Patent Description:
The invention further relates to a method of treating hair by means of such compositions.

Shampoo compositions having beneficial ingredients suspended are desirable to the consumer seeking to deliver benefit to their hair. Shampoo formulations have suspended materials that typically impart, or contribute to, certain user benefits, including: visual product aesthetics, various active effects and encapsulation/release of separate phases during use. To be acceptable to consumers, such aqueous compositions desirably exhibit both an appealing look and feel. Such suspensions, however, in complex aqueous formulations for rinse-off applications in home and personal care applications present significant challenges.

Notwithstanding, the benefits associated with the incorporation of cosmetic ingredients suspended in aqueous compositions, their incorporation creates a variety of complications. For example, cosmetic ingredients typically have a density disparate from the continuous phase of the composition. This density mismatch can lead to compositional instability. In systems containing insoluble materials with a density less than that of the continuous phase, the cosmetic ingredients tend to float to the top surface of the continuous phase (i.e., creaming). In systems containing insoluble materials with a density greater than that of the continuous phase, the insoluble materials tend to sink to the bottom of the continuous phase (i.e., settling).

To further exacerbate the complications associated with the desirable incorporation of cosmetic ingredients suspended in aqueous shampoo compositions, many of these compositions are desirably provided at acidic pH. As a result, conventional anti-settling, thickening polymers fail to provide adequate stability for such low pH compositions.

Commercial products have utilized cationic polymers as structurants. For instance, <CIT> discloses a cationically modified cellulose in a cleansing system that includes alkyl ether sulfate (<NUM> EO), cocoamidopropylbetaine and cocoamidopropylhydroxysultaine, and as a conditioning active a non-volatile silicone. <CIT> reports use of a cationic derivative of polygalactomannan gum to stabilize a sodium alkyl sulfate and alkyl ether sulfate surfactant system.

Another group of commercially popular structurants are the acrylic polymers, particularly those known as Carbomers. For example, <CIT> and <CIT> regulate silicone deposition through use of crosslinked polymers of acrylic acid, commercially available under the trademark Carbopol(R). <CIT> utilizes structurant combinations of xanthan gum and Carbopol(R) for stabilizing liquid cleansing compositions. <CIT> reports liquid cleansers structured with soluble and water swellable starches combined with linear Cs-Ci3 fatty acids. <CIT> reports personal care liquid compositions formulated with a bacterially produced microfibrous cellulose as a suspending system.

An approach to the suspending of insoluble materials in an aqueous cleansing formulation is disclosed in <CIT> Souzy, et al. disclose a method for thickening a formulation, comprising contacting a cosmetic formulation with a direct aqueous emulsion of a polymer, followed by regulation of the pH to a value between <NUM> and <NUM>, thereby forming a thickened formulation, wherein the emulsion is free from surfactants and organic solvents other than water and the polymer consists, expressed as a % by weight of each of the monomers therein, of: a) <NUM>% to <NUM>% by weight of methacrylic acid and/or acrylic acid, where the % by weight of acrylic acid, if present, compared to the total weight of acrylic acid and methacrylic acid is at least <NUM>%, b) <NUM>% to <NUM>% by weight of at least one monomer chosen from among ethyl acrylate, butyl acrylate, and methyl methacrylate, c) <NUM>% to <NUM>% by weight of a monomer comprising a hydrophobic group, d) <NUM>% to <NUM>% by weight of <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid, and e) <NUM> to <NUM>% by weight of at least one cross-linked monomer, wherein the monomer comprising a hydrophobic group has the general formula:.

m and n are integers of less than or equal to <NUM>, at least one of which is non-zero, OE and OP are respectively ethylene oxide and propylene oxide, R is a polymerizable group selected from the groups consisting of methacrylate and methacrylurethane groups, R' is a hydrophobic group having at least <NUM> and at most <NUM> carbon atoms.

