A method for dyeing keratinous fibres, in particular human hair

Abstract

A process for dyeing keratinous fibres, in particular human hair, comprises the following steps in the order given: (1) application of an agent (a) to the keratinous fibres; (2) application of an agen

Description

[01] The subject of the present application is a method for dyeing keratinous fibres, in particular human hair, which comprises the use of two agents (a) and (b). Agent (a) is low in water or anhydrous and is characterized by its content of at least one organic silicon compound of the formula (I) and a pigment. Agent (a) is first applied to the keratin fibres or the hair. The water-containing agent (b) is then applied to the keratin fibres or hairs that are still exposed to the agent (a), whereby the water contained in the agent (b) leads to a targeted hydrolysis of the silicon compounds on contact with agent (a). Agent (b) contains water (b1), polyethylene glycol(s) (b2) and Cs-Csofatty alcohol(s) (b3), each in specific quantity ranges. After allowing both agents (a) and (b) to take effect, they are then rinsed out together.

[02] The change in shape and colour of keratin fibres, especially hair, is an important area of modern cosmetics. To change the hair colour, the expert knows various colouring systems depending on colouring requirements. Oxidation dyes are usually used for permanent, intensive dyeing with good fastness properties and good grey coverage. Such dyes usually contain oxidation dye precursors, so-called developer components and coupler components, which form the actual dyes with one another under the influence of oxidizing agents, such as hydrogen peroxide. Oxidation dyes are characterized by very long-lasting dyeing results.

[03] When direct dyes are used, ready-made dyes diffuse from the colorant into the hair fibre. Compared to oxidative hair dyeing, the dyeing obtained with direct dyes have a shorter shelf life and quicker washability. Colourings with direct dyes usually remain on the hair for a period of between 5 and 20 washes.

[04] The use of colour pigments is known for short-term colour changes on the hair and / or skin. Colour pigments are generally understood to be insoluble, colouring substances. These are present undissolved in the dye formulation in the form of small particles and are only deposited from the outside on the hair fibres and / or the skin surface. Therefore, they can usually be removed without residue by a few washes with surfactant-containing cleaning agents. Various products of this type are available on the market under the name hair mascara.

[05] EP 2168633 B1 deals with the task of producing long-lasting hair colorations using pigments. The script teaches that when the combination of a pigment, an organic silicon compound, a filmforming polymer and a solvent is used on hair, it is possible to produce colorations that are particularly resistant to abrasion and / or shampooing.

[06] The great advantage of the alkoxy silanes used in EP 2168633 B1 is that the high reactivity of this class of compounds enables very fast coating. This means that extremely good colouring results can be achieved after very short application periods of just a few minutes. In addition to these advantages, however, the high reactivity of alkoxy silanes also has some disadvantages.

[07] The organic silicon compounds used in the dyes are highly reactive compounds that undergo hydrolysis, oligomerization and / or polymerization in the presence of water. It is important to adjust the speed of oligomerization or polymerization in such a way that the dye can be applied within a period of time that is acceptable to the user.

[08] Due to their high reactivity, the organic alkoxy silanes cannot be prepared together with larger amounts of water, as a large excess of water initiates immediate hydrolysis and subsequent polymerisation. The polymerisation that takes place during storage of the alkoxy silanes in aqueous medium manifests itself in a thickening or gelation of the aqueous preparation. As a result, the preparations become so highly viscous, gel-like or gelatinous that they can no longer be applied evenly to the keratin fibres. In addition, the storage of alkoxy silanes in the presence of large amounts of water is associated with a loss of their reactivity, so that the formation of a resistant and uniform coating on the keratin fibres is no longer possible. However, the formation of a uniform coating is particularly important in dyeing processes.

[09] For these reasons, it is necessary to store the organic alkoxy silanes in a water-free or waterpoor environment and to prepare the corresponding preparations in a separate container. The low-water preparations containing the alkoxy silanes can also be referred to as “silane blend”.

[10] For application to the keratin fibres, the user must now convert this silane blend into a watercontaining ready-to-use mixture so that the formation of the coating is initiated.

[11] If the silane blend is mixed with a water-containing carrier formulation before application to the hair, the oligomerization or polymerization of the silanes begins directly on contact with the water in the application mixture, which is not yet on the hair at this point. With this procedure, the colour result depends heavily on the skill of the user and the speed with which he applies the application mixture to the hair. As a result - especially with slow application, inexperienced first-time users or large areas of hair to be dyed - the hair can be dyed very unevenly or insufficiently in certain areas.

[12] This problem was addressed in WO 2023 / 025452 A1. Two different dyeing processes were compared in this paper. In the first dyeing process, the low-water silane blend was first mixed with an aqueous gel before being applied to hair. This application mixture was then applied to strands of hair. In the second method, the silane blend was first applied to strands of hair, and mixing with the aqueous gel was carried out directly on the hair strand by applying the gel to the hair still covered with the silane blend. An assessment of the staining results obtained using both methods revealed a very uneven colouring in the first case and a much more uniform and reproducible colouring when the application mixture was produced on head.

[13] Even though the dyeing process described in WO 2023 / 025452 A1 has greatly improved the reproducibility and uniformity of dyeing with pigments and reactive silanes in this way, this process still has some disadvantages.

[14] In the work of WO 2023 / 025452 A1, a solvent such as polyethylene glycol was used as the cosmetic carrier of the blend. Polyethylene glycol served as a water substitute, but was also responsible for thickening the silane blend. The polyethylene glycol was used to adjust the viscosity of the silane blend so that it was thin enough to be evenly distributed on the hair, but also thick enough to prevent the product from dripping during application time.

[15] However, when this silane blend was mixed with an aqueous gel on the hair, the thickening of the formulation broke down and the water-rich application mixture dripped off the subject’s head in an unfavourable manner during the application period. This is highly undesirable for the user. It was therefore the task of the present invention to find a dyeing process which, on the basis of pigments and reactive Ci-Ce alkoxy silanes, produces intensive, uniform and reproducible dyeing with good fastness to washing. The process should allow the formation of a coloured film that results in a uniform coloration all over the user’s head, regardless of the application conditions and the time required for coloration. The silane blend used in the process should be easy to apply and, especially when mixed with a water-based formulation, should not become runny or drip from the hair.

[16] Surprisingly, it has now been found that this task can be solved if keratinous fibres are dyed using the process described below.

[17] A first object of the present invention is a method for dyeing keratinous fibres, in particular human hair, comprising the following steps in the order given: (1) Application of an agent (a) to the keratinous fibres, wherein the agent (a) contains -based on the total weight of agent (a): (a1) less than 10% by weight of water, and (a2) at least one organic silicon compound of the formula (I) RiR2N-L-Si(OR3)a(R4)b (I), where Ri, R2 independently represent a hydrogen atom or a Ci-Ce alkyl group, - L is a linear or branched divalent Ci-C2o alkylene group, - R3 represents a hydrogen atom or a Ci-Ce alkyl group, - R4 represents a Ci-Ce alkyl group, - a, represents an integer from 1 to 3, and - b represents the integer 3 - a, and (a3) at least one pigment, (2) Application of an agent (b) to the keratinous fibres which are still coated with agent (a), the agent (b) containing, based on the total weight of the agent (b) (b 1) 19.0 to 70.0% by weight water, and (b2) 20.0 to 80,0% by weight polyethylene glycol(s), and (b3) 1.0 to 10.0% by weight of Cs-Cso fatty alcohol(s), (3) Allowing both agents (a) and (b) to act on the keratinous fibres, and (4) Rinse out both agents (a) and (b).

[18] It has been shown that when this new method is applied to human hair, a reproducible and uniform colour result can be obtained, which is also characterized by intense colour intensities and very good fastness. The colour result was not dependent on the time the user needed for colouring. In particular, there was no liquefaction of the application mixture when the two agents (a) and (b) were mixed on the hair, so that the application mixture remained on the hair and did not drip down.

[19] Keratin fibres

[20] Keratin fibres are hair, wool and fur. Preferably, keratin fibres are understood to be human hair.

[21] Dyeing keratinous fibres

[22] The term “method for dyeing keratinous fibres” in the context of the present invention refers to all those dyeing methods in which a dyed film is produced on the keratin material. The coloration of the film is caused by the pigments that are deposited on the surface of the keratin fibres and incorporated into the film formed by the silanes.

[23] In the method described, agents (a) and (b) are applied successively to the keratin fibres, in particular to human hair. Agents (a) and (b) are ready-to-use agents, i.e. the agents can be applied to the hair in the form in which they are available. The application mixture of (a) and (b) is prepared by mixing directly on the keratin fibres or hairs.

[24] Step (1). application of agent (a) to the keratinous fibres

[25] In step (1) of the method according to the invention, agent (a) is applied to the keratinous fibres, in particular the human hair.

[26] The agent (a) is applied, for example, by spreading or distributing and massaging the agent (a) onto the keratinous fibres (or hair) using a gloved hand, a brush, an applicator bottle or an applicette. The keratin fibres or the hair are preferably towel-dried or dry at this point.

[27] Dry keratin fibres, especially dry hair, are fibres that have not undergone any additional treatment directly before the dyeing process (i.e. up to three hours before the dyeing process) and have not been moistened with water or with water / shampoo.

[28] Towel-dried keratin fibres, in particular towel-dried hair, are fibres / hair that have been wetted orwashed with water within a maximum of 30 minutes, preferably 15 minutes, before the start ofthe dyeing process and then rubbed dry with a towel for approx. 30 seconds.

[29] Example: The user wets their hair completely under the tap by soaking it completely with water at a temperature of approx. 35°C under running water. He then dries the hair for 30 seconds with a dry towel.

[30] Towel-dried hair is characterized by the fact that it is no longer dripping wet, i.e. there is no longer any significant amount of water on the surface ofthe hair. Nevertheless, the hair still has residual moisture due to the water molecules present within the hair fibres, which causes the hair fibres to swell. The application of agent (a) on towel-dried keratin fibres, in particular towel-dried hair, is particularly preferred. The small amount of water present in towel-dried hair makes it easier to apply and spread the product (a), but without too much water initiating any significant oligomerization or polymerization.

[31] In a further embodiment, a method according to the invention is characterized in that agent (a) is applied in step (1) to towel-dried or dry keratinous fibres.

[32] In a further embodiment, a method according to the invention is characterized in that agent (a) is applied in step (1) to towel-dried or dry human hair, most preferably to towel-dried human hair.

[33] After application to the keratin fibres or hair, product (a) can be massaged in. Massaging in can be done by mechanically rubbing the hair with a gloved hand, for example.

[34] Agent (a)

[35] Agent (a) is a ready-to-use agent. It is characterized in that it contains - based on the total weight of agent (a) - less than 10% by weight of water (a 1), and contains at least one organic silicon compound (a2) ofthe formula (I) and at least one pigment (a3).

[36] Water content (a1) in agent (a)

[37] Based on the total weight of agent (a), it contains less than 10% water by weight. This ensures that agent (a) remains stable over the entire application period and that premature, undesirable oligomerization or polymerization ofthe silanes can be sufficiently avoided. Even if the stability ofthe agent can already be ensured at a water content of up to 10% by weight, it has proven to be preferable to adjust the water content of agent (a) to a value below 10% by weight in order to further optimize the stability and colour intensities. Therefore, particularly good results were obtained when the water content in agent (a) - based on the total weight of agent (a) - was 0 to 7.5% by weight, preferably 0.0 to 5.0% by weight, more preferably 0.0 to 4.0% by weight and most preferably 0 to 2.5% by weight.

[38] In a further particularly preferred embodiment, a method according to the invention is characterised in that agent (a) - based on the total weight of agent (a) - contains water (a 1) from 0 to 7.5% by weight, preferably from 0.01 to 5.0% by weight, more preferably from 0.01 to 4.0% by weight and most preferably from 0.05 to 2.5% by weight.

[39] The range of 0 to 7.5% water by weight means that the composition contains as little water as possible or that the amount of water which may be introduced into agent (a) by other ingredients contained in agent (a) does not exceed 7.5% by weight. r401Qrqanic silicon compounds (a2) of the formula (I) in agent (a)

[41] As the second essential ingredient (a2) of the invention, agent (a) contains at least one organic silicon compound of the formula (I).

[42] The organic silicon compounds of formula (I) are silanes. According to IUPAC rules, the term silane stands for a group of chemical compounds based on a silicon skeleton and hydrogen. In organic silanes, the hydrogen atoms are completely or partially replaced by organic groups such as (substituted) alkyl groups and / or alkoxy groups. In organic silanes, some of the hydrogen atoms may also be replaced by hydroxy groups.

