WO2005027865A1

WO2005027865A1 - Anhydrous antiperspirant composition containing a lipophilic polyamide of low molecular mass; aerosol device

Info

Publication number: WO2005027865A1
Application number: PCT/EP2004/010990
Authority: WO
Inventors: Cyril Lemoine; Nathalie Beau
Original assignee: L'oreal
Priority date: 2003-09-23
Filing date: 2004-09-15
Publication date: 2005-03-31

Abstract

The present invention relates to an antiperspirant composition, characterized in that it contains, in a cosmetically acceptable liquid anhydrous vehicle: (a) at least one antiperspirant active agent; (b) at least one lipophilic polyamide with a weight-average molar mass (MW) of less than 1000; (d) at least one propellant. The invention also relates to an aerosol device consisting of: (A) a container comprising a composition consisting firstly of an anhydrous liquid phase (or fluid) comprising at least one antiperspirant active agent, at least one lipophilic polyamide with a weight-average molar mass (MW) of less than 1000, and (B) at least one propellant, and of a means for distributing the said aerosol composition. The invention also relates to a process for treating human body odour and especially underarm odour using this device.

Description

ANHYDROUS ANTIPERSPIRANT COMPOSITION CONTAINING A LIPOPHILIC POLYAMIDE OF LOW MOLECULAR MASS; AEROSOL DEVICE The present invention relates to an antiperspirant composition, characterized in that it contains, in a cosmetically acceptable liquid anhydrous vehicle: (a) at least one antiperspirant active agent; <b) at least one lipophilic polyamide with a weight- average molar mass (MW) of less than 1000; (d) at least one propellant. The invention also relates to an aerosol device consisting of: (A) a container comprising a composition consisting firstly of a anhydrous liquid phase (or fluid) comprising at least one antiperspirant active agent, at least one lipophilic polyamide with a weight-average molar mass (MW) of less than 1000, and (B) at least one propellant, and of a means for distributing the said aerosol composition. The invention also relates to a process for treating human body odour and especially underarm odour using this device. It is well known in the cosmetics field to use, in topical application, antiperspirant products containing active substances of antiperspirant type to reduce, or even eliminate, the generally unpleasant underarm odour. Antiperspirant substances have the effect of limiting the flow of sweat. They generally consist of aluminium and/or zirconium salts. In the field of antiperspirants, the anhydrous aerosols most commonly used mainly contain a solid antiperspirant active agent suspended in an emollient oil by means of a modified clay. The phase proportion between fluid/propellant is generally within concentration ratios, expressed as weight percentages, of between 10/90 and 25/75. The emollient oils used have the advantage of having a good, dry feel, but this feel is far from pleasant when they are used in high proportion (excessively greasy and oily feel) . This is why the content of antiperspirant anhydrous aerosol fluids is generally less than 25%. Under these conditions, the product has a dry and pleasant feel, but the active agent content and thus the efficacy of the product cannot be high. The anhydrous antiperspirant aerosols currently commercially available are confronted with various formulation problems that do not satisfactorily allow good cosmetic properties to be combined with good antiperspirant efficacy. Anhydrous antiperspirant aerosols are subject to environmental regulations that limit the possibility of using large amounts of propellants. The propellants usually used are VOCs (volatile organic compounds) , which are known to be environmentally unfriendly. In order to have good cosmetic properties (dry feel) , the ratio between the fluid and the propellant should be as low as possible. Under these conditions, the content of antiperspirant active agent introduced into the anhydrous aerosol formulations is too low to ensure very good antiperspirant activity of the products. The anhydrous antiperspirant aerosols known in the prior art generally contain suspension agents of the modified clay type. However, the settling-out of the antiperspirant active agent is often rapid and can result in product being delivered non-uniformly . Furthermore, the sedimentation cake of the antiperspirant active agent that forms at the bottom of the container is often difficult to redisperse after shaking, or even remains stuck to the bottom. In order to incorporate a maximum amount of antiperspirant active agent, anhydrous antiperspirant aerosols generally contain a large content of volatile oil, which does not make it possible to have an optimized final cosmetic efficacy. There is thus still a need to find novel aerosol -anhydrous antiperspirant formulations which, at lower propellant contents, make it possible to obtain both better efficacy and good cosmetic properties without the drawbacks mentioned previously. After extensive research conducted in this matter, the Applicant has now discovered, surprisingly and unexpectedly, that by using a lipophilic polyamide with a weight-average molar mass (MW) of less than 1000 in an antiperspirant aerosol composition, antiperspirant anhydrous aerosol compositions are obtained that can contain lower propellant contents, larger amounts of antiperspirant active agent, in which the active agent sedimentation times are substantially longer, and whose feel qualities are substantially better. Furthermore, the aggregates of antiperspirant active agent that may be formed at the bottom of the container are easily redispersed in the fluid after shaking a few times, even after storage for 1 month. This discovery forms the basis of the present invention . One subject of the invention is thus an antiperspirant composition, characterized in that it contains, in a cosmetically acceptable liquid anhydrous vehicle: (a) at least one antiperspirant active agent; (b) at least one lipophilic polyamide with a weight- average molar mass (MW) of less than 1000, (c) at least one propellant. ^• A second subject of the present invention is also a process that consists in using such a composition to prevent or attenuate the development of body odour. For the purposes of the invention, the term "anhydrous" means a composition whose content of free or added water is less than 3% and preferably whose content of added water is less than 1% by weight relative to the total weight of the composition. The term "polyamide" means any organic compound comprising in the main carbon-based chain at least two amide groups. This notion includes diamides (difunctional compounds) and polymers comprising several amide functions in the skeleton. The polyamides of the invention may be in the form of a mixture of diamides or a mixture of polymers comprising several amide functions in the skeleton. The polymers according to the invention may be obtained by polycondensation of dicarboxylic acid monomers and of diamine monomers. The term "lipophilic polyamide" means any diamide compound or polyamide polymer comprising at least one lipophilic end chain and/or one lipophilic side chain linked to one of the amide groups, and which.,_. may be:

