PIGMENT SUSPENSION AND A METHOD FOR COLORING KERATINIC MATERIAL USING THE PIGMENT SUSPENSION

Description

[0001] The subject matter of the present application is a pigment suspension comprising a pigment and a carrier medium. A further subject matter is a method for dyeing keratinous material using the pigment suspension.

[0002] Pigments, especially metal-containing pigments, are frequently used in paints, varnishes, printing inks, powder coatings, cosmetics, and plastics for coloring. Paints, varnishes, printing inks, cosmetics, and powder coatings are liquid or powder coating materials applied to surfaces to achieve improved or altered optical and physical properties.

[0003] Altering the shape and color of keratin fibers, especially 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 usually contain oxidation dye precursors, so-called developer components and coupler components, which react with oxidizing agents such as hydrogen peroxide to form the actual dyes. Oxidation dyes are characterized by very long-lasting color results.

[0004] When using direct dyes, pre-formed pigments diffuse from the dye into the hair fiber. Compared to oxidative hair coloring, dyes produced with direct dyes are less durable and wash out more quickly. Dyes made with direct dyes typically remain on the hair for between 5 and 20 washes.

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

[0006] Metallic luster pigments or metallic effect pigments are widely used in many areas of technology. For example, they are used to color paints, printing inks, inks, plastics, glass, ceramic products, and decorative cosmetic preparations such as nail polish.

[0007] They are characterized above all by their attractive angle-dependent color impression (goniochromism) and their metallic-looking luster.

[0008] Hair with a metallic finish or metallic highlights is trending. The metallic tone makes the hair appear thicker and shinier.

[0009] For cosmetic applications, such as color-changing keratin fibers with pigments, it is important that the pigments are provided to the user in a storage-stable and dosable form. This can be achieved, in particular, in the form of a storage-stable pigment suspension.

[0010] The production of inorganic pigment suspensions typically uses ground pigment powders and water. Small amounts of organic or inorganic dispersing agents may need to be added.

[0011] The object of the present invention is to provide pigment suspensions that are easy and inexpensive to produce and are stable over time. In particular, the pigments should not agglomerate and / or settle. The carrier medium and any excipients should be compatible with the application modalities of the pigment suspension.

[0012] It has been shown that pigment suspensions containing a C1-C10 alcohol, a diol and water as a carrier medium, as well as a thickening agent, meet these requirements.

[0013] Accordingly, a first subject of the application is a comprehensive a) at least one colouring compound from the group of pigments, wherein the pigment comprises a substrate platelet of natural mica or synthetic mica, b) at least one C 1 -C 10 alcohol, c) at least one diol selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol and mixtures thereof, d) at least one thickening agent and e) water.

[0014] The first essential ingredient of the invention is that the pigment suspensions contain at least one selected color-giving compound from the group of pigments.

[0015] For the purposes of the present 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.

[0016] At least one pigment has a substrate platelet.

[0017] In principle, the substrate plate can be made from any material that can be formed into platelet form.

[0018] They can be of natural origin or synthetically produced. The substrate platelets are composed of mica. The mica can be of natural or synthetic origin.

[0019] The pigment comprises a substrate platelet, the substrate platelet comprising natural or synthetic mica.

[0020] In a particularly preferred embodiment, the pigment comprises a substrate platelet made of synthetic mica (INCI: Synthetic Fluorphlogopite).

[0021] The mica substrate platelet preferably has an average thickness of 50 to 1500 nm and more preferably of 90 to 1000 nm.

[0022] The size of the substrate platelet can be tailored to the specific application, for example, the desired effect on a keratinous material. Typically, mica substrate platelets have a mean maximum diameter of approximately 1 to 200 µm, particularly approximately 5 to 100 µm, and even more preferably approximately 5 to 25 µm.

[0023] 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 Helos instrument with Quixel wet dispersion. For sample preparation, the sample to be tested was pre-dispersed in isopropanol for 3 minutes.

[0024] The substrate plates can have different shapes.

[0025] A coating can modify the surface and / or optical properties of the pigment and increase its mechanical and chemical resistance. For example, only the top and / or bottom surface of the substrate platelet can be coated, leaving the side surfaces uncoated. Preferably, the entire surface of the optionally passivated substrate platelets, including the side surfaces, is covered by the coating. The substrate platelets are preferably completely encased by the coating.

[0026] The coating can consist of one or more layers. In a preferred embodiment, the coating has only one layer A. In another preferred embodiment, the coating has at least two, preferably two or three, layers. It may be preferred that the coating has two layers A and B, wherein layer B is different from layer A. Preferably, layer A is located between layer B and the surface of the substrate plate. In yet another preferred embodiment, the coating has three layers A, B, and C. In this embodiment, layer A is located between layer B and the surface of the substrate plate, and layer C, which is different from the underlying layer B, is located on top of layer B.

[0027] Suitable materials for layers A and optionally B and C are any substances that can be permanently applied to the substrate plates. The materials should preferably be film-like and applicable. Preferably, the entire surface of the optionally passivated substrate plates, including the side faces, is coated by layer A, or by layers A and B, or by layers A, B, and C.

[0028] The layers can each contain at least one metal oxide (hydrate).

[0029] It is preferred that the metal oxide (hydrate) is selected from the group consisting of silicon dioxide, silicon dioxide hydrate, aluminum oxide, aluminum oxide hydrate, boron oxide, germanium oxide, manganese oxide, magnesium oxide, iron oxide, cobalt oxide, chromium oxide, titanium dioxide, vanadium oxide, zirconium oxide, tin oxide, zinc oxide and mixtures thereof.

[0030] In the case of pigments with a substrate platelet of mica, in particular synthetic mica, layer A comprises a metal oxide (hydrate) selected from the group consisting of titanium dioxide (TiO₂), iron oxide (Fe₂O₃ and / or Fe₃O₄), and mixtures thereof. In a highly preferred embodiment, layer A comprises titanium dioxide (TiO₂) and / or iron oxide (Fe₂O₃). In a most preferred embodiment, layer A comprises titanium dioxide (TiO₂).

[0031] Layer B, if present, is also different from the first metal oxide (hydrate) layer in the case of pigments with a mica substrate platelet.