[43] For the silanes of formula (I) RiR2N-L-Si(OR3)a(R4)b (I), - Ri, R2 independently of one another represent a hydrogen atom or a Ci-Ce alkyl group, - L represents a linear or branched, divalentCi-C2o alkylene group, - R3 represents a hydrogen atom or a Ci-Ce alkyl group, - R4 represents a Ci-Ce alkyl group, - a, represents an integer from 1 to 3, and - b represents the integer 3 - a.

[44] The substituents Ri, R2, R3, R4 and L in the compounds of formula (I) and (II) are explained by way of example below:

[45] Examples of a Ci-Ce 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 radicals. Examples of a C2-Ce alkenyl group are vinyl, allyl, but-2-enyl, but-3-enyl and isobutenyl, preferred C2-Ce alkenyl radicals are vinyl and allyl. Examples of a linear divalent Ci-C2o alkylene group include 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 C atoms, divalent alkylene groups may also be branched. Examples of branched divalent, bivalent Cs-C2o alkylene groups are (-CH2-CH(CH3)-) and (-CH2-CH(CH3)-CH2-).

[46] In the organic silicon compounds of the formula (I)

[47] RiR2N-L-Si(OR3)a(R4)b (I),

[48] the radicals Ri and R2 independently of one another represent a hydrogen atom or a Ci-Ce alkyl group. Particularly preferably, radicals Ri and R2 both represent a hydrogen atom.

[49] In the middle part of the organic silicon compound is the structural unit or the linker -L-which stands for a linear or branched, divalent C1-C20 alkylene group.

[50] A divalent C1-C20 alkylene group can alternatively also be referred to as a divalent C1-C20 alkylene group, which means that each grouping L can form two bonds. One bond is from the amino group R1R2N to the linker L, and the second bond is between the linker L and the silicon atom.

[51] Preferably, -L- represents a linear, divalent C1-C20 alkylene group. Further preferably -L- stands for a linear bivalent Ci-Ce alkylene group. Particularly preferred -L stands for a methylene group (-CH2-), an ethylene group (-CH2-CH2-), a propylene group (-CH2-CH2-CH2-) or a butylene group (-CH2-CH2-CH2-CH2-). In particular, L stands for a propylene group (-CH2-CH2-CH2-)

[52] The linear propylene group (-CH2-CH2-CH2-) can alternatively be referred to as the propane-1,3-diyl group.

[53] The organic silicon compounds of formula (I)

[54] RiR2N-L-Si(OR3)a(R4)b (I),

[55] one end of each carries the silicon-containing group -Si(OR3)a(R4)b

[56] In the terminal structural unit -Si(OR3)a(R4)b, radical R3 represents a hydrogen or a Ci-Ce alkyl group, and radical R4 represents a Ci-Ce alkyl group. Particularly preferably, R3 and R4 represent independently of one another a methyl group or an ethyl group.

[57] Here a represents an integer from 1 to 3, and b represents the integer 3 - a. If a represents the number 3, then b is equal to 0. If a represents the number 2, then b is equal to 1. If a represents the number 1, then b is equal to 2.

[58] If the index number a represents number 2 or 3, several OR3 units are present in the silane molecule of formula (I). In this case, the radical R3 in each of the OR3 units can be selected independently of the other OR3 units. For example, if a represents the number 3, the silane molecule comprises three OR3 units, ofwhich one unit may represent a hydroxyl group and two units an ethoxy group.

[59] Particularly resistant films could be produced if agent (a) contains at least one organic silicon compound (a2) of formula (I) in which the radicals R3, R4 independently of one another represent a methyl group or an ethyl group.

[60] When using the method for colouring human hair, colourings with the best washabilities could be obtained if agent (a) contains at least one organic silicon compound (a2) of formula (I) in which the radicals R3, R4 independently of one another represent a methyl group or an ethyl group.

[61] Furthermore, dyeings with the best washabilities could be obtained if agent (a) contains at least one organic silicon compound of formula (I) in which radical a represents the number 3. In this case radial b represents the number 0.

[62] In a further preferred embodiment, agent (a) used in the method is characterized in that it comprises at least one organic silicon compound (a2) of formula (I), wherein R3 represents a hydrogen atom, a methyl group or an ethyl group, and R4 represents a methyl group or an ethyl group, and a represents the number 3, and b represents the number 0.

[63] In a further preferred embodiment, a method according to the invention is characterized in that agent (a) comprises at least one organic silicon compound (a2) of the formula (I), RiR2N-L-Si(OR3)a(R4)b (I), where - Ri, R2 both represent a hydrogen atom, and - L represents a linear, divalent Ci-Ce alkylene group, preferably a propylene group (-CH2-CH2-CH2-) or an ethylene group (-CH2-CH2-), - R3 represents a hydrogen atom, 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.

[64] Organic silicon compounds of formula (I) which are particularly suitable for solving the problem according to the invention are - (3-Aminopropyl)triethoxysilane - (3-Aminopropyl)trimethoxysilane - 1-(3-Aminopropyl)silanetriol - (2-Aminoethyl)triethoxysilane - (2-Aminoethyl)trimethoxysilane 1-(2-Aminoethyl)silanetriol - (3-Dimethylaminopropyl)triethoxysilane - (2-Dimethylaminoethyl)triethoxysilane. 1 -(2-Dimethy laminoethyl)silanetriol

[65] In a further preferred embodiment, a method is characterised in that agent (a) comprises at least one organic silicon compound (a2) of the formula (I) which is selected from the group consisting of - (3-Aminopropyl)triethoxysilane - (3-Aminopropyl)trimethoxysilane - 1-(3-Aminopropyl)silanetriol - (2-Aminoethyl)triethoxysilane - (2-Aminoethyl)trimethoxysilane - 1-(2-Aminoethyl)silanetriol - (3-Dimethylaminopropyl)triethoxysilane - (3-Dimethylaminopropyl)trimethoxysilane - 1-(3-Dimethylaminopropyl)silanetriol - (2-Dimethylaminoethyl)triethoxysilane. - (2-dimethylaminoethyl)trimethoxysilane and / or - 1-(2-Dimethylaminoethyl)silanetriol.

[66] The aforementioned organic silicon compounds of formula (I) are commercially available.

[67] (3-aminopropyl)trimethoxysilane, for example, can be purchased from Sigma-Aldrich. Also (3-aminopropyl)triethoxysilane is commercially available from Sigma-Aldrich.

[68] In further colouring tests, it proved to be particularly advantageous if agent (a) used in the method additionally contained at least one organic silicon compound (a2) of formula (II) R5Si(OR6)k(R7)m (II).

[69] The organic silicon compound(s) of formula (II) may also be referred to as silanes of the alkylalkoxysilane or alkylhydroxysilane type, R5Si(OR6)k(R7)m (II), where - Rs represents a C1-C18 alkyl group, - Re represents a hydrogen atom or a Ci-Ce alkyl group, - R7 represents a Ci-Ce alkyl group - k represents an integer from 1 to 3, and - m represents the integer 3 - k.

[70] In a further preferred embodiment, a method according to the invention is characterised in that agent (a) additionally contains at least one organic silicon compound (a2) of formula (II) R5Si(OR6)k(R7)m (II), where - Rs represents a C1-C18 alkyl group, - Re represents a hydrogen atom or a Ci-Ce alkyl group, - R7 represents a Ci-Ce alkyl group - k represents an integer from 1 to 3, and - m represents the integer 3 - k.

[71] In the organic silicon compounds of formula (II), radical Rs represents a C1-C18 alkyl group. This C1-C18 alkyl group is saturated and can be linear or branched. Preferably, Rs represents a linear C1-C18 alkyl group. Preferably, Rs 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, an n-dodecyl group or an n-octadecyl group. Particularly preferably, Rs represents a methyl group, an ethyl group, an n-hexyl group or an n-octyl group.

[72] In the organic silicon compounds of form (II), radical Re represents a hydrogen atom or a Ci-Ce alkyl group. Especially preferably, Re represents a methyl group or an ethyl group.

[73] If the index number k stands for the number 2 or 3, several ORe units are present in the silane molecule of formula (II). In this case, radical Re in each of the ORe units can be selected independently of the other ORe units. For example, if k stands forthe number 3, the silane molecule comprises three ORe units, of which one unit may be a hydroxyl group and two units an ethoxy group.

[74] In the organic silicon compounds of form (II), radical R7 represents a Ci-Ce alkyl group. Particularly preferably, R7 represents a methyl group or an ethyl group.

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

[76] Particularly stable films, i.e. colourings with particularly good washabilities, could be obtained if an agent (a) was used in the method which, in addition to the silane(s) (a2) of formula (I), contained at least one organic silicon compound of formula (II) in which radical k represents the number 3. In this case, radical m represents the number 0.

[77] Organic silicon compounds of formula (II) which are particularly suitable for solving the problem according to the invention are - Methyltrimethoxysilane - Methyltriethoxysilane - Ethyltrimethoxysilane - n-Hexyltrimethoxysilane - n-Hexyltriethoxysilane - n-Octyltriethoxysilane - n-dodecyltriethoxysilane. n-octadecyltrimethoxysilane and / or n-octadecyltriethoxysilane.

[78] In a further preferred embodiment, a method according to the invention is characterised in that agent (a) additionally comprises at least one organic silicon compound of formula (II) selected from the group consisting of - Methyltrimethoxysilane - Methyltriethoxysilane - Ethyltrimethoxysilane - Ethyltriethoxysilane - Propyltrimethoxysilane - Propyltriethoxysilane - Hexyltrimethoxysilane - Hexyltriethoxysilane - Octyltrimethoxysilane - Octyltriethoxysilane - Dodecyltrimethoxysilane, - Dodecyltriethoxysilane, - Octadecyltrimethoxysilane und - Octadecyltriethoxysilane.

[79] The organic silicon compounds described above are reactive compounds. In this context, it has been found to be preferable if agent (a) - based on the total weight of agent (a) - contained one or more organic silicon compounds of formula (I) in a total amount of 0.1 to 20% by weight, preferably from 1 to 15% by weight and particularly preferably from 2 to 10% by weight.

[80] When silanes of formulae (I) and (II) were used together in agent (a), it was advantageous if agent (a) - based on the total weight of agent (a) - contained one or more organic silicon compounds of formulae (I) and (II) in a total amount of from 0.1 to 20% by weight, preferably from 1 to 15% by weight and particularly preferably from 2 to 10% by weight.

[81] In a further particularly preferred embodiment, a method according to the invention is characterised in that agent (a) contains - based on the total weight of agent (a) - one or more organic silicon compounds of formula (I) or one or more organic silicon compounds of formulae (I) and (II) in a total amount of from 0.1 to 20% by weight, preferably from 1 to 15% by weight and particularly preferably from 2 to 10% by weight.

[82] In an explicitly particularly preferred embodiment, a method is characterised in that agent (a) is applied to the keratinous fibres which contains at least one organic silicon compound of formula (I) which is selected from the group consisting of (3-aminopropyl)triethoxysilane and (3-aminopropyl)trimethoxysilane, and additionally comprises at least one organic silicon compound of formula (II) selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, hexyltrimethoxysilane and hexyltriethoxysilane.

[83] In a further preferred embodiment, a method is characterized in that the agent (a) comprises - based on the total weight of the agent (a): - 0.5 to 5% by weight of at least one first organic silicon compound (a2) of formula (I), which is selected from the group consisting of (3-aminopropyl)trimethoxysilane, (3-aminopropyl)triethoxysilane, (2-aminoethyl)trimethoxysilane (2-aminoethyl)trimethoxysilane, (3-dimethylaminopropyl)trimethoxysilane, (3-dimethylaminopropyl)trimethoxysilane, (2-dimethylaminoethyl)trimethoxysilane and (2-dimethylaminoethyl)trimethoxysilane, and - 3.2 to 10% by weight of at least one second organic silicon compound of formula (II) selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, octadecyltrimethoxysilane and octadecyltriethoxysilane.

[84] Oligomers and / or condensation products of orqanosilicon compounds (a2)

[85] In the case of the organic silicon compounds or silanes of formulae (I) and (II) described above, the addition of even small amounts of water leads to hydrolysis or oligomerization and / or polymerization. The extent of oligomerization or polymerization depends on the amount of water that comes into contact with the silane(s) of formulae (I) or (II). The aim of the method according to the invention is that the formation of the coloured film, i.e. the final polymerization starting from the silanes (a2), only takes place in step (2) of the method when agent (a) is already on the keratin fibres. Nevertheless, due to the high reactivity of the silanes (a2), oligomerization or pre-condensation may have already taken place prior to application of agent (a), and the silanes (a2) may already be oligomerized or, in small proportions, polymerized in agent (a).

