Layering method for dyeing hair

Abstract

The invention relates to a method for dyeing hair, in particular human hair, having the following steps in the specified order: (1) applying a dye (F1) to at least some of the hairs, the dye (F1) containing (F1-1) at least one dyeing compound chosen from the group of pigments and direct dyes and (F1-2) at least one chitosan and / or a chitosan derivative; (2) drying the hair, with the dye (F1) still applied; (3) applying a dye (F2) to at least some of the hairs, the dye (F2) containing (F2-1) at least one dyeing compound chosen from the group of pigments and direct dyes and (F2-2) at least one chitosan and / or a chitosan derivative; and (4) drying the hair, with the dye (F2) still applied, the dyes (F1) and (F2) being the same or different, and the hair not being washed between steps (1) and (4).

Description

[0001] Henkel AG & Co. KGaA

[0002] 2024P00202WO

[0003] Layering method for dyeing hair

[0004] The present application relates to a method for dyeing hair, in particular human hair, comprising steps (1) to (4). In step (1), a dye (F1) containing at least one coloring compound and a chitosan (derivative) is applied to at least a portion of the hair. In step (2), the hair still coated with the dye (F1) is dried. In step (3), a dye (F2) containing a coloring compound and a chitosan (derivative) is again applied to at least a portion of the hair, after which the hair covered with (F2) is dried again in step (4). The dyes (F1) and (F2) can be the same or different, and no hair washing takes place between steps (1) to (4).

[0005] Another subject matter of the present application is a hair dyeing kit, which comprises two different dyeing agents (F1) and (F2) packaged separately in two different containers.

[0006] Altering the shape and color of keratin fibers, especially human hair, is an important area of ​​modern cosmetics. Depending on the desired color, professionals are familiar with various dyeing systems for changing hair color. For permanent, intense colorations with good colorfastness and gray coverage, oxidation dyes are typically used. These dyes contain oxidation dye precursors, so-called developer components and coupler components, which react with oxidizing agents such as hydrogen peroxide to form the actual dyes. Oxidation dyes are characterized by very long-lasting color results.

[0007] When using direct dyes, pre-formed pigments diffuse from the dye into the hair fiber. Compared to oxidative hair coloring, dyes produced with direct dyes are less durable and wash out more quickly. Dyes made with direct dyes typically remain on the hair for between 5 and 20 washes.

[0008] The use of color pigments is well-known for temporary color changes to hair and / or skin. Color pigments are generally understood to be insoluble, coloring substances. These are present in the coloring formulation in the form of small particles and are simply deposited on the hair fibers and / or skin surface. Therefore, they can usually be removed completely after a few washes with surfactant-containing cleansers. Various products of this type are available on the market under the name "hair mascara."

[0009] Dyeing with pigments offers several significant advantages. Since the pigments adhere only to the keratin material, particularly the hair fibers, unwanted colors can be removed quickly and easily without leaving any residue. This allows users to return to their original hair color immediately and effortlessly. This dyeing process is therefore particularly attractive for consumers who do not want to regularly dye their hair.

[0010] Despite these many advantages, the pigment-based dyeing system still has some disadvantages, which stem from the limited penetration depth of the pigments into the keratinous material. Since the pigments do not diffuse into the keratin fiber but merely deposit on the outside of the fiber in the form of a coating or film, the wash fastness of dyes produced with this system still needs improvement. Various studies have attempted to bind the pigment(s) more permanently to the hair surface using film-forming materials, mostly polymers.

[0011] For example, German patent DE 19847883 A1 deals with achieving pigment-based colorations using dyes containing at least one chitosan and one pigment. Combining the pigments with chitosan was intended to improve the abrasion resistance of the colorations. The major advantage of chitosan as a film-forming material lies in the fact that it is based on biopolymers and therefore 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 with regard to their color intensity, rub fastness, and feel.

[0012] To achieve the most intense color possible, those skilled in the art generally use dyes with a higher concentration of dye or pigment. However, the work leading to this invention has shown that while the use of dyes with high pigment concentrations does increase color intensity, it also significantly impairs the rub fastness and the feel of the dyed hair.

[0013] The objective of this application was therefore to discover a dyeing process based on pigments and / or direct dyes that achieves intense colorations with improved rub fastness and a better hair feel. Chitosan, a polymer of natural origin, was to be used for film formation. The dyeing process was to be suitable for both individual strand coloring and full-head coloring. Color transitions were also to be possible. Furthermore, the objective of this application was to provide a process with which multi-colored highlighting could also be achieved in a simple and convenient manner.

[0014] Surprisingly, it has now been found that these problems can be solved by coloring the hair using a method in which the dyes (F1) and (F2) are applied to the hair as a leave-on treatment. The method according to the invention is hereinafter also referred to as the layering method.

[0015] A first subject matter of the present application is a method for dyeing hair, in particular human hair, comprising the following steps in the specified order:

[0016] (1) Application of a dye (F1) to at least part of the hair, wherein the dye (F1) contains

[0017] (F1-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0018] (F1-2) at least one chitosan and / or one chitosan derivative,

[0019] (2) Drying the hair still coated with the dye (F1),

[0020] (3) Application of a dye (F2) to at least part of the hair, wherein the dye (F2) contains

[0021] (F2-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0022] (F2-2) at least one chitosan and / or a chitosan derivative, and

[0023] (4) Drying the hair still exposed to the dye (F2), wherein the dyes (F1) and (F2) are the same or different, and wherein no hair washing takes place between steps (1) to (4).

[0024] Hair strands colored using the inventive method were characterized by very high color intensity, along with improved hair feel and colorfastness. Furthermore, the method was very versatile, allowing for various highlighting techniques as well as full-head coloring in one shade, in different shades, and with attractive color transitions.

[0025] Hair

[0026] The term "hair" refers to both human hair and mammalian hair. Mammalian hair can also include wool or fur, for example. Human hair is the preferred term. Agents (F1) and (F2) for dyeing.

[0027] In the process according to the invention, the dyes (F1) and (F2) are used. These can be the same or different.

[0028] If the dyes (F1) and (F2) are the same, then in steps (1) and (3) of the dyeing process, the same dye is repeatedly applied to the hair. In this case, the method according to the invention corresponds to a method for dyeing hair, in particular human hair, comprising the following steps in the specified order:

[0029] (1) Application of a dye (F1) to at least part of the hair, wherein the dye (F1) contains

[0030] (F1-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0031] (F1-2) at least one chitosan and / or one chitosan derivative,

[0032] (2) Drying the hair still coated with the dye (F1),

[0033] (3) Application of the dye (F1) to at least part of the hair,

[0034] (4) Drying the hair still exposed to the dye (F1), without washing the hair between steps (1) to (4).

[0035] In a further embodiment, the dyes (F1) and (F2) can also be different from each other. In this case, the method according to the invention corresponds to a

[0036] Methods for dyeing hair, especially human hair, comprising the following steps in the specified order:

[0037] (1) Application of a dye (F1) to at least part of the hair, wherein the dye (F1) contains

[0038] (F1-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0039] (F1-2) at least one chitosan and / or one chitosan derivative,

[0040] (2) Drying the hair still coated with the dye (F1),

[0041] (3) Application of a dye (F2) to at least part of the hair, wherein the dye (F2) is different from the dye (F1) and contains

[0042] (F2-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0043] (F2-2) at least one chitosan and / or a chitosan derivative, and

[0044] (4) Drying the hair still coated with the dye (F2), without washing the hair between steps (1) to (4). Coloring compounds in the dyes (F1) and (F2): As an essential component, the dyes (F1) and (F2) (or the dye (F1) if the same dye is repeatedly applied in steps (1) and (3) of the process) contain at least one coloring compound from the group consisting of pigments and direct dyes.

[0045] The coloring compounds contained in the dye (F1) are referred to as coloring compounds (F1-1). The coloring compounds contained in the dye (F2) are referred to as coloring compounds (F2-1).

[0046] For the purposes of this invention, pigments are understood to be coloring compounds which have a solubility in water at 25 °C of less than 0.5 g / L, preferably less than 0.1 g / L, and even more preferably less than 0.05 g / L. The water solubility can be determined, for example, by the method described below: 0.5 g of the pigment is weighed into a beaker. A magnetic stir bar is added. Then one liter of distilled water is added. This mixture is heated to 25 °C for one hour while stirring on a magnetic stirrer. If undissolved components of the pigment are still visible in the mixture after this period, the solubility of the pigment is below 0.5 g / L. If the pigment-water mixture cannot be visually assessed due to the high intensity of the pigment, which may be finely dispersed, the mixture is filtered.If a proportion of undissolved pigments remains on the filter paper, the solubility of the pigment is below 0.5 g / L.

[0047] The layering process is particularly preferred when using pigments. In this case, the colorant (F1) most preferably contains at least one pigment. The colorant (F2) also most preferably contains at least one pigment.

[0048] In a particularly well-suited embodiment, at least one of the two colorants (F1) and (F2) contains at least one pigment. For example, it is possible that colorant (F1) contains at least one pigment, while colorant (F2) contains at least one direct dye. Similarly, colorant (F1) can also contain at least one direct dye, and colorant (F2) can then contain at least one pigment.

[0049] In a further embodiment, it is particularly preferred if both the dyeing agent (F1) and the dyeing agent (F2) contain at least one pigment.

