Leave-in dyeing method for keratin fibres comprising the application of a dyeing agent including chitosan, pigment, acid and water and subsequent heating

Abstract

The invention relates to a method for dyeing keratin fibres, in particular human hair, comprising applying a dyeing agent (F) to the keratin fibres, wherein the dyeing agent comprises (F-1) at least one chitosan and / or a chitosan derivative, (F-2) at least one pigment, (F-3) at least one organic and / or inorganic acid, and (F-4) water, and heating the keratin fibres covered with the dyeing agent (F) to a temperature of greater than 40°C.

Description

[0001] Leave-on dyeing process for keratin fibers comprising the application of a dye containing chitosan, pigment, acid and water followed by heating

[0002] The present application relates to a cosmetic method for dyeing keratin fibers, in particular human hair, comprising the application of a dyeing agent (F) with at least one chitosan, a pigment, an acid and water and heating the keratin fibers covered with the dyeing agent (F) to a temperature of more than 40 °C.

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

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

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

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

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

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

[0009] The objective of this application was therefore to find a pigment-based dyeing process that would achieve intense colors with improved washfastness. The dyeing process should be carried out with the aid of biopolymers, and the keratin fibers or hair dyed with this process should not feel coated or greasy, exhibit a well-groomed shine, and the curl behavior of the keratin fibers should not be negatively affected.

[0010] Surprisingly, it has now been found that this problem can be solved if a dye containing a chitosan, a pigment, an acid and water is used for coloring and if the hair then covered with the dye (F) is heated to a temperature of more than 40 °C.

[0011] A first subject of the present invention is a process for dyeing keratin fibers, in particular human hair, comprising

[0012] - the application of a colorant (F) to the keratin fibers, wherein the colorant contains (F-1) at least one chitosan and / or a chitosan derivative, (F-2) at least one pigment,

[0013] (F-3) at least one organic and / or inorganic acid, and

[0014] (F-4) Water, and

[0015] - heating the keratin fibres covered with the colouring agent (F) to a temperature exceeding 40 °C.

[0016] Hair colored using the above-mentioned method was characterized by an intense color result with improved washfastness. Furthermore, the hair colored this way was very evenly colored and possessed a beautiful, natural shine without feeling greasy or coated. The hair was not weighed down, and its bounce was not negatively affected.

[0017] Keratin fibers

[0018] Keratin fibers include hair, wool, and fur. Human hair is particularly preferred as keratin fibers.

[0019] Coloring agents

[0020] In the context of this invention, the term "coloring agent" refers to the coloring of keratin fibers, particularly hair, caused by the use of pigments. During this coloring, the pigments, as color-imparting compounds, are deposited in a homogeneous, uniform, and smooth film on the surface of the keratin fibers. The film is formed by the chitosan(s).

[0021] Dye (F)

[0022] In the process according to the invention, the colorant (F) is applied to the keratin fibers, wherein the colorant (F) is characterized by its content of the components (F-1), (F-2), (F-3), and (F-4). The colorant can be applied to the keratin fibers, for example, with a gloved hand or using a brush or applicator. After application, the colorant can be distributed over the keratin fibers and, if necessary, lightly massaged in.

[0023] Chitosans (F-1) in the dye (F)

[0024] As a first essential component, the colorant used in the process according to the invention contains at least one chitosan or a derivative of chitosan (F-1).

[0025] Chitosan, also known as polyglusam, poly-D-glucosamine, or polyglucosamine, is a naturally occurring biopolymer derived from chitin, which is composed of ß-1,4-glycosidically linked N-acetylglucosamine residues (more precisely, 2-acetamido-2-deoxy-ß-D-glucopyranose residues), and is thus, like chitin, a polyaminosaccharide. To produce chitosan, chitin is deacetylated, so that the molecule ultimately consists of only approximately 2,000 linearly linked 2-amino-2-deoxy-ß-D-glucopyranose or glucosamine monomers. Chitosan has the CAS number 9012-76-4.

[0026] Chitosan is preferably produced from the chitin found in shellfish or crustaceans. Chitosan is industrially obtained from chitin by deacetylation. This can be achieved, for example, using (hot) sodium hydroxide solution or enzymatically. Both processes are used industrially, but the alkaline procedure is clearly the most widely used. The degree of resulting deacetylation can vary considerably: deacetylation can be complete or partial, resulting in a distribution of highly deacetylated regions alongside less deacetylated regions, or a homogeneous deacetylation distribution. At the same time, this chemical intervention can decrease the chain length of the polymer (depolymerization). The molecular weight of chitosan can vary over a wide range, for example, from 20,000 to approximately 5 million g / mol.

[0027] Chitosan derivatives are compounds with a chitosan base structure in which at least some of the functional groups present have been chemically modified. Chitosan derivatives are also based on a poly-D-glucosamine or polyglucosamine structure.

[0028] For example, a chitosan with a molecular weight of 20,000 to 800,000 g / mol, preferably 50,000 to 600,000 g / mol, more preferably 80,000 to 450,000 g / mol and most preferably 100,000 to 300,000 g / mol is very suitable.

[0029] In a further very particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least one chitosan and / or a chitosan derivative (F-1) with a molecular weight of 20,000 to 800,000 g / mol, preferably of 50,000 to 600,000 g / mol, more preferably of 80,000 to 450,000 g / mol and very particularly preferably of 100,000 to 300,000 g / mol.

[0030] In a further very particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least one chitosan (F-1) having a molecular weight of 20,000 to 800,000 g / mol, preferably of 50,000 to 600,000 g / mol, more preferably of 80,000 to 450,000 g / mol and very particularly preferably of 100,000 to 300,000 g / mol.

[0031] Chitosan with a molecular weight of 100,000 to 300,000 g / mol can be purchased commercially from Sigma-Aldrich, for example. Chitosan with a lower molecular weight of 10,000 to 30,000 g / mol (or Daltons) is available in pharmaceutical grade from BioLog Heppe (Kraeber), for example. The degree of deacetylation of this chitosan is 88-95%.

