HAIR CONDITIONER PRODUCTS AND METHODS TO INCREASE THE TEMPERATURE OF PROTEIN DAMAGE IN HEAT-DAMAGED HAIR

Abstract

The conditioning preparation consists of: (a) a conditioning gel phase comprising cationic conditioning surfactants and fatty materials; and (b) an amino acid mixture comprising (i) cysteine, (ii) histidine, and (iii) glycine which dramatically enhances the thermal denaturation of proteins in heat-damaged hair, whereas this preparation does not contain other amino acids.

Description

[0001] HAIR CONDITIONER COMPOSITION

[0002] Field of the Invention

[0003] The present invention relates to a conditioner composition for hair, comprising mixtures of amino acids, its use to repair and / or strengthen heat damaged hair, and a method of treating heat damaged hair using said composition.

[0004] Background of the Invention

[0005] Consumers regularly subject their hair to intensive treatment, care, and styling routines to help achieve their desired look. The actions performed by consumers introduce modifications to the chemistry of hair keratin protein which results in micro- and macro-structural changes, including loss of proteins and amino acids, and in turn, changes fibre physical properties: the consequences of these are generally perceived by the consumer as damage.

[0006] Hair is composed mainly of proteins, specifically keratins. Differential Scanning Calorimetry (DSC) can be used to measure the denaturation temperature of the internal hair proteins. The higher the temperature required to “melt” hair protein (ie the more energy that is required) the stronger and more stable the protein structure is. A decrease in the denaturation temperature of internal hair proteins is an indicator that the proteins have been damaged and that loss of bonds, including hydrogen bonds, and loss of crystalline molecular structure has occurred. Therefore, an increase in denaturation temperature of hair is desirable. This indicates strengthening of hair and / or repair of damage by formation of bonds and increased stability, molecular structure and crystallinity of the proteins.

[0007] Consumers use heat on hair primarily for styling purposes. Heat styling tools, such as hairdryers, straighteners, curling irons, and hot rollers, are commonly employed to achieve various hairstyles. For example, hair dryers are used to quickly dry wet hair after washing by blowing hot air directly onto the hair. Hair straighteners, also known as flat irons, are used to achieve sleek, straight hair by applying heated flat plates to the hair shaft, whilst curling tongs (also known as irons or wands) are used to create curls or waves by wrapping sections of hair around a heated barrel. Hot rollers add volume and body to hair by rolling sections of hair onto heated rollers before allowing them to cool and set. Heat may be used to set certain hairstyles, such as updos or braids, in place. Finally, some hair products can be activated by heat, to enhance or trigger their effectiveness. However, repeated or excessive application of heat can damage hair, leading to issues like split ends, breakage, and dryness.

[0008] The level of damage can be measured by the degree of reduction in the denaturation temperature following a damaging treatment. Conversely, the level of repair or strengthening is indicated by the size of the increase of the denaturation temperature with treatments designed for this purpose. Treatments are known which address the problem of hair damage due to chemical hair treatments, and which may involve the use of amino acids. WO 2018 / 065237 and WO 2018 / 065248, disclose the use of glutamic acid with proline and aniline to provide improved damage repair as evidenced by an increase in the denaturation temperature of bleached hair. WO 00 / 51556 discloses a hair care composition comprising four or more amino acids where each amino acid is selected from a different group of amino acids. The composition aims to treat hair that is subjected to a wide range of insults that can cause weakening and damage. KR2019 0041626 discloses compositions that comprise an amino acid complexes that may include any one or more of lysine, histidine, arginine, aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, methionine, leucine, tyrosine, phenylalanine or cysteine, at 0.3 to 5 parts by weight. The compositions can be applied to hair prior to perming.

[0009] However, we have found that not all amino acids are equally lost due to damage or are equally restored. Further, the content of lost amino acids depends upon the type of damage, with damage by heat producing particular loss of cysteine, histidine and glycine.

[0010] There remains a need for more effective treatments for hair and particularly heat damaged hair which deliver fortification benefits such as repair or strengthening during everyday hair-care regimes.

[0011] We have now found that a mixture of specific amino acids, namely cysteine, histidine and glycine, in a conditioner, can advantageously increase the denaturation temperature of hair that has been damaged by heat. Surprisingly, the conditioner vehicle is crucial for achieving successful increase in denaturation temperature.

