WO2012120114A1 - Method for the cosmetic treatment of human perspiration comprising the application of a solubilizable antiperspirant polymer film - Google Patents

Abstract

The present invention relates to a method for the cosmetic treatment of human perspiration and optionally body odours linked to human perspiration, especially auxiliary odours, characterized in that it comprises: (i) a step consisting in applying an antiperspirant cosmetic polymer film to the skin, and (ii) a step consisting in partially dissolving said film on contact with a cosmetic composition containing one or more cosmetically acceptable solvents prior to, during or subsequent to the application of said film to the skin so that said film adheres to the skin.

Description

Meth od for the cosm etic treatment of hum an perspiration comp rising the application of a solubilizable antiperspirant p olym er film

The present invention relates to a method for the cosmetic treatment of human perspiration and optionally body odours linked to human perspiration, especially auxiliary odours, comprising a step consi sting in applying an antiperspirant cosmetic polymer film to the skin, and a step consi sting in partially di ssolving said film so that the film adheres to the skin.

The armpits and also certain other parts of the body are generally the site of much di scomfort that may ari se directly or indirectly from perspiration. Thi s perspiration often leads to unpleasant and di sagreeable sensations that are mainly due to the presence of sweat resulting from perspiration, which may, in certain cases, make the skin and clothing wet, especially in the regi on of the armpits or on the back, thus leaving unattractive vi sible marks. Moreover, the presence of sweat generally gives rise to the production of body odours, which are generally unpleasant. Finally, during its evaporation, sweat may also leave salts and/or proteins on the surface of the skin, which may result in whitish marks on clothing. Such di scomfort is noticed, including in the case of moderate perspiration.

In the cosmetic field, it is thus well known to use, in topical application, antiperspirant products containing sub stances that have the effect of limiting or even preventing the flow of sweat in order to overcome the problems mentioned ab ove. These products are generally available in the form of roll-ons, sticks, aerosol s or sprays . Antiperspirant sub stances are generally formed from aluminium salts, such as aluminium chloride and aluminium hydroxyhalides, or complexes of aluminium and zirconium. These sub stances reduce the flow of sweat by forming a plug in the sweat duct.

The antiperspirant efficacy of these sub stances i s often limited, which means that they need to be applied regularly to the skin in order to obtain a satisfactory effective antiperspirant effect.

However, in the case of certain users, repeated application of these sub stances has the drawback of leading to skin irritation. Furthermore, despite these multiple applications, the effectiveness of these sub stances may still remain insufficient and it is ob served that, halfway through the day, odours may b egin to develop .

Moreover, another drawback associated with the use of these aluminium salts lies in the fact that the antiperspirant effect imparted by such sub stances generally has a tendency to di sappear, especially in the case of successive washing or in the case of heavy perspiration.

Finally, these antiperspirant sub stances may al so leave marks during their application to the skin, which has the consequence of staining clothing.

As a vari ant, it has al so been proposed to develop a method that consi sts in using botulinum toxin to give a sati sfactory antiperspirant effect. However, the need to inj ect such a toxin at each use greatly limits the exploitation of thi s method.

To overcome all of the drawbacks mentioned above, it has been proposed to seek other effective active sub stances, which are well tolerated by the skin and easy to formulate, in order to replace all or some of the aluminium salts and/or aluminium and zirconium complexes .

Specifically, limiting the flow of sweat may be achieved by partially ob structing the sweat ducts by means of forming a plug in the sweat duct, but al so by forming at the surface of the skin a film that i s resi stant to sweat. Thus, many approaches directed towards covering the surface of the skin with a film have been developed in order to limit the flow of sweat.

By way of example, patent applications WO 93/24 105 and

US 5 508 024 describ e antiperspirant compositions essentially compri sing, in a cosmetically acceptable medium, at least one water-insoluble nontoxic polymer that i s capable of forming an antiperspirant occlusive film on the skin. In particular, the water-insoluble polymers used in such compositions are solubilized or di spersed in a medium based on alcohols, especially aliphatic alcohols containing short alkyl chains, and form a flexible occlusive film on the skin.

Patent application US 2003/01 94387 describes an antiperspirant composition for topical application compri sing, in a cosmetically acceptable medium, at least one active antiperspirant sub stance, which i s chosen especially from aluminium salts, and at least one water-insoluble non-toxic polyester that is capable of forming an occlusive film on the skin. The film thus formed, following application of the polyester to the skin, has the purpose of reinforcing the efficacy of the aluminium salts and of being able to formulate compositions having low contents of aluminium salts.

Similarly, patent application US 6 387 356 describes a composition compri sing, in a medium comprising alcoholic solvents, at least one cellulo se ester that is soluble in an aqueous-alcoholic medium, capable of forming a thin film on the surface of the skin, and at least one antiperspirant sub stance that is generally chosen from aluminium salts .

Similarly, patent application DE 2 947 060 describes a composition, in particular a composition packaged in an aerosol devi ce, compri sing at least one acrylic polymer capable of forming a film on the skin and at least one antiperspirant sub stance, which may especially be aluminium salts .

These approaches are often limited since the film that is formed on the skin does not last well over time. Thus, unless the compositions mentioned above are applied regularly, the antiperspirant effect does not last the day.

Another approach consi sted in using compositions comprising fatty sub stances capable of forming an occlusive layer on the skin . In particular, international patent application WO 00/ 13653 describes a composition with the consi stency of a gel, compri sing (a) at least one volatile or nonvolatile organosilicon compound and (b) at least one gelling agent compri sing a non-volatile organosilicon compound containing an aliphati c hydrocarbon-based chain.

However, the film formed after applying these compositions to the skin has a tendency to degrade easily, which means that the desired antiperspirant effects are not entirely sati sfactory.

In order to overcome these drawbacks, a method consi sting in using a polymer film that is capable of ab sorbing sweat was developed. In particular, patent application US 93 /8753 8 describes the use of a polymer such as a cellulo se ester, which forms a film on the skin that ab sorb s perspiration.

However, the film formed on the skin is not entirely sati sfactory since the amount of water to be ab sorbed i s generally greater than the amount of water that can be ab sorb ed by such compounds .

Moreover, it has al so been proposed in international patent application WO 2001 /054 658 to use anhydrous, non-adhesive antiperspirant compositions comprising at least one water-reactive cyanoacrylate monomer, an anhydrous medium, a polymerization inhibitor and an active sub stance chosen from a deodorant sub stance, an antiperspirant sub stance and a fragrancing sub stance, or a mixture of these sub stances. The cyanoacrylate monomers used in such compositions polymerize anioni cally directly on the surface of the skin in the presence of a nucleophilic agent, such as hydroxide ions (OH^") contained in water, to form a water-resi stant polymer film. In other words, the cyanoacrylate monomers react with the sweat to form in situ, vi a anionic polymerization, a film on the skin that blocks the sweat ducts .

However, these occlusive film-forming polymers do not afford entirely sati sfactory antiperspirant efficacy and still pose formulation problems due to the amounts of solvent required to solubilize the cyanoacrylate monomers .

Other approaches have consisted in using, on the skin, patches intended to ab sorbe perspiration or impermeable patches capable of blocking sweat output.

In the first case, the patches capable of ab sorbing perspiration generally compri se an adhesive layer and an ab sorbent layer placed on an aerated support, for example a fabric. Such patches are commercially available. However, the ab sorbent layer is generally thick due to the large amounts of sweat to be ab sorb ed, which makes the use of these patches vi sible and not very attractive . Such patches are especially used in cases of excessive perspiration, such as hyperhidrosi s .

In the second case, the impermeable patches capable of blocking sweat output generally compri se a layer constituted of an impermeable material and a highly adhesive layer. Such patches must be thin enough and elastic enough not to hamper the movements of the skin. By way of example, patent application US 2010/01 89753 describes a thin patch produced from a pressure- sensitive adhesive layer and patent application US 2006/0041987 relates to a patch produced from the superposition of an adhesive layer, an ab sorbant layer and an impermeable film . The impermeable patches must especially have a certain resi stance and a highly adhesive layer in order to be abl e to effectively block flows of water. As a result, impermeable patches are generally difficult to remove due to their highly adhesive nature.

As a vari ant, patches intended to deposit antiperspirant active agents on the skin have al so been developed, i. e. patches that act as a means of application. For example, patent application US 2007/0053959 describes an antiperspirant/deodorant strip intended to be applied to the skin, which may be oval or rectangular.

