WO2025119713A1

WO2025119713A1 - Cleansing compositions

Info

Publication number: WO2025119713A1
Application number: PCT/EP2024/083664
Authority: WO
Inventors: Charlotte BEDDOES; Ryan BROCKLEBANK; Jules ORIOU; Pierre Starck
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: 2023-12-07
Filing date: 2024-11-26
Publication date: 2025-06-12
Anticipated expiration: 2026-06-07

Abstract

Superior viscosity robustness and deposition is provided by a cleansing composition comprising: a) from 5 to 9 wt %, of a surfactant system consisting of: i) from 3 to 8 wt % of an anionic surfactant combination comprising a combination of alkyl ether sulphates that have the general formula (I): R-O-(CH₂CH₂-O)n-SO₃ -M+ (I) in which, R is selected from linear alkyl groups having from C8 to C14 carbon atoms and mixtures thereof; n is a number that represents the average degree of ethoxylation and ranges from 0.5 to 1.4; and M is a solubilizing cation; the combination of alkyl ether sulphates comprising: - from at least 70 wt %, preferably from 70 to 95 wt %, more preferably from 70 to 90 wt %, by wt of the anionic surfactant combination, of a first alkyl ether sulphate having a chain length of C12/C14, where R in general formula (I) comprises from 65 to 78 wt % of C12 chains, and 20 to 35 wt % of C14 chains, by weight of R; - from 0 to 30 wt % of a second alkyl ether sulphate having a primary chain length selected from C16, wherein R comprises 100 % C16; - from 0 to 30 wt % of a third alkyl ether sulphate having a primary chain length selected from C18, where R comprises 100 % C18; and wherein the total amount of second and third alkyl ether sulphates is from 4 to 30 wt %,; and ii) from 1 to 10 wt %, preferably 1 - 9, of a zwitterionic or amphoteric co-surfactant, based on the total weight of the total composition; b) from 0.1 to 3 wt %, by weight of the total composition, of a viscosity modifier, which is an inorganic electrolyte; c) water; d) from 0.01 to 5 wt % of a fragrance; wherein the weight ratio of anionic (i) to zwitterionic (ii) is from 1:1 to 9:1, preferably 1:1 to 8:1; and wherein the composition has a viscosity of from 2,000 to 100,000 mPa.s.

Description

CLEANSING COMPOSITIONS

Field of the Invention

The present invention is directed to cleansing compositions comprising a combination of alkyl ether sulphate surfactants having improved viscosity and conditioning properties. This invention has particular application in the field of personal care, especially hair care.

Background of the Invention

Consumers reap numerous advantages from a broad selection of perfumes integrated into hair products. Firstly, scent plays a pivotal role in personal grooming and self-expression, and having a diverse range of fragrances allows individuals to match their haircare to their unique preferences and moods. This variety enhances the overall sensory experience of hair care, making it more enjoyable and satisfying. Additionally, a wider range of perfumes provides consumers with the opportunity to choose products that complement their chosen fragrances, creating a harmonious and long-lasting scent profile. It is also found that the incorporation of different scents in hair products can have psychological benefits, such as boosting one’s confidence and mood, making the haircare routine a more holistic and pleasurable part of daily life.

It is thus desirable to provide a wider range of fragrances in hair products.

However, a common problem occurs upon addition of fragrance to surfactant based systems, whereby viscosity can suffer significant reduction. This is discussed in, for example, “Effect of Perfumes on the viscosity of Surfactant Systems”, D.R. Munden, Quest International Ltd, Cosmetics & Toiletries, 13 Sep 2013. Further, even if viscosity can be rebuilt, it is found to have low robustness if a different perfume is then used. Thus, fragrances often have to be specially formulated in order to be compatible with a particular formulation. The range of fragrances that can be used for such formulations is thus limited.

