Hair care composition

Abstract

The present invention relates to hair care compositions for conditioning hair, in particular hair care compositions providing conditioning to hair without the use of silicones. Despite the apparent effects in making hair look full and shiny, conditioning formulations that contain silicone-based conditioning agents raise concerns among consumers. There remains a need to provide compositions which can provide superior conditioning performance in a sustainable manner. It is therefore an object of the present invention to provide a hair conditioning composition that provides superior conditioning performance without the use of silicones. It has been found that the conditioning performance of a conditioning oil such as mineral oils, vegetable oils etc can be improved by providing a conditioning system comprising the conditioning oil and an acrylate polymer with side chains having a specific carbon chain length and particular thermal properties.

Description

[0001] HAIR CARE COMPOSITION

[0002] Field of the Invention

[0003] The present invention relates to hair care compositions for conditioning hair, in particular hair care compositions providing conditioning to hair without the use of silicones.

[0004] Background of the Invention

[0005] For years silicones have been widely used as conditioning agents in hair care products. For example, silicone based conditioning agents, such as dimethicone and cyclodimethicone, have been popular in hair care products because they are useful in making hair look full, shiny, smooth as well as making it easy to comb.

[0006] Historically, silicone was seen as a reliable, universal and highly efficient hair care ingredient. Recently, however, consumers and formulators are becoming more aware of the bioaccumulation and potential for build-up on hair and scalp that can sometimes result from silicone use. Concerns have also been raised about the energy required to produce silicone polymers. Hair care consumers now expect sustainably formulated, environmentally friendly, silicone-free solutions that maintain excellent performance when compared to products traditionally formulated with silicone.

[0007] Therefore, despite their apparent effects in making hair look full and shiny, conditioning formulations that contain silicone-based conditioning agents raise concerns among consumers.

[0008] The use of non-silicone based conditioning agents such as mineral oil, coconut oil etc have been well known for conditioning for decades. However, their conditioning effect does not match that of silicones.

[0009] Polymers are known in providing conditioning effects. One such type of polymer is in US 2005 / 0169865 disclosing cosmetic compositions comprising at least one cationic agent, at least one oil and at least one semi-crystalline polymer having a melting point of greater than or equal to 30°C. However, incorporation of high-melting point waxy polymers into conditioning compositions can be challenging when blending with cosmetic oils. Providing formulations with high melting point polymers require large amounts of energy due to the need to melt ingredients and maintain them at a controlled temperature during formulation.

[0010] Therefore, there is still a need to provide compositions which can provide superior conditioning performance in a sustainable manner without the use of silicones.

[0011] It is an object of the present invention to provide a hair conditioning composition that provides superior conditioning performance when compared to compositions comprising conditioning oils such as mineral oils, vegetable oils etc.

[0012] It is another object of the present invention is to improve the conditioning performance of conditioning oils such as mineral oils, vegetable oils etc.

[0013] It is yet another object of the present invention to provide a hair conditioning composition free of silicones.

[0014] Surprisingly, it has been found that the conditioning performance of a conditioning oil such as mineral oils, vegetable oils etc can be improved by providing a conditioning system comprising the conditioning oil and an acrylate polymer with side chains having a specific carbon chain length and particular thermal properties.

[0015] Summary of the Invention

[0016] Accordingly, in a first aspect, the present invention relates to a silicone-free conditioning system comprising: a a conditioning oil selected form a natural oil or a mineral oil and; b a polymer comprising monomers of formula I

[0017] Formula I wherein

[0018] A is CO2R1;

[0019] B is selected from hydrogen and methyl;

[0020] R1 is a linear or branched alkyl or alkenyl group and comprises 2 to 16 carbon atoms; the polymer having a glass transition temperature of < 25°C as measured using dynamic mechanical analysis and; the polymer being in a liquid state at 25°C.

[0021] In a further aspect, the present invention relates to a hair care composition comprising: the conditioning system of the invention; a conditioning gel phase comprising a cationic surfactant, a high melting point (25°C or higher) fatty compound and an aqueous carrier.

[0022] In a further aspect, the present invention relates to a hair care composition obtainable by blending a conditioning gel phase with the conditioning system.

[0023] In a further aspect, the present invention relates to use of a polymer comprising at least one monomer of formula I

[0024] Formula I wherein

[0025] A is CO2R1;

[0026] B is selected from hydrogen and methyl;

[0027] R1 is a linear, branched alkyl or alkenyl group and comprises 2 to 16 carbon atoms; the polymer having a glass transition temperature of < 25°C as measured using dynamic mechanical analysis and; the polymer being in a liquid state at 25°C; in a conditioning composition for silicone-free conditioning of hair.

[0028] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of” or “composed of.” In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word “about”. Numerical ranges expressed in the format "from x to y" are understood to include x and y.

[0029] When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated. of the Invention

[0030] The invention includes a polymer comprising monomers of Formula I

[0031] Formula I wherein

[0032] A is CO2R1;

[0033] B is selected from hydrogen or methyl;

[0034] R1 is a linear or branched alkyl or alkenyl group and comprises 2 to 16 carbon atoms;

[0035] The polymer having a glass transition temperature of < 25°C. The glass transition temperature can be measured using dynamic mechanical analysis.

[0036] The polymer of the invention is in a liquid state at 25°C. Preferably the polymer is a liquid at 20°C, such as a liquid at 10°C. For example, the polymer is a liquid at 5°C.

[0037] The polymer of the invention is a homopolymer or a copolymer, preferably a homopolymer. Preferably, B in Formula I is hydrogen. More preferably, the polymer is a homopolymer and B is hydrogen.

[0038] R1is a linear or branched alkyl or alkenyl group. More preferably R1is an alkyl group.

[0039] Preferably, R1comprises up to 14 carbon atoms, more preferably up to 12 carbon atoms. Typically, R1comprises at least 4 carbon atoms.

[0040] Preferably, when B is hydrogen and R1is linear, R1comprises 2 to 14 carbon atoms. Alternatively, when B is hydrogen and R1is branched, R1comprises 5 to 14 carbon atoms. Preferably, when B is a methyl group, R1comprises 4 to 16 carbon atoms.

[0041] The polymer may be a copolymer as long as the glass transition temperature and state requirements of the polymer are met. When the polymer is a copolymer preferably at least 50% of the polymer consists or consists essentially of monomers of Formula I. More preferably at least 70% of the polymer consists of or consists essentially of monomers of Formula I, such as at least 75%, at least 80%, at least 90%, at least 95% or at least 99%. In some embodiments, the copolymer consists of or consists essentially of monomers of Formula I.

[0042] Preferably the copolymer further comprises at least one monomer of Formula II:

[0043] Formula II wherein D is CO2R2; E is selected from hydrogen or methyl; R2 a linear or branched alkyl or alkenyl group and comprises 2 to 22 carbon atoms.