As a result, approaches based on the use, on the skin, of patches intended for the treatment of perspiration are not entirely sati sfactory in terms of efficacy and the necessary presence of an adhesive layer within their structure makes their removal difficult, especi ally when these patches are applied to areas of the skin where the hair has not b een removed.

Thus, there i s still a real need to research novel pathways that do not have the drawb acks mentioned ab ove, i. e. that involve the use, on the skin, of cosmetic compositions capable of imparting a sati sfactory antiperspirant effect, having a controlled permeability to water vapour and a controlled impermeability to sweat, for which the application to and the removal from the skin are facilitated.

The applicant has di scovered, surpri singly, that by carrying out a process in which use i s made, on the skin, of an antiperspirant polymer film that is partially di ssolved on contact with a cosmetic composition containing one or more solvents so that the film adheres to the skin, it was possible to obtain the desired properties, i . e . a film capable of effectively blocking the flow of sweat, the resi stance of which is improved, and for which the application to and the removal from the skin are facilitated.

In other words, the applicant has ob served that by applying an antiperspirant cosmetic polymer material in the form of a film and by arranging for a portion of thi s material to dissolve on contact with a cosmetic composition containing one or more solvents, it was possible to have a film that is pressed easily onto the skin, the resi stance of which is improved over time and the permeability to water vapour and the impermeability to sweat of whi ch are sati sfactory.

The partial di ssolution of the antiperspirant cosmetic film takes place at the moment when the film i s brought into contact with the cosmetic composition containing the solvent(s) and occurs either before, after or during the application of the film to the skin.

Thus, the partial di ssolution of the antiperspirant cosmetic film makes it possible to effectively press the film onto the skin without using an adhesive layer. In other words, the partial dissolution that occurs at the moment of the film coming into contact with the composition compri sing the solvent(s) makes it possible to make the film adhere to the skin in the ab sence of an adhesive layer within its structure.

More particularly, once partially di ssolved, the film does not fragment and the di ssolved portion will enable the film to adhere to the skin in a sati sfactory manner. During the evaporation of the solvent, the adhesion of the film to the skin is strengthened and results in an effect of temporary binding to the skin.

The antiperspirant film thus deposited on the skin has a sati sfactory controlled permeability, in particular permeable to water vapour and impermeable to sweat.

Furthermore, the antiperspirant film remains easy to remove from the skin and i s easily eliminated by means of a solvent. Given that the antiperspirant film does not require the use of an adhesive layer, the film can be easily removed without leaving traces of adhesive compounds on the skin. Moreover, the film thus deposited on the skin has a sati sfactory resi stance, especi ally relative to the pressure exerted by water droplets, by the movements of the body or by sweat leaving the skin pores, which makes it possible to block perspiration in a long-lasting manner.

The cosmetic treatment method according to the present invention makes it possible to result in a better blocking of the perspiration compared to a process in which an identical film i s applied straight to the skin without partial di ssolution with a composition containing one or more cosmetically acceptable solvents .

One particular subj ect of the present invention i s therefore a method for the cosmetic treatment of human perspiration and optionally body odours linked to human perspiration, especially auxiliary odours, compri sing :

(i) a step consi sting in applying an antiperspirant cosmetic polymer film to the skin, and

(ii) a step consi sting in partially di ssolving said film on contact with a cosmetic composition containing one or more cosmetically acceptabl e solvents prior to, during or sub sequent to the application of said film to the skin so that said film adheres to the skin.

In other words, the cosmetic polymer film according to the present invention may be partially di ssolved either separately relative to its application to the skin, i . e . the film i s first partially di ssolved by bringing it into contact with the solvent(s) and the partially dissolved film is then applied to the skin, or, at the time of its application to the skin, i . e. the solvent(s) i s (are) applied to the skin and then the film i s applied, or after its application to the skin, i . e . firstly the film is applied to the skin and then the solvent(s) i s (are) applied.

In particular, the cosmetic treatment method according to the present invention uses : (a) a step consi sting in applying to the skin a cosmetic composition compri sing one or more cosmetically acceptable solvents, then a step consi sting in applying, to the area of the skin treated with the sai d solvent(s), an antiperspirant cosmetic polymer film so that said film adheres to the skin, said film being partially di ssolved at the time of its application to the skin, or

(b) a step consi sting in applying an antiperspirant cosmetic polymer film to the skin followed by a step consi sting in applying, to the area of the skin covered by said film, a cosmetic composition comprising one or more cosmetically acceptable solvents so that said film adheres to the skin, said film being partially di ssolved after its application to the skin, or

(c) a step consi sting in bringing an antiperspirant cosmetic polymer film into contact with a cosmetic composition comprising one or more cosmetically acceptable solvents so as to partially di ssolve said film, and a step consi sting in applying said film to the skin.

The expression "partially di ssolved" is understood, within the meaning of the present invention, to mean that only a small portion of the cosmetic film i s solubilized, without the rest of the film di sintegrating, i . e. the rest of the film retains its integrity and does not fragment.

In other words, the solubilization of the film is not immediate and complete when it is brought into contact with the cosmetic composition containing the solvent(s), i. e. the film does not completely di ssolve immediately.

Thus, a portion of the film is di ssolved on contact with the cosmetic composition containing the solvent(s) so as to enable the rest of the film to adhere to the skin. In particular, the portion of the film not dissolved remains grippable.

A person skilled in the art will in particular take care to select the thickness of the film, the nature of the solvent and al so the material forming the film so that only one portion of the film i s solubilized and the other portion of the film adheres to the skin.

Preferably, for the purposes of the present invention, the expression "partially di ssolved" i s understood to mean that the film i s solubilized in an amount of less than 40% by weight, and better still in an amount ranging from 5% to 20% by weight relative to the total weight of the film .

More preferably, the film i s solubilized in an amount of less than 20% by weight after 2 seconds to 1 minute, and more preferably after 5 to 30 seconds.

Other subj ects, features, aspects and advantages of the invention will emerge even more clearly from reading the description and examples which follow.

As indicated previously, the cosmetic treatment method according to the present invention uses a cosmetic composition containing one or more cosmetically acceptable organic solvents .

For the purposes of the present invention, the expression " cosmetically acceptable solvent" is understood to mean a solvent that i s compatible with the skin and keratin material s .

The solvent(s) may be water and one or more organic solvents .

Preferably, the cosmetic composition compri ses one or more organic solvents .

As organic solvents that may advantageously be used, mention may especially be made of alcohols such as ethanol, i sopropanol, benzyl alcohol, phenylethyl alcohol, the alcohol 1 ,2, 3 -propanetriol or glycols or glycol ethers such as, for example, ethylene glycol monomethyl , monoethyl and monobutyl ethers, propylene glycol, butylene glycol, dipropylene glycol, and al so diethylene glycol monobutyl ether.

Preferably, the organic solvent(s) may be chosen from alcohol s such as ethanol, glycol, glycerol or mixtures thereof. In particular, the solvent(s) may be chosen from solvents capable of being able to be partly ab sorbed by the skin, such as glycol or glycerol.

The cosmetic composition containing the cosmetically acceptabl e solvent(s) may al so contain one or more standard additives that are well known in the art, such as natural or synthetic thickeners or vi scosity regulators, ceramides or pseudoceramides, sequestrants, solubilizers, proteins, reducing agents or antioxidants, oxidizing agents, vitamins or provitamins, cationic or amphoteric polymers, fragrances, pH stabilizers, preserving agents, moi sturizers, antiperspirant active agents, antibacterial agents, deodorizing active agents such as cyclodextrin, dyes, depilatory agents or agents that prepare the hairs for depilation, or mixtures thereof.

For the purposes of the present invention, the term "thickener" means any compound whose presence increases the vi scosity of the composition into which it is introduced by at least 25 cps and preferably 50 cps at 25 °C and at a shear rate of 1 s^{" 1}.

The thickener(s) may be chosen from cellulose-based thickeners, for exampl e hydroxyethyl cellulose, hydroxypropyl cellulo se and carboxymethyl cellulose, guar gum and derivatives thereof, for example the hydroxypropyl guar sold by the company Rhodia under the reference Jaguar HP 105 , gums of microbial origin, such as xanthan gum and scleroglucan gum, synthetic thickeners such as crosslinked acrylic acid or acrylamidopropanesulphonic acid homopolymers, for example Carbomer, nonionic, anionic, cationi c or amphoteric associative polymers, such as the polymers sold under the names Pemul en TR 1 or TR2 by the company Goodrich, Salcare S C90 by the company Ciba, Aculyn 22, 28 , 33 , 44 or 46 by the company Rohm & Haas, and Elfacos T210 and T212 by the company Akzo.

