Hair treatment compositions and methods

Abstract

A sulfate-free cleansing composition for hair and scalp comprising: i) an alpha-olefin sulfonate anionic surfactant of general formula (I): R1-CH = CH-CH2-SO3-M + (I) wherein R1 is selected from the group consisting of linear or branched alkyl groups having 11 to 13 carbon atoms and mixtures thereof; and M is a solubilizing cation; (ii) an amphoteric or zwitterionic surfactant selected from the group consisting of alkyl betaine of the general formula (II) R2-N + (CH3) 2-CH2-COO-M + (II) wherein R2 = C12 (lauryl), cocamidopropyl or coconut oil derived; an alkylhydroxysulfobetaine of the general formula (III): R3-N + (CH3) 2-CH2-CH (OH)-CH2-SO3-M + (III), wherein R3 = C12 (lauryl) or coconut oil derived; an alkylaminopropyl hydroxysulfobetaine of the general formula (IV) R4-CO-NH-(CH2) 3-N + (CH3) 2-CH2-CH (OH)-CH2-SO3-M + (IV), wherein R4 = C12 (lauryl) or coconut oil derived; alkyl amphoteric acetate salts of the general formula (V) R5-CO-NH-(CH2) 2-N (CH2-CH2-OH) (CH2-COO-M +) (V), wherein R5 = C12 (lauryl) or coconut oil derived; and mixtures thereof, and iii) a piroctone compound; wherein the weight ratio of the alpha-olefin sulfonate anionic surfactant (i) to the amphoteric or zwitterionic surfactant (ii) ranges from 1: 1 to 6: 1.

Description

Technical Field

[0001] The present invention relates to a hair treatment composition, and particularly to an anti-dandruff shampoo composition. Background Art

[0002] Dandruff is a problem that affects many people worldwide. This condition presents as clumps of dead skin cells that flake off the scalp, which are white and result in an aesthetically unpleasant appearance. The factors that cause dandruff are certain members of the Malassezia yeast. To combat these yeasts, hair treatment compositions containing various active substances have been developed due to their anti-dandruff efficacy. A pyrithione compound such as zinc pyrithione ethanolamine is one such active substance.

[0003] A common problem with pyrithione compounds is the minimal deposition of the active substance on the desired surface during the washing process. The desired surface is typically the scalp and / or hair. For example, pyrithione compounds such as zinc pyrithione ethanolamine are usually soluble in the surfactant of the cleaning phase contained in the hair treatment composition. During the excessive rinsing process, most of the pyrithione is likely to be washed away with the surfactant. Poor deposition is associated with low anti-dandruff activity, and thus hardly alleviates the adverse effects of dandruff. To date, attempts have been made to compensate for this drawback by increasing the content of zinc pyrithione ethanolamine in the hair treatment composition. This method leads to various problems, such as increased cost, potential instability of the formulation, and potential adverse effects on the hair's sensory properties. Therefore, this is not the preferred way in the industry.

[0004] DE102012203240A1 describes a hair treatment composition having an increased anti-dandruff effect and improved hair combability, gloss, and elasticity. The composition contains an anti-dandruff agent selected from zinc pyrithione, climbazole, octopirox, ketoconazole, selenium disulfide, selenium-containing vegetable oil, selenium-containing plant extract, and cationic aminosiloxane. Examples include shampoos and conditioners that contain (zinc pyrithione ethanolamine), aminosiloxane, and surfactant.

[0005] US2013 / 0059929A1 describes a cosmetic or dermatological preparation, wherein the preparation contains at least one of benzethonium chloride, methylisothiazolinone, zinc pyrithione ethanolamine, and lauroyl ethyl arginine ester, and does not contain a phenol-based preservative. The preparation shows improved sensory properties and sufficient microbial stability.

[0006] US2002 / 0035161A1 describes a cosmetic / drug oil-in-water emulsion, which comprises a discontinuous fatty phase dispersed in a continuous aqueous phase and contains an effective amount of at least one bioactive agent (A) and an effective amount of an emulsifying system (B), whereby said at least one bioactive agent (A) is insoluble therein in the micronized particle state, at least 80% numerically of said micronized particles having a diameter in the range of 1 to 10 μm and at least 50% numerically having a diameter less than 5 μm.