[0032] Suitable metal oxides (hydrates) for layer B are tin oxide (SnO₂), silicon oxide (SiO₂), aluminum oxide (Al₂O₃), and / or iron oxide (Fe₂O₃ and / or Fe₃O₄). It is preferred that layer B contains a metal oxide (hydrate) selected from the group consisting of tin oxide (SnO₂), silicon oxide (SiO₂), aluminum oxide (Al₂O₃), iron oxide (Fe₂O₃ and / or Fe₃O₄), and mixtures thereof. It is particularly preferred that, in the case of pigments with a substrate platelet of mica, preferably synthetic mica, layer B contains tin oxide (SnO₂).

[0033] Layer B may also contain a selectively absorbing dye or pigment. Suitable dyes and / or pigments include, for example, carmine, ferric hexacyanoferrate(II / III), and chromium oxide green (Cr₂O₃).

[0034] The pigments with a mica substrate platelet can have a further layer C, which acts as a protective layer and comprises a metal oxide (hydrate) or a polymer, for example, a synthetic resin. Suitable metal oxides (hydrates) include, for example, silicon dioxide, silicon dioxide hydrate, aluminum oxide, aluminum oxide hydrate, zinc oxide, tin oxide, titanium dioxide, zirconium oxide, iron(III) oxide, and chromium(III) oxide. Silicon dioxide is preferred.

[0035] It is particularly preferred that a pigment with a substrate platelet of synthetic mica (INCI: Synthetic Fluorphlogopite) has a layer A comprising titanium dioxide (TiO 2 ).

[0036] It is also preferred that a pigment with a substrate platelet of synthetic mica (INCI: Synthetic Fluorphlogopite) has a layer A comprising iron(III) oxide (Fe 2 O 3 ).

[0037] It is also preferred that a pigment with a substrate platelet of synthetic mica (INCI: Synthetic Fluorphlogopite) has a layer A comprising titanium dioxide (TiO 2 ) and iron(III) oxide (Fe 2 O 3 ), and a layer B comprising tin dioxide (SnO 2 ).

[0038] It is highly preferred that a pigment with a substrate platelet of synthetic mica (INCI: Synthetic Fluorphlogopite) has a layer A comprising titanium dioxide (TiO 2 ) and a layer B comprising tin dioxide (SnO 2 ).

[0039] Preferred pigments with a substrate platelet made of synthetic mica include, for example, Timiron® SynWhite Satin, Colorona® SynCopper and / or Colorona® SynBronze from Merck.

[0040] The amount of pigment in the pigment suspension depends in particular on the type of pigment(s) and its intended use. Preferably, the amount of pigment is between 1 and 90 wt.%, more preferably between 5 and 80 wt.%, and most preferably between 10 and 70 wt.%, in each case based on the total weight of the pigment suspension.

[0041] In addition to the aforementioned pigments with mica substrate platelets, the pigment suspension may contain other coloring compounds. These other coloring compounds may include, for example, further inorganic pigments, organic pigments, and / or direct dyes.

[0042] The second essential ingredient of the invention is that the pigment suspension comprises at least one C1-C10 alcohol.

[0043] The C1-C10 alcohol is preferably an aliphatic C1-C10 alcohol, which may be linear or branched and saturated or unsaturated.

[0044] Bevorzugte C 1 -C 10 Alkohole sind ausgewählt aus der Gruppe bestehend aus Methanol, Ethanol, 1-Propanol, 2-Propanol, 1-Butanol, 2-Butanol, 2-Methylpropan-1-ol, 2-Methylpropan-1-ol (tert.-Butanol), 1-Pentanol, 2-Pentanol, 3-Pentanol, 3-Methylbutan-1-ol, 2-Methylbutan-1-ol, 2,2-Dimethylpropan-1-ol, 3-Methylbutan-2-ol, 2-Methylbutan-2-ol, 1-Hexanol, 2-Hexanol, 3-Hexanol, 2-Methylpentan-1-ol, 3-Methylpentan-1-ol, 4-Methylpentan-1-ol, 2-Methylpentan-2-ol, 3-Methylpentan-2-ol, 4-Methylpentan-2-ol, 2-Methylpentan-3-ol, 3-Methylpentan-3-ol, 2,2-Dimethylbutan-1-ol, 2,3-Dimethylbutan-1-ol, 3,3-Dimethylbutan-1-ol, 2,3-Dimethylbutan-2-ol, 3,3-Dimethylbutan-2-ol, 2-Ethylbutan-1-ol, 1-Heptanol, 2-Heptanol, 3-Heptanol, 4-Heptanol, 1-Octanol, 2-Octanol, 1-Nonanol, 1-Decanol, 2-Methylhexan-2-ol, 2-Methylheptan-2-ol, 3-Methyl-3-pentanol und Mischungen davon.

[0045] Of the C 1 -C 10 alcohols, the pigment suspension preferably contains at least one C 1 -C 10 alcohol selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methylpropan-1-ol, 2-methylpropan-1-ol (tert-butanol) and mixtures thereof.

[0046] In a highly preferred embodiment, the pigment suspension is characterized in that the pigment suspension contains at least one C 1 -C 10 alcohol selected from the group consisting of ethanol, 2-propanol and mixtures thereof.

[0047] Particularly stable pigment suspensions could be obtained if the pigment suspension - based on the total weight of the pigment suspension - contains one or more C 1 -C 10 alcohols in a total amount of 1 to 80 wt.%, preferably 5 to 60 wt.% and most preferably 10 to 40 wt.%.

[0048] The third essential ingredient of the invention is that the pigment suspension comprises at least one selected diol.

[0049] A diol is a chemical compound with two hydroxyl groups (-OH groups). An aliphatic diol is also called a glycol.

[0050] The pigment suspension is characterized in that the pigment suspension contains at least one diol selected from the group consisting of ethylene glycol, 1,2-propylene glycol and 1,3-propylene glycol.

[0051] Particularly stable pigment suspensions could be obtained if the pigment suspension - based on the total weight of the pigment suspension - contains one or more diols in a total amount of 1 to 50 wt.%, preferably 1 to 40 wt.%, more preferably 1 to 30 wt.% and most preferably 1 to 20 wt.%.

[0052] The fourth essential ingredient of the invention is that the pigment suspension comprises at least one thickening agent.

[0053] Suitable thickening agents include, in particular, chemically modified celluloses such as propylcellulose, methylethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, methylhydroxyethylcellulose, ethylhydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylhydroxyethylcellulose, sulfoethylcellulose, carboxymethylsulfoethylcellulose, hydroxypropylsulfoethylcellulose, hydroxyethylsulfoethylcellulose, methylethylhydroxyethylcellulose, methylylsulfoethylcellulose and / or ethylsulfoethylcellulose.

