WO2024042024A1

WO2024042024A1 - Hair care compositions leading to an increase of the colour resistance of dyed hair

Info

Publication number: WO2024042024A1
Application number: PCT/EP2023/072910
Authority: WO
Inventors: Désirée Sarah HAAG; Karina HECKER; Christine Mendrok-Edinger
Original assignee: Dsm Ip Assets B.V.
Priority date: 2022-08-22
Filing date: 2023-08-21
Publication date: 2024-02-29

Abstract

The present invention relates to hair care compositions comprising a specific mixture of branched and linear saturated C15-C19 alkanes, an ester of a fatty acid and dextrin and a cationic emulsifier. It has been shown that these hair care compositions lead to a significant increase of colour resistance of dyed hair.

Description

HAIR CARE COMPOSITIONS LEADING TO AN INCREASE OF THE COLOUR RESISTANCE OF DYED HAIR

TECHNICAL FIELD

The present invention relates to the field of cosmetic compositions, particularly to the field of cosmetic compositions for the care of dyed hair.

Background of the invention

The hair colouration is a specific field of cosmetics. The hair colouration is a common procedure particularly among women and is performed by using hair dyes.

Hair dyes are classified, according to colour resistance, into temporary, semipermanent, demipermanent and permanent. The first two are based on molecules which are already coloured. Temporary dyes act through dye deposition on cuticles, but semipermanent may penetrate a little into the cortex and so the colour resists up to typically six washes. Demipermanent and permanent hair dyes are based on colour precursors, called oxidation dyes, and the final shade is developed by their interactions with an oxidizing agent, but they differ from the alkalizing agent used. In oxidation systems, there is an intense diffusion of the molecules into the cortex, what promotes a longer colour resistance.

Washing of hair, particularly by shampoos, leads to a fading of the colour. A semipermanent hair dye is washed out after typically 4-6 shampooing. Although, due to the chemical fixation, a permanent dye persists for a significantly longer time to water, respectively to shampoos, also the colour resistance of permanent hair dyes is not perfect.

Because the customer desires to have a constant hair colour and appearance over an extended period, an increase of the colour resistance of a hair dye is a strong desire in the market of hair care products used in the field of hair colouration. Summary of the invention

Therefore, the problem to be solved by the present invention is to offer a product which increases the colour resistance of dyed hair.

Surprisingly, it has been found that this problem can be solved by a hair care composition according to claim 1 .

It has been observed that the colour of dyed hair resists much longer to the negative washing-out effect of shampoos and water when the dyed hair is treated with a hair composition which comprises a specific mixture of branched and linear saturated C15-C19 alkanes, an ester of a fatty acid and dextrin and a cationic emulsifier.

Further aspects of the invention are subject of further independent claims. Particularly preferred embodiments are subject of dependent claims.

Detailed description of the invention

In a first aspect, the present invention relates to a hair care composition comprising

- a mixture of branched and linear saturated C15-C19 alkanes; and

- an ester of a fatty acid and dextrin; and

- a cationic emulsifier wherein the amount of branched saturated C15-C19 alkane in said mixture of branched and linear saturated C15-C19 alkanes is more than 80 % by weight, preferably more that 90 % by weight, most preferred more than 92 % by weight, in respect to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

In the present document, a “C_x-y-alkyl” group is an alkyl group comprising x to y carbon atoms, i.e. , for example, a C_1-3 -alkyl group is an alkyl group compri- sing 1 to 3 carbon atoms. The alkyl group can be linear or branched. For example -CH(CH₃)-CH₂-CH₃ is considered as a C₄-alkyl group.

In case identical labels for symbols or groups are present in several formulae, in the present document, the definition of said group or symbol made in the context of one specific formula applies also to other formulae which comprises the same said label.

The term "UV filter" in the present document stands for a substance that absorbs ultraviolet light (=UV light), i.e. electromagnetic radiation of the wavelength between 280 and 400 nm. UV(A) filters are UV filters that absorb UV(A) light, i.e. electromagnetic radiation of the wavelength between 315 and 400 nm. UV(B) filters are UV filters that absorb UV(B) light, i.e. electromagnetic radiation of the wavelength between 280 and 315 nm.

A liquid organic UV filter is liquid at ambient temperature (i.e. 25°C).

A solid organic UV filter is solid at ambient temperature (i.e. 25°C).

A "mixture of branched and linear saturated C15-C19 alkanes" in the present document means that said mixture comprises different alkanes each of them only having 15, 16, 17, 18 or 19 carbon atoms but does not comprise any alkanes having less carbons. Therefore, such a mixture does not contain for example dodecane or isododecane. Said mixture comprises both branched and linear C15-C19 alkanes.

The term "shampoo" as used in the present document relates to hair care compositions used for cleansing of hair, i.e. the removal of oils, dirt, skin particles, dandruff, environmental pollutants and other contaminant particles that gradually build up in hair. The term shampoo also encompasses conditioning shampoos. The shampoo preparations according to the invention are applied to the hair and then rinsed away with water and are well known to a person skilled in the art.

The term "hair conditioner" refers in the present document to hair care compositions which are applied after washing the hair with cleansing compositions, such as a shampoo. The conditioners leave the hair more soft and pliable, facilitates combing and impart other positive attributes to the hair. Such hair conditioners can be leave in or rinse off products and are well known to a person skilled in the art.

White is not regarded as “colour” in the present document.

The term "colour resistance" refer to the resistance of a dye to be washed out by water, respectively by a cleansing product, typically a shampoo, of the dyed hair. An increase in colour resistance, therefore, means that the removal of the hair dye from the dyed hair by washing/shampooing is reduced.

Mixture of branched and linear saturated C15-C19 alkanes

The hair care composition comprises a mixture of branched and linear saturated C15-C19 alkanes.

Particular suitable mixtures of C15-C19 alkanes are particularly the ones disclosed in WO 2016/185046, WO 2017/046177, WO 2018/109353 A1 and WO 2018/109354 A1 and WO 2018/172228 A1 .

Preferably, the mixture of branched and linear saturated C15-C19 alkanes has a content of carbon of biological origin being greater or equal to 90% with respect of the total weight of the mixture of branched and linear saturated C15- C19 alkanes. The biological origin of chemicals is very advantageous as such material has a high degree of sustainability. High sustainable products or compositions are highly demanded in the market.

The determination of the content of biomaterial or content of biocarbon is given pursuant to standards ASTM D 6866-12, method B (ASTM D 6866-06) and ASTM D 7026 (ASTM D 7 026-04). Standard ASTM D 6866 concerns "Determi- ning the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis", while standard ASTM D 7 026 concerns ’’Sampling and Reporting of Results for Determination of Biobased Content of Materials via Carbon Isotope Analysis". The second standard mentions the first in its first paragraph. The first standard describes a test of measurement of the ratio ¹⁴C/¹²C of a sample and compares it with the ratio ¹⁴C/¹²C of a sample renewable reference of origin 100%, to give a relative percentage of C of origin renewable in the sample. The standard is based on the same concepts that the dating with ¹⁴C.