The most commonly used alkyl chains for isotropic surfactant based cleaning surfactants predominantly have carbon-carbon lengths of 8 to 18 carbon atoms, with a dominance at 12 to 14 carbon atoms (sodium lauryl ether sulphate (SLES) is a traditional example). These are defined only in even numbers as found in nature, although odd number chain lengths can be obtained from petrochemical sources. Natural materials can be synthesized from fatty acids extracted from vegetable triglyceride oils, most commonly palm kernel oil and coconut oil, which are the most common sources of C12 to C14 carbon chains. Most other vegetable oils have a lower content of chains of length below C16, and those that do (e.g. babassu oil and macauba oil) are not available commercially at an industrial scale. There is much current interest in moving away from a chain length distribution of C12 to C14.

The formation of an isotropic phase during manufacture of liquid cleansing formulations is known to produce products having high quality cleansing and foaming properties, along with ideal rheological properties for manufacturing and consumer use.

In the past, attempts have been made to provide high foaming surfactants using mixtures of surfactants. Using petrochemically derived materials, US6001787 describes an aqueous cleansing composition, which consists of: (a) a short-chain anionic surfactant having C6 -C9 chains; (b) a long-chain anionic surfactant having C13 -C18 carbon chains; and (c) optionally, a medium-chain anionic surfactant having C10 -C12 chains; at a ratio of (c):[(a) + (b)] of less than 1 :1 ; (d) a surfactant suitable for topical application to the human body selected from the group consisting of non ionic, zwitterionic and cationic surfactants, (e) a structurant; (f) a thickening agent and other adjuncts.

US20050136026A1 describes an (non-isotropic) ordered liquid crystalline phase cleansing composition comprising: a) at least 3 wt % of an anionic surfactant other than a C16 to C24 normal monoalkylsulfosuccinate; b) a structuring base including at least one compound selected from C16 to C24 normal monoalkylsulfosuccinates and at least one compound selected from C16 to C24 normal alkyl fatty acids; c) wherein the at least one monoalkylsulfocuccinate has an alkyl group with a carbon number n and the at least one normal fatty acid has an alkyl group with a carbon number m and the absolute value of n-m is 4 or less; and d) wherein the mole ratio of said at least one monoalkylsulfosuccinate to said at least one fatty acid is in the range of about 3 to 0.2. It is disclosed that the composition provides fast dispersion kinetics (with the same product viscosity), high product viscosity, fast release of active ingredients (i.e. lather-forming surfactants) and improved rinse and clean/fresh feeling accompanying product use.

EP3773457 discloses a personal cleansing comprising a total amount of anionic surfactant, amphoteric surfactant and zwitterionic surfactant consisting of: (i) from 3 wt % to less than 7 wt %, of an alkyl ether sulfate anionic surfactant, (ii) a betaine surfactant, (iii) an emulsified silicone with a diameter of 4 micrometres or less, (iv) an inorganic electrolyte; wherein the weight ratio of (i) to (ii) is from 1: 1 to 4.5:1 and a pH of 3 to 6.5; and the combined amount of (i) and (ii) ranges from 5 wt % to 9 wt %. Viscosity can be built at low total surfactant levels at specific ratios of SLES/CAPB and the compositions rely on the use of SLES2EO to bring conditioning back up.

However, we have found that when long chain length (eg C16 and C18) materials are introduced into SLES (C12/C14) based surfactant systems, solubility issues arise within the isotropic liquid (due to the insolubility of the C16 and C18 chains). This results in inferior foam properties, reduced deposition of benefit agents such as conditioning oil, silicone and antidandruff agents, as well as reduced viscosity that can be difficult to build (for example with salt).

We have now found that a combination of surfactants having different chain lengths, including longer chain lengths, can be used in controlled amounts and at specific ratios, to enable viscosity to be built, whilst still being an isotropic liquid and also retaining the advantages of the traditional SLES based system, namely good cleaning, foaming and excellent deposition of conditioning oil.

Advantageously, less salt and/or additional viscosity modifiers are required to achieve desired viscosity. Additionally, this combination presents dramatically improved viscosity robustness to a wider range of fragrance oils compared with a standard SLES based shampoo. Robustness is different from simple viscosity build. It relies on the ability of the microstructure (formed from the surfactants) to withstand other ingredients, particularly fragrance.