[0007] Despite all the prior art, there is still a need to improve the deposition of piroctone compounds, in particular piroctone olamine or piroctone ethanolamine, on the scalp and / or hair surface during the washing process. There is also a need to improve the deposition on said surface without adverse side effects on the sensory properties, formulation rheology and conditioning properties. Summary of the Invention

[0008] The present invention relates to a sulfate-free cleansing composition for hair and scalp, which comprises:

[0009] (i) an α-olefin sulfonate anionic surfactant of general formula (I):

[0010] R 1 -CH=CH-CH2-SO3 - M + (I)

[0011] wherein R 1 is selected from straight-chain or branched-chain alkyls having 11 to 13 carbon atoms and mixtures thereof; and M is a solubilizing cation;

[0012] (ii) an amphoteric or zwitterionic surfactant selected from alkyl betaines of general formula (II):

[0013] R 2 -N + (CH3)2-CH2-COO - M + (II)

[0014] wherein R 2 = C12 (lauryl), cocoamidopropyl or coconut-derived;

[0015] an alkyl hydroxy sulfobetaine of general formula (III),

[0016] R 3 -N + (CH3)2-CH2-CH(OH)-CH2-SO3 - M + (III)

[0017] wherein R 3= C12 (lauryl) or coconut oil-derived;

[0018] An alkylaminopropyl hydroxysulfobetaine of general formula (IV),

[0019] R 4 -CO-NH-(CH2)3-N + (CH3)2-CH2-CH(OH)-CH2-SO3 - M + (IV)

[0020] wherein R 4 = C12 (lauryl) or coconut oil-derived;

[0021] An alkyl amphoacetate of general formula (V),

[0022] R 5 -CO-NH-(CH2)2-N(CH2-CH2-OH)(CH2-COO - M + )(V)

[0023] wherein R 5 = C12 (lauryl) or coconut oil-derived;

[0024] and mixtures thereof; and

[0025] iii) a piroctone compound;

[0026] wherein the weight ratio range of the α-olefin sulfonate anionic surfactant (i) to the amphoteric or zwitterionic surfactant (ii) is from 1:1 to 6:1.

[0027] The present invention also relates to a non-therapeutic method of treating hair or scalp, which comprises applying the personal care composition as described above.

[0028] The above composition is further described for use in treating hair or scalp.

[0029] For the avoidance of doubt, any feature of one aspect of the present invention can be used in any other aspect of the present invention. Any feature described as "preferred" should be understood to be particularly preferred in combination with one or more further preferred features. Herein, any feature of a particular embodiment can be used in any other embodiment of the present invention. The examples given in the following description are intended to illustrate the present invention and not to limit the present invention. Unless otherwise stated, all percentages are weight / weight percentages. DETAILED DESCRIPTION OF THE INVENTION

[0031] "Aqueous continuous phase" means a continuous phase having water as its matrix.

[0032] In the case of the present invention, "sulfate-free" means containing less than 0.1% by weight, preferably less than 0.05% by weight, of sulfate surfactant based on the total composition.

[0033] Suitably, the composition of the present invention comprises from about 60 to about 95% by weight, preferably from 65 to 95% by weight, more preferably from 70 to 90% by weight of water (by weight based on the total weight of the composition).

[0034] Preferably, the composition comprises an isotropic surfactant phase, wherein upon dilution, the isotropic micelles provide higher monomer availability at the air / water interface, while the anisotropic micelles can diffuse at a slower rate, resulting in lower flash foam performance. Thus, the isotropic phase is beneficial for the appearance, clarity and good flash foam characteristics of the product.

[0035] Unless otherwise stated, all amounts referred to herein are based on 100% activity (or "active substance"). 100% activity (or "active substance") means that the material is undiluted and is 100% v / v or weight / weight. Many materials used in personal care formulations are commercially available at different active substance concentrations, such as 70% active substance or 60% active substance. For example, 100 mL of a 70% active surfactant provides the same amount of active substance as 70 mL of a 100% active surfactant. Thus, in order to account for variations in the active substance of materials, all amounts are based on 100% active substance material.