Another approach to the suspending of insoluble materials in an aqueous cleansing formulation is disclosed in <CIT>. Hitchen discloses an aqueous conditioning shampoo composition comprising, in addition to water: (a) from <NUM> to <NUM>% by weight of surfactant selected from the group consisting of anionic, nonionic and amphoteric surfactants, and mixtures thereof; (b) from <NUM> to <NUM>% by weight of insoluble, non-volatile silicone which conditions hair; (c) from <NUM> to <NUM>% by weight of titanium dioxide coated mica particles dispersed in the shampoo matrix; and (d) from <NUM> to <NUM>% by weight of a crosslinked acrylic acid polymer for suspending the dispersed titanium dioxide coated mica particles and preventing them from settling in the composition as well as the insoluble, non-volatile silicone conditioning agent from creaming to the top of the composition on standing.

Additionally, in acidic pH aqueous compositions, conventional hydrophobically modified alkali swellable emulsions (HASE) polymers, used for anti-settling and thickening applications, can have the effect of reducing the deposition of the included cosmetic ingredients (for example; silicone oil droplets) to the hair and the scalp. Aqueous compositions comprising other available thickening polymers are able to deliver good deposition of cosmetic ingredients, but have compromised visual characteristics.

<CIT> discloses aqueous shampoo compositions comprising HASE copolymers which comprise a) <NUM> to <NUM> percent by weight of methacrylic acid and, optionally, of acrylic acid; b)<NUM> to <NUM> percent by weight of at least one non-ionic vinyl monomer; c) <NUM> to <NUM> percent by weight of <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid or a salt thereof; d) <NUM> to <NUM> percent by weight of at least one monomer containing at least one hydrophobic group; and e) <NUM> to <NUM> percent by weight of at least one crosslinking monomer. The copolymers are said to be useful for thickening personal care or cosmetic formulations in acidic conditions. Accordingly, there is a need for a composition that provides superior visual characteristics, without impairing other product attributes such as stability and benefit performance.

It is well known that the addition of thickening polymers causes a reduction in the transparency of a composition to which they are added. This can be demonstrated by starting with a highly transparent simple aqueous composition, comprising for example, surfactant and water, and then adding a thickening polymer. The resultant reduction in transparency of the composition can be clearly observed. However, we have now surprisingly found that the high visual transparency of the starting aqueous composition is preserved upon addition of the specific anti-settling thickening polymer, herein defined. The impact of this high transparency has a positive visual effect even after insoluble ingredients, such as mica, titanium dioxide or silicone are subsequently added to the composition. Whilst no longer transparent, the resulting composition has an improved visual appearance that is appealing for the consumer. We believe that the polymer for use in the compositions of the invention prevents aggregation of suspended material, which results in reduced turbidity and higher reflection of light from the surfaces of the suspended material, thus resulting in the improved visual appearance.

We have now found that an aqueous composition comprising a specific anti-settling thickening polymer, herein defined, provides superior visual properties, whilst maintaining good levels of deposition of a benefit agent as well as stability.

A first aspect of the invention provides an acidic aqueous shampoo composition, which comprises:.

A second aspect of the invention provides a method of treating a surface comprising the step of applying to the surface a composition of the first aspect of the invention.

In the method of the invention, the preferred surface is hair.

The method of the invention preferably further comprises the additional step of rinsing the surface with water.

The aqueous shampoo composition of the present invention contains an anti-settling thickening polymer, for use in the treatment of surfaces.