- a carbon-based chain, especially a hydrocarbon-based chain, containing from 8 to 60 carbon atoms, which is optionally functionalized, and better still from 12 to 40 carbon atoms, this chain in particular being an alkyl or alkoxy chain;

- a silicone-based chain of the polyorganosiloxane type, optionally comprising Ci to C₃₀ and better still e to C₂₄ alkyl or alkoxy radicals or phenyl radicals, the hydrocarbon-based chain or the silicone chain possibly being fluorinated or perfluorinated, i.e. all or some of the hydrogen atoms may be replaced with a fluorine atom; - or a mixture of these lipophilic chains. The carbon-based chain and the alkyl or alkoxy radicals may be linear, branched, saturated or unsaturated, and cyclic or non-cyclic. The lipophilic polyamides of the composition of the invention advantageously have a softening point of greater than 65°C, which may be up to 190°C. They preferably have a softening point ranging from 70 to 130°C. These polymers are in particular non-waxy and/or non-crystalline polymers. Advantageously, the lipophilic polyamides according to the invention comprise a weight-average molecular mass of greater than 200 and better still greater than 250, or even greater than 290. The low-molecular-mass lipophilic polyamides according to the invention are especially chosen from

A) Diamides resulting from the amidation reaction between : (i) a diamine of any nature, of formula H₂N- F NHa or -R7 HN NH

(if cyclic diamine) with Ri denoting a linear or branched alkyl radical containing from 1 to 50 carbon atoms and better still from 2 to 40 carbon atoms, for instance ethylenediamine, propylenediamine, 1,6- diaminohexane, cyclohexanediamine, isophoronediamine, 2-methyl-l, 5-pentanediamine, 1, 12-diaminododecane, phenylenediamine (including the 1,2 or 1,3 or 1,4 isomers) , for instance adamantanediamine, and (ii) at least one monocarboxylic acid of formula R₂-COOH in which R₂ denotes a linear or branched or cyclic, saturated or unsaturated alkyl group comprising at least 8 carbon atoms, and in particular from 8 to 60 carbon atoms (for example C_i2 to C₄₀) , for instance decanoic acid, dodecanoic acid (lauric acid) and hexadecanoic acid (palmitic acid) . This monocarboxylic acid also preferably contains at least one hydroxyl group, for instance 12-hydroxystearic acid. If the reaction comprises only one monoacid of the type R₂-COOH, the resulting diamide is obtained as follows: ₂HN—R,—NH₂+ 2 FL,—COOH -→-

If the reaction comprises two different monoacids of the type:

R₂-COOH and R₃-COOH, respectively (with R₃ different from R₂, representing a Cβ to Ceo alkyl group as defined for Ri) , the resulting product is a mixture of: . R₂—C—NH — R,—NH — C — R₂ O O . R₂—C—NH — R-x — NH — C— R₃ II II o o .R₃— C— NH — R, —NH —C— R₃ I I I I o o

In one variant for obtaining the lipophilic polyamide compound, this compound may result from the trans-amidation between: (a) a diamine as mentioned above (point i) , and (b) a monoacid of the oil or fatty ester type comprising at least one carboxylic acid ester group containing a Cs to Ceo and for example Cι₂ to C₄₀ linear, branched, cyclic, saturated or unsaturated alkyl group R₂. Examples that may be mentioned include unsaturated monohydroxylated monoaliphatic acid esters such as ricinoleic acid (or 12-hydroxy (cis) 9-octadecenoic acid) esters, for instance butyl ricinoleate, octyl- dodecyl ricinoleate, cetyl ricinoleate or glyceryl triricinoleate (castor oil) ; saturated linear mono- hydroxylated aliphatic monoacid esters such as: lactic acid esters, for instance isostearyl lactate, the lactate derived from a Cι₂-Cι₃ alcohol, octyldodecyl lactate, oleyl lactate, myristyl lactate or 2-ethyl- hexyl palmitate; 12-hydroxyoctadecanoic acid (or 12-hydroxystearic acid) esters, for instance 2-ethyl- hexyl 12-hydroxystearate, octyldodecyl 12-hydroxy- stearate, isostearyl 12-hydroxystearate, isodecyl