[0036] The aqueous continuous phase comprises the total amount of anionic, zwitterionic and amphoteric surfactants consisting of (i) and (ii) below. That is, no further anionic, zwitterionic and amphoteric surfactants are present in the composition of the present invention. Preferably, no other surfactants, such as nonionic surfactants, are present in the composition of the present invention.

[0037] (i) α-olefin sulfonate anionic surfactant

[0038] The composition of the present invention comprises (i) one or more α-olefin sulfonate anionic surfactants of general formula (I)

[0039] R 1 -CH=CH-CH2-SO3 - M + (I)

[0040] wherein R 1 is selected from straight-chain or branched-chain alkyl groups having 11 to 13 carbon atoms and mixtures thereof; and M is a solubilizing cation;

[0041] Preferably, R in general formula (I) 1 is C 14 or C16 A linear alkyl group. Preferably, R in the general formula (I) 1 is C 11 or C 13 a linear alkyl group.

[0042] Preferably, M in the general formula (I) is selected from alkaline earth metal cations (such as sodium or potassium), ammonium cations, and substituted ammonium cations (such as alkylammonium, alkanolammonium, or glucammonium).

[0043] Commercially produced α-olefin sulfonate anionic surfactants of the general formula (I) can be prepared by sulfating C14-16 olefins derived from natural gas. This process can also produce a mixture of homologues and a low content of unreacted olefins.

[0044] Particularly preferred are α-olefin sulfonates having an average of 14-16 carbons. Suitable examples of such materials are Biotegre (from Stepan).

[0045] The amount of the α-olefin sulfonate anionic surfactant (100% active) of the general formula (I) ranges from 3 to 13%, preferably from 3.5 to 12%, more preferably from 3 to 10% (by weight based on the total weight of the composition).

[0046] (ii) zwitterionic or amphoteric surfactant of general formula (II), (III), (IV) or (V)

[0047] The composition of the present invention comprises (ii) an amphoteric or zwitterionic surfactant selected from alkyl betaines of the general formula (II)

[0048] R 2 -N + (CH3)2-CH2-COO - M + (II)

[0049] wherein R 2 = C12 (lauryl), cocoamidopropyl, or coconut-derived;

[0050] alkyl hydroxy sulfobetaines of the general formula (III),

[0051] R 3 -N + (CH3)2-CH2-CH(OH)-CH2-SO3 - M + (III)

[0052] wherein R 3 = C12 (lauryl) or coconut-derived;

[0053] alkyl aminopropyl hydroxy sulfobetaines of the general formula (IV),

[0054] R 4 -CO-NH-(CH2)3-N + (CH3)2-CH2-CH(OH)-CH2-SO3 - M + (IV)

[0055] wherein R 4 = C12 (lauryl) or coconut oil-derived;

[0056] alkyl amphoacetate of general formula (V),

[0057] R 5 -CO-NH-(CH2)2-N(CH2-CH2-OH)(CH2-COO - M + )(V)

[0058] wherein R 5 = C12 (lauryl) or coconut oil-derived;

[0059] and mixtures thereof.

[0060] Preferably, R 2 = C12 (lauryl) or coconut oil-derived.

[0061] The preferred surfactant (ii) is selected from cocamidopropyl betaine, lauryl hydroxy sulfobetaine, cocamidopropyl hydroxy sulfobetaine, lauryl amphoacetate, and mixtures thereof, most preferably from cocamidopropyl betaine, lauryl hydroxy sulfobetaine, and mixtures thereof. Alkyl hydroxy sulfobetaine is preferred, particularly lauryl hydroxy sulfobetaine.

[0062] The amount of the zwitterionic or amphoteric surfactant of general formula (II), (III), (IV) or (V) or mixtures thereof is preferably in the range of 1 to 6%, more preferably 1.5 to 5%, most preferably 2 to 3.5% (based on the total weight of the composition and 100% activity).

[0063] In a more preferred composition, the zwitterionic or amphoteric surfactant (ii) is selected from betaine amphoteric surfactants of general formula (II), which are cocamidopropyl betaine or lauryl hydroxy sulfobetaine, and mixtures thereof, and the amount thereof is 1 to 4% (by weight based on the total weight of the composition and 100% activity).