[0044] Preferably, R2 is linear or branched. In some preferred embodiments, the copolymer consists of or consists essentially of monomers of Formula I and Formula II. For example, the copolymer consists of or consists essentially of monomers of Formula I where R1 comprises 2 to 12 carbon atoms and monomers of Formula II where R2 comprises 2 to 22 carbon atoms. In some preferred embodiments the average length of the side chains in a copolymer is less than 20 carbon atoms, such as less than 18 carbon atoms, less than 15 carbon atoms, preferably less than 12 carbon atoms.

[0045] Preferably, up to 50% of the copolymer consists of or consists essentially of monomers of Formula II. More preferably up to 30% of the polymer consists of or consists essentially of monomers of Formula II, such as up to 25%, up to 20%, up to 10%, up to 5% or up to1 %.

[0046] In certain preferred embodiments the copolymer consists of or consists essentially of at least 75% monomers of Formula I and up to 25% monomers of Formula II.

[0047] Preferably, the copolymer comprises monomers where B is hydrogen and monomers where B is a methyl group. Preferably, the copolymer consists of or consists essentially of monomers according to Formula I. In some embodiments, the polymer comprises one or more monomers selected from the group of ethyl acrylate, propyl acrylate, isobutyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, isononyl acrylate, decyl acrylate, propylheptyl acrylate, undecyl acrylate, dodecyl acrylate, tetradecyl acrylate, butyl methacrylate, isoamyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, 2-propylheptyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate and hexadecyl methacrylate.

[0048] Preferably the polymer is poly (hexyl acrylate), poly(2-ethylhexyl acrylate), poly (nonyl acrylate) poly (decyl acrylate), poly (undecyl acrylate) or poly (dodecyl acrylate).

[0049] In some embodiments, the polymer further comprises one or more monomers selected from hexadecyl acrylate, octadecyl acrylate, octadecyl methacrylate and behenyl acrylate and behenyl methacrylate.

[0050] The weight average molecular weight of the polymer of the present invention is preferably below 8,000,000 Da, such as below 7,500,000 Da, still more preferably less than 7,000,000 Da, even more preferably less than 500,000 Da, even more preferably less than 400,000 Da such as less than 350,000 Da, but typically more than 5,000 Da, preferably more than 6,000 Da, preferably more than 7,000 Da, preferably more than 20,000 Da, preferably more than 30,000 Da, most preferably more than 35,000 Da as measured using gel permeation size exclusion chromatography. For the avoidance of doubt, the unit Dalton (Da) is also known as unified atomic mass unit (u). Preferably, the GPC is calibrated using poly(methyl methacrylate) (PMMA).

[0051] The number average molecular weight of the polymer of the present invention is preferably below 80,000 Da, such as below 70,000 Da, still more preferably less than 50,000 Da, even more preferably less than 30,000 Da, but typically more than 5,000 Da, preferably more than 6,000 Da, preferably more than 7,000 Da, preferably more than 10,000 Da as measured using gel permeation size exclusion chromatography. For the avoidance of doubt, the unit Dalton (Da) is also known as unified atomic mass unit (u). Preferably, the GPC is calibrated using poly(methyl methacrylate) (PMMA).

[0052] Preferably, the polymer is synthesized by free radical polymerization (FRP) or emulsion polymerization. Most preferably, the polymer is synthesized using free radical polymerization. In hair care compositions according to the invention, such as rinse-off conditioner compositions, the polymer can be present in a concentration of 0.001 to 5% by weight of the composition. Preferably, at least 0.01%, more preferably at least 0.02%, still more preferably at least 0.05%, but typically not more than 3%, preferably not more than 2.5%, more preferably not more than 2%, still more preferably not more than 1 %, even more preferably not more than 0.5% by weight of the composition.

[0053] In the application, a “monomer” can be defined as a molecule which is polymerised to form a polymer e.g. ethyl acrylate. The monomer may also be represented in the application as the repeating structural unit provided by a molecule in a polymeric structure after polymerisation has occurred e.g. Formula I or II.

[0054] Conditioning oil

[0055] Conditioning oils which are used in the present invention are chosen from mineral oils, or natural oils or combinations thereof e.g. plant oils such as vegetable oils.

[0056] Preferably, the conditioning oil has a melting point below 35°C, preferably below 30°C, more preferably below 28°C.

[0057] As understood by a person skilled in the art, a natural oil in the context of conditioning oils is a cosmetic oil derived from plants, seeds, nuts and fruits which is suitable for providing lubrication to the hair. Typically, natural oils have a melting point below 35°C, such as below 30°C, more preferably below 28°C.

[0058] Non-limiting examples of natural oils that may be used include sweet almond oil, argan oil, avocado oil, castor oil, olive oil, jojoba oil, moringa oil, sunflower oil, wheat germ oil, sesame oil, ground- nut oil, grape seed oil, soybean oil, rapeseed oil, safflower oil, coconut oil, maize oil, hazelnut oil, palm oil, apricot kernel oil and calophyllum oil and squalane.

[0059] In some embodiments, preferably the conditioning oil is a fatty acid ester oil formed from fatty acid and alcohol. Preferably, the conditioning oil comprises fatty acid esters formed from polyols such as triglycerides. Preferably, the conditioning oil comprises triglycerides comprising fatty acyl chains with a C chain length from 10 to 18 C atoms. The portion of the fatty acyl chains with 10 to 18 C atoms is preferably in the range of 45 to 95%, preferably 55 to 95%, more preferably 65 to 95% by weight, calculated to the total fatty acyl chain content of the triglyceride. Preferably, the conditioning oil comprises triglycerides with a carbon number of 15 to 60 C, preferably 30 to 55 C.

[0060] In some embodiments, the conditioning oil is a triglyceride-based vegetable oil such as sunflower oil, sesame oil, rapeseed oil, sweet almond oil, calophyllum oil, palm oil, avocado oil, jojoba oil, olive oil, coconut oil, castor oil or cereal germ oils such as wheat germ oil. Preferably, the conditioning oil is sunflower oil or coconut oil.

[0061] In some embodiments, preferably the conditioning oil is a hydrocarbon oil. Preferably, the hydrocarbon oil comprises a carbon chain number of from 10 to 50 C atoms. Preferably, the hydrocarbon oil comprises substantially saturated carbon chains which may be linear or branched. Preferably, the carbon number of the hydrocarbon oil is from 15 to 40 C atoms, preferably not more than 30 carbon atoms. In some preferred embodiments, the conditioning oil is squalane.

[0062] Squalane from a variety of sources, whether vegetable or otherwise, is suitable for use in the invention.

[0063] As understood by a person skilled in the art, a mineral oil in the context of conditioning oils is a liquid derived from petroleum which is suitable for providing lubrication to the hair. Typically, mineral oils have a melting point below 25°C, such as below 10°C, more preferably below 0°C.

