Method for decolorizing keratinous fibers that have been dyed using a dye containing a chitosan and a dyeing compound

Abstract

The invention relates to a method for decolorizing keratinous fibers that have been dyed using a dye containing at least one chitosan and at least one dyeing compound, wherein a water-containing decolorizing agent with a pH value of 1.4 to 3.4 is applied to the dyed keratinous fibers and rinsed off again after an exposure time.

Description

[0001] Henkel AG & Co. KGaA

[0002] 2024P00203WO

[0003] Method for decolorizing keratin fibers that have been dyed with a dye containing chitosan and a coloring compound

[0004] The present application relates to a method for decolorizing keratinous fibers that have been dyed by applying a dye containing at least one chitosan and at least one coloring compound. For decolorization, an aqueous decolorizing agent having a pH of 1.4 to 3.4 is applied to the dyed keratinous fibers and rinsed off after a reaction time.

[0005] A second subject matter of the present application is a multi-component packaging unit (kit-of-parts) which comprises the dyeing agent and the decolorizing agent described above in separately packaged containers.

[0006] A third subject of this application is the use of the previously described decolorizing agent for the decolorization of dyed keratinous fibers.

[0007] 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.

[0008] 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.

[0009] The use of color pigments is known for temporary color changes on hair and / or skin. Pigments or color pigments are generally understood to be insoluble, coloring substances. These are present undissolved in the form of small particles in the coloring formulation and are simply deposited on the outside of the hair fibers and / or the skin.

[0010] 2

[0011] They adhere to the skin's surface. Therefore, they can usually be removed completely after a few washes with surfactant-based detergents. Various products of this type are available on the market under the name "hair mascara."

[0012] 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.

[0013] For example, German patent DE 19847883 A1 deals with the implementation of 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 lies in the fact that it is based on biopolymers and therefore possesses improved environmental compatibility and biodegradability. Since many users are showing increasing interest in products with sustainable or renewable raw materials, the use of biopolymers is increasingly coming into focus.

[0014] In the previously described coloring processes, it may be necessary to reverse the coloring, either partially or completely, for various reasons. Partial removal of the color might be required, for example, if the result is darker than desired. Conversely, complete removal of the color may be desired in some cases. For instance, one might want to color their hair a specific shade for a particular occasion and then want to restore the original color after a few days.

[0015] The object of the present invention was therefore to provide a decolorizing agent for removing the color from dyed keratin fibers, in particular human hair, which had previously been dyed by applying at least one chitosan and a coloring compound (in particular a pigment and / or a direct dye). The decolorization should be as complete as possible, so that ideally the color of the keratin fibers can be restored to its original state. The decolorization should be long-lasting and uniform, and the decolorized keratin fibers should not suffer any shifts in shade or inconsistencies in the color result. Furthermore, the decolorizing agent should cause as little damage as possible to the keratin fibers, and the ingredients should be toxicologically and ecologically safe. 2024P00203WG

[0016] 3

[0017] Surprisingly, it has now been found that this problem can be solved very effectively by treating keratin fibers, previously dyed with at least one chitosan and one pigment or direct dye, with a highly acidic bleaching agent. Crucially, the bleaching agent used must have a pH value between 1.4 and 3.4.

[0018] A first object of the present invention is a method for decolorizing keratinous fibers which have been colored by applying a dye containing at least one chitosan and at least one coloring compound, wherein an aqueous decolorizing agent having a pH value of 1.4 to 3.4 is applied to the colored keratinous fibers and rinsed off after an exposure time.

[0019] The keratin fibers treated with chitosan and pigment (or direct dye) were previously colored via a surface coloration. This means that the coloring compounds did not diffuse into the hair fiber but were deposited on the fiber's surface, embedded in the film formed by the chitosan, and thus immobilized. It was found that a strongly acidic post-treatment caused this film to swell so effectively that the coloring compounds and the film itself detached almost completely and very uniformly from the fibers. In this way, a very uniform decolorization was achieved along the entire length of the fiber.

[0020] Decolorization of keratinous fibers

[0021] Keratinous fibers include wool, fur, feathers, and especially human hair. Human hair is particularly favored as a keratinous fiber.

[0022] In the context of this invention, the term "decolorizing agent" means that a coloration is applied to the keratin material by applying at least one chitosan and at least one coloring compound, in particular a coloring compound from the group consisting of pigments and direct dyes. During the coloring process, the keratin material or keratin fiber is coated with a colored film formed by the chitosan and dye. According to the invention, the decolorizing agent is applied after the application of the coloring agent, and the decolorizing agent is capable of removing this colored film from the keratin material.

[0023] Characteristic of the process according to the invention is the application of the decolorizing agent to keratin material which has previously been colored by applying at least one chitosan and the aforementioned coloring compound.

[0024] A preferred method is for the decolorization of hair which is caused by the application of a dye containing at least one chitosan and at least one coloring compound 2024P00203WG

[0025] 4 were dyed, whereby a water-based bleaching agent, which has a pH value of 1.4 to 3.4, is applied to the dyed hair and rinsed off after a reaction time.

[0026] Staining using chitosans

[0027] According to the invention, the decolorizing agent is applied after using a dye containing at least one chitosan.

[0028] 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 solely of linearly linked 2-amino-2-deoxy-β-D-glucopyranose or glucosamine monomers. Chitosan has the CAS number 9012-76-4.

[0029] 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: it 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 widely, for example, from 20,000 to approximately 5 million g / mol.

[0030] 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.

[0031] 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.

[0032] In a further particularly preferred embodiment, a process according to the invention is characterized in that the dye contains at least one chitosan and / or a chitosan derivative with a molecular weight of 20,000 to 800,000 g / mol, preferably 50,000 to 600,000 g / mol, more preferably 80,000 to 450,000 g / mol, and most preferably 100,000 to 300,000 g / mol. 2024P00203WG

[0033] In a further particularly preferred embodiment, a method according to the invention is characterized in that the dye contains at least one chitosan 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.

[0034] Chitosan with a molecular weight of 100,000 to 300,000 g / mol can, for example, be purchased commercially from the company Sigma Aldrich.

[0035] 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%.

[0036] Another low molecular weight chitosan with a molecular weight of approximately 70,000 g / mol, which also bears the CAS number 9012-76-4, can be obtained commercially from the company Fluka as deacetylated chitin of a white solid.

[0037] 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.

[0038] 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.

[0039] It has proven particularly advantageous if the previously used dye contains the chitosans and / or chitosane derivatives in certain quantity ranges. Particularly good results were obtained when the dye—based on the total weight of the dye—contained one or more chitosans and / or chitosane derivatives in a total amount of 0.1 to 10.0 wt.%, preferably 0.2 to 8.0 wt.%, more preferably 0.5 to 6.0 wt.%, and most preferably 0.7 to 2.5 wt.%.

[0040] Dyeing using coloring compounds

[0041] According to the invention, the decolorizing agent is applied after using a dye containing at least one coloring compound.

[0042] The decolorizing agent is particularly preferably used after the application of a dye containing at least one coloring compound from the group consisting of pigments and direct dyes. 2024P00203WG

[0043] In a particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent is applied to keratinous fibers which have been colored by the application of at least one pigment.

[0044] 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.

[0045] Suitable color pigments can be of inorganic and / or organic origin. In a preferred embodiment, a method according to the invention is characterized in that the post-treatment agent is applied to keratin material which has been colored by the application of at least one inorganic and / or organic pigment.