[0064] The combined amount of (i) and (ii) is preferably in the range of 4 to 20% by weight, preferably 5 to 17% by weight, most preferably 8 to 15% by weight (based on the total weight of the composition and 100% activity).

[0065] A particularly preferred composition according to the invention comprises (i) an α-olefin sulfonate in an amount ranging from 3.25 to 8% (by weight and based on 100% active substance material of the total weight of the composition); and

[0066] (ii) an amphoteric or zwitterionic surfactant selected from coco betaine, cocoamidopropyl betaine, lauryl hydroxysulfobetaine, cocoaminopropyl hydroxysulfobetaine, lauryl amphoacetate or mixtures thereof, in an amount ranging from 1 to 4% (by weight, based on the total weight of the composition and 100% active substance).

[0067] The weight ratio of the α-olefin sulfonate anionic surfactant (i) to the amphoteric surfactant (ii) ranges from 1:1 to 6:1, preferably from 1.5:1 to 5.

[0068] Preferably, the composition of the invention has a pH range of 3 to 6.5, preferably 3.5 to 5.1, more preferably 4 to 5.

[0069] A protonating agent can be used to achieve a low pH value. Suitable protonating agents are acids. Suitable acids applicable herein include hydrochloric acid, citric acid, acetic acid, tartaric acid, fumaric acid, lactic acid, malic acid, succinic acid and mixtures thereof. Preferably, the acid is selected from citric acid, acetic acid, tartaric acid, hydrochloric acid, fumaric acid, lactic acid and mixtures thereof.

[0070] The piroctone compounds for use in the present invention include piroctone oic acid, the primary, secondary and tertiary ethanolamine salts of piroctone oic acid (e.g., diethanolamine and triethanolamine salts), and mixtures thereof, preferably piroctone oic acid, the primary ethanolamine salt of piroctone oic acid (i.e., piroctone ethanolamine, also known as ) and mixtures thereof.

[0071] Piroctone ethanolamine is the ethanolamine salt of the hydroxamic acid derivative piroctone. It is commonly referred to as piroctone ethanolamine and has the trade name

[0072] The piroctone ethanolamine according to the present invention is a 1:1 compound of 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2(1H)-pyridinone and 2-aminoethanol, and is also known as 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2(1H)pyridinone monoethanolamine salt. The CAS number is 68890-66-4, and the compound has the following general formula (I):

[0073]

[0074] The piroctone compound, especially piroctone olamine, is preferably present in an amount of 0.01 to 5% by weight, more preferably 0.1 to 5% by weight, and most preferably 0.2 to 3% by weight of the total composition.

[0075] The personal care composition may comprise at least one cationic deposition polymer.

[0076] The cationic polymer comprises a dimethyldiallylammonium moiety.

[0077] Preferred cationic deposition polymers are homopolymers or copolymers in which the dimethyldiallylammonium moiety is one of the monomers. More preferred cationic polymers are polyquaternium-6, polyquaternium-7, and polyquaternium-22. A particularly preferred cationic polymer is polyquaternium-6.

[0078] Generally, the cationic polymer is present in an amount of 0.01 to 5% by weight, preferably 0.05 to 2% by weight, and more preferably 0.1 to 1% by weight of the total composition.

[0079] Additional cationic deposition polymers may be included, but they are not preferred.

[0080] Other cationic polymers include galactomannan and polysaccharide polymers such as cationic cellulose derivatives and cationic starch derivatives.

[0081] Mixtures of any of the above cationic polymers may be used.

[0082] Preferably, the weight ratio of the cationic polymer to the total surfactant (preferably an olefin sulfonate anionic surfactant (i) and an amphoteric or zwitterionic surfactant (ii)) is from 20:1 to 50:1, preferably from 25:1 to 40:1.