[0054] In a preferred embodiment, a pigment suspension is characterized in that the pigment suspension contains a thickening agent selected from the group consisting of propylcellulose, methylethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, methylhydroxyethylcellulose, ethylhydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylhydroxyethylcellulose, sulfoethylcellulose, carboxymethylsulfoethylcellulose, hydroxypropylsulfoethylcellulose, hydroxyethylsulfoethylcellulose, methylethylhydroxyethylcellulose, methylylsulfoethylcellulose, ethylsulfoethylcellulose and mixtures thereof.

[0055] Particularly suitable thickening agents are selected from hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose and mixtures thereof.

[0056] In a particularly preferred embodiment, a pigment suspension is characterized in that the agent (a) and / or the agent (b) further comprises a thickening agent selected from the group consisting of hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose and mixtures thereof.

[0057] The amount of thickening agent is preferably between 0.1 and 10 wt.% and more preferably between 0.25 and 5 wt.%, in each case based on the total amount of pigment suspension.

[0058] The fifth essential ingredient of the invention is water in the pigment suspension. The amount of water is preferably 1 to 50 wt.%, more preferably 1 to 40 wt.%, further preferably 1 to 30 wt.%, and most preferably 1 to 20 wt.%, in each case based on the total amount of pigment suspension.

[0059] It has been shown that the pigments, with substrate plates of natural mica or synthetic mica, can be stored stably and dosed precisely using the pigment suspension.

[0060] A second object of the present invention relates to a method for dyeing keratinous material, in particular human hair, comprising the following steps: Application of an agent (a) to the keratinous material, wherein the agent (a) contains: (a1) at least one organic C1-C6 alkoxysilane, and application of an agent (b) to the keratinous material, wherein the agent (b) contains: (b1) at least one sealing reagent, wherein at least one of the means (a) and (b) further comprises a pigment suspension according to any one of claims 1 to 4.

[0061] The process may comprise an agent (a) which is prepared by combining a pigment suspension according to the present invention with one or more organic C 1 -C 6 -alkoxysilanes (a1) and / or their condensation products.

[0062] Alternatively, the method may comprise an agent (b) which is produced by combining a pigment suspension according to the present invention with one or more sealing reagents (b1).

[0063] The agent (a) used in the process is characterized in that it contains one or more organic C 1 -C 6 -alkoxysilanes and / or their condensation products.

[0064] The organic C1-C6 alkoxysilanes are organic, non-polymeric silicon compounds, preferably selected from the group of silanes with one, two or three silicon atoms.

[0065] Organic silicon compounds, also alternatively referred to as organosilicon compounds, are compounds that either have a direct silicon-carbon bond (Si-C) or in which the carbon is linked to the silicon atom via an oxygen, nitrogen, or sulfur atom. The organic silicon compounds according to the invention are preferably compounds containing one to three silicon atoms. Particularly preferably, the organic silicon compounds contain one or two silicon atoms.

[0066] According to IUPAC rules, the term silane refers to a group of chemical compounds based on a silicon skeleton and hydrogen. In organic silanes, the hydrogen atoms are wholly or partially replaced by organic groups such as (substituted) alkyl groups and / or alkoxy groups.

[0067] A characteristic feature of C1-C6 alkoxysilanes is that at least one C1-C6 alkoxy group is directly bonded to a silicon atom. The C1-C6 alkoxysilanes according to the invention thus comprise at least one structural unit R'R"R‴Si-O-(C1-C6 alkyl), where the R', R", and R‴ groups represent the three remaining bonding valences of the silicon atom.

[0068] The C1-C6 alkoxy group(s) bonded to the silicon atom are highly reactive and hydrolyze rapidly in the presence of water. The reaction rate depends, among other things, on the number of hydrolyzable groups per molecule. If the hydrolyzable C1-C6 alkoxy group is an ethoxy group, the organic silicon compound preferentially contains a structural unit R'R"R‴Si-O-CH2-CH3. The substituents R', R", and R‴ represent the three remaining free valences of the silicon atom.

[0069] Even the addition of small amounts of water initially leads to hydrolysis and then to a condensation reaction between the organic alkoxysilanes. For this reason, both the organic alkoxysilanes and their condensation products can be present in the product.

[0070] A condensation product is understood to be a product that is formed by the reaction of at least two organic C 1 -C 6 -alkoxysilanes with the elimination of water and / or with the elimination of a C 1 -C 6 -alkanol.

[0071] The condensation products can be, for example, dimers, but also trimers or oligomers, with the condensation products being in equilibrium with the monomers.

[0072] Depending on the amount of water used or consumed in the hydrolysis, the equilibrium shifts from monomeric C 1 -C 6 -alkoxysilane to condensation product.

[0073] In a particularly preferred embodiment, a method is characterized in that the agent (a) contains one or more organic C 1 -C 6 -alkoxysilanes selected from silanes having one, two or three silicon atoms, wherein the organic silicon compound also comprises one or more basic chemical functions.

[0074] This basic group can be, for example, an amino group, an alkylamino group, or a dialkylamino group, preferably linked to a silicon atom via a linker. Preferably, the basic group is an amino group, a C1-C6 alkylamino group, or a di(C1-C6)alkylamino group.

[0075] A particularly preferred agent (a) which can be used in the process is characterized in that the cosmetic agent contains one or more organic C 1 -C 6 ⁻⁵ alkoxysilanes selected from the group of silanes having one, two or three silicon atoms, and wherein the C 1 -C 6 ⁻⁵ alkoxysilanes further comprise one or more basic chemical functions.

[0076] Particularly good results were obtained when (a) C1-C6 alkoxysilanes of formula (SI) and / or (S-II) and / or (S-IV) were used in the composition. Since, as previously described, hydrolysis / condensation begins even in trace amounts of moisture, the condensation products of the C1-C6 alkoxysilanes of formula (SI) and / or (S-II) and / or (S-IV) are also included in this embodiment.