[0046] Preferred color pigments are selected from synthetic or natural inorganic pigments. Inorganic color pigments of natural origin can be produced, for example, from chalk, ochre, umber, green earth, burnt sienna, or graphite. Furthermore, black pigments such as iron oxide black, colored pigments such as ultramarine or iron oxide red, as well as fluorescent or phosphorescent pigments can be used as inorganic color pigments.

[0047] Particularly suitable are colored metal oxides, hydroxides and oxide hydrates, mixed-phase pigments, sulfur-containing silicates, silicates, metal sulfides, complex metal cyanides, metal sulfates, chromates and / or molybdates. Especially preferred color pigments are black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and brown iron oxide (CI 77491), manganese violet (CI 77742), ultramarine (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), iron blue (ferric ferrocyanide, CI 77510) and / or carmine (cochineal).

[0048] 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.

[0049] 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).

[0050] In a further preferred embodiment, a method according to the invention is characterized in that the previously applied coloring agent contains at least an inorganic pigment, 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.

[0051] In a further preferred embodiment, a method according to the invention is characterized in that the previously applied coloring agent 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).

[0052] 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.

[0053] Particularly favored color pigments with the trade name Colorona® include, for example:

[0054] Colorona Copper, Merck, MICA, CI 77491 (IRON OXIDES)

[0055] Colorona Passion Orange, Merck, Mica, CI 77491 (Iron Oxides), Alumina

[0056] Colorona Patina Silver, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE) Colorona RY, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 75470 (CARMINE)

[0057] Colorona Oriental Beige, Merck, MICA, CI 77891 (TITANIUM DIOXIDE), CI 77491 (IRON OXIDES) Colorona Dark Blue, Merck, MICA, TITANIUM DIOXIDE, FERRIC FERROCYANIDE

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

[0059] Colorona Aborigine Amber, Merck, MICA, Cl 77499 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE)

[0060] Colorona Blackstar Blue, Merck, Cl 77499 (IRON OXIDES), MICA

[0061] Colorona Patagonian Purple, Merck, MICA, Cl 77491 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE), Cl 77510 (FERRIC FERROCYANIDE)

[0062] Colorona Red Brown, Merck, MICA, Cl 77491 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE)

[0063] Colorona Russet, Merck, Cl 77491 (TITANIUM DIOXIDE), MICA, Cl 77891 (IRON OXIDES)

[0064] Colorona Imperial Red, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), D&C RED NO. 30 (Cl 73360)

[0065] Colorona Majestic Green, Merck, Cl 77891 (TITANIUM DIOXIDE), MICA, Cl 77288 (CHROMIUM OXIDE GREENS)

[0066] Colorona Light Blue, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), FERRIC FERROCYANIDE (Cl 77510)

[0067] Colorona Red Gold, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0068] Colorona Gold Plus MP 25, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), IRON OXIDES (Cl 77491)

[0069] Colorona Carmine Red, Merck, MICA, TITANIUM DIOXIDE, CARMINE

[0070] Colorona Blackstar Green, Merck, MICA, Cl 77499 (IRON OXIDES)

[0071] Colorona Bordeaux, Merck, MICA, Cl 77491 (IRON OXIDES)

[0072] Colorona Bronze, Merck, MICA, Cl 77491 (IRON OXIDES)

[0073] Colorona Bronze Fine, Merck, MICA, Cl 77491 (IRON OXIDES)

[0074] Colorona Fine Gold MP 20, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0075] Colorona Sienna Fine, Merck, Cl 77491 (IRON OXIDES), MICA

[0076] Colorona Sienna, Merck, MICA, Cl 77491 (IRON OXIDES)

[0077] Colorona Precious Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Silica, Cl 77491 (Iron oxides), Tin oxide

[0078] Colorona Sun Gold Sparkle MP 29, Merck, MICA, TITANIUM DIOXIDE, IRON OXIDES, MICA, Cl 77891 , Cl 77491 (EU)

[0079] Colorona Mica Black, Merck, Cl 77499 (Iron oxides), Mica, Cl 77891 (Titanium dioxide)

[0080] Colorona Bright Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Cl 77491 (Iron oxides)

[0081] Colorona Blackstar Gold, Merck, MICA, Cl 77499 (IRON OXIDES)

[0082] Weiterhin besonders bevorzugte Farbpigmente mit der Handelsbezeichnung Xirona® sind beispielsweise:

[0083] Xirona Golden Sky, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0084] Xirona Caribbean Blue, Merck, Mica, CI 77891 (Titanium Dioxide), Silica, Tin Oxide

[0085] Xirona Kiwi Rose, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide 2024P00203WG

[0086] 9

[0087] Xirona Magic Mauve, Merck, Silica, Cl 77891 (Titanium Dioxide), Tin Oxide.

[0088] In addition, particularly preferred color pigments with the trade name Unipure® include, for example:

[0089] Unipure Red LC 381 EM, Sensient CI 77491 (Iron Oxides), Silica

[0090] Unipure Black LC 989 EM, Sensient, CI 77499 (Iron Oxides), Silica

[0091] Unipure Yellow LC 182 EM, Sensient, CI 77492 (Iron Oxides), Silica

[0092] In another embodiment, the keratinous fibers may also have been previously dyed with a dye containing at least one organic pigment.

[0093] 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.

[0094] 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.

[0095] In a further particularly preferred embodiment, a method according to the invention is characterized in that the previously applied coloring agent 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. 2024P00203WG

[0096] 10

[0097] 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.

[0098] For example, alizarin lacquer can be used as a colored lacquer.

[0099] 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.

[0100] In a further preferred embodiment, a method according to the invention is characterized in that the dyeing agent contains at least one pigment selected from the group consisting of pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet, and vacuum metallized pigments.

[0101] 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.

[0102] 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.

[0103] The size of the substrate platelet can be tailored to the specific application, particularly the desired effect on the keratinous material. Typically, the 2024P00203WG

[0104] 11

[0105] Substrate platelets have a mean maximum diameter of about 2 to 200 pm, especially about 5 to 100 pm.

[0106] 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.

[0107] The substrate plates can be made from any material that can be formed into platelet form.

[0108] 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).

[0109] 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.

[0110] Lamellar substrate platelets are characterized by an irregularly structured edge and are also referred to as "cornflakes" due to their appearance.

[0111] 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.

[0112] Lenticular (lens-shaped) substrate plates have a generally regular, rounded edge and are also called "silver dollars" due to their appearance. 2024P00203WG

[0113] 12

[0114] Due to their regular structure, the proportion of reflected light predominates in pigments based on lenticular substrate platelets.

[0115] 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.

[0116] The substrate plates made of metal or metal alloy can be passivated, for example by anodizing (oxide layer) or chromating.

[0117] 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.

[0118] Suitable pigments based on a lamellar substrate platelet include, for example, the VISIONAIRE series pigments from Eckart.

[0119] Pigments based on a lenticular substrate platelet are available, for example, under the name Alegrace® Gorgeous from the company Schlenk Metallic Pigments GmbH.

[0120] Pigments based on a substrate platelet comprising a vacuum metallized pigment are available, for example, under the name Alegrace® Marvelous or Alegrace® Aurous from Schlenk Metallic Pigments GmbH.

[0121] Due to their excellent light and temperature resistance, the use of the aforementioned pigments in the composition 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). 2024P00203WG

[0122] 13

[0123] In another embodiment, the decolorizing agent can also be applied to keratinous fibers that have previously been colored by the use of at least one direct dye.

[0124] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent is applied to keratinous fibers which have been colored by the application of at least one direct dye, particularly preferably at least one anionic direct dye.

[0125] Direct dyes are dyes that adhere directly to the hair and do not require an oxidative process to develop color. Direct dyes are typically nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinones, triarylmethane dyes, or indophenols.