[0050] Suitable color pigments can be of inorganic and / or organic origin. Pigments with specific shapes and metallic pigments are also particularly well suited for use in the dye according to the invention. In a particularly preferred embodiment, a method according to the invention is characterized in that

[0051] - the colorant (F1) contains at least one coloring compound (F1-1) from the group consisting of inorganic pigments, organic pigments, pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments, and / or

[0052] - the colorant (F2) contains at least one coloring compound (F2-1) from the group consisting of inorganic pigments, organic pigments, pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

[0053] A particularly suitable method for dyeing hair, especially human hair, comprises the following steps in the given order:

[0054] (1) Application of a dye (F1) to at least part of the hair, wherein the dye (F1) contains

[0055] (F1-1) at least one coloring compound (F1-1) from the group consisting of inorganic pigments, organic pigments, pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments, and

[0056] (F1-2) at least one chitosan and / or one chitosan derivative,

[0057] (2) Drying the hair still coated with the dye (F1),

[0058] (3) Application of the dye (F1) to at least part of the hair,

[0059] (4) Drying the hair while it is still coated with the dye (F1), without washing the hair between steps (1) to (4).

[0060] In a further embodiment, a preferred method is one for dyeing hair, in particular human hair, comprising the following steps in the specified order:

[0061] (1) Application of a dye (F1) to at least part of the hair, wherein the dye (F1) contains

[0062] (F1-1) at least one colouring compound 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, and

[0063] (F1-2) at least one chitosan and / or one chitosan derivative,

[0064] (2) Drying the hair still coated with the dye (F1),

[0065] (3) Application of a coloring agent (F2) to at least part of the hair, wherein the coloring agent (F2) is different from the coloring agent (F1) and contains (F2-1) at least one coloring compound 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, and

[0066] (F2-2) at least one chitosan and / or a chitosan derivative, and

[0067] (4) Drying the hair still coated with the dye (F2), without washing the hair between steps (1) to (4).

[0068] Preferred inorganic color pigments are selected from synthetic or natural sources. Naturally derived inorganic color pigments can be produced, for example, from chalk, ochre, umber, green earth, burnt sienna, or graphite. Other inorganic color pigments that can be used include black pigments such as iron oxide black, colored pigments such as ultramarine or iron oxide red, as well as fluorescent or phosphorescent pigments.

[0069] Particularly suitable are colored metal oxides, hydroxides and oxide hydrates, mixed-phase pigments, sulfur-containing silicates, silicates, metal sulfides, complex metal cyanides, metal sulfates, chromates and / or molybdates. Especially preferred color pigments are black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and brown iron oxide (CI 77491), manganese violet (CI 77742), ultramarine (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), iron blue (ferric ferrocyanide, CI 77510) and / or carmine (cochineal).

[0070] 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.

[0071] 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).

[0072] In a further preferred embodiment, a coloring agent according to the invention is characterized in that it contains at least one inorganic pigment, which is preferably selected from the group consisting of colored metal oxides, metal hydroxides, metal oxide hydrates, silicates, metal sulfides, complex metal cyanides, metal sulfates, bronze pigments and / or colored pigments based on mica or micaceous oxide, which are coated with at least one metal oxide and / or one metal oxychloride.

[0073] In a further preferred embodiment, a coloring agent according to the invention is characterized in that it contains at least one pigment selected from mica- or micaceous-based pigments coated with one or more metal oxides from the group consisting of titanium dioxide (CI 77891), black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and / or brown iron oxide (CI 77491, CI 77499), manganese violet (CI 77742), ultramarine (sodium aluminum sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), chromium oxide (CI 77288) and / or iron blue (ferric ferrocyanide, CI 77510).

[0074] 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.

[0075] Please be sure to drink the color pigments with the Handelsbezeichnung Colorona® and beispielsweise:

[0076] Colorona Copper, Merck, MICA, CI 77491 (IRON OXIDES)

[0077] Colorona Passion Orange, Merck, Mica, CI 77491 (Iron Oxides), Alumina

[0078] Colorona Patina Silver, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE) Colorona RY, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 75470 (CARMINE)

[0079] Colorona Oriental Beige, Merck, MICA, CI 77891 (TITANIUM DIOXIDE), CI 77491 (IRON OXIDES) Colorona Dark Blue, Merck, MICA, TITANIUM DIOXIDE, FERRIC FERROCYANIDE

[0080] Colorona Chameleon, Merck, CI 77491 (IRON OXIDES), MICA

[0081] Colorona Aborigine Amber, Merck, MICA, CI 77499 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE)

[0082] Colorona Blackstar Blue, Merck, CI 77499 (IRON OXIDES), MICA

[0083] Colorona Patagonian Purple, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE), CI 77510 (FERRIC FERROCYANIDE)

[0084] Colorona Red Brown, Merck, MICA, CI 77491 (IRON OXIDES), CI 77891 (TITANIUM DIOXIDE) Colorona Russet, Merck, CI 77491 (TITANIUM DIOXIDE), MICA, CI 77891 (IRON OXIDES) Colorona Imperial Red, Merck, MICA, TITANIUM DIOXIDE (CI 77891), D&C RED NO. 30 (CI 73360) Colorona Majestic Green, Merck, CI 77891 (TITANIUM DIOXIDE), MICA, CI 77288 (CHROMIUM OXIDE GREENS)

[0085] Colorona Light Blue, Merck, MICA, TITANIUM DIOXIDE (CI 77891), FERRIC FERROCYANIDE (Cl 77510)

[0086] Colorona Red Gold, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES) Colorona Gold Plus MP 25, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), IRON OXIDES (Cl 77491)

[0087] Colorona Carmine Red, Merck, MICA, TITANIUM DIOXIDE, CARMINE

[0088] Colorona Blackstar Green, Merck, MICA, Cl 77499 (IRON OXIDES)

[0089] Colorona Bordeaux, Merck, MICA, Cl 77491 (IRON OXIDES)

[0090] Colorona Bronze, Merck, MICA, Cl 77491 (IRON OXIDES)

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

[0092] Colorona Fine Gold MP 20, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES)

[0093] Colorona Sienna Fine, Merck, Cl 77491 (IRON OXIDES), MICA

[0094] Colorona Sienna, Merck, MICA, Cl 77491 (IRON OXIDES)

[0095] Colorona Precious Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Silica, Cl 77491 (Iron oxides), Tin oxide

[0096] Colorona Sun Gold Sparkle MP 29, Merck, MICA, TITANIUM DIOXIDE, IRON OXIDES, MICA, Cl 77891 , Cl 77491 (EU)

[0097] Colorona Mica Black, Merck, Cl 77499 (Iron oxides), Mica, Cl 77891 (Titanium dioxide)

[0098] Colorona Bright Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Cl 77491 (Iron oxides)

[0099] Colorona Blackstar Gold, Merck, MICA, Cl 77499 (IRON OXIDES)

[0100] Other particularly preferred color pigments with the trade name Xirona® include, for example:

[0101] Xirona Golden Sky, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0102] Xirona Caribbean Blue, Merck, Mica, CI 77891 (Titanium Dioxide), Silica, Tin Oxide

[0103] Xirona Kiwi Rose, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide

[0104] Xirona Magic Mauve, Merck, Silica, CI 77891 (Titanium Dioxide), Tin Oxide.

[0105] In addition, particularly preferred color pigments with the trade name Unipure® include, for example:

[0106] Unipure Red LC 381 EM, Sensient CI 77491 (Iron Oxides), Silica

[0107] Unipure Black LC 989 EM, Sensient, CI 77499 (Iron Oxides), Silica

[0108] Unipure Yellow LC 182 EM, Sensient, CI 77492 (Iron Oxides), Silica

[0109] In a further embodiment, the colorants (F1) and / or (F2) used in the inventive method can also contain one or more organic pigments.

[0110] 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.

[0111] 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.

[0112] In a further particularly preferred embodiment, a coloring agent according to the invention is characterized in that it contains at least one organic pigment, preferably selected from the group consisting of carmine, quinacridone, phthalocyanine, sorghum, blue pigments with the color index numbers CI 42090, CI 69800, CI 69825, CI 73000, CI 74100, CI 74160, yellow pigments with the color index numbers CI 11680, CI 11710, CI 15985, CI 19140, CI 20040, CI 21100, CI 21108, CI 47000, CI 47005, green pigments with the color index numbers CI 61565, CI 61570, CI 74260, and orange pigments with the color index numbers CI 11725, CI 15510, CI 45370, CI 71105, red pigments with the color index numbers CI 12085, CI 12120, CI 12370, CI 12420, CI 12490, CI 14700, CI 15525, CI 15580, CI 15620, CI 15630, CI 15800, CI 15850, CI 15865, CI 15880, CI 17200, CI 26100, CI 45380, CI 45410, CI 58000, CI 73360, CI 73915 and / or CI 75470.

[0113] The organic pigment can also be a paint lake. For the purposes of the 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. The particles can be, for example, inorganic substrates such as aluminum, silica, calcium borosilicate, calcium aluminum borosilicate, or even aluminum.

[0114] For example, alizarin lacquer can be used as a colored lacquer.