[0064] Non-limiting examples of mineral oils that may be used include highly refined white mineral oils such as, liquid paraffin, liquid petrolatum, isododecane, isohexadecane, as well as several cosmetic grade oils of varying chain length distribution and viscosity, such as Parol™, or Lytol™ white mineral oils ex Sonneborn, Netherlands.

[0065] In addition to the conditioning oils of the invention, further conditioning oils may be used in the conditioning system. For example, the conditioning system may comprise synthetic oils. Among the synthetic oils that can be used, non- limiting examples include those chosen from hydrogenated polydecenes, poly(alpha-olefin)s, transesterified vegetable oils and squalane.

[0066] Further non-limiting examples of synthetic oils that can be used include oil derived emollient esters such as isononyl isononanoate and dioctyldodecyl dodecanedioate, as well as low molecular weight terpene derived liquid polymers such as those commercially available within the Citropol™ series from P2 Science Inc. of Woodbridge, Connecticut, USA, such as Citropol™ 1 A, or Citropol™ HA, or Bioestolides™, such as Bioestolide™ 1300 from Biosynthetic® Technologies of Indianapolis, USA.

[0067] The conditioning oil according to the invention is a natural oil or a mineral oil.

[0068] Preferably, the conditioning oil is selected from a plant oil and / or a hydrocarbon oil with a melting point below 35°C, preferably below 30°C, more preferably below 28°C. More preferably, the conditioning oil is selected from a fatty acid ester oil and / or a saturated hydrocarbon oil comprising a carbon number of 10 to 60 C atoms or combinations thereof. More preferably, the conditioning oil is selected from a hydrocarbon oil with a carbon number of from 15 to 40 C atoms and a triglyceride oil or combinations thereof. More preferably, the conditioning oil is selected from one or more of sunflower seed oil, coconut oil, soya bean oil and squalane. Most preferably, the conditioning oil is sunflower seed oil.

[0069] In certain embodiments, particularly preferred are natural oils, particularly those such as sunflower seed oil, which are soluble with a wide range of example polymers. This provides flexibility to add polymer and oil together as a pre-blend, or separately as two distinct emulsions.

[0070] In hair care compositions according to the invention, such as rinse-off conditioner compositions, the conditioning oil can be present in a concentration of 0.1 to 5% by weight of the composition. Preferably, at least 0.2%, more preferably at least 0.5%, still more preferably at least 1 %, most preferably at least 1.2% but typically not more than 3.5%, preferably not more than 3%, more preferably not more than 2.5% by weight of the composition.

[0071] The conditioning oil may be emulsified before inclusion in a conditioning system and / or hair care composition e.g. the conditioning oil is emulsified in an aqueous solvent, preferably water before inclusion in a conditioning system and / or hair care composition.

[0072] Conditioning System

[0073] The polymer and conditioning oil of the conditioning system may be in the form of a blend, or the polymer of the conditioning system can be added to a composition separately to the conditioning oil, for example as an emulsion polymer.

[0074] Without wishing to be bound by theory, it is believed that for any conditioning oil to condition hair, it must be present at the junction between the contacting bodies, e.g. two hair fibres, or hair fibre and comb, or hair fibres and fingers. Consequently, when the hair is being touched, or combed, a conditioning oil must not be fully squeezed out of the contact. A natural / mineral based conditioning oil is much lower in viscosity than a high molecular weight conditioning silicone polymer. So, an oil is more likely to be squeezed out of the gap under contact conditions relevant to the tactile assessment or grooming of hair. The polymer of the present invention helps to maintain the conditioning oil within the contact to be conditioned.

[0075] In hair care compositions according to the invention, such as rinse-off conditioner compositions, the polymer and conditioning oil can be present in a total concentration of 0.1 to 5% by weight of the composition. Preferably, at least 0.2%, more preferably at least 0.5%, still more preferably at least 1%, most preferably at least 1.2% but typically not more than 3.5%, preferably not more than 3%, more preferably not more than 2.5% by weight of the composition.

[0076] The ratio of polymer to conditioning oil in the hair care composition preferably ranges from 1 :1 to 1 :1000, preferably 1:1 to 1:200, more preferably from 1 :3 to 1:99 to still more preferably from 1 :4 to 1:50, even more preferably from 1 :5 to 1:35, most preferably from 1:5 to 1 :15, such as a ratio of 1 :9.

[0077] Preferably, the polymer and conditioning oil is in the form of a blend. Formation of a blend can be achieved either by mechanical mixing of oil with polymer, or through polymerization from the relevant monomers dissolved within the oil.

[0078] The blend preferably comprises, 50 wt% to 99.9 wt% conditioning oil, preferably at least 70 wt%, more preferably at least 80 wt%, more preferably at least 90 wt% conditioning oil, but not more than 99.5 wt%, such as not more than 98.9 wt%, preferably not more than 98 wt% conditioning oil. Most preferably the blend comprises 90 wt% conditioning oil and 10 wt% polymer. For example, a 10 wt% blend of a homopolymer in 90 wt% sunflower seed oil.

[0079] Preferably, a blend of the polymer with the conditioning oil is emulsified in an aqueous solvent. Preferably, the conditioning system comprises an aqueous emulsion with an aqueous continuous phase of water and a dispersed phase containing the blend. The emulsification of a blend of the polymer with the oil serves to ensure delivery locally of both components into the contact to be conditioned. This is preferred over formation of separate emulsions of oil and of polymer, for which case, the two components may not always both reside simultaneously in a contact to be lubricated. Preferably, the conditioning system / hair care composition of the invention comprises an emulsion of a blend of the inventive polymer with the conditioning oil.

[0080] Blends of the polymers with the thermal properties of the invention can be formed more favourably than blends containing polymers with higher glass transition temperatures and / or high melting points. Emulsification of a blend of a cosmetic oil with a waxy polymer of high melting point is challenging and can lead to poor results. The emulsion of blends of waxy polymer becomes inhomogeneous on handling, making formulating difficult. Furthermore, the emulsification of the blends comprising waxy polymer of high melting point also requires significant amounts of energy, due to the need to melt ingredients and maintain and control temperature.

[0081] Particle size of the dispersed oil / blend

[0082] One characteristic of an oil or oil / polymer blend in a composition (either directly dispersed in a composition or emulsified before inclusion in a composition) is particle size. This can be measured for example by laser diffraction particle size analysis methods, which are well documented in the art. There are several parameters which can be used to characterise emulsion particle size. For example the parameter Dv(50) represents an upper limit on a range of particle diameters, in which 50% of the volume of all dispersed material is contained.

[0083] Preferably an emulsion of the invention (such as an emulsion of a blend of the inventive polymer with the conditioning oil) has a particle size characterised by Dv(50) as measured by dynamic light scattering, for example using a Malvern Instruments Mastersizer 2000 particle size analyser with Hydro 2000SM Dispersion Unit (Malvern Instruments UK), of between 0.5 and 20 microns, more preferably between 1.5 and 15 microns, even more preferably between 1.5 and 10 microns and most preferably between 2 and 10 microns.