In particular, the thickener(s) that may be used in the cosmetic composition according to the invention are chosen from cellulose-based thickeners, in particular hydroxyalkyl celluloses. Preferably, the thickener(s) are chosen from hydroxyethyl cellulo se, hydroxypropyl cellulo se and carboxymethyl cellulose, in particular hydroxyethyl cellulo se.

Thus the thickener(s) make it possible to facilitate the application of the cosmetic composition containing the solvent(s) and to limit its drying.

According to one preferred emb odiment, the cosmetic composition contains ethanol and one or more thickeners chosen from cellulo se-based thickeners, in particular hydroxyalkyl cellulo ses, especially the hydroxypropyl cellulo se sold under the trade name Klucel .

The antiperspirant active agent(s) that can be used in the composition containing the solvent(s) may be chosen from aluminium salts and/or zirconium salts, complexes of zirconium hydroxychloride and of aluminium hydroxychloride with an amino acid and/or mixtures thereof.

Among the aluminium salts, mention may especially be made of aluminium chlorohydrate in activated or unactivated form, aluminium chlorohydrex, the aluminium chlorohydrex-polyethylene glycol compl ex, the aluminium chlorohydrex-propylene glycol complex, aluminium dichlorohydrate, the aluminium dichlorohydrex-polyethylene glycol complex, the aluminium dichlorohydrex-propylene glycol complex, aluminium sesquichlorohydrate, the aluminium sesquichlorohydrex- polyethylene glycol complex, the aluminium sesquichlorohydrex-propylene glycol complex, aluminium sulphate buffered with sodium aluminium lactate.

Among the aluminium-zirconium salts, mention may be made in particular of aluminium zirconium octachlorohydrate, aluminium zirconium pentachlorohydrate, aluminium zirconium tetrachlorohydrate and aluminium zirconium trichlorohydrate. The complexes of zirconium hydroxychloride and of aluminium hydroxychloride with an amino acid are generally known under the name ZAG (when the amino acid i s glycine) . Among these products, mention may be made of the aluminium zirconium octachlorohydrex-glycine complexes, the aluminium zirconium pentachlorohydrex-glycine complexes, the aluminium zirconium tetrachlorohydrex-glycine complexes and the aluminium zirconium trichlorohydrex-glycine complexes .

Thus, the antiperspirant active agent(s) may be chosen from aluminium chlorohydrates and the complexes containing them used in the pressure-sensitive adhesive layer, mention may be made of the following sub stances used and approved by the FDA (Food & Drug Admini stration) : aluminium chlorohydrate, aluminium chlorohydrex-PEG, aluminium chlorohydrex-PG, aluminium di chlorohydrate, aluminium di chlorohydrex- PEG, aluminium di chlorohydrex-PG, aluminium sesquichlorohydrate, aluminium sesquichlorohydrex-PEG, aluminium sesquichlorohydrex-PG, aluminium zirconium octachlorohydrate, aluminium zirconium octachlorohydrex-GLY, aluminium zirconium pentachlorohydrate, aluminium zirconium pentachlorohydrex-GLY, aluminium zirconium tetrachlorohydrate, aluminium zirconium trichlorohydrate, aluminium zirconium tetrachlorohydrex-GLY, and aluminium zirconium trichlorohydrex-GLY, given that the abbreviations PEG, PG and GLY denote, respectively, polyethylene glycol, propylene glycol and glycine. Commercial products of this type are sold, for example, by the company Clariant under the name Locron S (aluminium chlorohydrate), by the company Rehei s under the name Reach 301 or by the company Guilini Chemie under the name Aloxicoll PF 40 (aluminium chlorohydrex), by the company Rehei s under the name Rezal 67 S olution (aluminium zirconium pentachlorohydrate sold as an aqueous solution containing 40% active material). A person skilled in the art will take care to select the optional additives and the amount thereof such that they do not harm the properties of the compositions of the present inventi on.

The additives are generally present in the composition according to the invention in an amount ranging from 0 to 20% by weight relative to the total weight of the composition.

The solvent(s) may be present in the cosmetic composition in a content ranging from 5% to 100% by weight and preferably from 20% to 90% by weight, relative to the total weight of the composition.

The amount of solvents i s chosen so as to solubilize one portion of the cosmetic film and so that the other portion adheres to the skin.

As indicated previously, the cosmetic treatment method according to the invention compri ses a step that consi sts in applying an antiperspirant cosmetic polymer film to the skin.

For the purposes of the present invention, the term " film " means a thin and grippable soli d. The term "thin" means a soli d having a thickness of at most 1000 μιη. The film generally has a size suitable for being able to be handled easily by the user. It may have a square, rectangular or di sc shape, or any other shape.

The thickness of the cosmetic film i s chosen so that the latter i s partially di ssolved when it is brought into contact with a composition containing one or more solvents .

Preferably, the polymer film has a thickness ranging from 1 0 μιη to 1000 μιη, preferentially from 20 μιη to 500 μιη and more preferentially from 50 μιη to 300 μιη. It may have a surface area ranging from 10 to 800 cm² and preferably from 100 to 600 cm².

In particular, the film may be used on vi sible areas of the skin, such as the face and the chest due to its small thickness . For the purposes of the present invention, the expression " antiperspirant film " means a film capable, by itself, of reducing or limiting the flow of sweat.

In other words, the antiperspirant film according to the present invention corresponds to the antiperspirant active agent responsible of the reduction or the limitation of the flow of sweat.

According to a particular embodiment of the invention, the antiperspirant film i s the sole antiperspirant active agent. In other words, the antiperspirant film of the present invention i s free from any additional antiperspirant active agent.

For the purposes of the present invention, the expression "polymer film " means a film made from a polymer materi al that is obtained from a cosmetic composition containing one or more film-forming polymers .

Thus, in accordance with the present invention, the polymer film, once it is formed, i s applied to the skin. In other words, a polymer material is formed from a cosmetic composition containing one or more film- forming polymers that may or may not be used directly as a polymer film in accordance with the treatment method according to the present invention.

For example, the cosmetic composition containing one or more film-forming polymers may lead to the formation of a polymer layer that may be deposited on a smooth, non-porous and non-adhesive support so as to produce a film having a particular thickness. The film obtained i s then used in the cosmetic treatment method according to the present invention.

The expression " film-forming polymer" means a polymer that i s capable, by itself or in the presence of an auxiliary film-forming agent, of forming a separable, in particular continuous film on a support, especially on keratin material s or the skin. According to one embodiment, the film-forming polymer(s) is (are) water-soluble.

For the purposes of the present invention, the term "water-soluble " means polymers having a solubility in water, measured at 25 °C, whi ch i s at least equal to 10 gram/litre (g/1) (production of a macroscopically i sotropic and transparent, coloured or colourless solution) . Thi s solubility i s preferably greater than or equal to 100 g/1.

The water-soluble film-forming polymers according to the invention are in particular chosen from:

• Homopolymers or copolymers of (meth)acrylic acid or salts thereof.

The proportion of (meth)acrylic acid monomers or monomers of the salt thereof in the polymer i s chosen so as to obtain an acid value of greater than 100 mg KOH/g, preferably greater than 200 mg KOH/g.

• Copolymers of vinyl acetate and of a hydrophilic monomer such as copolymers of vinyl acetate and of vinylpyrrolidone, and copolymers of vinyl acetate and of vinyl alcohol, the proportion of vinyl acetate monomer preferably being greater than 30% . Such compounds are especially available from the company BASF under the reference Luvi skol VA 64 Powder.

• Polysaccharides or derivatives of polysaccharides such as hydroxyethyl cellulose, hydroxypropyl cellulo se, carboxymethyl cellulo se and carboxyethyl cellulo se.

According to one embodiment, the film-forming polymer(s) is (are) water-di spersible.

