Method for producing dyes with improved performance

Abstract

The present invention relates to a method for producing a dye (F) for dyeing keratin fibres, in particular human hair, comprising the grinding of at least one mixture, containing chitosan and / or a chitosan derivative, and at least one pigment. The invention further relates to the dye that can be obtained by the production method and to the use thereof.

Description

[0001] .Method for the production of dyes with improved performance'

[0002] The present invention relates to a process for producing a dye (F) for dyeing keratinous fibers, in particular human hair, comprising milling at least one mixture containing chitosan and / or a chitosan derivative and at least one pigment. Further aspects include the dye obtainable by the manufacturing process and its application.

[0003] 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.

[0004] 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.

[0005] The use of color pigments is well-known for temporary color changes to hair and / or skin. Color pigments are generally understood to be insoluble, coloring substances. These are present in the coloring formulation in the form of small particles and are simply deposited on the hair fibers and / or skin surface. Therefore, they can usually be removed completely after a few washes with surfactant-containing cleansers. Various products of this type are available on the market under the name "hair mascara."

[0006] Dyeing with pigments offers several significant advantages. Since the pigments adhere only to the outside of the keratin fibers, especially the hair fibers, unwanted colorings can be removed quickly and easily without leaving any residue. This allows the user to return to their original hair color immediately and without much effort. This dyeing process is therefore particularly attractive for consumers who do not want to dye their hair regularly. However, in addition to these many advantages, the pigment-based dyeing system still has some disadvantages, which stem from the limited penetration depth of the pigments into the keratin fibers. Because the pigments do not diffuse into the keratin fiber but merely form a coating or...Since the pigment(s) are deposited as a film on the outside of the fiber, the wash fastness of dyes produced with this system still needs improvement. Various studies have attempted to bind the pigment(s) more permanently to the hair surface using film-forming materials, mostly polymers.

[0007] For example, German patent DE 19847883 A1 deals with achieving pigment-based colorations using dyes containing at least one chitosan and one pigment. Combining the pigments with chitosan was intended to improve the abrasion resistance of the colorations. The major advantage of chitosan as a film-forming material is that it is based on biopolymers and therefore offers improved environmental compatibility and biodegradability. As many users show increasing interest in products made with sustainable or renewable raw materials, the use of biopolymers is gaining in importance. Nevertheless, colorations obtained with pigment and chitosan still have disadvantages regarding their wash fastness.Achieving even coloring across the entire length of the hair cannot yet be considered optimal, as the durability of the films varies on different parts of the hair, especially in the areas at the roots and tips.

[0008] The objective of the present application was therefore to provide a pigment-based dye that enables intense coloring with improved wash fastness. The dyeing process should utilize biopolymers, and the keratin fibers or hair dyed with this dye should not feel coated or greasy, should exhibit a healthy shine, and the elasticity of the keratin fibers should not be negatively affected.

[0009] Another objective of the present application was to provide a method for producing a dye that leads to improved intensity, homogeneity in combination with higher wash stability of the dye on the hair.

[0010] Surprisingly, it has now been found that this task can be solved if a dye containing a chitosan and / or a chitosan derivative and a pigment is ground to produce a suspension of these two components.

[0011] A first object of the present invention is therefore a process for producing a dye (F) for dyeing keratinous fibers, in particular human hair, comprising the following steps: a) mixing at least one chitosan / chitosan derivative (F-1) with an aqueous medium (F-2) and optionally at least one organic acid (F-3); b) optionally allowing the mixture to swell; c) mixing the composition according to a) or b) with at least one pigment (F-4) or a composition containing at least one pigment (F-4); d) subsequently grinding the mixture according to c); and e) optionally adding further ingredients to the mixture according to d).

[0012] Hair dyed with the dye according to the invention, or with the dye produced according to the inventive method, was characterized by an intense color result with improved wash fastness. Furthermore, the dyed hair was very evenly colored and possessed a beautiful, natural shine without feeling greasy or coated. The hair was not weighed down, and its natural movement was not negatively affected. Additionally, the hair dyed with the dye exhibited improved adhesion of the dye.

[0013] Keratinous fibers

[0014] Keratinous fibers include hair, wool, and fur. Human hair is particularly often considered a keratinous fiber.

[0015] dyeing agents

[0016] The term "coloring agent" is used in this invention to describe the coloring of keratin fibers, particularly hair, by the use of pigments. In this coloring process, the pigments are deposited as coloring compounds in a homogeneous, uniform, and smooth film on the surface of the keratin fibers. This film is formed by the chitosan(s) and / or chitosan derivative(s).

[0017] Method for the production of a dye (F):

[0018] The process for producing a dye (F) comprises in a first step a) mixing at least one chitosan / chitosan derivative (F-1) with an aqueous medium (F-2) and optionally at least one organic acid (F-3).

[0019] The chitosan / chitosan derivative (F-1) described in more detail below is brought into contact with the aqueous medium. The aqueous medium (F-2) can consist exclusively of water (F-2) or it can be an aqueous solution containing other components. The weight fraction of water (F-2) in the mixture produced according to step a) is, based on the total weight of this mixture, preferably 10 to 99.9 wt.%, particularly preferably 20 to 99.5 wt.%, particularly preferably 50 to 99.0 wt.%, and most preferably 70 to 98.5 wt.%.

[0020] Preferably the mixing is supported by the use of conventional stirring tools, so that a suitable, in particular homogeneous, mixture is obtained after carrying out step a).

[0021] According to a preferred embodiment, the mixture prepared in step a) comprises, based on its total weight, one or more chitosans and / or chitosan derivatives (F-1) in a total amount of 0.1 to 50 wt.%, preferably 0.2 to 30 wt.%, more preferably 0.5 to 10.0 wt.%, and most preferably 1.0 to 5.0 wt.%.

[0022] Chitosans and / or chitosan derivatives (F-1)

[0023] As the first essential component, at least one chitosan and / or a derivative of chitosan (F-1) is used in step a).

[0024] Chitosan, also known as polyglucosamine or poly-D-glucosamine, is a naturally occurring biopolymer derived from chitin, which is composed of β-1,4-glycosidically linked N-acetylglucosamine residues (specifically, 2-acetamido-2-deoxy-β-D-glucopyranose residues). Like chitin, it is a polyaminosaccharide. Chitosan is produced by deacetylating chitin, resulting in a molecule consisting of approximately 2000 linearly linked 2-amino-2-deoxy-β-D-glucopyranose or glucosamine monomers. Chitosan has the CAS number 9012-76-4.