[0032] Chitosan in the form of its hydrochloride can be purchased as vegan chitosan from Sandream Impact. The chitosan hydrochloride is a chitosan derivative according to the invention.

[0033] Chitosan 027 is a suitable, commercially available, high-molecular chitosan from Polymar, which has a molecular weight of 100,000 - 2,000,000 g / mol.

[0034] It has proven particularly advantageous if the colorant according to the invention contains the chitosan(s) and / or chitosan derivative(s) (F-1) in specific quantity ranges. Particularly good results were obtained when the colorant—based on the total weight of the colorant—contained one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 10.0 wt.%, preferably 0.2 to 8.0 wt.%, more preferably 0.5 to 6.0 wt.%, and most preferably 0.7 to 2.0 wt.%.

[0035] In a further particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) - based on the total weight of the colorant (F) - contains one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 10.0 wt.%, preferably 0.2 to 8.0 wt.%, more preferably 0.5 to 6.0 wt.% and most preferably 0.7 to 2.0 wt.%.

[0036] In a further particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) - based on the total weight of the colorant (F) - contains one or more chitosans in a total amount of 0.1 to 10.0 wt.%, preferably 0.2 to 8.0 wt.%, more preferably 0.5 to 6.0 wt.% and most preferably 0.7 to 2.0 wt.%.

[0037] Pigments (F-2) in the colorant (F)

[0038] As a second essential component, the colorant (F) used in the process according to the invention contains at least one pigment. Pigments within the meaning of the present invention are understood to mean color-imparting compounds which have a solubility in water at 25°C of less than 0.5 g / L, preferably less than 0.1 g / L, and even more preferably less than 0.05 g / L. The water solubility can be determined, for example, using the method described below: 0.5 g of the pigment is weighed into a beaker. A stir bar is added. Then, one liter of distilled water is added. This mixture is heated to 25°C for one hour while stirring on a magnetic stirrer. If undissolved components of the pigment are still visible in the mixture after this period, the solubility of the pigment is below 0.5 g / L.If the pigment-water mixture cannot be visually assessed due to the high intensity of the finely dispersed pigment, the mixture is filtered. If a portion of undissolved pigment remains on the filter paper, the pigment's solubility is below 0.5 g / L.

[0039] Suitable color pigments can be of inorganic and / or organic origin.

[0040] In a preferred embodiment, a colorant (F) according to the invention is characterized in that it contains at least one color-providing compound (F-2) from the group of inorganic and / or organic pigments.

[0041] In a preferred embodiment, a colorant (F) according to the invention is characterized in that it contains at least one inorganic and / or organic pigment (F-2).

[0042] Preferred color pigments are selected from synthetic or natural inorganic pigments. Inorganic color pigments of natural origin can be made from chalk, ochre, umber, green earth, burnt sienna, or graphite, for example. Other inorganic color pigments that can be used include black pigments such as iron oxide black, colored pigments such as ultramarine or iron oxide red, as well as fluorescent or phosphorescent pigments.

[0043] Particularly suitable are colored metal oxides, hydroxides, and oxide hydrates, mixed-phase pigments, sulfur-containing silicates, silicates, metal sulfides, complex metal cyanides, metal sulfates, chromates, and / or molybdates. Particularly preferred color pigments are black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and brown iron oxide (CI 77491), manganese violet (CI 77742), ultramarines (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), iron blue (ferric ferrocyanide, CI 77510), and / or carmine (cochineal).

[0044] Also particularly preferred color pigments according to the invention are colored pearlescent pigments. These are typically based on mica and / or mica and can be coated with one or more metal oxides. Mica belongs to the class of layered silicates. The most important representatives of these silicates are muscovite, phlogopite, paragonite, biotite, lepidolite, and margarite. To produce pearlescent pigments in combination with metal oxides, the mica, predominantly muscovite or phlogopite, is coated with a metal oxide.

[0045] As an alternative to natural mica, synthetic mica, optionally coated with one or more metal oxides, can also be used as a pearlescent pigment. Particularly preferred pearlescent pigments are based on natural or synthetic mica and coated with one or more of the aforementioned metal oxides. The color of the respective pigments can be varied by varying the layer thickness of the metal oxide(s).

[0046] In a further preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least inorganic pigment (F-2), which is preferably selected from the group of colored metal oxides, metal hydroxides, metal oxide hydrates, silicates, metal sulfides, complex metal cyanides, metal sulfates, bronze pigments and / or colored pigments based on mica or mica, which are coated with at least one metal oxide and / or one metal oxychloride.

[0047] In a further preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least one pigment which is selected from mica- or mica-based pigments coated with one or more metal oxides from the group consisting of titanium dioxide (CI 77891), black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and / or brown iron oxide (CI 77491, CI 77499), manganese violet (CI 77742), ultramarines (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), chromium oxide (CI 77288) and / or iron blue (ferric ferrocyanide, CI 77510).

[0048] Examples of particularly suitable color pigments are commercially available under the trade names Rona®, Colorona®, Xirona®, Dichrona® and Timiron® from Merck, Ariabel® and Unipure® from Sensient, Prestige® from Eckart Cosmetic Colors and Sunshine® from Sunstar.