[0115] Due to their excellent light and temperature resistance, the use of the aforementioned pigments in the dye of the process according to the invention is particularly preferred. Furthermore, it is preferred if the pigments used have a specific particle size. Therefore, according to the invention, it is advantageous if the at least one pigment has a mean particle size D50 of 1.0 to 50 pm, preferably of 5.0 to 45 pm, more preferably of 10 to 40 pm, and particularly of 14 to 30 pm. The mean particle size D50 can be determined, for example, using dynamic light scattering (DLS).

[0116] Pigments with a specific shape can also be used to stain keratin fibers. For example, a pigment based on a lamellar and / or lenticular substrate platelet can be used. Furthermore, staining based on a substrate platelet containing a vacuum-metallized pigment is also possible.

[0117] In a further preferred embodiment, a means according to the invention is characterized in that it contains at least one pigment selected from the group of pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] The substrate plates can be made from any material that can be formed into platelet form.

[0123] 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).

[0124] 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.

[0125] Lamellar substrate platelets are characterized by an irregularly structured edge and are also referred to as "cornflakes" due to their appearance.

[0126] 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.

[0127] 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.

[0128] 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. Aluminum VMP substrate platelets can be obtained, for example, by releasing aluminum from metallized films.

[0129] The substrate plates made of metal or metal alloy can be passivated, for example by anodizing (oxide layer) or chromating.

[0130] Uncoated lamellar, lenticular and / or VPM substrate platelets, especially those made of metal or metal alloy, reflect the incident light to a high degree and produce a light-dark flop. These have proven particularly advantageous for use in dyes.

[0131] Suitable pigments based on a lamellar substrate platelet include, for example, the VISIONAIRE series pigments from Eckart.

[0132] Pigments based on a lenticular substrate platelet are available, for example, under the name Alegrace® Gorgeous from the company Schlenk Metallic Pigments GmbH.

[0133] 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.

[0134] The pigment(s) (F-1) constitute the first essential component of the dyeing agent (F1) according to the invention and are preferably used in specific average quantities. Particularly good results are obtained when the dyeing agent (F1) contains one or more pigments (F1-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.2 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.%, and most preferably 0.30 to 0.60 wt.%.

[0135] Particularly good results are obtained when the dye (F2) contains one or more pigments (F2-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.2 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.%.

[0136] The colorants (F1) and / or (F2) may also contain at least one direct dye as the coloring compound(s). Direct dyes are dyes that adhere directly to the hair and do not require an oxidative process to develop the color. Typical direct dyes are nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinones, triarylmethane dyes, or indophenols.

[0137] The direct-acting dyes according to the present invention have a solubility in water (760 mmHg) at 25 °C of more than 0.5 g / L and are therefore not to be considered pigments. Preferably, the direct-acting dyes according to the present invention have a solubility in water (760 mmHg) at 25 °C of more than 1.0 g / L.

[0138] Direct-drawing dyes can be divided into anionic, cationic, and nonionic direct-drawing dyes.

[0139] Cationic direct dyes include Basic Blue 7, Basic Blue 26, HC Blue 16, Basic Violet 2 and 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.

[0140] Examples of nonionic direct-drawing dyes include nonionic nitro and quinone dyes and neutral azo dyes. Examples of nonionic direct-drawing dyes are those known by their international names.Handelsnamen HC Yellow 2, HC Yellow 4, HC Yellow 5, HC Yellow 6, HC Yellow 12, HC Orange 1 , Disperse Orange 3, HC Red 1 , HC Red 3, HC Red 10, HC Red 11 , HC Red 13, HC Red BN, HC Blue 2, HC Blue 11 , HC Blue 12, Disperse Blue 3, HC Violet 1 , Disperse Violet 1 , Disperse Violet 4, Disperse Black 9 bekannten Verbindungen, sowie 1 ,4-Diamino-2-nitrobenzol, 2-Amino-4-nitrophenol, 1 ,4-Bis-(2-hydroxyethyl)- amino-2-nitrobenzol, 3-Nitro-4-(2-hydroxyethyl)-aminophenol, 2-(2-Hydroxyethyl)amino-4,6-dinitro- phenol, 4-[(2-Hydroxyethyl)amino]-3-nitro-1 -methylbenzol, 1-Amino-4-(2-hydroxyethyl)-amino-5- chlor-2-nitrobenzol, 4-Amino-3-nitrophenol, 1-(2'-Ureidoethyl)amino-4-nitrobenzol, 2-[(4-Amino-2- nitrophenyl)amino]-benzoesäure, 6-Nitro-1 ,2,3,4-tetrahydrochinoxalin, 2-Hydroxy-1 ,4-naphtho- chinon, Pikraminsäure und deren Salze, 2-Amino-6-chloro-4-nitrophenol, 4-Ethylamino-3-nitro- benzoesäure und 2-Chlor-6-ethylamino-4-nitrophenol.

[0141] Anionic direct-drawing dyes are also known as acid dyes. Acid dyes are defined as direct-drawing dyes that possess at least one carboxylic acid group (-COOH) and / or one sulfonic acid group (-SO3H). Depending on the pH, the rudimentary forms (-COOH, -SO3H) of the carboxylic acid or sulfonic acid groups exist in equilibrium with their deprotonated forms (-COO-, -SOs). The proportion of rudimentary forms increases with decreasing pH. When direct-drawing dyes are used in the form of their salts, the carboxylic acid or sulfonic acid groups exist in deprotonated form and are neutralized with corresponding stoichiometric equivalents of cations to maintain electroneutrality. Acid dyes according to the invention can also be used in the form of their sodium salts and / or potassium salts.

[0142] The acid dyes according to the present invention have a solubility in water (760 mmHg) at 25 °C of more than 0.5 g / L and are therefore not to be considered pigments. Preferably, the acid dyes according to the present invention have a solubility in water (760 mmHg) at 25 °C of more than 1.0 g / L.

[0143] The alkaline earth salts (such as calcium and magnesium salts) and aluminum salts of acid dyes often have lower solubility than the corresponding alkali salts. If the solubility of these salts in water is below 0.5 g / L, preferably less than 0.1 g / L, and even more preferably less than 0.05 g / L (each at 25 °C, 760 mmHg), they do not fall under the definition of a direct-drawing dye.

[0144] In a further particularly preferred embodiment, a method according to the invention is characterized in that

[0145] - the colorant (F1) contains at least one coloring compound (F1-1) from the group of direct dyes, particularly preferably from the group of anionic direct dyes, and / or

[0146] - the coloring agent (F2) contains at least one coloring compound (F2-1) from the group of direct dyes, particularly preferably from the group of anionic direct dyes.

[0147] Direct dyes can be nonionic, cationic, or anionic. It is particularly preferred if the dye (F) contains at least one anionic direct dye, which can alternatively also be referred to as an acid dye.

[0148] Anionic direct-drawing dyes are also known as acid dyes. Acid dyes are defined as direct-drawing dyes that possess at least one carboxylic acid group (-COOH) and / or one sulfonic acid group (-SO3H) and / or one sulfate group (-OSO3H). Depending on the pH, the rheumenized forms (-COOH, -SO3H) of the carboxylic acid or sulfonic acid groups exist in equilibrium with their deprotonated forms (-COO-, -SOs, or -OSOs-). The proportion of rheumenized forms increases with decreasing pH. When direct-drawing dyes are used in the form of their salts, the carboxylic acid or sulfonic acid groups exist in deprotonated form and are neutralized with corresponding stoichiometric equivalents of cations to maintain electroneutrality. Acid dyes according to the invention can also be used in the form of their sodium salts and / or their potassium salts.Alkaline earth salts (such as calcium and magnesium salts) and aluminum salts of acid dyes often have lower solubility than the corresponding alkali salts. If the solubility of these salts is below 0.5 g / L (25 °C, 760 mmHg), they do not fall under the definition of a direct-drawing dye.

[0149] A key characteristic of acid dyes is their ability to form anionic charges, with the carboxylic acid or sulfonic acid groups responsible for this typically being linked to various chromophoric systems. Suitable chromophoric systems can be found, for example, in the structures of nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinone dyes, triarylmethane dyes, xanthene dyes, rhodamine dyes, oxazine dyes, and / or indophenol dyes.