It is further preferred that the composition has no or a very small amount (less than 100 ppm, particularly less than 30 ppm) of aromatic hydrocarbons with respect to the total weight of the mixture of branched and linear saturated C15- C19 alkanes. The mixture of branched and linear saturated C15-C19 alkanes is particularly produced by catalytic hydrogenation of hydrocarbon biomass feedstock, such as described in detail in WO 2016/185046, particular the one disclosed as example 3 of WO 2016/185046.

It is preferred that the amount of linear saturated C15-C19 alkanes in said mixture of branched and linear saturated C15-C19 alkanes is less than 10 % by weight, preferably less than 8 % by weight, most preferred more than 5 % by weight, in respect to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

It is further preferred that the amount of C15 is less than 3 %, particularly less than 1 %, preferably less than 0.05 %, by weight in respect to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

It is preferred that the mixture of branched and linear saturated C15-C19 alkanes is a mixture of branched and linear saturated C16-C19 alkanes.

It is further preferred that amount of branched saturated C16-C18 alkane is more than 90% by weight, preferably more than 95 % by weight in respect to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

It is further preferred that the amount of C15 alkanes is less than 5 %, particularly less than 2%, by weight in respect to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

It is further preferred that amount of branched saturated C17-C18 alkane is more than 85% by weight, preferably more than 92 % by weight in respect to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

It is further preferred that the amount of C17 alkanes is more between 15 and 20 % by weight in respect to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

It is further preferred that amount of branched saturated C18 alkane is more than 50% by weight, preferably more than 60 % by weight, even more preferably more than 70 % by weight, relative to the weight of said mixture of branched and linear saturated C15-C19 alkanes. It is further preferred that the amount of C18 alkanes is particularly between 70 and 75 % by weight in respect to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

In other words, the mixture of branched and linear saturated C15-C19 alkanes consist preferably mainly of C18 alkane(s), most preferably mainly of branched C18 alkane(s).

As the hair care composition comprises a mixture of branched and linear saturated C15-C19 alkanes, said composition does not comprise any lower alkanes, i.e. it does particularly not comprise any C12 alkanes and particularly does not comprise any C12 or C13 or C14 alkanes.

It is further preferred that the mixture of C15-C19 alkanes has at 20°C, a viscosity of 3-15 mPa·s, particularly between 6 and 12 mPa·s.

It is further preferred that the mixture of C15-C19 alkanes has at 20°C a refractive index of between 1 .40 and 1 .48, particularly of between 1 .42 and 1 .45, most preferably between 1.43 and 1.44.

It is further preferred that the mixture of C15-C19 alkanes is the mixtures of C15-C19 alkanes as commercialized as EMOGREEN™ L19 by SEPPIC.

The amount of the mixture of branched and linear saturated C15-C19 alkanes is in the range of between 0.015 and 12.0 % by weight, particularly between 0.5 and 11 .0 % by weight, preferably between 1 .0 and 10.0 % by weight, more preferably between 1 .5 and 8.0 % by weight, even more preferably between 2.0 and 6.0 % by weight, based on the weight of the hair care composition.

Ester of a fatty acid and dextrin

The hair care composition further comprises an ester of a fatty acid and dextrin.

Dextrin is an oligomer of D-glucose. Its structure can be represented simplified by the following structure

Dextrins have different average degrees of glycopolymerization which leads to different molecular weights.

In the present invention, the dextrin of said ester of a fatty acid and dextrin has preferably an average degree of glycopolymerization of between 3 and 20, particularly between 8 and 16.

It is preferred that the fatty acid of said ester of a fatty acid and dextrin is a C14-C18 fatty acid, particularly a linear C14-C18 fatty acid, most preferably palmitic acid.

As particular suitable ester of a fatty acid and dextrin is a dextrin palmitate as commercialized as Rheopearl® KL2 by Chiba Flour Milling.

Dextrin has several hydroxyl groups which can be esterified.

It is preferred that said ester of a fatty acid and dextrin has an average number of esterified hydroxyl groups of more than 2.5, preferably between 2.5 and 3.5, more preferably between 2.5 and 3.4, most preferably between 2.5 and 3.2, per glucose unit.

In other words, preferably the majority of all of the hydroxyl groups of the dextrin are esterified. It is further preferred that said ester of a fatty acid and dextrin has a molecular weight M_n of between 8'000 and 16'000 Da, preferably between 9'000 and 13'000 Da, more preferably between 10'000 and 11'500 Da.

The molecular weight Mn is determined in Dalton (Da) particularly by SEC/GPC using polystyrene as standard.

Both fatty acid and dextrin have biological origin. The biological origin of chemicals is very advantageous as such material or products thereof have a high degree of sustainability. High sustainable products or compositions are highly demanded in the market.

The amount of the ester of a fatty acid and dextrin is preferably in the range of between 0.01 and 15 % by weight, particularly between 0.1 and 12 % by weight, preferably between 0.2 and 8 % by weight, more preferably between 0.6 and 7 % by weight, even more preferably between 0.8 and 6 % by weight, most preferably between 1 .3 and 4 % by weight, based on the weight of the hair care composition.

In the said hair care composition, the ratio of the weight of said ester of a fatty acid and dextrin to the weight of said mixture of branched and linear saturated C15-C19 alkanes is preferably less than 1 , preferably in the range of 0.5 to 0.8, most preferred in the range of 0.55 - 0.70.

In other words, the composition comprises preferably more, by weight, of the C15-C19 alkanes than of the ester of a fatty acid and dextrin.

Cationic emulsifier

The hair care composition of the present invention further comprises a cationic emulsifier.

The cationic emulsifier is preferably an organic ammonium compound, particularly a quaternary ammonium compound.

Said ammonium compound has preferably at least an ammonium group of the following structure:

wherein R¹, R² and R³ represent independently from each other either H or a linear or branched C_1-6 -alky I group; and wherein R⁴ represents a linear or branched C_1-6 -alkyl group; and wherein R⁵ represents a linear or branched, saturated or olefinically unsaturated C_1-25-alkyl group and wherein the dotted line represents the bond by which the ammonium group is bound to the rest of the ammonium compound, i.e. of the cationic emulsifier.

It is, furthermore, preferred that said organic ammonium compound has a molecular weight of at least 350 Dalton (g/mol), preferably between 350 and 1'000 Dalton (g/mol).

The cationic emulsifier is preferably a quaternary ammonium compound.

It is preferred that the cationic emulsifier is a substance which is defined by a CAS-number which is selected from the group consisting of [17301 -53-0], [92201 -88-2], [1156505-34-8] and [51277-96-4],

Particularly preferred as cationic emulsifiers are Behentrimonium chloride, quaternium-87, Brassicyl Isoleucinate Esylate, Palmitamidopropyltrimonium Chloride as defined by their INCI names.

The hair care composition comprises a cationic emulsifier, preferably in such an amount that it is in the range of between 0.5 and 10 % by weight, particularly between 0.5 and 8 % by weight, preferably between 1 and 6 % by weight, based on the weight of the hair care composition

The hair care composition is applied to hair, particular to human hair. In one of the embodiments, a hair care composition is a product for cleansing hair. Particularly such a cleansing hair care composition is a shampoo.