[0012] Summary of the Invention

[0013] In a first aspect, the invention provides a conditioner composition comprising: (1) a conditioning gel phase comprising:

[0014] (a) a cationic conditioning surfactant; and

[0015] (b) a fatty material; and

[0016] (2) a blend of amino acids consisting of (i) cysteine, (ii) histidine and (iii) glycine; the composition being free from other amino acids.

[0017] A second aspect of the invention provides a method of treating heat damaged hair comprising the step of applying to the hair a composition of the first aspect. The method results in an increase in the denaturation temperature of the internal proteins of the hair. The increase in denaturation temperature is compared with the same composition that does not comprise a blend of amino acids consisting of (i) cysteine, (ii) histidine and (iii) glycine.

[0018] Preferably the method comprises an additional step of rinsing the composition from the hair.

[0019] The method preferably additionally comprises the step of leaving the composition on the hair for 2 seconds to 20 minutes, preferably 10 seconds to 3 minutes, most preferably 20 seconds to 1 minute, and then rinsing the composition from the hair.

[0020] Preferably, the method additionally comprises the step of repeating the application of the composition to the hair. Preferably, the step of repeating the application of the composition to the hair is made during a later treatment and is repeated 1 to 10 times. This provides progressive increase in the denaturation temperature of the internal proteins of the hair.

[0021] In the context of this invention, by virgin hair is meant hair that has not been subjected to intensive physical and / or chemical treatment, for example, bleaching, dyeing, perming, reducing treatment, heat treatment and strong and / or prolonged exposure to solar radiation; nor displays features characteristic of damaged hair, for example, split ends and / or excessive dryness and / or increased surface friction compared with hair that has sustained low level damage. Virgin hair includes hair that has sustained low levels of damage during the natural hair life cycle. Sources of low level damage likely include but are not necessarily limited to, washing, brushing, combing and natural processes such as limited solar photo-degradation for example. That is to say no intensive physical and / or chemical treatment has been applied. A third aspect of the invention provides a use of a blend of cysteine, histidine and glycine to increase the denaturation temperature of the internal proteins of heat damaged hair. Preferably, the blend of cysteine, histidine and glycine is present in a composition of the first aspect. The increase in denaturation temperature is compared with the same composition that does not comprise a blend of amino acids consisting of (i) cysteine, (ii) histidine and (iii) glycine.

[0022] The heat damage to the hair arises from the use of heat styling. The application of heat is such that damage occurs to the hair proteins. Tools used in heat styling are preferably selected from hairdryers, straighteners, curling tongs / irons and hot rollers.

[0023] Detailed Description of the Invention

[0024] Compositions in accordance with the invention are preferably formulated as conditioners for the treatment of hair (typically after shampooing) and subsequent rinsing.

[0025] Each amino acid can be added separately at different stages, during the manufacture of the compositions of the invention, or the same stage, for example as a premix. Alternatively, 2 or 3 of the amino acids can be premixed before addition. They can be added, for example, as a dispersion in water or combined with the fragrance oil.

[0026] General description of the invention

[0027] The amino acids (2)

[0028] The amino acids for use the compositions of the invention are (i) cysteine, (ii) histidine and (iii) glycine. The composition is free from other amino acids; the composition does not comprise other amino acids in addition to the blend (2).

[0029] The amino acid mixture is preferably used in solution or emulsified form. It may be dissolved or dispersed in a suitable solvent or carrier.

[0030] The amount of the amino acid mixture in a hair composition is preferably from 0.1 wt % to 10 wt %, more preferably from 0.2 wt % to 5 wt %, most preferably from 0.25 wt % to 2 wt %, by total weight of the composition. The weight ratio of cysteine: histidine: glycine is preferably 2:1:1 to 1 :2:1 to 1:1 :2, more preferably 1 :1 :1.

[0031] Amino acids, including cysteine, histidine and glycine are available from many suppliers, for example Kusuma Pharma and Ajinomoto co Inc.

[0032] The conditioner composition

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] The conditioning base comprises a cationic conditioning surfactant and a fatty alcohol.