[86] For this reason, both the silanes of formulae (I) or (II) and their oligomers and / or condensation products may be contained in agent (a). According to the invention, the term “silanes of formulae (I) or (II)” therefore also includes their hydrolysis products, oligomers and / or their condensation products.

[87] The corresponding hydrolysis, oligomers and / or condensation products are, for example, the following compounds. Here, the condensation products represent maximally oligomeric compounds, but not polymers.

[88] Hydrolysis of Ci-Ce alkoxy silane of formula (I) with water (reaction scheme using 3-aminopropyltriethoxysilane as an example): OEt OEt I                                                                                                                                                                                                                                           I QEt + H2O ----► H2N^X^X^ / Si—OH + Et0H OEt OEt

[89] Depending on the amount of water used, the hydrolysis reaction can also take place several times per Ci-Ce alkoxy silane used: OEt I H2N. / Si—OEt + OEt 2 H2O OH I 5i—I I OEt + 2 EtOH OEt I HzN^^ / X^^xSi—OEt + 3 h2° OEt OH I 3i— I OH + 3 EtOH

[90] Hydrolysis of Ci-Ce alkoxy silane of formula (II) with water (reaction scheme using methyltrimethoxysilane as an example): OMe OMe I                                                                                                                                                                                             | CH3—Si—OMe + H2O -----► CH Si_OH + Me0H I                                                                                                                                                                                             I OMe OMe

[91] Depending on the amount of water used, the hydrolysis reaction can also take place several times per Ci-Ce alkoxy silane used: OMe I CH3—Si—OMe + 2 H2O -----► I OMe or OMe I CH3—Si—OMe + 3 H2O -----► I OMe OH I CH3—Si—OH + 2 MeOH OMe OH I CH3—Si—OH OH + 3 MeOH

[92] Possible condensation reactions include (shown using the mixture (3- aminopropyl)triethoxysilane and methyltrimethoxysilane): OEt I OH OEt OEt Si—OEt OEt and / or OEt OEt OEt OEt h2n. •Si—OH + H2N •Si—OH OEt OEt OEt—Si—O—Si—OEt H2O NH2 NH2 and / or OEt OH OEt OEt H2N Si—OH + H2N ■Si—OH OEt OEt OEt—Si—O—Si—OEt EtOH NH2 NH2 and / or OEt OMe OEt OMe H2N Si—OH --Si—OMe OEt—Si—O—Si—OMe OEt OMe NH2 MeOH and / or OEt OMe OEt OMe H2N •Si—OH --Si—OH OEt—Si—O—Si—OMe OEt OMe H2O NH2 and / or OEt OMe OH OMe h2n Si—OH --Si—OH EtO—Si—O—Si—OMe OEt OMe NH2 EtOH and / or OMe OMe OMe OMe —Si—OH --Si—OMe MeO—Si—O—Si—OMe MeOH OMe OMe

[93] 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 also preferred.

[94] A condensation product is understood to be a product formed by the reaction of at least two organic silicon compounds each having at least one hydroxyl group or hydrolysable group per molecule with elimination of water and / or with elimination of an alkanol. The condensation products can be, for example, dimers, but also trimers or oligomers, with the condensation products being in equilibrium with the monomers. Depending on the amount of water used or consumed in the hydrolysis, the equilibrium shifts from monomeric organic silicon compounds to condensation product.

[95] Particularly good results were obtained when organic silicon compounds of the formulae (I) and (II) were used in the method. Since, as already described above, hydrolysis / condensation already occurs at traces of moisture, the hydrolysis and / or condensation products of the organic silicon compounds (I) and (II) are also included in this embodiment.

[96] Pigments (a3) in agent (a)

[97] As a third component essential to the invention, agent (a) contains at least pigment. During the formation of the film resulting from the polymerization of the silanes (a2), the pigments are embedded in the film and therefore fixed to the surface of the keratin fibres.

[98] Pigments within the meaning of the present invention are understood to be colouring compounds which have a solubility in water at 25°C of less than 0.5g / L, preferably less than 0.1g / L, still more preferably less than 0.05g / L. Water solubility can be determined, for example, by the method described below: 0.5g of the pigment is weighed in a beaker. A magnetic stir bar is added. Then one litre 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 0.5g / L. If the pigment-water mixture cannot be assessed visually due to the high intensity of the possibly finely dispersed pigment, the mixture is filtered. If a proportion of undissolved pigments remains on the filter paper, the solubility of the pigment is below 0.5g / L.

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

[100] In a preferred embodiment, a method is characterised in that agent (a) contains at least one pigment (a3) from the group of inorganic and / or organic pigments.

[101] Preferred pigments are selected from synthetic or natural inorganic pigments. Inorganic pigments of natural origin can be produced, for example, from chalk, ochre, umber, green earth, fired Terra di Siena or graphite. Furthermore, black pigments such as iron oxide black, coloured pigments such as ultramarine or iron oxide red, and fluorescent or phosphorescent pigments can be used as inorganic pigments.

[102] Particularly suitable are coloured metal oxides, metal hydroxides and metal oxide hydrates, mixed-phase pigments, sulphur-containing silicates, silicates, metal sulphides, complex metal cyanides, metal sulphates, metal chromates and / or metal molybdates. Particularly preferred pigments are black iron oxide (Cl 77499), yellow iron oxide (Cl 77492), red and brown iron oxide (Cl 77491), manganese violet (Cl 77742), ultramarines (sodium aluminium sulfo silicates, Cl 77007, Pigment Blue 29), chromium oxide hydrate (CI77289), iron blue (ferric ferrocyanide, CI77510) and / or carmine (cochineal).

[103] Also particularly preferred pigments are coloured pearlescent pigments. These are usually mica and / or mica-based and can be coated with one or more metal oxides. Mica belongs to the layer 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, mica, mainly muscovite or phlogopite, is coated with a metal oxide.

[104] Accordingly, a preferred method is characterised in that agent (a) contains at least one inorganic pigment (a3), which is preferably selected from the group of coloured metal oxides, metal hydroxides, metal oxide hydrates, silicates, metal sulphides, complex metal cyanides, metal sulphates, bronze pigments and / or coloured pigments based on mica, which are coated with at least one metal oxide and / or one metal oxychloride.

[105] A preferred suitable pigment based on synthetic mica is, for example, Timiron® SynWhite Satin from Merck.

[106] In a further preferred embodiment, the method is characterised in that agent (a) comprises at least one pigment (a3) selected from pigments based on natural or synthetic mica which are mixed with one or more metal oxides from the group consisting of titanium dioxide (Cl 77891) black iron oxide (Cl 77499), yellow iron oxide (Cl 77492), red and / or brown iron oxide (Cl 77491, Cl 77499), manganese violet (Cl 77742), ultramarine (sodium aluminium sulfo silicates, Cl 77007, pigment blue 29), chromium oxide hydrate (Cl 77289), chromium oxide (Cl 77288) and / or iron blue (ferric ferrocyanide, Cl 77510).

[107] Other suitable pigments are based on metal oxide-coated platelet-shaped borosilicates. These are, for example, coated with tin oxide, iron oxide(s), silicon dioxide and / or titanium dioxide. Such borosilicate-based pigments are available, forexample, underthe name MIRAGE®from Eckart or Reflecks® from BASF SE.

[108] Examples of particularly suitable pigments are commercially available underthe trade names Rona®, Colorona®, Xirona®, Dichrona® and Timiron® from Merck, Ariabel® and Unipure® from Sensient, Prestige® or SynCrystal® from Eckart Cosmetic Colors, Flamenco®, Cellini®, Cloisonne®, Duocrome®, Gemtone®, Timica®, MultiReflections, Chione from BASF SE and Sunshine® from Sunstar.

[109] Very particularly preferred pigments with the trade name Colorona® are, for example: Colorona® Copper, Merck, MICA, Cl 77491 (IRON OXIDES) Colorona® Copper Fine, Merck, MICA, Cl 77491 (IRON OXIDES) Colorona® Passion Orange, Merck, Mica, Cl 77491 (Iron Oxides), Alumina Colorona® Patina Silver, Merck, MICA, Cl 77499 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE) Colorona® RY, Merck, Cl 77891 (TITANIUM DIOXIDE), MICA, Cl 75470 (CARMINE) Colorona® Oriental Beige, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES) Colorona® Dark Blue, Merck, MICA, TITANIUM DIOXIDE, FERRIC FERROCYANIDE Colorona® Chameleon, Merck, Cl 77491 (IRON OXIDES), MICA Colorona® Aborigine Amber, Merck, MICA, Cl 77499 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE) Colorona® Blackstar Blue, Merck, Cl 77499 (IRON OXIDES), MICA Colorona® Patagonian Purple, Merck, MICA, Cl 77491 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE), Cl 77510 (FERRIC FERROCYANIDE) Colorona® Red Brown, Merck, MICA, Cl 77491 (IRON OXIDES), Cl 77891 (TITANIUM DIOXIDE) Colorona® Russet, Merck, Cl 77491 (TITANIUM DIOXIDE), MICA, Cl 77891 (IRON OXIDES) Colorona® Imperial Red, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), D&C RED NO. 30 (Cl 73360) Colorona® Majestic Green, Merck, Cl 77891 (TITANIUM DIOXIDE), MICA, Cl 77288 (CHROMIUM OXIDE GREENS) Colorona® Light Blue, Merck, MICA, TITANIUM DIOXIDE (Cl 77891), FERRIC FERROCYANIDE (Cl 77510) 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) Colorona® Carmine Red, Merck, MICA, TITANIUM DIOXIDE, CARMINE Colorona® Blackstar Green, Merck, MICA, Cl 77499 (IRON OXIDES) Colorona® Bordeaux, Merck, MICA, Cl 77491 (IRON OXIDES) Colorona® Bronze, Merck, MICA, Cl 77491 (IRON OXIDES) Colorona® Bronze Fine, Merck, MICA, Cl 77491 (IRON OXIDES) Colorona® Fine Gold MP 20, Merck, MICA, Cl 77891 (TITANIUM DIOXIDE), Cl 77491 (IRON OXIDES) Colorona® Sienna Fine, Merck, Cl 77491 (IRON OXIDES), MICA Colorona® Sienna, Merck, MICA, Cl 77491 (IRON OXIDES) Colorona® Precious Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Silica, Cl 77491 (Iron oxides), Tin oxide Colorona® Sun Gold Sparkle MP 29, Merck, MICA, TITANIUM DIOXIDE, IRON OXIDES, MICA, Cl 77891, Cl 77491 (EU) Colorona® Mica Black, Merck, Cl 77499 (Iron oxides), Mica, Cl 77891 (Titanium dioxide) Colorona® Bright Gold, Merck, Mica, Cl 77891 (Titanium dioxide), Cl 77491 (Iron oxides) Colorona® Blackstar Gold, Merck, MICA, Cl 77499 (IRON OXIDES) Colorona® SynCopper, Merck, Synthetic Fluorophlogopite (and) Iron Oxides Colorona® SynBronze, Merck, Synthetic Fluorphlogopite (and) Iron Oxides

[110] Further particularly preferred pigments with the trade name Xirona® are, for example: Xirona® Golden Sky, Merck, Silica, Cl 77891 (Titanium Dioxide), Tin Oxide Xirona® Caribbean Blue, Merck, Mica, Cl 77891 (Titanium Dioxide), Silica, Tin Oxide Xirona® Kiwi Rose, Merck, Silica, Cl 77891 (Titanium Dioxide), Tin Oxide Xirona® Magic Mauve, Merck, Silica, Cl 77891 (Titanium Dioxide), Tin Oxide Xirona® Le Rouge, Merck, Iron Oxides (and) Silica

[111] In addition, particularly preferred pigments with the trade name Unipure®are, for example: Unipure® Red LC 381 EM, Sensient Cl 77491 (Iron Oxides), Silica Unipure® Black LC 989 EM, Sensient, Cl 77499 (Iron Oxides), Silica Unipure® Yellow LC 182 EM, Sensient, Cl 77492 (Iron Oxides), Silica

[112] Also particularly preferred pigments with the trade name Flamenco® are, for example: Flamenco® Summit Turquoise T30D, BASF, Titanium Dioxide (and) Mica Flamenco® Super Violet 530Z, BASF, Mica (and) Titanium Dioxide

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

[114] Examples of particularly suitable organic pigments are carmine, quinacridone, phthalocyanine, sorghum, blue pigments with the Colour Index numbers Cl 42090, Cl 69800, Cl 69825, Cl 73000, Cl 74100, Cl 74160, yellow pigments with the Colour Index numbers Cl 11680, Cl 11710, Cl 15985, Cl 19140, Cl 20040, Cl 21100, Cl 21108, Cl 47000, Cl 47005, green pigments with the Colour Index numbers Cl 61565, Cl 61570, Cl 74260, orange pigments with the Colour Index numbers Cl 11725, Cl 15510, Cl 45370, Cl 71105, red pigments with the Colour Index numbers Cl 12085, Cl 12120, Cl 12370, Cl 12420, Cl 12490, Cl 14700, Cl 15525, Cl 15580, Cl 15620, Cl 15630, Cl 15800, Cl 15850, Cl 15865, Cl 15880, Cl 17200, Cl 26100, Cl 45380, Cl 45410, Cl 58000, Cl 73360, Cl 73915 and / or Cl 75470.