[0077] In a further particularly preferred embodiment, a method is characterized in that the agent (a) contains one or more organic C1-C6 alkoxysilanes of formula (SI) and / or (S-II), R1 R2 NL-Si(OR3) a (R4) b (SI) wherein R1, R2 independently represent a hydrogen atom or a C1-C6 alkyl group, L represents a linear or branched divalent C1-C20 alkylene group, R3, R4 independently represent a C1-C6 alkyl group, a represents an integer from 1 to 3, and b represents the integer 3 - a, and (R 5 O) c (R 6 ) d Si-(A) e -[NR 7 -(A')] f -[O-(A")] G -[NR 8 -(A‴)] h -Si(R 6 ') the (OR) 5 ') c' (S-II), although R5, R5', R5", R6, R6' and R6" independently represent a C1-C6 alkyl group; A, A', A", A‴ and A"" independently represent a linear or branched divalent C1-C20 alkylene group; R7 and R8 independently represent a hydrogen atom, a C1-C6 alkyl group, a hydroxy C1-C6 alkyl group, a C2-C6 alkenyl group, an amino C1-C6 alkyl group or a grouping of formula (S-III); - (Aʺʺ)-Si(R6") d "(OR5") c " (S-III), c represents an integer from 1 to 3, d represents the integer 3 - c, c' represents an integer from 1 to 3, d' represents the integer 3 - c' where c" represents an integer from 1 to 3, d" represents the integer 3 - c", e represents 0 or 1, f represents 0 or 1, g represents 0 or 1, h represents 0 or 1, provided that at least one of the residues of e, f, g and h is different from 0, and / or their condensation products.

[0078] The substituents R1, R2, R3, R4, R5, R5', R5'', R6, R6', R6'', R7, R8, L, A, A', A", A‴, and A''" in the compounds of formulas (SI) and (S-II) are explained below by way of example: Examples of a C1-C6 alkyl group are the groups methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, and t-butyl, n-pentyl, and n-hexyl. Propyl, ethyl, and methyl are preferred alkyl groups. Examples of a C2-C6 alkenyl group are vinyl, allyl, but-2-enyl, but-3-enyl, and isobutenyl; preferred C2-C6 alkenyl groups are vinyl and allyl. Preferred examples of a Hydroxy-C1-C6 alkyl groups include hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 4-hydroxybutyl, 5-hydroxypentyl, and 6-hydroxyhexyl groups; a 2-hydroxyethyl group is particularly preferred. Examples of amino-C1-C6 alkyl groups are aminomethyl, 2-aminoethyl, and 3-aminopropyl.The 2-aminoethyl group is particularly preferred. Examples of a linear divalent C1-C20 alkylene group are, for example, the methylene group (-CH2-), the ethylene group (-CH2-CH2-), the propylene group (-CH2-CH2-CH2-), and the butylene group (-CH2-CH2-CH2-CH2-). The propylene group (-CH2-CH2-CH2-) is particularly preferred. From a chain length of 3 carbon atoms, divalent alkylene groups can also be branched. Examples of branched, divalent C3-C20 alkylene groups are (-CH2-CH(CH3)-) and (-CH2-CH(CH3)-CH2-).

[0079] In the organic silicon compounds of formula (SI) R1R2NL-Si(OR3)a(R4)b (SI), the R1 and R2 substituents independently represent a hydrogen atom or a C1-C6 alkyl group. Most preferably, both R1 and R2 substituents represent a hydrogen atom.

[0080] In the central part of the organic silicon compound is the structural unit or linker -L-, which represents a linear or branched, divalent C1-C20 alkylene group. The divalent C1-C20 alkylene group can alternatively be described as a divalent or two-coordinate C1-C20 alkylene group, meaning that each -L- group can form two bonds.

[0081] Preferably, -L- represents a linear, divalent C1-C20 alkylene group. More preferably, -L- represents a linear, divalent C1-C6 alkylene group. Particularly preferably, -L- represents a methylene group (-CH2-), an ethylene group (-CH2-CH2-), a propylene group (-CH2-CH2-CH2-), or a butylene group (-CH2-CH2-CH2-CH2-). Most preferably, L represents a propylene group (-CH2-CH2-CH2-).

[0082] The alkoxysilanes of formula (SI) R 1 R 2 NL-Si(OR 3 ) a (R 4 ) b (SI) each have at one end the silicon-containing group -Si(OR 3 ) a (R 4 ) b .

[0083] In the terminal structural unit -Si(OR 3 ) a (R 4 ) b, the residues R3 and R4 independently represent a C 1 -C 6 alkyl group. Particularly preferably, R 3 and R 4 independently represent a methyl group or an ethyl group.

[0084] Here, 'a' represents an integer from 1 to 3, and 'b' represents the integer 3 - 'a'. If 'a' represents the number 3, then 'b' equals 0. If 'a' represents the number 2, then 'b' equals 1. If 'a' represents the number 1, then 'b' equals 2.

[0085] Agents (a) with particularly good dyeing properties on keratinous materials could be produced if the agent (a) contains at least one organic C 1 -C 6 -alkoxysilane of formula (SI) in which the residues R 3 , R 4 independently represent a methyl group or an ethyl group.

[0086] Furthermore, dyes with the best wash fastness could be obtained when the agent (a) contains at least one organic C1-C6 alkoxysilane of formula (SI), where the substituent a represents the number 3. In this case, the substituent b represents the number 0.

[0087] In a further preferred embodiment, the agent (a) is characterized in that it contains one or more organic C1-C6 alkoxysilanes of formula (SI), wherein R 3 , R 4 independently represent a methyl group or an ethyl group, and a represents the number 3 and b represents the number 0.

[0088] In a further preferred embodiment, a method according to the invention is characterized in that the agent (a) contains at least one or more organic C 1 -C 6 -alkoxysilanes of formula (SI), R 1 R 2 NL-Si(OR 3 ) a (R 4 ) b (SI), wherein R1, R2 both represent a hydrogen atom, and L represents a linear, divalent C1-C6 alkylene group, preferably a propylene group (-CH2-CH2-CH2-) or an ethylene group (-CH2-CH2-), R3 represents an ethyl group or a methyl group, R4 represents a methyl group or an ethyl group, a represents the number 3 and b represents the number 0.

[0089] Particularly suitable organic silicon compounds of formula (I) are (3-Aminopropyl)triethoxysilane (3-Aminopropyl)trimethoxysilane (2-Aminoethyl)triethoxysilane (2-Aminoethyl)trimethoxysilane (3-Dimethylaminopropyl)triethoxysilane (3-Dimethylaminopropyl)trimethoxysilane (2-Dimethylaminoethyl)triethoxysilane. (2-Dimethylaminoethyl)trimethoxysilane and / or

[0090] In a further preferred embodiment, a method according to the invention is characterized in that the agent (a) contains at least one organic C1-C6 alkoxysilane of formula (SI) selected from the group consisting of (3-Aminopropyl)triethoxysilane (3-Aminopropyl)trimethoxysilane (2-Aminoethyl)triethoxysilane (2-Aminoethyl)trimethoxysilane (3-Dimethylaminopropyl)triethoxysilane (3-Dimethylaminopropyl)trimethoxysilane (2-Dimethylaminoethyl)triethoxysilane, (2-Dimethylaminoethyl)trimethoxysilane and / or their condensation products.