Therefore, in this embodiment, such a product comprises a cleansing agent which is typically a surfactant, preferably an anionic surfactant or a nonionic surfactant or a amphoteric or zwitterionic surfactants.

Exemplary anionic surfactants comprise alkylsulfate, alkylethersulfate, alkylsulfonate, alkylarylsulfonate, alkylsuccinate, alkylsulfosuccinate, N-alkoyl- sarkosinate, acyltaurate, acylisethionate, alkylphosphate, alkyletherphosphate, alkylethercarboxylate, alpha-olefinsulfonate, especially the alkali-und earth alkali salts, e.g. sodium, potassium, magnesium, calcium, as well as ammonium- and triethanol amine-salts. The alkylethersulfate, alkyletherphosphate and alkylether- carboxylate may comprise between 1 to 10 ethylenoxide or propylenoxide units, preferably 1 to 3 ethylenoxide-units per molecule. Suitable anionic surfactants are e.g. sodium laurylsulfate, ammonium lauryl sulfate, sodium lauryl ether sulfate (also known as sodium laureth sulfate), ammonium lauryl ether sulfate (also known as ammonium laureth sulfate), sodium lauroylsarkonisate, sodium oleyl succinate, ammonium lauryl sulfosuccinate, sodium dodecylbenzol sulfonate, triethanol amidodecylbenzol sulfonate. Particularly preferred anionic surfactants to be used in the shampoo according to the present invention are sodium lauryl sulfate, ammonium lauryl sulfate, sodium lauryl ether sulfate and ammonium lauryl ether sulfate as well as mixtures thereof.

Anionic surfactants are typically included in an amount (as active ingredient) ranging from 0.1 to 50 weight-%, more preferably in the range of 5 to 20 weight-% based on the total weight of the shampoo.

Exemplary nonionic surfactants, nonionic surfactants that can be included into shampoos according to the invention include condensation products of aliphatic (C8-C18) primary or secondary linear or branched chain alcohols with alkylene oxides, usually ethylene oxide and generally having from 6 to 30 ethylene oxide groups. Other representative nonionic surfactants include mono- or di-alkyl alkanolamides such as e.g. coco mono- or di- ethanolamide and coco mono- isopropanolamide. Further nonionic surfactants which can be included in shampoo preparations of the invention are the alkyl polyglycosides (APGs). Typically, the APG is one which comprises an alkyl group connected (optionally via a bridging group) to a block of one or more glycosyl groups such as e.g. Oramix NS 10 ex Seppic; Plantacare 818UP , Plantacare 1200 and Plantacare 2000 ex Cognis.

Nonionic surfactants are typically included in an amount (as active ingredient) ranging from 0.5 to 8 weight-%, preferably from 2 to 5 weight-%, based on the total weight of the shampoo.

Exemplary amphoteric or zwitterionic surfactants include alkyl amine oxides, alkyl betaines, alkyl amidopropyl betaines, alkyl sulphobetaines (sultaines), alkyl glycinates, alkyl carboxyglycinates, alkyl amphoacetates, alkyl amphopropionates, alkylamphoglycinates, alkyl amidopropyl hydroxysultaines, acyl taurates and acyl glutamates, wherein the alkyl and acyl groups have from 8 to 19 carbon atoms. Typical amphoteric and zwitterionic surfactants for use in said shampoos include lauryl amine oxide, cocodimethyl sulphopropyl betaine, lauryl betaine, cocamidopropyl betaine (CAPB), sodium cocoamphoacetate and disodium cocoamphodiacetate. Particularly preferred amphoteric or zwitterionic surfactant to be used in the shampoos are cocamidopropyl betaine and disodium cocoamphodiacetate as well as a mixture thereof.

Amphoteric or zwitterionic surfactants are typically included in an amount (as active ingredient) ranging from 0.5 to 8 weight-%, preferably from 1 to 4 weight- % based on the total weight of the shampoo.

In another, more preferred, embodiment, a hair care composition is a hair conditioner.

The hair care composition, particularly the hair conditioner, is preferably an emulsion, microemulsion, oleo gel, hydrodispersion or lipodispersion.

The hair care cosmetic compositions may be in the form of a suspension or dispersion in solvents or fatty substances, or alternatively in the form of an emulsion or micro emulsion (in particular of oil-in-water (O/W-) or water-in-oil (W/O-)type, silicone-in-water (Si/W-) or water-in-silicone (W/Si-)type, PIT- emulsion, multiple emulsion (e.g. oil-in-water-in oil (O/W/O-) or water-in-oil-in- water (W/O/W-)type), pickering emulsion, hydrogel, alcoholic gel, lipogel, one- or multiphase solution or vesicular dispersion.

Preferred hair care compositions in all embodiments of the present invention comprise water. The amount of water is preferably between 55 and 99 % by weight, particularly between 80 and 95 % by weight, based on the weight of the hair care composition.

The preferred hair care compositions comprise water and are in the form of an emulsion.

The emulsion particularly contains an oily phase and an aqueous phase such as in particular O/W, W/O, Si/W, W/Si, O/W/O, W/O/W multiple or a pickering emulsions.

The total amount of the oily phase present in such emulsions is preferably at least 4 wt.-%, such as in the range from 4 to 30 wt.-%, preferably in the range from 6 to 24 wt.-%, most preferably in the range from 8 to 18 wt.-%, based on the total weight of the hair care composition.

The amount of the aqueous phase present in such emulsions is preferably at least 50 wt. %, such as in the range from 50 to 98 wt.-%, preferably in the range from 60 to 95 wt.-%, most preferably in the range from 70 to 92 wt.-%, based on the total weight of the hair care composition.

More preferably, the cosmetic compositions are in the form of an oil-in- water (O/W) emulsion comprising an oily phase dispersed in an aqueous phase in the presence of an O/W- respectively Si/W-emulsifier. The preparation of such O/W emulsions is well known to a person skilled in the art.

The compositions in form of O/W emulsions can be provided, for example, in all the formulation forms for O/W emulsions, for example in the form of serum, milk or cream, and they are prepared according to the usual methods. The hair care composition comprises preferably a UV filter. The UV filter may be solid or liquid.

Suitable liquid organic UV-filter absorb light in the UV(B) and/ or UV(A) range and are liquid at ambient temperature (i.e. 25°C). Such liquid UV-filter are well known to a person in the art and encompass in particular cinnamates such as e.g. octyl methoxycinnamate (PARSOL® MCX) and isoamyl methoxycinnamate (Neo Heliopan® E 1000), salicylates such as e.g. homosalate (3,3,5 trimethyl- cyclohexyl 2-hydroxybenzoate, PARSOL® HMS) and ethylhexyl salicylate (also known as ethylhexyl salicylate, 2-ethylhexyl-2-hydroxybenzoate, PARSOL® EHS), acrylates such as e.g. octocrylene (2-ethylhexyl-2-cyano-3,3-diphenylacrylate, PARSOL® 340) and ethyl 2-cyano-3,3 diphenylacrylate, esters of benzalmalonic acid such as in particular dialkyl benzalmalonates such as e.g. di (2-ethylhexyl) 4- methoxybenzalmalonate and polysilicone 15 (PARSOL® SLX), dialkylester of naphthalates such as e.g. diethylhexyl 2,6-naphthalate (Corapan® TQ), syringylidene malonates such as e.g. diethylhexyl syringylidene malonate (Oxynex® ST liquid) as well as benzotriazolyl dodecyl p-cresol (Tinoguard® TL) as well as benzophenone-3 and drometrizole trisiloxane.

