Composition for dyeing keratin fibres, comprising at least one colouring compound, a chitosan, an organic acid and a fragrance

Abstract

The present invention relates to a composition for dyeing keratin fibres, more particularly human hair, comprising (F-1) at least one colouring compound from the group of pigments and direct dyes, and (F-2) at least one chitosan and / or a chitosan derivative, and (F-3) at least one organic acid and / or salt thereof, and (F-4) at least one fragrance.

Description

[0001] Henkel AG & Co. KGaA

[0002] 2024P00245WO

[0003] A dyeing agent for keratinous fibers, containing at least one coloring compound, a chitosan, an organic acid and a fragrance.

[0004] The subject of the present application is a dyeing agent for keratinous fibers, in particular human hair, which contains at least one coloring compound from the group consisting of pigments and direct dyes, at least one chitosan and / or chitosan derivative, at least one organic acid and / or its salt and at least one fragrance.

[0005] Another subject matter of the present application is a method for dyeing keratinous fibers, in particular human hair, in which the dye described above is applied to the keratinous fibers and, if necessary, rinsed off after an exposure time.

[0006] Altering the shape and color of keratin fibers, 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, oxidation dyes are typically used. These dyes contain oxidation dye precursors, so-called developer components and coupler components, which react with oxidizing agents such as hydrogen peroxide to form the actual dyes. Oxidation dyes are characterized by very long-lasting color results.

[0007] 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.

[0008] 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."

[0009] 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.

[0010] Despite these many advantages, the pigment-based dyeing system still has some disadvantages, stemming 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 outer surface of the fiber as 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.

[0011] For example, German patent DE 19847883 A1 deals with achieving pigment-based colorations using dyes containing at least one chitosan and one pigment. Combining the pigments with chitosan should improve the abrasion resistance of the colorations. The major advantage of chitosan as a film-forming material is that it is based on biopolymers and therefore 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 in importance. Nevertheless, the colorations obtained with pigment and chitosan still have room for improvement.

[0012] The coloring achieved through pigments (or direct dyes, especially poorly soluble direct dyes) and chitosan is a surface coloring, meaning that the applied coloring compounds do not diffuse into the hair, but are deposited on the hair surface and embedded there in a film by the chitosan applied at the same time.

[0013] It has been found that chitosan must be dissolved for application, which can be achieved by protonating the amino groups of the chitosan. For protonation to occur, the pH of the dye must be lowered, so the dye should contain at least one acid. Dissolving chitosan is particularly successful with organic acids, especially acetic acid. However, due to the presence of these acids, especially acetic acid, the dye has a stronger inherent odor, which may be perceived as unpleasant by the user.

[0014] The objective of the present application was therefore to find a dye based on pigments or direct dyes and chitosan that allows the use of strong-smelling organic acids, especially acetic acid, and reliably masks their inherent odor.

[0015] It has now been shown that this task can be solved if a dye is used to color the keratin fibers which contains one or more pigments and / or direct dyes, one or more chitosans and / or chitosan derivatives, as well as at least one organic acid (or its salt) and at least one fragrance.

[0016] A first object of the present invention is a means for dyeing keratinous fibers, in particular human hair, comprising

[0017] (F-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0018] (F-2) at least one chitosan and / or a chitosan derivative, and

[0019] (F-3) at least one organic acid and / or its salt, and

[0020] (F-4) at least one fragrance.

[0021] Hair dyed with one of these agents exhibited colorations with particularly high color intensity and had a pleasant, cosmetic, and inconspicuous odor.

[0022] During the dyeing process, the color-imparting compounds are deposited in a homogeneous, uniform, and smooth film on the surface of the keratin fibers. This film is formed by the chitosans, which have been previously dissolved uniformly by the organic acid, primarily acetic acid.

[0023] Keratinous fibers

[0024] Keratinous fibers include hair, wool, and fur. Human hair is particularly often considered a keratinous fiber.

[0025] dyeing agents

[0026] The term "coloring agent" is used in this invention to describe the coloring of keratin fibers, particularly hair, by the use of pigments and / or direct dyes. The agent can alternatively be referred to as a dye or coloring agent (F). During the coloring process, the coloring compounds are deposited in a homogeneous, uniform, and smooth film on the surface of the keratin fibers. This film is formed by the chitosans. Coloring compounds (F-1) in the dye

[0027] The dye according to the invention contains, as its first essential component (F-1), at least one coloring compound from the group consisting of pigments and direct dyes.

[0028] 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 pigment, which may be finely dispersed, the mixture is filtered.If a proportion of undissolved pigments remains on the filter paper, the solubility of the pigment is below 0.5 g / L.

[0029] In a particularly suitable embodiment, the dye contains at least one pigment. Suitable color pigments can be of inorganic and / or organic origin. Pigments with specific shapes and metallic pigments are also particularly well suited for use in the dye according to the invention.

[0030] In a particularly preferred embodiment, a dye according to the invention is characterized in that it contains at least one pigment (F-1) from the group consisting of inorganic pigments, organic pigments, pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

[0031] Preferred inorganic color pigments are selected from synthetic or natural sources. Naturally derived inorganic color pigments can be produced, for example, from chalk, ochre, umber, green earth, burnt sienna, or graphite. Other inorganic color pigments that can be used include black pigments such as iron oxide black, colored pigments such as ultramarine or iron oxide red, as well as fluorescent or phosphorescent pigments. Particularly suitable are colored metal oxides, hydroxides, and oxide hydrates, mixed-phase pigments, sulfur-containing silicates, silicates, metal sulfides, complex metal cyanides, metal sulfates, chromates, and / or molybdates.Particularly preferred color pigments are black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and brown iron oxide (CI 77491), manganese violet (CI 77742), ultramarine (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), iron blue (ferric ferrocyanide, CI 77510) and / or carmine (cochineal).

[0032] 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.

[0033] 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).

[0034] In a further preferred embodiment, a coloring agent according to the invention is characterized in that it contains at least one inorganic pigment, 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.

[0035] In a further preferred embodiment, a coloring agent 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).

[0036] 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. Particularly favored color pigments with the trade name Colorona® include, for example:

[0037] Colorona Copper, Merck, MICA, CI 77491 (IRON OXIDES)

[0038] Colorona Passion Orange, Merck, Mica, CI 77491 (Iron Oxides), Alumina

[0039] Colorona Patina Silver, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0040] Colorona RY, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 75470 (CARMINE)

[0041] Colorona Oriental Beige, Merck, MICA, CI 77891 (TITANIUM DIOXIDE), CI 77491 (IRON OXIDES)

[0042] Colorona Dark Blue, Merck, MICA, TITANIUM DIOXIDE, FERRIC FERROCYANIDE

[0043] Colorona Chameleon, Merck, CI 77491 (IRON OXIDES), MICA

[0044] Colorona Aborigine Amber, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0045] Colorona Blackstar Blue, Merck, CI 77499 (IRON OXIDES), MICA

[0046] Colorona Patagonian Purple, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM

[0047] DIOXIDE), CI 77510 (FERRIC FERROCYANIDE)

[0048] Colorona Red Brown, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0049] Colorona Russet, Merck, CI 77491 (TITANIUM DIOXIDE), MICA, CI 77891 (IRON OXIDES)

[0050] Colorona Imperial Red, Merck, MICA, TITANIUM DIOXIDE (CI 77891), D&C RED NO. 30 (CI 73360)

[0051] Colorona Majestic Green, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 77288 (CHROMIUM OXIDE GREENS)

[0052] Colorona Light Blue, Merck, MICA, TITANIUM DIOXIDE (CI 77891), FERRIC FERROCYANIDE (Cl 77510)

[0053] Colorona Red Gold, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0054] Colorona Gold Plus MP 25, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), IRON OXIDES (Cl 77491)

[0055] Colorona Carmine Red, Merck, MICA, TITANIUM DIOXIDE, CARMINE

[0056] Colorona Blackstar Green, Merck, MICA, Cl 77499 (IRON OXIDES)

[0057] Colorona Bordeaux, Merck, MICA, Cl 77491 (IRON OXIDES)

[0058] Colorona Bronze, Merck, MICA, Cl 77491 (IRON OXIDES)

[0059] Colorona Bronze Fine, Merck, MICA, Cl 77491 (IRON OXIDES)

[0060] Colorona Fine Gold MP 20, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0061] Colorona Sienna Fine, Merck, Cl 77491 (IRON OXIDES), MICA

[0062] Colorona Sienna, Merck, MICA, Cl 77491 (IRON OXIDES)

[0063] Colorona Precious Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Silica, Cl 77491 (Iron oxides), Tin oxide

[0064] Colorona Sun Gold Sparkle MP 29, Merck, MICA, TITANIUM DIOXIDE, IRON OXIDES, MICA, Cl 77891 , Cl 77491 (EU)

[0065] 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)

[0066] Colorona Blackstar Gold, Merck, MICA, Cl 77499 (IRON OXIDES)

[0067] Weiterhin besonders bevorzugte Farbpigmente mit der Handelsbezeichnung Xirona® sind beispielsweise:

[0068] Xirona Golden Sky, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0069] Xirona Caribbean Blue, Merck, Mica, CI 77891 (Titanium Dioxide), Silica, Tin Oxide

[0070] Xirona Kiwi Rose, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0071] Xirona Magic Mauve, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide.