[0126] Direct dyes can be nonionic, cationic, or anionic. It is particularly preferred if the dye (F) contains at least one anionic direct dye, which can alternatively also be referred to as an acid dye.

[0127] 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 rudimentary forms (-COOH, -SO3H) of the carboxylic acid or sulfonic acid groups exist in equilibrium with their deprotonated forms (-COO-, -SCh, or -OSCh-). The proportion of rudimentary forms increases with decreasing pH. When direct-drawing dyes are used in the form of their salts, the carboxylic acid or sulfonic acid groups exist in deprotonated form and are neutralized with corresponding stoichiometric equivalents of cations to maintain electroneutrality. Acid dyes according to the invention can also be used in the form of their sodium salts and / or potassium salts.

[0128] 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.

[0129] 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.

[0130] Als Beispiele für Säurefarbstoffe können können genannt werden: Acid Yellow 1 (D&C Yellow 7, Citronin A, Ext. D&C Yellow No. 7, Japan Yellow 403, CI 10316, COLIPA n° B001), Acid Yellow 3 (COLIPA n° : C 54, D&C Yellow N° 10, Quinoline Yellow, E104, Food Yellow 13), Acid Yellow 9 (CI 13015), Acid Yellow 17 (C1 18965), Acid Yellow 23 (COLIPA n° C 29, Covacap Jaune W 1 100 (LCW), Sicovit Tartrazine 85 E 102 (BASF), Tartrazine, Food Yellow 4, Japan Yellow 4, FD&C Yellow No. 5), Acid Yellow 36 (CI 13065), Acid Yellow 121 (CI 18690), Acid Orange 6 (CI 14270), Acid Orange 7 (2-Naphthol orange, Orange II, C1 15510, D&C Orange 4, COLIPA n° C015), Acid Orange 10 (C.l. 16230; Orange G sodium salt), Acid Orange 11 (Cl 45370), Acid Orange 15 (Cl 50120), Acid Orange 20 (Cl 14600), Acid Orange 24 (BROWN 1 ;CI20170;KATSU201 ;nosodiumsalt;Brown No.201 ;RESORCIN BROWN;ACID ORANGE 24;Japan Brown 201 ;D & C Brown No.1), Acid Red 14 (C.1.14720), Acid Red 18 (E124, Red 18; Cl 16255), Acid Red 27 (E 123, Cl 16185, C-Rot 46, Echtrot D, FD&C Red Nr.2, Food Red 9, Naphtholrot S), Acid Red 33 (Red 33, Fuchsia Red, D&C Red 33, Cl 17200), Acid Red 35 (Cl C.l.18065), Acid Red 51 (Cl 45430, Pyrosin B, Tetraiodfluorescein, Eosin J, lodeosin), Acid Red 52 (Cl 45100, Food Red 106, Solar Rhodamine B, Acid Rhodamine B, Red n° 106 Pontacyl Brilliant Pink), Acid Red 73 (Cl Cl 27290), Acid Red 87 (Eosin, Cl 45380), Acid Red 92 (COLIPA n° C53, Cl 45410), Acid Red 95 (Cl 45425, Erythtosine.Simacid Erythrosine Y), Acid Red 184 (Cl 15685), Acid Red 195, Acid Violet 43 (Jarocol Violet 43, Ext. D&C Violet n° 2, C.l. 60730, COLIPA n° C063), Acid Violet 49 (Cl 42640), Acid Violet 50 (Cl 50325), Acid Blue 1 (Patent Blue, Cl 42045), Acid Blue 3 (Patent Blau V, Cl 42051), Acid Blue 7 (Cl 42080), Acid Blue 104 (Cl 42735), Acid Blue 9 (E 133, Patentblau AE, Amidoblau AE, Erioglaucin A, Cl 42090, C.l.Food Blue 2), Acid Blue 62 (Cl 62045), Acid Blue 74 (E 132, Cl 73015), Acid Blue 80 (Cl 61585), Acid Green 3 (Cl 42085, Foodgreenl), Acid Green 5 (Cl 42095), Acid Green 9 (C.1.42100), Acid Green 22 (C.1.42170), Acid Green 25 (Cl 61570, Japan Green 201 , D&C Green No. 5), Acid Green 50 (Brillantsäuregrün BS, C.l. 44090, Acid Brilliant Green BS, E 142), Acid Black 1 (Black n° 401 , Naphthalene Black 10B, Amido Black 10B, Cl 20 470, COLIPA n° B15), Acid Black 52 (Cl 15711), Food Yellow 8 (Cl 14270), Food Blue 5, D&C Yellow 8, D&C Green 5, D&C Orange 10, D&C Orange 11 , D&C Red 21 , D&C Red 27, D&C Red 33, D&C Violet 2 und / oder D&C Brown 1 .

[0131] In a further embodiment, a method according to the invention is characterized in that the dye (F) contains at least one acid dye (F-2) 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, 2024P00203WG

[0132] 15

[0133] Acid Green 5, Acid Green 9, Acid Green 22, Acid Green 25, Acid Green 50, Acid Black 1, Acid Black 52, Food Yellow 8, Food Blue 5, D&C Yellow 8, D&C Green 5, D&C Orange 10, D&C Orange 11, D&C Red 21, D&C Red 27, D&C Red 33, D&C Violet 2 and / or D&C Brown 1 .

[0134] 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.

[0135] 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 whose solubility is so high that they can no longer be classified as organic pigments, but which nevertheless possess relatively poor solubility.

[0136] For this reason, acid dyes are particularly preferred as organic coloring compounds which have a solubility of less than 20 g / L, preferably less than 18 g / L, even more preferably less than 15 g / L and most preferably less than 12 g / L in water at 25 °C.

[0137] In a further particularly preferred embodiment, the decolorizing agent according to the invention is applied to keratinous fibers that have previously been dyed by a dye containing at least one acid dye which has a solubility in water at 25 °C of less than 20 g / L, preferably less than 18 g / L, more preferably less than 15 g / L and most preferably less than 12 g / L.

[0138] The water solubility of anionic direct-acting dyes can be determined, for example, using the following method. Place 0.1 g of the anionic direct-acting dye into a beaker. Add a magnetic stir bar. Then add 100 ml of water. Heat this mixture to 25 °C on a magnetic stirrer while stirring. Stir for 60 minutes. Afterward, visually inspect the aqueous mixture. If undissolved dye remains, increase the amount of water—for example, in 10 ml increments—until the dye is completely dissolved. If the dye-water mixture cannot be visually assessed due to the high intensity of the dye, filter the mixture. If some undissolved dye remains on the filter paper, repeat the solubility test with a larger amount of water.If 0.1 g of the anionic direct-drawing dye dissolves in 100 ml of water at 25 °C, the solubility of the dye is 1.0 g / L.

[0139] 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).

[0140] 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).

[0141] 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).

[0142] 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.

[0143] 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).

[0144] 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.%.

[0145] 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).

[0146] 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).

[0147] 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).

[0148] 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 the form of its disodium salt, has a solubility of 10 g / L in water at 25 °C.

[0149] Application of the bleaching agent

[0150] The bleaching agent is applied to the keratin fibers, which have been dyed as described above, for the purpose of bleaching. Since the bleaching agent is applied to the dyed hair, it must be applied to the keratin material after the application of the dye described above. 2024P00203WG

[0151] 17

[0152] In other words, the bleaching agent is applied to the keratin fibers after the dye has been rinsed out and the fibers have preferably been dried to accurately determine the color result.