For the purposes of the present invention, the term "water- di spersible " means polymers in the form of particles in di spersion in an aqueous phase (production of a macroscopically non-transparent, coloured or colourless solution) . The water-dispersible film-forming polymers according to the invention are in particular chosen from:

• Copolymers of (meth)acrylic acid or salts thereof. The proportion of (meth)acrylic acid monomers or monomers of the salt thereof in the polymer i s chosen so as to obtain an aci d value of less than 100 mg KOH/g, preferably less than 50 mg KOH/g, in order to limit the solubility in water. Such compounds are especially available from the company Interpolymer under the reference Syntran 5760.

• The acrylic homopolymers or copolymers obtained in particular from hydrophilic monomers chosen from hydroxyalkyl (meth)acrylate such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate, and aminoalkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate and butylaminoethyl (meth)acrylate. Such compounds are especially available from the company Interpolymer under the reference Syntran PC 5 1 00.

• Polycondensates such as polyesters, polyamides and polyurethanes .

Preferably, the polycondensates are chosen from di spersions of polyurethane in water. Such compounds are especially available from the company Bayer under the commerci al Baycusan range.

• Derivatives of polysaccharides such as carboxymethyl cellulose acetobutyrates .

In accordance with thi s embodiment, the water-solubl e or water- di spersible polymers are chosen from polymers that swell slightly or not at all on contact with water, and polymers that are slowly solubilized in water.

Preferably, the water-soluble polymers are chosen from polymers that are slowly solubilized in water, especially in an amount of 50% after 10 seconds to 10 minutes . According to another emb odiment, the film-forming polymer(s) are chosen from polymers that are insoluble in water and soluble in an organic solvent.

For the purposes of the present invention, the expression " insoluble in water" means polymers having a solubility in water, measured at 25 ° C, of less than 10 gram/litre, preferably le ss than 1 gram/litre and for the purposes of the present invention the expression " soluble in in an organi c solvent" means polymers having a solubility in an organi c solvent, measured at 25 °C, of greater than 1 0 gram/litre, and preferably 1 00 gram/litre.

Preferably, the film-forming polymer(s) that is (are) insoluble in water is (are) chosen from (meth)acrylate polymers or copolymers, polyurethanes, polyamides, polyesters, polymers of polyamide-polyether type and mixtures thereof.

Preferably, the film-forming polymer(s) is (are) chosen from polymers of polyamide-polyether type .

According to one particular embodiment of the invention, the polymers of the polyamide-polyether type of the invention have a permeability to water vapour of greater than 1000 g/m²/24 h. Thi s permeability is determined by measuring the amount of water vapour in grams that crosses 1 m² of coating in 24 hours, from a wet zone to a dry zone (ASTM E 96 E) . The operating conditions adopted are a relative humidity percentage of 90% and a temperature of 38° C . The measurement i s performed on a sample of coating 1 5 μιη thick. The permeability measurement may be measured using permeability-measuring equipment such as the equipment bearing the reference Perme™ W3 -060 avail abl e from the company Labthink Instruments Co . Limited. According to another particular embodiment of the invention, the polymers of polyamide-polyether type of the invention may be characterized by adhesion properties on the skin higher than the adhesion properties obtained with water-resi stant elastomeri c polymers such as certain di spersions of polyurethane in aqueous phase available especially under the reference Baycusan C l OO l from B ayer.

The polyamide-polyether polymers of the invention are preferably chosen from copolymers bearing polyamide blocks (in particular polyamide-6 or polyamide- 12) and polyether blocks (in particular polyethylene glycol or polytetramethyl ene glycol) .

The copolymers bearing polyamide blocks and polyether blocks according to the invention result from the copolycondensation of polyamide blocks bearing reactive ends with polyether blocks bearing reactive ends, such as, inter alia:

1 ) Polyamide blocks bearing diamine chain ends with polyoxyalkyl ene blocks bearing dicarboxylic chain ends .

2) Polyamide blocks bearing dicarboxylic chain ends with polyoxyalkylene blocks bearing diamine chain ends obtained by cyanoethylation and hydrogenation of α, ω-dihydroxylated aliphatic polyoxyalkyl ene blocks known as polyether diols.

3 ) Polyamide blocks b earing dicarb oxyli c chain ends with polyether diols, the products obtained being, in thi s particular case, polyetheresteramides. The copolymers of the invention are advantageously of thi s type. The polyamide blocks bearing dicarboxylic chain ends originate, for example, from the condensation of polyamide precursors in the presence of a chain-limiting dicarboxylic acid. The polyamide blocks bearing diamine chain ends originate, for example from the condensation of polyamide precursors in the presence of a chain-limiting diamine.

The polymers bearing polyami de blocks and polyether blocks of the invention may also compri se randomly di stributed units. These polymers may be prepared by the simultaneous reaction of the polyether and of the precursors of the polyamide blocks .

For example, it is possibl e to react polyether diol, polyamide precursors and a chain-limiting diacid. A polymer is obtained essentially having polyether blocks and polyamide blocks of very variable length, but al so the various reagents that have reacted randomly, whi ch are di stributed randomly (statistically) along the polymer chain.

It is al so possibl e to react polyetherdiamine, polyamide precursors and a chain-limiting diacid. A polymer i s obtained essentially having polyether blocks and polyamide blocks of very variable length, but al so the various reagents that have reacted randomly, which are di stributed randomly (statistically) along the polymer chain.

Three types of polyamide block may advantageously be used.

According to a first type, the polyamide blocks originate from the condensation of a di carboxylic acid and a di amine.

According to a second type, the polyamide blocks result from the condensation of one or more α, ω-aminocarboxylic acids and/or of one or more lactams containing from 6 to 12 carbon atoms in the presence of a dicarboxyli c aci d containing from 4 to 12 carbon atoms or of a diamine.

According to a third type, the polyamide blocks result from the condensation of at least one α, ω-aminocarboxylic acid (or a lactam), at least one diamine and at least one dicarboxylic acid.

According to one variant of thi s third type, the polyamide blocks result from the condensation of at least two α, ω-aminocarboxylic acids or from at least two lactams containing from 6 to 12 carbon atoms or from one lactam and one aminocarboxylic acid not having the same number of carbon atoms, in the optional presence of a chain limiter. Advantageously, the polyamide blocks of the second type are made of polyamide-12 or polyamide-6. As examples of polyamide blocks of the third type, mention may be made of the following:

a) 6.6/Pip. 10/12 in which 6.6 denotes hexamethyleneadipamide units (hexamethylenediamine condensed with adipic acid). Pip. 10 denotes units resulting from the condensation of piperazine and of sebacic acid. 12 denotes units resulting from the condensation of lauryllactam. The weight proportions are, respectively, 25 to 35/20 to 30/20 to 30; the total being 80, and advantageously 30 to 35/22 to 27/22 to 27; the total being 80. For example, 32/24/24 proportions give a melting point from 122 to 137°C. b) 6.6/6.10/11/12 in which 6.6 denotes hexamethylenediamine condensed with adipic acid, 6.10 denotes hexamethylenediamine condensed with sebacic acid, and 11 denotes units resulting from the condensation of aminoundecanoic acid, and 12 denotes units resulting from the condensation of lauryllactam. The weight proportions are, respectively, 10 to 20/15 to 25/10 to 20/15 to 25; the total advantageously being 70: 12 to 16/18 to 25/12 to 16/18 to 25; the total being 70. For example, 14/21/14/21 proportions give a melting point from 119 to 131°C.

The polyamide blocks are obtained in the presence of a chain- limiting diacid or diamine if polyamide blocks bearing acid or amine ends are desired. If the precursors already comprise a diacid or a diamine, it suffices, for example, to use it in excess. By way of example of an aliphatic α,ω-aminocarboxylic acid, mention may be made of aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid and 12- aminododecanoic acid. As examples of a lactam, mention may be made of caprolactam, oenantholactam and lauryllactam. As examples of aliphatic diamines, mention may be made of hexamethylenediamine, dodecamethylenediamine and trimethylhexamethylenediamine. As examples of cycloaliphatic diacids, mention may be made of 1 ,4- cyclohexyldicarb oxyli c acid. As examples of aliphatic diacids, mention may be made of butanedioic acid, adipi c acid, azelaic acid, suberic aci d, sebacic acid, dodecanedicarboxylic acid, dimerized fatty acids (these dimerized fatty acids preferably have a dimer content of at least 98%; they are preferably hydrogenated; they are sold under the brand name Pripol by the company Unichema, or under the brand name Empol by the company Henkel) and α, ω -diacid polyoxyalkylenes. As examples of aromatic diacids, mention may be made of terephthalic acid (T) and i sophthalic acid (I) . The cycloaliphati c diamines may be isomers of bi s(4- aminocyclohexyl)methane (BACM), bis(3 -methyl-4- aminocyclohexyl)methane (BMACM), 2-2-bi s(3 -methyl-4- aminocyclohexyl)propane (BMACP) and /?ara-aminodicyclohexylmethane (PACM). The other diamines commonly used may be i sophoronediamine (IPDA), 2, 6-bi s(aminomethyl)norbornane (BAMN) and piperazine.

