MXPA99010679A - Brush for nail enamel and nail enamel application set with talpin - Google Patents

Abstract

The invention relates to a brush for the application of a make-up or toilet product, comprising a bundle (2) of hairs (3) substantially parallel, a first end of these hairs (3) being fixed at one end (4a) ) free of a handle (4), the hairs (3) of the beam (2) being impregnated on the surface with a partially acetylated polyvinyl alcohol which comprises at least units of formula (I) and (II) :( See Formula) where the units of formulas (II) are presented in proportions of between 3 and 40% in mol relative to the polymer, said polyvinyl alcohol having a weight average molecular weight of between 10,000 and 190,000. The subject invention also has the method of treating the hairs of the brush beam, as well as a nail polish application assembly comprising such a fingernail.

Description

BRUSH FOR ENAMEL OF ONE AND SET OF APPLICATION OF NAIL ENAMEL EQUIPPED WITH SUCH BRUSH The present invention relates to a brush for the application of a makeup or toilet product such as an enamel or a product for the care of the nails, a liquid blusher for the lips or a liquid makeup base, of the type of what comprise hairs arranged substantially parallel to each other forming a beam, and fixed on a support that we will call the handle of the brush.

Nail polishes are generally 1 packaged in an application set consisting of a container with a neck and a plug attached to ur. application brush submerged, in conservation position, inside the product that constitutes the nail polish ccnter.iac er. the container. For a good application of nail polish, it is important that the hair of the brush be uniform, in order to deposit a regular layer of nail polish on the nails. Ar.cra well, in the course of - > <; crar.spcrte and the storage of the brush before its ^: 32078 packaged with the container containing the enamel product, the hair bundle can be deformed, for example by bending or bending one or more hairs of the bundle; Then the hairs are separated and they stop forming a homogeneous beam. Such a deformed beam does not allow a regular application of the product on the nails; In addition, the brush remains in a state that is difficult to introduce through the neck of the container, thus damaging the good development of the industrial process of enamel packaging.

In order to avoid deformation of the hair bundle, it is possible to treat it, prior to its packaging in the container, by impregnation with a solution of fumaric polymer, called a reinforcing solution. After drying, a deposit of the smoke polymer remains on the surface of the hairs, preventing them from deforming or separating; the hairs are thus reinforced.

The reinforcing solution must be sufficiently fluid to allow rapid impregnation of the hair bundle. The solution must be able to impregnate a sufficient part of the beam by capillarity to ensure good conservation of the beam. The solution, after being deposited on the beam, should be dried quickly to leave on the beam a deposit of nonadherent polymer, which does not crumble, not rigid and not brittle. The polymer deposit must be able to dissolve quickly when the hair bundle is immersed in the nail polish product, without disturbing the cosmetic properties of the product, nor destabilizing it.

Nitrocellulose is one of the smoke-forming polymers most commonly used in nail enamels in organic solvent. For these enamels, the reinforcing solution is a solution of icrocellulose and plasticizing agent. Nail enamels are also known in an aqueous medium comprising smoke-polymer particles dispersed in the aqueous medium, as described for example in EP-A-648485; In these products, the smoke polymer in the state of dispersed particles is insoluble in water. To treat brushes intended for the application of enamel in water, it is possible to use as a reinforcing solution an aqueous solution containing a water-soluble polymer. This water-soluble polymer is of a different nature from that of the smoke-insoluble polymer in the water present in the enamel product. Contrary to the enamels in solvent medium comprising nitrocellulose, it is difficult to treat the hair bundle of the brush with the same smoke polymer present in the enamel product.

The object of the present invention is therefore to propose a reinforced brush suitable for the application of nail polish in an aqueous medium.

Surprisingly, the Applicant has found that such a brush could be obtained by using a particular polyvinyl alcohol to reinforce the hair bundle. This polymer dissolves easily in the water and allows to obtain a fluid aqueous solution that allows a fast impregnation of the hair bundle; the. The aqueous solution deposited on the hair bundle dries quickly and leaves a non-sticky deposit on the hairs, which does not crumble. The hairs thus treated remain sufficiently flexible and without separating, and form a homogeneous beam, even after compressions for the transport and storage of the brush before packaging. In addition, after placing the brush on the enamel container, the polymer deposit rapidly dissolves in the enamel product containing water, without modifying the cosmetic properties of the enamel, nor destabilizing the product.