[0083] Preferably, the composition of the present invention, particularly the aqueous shampoo composition of the present invention, further comprises a suspending agent. Suitable suspending agents are selected from polyacrylic acid, cross-linked polymers of acrylic acid, copolymers of acrylic acid and hydrophobic monomers, copolymers of carboxylic acid-containing monomers and acrylates, cross-linked copolymers of acrylic acid and acrylates, heteropolysaccharide gums, and crystalline long-chain acyl derivatives. The long-chain acyl derivatives are preferably selected from ethylene glycol stearate, alkanolamides of fatty acids having 16 to 22 carbon atoms, and mixtures thereof. Ethylene glycol distearate and polyethylene glycol 3 distearate are preferred long-chain acyl derivatives because they impart pearlescence to the composition. Polyacrylic acid is commercially available as Carbopol 420, Carbopol 488, or Carbopol 493. Acrylic acid polymers cross-linked with polyfunctional reagents can also be used; they are commercially available as Carbopol 910, Carbopol 934, Carbopol 941, and Carbopol 980. An example of a suitable copolymer of carboxylic acid-containing monomers and acrylates is Carbopol 1342. All Carbopol (trademark) materials are available from Goodrich.

[0084] Based on the total weight of the composition, the suspending agent is generally present in the shampoo composition for the present invention at a level of 0.1 to 10%, preferably 0.15 to 6%, more preferably 0.2 to 4% of the total weight of the suspending agent.

[0085] The cosmetic composition may optionally comprise one or more components provided that the optional component is physically and chemically compatible with the essential components described above and does not otherwise unduly impair the sensory, formulation rheology, and conditioning properties. The individual concentration of such optional components can range from 0.001% to 10% by weight, preferably 0.01% to 5% by weight of the total composition. Such components can include conditioners, fragrances, dyes, pigments, pH adjusters, pearlescent or opacifying agents, viscosity modifiers, preservatives, and natural hair nutrients such as plant preparations, fruit extracts, sugar derivatives, and amino acids.

[0086] One of the preferred optional components is a suspending agent. Suitable suspending agents are selected from polyacrylic acid, cross-linked polymers of acrylic acid, copolymers of acrylic acid and hydrophobic monomers, copolymers containing carboxylic acid monomers and acrylates, cross-linked copolymers of acrylic acid and acrylates, heteropolysaccharide gums, and crystalline long-chain acyl derivatives. The long-chain acyl derivatives are preferably selected from ethylene glycol stearate, alkanolamides of fatty acids having 16 to 22 carbon atoms, and mixtures thereof. Ethylene glycol distearate and polyethylene glycol 3 distearate are preferred long-chain acyl derivatives because they impart pearlescence to the composition. Polyacrylic acid is commercially available as Carbopol 420, Carbopol 488, or Carbopol 493. Cross-linked acrylic polymers with polyfunctional reagents can also be used; they are commercially available as Carbopol 910, Carbopol 934, Carbopol 941, and Carbopol 980. An example of a suitable copolymer containing carboxylic acid monomers and acrylates is Carbopol 1342. All Carbopol (trademark) materials are available from Goodrich. Suitable cross-linked polymers of acrylic acid and acrylates are Pemulen TR1 or Pemulen TR2. A suitable heteropolysaccharide gum is xanthan gum, for example, available as Kelzan mu.

[0087] Mixtures of any of the above suspending agents can be used. Preferred is a mixture of a cross-linked polymer of acrylic acid and a crystalline long-chain acyl derivative.

[0088] The most preferred example is a cross-linked polyacrylate polymer.

[0089] The suspending agent, if included, is generally present in the composition in an amount of 0.01 to 5% by weight, preferably 0.1 to 2.5% by weight, more preferably 0.25 to 1% by weight.

[0090] Another preferred optional component is a conditioning agent to provide conditioning benefits. Generally, the most common conditioning agents used in cosmetic compositions are water-insoluble oily materials such as mineral oil, naturally occurring oils such as triglycerides, and silicone oils. The conditioning benefit is achieved by depositing the oily material on the hair to form a film, which makes the hair more lubricated and less dry. Preferably, the conditioning agent is non-volatile, meaning it has a vapor pressure of less than 1000 Pa at 25°C.

[0091] Preferably, the composition contains discrete dispersed droplets of a water-insoluble conditioning agent, the average droplet diameter (D 3,2 ) being less than 50 microns, preferably less than 30 microns, more preferably less than 15 microns, and most preferably less than 10 microns. The average droplet diameter (D 3,2), for example, using a 2600D Particle Sizer from Malvern Instruments.