The polyether blocks may represent 5% to 85% by weight of the copolymer b earing polyamide and polyether blocks.

The polyether blocks are formed from alkylene oxide units . These units may be, for example, ethylene oxide units, propylene oxide units or tetrahydrofuran (which leads to polytetramethylene glycol chains) . Use i s thus made of PEG blocks, i. e. blocks formed from ethylene oxide units, PPG blocks, i . e . blocks formed from propylene oxide units, polytrimethylene glycol ether units (such copolymers with polytrimethylene ether blocks are described in patent US 6 590 065), and PTMG blocks, i . e. blocks formed from tetramethylene glycol units, al so known as polytetrahydrofuran. Use i s advantageously made of PEG blocks or of blocks obtained by oxyethylation of bi sphenol s, for instance bi sphenol A. The latter products are described in patent EP 613 919.

The polyether blocks may al so be formed from ethoxylated primary amines.

These blocks are al so advantageously used. As examples of ethoxylated primary amines, mention may be made of the products of formula:

H (OCH₂CH₂)_m— N (CH₂CH₂0)_u— H

(CH₂)_X CH₃

in which m and n are between 1 and 20, and x is between 8 and 1 8. These products are available commercially under the brand name Noramox® from the company Ceca and under the brand name Genamin® from the company Clariant.

The amount of polyether blocks in these copolymers bearing polyamide blocks and polyether blocks i s advantageously from 10% to 70% by weight and preferably from 35% to 60% by weight of the copolymer.

The polyether diol blocks are either used in unmodified form and copolycondensed with polyamide blocks bearing carboxylic end group s, or they are aminated to be converted into polyetherdiamines and condensed with polyamide blocks bearing carboxylic end group s. They may al so be mixed with polyamide precursors and a chain-limiting diacid to make polymers bearing polyamide blocks and polyether blocks having randomly di stributed units . The number-average molar mass Mn of the polyamide blocks i s between 500 and 10 000 and preferably between 500 and 4000, except for the polyamide blocks of the second type .

The mass Mn of the polyether blocks i s between 100 and 6000 and preferably between 200 and 3000.

These polymers bearing polyamide blocks and polyether blocks, whether they originate from the copolycondensation of polyamide and polyether blocks prepared previously or from a one-step reaction, have, for example, an intrinsic vi scosity of between 0.8 and 2.5 measured in meta- cresol at 25 °C for an initial concentration of 0.8 g/ 100 ml .

As regards the preparation of the copolymers bearing polyamide blocks and polyether blocks, they may be prepared via any means for attaching polyamide blocks and polyether blocks .

In practice, essentially two processes are used, one known as a two- step process, the other a one-step process.

In the two-step process, the polyamide blocks are first made, and in a second step the polyamide blocks and the polyether blocks are then attached.

In the one-step process, the polyamide precursors, the chain limiter and the polyether are mixed together; a polymer i s then obtained that has essentially polyether blocks and polyamide blocks of very variable length, but al so the various reagents that have reacted randomly, which are di stributed randomly (statistically) along the polymer chain.

Whether it is a one-step or a two-step process, it is advantageous to perform the process in the presence of a catalyst. The catalysts described in patents US 4 33 1 786, US 4 1 1 5 475 , US 4 195 01 5 , US 4 839 441 , US 4 864 014, US 4 230 83 8 and US 4 332 920, WO 04/037 898 , EP 1 262 527, EP 1 270 21 1 , EP 1 136 5 12, EP 1 046 675 , EP 1 057 870, EP 1 1 55 065 , EP 506 495 and EP 504 058 may be used. Polyamide blocks are al so manufactured in the one- step process .

Use will more particularly be made of copolymers bearing polyamide blocks (in particular PA-6 or PA- 12) and polyether blocks (in particular polyethylene glycol or polytetramethylene glycol ether) and even more particularly those sold under the name Pebax® by the company Arkema. Preferably, the polymer i s cho sen from the references Pebax® 2533 SA 01 , Pebax® 2533 SD 02, Pebax® 3533 SA 01 , and Pebax® 2533 SP 01 . Preferably, the polymer according to the invention i s the reference Peb ax® 2533 SA 01 .

Preferably, the polymer film i s formed from a cosmetic composition compri sing one or more film-forming polymers that are insoluble in water and soluble in an organi c solvent, especially those chosen from polymers of polyamide-polyether type .

More preferably still, the antiperspirant cosmetic film i s formed from a cosmetic composition containing one or more copolymers bearing polyamide blocks (in particular PA-6 or PA- 12) and polyether blocks .

The cosmetic composition containing one or more film-forming polymers may also contain one or more plasticizers .

By way of example, use may especially be made of the plasticizers described in document FR-A-2 782 9 17.

The cosmetic composition containing one or more film-forming polymers may al so contain one or more standard additives that are well known in the art, such as natural or synthetic thickeners or vi scosity regulators, surfactants, ceramides or pseudoceramides, sequestrants, solubilizers, proteins, reducing agents or antioxidants, oxidizing agents, vitamins or provitamins, cationic or amphoteric polymers, fragrances, pH stabilizers, preserving agents, moi sturizers, antiperspirant active agents, antibacterial agents, deodorizing active agents such as cyclodextrin, ab sorbent powders, dyes, depilatory agents or agents that prepare the hairs for depilation, or mixtures thereof.

In thi s way, the antiperspirant cosmetic film may contain the additives as described above.

In particular, the film may contain one or more surfactants whi ch may be released at the time of makeup removal to produce a washing or foaming effect.

Preferably, the surfactant(s) is (are) chosen from cationic, anioni c, nonionic, amphoteric or zwitterioni c surfactants .

For the purposes of the present invention, the term " cationi c surfactant" means a surfactant that i s positively charged when it i s contained in the composition according to the invention. Thi s surfactant may bear one or more positive permanent charges or may contain one or more cationizable functions in the composition according to the invention.

As examples of cationic surfactants, mention may be made especially of optionally polyoxyalkylenated primary, secondary or tertiary fatty amines, or salts thereof, and quaternary ammonium salts, and mixtures thereof.

Fatty amines generally compri se at least one C 8 - C 3 0 hydrocarbon- based chain. Among the fatty amines that can be used according to the invention, an example that may be mentioned i s stearyl amidopropyl dimethylamine.

Examples of quaternary ammonium salts that may especially be mentioned include :

- those that have the general formula (VIII) below : ^R8 \ ,^R10

N X-

R₉ R_n

(VIII) in which the R₈ to Rn radicals, which may be identical or different, represent a linear or branched aliphatic radical comprising from 1 to 30 carbon atoms, or an aromatic radical, such as aryl or alkylaryl, at least one of the R₈ to Rn radicals comprising from 8 to 30 carbon atoms, preferably from 12 to 24 carbon atoms. The aliphatic radicals may comprise heteroatoms especially such as oxygen, nitrogen, sulphur and halogens.