[0072] In addition, particularly preferred color pigments with the trade name Unipure® include, for example:

[0073] Unipure Red LC 381 EM, Sensient CI 77491 (Iron Oxides), Silica

[0074] Unipure Black LC 989 EM, Sensient, CI 77499 (Iron Oxides), Silica

[0075] Unipure Yellow LC 182 EM, Sensient, CI 77492 (Iron Oxides), Silica

[0076] In a further embodiment, the dyes according to the invention can also contain one or more organic pigments (F-1).

[0077] 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.

[0078] 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 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.

[0079] In a further particularly preferred embodiment, a coloring agent according to the invention is characterized in that it contains at least one organic pigment, 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.

[0080] The organic pigment can also be a paint lake. For the purposes of this 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. These particles can be, for example, inorganic substrates such as aluminum, silica, calcium borosilicate, calcium aluminum borosilicate, or even aluminum itself.

[0081] For example, alizarin lacquer can be used as a colored lacquer.

[0082] Due to their excellent light and temperature resistance, the use of the aforementioned pigments in the dye of the process according to the invention 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).

[0083] Pigments with a specific shape can also be used to stain keratin fibers. For example, a pigment based on a lamellar and / or lenticular substrate platelet can be used. Furthermore, staining based on a substrate platelet containing a vacuum-metallized pigment is also possible.

[0084] In a further preferred embodiment, a means according to the invention is characterized in that it contains at least one pigment selected from the group of pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] The substrate plates can be made from any material that can be formed into platelet form.

[0090] They can be of natural origin or synthetically produced. Materials from which the substrate plates can be constructed 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 composed of metal (alloys).

[0091] 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.

[0092] Lamellar substrate platelets are characterized by an irregularly structured edge and are also referred to as "cornflakes" due to their appearance.

[0093] 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.

[0094] 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.

[0095] Vacuum metallized pigments (VMPs) can be obtained, for example, by releasing metals, metal alloys, or metal oxides from appropriately coated films. 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, for example, can be obtained by releasing aluminum from metallized films.

[0096] The substrate plates made of metal or metal alloy can be passivated, for example by anodizing (oxide layer) or chromating.

[0097] 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.

[0098] Suitable pigments based on a lamellar substrate platelet include, for example, the VISIONAIRE series pigments from Eckart.

[0099] Pigments based on a lenticular substrate platelet are available, for example, under the name Alegrace® Gorgeous from Schlenk Metallic Pigments GmbH. Pigments based on a substrate platelet containing a vacuum metallized pigment are available, for example, under the names Alegrace® Marvelous or Alegrace® Aurous from Schlenk Metallic Pigments GmbH.

[0100] Instead of or in addition to the pigment(s), the dyes according to the invention can also contain one or more direct dyes. Direct dyes are dyes that adhere directly to the hair and do not require an oxidative process to develop the color. Typical direct dyes are nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinones, triarylmethane dyes, or indophenols.

[0101] 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.

[0102] Direct-drawing dyes can be divided into anionic, cationic, and nonionic direct-drawing dyes.

[0103] Kationische direktziehende Farbstoffe sind beispielsweise Basic Blue 7, Basic Blue 26, HC Blue 16, Basic Violet 2 und Basic Violet 14, Basic Yellow 57, Basic Red 76, Basic Blue 16, Basic Blue 347 (Cationic Blue 347 / Dystar), HC Blue No. 16, Basic Blue 99, Basic Brown 16, Basic Brown 17, Basic Yellow 57, Basic Yellow 87, Basic Orange 31 , Basic Red 51 Basic Red 76.

[0104] 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.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.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 rheumenized forms (-COOH, -SO3H) of the carboxylic acid or sulfonic acid groups exist in equilibrium with their deprotonated forms (-COO-, -SCh). The proportion of rheumenized 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 their potassium salts.

[0105] 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.

[0106] The 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 in water is below 0.5 g / L, preferably less than 0.1 g / L, and even more preferably less than 0.05 g / L (each at 25 °C, 760 mmHg), they do not fall under the definition of a direct-drawing dye.

[0107] In a further particularly preferred embodiment, a dye according to the invention is characterized in that it contains at least one color-imparting compound (F-1) from the group of direct dyes, particularly preferably from the group of anionic direct dyes.

[0108] 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) and / or one sulfate group (-OSO3H). Depending on the pH, the rheumenized forms (-COOH, -SO3H) of the carboxylic acid or sulfonic acid groups exist in equilibrium with their deprotonated forms (-COO-, -SOs, or -OSOs-). The proportion of rheumenized 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 their potassium salts.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.

[0109] 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.

[0110] Als Beispiele für Säurefarbstoffe 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 (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.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 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, Cl 44090, Acid Brilliant Green BS, E 142), Acid Black 1 (Black n° 401 , Naphthalene Black 10B, Amido Black 10B, Cl 20 470, COLIPA n° B15), Acid Black 52 (Cl 15711), Food Yellow 8 (Cl 14270), Food Blue 5, D&C Yellow 8, D&C Green 5, D&C Orange 10, D&C Orange 11 , D&C Red 21 , D&C Red 27, D&C Red 33, D&C Violet 2 and / or D&C Brown 1. In the context of a further embodiment, a dye according to the invention is characterized in that it contains 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 1 1 , D&C Red 21 , D&C Red 27, D&C Red 33, D&C Violet 2 und / oder D&C Brown 1 .,

[0111] Since the alkaline earth salts (such as calcium and magnesium salts) or aluminum salts of acid dyes have lower solubility than the corresponding alkali metal salts, an organic dye that can be considered an acid dye in the form of its alkali metal salt can also exist as a pigment if the counterion for the acid group(s) is not an alkali metal ion, but an alkaline earth metal 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-drawing dye.

[0112] Like pigments, acid dyes are not intended to diffuse primarily into the keratin fiber, but rather to be preferentially deposited embedded in the chitosan film on the surface of the keratin fibers. For this reason, acid dyes are particularly preferred, as they have a solubility so high that they can no longer be classified as organic pigments, but which nevertheless exhibit relatively poor solubility.

[0113] For this reason, dyes or acid dyes are particularly preferred as organic coloring compounds which have a solubility in water at 25 °C between 0.5 g / l and 20 g / l, preferably between 1.0 g / l and 17 g / l and most preferably between 2.0 g / l and 15 g / l.

[0114] In a further particularly preferred embodiment, a dye according to the invention is characterized in that it contains at least one direct dye (F-1) which has a solubility in water at 25 °C between 0.5 g / l and 20 g / l, preferably between 1.0 g / l and 17 g / l and most preferably between 2.0 g / l and 15 g / l.

[0115] In a further particularly preferred embodiment, a dye according to the invention is characterized in that it contains at least one anionic direct dye (F-1) which has a solubility in water at 25 °C between 0.5 g / l and 20 g / l, preferably between 1.0 g / l and 17 g / l and most preferably between 2.0 g / l and 15 g / l.

[0116] The water solubility of anionic direct-acting dyes can be determined, for example, as follows. 0.1 g of the anionic direct-acting dye is placed in a beaker. A magnetic stir bar is added. Then, 100 ml of water is added. This mixture is heated to 25 °C on a magnetic stirrer while stirring. Stirring continues for 60 minutes. The aqueous mixture is then visually inspected. If undissolved dye remains, the amount of water is increased—for example, in 10 ml increments. Water is added until the dye is completely dissolved. If the dye-water mixture cannot be visually inspected due to the high intensity of the dye, the mixture is filtered. If some undissolved dye remains on the filter paper, the solubility test is repeated 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.

[0117] 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).

[0118] 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).

[0119] 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).

[0120] 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.

[0121] 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).

[0122] 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.%.

[0123] 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).

[0124] 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).

[0125] Brilliant Blue FCF, also known as Food Blue 2 or Acid Blue 9, is known as disodium 2-[(Z)-{4-[ethyl(3-sulfonatobenzyl)amino]phenyl}{(4Z)-4-[ethyl(3-sulfonatobenzyl)amino]-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% by weight (25 °C).

[0126] Acid Blue 74 is also known as Indigo Carmine, Food Blue 1, or FD&C Blue 2, and its chemical name is 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 its disodium salt form, has a solubility of 10 g / L in water at 25 °C. Acid Blue 74 (disodium salt) has the Color Index number 73015 and can be purchased, for example, under the trade name Bleu Covalac W6504.

[0127] The dye preferably contains the coloring compound(s) in certain quantity ranges. Good results can be obtained, for example, if the dye contains one or more coloring compounds (F-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 2.00 wt.%, more preferably 0.2 to 1.50 wt.%, even more preferably 0.25 to 1.25 wt.%, and most preferably 0.30 to 1.00 wt.%.

[0128] In a further particularly preferred embodiment, a dyeing agent according to the invention is characterized in that it contains – based on the total weight of the dyeing agent – ​​one or more color-imparting compounds (F-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 2.00 wt.%, more preferably 0.2 to 1.50 wt.%, even more preferably 0.25 to 1.25 wt.% and most preferably 0.30 to 1.00 wt.%.

[0129] In a further particularly preferred embodiment, a dyeing agent according to the invention is characterized in that it contains – based on the total weight of the dyeing agent – ​​one or more pigments (F-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 2.00 wt.%, more preferably 0.2 to 1.50 wt.%, even more preferably 0.25 to 1.25 wt.% and most preferably 0.30 to 1.00 wt.%.