The anti-settling, thickening polymer for use in the aqueous compositions of the invention, comprises: (a) <NUM> to <NUM> wt% (preferably, <NUM> to <NUM> wt%; more preferably, <NUM> to <NUM> wt%; most preferably, <NUM> to <NUM> wt%) of structural units of C<NUM>-<NUM> alkyl acrylate (preferably, C<NUM>-<NUM> alkyl acrylate; more preferably, C<NUM>-<NUM> alkyl acrylate; most preferably, ethyl acrylate); (b) <NUM> to <NUM> wt% (preferably, <NUM> to <NUM> wt%; more preferably, <NUM> to <NUM> wt%; most preferably, <NUM> to <NUM> wt%) of structural units of methacrylic acid; (c) <NUM> to < <NUM> wt% (preferably, <NUM> to <NUM> wt%; more preferably, <NUM>. <NUM> to <NUM> wt%; most preferably, <NUM> to <NUM> wt%) of structural units of <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid (AMPS); (d) <NUM> to <NUM> wt% (preferably, <NUM> to <NUM> wt%; more preferably, <NUM> to <NUM> wt%; most preferably, <NUM> to <NUM> wt%) of structural units of a specialized associated monomer having the following structure (formula <NUM>):-
<CHM>
wherein R<NUM> is a linear saturated C<NUM>-<NUM> alkyl group; wherein R<NUM> is a hydrogen or a methyl group (preferably, wherein R<NUM> is a methyl group); and wherein n is an average of <NUM> to <NUM>; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group; more preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group); (ii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> and a linear saturated C<NUM> alkyl group; or (iii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group; (e) <NUM> to <NUM> wt% (preferably, <NUM> to <NUM> wt%; more preferably, <NUM> to <NUM> wt%; most preferably, <NUM>) of structural units of acrylic acid; wherein the sum of the weight percentages of structural units (a)-(e) is equal to <NUM> wt% of the anti-settling, thickening polymer.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention, comprises: (a) <NUM> to <NUM> wt% of structural units of ethyl acrylate; (b) <NUM> to <NUM> wt% of structural units of methacrylic acid; (c) <NUM> to <NUM> wt% of structural units of <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid (AMPS); (d) <NUM> to <NUM> wt% of structural units of the specialized associated monomer; (e) <NUM> to <NUM> wt% of structural units of acrylic acid; wherein the sum of the weight percentages of structural units (a)-(e) is equal to <NUM> wt% anti-settling, thickening polymer.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention has a weight average molecular weight of <NUM>,<NUM>,<NUM> to <NUM>,<NUM>,<NUM> Daltons. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention has a weight average molecular weight of <NUM>,<NUM>,<NUM> to <NUM>,<NUM>,<NUM> Daltons. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention has a weight average molecular weight of <NUM>,<NUM>,<NUM> to <NUM>,<NUM>,<NUM> Daltons. In reference to the anti-settling thickening polymer the weight average molecular weight refers to the weight average molecular weight as measured using asymmetric flow field flow fractionation (AF4) with inline Multi-Angle Light Scattering (MALS) and differential Refractive Index (RI) detections. The AF4 instrument used consisted of an Eclipse™ DualTec™ separation system (from Wyatt Technology Corp. ) that was coupled in series to an <NUM> angle multi-angle light scattering (MALS) detector (DAWN HELOS II; from Wyatt Technology Corp. ) and a differential refractometer (RI) (Optilab rEX; from Wyatt Technology Corp. Flows through the AF4 instrument were provided using an Agilent Technologies <NUM> series isocratic pump equipped with a micro-vacuum degasser. All injections were performed with an auto sampler (Agilent Technologies <NUM> series). Data from the AF4 instrument were collected and processed using Astra software version <NUM>. <NUM> (from Wyatt Technology Corp. Samples were prepared at a concentration of <NUM>/mL in <NUM> ammonium acetate solution at pH <NUM> (filtered with a <NUM> pore nylon membrane). Samples (<NUM>µL) were injected into the standard separation channel system (<NUM> long and a width dimension starting at <NUM> and reducing to <NUM> over the length) with a channel thickness of <NUM> and equipped with a <NUM> kDA cutof regenerated cellulose ultrafiltration membrane (Wyatt Technology). The mobile phase used for the AF4 analysis was <NUM> ammonium acetate solution at pH <NUM>. Separation was performed with an applied channel flow of <NUM>/min. The sample was introduced to the channel with a focus flow at <NUM>/min for <NUM> minutes. The elution flow as then started at <NUM>/min for <NUM> minutes and then followed by a linearly decreasing cross flow gradient (from <NUM>/min to <NUM>/min over <NUM> minutes), then a hold at <NUM>/min for another <NUM> minutes. The average molecular weight was calculated using Astra software version <NUM>. <NUM> after subtracting a blank injection with a refractive index increment (dn/dc) of <NUM>/g for all calculation with Berry model <NUM>nd order fit. Molecular weights are reported herein in units of Daltons.