[0038] The composition according to the invention comprises one or more conditioning surfactants which are cosmetically acceptable and suitable for topical application to the hair.

[0039] Suitable conditioning surfactants are selected from cationic surfactants, used singly or in admixture. Examples include quaternary ammonium cationic surfactants corresponding to the following general formula:

[0040] [N(R1)(R2)(R3)(R4)]+(X)- in which R R2, R3, and R^ are each independently selected from (a) an aliphatic group of from 16 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, for example methosulphate, radicals.

[0041] The aliphatic groups can contain, in addition to carbon and hydrogen atoms, ether linkages, and other groups such as amino groups. The aliphatic groups, e.g., those of about 12 carbons, or higher, can be saturated or unsaturated.

[0042] 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.

[0043] In a preferred class of cationic surfactant of the above general formula, R-' is a C16 to C22 saturated or unsaturated, preferably saturated, alkyl chain and R^, R3 and R^ are each independently selected from CH3 and CH2CH2OH, preferably CH3.

[0044] Specific examples of such preferred quaternary ammonium cationic surfactants are cetyltrimethylammonium chloride (CTAC), behenyltrimethylammonium chloride (BTAC) and mixtures thereof.

[0045] Preferably, the quaternary ammonium cationic surfactant has a cation selected from cetyltrimethylammonium and behenyltrimethylammonium. Alternatively, primary, secondary or tertiary fatty amines may be used in combination with an acid to provide a cationic surfactant 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.

[0046] Suitable fatty amines of this type include amidoamines of the following general formula:

[0047] R1-C(O)-N(H)-R2-N(R3)(R4) in which R^ is a fatty acid chain containing from 12 to 22 carbon atoms, R2is an alkylene group containing from one to four carbon atoms, and R3and R4are each independently, an alkyl group having from one to four carbon atoms.

[0048] 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.

[0049] Also useful are dimethylstearamine, dimethylsoyamine, oyamine, myristylamine, tridecylamine, ethylstearylamine, N-tallowpropane diamine, ethoxylated (with 5 moles of ethylene oxide) stearylamine, dihydroxyethylstearylamine, and arachidyl behenylamine.

[0050] Particularly preferred is stearamidopropyldimethylamine.

[0051] The conditioning surfactant is present in the composition in a concentration of 0.1 to 10%, preferably at least 0.5%, more preferably at least 1%, still more preferably at least 2%, even more preferably at least 3% or even at least 4% but typically not more than 9%, preferably not more than 8%, more preferably not more than 7%, still more preferably not more than 6%, even more preferably not more than 5% by weight of the composition.

[0052] The fatty material The compositions of the invention comprise a fatty material. Preferably the fatty material is a fatty acid or a fatty alcohol, most preferably a fatty alcohol. Preferred fatty materials have a carbon-carbon chain length of from Cs to C22.

[0053] The combined use of fatty material and cationic surfactants in conditioning compositions is preferred because this leads to the formation of a lamellar phase, in which the cationic surfactant is dispersed.

[0054] The fatty alcohol comprises from 8 to 22 carbon atoms, preferably 16 to 22, most preferably C16 to C18. Fatty alcohols are typically compounds containing straight chain alkyl groups. Preferably, the alkyl groups are saturated. Examples of preferred fatty alcohols include cetyl alcohol, stearyl alcohol and mixtures thereof. The use of these materials is also advantageous in that they contribute to the overall conditioning properties of compositions for use in the invention.

[0055] The level of fatty material in conditioners for use in the invention will generally range from 0.01 to 10%, preferably from 0.1 to 8%, more preferably from 0.2 to 7%, most preferably from 0.3 to 6% by weight of the composition.

[0056] The weight ratio of cationic-surfactant to fatty material is suitably from 1 :1 to 1 :10, preferably from 1 :1.5 to 1 :8, optimally from 1 :2 to 1 :5. If the weight ratio of cationic surfactant to fatty alcohol is too high, this can lead to eye irritancy from the composition. If it is too low, it can make the hair feel squeaky for some consumers.

[0057] A preferred conditioner comprises a conditioning gel phase having little or no vesicle content. Such conditioners and methods for making them are described in WO2014 / 016354, WO2014 / 016353, WO2012 / 016352 and WO2014 / 016351.