[0130] In a further particularly preferred embodiment, a dyeing agent according to the invention is characterized in that it contains – based on the total weight of the dyeing agent – ​​one or more direct dyes (F-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 2.00 wt.%, more preferably 0.2 to 1.50 wt.%, even more preferably 0.25 to 1.25 wt.% and most preferably 0.30 to 1.00 wt.%.

[0131] Chitosan (F-2) in the dye (F) As a second essential component, the dye (F) according to the invention contains at least one chitosan or a derivative of chitosan (F-2).

[0132] Chitosan, also known as polyglucosamine or poly-D-glucosamine, 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.

[0133] Chitosan is preferably produced from chitin, which is found in shellfish or crustaceans. Chitosan is industrially produced from chitin by 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. 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 process can decrease the polymer chain length (depolymerization). The molecular weight of chitosan can range over a wide spectrum, for example, from 20,000 to approximately 5 million g / mol.

[0134] Chitosan derivatives are compounds with a chitosan core 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.

[0135] A derivative of chitosan therefore has a poly-D-glucosamine or polyglucosamine structure, which has either been converted into its salt by protonation of one or more nitrogen atoms or which bears an organic substituent on at least one oxygen atom and / or at least one amino group.

[0136] 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.

[0137] In a further particularly preferred embodiment, a dye according to the invention is characterized in that it contains at least one chitosan and / or one chitosan derivative (F-2) with a molecular weight of 20,000 to 800,000 g / mol, preferably of 50,000 to 600,000 g / mol, more preferably of 80,000 to 450,000 g / mol and most preferably of 100,000 to 300,000 g / mol.

[0138] Chitosan with a molecular weight of 100,000 to 300,000 g / mol can be purchased commercially from the company Sigma Aldrich, for example.

[0139] 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%.

[0140] Chitosan in the form of its hydrochloride can be obtained as vegan chitosan from the company Sandream Impact. The hydrochloride of chitosan is a chitosan derivative according to the invention.

[0141] 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.

[0142] It has proven particularly advantageous if the dye according to the invention contains the chitosans and / or chitosane derivatives (F-2) in certain quantity ranges. Particularly good results were obtained when the dye (F) – based on the total weight of the dye (F) – contained one or more chitosans and / or chitosane derivatives in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%.

[0143] In a further explicitly preferred embodiment, a dyeing agent according to the invention is characterized in that it contains – based on the total weight of the dyeing agent – ​​one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%.

[0144] In a further explicitly preferred embodiment, a dyeing agent (F) according to the invention is characterized in that it contains - based on the total weight of the dyeing agent - one or more chitosans in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%.

[0145] Organic acids (F-3) in the dye

[0146] As a third essential component (F-3) of the invention, the dye contains at least one organic acid and / or its salt. The use of one or more acids lowers the pH of the dye, thereby wholly or partially deprotonating the chitosan and allowing it to dissolve more readily. In aqueous or water-containing media, the organic acid is deprotonated and therefore exists in equilibrium with its salt. Since the pH is to be lowered, the acid itself is preferably used in the medium.

[0147] A particularly preferred agent is therefore one for dyeing keratinous fibers, especially human hair, containing

[0148] (F-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0149] (F-2) at least one chitosan and / or a chitosan derivative, and

[0150] (F-3) at least one organic acid, and

[0151] (F-4) at least one fragrance.

[0152] Macroscopically, the protonation of chitosan in water is observed as swelling, from which, when the preferred or highly preferred pH value 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. With the formation of a particularly uniform film, colorations with especially good wash fastness have also been achieved. Furthermore, the presence of the acid(s) (F-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 offers better resistance to external mechanical stresses.

[0153] Particularly suitable organic acids include, for example, organic acids (F-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.

[0154] Formic acid and propanoic acid are also suitable acids (F-3).

[0155] In a further particularly preferred embodiment, a dye according to the invention is characterized in that it contains at least one organic acid (F-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, aleuritic acid, ribonic acid, fumaric acid, their mixtures and / or their salts, in particular acetic acid and / or a salt of acetic acid.

[0156] Acetic acid dissolves chitosan particularly well and leads to very thin and uniform films; therefore, a dye (F) containing acetic acid is particularly preferred.

[0157] In a further explicitly preferred embodiment, a dyeing agent (F) according to the invention is therefore characterized in that it contains acetic acid (F-3).

[0158] A particularly preferred agent is therefore one containing a dye for keratinous fibers, especially human hair.

[0159] (F-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0160] (F-2) at least one chitosan and / or a chitosan derivative, and

[0161] (F-3) Acetic acid, and

[0162] (F-4) at least one fragrance.

[0163] 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 contained water and was adjusted to a pH in the range of 2.0 to 7.5, preferably 2.5 to 6.5, more preferably 3.0 to 6.0, and most preferably 3.0 to 5.0.

[0164] In a further particularly preferred embodiment, a dye according to the invention is characterized in that it has a pH value of 2.0 to 7.5, preferably of 2.5 to 6.5, more preferably of 3.0 to 6.0 and most preferably of 3.0 to 5.0.

[0165] Fragrances

[0166] As a fourth essential component of the invention (F-4), the dye according to the invention contains at least one fragrance.

[0167] Odorants or fragrances are all natural and synthetic substances that are perceived olfactorily and develop a pleasant smell.

[0168] For the purposes of the present invention, an odorant is therefore understood to be a substance that is perceived by the user as pleasant and that gives the dye a good smell. The term fragrance can also be used synonymously with odorant.

[0169] A fragrance ingredient, or several fragrance ingredients in their mixture, constitute a perfume. A fragrance ingredient can therefore also be referred to as a perfume component.

[0170] To be effective olfactorily, odorants are generally monomolecular compounds with a relatively low molecular weight. An odorant (or fragrance) within the meaning of this application is therefore preferably a substance whose molecular structure has a molecular weight of less than 500 g / mol, preferably less than 400 g / mol, and particularly preferably less than 300 g / mol.

[0171] The experiments conducted showed that particularly good colorations are obtained when the chitosan (derivative) (F-2) is protonated by an organic acid and thus dissolved. Although various organic acids can, in principle, be used for protonation, the best results were obtained with acetic acid, making it the most preferred acid. However, apart from the very advantageous color results, acetic acid has a very strong inherent odor, which is generally perceived as very unpleasant by users of the dye. Therefore, acetic acid does not constitute an odorant within the meaning of the present application.

[0172] To mask the unpleasant odor of the acids used, especially acetic acid, at least one odorant (F-4) is added to the dye. The following substances are therefore well or particularly well suited for use as odorants (F-4).

[0173] 2-Phenylethanol can alternatively be called β-(hydroxyethyl)benzene and bears the CAS number 60-12-8. 2-Phenylethanol is a component of a large number of natural essential oils, such as hyacinth oil, clove oil, geranium oil, and black walnut oil. 2-Phenylethanol is also the main component of rose oil. 2-Phenylethanol is a colorless liquid with an odor of rose petals and honey. The use of 2-phenylethanol in the dye according to the invention is most preferred.

[0174] 1-(1,2,3,4,5,6,7,8-Octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one is alternatively also referred to as 1-(1,2,3,5,6,7,8,8a-Octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)ethanone and has the CAS number 68155-66-8. Further stereoisomers of this substance have the CAS numbers 54464-57-2, 144651-56-9, and 68155-67-9. All stereoisomers of this group of substances are according to the invention. The substances in this group emit a sandalwood- and cedar-like fragrance. The use of 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one is also particularly preferred. Geraniol can alternatively be referred to as 2,6-dimethyl-f / 'ans-2,6-octadien-8-ol, 3,7-dimethyl-frans-2,6-octadien-1-ol, or (E)-3,7-dimethyl-2,6-octadien-1-ol and bears the CAS number 106-24-1. Geraniol has a rose-like scent with a hint of citrus. The use of geraniol is also particularly preferred.

[0175] 2,6-Dimethyloct-7-en-2-ol is also known as dihydromyrcenol and has the CAS number 18479-58-8. The substance has a fresh, limonene- and citrus-like odor. The use of 2,6-dimethyloct-7-en-2-ol is also particularly preferred.

[0176] 2-tert-Butylcyclohexyl acetate can alternatively be called 1-acetoxy-2-tert-butylcyclohexane and has the CAS number 88-41-5. 2-tert-Butylcyclohexyl acetate has a fruity odor. The use of 2-tert-Butylcyclohexyl acetate is also particularly preferred.

[0177] Citronellol can alternatively be called 3,7-dimethyloct-6-en-1-ol or β-citronellol and bears the CAS number 106-22-9. Further stereoisomers of citronellol have the CAS numbers 1117-61-9 [(R)-(+)-citronellol] and 7540-51-4 [(S)-(-)-citronellol]. Citronellol contains a stereocenter, so that two enantiomers exist which differ in their odor. (R)-citronellol has the odor of citronella oil, and (S)-citronellol smells of geranium oil. Citronellol is particularly preferred in the dye according to the invention.

[0178] Pentadecane-15-olide can alternatively also be referred to as pentadecano-1,15-lactone or as 1-oxa-2-cyclohexadecanone and bears the CAS number 106-02-5. Pentadecane-15-olide belongs to the musk fragrances and is particularly preferably used in the dye (F) according to the invention.