[0025] Suitable chitosans are freely available commercially under the trade names Hydagen® CMF (1 wt% active substance in aqueous solution with 0.4 wt% glycolic acid, molecular weight 500000 to 5000000 g / mol; Cognis), Hydamer® HCMF (chitosan (80% deacetylated), molecular weight 50000 to 1000000 g / mol, Chitinor, formerly Cognis), Kytamer® PC (approximately 80 wt% active substance of chitosan pyrolidone carboxylate (INCI name: Chitosan PCA), Amerchol), Chitolam® NB / 101 and Chitosan 90 / 100 / A1® (chitosan (approximately 90% deacetylated); BioLog Heppe).

[0026] Chitosan is preferably produced from chitin, which is found in shellfish or crustaceans. Chitosan is industrially produced from chitin by deacetylation. This can be achieved, for example, using (hot) sodium hydroxide or enzymatically. Both processes are used industrially, but the alkaline method is clearly the most prevalent in terms of volume. The degree of deacetylation can vary considerably: deacetylation can be complete or partial, resulting in a distribution of strongly deacetylated areas alongside weakly deacetylated areas, or a homogeneous deacetylation distribution. Simultaneously, this chemical process can decrease the polymer chain length (depolymerization). The molecular weight of chitosan can range over a wide spectrum, for example, from 20,000 to approximately 5 million g / mol.

[0027] 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.

[0028] 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.

[0029] In a further particularly preferred embodiment, in the process according to the invention, in step a) at least one chitosan and / or one 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 most preferably of 100,000 to 300,000 g / mol is used or such a substance is preferably contained in the dyes according to the invention.

[0030] Chitosan with a molecular weight of 100,000 to 300,000 g / mol can be purchased commercially from the company Sigma Aldrich, for example.

[0031] 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%.

[0032] 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.

[0033] 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.

[0034] Acids

[0035] Optionally, but preferably, an acid is additionally used in the process step according to a).

[0036] As an optional component, the mixture in step a) can also contain at least one organic and / or inorganic acid (F-3). The use of one or more acids can lower the pH of the mixture prepared in step a) or of the resulting dye (F), thereby partially or completely deprotonating the chitosan and allowing it to dissolve more readily. Macroscopically, the protonation of the chitosan in water is observed as swelling, from which, when the preferred or highly preferred pH is established, a particularly uniform and thin film is deposited on the keratin fibers, such as hair. It has been shown that the more uniformly the film forms on the hair, the better its durability. By forming a particularly uniform film, dyes with especially good wash fastness have also been achieved.Furthermore, the presence of the acid(s) in the dye also allows the chitosan to form a particularly thin film on the hair. Comparative studies have shown that a uniformly thin film offers better resistance to external mechanical stresses.

[0037] Particularly suitable organic acids include, for example, acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid.

[0038] Formic acid and propanoic acid are also suitable acids.

[0039] In a further particularly preferred embodiment, the product is characterized in that in step a) one or more organic acids (F3) are used or the dye (F) to be produced contains one or more organic acids (F-3), which are preferably selected from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid.

[0040] Acetic acid dissolves chitosan particularly well and leads to very thin and uniform films; therefore, a dye (F) containing acetic acid is particularly preferred.

[0041] In a further explicitly preferred embodiment, a dyeing agent (F) according to the invention is therefore characterized in that acetic acid is used in step a) of the manufacturing process or that the dyeing agent (F) contains acetic acid (F-3).

[0042] By using the acid(s) in suitable quantities, the pH of the mixture according to steps a), b) and / or c) or of the dye can be adjusted to the desired pH range. Particularly thin and uniform films were obtained when the dye (F) was adjusted to a pH in the range of 2.0 to 7.5, preferably 2.25 to 7.0, more preferably 2.5 to 6.5, and most preferably 3.0 to 5.0. Preferably, this pH adjustment is carried out directly in the mixture prepared in step a).

[0043] In a further particularly preferred embodiment, a dyeing agent (F) according to the invention is therefore characterized in that the dyeing agent (F) has a pH value of 2.0 to 7.5, preferably of 2.25 to 7.0, more preferably of 2.5 to 6.5, in particular of 2.75 to 6.0 and most preferably of 3.0 to 5.0.

[0044] Optionally, step c) does not immediately follow step a). A step b) can take place between step a) and step c), in which the mixture according to a) is not processed further directly, particularly to allow the homogenization of mixture a) to continue. This step, as mentioned above, is also perceived macroscopically as "swelling." This results in a particularly homogeneous dye produced in this way.

[0045] According to a preferred embodiment, step b) can be improved and supported by the use of stirring agents.

[0046] The optional step b) may preferably last from 0.1 to 120 min, in particular from 1 to 90 min, most preferably from 5 to 60 min.

[0047] In a preferred embodiment, the mixture according to a) or b) (i.e., the mixture resulting from carrying out process step a) or a) and b) respectively) comprises, based on its total weight, one or more chitosans and / or chitosan derivatives (F-1) in a total amount of 0.1 to 20%, preferably 0.2 to 10% by weight, more preferably 0.5 to 8.0% by weight, and most preferably 1.0 to 5.0% by weight. These mixtures have proven advantageous in the production of the dye.

[0048] Particularly preferably, the mixture according to a) or b) (i.e., the mixture resulting from carrying out process step a) or a) and b) comprises, based on its total weight, one or more chitosans and / or chitosan derivatives (F-1) in a total amount of 0.2 to 10 wt.%, more preferably 0.5 to 8.0 wt.%, and most preferably 1.0 to 5.0 wt.%, and has a pH value of 2.75 to 6.0, in particular 3.0 to 5.0.

[0049] The manufacturing process according to the invention is characterized in step c) by mixing the composition according to a) or b) with at least one pigment (F-4) or a composition containing at least one pigment (F-4).

[0050] The mixing is carried out in a manner known to those skilled in the art, for example by stirring. The mixing of the composition prepared in step a) or b) can be achieved by adding the pigment or the pigment mixture. Alternatively, it is also possible to carry out step c) according to the invention by presenting the pigment mixture and adding the composition from step a) or b). However, it is particularly preferred that the composition prepared in step a) or b) be presented and the at least one pigment or the composition containing at least one pigment (F-4) be added.