Summary of the Invention

In a first aspect, the invention provides a cleansing composition comprising: a) from 5 to 9 wt %, of a surfactant system consisting of: i) from 3 to 8 wt %, by weight of the total cleansing composition, of an anionic surfactant combination comprising a combination of alkyl ether sulphates that have the general formula (I): R-O-(CH₂CH2-O)n-SO₃-M⁺ (I) in which, R is selected from linear alkyl groups having from C8 to C14 carbon atoms and mixtures thereof; n is a number that represents the average degree of ethoxylation and ranges from 0.5 to 1.4; and M is a solubilizing cation; the combination of alkyl ether sulphates comprising, by weight of the anionic surfactant composition:

- from at least 70 wt %, preferably from 70 to 95 wt %, more preferably from 70 to 90 wt %, by weight of the anionic surfactant combination, of a first alkyl ether sulphate having a chain length of C12/C14, where R in general formula (I) comprises from 65 to 78 wt % of C12 chains, and 20 to 35 wt % of C14 chains, by weight of R;

- from 0 to 30 wt % of a second alkyl ether sulphate having a primary chain length selected from C16, wherein R comprises 100 % C16;

- from 0 to 30 wt % of a third alkyl ether sulphate having a primary chain length selected from C18, where R comprises 100 % C18; and wherein the total amount of second and third alkyl ether sulphates is from 4 to 30 wt %, preferably 5 to 30 wt %, more preferably from 10 to 30 wt %, by weight of the anionic surfactant combination; and ii) from 1 to 6 wt %, preferably 1 to 5 wt %, of a zwitterionic or amphoteric co-surfactant, based on the total weight of the total composition; b) from 0.1 to 3 wt %, by weight of the total composition, of a viscosity modifier, which is an inorganic electrolyte; c) water; d) from 0.01 to 5 wt % of a fragrance; e) an optional conditioning oil; and f) an optional cationic deposition polymer; wherein the weight ratio of anionic surfactant (i) to zwitterionic or amphoteric co-surfactant (ii) is from 4:1 to 9:1 , preferably 5:1 to 8:1 ; and wherein the composition has a viscosity of from 2,000 to 100,000 mPa.s, preferably from 2,000 to 50,000 mPa.s, more preferably from 2100 to 40,000 mPa.s, when measured at 30 degrees C and 4s-7, using sandblasted 40mm parallel plates, on a Wingspan rheometer (TA instruments).

A second aspect of the invention provides a method of cleansing hair including the step of applying to the hair a composition of the first invention.

Detailed Description of the Invention

Many raw materials contain, what are known in the industry as, carry-over ingredients. These are often used for example as processing aids, preservatives, emulsifiers, etc. These carry-over ingredients are present in very small quantities and perform a function for the raw material (for example as an emulsifier for a silicone). Carry-over ingredients are present in the full compositions at levels that are too low to have a material effect on the properties of the composition. They are not intended to be part of the invention.

The surfactant system (a)

The compositions of the invention comprise a surfactant system that consists of i) an anionic surfactant combination and ii) a zwitterionic/amphoteric co-surfactant.

The compositions of the invention are free from anionic surfactants and zwitterionic/amphoteric surfactants other than those defined in i) and ii).

In the context of this invention, by free from anionic, zwitterionic and amphoteric surfactants, other than those defined in i) and ii) means preferably the level of anionic, zwitterionic and amphoteric surfactants other than those defined in i) and ii) is less than 0.75 weight %, more preferably less than 0.5 weight %, more preferably less than 0.3 weight %, still more preferably less than 0.1 weight %, yet more preferably less than 0.01 weight %, still yet more preferably less than 0.001 weight %, and most preferably 0 weight % by weight of the total composition. The surfactant system (a) is present in an amount of from 5 to 9 wt %, based on the weight of the total cleansing composition.