[0179] 4-tert-Butylcyclohexyl acetate, which can alternatively also be called 4-(1,1-Dimethylethyl)cyclohexyl acetate or cyclohexanol-4-(1,1-dimethylethyl) acetate, bears the CAS number 32210-23-4 and is characterized by its pleasant fruity and floral odor. The use of 4-tert-butylcyclohexyl acetate in the dye according to the invention is also particularly preferred.

[0180] The term terpineols refers to a group of chemically isomeric compounds. The mixture of isomers bears the CAS number 98-55-5. Terpineols include (R)-(+)-α-terpineol (CAS No. 7785-53-7), (S)-(-)-α-terpineol (CAS No. 10482-56-1), β-terpineol (CAS No. 138-87-4), γ-terpineol (CAS No. 586-81-2), and β-terpineol (CAS No. 7299-42-5). For example, an intense lilac fragrance can be produced by mixing α-terpineol and γ-terpineol. Terpineols are particularly preferred in the dye according to the invention. 3,7-Dimethyloctan-1-ol is an alternative name for tetrahydrogeraniol or dihydrocitronellol and has the CAS number 106-21-8. Dihydrocitronellol has a floral odor and occurs naturally, for example, in citrus oils. The use of 3,7-dimethyloctan-1-ol as a fragrance (F-4) is also particularly favored.

[0181] Geranyl acetate, which can also be called 3,7-dimethyl-2,6-octadiene acetate or acetic acid geranyl ester, has the CAS number 105-87-3 and possesses a rose-like odor. Geranyl acetate is another particularly favored fragrance ingredient.

[0182] Tetrahydro-4-methyl-2-(2-methylprop-1-enyl)pyran can alternatively be called rose oxide or tetrahydro-4-methyl-2-(2-methylpropenyl)-2 / 7-pyran. The INCI name is Isobutenyl Methyltetrahydropyran. Rose oxide has the CAS number 16409-43-1. Rose oxide is a mixture of the isomeric cis and frans forms of the compound with the CAS numbers 876-17-5 (-)-c / s-rose oxide and 876-18-6 (-)-trans-rose oxide. Rose oxide is responsible for the characteristic fragrance of rose oil and geranium oil and is also a highly prized fragrance ingredient.

[0183] 4-(2,6,6-Trimethyl-1-cyclohexen-1-yl)butan-2-one can alternatively also be called dihydro-beta-ionone and bears the CAS number 17283-81-7. 4-(2,6,6-Trimethyl-1-cyclohexen-1-yl)butan-2-one is a preferred fragrance ingredient for the dyes according to the invention.

[0184] 2-Ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1 - ol can alternatively be called Sandranol, has the CAS number 28219-61 -6 and is also a preferred fragrance ingredient.

[0185] Undecan-4-olide can alternatively be called gamma-n-heptylbutyrolactone or 5-heptyldihydro-2(3H)-furanone and bears the CAS number 104-67-6. Undecan-4-olide has a rather characteristic fruity odor and is also a preferred fragrance (F-4).

[0186] Nerol, which is also very suitable, can alternatively be called 2,6-dimethyl-2,6-octadien-8-ol or (Z)-3,7-dimethyl-2,6-octadien-1-ol. Nerol has the CAS number 106-25-2 and a fresh, rosy-citrus odor.

[0187] 2-Methyl-1-phenylpropan-2-ol has the CAS number 100-86-7 and is also suitable for use as a fragrance in dyes.

[0188] 4-(2,6,6-Trimethylcyclohex-1-ene-1-yl)-but-3-ene-2-one, CAS number 14901-07-6, has a sweet, floral to woody odor and is also a suitable fragrance ingredient. Indole, which can alternatively be called 2,3-benzopyrrole or benzo[b]pyrrole, has CAS number 120-72-9. The odor of indole is floral. Indole occurs naturally, for example, in jasmine flower oil, wallflower oil, and in the flowers of the black locust, garden hyacinth, and common lilac. Indole is also a very suitable fragrance ingredient.

[0189] Decan-1-ol, which can also be called decyl alcohol or capric alcohol, has the CAS number 112-30-1. Decan-1-ol has a sweet odor. It is also a suitable fragrance ingredient (F-4).

[0190] Anethole can alternatively be called 1-methoxy-4-(1-propenyl)benzene and has the CAS number 104-46-1. The odor of anethole is responsible for the typical anise aroma. Anethole is a suitable fragrance ingredient.

[0191] Benzophenone, which is also suitable as a fragrance, can alternatively be called diphenyl ketone and bears the CAS number 119-61-9. Benzophenone has a geranium-like odor.

[0192] Benzyl acetate, which is also suitable as a fragrance and bears the name benzyl acetate, has the CAS number 140-11-4 and smells like jasmine.

[0193] Bornyl acetate, which is also suitable as a fragrance and can alternatively be called 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl acetate, has the CAS numbers 5655-61-8 (-)-bornyl acetate, 20347-65-3 (+)-bornyl acetate, and 76-49-3 (±)-racemate. Bornyl acetate has a strong pine odor.

[0194] Eugenol, also known as 4-allyl-2-methoxyphenol, which is also suitable as a fragrance ingredient, has the CAS number 97-53-0 and is primarily used for spicy notes in the perfume industry. Eugenol is also a well-suited fragrance ingredient.

[0195] Coumarin, which is also suitable as a fragrance ingredient and is alternatively known as 2-H-1-benzopyran-2-one, has the CAS number 91-64-5. Its odor is described as reminiscent of vanilla or bittersweet and hay-like.

[0196] Ethyl butanoate, also suitable as a fragrance, which can also be called ethyl butyrate or ethyl butyrate, has the CAS number 105-54-4 and a pineapple-like odor. Isoamyl acetate, also suitable as a fragrance, which can alternatively be called 3-methylbutyl acetate, has the CAS number 123-92-2 and a fruity or banana-like odor.

[0197] The ionones include alpha-ionone, beta-ionone, and gamma ions. Alpha-ionone is also known as violone or (E)-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one and has the CAS numbers 127-41-3 (racemate), 24190-29-2 (R), and 14398-36-8 (S). The (R)-enantiomer has a violet-like, raspberry-like, and floral odor. The (S)-enantiomer has a woody, violet-like odor. Beta-ionone is also known as (E)-megastigma-5(13),7-dien-9-one and has the CAS number 79-77-6. Alpha-isomethyl ionone, also known as 3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one, has the CAS number 127-51-5 and a floral odor. Ionones are also well-suited fragrances.

[0198] The nerolidols are a group of isomeric sesquiterpenes and include

[0199] - (R)-c / s-Nerolidol with the CAS number 132958-73-7, which has an intensely floral, sweet and fresh scent,

[0200] - (S)-c / s-Nerolidol with CAS number 142-50-7 with a pleasant woody odor,

[0201] - (R)-trans-Nerolidol with CAS number 77551-75-8, which has a woody, green, and bark-like odor, and (S)-f / 'ans-Nerolidol with CAS number 1119-38-6, which has a sweet, mildly floral odor. All nerolidols are well-suited fragrances.

[0202] Allyl (cyclohexyloxy) acetate has the CAS number 68901-15-5 and possesses a strong fruity, green odor reminiscent of herbs. Allyl (cyclohexyloxy) acetate is also a very suitable fragrance ingredient.

[0203] Allyl heptanoate has the CAS number 142-19-8 and can alternatively be called prop-2-enyl heptanoate. Its scent is fruity and sweet, reminiscent of pineapple with a hint of banana.

[0204] Bornan-2-one can alternatively be called camphor and has the CAS number 76-22-2. Other CAS numbers for the stereoisomers of camphor are 464-49-3 ((+)-camphor) and 464-48-2 ((-)-camphor). Bornan-2-one is also a very suitable fragrance ingredient.

[0205] N-Butyl acetate has the CAS number 123-86-4 and can also be called n-butyl acetate. N-Butyl acetate has a fruity odor.

[0206] Cyclopentadecanolide has the CAS number 106-02-5 and is also known as 1-oxa-2-cyclohexadecanone or 15-hydroxypentadecanoic acid lactone. This substance is classified as a musk fragrance ingredient. Dimethyl-2-heptanol has the CAS number 13254-34-7. Its odor is described as floral to woody with a citrus note. Dimethyl-2-heptanol is also a very suitable fragrance ingredient.

[0207] 3,7-Dimethylocta-1,3,6-triene has the CAS number 13877-91-3 and is also suitable as a fragrance.

[0208] 3,7-Dimethyloctan-3-ol has the CAS number 78-69-3, is used for honey flavorings and is also suitable as a fragrance agent.

[0209] 1,4-Dioxacyclohexadecane-5,16-dione has the CAS number 54982-83-1, can alternatively be called ethylene dodecanedioate or musconate, and is also a suitable fragrance ingredient.

[0210] Diphenyl ether has the CAS number 101-84-8 and is also known as 1,1'-oxybisbenzene. Diphenyl ether has a geranium-like odor and is also a very suitable fragrance.

[0211] (Ethoxymethoxy)cyclododecane has the CAS number 58567-11-6 and is also a suitable fragrance ingredient with a wood and amber note.