The aliphatic radicals are, for example, chosen from alkyl, alkoxy, polyoxy(C₂-Ce)alkylene, alkyl amide, (Ci₂-C₂₂)alkylamido(C₂-C6)alkyl, (Ci₂-C₂₂) lkyl acetate or hydroxyalkyl radicals comprising approximately from 1 to 30 carbon atoms; X^" is an anion chosen from the group of the halides, phosphates, acetates, lactates, (C₂-C₆)alkyl sulphates, and alkyl sulphonates or alkylaryl sulphonates;

- quaternary ammonium salts of imidazoline, such as, for example, those of formula (IX) below:

in which Ri₂ represents an alkenyl or alkyl radical comprising from 8 to 30 carbon atoms, for example derived from tallow fatty acids, Rn represents a hydrogen atom, a C₁-C₄ alkyl radical or an alkenyl or alkyl radical comprising from 8 to 30 carbon atoms, Ri₄ represents a C₁-C₄ alkyl radical, R15 represents a hydrogen atom or a C ₁ -C₄ alkyl radical and X^" is an anion chosen from the group of the halides, phosphates, acetates, lactates, alkyl sulphates, and alkyl or alkylaryl sulphonates . Preferably, R12 and Ri 3 denote a mixture of alkenyl or alkyl radi cal s comprising from 12 to 21 carbon atoms, for exampl e derived from tallow fatty acids, R14 denotes a methyl radical and R15 denotes a hydrogen atom. Such a product is sold, for example, under the name Rewoquat® W 75 by the company Rewo;

- di- or tri-quaternary ammonium salts, in particular of formula (X) :

++

^R17 ^R19

R ₁₆-N-(CH₂)₃-N-R 21 2X-

I I

R 18 R 20

(X) in which Ri ₆ denotes an alkyl radical containing approximately from 16 to 30 carbon atoms, which i s optionally hydroxylated and/or interrupted with one or more oxygen atom s and optionally branched, R17 i s selected from an alkyl radical containing from 1 to 4 carbon atoms or a group (Ri 6a) (Rl 7a) (Rl 8a)N -(CH₂)₃ -, Rl 6a, Rl 7a, R i 8a, Ri 8 , Ri 9 , R20 and R21 , which may be identical or different, are selected from hydrogen or an alkyl radical containing from 1 to 4 carbon atoms, and X^" i s an anion selected from the group of halides, acetates, phosphates, nitrates and methyl sulphates. Such compounds are, for example, Finquat CT-P, availabl e from the company Finetex (Quaternium 89), and Finquat CT, available from the company Finetex (Quaternium 75),

- quaternary ammonium salts containing at least one ester function, such as those of formula (XI) b elow:

in which:

R₂2 is chosen from Ci-C₆ alkyl radicals and Ci-C₆ hydroxyalkyl or dihydroxyalkyl radicals;

R₂3 is chosen from:

O II

- the radical R₂₆— C—

- radicals R₂₇, which are linear or branched, saturated or unsaturated Ci-C₂₂ hydrocarbon-based radicals;

- a hydrogen atom;

R₂5 is chosen from:

O II

- the radical R₂s— C—

- radicals R₂g, which are linear or branched, saturated or unsaturated Ci-C₆ hydrocarbon-based radicals;

- a hydrogen atom;

R₂4, R₂6 and R₂₈, which are identical or different, are chosen from linear or branched, saturated or unsaturated C₇-C₂i hydrocarbon radicals; r, s and t, which are identical or different, are integers having values from 2 to 6; y is an integer having a value from 1 to 1 0;

x and z, which are i dentical or different, are integers having values from 0 to 1 0;

X^" i s a simple or complex, organic or inorganic anion;

with the provi so that the sum x + y + z has a value from 1 to 1 5 , that, when x has a value of 0, then R₂₃ denotes R₂₇ and that, when z has a value of 0, then R₂₅ denotes R₂ g .

The alkyl radi cal s R₂₂ may be linear or branched, and more particularly linear.

Preferably, R₂₂ denotes a methyl, ethyl, hydroxyethyl or dihydroxypropyl radical and more particularly a methyl or ethyl radical.

Advantageously, the sum x + y + z has a value from 1 to 1 0.

When R₂₃ i s a hydrocarbon-based radical R₂₇, it may be long and have from 12 to 22 carbon atoms, or may be short and have from 1 to 3 carbon atoms .

When R₂₅ is a hydrocarbon-based radical R₂ g , it has preferably 1 to 3 carbon atoms .

Advantageously, R₂₄, R₂₆ and R₂₈, which are identical or different, are chosen from linear or branched, saturated or unsaturated C n -C_{2 1} hydrocarbon-based radicals, and more particularly from linear or branched, saturated or unsaturated C n -C_{2 1} alkyl and alkenyl radical s .

Preferably, x and z, whi ch are identical or different, have values of 0 or 1 .

Advantageously, y is equal to 1 .

Preferably, r, s and t, which are identical or different, have values of 2 or 3 and more particularly still are equal to 2.

The anion X^" i s preferably a halide (chloride, bromide or iodide) or an alkyl sulphate, more particularly methyl sulphate. However, it is possible to use methanesulphonate, phosphate, nitrate, tosylate, an anion derived from an organic acid, such as acetate or lactate, or any other anion that is compatible with the ammonium containing an ester function.

The anion X^" is even more particularly chloride or methyl sulphate.

Use is made more particularly in the composition according to the invention of the ammonium salts of formula (XI) in which:

- R22 denotes a methyl or ethyl radical;

- x and y are equal to 1;

- z is equal to 0 or 1;

- r, s and t are equal to 2;

- R23 is chosen from:

O II

- the radical R₂6— C—

- methyl, ethyl or C14-C22 hydrocarbon-based radicals;

- a hydrogen atom;

- R25 is chosen from:

O II

- the radical R₂s— C—

- a hydrogen atom;

- R24, R26 and R28, which are identical or different, are chosen from linear or branched, saturated or unsaturated C₁₃-C₁₇ hydrocarbon-based radicals and preferably from linear or branched, saturated or unsaturated C13-C17 alkyl and alkenyl radicals.

The hydrocarbon-based radicals are advantageously linear.

Mention may be made, for example, of the compounds of formula (XI) such as diacyloxyethyldimethylammonium, diacyloxyethylhydroxy- ethyl methyl ammonium, mo no acyloxyethyldi hydroxy ethyl methyl- ammonium, triacyloxyethylmethylammonium or monoacyloxyethyl- hydroxyethyldimethylammonium salts (chloride or methyl sulphate, in particular), and mixtures thereof. The acyl radi cal s preferably have from 14 to 1 8 carb on atoms and originate more particularly from a vegetable oil, such as palm oil or sunflower oil . When the compound contains several acyl radical s, these radical s may be identical or different.

These products are obtained, for example, by direct esterification of triethanolamine, trii sopropanolamine, alkyldiethanolamine or alkyldii sopropanolamine, which are optionally oxyalkylenated, with fatty acids or with mixtures of fatty acids of plant or animal origin, or by transesterification of the methyl esters thereof. Thi s esterifi cation i s followed by a quaternization using an alkylating agent such as an alkyl (preferably methyl or ethyl) halide, a dialkyl (preferably dimethyl or diethyl) sulphate, methyl methanesulphonate, methyl para- toluenesulphonate, glycol chlorohydrin or glycerol chlorohydrin.

Such compounds are, for example, sold under the names Dehyquart^® by the company Henkel, Stepanquat^® by the company Stepan, Noxamium^® by the company Ceca or Rewoquat^® WE 1 8 by the company Rewo-Witco .

The film preferably contains a mixture of quaternary ammonium monoester, diester and triester salts with a weight maj ority of diester salts .

Examples of mixtures of ammonium salts that may be used include the mixture containing 1 5 % to 30% by weight of acyloxyethyldihydroxy- ethylmethylammonium methyl sulphate, 45% to 60% of diacyloxyethyl- hydroxy ethylmethylammonium methyl sulphate and 1 5 % to 30% of triacyloxyethylmethylammonium methyl sulphate, the acyl radi cal s containing from 14 to 1 8 carbon atoms and originating from palm oil that i s optionally partially hydrogenated. It is also possible to use the ammonium salts containing at least one ester function that are described in patents US-A-4 874 554 and US-A-4 137 180.

Preferably, the cationic surfactant(s) is (are) chosen from the compounds of formula (VIII) or (XI).

Preference is given, among the quaternary ammonium salts of formula (VIII), on the one hand, to tetraalkylammonium chlorides, such as, for example, dialkyldimethylammonium or alkyltrimethylammonium chlorides in which the alkyl radical comprises approximately from 12 to 22 carbon atoms, in particular behenyltrimethylammonium chloride, distearyl- dimethylammonium chloride, cetyltrimethylammonium chloride or benzyl- dimethylstearylammonium chloride, or else, on the other hand, to distearoylethylhydroxyethylmethyl ammonium methosulphate, dipalmitoyl- ethylhydroxyethylammonium methosulphate or distearoylethyl- hydroxyethylammonium methosulphate, or else, finally, to palmitylamido- propyltrimethylammonium chloride or stearamidopropyldimethyl(myristyl acetate)ammonium chloride, sold under the name Ceraphyl® 70 by Van Dyk.