[0091] The aforementioned organic silicon compounds of formula (I) are commercially available. (3-Aminopropyl)trimethoxysilane, for example, can be purchased from Sigma-Aldrich. (3-Aminopropyl)triethoxysilane is also commercially available from Sigma-Aldrich.

[0092] In a further embodiment of the method according to the invention, agent (a) can also contain one or more organic C 1 -C 6 -alkoxysilanes of formula (S-II), (R 5 O) c (R 6 ) d Si-(A) e -[NR 7 -(A')] f -[O-(A")] g -[NR 8 -(A‴)] h -Si(R 6 ') d' (OR 5 ') c' (S-II).

[0093] The alkoxysilanes of formula (S-II) each have silicon-containing groups (R 5 O) c (R 6 ) d Si- and -Si(R 6 ') d' (OR 5 ') c' .

[0094] The central part of the molecule of formula (S-II) contains the groups -(A) e - and -[NR 7 -(A')] f - and -[O-(A")] g - and -[NR 8 -(A‴)] h -. Each of the residues e, f, g, and h can independently represent the number 0 or 1, provided that at least one of the residues e, f, g, and h is non-0. In other words, a preferred alkoxysilane of formula (II) contains at least one group from the group consisting of -(A)- and -[NR 7 -(A')]- and -[O-(A")]- and -[NR 8 -(A‴)]-.

[0095] In the two terminal structural units (R 5 O) c (R 6 ) d Si- and -Si(R 6 ') d' (OR 5 ') c', the residues R5, R5', R5" independently represent a C 1 -C 6 alkyl group. The residues R6, R6' and R6" independently represent a C 1 -C 6 alkyl group.

[0096] Here, c represents an integer from 1 to 3, and d represents the integer 3 - c. If c represents the number 3, then d equals 0. If c represents the number 2, then d equals 1. If c represents the number 1, then d equals 2.

[0097] Similarly, c' represents an integer from 1 to 3, and d' represents the integer 3 - c'. If c' represents the number 3, then d' equals 0. If c' represents the number 2, then d' equals 1. If c' represents the number 1, then d' equals 2.

[0098] Dyes with the best wash fastness were obtained when the residues c and c' both represent the number 3. In this case, d and d' both represent the number 0.

[0099] In a further preferred embodiment, a method is characterized in that the agent (a) contains one or more organic C1-C6 alkoxysilanes of formula (S-II), (R5O)c(R6)dSi-(A)e-[NR7-(A')]f-[O-(A")]g-[NR8-(A‴)]h-Si(R6')d'(OR5')c'(S-II), wherein R5 and R5' independently represent a methyl group or an ethyl group, c and c' both represent the number 3, and d and d' both represent the number 0.

[0100] If c and c' both represent the number 3 and d and d' both represent the number 0, the organic silicon compounds according to the invention correspond to the formula (S-IIa) (R 5 O) 3 Si-(A) e -[NR 7 -(A')] f -[O-(A")] g -[NR 8 -(A‴)] h -Si(OR 5 ') 3 (S-IIa).

[0101] The residues e, f, g, and h can independently represent the number 0 or 1, with at least one residue from e, f, g, and h being non-zero. The abbreviations e, f, g, and h thus define which of the groupings -(A) e - and -[NR 7 -(A')] f - and -[O-(A")] g - and -[NR 8 -(A‴)] h - are located in the middle section of the organic silicon compound of formula (II).

[0102] In this context, the presence of certain groupings has proven particularly advantageous for achieving wash-fast dyeing results. Especially good results were obtained when at least two of the residues e, f, g, and h represent the number 1. It is particularly advantageous when e and f both represent the number 1. Furthermore, it is particularly advantageous when g and h both represent the number 0.

[0103] If e and f both represent the number 1 and g and h both represent the number 0, the organic silicon compounds according to the invention correspond to the formula (S-IIb) (R 5 O) c (R 6 ) d Si-(A)-[NR 7 -(A')]-Si(R 6 ') d' (OR 5 ') c' (S-IIb).

[0104] The residues A, A', A", A‴, and A''" independently represent a linear or branched, divalent C1-C20 alkylene group. Preferably, the residues A, A', A", A‴, and A''" independently represent a linear, divalent C1-C20 alkylene group. More preferably, the residues A, A', A", A‴, and Aʺʺ independently represent a linear, divalent C1-C6 alkylene group.

[0105] The divalent C 1 -C 20 alkylene group can alternatively also be referred to as a divalent or divalent C 1 -C 20 alkylene group, meaning that each group A, A', A", A‴ and Aʺʺ can form two bonds.

[0106] Particularly preferably, the residues A, A', A", A‴ and A"" independently represent a methylene group (-CH₂-), an ethylene group (-CH₂-CH₂-), a propylene group (-CH₂-CH₂-CH₂-), or a butylene group (-CH₂-CH₂-CH₂-CH₂-). Most preferably, the residues A, A', A", A‴ and A"" represent a propylene group (-CH₂-CH₂-CH₂-).

[0107] If the remainder f represents the number 1, then the organic silicon compound of formula (II) contains a structural grouping -[NR 7 -(A')]-.

[0108] If the remainder h represents the number 1, then the organic silicon compound of formula (II) contains a structural grouping -[NR 8 -(A‴)]-.

[0109] Here, the residues R 7 and R 8 independently represent a hydrogen atom, a C 1 -C 6 alkyl group, a hydroxy-C 1 -C 6 alkyl group, a C 2 -C 6 alkyl group, an amino-C 1 -C 6 alkyl group or a group of the formula (S-III) - (Aʺʺ)-Si(R 6 ") d "(OR 5 ") c " (S-III).

[0110] The residues R 7 and R 8 are particularly preferred to represent, independently of each other, a hydrogen atom, a methyl group, a 2-hydroxyethyl group, a 2-alkenyl group, a 2-aminoethyl group or a grouping of the formula (S-III).

[0111] If the residue f represents the number 1 and the residue h represents the number 0, the organic silicon compound according to the invention contains the group [NR 7 -(A')], but not the group -[NR 8 -(A‴)]. If the residue R7 now represents a group of formula (III), the organic silicon compound comprises 3 reactive silane groups.