[0212] 2-Ethyl-3-hydroxy-4-pyrone has the CAS number 4940-11-8 and can also be called ethyl maltol. Due to its sweet, caramelized fruit-like odor, 2-Ethyl-3-hydroxy-4-pyrone is also a suitable fragrance ingredient.

[0213] 3a,4,5,6,7,7a-Hexahydro-4,7-methano-1 H-inden-6-yl propionate has the CAS number 17511-60-3. The substance is also alternatively known as 3a,4,5,6,7,7a-Hexahydro-1 H-4,7-methanoinden-6-yl propionate or as tricyclodecenyl propionate and is also suitable as a fragrance ingredient.

[0214] [3R-(3a,3ab,7b,8aa)]-2,3,4,7,8,8a-Hexahydro-3,6,8,8-tetramethyl-1 H-3a,7-methanoazulene has the CAS number 469-61-4 and is also a suitable fragrance ingredient. cis-3-Hexenyl salicylate has the CAS number 65405-77-8 and can alternatively be used as salicylic acid-

[0215] 3-hexen-1-yl ester, has a fresh, floral, green fragrance profile and is also a particularly suitable fragrance ingredient.

[0216] Hexyl salicylate, CAS number 6259-76-3, is also known as hexyl 2-hydroxybenzoate and is a suitable fragrance ingredient. Isopentyl acetate, CAS number 123-92-2, is also known as acetic acid (3-methylbutyl) ester or isoamyl acetate. Due to its floral odor, isopentyl acetate is a very suitable fragrance ingredient and is also a key component of banana flavoring. cis-4-(isopropyl)cyclohexanemethanol, CAS number 13828-37-0, is a suitable fragrance ingredient.

[0217] Isopulegol has the CAS number 89-79-2 and can alternatively be called 2-isopropenyl-5-methylcyclohexanol. The CAS numbers of other stereoisomers of isopulegol are 104870-56-6 (+)-isopulegol and 7786-67-6 (isomer mixture). All stereoisomers and isomer mixtures are suitable fragrances.

[0218] Limonene bears the CAS number 138-86-3 and can alternatively be referred to as 1-methyl-4-(prop-1-en-2-yl)cyclohex-1-ene or as 1-methyl-4-(1-methylethenyl)cyclohexene. Further CAS numbers of the stereoisomers are 5989-27-5 ((+)-limonene) and 5989-54-8 ((-)-limonene). Limonene is another particularly preferred fragrance ingredient. All stereoisomers are according to the invention.

[0219] Linalool has the CAS number 78-70-6 and can alternatively be called 3,7-dimethylocta-1,6-dien-3-ol. Other CAS numbers for the stereoisomers are 126-91-0 ((R)-(-)-linalool) and 126-90-9 ((S)-(+)-linalool). Linalool has a fresh, lily-of-the-valley-like odor and is another particularly favored fragrance ingredient. p-Menthan-8-yl acetate has the CAS number 58985-18-5 and can alternatively be called dihydroterpinyl acetate. The odor of p-Menthan-8-yl acetate is reminiscent of pine and citrus and also has a woody note. p-Menthan-8-yl acetate is also a very suitable fragrance ingredient.

[0220] L-menthol has the CAS number 2216-51-5. The CAS numbers of other stereoisomers of menthol are 89-78-1 [(±)-menthol, DL-menthol, racementhol], 15356-60-2 [(+)-menthol], and 1490-04-6 (menthol). All stereoisomers of menthol are well-suited as fragrances.

[0221] 4-Methyl-3-decen-5-ol has the CAS number 81782-77-6, has a green, fresh, floral odor and is also a suitable fragrance ingredient.

[0222] 7-Methyl-3-methyleneocta-1,6-diene has the CAS number 123-35-3 and can alternatively be called beta-myrcene; it is another suitable fragrance ingredient. 3-Methyl-5-phenylpentanol has the CAS number 55066-48-3 and can alternatively be called phenoxanol. Its scent is fresh, floral-rosy, somewhat sweet, and reminiscent of geranium and hyacinth. 3-Methyl-5-phenylpentanol is also very well suited as a fragrance ingredient.

[0223] 3-Methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)pent-4-en-2-ol has the CAS number 67801-20-1 and can alternatively be called mohanol or prabanol. Its odor has a typical sandalwood note. 3-Methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)pent-4-en-2-ol is another very suitable fragrance ingredient.

[0224] Oxacyclohexadecen-2-one has the CAS number 111879-80-2 and is another suitable fragrance ingredient. Alpha,beta-2,2,3-Pentamethylcyclopent-3-ene-1-butanol has the CAS number 65113-99-7, possesses a sandalwood note, and is also suitable as a fragrance ingredient.

[0225] Phenylethyl acetate, also known as 2-phenylethyl acetate, has the CAS number 103-45-7 and can alternatively be called 2-phenylethyl acetate. 2-Phenylethyl acetate has a rose-like scent and is particularly well-suited as a fragrance.

[0226] Pin-2(10)-ene has the CAS number 127-91-3. Pin-2(3)-ene has the CAS number 80-56-8. Both substances belong to the pinenes, whose stereoisomers bear the further CAS numbers 7785-70-8, 7785-26-4, 19902-08-0, and 18172-67-3. All pinenes are well-suited fragrances.

[0227] Tetrahydro-2-isobutyl-4-methylpyran-4-ol has the CAS number 63500-71-0 and can alternatively be called 2-isobutyl-4-hydroxy-4-methyltetrahydropyran. Further CAS numbers exist for the stereoisomers 65418-69-1 (rel-2R,4R) and 65418-70-4 (rel-2R,4S). Tetrahydro-2-isobutyl-4-methylpyran-4-ol has a floral odor. All stereoisomers are also very well suited as fragrances.

[0228] (E)-1-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-2-buten-1-one has the CAS number 24720-09-0 and can alternatively be called alpha-damascone. Its odor is reminiscent of apple, mint, and blackcurrant. (E)-1-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-2-buten-1-one is also particularly well-suited as a fragrance.

[0229] 1-(2,6,6-Trimethyl-3-cyclohexen-1-yl)-2-buten-1-one, CAS number 57378-68-4, is also known as delta-damascone and is another very suitable fragrance ingredient. Undecan-2-one, CAS number 112-12-9, is also known as methyl nonyl ketone. Undecan-2-one has a pleasant, strong odor and is also a particularly suitable fragrance ingredient.

[0230] In a further preferred embodiment, a dye (F) according to the invention is characterized in that it contains at least one fragrance (F-4) selected from the group consisting of 2-phenylethanol, 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one, geraniol, 2,6-dimethyloct-7-en-2-ol, 2-tert-butylcyclohexyl acetate, citronellol, pentadecan-15-olide, 4-tert-butylcyclohexyl acetate, terpineols, 3,7-dimethyloctan-1-ol, geranyl acetate, tetrahydro-4-methyl-2-(2-methylprop-1-enyl)pyran, 4-(2,6,6-trimethyl-1- cyclohexen-1-yl)butan-2-one, 2-Ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol, Undecan-4-olide, Nerol, 2-Methyl-1-phenylpropan-2-ol, 4-(2,6,6-Trimethylcyclohex-1- ene-1-yl)-but-3-ene-2-one, indole, decan-1-ol, anethole, benzophenone, benzyl acetate, bornyl acetate, eugenol, coumarin, ethyl butanoate, isoamyl acetate, ionone, nerolidoien, allyl (cyclohexyloxy) acetate, allyl heptanoate, bornan-2-one, N-butyl acetate, cyclopentadecanolide,Dimethyl-2-heptanol, 3,7-Dimethylocta-1 ,3,6-trien, 3,7- Dimethyloctan-3-ol, 1 ,4-Dioxacyclohexadecane-5,16-dion, Diphenylether,

[0231] (Ethoxymethoxy)cyclododecan, 2-Ethyl-3-hydroxy-4-pyron, 3a,4,5,6,7,7a-Hexahydro-4,7-methano- 1 H-inden-6-yl propionat, [3R-(3a,3ab,7b,8aa)]-2,3,4,7,8,8a-Hexahydro-3,6,8,8-tetramethyl-1 H-3a,7- methanoazulen, cis-3-Hexenyl salicylat, Hexyl salicylat, Isopentyl acetat, cis-4-(lsopropyl)cyclo- hexanemethanol, Isopulegol, Limonen, Linalool, p-Menthan-8-yl acetat, L-Menthol, 4-Methyl-3- decen-5-ol, 7-Methyl-3-methylenocta-1 ,6-dien, 3-Methyl-5-phenylpentanol, 3-Methyl-5-(2,2,3- trimethyl-3-cyclopenten-1-yl)pent-4-en-2-ol, Oxacyclohexadecen-2-on, alpha, beta-2, 2,3-

[0232] Pentamethylcyclopent-3-en-1 -butanol, Phenylethyl acetat, Pin-2(10)-en, Pin-2(3)-en, Tetrahydro-2- isobutyl-4-methylpyran-4-ol, (E)-1-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-2-buten-1-on, 1 -(2,6,6- Trimethyl-3-cyclohexen-1-yl)-2-buten-1-on und Undecan-2-on.

[0233] In this context, it has been found that while all the aforementioned odorants mask the odor of acetic acid to some extent, with some odorants, even when used in higher quantities, a residual odor of the acid (especially acetic acid) cannot be completely masked. The following odorants have proven to be particularly well-suited for completely masking the unpleasant odor caused by the acid.