[115] In a further particularly preferred embodiment of the method according to the invention, characterised in that agent (a) contains at least one organic pigment (a3) which is preferably selected from the group consisting of carmine, quinacridone, phthalocyanine, sorghum, blue pigments with the Color Index numbers Cl 42090, Cl 69800, Cl 69825, Cl 73000, Cl 74100, Cl 74160, yellow pigments with the Colour Index numbers Cl 11680, Cl 11710, Cl 15985, Cl 19140, Cl 20040, Cl 21100, Cl 21108, Cl 47000, Cl 47005, green pigments with the Colour Index numbers Cl 61565, Cl 61570, Cl 74260, orange pigments with the Colour Index numbers Cl 11725, Cl 15510, Cl 45370, Cl 71105, red pigments with the Colour Index numbers Cl 12085, Cl 12120, Cl 12370, Cl 12420, Cl 12490, Cl 14700, Cl 15525, Cl 15580, Cl 15620, Cl 15630, Cl 15800, Cl 15850, Cl 15865, Cl 15880, Cl 17200, Cl 26100, Cl 45380, Cl 45410, Cl 58000, Cl 73360, Cl 73915 and Cl 75470.

[116] The organic pigment can also be a colour lacquer. Within the meaning of the invention, the term colour lacquer means particles comprising a layer of absorbed dyes, the unit of particle and dye being insoluble under the above-mentioned conditions. The particles can, for example, be inorganic substrates, which can be aluminium, silica, calcium borosilate, calcium aluminium borosilicate or even aluminium.

[117] For example, alizarin colour varnish can be used.

[118] Pigments with a specific shape may also be used to dye the keratin fibres. For example, a pigment based on a lamellar and / or a lenticular substrate platelet can be used. Furthermore, colouring based on a substrate platelet comprising a vacuum metallized pigment is also possible.

[119] In a further embodiment, a method according to the invention is characterized in that agent (a) comprises one or more pigments based on a lamellar substrate platelet, pigments based on a lenticular substrate platelet and vacuum metallized pigments.

[120] Substrate platelets of this type have an average thickness of at most 50nm, preferably less than 30nm, particularly preferably at most 25nm, for example at most 20nm. The average thickness of the substrate platelets is at least 1nm, preferably at least 2.5nm, particularly preferably at least 5nm, for example at least 10nm. Preferred ranges for substrate wafer thickness are 2.5 to 50nm, 5 to 50nm, 10 to 50nm; 2.5 to 30nm, 5 to 30nm, 10 to 30nm; 2.5 to 25nm, 5 to 25nm, 10 to 25nm, 2.5 to 20nm, 5 to 20nm, and 10 to 20nm. Preferably, each substrate platelet has a thickness that is as uniform as possible.

[121] Due to the low thickness of the substrate platelets, the pigment exhibits particularly high hiding power.

[122] The substrate platelets are preferably monolithic in structure. Monolithic in this context means consisting of a single closed unit without fractures, stratifications or inclusions, although structural changes may occur within the substrate platelets. The substrate platelets are preferably homogeneously structured, i.e. there is no concentration gradient within the platelets. In particular, the substrate platelets do not have a layered structure and do not have any particles or particles distributed in them.

[123] The size of the substrate platelet can be adapted to the respective application purpose, in particular the desired effect on the keratinous fibres. Typically, the substrate platelets have an average largest diameter of about 2 to 200pm, especially about 5 to 100pm.

[124] In a preferred design, the aspect ratio, expressed by the ratio of the average size to the average thickness, is at least 80, preferably at least 200, more preferably at least 500, most preferably more than 750. The average size of the uncoated substrate platelets is the d50 value of the uncoated substrate platelets. Unless otherwise stated, the d50 value was determined using a Sympatec Helos device with quixel wet dispersion. To prepare the sample, the sample to be analysed was pre-dispersed in isopropanol for 3 minutes.

[125] The substrate platelets can be composed of any material that can be formed into platelet shape.

[126] They can be of natural origin, but also synthetically produced. Materials from which the substrate platelets can be constructed include metals and metal alloys, metal oxides, preferably aluminium oxide, inorganic compounds and minerals such as mica and (semi-)precious stones, and plastics. Preferably, the substrate platelets are constructed of metal (alloy).

[127] Any metal suitable for metallic lustre 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 aluminium bronzes and brass. Preferred metals are aluminium, copper, silver and gold. Preferred substrate platelets include aluminium platelets and brass platelets, with aluminium substrate platelets being particularly preferred.

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

[129] Due to their irregular structure, pigments based on lamellar substrate platelets generate a high proportion of scattered light. In addition, the pigments based on lamellar substrate platelets do not completely cover the existing colour of keratin fibres, and, for example, effects similar to natural greying can be achieved.

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

[131] Vacuum metallized pigments (VMPs) can be obtained, for example, by releasing metals, metal alloys or metal oxides from suitably coated films. They are characterised by a particularly low thickness of the substrate platelets in the range of 5 to 50nm and a particularly smooth surface with increased reflectivity. Substrate platelets comprising a vacuum metallized pigment are also referred to as VMP substrate platelets in the context of this application. VMP substrate platelets of aluminium can be obtained, for example, by releasing aluminium from metallised films.

[132] The metal or metal alloy substrate platelets can be passivated, for example by anodizing (oxide layer) or chromating.

[133] 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 to be particularly preferable for use in agent (a).

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

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

[136] 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.

[137] In a further embodiment, a method according to the invention is characterised in that agent (a) contains - based on the total weight of agent (a) - one or more pigments in a total amount of from 0.001 to 20% by weight, in particular from 0.05 to 5% by weight.

[138] In addition to the pigments, agent (a) used in the method may also contain one or more direct dyes. Direct-acting dyes are dyes that draw directly onto the hair and do not require an oxidative process to form the colour. Direct dyes are usually nitrophenylene diamines, nitroaminophenols, azo dyes, anthraquinones, triarylmethane dyes or indophenols.

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

[140] Preferably, the direct dyes within the meaning of the present invention have a solubility in water (760mmHg) at 25°C of more than 1 g / L.

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

[142] In a further preferred embodiment, the method is characterized in that agent (a) comprises at least one anionic, cationic and / or non-ionic direct dye as the colouring compound (a3).

[143] Suitable cationic direct dyes include Basic Blue 7, Basic Blue 26, 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 und Basic Red 76.

[144] As non-ionic direct dyes, non-ionic nitro and quinone dyes and neutral azo dyes can be used. Suitable non-ionic direct dyes are those listed under the international designations or trade names 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 known compounds, as well as 1,4-diamino-2-nitrobenzene, 2-amino-4-nitrophenol, 1,4-bis-(2-hydroxyethyl)-amino-2-nitrobenzene, 3-nitro-4-(2-hydroxyethyl)-aminophenol 2-(2-hydroxyethyl)amino-4,6-dinitrophenol, 4-[(2-hydroxyethyl)amino]-3-nitro-1-methylbenzene, 1-amino-4-(2-hydroxyethyl)-amino-5-chloro-2-nitrobenzene, 4-amino-3-nitrophenol, 1-(2'-ureidoethyl)amino-4-nitrobenzene, 2-[(4-amino-2-nitrophenyl)amino]benzoic acid, 6-nitro-1,2,3,4-tetrahydroquinoxaline, 2-hydroxy-1,4-naphthoquinone, picramic acid and its salts, 2-amino-6-chloro-4-nitrophenol, 4-ethylamino-3-nitrobenzoic acid and 2-chloro-6-ethylamino-4-nitrophenol.

[145] Anionic direct dyes are also called acid dyes. Acid dyes are direct dyes that have at least one carboxylic acid group (-COOH) and / or one sulphonic acid group (-SO3H). Depending on the pH value, the protonated forms (-COOH, -SO3H) of the carboxylic acid or sulphonic acid groups are in equilibrium with their deprotonated forms (-OO; -SO3- pre). The proportion of protonated forms increases with decreasing pH value. If direct dyes are used in the form of their salts, the carboxylic acid groups or sulphonic acid groups are present in deprotonated form and are neutralised with corresponding stoichiometric equivalents of cations to maintain electro-neutrality. The acid dyes can also be used in the form of their sodium salts and / or their potassium salts.

[146] Acid dyes according to the present invention have a solubility in water (760mmHg) at 25°C of more than 0.5g / L and are therefore not to be regarded as pigments. Preferably, acid dyes according to the present invention have a solubility in water (760mmHg) at 25°C of more than 1 g / L.

[147] Alkaline earth salts (such as calcium salts and magnesium salts) or aluminium salts of acid dyes often have a lower solubility than the corresponding alkali salts. If the solubility of these salts is below 0.5g / L (25°C, 760mmHg), they do not fall under the definition of a direct dye.

[148] An essential characteristic of acid dyes is their ability to form anionic charges, whereby the carboxylic acid or sulphonic acid groups responsible for this are usually linked to different 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.

[149] For example, one or more compounds from the following group can be selected as suitable acid dyes: Acid Yellow 1 (D&C Yellow 7, Citronin A, Ext. D&C Yellow No. 7, Japan Yellow 403,Cl 10316, COLIPA n° B001), Acid Yellow 3 (COLIPA no. C 54, D&C Yellow no. 10, Quinoline Yellow, E104, Food Yellow 13), Acid Yellow 9 (Cl 13015), Acid Yellow 17 (Cl 18965), Acid Yellow 23 (COLIPA no. 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 (Cl 13065), Acid Yellow 121 (Cl 18690), Acid Orange 6 (Cl 14270), Acid Orange 7 (2-Naphthol Orange, Orange II, Cl 15510, D&C Orange 4, COLIPA no. C015), Acid Orange 10 (Cl 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; Cl 20170; KATSU201; no sodium salt; Brown no. 201; RESORCIN BROWN; ACID ORANGE 24; Japan Brown 201; D&C Brown no. 1), Acid Red 14 (CI14720), Acid Red 18 (E124, Red 18; Cl 16255), Acid Red 27 (E 123, Cl 16185, C-Rot46, Echtrot D, FD&C Red No. 2, Food Red 9, Naphtholrot S), Acid Red 33 (Red 33, Fuchsia Red, D&C Red 33, Cl 17200), Acid Red 35 (Cl 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 no. 106 Pontacyl Brilliant Pink), Acid Red 73 (Cl 27290), Acid Red 87 (Eosin, Cl 45380), Acid Red 92 (COLIPA no. 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 no. 2, Cl 60730, COLIPA no. 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, Cl 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 (Cl 42100), Acid Green 22 (Cl 42170), Acid Green 25 (Cl 61570, Japan Green 201, D&C Green No. 5), Acid Green 50 (Brilliant Acid Green BS, Cl 44090, Acid Brilliant Green BS, E 142), Acid Black 1 (Black no. 401, Naphthalene Black 10B, Amido Black 10B, Cl 20470, COLIPA no. 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.

[150] For example, the water solubility of anionic direct dyes can be determined in the following way. 0.1g of the anionic direct dye is placed in a beaker. A magnetic stir bar is added. Then 100ml of water is added. This mixture is heated to 25°C on a magnetic stirrer while stirring. It is stirred for 60 minutes. The aqueous mixture is then visually assessed. If there are still undissolved residues, the amount of water is increased - for example in steps of 10ml. Water is added until the amount of dye used is completely dissolved. If the dye-water mixture cannot be assessed visually due to the high intensity of the dye, the mixture is filtered. If a proportion of undissolved dyes remains on the filter paper, the solubility test is repeated with a higher quantity of water. If 0.1g of the anionic direct dye is dissolved in 100ml of water at 25°C, the solubility of the dye is 1 g / L.