12-hydroxystearate, glyceryl tris (12-hydroxystearate) (or hydrogenated castor oil) and dipentaerythrityl hexa-12-hydroxystearate; and mixtures thereof. Preferably, hydrogenated monohydroxylated esters are used, and especially triglycerides in general, preferably hydrogenated triglycerides, for instance hydrogenated castor oil or hydrogenated 14-hydroxyeicosenoic acid (lesquirolic acid) . In the case of the reaction between a triglyceride and a diamine of the type + H₂N-Rι-NH₂, the following compounds may be obtained:

CH₂—O—CO—R₂ I CH—O—CO—R₂ +H₂N—R, —NH₂ →

CH₂—O—CO —R₂ CH₂— O — CO— R₂ CH O— CO CHz— O— CO —R₂ Mixture of unreacted + R₂_ C— NH — R, — NH —C —R₂ I I I I o o + CH₂ — OH CH₂—O—COR₂ I I CH —O —CO— R₂ + CHOH CH₂— OH CH₂—OH

+ products of partial hydrolysis completing those mentioned above o

+ H₂N — Rι— NH — 0-R₂

B) Polymeric polyamides comprising more than two amide groups, which may result from the amidation between: (i) a diamine of formula H₂N-Rχ-NH₂ as defined above, (ii) a diacid HOOC-R4-COOH (or a mixture of diacids) with R₄ representing (CH₂)_n in which n is from 8 to 60 (especially 12 to 40) , an aryl or alkylaryl group containing from 6 to 40 carbon atoms. Examples that may be mentioned include linear acids such as adipic acid or sebacic acid, or aromatic acids such as phthalic acid or terephthalic acid, and fatty acid dimers, (iii) at least one monoacid R₂-COOH as defined above (point A(ii) ) . The final product then has the structure: R₂-CO-NH-R_!-NH- [CO-R₄-CO-NH-Rι-NH] _x-CO-R₂ with x being from 0 to 4; when x = 0, this means that there is no reaction with a diacid of the type HOOC-R₄-COOH .

C) Compounds containing amide groups comprising silicone portions, which may be obtained by reacting (i) a diamine comprising silicone groups, for example of the type (A) :

with a ranging from 1 to 18 and y ranging from 1 to 10. In this case, the groups Si-0 are then in the polymer skeleton; or alternatively a polydimethyl- siloxane (PDMS) containing only one functional end in the reaction mixture, this end possibly being a carboxylic acid, amine or epoxy group, with (ii) one or more carboxylic acids defined above. An example of a compound corresponding to formula (A) that may be mentioned is the product Tegomer A-Si 2122 sold by the company Goldschmidt. As examples of PDMSs containing amine groups that may be used in the invention, mention may be made of the products KF-864 and KF-865 from Shin-Etsu. As examples of PDMSs containing epoxy groups that may be used in the invention, mention may be made of the products KF-100T and KF-101 from Shin-Etsu, and as an example of a PDMS containing carboxylic acid groups that may be used in the invention, mention may be made of the product X-22-3701 from Shin-Etsu. According to one particularly preferred form of the invention, a diamide resulting from the amidation of a hydroxylated fatty acid triglyceride containing from 12 to 30 carbon atoms with a diamine as defined above in the presence of a C_i2 to do monocarboxylic acid will be used. This compound is in particular the compound described in document EP-A-0 984 025. The triglyceride is in particular ricinoleic acid (or castor oil) and the monocarboxylic acid is 12-hydroxystearic acid. The diamine is in particular ethylenediamine . Such a product has the structure

and is especially sold under the name Cray Vallac SF or Cray Vallac MT by the company Cray Valley Limited. The antiperspirant compositions according to the invention preferably contain the lipophilic polyamide (s) in amounts ranging from 0.001% to 10% by weight and preferably from 0.1% to 5% by weight relative to the total weight of the composition. The antiperspirant active agents present in the compositions of the invention are preferably chosen from aluminium and/or zirconium salts; complexes of zirconium hydroxychloride and of aluminium hydroxy- chloride with an amino acid, such as those described in patent US-3 792 068, commonly known as "ZAG complexes". Such complexes are generally known under the name "ZAG" (when the amino acid is glycine) . The ZAG complexes ordinarily have an Al/Zr quotient ranging from about