[0234] In a further particularly preferred embodiment, a dye (F) according to the invention is characterized in that it contains at least one fragrance (F-4) selected from the group consisting of 2-phenylethanol, 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one, geraniol, 2,6-dimethyloct-7-en-2-ol, 2-tert-butylcyclohexyl acetate, citronellol, pentadecan-15-olide, 4-tert-butylcyclohexyl acetate, terpineols, 3,7-dimethyloctan-1-ol, geranyl acetate, tetrahydro-4-methyl-2-(2-methylprop-1-enyl)pyran, 4-(2,6,6-trimethyl-1- cyclohexen-1-yl)butan-2-one, 2-Ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol, Undecan-4-olide, Nerol, 2-Methyl-1-phenylpropan-2-ol, 4-(2,6,6-Trimethylcyclohex-1- ene-1-yl)-but-3-ene-2-one, indole, and decan-1-ol.

[0235] In a further explicitly preferred embodiment, a dye (F) according to the invention is characterized in that it contains at least one fragrance (F-4) selected from the group consisting of 2-phenylethanol, 1-(1 ,2,3,4,5,6,7,8-Octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1 -one, geraniol, 2,6-dimethyloct-7-en-2-ol, 2-tert-butylcyclohexyl acetate, citronellol and pentadecane-15-olide.

[0236] All of the aforementioned suitable, preferred and particularly preferred fragrances have in common that their structure does not include an aldehyde group, i.e., a functional group -CHO.

[0237] The odorant(s) (F-4) are preferably used in an amount high enough to ensure good odor masking, but still low enough not to negatively affect the formation of the chitosan film. This is particularly achievable when the dye is

[0238] - based on its total weight - contains one or more fragrance substances (F-4) in a total amount of 0.01 to 4.0 wt.%, preferably 0.05 to 2.5 wt.%, more preferably 0.1 to 1.5 wt.%, even more preferably 0.15 to 1.0 wt.% and most preferably 0.2 to 0.6 wt.%.

[0239] In a further particularly preferred embodiment, a dyeing agent according to the invention is characterized in that it - based on the total weight of the dyeing agent

[0240] - contains one or more fragrance substances (F-4) in a total amount of 0.01 to 4.0 wt.%, preferably 0.05 to 2.5 wt.%, more preferably 0.1 to 1.5 wt.%, even more preferably 0.15 to 1.0 wt.% and most preferably 0.2 to 0.6 wt.%.

[0241] Fragrances without aldehyde group

[0242] The odorants (F-4) reliably mask the inherent odor of the acids used, thus making the dyeing process more comfortable for the user. In particular, the use of the odorants (F-4) allows the application-related advantages of acetic acid in the dye to be utilized without its unpleasant odor deterring the user.

[0243] Further studies have revealed that the use of fragrances with an aldehyde group in their molecular structure can also have disadvantages. Fragrances whose molecular structure includes an aldehyde group can negatively impact the stability of the formulation. In this context, it is suspected that the instability could be due to a reaction between the aldehyde and the chitosan, which alters the chitosan in such a way that it can no longer deposit onto the keratinous fibers as a continuous film. A possible mechanism could be the formation of a Schiff base between the aldehyde group of the chitosan and the aldehyde moiety of the fragrance. When the corresponding formulations were stored for extended periods, precipitation or flocculation of the chitosan was observed, and such formulations also resulted in dyeing with reduced color intensity.

[0244] Due to the formation of a Schiff base between the aldehyde group of the fragrance and the amino group of the chitosan, not only the structure of the chitosan but also that of the fragrance is altered. As the formulation ages, these fragrances can therefore lose their odor, making reliable masking of the acetic acid smell impossible. In the worst case, the odor of the fragrances themselves can be negatively altered, so that after extended storage periods, a second unpleasant odor, caused by the altered fragrance, is added to the unpleasant odor of the acetic acid. For this reason, compounds whose molecular structure does not include an aldehyde group are particularly favored as fragrances (F-4).

[0245] In a further particularly preferred embodiment, a dye according to the invention is characterized in that it contains at least one fragrance (F-4) whose structure does not include an aldehyde group.

[0246] In a further particularly preferred embodiment, a dyeing agent according to the invention is characterized in that it - based on the total weight of the dyeing agent

[0247] - one or more fragrance substances (F-4) whose structure does not include an aldehyde group, in a total amount of 0.01 to 4.0 wt.%, preferably 0.05 to 2.5 wt.%, more preferably 0.1 to 1.5 wt.%, even more preferably 0.15 to 1.0 wt.% and most preferably 0.2 to 0.6 wt.%.

[0248] Fragrance substances with an aldehyde group, which are preferably not used in dyes, include, for example...

[0249] - Anisaldehyde, also known as 4-methoxybenzaldehyde,

[0250] - Benzaldehyde, also known as phenylmethanal,

[0251] - Citronellal, also known as 3,7-Dimethyl-6-octen-1-al,

[0252] - Citral, which is also alternatively known as 3,7-dimethylocta-2,6-dienal,

[0253] - Decanal, also alternatively referred to as 1-decanal,

[0254] - Ethyl vanillin, also known as 3-ethoxy-4-hydroxybenaldehyde,

[0255] - Heliotropin, also known as (3,4-methylenedioxy)benzaldehyde, - Hydroxycitronellal, also known as 7-hydroxy-3,7-dimethyloctanal,

[0256] - trans-Hex-2-enal and c / s-Hex-2-enal and Hex-2-enal,

[0257] - Phenylacetaldehyde, also known as phenylethanal,

[0258] - Salicylaldehyde, also known as 2-hydroxybenzaldehyde,

[0259] - Vanillin, also known as 4-hydroxy-3-methoxybenzaldehyde,

[0260] - 3-p-cumenyl-2-methylpropionaldehyde, which bears the CAS number 103-95-7, and

[0261] - Veratraldehyde, alternatively also known as 3,4-dimethoxybenzaldehyde.

[0262] In a further preferred embodiment, a dyeing agent (F) according to the invention is characterized in that it is free of odorants from the group consisting of anisaldehyde, benzaldehyde, citronellal, citral, decanal, ethyl vanillin, heliotropin, hydroxycitronellal, trans-hex-2-enal, phenylacetaldehyde, salicylaldehyde, vanillin, 3-p-cumenyl-2-methylpropionaldehyde and veratraldehyde.

[0263] In a further preferred embodiment, a dye (F) according to the invention is characterized in that it does not contain any fragrances from the group consisting of anisaldehyde, benzaldehyde, citronellal, citral, decanal, ethyl vanillin, heliotropin, hydroxycitronellal, trans-hex-2-enal, phenylacetaldehyde, salicylaldehyde, vanillin, 3-p-cumenyl-2-methylpropionaldehyde and veratraldehyde.

[0264] To avoid a reduction in color intensity and storage instabilities, the dyes are particularly preferably free of fragrances whose structure includes an aldehyde group.

[0265] In a further preferred embodiment, a dyeing agent (F) according to the invention is characterized in that it is free of fragrances whose structure comprises an aldehyde group.

[0266] In dyes that are free of fragrances containing aldehyde groups, the total content of all fragrances whose structure (or molecular structure) includes an aldehyde group is 0% by weight. This 0% by weight refers to the total weight of the dye.

[0267] Weight ratio of organic acids (F-3) to odorants (F-4)

[0268] The odorant(s) (F-4) mask the odor of the organic acids (F-3) used. In particular, the odorant(s) (F-4) mask the unpleasant odor of acetic acid.

[0269] To achieve the most complete odor masking possible, it has proven particularly advantageous to use the organic acids (F-3) and the odorants (F-4) in specific weight ratios within the dye. The acid(s) (F-3) lowers the pH of the dye and dissolves the chitosan through protonation, so that the amount of acid used is determined by the desired pH value. Therefore, it is particularly preferred to adjust the amount of odorants (F-4) to the amount of organic acids (F-3).

[0270] Particularly good masking of the acid odor was achieved when the weight ratio of the total amount of acids (F-3) contained in the average to the total amount of odorants (F-4) contained in the average was in the range of 3:1 to 1:3, preferably from 3:1 to 1:1, and most preferably from 2.5:1 (corresponding to the ratio 5:2) to 1:1. Within this (F-3) / (F-4) range, sufficiently high amounts of odorants were present to ensure reliable odor masking, but the odor of the odorants themselves was pleasant and not too strong.

[0271] In a further preferred embodiment, a coloring agent (F) according to the invention is characterized in that the weight ratio of the total amount of acids (F-3) contained in the compound to the total amount of odorants (F-4) contained in the compound, i.e., the weight ratio (F-3) / (F-4), is in the range of 3:1 to 1:3, preferably from 3:1 to 1:1, and most preferably from 2.5:1 to 1:1. Aliphatic Ci-Cs monoalcohols (F-5)

[0272] In another embodiment, it has proven particularly advantageous for achieving intense color results if the dye additionally contains at least one aliphatic Ci-Ce monoalcohol.

[0273] An aliphatic Ci-Ce monoalcohol is an organic compound with one to six carbon atoms that possesses an OH group (hydroxyl group) bonded to one of the carbon atoms. This alcohol is aliphatic, meaning it is not an aromatic alcohol.

[0274] Particularly suitable aliphatic Ci-Ce monoalcohols can be selected, for example, from the group consisting of methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol and 1-hexanol.