[0084] Conditioning gel phase

[0085] In some embodiments of the invention a hair care composition such as a silicone-free hair care composition is obtainable by blending the conditioning system with a conditioning gel phase.

[0086] Preferably, the conditioning gel phase is formed from a cationic surfactant, a high melting point (25°C or higher) fatty compound and an aqueous carrier. Examples of suitable cationic surfactants which are useful for forming the conditioning gel phase include quaternary ammonium cationic surfactants corresponding to the following general formula:

[0087] [N(R3)(R4)(R5)(R6)]+(X)- in which R3 R4 R5ANC| R6areeach independently selected from (a) an aliphatic group of from 1 to 22 carbon atoms, or (b) an aromatic, alkoxy, polyoxyalkylene, alkylamido, hydroxyalkyl, aryl or alkylaryl group having up to 22 carbon atoms; and X is a salt-forming anion such as those selected from halide, (e.g. chloride, bromide), acetate, citrate, lactate, glycolate, phosphate nitrate, sulphate, and alkylsulphate radicals.

[0088] The aliphatic groups can contain, in addition to carbon and hydrogen atoms, ether linkages, and other groups such as amino groups. The longer chain aliphatic groups, e.g., those of about 12 carbons, or higher, can be saturated or unsaturated.

[0089] Specific examples of such quaternary ammonium cationic surfactants of the above general formula are cetyltrimethylammonium chloride, behenyltrimethylammonium chloride (BTAC), cetylpyridinium chloride, tetramethylammonium chloride, tetraethylammonium chloride, octyltrimethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, octyldimethylbenzylammonium chloride, decyldimethylbenzylammonium chloride, stearyldimethylbenzylammonium chloride, didodecyldimethylammonium chloride, dioctadecyldimethylammonium chloride, tallowtrimethylammonium chloride, cocotrimethylammonium chloride, dipalmitoylethyldimethylammonium chloride, PEG-2 oleylammonium chloride, and salts of these, where the chloride is replaced by other halide (e.g., bromide), acetate, citrate, lactate, glycolate, phosphate nitrate, sulphate, or alkylsulphate.

[0090] In a preferred class of cationic surfactant of the above general formula, R3 is a C16 to C22 saturated or unsaturated, preferably saturated, alkyl chain and R4, R5 and R® are each independently selected from CH3and CH2CH2OH, preferably CH3. Specific examples of such preferred quaternary ammonium cationic surfactants for use in forming the conditioning gel phase are cetyltrimethylammonium chloride (CTAC), behenyltrimethylammonium chloride (BTAC) and mixtures thereof.

[0091] Alternatively, primary, secondary or tertiary fatty amines may be used in combination with an acid to provide a cationic surfactant suitable for providing the conditioning gel phase suitable for use in the invention. The acid protonates the amine and forms an amine salt in situ in the hair care composition. The amine is therefore effectively a non-permanent quaternary ammonium or pseudo-quaternary ammonium cationic surfactant.

[0092] Suitable fatty amines of this type include amidoamines of the following general formula:

[0093] R7-C(O)-N(H)-R8-N(R9)(R1°) in which R7is a fatty acid chain containing from 12 to 22 carbon atoms, R8is an alkylene group containing from one to four carbon atoms, and R9and R"'9are each independently, an alkyl group having from one to four carbon atoms.

[0094] Specific examples of suitable materials of the above general formula are stearamidopropyldimethylamine, stearamidopropyldiethylamine, stearamidoethyldiethylamine.stearamidoethyldimethylamine, palmitamidopropyldimethylamine, palmitamidopropyldiethylamine, palmitamidoethyldiethylamine, palmitamidoethyldimethylamine, behenamidopropyldimethylamine, behenamidopropyldiethylamine, behenamidoethyldiethylamine, behenamidoethyldimethylamine, arachidamidopropyldimethylamine, arachidamidopropyldiethylamine, arachidamidoethyldiethylamine, arachidamidoethyldimethylamine, and diethylaminoethylstearamide.

[0095] Also useful are dimethylstearamine, dimethylsoyamine, soyamine, myristylamine, tridecylamine, ethylstearylamine, N-tallowpropane diamine, ethoxylated (with 5 moles of ethylene oxide) stearylamine, dihydroxyethylstearylamine, and arachidyl behenylamine.

[0096] Particularly preferred is stearamidopropyldimethylamine. The acid used may be any organic or mineral acid which is capable of protonating the amine in the hair care composition. Suitable acids include hydrochloric acid, acetic acid, tartaric acid, fumaric acid, lactic acid, malic acid, succinic acid, and mixtures thereof. Preferably, the acid is selected from the group consisting of acetic acid, tartaric acid, hydrochloric acid, fumaric acid, lactic acid and mixtures thereof.

[0097] Mixtures of any of the above-described cationic surfactants may also be suitable.

[0098] The level of cationic surfactant suitably ranges from 0.1 to 10 wt%, preferably from 0.2 to 5 wt% and more preferably from 0.25 to 4 wt% (by total weight of cationic surfactant based on the total weight of the hair care composition).

[0099] By “high melting point” in the context of the fatty compound of the invention it is generally meant a melting point of 25°C or higher. Generally, the melting point ranges from 25°C up to 90°C, preferably from 40°C up to 70° C and more preferably from 50°C up to about 65°C.

[0100] The high melting point fatty compound can be used as a single compound or as a blend or mixture of at least two high melting point fatty compounds. When a blend or mixture of fatty compounds is used, the melting point means the melting point of the blend or mixture.

[0101] Suitable fatty compounds of this type have the general formula R-X, wherein R is an aliphatic carbon chain and X is a functional group (e.g. alcohol or carboxylic acid or a derivative thereof such as ester or amide).

[0102] R is preferably a saturated aliphatic carbon chain comprising from 8 to 30 carbon atoms, preferably from 14 to 30 carbon atoms, more preferably from 16 to 22 carbon atoms.

[0103] R can contain, in addition to carbon and hydrogen atoms, ether linkages, and other groups such as amino groups. Preferably R is a linear alkyl chain comprising from 8 to 30 carbon atoms, preferably from 14 to 30 carbon atoms, more preferably from 16 to 22 carbon atoms.

[0104] X is preferably an -OH group.

[0105] Most preferably, the fatty compound is a fatty alcohol of general formula CH3(CH2)n OH, where n is an integer from 7 to 29, preferably from 15 to 21. Specific examples of suitable fatty alcohols are cetyl alcohol, stearyl alcohol, behenyl alcohol, and mixtures thereof. Cetyl alcohol, stearyl alcohol and mixtures thereof are particularly preferred.

[0106] Mixtures of any of the above-described fatty compounds may also be suitable.