Particular advantageous liquid organic UV-filter are octyl methoxycinna- mate, homosalate, ethylhexyl salicylate, octocrylene, diethylhexyl 2,6-naphthalate, diethylhexyl syringylidene malonate, benzotriazolyl dodecyl p-cresol, benzo- phenone-3, drometrizole trisiloxane as well as mixtures thereof.

In a preferred embodiment, the liquid UV filter is a liquid UV(B) filter which is selected from the group consisting of ethylhexyl methoxycinnamate, octocrylene, homosalate, ethylhexyl salicylate, benzophenone-3 and drometrizole trisiloxane.

Suitable solid organic UV-filter absorb light in the UV(B) and/ or UV(A) range and are solid at ambient temperature (i.e. 25°C). Particularly suited solid UV-filters are of the group consisting of bis-ethylhexyloxyphenol methoxyphenyl triazine, butyl methoxydibenzoyl methane, diethylamino hydroxybenzoyl hexyl benzoate, ethylhexyl triazone, diethylhexyl butamido triazone, 4-methylbenzyli- dene camphor and 1 ,4-di(benzoxazol-2’-yl)benzene, and methylene bis- benzotriazolyl tetramethylbutylphenol (Bisoctrizole).

Bisoctrizole is a broad-spectrum ultraviolet radiation filter, absorbing UV(B) as well as UV(A) rays and has an excellent photostability. It has an absorp- tion maximum at 308 nm and 349 nm. However, next to absorption of UV light, it also reflects and scatters UV light. Therefore, Bisoctrizole is a hybrid UV absorber, an organic UV filter produced in microfine organic particles (< 200 nm). Where other organic UV filters need to be dissolved in either the oil or water phase, bisoctrizole dissolves poorly in both and is applied as invisible particle.

A preferred solid organic UV(A) filter is a UV(A) filter which is selected from the group consisting of bis-ethylhexyloxyphenol methoxyphenyl triazine, butyl methoxydibenzoyl methane, diethylamino hydroxybenzoyl hexyl benzoate and tris- biphenyl triazine.

A preferred solid organic UV(B) filter is a UV(B) filter which is selected from the group consisting of ethylhexyl triazone (= Uvinul® T150), diethylhexyl butamido triazone (= Uvasorb® HEB), and 4-methylbenzylidene camphor (=PARSOL® 5000).

The hair care composition, particularly the hair conditioner, may contain the usual oily and fatty components which may be chosen from mineral oils and mineral waxes; oils such as triglycerides of caprinic acid and/or caprylic acid or castor oil; oils or waxes and other natural or synthetic oils, in a preferred embodiment esters of fatty acids with alcohols e.g. isopropanol, propyleneglycol, glycerin or esters of fatty alcohols with carbonic acids or fatty acids; alkyl- benzoates; and/or silicone oils.

Exemplary fatty substances which can be particularly incorporated in the oil phase of the emulsion, microemulsion, oleo gel, hydrodispersion or lipodispersion are advantageously chosen from esters of saturated and/or unsaturated, linear or branched alkyl carboxylic acids with 3 to 30 carbon atoms, and saturated and/or unsaturated, linear and/or branched alcohols with 3 to 30 carbon atoms as well as esters of aromatic carboxylic acids and of saturated and/or unsaturated, linear or branched alcohols of 3-30 carbon atoms. Such esters can advantageously be selected from octylpalmitate, octylcocoate, octylisostearate, octyldodecylmyris- tate, cetearylisononanoate, isopropylmyristate, isopropylpalmitate, isopropyl- stearate, isopropyloleate, n-butylstearate, n-hexyllaurate, n-decyloleate, isooctyl- stearate, isononylstearate, isononylisononanoate, 2-ethyl hexylpalmitate, 2-ethyl- hexyllaurate, 2-hexyldecylstearate, 2-octyldodecylpalmitate, stearylheptanoate, oleyloleate, oleylerucate, erucyloleate, erucylerucate, tridecylstearate, tridecyl- trimellitate, as well as synthetic, half-synthetic or natural mixtures of such esters e.g. jojoba oil.

Other fatty components, particularly suitable for hair conditioner, include polar oils such as lecithins and fatty acid triglycerides, namely triglycerol esters of saturated and/or unsaturated, straight or branched carboxylic acid with 8 to 24 carbon atoms, preferably of 12 to 18 carbon-atoms whereas the fatty acid triglycerides are preferably chosen from synthetic, half synthetic or natural oils (e.g. cocoglyceride, olive oil, sun flower oil, soybean oil, peanut oil, rape seed oil, sweet almond oil, palm oil, coconut oil, castor oil, hydrogenated castor oil, wheat oil, grape seed oil, macadamia nut oil and others); apolar oils such as linear and/ or branched hydrocarbons and waxes e.g. mineral oils, vaseline (petrolatum); paraffins, squalane and squalene, polyolefins, hydrogenated polyisobutenes and isohexadecanes, favored polyolefins are polydecenes; dialkyl ethers such as dicaprylylether; linear or cyclic silicone oils such as preferably cyclomethicone (octamethylcyclotetrasiloxane; cetyldimethicone, hexamethylcyclotrisiloxane, polydimethylsiloxane, poly(methylphenylsiloxane) and mixtures thereof.

Other fatty components which can advantageously be incorporated in hair conditioners are isoeicosane; neopentylglycoldiheptanoate; propyleneglycol- dicaprylate/ dicaprate; caprylic/ capric/ diglycerylsuccinate; butyleneglycol caprylat/caprat; C_12-13-alkyllactate; di- C_12-13-alkyltartrate; triisostearin; dipenta- erythrityl hexacaprylat/hexacaprate; propyleneglycolmonoisostearate; tricaprylin or dimethylisosorbid. Especially beneficial is the use of mixtures C_12-15-alky I- benzoate and 2-ethylhexylisostearate, mixtures C_12-15-alkylbenzoate and isotri- decylisononanoate as well as mixtures of C_12-15-alkylbenzoate, 2-ethylhexyl- isostearate and isotridecylisononanoate.

The oily phase of the conditioner preparation can also contain natural vegetable or animal waxes such as bees wax, china wax, bumblebee wax and other waxes of insects as well as shea butter and cocoa butter.

Suitable silicone oils are e.g. dimethylpolysiloxane, diethylpolysiloxane, diphenylpolysiloxane, cyclic siloxanes, poly(methylphenylsiloxanes) as well as amino-, fatty acid-, alcohol-, polyether-, epoxy-, fluor-, glycoside-, and/or alkyl modified silicone compounds which are liquid or solid at room temperature and mixtures thereof. The number average molecular weight of the dimethicones and poly(methylphenylsiloxanes) is preferably in the range of 100 to 150'000 g/mol. Preferred cyclic siloxanes comprise 4- to 8- membered rings which are for example commercially available as cyclomethicones.