More precisely, the invention has as its object a brush for the application of a make-up or toilet product in general, comprising a bundle of substantially parallel hairs, a first end of these hairs being fixed on a free end of a handle or rod. , characterized in that the hairs of the beam are impregnated on the surface with a partially acetylated polyvinyl alcohol comprising at least units of the formulas (I) and (II): wherein the units of formula (II) are present in proportions of between 3 and 40 mol% relative to the polymer, said polyvinyl alcohol having a weight average molecular weight of between 10,000 and 190,000.

Another subject of the invention is a method for coating the hairs of a brush beam for the application of a make-up product, comprising a bundle of substantially parallel hairs, a first end of these hairs being fixed at a free end thereof. a handle, characterized in that at least a part of the hair bundle is contacted with an aqueous composition comprising a polyvinyl alcohol as defined above, and that the hair bundle is removed from the composition and left to dry .

Another object of the invention is a brush for the application of a makeup product capable of being obtained according to the procedure defined above.

The invention also has as an object an application assembly of enamel product or of care of the ones constituted by a container provided with a neck and a plug integral with a brush as it is defined above, submerged, in conservation position, in a nail polish product, which comprises an aqueous medium contained in this container.

Another object of the invention is an enamel or nail care product application set consisting of a container provided with a neck and a plug integral with a brush, submerged, in a conservation position, in an enamel product or of care of the nails contained in this container, characterized in that said product comprises an aqueous medium containing at least one polyvinyl alcohol as defined above.

The polyvinyl alcohol used according to the invention has a weight-average molecular weight of between 10,000 and 190,000, preferably from 10,000 to 120,000, and better still from 31,000 to 50,000, in order to obtain a sufficiently fluid reinforcing solution in order to be able to impregnate the bundle with capillarity. brush hairs.

Advantageously, the units of formula (II) can be present in the polyvinyl alcohol in a proportion of 10 to 15 mol%.

In a preferred embodiment of the invention, the polyvinyl alcohol consists essentially of units of formulas (I) and (II). As the polyvinyl alcohol usable according to the invention, those sold under the names "AIRVOL 203", "AIRVOL 205", "AIRVOL 6108", "AIRVOL 523", "AIRVOL 540" by the AIR PRODUCTS CHEMICAL Company can be used, " RHODOVIOL 4/125"," RHODOVIOL 14/135"," RHODOVIOL 25/140"by the Company RHONE POULENC," MO IOL 4-88"," MOWIOL 40-18"," MO IOL 18-88"by the Company HOECHST, "ELVANOL 51-05", "ELVANOL 52-22" by the DUPONT Company.

The hairs of the beam can be of a material chosen from polyamides, polyesters, polyether-block-amides, polyethylene, polytetrafluoroethylene, vinylidene polyfluoride, polyvinyl chloride, viscose, rayon, polyacetals, natural silks, or their mixtures.

The hairs constituting the brush can preferably have a section inscribed in a circle [f) of diameter between, for example, 4/100 and 40/100 of mm. According to a variant embodiment of the invention, the hair bundle may comprise a mixture of small-section hairs, or hairs, and hairs of more important cross-section or thick hairs, which may be the proportion of coarse hairs of 2 to 95% by volume, in relation to the total volume of the hair bundle of the brush, and preferably from 10 to 90%. In particular, the hairs may have an inscribed section from 4/100 to 10/100 of mm and the thick hairs may have an inscribed section from 11/100 to 40/100 mm.

Advantageously, the hair bundle of the brush can have a length of 5 to 25 mm and preferably a length of between 13 and 20 mm.

According to an interesting aspect of the invention, the hairs have a first end obtained by folding a fiber bundle into a U-shape, the base of the U being held by a staple inserted in a housing made in the free end of the handle of the brush. Advantageously, this housing can be a cylinder of revolution. It can also be considered the configuration in oval, elongated, cruciform, or in the form of tile is i-round. This housing may be flared toward the free end of the handle. The fixing of the hair bundle in this housing can also be effected by gluing or by any other means usually used for the manufacture of brushes, for example by a ferrule. The number of hairs constituting the beam can advantageously be from 100 to 600.

