic coloring compound with acid group, (F-3) organic acid, and (F-4) water, together 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.%. Remedy according to one of the Claims 1 until 11 , characterized in that it has a viscosity of 1 to 10 000 mPas, preferably 10 to 5 000 mPas, more preferably 10 to 3 000 mPas and most preferably 10 to 2 000 mPas (22 °C / Brookfield viscometer / spindle 3 / 30 rpm). Process for dyeing keratin fibres, in particular human hair, in which an agent (F) according to one of the Claims 1 until 12 applied to the keratin fibers, left to act on the keratin fibers for a period of 1 to 60 minutes, preferably 30 to 45 minutes, and then rinsed out if necessary.