1.67 to 12.5 and a metal/Cl quotient ranging from about 0.73 to 1.93. Among these products, mention may be made of aluminium zirconium octachlorohydrex GLY, aluminium zirconium pentachlorohydrex GLY, aluminium zirconium tetrachlorohydrate GLY and aluminium zirconium tri- chlorohydrate GLY. Among the aluminium salts that may be mentioned are aluminium chlorohydrate, aluminium chlorohydrex, aluminium chlorohydrex PEG, aluminium chlorohydrex PG, aluminium dichlorohydrate, aluminium dichlorohydrex PEG, aluminium dichlorohydrex PG, aluminium sesquichlorohydrate, aluminium sesquichlorohydrex PEG, aluminium sesquichlorohydrex PG, alum salts, aluminium sulfate, aluminium zirconium octachlorohydrate, aluminium zirconium pentachlorohydrate, aluminium zirconium tetrachlorohydrate, aluminium zirconium trichloro- hydrate and more particularly the aluminium hydroxy- chloride sold by the company Reheis under the name Reach 301 or by the company Guilini Chemie under the name Aloxicoll PF 40. Aluminium zirconium salts are, for example, the salt sold by the company Reheis under the name Reach AZP-908-SUF. The antiperspirant active agents may be present in the composition according to the invention in a proportion of about 0.001% to 30% by weight and preferably in a proportion of about 0.1% to 25% by weight relative to the total composition. The propellant may be chosen from dimethyl ether, volatile hydrocarbons such as n-butane, propane, isopropane, n-butane, isobutane, pentane and isopentane, and mixtures thereof; volatile fluoro- hydrocarbons such as 1, 1-difluoroethane and 1,1,1- trifluoro-2-fluoroethane . Carbon dioxide, nitrous oxide, nitrogen or compressed air may also be used as propellant. The composition containing the antiperspirant active agent (s) and the propellant (s) may be in the same compartment or in different compartments in the aerosol container. According to the invention, the propellant concentration generally ranges from 5% to 90% and more preferably from 15% to 60% by pressurized weight relative to the total weight of the pressurized composition. The cosmetic composition according to the invention may thus be in the form of a lotion, a cream or a fluid gel distributed as an aerosol spray, and may contain, in this respect, the ingredients generally used in products of this type and that are well known to those skilled in the art. The distribution means, which forms a part of the aerosol device, generally consists of a distribution valve controlled by a distribution head, which itself comprises a nozzle via which the aerosol composition is vaporized. The container containing the pressurized composition may be opaque or transparent. It may be made of glass, of polymer or of metal, optionally coated with a layer of protective varnish. In addition to the antiperspirant active agent (s), the composition according to the invention may also contain at least one additional deodorant active agent. Among the additional deodorant active agents that may be mentioned, for example, are: zinc pyrrolidonecarboxylate (more commonly known as zinc pidolate) , zinc sulfate, zinc chloride, zinc lactate, zinc gluconate and zinc phenolsulfonate, 2,4,4'- trichloro-2' -hydroxydiphenyl ether (Triclosan) , 2,4- dichloro-2' -hydroxydiphenyl ether, 3' , ' , 5' -trichloro- salicylanilide, 1- (3' , 4' -dichlorophenyl) -3- (4' -chloro- phenyl)urea (Triclocarban) or 3, 7, 11-trimethyldodeca- 2, 5, 10-trienol (Farnesol) ; quaternary ammonium salts, for instance cetyltrimethylammonium salts and cetylpyridinium salts; chlorhexidine and its salts; diglyceryl monocaprate; diglyceryl monolaurate, glyceryl monolaurate; polyhexamethylene biguanide salts . The preferred active agents are 2,4,4'- trichloro-2' -hydroxydiphenyl ether (Triclosan) ; poly- hexamethylene biguanide salts (known as polyaminopropyl biguanide salts) - for example the product Cosmocil CQTM (Zeneca); 3, 7, ll-trimethyldodeca-2, 5, 10-trienol (Farnesol) . The cosmetically acceptable anhydrous, liquid vehicle generally contains one or more volatile or nonvolatile silicone or hydrocarbon-based emollient oils. These emollient oils are especially described in patents US 4 822 596 and US 4 904 463. The emollient oils according to the invention may be chosen from products of the volatile silicone, non-volatile silicone and other non-volatile emollient type. The volatile silicones are defined, in a known manner, as compounds that are volatile at room temperature. Among these compounds, mention may be made of cyclic and linear volatile silicones of the dimethylsiloxane type in which the chains comprise from 3 to 9 silicone residues. Cyclomethicones D4, D5 or D6 are preferably chosen. The non-volatile silicones are defined, in a known manner, as compounds with a low vapour pressure at room temperature . The following are included among these compounds: polyalkylsiloxanes, in particular linear polyalkylsiloxanes, for instance the linear polydimethylsiloxanes, or dimethicones, sold by the company Dow Corning under the name "Dow Corning 245 Fluid"; polyalkylarylsiloxanes, for instance the poly- methylphenylsiloxanes sold by the company Dow Corning under the name "Dow Corning 556 Fluid"; polyether and siloxane copolymers, for instance dimethicone copolyols . Among the non-volatile emollient oils that may be used in the present invention, mention may be made, for example, of: hydrocarbon-based derivatives, mineral oils, fatty alcohols, esters of C₃-Cι₈ alcohols with C₃-Cιβ acids, esters of benzoic acid with Cι₂-Cιβ alcohols and mixtures thereof, C₂-Cε polyols preferably chosen from glycerol, propylene glycol and sorbitol, and polyalkylene glycol polymers. The emollient oils are preferably present in amounts ranging from 1% to 50% by weight and more preferably from 5% to 40% by weight relative to the total weight of the composition. In order to prevent or reduce the phenomenon of formation of a cake or of sedimentation of the astringent salt in the aerosol container, a suspension agent is preferably used, which is preferably chosen from hydrophobic modified montmorillonite clays, for instance hydrophobic modified bentonites or hectorites. Examples that may be mentioned include the product stearalkonium bentonite (CTFA name) (product of reaction of bentonite and the quaternary ammonium stearalkonium chloride) , such as the product sold under the name Tixogel MP 250 by the company Sud Chemie Rheologicals, United Catalysts Inc. or the product disteardimonium hectorite (CTFA name) (product of reaction of hectorite and of distearyldimonium chloride) sold under the name Bentone 38V by the company Elements Specialities. The suspension agents are preferably present in amounts ranging from 0.1% to 5% by weight and more preferably from 