WO2025078215A1 - Hair treatment compositions - Google Patents

Abstract

A hair treatment composition comprising: (a) a surfactant a selected from an anionic surfactant, a zwitterionic surfactant, an amphoteric surfactant, a cationic surfactant and mixtures thereof; and (b) a blend of amino acids consisting of (i) cysteine (ii) histidine and (iii) glycine. gives surprising protection to hair protein from damage, during application of heat, wherein the composition is free from other amino acids.

Description

HAIR TREATMENT COMPOSITIONS

Field of the Invention

The invention relates to compositions and methods for protecting hair, particularly the internal protein of hair, from damage caused by exposure to heat, by use of a hair treatment composition comprising amino acids and to a use of such hair treatment compositions in the protection of hair from heat damage.

Background of the Invention

Consumers regularly subject their hair to intensive treatment and care and styling routines to help them 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 which, in turn, change physical properties of the fibre: the consequences of these changes are generally perceived by the consumer as damage.

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, or maintenance of denaturation temperature of hair is desirable.

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. Heat protection products for hair are known, which contain ingredients, for example, PVP/DMAPA acrylates copolymer, quaternium 70 and hydrolyzed wheat protein. These products are typically applied to hair just prior to application of heat. These generally work by forming thin films on the hair surface which slows down heat conduction and distributes heat more evenly.

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.

Despite the prior art, there remains a need for better protection of hair from damage. Protection is distinct from repair in that it helps to prevent damage from occurring. Repair is required for hair that is already damaged and repair treatments are typically applied to hair after the hair has suffered a damage occurance. In contrast, protection is required before damage occurs, such as heat being applied to hair, thus reducing or preventing damage from occurring to the hair. Thus, the impact of the damage insult is reduced.

We have now found that hair can be protected from heat damage by the application of a hair treatment composition comprising a blend of cysteine, histidine & glycine amino acids prior to the application of heat to the hair.

Summary of the Invention

In a first aspect, the invention provides a hair treatment composition comprising:

(a) a surfactant selected from a cationic surfactant, an anionic surfactant, a zwitterionic surfactant and a nonionic surfactant; and

(b) a blend of amino acids consisting of (i) cysteine (ii) histidine and (iii) glycine; the composition being free from other amino acids.

A second aspect of the invention provides a method of protecting hair from heat damage, comprising the steps of applying to the hair a composition of the first aspect and then applying heat to 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.

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

Applying heat to hair results in a decrease of the denaturation temperature of the internal proteins of the hair, compared to before the application of the heat. The method of the present invention results in a smaller decrease, or no decrease in the denaturation temperature after the application of heat, compared to a method where no composition of the first aspect, or no blend of amino acids consisting of (i) cysteine (ii) histidine and (iii) glycine is applied to hair before the application of heat.

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. Preferably the composition is then rinsed from the hair. This aims to provide a higher level of protection of the internal proteins of the hair from damage caused by heat, such that the decrease in denaturation temperature of the internal proteins of the hair is reduced more than if the composition was immediately rinsed off. The longer the period of time that the composition is left on the hair, the greater the reduction of the decrease in denaturation temperature of the internal proteins of the hair.

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 may provide greater increase in protection of the internal proteins of the hair. This may be shown by the further reduction in the size of the decrease of the denaturation temperature of the internal proteins of the hair following application of heat.

In the method of the invention the heat is applied to the hair by the use of heat styling. Tools used in heat styling are preferably selected from hairdryers, straighteners, curling tongs/irons and hot rollers.

In the method of the invention, where the composition of the first invention is provided first as a shampoo and secondly as a conditioner, it is preferred that the shampoo and conditioner are used sequentially, prior to application of heat to the hair. A third aspect of the invention provides a use of a blend of (i) cysteine (ii) histidine and (iii) glycine to protect hair from heat damage. Preferably, the blend of (i) cysteine (ii) histidine and (iii) glycine is present in a composition of the first aspect. When repeated, this use provides a progressive increase in protection of the protein, as defined above.

The third aspect of the invention provides a reduction in the decrease in denaturation temperature of the internal proteins hair when heat is applied to the hair, compared with a use where no blend of cysteine, histidine and glycine is applied to hair before the application of heat. Preferably, the blend of cysteine, histidine and glycine is present in a composition of the first aspect.

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.

Detailed Description of the Invention

Compositions in accordance with the invention are preferably formulated as shampoos or conditioners for the treatment of hair and subsequent rinsing.

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.