[0107] The level of fatty compound suitably ranges from 0.01 to 10 wt%, preferably from 0.1 to 8 wt%, more preferably from 0.2 to 7 wt% and most preferably from 0.3 to 6 wt% (by total weight of fatty compound based on the total weight of the hair care composition).

[0108] The weight ratio of cationic surfactant to fatty compound is suitably from 1 :1 to 1 :10, preferably from 1 :1.5 to 1 :8, optimally from 1 :2 to 1 :5.

[0109] Conditioning gel phases suitable for use in the invention may be characterized as gel (Lp) surfactant mesophases consisting of surfactant bilayers.

[0110] In a general process for the preparation of such conditioning gel phases, the cationic surfactant, high melting point fatty compound and aqueous carrier are heated to form a mixture, which is cooled under shear to room temperature. The mixture undergoes a number of phase transitions during cooling, normally resulting in a gel (Lp) surfactant mesophase consisting of surfactant bilayers. The bilayers may grow, swell or fold to form extended sheets or spherical vesicles.

[0111] Preferably, the formation of the gel (Lp) surfactant mesophase is controlled by maintaining the temperature of the mixture so that it falls within a specified range, generally, from about 55 to about 67°C, in the mixing vessel.

[0112] In an example of such a preferred process, the fatty compound and the cationic surfactant may be “comelted” in a first vessel to form an isotropic phase. The comelt will typically comprise from 45 to 90 wt% fatty alcohol of general formula CH3(CH2)n OH, where n is an integer from 7 to 29, preferably from 15 to 21 ; from 10 to 40 wt% cationic surfactant of general formula [N(R3)(CH3)3]+(X)', where RS is a C16 to C22 saturated alkyl chain and X is halide; and from 0 to 15 wt% water (by weight based on the total weight of the comelt). The comelt in the first vessel is typically maintained at a temperature sufficient to maintain the fatty compound in a liquid phase (usually around 80 to 85°C). The comelt is then added to a second vessel containing water at about 50 to about 60°C, and the comelt and the water are mixed. In the second vessel, the temperature of the mixture of the comelt and the water is controlled such that it is maintained at from 56 to 65°C, preferably from 58 to 62°C, more preferably around 60°C. The cationic surfactant component of the comelt as described above may also comprise or consist of a fatty amidoamine of general formula:

[0113] R7-C(O)-N(H)-R8-N(R9)(R1°) in which R7is a fatty acid chain containing from 12 to 22 carbon atoms, R8is an alkylene group containing from one to four carbon atoms, and R9and R^9are each independently, an alkyl group having from one to four carbon atoms. In this case the water in the second vessel will suitably include from 0.01 to 3 wt% of an organic or mineral acid which is capable of protonating the fatty amidoamine.

[0114] In an alternative example of a preferred process, a ‘comelt’ (such as described above) and water may be independently added to a mixing vessel and mixed in a continuous process in which the temperature of the mixture of comelt and water is controlled by modifying the temperature of water added to the mixture. Water may be added in a single dose or in aliquots. Typically, a first water vessel is maintained at around 40°C and is pumped into the mixing vessel while a second water vessel is maintained at a sufficient temperature to modify the temperature of the mixture of water with comelt such that it falls within the required range as specified above.

[0115] In another example of a preferred process, the fatty compound and the cationic surfactant may be combined in an aqueous dispersion. According to this process, an aqueous dispersion is prepared, which dispersion typically comprises from 25 to 50 wt% water, from 4 to 20 wt% fatty alcohol of general formula CH3(CH2)nOH, where n is an integer from 7 to 29, preferably from 15 to 21 ; and from 1 to 5wt% fatty amidoamine of general formula:

[0116] R7-C(O)-N(H)-R8-N(R9)(R1°) in which R7is a fatty acid chain containing from 12 to 22 carbon atoms, R8is an alkylene group containing from one to four carbon atoms, and R9and R^9are each independently, an alkyl group having from one to four carbon atoms (by weight based on the total weight of the dispersion). Preferably, the temperature of the aqueous dispersion is maintained above the melting temperature of the fatty alcohol, preferably at least 5°C higher than the melting point of the fatty alcohol. A cationic surfactant of general formula [N(R3)(CH3)3]+(X)_, where R^ is a C16 to C22 saturated alkyl chain and X is halide; may then be added and mixed into the aqueous dispersion, generally at a level of from 0.5 to 5 wt% (by weight based on the total weight of the mixture).

[0117] Preferably the mixing of the cationic surfactant with the aqueous dispersion is monitored by measurement of viscosity, such that when the viscosity change plateaus, mixing is complete (generally after about 20 to 60 minutes of mixing). After mixing is complete, the fatty amidoamine is neutralised with a suitable acid as described above. Preferably, the temperature of the mixture of the aqueous dispersion and the cationic surfactant is maintained at from 56 to 67°C, preferably from 58 to 65°C, more preferably around 63°C. Preferably, the process is a batch process.

[0118] Another preferred process for making a conditioning gel phase suitable for use in the invention comprises forming an aqueous isotropic solution of cationic surfactant (typically of general formula [N(R3)(CH3)3]+(X)', where R^ is a C16 to C22 saturated alkyl chain and X is halide); and mixing the aqueous isotropic solution of cationic surfactant with molten fatty compound (typically a fatty alcohol of general formula CH3(CH2)nOH, where n is an integer from 7 to 29, preferably from 15 to 21). Typically, the fatty alcohol is maintained at a temperature sufficient to maintain it in a liquid phase (usually around 80 to 85°C), prior to its addition to the aqueous isotropic solution of cationic surfactant. Preferably, the temperature of the mixture of the fatty alcohol and aqueous isotropic solution is maintained at from 55°C to 65°C, more preferably at from 58°C to 62°C and most preferably at about 60°C.

[0119] Product Form and Optional Ingredients

[0120] The hair care compositions of the invention are primarily intended for topical application to the hair and / or scalp of a human subject in order to improve hair properties such as hair fibre lubrication and friction reduction, but also smoothness, softness, manageability, alignment, bodification, shaping power and shine.

[0121] Preferably, the treatment composition is selected from a rinse-off hair conditioner, a hair mask, a leave-on conditioner composition, and a pre-treatment composition, more preferably selected from a rinse-off hair conditioner, a hair mask, a leave-on conditioner composition, and a pretreatment composition, for example an oil treatment, and most preferably selected from a rinse- off hair conditioner, a hair mask and a leave-on conditioner composition. The treatment composition is preferably selected from a rinse-off hair conditioner and a leave-on conditioner. The hair care compositions of the invention are typically "rinse-off" compositions to be applied to the hair and then, in part, rinsed away.

[0122] Rinse off conditioners for use in the invention are conditioners that are typically left on wet hair for 1 to 2 minutes before being rinsed off. Typically, from about 1g to about 50g of the composition is applied to the hair or scalp.

[0123] Hair masks for use in the present invention are treatments that are typically left on the hair for 3 to 10 minutes, preferably from 3 to 5 minutes, more preferably 4 to 5 minutes, before being rinsed off.