The constituent material of the hairs can advantageously contain an agent modifying its surface state and / or its sliding characteristics and / or reducing its wettability in the water and / or in the solvent contained in the makeup product and in particular in the enamel, or an antistatic agent.

Advantageously, the agent for improving the hair sliding characteristic and reducing its wettability in water can be incorporated into the constituent material of the hairs in a proportion of 0.2 to 15% by weight.

This slip agent can preferably be selected from the group consisting of polytetrafluoroethylene, boron nitride, molybdenum disulphide, graphite, silicones, fullerene, talc.

Advantageously, a part of the hairs at least may have slight undulations in their length. The hairs may have cross-sections whose shape has been chosen within the group of circular, annular, polygonal, cruciform, rectangular, polylebic, U-shaped, C-shaped or V-shaped shapes, and shapes comprising at least one capillary slot .

The free end of the bristles constituting the brush can be arranged in the form of a pinhead, obtained in particular by heat treatment, for example by flaming. The free end of the hairs can also be pointed, which will be obtained for example by grinding or carding.

The brush cross section can have different shapes; in particular, the beam may have a circular section, a section in the form of a semi-round tile, an oval or cruciform section. On the other hand, the hairs can have different lengths. In particular, the free end of the brush can be flat or rounded.

Brushes that can be used according to the invention are described, in particular, in EP-A-556081, EP-A-581922, EP-A-651955 and EP-A-673612, the content of which is incorporated in the present application as reference .

To obtain the brush according to the invention, at least a part, or even all, of the hair bundle of the brush is contacted with an aqueous composition comprising polyvinyl alcohol as defined above. Advantageously, half the length of the hair bundle can be submerged in the composition; it is also possible to rub the end of the hair bundle with the composition for a sufficient time so that it is impregnated by capillarity. The contact time can be relatively short and in particular less than or equal to 5 seconds; You can even proceed to an instant dive.

When the polyvinyl alcohol is dissolved perfectly in the water, the aqueous composition used in the process according to the invention, called a reinforcing solution, is presented in the form of an aqueous solution of said polyvinyl alcohol.

Preferably, the polyvinyl alcohol can be present in the composition with a content of 0.1 to 10% by weight, and preferably of 0.5 to 5% by weight, relative to the total weight of the composition, to allow obtaining a very fluid solution that favors a good impregnation of the hair bundle.

After impregnation, the brush is removed from the reinforcing solution and allowed to dry until the deposit of polymer deposited on the hairs is dry. The drying can be carried out in the ambient air or by means of a source of heat or pulsed air (fan).

In order to improve the drying time of the reinforcing solution after the impregnation of the hair bundle, the reinforcing solution may further comprise at least one lower C2-C5 alcohol, and in particular ethanol. The lower alcohol content in the composition can be from 0 to 80% by weight, relative to the total weight of the composition, and preferably from 40 to 70% by weight.

The reinforcing solution may further comprise a wetting agent to lower the surface tension of the solution and to promote good impregnation of the bristles of the brush. As the wetting agent, it is possible, for example, to use a dimethicone copolyol. The wetting agent can be present in particular in a proportion of between 0.1 and 15% by weight, based on the total weight of polyvinyl alcohol, and preferably 0.5 to 5% by weight.

The dimethicone copolyol can be chosen from the compounds of general formula (III): (neither) formula in which: -Ri, identical or different, represent a hydrogen atom, a linear or branched alkyl radical in C? C30 or a phenyl radical, -R2, identical or different, represent - (CxH2x,) - (OC2H4,) 8- (OC3H6) b-OR3, - R ^, identical or different, are chosen from a hydrogen atom, a alkyl radical, linear or branched, with 1 to 12 carbon atoms, an acyl radical, linear or branched with 2 to 12 carbon atoms, - n varies from 0 to 1000, - p varies from 1 to 30, - a varies from 0 to 50, - b varies from 0 to 50, - a + b is greater than or equal to 1, - x varies from 1 to 5 , - the number average molecular weight being greater than or equal to 15,000 and preferably between 25,000 and 75,000.