[0112] In a further preferred embodiment, a method is characterized in that the agent (a) contains one or more organic C1-C6 alkoxysilanes of formula (S-II) (R5O)c(R6)dSi-(A)e-[NR7-(A')]f-[O-(A")]g-[NR8-(A‴)]h-Si(R6')d'(OR5')c'(II), wherein e and f both represent the number 1, g and h both represent the number 0, A and A' independently represent a linear, divalent C 1 -C 6 -alkylene group and R 7 represents a hydrogen atom, a methyl group, a 2-hydroxyethyl group, a 2-alkenyl group, a 2-aminoethyl group or a grouping of the formula (S-III).

[0113] In a further preferred embodiment, a method is characterized in that agent (a) contains one or more organic C1-C6 alkoxysilanes of formula (S-II), wherein e and f both represent the number 1, g and h both represent the number 0, A and A' independently represent a methylene group (-CH 2 -), an ethylene group (-CH 2 -CH 2 -) or a propylene group (-CH 2 -CH 2 -CH 2 ), and R 7 represents a hydrogen atom, a methyl group, a 2-hydroxyethyl group, a 2-alkenyl group, a 2-aminoethyl group or a grouping of the formula (S-III).

[0114] Suitable organic silicon compounds of formula (S-II) are 3-(Trimethoxysilyl)-N-[3-(trimethoxysilyl)propyl]-1-propanamine 3-(Triethoxysilyl)-N-[3-(triethoxysilyl)propyl]-1-propanamine N-Methyl-3-(trimethoxysilyl)-N-[3-(trimethoxysilyl)propyl]-1-propanamine N-Methyl-3-(triethoxysilyl)-N-[3-(triethoxysilyl)propyl]-1-propanamine 2-[Bis[3-(trimethoxysilyl)propyl]amino]-ethanol 2-[Bis[3-(triethoxysilyl)propyl]amino]-ethanol 3-(Trimethoxysilyl)-N,N-bis[3-(trimethoxysilyl)propyl]-1-propanamine 3-(Triethoxysilyl)-N,N-bis[3-(triethoxysilyl)propyl]-1-propanamine N1,N1-Bis[3-(trimethoxysilyl)propyl]-1,2-ethanediamine, N1,N1-Bis[3-(triethoxysilyl)propyl]-1,2-ethanediamine, N,N-Bis[3-(trimethoxysilyl)propyl]-2-propen-1-amine N,N-Bis[3-(triethoxysilyl)propyl]-2-propen-1-amine

[0115] The aforementioned organic silicon compounds of formula (S-II) are commercially available. Bis(trimethoxysilylpropyl)amine with CAS number 82985-35-1, for example, can be purchased from Sigma-Aldrich.

[0116] Bis[3-(triethoxysilyl)propyl]amine with CAS number 13497-18-2 can be purchased from Sigma-Aldrich, for example.

[0117] N-Methyl-3-(trimethoxysilyl)-N-[3-(trimethoxysilyl)propyl]- 1-propanamine is also alternatively known as Bis(3-trimethoxysilylpropyl)-N-methylamine and can be purchased commercially from Sigma-Aldrich or Fluorochem.

[0118] 3-(Triethoxysilyl)-N,N-bis[3-(triethoxysilyl)propyl]-1-propanamine with CAS number 18784-74-2 can be purchased, for example, from Fluorochem or Sigma-Aldrich.

[0119] In a further preferred embodiment, a method is characterized in that the agent (a) contains one or more organic C1-C6 alkoxysilanes of formula (S-II) selected from the group consisting of 3-(Trimethoxysilyl)-N-[3-(trimethoxysilyl)propyl]-1-propanamin 3-(Triethoxysilyl)-N-[3-(triethoxysilyl)propyl]-1-propanamin N-Methyl-3-(trimethoxysilyl)-N-[3-(trimethoxysilyl)propyl]-1-propanamin N-Methyl-3-(triethoxysilyl)-N-[3-(triethoxysilyl)propyl]-1-propanamin 2-[Bis[3-(trimethoxysilyl)propyl]amino]-ethanol 2-[Bis[3-(triethoxysilyl)propyl]amino]-ethanol 3-(Trimethoxysilyl)-N,N-bis[3-(trimethoxysilyl)propyl]-1-Propanamin 3-(Triethoxysilyl)-N,N-bis[3-(triethoxysilyl)propyl]-1-Propanamin N1,N1-Bis[3-(trimethoxysilyl)propyl]-1,2-Ethanediamin, N1,N1-Bis[3-(triethoxysilyl)propyl]-1,2-Ethanediamin, N,N-Bis[3-(trimethoxysilyl)propyl]-2-Propen-1-amin und / oder N,N-Bis[3-(triethoxysilyl)propyl]-2-Propen-1-amin, und / oder deren Kondensationsprodukten.

[0120] In dyeing experiments, it has also proven to be particularly advantageous if the agent used in the process (a) contains at least one organic C 1 -C 6 -alkoxysilane of formula (S-IV) R 9 Si(OR 10 ) k (R 11 ) m (S-IV).

[0121] The compounds of formula (S-IV) are organic silicon compounds selected from silanes having one, two or three silicon atoms, wherein the organic silicon compound comprises one or more hydrolyzable groups per molecule.

[0122] The organic silicon compounds of formula (S-IV) can also be referred to as silanes of the type of alkyl-C 1 -C 6 -alkoxysilanes, R 9 Si(OR 10 ) k (R 11 ) m (S-IV), wherein R 9 represents a C 1 -C 12 alkyl group, R 10 represents a C 1 -C 6 alkyl group, R 11 represents a C 1 -C 6 alkyl group, k represents an integer from 1 to 3, and m represents the integer 3 - k.

[0123] In a further embodiment, a method is characterized in that the agent (a) contains one or more organic C 1 -C 6 -alkoxysilanes of formula (S-IV), R 9 Si(OR 10 ) k (R 11 ) m (S-IV), wherein R9 represents a C1-C12 alkyl group, R10 represents a C1-C6 alkyl group, R11 represents a C1-C6 alkyl group, k represents an integer from 1 to 3, and m represents the integer 3 - k. and / or their condensation products.

[0124] In the organic C1-C6 alkoxysilanes of formula (S-IV), the group R9 represents a C1-C12 alkyl group. This C1-C12 alkyl group is saturated and can be linear or branched. Preferably, R9 represents a linear C1-C8 alkyl group. More preferably, R9 represents a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, or an n-dodecyl group. Particularly preferably, R9 represents a methyl group, an ethyl group, or an n-octyl group.