[0051] Pigments (F-4)

[0052] As a second essential component, at least one pigment is used in step c) of the process according to the invention. For the purposes of this invention, pigments are understood to be coloring compounds which have a solubility in water at 25 °C of less than 0.5 g / L, preferably less than 0.1 g / L, and even more preferably less than 0.05 g / L. The water solubility can be determined, for example, by the method described below: 0.5 g of the pigment is weighed into a beaker. A magnetic stir bar is added. Then one liter of distilled water is added. This mixture is heated to 25 °C for one hour while stirring on a magnetic stirrer. If undissolved components of the pigment are still visible in the mixture after this period, the solubility of the pigment is below 0.5 g / L.If the pigment-water mixture cannot be visually assessed due to the high intensity of the potentially finely dispersed pigment, the mixture is filtered. If a proportion of undissolved pigment remains on the filter paper, the pigment's solubility is below 0.5 g / L.

[0053] Suitable color pigments can be of inorganic and / or organic origin.

[0054] In a preferred embodiment, the inventive method or a dyeing agent (F) according to the invention is characterized in that at least one coloring compound (F-4) from the group of inorganic and / or organic pigments is included.

[0055] In a preferred embodiment, the inventive method or a dyeing agent (F) according to the invention is characterized in that it contains at least one inorganic and / or organic pigment (F-4).

[0056] 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. Particularly suitable are colored metal oxides, hydroxides, and oxide hydrates, mixed-phase pigments, sulfur-containing silicates, silicates, metal sulfides, complex metal cyanides, metal sulfates, chromates, and / or molybdates.Particularly preferred color pigments are black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and brown iron oxide (CI 77491), manganese violet (CI 77742), ultramarine (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), iron blue (ferric ferrocyanide, CI 77510) and / or carmine (cochineal).

[0057] 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.

[0058] 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).

[0059] In a further preferred embodiment, an at least inorganic pigment (F-4) is used in the process according to the invention or is contained in the coloring agent according to the invention, 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 micaceous oxide, which are coated with at least one metal oxide and / or one metal oxychloride.

[0060] In a further preferred embodiment, a dyeing agent (F) according to the invention is characterized in that the dyeing agent (F) 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).

[0061] 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.

[0062] Particularly favored color pigments with the trade name Colorona® include, for example:

[0063] Colorona Copper, Merck, MICA, CI 77491 (IRON OXIDES)

[0064] Colorona Passion Orange, Merck, Mica, CI 77491 (Iron Oxides), Alumina

[0065] Colorona Patina Silver, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0066] Colorona RY, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 75470 (CARMINE)

[0067] Colorona Oriental Beige, Merck, MICA, CI 77891 (TITANIUM DIOXIDE), CI 77491 (IRON OXIDES)

[0068] Colorona Dark Blue, Merck, MICA, TITANIUM DIOXIDE, FERRIC FERROCYANIDE

[0069] Colorona Chameleon, Merck, CI 77491 (IRON OXIDES), MICA

[0070] Colorona Aborigine Amber, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM

[0071] DIOXIDE)

[0072] Colorona Blackstar Blue, Merck, CI 77499 (IRON OXIDES), MICA

[0073] Colorona Patagonian Purple, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM

[0074] DIOXIDE), CI 77510 (FERRIC FERROCYANIDE)

[0075] Colorona Red Brown, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0076] Colorona Russet, Merck, CI 77491 (TITANIUM DIOXIDE), MICA, CI 77891 (IRON OXIDES)

[0077] Colorona Imperial Red, Merck, MICA, TITANIUM DIOXIDE (CI 77891), D&C RED NO. 30 (CI 73360)

[0078] Colorona Majestic Green, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 77288

[0079] (CHROMIUM OXIDE GREENS)

[0080] Colorona Light Blue, Merck, MICA, TITANIUM DIOXIDE (CI 77891), FERRIC FERROCYANIDE (Cl

[0081] 77510)

[0082] Colorona Red Gold, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0083] Colorona Gold Plus MP 25, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), IRON OXIDES (Cl 77491)

[0084] Colorona Carmine Red, Merck, MICA, TITANIUM DIOXIDE, CARMINE

[0085] Colorona Blackstar Green, Merck, MICA, Cl 77499 (IRON OXIDES)

[0086] Colorona Bordeaux, Merck, MICA, Cl 77491 (IRON OXIDES)

[0087] Colorona Bronze, Merck, MICA, Cl 77491 (IRON OXIDES)

[0088] Colorona Bronze Fine, Merck, MICA, Cl 77491 (IRON OXIDES)

[0089] Colorona Fine Gold MP 20, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON

[0090] OXIDES)

[0091] Colorona Sienna Fine, Merck, Cl 77491 (IRON OXIDES), MICA

[0092] Colorona Sienna, Merck, MICA, Cl 77491 (IRON OXIDES)

[0093] Colorona Precious Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Silica, Cl 77491 (Iron oxides), Tin oxide Colorona Sun Gold Sparkle MP 29, Merck, MICA, TITANIUM DIOXIDE, IRON OXIDES, MICA, Cl 77891 , Cl 77491 (EU)

[0094] Colorona Mica Black, Merck, Cl 77499 (Iron oxides), Mica, Cl 77891 (Titanium dioxide) Colorona Bright Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Cl 77491 (Iron oxides) Colorona Blackstar Gold, Merck, MICA, Cl 77499 (IRON OXIDES)

[0095] Weiterhin besonders bevorzugte Farbpigmente mit der Handelsbezeichnung Xirona® sind beispielsweise:

[0096] Xirona Golden Sky, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0097] Xirona Caribbean Blue, Merck, Mica, CI 77891 (Titanium Dioxide), Silica, Tin Oxide

[0098] Xirona Kiwi Rose, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0099] Furthermore, particularly preferred color pigments with the trade name Unipure® include, for example:

[0100] Unipure Red LC 381 EM, Sensient CI 77491 (Iron Oxides), Silica

[0101] Unipure Black LC 989 EM, Sensient, CI 77499 (Iron Oxides), Silica

[0102] Unipure Yellow LC 182 EM, Sensient, CI 77492 (Iron Oxides), Silica

[0103] In a further embodiment, one or more organic pigments can be used in the inventive method, or the inventive dye (F) may also contain one or more organic pigments.

[0104] 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.

[0105] 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.In a further particularly preferred embodiment, a coloring agent (F) according to the invention is characterized in that it contains at least one organic pigment (F-4) 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.

[0106] 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.