[0153] The exact timing of the bleaching agent application depends on the user's desire to remove the unwanted or no longer needed color. For example, the bleaching agent can be applied to the colored keratin fibers 12 to 24 hours after applying the dye. Alternatively, the user can wear the colored keratin fibers, particularly the hair, for several days to weeks until they decide to change the color or until they want to return to their original hair color. The pH value of the bleaching agent is...

[0154] The aqueous decolorizing agent is characterized by its acidic pH value of 1.4 to 3.4. This acidic pH causes the chitosan film to swell and become permeable, allowing the pigments or dyes embedded in the film to be released and dispersed back into the decolorizing agent. The chitosan film is at least partially exposed and can thus be easily removed from the keratin surface.

[0155] It was found that the chitosan film coating the fibers begins to swell when the decolorizing agent has a sufficiently low pH value. The film then becomes softer and less stable, detaches more quickly from the keratin fiber, and in this way also separates the color-imparting compounds from the surface of the keratin fibers.

[0156] Very good decolorizing effect occurs at a pH of 3.4 or lower. This effect can be further optimized by lowering the pH. In this context, it has proven particularly advantageous for the decolorizing agent to have a pH of 1.4 to 3.8, preferably 1.6 to 3.5, more preferably 1.8 to 3.3, and most preferably 2.0 to 3.0.

[0157] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent has a pH value of 1.4 to 3.8, preferably 1.6 to 3.5, more preferably 1.8 to 3.3 and most preferably 2.0 to 3.0.

[0158] Lowering the pH value in the decolorizing agent can be achieved by using at least one inorganic and / or organic acid.

[0159] Suitable inorganic acids include hydrochloric acid, phosphoric acid, and sulfuric acid. Decolorizing agents containing at least one organic acid dissolve or partially dissolve the chitosan film particularly well and are therefore especially preferred. Particularly suitable organic acids include citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid, benzoic acid, and acetic acid.

[0160] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent contains at least one organic acid, which is preferably selected from the group consisting of citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid, benzoic acid and acetic acid.

[0161] Formic acid and propanoic acid are also suitable as organic acids.

[0162] Water content in the decolorizing agent

[0163] The decolorizing agent is adjusted to an acidic pH value and therefore contains water.

[0164] It is preferred if the decolorizing agent has a water content of 20.0 to 99.5 wt.%, preferably 40.0 to 99.0 wt.%, more preferably 60 to 98.0 wt.%, even more preferably 70 to 95.0 wt.% and most preferably 75.0 to 93.0 wt.%, based on the total weight of the decolorizing agent.

[0165] Surfactants in the decolorizing agent

[0166] As an optional component, the decolorizing agent used in the process according to the invention contains at least one surfactant. The surfactants ensure that the released color-causing compounds and film components are well stabilized or dispersed in the decolorizing agent and do not redeposit on the surface of the keratin fibers.

[0167] It has been found that certain classes of surfactants are particularly good at dissolving or dispersing the dyes and / or the detached film components.

[0168] If the decolorizing agent contained at least one sugar surfactant, a particularly good decolorizing effect without redeposition of the dyes on the keratin surface could be observed.

[0169] Furthermore, sugar surfactants have the distinct advantage of being biologically based, meaning that users who have colored their hair with the most environmentally friendly dyes possible can also rely on a particularly sustainable and natural product for the bleaching step. 2024P00203WG

[0170] 19

[0171] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent contains at least one sugar surfactant, particularly preferably at least one non-ionic sugar surfactant.

[0172] For the purposes of this application, sugar surfactants are understood to be surfactants whose molecular structure comprises at least one sugar unit.

[0173] Non-ionic sugar surfactants are defined as uncharged surfactants, i.e., neither cationic nor cationizable, nor anionic or anionizable, whose molecular structure includes at least one sugar unit. Suitable sugar surfactants include, for example, alkyl polyglycosides and / or esters of fatty acids with sugars or sugar derivatives.

[0174] Alkyl polyglucosides, or alkyl glucosides for short, can be described by the structural formula (T-1). where

[0175] Rb represents a linear or branched Ce-C24 alkyl group and

[0176] P represents an integer from 1 to 100, preferably from 1 to 30 and particularly preferably from 1 to 10.

[0177] Alkyl polyglucosides are also known to those skilled in the art by the abbreviation APG.

[0178] Decyl polyglucoside and lauryl polyglucoside, marketed by BASF under the trade names Plantacare 2000, Plantaren 2000, and Plantaren 1200 respectively, are particularly preferred. Lauryl glucoside is commercially available from BASF as an approximately 51% aqueous solution under the trade names Plantacare 1200 UP or NP. The CAS numbers for lauryl glucoside are 59122-55-3, 27836-64-2, 110615-47-9, and 113976-90-2. Furthermore, particularly good results have been obtained with surfactants from the mannosylerythritol lipid group, also known to those skilled in the art by the abbreviation MEL or MEL surfactants.

[0179] Mannosylerythritol lipids (MELs) are surfactants consisting of a hydrophilic part, 4-ObD-mannopyranosyl-meso-erythritol, and a hydrophobic part, which is a fatty acid or an acetyl group. They are obtained by fermentation from various microorganisms, primarily Pseudozyma sp., but also Ustilago sp. and Schizonella melanogramma. Due to their origin, they are classified as biosurfactants. The MELs used according to this invention are particularly preferably compounds of the general formula (T-2). where

[0180] Rc and Rd independently represent a hydrogen atom or an acetyl group, where r is an integer from 6 to 10 and s is an integer from 6 to 10.

[0181] A distinction is made between

[0182] MEL-A: Rc = Rd = Ac

[0183] MEL-B: Rc = Ac, Rd = H

[0184] MEL-C: Rc = H, Rd = Ac

[0185] MEL-D: Rc = Rd = H.

[0186] In a preferred embodiment, a mixture of MEL-A and MEL-B is used in the surfactant system according to the invention. 2024P00203WG

[0187] 21

[0188] In a particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent contains one or more non-ionic sugar surfactants from the group consisting of alkyl(poly)glucosides and mannosyl erythritol lipids.

[0189] Other suitable sugar surfactants include, for example, non-ionic surfactants of the sugar fatty acid ester or alkyl sugar ester type. These are esters of Ce-C24 fatty acids and sugars or alkyl sugars.

[0190] Methylglucoside monostearate is a corresponding product sold under the name GRILLOCOSE IS by the company GRILLOWERKE.

[0191] Methylglucosides sesquistearate is sold under the name GLUCATE SS by the company AMERCHOL.

[0192] Ethyl 6-glucoside decanoate is sold by NOVO under the name BIOSURF 10. A mixture of ethyl 6-glucoside mono- and dicocoat (82 / 7), such as the product sold by NOVO under the name BIOSURF COCO;

[0193] The mixture of ethyl 6-glucoside mono- and dilaurate (84 / 8) is sold by NOVO under the name BIOSURF 12.

[0194] C-fatty acid monoesters of butyl glucoside, such as butyl glucoside monocoat, are sold by REWO under the names REWOPOL V3101 or REWOSAN V3101. Butyl glucoside monocoat, polyoxyethylated with 3 mol ethylene oxide, is sold by REWO under the name REWOPOL V3122.

[0195] The sugar surfactant(s) of the group are preferably present in the decolorizing agent in specific quantity ranges, based on the total weight of the decolorizing agent. Preferably, the decolorizing agent contains one or more sugar surfactants in a total amount of 0.1 to 15.0 wt.%, more preferably 0.2 to 9.5 wt.%, further preferably 0.5 to 4.5 wt.%, and particularly preferably 0.8 to 3.0 wt.%.