Preferably, the structural units of C<NUM>-<NUM> alkyl acrylate in the anti-settling, thickening polymer for use in the aqueous compositions of the invention are structural units of C<NUM>-<NUM> alkyl acrylate. More preferably, the structural units of C<NUM>-<NUM> alkyl acrylate in the anti-settling, thickening polymer for use in the aqueous compositions of the invention are structural units of C<NUM>-<NUM> alkyl acrylate. Most preferably, the structural units of C<NUM>-<NUM> alkyl acrylate in the anti-settling, thickening polymer for use in the aqueous compositions of the invention are structural units of ethyl acrylate.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of C<NUM>-<NUM> alkyl acrylate (preferably,
C<NUM>-<NUM> alkyl acrylate; more preferably, C<NUM>-<NUM> alkyl acrylate; most preferably, ethyl acrylate). More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of C<NUM>-<NUM> alkyl acrylate (preferably, C<NUM>-<NUM> alkyl acrylate; more preferably, C<NUM>-<NUM> alkyl acrylate; most preferably, ethyl acrylate). Still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of C<NUM>-<NUM> alkyl acrylate (preferably, C<NUM>-<NUM> alkyl acrylate; more preferably, C<NUM>-<NUM> alkyl acrylate; most preferably, ethyl acrylate). Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of C<NUM>-<NUM> alkyl acrylate (preferably, C<NUM>-<NUM> alkyl acrylate; more preferably, C<NUM>-<NUM> alkyl acrylate; most preferably, ethyl acrylate).

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of methacrylic acid. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of methacrylic acid. Still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of methacrylic acid. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of methacrylic acid.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to < <NUM> wt% of structural units of <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid (AMPS), for example <NUM> to <NUM> wt%. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of
the invention comprises <NUM> to <NUM> wt% of structural units of <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid (AMPS). Even more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid (AMPS). Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM>, of structural units of <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid (AMPS).

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of a specialized associated monomer having the following structure:
<CHM>
wherein R<NUM> is a linear saturated C<NUM>-<NUM> alkyl group; wherein R<NUM> is a hydrogen or a methyl group (preferably, wherein R<NUM> is a methyl group); and wherein n is an average of <NUM> to <NUM>; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group; more preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group); (ii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> and a linear saturated C<NUM> alkyl group; or (iii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of a specialized associated monomer having the following structure:
<CHM>
wherein R<NUM> is a linear saturated C<NUM>-<NUM> alkyl group; wherein R<NUM> is a hydrogen or a methyl group (preferably, wherein R<NUM> is a methyl group); and wherein n is an average of <NUM> to <NUM>; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group; more preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group); (ii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> and a linear saturated C<NUM> alkyl group; or (iii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group. Still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of a specialized associated monomer having the following structure:
<CHM>
wherein R<NUM> is a linear saturated C<NUM>-<NUM> alkyl group; wherein R<NUM> is a hydrogen or a methyl group (preferably, wherein R<NUM> is a methyl group); and wherein n is an average of <NUM> to <NUM>; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group; more preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group); (ii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> and a linear saturated C<NUM> alkyl group; or (iii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises <NUM> to <NUM> wt% of structural units of a specialized associated monomer having the following structure:
<CHM>
wherein R<NUM> is a linear saturated C<NUM>-<NUM> alkyl group; wherein R<NUM> is a hydrogen or a methyl group (preferably, wherein R<NUM> is a methyl group); and wherein n is an average of <NUM> to <NUM>; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group; more preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group); (ii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> and a linear saturated C<NUM> alkyl group; or (iii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes <NUM> to <NUM> wt% of structural units of acrylic acid. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes <NUM> to <NUM> wt% of structural units of acrylic acid. Still more preferably, anti-settling, thickening polymer for use in the aqueous compositions of the invention contains <NUM> to <NUM> wt% of structural units of acrylic acid. Yet still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes less than the detectable limit of structural units of acrylic acid. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention contains <NUM> wt% structural units of acrylic acid.