[0092] Water-insoluble conditioning agents may include non-silicone conditioning agents, which comprise non-silicone oily or fatty substances such as hydrocarbon oils, fatty esters, and mixtures thereof. Preferably, the water-insoluble conditioning agent is an emulsified silicone oil.

[0093] Suitable silicones include polydiorganosiloxanes, particularly polydimethylsiloxane having the CTFA name dimethicone. Also suitable for the compositions of the present invention (particularly shampoos and conditioners) are polydimethylsiloxanes having hydroxyl end groups, which have the CTFA name dimethicone copolyol. Silicone rubbers with a slight degree of crosslinking are also suitable for the compositions of the present invention, as described, for example, in WO 96 / 31188. Preferably, the silicone oil comprises polydimethylsiloxane, dimethicone copolyol, or a mixture thereof.

[0094] The viscosity of the emulsified silicone itself (not the emulsion or the final hair care composition) is generally at least 10,000 cSt (centistokes = mm 2 ·S -1 ) at 25 °C, preferably at least 60,000 cSt, most preferably at least 500,000 cSt, and ideally at least 1,000,000 cSt. For ease of formulation, preferably the viscosity does not exceed 10 9 cSt. Suitable methods for measuring the kinematic viscosity of silicone oils are known to those skilled in the art, such as capillary viscometers. For high-viscosity silicones, a constant stress rheometer can be used to measure the viscosity.

[0095] Suitable emulsified silicones for the compositions can be obtained as preformed silicone emulsions from silicone suppliers such as Dow Corning and GE silicones. For ease of processing and control of silicone particle size, it is preferred to use such preformed silicone emulsions. Such preformed silicone emulsions usually additionally contain suitable emulsifiers and can be prepared by chemical emulsification processes such as emulsion polymerization or by mechanical emulsification using a high-shear mixer.

[0096] Examples of suitable preformed silicone emulsions include DC1785, DC1788, DC7128, all of which are available from Dow Corning. These are emulsions of dimethicone copolyol / dimethicone.

[0097] Another class of siloxanes that can be used are functionalized siloxanes, such as amino-functional siloxanes, meaning siloxanes containing at least one primary, secondary or tertiary amine group or quaternary ammonium group. Examples of suitable amino-functional siloxanes include polysiloxanes having the CTFA name "aminoterminated polydimethylsiloxane".

[0098] Preferably, the siloxane emulsion droplets are blended with certain types of high molecular weight surfactant block polymers to form a siloxane emulsion, as described, for example, in WO03 / 094874. A preferred form of the surfactant block polymer having polyoxypropylene and polyoxyethylene groups as the hydrophobic and hydrophilic moieties, respectively, has the formula V and has the CTFA name poloxamer, and is known to be commercially available under the trade name "Pluronic" from BASF.

[0099] V) HO(CH2CH2O) x (CH(CH3)CH2O) y (CH2CH2O) x H

[0100] Suitably, the average value of x in formula I is 4 or greater, preferably 8 or greater, more preferably 25 or greater, still more preferably 50 or greater, and most preferably 80 or greater. The average value of x is generally not greater than 200. Suitably, the average value of y is 25 or greater, preferably 35 or greater, more preferably 45 or greater, and most preferably 60 or greater. The average value of y is generally not greater than 100.

[0101] Another preferred form of the surfactant block polymer is according to formula VI and has the CTFA name Poloxamine. These are commercially available from BASF under the trade name "Tetronic".

[0102] VI)

[0103] (HO(CH2CH2O) a (CH(CH3)CH2O) b )2-N-CH2-CH2-N-((OCH2CH(CH3)) b (OCH2CH2) a OH)2

[0104] Suitably, the average value of a is 2 or greater, preferably 4 or greater, more preferably 8 or greater, even more preferably 25 or greater, and most preferably 40 or greater. The average value of a is generally not greater than 200. The average value of b is suitably 6 or greater, preferably 9 or greater, more preferably 11 or greater, and most preferably 15 or greater. The average value of b is generally not greater than 50.