The amino acids(b)

The amino acids for use the compositions of the invention are (i) cysteine, (ii) histidine & (iii) glycine. The composition is free from other amino acids the composition does not comprise other amino acids in addition to the blend (b).. The amino acid mixture is preferably used in solution or emulsified form. It may be dissolved or dispersed in a suitable solvent or carrier.

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.

Amino acids, including (i) cysteine, (ii) histidine & (iii) glycine are available from many suppliers, for example Kusuma Pharma and Ajinomoto co Inc.

The treatment composition of the present invention is preferably a shampoo or a conditioner. A shampoo comprises at least one anionic surfactant for cleansing of the hair, whilst a conditioner comprises at least one cationic surfactant.

Shampoo compositions are generally aqueous, i.e. they have water or an aqueous solution or a lyotropic liquid crystalline phase as their major component.

Suitably, the shampoo composition will comprise from 50 to 98%, preferably from 60 to 90% water by weight based on the total weight of the composition.

Shampoo compositions will generally comprise one or more cleansing surfactants.

Surfactants are compounds which have hydrophilic and hydrophobic portions that act to reduce the surface tension of the aqueous solutions they are dissolved in. Shampoo compositions for use in the method of the invention will generally comprise one or more cleansing surfactants, which are cosmetically acceptable and suitable for topical application to the hair. The cleansing surfactant may be chosen from anionic, non-ionic, amphoteric and zwitterionic compounds and mixtures thereof, preferably anionic. The total amount of cleansing surfactant in a shampoo composition for use in the invention is generally from 1 to 50%, preferably from 2 to 40%, more preferably from 4 to 25% by total weight surfactant based on the total weight of the composition.

Non-limiting examples cleansing surfactants include anionic cleansing surfactants include; alkyl sulphates, alkyl ether sulphates, alkaryl sulphonates, N-alkyl sarcosinates, alkyl phosphates, alkyl ether phosphates, acyl amino acid based surfactants, alkyl ether carboxylic acids, acyl taurates, acyl glutamates, alkyl glycinates and salts thereof, especially their sodium, magnesium, ammonium and mono-, di- and triethanolamine salts. The alkyl and acyl groups in the preceding list generally contain from 8 to 18, preferably from 10 to 16 carbon atoms and may be unsaturated. The alkyl ether sulphates, alkyl ether phosphates and alkyl ether carboxylic acids and salts thereof may contain from 1 to 20 ethylene oxide or propylene oxide units per molecule.

Further non-limiting examples of cleansing surfactants may include non-ionic cleansing surfactants including; aliphatic (Cs - Cis) primary or secondary linear or branched chain alcohols with alkylene oxides, usually ethylene oxide and generally having from 6 to 30 ethylene oxide groups. Other representative cleansing surfactants include mono- or di-alkyl alkanolamides (examples include coco mono-ethanolamide and coco mono-isopropanolamide) and alkyl polyglycosides (APGs). Suitable alkyl polyglycosides for use in the invention are commercially available and include for example those materials identified as: Plantapon 1200 and Plantapon 2000 ex BASF. Other sugarderived surfactants, which can be included in compositions for use in the invention include the C - Ci8 N-alkyl (Ci-Ce) polyhydroxy fatty acid amides, such as the C12-C18 N-methyl glucamides, as described for example in WO 92 06154 and US 5 194639, and the N-alkoxy polyhydroxy fatty acid amides, such as C10-C18 N-(3-methoxypropyl) glucamide.

Additional non-limiting examples of cleansing surfactants may include amphoteric or zwitterionic cleansing surfactants including; alkyl amine oxides, alkyl betaines, alkyl amidopropyl betaines, alkyl sulphobetaines (sultaines), alkyl glycinates, alkyl carboxyglycinates, alkyl amphoacetates, alkyl amphopropionates, alkylamphoglycinates, alkyl amidopropyl hydroxysultaines, acyl taurates and acyl glutamates, wherein the alkyl and acyl groups have from 8 to 19 carbon atoms.

Typical cleansing surfactants for use in shampoo compositions for use in the invention include sodium oleyl succinate, ammonium lauryl sulphosuccinate, sodium lauryl sulphate, sodium lauryl ether sulphate, sodium lauryl ether sulphosuccinate, ammonium lauryl sulphate, ammonium lauryl ether sulphate, sodium cocoyl isethionate, sodium lauryl isethionate, lauryl ether carboxylic acid and sodium N-lauryl sarcosinate, sodium pareth sulphate, cocodimethyl sulphopropyl betaine, lauryl betaine, coco betaine, cocamidopropyl betaine, sodium cocoamphoacetate.