The hair care composition is preferably a hair conditioner.

The hair care composition is, furthermore, preferably free of any anionic surfactants and/or free of any non-ionic surfactants. Even more preferred, the hair care composition is a hair conditioner which is free of any anionic surfactants or any non-ionic surfactants.

The hair care composition, particularly the shampoo or the hair conditioner, may comprise further ingredients which are known to be typically used for the preparation of hair care compositions, particularly for shampoos or hair conditioners, respectively. The hair care composition preferably comprises

- 0.015 - 12.0 % by weight, particularly 0.5 -11 % by weight, preferably 1 -10 % by weight, more preferably 1 .5 - 8% by weight, most preferably 2 - 6 % by weight, of a mixture of branched and linear saturated C15-C19 alkanes as described above in great detail;

- 0.01 - 15.0 % by weight, particularly 1 -1 12 % by weight, preferably 0.2 - 8.0 % by weight, more preferably 0.6 - 7 % by weight, even mor preferably 0.8 - 6 % by weight, most preferably 1.3 - 4 % by weight, of an ester of a fatty acid and dextrin as described above in great detail;

- 0.5 - 10.0 % by weight, preferably 1 .0 - 6.0 % by weight, of a cationic emulsifier as described above in great detail

- 50 - 99 % by weight, preferably 80 - 95 % by weight, of water, with the proviso that the sum of the individual amounts of ingredients do not exceed 100%.

Resistance of hair dye applied on hair

It has been observed that the hair care composition, as described above in great detail, leads to an increased colour resistance of a hair dye which is applied to hair.

Colours are difficult to describe. One of the methods is the representation of colour by the so-called Lab colour space. Currently the mostly used Lab method is the CIE-L*a*b*as proposed by CIE in 1976. In this representation the para- meters “L”, resp. “L*”, is lightness, and the parameters “a”, resp. “a*”, and “b”, resp. “b*”, are colour-opponent dimensions. The parameter L, resp. L*, has a value between 0 and 100, parameters a and b, resp. a* and b*, have a value between - 100 and 100.

Changes in colour are, hence, defined by a change of L, resp. L*, (= ΔL resp. ΔL*), a, resp. a*, (= Δa resp. Δa*), and/or b, resp. b*, (= Δb resp. Δb*) values.

Despite the background theory is rather complex, a decrease of value of L, resp. L* leads to a sensation of a darker colour. An increase of the value a, resp. a* leads to a sensation of enhancing of the red colour component. An increase of the value b, resp. b* leads to a sensation of enhancing of the yellow colour component.

A colour change is usually not only a change of an individual parameter L, a or b, resp. L*, a* or b*, but a change of more than one of these parameters simultaneously.

Hence, there has been the colour difference defined which is expressed by ΔE, resp. ΔE*, according to the following formula

Assessing the advantage of this invention is best realized by comparing the measured colour of dyed hair before and after washing and conditioning cycles.

Hair Dyes

Principally, the invention relates to any hair dyes known to the person skilled in the art.

Semipermanent Hair Dyes

In a preferred embodiment, the hair dye is a semipermanent hair dye.

The semipermanent hair dye is advantageous in that it is very easy for application and suitable for regular use and is a way of colouring the hair particularly mild to the hair and the skin as they are not using an oxidizing agent. The number of different shades of hair colours, however, is somehow more limited. Furthermore, semipermanent hair dyes are less suitable to colour gray or white hair. Finally semipermanent hair dyes cannot be used to obtain a lighter shade of the actual hair colour, which limits the possibilities of colouration for people having a natural dark or black hair colour.

Semipermanent hair dyes typically include compounds having a chromophore system that is common in dye chemistry such as nitro, azo, anthraquinone, triphenylmethane, triarylmethane, and azomethane, which may be used as disperse dyes, nitro dyes, cationic (basic) dyes, anionic (acidic) dyes and metal complex dyes (as disclosed indicated in Ullmann's Encyclopedia of Industrial Chemistry Vol A 12, page 586, 5th, completely revised edition, 1989). Of particular interest are e.g. anthraquinone dyes, especially those containing a dialkylaminoalkylamino (DAAA) group. Specific examples include the following compounds available under the trademark ARIANOR® from Warner Jenkinson Ltd.: ARIANOR Straw Yellow, ARIANOR Mahogany, ARIANOR Steel Blue, ARIANOR Madder Red, ARIANOR Ebony and ARIANOR Sienna Brown.

Furthermore, very suitable anthraquinone dyes are anthraquinone having a quaternary ammonium side chain.

Specific examples for nitro dyes are compounds selected from the group consisting of 2-((2-nitrophenyl)amino)ethan-1-ol (CAS: 4926-55-0), 4-((2- hydroxyethyl)amino)-3-nitrophenol (CAS: 92952-81-3), 2-((4-amino-2- nitrophenyl)amino)ethan-1-ol (CAS: 2871-04), N,N'-Bis(2-hydroxyethyl)-2-nitro-p- phenylenediamine (CAS: 84041-77-0) and 2,2'-((4-((2-Hydroxyethyl)amino)-3- nitrophenyl)imino)bisethanol) (CAS: 33229-34-4), 2-nitro-p-phenylenediamine (CAS: 5307-14-2) and 4-nitro-o-phenylenediamine (CAS: 99-56-9).

Semipermanent hair dyes are commercially available in a great variety of chemistry and colours. Particularly suitable as semipermanent hair dyes are those implemented in the commercial product lines selected from the group consisting of Revlon® Professional Nutri Color™ Filters from Revlon®, John Freida Violet Crush for Blondes from Kao Brands, Revolution Haircare Tones for Brunettes from Revlon®, Good Dye Young from Good Dye Young, Wella Color by You from Coty and Syoss Color Glow from Schwarzkopf & Henkel.

Permanent Hair Dyes

In another preferred embodiment, the hair dye is a permanent hair dye.

The permanent hair dye is advantageous over the other types of hair dyes in that it offers the highest colour resistance of hair dyes, has an excellent colour coverage, particularly also for white or gray hair, and offers the broadest variety of colours and shades available. Permanent hair dyes, however, are rather aggressive, due to the chemical oxidation and fixation process.

Typically, a permanent hair dye is produced by a permanent hair colouring composition requires three components:

(1) a primary intermediate agent,

(2) a coupling agent, and

(3) an oxidant.

The process of permanent hair dye formation is typically performed under basic conditions by the use of an alkalizing agent.

The mechanism of oxidation involves three steps:

1 ) Oxidation of the primary intermediate;

2) Reaction of this with a coupling agent; and

3) Oxidation of the resulting compound by an oxidizing agent to give the final dye.