[0124] Leave-on conditioners for use in the invention are typically applied to the hair and left on the hair for more than 10 minutes, and preferably are applied to the hair after washing and not rinsed out until the next wash.

[0125] A particularly preferred product form is a conditioner for the treatment of hair (typically after shampooing) and subsequent rinsing.

[0126] A particular preferred use of the composition is on damaged hair, such as chemically damaged hair, particularly bleached hair.

[0127] The hair care compositions of the invention will generally comprise from about 20% to about 95% of water, preferably at least 30%, more preferably at least 40%, still more preferably at least 50%, even more preferably at least 60% or even at least 70%, but typically not more than 94%, preferably not more than 93%, more preferably not more than 92%, still more preferably not more than 91%, even more preferably not more than 90% or even not more than 80% by weight based on total weight. Other organic solvents may also be present, such as lower alkyl alcohols and polyhydric alcohols. Examples of lower alkyl alcohols include C1 to C6 monohydric alcohols such as ethanol and isopropanol. Examples of polyhydric alcohols include propylene glycol, hexylene glycol, glycerin, and propanediol. Mixtures of any of the above-described organic solvents may also be used. The hair care compositions of the invention may also incorporate other optional ingredients to enhance performance and / or consumer acceptability. Suitable optional ingredients include, but are not limited to: preservatives e.g. Disodium EDTA or CIT MIT, colouring agents, chelating agents, antioxidants, fragrances, antimicrobials, antidandruff agents, cationic conditioning polymers, styling ingredients, sunscreens, proteins, hydrolyzed proteins, emulsion stabilizers and fiber actives for improving the health of the hair fibers.

[0128] In some embodiments, the hair care composition comprises a further nonionic or cationic surfactant or combinations thereof. For example the hair care composition comprises an alkoxylated alcohol such as PEG-7 propylheptyl ether or a quaternary ammonium surfactant such as cetrimonium chloride or behentrimonium chloride . The level of the non-ionic and / or cationic surfactant suitably ranges from 0.001 to 5 wt%, preferably from 0.005 to 2 wt%, most preferably from 0.01 to 1 wt% such as 0.02 wt% by total weight of non-ionic and / or cationic surfactant based on the total weight of the hair care composition.

[0129] Preferably, the hair care composition is silicone-free.

[0130] The invention will now be further described by reference to the following Examples. In the Examples, all percentages are by weight based on total weight, unless otherwise specified.

[0131] Example 1

[0132] Melting points were measured using differential scanning calorimetry (DSC). The DSC experiments were conducted using a Perkin Elmer DSC 7 with polymer samples weighing approximately 15 mg., by initially heating the polymer to a temperature well above the melting point (T m) at 20°C / min, cooling to 5°C or well below the Tm of a polymer at a rate of 1 °C / min, and a second heating at 10°C / min. The constant cooling rate ensured a controlled thermal history for all polymers examined, while the second heating was used to acquire the Tm. The melting point was recorded as the peak in the heat flow versus temperature plot. The polymers were analyzed by dynamic mechanical analysis (DMA) and by Gel Permeation Size Exclusion Chromatography (GPC). DMA data were recorded on a Perkin Elmer DMA8000 with 1 L liquid nitrogen dispenser. The method used was cooling to -100 °C with liquid nitrogen then heating to 100 °C at 2 °C / minute. Samples were run in a stainless-steel envelope using single cantilever mode at a frequency of 1 Hz. Polymer Molecular Weight was characterized using tetrahydrofuran (THF) Gel Permeation Size Exclusion Chromatography. All size exclusion chromatography data were recorded on an Agilent Technologies Infinity II MDS instrument equipped with a differential refractive index (DRi), dual angle light scatter (LS), viscometry (VS) and variable wavelength UV detectors. The system was equipped with 2 x PLgel Mixed C columns (300 x 7.5 mm) and a PLgel 5 pm guard column. The mobile phase was THF stabilised with 2 % triethanolamine (TEA) and 0.01 % butylated hydroxytoluene (BHT) and run at a flow rate of 1 mL / minute at 30 °C. Agilent Technologies poly(methyl methacrylate) (PMMA) Easi- Vials were used to create a third order calibration from DRi data between 1,568,000 and 550 g I mol. Glass transition temperatures were calculated based on analysis of the DMA thermogram.

[0133] Polymer Example P1 : Poly (2-ethylhexyl acrylate)

[0134] Poly (2-ethylhexyl acrylate) was produced via free radical polymerisation, using toluene as solvent and V601 (dimethyl 2,2’-azobis(2-methylpropionate)) as initiator. 2-ethylhexyl acrylate monomer 98% (Sigma Aldrich) was filtered through active basic alumina to remove inhibitor before reaction. A 2 to 1 ratio by weight of monomer to (40 ml) toluene was used with 15 mg of initiator. These were added to a 250 ml round bottom flask and degassed with nitrogen for 30 minutes before heating. After 12 hours an extra 15 mg V601 was added to increase conversion. The reaction was stirred at 70 °C for 24 hours. After 24 hours, toluene and remaining monomer were removed by rotary evaporation at 50 °C and ~ 5 bar. The resulting material was then transferred into a jar by freezing the round bottom flask in liquid nitrogen and removing the frozen, solid material. This was then dried in a vacuum oven at 50 °C for 24 hours.

[0135] The weight average molecular weight was calculated as 79,000 g / mol and the number average molecular weight was calculated as 17,300 g / mol, from the GPC chromatogram. The glass transition temperature was calculated as -65.6 °C. The melting point was below 5°C.

[0136] Polymer Example P2: Poly (tetradecyl acrylate)

[0137] Poly (tetradecyl acrylate) was produced via free radical polymerisation using cyclohexane as solvent and Trigonox 21s (tert-butyl peroxy-2-ethyl hexanoate) as initiator. Tetradecyl acrylate monomer, (TCI Chemical UK Ltd., Oxford) was filtered through active basic alumina to remove monomethyl ether hydroquinone inhibitor before reaction. Cyclohexane solvent and tetradecyl acrylate monomer at a 70 / 30 ratio by weight and initiator (13 mol% referred to monomer) were placed in a round bottom flask with a stirrer bar, sealed with a suba-seal and purged with nitrogen for 1 hour prior to the experiment starting. Then, the temperature was set to 80 °C. The reaction was monitored by regular sampling using a 1 mL degassed syringe. The polymer in solvent was collected after 21 hours. Finally, the solvent was removed by rotary evaporator.

[0138] The weight average molecular weight was calculated as 130,000 g / mol and the number average molecular weight was calculated as 65,000 g / mol, from the GPC chromatogram. The melting point and glass transition temperature of the polymer was below 25°C.