[0150] Als Beispiele für Säurefarbstoffe können genannt werden: Acid Yellow 1 (D&C Yellow 7, Citronin A, Ext. D&C Yellow No. 7, Japan Yellow 403, CI 10316, COLIPA n° B001), Acid Yellow 3 (COLIPA n° : C 54, D&C Yellow N° 10, Quinoline Yellow, E104, Food Yellow 13), Acid Yellow 9 (CI 13015), Acid Yellow 17 (CI 18965), Acid Yellow 23 (COLIPA n° C 29, Covacap Jaune W 1100 (LCW), Sicovit Tartrazine 85 E 102 (BASF), Tartrazine, Food Yellow 4, Japan Yellow 4, FD&C Yellow No. 5), Acid Yellow 36 (CI 13065), Acid Yellow 121 (CI 18690), Acid Orange 6 (CI 14270), Acid Orange 7 (2- Naphthol orange, Orange II, CI 15510, D&C Orange 4, COLIPA n° C015), Acid Orange 10 (C.l. 16230; Orange G sodium salt), Acid Orange 11 (Cl 45370), Acid Orange 15 (Cl 50120), Acid Orange 20 (Cl 14600), Acid Orange 24 (BROWN 1 ;CI20170;KATSU201 ;nosodiumsalt;Brown No.201 ;RESORCIN BROWN;ACID ORANGE 24;Japan Brown 201 ;D & C Brown No.1), Acid Red 14 (C.1.14720), Acid Red 18 (E124, Red 18; Cl 16255), Acid Red 27 (E 123, Cl 16185,C-Rot 46, Echtrot D, FD&C Red Nr.2, Food Red 9, Naphtholrot S), Acid Red 33 (Red 33, Fuchsia Red, D&C Red 33, Cl 17200), Acid Red 35 (Cl C.l.18065), Acid Red 51 (Cl 45430, Pyrosin B, Tetraiodfluorescein, Eosin J, lodeosin), Acid Red 52 (Cl 45100, Food Red 106, Solar Rhodamine B, Acid Rhodamine B, Red n° 106 Pontacyl Brilliant Pink), Acid Red 73 (Cl 27290), Acid Red 87 (Eosin, Cl 45380), Acid Red 92 (COLIPA n° C53, Cl 45410), Acid Red 95 (Cl 45425, Erythtosine, Simacid Erythrosine Y), Acid Red 184 (Cl 15685), Acid Red 195, Acid Violet 43 (Jarocol Violet 43, Ext. D&C Violet n° 2, C.l. 60730, COLIPA n° C063), Acid Violet 49 (Cl 42640), Acid Violet 50 (Cl 50325), Acid Blue 1 (Patent Blue, Cl 42045), Acid Blue 3 (Patent Blau V, Cl 42051), Acid Blue 7 (Cl 42080), Acid Blue 104 (Cl 42735), Acid Blue 9 (E 133, Patentblau AE, Amidoblau AE, Erioglaucin A, Cl 42090, C.l. Food Blue 2), Acid Blue 62 (Cl 62045), Acid Blue 74 (E 132, Cl 73015), Acid Blue 80 (Cl 61585), Acid Green 3 (Cl 42085,Foodgreenl), Acid Green 5 (Cl 42095), Acid Green 9 (C.1.42100), Acid Green 22 (C.1.42170), Acid Green 25 (Cl 61570, Japan Green 201 , D&C Green No. 5), Acid Green 50 (Brillantsäuregrün BS, Cl 44090, Acid Brilliant Green BS, E 142), Acid Black 1 (Black n° 401 , Naphthalene Black 10B, Amido Black 10B, Cl 20 470, COLIPA n° B15), Acid Black 52 (Cl 15711), Food Yellow 8 (Cl 14270), Food Blue 5, D&C Yellow 8, D&C Green 5, D&C Orange 10, D&C Orange 11 , D&C Red 21 , D&C Red 27, D&C Red 33, D&C Violet 2 and / or D&C Brown 1. In the context of a further embodiment, an inventive method is characterized in that the dye (F1) and / or the dye (F2) contains or contains at least one acid dye selected from the group consisting of Acid Yellow 1, Acid Yellow 3, Acid Yellow 9, Acid Yellow 17, Acid Yellow 23, Acid Yellow 36, Acid Yellow 121, Acid Orange 6, Acid Orange 7, Acid Orange 10, Acid Orange 11 , Acid Orange 15, Acid Orange 20, Acid Orange 24,Acid Red 14, Acid Red 18, Acid Red 27, Acid Red 33, Acid Red 35, Acid Red 51 , Acid Red 52, Acid Red 73, Acid Red 87, Acid Red 95, Acid Red 184, Acid Red 195, Acid Violet 43, Acid Violet 49, Acid Violet 50, Acid Blue 1 , Acid Blue 3, Acid Blue 7, Acid Blue 104, Acid Blue 9, Acid Blue 62, Acid Blue 74, Acid Blue 80, Acid Green 3, Acid Green 5, Acid Green 9, Acid Green 22, Acid Green 25, Acid Green 50, Acid Black 1 , Acid Black 52, Food Yellow 8, Food Blue 5, D&C Yellow 8, D&C Green 5, D&C Orange 10, D&C Orange 11 , D&C Red 21 , D&C Red 27, D&C Red 33, D&C Violet 2 und / oder D&C Brown 1 .,

[0151] Since the alkaline earth salts (such as calcium and magnesium salts) or aluminum salts of acid dyes have lower solubility than the corresponding alkali metal salts, an organic dye that can be considered an acid dye in the form of its alkali metal salt can also exist as a pigment if the counterion for the acid group(s) is not an alkali metal ion, but an alkaline earth metal or an analogous, correspondingly more highly charged counterion. If the solubility of these salts is below 0.5 g / L (25 °C, 760 mmHg), the compounds do not fall under the definition of a direct-drawing dye.

[0152] Like pigments, acid dyes are not intended to diffuse primarily into the keratin fiber, but rather to be preferentially deposited embedded in the chitosan film on the surface of the keratin fibers. For this reason, acid dyes are particularly preferred, as they have a solubility so high that they can no longer be classified as organic pigments, but which nevertheless exhibit relatively poor solubility.

[0153] For this reason, acid dyes are particularly preferred as organic coloring compounds which have a solubility in water at 25 °C of more than 0.5 g / L and less than 20 g / L, preferably less than 18 g / L, even more preferably less than 15 g / L and most preferably less than 12 g / L.

[0154] In a further particularly preferred embodiment, a method according to the invention is therefore characterized in that

[0155] - the dye (F1) as a coloring compound (F1-1) contains at least one acid dye which, at 25 °C in water, has a solubility of more than 0.5 g / L and less than 20 g / L, preferably more than 0.5 g / L and less than 18 g / L, more preferably more than 0.5 g / L and less than 15 g / L, and most preferably more than 0.5 g / L and less than 12 g / L, and / or - the dye (F2) as a coloring compound (F2-1) contains at least one acid dye which, at 25 °C in water, has a solubility of more than 0.5 g / L and less than 20 g / L, preferably more than 0.5 g / L and less than 18 g / L, more preferably more than 0.5 g / L and less than 15 g / L, and most preferably more has a concentration of less than 0.5 g / L and less than 12 g / L.

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

[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)- 1 H-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)-1H-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 given as greater than 10 g / L (25 °C).

[0165] Brilliant Blue FCF, also known as Food Blue 2 or Acid Blue 9, carries as

[0166] The disodium salt is called disodium 2-[(Z)-{4-[ethyl(3-sulfonatobenzyl)amino]phenyl}{(4Z)-4-[ethyl(3-sulfonatobenzyl)amino]-2,5-cyclohexadien-1-ylidene}methyl]benzenesulfonate and has the CAS number 3844-45-9. The disodium salt of Acid Blue 9 has a water solubility of more than 20 wt% (25 °C).

[0167] Acid Blue 74 is also known as Indigo Carmine, Food Blue 1, or FD&C Blue 2, and its chemical name is indigo-5,5'-disulfonic acid, disodium salt, or disodium 5,5'-(2-(1,3-dihydro-3-oxo-2H-indazol-2-ylidene)-1,2-dihydro-3H-indol-3-one)disulfonate. Acid Blue 74, in its disodium salt form, has a solubility of 10 g / L in water at 25 °C. Acid Blue 74 (disodium salt) has the Color Index number 73015 and can be purchased, for example, under the trade name Bleu Covalac W6504.

[0168] As a rule, experts assume that a dye containing the coloring compound(s) in higher concentrations will also lead to a more intense color result. Therefore, the application of a dye (F1) (or (F2)) containing the coloring compounds (F1-1) (or (F2-1)) in increased concentrations will also result – at least up to a certain point beyond which further increasing the amount of dye provides no additional benefit – in more intensely colored hair.

[0169] However, since the present coloring principle is a surface coloring, the applied dyes do not diffuse into the hair, but are deposited on the hair surface and are embedded there in a film by the chitosans applied at the same time.

[0170] Depending on the amount of embedded dyes, this film is modified to a greater or lesser extent. The work leading to this invention revealed that the properties of a film encapsulating a large number of dyes are also significantly altered. In particular, the feel and rub fastness of films with very high dye concentrations are adversely affected.

[0171] A film that is too heavily loaded with direct dyes and / or pigments therefore leads to a poorer feel to the hair; that is, the dyed hair feels particularly dull and coated. The film's rub fastness also decreases, so that the film flakes off very easily under mechanical stress, and textiles that come into contact with the dyed hair become heavily stained.

[0172] For these reasons, it is particularly preferred not to choose excessively high amounts of coloring compounds in the dyes (F1) and / or (F2). It is therefore preferred that the dyes used in the process contain – based on the total weight of the respective dye – 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.2 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.%, and most preferably 0.30 to 0.60 wt.%.

[0173] In a further particularly preferred embodiment, a method according to the invention is characterized in that

[0174] - the dye (F1) - based on the total weight of the dye (F1) - contains one or more coloring compounds (F1-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.20 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.%, and / or

[0175] - the dyeing agent (F2) - based on the total weight of the dyeing agent (F2) - contains one or more coloring compounds (F2-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.20 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.%.

[0176] In a further particularly preferred embodiment, a method according to the invention is characterized in that

[0177] - the coloring agent (F1) - based on the total weight of the coloring agent (F1) - contains one or more pigments (F1-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.20 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.%, and / or

[0178] - the coloring agent (F2) - based on the total weight of the coloring agent (F2) - contains one or more pigments (F2-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.20 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.%.