The anionic surfactant combination (i)

The anionic surfactant combination (i) comprises a combination of alkyl ether sulphates that have the general formula (I):

R-O-(CH₂CH2-O)n-SO₃-M⁺ (I) in which, R is selected from linear alkyl groups having from C8 to C14 carbon atoms and mixtures thereof; n is a number that represents the average degree of ethoxylation and ranges from 0.5 to 1.4, preferably 0.75 to 1.25, more preferably from 0.8 to 1.2, most preferably 1 ; and M is a solubilizing cation.

The combination of alkyl ether sulphates comprises:

From at least 70 wt %, preferably from 70 to 95 wt %, more preferably from 70 to 90 wt %, by wt of the anionic surfactant combination, of a first alkyl ether sulphate having a chain length of C12/C14. Preferably, the first alkyl ether sulphate is sodium lauryl ether sulphate (SLES), where R in general formula (I) comprises from 65 to 78 wt % of C12 chains, and 20 to 35 wt % of C14 chains, by weight of R.

From 0 to 30 wt %, of a second alkyl ether sulphate having a primary chain length selected from C16, wherein R comprises 100 % C16.

From 0 to 30 wt %, of a third alkyl ether sulphate having a primary chain length selected from C18, where R comprises 100 % C18.

The total amount of second and third alkyl ether sulphates is from 4 to 30, preferably from 5 to 30 wt %, preferably from 10 to 30 wt %, by weight of the anionic surfactant combination. The average degree of ethoxylation (n) of added ethylene oxide (EO) is from 0.5 to 1.4, preferably 0.75 to 1.25, more preferably from 0.8 to 1.2, most preferably 1.

The anionic surfactant system (i) is present in an amount of from 3 to 8 wt %, by total weight of the composition.

The zwitterionic/amphoteric co-surfactant (ii)

Examples of suitable amphoteric or zwitterionic co-surfactants include alkyl amine oxides (for example lauryl amine oxide); alkyl betaines, alkyl amidopropyl betaines, alkyl sulphobetaines; alkyl amphoacetates (for example sodium cocoamphoacetate); alkyl amphopropionates, alkylamphoglycinates; alkyl amidopropyl hydroxysultaines; and mixtures thereof.

Preferably, the amphoteric or zwitterionic co-surfactant is selected from alkyl betaines, alkyl amidopropyl betaines, alkyl hydroxsultaines, alkyl amidopropyl hydroxy sultaines, and mixtures thereof.

Most preferred examples of amphoteric and zwitterionic surfactants for use in shampoos of the invention include lauryl betaine, cocamidopropyl betaine, lauryl hydroxysultaine.cocamidopropyl hydroxysultaine, and mixtures thereof.

A particularly preferred amphoteric or zwitterionic co-surfactant is cocamidopropyl betaine.

The zwitterionic or amphoteric co-surfactant is present in an amount of from 0.5 to 2 wt %, preferably 0.5 to 1.5 wt %, based on the weight of the total composition.

Ratio of anionic (i) : zwitterionic

The weight ratio of the anionic surfactant combination (i) to the zwitterionic/amphoteric cosurfactant (ii) is preferably 4:1 to 9:1 , preferably 5:1 to 8:1. The viscosity modifier (b)

The viscosity modifier, for use in the compositions of the invention, is an inorganic electrolyte. Suitable inorganic electrolytes for use in the invention include metal chlorides (such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, zinc chloride, ferric chloride and aluminum chloride) and metal sulphates (such as sodium sulphate and magnesium sulphate). The inorganic electrolyte is used to provide viscosity to the composition.

Examples of preferred inorganic electrolytes for use in the invention include sodium chloride, potassium chloride, magnesium sulphate and mixtures thereof, most preferably sodium chloride.

Mixtures of any of the above described materials may also be suitable.

The level of inorganic electrolyte in compositions of the invention ranges from 0.1 to 3%, preferably from 0.25 to 2.5% (by total weight of the composition).

The viscosity of the composition suitably ranges from 2,000 to 100,000 mPa.s, preferably from 2,000 to 50,000 mPa.s, more preferably from 2100 to 40,000 mPa.s, when measured at 30 degrees C and 4s- 1, using sandblasted 40mm parallel plates, on a Wingspan rheometer (TA instruments).