[151] Acid Yellow 1 is called 8-hydroxy-5,7-dinitro-2-naphthalene sulfonic acid disodium salt and has a solubility in water of at least 40g / L (25°C).

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

[153] Acid Yellow 9 is the disodium salt of 8-hydroxy-5,7-dinitro-2-naphthalene sulphonic acid, its water solubility is above 40g / L (25°C).

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

[155] Acid Orange 7 is the sodium salt of 4-[(2-hydroxy-1-naphthyl)azo]benzene sulphonate. Its solubility in water is more than 7g / L (25 °C).

[156] 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% by weight.

[157] Acid Red 33 is the disodium salt of 5-amino-4-hydroxy-3-(phenyl azo)-naphthalene-2,7-disulphonate, its solubility in water is 2.5g / L (25°C).

[158] 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, its water solubility is given as greater than 10g / L (25°C).

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

[160] The direct dye(s), in particular the anionic direct dyes, can be used in various amounts in agent (a) depending on the desired colour intensity. Good results have been obtained when agent (a) contains - based on the total weight of agent (a) - one or more direct dyes (a3) in a total amount of from 0.01 to 10% by weight, preferably from 0.1 to 8% by weight, more preferably from 0.2 to 6% by weight and most preferably from 0.5 to 4.5% by weight.

[161] Cosmetic carrier (a4) in agent (a)

[162] Agent (a) contains organic silanes (a2) and pigments (a3) particularly preferably in a cosmetic carrier. Since agent (a) is low in water or anhydrous, this cosmetic carrier is not water. Compounds from the group of poly Ci-Cealkylene glycols, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, dipropylene glycol, ethanol, isopropanol, diethylene glycol monoethyl ether, glycerine, phenoxyethanol and benzyl alcohol are particularly suitable as cosmetic carriers. Poly Ci-Ce alkylene glycols, in particular polyethylene glycols, have shown particularly good suitability for this purpose.

[163] In a further particularly preferred embodiment, a method according to the invention is characterised in that agent (a) comprises at least one cosmetic carrier (a4) from the group consisting of poly Ci-Ce alkylene glycols, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, dipropylene glycol, ethanol, isopropanol, diethylene glycol monoethyl ether, glycerol, phenoxyethanol and benzyl alcohol, most preferably from polyethylene glycols.

[164] 1,2-propylene glycol is alternatively also referred to as 1,2-propanediol and bears the CAS numbers 57-55-6 [(RS)-1,2-dihydroxypropane], 4254-14-2 [(R)-1,2-dihydroxypropane] and 4254-153 [(S)-1,2-dihydroxypropane], Ethylene glycol is alternatively known as 1,2-ethanediol and bears the CAS number 107-21-1. Glycerol is alternatively known as 1,2,3-propanetriol and bears the CAS number 56-81-5. Phenoxyethanol bears the CAS number 122-99-6.

[165] All of the solvents described previously are commercially available from various chemical suppliers, such as Aldrich or Fluka.

[166] A particularly suitable solvent for agent (a) is polyethylene glycols of formula (EG) H—0—CH2 —CH2—0--H X (EG), where x represents an integer from 2 to 10,000, preferably an integer from 2 to 800, more preferably an integer from 3 to 600, still more preferably an integer from 3 to 400 and most preferably an integer from 4 to 200.

[167] In a further particularly preferred embodiment, a method according to the invention is therefore characterised in that agent (a) comprises one or more polyethylene glycols (a4) of formula (EG), H—O—CH2 — CH2—O--H X (EG), where x represents an integer from 2 to 10,000, preferably an integer from 2 to 800, more preferably an integer from 3 to 600, still more preferably an integer from 3 to 400 and most preferably an integer from 4 to 200.

[168] The polyethylene glycols of formula (EG) are protic substances with at least two hydroxyl groups, which can also be referred to as polyalkylene glycols or polyethylene glycols due to their repeating unit -CH2-CH2-O-, since x stands for a value of at least 2. In the alkylene glycols of formula (EG), x is an integer from 2 to 10,000. In the course of the work leading to this invention, it has been found that these polyethylene glycols are particularly suitable for improving the fastness properties of the colorants and also for optimally adjusting the viscosity of the colorants.

[169] Depending on their chain length, polyethylene glycols are liquid or solid, water-soluble polymers. Polyethylene glycols with a molecular mass between 200g / mol and 400g / mol are nonvolatile liquids at room temperature. PEG 600 has a melting range of 17 to 22°C and thus a paste like consistency. With molecular masses above 3000g / mol, PEGs are solid substances and are marketed as flakes or powder.

[170] In particular, the use of low molecular weight alkylene glycols (or polyethylene glycols) has proven to be well suited for solving the problem according to the invention. In the case of low molecular weight alkylene glycols (or polyethylene glycols) within the meaning of the present invention, x is an integer from 1 to 100, preferably an integer from 1 to 80, more preferably an integer from 2 to 60, still more preferably an integer from 3 to 40, still more preferably an integer from 4 to 20 and very particularly preferably an integer from 6 to 15.

[171] In a further particularly preferred embodiment, a composition according to the invention is characterised in that it comprises at least one polyethylene glycol (a4) of formula (EG-1), HO--CH2 — CH2—O--H " "X 1 (EG-1), where x1 represents an integer from 2 to 100, preferably an integer from 2 to 80, more preferably an integer from 2 to 60, still more preferably an integer from 3 to 40, still more preferably an integer from 4 to 20 and most preferably an integer from 6 to 15.

[172] A particularly preferred low-molecular polyethylene glycol is, for example, PEG-8. PEG-8 comprises an average of 8 ethylene glycol units (x1 = 8), has an average molecular weight of 400g / mol and bears the CAS number 25322-68-3. PEG-8 is alternatively known as PEG 400 and is commercially available from APS, for example.

[173] Other suitable low-molecular polyethylene glycols include PEG-6, PEG-7, PEG-9 and PEG-10.

[174] Another suitable polyethylene glycol is PEG-32, for example. PEG-32 comprises 32 ethylene glycol units (x1 = 32), has an average molecular weight of 1500g / mol and bears the CAS number 25322-68-3. PEG-32 is also known as PEG 1500 and can be purchased commercially from Clariant, for example.

[175] Furthermore, the use of high molecular weight polyethylene glycols has also proved to be well suited to solving the problem according to the invention.

[176] High molecular weight polyethylene glycols within the meaning of the present invention can be represented by formula (EG-2), wherein the index number x2 stands for an integer from 101 to 10,000 HO--CH2 —CH2-0--H - y7 (EG-2).

[177] In the case of particularly suitable high molecular weight polyethylene glycols, x2 represents an integer from 101 to 1000, preferably an integer from 105 to 800, more preferably an integer from 107 to 600, still more preferably an integer from 109 to 400 and most preferably an integer from 110 to 200.

[178] In a further particularly preferred embodiment, an agent according to the invention is characterised in that it comprises at least one alkylene glycol (a4) of the formula (EG-2), HO--CH2 —CH2-0--H ■ ■ (EG-2), where x2 represents an integer from 101 to 1000, preferably an integer from 105 to 800, more preferably an integer from 107 to 600, still more preferably an integer from 109 to 400 and most preferably an integer from 110 to 200.

[179] A particularly suitable high-molecular polyethylene glycol is PEG 6000, for example, which can be obtained commercially from National Starch (China). The molecular weight of PEG 6000 is 6000 to 7500g / mol, which corresponds to an x2 value of 136 to 171.

[180] Another suitable polyethylene glycol is PEG 12000, which is sold commercially by CG Chemikalien under the trade name Polyethylene Glycol 12000 S (or PEG 12000 S). The molecular weight of PEG 12000 is given as 10500 to 15000g / mol, corresponding to an x2 value of 238 to 341.

[181] Another suitable polyethylene glycol is PEG 20000, which can be purchased from Clariant under the trade name Polyglycol 20000 P or under the alternative name PEG-350. An average molecular weight of 20000g / mol is given for PEG 20000, which corresponds to an x2 value of 454.

[182] Preferably, agent (a) contains - based on the total weight of agent (a) - the cosmetic carrier(s) (a4) described above in a total amount from 10.0 to 99.0% by weight, preferably from 30.0 to 99.0% by weight, more preferably from 50.0 to 99.0% by weight and very particularly preferably from 70.0 to 99.0% by weight.

[183] In a further particularly preferred embodiment, a method according to the invention is characterised in that agent (a) contains - based on the total weight of the agent (a) - one or more polyethylene glycol(s) (a4) in a total amount of 50.0 to 99.0% by weight, preferably from 60 to 97.0% by weight, more preferably from 70 to 96.0% by weight and particularly preferably from 80.0 to 95.0% by weight.

[184] In a further explicitly particularly preferred embodiment, a method according to the invention is characterised in that agent (a) contains - based on the total weight of agent (a) - one or more alkylene glycols (a4) of the formula (EG) in a total amount of 50.0 to 99.0% by weight, preferably from 60 to 97.0% by weight, more preferably from 70 to 96.0% by weight and particularly preferably from 80.0 to 95.0% by weight.

[185] It is understood that the sum of all ingredients from groups (a1), (a2), (a3) and optionally (a4) contained in agent (a) cannot be more than 100% by weight. If other, optional ingredients are to be used in the product, the total sum of the above-mentioned ingredients is reduced accordingly to values of less than 100% by weight. [1861Step (2). application of agent (bl on the keratinous fibres

[187] In the second step of the method according to the invention, agent (b) is applied to the keratinous fibres or the hairs that are still coated with agent (a). Step (2) takes place after step (1), i.e. after agent (a) has been applied to the keratin fibres, agent (b) is applied. The successive application of the two agents (a) and (b) takes place within a period of one hour, preferably within 30 minutes. Most preferably, agent (b) is applied to the keratin fibres within 10 minutes, most preferably within 5 minutes after application of agent (a). An application of agent (b) within 10 minutes means that the application of agent (b) is started within a maximum period of 10 minutes after the application of agent (a) to the keratin fibres has been completed.

[188] In a further particularly preferred embodiment, a method according to the invention is characterised by the application of agent (b) within 10 minutes, preferably within 5 minutes after application of agent (a).

[189] By applying agent (b), a mixture of agents (a) and (b) is produced on the fibres to which agent (a) has been applied. As an essential component, agent (b) contains a defined amount of water (b1), which causes the silanes (a2) now on the keratin fibres to undergo the oligomerization or polymerization reaction that leads to the formation of the coloured film. It is therefore essential for the method according to the invention that the mixture of (a) and (b) is formed at all the points of the keratin fibres that are to be dyed.

[190] In addition to the amount of water (b1), the composition (B) also contains 20.0 to 80.0% by weight of polyethylene glycol(s) (b2) and 1.0 to 10.0% by weight of Cs-Cso fatty alcohol(s) (b3) as essential components.

[191] Due to the content of polyethylene glycol(s) (b2) and Cs-Cso fatty alcohol(s) (b3), undesired liquefaction of the mixture prepared from agents (a) and (b) is avoided, so that the mixture of (a) and (b) also remains sufficiently thickened and does not drip off the user’s hair.

[192] In this context, it was surprising that mixing agent (b) according to the invention with agent (a) enables a particularly uniform coloration without changing the viscosity or the rheological properties of the mixture.

[193] .Water content (b11 in agent (b)

[194] By mixing agents (a) and (b), the two agents are emulsified together so that the silanes (a2) and the amount of water initiating the polymerization (b1) come into direct contact with each other. Mixing can be done manually with a gloved hand, for example, by massaging or working the two agents into the keratin fibres.

[195] In the context of a further particularly preferred embodiment, a method according to the invention is accordingly characterised by the (2) Application of an agent (b) to the keratinous fibres still coated with agent (a) and preparation of a mixture of both agents (a) and (b) on the keratinous fibres by manual mixing of both agents.

[196] The water contained in agent (b) initiates the polymerization. Forthis purpose, the water content in agent (b) - based on the total weight of agent (b) - is adjusted to a range of 19.0 to 70.0% by weight. In this context, it has proved to be particularly advantageous if agent (b) - based on the total weight of agent (b) - contains water from 20 to 65% by weight, further preferably 30 to 65% by weight and very particularly preferably 45.0 to 65.0% by weight.