Preferred cleansing surfactants are sodium lauryl sulphate, sodium lauryl ether sulphate (n)EO, (where n is from 1 to 3, preferably 2 to 3, most preferably 3), ammonium lauryl sulphate, ammonium lauryl ether sulphate(n)EO, (where n is from 1 to 3, preferably 2 to 3, most preferably 3), sodium cocoyl isethionate and lauryl ether carboxylic acid, coco betaine, cocamidopropyl betaine, sodium cocoamphoacetate.

Mixtures of any of the foregoing anionic, non-ionic and amphoteric cleansing surfactants may also be suitable, preferably where the primary to secondary surfactant ratio is between 1 :1 - 10:1 , more preferably 2:1 - 9:1 and most preferably 3:1 - 8:1 , based on the inclusion weight of the cleansing surfactant in the shampoo composition.

Cationic deposition polymers are used in the shampoo compositions of the invention.

Suitable cationic deposition polymers may be homopolymers which are cationically substituted or may be formed from two or more types of monomers. The weight average (M_w) molecular weight of the polymers will generally be between 100 000 and 3 million daltons. The polymers will have cationic nitrogen containing groups such as quaternary ammonium or protonated amino groups, or a mixture thereof. If the molecular weight of the polymer is too low, then the conditioning effect is poor. If too high, then there may be problems of high extensional viscosity leading to stringiness of the composition when it is poured.

The cationic nitrogen-containing group will generally be present as a substituent on a fraction of the total monomer units of the cationic deposition polymer. Thus when the polymer is not a homopolymer it can contain spacer non-cationic monomer units. Such polymers are described in the CTFA Cosmetic Ingredient Directory, 3rd edition. The ratio of the cationic to non-cationic monomer units is selected to give polymers having a cationic charge density in the required range, which is generally from 0.2 to 3.0 meq/gm. The cationic charge density of the polymer is suitably determined via the Kjeldahl method as described in the US Pharmacopoeia under chemical tests for nitrogen determination.

Suitable cationic deposition polymers include, for example, copolymers of vinyl monomers having cationic amine or quaternary ammonium functionalities with water soluble spacer monomers such as (meth)acrylamide, alkyl and dialkyl (meth)acrylamides, alkyl (meth)acrylate, vinyl caprolactone and vinyl pyrrolidine. The alkyl and dialkyl substituted monomers preferably have C1-C7 alkyl groups, more preferably C1-3 alkyl groups. Other suitable spacers include vinyl esters, vinyl alcohol, maleic anhydride, propylene glycol and ethylene glycol.

The cationic amines can be primary, secondary or tertiary amines, depending upon the particular species and the pH of the composition. In general, secondary and tertiary amines, especially tertiary, are preferred.

Amine substituted vinyl monomers and amines can be polymerised in the amine form and then converted to ammonium by quaternization.

The cationic deposition polymers can comprise mixtures of monomer units derived from amine- and/or quaternary ammonium-substituted monomer and/or compatible spacer monomers.

Preferred cationic deposition polymers are selected from cationic diallyl quaternary ammonium- containing polymers, mineral acid salts of amino-alkyl esters of homo-and co-polymers of unsaturated carboxylic acids having from 3 to 5 carbon atoms, cationic polyacrylamides, cationic polysaccharide polymers and mixtures thereof.

Suitable (non-limiting examples of) cationic deposition polymers include: cationic diallyl quaternary ammonium-containing polymers including, for example, dimethyldiallylammonium chloride homopolymer and copolymers of acrylamide and dimethyldiallylammonium chloride, referred to in the industry (CTFA) as Polyquaternium 6 and Polyquaternium 7, respectively; mineral acid salts of amino-alkyl esters of homo-and co-polymers of unsaturated carboxylic acids having from 3 to 5 carbon atoms, (as described in U.S. Patent 4,009,256); cationic polyacrylamides (as described in WO95/22311). Other cationic deposition polymers that can be used include cationic polysaccharide polymers, such as cationic cellulose derivatives, cationic starch derivatives, and cationic guar gum derivatives.

Cationic polysaccharide polymers suitable for use in compositions for use in the invention include monomers of the formula:

A-O-[R-N⁺(R¹)(R²)(R³)X’], wherein: A is an anhydroglucose residual group, such as a starch or cellulose anhydroglucose residual. R is an alkylene, oxyalkylene, polyoxyalkylene, or hydroxyalkylene group, or combination thereof. R¹, R² and R³ independently represent alkyl, aryl, alkylaryl, arylalkyl, alkoxyalkyl, or alkoxyaryl groups, each group containing up to about 18 carbon atoms. The total number of carbon atoms for each cationic moiety (i.e., the sum of carbon atoms in R¹, R² and R³) is preferably about 20 or less, and X is an anionic counterion.