[0049] Particularly preferred color pigments with the trade name Colorona® are, for example:

[0050] Colorona Copper, Merck, MICA, CI 77491 (IRON OXIDES)

[0051] Colorona Passion Orange, Merck, Mica, CI 77491 (Iron Oxides), Alumina

[0052] Colorona Patina Silver, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE) Colorona RY, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 75470 (CARMINE)

[0053] Colorona Oriental Beige, Merck, MICA, CI 77891 (TITANIUM DIOXIDE), CI 77491 (IRON OXIDES) Colorona Dark Blue, Merck, MICA, TITANIUM DIOXIDE, FERRIC FERROCYANIDE

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

[0055] Colorona Aborigine Amber, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0056] Colorona Blackstar Blue, Merck, CI 77499 (IRON OXIDES), MICA

[0057] Colorona Patagonian Purple, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE), CI 77510 (FERRIC FERROCYANIDE)

[0058] Colorona Red Brown, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE) Colorona Russet, Merck, Cl 77491 (TITANIUM DIOXIDE), MICA, Cl 77891 (IRON OXIDES)

[0059] Colorona Imperial Red, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), D&C RED NO. 30 (Cl 73360)

[0060] Colorona Majestic Green, Merck, Cl 77891 (TITANIUM DIOXIDE), MICA, Cl 77288 (CHROMIUM OXIDE GREENS)

[0061] Colorona Light Blue, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), FERRIC FERROCYANIDE (Cl 77510)

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

[0063] Colorona Gold Plus MP 25, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), IRON OXIDES (Cl 77491)

[0064] Colorona Carmine Red, Merck, MICA, TITANIUM DIOXIDE, CARMINE

[0065] Colorona Blackstar Green, Merck, MICA, Cl 77499 (IRON OXIDES)

[0066] Colorona Bordeaux, Merck, MICA, Cl 77491 (IRON OXIDES)

[0067] Colorona Bronze, Merck, MICA, Cl 77491 (IRON OXIDES)

[0068] Colorona Bronze Fine, Merck, MICA, Cl 77491 (IRON OXIDES)

[0069] Colorona Fine Gold MP 20, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON

[0070] OXIDES)

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

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

[0073] Colorona Precious Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Silica, Cl 77491 (Iron oxides), Tin oxide

[0074] Colorona Sun Gold Sparkle MP 29, Merck, MICA, TITANIUM DIOXIDE, IRON OXIDES, MICA, Cl 77891 , Cl 77491 (EU)

[0075] Colorona Mica Black, Merck, Cl 77499 (Iron oxides), Mica, Cl 77891 (Titanium dioxide)

[0076] Colorona Bright Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Cl 77491 (Iron oxides)

[0077] Colorona Blackstar Gold, Merck, MICA, Cl 77499 (IRON OXIDES)

[0078] Weiterhin besonders bevorzugte Farbpigmente mit der Handelsbezeichnung Xirona® sind beispielsweise:

[0079] Xirona Golden Sky, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0080] Xirona Caribbean Blue, Merck, Mica, CI 77891 (Titanium Dioxide), Silica, Tin Oxide

[0081] Xirona Kiwi Rose, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0082] Xirona Magic Mauve, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide.

[0083] In addition, particularly preferred color pigments with the trade name Unipure® are, for example:

[0084] Unipure Red LC 381 EM, Sensient CI 77491 (Iron Oxides), Silica

[0085] Unipure Black LC 989 EM, Sensient, CI 77499 (Iron Oxides), Silica

[0086] Unipure Yellow LC 182 EM, Sensient, CI 77492 (Iron Oxides), Silica In a further embodiment, the pretreatment agent (V) according to the invention can also contain one or more organic pigments

[0087] The organic pigments according to the invention are correspondingly insoluble, organic dyes or lakes which can be selected, for example, from the group of nitroso, nitro-azo, xanthene, anthraquinone, isoindolinone, isoindoline, quinacridone, perinone, perylene, diketopyrrolopyorrole, indigo, thioindido, dioxazine and / or triarylmethane compounds.

[0088] Particularly suitable organic pigments are, for example, carmine, quinacridone, phthalocyanine, sorghum, blue pigments with the color index numbers CI 42090, CI 69800, CI 69825, CI 73000, CI 74100, CI 74160, yellow pigments with the color index numbers CI 11680, CI 11710, CI 15985, CI 19140, CI 20040, CI 21100, CI 21108, CI 47000, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, CI 74260, orange pigments with the color index numbers CI 1 1725, CI 15510, CI 45370, CI 71105, red pigments with the color index numbers CI 12085, CI 12120, CI 12370, CI 12420, CI 12490, CI 14700, CI 15525, CI 15580, CI 15620, CI 15630, CI 15800, CI 15850, CI 15865, CI 15880, CI 17200, CI 26100, CI 45380, CI 45410, CI 58000, CI 73360, CI 73915 and / or CI 75470.

[0089] In a further particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains at least one organic pigment (F-2), which is preferably selected from the group consisting of carmine, quinacridone, phthalocyanine, sorghum, blue pigments with the color index numbers CI 42090, CI 69800, CI 69825, CI 73000, CI 74100, CI 74160, yellow pigments with the color index numbers CI 1 1680, CI 11710, CI 15985, CI 19140, CI 20040, CI 21100, CI 21108, CI 47000, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, CI 74260, orange pigments with the color index numbers C1 11725, CI 15510, CI 45370, CI 71 105, red pigments with the color index numbers CI 12085, CI 12120, CI 12370, CI 12420, CI 12490, CI 14700, CI 15525, CI 15580, CI 15620, CI 15630, CI 15800, CI 15850, CI 15865, CI 15880, CI 17200, CI 26100, CI 45380, CI 45410, CI 58000, CI 73360, CI 73915 and / or CI 75470.

[0090] The organic pigment can also be a colored lake. For the purposes of the invention, the term colored lake refers to particles comprising a layer of absorbed dyes, the particle-dye unit being insoluble under the aforementioned conditions. The particles can be, for example, inorganic substrates, which can be aluminum, silica, calcium borosilicate, calcium aluminum borosilicate, or even aluminum.

[0091] Alizarin lake, for example, can be used as the colored lake. Due to their excellent light and temperature stability, the use of the aforementioned pigments in the colorant (F) of the process according to the invention is very particularly preferred. Furthermore, it is preferred if the pigments used have a specific particle size. It is therefore advantageous according to the invention if the at least one pigment has an average particle size D50 of 1.0 to 50 pm, preferably from 5.0 to 45 pm, more preferably from 10 to 40 pm, in particular from 14 to 30 pm. The average particle size D50 can be determined, for example, using dynamic light scattering (DLS).