Preferably, the oxyalkylenated silicones of general formula (III) are used which respond to at least one of the following conditions and preferably to all of them: - Ri, designates the methyl radical, - R3, represents a hydrogen atom, a radical methyl or an acetyl radical, and preferably hydrogen, - p varies from 8 to 20, - a is between 5 and 40 and preferably between 15 and 30, - b is between 5 and 40 and preferably between 15 and 30 , - x is equal to 2 or 3, - n varies from 20 to 600, preferably from 50 to 500 and more particularly from 100 to 300. Such silicones are described, for example, in US Pat. No. 4,311,695, which is included in the title. reference.

Copolyol labels were presented in particular by the Dow Corning Society during the 17th International Congress of the I.F.S.C.C. October 1992 and consigned in the article "Water-soluble dimethicone copolyol waxes for personal care industry" by Linda Madore et al., pages 1 to 3.

These dimethicones copolyols are polydimethylsiloxanes (PDMS) comprising one or more functions of ethers, soluble in water (oxyalkylene, particularly oxyethylene and / or oxypropylene).

Such dimethicones copolyols are in particular sold by the company GQLDSCHMIDT under the name ABIL B8851 or ABIL B88183. We can also mention the compounds KF 351 to 354 and KF 615 A sold by the SHIN ETSU Company or the DMC 6038 of the WACKER Company.

The dimethicone copolyol derivatives which can be used can be, in particular, the dimethicones copolyols with phosphate group, sulfate, myristamide propyldimethylammonium chloride, stearate, amine, glyco-modified, etc. Dimethicone copolyols can be used as derivatives, in particular the compounds extended by the company SILTECH under the designation Silphos A100, Siltech amine 65, Silwax WDIS, myristamido silicone quat, or by the company PHOENIX under the name Pecosil PS 100.

The derivatives expanded by the company WACKER under the name VP 1661, or by the company DOW CORNING under the name 2501 cosmetic wax can also be used. You can also use the derivatives sold by the company WACKER under the name VP 1661, or by the company DOW CORNING under the name 2501 cosmetic wax.

The most particularly preferred silicones are, for example, those sold by the company Dow Corning under the trade name Q2-5220 and by the company Rhone Polenc under the name MIRASIL DMCO.

The brush according to the invention is particularly adapted for the packaging and application of enamel product or nail care, comprising an aqueous medium. The enamel or nail care application assembly comprises a container provided with a neck and a plug integral with a brush as defined above, submerged, in the conservation position, in an enamel or care product. the nails comprising an aqueous medium contained in this container.

After mounting the brush on the container, the polyvinyl alcohol present on the surface of the brush hairs easily dissolves in the aqueous product of enamel or nail care. This product thus packaged with the application assembly thus contains, in the aqueous medium, the dissolved polyvinyl alcohol which can be present in a proportion of 0.005 to 0.5% by weight, based on the total weight of the product.

The cosmetic enamel or nail care products generally comprise at least one fumaric polymer, insoluble in water, in the form of particles dispersed in the aqueous medium, this polymer being insoluble in water, therefore it is chemical in nature. different from the water-soluble polyvinyl alcohol used to treat the brush that is defined.

As the smoke polymer, the synthetic polymers, of the radical type or of the polycondensate type, the polymers of natural origin, and their mixtures can be used in a known manner.

By "radical-fuming polymer" is meant a polymer obtained by polymerization of particularly ethylenic unsaturation monomers, each monomer being able to homopolymerize (unlike polycondensates).

The fumidogenic polymers of the radical type can be in particular vinyl polymers or copolymers, particularly acrylic polymers.

The vinyl fumido polymers can result from the polymerization of ethylenically unsaturated monomers having at least one acid group and / or esters of these acid monomers and / or amides of these acidic monomers.

As the monomer carrying the acid group, unsaturated α, β-ethylenic carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid can be used.

The acidic monomeric esters can be chosen from the esters of (meth) acrylic acid (also called) (meth) acrylates), in particular alkyl (meth) acrylates, in particular C 1 -C 20 alkyl. (meth) acrylates of aryl, in particular of aryl in Ce-Cι, (meth) acrylates of hydroxyalkyl, in particular of hydroxyalkyl in C 2 -C 6.

As amides of the acid monomers, mention may be made, for example, of the (meth) acrylamides, and in particular the N-alkyl (meth) acrylamides, in particular C 2 -C 2 alkyl.