Another type of cationic cellulose includes the polymeric quaternary ammonium salts of hydroxyethyl cellulose reacted with lauryl dimethyl ammonium-substituted epoxide, referred to in the industry (CTFA) as Polyquaternium 24. These materials are available from the Amerchol Corporation, for instance under the tradename Polymer LM-200.

Other suitable cationic polysaccharide polymers include quaternary nitrogen-containing cellulose ethers (e.g. as described in U.S. Patent 3,962,418), and copolymers of etherified cellulose and starch (e.g. as described in U.S. Patent 3,958,581). Examples of such materials include the polymer LR and JR series from Dow, generally referred to in the industry (CTFA) as Polyquaternium 10.

A particularly suitable type of cationic polysaccharide polymer that can be used is a cationic guar gum derivative, such as guar hydroxypropyltrimethylammonium chloride (commercially available from Rhodia in their JAGUAR trademark series). Examples of such materials are JAGUAR C13S, JAGUAR C14 and JAGUAR C17.

Mixtures of any of the above cationic deposition polymers may be used.

Cationic deposition polymer will generally be present in a shampoo composition for use in the invention at levels of from 0.01 to 5%, preferably from 0.02 to 1%, more preferably from 0.05 to 0.8% by total weight of cationic polymer based on the total weight of the composition. A composition for use in the method and use of the invention comprises a suspending agent. Suitable suspending agents are selected from polyacrylic acids, cross-linked polymers of acrylic acid, copolymers of acrylic acid with a hydrophobic monomer, copolymers of carboxylic acidcontaining monomers and acrylic esters, cross-linked copolymers of acrylic acid and acrylate esters, heteropolysaccharide gums and crystalline long chain acyl derivatives and mixtures thereof. The long chain acyl derivative is desirably selected from ethylene glycol stearate, alkanolamides of fatty acids having from 16 to 22 carbon atoms and mixtures thereof. Ethylene glycol distearate and polyethylene glycol 3 distearate are preferred long chain acyl derivatives, since these impart pearlescence to the composition. Polyacrylic acid is available commercially as Carbopol 420, Carbopol 488 or Carbopol 493. Polymers of acrylic acid cross-linked with a polyfunctional agent may also be used; they are available commercially as Carbopol 910, Carbopol 934, Carbopol 941 and Carbopol 980. An example of a suitable copolymer of a carboxylic acid containing monomer and acrylic acid esters is Carbopol 1342. All Carbopol (trademark) materials are available from Goodrich.

Suitable cross-linked polymers of acrylic acid and acrylate esters are Pemulen TR1 or Pemulen TR2. A suitable heteropolysaccharide gum is xanthan gum, for example that available as Kelzan mu.

Mixtures of any of the above suspending agents may be used. Preferred is a mixture of crosslinked polymer of acrylic acid and crystalline long chain acyl derivative.

Suspending agent will generally be present in a shampoo composition for use in the method and use of the invention at levels of from 0.1 to 10%, preferably from 0.1 to 5%, more preferably from 0.1 to 3% by total weight of suspending agent based on the total weight of the composition.

Compositions for use in the method of the invention will preferably also contain one or more emulsified silicones, for enhancing conditioning performance.

The emulsified silicone is preferably selected from the group consisting of polydiorganosiloxanes, silicone gums, amino functional silicones and mixtures thereof.

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

The viscosity of the emulsified silicone itself (not the emulsion or the final hair conditioning 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 10⁹ cst for ease of formulation.

Emulsified silicones for use in the shampoo compositions 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.

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

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.

A further preferred class of silicones for inclusion in shampoos and conditioners 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).

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. 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).

The total amount of silicone emulsion is from 0.01 wt% to 10 wt% of the total composition preferably from 0.1 wt% to 5 wt%, more preferably 0.5 wt% to 3 wt% is a suitable level.

The compositions for use in the method and use of the invention preferably comprise a preservative. A preferred preservative is sodium benzoate.

Where present, the preservative is preferably present in an amount of from 0.01 to 2 wt %, more preferably 0.01 to 1 wt %, most preferably 0.1 to 1 wt %, by total weight of the composition.

Where the composition of the invention is a conditioner, it is advantageously 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 pre-treatment 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.

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.

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.

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.

The conditioning base comprises a cationic conditioning surfactant and a fatty material, preferably a fatty alcohol. The composition according to the invention comprises one or more conditioning surfactants which are cosmetically acceptable and suitable for topical application to the hair.