At these ranges our products are pourable yet thick enough to satisfy the consumer desire for thick compositions.

It is intended that the inorganic electrolyte is distinct from any inorganic electrolytes that may be present in the raw materials of the invention, as “carry over”.

Water (c)

The compositions of the invention are aqueous. The amount of water included in the compositions is such that the composition is 100 weight %. That is to say that water is added to “balance” the composition to 100 % weight. Thus the amount of water is such that the composition is 100 wt % The compositions of the invention will typically comprise greater than 50 wt % water, preferably 60 wt % water, more preferably greater than 70 %, still more preferably greater than 80 %, most preferably greater than 90 % water. The upper limit of water is determined by the amount of the other ingredients of the invention.

For example, the compositions of the invention may comprise from 60 to 94.2 wt % water. Or 60 to 94 wt %, or 80 to 90 wt % water.

A preferred method of making the compositions is as follows:

1 . A vessel was charged with water. Surfactants and any structurant were added with stirring.

2. The mixture was heated to 50 - 60° C and mixed until homogenous.

3. When used, cationic polymer and silicone emulsion were then added and mixed well.

4. Any preservative was added.

5. The pH was adjusted to pH 4.5 using organic acid.

6. Salt was then added to adjust the viscosity.

By combination, in the context of this invention, is meant that the first alkyl ether sulphate and the second alkyl ether surfactant may be mixed together before being used in the compositions of the invention or may be added separately to the compositions.

The fragrance (d)

Fragrances and fragrance components can disrupt micelles in a structured formulation, such as shampoo. This causes a drop in viscosity.

The fragrance for use in the compositions of the invention causes such a drop in viscosity when added to the unfragranced SLES/CAPB composition with standard C12/C14 chain.

Preferably, the viscosity is reduced by less than 10 % upon addition to the composition, as calculated with the following equation:

Viscosity of composition without fragrance - viscosity of composition with fragrance x 100 Viscosity of composition without fragrance The fragrance is present in an amount of from 0.01 to 5 wt %, preferably from 0.1 to 4 wt %, more preferably from 0.5 to 2 wt %.

The conditioning oil

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

Preferably, the conditioning oil is selected from fatty ester oils, hydrocarbon oils and silicone oils. Most preferably, the conditioning oil is a silicone oil.

The hydrocarbon oils can be natural or synthetic.

Straight chain hydrocarbon oils will preferably contain from about 12 to about 30 carbon atoms. Also suitable are branched chain hydrocarbon oils, which preferably contain from about 12 to about 42 carbon atoms. Also suitable are polymeric hydrocarbons of alkenyl monomers, such as C2 to C6 alkenyl monomers.

Specific examples of suitable hydrocarbon oils include paraffin oil, mineral oil, polyalphaolefin, squalane, saturated and unsaturated dodecane, saturated and unsaturated tridecane, saturated and unsaturated tetradecane, saturated and unsaturated pentadecane, saturated and unsaturated hexadecane, and mixtures thereof. Branched-chain isomers of these compounds, as well as of higher chain length hydrocarbons, can also be used. Another suitable material is polyisobutylene. A preferred polyalphaolefin is commercially available as Silkflo 366 ™ (dec-1- ene) ex Ineos.

Suitable fatty esters are characterised by having at least 6 carbon atoms and include esters with hydrocarbyl chains derived from fatty acids or alcohols. Monocarboxylic acid esters include esters of alcohols and/or acids of the formula R'COOR in which R' and R independently denote alkyl or alkenyl radicals and the sum of carbon atoms in R' and R is at least 10, preferably at least 20. Di- and trialkyl and alkenyl esters of carboxylic acids can also be used.