[0058] Such a conditioning gel phase comprises, by total weight of the composition, i) from 0.4 to 8 wt % of fatty alcohol having from 8 to 22 carbons, ii) from 0.1 to 2 wt % of cationic surfactant, and the composition confers a Draw Mass of from 1 to 250 g, preferably 2 to 100 g, more preferably 2 to 50 g, even more preferably 5 to 40 g and most preferably 5 to 25 g to hair treated with the composition. Draw Mass is the mass required to draw a hair switch through a comb or brush. Thus the more tangled the hair the greater the mass required to pull the switch through the comb or brush, and the greater the level of condition of the hair, the lower the Draw Mass.

[0059] The Draw Mass is the mass required to draw a hair switch, for example of weight 1 to 20 g, length 10 to 30 cm, and width 0.5 to 5 cm through a comb or brush, as measured by first placing the hair switch onto the comb or brush, such that from 5 to 20 cm of hair is left hanging at the glued end of the switch, and then adding weights to the hanging end until the switch falls through the comb or brush.

[0060] Preferably, the hair switch is of weight 1 to 20 g, more preferably 2 to 15 g, most preferably from 5 to10 g. Preferably, the hair switch has a length of from 10 to 40 cm, more preferably from 10 to 30 cm, and a width of from 0.5 to 5 cm, more preferably from 1.5 to 4 cm.

[0061] Most preferably, the Draw Mass is the mass required to draw a hair switch, for example of weight 10 g, length 20 cm, and width 3 cm through a comb or brush, as measured by first placing the hair switch onto the comb or brush, such that from 20 cm of hair is left hanging at the glued end of the switch, and then adding weights to the hanging end until the switch falls through the comb or brush.

[0062] Preferably, the composition of the invention comprises a preservative. Illustrative preservatives for use include sodium benzoate, iodopropynyl butyl carbamate, phenoxyethanol, hydroxyacetophenone, ethylhexylglycerine, methyl paraben, propyl paraben, imidazolidinyl urea, sodium dehydroacetate, dimethyl-dimethyl (DMDM) hydantoin, potassium sorbate, sodium salicylate, levulinic acid, ansic, acid, and benzyl alcohol, or a combination thereof. Other preservatives suitable for use include sodium dehydroacetate, chlorophenesin, and decylene glycol. Preservatives are preferably employed in amounts of 0.01% to 2.0%, more preferably 0.05 to 1 wt %, by weight of the total weight of hair treatment composition. Preferably the preservative is an organic acid, most preferably sodium benzoate. Preferably it is used at a level of 0.01% to 2.0%, more preferably 0.05 to 1 wt %, most preferably from 0.1 to 0.7 wt %, by total weight of the composition. It may be used in conjunction with disodium EDTA, preferably at a ratio of sodium benzoate to EDTA of 10:1.

[0063] A preferred composition has a pH of from 3 to 5.8, preferably 4 to 5. The composition of the invention preferably comprises a pre-formed emulsified silicone. Mixtures of emulsified silicones can be used.

[0064] Suitable silicones include polydiorganosiloxanes, in particular polydimethylsiloxanes which have the CTFA designation dimethicone. Also suitable for use compositions of the invention are polydimethyl siloxanes having hydroxyl end groups, which have the CTFA designation dimethiconol. Also suitable for use in compositions of the invention are silicone gums having a slight degree of cross-linking, as are described for example in WO 96 / 31188.

[0065] The viscosity of the emulsified silicone itself (not the emulsion or the final hair composition) is typically at least 10,000 cst at 25 °C the viscosity of the silicone itself is preferably at least 60,000 cst, most preferably at least 500,000 cst, ideally at least 1,000,000 cst. Preferably the viscosity does not exceed 109cst for ease of formulation.

[0066] Emulsified silicones for use in the compositions of the invention will typically have a D90 silicone droplet size in the composition of less than 30, preferably less than 20, more preferably less than 10 micron, ideally from 0.01 to 1 micron. Silicone emulsions having an average silicone droplet size (D50) of 0.15 micron are generally termed microemulsions.

[0067] Silicone particle size may be measured by means of a laser light scattering technique, for example using a 2600D Particle Sizer from Malvern Instruments.