[0139] Polymer Examples P3 to P6: Poly (dodecyl acrylate), Poly (hexyl acrylate), Poly (n-butyl acrylate) and Poly (iso-butyl acrylate)

[0140] Poly (dodecyl acrylate), Poly (hexyl acrylate), Poly (n-butyl acrylate) and Poly (iso-butyl acrylate) were each produced via free radical polymerisation using the same method as set out in Polymer Example P1. However, dodecyl acrylate, hexyl acrylate, n-butyl acrylate or iso-butyl acrylate were used as the monomer instead of 2-ethylhexyl acrylate.

[0141] For poly (dodecyl acrylate) (P3), the weight average molecular weight was calculated as 59,800 g / mol and the number average molecular weight was calculated as 16,900 g / mol, from the GPC chromatogram. The glass transition temperature was calculated as -4 °C, from the DMA thermogram. The melting point was found to be below 5°C.

[0142] For poly (hexyl acrylate) (P4), the weight average molecular weight was calculated as 72,500 g / mol and the number average molecular weight was calculated as 15,100 g / mol, from the GPC chromatogram. The glass transition temperature was calculated as -62.6 °C, from the DMA thermogram. The melting point was found to be below 5°C.

[0143] For poly (n-butyl acrylate) (P5), the weight average molecular weight was calculated as 111 ,200 g / mol and the number average molecular weight was calculated as 29,600 g / mol, from the GPC chromatogram. The glass transition temperature was calculated as -49.2 °C, from the DMA thermogram. The melting point was found to be below 5°C. For poly (iso-butyl acrylate) (P6), the weight average molecular weight was calculated as 111 ,700 g / mol and the number average molecular weight was calculated as 23,300 g / mol, from the GPC chromatogram. The glass transition temperature was calculated as -45.5 °C, from the DMA thermogram. The melting point was found to be below 5°C.

[0144] Comparative Polymer Example PA: Poly (octadecyl acrylate)

[0145] Poly (octadecyl acrylate) was produced via free radical polymerisation using the same method as set out in Polymer Example P2. However, octadecyl acrylate was used as the monomer.

[0146] The weight average molecular weight was calculated as 83,000 g / mol and the number average molecular weight was calculated as 51 ,000 g / mol, from the GPC chromatogram. The polymer was crystalline at room temperature. The melting point was measured to be 50 °C.

[0147] Emulsion example EA: Emulsion of sunflower seed oil

[0148] Sunflower seed oil from Helianthus Annus (Merck KGaA, Darmstadt, Germany) was emulsified mechanically as follows. A T-25 Ultra Turrax, Basic S2 high shear homogeniser (IKA®-Werke GmbH & CO. KG of Staufen, Germany) equipped with an S25N-10G dispersing tool, comprising a 7.5 mm rotor housed within a 10 mm stator, was used. 25 g of sunflower seed oil, 24.5 g of deionized water and 0.5 g of PEG-7-propylheptyl ether (Lutensol XP-79 ex BASF) were added to a stainless-steel beaker. The contents were mixed at 11,000 rpm for 5 minutes.

[0149] Emulsion examples E1-E3 and EB-EC: Emulsion of polymer and sunflower seed oil blend. Sunflower seed oil from Helianthus Annus (Merck KGaA, Darmstadt, Germany), was mechanically blended with the polymer in the amounts specified in Table 1. The blends were then emulsified as set out for Example EA above. It is noted that emulsion EC was difficult to handle and required maintenance of a temperature above 50° C during emulsification.

[0150] Table 1

[0151]

[0152] Table 2 Table 3

[0153] Evaluation

[0154] Bleaching

[0155] Hair switches were bleached by the following method. For every 1.5 pounds of hair, 8400 ml of solution are prepared from the following ingredients: 57% Cold Water, 29% Peroxide (34% Concentrate) and 14% Ammonia (6% Concentrate) was made up. Hair is submerged in solution, with a starting pH of approximately 9.0 and left for 1 hour 45 minutes, before washing in light surfactant (Texapon ES2) and water at 30-35 degrees Celsius. It is then left to dry at room temperature.

[0156] Hair Switch Preparation and Friction Measurement of Dry, Treated Switches.

[0157] 2.5 g, 150 mm (6”) European Dark Brown hair switches (also known as swatches, or tresses) (ex I HIP, New York) were used to test the frictional properties of comparative and example formulations. For treatment with any formulation, switches were handled in bundles of 5 per formulation. Such bundles were first washed with a simple stripping shampoo comprising sodium lauryl ether sulphate and water, before 2.5 g of the test product was applied and massaged into the hair bundles for one minute. Rinsing, following massaging was for a further minute under tap water set at 37° C and a flow rate of 4 litres per minute. Switches were then individually detangled and combed through before drying in an oven at 50° C. For friction measurement, individual 2.5 g, 150 mm switches (5 replicate switches per product in turn) were mounted on a flat, metal block. These were held in place using clamps at either end. After fixing the root end, each hair switch was combed through. The switch was held under tension before fixing the second clamp in place, to ensure that fibres remained immobile when a cylindrical, neoprene rubber friction probe was passed over them.

[0158] Frictional properties of individual switches were measured in the dry state, using a Texture Analyser (Model TA XT2i, ex Stable Microsystems, Godaiming, UK). The apparatus was housed in a controlled environment at 20 °C and at 50% relative humidity. The cylindrical, neoprene friction probe was placed in contact with the hair switch under a load of 500 g and driven for 40 mm forward (from root to tip) and then 40 mm backward at a speed of 10 mm / s to generate a plot of frictional force versus distance. For each test run the resulting hysteresis loop was integrated to yield a data point units of grams multiplied by millimetres. On averaging these data across all five switches per product, the resulting mean value was used to represent the frictional properties of dry hair following treatment with test product. Example and comparative test formulation data where formulations contained polymer (and oil), were referenced to example test data for formulations where no polymer / oil was added. The result was a mean friction reduction plotted in tables 4 and 5. Results

[0159] Table 4

[0160] Table 5

[0161] A high value of mean friction reduction is desirable as it indicates that the silicone-free formulations of the examples comprising the particular conditioning system of the invention make hair smooth to touch, well aligned, manageable and easy to comb. All of the formulations of the invention containing both a conditioning oil and a polymer within the scope of the invention show improved friction reduction compared to compositions containing only a conditioning oil and compositions including polymers with thermal properties outside the scope of the invention. Example 2 - Hair Treated with Emulsions

[0162] Lytol white mineral oil, ex Sonneborn was used as the mineral oil in Example 2.

[0163] Polymer Example P7: Poly hexyl acrylate was synthesised in mineral oil as follows: Hexyl acrylate monomer was filtered through active basic alumina to remove inhibitor before reaction. Monomer, toluene and initiator (Trigonox T21S)) were added to a 250 ml round bottom flask and degassed with nitrogen for 30 minutes before heating. 30 g of monomer and 70 g of mineral oil were mixed along with 77 microlitres of T21S. After 24 hours an extra 15 microlitres of T21S was added to increase conversion. The reaction was stirred at 70 °C throughout. The resulting material of example P7 was a blend of mineral oil and poly hexyl acrylate at a ratio of 70 to 30 by mass.