[0107] For example, alizarin lacquer can be used as a colored lacquer.

[0108] Due to their excellent light and temperature resistance, the use of the aforementioned pigments in the dye (F) of the process according to the invention is particularly preferred. Furthermore, it is preferred if the pigments used have a specific particle size. Therefore, according to the invention, it is advantageous if the at least one pigment has a mean particle size D50 of 1.0 to 50 pm, preferably of 5.0 to 45 pm, more preferably of 10 to 40 pm, and particularly of 14 to 30 pm. The mean particle size D50 can be determined, for example, using dynamic light scattering (DLS).

[0109] Pigments (F-4) 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.

[0110] In a further preferred embodiment, the method or the agent according to the invention is characterized in that it contains at least one pigment (F-4) selected from the group consisting of pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

[0111] 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.

[0112] 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.

[0113] The size of the substrate platelet can be tailored to the specific application, particularly the desired effect on the keratinous material. Typically, the substrate platelets have a mean maximum diameter of approximately 2 to 200 pm, especially approximately 5 to 100 pm.

[0114] 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.

[0115] The substrate plates can be made from any material that can be formed into platelet form.

[0116] 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).

[0117] 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.

[0118] Lamellar substrate platelets are characterized by an irregularly structured edge and are also referred to as "cornflakes" due to their appearance.

[0119] 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.

[0120] Lenticular (lens-shaped) substrate platelets have a generally regular, rounded edge and are also referred to as "silver dollars" due to their appearance. Because of their regular structure, pigments based on lenticular substrate platelets have a high proportion of reflected light.

[0121] 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 thickness in the range of 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.

[0122] VMP substrate plates made of aluminum can be obtained, for example, by releasing aluminum from metallized foils.

[0123] The substrate plates, made of metal or metal alloy, can be passivated, for example by anodizing (oxide layer) or chromating. Uncoated lamellar, lenticular, and / or VPM substrate plates, 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.

[0124] Suitable pigments based on a lamellar substrate platelet include, for example, the VISIONAIRE series pigments from Eckart.

[0125] Pigments based on a lenticular substrate platelet are available, for example, under the name Alegrace® Gorgeous from the company Schlenk Metallic Pigments GmbH.

[0126] 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.

[0127] The pigment(s) (F-4) are preferably used in certain quantity ranges in the dyes (F) according to the invention or in the processes according to the invention in the mixtures according to c), d) or e).

[0128] Particularly good results were obtained when the dyeing agent – ​​based on the total weight of the dyeing agent or the mixture according to step c), d) or e) – contained one or more pigments (F-4) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 2.00 wt.%, more preferably 0.20 to 1.50 wt.%, even more preferably 0.25 to 1.25 wt.% and most preferably 0.30 to 1.00 wt.%.

[0129] In a further particularly preferred embodiment, a dyeing agent (F) according to the invention is characterized in that it contains – based on the total weight of the dyeing agent (F) – one or more pigments (F-4) in a total amount of 0.11 to 7.35 wt.%, preferably 0.16 to 4.90 wt.%, more preferably 0.21 to 3.70 wt.%, even more preferably 0.25 to 1.25 wt.% and most preferably 0.27 to 1.20 wt.%.

[0130] According to a preferred embodiment of the process according to the invention, in step c) a composition containing at least one pigment (F4), hereinafter referred to as the pigment-containing composition (F-4), is used. The amounts mentioned below refer to the pigment-containing composition (F-4) before it is mixed in step c) with the mixture according to a) or b).

[0131] It is preferred that the pigment-containing composition (F-4) contains one or more organic solvents (F-5). It is particularly preferred that the total amount of organic solvents (F-5), based on the pigment-containing composition (F-4), before it is mixed in step c) with the mixture from step a) or b), is preferably 20 to 100 wt.%, more preferably 50 to 100 wt.%, and particularly 80 to 100 wt.%.

[0132] A particularly preferred embodiment of the process according to the invention is characterized in that at least one of the following is selected as the organic solvent (F-5): ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, 1-butanol, phenoxyethanol, benzyl alcohol and polyethylene glycol, preferably a C2 to C4 alkanol, particularly preferably ethanol.

[0133] According to a particularly preferred embodiment, the pigment-containing composition (F-4) comprises ethanol, preferably in an amount of 50 to 100 wt.%, and more specifically 80 to 100 wt.%, based on the total weight of the pigment-containing composition (F-4), before it is mixed in step c) with the mixture according to step a) or b). This is particularly advantageous because the pigments preferred according to the invention dissolve well in ethanol, and the pigment-containing composition (F-4) mixes particularly well with the aqueous solution of chitosan or the chitosan derivative. At the same time, the viscosity of the resulting dye is not negatively affected.

[0134] The method according to the invention is further characterized by step d), in which the mixture is ground according to c).

[0135] Surprisingly, grinding the mixture resulting from step c) produced dyes that led to improved color intensity, greater color homogeneity, and higher wash stability on the hair.

[0136] According to a preferred embodiment, step d) has a duration of 0.1 to 400 min, preferably 1 to 300 min, particularly preferably 5 to 200 min, particularly preferably 15 to 180 min, most preferably 20 to 90 min.

[0137] According to another preferred embodiment, step d) is carried out in a grinding media mill. This has the advantage that the liquid mixtures can be ground particularly well in it to produce a homogeneous mixture with significantly smaller particles.

[0138] A particularly preferred embodiment of the method according to the invention is characterized in that at least one grinding media is used in step d), which has a size of 0.1 to 10 mm, preferably 0.5 to 8.0 mm, and in particular 1.0 to 5.0 mm. These grinding media sizes result in particularly homogeneous mixtures, in which the resulting dye enables particularly intense coloring.

[0139] According to a further preferred embodiment of the method according to the invention, step d) is carried out at a rotational speed of 1 to 10,000, preferably 100 to 8,000, particularly preferably 500 to 5,000, and especially 1,000 to 3,000 revolutions per minute. These speeds enable rapid and intensive mixing of the composition. In particular, the preferred rotational speeds of 1,000 and more revolutions per minute result in a particularly cost-efficient process, since the smallest achievable particle size is reached particularly quickly.

[0140] According to the invention, it is particularly preferred if the pigments, after milling step d), have particle sizes of 100 to 2000 nm, preferably 120 to 1600 nm, and most preferably 150 to 1300 nm. These particle sizes are also determined, as described in the example, by the method of dynamic light scattering.