Oxidizing agents are usually hydrogen peroxide, and the alkaline environment is usually provided by ammonia. The combination of hydrogen peroxide and ammonia causes the natural hair to be lightened, providing a "blank canvas" for the dye. Ammonia opens the hair shaft pores so that the dye can actually diffuse inside the fiber. These dye intermediate and coupling agent can undergo oxidation and coupling reaction to form high molecular weight products, which are trapped in the hair matrix and cannot be readily removed through washing. Primary intermediate agent

Primary intermediate agents are well known for use in hair colour, and include ortho or para substituted aminophenols or phenylenediamines, particularly para-phenylenediamines of the formula:

wherein R¹¹ and R¹² are each independently hydrogen, C_1-6 -alkyl, or C_1-6 - alkyl substituted with one or more hydroxy, methoxy, methylsulphonylamino, aminocarbonyl, furfuryl, unsubstituted phenyl, or amino substituted phenyl groups; and

R¹³, R¹⁴, R¹⁵ and R¹⁶ are each independently hydrogen, C_1-6 -alkyl, C_1-6 - alkoxy, halogen, or C_1-6 -alkyl substituted with one or more hydroxy or amino groups.

Preferred primary intermediate agent are selected from the group consis- ting of para-phenylenediamine, 2-methyl-1 ,4-diaminobenzene, 2,6-dimethyl-1 ,4- diaminobenzene, 2,5-dimethyl-1 ,4-diaminobenzene, 2,3-dimethyl-1 ,4-diaminoben- zene, 2-chloro-1 ,4-diaminobenzene, 2-methoxy-1 ,4-diaminobenzene, 1 -phenyl- amino-4-aminobenzene, 1-dimethylamino-4-aminobenzene, 1-diethylamino-4- aminobenzene, 1-bis(beta-hydroxyethyl)amino-4-aminobenzene, 1 -methoxy- ethylamino-4-aminobenzene, 2-hydroxymethyl-1 ,4-diaminobenzene, 2-hydroxy- ethyl-1 ,4-diaminobenzene, 2-isopropyl-1 ,4-diaminobenzene, 1-hydroxypropyl- amino-4-aminobenzene, 2,6-dimethyl-3-methoxy-1 ,4-diaminobenzene, 1 -amino-4- hydroxybenzene, 1 -hydroxyethyl 4,5-diamino pyrazole, 6-methoxy-2-methylamino- 3-aminopyridine and derivatives thereof, and acid or basic salts thereof. Particularly preferred primary intermediate agent are p-phenylenediamine, p-aminophenol, o-aminophenol, N,N-bis(2-hydroxyethyl)-p-phenylenediamine, 2,5- diaminotoluene, their salts and mixtures thereof.

Colour Coupling agents

The colour coupling agent is particularly selected from the group consis- ting of m-aminophenol, 2,4-diaminotoluene, 4-amino-2-hydroxytoluene, phenyl methyl pyrazolone, (3-methyl-1 -phenyl-5-pyrazolone), 3,4-methylenedioxyphenol, 3,4-methylenedioxy-1 -[(beta-hydroxyethyl)amino]benzene, 1 -methoxy-2-amino-4- [(beta-hydroxyethyl)amino]benzene, 1 -hydroxy-3-(dimethylamino)benzene, 6- methyl-1-hydroxy-3[(beta-hydroxyethyl)amino]benzene, 2,4-dichloro-1 -hydroxy-3- am inobenzene, 1 -hydroxy-3-(diethylam ino)benzene, 1 -hydroxy-2-methyl-3-am ino- benzene, 2-chloro-6-methyl-1 -hydroxy-3-aminobenzene, 1 ,3-diaminobenzene, 6- methoxy- 1 ,3-diaminobenzene, 6-hydroxyethoxy-1 ,3-diaminobenzene, 6-methoxy- 5-ethy 1-1 ,3-diaminobenzene, 6-ethoxy-1 ,3-diaminobenzene, 1 -bis(beta-hydroxy- ethyl)amino-3-am inobenzene, 2-methyl-1 ,3-diaminobenzene, 6-methoxy-1-amino- 3-[(beta-hydroxyethyl)amino]-benzene, 6-(beta-aminoethoxy)-1 ,3-diamino- benzene, 6-(beta-hydroxyethoxy)-1 -amino-3-(methylamino)benzene, 6-carboxy- methoxy-1 ,3-diaminobenzene, 6-ethoxy-1-bis(beta-hydroxyethyl)amino-3-am ino- benzene, 6-hydroxyethyl-1 ,3-diaminobenzene, 1 -hydroxy-2-isopropyl-5-methyl- benzene, 1 ,3-dihydroxybenzene, 2-chloro-1 ,3-dihydroxybenzene, 2-methyl-1 ,3- dihydroxybenzene, 4-chloro-1 ,3-dihydroxybenzene, 5,6-dichloro-2-methyl-1 ,3- dihydroxybenzene, 1 -hydroxy-3-amino-benzene, 1 -hydroxy-3-(carbamoylmethyl- amino)benzene, 6-hydroxybenzomorpholine, 4-methyl-2,6-dihydroxypyridine, 2,6- dihydroxypyridine, 2,6-diaminopyridine, 6-aminobenzomorpholine, 1-phenyl-3- methyl-5-pyrazolone, 1 -hydroxynaphthalene, 1 ,7-dihydroxynaphthalene, 1 ,5- dihydroxynaphthalene, 5-amino-2-methyl phenol, 4-amino-2-hydroxytoluene, 2- amino-3-hydroxytoluene, 2-amino-5-hydroxytoluene, 4-hydroxyindole, 4-hydroxy- indoline, 6-hydroxyindole, 6-hydroxyindoline, 2,4-diaminophenoxyethanol, 1- naphthol, 2-naphthol, phenol, catechol, m-amino phenol, m-phenylenediamine, phenol which is substituted on the amino group or benzene ring with at least one alkyl, hydroxyalkyl, alkylamino group; catechol which is substituted on the amino group or benzene ring with at least one alkyl, hydroxyalkyl, alkylamino group; m- amino phenol which is substituted on the amino group or benzene ring with at least one alkyl, hydroxyalkyl, alkylamino group; m-phenylenediamine, which is substituted on the amino group or benzene ring with at least one alkyl, hydroxyalkyl, alkylamino group; and mixtures thereof.

Preferred coupling agents are selected from the group consisting of resorcinol, 1 -naphthol, 2-methylresorcinol, 4-amino-2-hydroxy toluene, m-amino- phenol, 2,4-diaminophenoxyethanol, 3-methyl-1-phenyl-5-pyrazolone, their salts, or mixtures.