[0068] Examples of suitable pre-formed emulsions include Xiameter MEM 1785 and microemulsion DC2-1865 available from Dow Corning. These are emulsions / microemulsions of dimethiconol. Cross-linked silicone gums are also available in a pre-emulsified form, which is advantageous for ease of formulation.

[0069] A further preferred class of emulsified silicones for inclusion in compositions of the invention are amino functional silicones. By "amino functional silicone" is meant a silicone containing at least one primary, secondary or tertiary amine group, or a quaternary ammonium group. Examples of suitable amino functional silicones include: polysiloxanes having the CTFA designation "amodimethicone". Specific examples of amino functional silicones suitable for use in the invention are the aminosilicone oils DC2-8220, DC2-8166 and DC2-8566 (all ex Dow Corning).

[0070] Suitable quaternary silicone polymers are described in EP-A-0 530 974. A preferred quaternary silicone polymer is K3474, ex Goldschmidt. Also suitable are emulsions of amino functional silicone oils with non ionic and / or cationic surfactant.

[0071] Pre-formed emulsions of amino functional silicone are also available from suppliers of silicone oils such as Dow Corning and General Electric. Specific examples include DC939 Cationic Emulsion and the non-ionic emulsions DC2-7224, DC2-8467, DC2-8177 and DC2-8154 (all ex Dow Corning).

[0072] Preferably, the silicone is selected from the group consisting of dimethicone, dimethiconol, amodimethicone and mixtures thereof. Also preferred are blends of amino-functionalised silicones with dimethicones.

[0073] The amount of silicone in compositions of the invention may suitably range from 0.05 to 10%, preferably from 0.1 to 8%, more preferably 0.5 to 6.5 %, most preferably 0.6 to 3 % at 100 % activity, based on the total weight of the composition).

[0074] The composition of the invention preferably includes at least one inorganic electrolyte. The inorganic electrolyte provides viscosity to the composition. It is intended that the inorganic electrolyte is separate from any inorganic electrolytes that may be present in the raw materials of the invention.

[0075] Suitable inorganic electrolytes include metal chlorides (such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, zinc chloride, ferric chloride and aluminium chloride) and metal sulfates (such as sodium sulfate and magnesium sulfate. Preferred inorganic electrolytes for use in the invention include sodium chloride, potassium chloride, magnesium sulfate and mixtures thereof.

[0076] The amount of inorganic electrolyte in compositions of the invention preferably ranges from 0.5 to 10 %, more preferably from 0.75 to 7 %, even more preferably from 1 to 5 % and most preferably from 1 to 3 % (by weight based on the total weight of the composition).

[0077] A composition of the invention may contain other ingredients for enhancing performance and / or consumer acceptability. Such ingredients include, for example, fragrance, dyes and pigments, pH adjusting agents (for examples organic acids, sodium hydroxide), pearlescers, opacifiers, viscosity modifiers, antimicrobials. Each of these ingredients will be present in an amount effective to accomplish its purpose. Generally, these optional ingredients are included individually at a level of up to 5% by weight of the total composition.

[0078] For the avoidance of doubt the word “comprising” is intended to mean “including” but not necessarily “consisting of’ or “composed of.” In other words, the listed steps, options, or alternatives need not be exhaustive.

[0079] The disclosure of the invention as found herein is to be considered to cover all aspects as found in the claims as being multiply dependent upon each other irrespective of the fact that claims may be found without multiple dependency or redundancy. Unless otherwise specified, numerical ranges expressed in the format "from x to y" are understood to include x and y. In specifying any range of values or amounts, any particular upper value or amount can be associated with any particular lower value or amount. All percentages and ratios contained herein are calculated by weight unless otherwise indicated. The various features of the present invention referred to in individual sections above apply, as appropriate, to other sections mutatis mutandis. Consequently, features specified in one section may be combined with features specified in other sections as appropriate. Any section headings are added for convenience only and are not intended to limit the disclosure in any way.

[0080] Unless otherwise indicated, ratios, percentages, parts, and the like, referred to herein, are by weight.

[0081] Examples

[0082] Two comparative examples were prepared as follows:

[0083] Shampoo B: Shampoo comprising cysteine, histidine and glycine Shampoo A: The same as Shampoo B, only without the amino acids.