[0179] In a further particularly preferred embodiment, a method according to the invention is characterized in that

[0180] - the dye (F1) - based on the total weight of the dye (F1) - contains one or more direct dyes (F1-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.20 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.%, and / or

[0181] - the dyeing agent (F2) - based on the total weight of the dyeing agent (F2) - contains one or more direct dyes (F2-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.2 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.%.

[0182] By using a dye quantity of 0.2 to 0.90 wt.%, preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.% in the dyeing agents (F1) and (F2), a high color intensity can be produced by repeated application of the two agents without negatively affecting the hair feel and rub fastness.

[0183] As previously described, the dyes (F1) and (F2) can be the same or different.

[0184] If the dyes (F1) and (F2) are the same, then both dyes have the same composition, or in other words, in the inventive process, the dye (F1) is applied to the hair at least twice, first in step (1) and then again in step (3) of the process.

[0185] If the dyes (F1) and (F2) are different, they may differ due to the presence of different coloring compounds (F1-1) and (F2-1) or due to the presence of other ingredients.

[0186] If the two dyes (F1) and (F2) differ due to the coloring compounds, this difference can arise either from the presence of different coloring compounds (i.e., the nature of the coloring compounds is different), or from the quantity of the coloring compounds. The coloring compounds (F1-1) and (F2-1) can therefore differ qualitatively or quantitatively.

[0187] Furthermore, the coloring compounds in dyes (F1) and (F2) can be of different nature and present in different quantities. In this case, the coloring compounds (F1-1) and (F2-1) in dyes (F1) and (F2) differ qualitatively and quantitatively.

[0188] In a further particularly preferred embodiment, a method according to the invention is characterized in that the color-imparting compounds (F1-1) and (F2-1) in the dyes (F1) and (F2) are qualitatively and / or quantitatively different.

[0189] Chitosans in the dyes (F1) and (F2)

[0190] As a second essential component, the dyes (F1) and (F2) used in the process according to the invention each contain a chitosan and / or a derivative of chitosan.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] A derivative of chitosan therefore has a poly-D-glucosamine or polyglucosamine structure, which has either been converted into its salt by protonation of one or more nitrogen atoms or which bears an organic substituent on at least one oxygen atom and / or at least one amino group.

[0195] 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.

[0196] In a further particularly preferred embodiment, a dyeing agent (F1) or (F2) according to the invention is characterized in that it contains at least one chitosan and / or one chitosan derivative (F1-2) or (F2-2) with a molecular weight of 20,000 to 800,000 g / mol, preferably of 50,000 to 600,000 g / mol, more preferably of 80,000 to 450,000 g / mol and most preferably of 100,000 to 300,000 g / mol.

[0197] Chitosan with a molecular weight of 100,000 to 300,000 g / mol can be purchased commercially from the company Sigma Aldrich, for example.

[0198] Chitosan with a lower molecular weight of 10,000 to 30,000 g / mol (or Daltons) is commercially available in pharmaceutical purity, for example, from BioLog Heppe (Kraeber). The degree of deacetylation of this chitosan is 88–95%. Chitosan in the form of its hydrochloride can be obtained as vegan chitosan from Sandream Impact. The hydrochloride of the chitosan is a chitosan derivative according to the invention.

[0199] 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.

[0200] It has proven particularly advantageous if the dyes (F1) and (F2) according to the invention contain the chitosans and / or chitosan derivatives in certain quantity ranges. Particularly good results were obtained when the respective dye contained one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%.

[0201] In a further particularly preferred embodiment, a method according to the invention is characterized in that

[0202] - the dye (F1) - based on the total weight of the dye (F1) - contains one or more chitosans and / or chitosan derivatives (F1-2) in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%, and / or

[0203] - the dye (F2) - based on the total weight of the dye (F2) - contains one or more chitosans and / or chitosan derivatives (F2-2) in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%.

[0204] Within the framework of a characterized by the fact that

[0205] - the dye (F1) - based on the total weight of the dye (F1) - contains one or more chitosans in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%, and / or

[0206] - the dye (F2) - based on the total weight of the dye (F2) - contains one or more chitosans in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%.

[0207] Particularly preferred is a method for dyeing hair, especially human hair, comprising the following steps in the specified order: (1) applying a dye (F1) to at least a part of the hair, wherein the dye (F1) contains - based on the total weight of the dye (F1) -

[0208] (F1-1) one or more colouring compounds from the group consisting of pigments and direct dyes in a total amount of 0.25 to 0.70 wt.%, and (F1-2) one or more chitosans and / or chitosan derivatives in a total amount of 0.4 to 1.2 wt.%,

[0209] (2) Drying the hair still coated with the dye (F1),

[0210] (3) Application of a dye (F2) to at least part of the hair, wherein the dye (F2) contains - based on the total weight of the dye (F2) -

[0211] (F2-1) one or more colouring compounds from the group consisting of pigments and direct dyes in a total amount of 0.25 to 0.70 wt.%, and (F2-2) one or more chitosans and / or chitosan derivatives in a total amount of 0.4 to 1.2 wt.%, and

[0212] (4) Drying the hair still exposed to the dye (F2), wherein the dyes (F1) and (F2) are the same or different, and wherein there is an interval between the steps

[0213] (1) to (4) no hair washing takes place.

[0214] A method for dyeing hair, especially human hair, is particularly preferred, comprising the following steps in the specified order:

[0215] (1) Application of a dye (F1) to at least part of the hair, wherein the dye (F1) contains - based on the total weight of the dye (F1) -

[0216] (F1-1) one or more colouring compounds from the group consisting of pigments and direct dyes in a total amount of 0.25 to 0.70 wt.%, and (F1-2) one or more chitosans in a total amount of 0.4 to 1.2 wt.%,

[0217] (2) Drying the hair still coated with the dye (F1),

[0218] (3) Application of a dye (F2) to at least part of the hair, wherein the dye (F2) contains - based on the total weight of the dye (F2) -

[0219] (F2-1) one or more colouring compounds from the group consisting of pigments and direct dyes in a total amount of 0.25 to 0.70 wt.%, and (F2-2) one or more chitosans in a total amount of 0.4 to 1.2 wt.%, and

[0220] (4) Drying the hair still exposed to the dye (F2), wherein the dyes (F1) and (F2) are the same or different, and wherein no hair washing takes place between steps (1) to (4). organic and / or inorganic acids in the dyes (F1) and / or (F2)

[0221] As an optional component, the dyes (F1) and / or (F2) according to the invention can contain at least one organic and / or inorganic acid. The use of one or more acids can lower the pH of the 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, upon adjustment to the preferred or particularly preferred pH, a particularly uniform and thin film is deposited on the keratin fibers, such as hair. It has been shown that the more uniformly the film forms on the hair, the better its durability. With the formation of a particularly uniform film, dyes with especially good wash fastness could also be obtained.Furthermore, the presence of the acid(s) (F-3) 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.

[0222] 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.

[0223] Formic acid and propanoic acid are also suitable acids.

[0224] Acetic acid dissolves chitosan particularly well and leads to very thin and uniform films; therefore, a dye (F) containing acetic acid is particularly preferred.

[0225] In a further particularly preferred embodiment, a method according to the invention is characterized in that the dyeing agent (F1) and / or the dyeing agent (F2) contains one or more organic acids from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid, most preferably acetic acid.

[0226] In a further particularly preferred embodiment, a method according to the invention is characterized in that

[0227] - the coloring agent (F1) contains one or more organic acids (F1-3) from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid, most preferably acetic acid, and / or

[0228] - the coloring agent (F2) contains one or more organic acids (F2-3) from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid, most preferably acetic acid.

[0229] By using the acid(s) in suitable quantities, the pH of the dye can be adjusted to the desired pH range. Particularly thin and uniform films were obtained when the dye (F1) and / or the dye (F2) contained water and was adjusted to a pH in the range of 2.0 to 7.5, preferably 2.5 to 6.5, more preferably 3.0 to 6.0, and most preferably 3.0 to 5.0.

[0230] In a further particularly preferred embodiment, a method according to the invention is therefore characterized in that the dye (F1) has a pH value of 2.0 to 7.5, preferably of 2.5 to 6.5, more preferably of 3.0 to 6.0 and most preferably of 3.0 to 5.0.

[0231] In a further particularly preferred embodiment, a method according to the invention is therefore characterized in that the dye (F2) has a pH value of 2.0 to 7.5, preferably of 2.5 to 6.5, more preferably of 3.0 to 6.0 and most preferably of 3.0 to 5.0.

[0232] Cosmetic carrier of the dyes (F1) and (F2)

[0233] The coloring agent (F1) contains the essential ingredients (F1-1) and (F2-2) as well as the optionally present acids (F1-3) in a cosmetic carrier, particularly preferably in a suitable aqueous, alcoholic, or aqueous-alcoholic carrier. Such carriers can be, for example, creams, emulsions, gels, or surfactant-containing foaming solutions, such as shampoos, foam aerosols, foam formulations, or other preparations suitable for application to hair. The same applies to the coloring agent (F2).

[0234] Particularly good results were obtained when the cosmetic carrier was a solvent-based system. For example, aliphatic C1-C22 monoalcohols selected from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol, and 1-hexanol are particularly suitable as solvents for solving the problem described in the invention.