Alkalizing agents

Preferably, the permanent hair colouring composition comprises an alkalizing agent. The term "alkalizing agent" means an ingredient that is capable of imparting alkalinity (e. g. a pH of greater than 7) to the oxidative composition. Preferred alkalizing agents are ammonium hydroxide, metal hydroxides, alkanolamines, sodium silicate, metal carbonates, sodium metasilicate, and mixtures thereof. Suitable metal hydroxides and carbonates include alkali metal and alkaline earth metal hydroxides or carbonates. Examples of such metal hydroxides are hydroxides of sodium, potassium, lithium, calcium, magnesium or. A particularly preferred alkaline earth metal hydroxide is sodium hydroxide. Preferably the alkanolamine is selected from the group consisting of mono-, di-, and trialkanolamines such as monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), 2-aminobutanol, aminoethyl propanediol, aminomethyl propanediol, bis-hydroxyethyl tromethamine (=bis(2-hydroxyethyl)amino-tris- (hydroxymethyl)methane), diethyl ethanolamine, diisopropanolamine, dimethylaminomethylpropanol, dimethyl MEA (=2-(dimethylamino)-ethan-1-ol), isopropanolamine, methylethanolamine, mixed isopropanolamines, triisopro- panolamine, tromethamine (=tris(hydroxymethyl)aminomethane) and mixtures thereof. A particularly preferred alkanolamine is monoethanolamine (MEA). Most preferred are dye mixtures that contain ammonium hydroxide as alkalizing agent in combination with a second alkalizing agent such as an alkanolamine.

Permanent hair colouring compositions are commercially available in a great variety of chemistry and colours. Particularly suitable as permanent hair dyes are those obtained from the commercial product lines selected from the group consisting of Schwarzkopf Brilliance from Schwarzkopf, Schwarzkopf got2b Edelmetall from Schwarzkopf & Henkel, L' Oreal Preference Vivid Colors from L’ Oreal, Revlon © Total Color™ from Revlon, Schwarzkopf Brilliance Gem Collection from Schwarzkopf & Henkel, Wella Professional Koleston Perfect Pure Naturals from Wella, Wella Koleston from Coty, Beautycolor Bela&Cor from Bonyplus, Miracle System from Josh Wood Colour, Garnier Nutrisse Ultra Creme Permanent Hair Dye from L'Oreal and Hello!! Bubble Foam Color - Mise en Scene from Amorepacific.

As mentioned, it has been observed that the hair care composition, as described above in great detail, leads to an increased colour resistance of a hair dye which is applied to hair.

Hence, in a further aspect, the present invention relates to the use of a mixture of branched and linear saturated C15-C19 alkanes, in combination with an ester of a fatty acid and dextrin, and a cationic emulsifier for increasing the colour resistance of a hair dye which is applied to hair.

More specifically, the hair dye is in a one preferred embodiment a semi- permanent hair dye and in another preferred embodiment a permanent hair dye. Examples

The following examples are provided to further illustrate the compositions and effects of the present invention. These examples are illustrative only and are not intended to limit the scope of the invention in any way.

Experimental series 1 : semipermanent hair dye

Dyeing of hair by semipermanent hair dyes

Hair tresses (Kerling Nr. 826204 KT dicht, Euro-hair, remis extra bleached, color 10/0, length: 120 mm) have been dyed according to the instruction provided in the package of the semipermanent hair dye.

-Revelon Professional® Nutri Color™ Filters 190 Blau (comprising the semiperma- nent hair dye HC blue No. 16 (=dimethyl-[3-[[4-(methylamino)-9,10-dioxo- anthracen-1-yl]amino]propyl]-propylazanium bromide);

-Revelon Professional® Nutri Color™ Filters 200 Violet (comprising the semipermanent hair dyes HC blue No. 16 and Basic Violet 2 (=4-[(4-amino-3- methylphenyl)-(4-imino-3-methylcyclohexa-2,5-dien-1 -ylidene)methyl]-2- methylaniline hydrochloride);

-Revelon Professional® Nutri Color™ Filters 740 Light Copper (comprising the semipermanent hair dyes Basic Brown 17 (=[8-[(4-Amino-2-nitrophenyl)azo]-7- hydroxy-2-naphthyl]trimethylammoniumchlorid) and Basic Red 76 (=[7-Hydroxy-8- [(2-methoxyphenyl)azo]-2-naphthyl]trimethylammoniumchlorid);

-Revelon Professional® Nutri Color™ Filters 524 Coppery Pearl Brown Copper (comprising the semipermanent hair dyes Basic Brown 17, Basic red 51 (=2-[[4- (Dimethylamino)phenyl]azo]-1 ,3-dimethyl-1 H-imidazoliumchlorid), Basic Yellow 57 (=3-[(4,5-Dihydro-3-methyl-5-oxo-1-phenyl-1 H-pyrazol-4-yl)azo]-N,N,N- trimethylaniliniumchlorid), Basic Violet 2, HC Blue No.16): The hair tresses have been treated with 1 ml undiluted hair dye for 5 minutes. The tress has been rinsed for 30 seconds with warm water (38°C) and dried at room temperature overnight. 3 tresses have been prepared per sample. Shampooinp/Conditioninp of hair dyed by semipermanent hair dye

For each shampooing/conditioning cycle the dyed tresses have been washed with 0.5 ml of a shampoo of the composition according to table 1 per hair tress for 30 seconds, and then rinsed for 30 seconds with warm water (38°C). Then 0.5 ml of the respective conditioner (composition see table 2) is applied on each hair tress, the conditioner has remained on the hair tress for 2 minutes and washed out by 30 seconds rinsing with warm water (38°C). This procedure has been repeated 5 times so that the tresses have been washed and conditioned 5 times in total for each shampooing/conditioning cycle. At the end of each shampooing/conditioning cycle the tresses have been dried at room temperature overnight.

Table 1 Composition of shampoo.

*amounts in % by weight.

Hair care compositions

The cosmetic composition as outlined in table 1 have been prepared according to standard methods in the art. Color measuring

The L*a*b*-values of the hair tresses have been measured before the first (i.e. “after 0 cycles") and after the respective shampooing/conditioning cycles (i.e. “after 1 cycle", “after 2 cycles" etc.), using a Konica Minolta-CM 600d color measurement device. The respective 3 tresses have been positioned next to each other and the L*a*b*-values have been 25 times measured and their average has been reported in tables 3, 5, 7 and 9. The changes in colour indicated as ΔL*, Δa*, Δb* and ΔE * in tables 4, 6, 8 and 10 are calculated from the color measurements of the initial values and after the respective shampooing/conditioning cycles.

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Experimental series 2: semipermanent hair dye (II)

The experiments of the experimental series 2 are performed in an identical manner as those of the experimental series 1 with the only exception that the hair tresses (Kerling Nr. 826204 KT dicht, Euro-hair, remis extra bleached, color 10/0, length: 120 mm) were of a different batch.

The semipermanent hair dyes used in the second series where:

- Schwarzkopf Pillar Box Red 092 (comprising the semipermanent hair dyes Basic Orange 31 (= 2-[(4-Aminophenyl)azo]-1 ,3-dimethyl-1 H-imidazolium chloride) and Basic Red 51 (=2-((4-(Dimethylamino)phenyl)azo)-1 ,3-dimethyl-1 H-imidazolium chloride).

For this series the cosmetic composition as outlined in table 11 have been used.