[0084] Table 1 : Compositions of Shampoo A and Shampoo B

[0085] The shampoos A and B were prepared using the following method: . In the compositions in accordance with the invention, the amino acids were added to water in a suitable vessel, with stirring.

[0086] 2. Carbomer, SPES and CAPB were then added.

[0087] 3. The mixture was heated to 30° C and mixed until homogenous.

[0088] 4. Guar polymer was then added and mixed.

[0089] 5. Glycerin and PEG-45M, fragrance, silicone and preservatives and any other ingredients were added.

[0090] 6. The pH was adjusted to pH 4 to 5.

[0091] 7. Salt and polypropylene glycol were then added to adjust the viscosity as desired. Example 2: Conditioner Composition 1, in accordance with the invention and Comparative Conditioner A

[0092] Conditioner 1 : Conditioner comprising cysteine, histidine and glycine. Conditioner A: The same as Conditioner 1 , but without the amino acids.

[0093] Table 3: Compositions of Conditioner 1, in accordance with the invention and comparative Conditioner A The conditioners were prepared using the following method:

[0094] 1. Water was added to a suitable vessel and heated to 80 °C.

[0095] 2. Cetearyl alcohol was then added along with tertiary amine salt (TAS).

[0096] 3. The formulation was allowed to cool and BTAC was added with mixing until opaque and thick.

[0097] 4. Lactic acid was added and the formulation was stirred for a further 10 minutes to ensure protonation of the TAS. 5. The heat was then turned off and quench water added.

[0098] 6. The amino acids were added.

[0099] 7. The mixture was then cooled to below 55°C and the preservatives and NaCI were added.

[0100] 8. The rest of the materials were then added.

[0101] 9. Finally, the formulation was mixed at high shear for 5 minutes. A and B, Conditioner 1, in accordance with the invention and Conditioner A

[0102] Hair was treated with the compositions given above and then subjected to heat damage.

[0103] Virgin hair was measured by DSC; an average was taken of all the hair switches in order to establish a base line measurement. The hair switches were then subjected to heat damage using the protocol below and the DSC measurement taken (this is shown as “Before wash” in the table below). The heat treated hair was then treated with the compositions given above.

[0104] Treatment of hair

[0105] The hair used in these examples had not been subjected to chemical treatments including bleaching, colouring, perming or straightening. The hair used was dark brown European hair, in switches of 5g weight and 10 inch length. This is referred to in these examples as Virgin hair.

[0106] Hair was subjected to heat as follows:

[0107] Tresses were hung from a stand and heat styled with the hair straighteners set to 230 °C. The straighteners were passed down the length of the hair from a root to tip direction; the exposure time was 12 seconds for each pass. Hair was treated to 3 passes at a time and allowed to cool back to room temperature before the next application. There were 18 passes in total for each tress.

[0108] Hair was treated with shampoo compositions (given above) using the following method:-

[0109] The hair fibres were held under running water for 30 seconds, shampoo applied at a dose of 0.1 g of shampoo per 1g of hair and rubbed into the hair for 30 seconds. Excess lather was removed by holding under running water for 30 seconds and the shampoo stage repeated. The hair was rinsed under running water for 1 minute. Conditioner only

[0110] Hair was treated with conditioner compositions (given above) using the following method:-

[0111] The hair fibres were held under running water for 30 seconds, conditioner applied at a dose of 0.2 g of conditioner per 1g of hair and rubbed into the hair for 1 minute. The hair was then rinsed under running water for 1 minute.

[0112] Table 3: Denaturation temperature of hair before treatment and after treatment with Shampoo A and Shampoo B, for 5 and 10 washes.

[0113] Same letters indicate no significant difference No significant difference is apparent between hair treated with shampoo A (with no amino acids) and shampoo B (with amino acids cysteine, histidine and glycine), after 5 and 10 washes.

[0114] Table 4: Denaturation temperature of hair before treatment and after treatment with Conditioner 1 and Conditioner A, for 5 and 10 washes

[0115] It will be seen that Conditioner 1, in accordance with the invention, provides a significant increase in denaturation temperature after 5 and 10 washes, whereas the comparative conditioners did not.