Particularly preferred fatty esters are mono-, di- and triglycerides, more specifically the mono-, di-, and tri-esters of glycerol and long chain carboxylic acids such as C1-C22 carboxylic acids. Most preferably, the fatty esters are tri-esters of glycerol and carboxylic acids having carbon- carbon chain length of C8 - C22, preferably C10 - C18. Preferred materials include cocoa butter, palm stearin, sunflower oil, soyabean oil and coconut oil.

A non-silicone conditioning oil is preferably selected from hydrocarbon oils selected from paraffin oil, mineral oil, polyalphaolefin oil, esters with hydrocarbyl chains derived from fatty acids or alcohols, and mixtures thereof.

Preferred silicone oils are 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 Cationic

Cationic deposition polymers are preferably 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.

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 preferred 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 composition of 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.

The inventive compositions may comprise 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 acid-containing 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. The Method

The invention provides a method of treating hair including the steps of applying to the hair, which is preferably wet, a composition of the first invention and preferably rinsing the composition from the hair.

Preferably, the method is a method of conditioning hair. Preferably, conditioning is selected from slippery feel under running water, ease of damp detangle, slippery feel, ease of styling, ease of dry comb, smooth dry feel, and softness and mixtures thereof.

Free from polymeric thickeners

Preferably, the composition is free from polymeric thickeners.

In the context of this invention, by free from polymeric thickeners means preferably the level of polymeric thickeners is less than 0.75 weight %, more preferably less than 0.5 weight %, more preferably less than 0.3 weight %, still more preferably less than 0.1 weight %, yet more preferably less than 0.01 weight %, still yet more preferably less than 0.001 weight %, and most preferably 0 weight % by weight of the total composition.

Whilst many polymers, regardless of their intended function (such as wet feel polymers, deposition polymers, structurants and so on) may influence viscosity, they are used at such a level so as to cause insubstantial or no thickening. For example, preferably at 0.005 to less than 0.75 wt %, preferably 0.005 to 0.5 wt %, typically 0.2 wt %.

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.

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.

Other

A composition of the invention may contain further optional ingredients to enhance performance and/or consumer acceptability. Examples of such ingredients include, for example, fragrance, dyes and pigments, pH adjusting agents (for examples organic acids, sodium hydroxide), pearlescers, opacifiers, viscosity modifiers, preservatives, antimicrobials, structurants, solvents, feel modifying polymers. Each of these ingredients will be present in an amount effective to accomplish its purpose. Generally, these optional ingredients are included individually at an amount of up to 5% (by weight based on the total weight of the composition).

The composition of the invention is primarily intended for topical application to the hair and scalp.

Most preferably the composition of the invention is topically applied to the hair and then massaged into the hair and scalp. The composition is then rinsed off the hair and scalp with water prior to drying the hair.

All amounts herein are by weight of the total composition, unless otherwise stated.

The invention will be further illustrated by the following, non-limiting Examples.

Building viscosity through salt-thickening and mildness are formulation properties which mostly depend on surfactant ingredients. Therefore, the following examples correspond to either simple formulations containing only surfactants and preservatives (such as examples in Table 2), or more complex formulations containing conditioning and structuring agents (such as example in Table 1).

Each of the Tables below contain compositions at a comparable total surfactant (anionic + amphoteric) concentration. For instance, compositions in Table 1 contain 7.8 wt% total surfactants corresponding to 6.5 wt% SLES + 1.3 wt% CAPB. However, the example compositions where part of the SLES has been replaced by a longer chain alkyl ether sulfate will show a slightly higher total surfactant value (see for instance Example 1 in Table 1 having 8.04 wt% total surfactants (4.88 wt% SLES + 1.86 wt% C16 AES + 1.3 wt% CAPB). This is to account for the difference in molecular weight between the materials and enable a fair comparison of their properties based on comparable number of molecules in the formulation rather than comparable added weight of material.

All the shampoos were prepared using the following method:

1. A vessel was charged with water and anionic surfactants added at 50 - 60 °C.

2. The mixture was then cooled to below 45 °C and the zwitterionic surfactant (and any structurant) added with stirring.

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

4. When used, cationic polymer and silicone emulsion were then added and mixed well.

5. Any preservative was added.

6. The pH was adjusted to pH 4 - 5 using citric acid.

7. Salt was then added to adjust the viscosity.

1 and 2, in accordance with the invention and

Rinse-off aqueous hair cleansing shampoo formulations were prepared, having different chain length content, as shown in Table 1 below.