[0092] Pigments with a specific shape can also be used to color the keratin fibers. For example, a pigment based on a lamellar and / or lenticular substrate plate can be used. Furthermore, coloring based on a substrate plate containing a vacuum-metallized pigment is also possible.

[0093] In a further preferred embodiment, an agent according to the invention is characterized in that it contains at least one pigment which is selected from the group of pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

[0094] The substrate platelets of this type have an average thickness of at most 50 nm, preferably less than 30 nm, more preferably at most 25 nm, for example at most 20 nm. The average thickness of the substrate platelets is at least 1 nm, preferably at least 2.5 nm, more preferably at least 5 nm, for example at least 10 nm. Preferred ranges for the thickness of the substrate platelets are 2.5 to 50 nm, 5 to 50 nm, 10 to 50 nm; 2.5 to 30 nm, 5 to 30 nm, 10 to 30 nm; 2.5 to 25 nm, 5 to 25 nm, 10 to 25 nm, 2.5 to 20 nm, 5 to 20 nm and 10 to 20 nm. Each substrate platelet preferably has a thickness that is as uniform as possible. Due to the low thickness of the substrate platelets, the pigment has particularly high hiding power.

[0095] The substrate platelets are preferably monolithic in structure. Monolithic in this context means consisting of a single, closed unit without fractures, stratification, or inclusions, although structural changes may occur within the substrate platelets. The substrate platelets are preferably homogeneous in structure, meaning that no concentration gradient occurs within the platelets. In particular, the substrate platelets are not layered and do not contain any particles or particles distributed within them.

[0096] The size of the substrate platelet can be tailored to the specific application, especially the desired effect on the keratin material. Typically, the substrate platelets have an average diameter of approximately 2 to 200 pm, particularly approximately 5 to 100 pm.

[0097] In a preferred embodiment, the aspect ratio, expressed as the ratio of the average size to the average thickness, is at least 80, preferably at least 200, more preferably at least 500, and particularly preferably more than 750. The average size of the uncoated substrate platelets is understood to be the d50 value of the uncoated substrate platelets. Unless otherwise stated, the d50 value was determined using a Sympatec Heios device with Quixel wet dispersion. For sample preparation, the sample to be tested was predispersed in isopropanol for 3 minutes.

[0098] The substrate platelets can be made of any material that can be formed into platelets.

[0099] They can be of natural origin or synthetically produced. Materials from which the substrate platelets can be constructed include metals and metal alloys, metal oxides, preferably aluminum oxide, inorganic compounds and minerals such as mica and (semi-)precious stones, as well as plastics. The substrate platelets are preferably made of metal (or metal alloys).

[0100] Any metal suitable for metallic luster pigments can be considered. Such metals include iron and steel, as well as all air- and water-resistant (semi)metals such as platinum, zinc, chromium, molybdenum, and silicon, as well as their alloys such as aluminum bronze and brass. Preferred metals are aluminum, copper, silver, and gold. Preferred substrate platelets are aluminum platelets and brass platelets, with aluminum platelets being particularly preferred.

[0101] Lamellar substrate platelets are characterized by an irregularly structured edge and are also called "cornflakes" due to their appearance.

[0102] Due to their irregular structure, pigments based on lamellar substrate platelets generate a high degree of scattered light. Furthermore, pigments based on lamellar substrate platelets do not completely cover the existing color of a keratinous material, and effects similar to natural graying can be achieved, for example.

[0103] Lenticular (= lens-shaped) substrate platelets have a generally regular, round edge and are also called "silver dollars" due to their appearance. Due to their regular structure, the proportion of reflected light predominates in pigments based on lenticular substrate platelets.

[0104] Vacuum metallized pigments (VMPs) can be obtained, for example, by releasing metals, metal alloys, or metal oxides from appropriately coated foils. They are characterized by a particularly thin substrate platelet thickness in the range of 5 to 50 nm and a particularly smooth surface with increased reflectivity. Substrate platelets comprising a vacuum-metallized pigment are also referred to as VMP substrate platelets in this application. VMP substrate platelets made of aluminum can be obtained, for example, by releasing aluminum from metallized foils.

[0105] The substrate plates made of metal or metal alloy can be passivated, for example by anodizing (oxide layer) or chromating.

[0106] Uncoated lamellar, lenticular, and / or VPM substrate plates, especially those made of metal or metal alloy, reflect incident light to a high degree and produce a light-dark flop. These have proven particularly preferred for use in the colorant.

[0107] Suitable pigments based on a lamellar substrate platelet include, for example, the pigments of the VISIONAIRE series from Eckart.

[0108] Pigments based on a lenticular substrate platelet are available, for example, under the name Alegrace® Gorgeous from Schlenk Metallic Pigments GmbH.

[0109] 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.

[0110] The pigment(s) (F-2) represent(s) the second essential constituent of the colorant (F) according to the invention and are preferably used in the composition in specific quantity ranges. Particularly good results were obtained when the colorant—based on the total weight of the colorant—contained one or more pigments (F-2) in a total amount of 0.01 to 10.0 wt. %, preferably 0.1 to 5.0 wt. %, more preferably 0.2 to 2.5 wt. %, and most preferably 0.25 to 1.5 wt. %.

[0111] In a further very particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) - based on the total weight of the colorant (F) - contains one or more pigments (F-2) in a total amount of 0.01 to 10.0 wt. %, preferably 0.1 to 5.0 wt. %, more preferably 0.2 to 2.5 wt. % and very particularly preferably 0.25 to 1.5 wt. % organic and / or inorganic acids (F-3) in the colorant

[0112] As a third essential component, the colorant (F) used in the process according to the invention contains at least one organic and / or inorganic acid (F-3).