[0196] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent - based on the total weight of the decolorizing agent - contains one or more sugar surfactants, preferably one or more non-ionic sugar surfactants, particularly preferably one or more alkyl(poly)glucosides, in a total amount of 0.1 to 15.0 wt.%, preferably 0.2 to 9.5 wt.%, more preferably 0.5 to 4.5 wt.% and particularly preferably 0.8 to 3.0 wt.%.

[0197] The presence of zwitterionic and / or amphoteric surfactants in the decolorizing agent has also proven particularly advantageous for achieving a complete and uniform decolorizing effect. In a further, particularly preferred embodiment, a process according to the invention is characterized in that the decolorizing agent contains at least one zwitterionic and / or amphoteric surfactant.

[0198] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent contains at least one zwitterionic surfactant selected from the surfactants of formula (T-3), (T-4), (T-5) and / or (T-6),

[0199] (T-6) where

[0200] R2, R3, R4, R5 independently represent a linear or branched, saturated or unsaturated Ca-Cso alkyl group, preferably a linear, saturated or unsaturated Ci2-Cia alkyl group. 2024P00203WG

[0201] 23

[0202] The R2 group represents a linear or branched, saturated or unsaturated Ca-Cso alkyl group, preferably a linear, saturated or unsaturated Cn-C2i alkyl group, and most preferably a linear, saturated or unsaturated Cn-C alkyl group.

[0203] The R3 group represents a linear or branched, saturated or unsaturated Ca-Cso alkyl group, preferably a linear, saturated or unsaturated Cn-C2i alkyl group, and most preferably a linear, saturated or unsaturated Cn-C alkyl group.

[0204] The R4 group represents a linear or branched, saturated or unsaturated Ca-Cso alkyl group, preferably a linear, saturated or unsaturated Ci2-Cia alkyl group.

[0205] The residue R5 represents a linear or branched, saturated or unsaturated Ca-Cso alkyl group, preferably a linear, saturated or unsaturated Ci2-Cia alkyl group.

[0206] Particularly suitable zwitterionic surfactants of formula (T-3) are alkylamidoalkyl betaines. Particularly suitable amphoteric surfactants include those known under the INCI names cocamidopropyl betaine and cocamidopropyl betaine.

[0207] Particularly suitable zwitterionic surfactants of formula (T-4) include, for example, C12-C14 alkyldimethyl betaines, which can be obtained under the INCI name Coco-Betaine in the form of the trade product Genagen KB from Global Amines (formerly Clariant). Coco-Betaine has the CAS number 66455-29-6.

[0208] In particular, the zwitterionic surfactants of formula (T-3) and (T-5) have shown a particularly good suitability for solving the problem according to the invention.

[0209] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent contains at least one zwitterionic surfactant selected from the surfactants of formula (T-3) and / or (T-5).

[0210] To achieve particularly good decolorization performance with the process according to the invention, the decolorizing agent preferably contains the amphoteric or zwitterionic surfactants in specific quantity ranges. Particularly complete and uniform decolorization was observed when the decolorizing agent—based on the total weight of the decolorizing agent—contained one or more zwitterionic and / or amphoteric surfactants in a total amount of 0.1 to 20.0 wt.%, preferably 0.3 to 10.0 wt.%, more preferably 0.5 to 6.5 wt.%, and most preferably 1.0 to 4.5 wt.%. 2024P00203WG

[0211] 24

[0212] Furthermore, the decolorizing agent used in the process according to the invention can optionally also contain one or more anionic surfactants.

[0213] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent contains at least one anionic surfactant.

[0214] In principle, all anionic surfactants suitable for use on the human body can be used as anionic surfactants. These are characterized by a water-soluble anionic group, such as a carboxylate, sulfate, sulfonate, or phosphate group, and a lipophilic alkyl group with approximately 8 to 30 carbon atoms. Additionally, the molecule may contain glycol or polyglycol ether groups, ester, ether, and amide groups, as well as hydroxyl groups.Typical examples of anionic surfactants are alkylbenzenesulfonates, alkanesulfonates, olefin sulfonates, alkyl ethersulfonates, glycerol ethersulfonates, α-methyl ester sulfonates, sulfofatidic acids, alkyl sulfates, fatty alcohol ether sulfates, glycerol ether sulfates, hydroxomixed ether sulfates, monoglyceride (ether) sulfates, fatty acid amide (ether) sulfates, mono- and dialcyl sulfosuccinates, mono- and dialkyl sulfosuccinamates, sulfotriglycerides, amide soaps, ether carboxylic acids and their salts, fatty acid isethionates, fatty acid sarcosinates, fatty acid taurides, acyl lactylates, acyltartrates, acyl glutamates, acylaspartates, alkyl oligoglucoside sulfates, protein fatty acid condensates (especially plant-based wheat products) and alkyl (ether) phosphates. If the anionic surfactants contain polyglycol ether chains, these can have a conventional, but preferably a narrow homolog distribution.Examples of particularly suitable anionic surfactants are, in the form of sodium, potassium and ammonium as well as mono-, di- and trialkanolammonium salts with 2 to 4 C atoms in the alkanol group, linear and branched fatty acids with 8 to 30 C atoms (soaps).

[0215] Ethercarboxylic acids of the formula RO-(CH2-CH2O) X -CH2-COOH, in which R is a linear alkyl group with 8 to 30 C atoms and x = 0 or 1 to 16,

[0216] Acylsarcosides with 8 to 24 carbon atoms in the acyl group,

[0217] Acyltaurides with 8 to 24 carbon atoms in the acyl group,

[0218] Acyl isethionates with 8 to 24 carbon atoms in the acyl group are long-known, skin-friendly surfactants that can be obtained by esterifying fatty acids with the sodium salt of 2-hydroxyethanesulfonic acid (isethionic acid). When fatty acids with 8 to 24 carbon atoms, such as lauric, myristic, palimic, or stearic acid, or even technical fatty acid fractions, e.g., the C12-Cia fatty acid fraction obtained from coconut fatty acid, are used for this esterification, the C12-cis-acylisethionates, which are preferably suitable according to the invention, are obtained. It is known to process the sodium salts of C12-cis-acylisethionates into a suitable form for transport and application, similar to fatty acid-based soaps, by kneading, piling, extrusion, cutting, and pressing. (See 2024P00203WG)

[0219] 25. Needles, granules, noodles, or bars can be produced in this way. One application of acylisethionates is in toilet soap bars and syndets, sulfosuccinic acid mono- and dialkyl esters with 8 to 24 carbon atoms in the alkyl group, and sulfosuccinic acid monoalkyl polyoxyethyl esters with 8 to 24 carbon atoms in the alkyl group and 1 to 6 oxyethyl groups. The sulfosuccinic acid monoalkyl (C8-C24) ester disodium salts are produced by a known process, e.g., by reacting maleic anhydride with a fatty alcohol with 8-24 carbon atoms to form the maleic acid monoester of the fatty alcohol and sulfitizing this with sodium sulfite to form the sulfosuccinic acid ester. Particularly suitable sulfosuccinic acid esters are derived from fatty alcohol fractions with 12-18 carbon atoms, such as those found in... B. from coconut fatty acid or coconut fatty acid methyl esters accessible by hydrogenation, linear alkanesulfonates with 8 to 24 C atoms, linear alpha-olefin sulfonates with 8 to 24 C atoms,