[0125] In the alkoxysilanes of formula (S-IV), the R10 group represents a C1-C6 alkyl group. R10 particularly preferably represents a methyl group or an ethyl group.

[0126] In the alkoxysilanes of formula (S-IV), the R 11 group represents a C 1 -C 6 alkyl group. R 11 particularly preferably represents a methyl group or an ethyl group.

[0127] Furthermore, k represents an integer from 1 to 3, and m represents the integer 3 - k. If k represents the number 3, then m equals 0. If k represents the number 2, then m equals 1. If k represents the number 1, then m equals 2.

[0128] The best wash fastness results were achieved when the cosmetic product contained at least one organic C1-C6 alkoxysilane of formula (S-IV), where the residue k represents the number 3. In this case, the residue m represents the number 0.

[0129] Particularly suitable organic silicon compounds of the formula (S-IV) are Methyltrimethoxysilane Methyltriethoxysilane Ethyltrimethoxysilane Ethyltriethoxysilane n-Propyltrimethoxysilane (also known as n-propyltrimethoxysilane) n-Propyltriethoxysilane (also known as propyltriethoxysilane) n-Hexyltrimethoxysilane (also known as hexyltrimethoxysilane) n-Hexyltriethoxysilane (also known as hexyltriethoxysilane) n-Octyltrimethoxysilane (also known as octyltrimethoxysilane) n-Octyltriethoxysilane (also known as octyltriethoxysilane) n-Dodecyltrimethoxysilane (also referred to as dodecyltrimethoxysilane) and / or n-Dodecyltriethoxysilane (also known as dodecyltriethoxysilane) as well as octadecyltrimethoxysilane and / or octadecyltriethoxysilane.

[0130] In a further preferred embodiment, a method is characterized in that the agent (a) contains at least one organic C1-C6 alkoxysilane of formula (S-IV) selected from the group consisting of Methyltrimethoxysilane Methyltriethoxysilane Ethyltrimethoxysilane Ethyltriethoxysilane Propyltrimethoxysilane Propyltriethoxysilane Hexyltrimethoxysilane Hexyltriethoxysilane Octyltrimethoxysilane Octyltriethoxysilane Dodecyltrimethoxysilane, dodecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, their Mixtures and / or their condensation products.

[0131] It has been found that, with regard to staining keratinous material, it is particularly advantageous if the casemic agent contains two structurally different alkoxysilanes.

[0132] In a preferred embodiment, a method is characterized in that the agent (a) contains at least one alkoxysilane of formula (SI) and at least one alkoxysilane of formula (S-IV).

[0133] Examples of the corresponding hydrolysis or condensation products are the following compounds:

[0134] Hydrolysis of C1-C6 alkoxysilane of formula (SI) with water (reaction scheme using 3-aminopropyltriethoxysilane as an example):

[0135] Depending on the amount of water used, the hydrolysis reaction can also occur multiple times per C1-C6-alkoxysilane used: or

[0136] Hydrolysis of C1-C6 alkoxysilane of formula (S-IV) with water (reaction scheme using methyltrimethoxysilane as an example):

[0137] Depending on the amount of water used, the hydrolysis reaction can also occur multiple times per C1-C6-alkoxysilane used: or

[0138] Possible condensation reactions include (shown using the mixture of (3-aminopropyl)triethoxysilane and methyltrimethoxysilane): and / or and / or and / or and / or and / or and / or

[0139] In the above exemplary reaction schemes, the condensation to a dimer is shown in each case, but further condensations to oligomers with several silane atoms are also possible and preferred.

[0140] Both partially hydrolyzed and fully hydrolyzed C1-C6 alkoxysilanes of formula (SI) can participate in these condensation reactions, undergoing condensation with unreacted, partially or fully hydrolyzed C1-C6 alkoxysilanes of formula (SI). In this case, the C1-C6 alkoxysilanes of formula (SI) react with themselves.

[0141] Furthermore, both partially hydrolyzed and fully hydrolyzed C1-C6 alkoxysilanes of formula (SI) can participate in the condensation reactions, undergoing condensation with unreacted, partially or fully hydrolyzed C1-C6 alkoxysilanes of formula (S-IV). In this case, the C1-C6 alkoxysilanes of formula (SI) react with the C1-C6 alkoxysilanes of formula (S-IV).

[0142] Furthermore, both partially hydrolyzed and fully hydrolyzed C1-C6 alkoxysilanes of formula (S-IV) can participate in the condensation reactions, undergoing condensation with unreacted, partially or fully hydrolyzed C1-C6 alkoxysilanes of formula (S-IV). In this case, the C1-C6 alkoxysilanes of formula (S-IV) react with themselves.

[0143] The agent (a) may contain one or more organic C1-C6 alkoxysilanes in varying proportions. These proportions are determined by a person skilled in the art depending on the desired application. In the case of coloring keratinous material, for example, the amount may depend on the thickness of the silane coating on the keratinous material and on the quantity of keratinous material to be treated.

[0144] Particularly stable compositions (a) with very good staining results when applied to keratinous material could be obtained when the cosmetic composition - based on its total weight - contains one or more organic C 1 -C 6 -alkoxysilanes and / or the condensation products thereof in a total amount of 30 to 85 wt.%, preferably 35 to 80 wt.%, more preferably 40 to 75 wt.%, even more preferably 45 to 70 wt.% and most preferably 50 to 65 wt.%.

[0145] It may be preferred that the ready-to-use agent (a) contains, in addition to the pigment suspension according to the invention and the organic C 1 -C 6 -alkoxysilane(s), further ingredients.

[0146] The cosmetic product contains alkoxysilanes, a class of highly reactive compounds that can undergo hydrolysis, oligomerization, and / or polymerization during use. To avoid premature oligomerization or polymerization, it can be significantly advantageous for the user to prepare the ready-to-use cosmetic product only shortly before application.

[0147] To avoid premature oligomerization or polymerization, it is of significant advantage to the user to prepare the ready-to-use agent (a) only shortly before application.

[0148] For example, the user can mix or shake an agent (a') containing the alkoxysilanes (a1) with an agent (a") comprising the pigment suspension according to the invention. This mixture of (a') and (a") can be applied to the keratinous materials either directly after preparation or after a short reaction time of 10 seconds to 20 minutes. The user can then apply agent (b).

[0149] The process for staining keratinous material comprises, in addition to the application of agent (a), the application of agent (b). Agent (b) is characterized in that it contains at least one sealing reagent (b1).