Preferably, the shampoo of the present invention, includes from <NUM> to <NUM> wt% of the anti-settling, thickening polymer more preferably from <NUM> to <NUM> wt%, still more preferably from <NUM> to <NUM> wt% and most preferably from <NUM> to <NUM> wt% by weight of total composition.

The composition of the present invention comprises a surfactant selected from the group consisting of anionic surfactants, nonionic surfactants, zwitterionic surfactants and mixtures thereof.

Preferably, the cleansing surfactant is selected from the group consisting of sodium lauryl sulphate, sodium lauryl ether sulphate (n)EO, (where n is from <NUM> to <NUM>, preferably <NUM> to <NUM>, most preferably <NUM>), ammonium lauryl sulphate, ammonium lauryl ether sulphate(n)EO, (where n is from <NUM> to <NUM>, preferably <NUM> to <NUM>, most preferably <NUM>), sodium cocoyl isethionate and lauryl ether carboxylic acid, coco betaine, cocamidopropyl betaine, sodium cocoamphoacetate and mixtures thereof.

Preferably, mixtures of any of the anionic, non-ionic and amphoteric cleansing surfactants has a ratio of primary to secondary surfactant of between <NUM>:<NUM> - <NUM>:<NUM>, more preferably <NUM>:<NUM> - <NUM>:<NUM> and most preferably <NUM>:<NUM> - <NUM>:<NUM>, based on the inclusion weight of the cleansing surfactant in the shampoo composition.

Preferably, the composition of the present invention comprises from <NUM> to <NUM>%, preferably from <NUM> to <NUM>%, more preferably from <NUM> to <NUM>% of total surfactant, based on the total weight of the composition.

The compositions of the invention comprise, emulsified droplets of a silicone conditioning agent, for enhancing conditioning performance.

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

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

The viscosity of the emulsified silicone itself (not the emulsion or the final hair conditioning composition) is typically at least <NUM>,<NUM> cst at <NUM> the viscosity of the silicone itself is preferably at least <NUM>,<NUM> cst, most preferably at least <NUM>,<NUM> cst, ideally at least <NUM>,<NUM>,<NUM> cst. Preferably the viscosity does not exceed <NUM><NUM> cst for ease of formulation.

Emulsified silicones for use in the shampoo compositions of the invention will typically have a D90 silicone droplet size in the composition of less than <NUM>, preferably less than <NUM>, more preferably less than <NUM> micron, ideally from <NUM> to <NUM> micron. Silicone emulsions having an average silicone droplet size (D50) of <NUM> 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 <NUM> and microemulsion DC2-<NUM> 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-<NUM>, DC2-<NUM> and DC2-<NUM> (all ex Dow Corning).

Suitable quaternary silicone polymers are described in <CIT>. 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-<NUM>, DC2-<NUM>, DC2-<NUM> and DC2-<NUM> (all ex Dow Corning).

The total amount of silicone is preferably from <NUM> wt% to <NUM> %wt of the total composition more preferably from <NUM> wt% to <NUM> wt%, most preferably <NUM> wt% to <NUM> wt% is a suitable level.

In a preferred embodiment, the aqueous composition of the invention comprises at least one insoluble conditioning agent and at least one other cosmetic ingredient. Preferably, the at least one oily conditioning agent is selected from a silicone and a non-silicone oily conditioning agent.

Cosmetic ingredients are preferably selected from the group consisting of at least one of an antibacterial agent, a foam booster, a perfume, encapsulates (for example encapsulated fragrance) a dye, a colouring agent, a pigment, a preservative, a thickener, a protein, a phosphate ester, a buffering agent, a pH adjusting agent, an
opacifier, a viscosity modifier, an emollient, a sunscreen, an emulsifier, a sensate active (for example menthol and menthol derivatives), vitamins, mineral oils, essential oils, lipids, natural actives, glycerine, natural hair nutrients such as botanicals, fruit extracts, sugar derivatives and amino acids, microcrystalline cellulose and mixtures thereof.

Preferably, the aqueous composition of the present invention includes from <NUM> to <NUM> wt% of the cosmetc ingredient, more preferably from <NUM> to <NUM> wt%, still more preferably from <NUM> to <NUM> wt% and most preferably, from <NUM> to <NUM> wt% of the at least one cosmetic ingredient, by weight of the total composition.