The smoke-modified vinyl polymers can also result from the homopolymerization or the copolymerization of monomers selected from vinyl esters and styrenic monomers. In particular, these monomers can be polymerized with acidic monomers and / or their esters and / or amides, such as those mentioned above.

As an example of vinyl esters, mention may be made of vinyl acetate, vinyl neodecanoate, vinyl pivalate, vinyl benzoate and vinyl t-butyl benzoate.

Co or styrenic monomers, we can mention styrene and alpha-methyl styrene.

The list of monomers given here is not limiting and it is possible to use any monomer known to the person skilled in the art who falls into the categories of acrylic and vinyl monomers (including monomers modified by a silicone chain).

Particularly described are radical polymers which can be used in enamel or nail care products in US-A-4158053, WO-A-97/42930, FR-A-2755009.

Among the polycondensates which can be used as smoke-forming polymers, mention may be made of anionic, cationic, non-ionic or amphoteric polyurethanes, acrylic polyurethanes, polyurethanes-polyvinylpyrrolidones, polyester-polyurethanes, polyether-polyurethanes, polyureas, polyurea / polyurethanes, and their polyurethanes. mixtures Suitable polyurethanes are described, in particular, in EP-A-680742.

Among the polycondensates usable as smoke polymer, we can also mention polyesters, amide polyesters, fatty chain polyesters, polyamides and epoxy ester resins. Polyesters usable in US-A-3779993 are described in particular, and are sold on the other hand under the name of Eastman AQ® by the Eastman Chemical Company.

Polymers of natural origin, optionally modified, can be selected from shellac resin, water-gum gum, dammares, elemis, copals, water-insoluble cellulosic polymers, and mixtures thereof. Such polymers are described in particular in the application EP-A-676451.

The dispersion comprising one or more smoke-forming polymers can be prepared by the person skilled in the art on the basis of his general knowledge.

The size of the polymer particles in aqueous dispersion can be from 10 to 500 nm, and preferably from 20 to 300 nm.

The polymer in aqueous dispersion can be present in the enamel or nail care product in a proportion of 1 to 50% by weight, preferably 5 to 45% by weight of dry matter of fumaric polymers in relation to the weight total of the product.

The enamel or nail care product may contain plasticizing agents and / or coalescing agents that are well known to the skilled artisan.

The invention consists, apart from the provisions set forth, in a number of other provisions which will be dealt with more explicitly below, with respect to non-limiting embodiments, described with reference to the accompanying drawings.

Figure 1 is an elevational view of a nail polish brush according to the invention.

Figure 2 is an elevational view of a nail polish assembly according to the invention.

With reference to Figure 1, we will say that a brush 1 for application of nail polish can be seen in it, comprising a bundle 2 of hairs 3 fixed to one end 4a of a handle or spike 4 and oriented substantially in the axial direction of the nail. mango. There is a cylindrical sleeve 5 integral with the end of the pin 4 opposite the hair bundle 2, and fitted in this sleeve. This cylindrical sleeve 5 serves as the maneuvering member of the brush; It also serves as a stopper intended, for example, to be screwed onto the neck of an enamel bottle. The hair bundle 2 is obtained from a set of substantially parallel hairs folded in two, approximately half its length. The hair bundle 2 is fixed, in a known manner, to the end 4a of the handle 4 by adjusting the retracted part of the hair bundle in a housing (not shown in Figure 1) formed by a blind hole that opens at the end 4. The applications EP-A-651955 and EP-A-673612 can be used, the content of which is incorporated herein by reference. For a detailed description of the fixation of the hair bundle on the handle.

Figure 2 shows a set 6 for nail polish, comprising the brush 1 of figure 1 fixed on the neck 7 of a bottle 8 containing a nail polish product 9 which contains water, leaving the hair bundle 2 submerged in the product 9. The product 9 comprises the polyvinyl alcohol according to the invention dissolved in the aqueous medium; it further comprises a fumaric polymer, insoluble in water, in the form of particles dispersed in the aqueous medium.