[197] In a further particularly preferred embodiment, a method according to the invention is characterised in that agent (b) contains water - based on the total weight of agent (b) - 45.0 to 65.0% by weight. [1981 Polyethylene glvcolfs) (b2) in agent (b)

[199] In order to ensure that agents (a) and (b) are sufficiently miscible and to ensure that agent (b) does not drip off the keratin fibres or hair after application, agent (b) additionally contains 20.0 to 80.0% by weight of polyethylene glycol(s) (b2) in addition to the defined amount of water (b1).

[200] Polyethylene glycols particularly suitable for use in agent (b) have formula (EG) H—O—CH2 —CH2—O--H X (EG), where x represents an integer from 2 to 10,000, preferably an integer from 2 to 800, more preferably an integer from 3 to 600, still more preferably an integer from 3 to 400 and most preferably an integer from 4 to 200.

[201] In a further particularly preferred embodiment, the method according to the invention comprises applying an agent (b) to the keratinous fibres which are still exposed to agent (a), wherein agent (b) comprises, based on the total weight of agent (b) (b1) 19.0 to 70.0% by weight of water, and (b2) 20.0 to 80.0% by weight of polyethylene glycol(s) of formula (EC), H—O—CH2 — CH2—O--H X (EG), where x represents an integer from 2 to 10,000, preferably an integer from 2 to 800, more preferably an integer from 3 to 600, still more preferably an integer from 3 to 400 and most preferably an integer from 4 to 200, and (b3) 1,0 to 10,0% by weight of Cs-Cso fatty alcohol(s).

[202] The suitable, preferred and particularly preferred polyethylene glycol(s) are the compounds which have also been described as suitable, preferred and particularly preferred for use in agent (a), i.e. the polyethylene glycol(s) of formula(s) (EG), (EG-1) and / or (EG-2) can also be used in agent (b).

[203] In a further particularly preferred embodiment, the method according to the invention comprises applying an agent (b) to the keratinous fibres which are still coated with agent (a), wherein agent (b) comprises, based on the total weight of agent (b) (b1) 19.0 to 70.0% by weight of water, and (b2) 20.0 to 80.0% by weight of polyethylene glycol(s) of formula (EG-1), HO--CH2 — CH2—O--H " - Y 1 (EG-1), where x1 represents an integer from 2 to 100, preferably an integer from 2 to 80, more preferably an integer from 2 to 60, still more preferably an integer from 3 to 40, still more preferably an integer from 4 to 20 and most preferably an integer from 6 to 15. (b3) 1,0 to 10,0% by weight of Cs-Cso fatty alcohol(s).

[204] In a further preferred embodiment, the method according to the invention comprises applying an agent (b) to the keratinous fibres which are still exposed to agent (a), wherein agent (b) comprises, based on the total weight of the agent (b) (b1) 19.0 to 70.0% by weight of water, and (b2) 20.0 to 80.0% by weight of polyethylene glycol(s) of formula (EG-2), HO--CH2 —CH2-0--H ■ ■ yT (EG-2), where x2 represents an integer from 101 to 1000, preferably an integer from 105 to 800, more preferably an integer from 107 to 600, still more preferably an integer from 109 to 400 and most preferably an integer from 110 to 200, and (b3) 1,0 to 10,0% by weight of Cs-Cso fatty alcohol(s).

[205] Furthermore, it is particularly preferred if both agents (a) and (b) contain at least one polyethylene glycol of formula (EG).

[206] Furthermore, it is particularly preferred if both agent (a) and (b) contain at least one polyethylene glycol of formula (EG-1).

[207] Preferably, agent (b) contains one or more polyethylene glycol(s) in a total amount of 25.0 to 53.0% by weight.

[208] Fatty alcohols (b3) in agent (b)

[209] As the third essential component of the invention, agent (b) contains - based on the total weight of agent (b) - 1.0 to 10.0% by weight of Cs-Cso fatty alcohol(s) (b3). In combination with the polyethylene glycols (b2), these quantities of fatty alcohols (b3) prevent a change in viscosity when the mixture of both agents (a) and (b) is produced on the user’s head by applying (b).

[210] The Cs-Cso fatty alcohols can be saturated, mono- or polyunsaturated, linear or branched fatty alcohols with 8 to 30 carbon atoms.

[211] Examples of preferred linear, saturated C8-C30 fatty alcohols are octan-1-ol (carpyl alcohol), decan-1-ol, dodecan-1-ol (dodecyl alcohol, lauryl alcohol), tetradecan-1-ol (tetradecyl alcohol, myristyl alcohol), hexadecan-1-ol (hexadecyl alcohol, cetyl alcohol, palmityl alcohol), octadecan-1-ol (octadecyl alcohol, stearyl alcohol), arachyl alcohol (eicosan-1-ol), heneicosyl alcohol (heneicosan-1-ol) and / or behenyl alcohol (docosan-1-ol).

[212] Preferred linear, unsaturated fatty alcohols are (9Z)-octadec-9-en-1-ol (oleyl alcohol), (9E)-octadec-9-en-1-ol (elaidyl alcohol), (9Z,12Z)-octadeca-9,12-dien-1-ol (linoleyl alcohol), (9Z,12Z,15Z)-octadeca-9,12, 15-trien-1 -ol (linolenoyl alcohol), gadoleyl alcohol ((9Z)-eicos-9-en-1-ol), arachidone alcohol ((5Z,8Z, 11Z, 14Z)-eicosa-5,8,11,14-tetraen-1 -ol), erucyl alcohol ((13Z)-docos-13-en-1-ol) and / or brassidyl alcohol ((13E)-docosen-1-ol).

[213] The preferred representatives for branched fatty alcohols are 2-octyl-dodecanol, 2-hexyl-dodecanol and / or 2-butyl-dodecanol.

[214] In one embodiment, particularly good results were obtained when agent (b) contains - based on the total weight of agent (b) - one or more Cs-Cso fatty alcohol(s) (b3) from the group consisting of dodecan-1-ol, tetradecan-1-ol, hexadecan-1-ol, octadecan-1-ol, eicosan-1-ol and docosan-1-ol in a total amount of 1.0 to 10.0% by weight.

[215] In a further particularly preferred embodiment, the method according to the invention comprises applying an agent (b) to the keratinous fibres which are still impregnated with agent (a), wherein agent (b) contains - based on the total weight of agent (b) - (b1) 19.0 to 70.0% by weight of water, and (b2) 20.0 to 80.0% by weight of polyethylene glycol(s) of formula (EG-1), HO--CH2 —CH2-0--H - V 1 (EG-1), where x1 represents an integer from 2 to 100, preferably an integer from 2 to 80, more preferably an integer from 2 to 60, still more preferably an integer from 3 to 40, still more preferably an integer from 4 to 20 and most preferably an integer from 6 to 15, (b3) one or more Cs-Cso fatty alcohol(s) from the group consisting of dodecan-1-ol, tetradecan-1-ol, hexadecan-1-ol, octadecan-1-ol, eicosan-1-ol and docosan-1-ol in a total amount of 1.0 to 10.0% by weight.

[216] By setting the optimum quantity ranges of agents (b1), (b2) and (b3), the viscosity of the application mixture of (a) and (b) remains very constant for a particularly long period of time. For this reason, it is particularly preferable if agent (b) contains - based on the total weight of t agent (b): (b1) 45.0 to 65.0% by weight of water, and (b2) 25,0 to 53,0% by weight of polyethylene glycol(s), and (b3) 2,0 to 5,0% by weight of Cs-Cso fatty alcohol(s).

[217] In a further particularly preferred embodiment, a method according to the invention is characterised in that agent (b) contains - based on the total weight of agent (b): (b1) 45.0 to 65.0% by weight of water, and (b2) 25,0 to 53,0% by weight of polyethylene glycol(s), and (b3) 2,0 to 5,0% by weight of Cs-Cso fatty alcohol(s).

[218] In a further particularly preferred embodiment, the method according to the invention comprises applying an agent (b) to the keratinous fibres which are still coated with agent (a), wherein agent (b) - based on the total weight of agent (b) - contains (b1) 45.0 to 65.0% by weight of water, and (b2) 25.0 to 53.0% by weight of polyethylene glycol(s) of formula (EG-1), HO--CH2 — CH2—O--H " ■ x 1 (EG-1), where x1 represents an integer from 2 to 100, preferably an integer from 2 to 80, more preferably an integer from 2 to 60, still more preferably an integer from 3 to 40, still more preferably an integer from 4 to 20 and most preferably an integer from 6 to 15. (b3) 2.0 to 5.0% by weight of Cs-Cso fatty alcohol(s) from the group consisting of dodecan-1-ol, tetradecan-1-ol, hexadecan-1-ol, octadecan-1-ol, eicosan-1-ol and / or docosan-1-ol.

[219] Non-ionic surfactants in agent (b)

[220] Due to its water content (b1) and Cs-Cso fatty alcohol(s), agent (b) is present in the form of a polyethylene glycol-containing emulsion. In order to further optimize the formation of the emulsion, it has proven particularly preferable to continue using at least one surfactant in agent (b). Quite preferably, therefore, agent (b) additionally contains at least one surfactant.

[221] In another particularly preferred embodiment, a method according to the invention is characterised in that agent (b) contains at least one surfactant.

[222] The term surfactants (T) refers to surface-active substances that can form adsorption layers on surfaces and interfaces or aggregate in bulk phases to form micelle colloids or lyotropic mesophases. A distinction is made between anionic surfactants consisting of a hydrophobic radical and a negatively charged hydrophilic head group, amphoteric surfactants, which carry both a negative and a compensating positive charge, cationic surfactants, which have a positively charged hydrophilic group in addition to a hydrophobic radical, and non-ionic surfactants, which have no charges but strong dipole moments and are strongly hydrated in aqueous solution.

[223] In a particularly preferred embodiment, a method according to the invention is characterised in that agent (b) contains at least one non-ionic surfactant.