Among all the cationic surfactants, it is preferred to select the cationic surfactant(s) from among cetyltrimethylammonium (INCI: cetrimonium), behenyltrimethylammonium (INCI: behentrimonium), dip almitoylethylhydroxyethylmethyl ammonium, distearoylethyl- hydroxyethylmethyl ammonium, methyl (C9-Ci9)alkyl(Cio-C2o)alkyl- amidoethylimidazolium and stearamidopropyldimethylamine salts (preferably chloride or methosulphate), and the stearamidopropyldimethyl- ammonium salt, and mixtures thereof.

When they are present, the amount of the cationic surfactant(s) preferably ranges from 0.01% to 20% by weight and better still from 0.1% to 5 % by weight rel ative to the total weight of the composition resulting in the polymer film.

The expression " anionic surfactant" means a surfactant comprising, as ionic or ionizable groups, only anionic groups . These anionic groups are preferably chosen from C0₂H, C0₂ ^", S0₃H, S0₃ ^", O S0₃H, O S0₃ ^", H₂P0₃ , HP0₃ ^", P0₃ ^{2 "}, H₂P0₂, HP0₂, HP0₂ ^", P0₂ ^", POH and PO ^" groups .

As examples of anioni c surfactants, mention may be made of alkyl sulphates, alkyl ether sulphates, alkylamido ether sulphates, alkylaryl polyether sulphates, monoglyceride sulphates, alkyl sulphonates, alkylamide sulphonates, alkylaryl sulphonates, a-olefin sulphonates, paraffin sulphonates, alkyl sulphosuccinates, alkyl ether sulphosuccinates, alkylamide sulpho succinates, alkyl sulphoacetates, acyl sarcosinates, acyl glutamates, alkyl sulphosuccinamates, acyl isethionates and N- acyltaurates, salts of alkyl monoesters of polyglycoside-polycarb oxyli c acids, acyl lactylates, D-galactoside uronic acid salts, alkyl ether carboxylic acid salts, alkylaryl ether carboxylic acid salts, alkylamido ether carboxylic acid salts ; and the corresponding non-salified forms of all these compounds; the alkyl and acyl groups of all these compound s compri sing from 6 to 24 carbon atoms and the aryl group denoting a phenyl group .

These compounds may be oxyethylenated and then preferably compri se from 1 to 50 ethylene oxide units.

The salts of C₆-C₂4 alkyl monoesters of polyglycoside- polycarb oxylic acids can be selected from C₆-C₂4 alkyl polyglycoside- citrates, C₆-C₂4 alkyl polyglycoside-tartrates and C₆-C₂4 alkyl poly glycoside- sulphosuccinates .

When the anioni c surfactant(s) (ii) is (are) in salt form, it (they) may be chosen from alkali metal salts such as the sodium or potassium salt and preferably the sodium salt, the ammonium salts, the amine salts and in particular the amino alcohol salts or the alkaline-earth metal salts such as the magnesium salt.

Examples of amino alcohol salts that may especially be mentioned include monoethanolamine, di ethanolamine and triethanolamine salts, monoi sopropanolamine, dii sopropanolamine or trii sopropanolamine salts, 2-amino-2-methyl- l -propanol salts, 2 -amino-2-methy 1- 1 , 3 -propanediol salts and tris(hydroxymethyl)aminomethane salts.

Alkali metal or alkaline-earth metal salts, and in particular sodium or magnesium salts, are preferably used.

Among the anionic surfactants, it is preferred, according to the invention, to use alkyl sulphate salts and alkyl ether sulphate salts and mixtures thereof.

When they are present, the amount of the anionic surfactant(s) i s preferably within the range from 0. 1 % to 3 .5% by weight, relative to the total weight of the composition resulting in the polymer film .

Examples of additional nonionic surfactants that may be used in the compositions of the present invention are described, for example, in the Handbook of Surfactants by M.R. Porter, publi shed by Blackie & Son (Glasgow and London), 1991 , pp . 1 16- 178. They are especially chosen from alcohol s, a-diols and (C i_2 o)alkylphenol s, these compounds being polyethoxylated, polypropoxylated or polyglycerolated and containing at least one fatty chain compri sing, for example, from 8 to 1 8 carbon atoms, the number of ethylene oxi de or propylene oxide groups possibly ranging in particular from 2 to 50, and the number of glycerol groups possibly ranging in particular from 2 to 30.

Mention may al so be made of condensates of ethylene oxide and of propylene oxide with fatty alcohol s; polyethoxylated fatty amides preferably having from 2 to 30 ethylene oxide units, polyglycerolated fatty amides containing on average 1 to 5, and in particular 1.5 to 4 glycerol groups, ethoxylated fatty acid esters of sorbitan containing from 2 to 30 ethylene oxide units, fatty acid esters of sucrose, fatty acid esters of polyethylene glycol, (C₆-24 alkyl)polyglycosides, N-(C₆-24 alkyl)glucamine derivatives, amine oxides such as (C_10-14 alkyl)amine oxides or N(C_10-14 acyl)aminopropylmorpholine oxides.

When they are present, the amount of the additional nonionic surfactant(s) is preferably within the range from 0.1% to 3.5% by weight, relative to the total weight of the composition resulting in the formation of polymer film.

The amphoteric or zwitterionic surfactant(s) that can be used in the present invention may especially be optionally quaternized secondary or tertiary aliphatic amine derivatives, in which the aliphatic group is a linear or branched chain containing from 8 to 22 carbon atoms, said amine derivatives containing at least one anionic group such as, for example, a carboxylate, sulphonate, sulphate, phosphate or phosphonate group. Mention may be made in particular of (C8-C2o)alkylbetaines, sulphobetaines, (C₈-C2o alkyl)amido(C3-₈ alkyl)betaines or (C₈-C2o alkyl)amido(C6-C₈ alkyl)sulphobetaines. Among the optionally quaternized secondary or tertiary aliphatic amine derivatives that can be used, as defined above, mention may also be made of the compounds of respective structures (Al) and (A2) below:

R_a-CONHCH2CH2-N⁺(Rb)(Rc)(CH₂COO^") (Al) in which:

R_a represents a C10-C30 alkyl or alkenyl group derived from an acid Ra-COOH preferably present in hydrolysed coconut oil, a heptyl group, a nonyl group or an undecyl group, R_b represents a β-hydroxyethyl group, and

R_c represents a carboxymethyl group; and

R_a'-CONHCH₂CH₂-N(B)(B') (A2) in which:

B represents -CH₂CH₂OX',

B' represents -(CH₂)_Z-Y', with z = 1 or 2,

X' represents the group -CH₂-COOH, CH₂-COOZ\ -CH₂CH₂- COOH, -CH₂CH₂-COOZ', or a hydrogen atom,

Y^* represents -COOH, -COOZ', the group -CH₂-CHOH-S0₃H or -CH₂-CHOH-S0₃Z',

Z' represents an ion derived from an alkali metal or alkaline-earth metal, such as sodium, an ammonium ion or an ion derived from an organic amine,

Ra' represents a Cio-C₃₀ alkyl or alkenyl group of an acid Ra'- COOH which is preferably present in coconut oil or in hydrolysed linseed oil, or an alkyl group, especially a C₁₇ group, and its iso form, or an unsaturated C₁₇ group.

These compounds are classified in the CTFA dictionary, 5th edition, 1993, under the names disodium cocoamphodiacetate, disodium lauroamphodiacetate, disodium caprylamphodiacetate, disodium capryloamphodiacetate, disodium cocoamphodipropionate, disodium lauroamphodipropionate, disodium caprylamphodipropionate, disodium capryloamphodipropionate, lauroamphodipropionic acid and cocoampho- dipropionic acid. By way of example, mention may be made of the cocoamphodiacetate sold by the company Rhodia under the trade name Miranol^® C2M Concentrate.

Among the amphoteric or zwitterionic surfactants mentioned above, use is preferably made of (C₈ -2o alkyl)betaines and (C_{8 -}2o alkyl)amido(C6 -₈ alkyl)b etaines, and mixtures thereof.

When they are present, the amount of the amphoteric or zwitterionic surfactant(s) is preferably within the range from 0. 1 % to 3 .5 % by weight, relative to the total weight of the composition resulting in the polymer film .

Preferably, the cosmetic composition compri ses one or more cationic surfactants .

Even more preferentially, the cationic surfactant(s) is (are) chosen from the compounds of formul a (I) or (IV) and more particularly from cetyltrimethylammonium and b ehenyltrimethylammonium salts .