Materials used:

C12/C14 - Sodium Lauryl Ether Sulphate (SLES). Widely commercially available.

Sodium Alkyl (C16) Ether Sulpate odium Alkyl (C18) Ether Sulpate

C16 and C18 materials can be obtained from specialist suppliers using traditional synthesis methods on refined feedstocks (fatty alcohol with the required narrow chain length distribution). Rinse-off aqueous hair cleansing shampoo formulations were prepared, having different chain length content.

For these examples, ingredients leading to turbid/opaque formulations were purposefully set aside in order to assess the solubility of the surfactant mixture only. If the surfactant mixture shows insolubility, then turbidity and/or precipitation should be observed. This is undesirable as it can participate in destabilization of formulations, as well as poorer performance of the product such as foaming. These examples use a fragrance that causes a drop in the viscosity. The fragrance is available from Symrise as Diego LF BB.

Table 1 is for illustrative purposes only and illustrates the upper inclusion limit of long chain content, due to insolubility. The compositions contain no fragrance. The total surfactant concentration is 7.8% and the ratio of anionic surfactant (i) to zwitterionic surfactant (ii) is 5:1.

Table 1: Isotropic composition Examples 1 and 2, and non-isotropic compositions Examples A and B, and solubilities thereof.

It will be seen that at a content of 25 % C16 or C18 chains, an isotropic composition is obtained. However, when the content level is raised to 35 %, the compositions become non-isotropic.

This is because the long surfactant is insoluble and cannot form the product if the content is too high. Example 2: Composition 3, in accordance with the invention and Comparative Examples

C and D Materials used:

C12/C14 - Sodium Lauryl Ether Sulphate (SLES). Widely commercially available.

C16 Sodium Alkyl (C16) Ether Sulpate

C16 materials can be obtained from specialist suppliers using traditional synthesis methods on refined feedstocks (fatty alcohol with the required narrow chain length distribution).

Rinse-off aqueous hair cleansing shampoo formulations were prepared, having different chain length content.

Table 2 illustrates the viscosities and silicone deposition with inclusion of C16 chains at fixed total surfactant level and a range of ratios vs a standard SLES/CAPB system.

The total surfactant concentration is 8 wt % and the ratio of anionic surfactant (i) to zwitterionic surfactant (ii) is 3:1 or 7:1.

Viscosities were measured at 30 degrees C and 4s- 1, using sandblasted 40mm parallel plates, on a Wingspan rheometer (TA instruments).

Hair switches were treated with the compositions as follows:

The hair switches were held under running water for 30 seconds, the composition applied at a dose of 0.1 ml of composition 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 composition application repeated. The hair was rinsed under running water for 1 minute.

Switches were dried before the level of silicone was quantified using x-ray fluorescence (XRF).

Table 2: Compositions of Example 3 in accordance with the invention and Comparative Examples C and D, showing viscosity and silicone deposition.

It will be seen that both viscosity robustness (upon addition of fragrance) in combination with high silicone deposition are only achievable by the composition of the invention. Example 3: Salon test of Example 3, in accordance with the invention and Comparative Example C

The salt level of comparative C was modified in order to test in a salon test, as a fair equivalent to Example 3.

Salon testing protocol

A half head salon test was carried out, using a Paired Comparison method and 36 panelists.

4ml of a shampoo product (3 or C) was applied by a stylist to a half-head of a panelist and the hair washed and rinsed, before being dried with a hair dryer. A different shampoo product was used to wash the second half of the panelist’s head. The stylists were asked to choose one of the two sides as superior for a number of attributes.

In order to reach 90% confidence level, 24 choices out of 36 were required;

In order to reach 95% confidence level, 25 choices out of 36 were required;

In order to reach 99% confidence level, 27 choices out of 36 were required.