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:

[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.

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.

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.

In a preferred class of cationic surfactant of the above general formula, R1 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. Specific examples of such preferred quaternary ammonium cationic surfactants are cetyltrimethylammonium chloride (CTAC), behenyltrimethylammonium chloride (BTAC) and mixtures thereof.

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.

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

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

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.

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

Particularly preferred is stearamidopropyldimethylamine. 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.

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 materials having a carboncarbon chain length of from Cs to C,₂2.

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.

The fatty materail 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.

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.

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.

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, WO20 14/016353, WO2012/016352 and WO2014/016351.

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.

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.

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.

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.

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.

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. 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).

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.

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.

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.

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

Example 1 : Shampoo Composition 1, in accordance with the invention and comparative Composition A

The following shampoo compositions were prepared: Shampoo 1: Shampoo containing cysteine, histidine and glycine

Shampoo A: The same as Shampoo 1 , but without the amino acids.

Table 1 : Compositions of Shampoo 1, in accordance with the invention and Comparative

Shampoo A

The shampoos A and 1 were prepared using the following method: 1. In the compositions in accordance with the invention, the amino acids were added to water in a suitable vessel, with stirring.

2. Carbomer, SPES and CAPB were then added.

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

4. Guar polymer was then added and mixed.

5. Glycerin and PEG-45M, fragrance, silicone and preservatives were added.

6. The pH was adjusted to pH 4 to 5.

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

Conditioner 1 : Conditioner comprising cysteine, histidine and glycine

Conditioner A: The same as Conditioner 1, but without the amino acids.

Table 2: Compositions of Conditioner 1, in accordance with the invention and comparative Conditioner A

The conditioners were prepared using the following method:

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

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

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

4. Lactic acid was added and the formulation was stirred for a further 10 minutes.

5. The heat was then turned off and quench water added.

6. The amino acids were added.

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

8. The rest of the materials were then added.

9. Finally the formulation was mixed at high shear for 5 minutes.

Example 3: Treatment of hair with Shampoo Composition 1, in accordance with the invention Comparative Shampoo A, Conditioner Composition 1, in accordance with the invention and Comparative Conditioner A

Hair was treated with the compositions given above, ten times, and then subjected to heat damage. The protocols are given below.

Treatment of hair

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

Hair was subjected to heat as follows:

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. Shampoo only

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

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

Hair was treated with conditioner compositions (given above) using the following method:- The hair fibres were held under running water for 30 seconds, conditioner applied at a dose of 0.2 g of conditioner per 1 g of hair and rubbed into the hair for 1 minute. The hair was then rinsed under running water for 1 minute.

Table 3: Denaturation temperature of hair before treatment and after treatment with Shampoo 1, in accordance with the invention and Comparative Shampoo A, for 10 washes

Same letters indicate no significant difference 5 It will be seen that for shampoo 1, containing amino acids, there is no change in Td post heat damage. For shampoo A, without amino acids, the Td significantly decreases, therefore providing evidence that the amino acids have provided a protection benefit.

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

It will be seen that for the conditioner 1, which contained amino acids, there is no significant change in Td post heat damage. For conditioner A, without amino acids, Td significantly decreases. This illustrates the advantage of the invention in that the amino acids confer a protection effect to hair during exposure to heat.

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.

The ingredients given on the pack are as follows: 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.

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.

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

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

Same letters indicate no significant difference between Td

The Td decreases following heat damage indicating no protection for the conditioner.

Claims

Claims

1. A hair treatment composition comprising:

(a) a surfactant a selected from an anionic surfactant, a zwitterionic surfactant, an amphoteric surfactant, a cationic surfactant and mixtures thereof; 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 a method of protecting hair from heat damage, comprising the steps of applying to the hair a composition as defined in any one of claims 1 to 4 and then applying heat to the hair 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 is applied by use of a heated styling tool, preferably selected from hairdryers, straighteners, curling tongs or irons and hot rollers.

10. A method as claimed in any of claims 5 to 9, wherein the compositions defined in claims 1 to 4 are provided first as a shampoo and secondly as a conditioner and are used sequentially, prior to application of heat to the hair.

11. Use of a blend consisting of cysteine, histidine and glycine to protect hair from heat damage, as evidenced by a reduction in the decrease in denaturation temperature of the internal proteins of the hair when heat is applied to the hair, compared with a use where no blend consisting of cysteine, histidine and glycine is applied to hair before the application of heat.

12. Use as claimed in claim 11 , wherein the blend consisting of cysteine, histidine and glycine is present in a composition as defined in claims 1 to 4.

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