The aqueous composition of the present invention preferably has a pH from <NUM> to < <NUM> (for example <NUM> to <NUM>), preferably <NUM> to < <NUM>, more preferably <NUM> to <NUM>, most preferably from <NUM> to <NUM>.

The compositions of the present invention preferably include a pearlescer to improve visual appearance and/or consumer appeal of the product. Most preferably the pearlescer is selected from mica, titanium dioxide, titanium dioxide coated mica, ethylene glycol distearate (INCI glycol distearate) and mixtures thereof.

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

Suitably, the shampoo composition will comprise from <NUM> to <NUM>%, preferably from <NUM> to <NUM>% water by weight based on the total weight of the composition.

Surfactants are compounds which have hydrophilic and hydrophobic portions that act to reduce the surface tension of the aqueous solutions they are dissolved in. Shampoo compositions according to the invention will generally comprise one or more cleansing surfactants, which are cosmetically acceptable and suitable for topical application to the hair. The cleansing surfactant may be chosen from anionic, non-ionic, amphoteric and zwitterionic compounds and mixtures thereof.

The total amount of cleansing surfactant in a shampoo composition for use in the invention is generally from <NUM> to <NUM>%, preferably from <NUM> to <NUM>%, more preferably from <NUM> to <NUM>% by total weight surfactant based on the total weight of the composition.

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

Further non-limiting examples of cleansing surfactants may include non-ionic cleansing surfactants including; aliphatic (C<NUM> - C<NUM>) primary or secondary linear or branched chain.

alcohols with alkylene oxides, usually ethylene oxide and generally having from <NUM> to <NUM> ethylene oxide groups. Other representative cleansing surfactants include mono- or di-alkyl alkanolamides (examples include coco mono-ethanolamide and coco mono-isopropanolamide) and alkyl polyglycosides (APGs). Suitable alkyl polyglycosides for use in the invention are commercially available and include for example those materials identified as: Plantapon <NUM> and Plantapon <NUM> ex BASF. Other sugar-derived surfactants, which can be included in compositions for use in the invention include the C<NUM>-C<NUM> N-alkyl (CI-C<NUM>) polyhydroxy fatty acid amides, such as the C<NUM>-C<NUM> N-methyl glucamides, as described for example in <CIT> and <CIT>, and the N-alkoxy polyhydroxy fatty acid amides, such as C<NUM>-C<NUM> N-(<NUM>-methoxypropyl) glucamide.

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

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

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

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

Optionally, a shampoo composition for use in the invention may contain further ingredients, (non-limiting examples of which are described below) to enhance performance and/or consumer acceptability.

Cationic polymers are preferred ingredients in a shampoo composition for use in the invention for enhancing conditioning performance.

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

The cationic nitrogen-containing group will generally be present as a substituent on a fraction of the total monomer units of the cationic 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 <NUM> to <NUM> 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 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-<NUM> 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 polymers can comprise mixtures of monomer units derived from amine- and/or quaternary ammonium-substituted monomer and/or compatible spacer monomers.

Suitable (non-limiting examples of) cationic polymers include:.

Other cationic 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:.

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. R<NUM>, R<NUM> and R<NUM> independently represent alkyl, aryl, alkylaryl, arylalkyl, alkoxyalkyl, or alkoxyaryl groups, each group containing up to about <NUM> carbon atoms. The total number of carbon atoms for each cationic moiety (i.e., the sum of carbon atoms in R<NUM>, R<NUM> and R<NUM>) is preferably about <NUM> 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 <NUM>. These materials are available from the Amerchol Corporation, for instance under the tradename Polymer LM-<NUM>.

Other suitable cationic polysaccharide polymers include quaternary nitrogen-containing cellulose ethers (e.g. as described in <CIT>), and copolymers of etherified cellulose and starch (e.g. as described in <CIT>). Examples of such materials include the polymer LR and JR series from Dow, generally referred to in the industry (CTFA) as Polyquaternium <NUM>.

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 polymers may be used.