We give below an example of a brush treatment according to the method of the invention and some comparative examples made with a method that does not form part of the invention. Example 1: A reinforcing solution SI of the following composition was prepared: - Partially acetylated polyvinyl alcohol (AIRVOL 205 of the AIR PRODUCTS Society 1, 5 g CHEMICAL) - Ethyl alcohol 66 g - Water qsp 100 g A brush of the following characteristics was treated with this solution: apparent length of the hairs: 18 m 90% of cylindrical hairs of polyamide 11 (RILSAN), 15/100 m, loaded at 5% with molybdenum disulfide, approximately 110 hairs 10% cylindrical hairs of polyamide 6-12 (Nylon TYNEX), 8/100 mm, approximately 46 hairs.

The hair bundle of the brush was submerged to half its length in the solution for 1 second.

Then, the brush was removed and allowed to air dry. After drying, the deposit of polyvinyl alcohol on the surface of the hairs is not adherent and gives the hairs good flexibility while keeping them in a uniform beam. When the brush is submerged in a product. Aqueous nail polish, for example identical to those of the examples of the application EP-A-648485, the polymer on the surface of the hairs dissolves very well in the aqueous medium and does not modify the cosmetic properties of the enamel. The homogeneous hair bundle of the brush allows an application of a uniform layer of enamel on the nail.

The brush of Example 1 was placed in a bottle containing the following nail enamel product: - Aqueous dispersion of polyester-polyurethane with 35% dry matter (AVALURE UR 405 from GOODRICH) 25 g MA -tributyl citrate 2.5 g -ethanol 5 g - Clay 1 g -pigments 3 g -conservatives qs -water qsp _ 100 g After the brush hairs are immersed in the nail varnish product, the polyvinyl alcohol dissolves well in the enamel. The latter is not destabilized and retains its cosmetic properties.

Example 2: The procedure was as described in Example 1, using the following reinforcing solution 2: Solution 2: - partially acetylated polyvinyl alcohol (AIRVOL 540 from AIR PRODUCT) 1.7 g - 50 g ethanol - water qsp 100 g After the brush hairs are immersed in the nail polish product, the polyvinyl alcohol dissolves well in the enamel. The latter is not destabilized and retains its cosmetic properties.

Comparative examples 3 and 4: 2 reinforcing solutions were made, which do not form part of the invention, of the following composition: Solution 3-sodium polymethacrylate (DARVAN 7 of 2.5 g VANDERBILT) - ethanol 20 g - water qsp 100 g Solution 4: - Hydroxypropyl methylcellulose. { METHOCEL E4 M UG of DOW CHEMICAL) 0.67 g - ethanol 66, 6 g - water qsp 100 g For each solution, a brush of the same characteristics as that of Example 1 was treated, submerging it to half its length for 1 second in the solution.

It has been found that the treatment with solution 3 does not allow rapid drying of the impregnated hair bundle, since it does not remain dry to the touch after 30 minutes. This too long drying time is not suitable for an industrial implementation of the brush treatment.

The solution 4 leads, after immersion and drying, to the formation of a hard film. In addition, the film breaks easily when subjected to a small shock (for example, twisting of the hair bundle) and it follows that the hairs are no longer reinforced, so that the beam can then easily deform.

Only a brush treated according to example 1 or 2 according to the invention, allows to achieve a good reinforcement of the hair bundle, as well as a good dissolution of the polyvinyl alcohol in the aqueous enamel product without harming the stability, nor the cosmetic properties of the enamel .

It is noted that in relation to this date, the best method known to the applicant, to implement said invention is that which is clear from the manufacture of the objects to which it refers.

Having described the invention as above, property is claimed as contained in the following

Claims (26)

1. Brush for the application of a makeup or toilet product in general, comprising a beam of substantially parallel hairs, a first end of these hairs being fixed to a free end of a handle, characterized in that the hairs of the beam are impregnated on the surface by a partially acetylated polyvinyl alcohol comprising at least formula units (I) and (ID: wherein the units of formulas (II) are present in proportions of between 3 and 40% mol relative to the polymer, said polyvinyl alcohol having a weight average molecular weight of between 10,000 and 190,000.

2. Brush according to claim 1, characterized in that the polyvinyl alcohol has a weight average molecular weight of between 10,000 and 120,000, and better still between 31,000 and 50,000.

3. Brush according to any of claims 1 or 2, characterized in that the units of formulas (II) are present in a proportion of 10 to 15% mol.