[224] Non-ionic surfactants contain, for example, a polyol group, a polyalkylene glycol ether group or a combination of polyol and polyglycol ether group as the hydrophilic group. Such compounds include addition products of 2 to 50 mol ethylene oxide and / or 0 to 5 mol propylene oxide to linear and branched fatty alcohols with 6 to 30 C atoms, the fatty alcohol polyglycol ethers or the fatty alcohol polypropylene glycol ethers or mixed fatty alcohol polyethers, addition products of 2 to 50 mol ethylene oxide and / or 0 to 5 mol propylene oxide to linear and branched fatty acids with 6 to 30 C atoms, the fatty acid polyglycol ethers or the fatty acid polypropylene glycol ethers or mixed fatty acid polyethers, addition products of 2 to 50 mol ethylene oxide and / or 0 to 5 mol propylene oxide to linear and branched alkylphenols with 8 to 15 C atoms in the alkyl group, the alkylphenol polyglycol ethers or the alkylpolypropylene glycol ethers or mixed alkylphenol polyethers, with a methyl or C2-C6 alkyl radical end-group capped addition products of 2 to 50 moles of ethylene oxide and / or 0 to 5 moles of propylene oxide to linear and branched fatty alcohols with 8 to 30 C atoms, to fatty acids with 8 to 30 C atoms and to alkylphenols with 8 to 15 C atoms in the alkyl group, such as the grades available under the sales names Dehydol® LS, Dehydol® LT (Cognis), C12-C30 fatty acid mono- and diesters of addition products of 1 to 30 mol ethylene oxide to glycerol, addition products of 5 to 60 mol ethylene oxide to castor oil and hardened castor oil, polyol fatty acid esters, such as the commercial product Hydagen® HSP (Cognis) or Sovermol® types (Cognis), alkoxylated triglycerides, alkoxylated fatty acid alkyl esters of formula (Tnio-1) R1CO-(OCH2CHR2)wOR3 (Tnio-1) in which R1CO is a linear or branched, saturated and / or unsaturated acyl radical having 6 to 22 carbon atoms, R2 is hydrogen or methyl, R3 is linear or branched alkyl radicals having 1 to 4 carbon atoms and w is a number from 1 to 20, amine oxides, Hydroxy mixed ethers, as described for example in DE-OS 19738866, Sorbitan fatty acid esters and addition products of ethylene oxide to sorbitan fatty acid esters such as polysorbates, Sugar fatty acid esters and addition products of ethylene oxide to sugar fatty acid ester, Addition products of ethylene oxide to fatty acid alkanolamides and fatty amines, Sugar surfactants of the alkyl and alkenyl oligoglycoside type according to formula (E4-II), R4O-[G]P (Tnio-2) in which R4 is an alkyl or alkenyl radical containing 4 to 22 carbon atoms, G is a sugar radical containing 5 or 6 carbon atoms and p is a number from 1 to 10. They can be obtained by the relevant methods of preparative organic chemistry. The alkyl and alkenyl oligoglycosides can be derived from aldoses or ketoses with 5 or 6 carbon atoms, preferably glucose. The preferred alkyl and / or alkenyl oligoglycosides are therefore alkyl and / or alkenyl oligoglucosides. The index number p in the general formula (Tnio-2) indicates the degree of oligomerization (DP), i.e. the distribution of mono- and oligoglycosides and represents a number between 1 and 10. While p must always be an integer in the individual molecule and can assume the values p = 1 to 6, the value p for a certain alkyl oligoglycoside is an analytically determined arithmetical quantity, which usually represents a fraction. Preferably alkyl and / or alkenyl oligoglycosides with an average degree of oligomerization p of 1.1 to 3.0 are used. From an application technology point of view, those alkyl and / or alkenyl oligoglycosides are preferred whose degree of oligomerization is less than 1.7 and in particular lies between 1.2 and 1.4. The alkyl or alkenyl radical R4 can be derived from primary alcohols containing 4 to 11, preferably 8 to 10 carbon atoms. Typical examples are butanol, caproic alcohol, caprylic alcohol, caprinalkohol and undecyl alcohol as well as their technical mixtures, such as those obtained in the hydrogenation of technical fatty acid methyl esters or in the course of the hydrogenation of aldehydes from Roelen's oxo synthesis. Preferred are alkyl oligoglucosides of chain length Cs-Cio (DP = 1 to 3), which are produced as a precursor during the distillation separation of technical Cs-Cis coconut fatty alcohol and may be contaminated with less than 6% by weight of C12 alcohol, as well as alkyl oligoglucosides based on technical C9 / 11 oxoalcohols (DP = 1 to 3). The alkyl or alkenyl radical R15 can also be derived from primary alcohols having 12 to 22, preferably 12 to 14 carbon atoms. Typical examples are lauryl alcohol, myristyl alcohol, cetyl alcohol, palmoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, brassidyl alcohol and their technical mixtures, which can be obtained as described above. Preferred are alkyl oligoglucosides based on hardened C12 / 14 coconut alcohol with a DP of 1 to 3. Sugar surfactants of the fatty acid N-alkyl polyhydroxyalkylamide type, a non-ionic surfactant of formula (Tnio-3) R5CO-NR6-[Z] (Tnio-3) in which R5CO is an aliphatic acyl radical containing 6 to 22 carbon atoms, R6 is hydrogen, an alkyl or hydroxyalkyl radical containing 1 to 4 carbon atoms and [Z] is a linear or branched polyhydroxyalkyl radical containing 3 to 12 carbon atoms and 3 to 10 hydroxyl groups. The fatty acid N-alkyl polyhydroxyalkylamides are known substances that can usually be obtained by reductive amination of a reducing sugar with ammonia, an alkylamine or an alkanolamine and subsequent acylation with a fatty acid, a fatty acid alkyl ester or a fatty acid chloride. The fatty acid N-alkyl polyhydroxyalkylamides are preferably derived from reducing sugars with 5 or 6 carbon atoms, especially from glucose. The preferred fatty acid N-alkyl polyhydroxyalkylamides are therefore fatty acid N-alkylglucamides as represented by formula (Tnio-4): R7CO-(NR8) -CH2 - [CH(OH)]4 - CH2OH (Tnio-4)

[225] Preferably, glucamides of formula (Tnio-4) are used as fatty acid-N-alkyl polyhydroxyalkylamides, in which R8 represents hydrogen or an alkyl group and R7CO represents the acyl radical of caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselinic acid, linoleic acid, linolenic acid, arachidic acid, gadoleic acid, behenic acid or erucic acid or their technical mixtures. Particularly preferred are fatty acid N-alkyl glucamides of formula (Tnio-4), which are obtained by reductive amination of glucose with methylamine and subsequent acylation with lauric acid or C12 / 14 coconut fatty acid or a corresponding derivative. Furthermore, polyhydroxyalkylamides can also be derived from maltose and palatinose.

[226] The sugar surfactants may preferably be present in the agent used according to the invention in amounts of 0.1 to 20% by weight, based on the total agent. Amounts of 0.5 to 15% by weight are preferred, and amounts of 0.5 to 7.5% by weight are particularly preferred.

[227] Other typical examples of non-ionic surfactants are fatty acid amide polyglycol ethers, fatty amine polyglycol ethers, mixed ethers or mixed formals, protein hydrolysates (especially wheatbased vegetable products) and polysorbates. [2281 The alkylene oxide addition products to saturated linear fatty alcohols and fatty acids, each with 2 to 30 moles of ethylene oxide per mol of fatty alcohol or fatty acid, and the sugar surfactants have proved to be preferred non-ionic surfactants. Preparations with excellent properties are also obtained if they contain fatty acid esters of ethoxylated glycerol as non-ionic surfactants. [2291 These compounds are identified by the following parameters. The alkyl radical R contains 6 to 22 carbon atoms and can be either linear or branched. Primary linear and in 2-position methyl- branched aliphatic radicals are preferred. Such alkyl radicals are for example 1-octyl, 1-decyl, 1-lauryl, 1-myristyl, 1-cytyl and 1-stearyl. Especially preferred are 1-octyl, 1-decyl, 1-lauryl, 1-myristyl. When so-called “oxo-alcohols” are used as starting materials, compounds with an odd number of carbon atoms in the alkyl chain predominate. [2301 The compounds with alkyl groups used as surfactants can each be uniform substances. However, it is usually preferable to start from native plant or animal raw materials in the production of these substances, so that one obtains substance mixtures with different alkyl chain lengths depending on the respective raw material.

[231] For surfactants which are products of the addition of ethylene and / or propylene oxide to fatty alcohols or derivatives of these addition products, both products with a “normal” homologue distribution and those with a narrowed homologue distribution can be used. By “normal” homologue distribution we mean mixtures of homologues obtained in the reaction of fatty alcohol and alkylene oxide using alkali metals, alkali metal hydroxides or alkali metal alcoholates as catalysts. Constricted homologue distributions are obtained, on the other hand, when, for example, hydrotalcites, alkaline earth metal salts of ether carboxylic acids, alkaline earth metal oxides, hydroxides or alcoholates are used as catalysts. The use of products with narrowed homologue distribution may be preferred.

[232] Particularly good results were obtained when an agent (b) containing at least one ethoxylated fatty alcohol with a degree of ethoxylation of 80 to 120 was used in the method according to the invention.

[233] A suitable non-ionic surfactant is, for example, the ethoxylated fatty alcohol marketed under the trade name Brij S 100 or Brij S 100 PA SG. This is stearyl alcohol, ethoxylated with 100 EO, which is commercially available from Croda and bears the CAS number 9005-00-9.

[234] In a further particularly preferred embodiment, a method according to the invention is characterised in that agent (b) contains at least one non-ionic surfactant which is preferably selected from the non-ionic surfactants of formula (T-l), Ra—O—CH2--CH2--OH where Ra represents a saturated or unsaturated, unbranched or branched C8-C30 alkyl group, preferably a saturated, unbranched C16to C18 alkyl group, and n represents an integer from 10 to 120, preferably an integer from 15 to 100, more preferably an integer from 20 to 70 and most preferably an integer from 25 to 35.

[235] A particularly suitable non-ionic surfactant of this type is Ceteareth-30. Ceteareth-30 is a mixture of cetyl alcohol and stearyl alcohol, each ethoxylated with 30 units of ethylene oxide. The mixture of cetyl alcohol and stearyl alcohol is called cetearyl alcohol. Ceteareth-30 bears the CAS number 68439-49-6 and can be purchased from BASF, for example, under the trade name Eumulgin® B3. a The non-ionic surfactant(s) of formula (T-1) may be present in agent (b) - based on the total t of agent (b) - for example in amounts of 0.1 to 20% by weight, preferably from 0.5 to 5.0% by weight.

[237] Further ingredients in agents (a) and (b)

[238] Agents (a) and (b) described above may also contain one or more optional ingredients.

[239] The optional cosmetic ingredients in agents (a) and / or (b) may be any suitable ingredients to impart further beneficial properties to the agent. For example, agent (a) and / or (b) may additionally contain one or more surface-active compounds from the group of non-ionic, cationic, anionic or zwitterionic / amphoteric surfactants.

[240] The agents may also contain other active ingredients, auxiliaries and additives, such as solvents, fatty compounds such as Cs-Cso fatty acid triglycerides, Cs-Cso fatty acid monoglycerides, Cs-Cso fatty acid diglycerides and / or hydrocarbons; structurants such as glucose, maleic acid and lactic acid, hair-conditioning compounds such as phospholipids, for example lecithin and cephalins; perfume oils, dimethylisosorbide and cyclodextrins; fibre-structure-improving active ingredients, in particular mono-, di- and oligosaccharides such as glucose, galactose, fructose, fructose and lactose; dyes for colouring the product; anti-dandruff active ingredients such as piroctone olamine, zinc omadine and climbazole; amino acids and oligopeptides; protein hydrolysates on animal and / or vegetable basis, as well as in the form of their fatty acid condensation products or possibly anionically or cationically modified derivatives; vegetable oils; light stabilisers and UV blockers; active ingredients such as panthenol, pantothenic acid, pantolactone, allantoin, pyrrolidinone carboxylic acids and their salts as well as bisabolol; polyphenols, in particular hydroxycinnamic acids, 6,7-dihydroxycoumarins, hydroxybenzoic acids, catechins, tannins, leucoanthocyanidins, anthocyanidins, flavanones, flavones and flavonols; ceramides or pseudoceramides; vitamins, provitamins and vitamin precursors; plant extracts; fats and waxes such as fatty alcohols, beeswax, montan wax and paraffins; swelling and penetrating agents such as glycerine, propylene glycol monoethyl ether, carbonates, hydrogen carbonates, guanidines, ureas as well as primary, secondary and tertiary phosphates; opacifiers such as latex, styrene / PVP and styrene / acrylamide copolymers; pearlescent agents such as ethylene glycol mono- and distearate and PEG-3-distearate; and blowing agents such as propane-butane mixtures, N2O, dimethyl ether, CO2 and air.

[241] The selection of these other substances will be made by the specialist according to the desired properties of the agents. With regard to other optional components and the quantities of these components used, explicit reference is made to the relevant manuals known to the specialist. The additional active ingredients and auxiliary substances are preferably used in the preparations according to the invention in quantities of 0.0001 to 25% by weight each, in particular 0.0005 to 15% by weight, based on the total weight of the respective agent.

[242] Step (31, allowing both agents (a) and (bl to act on the keratinous fibres

[243] After mixing the two agents (a) and (b) together, the mixture is allowed to act on all the areas of the keratin fibres that have been exposed to the mixture of both agents.

[244] When the two agents (a) and (b) are mixed, the silanes (a2) contained in agent (a) come into contact with the defined amount of water (b1) present in agent (b), so that hydrolysis and oligomerization or polymerization of the silanes (a2) is initiated. In this way, the coating or film is formed on precisely those areas of the keratin fibres that are wetted with the mixture of both agents (a) and (b). The extent and speed of hydrolysis and polymerization are determined by the ratio of the amounts of silane (a2) and water (b 1) on the hair. The quantity ratio (a2) / (b 1) can be determined by the quantity of both agents (a) and (b) applied to the keratin fibres. In this context, it has proven to be particularly advantageous if agents (a) and (b) are applied to the keratinous fibres in a weight ratio of 1:3 to 3:1, preferably 1:2 to 2:1 and most preferably 2:3 to 3:2.

[245] In a further particularly preferred embodiment, a method according to the invention is characterised in that agents (a) and (b) are applied to the keratinous fibres in a weight ratio of 1:3 to 3:1, preferably 1:2 to 2:1 and most preferably 2:3 to 3:2.

[246] When using agents (a) and (b) in a weight ratio of 2:3, for example, 100g of silane blend (a) is first applied to the keratin fibres and massaged in if necessary, then 150g of agent (b) is applied to the fibres still covered with agent (a).

[247] Further influencing factors are the concentration of silanes (a2) on agent (a) and the water concentration on agent (b). In this context, it was found that the oligomerization or polymerization could be set to the optimum speed for the application if the weight ratio of the total amount of organic silicon compounds (a2) contained in agent (a) to the amount of water (b1) contained in agent (b), i.e. the weight ratio (a2) / (b 1), was at a value of 1:100 to 1:1, preferably from 1:60 to 1:2, more preferably from 1:40 to 1:2.i.e. the weight ratio (a2) / (b1), is at a value of from 1:100 to 1:1, preferably from 1:60 to 1:2, more preferably from 1:40 to 1:4 and most preferably from 1:20 to 1:5.