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Experimental series 3: permanent hair dye

Dyeing of hair by permanent hair dyes

Hair tresses (Kerling Nr. 826204 KT dicht, Euro-hair, remis extra bleached, color 10/0, length: 120 mm) (same batch as for experimental series 1 ) have been dyed according to the instruction provided in the package of the permanent hair dye

• Schwarzkopf Brilliance Intensive Color Creme, 849 Violette Wildseide (all-in multi-compartment package (i.e. a color cream part comprising 6-methoxy- 2-methylamino-3-aminopyridine (primary intermediate agent) and 4-amino- 2-hydroxytoluene (color coupling agent); and a developer part (comprising hydrogen peroxide (oxidation agent)); or

• Schwarzkopf Brilliance Intensive Color Creme, 872 Intensivrot (all-in multicompartment package (i.e. a color cream part comprising 2,5- diaminotoluene sulfate, 1 -hydroxyethyl 4,5-diamino pyrazole sulfate (primary intermediate agents) and 2-amino-3-hydroxytoluene, 2-amino-3 hydroxytoluene (=2-amino-5-hydroxytoluene) (color coupling agents); and a developer part (comprising hydrogen peroxide (oxidation agent)), or

• Schwarzkopf Brilliance Intensive Color Creme, 867 Mahagoni-Braun (all-in multi-compartment package (i.e. a color cream part comprising toluene 2,5- diamine sulfate (primary intermediate agent), 2-amino-3-hydroxypyridine, 2,7-naphthalenediol, 2-methylresorcinol (color coupling agents); and a developer part (comprising hydrogen peroxide (oxidation agent)) respectively, as commercially available.

The whole content of the color cream part was put into the developer bottle which comprised the oxidant and shaken until the composition has been completely mixed. Then the composition of the whole bottle was instantly applied on hair and made sure it is evenly distributed. Then the color was left on the hair for 30-45 minutes. After the exposure time (30-45 minutes) the hair tresses have been rinsed with warm water (38°C) until the water was colorless. Then the conditioner included in the package has been applied and remained on the hair tresses for 2 minutes. Then said conditioner has been washed out for 30 seconds at 38° water temperature. The tresses have been dried at room temperature overnight. The tresses have been cut in switches of 1 .0 cm width. For each test 3 tresses have been prepared.

The color of the dyed tresses has been measured to get the initial L* a* b* values value (i.e. “after 0 cycles") using the color measuring method as described below “Color measuring”.

Shampooing/Conditioning of hair dyed by permanent hair dye

For each shampooing/conditioning cycle the dyed tresses have been washed with 0.5 ml of a shampoo of the composition according to table 1 per hair tress for 30 se- conds, and then rinsed for 30 seconds with warm water (38°C). Then 0.5 ml of the respective conditioner (composition see table 2) is applied on each hair tress, the conditioner has remained on the hair tress for 2 minutes and washed out by 30 se- conds rinsing with warm water (38°C). This procedure has been repeated 9 times so that the tresses have been shampooed and washed and conditioned 10 times in total for each shampooing/conditioning cycle. At the end of each shampoo- ing/conditioning cycle the tresses have been dried at room temperature overnight. Color measuring

The L*a*b*-values of the hair tresses have been measured before the first (i.e. “after 0 cycles") and after the respective shampooing/ conditioning cycles (i.e. “after 1 cycle", “after 2 cycles" etc.) respectively, using a Konica Minolta-CM 600d color measurement device. The respective 3 tresses have been positioned next to each other and the L*a*b*-values have been 25 times measured and their average has been reported in table 18, 20 and 22. The changes in colour indicated as ΔL*, Δa*, Δb* and ΔE * in table 19, 21 and 23 are calculated from the color measurements of the initial values and after the respective shampooing/conditioning cycles.

The results of tables 3 - 23 show that the inventive hair care compositions (i.e. 1, 2, 3 and 4) show significantly higher colour resistance of dyed hair as compared to the comparative hair compositions (i.e. Ref.1, Ref.2, Ref.3 and Ref.4) with semi- permanent and permanent hair dyes. Such an increase of higher colour resistance is very advantageous to the end-customer as the hair colour remains visually more or less constant for a longer period of time and, as a result thereof, extends the time until a next hair coloration is needed.

T

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Claims

1 . A hair care composition comprising

- a mixture of branched and linear saturated C15-C19 alkanes; and

- an ester of a fatty acid and dextrin; and

2. The hair care composition according to claim 1 , characterized in that the amount of linear saturated C15-C19 alkanes in said mixture of branched and linear saturated C15-C19 alkanes is less than 10 % by weight, preferably less than 8 % by weight, most preferred more than 5 % by weight, in respect to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

3. The hair care composition according to claim 1 or 2, characterized in that the amount of branched saturated C18 alkane is more than 50% by weight, preferably more than 60 % by weight, even more preferably more than 70 % by weight, relative to the weight of said mixture of branched and linear saturated C15-C19 alkanes.

4. The hair care composition according to any of the preceding claims characterized in that the fatty acid of said ester of a fatty acid and dextrin is a C14-C18 fatty acid, particularly a linear C14-C18 fatty acid, most preferably palmitic acid.

5. The hair care composition according to any of the preceding claims characterized in that the dextrin of said ester of a fatty acid and dextrin has an average degree of glycopolymerization of between 3 and 20, particularly between 8 and 16.

6. The hair care composition according to any of the preceding claims characterized in that said ester of a fatty acid and dextrin has an average number of esterified hydroxyl groups of more than 2.5, preferably between 2.5 and 3.5, more preferably between 2.5 and 3.4, most preferably between 2.5 and 3.2, per glucose unit.

7. The hair care composition according to any of the preceding claims characterized in that said ester of a fatty acid and dextrin has a molecular weight M_n of between 8'000 and 16'000 Da, preferably between 9'000 and 13'000 Da, more preferably between 10'000 and 11'500 Da.

8. The hair care composition according to any of the preceding claims characterized in that the cationic emulsifier is an organic ammonium compound, particularly a quaternary ammonium compound.

9. The hair care composition according to any of the preceding claims characterized in that the cationic emulsifier is a substance defined by a CAS- number selected from the group consisting of [17301-53-0], [92201-88-2], [1156505-34-8] and [51277-96-4],

10. The hair care composition according to any of the preceding claims characterized in that the amount of cationic emulsifier is in the range of between 0.5 and 10 % by weight, particularly between 0.5 and 8 % by weight, preferably between 1 and 6 % by weight, based on the weight of the hair care composition.

11. The hair care composition according to any of the preceding claims characterized in that the amount of the mixture of branched and linear saturated C15-C19 alkanes is in the range of between 0.015 and 12.0 % by weight, particularly between 0.5 and 11 .0 % by weight, preferably between 1 .0 and 10.0 % by weight, more preferably between 1.5 and 8.0 % by weight, even more preferably between 2.0 and 6.0 % by weight, based on the weight of the hair care composition

12. The hair care composition according to any of the preceding claims characterized in that the hair composition is a hair conditioner.

13. The hair care composition according to any of the preceding claims characterized in that the composition is free of any anionic surfactants or any non-ionic surfactants.

14. Use of a mixture of branched and linear saturated C15-C19 alkanes, in combination with an ester of a fatty acid and dextrin, and a cationic emulsifier for increasing the colour resistance of a hair dye which is applied to hair.

15. The use according to claim 14, characterized in that the hair dye is a semi- permanent hair dye.

16. The use according to claim 14, characterized in that the hair dye is a permanent hair dye.