Cationic polymer will generally be present in a shampoo composition for use in the invention at levels of from <NUM> to <NUM>%, preferably from <NUM> to <NUM>%, more preferably from <NUM> to <NUM>% by total weight of cationic polymer based on the total weight of the composition.

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

The polymers, designated Polymers B - L, for use in the compositions of the invention were prepared in accordance with formula <NUM>. The details of Polymers A - L are given in Table <NUM> below, where the amount of AMPS is expressed over and above the combination of the other ingredients, in line with convention.

A <NUM> liter, <NUM> necked round bottom flask equipped with a mechanical stirrer, thermocouple, condenser and nitrogen sparge was charged with <NUM> of deionized water and <NUM> of sodium lauryl sulfate. The flask was then purged with nitrogen and its contents were warmed to <NUM>. Then a first initiator solution containing <NUM> of ammonium persulfate dissolved in <NUM> of deionized water was added to the flask. Then a monomer solution was gradually charged to the flask over a period of <NUM> minutes, wherein the monomer solution contained <NUM> deionized water, <NUM> of sodium lauryl sulfate and the amounts (as noted in TABLE <NUM>) of each of ethyl acrylate (EA), methacrylic acid (MAA), <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid (AMPS) and a lipophilically modified monomer (LIPO) having the following structure:
<CHM>
wherein R<NUM> was a linear saturated C<NUM>-<NUM> alkyl group; R<NUM> is selected from hydrogen or methyl(preferably, wherein R<NUM> is a methyl group); and n was an average of <NUM> to <NUM>. Starting simultaneously with the monomer solution charge, a second initiator solution containing <NUM> of ammonium sulfate in <NUM> of deionized water was gradually charged to the flask over a period of <NUM> minutes. Following the monomer charge and the second initiator solution charge, the transfer lines were rinsed with deionized water followed by a free radical catalyst and activator chase solution. The resulting latex products were recovered.

Shampoos in accordance with the invention comprised Polymers B - L, whilst and comparative shampoos comprised Carbopol and Polymer A.

Comparative shampoos SA and SC were prepared by the following method:.

Shampoos in accordance with the invention and comparative shampoo SB were prepared by the following method:.

The compositions are shown in the following tables.

The following analytical methods were used in these examples:.

Virgin hair switches were treated with the shampoo of interest. Switches were rinsed and dried before the level of silicone was quantified using x-ray fluorescence (XRF).

Thermal stability was tested by placing the shampoo compositions in an oven at <NUM> for <NUM> weeks. The compositions were then assessed at regular time intervals over the <NUM> week period for sedimentation of mica particles.

Viscosity was measured using a Brookfield RV5 spindle, at <NUM> rpm at <NUM>.

pH was measured using a calibrated pH meter (pH was <NUM> unless otherwise stated).

Transmission measurements were performed on a base composition comprising <NUM>% Sodium Laureth Sulphate, <NUM>% Cocoamidopropyl Betaine and the named Polymer, that had been adjusted to neutral pH using a pH modifier. Transmission of the resulting solution was measured using a Turbiscan or similar.

Shampoos were prepared, in accordance with the invention (designated S1 - S5) which comprised polymers (B)- (F), having increasing amounts of AMPs (as detailed in Table <NUM>).

A Comparative Shampoo, SA, was also made, which comprised a Carbomer structurant and Comparative Shampoo SB which comprised Polymer A.

It will be seen that as the amount of AMPS increases across shampoo <NUM> to shampoo <NUM>, the amount of silicone deposition peaks at shampoo <NUM>, which has a level of <NUM> % AMPS. It will also be seen that the stability of the formulation decreases as the amount of AMPS increases, therefore the AMPS level may be tailored to achieve the right balance of silicone deposition and stability for the desired application.

Shampoos were prepared, in accordance with the invention (designated S6 - S12) which comprised polymers (D) and (G) - (L), having different structural compositions (as detailed in Table <NUM>).

Comparative Shampoo, SA, was also made, which comprised a Carbomer polymer. Transmission measurements were performed on base compositions comprising <NUM>% Sodium Laureth Sulphate, <NUM>% Cocoamidopropyl Betaine and Polymers D, G - L and Carbomer, that were adjusted to neutral pH using a pH modifier.