[0220] Alpha-sulfofatis methyl esters of fatty acids with 8 to 30 carbon atoms,

[0221] Alkyl sulfates and alkyl polyglycol ether sulfates of the formula RO(CH2-CH2O) X -OSO3H, in which R is a preferably linear alkyl group with 8 to 30 C atoms and x = 0 or 1 to 12, hydroxysulfonates substantially according to at least one of the following two formulas or mixtures thereof, as well as their salts, CH3-(CH2)y-CHOH-(CH2)p-(CH-SO3M)-(CH2)z-CH2-O-(CnH2nO)xH, and / or

[0222] CH3-(CH2)y-(CH-SO3M)-(CH2)p-CHOH-(CH2)z- CH2-O-(CnH2nO)xH where in both formulas y and z = 0 or integers from 1 to 18, p = 0, 1 or 2 and the sum (y+z+p) a number from 12 to 18, x = 0 or a number from 1 to 30 and n an integer from 2 to 4, and M = H or alkali, in particular sodium, potassium, lithium, alkaline earth, in particular magnesium, calcium, zinc and / or an ammonium ion, which may optionally be substituted, in particular mono-, di-, tri- or tetraammonium ions with C1 to C4 alkyl, alkenyl or aryl groups, sulfated hydroxyalkyl polyethylene and / or hydroxyalkylene propylene glycol ethers of formula R 1 - (CHOSO3M)-CHR 3 -(OCHR 4 -CH2)n-OR 2 with R 1 , a linear alkyl group with 1 to 24 carbon atoms, R 2 for a linear or branched, saturated alkyl group with 1 to 24 carbon atoms, R 3 for hydrogen or a linear alkyl group with 1 to 24 carbon atoms, R 4for hydrogen or a methyl group and M for hydrogen, ammonium, alkylammonium, alkanolammonium, wherein the alkyl and alkanol groups each have 1 to 4 C atoms, or a metal atom selected from lithium, sodium, potassium, calcium or magnesium and n for a number in the range of 0 to 12 and furthermore the total number of in R 1 and R 3 containing 2 to 44 carbon atoms, sulfonates of unsaturated fatty acids with 8 to 24 carbon atoms and 1 to 6 double bonds, esters of tartaric acid and citric acid with alcohols, which are addition products of about 2-15 molecules of ethylene oxide and / or propylene oxide to fatty alcohols with 8 to 22 carbon atoms, alkyl and / or alkenyl ether phosphates of the formula,

[0223] R 1 (OCH2CH2)nO-(PO-OX)-OR 2 , 2024P00203WÖ

[0224] 26 in the R 1 preferably for an aliphatic hydrocarbon residue with 8 to 30 carbon atoms, R 2for hydrogen, a residue (CH2CH2O) n R 2 orX, n for numbers from 1 to 10 and X for hydrogen, an alkali or alkaline earth metal or NR 3 R 4 R 5 R 6 , with R 3 to R 6 independently representing hydrogen or a Ci to C4 hydrocarbon residue, stands for sulfated fatty acid alkylene glycol esters of the formula RCO(AlkO) n SO3M in the RCO- stands for a linear or branched, aliphatic, saturated and / or unsaturated acyl group with 6 to 22 carbon atoms, Alk for CH2CH2, CHCH3CH2 and / or CH2CHCH3, n for numbers from 0.5 to 5 and M for a metal, such as alkali metal, in particular sodium, potassium, lithium, alkaline earth metal, in particular magnesium, calcium, zinc, or ammonium ion, such as + NR 3 R 4 R 5 R 6 , with R 3 to R 6 independently representing hydrogen or a C1 to C4 hydrocarbon residue,

[0225] Monoglyceride sulfates and monoglyceride ether sulfates of formula R 8 OC-(OCH2CH2)x-OCH2-[CHO(CH2CH2O)yH]-CH2O(CH2CH2O)z-SO3X, in which R 8 CO represents a linear or branched acyl group with 6 to 22 carbon atoms, x, y, and z together represent 0 or numbers from 1 to 30, preferably 2 to 10, and X represents an alkali or alkaline earth metal. Typical examples of suitable monoglyceride (ether) sulfates according to the invention are the reaction products of lauric acid monoglyceride, coconut fatty acid monoglyceride, palmitic acid monoglyceride, stearic acid monoglyceride, oleic acid monoglyceride, and tallow fatty acid monoglyceride, as well as their ethylene oxide adducts with sulfur trioxide or chlorosulfonic acid in the form of their sodium salts. Preferably, monoglyceride sulfates are used in which R 8 CO stands for a linear acyl residue with 8 to 18 carbon atoms,

[0226] Amide ether carboxylic acids, R 1 -CO-NR 2 -CH2CH2-O-(CH2CH2Ö)n CH2COOM, with R 1 as a straight-chain or branched alkyl or alkenyl group with a number of carbon atoms in the chain of 2 to 30, n stands for an integer from 1 to 20 and R 2 represents hydrogen, a methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl or isobutyl group and M represents hydrogen or a metal such as an alkali metal, in particular sodium, potassium, lithium, an alkaline earth metal, in particular magnesium, calcium, zinc, or an ammonium ion, such as + NR 3 R 4 R 5 R 6 , with R 3 to R 6 These terms independently represent hydrogen or a C1 to C4 hydrocarbon residue. Such products are available, for example, from the company Chem-Y under the product name Akypo®.

[0227] Acylglutamates of the formula XOOC-CH2CH2CH(C(NH)OR)-COOX, in which RCO stands for a linear or branched acyl group with 6 to 22 carbon atoms and 0 and / or 1, 2 or 3 double bonds and X for hydrogen, an alkali and / or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium,

[0228] Condensation products from a water-soluble salt of a water-soluble protein hydrolysate-fatty acid condensation product. These are prepared by condensation of C8-C30 fatty acids, preferably fatty acids with 12-18 carbon atoms, with amino acids, mono-, di- and water-soluble oligopeptides and mixtures of such products, as described in 2024P00203WG.

[0229] 27. These protein hydrolysate-fatty acid condensation products are formed during the hydrolysis of proteins. They are neutralized with a base and then preferably exist as alkali, ammonium, mono-, di-, or trialkanolammonium salts. Such products have long been commercially available under the trademarks Lamepon®, Maypon®, Gluadin®, Hostapon® KCG, or Amisoft®.

[0230] The decolorizing agent may also optionally contain one or more cationic surfactants.

[0231] Peeling agents in the bleach

[0232] To enhance the decolorizing effect, the decolorizing agent used in the inventive method can optionally also contain at least one peeling agent.

[0233] The term "peeling" is primarily known from skincare and refers to a cosmetic or dermatological treatment in which superficial layers of the skin are removed. The removal of the upper skin layer can be mechanical, for example using mineral or plant-based abrasives, or chemical. It has been observed that the abrasive effect of peeling agents can also promote the shedding of the hair follicle on the hair surface.

[0234] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent contains at least one peeling agent.

[0235] Chemical (exfoliative) peeling is based on the effect of different classes of substances, prominent representatives of which include, for example, fruit acids, lipo-hydroxy acid (2-hydroxy-5-octanoylbenzoic acid LHA), trichloroacetic acids (TCA), phenolic compounds and tretinoin (vitamin A acid).