[0116] Example 4: Commerically available conditioner product, representative of the prior art The commercially available hair conditioner product, Lux CD Bath Glow Straight & Shine, comprising multiple amino acids, was obtained.

[0117] The ingredients given on the pack are as follows:

[0118] Water, stearyl alcohol, glycerin, dimethicone, behentrimonium chloride, DPG, paraffin, amodimethicone, lactic acid, C12-14 sec-pareth-7, EDTA-2Na, cetrimonium chloride, PEG-7 propylheptyl ether, C12-14 sec-pareth-5, tocopheryl acetate, acetic acid, PEG-180M, hydrolyzed keratin pg-propyl methylsilanediol, butylene glycol, steardimonium hydroxypropyl hydrolyzed keratin, PCA-Na, sodium lactate, Tremella fuciformis polysaccharide, ectoin, betaine, arginine, ethanol, aspartic acid, taurine, PCA, alanine, glycine, serine, valine, proline, threonine, lysine HCI, histidine HCI, isleucine, glutamic acid, phenylalanine, leucine, histidine, allantoin, glutamine, tyrosine, cystine, cysteine, tryptophan, methionine, sodium benzoate, phenoxyethanol, iodopropynyl butylcarbamate, potassium sorbate, fragrance.

[0119] The product was used to treat heat damaged hair. The hair was as described and heat damaged as in Example 3 above, and the “Conditioner only” protocol was used to treat the hair.

[0120] The denaturation temperature of the hair was measured before and after treatment. The results are given in Table 5:

[0121] Table 5: Denaturation temperature of hair before and after heat treatment and of heat treated hair before treatment and after treatment with Conditioner of the prior art, after 5 washes

[0122] Same letters indicate no significant difference between Td No significant difference is apparent on heat damaged hair after 5 washes with Lux CD Bath Glow Straight & Shine.

Claims

Claims1. A conditioner composition comprising:(a) a conditioning gel phase comprising a cationic conditioning surfactant and a fatty material; and(b) a blend of amino acids consisting of (i) cysteine (ii) histidine and (iii) glycine; and the composition is free from other amino acids.

2. Composition as claimed in claim 1, wherein the weight ratio of (i): (ii): (iii) is 2:1:1 to 1 :2:1 to 1 :1:2.

3. Composition as claimed in claim 1 or claim 2, wherein the blend of amino acids is present in an amount of from 0.1 to 10 % by weight of the total composition.

4. Composition as claimed in any preceding claim, which comprises a preservative, which is preferably sodium benzoate.

5. A method of increasing the denaturation temperature of the internal proteins of heat damaged hair comprising the step of applying to the hair a composition as defined in any one of claims 1 to 4 compared with the same composition that does not comprise a blend of amino acids consisting of (i) cysteine (ii) histidine and (iii) glycine.

6. A method as claimed in claim 5, which additionally comprises the step of leaving the composition on the hair for 2 seconds to 20 minutes, preferably 10 seconds to 3 minutes, most preferably 20 seconds to 1 minute.

7. A method as claimed in claim 5 or claim 6, which additionally comprises the step of repeating the application of the composition to the hair.

8. A method as claimed in claim 7 wherein the step of repeating the application of the composition to the hair is made during a later treatment and is repeated 1 to 10 times.

9. A method as claimed in any one of claims 5 to 8, wherein the heat damage has arisen due to use of a heated styling tool, preferably selected from hairdryers, straighteners, curling tongs / irons and hot rollers.

10. Use of a blend consisting of cysteine, histidine and glycine to increase the denaturation temperature of the internal proteins of heat damaged hair, compared with the same composition that does not comprise a blend of amino acids consisting of (i) cysteine (ii) histidine and (iii) glycine.

11. Use of a blend consisting of cysteine, histidine and glycine in a composition as defined in any of claims 1 to 4 to increase the denaturation temperature of the internal proteins of heat damaged hair, compared with the same composition that does not comprise a blend of amino acids consisting of (i) cysteine (ii) histidine and (iii) glycine.

12. A use as claimed in claim 10 or claim 11, wherein the heat damage has arisen due to use of a heated styling tool, preferably selected from hairdryers, straighteners, curling tongs / irons and hot rollers.