[0141] Surprisingly, dyes with such particle sizes exhibit particularly high dyeing intensity, improved homogeneity, and increased wash resistance.

[0142] Optionally, in the process according to the invention, further ingredients can be added in step e) after step d), in which the compositions are milled with pigment and chitosan or chitosan viate. This can be particularly advantageous for ingredients that are negatively affected by milling. For example, ingredients that are sensitive to milling or heating can still be incorporated into the dye. Preferably, at least one perfume, more preferably a perfume oil, is added in step e).

[0143] Dyeing agent (F)

[0144] Another object of the present invention is a dye (F) for dyeing keratinous fibers, in particular human hair, obtainable by a method as described above.

[0145] In comparison to the conventional production of such a dye (without step d), milling creates a particularly close bond between the chitosan or chitosan derivative and the pigment, resulting in particularly intense and homogeneous colorations and even higher wash resistance. Simply using pigments with a smaller particle size is not sufficient to achieve this effect. A preferred object of the present invention is therefore a dye (F) for coloring keratinous fibers, especially human hair, produced by a process as described above.

[0146] All of the above-mentioned ingredients, their preferred weight proportions and / or other characteristics also apply accordingly to dyes obtainable / produced by the process.

[0147] Another object of the present invention is a dyeing agent (F) for dyeing keratinous fibers, in particular human hair, comprising

[0148] (F-1) at least one chitosan and / or one chitosan derivative,

[0149] (F-2) Water and / or

[0150] (F-3) at least one organic solvent

[0151] (F-4) at least one pigment and

[0152] (F-5) optionally at least one organic acid, characterized in that the at least one pigment has a particle size D50 of 0.1 to 2 pm, preferably 0.2 to 1.0 pm, in particular 0.3 to 0.95 pm, preferably determined by dynamic light scattering.

[0153] Particularly preferred are dyes which already have a particularly small particle size D50 of 0.2 to 1.0 pm and especially of 0.3 to 0.95 pm, wherein the particle size D50 and possibly other particle sizes are preferably determined by means of dynamic light scattering, as described in the example.

[0154] The mean particle size D50 is defined as the particle diameter value at 50% of the cumulative distribution. For example, D50 = 200 nm means that 50% of the particles in the sample are larger than 200 nm and 50% are smaller than 200 nm.

[0155] It has been found that a particle size D50 in the range of 0.3 to 0.95 pm is particularly advantageous, as it results in especially suitable dyes that produce more intense color with improved homogeneity and increased wash stability. In particular, these especially suitable particle sizes also reduce dye abrasion and improve dye stability.

[0156] Furthermore, it is preferred if the pigment(s) used are not particularly small. The D10 value of the particles, which indicates the value at which 90% of the particles in the sample have a larger particle diameter than the specified value, is at least 100 nm, preferably at least 120 nm, and particularly preferably at least 150 nm. It is also particularly preferred if the particle size D10 is at least 120 nm and the particle size D50 is from 0.3 to 0.95 pm.

[0157] Furthermore, it is preferred if the particle size D90, at which 90% of the particles in the sample have a particle size smaller than the D90 value, is a maximum of 3 pm, preferably a maximum of 2.5 pm, preferably a maximum of 0.95 pm.

[0158] All of the aforementioned ingredients, their quantities and / or properties also apply accordingly to these dyes.

[0159] The dyeing agent (F) according to the invention is characterized by its content of the components (F-1), (F-2), (F-3) and (F-4).

[0160] In a further particularly preferred embodiment, a dye (F) according to the invention is characterized in that the dye (F) contains – based on the total weight of the dye (F) – one or more chitosans and / or chitosan derivatives in a total amount of 0.01 to 10.0 wt.%, preferably 0.05 to 5.0 wt.%, more preferably 0.1 to 1.5 wt.%, and most preferably 0.3 to 0.9 wt.%. Particularly good results were obtained with these weight proportions.

[0161] According to a further preferred embodiment of the coloring agent (F), the weight ratio of all pigments (F-4) contained in the mixture to all chitosan (derivatives) (F-1) contained in the mixture, i.e. the weight ratio (F-4) / (F-1), is in the range of 1.00:1.10 to 1.00:2.35, preferably from 1.00:1.20 to 1.00:2.35, more preferably from 1.00:1.30 to 1.00:2.30 and most preferably from 1.00:1.40 to 1.00:2.30.

[0162] Cosmetic carrier of the dye:

[0163] The colorant (F) contains components (F-1), (F-2) and optionally (F-3) in a cosmetic carrier, which is a mixture of water (F-2) and at least one organic solvent (F-5). The at least one organic solvent is cosmetically compatible.

[0164] It was surprisingly found that an amount of 20 to 95 wt.%, preferably 50 to 90 wt.%, particularly 55 to 85 wt.%, and most preferably 60 to 80 wt.% – in each case based on the total weight of the dye – of organic solvent significantly improves the quality properties of the dyeing (homogeneity, intensity, and wash stability). According to a preferred embodiment of the dye (F), it contains as organic solvent (F-5) at least one from the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, 1-butanol, phenoxyethanol, benzyl alcohol, and polyethylene glycol, preferably a C2 to C4 alkanol, and particularly preferably ethanol.

[0165] Mixtures of two or more organic solvents, preferably of two or more of the aforementioned solvents among each other, are also possible according to the invention.

[0166] The presence of at least one C2- to C4-alkanol (where the term alkanes with 2 to 4 carbons and one, two, or three alcohol groups) promotes the uniform and firm formation of the pigment-containing chitosan film on the hair, even after washing. Preferred C2-C4-alkanols are ethanol, isopropanol, 1-butanol, 1,2-propanediol, 1,3-propanediol, and glycerol.

[0167] In a further particularly preferred embodiment, a dyeing agent (F) according to the invention is therefore characterized in that it contains ethanol (F-5) as an organic solvent. The pigmented film formed with an ethanol / water mixture adheres to the hair particularly easily and evenly.

[0168] According to a particularly preferred embodiment, the dyeing agent (F) contains - based on the total weight of the dyeing agent - ethanol (F-5) in a total amount of 20 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

[0169] It was found that the aforementioned proportions of ethanol particularly promote the easy formation of the pigment-containing chitosan film on the hair. Specifically, the intensity, homogeneity, and wash stability of the hair color are enhanced by ethanol in proportions of 55 to 85 wt.%, and particularly preferably 60 to 80 wt.%, based on the total weight of the dye.