0.2% to 2% by weight relative to the total weight of the composition. The compositions according to the invention may also contain at least one organic powder. Among the fillers that may be used according to the invention, mention may be made of organic powders. In the present patent application, the term "organic powder" means any solid that is insoluble in the medium at room temperature (25°C) . As organic powders that may be used in the composition of the invention, examples that may be mentioned include polyamide particles and especially those sold under the name Orgasol by the company Atochem; polyethylene powders; microspheres based on acrylic copolymers, such as those made of ethylene glycol dimethacrylate/lauryl methacrylate copolymer, sold by- the company Dow Corning under the name Polytrap; polymethyl methacrylate microspheres, sold under the name Microsphere M-100 by the company Matsumoto or under the name Covabead LH85 by the company Wackherr; ethylene-acrylate copolymer powders, for instance those sold under the name Flobeads by the company Sumitomo Seika Chemicals; expanded powders such as hollow microspheres and especially microspheres formed from a terpolymer of vinylidene chloride, of acrylonitrile and of methacrylate and sold under the name Expancel by the company Kemanord Plast under the references 551 DE 12 (particle size of about 12 μm and density of 40 kg/m³) , 551 DE 20 (particle size of about 30 μm and a density of 65 kg/m³) and 551 DE 50 (particle size of about 40 μm) , or the microspheres sold under the name Micropearl F 80 ED by the company Matsumoto; powders of natural organic materials such as starch powders, especially of corn starch, wheat starch or rice starch, which may or may not be crosslinked, such as the starch powders crosslinked with octenylsuccinic anhydride, sold under the name Dry-Flo by the company National Starch; silicone resin microbeads such as those sold under the name Tospearl by the company Toshiba Silicone, especially Tospearl 240; amino acid powders such as the lauroyllysine powder sold under the name Amihope LL-11 by the company Ajinomoto; particles of wax microdispersion, which preferably have mean sizes of less than 1 μm and especially ranging from 0.02 μm- to 1 μm, and which consist essentially of a wax or a mixture of waxes, such as the products sold under the name Aquacer by the company Byk Cera, and especially: Aquacer 520 (mixture of synthetic and natural waxes) , Aquacer 514 or 513 (polyethylene wax) , Aquacer 511 (polymer wax) , or such as the products sold under the name Jonwax 120 by the company Johnson Polymer (mixture of polyethylene wax and paraffin wax) and under the name Ceraflour 961 by the company Byk Cera (micronized modified polyethylene wax) ; and mixtures thereof. The organic powder (s) may be present, for example, in an amount [lacuna] The cosmetic composition according to the invention may also comprise cosmetic adjuvants chosen from fatty substances, softeners, antioxidants, opacifiers, stabilizers, antifoams, moisturizers, vitamins, fragrances, preserving agents, polymers, fragrances, thickeners, or any other ingredient usually used in cosmetics for this type of application. Needless to say, a person skilled in the art will take care to select this or these optional additional compound (s) such that the advantageous properties intrinsically associated with the cosmetic composition in accordance with the invention are not, or are not substantially, adversely affected by the envisaged addition (s). The fatty substances may consist of an oil or a wax or a mixture thereof, petroleum jelly, paraffin, lanolin-, hydrogenated lanolin or acetylated lanolin; they also comprise fatty acids, fatty alcohols such as lauryl alcohol, cetyl alcohol, myristyl alcohol, stearyl alcohol, palmityl alcohol, oleyl alcohol and also 2-octyldodecanol, fatty acid esters such as glyceryl monostearate, polyethylene glycol monostearate, isopropyl myristate, isopropyl adipate, isopropyl palmitate, octyl palmitate, C_ι2-C_ι5 fatty alkyl benzoates (Finsolv TN from Finetex) , myristyl alcohol polyoxypropylenated with 3 mol of propylene oxide (Witconol APM from Witco) , C₆-C₁₈ fatty acid triglycerides such as caprylic/capric acid triglycerides . The oils are chosen from animal, plant, mineral and synthetic oils and especially hydrogenated palm oil, hydrogenated castor oil, liquid petroleum jelly, liquid paraffin, purcellin oil (stearyl octanoate) and silicone oils and isoparaffins . The waxes are chosen from waxes of animal, fossil, plant, mineral and synthetic waxes. Mention may be made especially of beeswaxes, carnauba wax, candelilla wax, sugar cane wax, Japan wax, ozokerites, montan wax, microcrystalline waxes, paraffins, and silicone waxes and resins. The thickeners, preferably nonionic thickeners, may be chosen from modified or unmodified guar gums and celluloses, such as hydroxypropyl guar gum and cetylhydroxyethylcellulose, and silicas, for instance bentone gel MiO sold by the company NL Industries or Veegum Ultra sold by the company Polyplastic. The amounts of these various constituents that may be present in the cosmetic composition according to the invention are those conventionally used in anhydrous antiperspirant aerosols. A subject of the present invention is also an aerosol device consisting of a container comprising an aerosol composition consisting of an anhydrous liquid phase (or fluid) comprising (a) at least one antiperspirant active agent; (b) at least one lipophilic polyamide with a weight-average molar mass (MW) of less than 1000 and (c) at least one propellant as defined above, and of a means for distributing the said aerosol composition. A subject of the present invention is also a cosmetic process for treating human underarm odour, which consists in applying an effective amount of a composition as defined above to the underarm area. "^ Another subject of the invention is the use of a lipophilic polyamide as defined above in an anhydrous antiperspirant composition packaged as an aerosol, as an agent for slowing down the settling-out time of the antiperspirant active agent. Another subject of the invention is the use of a lipophilic polyamide as defined above in an anhydrous antiperspirant composition packaged as an aerosol-, as an agent for facilitating the redispersion of the antiperspirant active agent in the composition after shaking the said composition. Another subject of the invention is the use of a lipophilic polyamide as defined above in an anhydrous antiperspirant composition packaged as an aerosol, as an agent for improving the feel after application of the said composition. Concrete, but in no way limiting, examples illustrating the invention will now be given.