[0105] Preferably, the surface-active block polymer is poloxamer and / or poloxamine, and more preferably, the surface-active block polymer is poloxamer.

[0106] Preferably, the surface-active block polymer is blended with dimethylpolysiloxane. The weight ratio range of dimethylpolysiloxane to the surface-active block polymer in the blend is preferably from 2:1 to 200:1, more preferably from 5:1 to 50:1, even more preferably from 10:1 to 40:1, and most preferably from 15:1 to 30:1.

[0107] The amount of the water-insoluble conditioner present in the composition is generally from 0.05 to 15% based on the total weight of the composition, preferably from 0.1 to 10%, more preferably from 0.5 to 8%, and most preferably from 1 to 5%, including all ranges therebetween.

[0108] The composition may preferably contain a pearlescent agent. The preferred pearlescent agent is the ethylene glycol ester as disclosed in US4885107, which is incorporated herein by reference. Preferably, the ethylene glycol ester is a monoester or diester of a diol, and more preferably a diester of a diol.

[0109] Preferably, the ethylene glycol monoester or diester is a 12-22 monoester or diester of a C fatty acid, and more preferably a saturated C 12-22 monoester or diester of a fatty acid. Most preferably, it is a diester containing a mixture of palmitate and stearate. The amount of stearate should be in the range of about 10% to about 42% or in the range of about 55% to about 80%, with palmitate making up the remainder. The amount of stearate is preferably about 60% to about 75%, more preferably about 80 - 95%, and most preferably 100%. The most suitable example of the pearlescent agent is ethylene glycol distearate. The pearlescent agent can also function as a suspending agent.

[0110] The content of the ethylene glycol ester can suitably be from about 0.5% to about 6% of the total composition weight, preferably from about 1% to about 4%.

[0111] When measured at 30 °C using a Brookfield V2 viscometer (rotor RTV5, 1 minute, 20 rpm), the viscosity range of the composition is suitably from 3,000 to 10,000 mPa·s, preferably from 4,000 to 8,000 mPa·s, and more preferably from 5,000 to 7,000 mPa·s.

[0112] The rinse-off composition is intended to be rinsed off from the user's scalp with water after use. Rinse-off compositions are preferred. Leave-on compositions are not intended to be rinsed off from the user's scalp immediately (i.e., within at least the first 2 hours, preferably at least 4 hours after application of the composition). In the context of the present invention, rinse-off compositions include shampoos and conditioners, as well as treatment compositions that can remain on the scalp for 0.5 minutes to a maximum of 15 minutes, preferably 1 minute to 10 minutes, more preferably 1 minute to 10 minutes before being rinsed off.

[0113] A preferred use of the cosmetic composition is for shampoos, especially rinse-off shampoos. The shampoo compositions for use in the present invention are generally aqueous, i.e., they have water or an aqueous solution or a lyotropic liquid crystal phase as their main component. Suitably, the shampoo composition contains 50 to 98% by weight, preferably 60 to 92% by weight of water based on the total weight of the composition. Such compositions are said to have an aqueous matrix.

[0114] The present invention will now be illustrated by the following non-limiting examples. Examples

[0115] Compositions were prepared according to Tables 1 and 2.

[0116] Table 1

[0117]

[0118] Table 2

[0119]

[0120]

[0121] The deposition of piroctone olamine was measured by thoroughly wetting 10 clean dark brown European hair tresses (2.5 g / 6”) with water. Five replicate tests were performed for each shampoo composition. 0.25 g of the shampoo was applied to one tress and then massaged for 30 seconds. The tress was then rinsed with water for 30 seconds. 0.25 g of the shampoo was reapplied and then massaged for another 30 seconds. The shampoo was then rinsed off with water for 30 seconds. The tress was allowed to dry naturally. The dried tress was extracted in 50 mL of ethanol. Care was taken not to expose the extraction to UV light. The piroctone acid deposition in the extract was analyzed by UPLC. The results are shown in Tables 1 and 2.

[0122] The results show that the examples of the present invention are more effective in depositing piroctone olamine than the comparative examples.