[0236] Mechanical exfoliating agents include, for example, abrasive solid particles such as silica, sand (e.g., sea sand) or salt (e.g., sea salt or sodium chloride), carbonate salts, bicarbonate salts, magnesium salts, polyethylene powder, crushed or ground kernels of walnuts, apricots, peaches and / or almonds, lactic acid particles, talc powder, zeolites, rhyolite, pumice powder, chalk, shell limestone powder, marble powder, microcrystalline cellulose, sugar and / or clay. The function of the abrasive components is essentially the removal of dead skin cells, as well as sebum deposits and oils from the skin, through friction. 2024P00203WG

[0237] 28

[0238] Abrasive solid particles from the group consisting of silica, sand, sea salt, sodium chloride, polyethylene powders, crushed or ground kernels of walnuts, apricots, peaches and / or almonds, lactic acid particles, talc powder, zeolites, rhyolite, pumice powder, chalk, shell limestone powder, marble powder, microcrystalline cellulose, sugar and / or clay are particularly compatible with the acid(s) of the decolorizing agent. Therefore, it is especially advantageous if the decolorizing agent contains one or more exfoliating agents from this group.

[0239] In a further particularly preferred embodiment, a method according to the invention is characterized in that the decolorizing agent contains, as peeling agent(s), abrasive solid particles from the group consisting of silica, sand, sea salt, sodium chloride, polyethylene powders, crushed or ground kernels of walnuts, apricots, peaches and / or almonds, lactic acid particles, talc powder, zeolites, rhyolite, pumice powder, chalk, shell limestone powder, marble powder, microcrystalline cellulose, sugar and / or clay.

[0240] The exfoliating agent(s) support the removal of the swollen chitosan film through the mechanical stress that occurs when massaging in the decolorizing agent. To achieve this effect, it has proven preferable to use the exfoliating agent(s) in specific quantities within the decolorizing agent. Particularly good results were obtained when the decolorizing agent contained one or more exfoliating agents in a total amount of 0.1 to 50.0 wt.%, preferably 0.3 to 25.0 wt.%, more preferably 1.0 to 10.0 wt.%, and most preferably 3.0 to 5.0 wt.%, based on the total weight of the decolorizing agent.

[0241] Avoiding silicone connections

[0242] For sustainability reasons, it is particularly advantageous to maximize the proportion of natural or nature-based ingredients used in the process. In particular, using chitosan as a natural polymer offers users an environmentally friendly dyeing method. The proportion of natural raw materials is also preferably kept especially high in the decolorizing agent. Particularly sustainable decolorizing agents can be formulated using organic food acids (such as citric or lactic acid) and nature-based sugar surfactants.

[0243] Accordingly, it is particularly advantageous to avoid all non-natural ingredients. Environmentally conscious users often have reservations, especially regarding silicone compounds. For these reasons, it is particularly advantageous to avoid silicone compounds during the process according to the invention. In a further, particularly preferred embodiment, a process according to the invention is characterized in that no silicone compounds are used during the process.

[0244] A silicone compound is understood to be an organic substance that comprises at least one silicon atom.

[0245] In a further embodiment, a preferred method is a process for decolorizing keratinous fibers which have been dyed by applying a silicone-free dyeing agent, wherein a silicone-free decolorizing agent is applied to the dyed keratinous fibers and rinsed off again after a reaction time.

[0246] If no silicone compounds are used during the dyeing process, this means that all agents used in the process according to the invention are free of silicone compounds. The term "free of silicone compounds" or "silicone-free" means that the silicone compound content in the respective agent is 0% by weight. This content refers to the total weight of the agent.

[0247] For example, in the process according to the invention, a dyeing agent and then a decolorizing agent (N) can be applied to the keratin fibers. In this embodiment, both agents are particularly preferably free of silicone compounds.

[0248] It is particularly preferred if the dye used in the process is free of silicone compounds and applied to the keratinous fibers.

[0249] It is also particularly advantageous if a decolorizing agent free of silicone compounds is used on the keratin fibers during the process. Further optional ingredients in the decolorizing agent

[0250] In addition to the essential and optional components already described, the decolorizing agent may also contain further optional ingredients, such as anionic, nonionic, zwitterionic and / or cationic polymers; structuring agents such as glucose; hair-conditioning compounds such as phospholipids, for example, lecithin and cephalins; perfume oils, dimethyl isosorbide and cyclodextrins; fiber-improving agents, in particular mono-, di- and oligosaccharides such as glucose, galactose, fructose, and lactose; anti-dandruff agents such as piroctone olamines, zinc omadine and climbazole; amino acids and oligopeptides; protein hydrolysates of animal and / or plant origin, as well as in the form of their fatty acid condensation products or optionally anionically or cationically modified derivatives; vegetable oils; light protectants and UV blockers; active ingredients such as 2024P00203WG

[0251] 30

[0252] Panthenol, pantothenic acid, pantolactone, allantoin, pyrrolidone carboxylic acids and their salts, and bisabolol; polyphenols, in particular hydroxycinnamic acids, 6,7-dihydroxycoumarins, hydroxybenzoic acids, catechins, tannins, leucoanthocyanidins, anthocyanidins, flavanones, flavones, and flavonols; ceramides or pseudoceramides; vitamins, provitamins, and vitamin precursors; plant extracts; fats and waxes such as fatty alcohols, beeswax, montan wax, and paraffins; swelling and penetrating agents such as glycerin, propylene glycol monoethyl ether, carbonates, hydrogen carbonates, guanidines, ureas, and primary, secondary, and tertiary phosphates; opacifying agents such as latex, styrene / PVP, and styrene / acrylamide copolymers; Pearlescent agents such as ethylene glycol mono- and distearate as well as PEG-3 distearate; and propellants such as propane-butane mixtures, N2O, dimethyl ether, CO2 and air.

[0253] The selection of these additional substances will be made by a person skilled in the art according to the desired properties of the composition. Regarding further optional components and the quantities of these components used, explicit reference is made to the relevant handbooks known to those skilled in the art. The additional active ingredients and excipients are preferably used in the preparations according to the invention in quantities of 0.0001 to 25 wt.%, and in particular 0.0005 to 15 wt.%, based on the total weight of the respective composition.

[0254] Application of the decolorizing agent in the middle of Is

[0255] In the process according to the invention, the previously described decolorizing agent is applied to the colored keratinous fibers and rinsed off again after a reaction time.

[0256] The application can be done, for example, with the (gloved) hand or with the aid of an applicator such as a brush or applicator, or even a comb or brush. Preferably, the bleaching agent is applied with a gloved hand.

[0257] Depending on whether the user desires complete color removal or whether only certain sections or strands are to be colored, the color removal agent can be applied either to the entire keratinous material (such as the entire head of hair) or to specific parts or corresponding strands of the keratin material or keratin fibers.

[0258] After application, the decolorizing agent is left to act on the keratin material for a specific period of time. For example, the exposure time can range from a few seconds to 60 minutes, preferably from 15 seconds to 30 minutes, more preferably from 30 seconds to 15 minutes, and most preferably from 40 seconds to 5 minutes. After this exposure time, the decolorizing agent is rinsed off with water. 2024P00203WC

[0259] 31

[0260] The application of the decolorizing agent to the keratin fibers can be carried out at room temperature or body temperature. However, to support or accelerate the color removal, the keratin fibers treated with the decolorizing agent can also be exposed to elevated temperatures. It is preferred if the decolorizing agent is applied to the dyed keratin fibers and the application takes place at a temperature of 20 to 70 °C, preferably 25 to 60 °C, more preferably 30 to 55 °C, and most preferably 40 to 55 °C.

[0261] In a further embodiment, a method according to the invention is characterized in that

[0262] - the bleaching agent is applied to the dyed keratin fibers

[0263] - the keratinous fibers are heated to a temperature of 20 to 70 °C, preferably 25 to 60 °C, more preferably 30 to 55 °C and most preferably 40 to 55 °C during the action of the decolorizing agent, and then

[0264] - the bleaching agent is rinsed off again.