[0170] In a further particularly preferred embodiment, the dyeing agent (F) contains - based on the total weight of the dyeing agent - 5 to 70 wt.%, preferably 10 to 60 wt.%, more preferably 15 to 50 wt.% and most preferably 20 to 40 wt.% water (F-2).

[0171] The presence of water, particularly in an amount of 15 to 50 wt.%, and especially preferably 20 to 40 wt.%, improves the solubility of the chitosan or chitosan derivative and, in combination with at least one organic solvent, leads to the formation of stable, intense, and homogeneous dyes. According to a particularly preferred embodiment of the present invention, the weight ratio of the amount of all organic solvents (F-5) to water (F-5) / (F-2) in the dyes (F) – based on the total composition – is 8:1 to 1:4, preferably 5:1 to 1:1, particularly preferably 4:1 to 1.5:1, especially 3:1 to 1.6:1, and most preferably 2.8:1 to 1.7:1. It has now been found that such dyes exhibit particularly good film-forming properties, homogeneity, and intensity, while simultaneously improving wash stability.

[0172] According to a preferred embodiment, the dye according to the invention therefore contains - based on the total weight of the dye - at least one chitosan (derivative) (F-1), 15.0 to 45.0 wt.%, preferably 20.0 to 40.0 wt.% water (F-2), at least one pigment (F-4), and 55 to 85 wt.%, particularly preferably 60 to 80 wt.% organic solvent (F-5) and optionally at least one organic acid, preferably acetic acid (F-3).

[0173] Preferably, the weight ratio of the amount of all organic solvents (F-5) to water (F-5) / (F-2) is 8:1 to 1:4, preferably 5:1 to 1:1, particularly preferably 4:1 to 1.5:1, in particular 3:1 to 1.6:1, most preferably 2.8:1 to 1.7:1.

[0174] According to a particularly preferred embodiment, the dye according to the invention contains - based on the total weight of the dye - at least one chitosan(derivative) (F-1),

[0175] 15.0 to 45.0 wt.%, preferably 20.0 to 40.0 wt.% water (F-2), at least one pigment (F-4) and 55 to 85 wt.%, particularly preferably 60 to 80 wt.% ethanol (F-5) and optionally at least one organic acid, preferably acetic acid (F-3).

[0176] The weight ratio of ethanol (F-5) to water (F2) (F-5) / (F-2) is particularly preferably 8:1 to 1:4, preferably 5:1 to 1:1, particularly preferably 4:1 to 1.5:1, in particular 3:1 to 1.6:1, and most preferably 2.8:1 to 1.7:1.

[0177] According to a particularly preferred embodiment, the dye according to the invention contains – based on the total weight of the dye – at least one chitosan (derivative) (F-1), 20.0 to 40.0 wt.% water (F-2), and at least one pigment (F-4), 60 to 80 wt.% ethanol (F-5), and at least one organic acid, preferably acetic acid (F-3). The weight ratio of ethanol (F-5) to water (F-5) / (F-2) is particularly preferably 4:1 to 1.5:1, in particular 3:1 to 1.6:1, and most preferably 2.8:1 to 1.7:1.

[0178] Particularly preferred compositions of such a particularly preferred dyeing agent contain - based on the total weight of the dyeing agent - 0.3 to 0.9 wt.% of at least one chitosan (derivative) (F-1), 20.0 to 40.0 wt.% water (F-2),

[0179] 0.2 to 1.5 wt% of at least one pigment (F-4) and

[0180] 60 to 80 wt% ethanol (F-5) and acetic acid (F-3).

[0181] These particularly prefer a pH value of 3.0 to 5.0.

[0182] The weight ratio of ethanol (F-5) to water (F-2), (F-5) / (F-2), is particularly preferably from 3:1 to 1.6:1, and most preferably from 2.8:1 to 1.7:1.

[0183] These particularly suitable mixtures of dye produce especially intense, even and wash-stable colorations that are still very clearly visible on the hair even after 3 hair washes.

[0184] Viscosity of the dye (F)

[0185] The work carried out within the scope of this application has shown that the dye (F) can be applied particularly well to keratinous fibers when the dye (F) itself is more viscous and thus spreads well on the keratin material without dripping from the hair. Therefore, it is further preferred if the dye (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 500 to 2,000 mPas (22 °C / Brookfield viscometer / spindle 4 / 20 rpm = revolutions per minute).

[0186] Methods for dyeing keratinous fibers

[0187] A second subject matter of the present application is a method for dyeing keratinous fibers, in particular human hair, with a dye (F) comprising the steps, in the specified order: applying the dye (F) to the keratinous fibers and drying the keratinous fibers covered with the dye (F). The dye (F) has already been described in detail in the description of the first subject matter of the invention. A further subject matter of the present invention is therefore a method for dyeing keratinous fibers, in particular human hair, with a dye (F), wherein the dye has already been disclosed in detail in the preceding description, and wherein the method comprises the following steps, in the specified order:

[0188] - the application of the dye (F) to the keratinous fibers and

[0189] - the drying of the keratinous fibers covered with the dye (F).

[0190] The dye can be applied to the keratin fibers, for example, with a gloved hand or using a brush or applicator, and the keratin fibers can be wet or dry. After application, the dye can be spread over the keratin fibers and, if necessary, gently massaged in.

[0191] After application of the dye (F), the keratin fibers covered with the dye (F) are dried. During drying, the cosmetic carrier present in the dye (F), such as the ethanol / water mixture, evaporates, allowing the film comprising the pigment and chitosan (derivative) to form. Since the dye is not washed out before drying, the process according to the invention is a leave-on dyeing process.

[0192] The drying of the keratin fibers begins in principle immediately after the application of the dye, as the evaporation of the cosmetic carrier also starts at this time. Drying can occur at room temperature (i.e., without any further heat application), or it can be supported or accelerated by heat treatment of the keratin fibers.

[0193] Heat treatment of keratin fibers

[0194] The dye (F) can be applied, massaged in, and distributed onto the wet or dry keratinous fibers. After application of the dye (F), the keratinous fibers covered with the dye (F) are preferably heated to a temperature above 40 °C by mechanical means (combing or kneading). In this embodiment, the heating takes place after the application of the dye (F). Heating accelerates the evaporation of the solvent or water present in the dye (F), allowing the film consisting of pigment and chitosan (derivative) to form. Since the dye is not washed out before drying, the process according to the invention is a leave-on dyeing process.