Claims

1. A sulfate-free cleansing composition for hair and scalp, comprising: i) an α-olefin sulfonate anionic surfactant of general formula (I): R 1 -CH=CH-CH2-SO3 - M + (I) wherein R 1 is selected from straight-chain or branched-chain alkyl groups having 11 to 13 carbon atoms and mixtures thereof; and M is a solubilizing cation; (ii) an amphoteric or zwitterionic surfactant selected from alkyl betaines of general formula (II): R 2 -N + (CH3)2-CH2-COO - M + (II) wherein R 2 = C12 (lauryl), cocoamidopropyl or coconut-derived; alkyl hydroxy sulfobetaines of general formula (III): R 3 -N + (CH3)2-CH2-CH(OH)-CH2-SO3 - M + (III) wherein R 3 = C12 (lauryl) or coconut oil-derived; alkylaminopropyl hydroxy sulfobetaines of general formula (IV): R 4 -CO-NH-(CH2)3-N + (CH3)2-CH2-CH(OH)-CH2-SO3 - M + (IV) wherein R 4 = C12 (lauryl) or coconut oil-derived; alkyl amphoacetates of general formula (V): R 5 -CO-NH-(CH2)2-N(CH2-CH2-OH)(CH2-COO - M + )(V) wherein R 5 = C12 (lauryl) or coconut oil-derived; and mixtures thereof; and iii) a piroctone compound; wherein the weight ratio of the α-olefin sulfonate anionic surfactant (i) to the amphoteric or zwitterionic surfactant (ii) ranges from 1:1 to 6:

1.

2. The sulfate-free cleansing composition according to claim 1, wherein the piroctone compound is piroctone olamine.

3. The sulfate-free cleansing composition according to any one of the preceding claims, comprising a total content of piroctone compound at a level of 0.1 to 5% by weight, preferably 0.2 to 3% by weight of the total composition.

4. The sulfate-free cleansing composition according to any one of the preceding claims, further comprising a cationic deposition polymer, preferably polyquaternium-6.

5. The sulfate-free cleansing composition according to any one of the preceding claims, wherein the weight ratio of the α-olefin sulfonate anionic surfactant (i) to the amphoteric or zwitterionic surfactant (ii) ranges from 1.5:1 to 5:

1.

6. The sulfate-free cleansing composition according to claim 4, wherein the weight ratio of the cationic polymer to the total surfactant as defined in claim 1 is from 20:1 to 50:1, preferably from 25:1 to 40:

1.

7. The sulfate-free cleansing composition according to any one of the preceding claims, wherein the pH of the composition is from 3 to 6.

5.

8. The sulfate-free cleansing composition according to any one of the preceding claims, wherein the total content of the anionic surfactant i) and the amphoteric and zwitterionic surfactants ii) is from 4 to 20% by weight, preferably from 6 to 15% by weight, more preferably from 7 to 13.5% by weight of the total composition.

9. The sulfate-free cleansing composition according to any one of the preceding claims, wherein the amount of the α-olefin sulfonate anionic surfactant (i) is from 3 to 13% by weight, preferably from 4 to 10% by weight of the total composition.

10. The sulfate-free cleansing composition according to any one of the preceding claims, wherein the amount of the amphoteric or zwitterionic surfactant ii) is from 1.5 to 5% by weight, preferably from 2 to 3.5% by weight of the total composition.

11. The sulfate-free cleansing composition according to any one of the preceding claims, wherein the amphoteric or zwitterionic surfactant (ii) is an amphoteric surfactant of general formula (III), which is an alkyl hydroxy sulfobetaine, preferably lauryl hydroxy sulfobetaine.

12. The sulfate-free cleansing composition according to any one of the preceding claims, which does not contain a cleansing surfactant not defined in claim 1.

13. A sulfate-free cleansing composition according to any one of the preceding claims, which is free from a thickener selected from thickening polymers and secondary surfactants not defined in (ii).

14. A sulfate-free cleansing composition according to any one of the preceding claims, which further comprises 0.5 to 6.5% by weight of a silicone conditioning agent, preferably a silicone emulsion.

15. A non-therapeutic method of treating hair and scalp, comprising the step of applying a composition as defined in any one of claims 1 to 13 to the hair and scalp.

16. A composition according to any one of claims 1 to 13, for reducing dandruff.

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