[0275] In a further particularly preferred embodiment, a dye according to the invention is characterized in that it contains at least one aliphatic Ci-Ce monoalcohol (F-5) from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol, and 1-hexanol. The experiments carried out have shown that ethanol is particularly compatible with the coloring compounds (F-1) or chitosans (F-2) and also with the optionally usable acetic acid; therefore, the use of ethanol in the dye (F) is especially preferred.

[0276] In one particularly preferred embodiment, a dye according to the invention is characterized by containing ethanol (F-5).

[0277] Particularly preferred is a dyeing agent for keratinous fibers, especially human hair, containing

[0278] (F-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0279] (F-2) at least one chitosan and / or a chitosan derivative, and

[0280] (F-3) Acetic acid, and

[0281] (F-4) at least one fragrance ingredient, and

[0282] (F-5) Ethanol.

[0283] Ethanol has the Cas number 64-17-5.

[0284] 1-Propanol, also known as propyl alcohol, has the CAS number 71-23-8.

[0285] Isopropanol is also alternatively called 2-propanol and has the CAS number 67-63-0.

[0286] 1-Butanol can alternatively be called n-butanol or butyl alcohol and has the CAS number 71-36-3.

[0287] 1-Pentanol has the CAS number 71-41-0 and is also known as amyl alcohol.

[0288] 2-Methyl-2-butanol has the CAS number 75-85-4 and is also known as tert-pentanol. 1-Hexanol has the CAS number 111-27-3 and is also known as hexyl alcohol or capron alcohol.

[0289] The aliphatic C1-C22 monoalcohols are preferably used in certain quantity ranges in the dye.

[0290] Particularly uniform and resistant colorations could be achieved when the dyeing agent contained one or more aliphatic C1-C6 monoalcohols (F-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.%.

[0291] In a further preferred embodiment, a dye according to the invention is characterized in that it contains - based on the total weight of the dye - one or more aliphatic C1-C6 monoalcohols (F-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.%.

[0292] In a further particularly preferred embodiment, a dye according to the invention is characterized in that it contains - based on the total weight of the dye - one or more aliphatic Ci-Ce monoalcohols (F-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.%.

[0293] A dyeing agent is explicitly and particularly preferred which contains 40 to 95 wt.%, preferably 50 to 90 wt.%, further preferably 55 to 85 wt.% and most preferably 60 to 80 wt.% ethanol (F-5) based on the total weight of the dyeing agent.

[0294] Water content (F-6)

[0295] Preferably, the cosmetic carrier contains water in addition to the aliphatic Ci-Ce monoalcohol(s) (F-5). Particularly preferably, the cosmetic carrier is a mixture of aliphatic Ci-Ce monoalcohol(s) (F-5) and water (F-6).

[0296] Ethanol is the most preferred aliphatic Ci-Ce monoalcohol (F-5), so the cosmetic carrier most preferably comprises a mixture of ethanol and water.

[0297] Since the content of the Ci-Ce monoalcohol(s) is particularly preferably relatively high, and most preferably in the range of 60 to 80 wt.%, it is advantageous to reduce the water content accordingly. The dye therefore particularly preferably contains 5 to 70 wt.%, more preferably 10 to 60 wt.%, further preferably 15 to 50 wt.%, and most preferably 20 to 40 wt.% water (F-6). The amounts of water given here are based on the total weight of the dye.

[0298] In a further particularly preferred embodiment, a dyeing agent according to the invention is characterized in that it contains - based on the total weight of the dyeing agent - 10 to 50 wt.%, preferably 15 to 45 wt.%, more preferably 20 to 40 wt.% and most preferably 25 to 35 wt.% water (F-6).

[0299] Proportion of components (F-1), (F-2), (F-3), (F-4), (F-5) and (F-6) in the dye

[0300] 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.

[0301] It was found that the films produced with the dye were particularly thin, uniform, and stable when the dye consisted largely of components (F-1), (F-2), (F-3), (F-4), (F-5), and (F-6). 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 (F-1), (F-2), (F-3), (F-4), (F-5), and (F-6) are present together in the dye at a proportion of at least 94.0 wt.%, preferably at least 95 wt.%, further preferably at least 96 wt.%, even more preferably at least 99 wt.%, and most preferably at least 99.7 wt.%.

[0302] If components (F-1), (F-2), (F-3), (F-4), (F-5), and (F-6) together constitute at least 99.7% by weight in the dye, then the dye—based on its total weight—consists of at least 99.7% by weight of components (F-1), (F-2), (F-3), (F-4), (F-5), and (F-6). In other words, in this case, other substances or ingredients different from (F-1) to (F-6) are present in the dye at a maximum of 0.3% by weight.

[0303] In a further preferred embodiment, a dyeing agent according to the invention is characterized in that the components (F-1), (F-2), (F-3), (F-4), (F-5) and (F-6) are together contained in the dyeing agent in a quantity of at least 94.0 wt.%, preferably at least 95 wt.%, more preferably at least 96 wt.%, even more preferably at least 99 wt.% and most preferably at least 99.7 wt.%.

[0304] In a further explicitly preferred embodiment, a dye according to the invention is characterized in that it consists of at least 94.0 wt.%, preferably at least 95 wt.%, more preferably at least 96 wt.%, even more preferably at least 99 wt.% and most preferably at least 99.7 wt.%.

[0305] (F-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0306] (F-2) at least one chitosan and / or one chitosan derivative, and

[0307] (F-3) at least one organic acid, and

[0308] (F-4) at least one fragrance ingredient, and

[0309] (F-5) at least one aliphatic Ci-Ce monoalcohol, and

[0310] (F-6) water. In a further explicitly preferred embodiment, a dye according to the invention is characterized in that it consists of at least 94.0 wt.%, preferably at least 95 wt.%, more preferably at least 96 wt.%, even more preferably at least 99 wt.%, and most preferably at least 99.7 wt.%.

[0311] (F-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0312] (F-2) at least one chitosan and / or one chitosan derivative, and

[0313] (F-3) Acetic acid, and

[0314] (F-4) at least one fragrance ingredient, and

[0315] (F-5) at least one aliphatic Ci-Ce monoalcohol, and

[0316] (F-6) Water exists.

[0317] In a further explicitly preferred embodiment, a dye according to the invention is characterized in that it consists of at least 94.0 wt.%, preferably at least 95 wt.%, more preferably at least 96 wt.%, even more preferably at least 99 wt.% and most preferably at least 99.7 wt.%.

[0318] (F-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0319] (F-2) at least one chitosan and / or a chitosan derivative, and

[0320] (F-3) Acetic acid, and

[0321] (F-4) at least one fragrance ingredient, and

[0322] (F-5) Ethanol, and

[0323] (F-6) Water exists.

[0324] If the dye consists of at least 99.7% by weight of components (F-1) to (F-6), this means that all other substances different from substance groups (F-1) to (F-6) are present in the dye at a maximum of 0.3% by weight.

[0325] Methods for dyeing keratinous fibers

[0326] The dye is used in processes for dyeing keratinous fibers, especially human hair.

[0327] A second subject matter of the present application is therefore a method for dyeing keratinous fibers, in particular human hair, in which a dye, 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 a reaction time. The application of the dye to the keratin fibers can be carried out, for example, with a gloved hand or using a brush or applicator. After application, the dye can be spread over the keratin fibers and optionally gently massaged in.

[0328] In one embodiment, the dye is rinsed off using a rinse-off method and, after a dwell time, is rinsed off with water or with water and the aid of shampoo. Suitable dwell 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.

[0329] The uniformity of the color and its wash fastness were particularly outstanding when the dye was applied as a "leave-on" dye. In this case, the dye was not rinsed out, but rather the keratin fibers still coated with the dye were dried. Drying of the keratin fibers can take place at room temperature in the open air, or the fibers still coated with the dye can be heated to accelerate the drying process.

[0330] A method for dyeing keratinous fibers, especially human hair, is therefore particularly preferred, comprising

[0331] - the application of a dye, as disclosed in detail in the description of the first subject matter of the invention, to the keratinous fibers, and

[0332] - heating the keratinous fibers covered with the dye (F) to 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.

[0333] 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 such devices include a hairdryer, a heat cap, a flat iron, a curling iron, or an infrared lamp.

[0334] In a particularly preferred embodiment, a method according to the invention is characterized in that the heating to more than 40 °C is carried out by using a hairdryer, a hair dryer, a heat cap, a flat iron, a curling iron or an infrared lamp, most particularly by using a hairdryer.

[0335] 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.

[0336] In the process according to the invention, the keratin fibers can be completely subjected to heat treatment, but the 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 treated with heat.

[0337] 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.

[0338] 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.

[0339] During heat treatment or heating, the keratin fibers can also be combed or brushed.

[0340] 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.

[0341] 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.

[0342] Regarding the other preferred embodiments of the methods according to the invention, what has been said about the dyes according to the invention applies mutatis mutantis. Examples

[0343] 1. Formulations

[0344] The following dyes were produced (all values, unless otherwise stated, are in wt.%):

[0345] V = Comparison E = Invention

[0346] Parfum 1: 30 wt% 2-Phenylethanol; 30 wt% 1-(1,2,3,4,5,6,7,8-Octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one, 10 wt% Geraniol, 10 wt% 2,6-Dimethyloct-7-en-2-ol, 10 wt% 2-tert-Butylcyclohexyl acetate and 10 wt% Tetrahydro-4-methyl-2-(2-methylprop-1-enyl)pyran

[0347] Parfum 2: 40% w / w Citronellal, 30% w / w Hydroxycitronellal, 20% w / w Decanal, 10% w / w Vanillin

[0348] A swelling solution was produced from the water, acetic acid and chitosan.