[0195] Heating or heat treatment refers to the process of 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 such devices include a hairdryer, a heat cap, a flat iron, a curling iron, or an infrared lamp.

[0196] In a particularly preferred embodiment, a method according to the invention is characterized in that the heating to more than 40 °C is carried out by using a hairdryer, a hair dryer, a heat cap, a flat iron, a curling iron or an infrared lamp.

[0197] Furthermore, it was found that it is preferred if the treatment temperature during the heat treatment is between 40 °C and 210 °C, preferably between 40 °C and 190 °C, more preferably between 45 °C and 170 °C, even more preferably between 45 °C and 100 °C, and most preferably between 50 °C and 80 °C. In other words, it has proven particularly preferred if the heat treatment is carried out with a device that is heated to a temperature of 40 °C to 210 °C, preferably between 40 °C and 190 °C, more preferably between 45 °C and 170 °C, even more preferably between 45 °C and 100 °C, and most preferably between 45 °C and 70 °C.

[0198] In a further particularly preferred embodiment, a method according to the invention is characterized by heating the keratinous fibers covered with the dye (F) to a temperature of 40 °C to 210 °C, preferably from 40 °C to 190 °C, more preferably from 45 °C to 170 °C, even more preferably from 45 °C to 100 °C and most preferably from 45 °C to 70 °C.

[0199] The duration of the heat treatment can be adjusted to the selected temperature range. For example, heat treatment can be carried out for a duration of 5 seconds to 60 minutes, preferably from 15 seconds to 45 minutes, more preferably from 15 seconds to 30 minutes, and most preferably from 15 seconds to 15 minutes.

[0200] In the process according to the invention, the keratin fibers can be completely subjected to heat treatment, but the treatment of partial areas of the keratin fibers can also be included. Complete heat treatment of the keratin fibers is preferred, i.e., preferably all keratin fibers to which the dye (F) has also been applied are treated with heat.

[0201] During heat treatment or heating, the keratin fibers can also be combed or brushed.

[0202] For example, the keratin fibers or the hair, possibly under combs or brushes, can be treated with a hairdryer that blows warm or hot air onto the fibers. This air is preferably between 45 and 70 °C. Alternatively, the keratin material or the hair can be held under an infrared lamp, preferably set to a temperature of 45 to 70 °C. For heat treatment, hair can also be pressed between two appropriately heated plates of a flat iron, which can simultaneously be moved along the hair fiber. The plates of the flat iron can, for example, be set to a temperature of up to 210 °C.

[0203] In a further particularly preferred embodiment, a method according to the invention is characterized in that the heat treatment is carried out by using a hairdryer, a hair dryer, a heat cap, a flat iron, a curling iron or an infrared lamp.

[0204] Examples:

[0205] The following dyes were produced (all values, unless otherwise stated, are in wt.%):

[0206] 1. Formulations

[0207] Dyes were produced as follows.

[0208] A) Chitosan formulation (Index A according to Table 1):

[0209] The chitosan was mixed with water containing acetic acid by stirring and then stirred for 2 hours.

[0210] B) Pigment suspension (index B according to Table 1)

[0211] The respective pigment was dispersed in ethanol under stirring (2).

[0212] Subsequently, both formulations A and B were combined. A portion of the dyes FM1 to FM3 obtained in this way was then additionally wet-milled in a ball mill at a rotational speed of 2500 revolutions per minute for 30 to 90 minutes. The milling medium consisted of zirconium spheres with a diameter of 2 mm.

[0213] Table 1: Complete formula of the dyes (all values ​​in wt.% unless otherwise stated):

[0214] The dyes FM1 and FM2 (each in a ground and unground state) were applied to strands of hair (Kerling company). For this purpose, 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 and combed. The dyed strands were visually assessed by a trained person under a daylight lamp.

[0215] Following the coloring process, each dyed strand underwent three manual washes. For each wash, the strand was moistened, then a standard shampoo (Schwarzkopf, Schauma 7 Herbs) was massaged into the strand for 25 seconds (0.25 g of shampoo per gram of hair). Afterward, the strand was rinsed with lukewarm tap water for 30 seconds and dried.

[0216] After the three hair washes, each strand was visually assessed again under the daylight lamp.

[0217] The hair strands produced in this way were assessed for color intensity and uniformity on a scale from 1 (very high color intensity and uniformity) to 6 (very low color intensity and uniformity) after application of the dye (F). A further assessment was carried out after three hair washes regarding wash stability on a scale from 1 (very high wash stability) to 6 (very low wash stability).

[0218] Table 2: Scale: 1 very high rating for the criterion (good uniformity, good color intensity, good wash fastness), 6 very low rating for the criterion (poor uniformity, poor color intensity, poor wash fastness)

[0219] In the coloring of hair strands with the ground compositions FM1 and FM2, the grinding step resulted in a significantly improved color intensity, uniformity and wash stability after 3 hair washes compared to the ground formulations of the same composition.

[0220] Measurement of the particle sizes resulting from grinding:

[0221] Various colorants according to FM3 (table) containing pigments according to Table 2) were prepared and wet-milled at 60 min and 2000 rpm in a ball mill with 2 mm zirconium beats as the milling medium.

[0222] The particle sizes of the pigments contained in the dyes were determined using dynamic light scattering (DLS, also known as photon correlation spectroscopy (PCS)) in a Malvern.UK Zetasizer Nano ZS as the mean of 3 measurements using Zetasizer software V8.02. The D50 value of the particle size (mean hydrodynamic particle diameter) as well as the corresponding D10 and D90 values ​​were measured.

[0223] 0.1 g of the dye sample was placed in a beaker and intensively mixed with 50 ml of demineralized water, then filled into a measuring cuvette and measured.

[0224] The D50 value is defined as the particle diameter at 50% of the cumulative distribution. For example, D50 = 200 nm means that 50% of the particles in the sample are larger than 200 nm and 50% are smaller than 200 nm.

[0225] Table 3: Particle sizes of the pigments in dye 3 after milling (in nm)

Claims

Patent claims 1. A method for producing a dye (F) for dyeing keratinous fibers, in particular human hair, comprising the following steps: a) mixing at least one chitosan / chitosan derivative (F-1) with an aqueous medium (F-2) and optionally at least one organic acid (F-3); b) optionally allowing the mixture to swell; c) mixing the composition according to a) or b) with at least one pigment (F-4) or a composition containing at least one pigment (F-4); d) subsequently grinding the mixture according to c); and e) optionally adding further ingredients to the mixture according to d).