Examples Four formulation examples were performed. Example 1 below not forming part of the invention is the reference formula without lipophilic polyamide . Examples 2 and 3 according to the invention are aerosols containing 80% propellant and Example 4 is an aerosol containing 50% propellant.

The procedure for the various formulations is as follows : The solvents, the diamide in accordance with the invention and the hydrophobic modified clay are introduced and the mixture is then stirred using a Turrax blender until homogenized. The aluminium salt (antiperspirant) is then added with continued stirring. The propellant is then introduced in a conventional manner (for example according to the process described in patent EP 570 085) . Formulae 1 to 4 are manufactured in 100 ml glass aerosols and are filled to one third (i.e. 33.3 grams). A reference mark is made using a marker pen at the level of the liquid in the pressurized glass aerosol and also 1 cm below this level. The amounts of the various ingredients present in Examples 1 to 4 in percentages by mass.

Several measurements are taken after 24 hours, such as the appearance of the dispersion and the settling-out time. The ease of redispersion of the cake after 30 days is also measured. Description of the tests : A Sensory evaluation test A sensory test is performed on a panel of 5 volunteers by performing the following steps:

1. The hands are prewashed using a high-frequency (laboratory) soap.

2. The aerosol is weighed and is sprayed 15 cm from the hand for 2 seconds. The aerosol is reweighed and the amount of product sprayed is noted.

3. The following different cosmetic criteria are evaluated:

- creamy feel (the deposit has a creamy appearance) - overall assessment (non-greasy, non-tacky, dry and pleasant feel) . Between each test, the hands are again washed with the high-frequency soap. The evaluation of each of the criteria is performed on a scale from 0 to 10. The quality of the feel includes the creamy feel and the overall assessment. This mark refers to the quality desired for an antiperspirant aerosol (dry, non-greasy, non-tacky) enhanced with a creamy aspect.

B Settling-out time after 24 hours: After leaving to stand for 24 hours, the aerosol is shaken vigorously and the settling-out time is defined when the settling front passes the 1 cm reference mark.