[0113] By using one or more acids, the pH of the colorant (F) can be lowered, whereby the chitosan is completely or partially profaned and dissolves more easily. Macroscopically, the protonation of the chitosan in water is perceived as swelling, from which, when the preferred or particularly preferred pH value is adjusted, a particularly uniform and thin film is deposited on the keratin fibers such as hair. It has been shown that the durability of the film is better the more even the film forms on the hair. By forming a particularly uniform film, colorations with particularly good washfastness could also be achieved. In addition, the presence of the acid(s) (F-3) in the colorant also means that the chitosan can form a particularly thin film on the hair.Comparative studies have shown that a uniformly thin film has better resistance to external mechanical influences.

[0114] For example, Figure 2 shows a laser microscope image of a detached film from the hair surface. Detachments of this type were observed after drying the hair when dyeing was carried out with a water-based dye (F) containing a chitosan (F-1) and a pigment (F-2), but no or insufficient amounts of acid (F-3).

[0115] Figure 3, on the other hand, shows a laser microscope image of a hair fiber with an intact thin film. These particularly thin films were obtained using a dye containing chitosan (F-1), pigment (F-2), acid (F-3) (in this case, acetic acid in an amount that resulted in a pH of 4.5), and water (F-4). This film remained intact even after the hair was dried.

[0116] Particularly suitable organic acids include acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid.

[0117] Formic acid and propanoic acid are also suitable acids (F-3).

[0118] In a further particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) contains one or more 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. Acetic acid dissolves chitosan particularly well and leads to particularly thin and uniform films; therefore, a colorant (F) containing acetic acid is particularly preferred.

[0119] In a further explicitly particularly preferred embodiment, a process according to the invention is therefore characterized in that the colorant (F) contains acetic acid (F-3).

[0120] By using the acid(s) in appropriate amounts, the pH of the colorant can be adjusted to the desired pH range. Particularly thin and uniform films were obtained when the colorant (F) was adjusted to a pH in the range of 2.0 to 7.5, preferably 3.0 to 7.0, more preferably 3.5 to 6.5, and most preferably 4.0 to 6.0.

[0121] In a further particularly preferred embodiment, a process according to the invention is therefore characterized in that the colorant (F) has a pH of 2.0 to 7.5, preferably of 3.0 to 7.0, more preferably of 3.5 to 6.5 and most preferably of 4.0 to 6.0.

[0122] Furthermore, particularly good results were also obtained when the colorant (F) contained water and acids in a specific weight ratio. It has been found particularly preferable to set the weight ratio of the water (F-4) contained in the colorant (F) to the acids (F-3), i.e., the weight ratio (F-4) / (F-3), to a value of 1000 to 10, preferably 500 to 40, more preferably 200 to 60, and most preferably 150 to 85.

[0123] In a further particularly preferred embodiment, a process according to the invention is therefore characterized in that the weight ratio of the water (F-4) contained in the colorant (F) to the acids (F-3), ie the weight ratio (F-4) / (F-3), is from 1000 to 10, preferably from 500 to 40, more preferably from 200 to 60 and most preferably from 150 to 85.

[0124] Amount of components (F-1), (F-2), (F-3) and (F-4) in the dye

[0125] As part of the work leading to this invention, microscopic images were taken which showed that a thin, uniform film on the keratin fibers has particularly good resistance to external influences such as mechanical friction or hair washing. The smoother and more closed the film, the smaller the surface area it has against external forces. Once the film has broken at one point, it can be completely detached very quickly due to the constant movement of the keratin fibers. It was discovered that the films produced with the colorant (F) were particularly thin, uniform, and stable when the colorant consisted largely of the components (F-1), (F-2), (F-3), and (F-4).One assumption is that additional components could disrupt the film's uniformity by embedding themselves in the film, weakening it at that point, or creating a surface vulnerable to external forces. For this reason, it is particularly preferred if components (F-1), (F-2), (F-.

[0126] 3) and (F-4) together are present in the colorant (F) in a proportion of at least 90.0 wt.%, preferably at least 93 wt.%, more preferably at least 96 wt.% and most preferably at least 99 wt.%.

[0127] If the components (F-1), (F-2), (F-3) and (F-4) are contained together in a proportion of at least 90.0 wt.% in the colorant, then the colorant consists of at least 90 wt.% of the components (F-1), (F-2), (F-3) and (F-4) based on its total weight. In other words, in this case, other substances or ingredients that are listed from (F-1) to (F-

[0128] 4) are different, are contained in the colorant (F) only in a maximum proportion of 10 wt.%, but preferably in even smaller proportions.

[0129] In a further particularly preferred embodiment, a process according to the invention is therefore characterized in that the components (F-1), (F-2), (F-3) and (F-4) are together present in the colorant (F) in a proportion of at least 90.0 wt.%, preferably of at least 93 wt.%, more preferably of at least 96 wt.% and most preferably of at least 99 wt.%.

[0130] Furthermore, it has also proven preferable if no solvents other than water are added to the colorant (F). Here, too, it was observed that the film produced on the keratin fibers was very thin and uniform when the colorant did not contain any solvent from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerin, 1-butanol, and / or polyethylene glycols.

[0131] In a further particularly preferred embodiment, a process according to the invention is therefore characterized in that the colorant (F) is substantially free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, 1-butanol, phenoxyethanol, benzyl alcohol and / or polyethylene glycols.

[0132] Some raw materials may contain one or more of the above-mentioned solvents in small amounts as a minor component, so that when this raw material is used, marginal amounts of this solvent are introduced. However, it has been found that the presence of such small amounts of solvent does not unduly impair film formation.

[0133] In a further particularly preferred embodiment, a process according to the invention is therefore characterized in that the colorant (F) is substantially free from solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, 1-butanol, phenoxyethanol, benzyl alcohol and polyethylene glycols.

[0134] In a further very particularly preferred embodiment, a process according to the invention is therefore characterized in that the colorant (F) is free from solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, 1-butanol, phenoxyethanol, benzyl alcohol and polyethylene glycols.