[0349] Ethanol was mixed with the pigment. This dispersion was homogenized by rapid stirring. Then, the aqueous chitosan swelling and the alcoholic pigment dispersion were mixed together and homogenized by rapid stirring. The respective perfume was then added dropwise while stirring rapidly. The comparator formulation FM1 contained no perfume.

[0350] 2. Application to strands: The dyes were applied to strands of hair (Kerling brand). For this, 2.0 g of dye (FM) per gram of hair strand was massaged in and left on for 1 minute. Afterwards, the strands, still coated with dye, were dried with a standard hairdryer. During drying, the strands were combed through.

[0351] 3. Evaluation of the fragrance during use

[0352] During the aforementioned application, the smell of the strands still coated with dye was evaluated. The smell was also evaluated by the people blow-drying the hair during the drying process.

[0353] 4. Storage tests

[0354] 50 g of each dye (FM1), (FM2) and (FM3) were placed in a 100 ml glass bottle, sealed with a lid, and stored in a warming oven at 40 °C for 30 days. The dyes were visually assessed before and after storage. The formulations FM1 (without perfume) and FM2 (with perfume 1, fragrances without aldehyde groups) were homogeneous both before and after storage, and the chitosan remained in solution or swelling.

[0355] Formulation FM3 (with perfume 2, fragrances with aldehyde groups) was homogeneous before storage, but showed inhomogeneities after storage. The theory was developed that these inhomogeneities arise from the reaction of the aldehyde groups of the fragrances with the amino groups of the chitosan, causing the chitosan to no longer swell and subsequently precipitate and conglomerate from the formulation.

[0356] 5. Discoloration and odor of the stored formulations

[0357] The formulations stored as described in point 4 were dyed again onto strands of hair.

[0358] The dyes were applied to strands of hair (Kerling brand). For this, 2.0 g of dye (FM) per gram of hair strand was massaged in and left on for 1 minute. Afterwards, the strands, still coated with dye, were dried with a standard hairdryer. During drying, the strands were combed through.

[0359] The color intensities achieved during the dyeing process were visually assessed by trained individuals. For this purpose, the hair strands were laid side by side under a daylight lamp, and the intensities of the different strands were compared. The color intensity of each strand was then rated using a school grading system (1 = very high color intensity, 6 = very low color intensity).

[0360] The odor that occurred during the discoloration of the stored formulations was also re-evaluated.

Claims

1. Patent claims 1. Agents for dyeing keratinous fibers, especially human hair, containing (F-1) at least one colouring compound from the group consisting of pigments and direct dyes, and (F-2) at least one chitosan and / or a chitosan derivative, and (F-3) at least one organic acid and / or its salt, and (F-4) at least one fragrance.

2. Dyeing agent according to claim 1, characterized in that it contains at least one pigment (F-1) from the group consisting of inorganic pigments, organic pigments, pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

3. Dyeing agent according to one of claims 1 to 2, characterized in that it contains at least one coloring compound (Fl) from the group of direct dyes, particularly preferably from the group of anionic direct dyes.

4. Dyeing agent according to one of claims 1 to 3, characterized in that it contains at least one direct dye (F-1) which has a solubility in water at 25 °C between 0.5 g / l and 20 g / l, preferably between 1.0 g / l and 17 g / l and most preferably between 2.0 g / l and 15 g / l.

5. Dyeing agent according to one of claims 1 to 4, characterized in that it contains - based on the total weight of the dyeing agent - one or more coloring compounds (F- 1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 2.00 wt.%, more preferably 0.2 to 1.50 wt.%, even more preferably 0.25 to 1.25 wt.% and most preferably 0.30 to 1.00 wt.%.

6. Dyeing agent according to any one of claims 1 to 5, characterized in that it contains at least one chitosan and / or one chitosan derivative (F-2) with a molecular weight of 20,000 to 800,000 g / mol, preferably of 50,000 to 600,000 g / mol, more preferably of 80,000 to 450,000 g / mol and most preferably of 100,000 to 300,000 g / mol.

7. Dyeing agent according to any one of claims 1 to 6, characterized in that it contains - based on the total weight of the dyeing agent - one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%.

8. Dyeing agent according to any one of claims 1 to 7, characterized in that it contains at least one organic acid (F-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. Dyeing agent 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 2.5 to 6.5, more preferably of 3.0 to 6.0 and most preferably of 3.0 to 5.

0.

10. Dyeing agent according to any one of claims 1 to 9, characterized in that it contains at least one fragrance (F-4) selected from the group consisting of 2-phenylethanol, 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethan-1-one, geraniol, 2,6-dimethyloct-7-en-2-ol, 2-tert-butylcyclohexyl acetate, citronellol, pentadecan-15-olide, 4-tert-butylcyclohexyl acetate, terpineols, 3,7-dimethyloctan-1-ol, geranyl acetate, tetrahydro-4-methyl-2-(2-methylprop-1-enyl)pyran, 4-(2,6,6-trimethyl-1- cyclohexen-1-yl)butan-2-one, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol, undecan-4-olide, nerol, 2-methyl-1-phenylpropan-2-ol, 4-(2,6,6-trimethylcyclohex-1- ene-1-yl)-but-3-ene-2-one, indole, decan-1-ol, anethole, benzophenone, benzyl acetate, bornyl acetate, eugenol, coumarin, ethyl butanoate, isoamyl acetate, ionone, nerolidoien, allyl (cyclohexyloxy) acetate, allyl heptanoate, bornan-2-one, N-butyl acetate, cyclopentadecanolide, Dimethyl-2-heptanol, 3,7-dimethylocta-1,3,6-trien, 3,7- Dimethyloctan-3-ol, 1 ,4-Dioxacyclohexadecane-5,16-dion, Diphenylether, (Ethoxymethoxy)cyclododecan, 2-Ethyl-3-hydroxy-4-pyron, 3a,4,5,6,7,7a-Hexahydro-4,7- methano-1 H-inden-6-yl propionat, [3R-(3a, 3ab, 7b, 8aa)]-2, 3, 4,7,8, 8a-Hexahydro-3, 6,8,8- tetramethyl-1 H-3a,7-methanoazulen, cis-3-Hexenyl salicylat, Hexyl salicylat, Isopentyl acetat, cis-4-(lsopropyl)cyclo-hexanemethanol, Isopulegol, Limonen, Linalool, p-Menthan-8-yl acetat, L-Menthol, 4-Methyl-3-decen-5-ol, 7-Methyl-3-methylenocta-1 ,6-dien, 3-Methyl-5- phenylpentanol, 3-Methyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)pent-4-en-2-ol, Oxacyclohexadecen-2-on, alpha, beta-2, 2, 3-Pentamethylcyclopent-3-en-1 -butanol, Phenylethyl acetat, Pin-2(10)-en, Pin-2(3)-en, Tetrahydro-2-isobutyl-4-methylpyran-4-ol, (E)- 1 -(2,6,6-T rimethyl-2-cyclohexen-1 -yl)-2-buten-1 -on, 1 -(2,6,6-T rimethyl-3-cyclohexen-1 -yl)-2- buten-1-on und Undecan-2-on.

11. Dyeing agent according to any one of claims 1 to 10, characterized in that it contains at least one fragrance (F-4) whose structure does not include an aldehyde group.

12. Dyeing agent according to one of claims 1 to 11, characterized in that it is free of fragrances whose structure comprises an aldehyde group.

13. Dyeing agent according to any one of claims 1 to 12, characterized in that the weight ratio of the total amount of acids (F-3) contained in the agent to the total amount of odorants (F-4) contained in the agent, i.e. the weight ratio (F-3) / (F-4), is in the range of 3:1 to 1:3, preferably from 3:1 to 1:1 and most preferably from 2.5:1 to 1:

1.

14. Dyeing agent according to one of claims 1 to 13, characterized in that it contains - based on the total weight of the dyeing agent - one or more aliphatic Ci-Ce monoalcohols (F-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.%.

15. Dyeing agent according to one of claims 1 to 14, characterized in that it contains - based on the total weight of the dyeing agent - 10 to 50 wt.%, preferably 15 to 45 wt.%, more preferably 20 to 40 wt.% and most preferably 25 to 35 wt.% water (F-6).

16. Dyeing agent according to any one of claims 1 to 15, characterized in that the components (F-1), (F-2), (F-3), (F-4), (F-5) and (F-6) are together contained in the dyeing agent in a quantity of at least 94.0 wt.%, preferably at least 95 wt.%, further preferably at least 96 wt.%, even more preferably at least 99 wt.% and most preferably at least 99.7 wt.%.

17. Method for dyeing keratinous fibers, in particular human hair, in which a dyeing agent according to one of claims 1 to 16 is applied to the keratinous fibers and optionally rinsed off after an exposure time.

18. The method according to claim 17 comprising - the application of the dye to the keratinous fibers, and - heating the keratinous fibers covered with the dye to 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.

Images