[0235] In a further particularly preferred embodiment, a method according to the invention is therefore characterized in that

[0236] - the dye (F1) contains one or more aliphatic C1-C22 monoalcohols (F1-4) from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol and 1-hexanol, and / or

[0237] - the coloring agent (F2) contains one or more aliphatic C1-C22 monoalcohols (F2-4) from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol and 1-hexanol

[0238] The experiments conducted have shown that ethanol is particularly compatible with pigments or chitosans and also with acetic acid; therefore, the use of ethanol in the dye (F) is especially preferred. Ethanol has the Cas number 64-17-5.

[0239] 1-Propanol, also known as propyl alcohol, has the CAS number 71-23-8.

[0240] Isopropanol is also alternatively called 2-propanol and has the CAS number 67-63-0.

[0241] 1-Butanol can alternatively be called n-butanol or butyl alcohol and has the CAS number 71-36-3.

[0242] 1-Pentanol has the CAS number 71-41-0 and is also known as amyl alcohol.

[0243] 2-Methyl-2-butanol has the CAS number 75-85-4 and is also known as tert-pentanol. 1-Hexanol has the CAS number 111-27-3 and is also known as hexyl alcohol or capron alcohol.

[0244] The solvent(s) are preferably used in certain quantity ranges in the respective dye (F).

[0245] Particularly uniform and resistant colorations could be achieved when the dyeing agent (F1) and / or (F2) - based on the total weight of the respective dyeing agent - contained one or more solvents other than water in a total amount of 40 to 95 wt. %, preferably 50 to 90 wt. %, further preferably 55 to 85 wt. %, and most preferably 60 to 80 wt. %,.

[0246] In a further particularly preferred embodiment, a method according to the invention is characterized in that the dyeing agent (F1) and / or the dyeing agent (F2) - based on the total weight of the respective dyeing agent - contains one or more aliphatic monoalcohols from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol and 1-hexanol in a total amount of 40 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

[0247] In a further particularly preferred embodiment, a method according to the invention is characterized in that

[0248] - the dye (F1 ) — based on the total weight of the dye (F1) - contains one or more aliphatic C1-C22 monoalcohols (F1-4) from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol and 1-hexanol in a total amount of 40 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%, and / or

[0249] - the dye (F2) - based on the total weight of the dye (F1) - contains one or more aliphatic C1-C22 monoalcohols (F2-4) from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol and 1-hexanol in a total amount of 40 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

[0250] In a further explicitly preferred embodiment, a method according to the invention is characterized in that

[0251] - the dye (F1) - based on the total weight of the dye (F1) - contains 40 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.% ethanol, and / or

[0252] - the dye (F2) - based on the total weight of the dye (F1) - contains 40 to 95 wt. %, preferably 50 to 90 wt. %, further preferably 55 to 85 wt. %, and most preferably 60 to 80 wt. %, ethanol.

[0253] Water content in the dyes (F1) and (F2)

[0254] Due to the high solvent or alcohol content in the dyes (F1) and / or (F2), the water content in the dyes is preferably chosen to be relatively low. Very good results were obtained when the dye (F1) and / or (F2) contained 10 to 50 wt.%, preferably 15 to 45 wt.%, more preferably 20 to 40 wt.%, and most preferably 25 to 35 wt.%, based on the total weight of the respective dye.

[0255] In a further particularly preferred embodiment, a method according to the invention is characterized in that the dyeing agent (F1) and / or the dyeing agent (F2) - based on the total weight of the respective dyeing agent - contains 10 to 50 wt.%, preferably 15 to 45 wt.%, more preferably 20 to 40 wt.% and most preferably 25 to 35 wt.% water.

[0256] In a further particularly preferred embodiment, a method according to the invention is characterized in that

[0257] - the dye (F1) - based on the total weight of the dye (F1) - contains 10 to 50 wt.%, preferably 15 to 45 wt.%, more preferably 20 to 40 wt.% and most preferably 25 to 35 wt.% water (F1-5), and / or

[0258] - the dye (F2) - based on the total weight of the dye (F2) - contains 10 to 50 wt. %, preferably 15 to 45 wt. %, further preferably 20 to 40 wt. %, and most preferably 25 to 35 wt. %, water (F2-5).

[0259] Proportion of components (F-1), (F-2), (F-3) (F-4) and (F-5) in the dye

[0260] Microscopic images taken of dyed hair have shown that a thin, uniform film on the keratin fibers offers particularly good resistance to external influences such as mechanical friction or washing. The smoother and more continuous the film, the less surface area it presents to external forces. Once the film is broken in one place, it can be completely removed very quickly by the constant movement of the keratin fibers.

[0261] It was found that the films produced with the dye (F) were particularly thin, uniform, and stable when the dye consisted largely of components (F-1), (F-2), (F-3), (F-4), and (F-5). It is suspected that other components could disrupt the uniformity of the film because they could become embedded in the film, weaken it at that point, or create a point of attack for external forces. For this reason, it is especially preferred that components (F-1), (F-2), (F-3), (F-4), and (F-5) are present together in the dye (F) in a proportion 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.%.

[0262] If components (F-1), (F-2), (F-3), (F-4) and (F-5) together constitute at least 90.0% by weight in the dye, then the dye consists – based on its total weight – of at least 90% by weight of components (F-1), (F-2), (F-3), (F-4) and (F-5). In other words, in this case, other substances or ingredients different from (F-1) to (F-5) are present in the dye (F) only in a maximum quantity of 10% by weight, most preferably a maximum of 0.3% by weight.

[0263] In a further preferred embodiment, a method according to the invention is characterized in that

[0264] - the components (F1-1), (F1-2), (F1-3), (F1-4) and (F1-5) together are contained in the dye (F1) 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.%, and / or

[0265] - the components (F2-1), (F2-2), (F2-3), (F2-4) and (F2-5) together are contained in the dye (F2) 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.%,

[0266] Sequence of procedural steps (1) to (4)

[0267] In the method according to the invention, steps (1) are followed by step (2), followed by step (3), followed by step (4).

[0268] In step (1), the dye (F1) is applied to at least a portion of the hair. This can be done, for example, with a gloved hand or using a brush or applicator. After application, the dye (F1) can be spread over the hair and, if necessary, gently massaged in.

[0269] The dye (F1) is applied to at least a portion of the hair. For example, it can be applied to one or more individual strands, one or more sections of hair, or even several wider segments of hair. Applying the dye (F1) to the user's entire head of hair is also possible.

[0270] After application, or application and distribution, the dye can be left to take effect for some time, for example from 10 seconds to 30 minutes.

[0271] If the hair is to be dried at room temperature in step (2), the drying process, or in other words the evaporation of the volatile components of the dye, begins immediately upon application of (F1). If drying is to be assisted by heat, the heat can be applied either directly after application or after a waiting period of 10 seconds to 30 minutes.

[0272] In step (2), the hair, still coated with the dye (F1), is dried, thus applying the dye (F1) as a leave-on treatment. The hair can be air-dried at room temperature, or the hair, still coated with the dye, can be warmed to accelerate the drying process.

[0273] In step (3) of the procedure, the dye (F2) is then applied to at least part of the hair.

[0274] Just like the dye (F1), the dye (F2) can also be applied, for example, with a gloved hand or using a brush or applicator. After application, the dye (F2) can be distributed on the hair and, if necessary, gently massaged in.

[0275] The coloring agent (F2) is also applied to at least a portion of the hair. For example, it can be applied to one or more individual strands, one or more sections of hair, or even several wider segments. Applying the coloring agent (F2) to the user's entire head of hair is also possible.

[0276] The two dyes (F1) and (F2) are either identical or different. If the dyes (F1) and (F2) are identical, dye (F1) is applied again in step (3). Since both dyes (F1) and (F2) are applied to at least part of the hair, different color effects can be achieved by choosing the application locations.

[0277] In a further particularly preferred embodiment, the method according to the invention is characterized in that the dyeing agents (F1) and (F2) are the same and that the dyeing agent (F2) is applied in step (3) to at least a part of the hair on which the dyeing agent (F1) has already been applied in step (1).

[0278] In other words, in this embodiment, the dye (F1) is repeatedly applied to the hair. In step (3), the dye (F1) is applied at least partially to the sections of hair that were already dyed with (F1) in step (1) of the process.

[0279] For example, in step (1) highlighting can be done with the dye (F1), followed by a full-head coloring with (F1) in step (3). Alternatively, the full-head coloring can be done in step (1) with the dye (F1), and the dye (F1) can then be applied again in step (3) only to individual strands. The result of this application method is hair colored in the same shade with defined accents in the form of highlights with higher color intensity.

[0280] Furthermore, within this embodiment, it is also possible for the user to color all hair with the dye (F1) (step 1), dry the hair still covered with (F1) (step 2), then apply the dye (F1) again to all hair (step 3) and dry the hair again (step 4). This application method allows for particularly intense coloring in a uniform shade with improved rub fastness and improved feel of the hair.

[0281] In a further particularly preferred embodiment, the method according to the invention is characterized in that the dyeing agents (F1) and (F2) are different and that the dyeing agent (F2) is applied in step (3) to at least a part of the hair that has not previously been treated with the dyeing agent (F1) in step (1).