D, G, H are polymers with increasing levels of hydrophobe. It will be seen that the silicone deposition increases as the hydrophobe level increases across S6 to S8.

I, J and K are polymers with mixed chain length hydrophobe chains. It will be seen that shampoos with mixed hydrophobe chain lengths, S9 - S11, show improved silicone deposition performance, especially those containing a mixture of C12 and C18 hydrophobes (polymers I and K in S9 and S11, respectively) compared to when only a single chain length hydrophobe was used (polymers D and L, in S8 and S12, respectively).

Additionally, it will be seen that the polymers in accordance with the present invention offer greater transmission than the carbomer in the base composition. We have found that greater transmission in a base is indicative of greater quality of appearance in the end shampoo product. The impact of the high transparency has a positive visual effect even when the insoluble ingredients are present in the composition. Whilst not transparent, the shampoo compositions comprising Polymers D and G - L have an improved visual appearance.

Additionally, it will be seen the shampoos in accordance with the present invention provide a good balance of acceptable thermal stability, appearance (transmission) and silicone deposition, which is not offered by the Comparative Shampoo SA, where transmission is unacceptably low.

Shampoos in accordance with the invention, S13 - S16, were prepared using the Polymer (D) as given in Table <NUM>, and the method described in Example <NUM>.

Comparative Shampoo, SC, was also made, which comprised a Carbomer structurant.

Target viscosity specification: <NUM> - <NUM> cP (Brookfield RV5 spindle, <NUM> rpm <NUM>) Target pH: <NUM> (calibrated pH meter).

It will be seen that increased levels of SLES ethoxylation give an increased level of silicone deposition with Polymer D. (Note: SC (comprising carbomer) is known to give high amount of silicone deposition. However, the appearance is of less good quality - see Table 3A).

Shampoos in accordance with the invention, S17 - S20, were prepared using the Polymer (D) as given in Table <NUM>, and the method described in Example <NUM>.

It will be seen that pH <NUM> was beneficial.

In a separate experiment, simple shampoo bases were prepared in accordance with the method described in Example <NUM> for measuring transmission. Mixture T1 was prepared according to the method containing <NUM>% of the linear Polymer D, according to the invention, as described in Table <NUM>. Comparative mixture TC was prepared via the same method and at the same active inclusion level (<NUM>%) with a commercially available cross-linked polymer, Carbopol Aqua SF2 supplied by Lubrizol. The measured transmission of the samples is provided in Table <NUM>.

Claim 1:
An acidic aqueous shampoo composition, which comprises:
(I) a cleansing surfactant selected from the group consisting of anionic surfactant, zwitterionic or amphoteric surfactant and nonionic surfactant;
(II) an emulsified silicone,
(III) an anti-settling, thickening polymer,
wherein the anti-settling, thickening polymer, comprises:
(a) <NUM> to <NUM> wt% of structural units of C<NUM>-<NUM> alkyl acrylate;
(b) <NUM> to <NUM> wt% of structural units of methacrylic acid;
(c) <NUM> to < <NUM> wt% of structural units of <NUM>-acrylamido-<NUM>-methylpropane sulfonic acid (AMPS);
(d) <NUM> to <NUM> wt% of structural units of a specialized associated monomer having the following structure:
<CHM>
wherein R<NUM> is a linear saturated C<NUM>-<NUM> alkyl group; wherein R<NUM> is a hydrogen or a methyl group (preferably, wherein R<NUM> is a methyl group); and wherein n is an average of <NUM> to <NUM>; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group; more preferably, a single specialized associated monomer wherein R<NUM> is selected from the group consisting of a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group); (ii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> and a linear saturated C<NUM> alkyl group; or (iii) two specialized associated monomers, wherein R<NUM> is, respectively, a linear saturated C<NUM> alkyl group and a linear saturated C<NUM> alkyl group; and
(e) <NUM> to <NUM> wt% of structural units of acrylic acid;
wherein the sum of the weight percentages of structural units (a)-(e) is equal to <NUM> wt% of the anti-settling, thickening polymer.