[0265] In addition to thermally assisting the decolorization process, it is also possible to subject the keratin material treated with the decolorizing agent to mechanical stress in order to improve the removal of the film formed on the keratin material during dyeing. For example, the keratin material can be massaged by hand or combed with a comb or brush during the decolorization process. Any other mechanical stress suitable for improving the removal of the dyed film from the keratin material under the influence of the decolorizing agent is also conceivable and encompassed by the method according to the invention.

[0266] In a further preferred embodiment, a method according to the invention is characterized in that

[0267] - the bleaching agent is applied to the dyed keratin fibers,

[0268] - the keratin fibers are combed, massaged, brushed or otherwise subjected to mechanical force during the application of the bleaching agent, and then

[0269] - the bleaching agent is rinsed off again.

[0270] As previously described, the decolorizing agent according to the invention can be used to decolorize keratin fibers that have been dyed by applying at least one chitosan and at least one of the previously described coloring compounds. If, for example, the user finds after dyeing that the color result does not meet their expectations, they can use this as an opportunity to remove the dye by applying the decolorizing agent. 2024P00203WG

[0271] 32

[0272] Furthermore, the user can plan the coloring and subsequent removal of the color in advance, for example, if they want to color their hair for a specific occasion and then remove the color afterwards. For this purpose, the user can also be provided with all the necessary products and formulations for both coloring and removal.

[0273] A method for dyeing and subsequently bleaching human hair, comprising the following steps in the specified order, is therefore particularly preferred.

[0274] (1) Applying the dye described above to the hair,

[0275] (2) Drying the hair covered with the dye,

[0276] (3) Applying the previously described bleaching agent to the dyed hair,

[0277] (4) Leave the bleach on the hair and

[0278] (5) Rinse the bleaching agent out of the hair.

[0279] Multi-component packaging unit and use

[0280] It is particularly convenient for the user if the appropriate dyeing and bleaching agents are provided in the form of a multi-component packaging unit.

[0281] A second object of the present invention is therefore a multi-component packaging unit (kit-of-parts) for dyeing and bleaching keratinous fibers, in particular human hair, comprising separately assembled a first container with a dyeing agent and a second container with a bleaching agent, wherein the dyeing agent and the bleaching agent have already been disclosed in detail in the description of the first object of the invention.

[0282] The multi-component packaging unit (kit-of-parts) may also include one or more additional containers with further formulations.

[0283] Use for decolorizing

[0284] Another object of the invention is the use of a decolorizing agent, as disclosed in detail in the description of the first object of the invention, for the decolorization of dyed keratinous fibers, preferably for the decolorization of keratinous fibers which have been dyed by applying a dye containing at least one chitosan and at least one coloring compound.

[0285] The colorant was also disclosed in detail in the description of the first subject matter of the invention. Regarding the further preferred embodiments of the multi-component packaging unit (kit-of-parts) and its use, what has been said about the methods according to the invention applies mutatis mutantis.

[0286] 2024P00203WG

[0287] 34

[0288] Examples

[0289] 1. Formulations

[0290] The following formulations were produced (all values, unless otherwise stated, are in wt.%):

[0291] EV = comparison decolorizing agent

[0292] EE = decolorizing agent according to the invention 2024P00203WG

[0293] 35

[0294] 2. Application to strands

[0295] The dyes were applied to hair strands (Kerling brand). For this, 2.0 g of dye (F) per gram of hair strand was massaged in and left to act for 1 minute. The strands, still coated with dye, were then dried with a standard hairdryer. The dyed strands were visually assessed by a trained person under a daylight lamp. The strands were then stored for 24 hours.

[0296] 3. Discoloration

[0297] Following the dyeing and storage, each dyed strand was treated with one of the color removers.

[0298] For this, the strand was moistened, then the color remover was massaged into the strand for 25 seconds (0.25 g of color remover per gram of hair). Afterwards, the color remover was left on for 3 minutes. Then the strand was rinsed with lukewarm tap water for 30 seconds and dried.

[0299] Afterwards, each strand was visually assessed again under the daylight lamp, with the strands bleached with EV and EE being laid side by side and compared.

[0300] The hair strands were assessed according to school grades with regard to their color intensity (1 = very high color intensity; 0 = undyed). 2024P00203WQ

[0301] 36

[0302] 4. Discoloration with peeling agents

[0303] The following formulations were produced (all values, unless otherwise stated, are in wt.%):

[0304] Strands of hair were dyed with one of the dyes (F1) or (F2) as described in point 2.

[0305] Following the coloring process, each colored strand was treated with one of the color removers (E1) or (E2) as described in point 3. After application of the color removers, the strands were completely colorless again.

Claims

1. 2024P00203WG 37 Patent claims 1. Method for decolorizing keratinous fibers which have been dyed by applying a dye containing at least one chitosan and at least one coloring compound, wherein an aqueous decolorizing agent having a pH of 1.4 to 3.4 is applied to the dyed keratinous fibers and rinsed off after a dwell time.

2. Method according to claim 1, characterized in that the decolorizing agent is applied to keratinous fibers which have been colored by the application of at least one pigment.

3. Method according to one of claims 1 to 2, characterized in that the destaining agent is applied to keratinous fibers which have been dyed by the application of at least one direct dye, particularly preferably at least one anionic direct dye.

4. Method according to one of claims 1 to 3, characterized in that the decolorizing agent has a pH value of 1.4 to 3.8, preferably 1.6 to 3.5, more preferably 1.8 to 3.3 and most preferably 2.0 to 3.

0.

5. Method according to one of claims 1 to 4, characterized in that the decolorizing agent contains at least one organic acid, preferably selected from the group consisting of citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid, benzoic acid and acetic acid.

6. Method according to one of claims 1 to 5, characterized in that the decolorizing agent contains at least one sugar surfactant, particularly preferably at least one non-ionic sugar surfactant.

7. Method according to any one of claims 1 to 6, characterized in that the decolorizing agent contains at least zwitterionic and / or amphoteric surfactant.

8. Method according to claim 7, characterized in that the decolorizing agent contains at least one zwitterionic surfactant selected from the surfactants of formula (T-3), (T-4), (T-5) and / or (T-6), 2024P00203WG 38 (T-6) where R2, R3, R4, R5 independently represent a linear or branched, saturated or unsaturated Ca-Cso alkyl group, preferably a linear, saturated or unsaturated Ci2-Cia alkyl group.

9. Method according to any one of claims 1 to 8, characterized in that the The decolorizing agent contains at least one anionic surfactant.

10. Method according to any one of claims 1 to 9, characterized in that the The bleaching agent must contain at least one exfoliating agent.

11. Method according to claim 10, characterized in that the descaling agent, acting as peeling agent(s), comprises solid particles from the group consisting of silica, sand, 2024P00203WC 39 Contains sea salt, sodium chloride, polyethylene powders, crushed or ground kernels of walnuts, apricots, peaches and / or almonds, lactic acid particles, talc powder, zeolites, rhyolite, pumice powder, chalk, shell limestone powder, marble powder, microcrystalline cellulose, sugar and / or clay.

12. Method according to any one of claims 1 to 11, characterized in that no silicone compounds are used during the method.

13. Multi-component packaging unit (kit-of-parts) for dyeing and bleaching keratinous fibers, in particular human hair, comprising separately assembled a first container with a dyeing agent and a second container with a bleaching agent, wherein the dyeing agent and the bleaching agent are defined in claims 1 to 12.

14. Use of a decolorizing agent as described in claims 1 to 12 for decolorizing dyed keratinous fibers, preferably for decolorizing keratinous fibers which have been dyed by applying a dye containing at least one chitosan and at least one coloring compound.

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