[248] In other words, a particularly uniform and resistant film could be produced on the keratin fibres if both the quantities of the agents (a) and (b) and the concentrations of the silanes (a2) and the water (b 1) in both agents were selected such that the silanes (a2) and the water (b 1) were present in a weight ratio from 1:100 to 1:1, preferably from 1:60 to 1:2, more preferably from 1:40 to 1:4 and most preferably from 1:20 to 1:5 on the keratin fibres.

[249] In a further particularly preferred embodiment, a method according to the invention is characterised in that the weight ratio of the total amount of organic silicon compounds (a2) contained in agent (a) to the amount of water (b1) contained in agent (b), i.e. the weight ratio (a2) / (b1), is from 1:100 to 1:1, preferably from 1:60 to 1:2, more preferably from 1:40 to 1:4 and most preferably from 1:20 to 1:5.

[250] A weight ratio (a2) / (b1) of 1:70 to 1:10 here means that the water (b1) originating from agent (b) is used in a 10-fold to 70-fold excess by weight compared to the total quantity of silanes (a2) originating from agent (a).

[251] Example 40g of agent (a) is applied to the hair of a test person, agent (a) is briefly massaged into the entire hair mass. Agent (a) contains 1.0% by weight of water (a 1) (or a mixture of water and acid or a mixture of water and base), 3.0% by weight of 3-(aminopropyl)-triethoxysilane (a2), 6,0% by weight of methyltriethoxysilane (a2), 1.0% by weight of pigment (e.g. Unipure® Red LC 3079), 89% by weight of polyethylene glycol (e.g. PEG-8). The total amount of silanes (a2) contained in agent (a) is 3.6g, i.e. agent (a) contains 1.2g of 3-(aminopropyl)-triethoxysilane and 2.4g of methyltriethoxysilane. Following the application of agent (a), 60g of agent (b) are applied. Agent (b) contains (in addition to other formulation components such as preservatives and non-ionic surfactants) (b1) 58% in weight of water, and (b2) 36% by weight of PEG-8 and (b3) 1,2% by weight of cetearyl alcohol. Agent (b) is also distributed evenly over the entire head of the test person. After applying agent (b), massage the hair vigorously with your fingers for 1 minute so that both agents (a) and (b) are completely mixed together. 60g of agent (b) contains 34.8g of water. The weight ratio of the total amount of organic silicon compounds (a2) contained in agent (a) to the amount of water (b1) contained in agent (b), i.e. the weight ratio (a2) / (b1), is 3.6:34,8 = 1:9.67 After mixing the two agents (a) and (b), both agents are now allowed to act together on the keratin fibres in the form of their mixture. Preferably, both agents (a) and (b) are left to act together on the keratin fibres, in particular on the human hair, for a period from 10 seconds to 30 minutes, preferably from 30 seconds to 20 minutes, more preferably from 1 minute to 15 minutes and very particularly from 5 minutes to 10 minutes. In context of a further preferred embodiment, a method according to the invention is characterized by: (3) allowing both agents (a) and (b) to act together on the keratinous fibres for a period from 10 seconds to 30 minutes, preferably from 30 seconds to 20 minutes, more preferably from 1 minute to 15 minutes and very particularly from 5 minutes to 10 minutes. Step (4), rinsing out both agents (a) and (b) The work leading to this invention has shown that after the exposure time in step (3) of the method has elapsed, a coloured film has formed which is characterized by particularly high uniformity. When used on hair in the form of a full head application, the entire head could be coloured with an even colour result. After the two agents (a) and (b) had been applied, they could then be rinsed off the keratin fibres or rinsed out of the hair. Step (4) of the method according to the invention therefore comprises rinsing out both agents (a) and (b). The two agents (a) and (b) are preferably rinsed out under running water. In the context of a further preferred embodiment, a method according to the invention is characterized by: (4) Rinsing out both agents (a) and (b) under running water.

[252] Examples The following formulations were produced (unless otherwise stated, all figures are in % by weight) Agent (a) Agent (a) % by weight (3-aminopropyl)triethoxysilane (a2) 3.0 Methyltriethoxysilane (a2) 6.0 Water (a1) 1.0 NaOH 0.01 Unipure® Red LC 3079 (Pigment Red 7, CAS No. 5281-04-9) (a3) 1.0 PEG 6000 (a1) (polyethylene cyclo I, molecular weight 6000 to 7500g / mol) 4.5 PEG-8 (polyethylene glycol, molecular weight 400g / mol) ad 100 Agent (b) Agent (b) Comparison agent (bV) % by weight Invention agent (bE) % by weight Water (b1) 98.9 59.0 Hydroxyethyl cellulose (Natrosol 250 HR) 1.0 — PEG-8 (polyethylene glycol, molecular weight 400g / mol) (b2) — 39.4 Cetearyl alcohol (Cib / Cisfatty alcohols) (b3) — 1.2 Ceteareth-30 (cetearyl alcohol, ethoxylated 30 EO) — 0.3 Symsave® H (4-hydroxyacetophenone), converting agent 0.1 0.1

[253] 10 strands of hair (Kerling natural white) were weighed, then moistened under running water and then rubbed dry with a towel for 30 seconds. The strands were then weighed again. Agent (a) was then applied to each towel-dried hair strand (0.4g agent (a) per gram of damp hair strand). Agent (a) was massaged into each strand of hair for 30 seconds. Immediately afterwards, agent (b) (comparison) was applied to 5 strands of hair (0.4g agent (bV) per gram of damp hair strand). Agent (bE) according to the invention (0.4g agent (bE) per gram of damp hair strand) was applied to the remaining 5 hair strands. Each strand of hair was massaged again for 30 seconds so that a mixture of agents (a) and (b) formed on the strand of hair.

[254] The strands exposed to the dye were hung on a rack and left to hang freely for 5 minutes. A bowl was placed under each strand and the amount of liquid dripping from the strand was collected and weighed. The higher the amount of liquid dripping from the strand, the worse the applicability of the dye. Dyeing process - comparison agent (a) + agent (bV) Weight of dry strand [g] Weight of wet strand [g]* Quantity application mixture Dripped liquid [g] Strand 1 1.7 3.0 1.20g (a) + 1.20g (bV) 0.28 Strand 2 1.8 3.2 1.28g (a) + 1.28g (bV) 0.30 Strand 3 1.9 3.4 1.36g (a) + 1.36g (bV) 0.32 Strand 4 2.0 3.5 1.40g (a) + 1.40g (bV) 0.33 Strand 5 1.8 3.2 1.28g (a) + 1.28g (bV) 0.31 * Weight of the towel-damp strand Dyeing process - invention agent (a) + agent (bE) Weight of dry strand [g] Weight of wet strand [g]* Quantity application mixture Dripped liquid [g] Strand 6 1.9 3.4 1.36g (a) + 1.36g (bE) 0 Strand 7 1.7 3.0 1.20g (a) + 1.20g (bE) 0 Strand 8 1.8 3.2 1.28g (a) + 1.28g (bE) 0 Strand 9 1.9 3.4 1.36g (a) + 1.36g (bE) 0 Strand 10 1.8 3.2 1.28g (a) + 1.28g (bE) 0 * Weight of the towel-damp strand

[255] Figure 1 also shows a qualitative comparison of the two dyeing processes. The photo on the left shows the strand that was dyed with agents (a) and (bV). On the right, the strand dyed using the method according to the invention with agents (a) and (bE) is shown. For better visualization, both strands were hung over white crepe paper. The application mixture from (a) and (bV) dripped continuously from the left strand (comparison). The right strand (invention) showed improved viscosity stability of mixture of (a) and (bE) without dripping. After exposure to the two agents (a) and (bV) or (a) and (bE) for 5 minutes, the strands were rinsed under running water for 30 seconds and dried with a hairdryer. All strands 1 to 10 were dyed evenly in an intense shade of red with comparable colour intensity.

Claims

1. A method of dyeing keratinous fibres, in particular human hair, comprising the following steps in the order given:(1) application of an agent (a) to the keratinous fibres, wherein agent (a) contains - based on the total weight of agent (a):(a1) less than 10% by weight of water, (a2) at least one organic silicon compound of formula (I)RiR2N-L-Si(OR3)a(R4)b (I), where - Ri, R2 independently represent a hydrogen atom or a Ci-Ce alkyl group, - L is a linear or branched divalent Ci-C2o alkylene group, - R3 represents a hydrogen atom or a Ci-Ce alkyl group, - R4 represents a Ci-Ce alkyl group, - a, represents an integer from 1 to 3, and - b represents an integer 3 - a, and (a3) at least one pigment, (2) application of an agent (b) to the keratinous fibres which are still coated with agent (a), agent (b) containing, based on the total weight of agent (b) (b 1) 19.0 to 70.0% by weight of water, (b2) 20.0 to 80.0% by weight of polyethylene glycol(s), and (b3) 1.0 to 10.0% by weight of Cs-Cso fatty alcohol(s), (3) allowing both agents (a) and (b) to act on the keratinous fibres, and (4) rinsing out both agents (a) and (b).

2. A method according to claim 1, characterized in that agent (a) in step (1) is applied to towel-dried or dry keratinous fibres.

3. A method according to one of claims 1 to 2, characterised in that agent (a) contains - based on the total weight of agent (a) - from 0 to 7.5% by weight of water (a1).4, A method according to one of claims 1 to 2, characterised in that agent (a) contains - based on the total weight of agent (a) - from 0.01 to 5.0% by weight of water (a1).

5. A method according to one of claims 1 to 2, characterised in that agent (a) contains - based on the total weight of agent (a) - from 0.01 to 4.0% by weight of water (a1).

6. A method according to one of claims 1 to 2, characterised in that agent (a) contains - based on the total weight of agent (a) - from 0.05 to 2.5% by weight of water (a1).

7. A method according to one of claims 1 to 6, characterised in that agent (a) additionally containsat least one organic silicon compound (a2) of formula (II)R5Si(OR6)k(R7)m (II), where - Rs represents a Ci-Cis alkyl group, - Re represents a hydrogen atom or a Ci-Ce alkyl group, - R? represents a Ci-Ce alkyl group - k represents an integer from 1 to 3, and - m represents the integer 3 - k.

8. A method according to one of claims 1 to 7, characterised in that agent (a) contains - based on the total weight of agent (a) - one or more organic silicon compounds of formula (I) or one or more organic silicon compounds of formulae (I) and (II) in a total amount from 0.1 to 20% by weight.

9. A method according to one of claims 1 to 8, characterised in that agent (a) contains - based on the total weight of agent (a) - one or more polyethylene glycol(s) (a4) in a total amount from 50.0 to 99.0% by weight.

10. A method according to one of claims 1 to 9, characterized by the application of agent (b) within 10 minutes.

11. A method according to one of claims 1 to 10, characterized by the(2) application of agent (b) to the keratinous fibres still coated with agent (a) and preparation of a mixture of both agents (a) and (b) on the keratinous fibres by manual mixing of both agents.

12. A method according to one of claims 1 to 11, characterised in that agent (b) contains - based on the total weight of agent (b):(b1) 45.0 to 65.0% by weight of water, and(b2) 25.0 to 53.0% by weight of polyethylene glycol(s), and(b3) 2.0 to 5.0% by weight of Cs-Cso fatty alcohol(s).

13. A method according to one of claims 1 to 12, characterised in that agent (b) contains at least one non-ionic surfactant.

14. A method according to claim 13, wherein the at least one non-ionic surfactant is selected from the non-ionic surfactants of formula (T-l),Ra—O—CH2--CH2--OHwhereRa represents a saturated or unsaturated, unbranched or branched Ca-Cso alkyl group, andn represents an integer from 10 to 120.

15. A method according to claim 14, wherein Ra represents a saturated, unbranched Cie-Cis alkyl group.

16. A method according to one of claims 1 to 15, characterised in that agents (a) and (b) are applied to the keratinous fibres in a weight ratio of 1:3 to 3:1.

17. A method according to one of claims 1 to 16, characterised in that the weight ratio of the total amount of organic silicon compounds (a2) contained in agent (a) to the amount of water (b1) contained in agent (b), i.e. the weight ratio (a2) / (b1), is from 1:100 to 1:1.

18. A method according to one of claims 1 to 17, characterised by(3) allowing both agents (a) and (b) to act together on the keratinous fibres for a period from 10 seconds to 30 minutes.

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