WO2007096046A1

WO2007096046A1 - Conditioning shampoo compositions

Info

Publication number: WO2007096046A1
Application number: PCT/EP2007/000860
Authority: WO
Inventors: Neil Scott Shaw; Stephen Lee Wire
Original assignee: Hindustan Lever Ltd; Hindustan Unilever Ltd; Unilever NV
Current assignee: Hindustan Unilever Ltd; Unilever NV
Priority date: 2006-02-20
Filing date: 2007-01-26
Publication date: 2007-08-30
Anticipated expiration: 2008-08-20
Also published as: AR059557A1; TW200800287A

Abstract

An aqueous shampoo composition comprising (a) from 2 to 40% by weight of an anionic cleansing surfactant, (b) from 0.01 to 5% by weight of a cationic polymer, and (c) from 0.01 to 10% by weight of an insoluble, nonionic silicone, present as emulsified particles with an average particle size (d50) of from 0.06 micron to 0.14 micron.

Description

CONDITIONING SHAMPOO COMPOSITIONS

FIELD OF THE INVENTION

This invention relates to shampoo compositions that are able to both condition and clean the hair.

BACKGROUND AND PRIOR ART

Shampoo compositions comprising various combinations of cleansing surfactant and conditioning agents are known. These products typically comprise an anionic cleansing surfactant in combination with a conditioning agent. Amongst the most popular conditioning agents used in shampoo compositions are oily materials such as mineral oils, naturally occurring oils such as triglycerides and silicone polymers. These are generally present in the shampoo as dispersed hydrophobic emulsion droplets. Conditioning is achieved by the oily material being deposited onto the hair resulting in the formation of a film.

One known method for improving deposition of a conditioning agent from such shampoo compositions involves the use of cationic deposition polymers. These polymers may be synthetic or natural polymers that have been modified with cationic substituents .

EP 432,951 Bl (Unilever, 1993) discloses aqueous shampoo compositions comprising surfactant, guar gum cationic conditioning polymer, and insoluble, silicone having an average particle size of less than 2 microns.

EP 529,883 Bl (Unilever, 1997) discloses shampoo compositions comprising micro-emulsified conditioning oil having a particle size of less than or equal to 0.15 microns, a deposition polymer, and at least one surfactant.

SUMMARY OF THE INVENTION

In a first aspect of the invention, there is provided an aqueous shampoo composition comprising (a) from 2 to 40% by weight of an anionic surfactant, (b) from 0.01 to 5% by weight of a cationic polymer, and (c) from 0.01 to 10% by weight of an insoluble, nonionic silicone, present as emulsified particles with an average particle size (d50) of from 0.06 micron to 0.14 micron.

In a second aspect of the invention, there is provided a method of treating hair, in particular human hair, with a composition comprising (a) from 2 to 40% by weight of an anionic cleansing surfactant, (b) from 0.01 to 5% by weight of a cationic polymer, and (c) from 0.01 to 10% by weight of weight of an insoluble, nonionic silicone, present as emulsified particles with an average particle size (d50) of from 0.06 micron to 0.14 micron. DETAILED DESCRIPTION OF THE INVENTION

Use of the present invention enables not only the cleansing of the hair, but also superior conditioning benefits, in particular superior dry smoothness and ease of dry combing. Use of the present invention also delivers the benefits of making the hair feel more silky, more voluminous, and more clean (both whilst wet and after drying) . In addition, hair style can be more easily retained and the hair can be more easy to retouch on the day after washing.

By "aqueous shampoo composition" is meant a composition which has water or an aqueous solution or a lyotropic liquid crystalline phase as its major component. Preferably, the composition will comprise from 50% to 98% by weight based on total weight of water, more preferably from 60% to 90%.

Anionic cleansing surfactant

Shampoo compositions according to the invention comprise one or more anionic cleansing surfactants, which are cosmetically acceptable and suitable for topical application to the hair.

Examples of suitable anionic cleansing surfactants are the alkyl sulphates, alkyl ether sulphates, alkaryl sulphonates, alkanoyl isethionates, alkyl succinates, alkyl sulphosuccinates, alkyl ether sulphosuccinates, N-alkyl sarcosinates, alkyl phosphates, alkyl ether phosphates, and alkyl ether carboxylic acids and salts thereof, especially their sodium, magnesium, ammonium and mono-, di- and triethanolamine salts. The alkyl and acyl groups generally contain from 8 to 18, preferably from 10 to 16 carbon atoms and may be unsaturated. The alkyl ether sulphates, alkyl ether sulphosuccinates, 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.

Typical anionic cleansing surfactants for use in shampoo compositions of 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 dodecylbenzene sulphonate, triethanolamine dodecylbenzene sulphonate, sodium cocoyl isethionate, sodium lauryl isethionate, lauryl ether carboxylic acid and sodium N-lauryl sarcosinate.