[0282] With this coloring method, for example, initial highlights in a first shade can be created using the coloring agent (F1). After these highlights have dried in step (2), further highlights in a different shade can then be created on some of the previously uncolored sections of hair using the coloring agent (F2). This coloring method provides the user with a simple and convenient way to obtain colored highlights in various shades. It is also possible to color all of the user's hair in at least two different shades. In a further, particularly preferred embodiment, the method according to the invention is characterized in that the coloring agents (F1) and (F2) are different and that the coloring agent (F2) is applied in step (3) to at least a portion of the hair to which the coloring agent (F1) has already been applied in step (1).

[0283] If the shades of the dyes (F1) and (F2) are different, a first part of the user's hair can be dyed with the dye (F1), and the subsequent application with (F2) is carried out at least partially on the parts of the hair that have already been dyed with (F1).

[0284] This makes it possible, for example, to first color adjacent strands in the first shade of (F1) (e.g., red), and then color second strands in the shade of (F2) (e.g., blue). In the area where both strands meet, there is then a region that has been colored with both (F1) and (F2) and consequently takes on the mixed color of both shades (F1) plus (F2) (in this example, violet). This allows for the coloring of adjacent strands or wider blocks of color with an attractive color transition.

[0285] Since both (F1) and (F2) are applied as "leave-on" applications, the placement of the dyes is particularly easy and it is possible to determine precisely and simply where the color transition should begin.

[0286] This method also makes it possible to create three different shades of color using only two dyes. It also allows for the creation of separate highlights, where, in this example, some strands are colored red, others blue, and still others violet.

[0287] In a further particularly preferred embodiment, the method according to the invention is characterized in that

[0288] - the dye (F1) is used to dye individual strands and the dye (F2) is used to dye all hair, or

[0289] - the dye (F1) is used to dye all hair and the dye (F2) is used to dye individual strands.

[0290] In a further particularly preferred embodiment, the method according to the invention is characterized in that the dyeing agent (F1) is used to dye individual strands and the dyeing agent (F2) is used to dye all hair.

[0291] In a further, particularly preferred embodiment, the method according to the invention is characterized in that the coloring agent (F1) is used to color all the hair and the agent (F2) is used to color individual strands. As previously described, these two embodiments enable all the hair of the test subjects to be colored in a base shade, which is accentuated by individual strands. If (F1) and (F2) are the same, the accentuation is achieved by increasing the color intensity. If (F1) and (F2) are different, the accentuation is achieved by creating a mixture of (F1) plus (F2) on the strands that are treated with both (F1) and (F2).

[0292] After application or application and distribution, the dye (F2) can be left to act for some time, for example from 10 seconds to 30 minutes.

[0293] If the hair is to be dried at room temperature in step (4), the drying process, or in other words the evaporation of the volatile components of the dye, begins immediately upon application of (F2). If drying is to be aided by heat, the heat can be applied either directly after application or after a waiting period of 10 seconds to 30 minutes.

[0294] In step (4), the hair, still coated with the dye (F2), is dried, thus applying the dye (F2) as a leave-on treatment. The hair can be air-dried at room temperature, or it can be warmed to accelerate the drying process.

[0295] Heat treatment in steps (2) and (4)

[0296] The dyeing process according to the invention is particularly convenient and time-saving if the drying of the hair covered with the dyes (F1) and (F2) in steps (2) and (4) is accelerated by heat treatment.

[0297] In a further, particularly preferred embodiment, the method according to the invention is therefore characterized by the fact that

[0298] (2) Drying the hair still exposed to the dye (F1) at 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, and / or the

[0299] (4) Drying the hair, which is still coated with the dye (F2), at 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. Heating or heat treatment means that the hair is brought into contact with a heated device or that this heated device is applied to or on the hair. Furthermore, the hair can also be brought into contact with warm / hot air for heat treatment. For example, a hairdryer, a hair dryer, a heat cap, a flat iron, a curling iron, or an infrared lamp can be used as a device.

[0300] In a particularly preferred embodiment, a method according to the invention is characterized in that the heating in steps (2) and (4) is carried out by using a hairdryer, a hair dryer, a heat cap, a flat iron, a curling iron or an infrared lamp, most particularly by using a hairdryer.

[0301] 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.

[0302] In the course of the inventive process, the hair can be completely subjected to heat treatment, but the treatment of partial areas of the hair can also be included. Complete heat treatment of the hair colored in this step is preferred; that is, preferably all hair sections to which the coloring agent (F1) and / or (F2) has been applied are also treated with heat in the subsequent step.

[0303] For example, the keratin fibers or the hair itself can be treated with a hairdryer, possibly under combs or brushes, blowing warm or hot air onto the fibers. This air is particularly preferred at a temperature of 40 to 70 °C. Alternatively, the hair can be held under an infrared lamp, preferably set to a temperature of 40 to 70 °C.

[0304] Do not wash your hair between steps (1) to (4)

[0305] The method according to the invention is characterized in that no hair washing takes place between steps (1) to (4). This means that steps (1) to (4) are carried out within one and the same dyeing process. Since both dyeing agents (F1) and (F2) (or the dyeing agent (F1) repeatedly) are applied via a leave-on application, the hair is not rinsed with tap water (or with tap water and shampoo or surfactant) during the process; or, in other words, no rinsing or hair washing takes place during the process.

[0306] Assuming that a user washes their hair on average at least every two days, the period within which steps (1) to (4) are carried out is practically limited to a maximum of 48 hours. However, it has proven particularly advantageous to further limit this period to a maximum of 24 hours, preferably a maximum of 12 hours, and most preferably a maximum of 4 hours. If steps (1) to (4) are carried out within a period of no more than 4 hours, then the user visits the hairdresser once or performs the coloring process once at home and, at the end of the process after completing step (4), achieves the desired result or the desired multi-colored highlighting.

[0307] In a further particularly preferred embodiment, the method according to the invention is characterized in that steps (1) to (4) are carried out within a period of at most 48 hours, preferably at most 24 hours, more preferably at most 12 hours and most preferably at most 4 hours.

[0308] Kit of parts

[0309] To increase user convenience, all dyes required for a dyeing process are preferably provided to the user in the form of a single product or in the form of a multi-component packaging unit.

[0310] If the dyes (F1) and (F2) are the same, it is practical to provide dye (F1) in a single outer package sized for multiple applications of dye (F1). If the dyes (F1) and (F2) are different, they are preferably packaged separately in two different outer packages or containers and supplied as a kit. A kit is understood to be a kit-of-parts or a multi-component packaging unit.

[0311] A second subject matter of the present application is therefore a kit for dyeing hair, in particular human hair, comprising in two separately prepared containers two different dyeing agents (F1) and (F2), wherein

[0312] - the dye (F1) contains

[0313] (F1-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0314] (F1-2) at least one chitosan and / or a chitosan derivative, and

[0315] - the dye (F2) contains

[0316] (F2-1) at least one colouring compound from the group consisting of pigments and direct dyes, and

[0317] (F2-2) at least one chitosan and / or a chitosan derivative, wherein the components (F1-1), (F1-2), (F2-1) and (F2-2) have already been disclosed in detail in the description of the first subject matter of the invention. Suitable containers may be, for example, bottles, tubes, sachets or cans. Preferably, the containers include an applicator suitable for application.

[0318] Regarding the other preferred embodiments of the kit according to the invention, what has been said about the method according to the invention applies mutatis mutantis.

[0319] Examples

[0320] 1. Formulations

[0321] The following dyes were produced (all values, unless otherwise stated, are in wt.%):

[0322] A swelling solution was produced from the water, acetic acid and chitosan.

[0323] The respective pigment was dispersed in ethanol. This dispersion was homogenized by rapid stirring. Subsequently, the aqueous chitosan swelling and the alcoholic pigment dispersion were mixed together and homogenized by rapid stirring.

[0324] 2. Application on counters

[0325] 2.1. Intensification of the color by repeated application of the same dye.

[0326] For the dyeing experiments, hair wefts (Kerling company) with a width of 2 cm were used.

[0327] The dye (M1) was applied to the left half of the hair weft. The weft, still coated with dye (M1), was then dried with a standard hairdryer. During drying, the weft was combed through.

[0328] After drying, the dye (M1) was applied again to the entire weft. The weft, still coated with dye (M1), was then dried again with a hairdryer. During the drying process, the weft was combed through again.

[0329] For comparison, the dye (M2) was applied to another weft, distributing it across the entire width of the weft. The weft, still coated with dye (M2), was then dried with a hairdryer. During drying, the weft was combed. The same procedures were repeated with formulations (M3) and (M4).

[0330] The color intensities achieved during the dyeing process were visually assessed by trained individuals. For this purpose, the hair wefts were laid side by side under a daylight lamp, and the color intensity was rated using school grades (1 = very high color intensity; 6 = very low color intensity).

[0331] Repeated dyeing with dye (M1) increased the color intensity of the hair weft. The color intensity was comparable to that of the hair weft dyed once with dye (M2).

[0332] Repeated dyeing with dye (M3) increased the color intensity of the hair weft. The color intensity was comparable to that of the hair weft dyed once with dye (M4).

[0333] 2.2. Assessment of hair feel

[0334] After assessing the color intensity, the dyed hair extensions were tested for their feel against the hair.