[0164] Emulsion Example E7: The material described in example P7 was emulsified as follows: 12.5 g of the example P7 material was placed in a steel beaker with 0.41 g of lutensol XP-79 a nonionic surfactant, with a C10 branched alkyl chain with 7 ethylene oxide groups forming the head-group (ex BASF). Deionized water was slowly added at approximately 0.5 g per minute while shearing in an Ultra Turrax T25 basic homogenizer (IKA Instruments) equipped with an S25N-10G dispersing tool, which has a 7.5mm rotor housed within an 10mm stator and is capable of speeds ranging from 110000 to 24000 rpm. The homogeniser was run at setting #2 until the inversion point was reached at which time it was increased to setting #4. Following inversion, the remaining water, to a total of 37.06 g was added at a rate of approximately 5 g per minute and with the setting dropped back to # 1. Once the water had been added, 0.03 g of preservative (Kathon CG ex Rohm & Haas) was also added.

[0165] Emulsion Example ED: An emulsion of Lytol white mineral oil, ex Sonneborn was formed comprising 25% of mineral oil, 0.7% of Lutensol XP-79, 0.05% of Kathon CG and the balance of distilled water.

[0166] Hair Switch Preparation and Friction Measurement of Dry, Treated Switches.

[0167] Virgin European Dark Brown hair switches (also known as swatches, or tresses) (ex IHIP, New York) were used to test the frictional properties of comparative and example formulations. For treatment with any emulsion, switches were handled in bundles of 5 per formulation. Such bundles were first washed with a simple stripping shampoo comprising sodium lauryl ether sulphate and water. Prior to application to hair swatches, each emulsion to be tested was diluted with deionised water by a factor calculated such that the amount of internal phase (comprising oil and polymer) delivered to the hair swatch from a 1 ml dose would be 1 mg per g of hair. Diluted emulsion was applied to switches following the latter's detangling and combing at the end of the shampooing and rinsing process. There were five replicate swatches per treatment. The combed switches were individually fully aligned and excess water was squeezed out by passing a gloved thumb and finger along the switch with gentle pressure from clamped end to free end. Each individual swatch was then laid down flat on aluminium foil and emulsion was applied dropwise from a syringe, ensuring an even coverage across the flat surface of hair the hair swatch. Swatches were left undisturbed and allowed to dry fully at room temperature prior to measurement of dry friction.

[0168] For friction measurement, individual 2.5 g, 150 mm switches (5 replicate switches per product in turn) were mounted on a flat, metal block. These were held in place using clamps at either end. After fixing the root end, each hair switch was combed through. The switch was held under tension before fixing the second clamp in place, to ensure that fibres remained immobile when a cylindrical, neoprene rubber friction probe was passed over them.

[0169] Frictional properties of individual switches were measured in the dry state, using a Texture Analyser (Model TA XT2i, ex Stable Microsystems, Godaiming, UK). The apparatus was housed in a controlled environment at 20 °C and at 50% relative humidity. The cylindrical, neoprene friction probe was placed in contact with the hair switch under a load of 500 g and driven for 40 mm forward (from root to tip) and then 40 mm backward at a speed of 10 mm / s to generate a plot of frictional force versus distance. For each test run the resulting hysteresis loop was integrated to yield a data point units of grams multiplied by millimetres. On averaging these data across all five switches per product, the resulting mean value was used to represent the frictional properties of dry hair following treatment with test product. Example and comparative test formulation data where formulations contained polymer (and oil), were referenced to example test data for formulations where no polymer / oil was added. The result was a mean friction reduction plotted in table 6 Table 6

[0170] A high value of mean friction reduction is desirable as it indicates that the silicone-free formulations of the examples comprising the particular conditioning system of the invention make hair smooth to touch, well aligned, manageable and easy to comb. The emulsion of Emulsion Example E7 contains both a mineral oil conditioning oil and a polyacrylate polymer within the scope of the invention. The example shows improved friction reduction compared to the use of emulsions containing only a mineral oil conditioning oil.

Claims

Claims1. A silicone-free conditioning system comprising: a a conditioning oil selected from a natural oil or a mineral oil and; b a polymer comprising monomers of Formula IFormula I whereinA is CO2R1;B is selected from hydrogen and methyl;Ri is a linear or branched alkyl or alkenyl group and comprises 2 to 16 carbon atoms; the polymer having a glass transition temperature of < 25°C as measured using dynamic mechanical analysis and; the polymer being in a liquid state at 25°C.

2. The conditioning system according to claim 1 wherein the conditioning oil is a natural oil selected from sweet almond oil, argan oil, avocado oil, castor oil, olive oil, jojoba oil, moringa oil, sunflower oil, wheat germ oil, sesame oil, ground- nut oil, grape seed oil, soybean oil, rapeseed oil, safflower oil, coconut oil, maize oil, hazelnut oil, palm oil, apricot kernel oil and calophyllum oil and squalane.

3. The conditioning system according to claim 1 wherein the conditioning oil is a plant oil and / or a hydrocarbon oil with a melting point below 35°C.

4. The conditioning system according to any of the preceding claims wherein R1comprises at least 4 carbon atoms.

5. The conditioning system according to any of the preceding claims wherein R1comprises 14 or less carbon atoms.

6. The conditioning system according to any of the preceding claims wherein the polymer is a homopolymer.

7. The conditioning system according to any of claims 1 to 5 wherein the polymer is a copolymer.

8. The conditioning system according to claim 7 wherein at least 75% of the polymer consists of or essentially consists of monomers of Formula I.

9. The conditioning system according to claim 7 or 8 wherein the polymer is a copolymer and in addition to monomers of Formula I comprises monomers of Formula II;Formula II whereinD is CO2R2;E is selected from hydrogen and methyl;R2is a linear or branched alkyl or alkenyl group and comprises 2 to 22 carbon atoms.

10. The conditioning system according to claim 9 wherein up to 25% of the polymer consists of monomers of Formula II.

11. The conditioning system according to any one of the preceding claims wherein the weight ratio of polymer to conditioning oil is between 1:1 to 1 :1000, preferably between 1:1 to 1 :200.

12. The conditioning system according to any one of the preceding claims wherein the polymer and the conditioning oil are in the form of a blend.

13. The conditioning system according to claim 12 wherein the conditioning system comprises an aqueous emulsion with an aqueous continuous phase of water and a dispersed phase containing the blend.

14. A silicone-free hair care composition comprising: a conditioning system according to any of claims 1 to 13; a conditioning gel phase comprising a cationic surfactant, high melting point (25°C or higher) fatty compound and an aqueous carrier.

15. Use of a polymer according to any of claims 1 to 13 in a conditioning composition for silicone-free conditioning of hair.

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