Preferred anionic cleansing surfactants are sodium lauryl sulphate, sodium lauryl ether sulphate (n) EO, (where n is from 1 to 3), sodium lauryl ether sulphosuccinate (n) EO, (where n is from 1 to 3) , ammonium lauryl sulphate, ammonium lauryl ether sulphate (n) EO, (where n is from 1 to 3), sodium cocoyl isethionate and lauryl ether carboxylic acid (n) EO (where n is from 10 to 20) . Particularly preferred anionic cleansing surfactants are lauryl ether sulphates, especially sodium lauryl ether sulphate IEO.

Mixtures of any of the foregoing anionic cleansing surfactants may also be suitable.

The total amount of anionic cleansing surfactant in the composition is preferably from 2.5 to 30%, more preferably from 5 to 20%, and most preferably from 10 to 15% by weight of the total weight of the composition.

Cationic polymer

A cationic polymer is used in the compositions of the present invention to aid the deposition of the nonionic silicone, as well as to give a conditioning benefit in its own right .

The cationic polymer contains cationic nitrogen-containing groups such as quaternary ammonium or protonated amino groups. The cationic protonated amines can be primary, secondary, or tertiary amines (preferably secondary or tertiary) . The average molecular weight of the cationic polymer is preferably from 5,000 to 10 million. The cationic polymer preferably has a cationic charge density of from 0.2 meq/gm to 7 meq/gm.

Any anionic counter-ion may be use in association with the cationic polymer, so long as the polymer remains soluble or readily dispersible in water, in the composition, or in a coacervate phase of the composition, and so long as the counter-ion is physically and chemically compatible with the essential components of the composition. Non limiting examples of such counter-ions include halides (e.g., chlorine, fluorine, bromine, iodine) , sulphate and methylsulphate .

The cationic nitrogen-containing moiety of the cationic polymer is generally present as a substituent on all, or more typically on some, of the repeat units thereof. The cationic polymer may be a homo-polymer or co-polymer (comprising type or more different repeat units) of quaternary ammonium or cationic amine-substituted repeat units, optionally in combination with non-cationic repeat units (referred to herein as spacer repeat units) . Non- limiting examples of such polymers are described in the CTFA Cosmetic Ingredient Dictionary, 6th edition, edited by Wenninger, JA and McEwen Jr, GN, (The Cosmetic, Toiletry, and Fragrance Association, 1995) . Particularly suitable cationic polymers for use in the composition include polysaccharide polymers, such as cationic cellulose derivatives, cationic starch derivatives, and cationic guars .

Examples of cationic cellulose derivatives are salts of hydroxyethyl cellulose reacted with trimethylammonium substituted epoxide, referred to in the industry (CTFA) as Polyquaternium 10. Further examples of cationic cellulose derivatives are prepared from hydroxyethyl cellulose and lauryldimethylammonium-substituted epoxide and are referred to in the industry (CTFA) as Polyquaternium 24.

Especially preferred cationic polymers are cationic guar gum derivatives, such as guar hydroxypropyltrimonium chloride, specific examples of which include the JAGUAR series commercially available from Rhodia Corp. (e.g., JAGUAR C17 or JAGUAR C13S) .

Other suitable cationic polymers include quaternary nitrogen-containing cellulose ethers, examples of which are described in US 3,962,418. Other suitable cationic polymers include derivatives of etherified cellulose, guar and starch, some examples of which are described in US 3,958,581.

Synthetic cationic polymers may also be employed. Examples include co-polymers of vinyl monomers having cationic protonated amine or quaternary ammonium functionality with water soluble spacer repeat units, typically derived from monomers such as acrylamide, methacrylamide, N-alkyl and

N,N-dialkyl acrylamides and methacrylamides, alkyl acrylate, allyl methacrylate, vinyl caprolactone, vinyl acetate, /alcohol . Other spacer repeat units may be derived from maleic anhydride, propylene glycol, or ethylene glycol.

Other suitable synthetic cationic polymers include copolymers of l-vinyl-2-pyrrolidone and l-vinyl-3- methylimidazolium salt (e.g., chloride salt), referred to in the industry (CTFA) as Polyquaternium-lβ; co-polymers of 1- vinyl-2-pyrrolidone and dimethylaminoethyl methacrylate, refereed to in the industry (CTFA) as Polyquaternium-11; cationic diallyl quaternary ammonium-containing polymers, including, for example, dimethyldiallylammonium chloride homo-polymer and co-polymers of acrylamide and dimethyldiallylammonium chloride, referred to in the industry (CTFA) as Polyquaternium 6 and Polyquaternium 7, respectively; and mineral acid salts of amino-alkyl esters of homo-polymers and co-polymers of unsaturated carboxylic acids having from 3 to 5 carbon atoms. The total amount of cationic polymer in the composition is preferably from 0.05% to 2% and more preferably from 0.1 to 0.5% by weight of the composition.