C Ease of redispersion of the cake after 30 days : After leaving to stand for 1 month without shaking, the ease of redispersing the cake found at the bottom of the aerosol is measured by manual shaking. The grading for qualifying the ease of redispersing the cake is performed subjectively.

Very easy: redispersion without vigorous shaking

Easy: redispersion after 1 to 2 vigorous shakes (normal use of the product)

Slightly difficult: redispersion after 3 to 4 vigorous shakes

Difficult: redispersion after 5 to 7 vigorous shakes Very difficult: redispersion after 7 to 10 vigorous shakes. Some pieces are not redispersed. Impossible: After 10 vigorous shakes, the cake remains stuck to the bottom.

The results of the various tests are indicated in the following table:

It is observed that the anhydrous aerosol compositions 2 to 4 according to the invention containing the lipophilic diamide have a better feel than the diamide-free composition 1, even at substantially lower propellant contents (50% instead of 80%) and at higher emollient oil contents. It is observed that the anhydrous aerosol compositions 2 to 4 according to the invention containing the lipophilic diamide have the advantage of having a substantially longer settling-out time after 24 hours than the diamide-free composition 1. After being left to stand for 1 month, the cake found at the bottom of the aerosol of compositions 2 to 4 redisperses more easily than that of composition 1.

Claims

1. Antiperspirant composition, characterized in that it contains, in a cosmetically acceptable liquid anhydrous vehicle:

(a) at least one antiperspirant active agent;

(b) at least one lipophilic polyamide with a weight- average molar mass (MW) of less than 1000;

(c) at least one propellant.

2. Composition according to Claim 1, in which the lipophilic polyamide (s) has (have) a softening point of greater than 65°C.

3. Composition^' according to Claim 1 or 2, in which the lipophilic polyamide (s) has (have) a softening point ranging up to 190°C.

4. Composition according to Claim 2 or 3, in which the lipophilic polyamide (s) has (have) a softening point ranging from 70 to 130°C.

5. Composition according to any one of Claims 1 to 4, in which the lipophilic polyamide (s) has (have) a weight-average molecular mass of greater than 200 and better still greater than 250, or even greater than 290.

6. Composition according to any one of Claims 1 to 5, in which the lipophilic polyamide (s) is (are) chosen from diamides resulting from the amidation reaction between: (i) a diamine of any nature, of formula H₂N- R₁-NH₂ or

RT

with Ri denoting a linear or branched alkyl radical containing from 1 to 50 carbon atoms and better still from 2 to 40 carbon atoms, and (ii) at least one monocarboxylic acid of formula R₂-COOH in which R₂ denotes a linear or branched or cyclic, saturated or unsaturated alkyl group of at least 8 carbon atoms, in particular from 8 to 60 carbon atoms.

7. Composition according to Claim 6, in which the diamine is chosen from ethylenediamine, propylenediamine, 1, 6-diaminohexane, cyclohexane- diamine, isophoronediamine, 2-methyl-l, 5-pentane- diamine, 1, 12-diaminododecane and phenylenediamine.

8. Composition according to Claim 7, in which the diamine is ethylenediamine.

9. Composition according to one of Claims 6 to 8, characterized in that the monocarboxylic acid comprises at least one hydroxyl group.

10. Composition according to one of Claims 6 to 9, characterized in that the monocarboxylic acid comprises at least one carboxylic acid ester group containing a linear, branched, cyclic, saturated or unsaturated C₈ to C_δo and in particular C₁₂ to C₄₀ alkyl group R₂.

11. Composition according to Claim 10, characterized in that the monocarboxylic acid is chosen from unsaturated monohydroxylated .monoaliphatic acid esters; saturated linear monohydroxylated aliphatic monoacid esters; mixtures thereof.

12. Composition according to Claim 10, characterized in that the monocarboxylic acid is chosen from hydrogenated monohydroxylated esters and in particular triglycerides.

13. Composition according to any one of Claims 6 to 12, characterized in that the lipophilic polyamide is a diamide resulting from the amidation of a Cι₂-C₃₀ hydroxylated fatty acid triglyceride with a diamine in the presence of a Cχ₂ to C₄o monocarboxylic acid.

14. Composition according to Claim 13, characterized in that the diamine is ethylenediamine, the monocarboxylic acid is 12-hydroxystearic acid and the triglyceride is ricinoleic acid (or castor oil) .