[0135] Ethanol has the Cas number 64-17-5.

[0136] Isopropanol is also known as 2-propanol and has the CAS number 67-63-0.

[0137] 1,2-Propylene glycol is alternatively also called 1,2-propanediol and has the CAS numbers 57-55-6 [(RS)-1,2-dihydroxypropane], 4254-14-2 [(R)-1,2-dihydroxypropane] and 4254-15-3 [(S)-1,2-dihydroxypropane],

[0138] 1,3-Propanediol or 1,3-Dihydroxypropane has the CAS number 504-63-2.

[0139] Glycerin is also known as 1,2,3-propanetriol and has the CAS number 56-81-5. 1-Butanol can also be known as n-butanol or butyl alcohol and has the CAS number 71-36-3.

[0140] Phenoxyethanol has the Cas number 122-99-6.

[0141] Benzyl alcohol is also known as phenylmethanol and has the CAS number 100-51-6.

[0142] Polyethylene glycols in the sense of the present invention are liquid polymers at room temperature (25 °C) of the general molecular formula C2nH4n+2O n +i. The repeating unit of the linear polymer is (-CH2-CH2-O-), with a molar mass of about 44 g mol -1 Chemically, it is a polyether. Polyethylene glycols are therefore ethylene glycols of the formula (EG) where x is an integer from 2 to 10000.

[0143] Direct dyes in the colorant (F) In principle, the colorants (F) used in the process according to the invention can also contain one or more direct dyes as optional components. Direct dyes are dyes that are absorbed directly into the hair and do not require an oxidative process to develop the color. Direct dyes are typically nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinones, triarylmethane dyes, or indophenols.

[0144] The direct dyes according to the present invention have a solubility in water (760 mmHg) at 25°C of more than 0.5 g / L and are therefore not considered pigments. Preferably, the direct dyes according to the present invention have a solubility in water (760 mmHg) at 25°C of more than 1.0 g / L.

[0145] However, it may be preferred if the colorant (F) does not contain direct dyes or contains them only in very small amounts.

[0146] In a further, very particularly preferred embodiment, a process according to the invention is characterized in that the total amount of the direct dyes contained in the colorant (F) - based on the total weight of the colorant (F) - is below 0.1% by weight, preferably below 0.05% by weight, more preferably below 0.01% by weight and very particularly preferably below 0.001% by weight.

[0147] In other words, in a further very particularly preferred embodiment, a process according to the invention is characterized in that the total amount of the direct dyes contained in the colorant (F) - based on the total weight of the colorant (F) - is below 0.1 wt.%, preferably below 0.05 wt.%, more preferably below 0.01 wt.% and very particularly preferably below 0.001 wt.%, wherein the direct dyes are characterized in that they have a solubility in water (760 mmHg) at 25 °C of more than 0.5 g / L.

[0148] In a further, very particularly preferred embodiment, a process according to the invention is characterized in that the colorant (F) is free from direct dyes.

[0149] Direct dyes can be divided into anionic, cationic and non-ionic direct dyes.

[0150] 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.

[0151] Examples of non-ionic direct dyes include non-ionic nitro and quinone dyes and neutral azo dyes. Examples of non-ionic direct dyes are those known under the international designations "N" and "N" respectively.Handelsnamen HC Yellow 2, HC Yellow 4, HC Yellow 5, HC Yellow 6, HC Yellow 12, HC Orange 1 , Disperse Orange 3, HC Red 1 , HC Red 3, HC Red 10, HC Red 11 , HC Red 13, HC Red BN, HC Blue 2, HC Blue 11 , HC Blue 12, Disperse Blue 3, HC Violet 1 , Disperse Violet 1 , Disperse Violet 4, Disperse Black 9 bekannten Verbindungen, sowie 1 ,4-Diamino-2-nitrobenzol, 2-Amino-4-nitrophenol, 1 ,4-Bis-(2-hydroxyethyl)- amino-2-nitrobenzol, 3-Nitro-4-(2-hydroxyethyl)-aminophenol, 2-(2-Hydroxyethyl)amino-4,6-dinitro- phenol, 4-[(2-Hydroxyethyl)amino]-3-nitro-1 -methylbenzol, 1-Amino-4-(2-hydroxyethyl)-amino-5- chlor-2-nitrobenzol, 4-Amino-3-nitrophenol, 1-(2'-Ureidoethyl)amino-4-nitrobenzol, 2-[(4-Amino-2- nitrophenyl)amino]-benzoesäure, 6-Nitro-1 ,2,3,4-tetrahydrochinoxalin, 2-Hydroxy-1 ,4-naphtho- chinon, Pikraminsäure und deren Salze, 2-Amino-6-chloro-4-nitrophenol, 4-Ethylamino-3-nitro- benzoesäure und 2-Chlor-6-ethylamino-4-nitrophenol.

[0152] Anionic direct dyes are also known as acid dyes. Acid dyes are defined as direct dyes that contain at least one carboxylic acid group (-COOH) and / or one sulfonic acid group (-SO3H). Depending on the pH, the profaned forms (-COOH, -SO3H) of the carboxylic acid or sulfonic acid groups exist in equilibrium with their deprotonated forms (-COO-, -SOs). As the pH decreases, the proportion of profaned forms increases. If direct dyes are used in the form of their salts, the carboxylic acid or sulfonic acid groups are present in deprotonated form and are neutralized with corresponding stoichiometric equivalents of cations to maintain electroneutrality. Acid dyes according to the invention can also be used in the form of their sodium salts and / or their potassium salts.

[0153] 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 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.