[0150] Agent (b) is a post-treatment agent, and its application to the keratinous material treated with agent (a) results in the colorations obtained in the process being more durable. In particular, the wash fastness and rub fastness of the colorations obtained in the process can be improved by applying agent (b).

[0151] It is preferred that the sealing reagent (b1) comprises a compound selected from the group consisting of film-forming polymers, alkalizing agents, acidifying agents and mixtures thereof.

[0152] In the case that the agent (b) contains the pigment suspension according to the invention, it may also be preferred to produce the ready-to-use agent (b) by mixing two agents (b') and (a"). In this embodiment, the agent (b') contains the sealing reagent (b1) and the agent (a") contains the pigment suspension.

[0153] To increase user convenience, all necessary resources are preferably provided to the user in the form of a multi-component packaging unit (kit-of-parts).

[0154] A third object of the present invention is therefore a multi-component packaging unit (kit-of-parts) for dyeing keratinous material, comprising separately assembled components. a first container with an agent (a') wherein the agent (a') contains: (a1) at least one or more organic C 1 -C 6 -alkoxysilanes, a second container with an agent (a") wherein the agent (a") contains: (a2) a pigment suspension according to the invention, and a third container with an agent (b') wherein the agent (b') contains: (b1) a sealing reagent.

[0155] Regarding other preferred embodiments of the multi-component packaging unit (kit-of-parts), what has been said about the pigment suspensions and / or methods applies mutatis mutandis. Example 1

[0156] The following formulations were produced (unless otherwise stated, all values ​​are in wt% active substance) Means (a)

[0157] Means (a) % by weight (3-Aminopropyl)triethoxysilane 20 Methyltriethoxysilane 70 Water ad 100 Medium (b') % by weight Ethylene / Sodium Acrylate Copolymer (b1) (25% solution) 15 Water ad 100 Pigment suspension % by weight Timiron SynWhite Satin (ex Merck) 45 1,2-Propanol 12 2-Propanol 30 Hydroxypropylmethylcellulose 1 Water ad 100

[0158] The ready-to-use agent (b) was prepared by mixing 60 g of the agent (b') and 40 g of the pigment suspension.

[0159] The product (a) was massaged into a strand of hair (Kerling, Euronaturhaar white) and left to act for 1 minute. Afterwards, the product (a) was rinsed out with water.

[0160] Subsequently, the agent (b) was applied to the strand of hair, left to act for 5 minutes and then rinsed out with water.

Claims

1. Pigment suspension comprising a) at least one coloring compound from the group of pigments, wherein the pigment comprises a substrate platelet of natural mica or synthetic mica, b) at least one C1-C10 alcohol, c) at least one diol selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol and mixtures thereof, d) at least one thickening agent, and e) water.

2. Pigment suspension according to claim 1, characterized in that the pigment comprises a substrate platelet of synthetic mica (INCI: Synthetic Fluorphlogopite).

3. Pigment suspension according to claim 1 or 2, characterized in that the at least one C1-C10 alcohol is selected from the group consisting of ethanol, 2-propanol, and mixtures thereof.

4. Pigment suspension according to any one of claims 1 to 3, characterized in that the at least one thickening agent is selected from the group consisting of propyl cellulose, methyl ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, carboxymethyl hydroxyethylcellulose, sulfoethylcellulose, carboxymethyl sulfoethylcellulose, hydroxypropyl sulfoethylcellulose, hydroxyethyl sulfoethylcellulose, methylethyl hydroxyethylcellulose, methyl sulfoethylcellulose, ethyl sulfoethylcellulose and mixtures thereof.

5. A method for coloring keratinous material, in particular human hair, comprising the following steps: - Applying an agent (a) to the keratinous material, wherein the agent (a) contains: (a1) at least one organic C1-C6 alkoxysilane, and - applying an agent (b) to the keratinous material, wherein the agent (b) comprises: (b1) at least one sealing reagent, wherein at least one of the agents (a) and (b) further comprises a pigment suspension according to any one of claims 1 to 4.

6. A method for coloring keratinous material according to claim 4, characterized in that agent (a) contains one or more organic C1-C6 alkoxysilanes of formula (S-I) and / or (S-II) and / or (S-IV),         R1R2N-L-Si(OR3)a(R4)b     (S-I) where - R1, R2 independently represent a hydrogen atom or a C1-C6 alkyl group, - L represents a linear or branched, divalent C1-C20 alkylene group, - R3, R4 independently represent a C1-C6 alkyl group, - a represents an integer from 1 to 3, and - b represents the integer 3 - a, and         (R50)c(R6)dSi-(A)e-[NR7-(A')]f-[O-(A")]g-[NR8-(A‴)]h-Si(R6')d'(OR5')c'     (S-II), wherein - R5, R5', R5", R6, R6' and R6'' independently represent a C1-C6 alkyl group, - A, A', A", A‴ and Aʺʺ independently represent a linear or branched, divalent C1-C20 alkylene group, - R7 and R8 independently represent a hydrogen atom, a C1-C6 alkyl group, a hydroxy-C1-C6 alkyl group, a C2-C6 alkenyl group, an amino-C1-C6 alkyl group or a group of formula (S-III),         - (Aʺʺ)-Si(R6'')d''(OR5'')c''     (S-III), - c is an integer from 1 to 3, - d is the integer 3 - c, - c' is an integer from 1 to 3, - d' is the integer 3 - c', - c'' is an integer from 1 to 3, - d'' is the integer 3 - c", - e is 0 or 1, - f is 0 or 1, - g is 0 or 1, - h stands for 0 or 1, - with the proviso that at least one of the radicals e, f, g and h is different from 0, and / or         R9Si(OR10)k(R11)m     (S-IV), where - R9 represents a C1-C12 alkyl group, - R10 represents a C1-C6 alkyl group, - R11 represents a C1-C6 alkyl group - k represents an integer from 1 to 3, and - m represents the integer 3 - k.

7. A method for coloring keratinous material according to claim 5 or 6, characterized in that the agent (a) contains at least two structurally different organic C1-C6 alkoxysilanes.

8. Multi-component packaging unit (kit of parts) for dyeing keratinous material, comprising, packaged separately from each other - a first container with an agent (a'), wherein the agent (a') contains: (a1) at least one or more organic C1-C6 alkoxysilanes, - a second container with an agent (a"), wherein the agent (a") contains: (a2) a pigment suspension according to one of claims 1 to 4, and - a third container with an agent (b"), wherein the agent (b") contains: (b1) a sealing reagent.