WO2025078216A1

WO2025078216A1 - Hair treatment composition

Info

Publication number: WO2025078216A1
Application number: PCT/EP2024/077619
Authority: WO
Inventors: Fraser Ian Bell; Robert Wayne Dawson; Julie Marie ROBERTS; Stephen John Singleton
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV; Conopco Inc
Priority date: 2023-10-13
Filing date: 2024-10-01
Publication date: 2025-04-17
Anticipated expiration: 2026-04-13

Abstract

A treatment composition for UV damaged hair comprising: (I) a surfactant selected from an anionic surfactant, a zwitterionic, an amphoteric, a cationic surfactant and mixtures thereof; and (II) a blend of amino acids consisting of (i) glutamic acid (ii) glycine and (iii) cysteine, gives surprising increase in denaturation temperature of the damaged hair protein, wherein the composition is free from other amino acids..

Description

HAIR TREATMENT COMPOSITION

Field of the Invention

The present invention relates to a treatment composition for hair that has been damaged by UV light, comprising mixtures of amino acids, its use to strengthen or repair the hair, and a method of treating UV damaged hair using said composition.

Background of the Invention

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. Daily exposure to environmental elements exacerbates the problem. Ultraviolet light is a particularly damaging environmental element and is a particular problem in countries with a high UV index.

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.

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. KR2010 0028722 discloses shampoo and conditioner compositions comprising a mixture of 17 amino acids for penetrating and damage improvement of hair caused by dyeing, bleaching, perming or heating with a hair dryer. An exemplified shampoo comprises lauramidopropyl betaine, polyquaternium-10, larueth-25 ad 17 amino acids.

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 itself.

There remains a need for more effective treatments for hair and damaged hair which deliver fortification benefits such as repair or strengthening during every day hair-care regimes. In particular, strong and/or prolonged exposure to solar radiation (ultraviolet (UV) light) can cause extensive damage to hair.

We have now found that a mixture of specific amino acids, namely glutamic acid, cysteine and glycine, in a hair treatment composition, can advantageously increase the denaturation temperature of hair that has been damaged by ultraviolet light.

Summary of the Invention

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

(I) a surfactant selected from an anionic surfactant, a zwitterionic, an amphoteric, a cationic surfactant and mixtures thereof; and

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

A second aspect of the invention provides a method of treating UV 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 UV damaged hair. The increase in denaturation temperature is compared with the same composition that does not comprise a blend of amino acids consisting of (i) glutamic acid (ii) cysteine and (iii) glycine. Preferably the method comprises an additional step of rinsing the composition from the hair.

The method preferably additionally comprises the step of leaving the composition on the UV damaged 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.

Preferably, the method additionally comprises the step of repeating the application of the composition to the UV damaged 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 UV damaged hair.

A third aspect of the invention provides a use of a blend of glutamic acid, cysteine and glycine to increase the denaturation temperature of the internal proteins of UV damaged hair. Preferably, the blend of glutamic acid, cysteine and glycine is present in a composition of the first aspect. In the uses of the invention, the increase in denaturation temperature is compared with the same composition that does not comprise a blend of amino acids consisting of (i) (i) glutamic acid (ii) cysteine and (iii) glycine.

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 (II)

The amino acids for use the compositions of the invention are (i) glutamic acid, (ii) cysteine and (iii) glycine. The composition is free from other amino acids; the composition does not comprise other amino acids in addition to those specified in (II).

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 glutamic acid : cysteine : glycine is preferably 2:1 :1 to 1:2:1 to 1 :1:2, more preferably 1 :1 :1.

Amino acids, including (i) glutamic acid (ii) cysteine and (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% and most preferably 4 to 15% 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 oC 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. Crosslinked 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.

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 R1, 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 R², R3 and R⁴ 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 R1 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 R^ and R^ 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 fatty materials have a carbon-carbon chain length of from Cs to C,₂2.

The combined use of fatty materials 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 material 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 alcohol 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 comprising glutamic acid, cysteine and glycine Shampoo A: The same as Shampoo B, but without the amino acids.

Table 1 : Compositions of Shampoo 1 and 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

The following conditioner compositions were prepared:

Conditioner G: Conditioner comprising glutamic acid, cysteine and glycine

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

Table 2: Compositions of Conditioner 1 and 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 to ensure protonation of the TAS.

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 subjected to ultraviolet radiation treatment before being treated with the compositions of Tables 1 and 2.

Treatment of hair

Virgin hair was used that had not been subjected to physical or chemical treatments including bleaching, colouring, perming, straightening, UV exposure, 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.

UV light exposure

The protocol for exposure to ultraviolet light was as follows:

An Atlas S3000 weatherometer set at 0.35W/m2 (340nm) giving an irradiance of 385 W/m2 in 300-800nm, was used to expose hair tresses to UV damage for 24 hours on each side, totaling 48 hours of UV exposure.

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 virgin and UV damaged hair before treatment and after treatment with Shampoo A and Shampoo 1, for 5 washes

Same letters indicate no significant difference

It will be seen that whilst both shampoos confer an increase in denaturation temperature after 5 washes, only Shampoo 1 , in accordance with the invention, provides a further significantly higher increase after a further 5 washes. Table 4: Denaturation temperature of hair before treatment and after treatment with Conditioner 1 and Conditioner A, for 5 and 10 washes

It will be seen that whilst both conditioners confer an increase in denaturation temperature after 5 and 10 washes, Conditioner 1, in accordance with the invention, provides a significantly higher increase after 10 washes than that conferred by the comparative Conditioner A, which did not comprise any amino acids.

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, 012-14 sec-pareth-7, EDTA-2Na, cetrimonium chloride, PEG-7 propylheptyl ether, 012-14 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, PGA, 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 UV damaged hair. The hair was as described and treated with UV light 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 exposure to UV light and of UV damaged hair before treatment and after treatment with Conditioner of the prior art, after 5 washes

Same letters indicate no significant difference between Td

No significant difference is apparent on UV damaged hair after 5 washes with Lux CD Bath Glow Straight & Shine.

Claims

1. A treatment composition for UV damaged hair comprising:

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

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