[0154] The alkaline earth metal salts (such as calcium and magnesium salts) or aluminum salts of acid dyes often have lower solubility than the corresponding alkali metal salts. If the solubility of these salts is below 0.5 g / L (25 °C, 760 mmHg), they do not fall under the definition of a direct dye. A key characteristic of acid dyes is their ability to form anionic charges, with the carboxylic acid or sulfonic acid groups responsible for this being usually linked to various chromophoric systems. Suitable chromophoric systems can be found, for example, in the structures of nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinone dyes, triarylmethane dyes, xanthene dyes, rhodamine dyes, oxazine dyes, and / or indophenol dyes.

[0155] 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 .

[0156] The water solubility of anionic direct dyes can be determined, for example, as follows: 0.1 g of the anionic direct dye is placed in a beaker. A stir bar is added. Then, 100 ml of water is added. This mixture is heated to 25 °C on a magnetic stirrer while stirring. It is stirred for 60 minutes. The aqueous mixture is then visually assessed. If undissolved residues remain, the amount of water is increased—for example, in 10 ml increments. Water is added until the added amount of dye has completely dissolved. If the dye-water mixture cannot be assessed visually due to the high intensity of the dye, the mixture is filtered. If a portion of undissolved dye remains on the filter paper, the solubility test is repeated using a larger amount of water.If 0.1 g of the anionic direct dye dissolves in 100 ml of water at 25 °C, the solubility of the dye is 1.0 g / L.

[0157] 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).

[0158] Acid Yellow 3 is a mixture of the sodium salts of mono- and disulfonic acids of 2-(2-quinolyl)-1H-indene-1,3(2H)-dione and has a water solubility of 20 g / L (25 °C).

[0159] 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).

[0160] Acid Yellow 23 is the trisodium salt of 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-4-((4-sulfophenyl)azo)- 1 H-pyrazole-3-carboxylic acid and is readily soluble in water at 25 °C.

[0161] 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).

[0162] 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%.

[0163] 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).

[0164] Acid Red 92 is the disodium salt of 3,4,5,6-tetrachloro-2-(1,4,5,8-tetrabromo-6-hydroxy-3-oxoxanthen-9-yl)benzoic acid, whose water solubility is stated to be greater than 10 g / L (25 °C).

[0165] Acid Blue 9 is the disodium salt of 2-({4-[N-ethyl(3-sulfonatobenzyl]amino]phenyl}{4-[(N-ethyl(3-sulfonatobenzyl)imino]-2,5-cyclohexadien-1-ylidene}methyl)-benzenesulfonate and has a water solubility of more than 20 wt% (25 °C).

[0166] Viscosity of the dye (F)

[0167] The work conducted within the scope of this application has shown that particularly thin films could be formed even when the colorant (F) was inherently thin and distributed quickly and with good spreading action on the keratin material. Therefore, it is further preferred if the colorant (F) has a viscosity of 10 to 10,000 mPas, preferably 10 to 5,000 mPas, more preferably 100 to 3,000 mPas, and most preferably 100 to 2,000 mPas (22°C / Brookfield viscometer / spindle 3 / 30 rpm). In a further particularly preferred embodiment, a process according to the invention is characterized in that the colorant has a viscosity of 10 to 10,000 mPas, preferably of 10 to 5,000 mPas, more preferably of 100 to 3,000 mPas and very particularly preferably of 100 to 2,000 mPas (22 °C / Brookfield viscometer / spindle 3 / 30 rpm).

[0168] Heat treatment of the keratin material

[0169] After applying the dye (F), the keratin fibers covered with the dye (F) are heated to a temperature of more than 40 °C. Heating therefore necessarily occurs after the dye has been applied. Heating accelerates the evaporation of the water present in the dye (F), allowing the film consisting of pigment, chitosan (derivative), and acid to form. Since the dye is not washed out before drying, the process according to the invention is a leave-on dyeing process.

[0170] Heating or heat treatment involves bringing the keratin material into contact with a heated device, or applying this heated device to or on the keratin material. Furthermore, the keratin material can also be exposed to warm / hot air for heat treatment. Examples of devices used include a hairdryer, a blow dryer, a thermal cap, a flat iron, a curling iron, or an infrared lamp.

[0171] 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 hair dryer, a blow dryer, a heat cap, a straightening iron, a curling iron or an infrared lamp.

[0172] Furthermore, it has been found that it is preferred if the treatment temperature during the heat treatment is between 40 °C and 210 °C, preferably from 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 50 °C to 80 °C. In other words, it has proven particularly preferred if the heat treatment is carried out using a device that is heated to a temperature of 40 °C to 210 °C, preferably from 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 50 °C to 80 °C.

[0173] Within the scope of a further particularly preferred embodiment, a method according to the invention is characterized by heating the keratin fibers covered with the colorant (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 50°C to 80°C. The duration of the heat treatment can be adapted to the selected temperature range. For example, a heat treatment can be carried out for a duration of 5 seconds to 60 minutes, preferably from 15 seconds to 45 minutes, more preferably from 15 seconds to 30 minutes, and most preferably from 15 seconds to 15 minutes.

[0174] In the course of the method according to the invention, the keratin fibers can be subjected to a heat treatment entirely, but the treatment of partial areas of the keratin fibers can also be included. Complete heat treatment of the keratin fibers is preferred, ie, preferably all keratin fibers to which the colorant (F) has been applied are treated with heat.

[0175] During the heat treatment or scratching, the keratin fibers can also be combed or brushed.

[0176] For example, the keratin fibers or the hair can be treated with a hairdryer that blows warm or hot air onto the fibers, possibly while combing or brushing. This air is particularly preferably between 50 and 80°C. Alternatively, the keratin material or the hair can be held under an infrared lamp, which is particularly preferably set to a temperature of 50 to 80°C. For the purpose of heat treatment, hair can also be pressed between two appropriately temperature-controlled plates of a straightening iron, with the plates simultaneously moving along the fiber. The plates of the straightening iron can, for example, be set to a temperature of up to 210°C.

[0177] 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 hair dryer, a blow dryer, a heat cap, a straightening iron, a curling iron or an infrared lamp.