Salon evaluation

The attributes and panelist scores are given in Table 3 below.

Table 3: Sensory attributes during rinsing, in the wet stage and at the dry stage, for Comparative Example C and Example 3 in accordance with the invention

It will be seen that the example in accordance with the invention provides far superior sensory benefits.

Claims

1. A cleansing composition comprising: a) from 5 to 9 wt %, of a surfactant system consisting of: i) from 3 to 8 wt % of an anionic surfactant combination comprising, by weight of the total composition, a combination of alkyl ether sulphates that have the general formula (I):

R-O-(CH₂CH2-O)n-SO₃-M⁺ (I) in which, R is selected from linear alkyl groups having from C8 to C14 carbon atoms and mixtures thereof; n is a number that represents the average degree of ethoxylation and ranges from 0.5 to 1.4; and M is a solubilizing cation; the combination of alkyl ether sulphates comprising:

- from 0 to 30 wt % of a third alkyl ether sulphate having a primary chain length selected from C18, where R comprises 100 % C18; and wherein the total amount of second and third alkyl ether sulphates is from 4 to 30 wt %, preferably 5 to 30 wt %, , by weight of the anionic surfactant combination; and ii) from 1 to 6 wt %, preferably 1 to 5 wt %, of a zwitterionic or amphoteric co-surfactant, based on the total weight of the total composition; b) from 0.1 to 3 wt %, by weight of the total composition, of a viscosity modifier, which is an inorganic electrolyte; c) water; d) from 0.01 to 5 wt % of a fragrance; wherein the weight ratio of anionic surfactant (i) to zwitterionic or amphoteric co-surfactant

(ii) is from 1:1 to 9:1; and wherein the composition has a viscosity of from 2,000 to 100,000 mPa.s, preferably from 2,000 to 50,000 mPa.s, more preferably from 2100 to 40,000 mPa.s, when measured at 30 degrees C and 4s-7, using sandblasted 40mm parallel plates, on a Wingspan rheometer (TA instruments).

2. A composition as claimed in claim 1, which comprises an isotropic phase.

3. A composition as claimed in any preceding claim, wherein the first alkyl ether sulphate is present at a level of 70 to 95 wt %.

4. A composition as claimed in any preceding claim, wherein the total amount of second alkyl ether sulphate and third alkyl ether sulphate is from 10 to 30 wt %.

5. A composition as claimed in any preceding claim, wherein the zwitterionic or amphoteric surfactant is, selected from alkyl betaines, alkyl amidopropyl betaines, alkyl hydroxysultaines, alkyl amidopropyl hydroxy sultaines, and mixtures thereof.

6. A composition as claimed in claim 5, wherein the zwitterionic or amphoteric surfactant is, selected from lauryl betaine, cocamidopropyl betaine, lauryl hydroxysultaine, cocamidopropyl hydroxysultaine and mixtures thereof, preferably cocamidopropyl betaine.

7. A composition as claimed in any preceding claim, wherein the weight ratio of the anionic surfactant combination (i) to the zwitterionic/amphoteric co-surfactant (ii) is 1:1 to 8:1.

8. A composition as claimed in any preceding claim, wherein the viscosity modifier is selected from sodium chloride, potassium chloride, magnesium sulphate and mixtures thereof, most preferably sodium chloride.

9. A composition as claimed in any preceding claim, wherein the fragrance is present at 0.5 to 2 wt %.

10. A composition according to any preceding claim, which is free from polymeric thickeners.

11. A composition as claimed in any preceding claim, which comprises one or more emulsified conditioning oil, preferably selected from fatty ester oils, hydrocarbon oils and silicone oils, most preferably silicone oil.

12. A composition according to any preceding claim, which comprises a cationic deposition polymer, which is preferably a cationic polysaccharide polymer more preferably a cationic guar gum derivative, most preferably a guar hydroxypropyltrimethylammonium chloride.

13. A method of treating hair comprising the step of applying to hair a composition as defined in any one of claims 1 to 12.