Insoluble, nonionic silicone

Shampoo compositions according to the invention comprise discrete, dispersed droplets of an insoluble, nonionic silicone having an average particle size (d50) of from 0.06 micron to 0.14 micron.

The restricted droplet size range of the emulsified nonionic silicone is critical. Inferior results are found at both higher and lower average particle sizes.

By "insoluble" it is meant that the silicone is insoluble in water, having a solubility in water at 25°C of 0.1% by weight or less.

By "nonionic" it is meant that the silicone does not contain charged groups or groups that become charged in use, such as amino groups. Thus, amino-silicones are not nonionic silicones according to this definition.

Preferably the average particle size (d50) of the nonionic silicone is from 0.08 micron to 0.12 micron and most preferably it is about 0.1 micron.

Particle sizes may be measured by means of commercially available instruments such as a Mastersizer 2000 or a Zetasizer NanoZS, both from Malvern instruments. _ ^Q —

Preferably the nonionic silicone is non-volatile, meaning that it has a vapour pressure of less than 1000 Pa at 25°C.

Suitable emulsified silicones include those formed from silicones such as polydiorganosiloxanes and hydroxy- substituted polydiorganosiloxanes, in particular polydimethylsiloxanes (dimethicones) and hydroxy-terminated • polydimethylsiloxanes (dimethiconols) . Hydroxy-terminated polydimethylsiloxanes are especially suitable. Preferred silicones are linear in nature, that is to say they are not crosslinked.

Silicones that may be used as emulsified silicones in the present invention preferably have a molecular weight of greater than 100,000 and more preferably a molecular weight of greater than 250,000.

Silicones that may be used as emulsified silicones in the present invention typically have a kinematic viscosity of at

2 -1 least 10,000 cS (mm . s ). Preferably, the kinematic

2 -1 viscosity is at least 60,000 cS (mm .s ), more preferably at

2 -1 least 500,000 cS (mm . s ), and most preferably at least

2 -1 1,000,000 cS (mm .s ) . It is preferred that the kinematic

9 2 -1 viscosity is not greater than 10 cS (mm . s ) . Kinematic viscosities as referred to in this specification are measured at 25°C and can be measured by means of a glass capillary viscometer as set out further in Dow Corning Corporate Test Method CTM004 July 20, 1970. It is highly preferred that the nonionic silicone is emulsified with an anionic surfactant, dodecylbenzene sulphonate (DOBS) being especially preferred as the emulsifier.

Suitable emulsified silicones for use in compositions of the invention are available as pre-formed silicone emulsions from suppliers of silicones such as Dow Corning. The use of such pre-formed silicone emulsions is preferred for ease of processing and control of silicone particle size. Such preformed silicone emulsions will typically additionally comprise a suitable emulsifier, and may be prepared by a chemical emulsification process such as emulsion polymerisation.

The total amount of the water-insoluble nonionic silicone is preferably from 0.05 to 5%, more preferably from 0.1 to 3%, and most preferably from 0.25 to 2.5% by weight of the total composition.

Other Ingredients

An amphoteric surfactant is a preferred additional ingredient in compositions of the invention. Suitable amphoteric surfactants are betaines, such as those having the general formula R(CH3)₂N CH2CO₂ , where R is an alkyl or alkylamidoalkyl group, the alkyl group preferably having 10- 16 carbon atoms. Particularly suitable betaines are oleyl betaine, caprylamidopropyl betaine, lauramidopropyl betaine, isostearylamidopropyl betaine, and cocoamidopropyl betaine. Other suitable betaine amphoteric surfactants are sulfobetaines, such as those having the general formula

R' (CH₃) ₂N⁺CH₂CH (OH) CH₂Sθ3^~, where R' is an alkyl or alkylamidoalkyl group, the alkyl group preferably having 10- 16 carbon atoms. Particularly suitable sulfobetaines are laurylamidopropyl hydroxysultaine and cocoamidopropyl hydroxysultaine .

Other suitable amphoteric surfactants are fatty amine oxides, such as lauryldimethylamine oxide.

When included, the total level of amphoteric surfactant is preferably from 1% to 20%, more preferably from 1% to 10%, and most preferably from 1.5% to 5% by weight of the composition.

A Carbomer may be advantageously employed in particular embodiments of the invention. A Carbomer is a homopolymer of acrylic acid crosslinked with an allyl ether of pentaerythritol or an allyl ether of sucrose.