15. Composition according to Claim 14, characterized in that the diamide is the compound of formula:

16. Composition according to any one of Claims 1 to 5, in which the lipophilic polyamide (s) is (are) chosen from polymers resulting from the amidation between: (i) a diamine of formula H₂N-R_η-NH₂ with Ri denoting a linear, branched, or cyclic alkyl radical containing from 1 to 50 carbon atoms and better still from 2 to 40 carbon atoms, (ii) a diacid HOOC-R₄-COOH (or a mixture of diacids) with R₄ representing (CH₂)_n in which n is from 8 to 60 (especially 12 to 40) , an aryl or alkylaryl group containing from 6 to 40 carbon atoms. Examples that may be mentioned include linear acids such as adipic acid or sebacic acid, or aromatic acids such as phthalic acid or terephthalic acid, and fatty acid dimers, (iii) at least one monoacid R₂-COOH in which R₂ denotes a linear or branched or cyclic, saturated or unsaturated alkyl group of at least 8 carbon atoms, in particular from 8 to 60 carbon atoms.

17. Composition according to any one of Claims 1 to 5, in which the lipophilic polyamide (s) is (are) chosen from polymers comprising silicone portions resulting from the amidation between: (i) a diamine comprising silicone groups or a poly- dimethylsiloxane containing only one functional end in the reaction mixture, this end possibly being a carboxylic acid, amine or epoxy group, with (ii) one or more carboxylic acids as defined in the preceding claims.

18. Composition according to any one of Claims 1 to 17, in which the lipophilic polyamide (s) is (are) present in amounts ranging from 0.001% to 10% by weight and preferably from 0.1% to 5% by weight relative to the total weight of the composition.

19. Composition according to any one of Claims 1 to 18, in which the antiperspirant active agent (s) is (are) chosen from aluminium and/or zirconium salts; complexes of zirconium hydroxychloride and of aluminium hydroxychloride and of an amino acid.

20. Composition according to any one of Claims 1 to 17, in which the antiperspirant active agent (s) is (are) present in the composition according to the invention in a proportion of from about 0.001% to 30% by weight and preferably in a proportion of from about 0.1% to 25% by weight relative to the total composition.

21. Composition according to any one of Claims 1 to 17, in which the propellant (s) is (are) chosen from dimethyl ether; volatile hydrocarbons; volatile fluorohydrocarbons; carbon dioxide; nitrous oxide; nitrogen or compressed air.

22. Composition according to any one of Claims 1 to 17, in which the concentration of propellant ranges from 5% to 90% by pressurized weight and more preferably from 15% to 60% by weight relative to the total weight of the pressurized composition.

23. Composition according to any one of

Claims 1 to 22, also containing an additional deodorant active agent.

24. Composition according to any one of Claims 1 to 22, in which the anhydrous liquid vehicle comprises at least one volatile or non-volatile silicone or hydrocarbon-based emollient oil.

25. Composition according to Claim 24, in which the emollient oil is a volatile silicone.

26. Composition according to Claim 25, in which the volatile silicone is a cyclomethicone tetramer or pentamer.

27. Composition according to any one of Claims 24 to 26, in which the emollient oil(s) is (are) preferably present in amounts ranging from 1% to 50% by weight and more preferably from 5% to 40% by weight relative to the total weight of the composition.

28. Composition according to any one of Claims 1 to 27, also containing at least one suspension agent. - 29. Composition according to Claim 28, in which the suspension agent is chosen from hydrophobic modified montmorillonite clays. 30. Composition according to Claim 29, in which the suspension agent is stearalkonium bentonite. 31. Composition according to Claim 29 or 30, in which the suspension agents are present in amounts ranging from 0.2% to 2% by weight relative to the total weight of the composition. 32. Composition according to any one of Claims 1 to 31, also containing at least one organic powder. 33. Composition according to any one of Claims 1 to 31, also containing a cosmetic adjuvant chosen from fatty substances, softeners, antioxidants, opacifiers, stabilizers, antifoams, moisturizers, vitamins, fragrances, preserving agents, polymers, fragrances and thickeners . 34. Aerosol device consisting of: (A) a container comprising a composition consisting firstly of an anhydrous liquid phase (or fluid) comprising at least one antiperspirant active agent, at least one lipophilic polyamide with a weight-average molar mass (MW) of less than 1000, and (B) at least one propellant, and of a means for distributing the said aerosol composition. 35. Cosmetic process for treating human underarm odour, which consists in applying to the underarm area an effective amount of a composition according to any one of Claims 1 to 33. 36. Use of a lipophilic polyamide with a weight-average molar mass (MW) of less than 1000, as defined in any one of the preceding claims, in an anhydrous antiperspirant composition packaged as an aerosol, as an agent for slowing down the settling-out time of the antiperspirant active agent. 37. Use of a lipophilic polyamide with a weight-average molar mass (MW) of less than 1000, as defined in any one of the preceding claims, in an anhydrous antiperspirant composition packaged as an aerosol, as an agent for facilitating the redispersion of the antiperspirant active agent in the composition after shaking it. 38. Use of a lipophilic polyamide with a weight-average molar mass (MW) of less than 1000, as defined in any one of the preceding claims, in an anhydrous antiperspirant composition packaged as an aerosol, as an agent for improving the feel after application of the said composition.