4. Brush according to any of the preceding claims, characterized in that the polyvinyl alcohol consists essentially of units of formula (I) and (II).

5. Brush according to any of the preceding claims, characterized in that the hairs are of a material chosen within the group formed between polyamides, polyesters, polyether-block-amides, polyethylene, polytetrafluoroethylene, vinylidene polyfluoride, polyvinyl chloride , viscose, rayon, polyacetals, natural silks, or their mixtures.

6. Brush according to any of the preceding claims, characterized in that the hairs have a section inscribed in a circle (f) with a diameter of 4 hundredths to 40 hundredths of a millimeter.

7. Brush according to any of the preceding claims, characterized in that the hair bundle has a length of between 5 and 25 millimeters.

8. Brush according to any of the preceding claims, characterized in that the number of hairs constituting the beam ranges from 100 to 600.

9. Brush for nail polish, characterized in that it consists of a brush according to any of the preceding claims.

10. Coating process of hairs of a hair bundle of a brush comprising a bundle of substantially parallel hairs, a first end of these hairs being fixed to a free end of a handle or tang, characterized in that it is brought into contact at least a part of the hair bundle with an aqueous composition of a partially acetylated polyvinyl alcohol, comprising at least units of formula (I) and (II): where the units of formulas (II) are present in proportions of 3 to 40% mol relative to the polymer, said polyvinyl alcohol having a weight average molecular weight of between 10,000 and 190,000, the hair bundle is then removed from the composition 10 and let it dry.

11. Process according to claim 10, characterized in that the polyvinyl alcohol has a weight average nolecular weight of between 10,000 and 120,000 and 15 better still between 31,000 and 50,000.

12. Method according to one of claims 10 or 11, characterized in that the units of formulas (II) are present in a 20 ratio of 10 to 15% in mol.

13. Process according to any of claims 10 to 12, characterized in that the polyvinyl alcohol is present in the composition in a proportion of 0.1 to 10% by weight, relative to the total weight of the composition, and better still of 0.5 to 5% by weight.

14. Process according to any of claims 10 to 13, characterized in that the composition further comprises at least one lower C2-C5 alcohol,.

15. Process according to claim 14, characterized in that the lower alcohol is ethanol.

16. Process according to any of claims 10 to 15, characterized in that the lower alcohol is present in a proportion of 0 to 80% by weight, based on the total weight of the composition, and better still of 40 to 70% by weight.

17. Process according to any of claims 10 to 16, characterized in that the composition further comprises a wetting agent.

18. Process according to claim 17, characterized in that the wetting agent is a dimethicone copolyol.

19. Brush capable of being obtained by the method according to any of claims 10 to 18.

20. Application set 6 of enamel product or nail care, consisting of a container with a neck and a plug attached to a submerged brush in preservation position, in an enamel or nail care product, contained in this container, characterized in that the product comprises an aqueous medium and in that the brush conforms to any of the claims 1 to 9 and 19.

21. Enamel or nail care application set, consisting of a container with a neck and a solidary plug of a submerged brush, in a conservation position, in an enamel or nail care product contained in this container , characterized in that the product comprises an aqueous medium containing at least one partially acetylated polyvinyl alcohol having at least units of formula (I) and (II): in which the units of formulas (II) are present in proportions of 3 to 40% in mol relative to the polymer, said polyvinyl alcohol having a weight average molecular weight of between 10,000 and 190,000.

22. Assembly according to claim 21, characterized in that the polyvinyl alcohol has a weight average molecular weight of between 10,000 and 120,000, and better still between 31,000 and 50,000.

23. Assembly according to claim 21 or 22, characterized in that the units of formulas (II) are present in a proportion of 10 to 15% mol relative to the polymer.

24. Assembly according to any of claims 21 to 23, characterized in that the polyvinyl alcohol consists essentially of units of formula (I) and (II).

The assembly according to any of claims 21 to 24, characterized in that said polyvinyl alcohol is present in the product in a proportion of 0.005 to 0.5% by weight, based on the total weight of the product.

26. Assembly according to any of claims 20 to 25, characterized in that the product comprises at least one fumaric polymer, insoluble in water, in the form of particles dispersed in the aqueous medium.