When included, the total level of Carbomer is preferably from 0.01% to 10%, more preferably from 0.1% to 5%, and most preferably from 0.25% to 1% by weight of the composition.

Compositions according to the invention may also contain other ingredients suitable for use in hair cleansing and conditioning compositions. Such ingredients include but are not limited to: fragrance, suspending agents, amino acids and protein derivatives, viscosity modifiers (such as electrolytes) and preservatives.

EXAMPLES

In the following examples, compositions according to the invention are indicated by numbers and comparative examples are indicated by letters.

The amounts of components are percentages by weight and are percentages by weight of the total composition, unless otherwise indicated.

The compositions indicated in Table 1 were prepared at ambient temperature by stirring together a 1% aqueous solution of the cationic guar, a 4% aqueous suspension of the Carbomer, the indicated silicone emulsion, and the other components as indicated.

Table 1

1. Sodium laureth sulphate. 2, Cocoamidopropyl betaine. 3. Cationic guar, ex Rhodia. 4. Carbomer, ex Goodrich. 5, Added as an aqueous emulsion of dimethiconol having an average particle size (d50) of 0.1 micron, the silicone having a viscosity of approximately 2 million cS

2 -1

(mm .s ), and the emulsifier being DOBS.

Added as an aqueous emulsion of dimethiconol having an average particle size (d50) of 0.035 micron, the silicone having a viscosity of approximately 2 million

2 -1 cS (mm .s ), and the emulsifier being DOBS/Laureth-23.

Compositions 1 and A were each used to treat identical hair switches and the hair switches, following drying, were assessed for "smoothness" and "ease of combing" in a paired comparison test by a trained panel. The results are shown in Table 2. Composition 1 was found to deliver better smoothness and better ease of combing, the differences being significant at the 95% level of confidence or greater.

Table 2

The compositions indicated in Table 3 were prepared in an analogous manner to compositions 1 and A.

Table 3

1. As indicated below Table 1.

2. Cationic guar, ex Rhodia.

3. Added as an aqueous emulsion of dimethiconol having an average particle size (d50) of 0.18 micron, the silicone having a viscosity of approximately 1 million

2 -1 cS (mm .s ), and the emulsifier being DOBS.

Shampoo compositions 2 and B were each assessed by a panel of naive consumers. Each panellist used the composition provided according to their own usual protocol for such a product. Following use, the consumers were asked to assess their own hair against a variety of attributes. Composition

2 was found to lead to significantly better scores (at the

95% level of confidence or greater) on: gives clean feeling hair (wet) ; makes hair slippery & silky (dry) ; gives voluminous hair (dry) ; gives clean feeling hair (dry) ; hair is easy to retouch (next day) ; hair style is easily retained (next day) .

The above attributes are often viewed as highly desirable by consumers .

Claims

1. An aqueous shampoo composition comprising (a) from 2 to 40% by weight of an anionic surfactant, (b) from 0.01 to 5% by weight of a cationic polymer, and (c) from 0.01 to 10% by weight of an insoluble, nonionic silicone, present as emulsified particles with an average particle size (d50) of from 0.06 micron to 0.14 micron.

2. An aqueous shampoo composition according to claim 1, wherein the emulsified silicone has an average particle size (d50) of from 0.08 micron to 0.12 micron.

3. An aqueous shampoo composition according to claim 1 or 2, wherein the silicone is emulsified with an anionic emulsifier .

4. An aqueous shampoo composition according to claim 3, wherein the silicone is emulsified with dodecylbenzene sulphonate .

5. An aqueous shampoo composition according to any of the preceding claims comprising an amphoteric surfactant.

6. An aqueous shampoo composition according to any of the preceding claims comprising Carbomer.

7. An aqueous shampoo composition according to any of the preceding claims comprising a dissolved alkaline metal halide salt or alkaline earth halide salt.

8. An aqueous shampoo composition according to claim 7, comprising dissolved sodium chloride.

9. An aqueous shampoo composition according to any of the preceding claims, wherein the silicone is non-volatile.

10. An aqueous shampoo composition according to any of the preceding claims, wherein the silicone has a viscosity of 10,000 mm sec^'1 or greater at 25°C.

11. An aqueous shampoo composition according to claim 10, wherein the silicone has a viscosity of from 10 to 10

2 -1 mm sec at 25°C.

12. A method of treating hair, in particular human hair, with a composition comprising (a) from 2 to 40% by weight of an anionic cleansing surfactant, (b) from 0.01 to 5% by weight of a cationic polymer, and (c) from 0.01 to 10% by weight of weight of an insoluble, nonionic silicone, present as emulsified particles with an average particle size (d50) of from 0.06 micron to 0.14 micron.