The composition compri sing the film-forming polymer(s) may al so compri se one or more organic solvents such as lower C ₁ -C₄ alcohol s, in particular C2 - C3 monoalcohol s and especially ethanol.

The polymer material may al so compri se one or more agents capable of increasing its mechanical strength, especially fibres .

According to one particular embodiment, the polymer material contains a fibre framework, such as a woven fabric framework. The fibres may be thin or transparent and have the same refractive index as the cosmetic film.

The polymer film may compri se one or more layers of polymers .

According to one particular embodiment, the film may compri se a layer of a polymer that can be solubilized in a solvent and a layer constituted of a more resi stant material that cannot be solubilized. According to one particular embodiment, the film, especially it s outer surface, may be treated so as to render its surface non- shiny and with an appearance close to that of the skin.

In the particular case of films in which the polymer i s water- soluble, it will be possible to cover the outer face of the film with a protective sub stance.

As indicated previously, the cosmetic polymer film according to the present invention may be partially di ssolved before, during or after its application to the skin.

Preferably, the cosmetic treatment method according to the invention compri ses a step consi sting in applying to the skin a cosmetic composition containing one or more cosmeti cally acceptable solvents, then a step consisting in applying, to the area of the skin treated with said solvent(s), an antiperspirant cosmetic polymer film so that said film adheres to the skin, said film being partially di ssolved at the time of its application to the skin.

According to one preferred embodiment, the cosmetic treatment method compri ses a step consi sting in applying to the skin a cosmetic composition comprising ethanol and a step consi sting in applying, to the area of the skin treated with the ethanol, an antiperspirant cosmetic polymer film obtained from a cosmetic composition comprising one or more water-insoluble polymers chosen from polymers of the polyamide- polyether type, in particular those chosen from copolymers bearing polyamide blocks (in particular PA-6 or PA- 12) and polyether blocks so that sai d film adheres to the skin, said film being partially di ssolved at the time of its application to the skin.

The film thus applied to the skin may be removed by applying water or an organic solvent. The cosmetic treatment method according to the present invention may be used on the face or the body, especi ally in the area of the armpits .

The film may compri se two protective faces. The first face may aid the appli cation of the film and the second face makes it possibl e to protect the face of the film that is intended to come into contact with the skin.

The film may be present on an applicator or a reel.

According to one emb odiment, use may be made of a device capable of bringing the film into contact with the composition containing the solvent(s) so that the film i s partially di ssolved. The film i s then applied to the skin manually or automatically using the device.

The device may compri se two parts, namely a film reel and a foam roller that may apply the cosmetic composition containing the solvent(s) .

During the start-up of the device, the film reel is moved so as to bring the foam roller into contact with the cosmetic film in order to impregnate the cosmetic film with the composition containing the solvent(s) and to partially dissolve the film .

In particular, during the movement of the reel, the portion of film that comes into contact with the foam roller i s solubilized, especially at the inner face of the film .

EXAMPLE

Example 1

A composition containing 5% by weight of a block copolymer of polyamide-polyether type sold under the name Pebax 2533 SA 0 1 (available from the company ARKEMA), in ethanol, is prepared. The composition is placed in a sealed flask, and it is heated at 60°C for 4 weeks in order to obtain a good solubilization of the copolymer in the ethanol.

The composition is applied to a smooth, porous and non-adhesive support so as to produce a film having a thickness of 5 μιη . The film i s left laying on its support (a sheet of baking parchment paper) .

Ethanol i s applied to the skin, then the film, with its support, i s applied to the area of the skin that was treated with the ethanol, before the solvent evaporates . During the application of the film to the skin, a portion of the film solubilizes and leads to the adhesion of the film to the skin.

Sauna tests show that a better blocking of perspiration is obtained than with the same composition containing the block copolymer of polyamide-polyether type sold under the trade name Pebax 2533 SA 01 applied straight to the skin. It is ob served that the film lasts well over the entire day . Example 2

A composition containing 5% by weight of a polymer of polyamide- polyether type sold under the name Pebax 2533 SA 01 , in ethanol, i s prepared.

The composition is applied to a flat box made of Teflon, equipped with a system for removing the sides .

After drying, a film having a thickness of 5 μιη is obtained. The film i s detached and carefully laid on a sheet of parchment paper.

Ethanol i s applied to the skin, then the film, with its support, i s applied to the area of the skin that was treated with the ethanol, before the solvent evaporates . During the application of the film to the skin, a portion of the film solubilizes and leads to the adhesion of the film to the skin.

Sauna tests show that a better blocking of perspiration is obtained than with the same composition containing the block copolymer of polyamide-polyether type sold under the trade name Pebax 2533 SA 01 applied straight to the skin. It is ob served that the film lasts well over the entire day .

Example 3

The same test as Example 1 is carried out, except that the formulation placed on the skin al so contains 5 % of an adhesive (AQ 1 350 from the company Eastman Chemical s) . Other tests were carried out by detaching the film from its support and it was ob served that the process led to an effective blocking of the perspiration being obtained.

Claims

1 . Method for the cosmetic treatment of human perspiration and optionally body odours linked to human perspiration, especially auxiliary odours, characterized in that it compri ses :

(i) a step consi sting in applying an antiperspirant cosmetic polymer film to the skin, and

(ii) a step consi sting in partially di ssolving said film on contact with a cosmetic composition containing one or more cosmetically acceptable solvents prior to, during or sub sequent to the application of said film to the skin so that said film adheres to the skin.

2. Cosmetic treatment method according to Claim 1 , characterized in that the cosmetic composition contains one or more solvents chosen from water or organic solvents .

3 . Cosmetic treatment method according to Claim 2, characterized in that the organic solvent or solvents are chosen from alcohols such as ethanol, isopropanol, benzyl alcohol, phenylethyl alcohol, the alcohol 1 ,2, 3 -propanetriol or glycols or glycol ethers such as, for example, ethylene glycol monomethyl, monoethyl and monobutyl ethers, propylene glycol, butylene glycol, dipropylene glycol, and al so diethylene glycol monobutyl ether.

4. Cosmetic treatment method according to any one of Claims 1 to 3 , characterized in that the film is produced from a polymer material that i s obtained from a cosmeti c composition containing one or more film-forming polymers.

5. Cosmetic treatment method according to Claim 4, characterized in that the film-forming polymer(s) is (are) water-soluble or water- di spersible.

6. Cosmetic treatment method according to Claim 4, characterized in that the film-forming polymer(s) i s (are) chosen from polymers that are insoluble in water and solubl e in an organic solvent.

7. Cosmetic treatment method according to Claim 6, characterized in that the film-forming polymers are chosen from (meth)acrylate polymers or copolymers, polyurethanes, polyamides, polyesters, polymers of polyamide-polyether type and mixtures thereof.

8. Cosmetic treatment method according to Claim 7, characterized in that the polymers of polyamide-polyether type are chosen from copolymers bearing polyamide blocks and polyether blocks and even more particularly copolymers bearing polyamide-6 or polyamide- 12 blocks and polyethylene glycol or polytetramethyl ene glycol blocks .

9. Cosmetic treatment method according to any one of the preceding claims, characterized in that the film al so has one or more surfactants .

10. Cosmetic treatment method according to any one of the preceding claims, characterized in that the film i s solubilized in an amount ranging from 5% to 20% by weight relative to the total weight of the film .

1 1 . Cosmetic treatment method according to any one of the preceding claims, characterized in that it comprises :

a step consi sting in applying to the skin a cosmetic composition containing one or more cosmetically acceptable solvents, then

- a step consi sting in applying, to the area of the skin treated with said solvent(s), an antiperspirant cosmetic polymer film so that said film adheres to the skin, said film being partially di ssolved at the time of its application to the skin.

12. Cosmetic treatment method according to any one of Claim s 1 to 10, characterized in that it compri ses :

a step consi sting in applying an antiperspirant cosmetic polymer film to the skin, then

a step consi sting in applying, to the area of the skin covered by said film, a cosmetic composition comprising one or more cosmetically acceptabl e solvents so that said film adheres to the skin,

said film being partially di ssolved after its appli cation to the skin.

13 . Cosmetic treatment method according to any one of Claim s 1 to 10, characterized in that it compri ses :

a step consi sting in bringing an antiperspirant cosmetic polymer film into contact with a cosmetic composition comprising one or more cosmetically acceptable solvents so as to partially di ssolve said film, and a step consi sting in applying said film to the skin.