[0178] Examples

[0179] 1 . Formulations

[0180] The following dyes were prepared (all data in wt.% unless otherwise stated):

[0181] 2. Application to strands

[0182] The dyes were applied to strands of hair (Kerling). 2.0 g of dye (F) was massaged into each gram of hair strand and left on for 1 minute. The strands still coated with the dye were then dried with a standard hairdryer. The dyed strands were visually assessed by a trained person under a daylight lamp.

[0183] 3. Laser microscopy images

[0184] After dyeing and heat treatment, the strands dyed with dyes F1, F2, and F3 were examined under a laser microscope (see also Figures 1, 2, and 3). It was checked whether the film obtained after drying was intact or whether initial detachments were already visible under the microscope.

[0185] 4. Measurement of wash fastness

[0186] Following coloring and heat treatment, each colored strand underwent five manual hair washes. For each wash, the strand was moistened, then a commercially available shampoo (Schwarzkopf, Schauma 7 Kräuter) was massaged into the strand for 25 seconds (0.25 g of shampoo per gram of hair). The strand was then rinsed with lukewarm tap water for 30 seconds and dried.

[0187] After each hair wash, the respective strand was again visually assessed under the daylight lamp.

[0188] The hair strands were assessed for their color intensity using a scale from 1 (very low color intensity) to 5 (very high color intensity).

[0189] 0 HW = Color result directly after coloring

[0190] The hair strands dyed with dyes (F3), (F6) and (F9) showed the best wash fastness when used as leave-on dyes with heat post-treatment.

Claims

Patent claims 1. A method for dyeing keratin fibers, in particular human hair, comprising - the application of a coloring agent (F) to the keratin fibers, the coloring agent containing (F-1) at least one chitosan and / or a chitosan derivative, (F-2) at least one pigment, (F-3) at least one organic and / or inorganic acid, and (F-4) Water, and - heating the keratin fibres covered with the colouring agent (F) to a temperature exceeding 40 °C.

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

3. Process according to one of claims 1 to 2, characterized in that the coloring agent (F) - based on the total weight of the coloring agent (F) - contains one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 10.0 wt.%, preferably of 0.2 to 8.0 wt.%, more preferably of 0.5 to 6.0 wt.% and most preferably of 0.7 to 2.0 wt.%.

4. The method according to any one of claims 1 to 3, characterized in that the colorant (F) contains at least one inorganic pigment (F-2), which is preferably selected from the group of colored metal oxides, metal hydroxides, metal oxide hydrates, silicates, metal sulfides, complex metal cyanides, metal sulfates, bronze pigments and / or colored pigments based on mica or mica, which are coated with at least one metal oxide and / or one metal oxychloride.

5. The method according to any one of claims 1 to 4, characterized in that the colorant (F) contains at least one organic pigment (F-2), which is preferably selected from the group consisting of carmine, quinacridone, phthalocyanine, sorghum, blue pigments with the color index numbers CI 42090, CI 69800, CI 69825, CI 73000, CI 74100, CI 74160, yellow pigments with the color index numbers CI 11680, CI 11710, CI 15985, CI 19140, CI 20040, CI 21100, CI 21108, CI 47000, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, CI 74260, orange pigments with the color index numbers CI 11725, CI 15510, CI 45370, CI 71105, red pigments with the color index numbers CI 12085, CI 12120, Cl 12370, Cl 12420, Cl 12490, Cl 14700, Cl 15525, Cl 15580, Cl 15620, Cl 15630, Cl 15800, Cl 15850, Cl 15865, Cl 15880, Cl 17200, Cl 26100, Cl 45380, Cl 45410, Cl 58000, Cl 73360, Cl 73915 and / or Cl 75470.

6. The method according to any one of claims 1 to 5, characterized in that the colorant (F) contains at least one pigment (F-2) selected from the group of pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

7. The method according to any one of claims 1 to 6, characterized in that the colorant (F) - based on the total weight of the colorant - contains one or more pigments (F-2) in a total amount of 0.01 to 10.0 wt.%, preferably 0.1 to 5.0 wt.%, more preferably 0.2 to 2.5 wt.% and most preferably 0.25 to 1.5 wt.%.

8. Process according to one of claims 1 to 7, characterized in that the coloring agent (F) contains one or more 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.

9. Process according to one of claims 1 to 8, characterized in that the colorant (F) has a pH of 2.0 to 7.5, preferably of 3.0 to 7.0, more preferably of 3.5 to 6.5 and most preferably of 4.0 to 6.

0.

10. The method according to any one of claims 1 to 9, characterized in that the weight ratio of the water (F-4) contained in the colorant (F) to the acids (F-3), ie the weight ratio (F-4) / (F-3), is from 1000 to 10, preferably from 500 to 40, more preferably from 200 to 60 and most preferably from 150 to 85.

11. Process according to one of claims 1 to 10, characterized in that the components (F-1), (F-2), (F-3) and (F-4) are contained together in a proportion of at least 90.0 wt.%, preferably of at least 93 wt.%, more preferably of at least 96 wt.% and most preferably of at least 99 wt.% in the colorant (F).

12. The method according to any one of claims 1 to 11, characterized in that the colorant (F) is substantially free of solvents from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, 1-butanol, phenoxyethanol, benzyl alcohol and / or polyethylene glycols.

13. Process according to one of claims 1 to 12, characterized in that the colorant has a viscosity of 10 to 10,000 mPas, preferably of 10 to 5,000 mPas, more preferably of 100 to 3,000 mPas and most preferably of 100 to 2,000 mPas (22 °C / Brookfield viscometer / spindle 3 / 30 rpm).

14. Method according to one of claims 1 to 13, characterized by heating the keratin fibers covered with the colorant (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 50 °C to 80 °C.

15. Method according to one of claims 1 to 14, characterized in that the heat treatment is carried out by using a hair dryer, a blow dryer, a heat cap, a straightening iron, a curling iron or an infrared lamp.

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