[0335] To assess the feel of the hair, trained individuals took each strand to be tested in their hand and ran their fingers through it several times. The feel of the dyed hair wefts from examples 1, 2, 3, and 4 was directly compared. The evaluation was based on a school grading system (1 = smooth, pleasant feel; 6 = particularly dull, rough feel).

[0336] The feel of the hair in the sections of the hair weft that were dyed once and twice with dye (M1) was comparable. The feel of the hair weft dyed with dye (M2) was particularly dull. The hair felt very coated, and resistance was noticeable when running the fingers through the weft.

[0337] The feel of the hair in the sections of the hair weft that were dyed once and twice with dye (M3) was comparable. The feel of the hair weft dyed with dye (M4) was particularly dull. The hair felt very coated, and resistance was noticeable when running the fingers through the weft.

[0338] 2.3. Assessment of rub fastness

[0339] The rub fastness was determined using the Ruf universal rub fastness tester. A box sliding in rails is fitted with a plastic membrane onto which a piece of cotton fabric measuring 4.2 cm x 10.5 cm is placed. This is secured with a lid featuring two windows. A second lid, also with two windows, is placed on top, and a dyed hair weft is attached to each window using adhesive tape. The top lid is then screwed on. The air cushion inside the rub fastness tester is inflated to approximately 0.3 bar. After 50 sliding motions, the rubbing process is stopped, and the cotton fabric is assessed. The rub fastness is evaluated using a school grading system (1 = very good rub fastness, cotton fabric virtually undyed; 6 = very poor rub fastness, very strong dye transfer to the cotton fabric).

[0340] The rub fastness of the hair weft sections dyed once and twice with dye (M1) was comparable, and color abrasion was minimal. In contrast, very strong color abrasion was observed in the hair weft section dyed once with dye (M2).

[0341] The rub fastness of the hair weft sections dyed once and twice with dye (M3) was comparable, and color abrasion was minimal. In contrast, very strong color abrasion was observed in the hair weft section dyed once with dye (M4).

[0342] 2.4. Summary of results

[0343] By using the inventive coloring method in layering (corresponding to the left side of the weft in examples 1 and 3), the hair wefts could be colored with a higher color intensity.

[0344] In comparison to a single dyeing of the wefts with a dye having double the dye concentration (examples 2 and 4), the color intensities were comparable.

[0345] However, a comparison of Example 1 with Example 2 showed that the coloring using the layering method according to the invention, with comparable color intensity, was associated with a significantly improved hair feel and also with much better rub fastness. The same applies to the comparison of Example 3 with Example 4.

[0346] A single dyeing with dye (M2), which contained twice the amount of dye as dye (M1), resulted in comparable color intensity, but a much poorer hair feel and significantly worse rub fastness. Similarly, a single dyeing with dye (M4), which contained twice the amount of dye as dye (M3), also resulted in comparable color intensity, but again, hair feel and rub fastness were significantly worse.

[0347] 3. Hairline dyeing with color gradient

[0348] For the dyeing experiments, hair wefts (Kerling company) with a width of 2 cm were used.

[0349] The dye (M1) was applied to the left half of the hair weft. The weft, still coated with dye (M1), was then dried with a standard hairdryer. During drying, the weft was combed through.

[0350] After drying, the dye (M3) was applied to the right half of the weft.

[0351] Afterwards, the weft, still coated with the dye (M3), was dried again with a hairdryer. During drying, the weft was combed through again.

[0352] The braid dyed in this way had a left half that was dyed only with dye (M1) and a right half that was dyed only with dye (M3). In the middle of the braid was an overlapping area where both dyes (M1) and (M3) were applied.

[0353] On hair weft 5, a particularly even and attractive color transition from red to violet to blue was achieved.

Claims

Patent claims 1. A method for dyeing hair, especially human hair, comprising the following steps in the specified order: (1) Application of a dye (F1) to at least part of the hair, wherein the dye (F1) contains (F1-1) at least one colouring compound from the group consisting of pigments and direct dyes, and (F1-2) at least one chitosan and / or one chitosan derivative, (2) Drying the hair still coated with the dye (F1), (3) Application of a dye (F2) to at least part of the hair, wherein the dye (F2) contains (F2-1) at least one colouring compound from the group consisting of pigments and direct dyes, and (F2-2) at least one chitosan and / or a chitosan derivative, and (4) Drying the hair still exposed to the dye (F2), wherein the dyes (F1) and (F2) are the same or different, and wherein no hair washing takes place between steps (1) to (4).

2. Method according to claim 1, characterized in that - the colorant (F1) contains at least one coloring compound (F1-1) from the group consisting of inorganic pigments, organic pigments, pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments, and / or - the colorant (F2) contains at least one coloring compound (F2-1) from the group consisting of inorganic pigments, organic pigments, pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

3. Method according to one of claims 1 to 2, characterized in that - the coloring agent (F1) contains at least one coloring compound (F1-1) from the group of direct dyes, particularly preferably from the group of anionic direct dyes, and / or - the coloring agent (F2) contains at least one coloring compound (F2-1) from the group of direct dyes, particularly preferably from the group of anionic direct dyes.

4. Method according to one of claims 1 to 3, characterized in that - the dyeing agent (F1) - based on the total weight of the dyeing agent (F1) - contains one or more coloring compounds (F1-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.2 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.%, and / or - the dyeing agent (F2) - based on the total weight of the dyeing agent (F2) - contains one or more coloring compounds (F2-1) in a total amount of 0.10 to 3.00 wt.%, preferably 0.15 to 1.50 wt.%, more preferably 0.2 to 0.90 wt.%, even more preferably 0.25 to 0.70 wt.% and most preferably 0.30 to 0.60 wt.%.

5. Method according to one of claims 1 to 4, characterized in that the coloring compounds (F1-1) and (F2-1) in the dyes (F1) and (F2) are qualitatively and / or quantitatively different.

6. Method according to any one of claims 1 to 5, characterized in that - the dye (F1) - based on the total weight of the dye (F1) - contains one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 7.0 wt.%, preferably 0.2 to 4.5 wt.%, more preferably 0.3 to 2.5 wt.%, and most preferably 0.4 to 1.2 wt.%, and / or - the dye (F2) - based on the total weight of the dye (F2) - contains one or more chitosans and / or chitosan derivatives in a total amount of 0.1 to 7.0 wt. %, preferably 0.2 to 4.5 wt. %, further preferably 0.3 to 2.5 wt. %, and most preferably 0.4 to 1.2 wt. %, 7. Method according to one of claims 1 to 6, characterized in that the dyeing agent (F1) and / or the dyeing agent (F2) contains one or more organic acids from the group consisting of acetic acid, citric acid, succinic acid, tartaric acid, lactic acid, malic acid, malonic acid, maleic acid and benzoic acid, most preferably acetic acid.

8. Method according to any one of claims 1 to 7, characterized in that the dye (F1) and / or the dye (F2) - based on the total weight of the respective dye - contains one or more aliphatic monoalcohols from the group consisting of ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, 2-methyl-2-butanol and 1-hexanol in a total amount of 40 to 95 wt.%, preferably 50 to 90 wt.%, more preferably 55 to 85 wt.% and most preferably 60 to 80 wt.%.

9. Method according to any one of claims 1 to 8, characterized in that the dye (F1) and / or the dye (F2) - based on the total weight of the respective Dyeing agent - contains 10 to 50 wt.%, preferably 15 to 45 wt.%, further preferably 20 to 40 wt.% and most preferably 25 to 35 wt.% water.

10. Method according to one of claims 1 to 9, characterized in that the dyeing agents (F1) and (F2) are the same and that the dyeing agent (F2) is applied in step (3) to at least a part of the hair on which the dyeing agent (F1) has already been applied in step (1).

11. Method according to any one of claims 1 to 10, characterized in that the dyeing agents (F1) and (F2) are different and that the dyeing agent (F2) is applied in step (3) to at least a part of the hair which has not previously been treated with the dyeing agent (F1) in step (1).

12. Method according to one of claims 1 to 11, characterized in that the dyeing agents (F1) and (F2) are different and that the dyeing agent (F2) is applied in step (3) to at least a part of the hair on which the dyeing agent (F1) has already been applied in step (1).

13. Method according to any one of claims 1 to 12, characterized in that - the dye (F1) is used to dye individual strands and the dye (F2) is used to dye all hair, or - the dye (F1) is used to dye all hair and the dye (F2) is used to dye individual strands.

14. Method according to any one of claims 1 to 13, characterized in that (2) Drying the hair still exposed to the dye (F1) at 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, and / or the (4) Drying the hair still exposed to the dye (F2) at 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.

15. Method according to any one of claims 1 to 14, characterized in that steps (1) to (4) are carried out within a period of at most 48 hours, preferably at most 24 hours, more preferably at most 12 hours and most preferably at most 4 hours.

16. Kit for dyeing keratinous fibers, in particular human hair, comprising in two separately prepared containers two different dyes (F1) and (F2), wherein - the dye (F1) contains (F1-1) at least one colouring compound from the group consisting of pigments and direct dyes, and (F1-2) at least one chitosan and / or a chitosan derivative, and - the dye (F2) contains (F2-1) at least one colouring compound from the group consisting of pigments and direct dyes, and (F2-2) at least one chitosan and / or one chitosan derivative, wherein the components (F1-1), (F1-2), (F2-1) and (F2-2) are defined in claims 1 to 9.

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