2. Method according to claim 1, characterized in that in step a) at least one chitosan and / or one 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 most preferably of 100,000 to 300,000 g / mol is used.

3. Method according to one of claims 1 to 2, characterized in that the mixture resulting from step a) or b) contains, based on its total weight, one or more chitosans and / or chitosane derivatives (F-1) in a total amount of 0.1 to 50 wt.%, preferably 0.2 to 30 wt.%, more preferably 0.5 to 10.0 wt.%, and most preferably 1.0 to 5.0 wt.%.

4. Method according to one of claims 1 to 3, characterized in that one or more organic acids (F-3), preferably selected from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid, are used.

5. Method according to one of claims 1 to 4, characterized in that the at least one pigment (F-4) used in step c) is selected from the group consisting of inorganic pigments, organic pigments, pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

6. A method according to any one of claims 1 to 5, characterized in that in step c) a composition containing at least one pigment (F4) and one or more organic solvents (F-5) is used, wherein the total amount of the organic solvent (F-5), based on the composition in step c), preferably from 20 to 100 wt.%, particularly preferably from 50 to 100 wt.%, in particular from 80 to 100 wt.%.

7. The method according to claim 6, characterized in that the organic solvent is (F-5) at least one of the group consisting of ethanol, isopropanol, 1,2-propylene glycol, 1,3-propanediol, glycerol, 1-butanol, phenoxyethanol, benzyl alcohol and polyethylene glycol, preferably a C2 to C4 alkanol, particularly preferably ethanol, is selected.

8. Method according to any one of claims 1 to 7, characterized in that the mixture according to step a), b), and / or c) has a pH value of 2.0 to 7.5, preferably 2.25 to 7.0, preferably 2.5 to 6.5, more preferably 2.75 to 6.0 and most preferably 3.0 to 5.

0.

9. Method according to any one of claims 1 to 8, characterized in that step d) comprises a Duration of 0.1 to 400 min, preferably 1 to 300 min, particularly preferably 5 to 200 min, particularly preferably 15 to 180 min, most preferably 20 to 90 min.

10. Method according to any one of claims 1 to 9, characterized in that step d) is carried out in a grinding media mill.

11. Method according to one of claims 1 to 10, characterized in that at least one grinding body is used in step d) which has a size of 0.1 to 10 mm, preferably 0.5 to 8.0 mm, in particular 1.0 to 5.0 mm.

12. Method according to any one of claims 1 to 11, characterized in that step d) is carried out at a rotational speed of 1 to 10000, preferably 100 to 8000, particularly preferably 500 to 5000, in particular 1000 to 3000 revolutions per minute.

13. Dyeing agent (F) for dyeing keratinous fibers, in particular human hair, obtainable by a method according to any one of claims 1 to 12.

14. Dyeing agent (F) for dyeing keratinous fibers, in particular human hair, produced according to a method according to any one of claims 1 to 12.

15. Dyeing agent (F) for dyeing keratinous fibers, especially human hair, containing (F-1) at least one chitosan and / or one chitosan derivative, (F-2) Water and / or (F-3) optionally at least one organic acid, (F-4) at least one pigment and (F-5) at least one organic solvent characterized in that the at least one pigment has a particle size D50 of 0.1 to 2 pm, preferably 0.2 to 1.0 pm, in particular 0.3 to 0.95 pm, preferably determined by dynamic light scattering.

16. Dyeing agent (F) according to one of claims 13 to 15, characterized in that it contains - based on the total weight of the dyeing agent - one or more organic solvents (F-5) in a total amount of 20 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

17. Dyeing agent according to one of claims to 16, characterized in that it contains - based on the total weight of the dyeing agent (F) - one or more pigments (F-4) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 2.00 wt.%, more preferably 0.20 to 1.50 wt.%, even more preferably 0.25 to 1.25 wt.% and most preferably 0.30 to 1.00 wt.%.

18. Dyeing agent according to any one of claims 13 to 17, characterized in that the dyeing agent (F) - based on the total weight of the dyeing agent (F) - contains one or more chitosans and / or chitosan derivatives in a total amount of 0.01 to 10.0 wt.%, preferably 0.05 to 5.0 wt.%, more preferably 0.1 to 1.5 wt.% and most preferably 0.3 to 0.9 wt.%.

19. Dyeing agent according to any one of claims 13 to 18, characterized in that the weight ratio of all pigments (F-4) contained in the mixture to all chitosan (derivatives) (F-1) contained in the mixture, i.e. the weight ratio (F-4) / (F-1), is in the range of 1.00:1.10 to 1.00:2.35, preferably from 1.00:1.20 to 1.00:2.35, more preferably from 1.00:1.30 to 1.00:2.30 and especially preferably from 1.00:1.40 to 1.00:2.

30.

20. Dyeing agent (F) according to one of claims 13 to 19, characterized in that it contains - based on the total weight of the dyeing agent - organic solvent (F-5), preferably ethanol, in a total amount of 20 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

21. Dyeing agent (F) according to one of claims 13 to 20, characterized in that it contains - based on the total weight of the dyeing agent - 5 to 70 wt.%, preferably 10 to 60 wt.%, more preferably 15 to 50 wt.% and most preferably 20 to 40 wt.% water (F-2).

22. Dyeing agent (F) according to one of claims 13 to 21, characterized in that the components (F-1), (F-2), optionally (F-3), (F-4) and (F-5) are together contained in the dyeing agent (F) in a quantity of at least 90.0 wt.%, preferably at least 93 wt.%, further preferably at least 96 wt.%, even more preferably at least 99 wt.% and most preferably at least 99.7 wt.%.

23. Method for dyeing keratinous fibers, in particular human hair, in which a dyeing agent (F) according to one of claims 13 to 22, characterized in that dyeing agent is applied to the keratinous fibers and optionally rinsed off after an exposure time.

24. The method according to claim 23 comprising - the application of a dye (F) to the keratinous fibers, and - heating the keratinous fibers covered with the dye (F) to a temperature of 40 °C to 210 °C, preferably from 40 °C to 190 °C, more preferably from 45 °C to 170 °C, even more preferably from 45 °C to 100 °C and most preferably from 45 °C to 70 °C.

25. Method according to one of claims 23 to 24, characterized in that the keratin fibers are combed or brushed during the heat treatment.

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