MXPA00003797A - Use of substantially amorphous cellulose nanofibrils associated with a polyhydroxylated organic compound in cosmetic formulations - Google Patents

Abstract

The invention concerns the use of substantially amorphous cellulose nanofibrils having a crystalline index not more than 50%in dispersible dry form associated with at least a polyhydroxylated (polyOH) organic compound, as texturizing and/or reinforcing agent in cosmetic formulations. The invention further concerns the resulting cosmetic formulations.

Description

USE OF NANOFIBRILLAS OF CELLULOSE SUSTANCIALME TE ASSOCIATED LOVERS AT LEAST ONE ORGANIC COMPOUND POLYHYDROXYLATE IN COSMETIC FORMULATIONS DESCRIPTION OF THE INVENTION The present invention relates to the operation of substantially amorphous cellulose nanofibrils, which have a crystallinity rate of less than or equal to 50% under a dispersible form in the cosmetic formulations and to the formulations obtained in this way. The present invention more specifically aims at a novel texturizing and / or reinforcing agent for cosmetic formulations. In the sense of the invention, cosmetic formulation is understood to mean all cosmetic products or preparations of the type of those or those described in Annex I ('illustrative list by category of cosmetic products') of European guideline No. 76/768 / CEE of July 25, 1976, known as the Cosmetic Directive.In general, cosmetic compositions are formulated in the form of a large number of types of products intended to be applied on the hair, such as foams, gels (hair styling mainly), conditioners, formulations for styling or to facilitate the combing and / or unraveling of hair, rinse formulations, either on the skin or hand and body lotions, the products that regulate the hydration of the skin, the milks of toilet, the make-up remover compositions, the epilators, the creams or lotions of protection against the sun and the radiations ultraviolet, cleaning creams, anti-acne preparations, local analgesics, mascara or mascara type makeup formulations, dye bottoms, nail varnishes, products intended to be applied to the lips or other mucous membranes, bars , solid soap-like toilet compositions as well as other formulations of the same type. Classically, these different formulations incorporate, in addition to one or more active ingredients specific to the application in question, a certain number of more conventional compounds that have, mainly, the function of conferring either a prolonged stability over time (conservative agent, for example) and / or a particular galenic form (of gel type, cream, milk, lotion for example). In general, they are surface agents and / or dispersing agents, stabilizers, emulsifiers, wetting agents, gelling agents or even thickeners. Representative of conventional stabilizers and / or thickeners are crosslinked polyacrylates, hydrocolloids obtained by fermentation, such as Xanthane-Rhodicare® gum and succinoglycan such as Rhéozan®, cellulose derivatives such as hydroxypropylcellulose, carboxymethylcellulose, the guares and their derivatives that are used alone or in association. The aim of the present invention is to propose a novel texturizing and / or reinforcing agent which possesses an advantageous rheological behavior in formulating the cosmetic compositions. More particularly, it is an agent based on essentially amorphous cellulose nanofibrils having a crystallinity rate of less than or equal to 50%, which are present in an anhydrous form dispersible in an aqueous medium.

In a general manner, native cellulose is always presented in the form of fibrils. These fibrils are well known materials that are in particular already proposed to modify the texture of the media in which they are introduced. In the case of fluid media, they modify their viscosities and even their rheological profiles. The nanofibrils may be of various origins, for example of plant, bacterial, fungal, amebic, etc. origin. In general, in fibers or plant walls there is a strong association between nanofibrils. Between the walls the secondary walls can be distinguished, mainly from wood, from the primary walls where a typical example is the parenchyma. Examples of parenchyma consist of sugar beet pulp, citrus fruits (lemons, oranges, grapefruit) and most fruits and vegetables. In the secondary walls, these fibrils are organized in the form of very oriented layers that form an indissociable fiber. These are presented classically in the form of aggregates of some tens of nanometers up to a few micrometers. These aggregates are constituted by elementary fibrils that can not be unraveled, at the moment of their homogenization, without causing their rupture. In the context of the present invention, the cellulose fibrils considered are essentially amorphous cellulose nanofibrils (NFC), preferably derived from primary-walled cells. Advantageously, the cellulose nanofibriils of the invention are derived from cells consisting of at least about 80% of primary walls, and preferably at least85% by weight. In this way, essentially amorphous cellulose nanofibrils, used according to the invention, preferably have at least 80% of primary-walled cells. In contrast to the cellulose fibrils of secondary walls discussed above, the cellulose nanofibrils have a diameter of at most a few nanometers and have the appearance of filaments that prove to be unraveling at the time of the homogenization stages. These preferably have a section comprised between about 2 and about 10 nm. More preferably, it is between about 2 and about 4 nm. In the context of the invention, the nanofibrils considered are nanofibrils termed essentially amorphous in opposition to the so-called crystalline fibrils. By essentially amorphous, it is meant to define nanofibrils where the crystallinity rate is less than or equal to 50%. According to a particular variant of the present invention, this crystallinity rate is comprised between 15% and 50%, and more preferably less than 50%. These essentially amorphous cellulose nanofibrils are particularly advantageous with respect to the crystalline microfibrils, in the sense that they are dispersible in aqueous media, conferring very specific rheological properties of the reofluidifying type and are stable either thermally or in media with fillers. important ionics. This good efficacy manifested, at a reduced dose, by the cellulose nanofibrils is in fact a consequence of its excellent rheological behavior in terms of the runoff threshold and the reofluidising power.

According to a preferred embodiment of the invention, the cellulose nanofibrils used according to the invention are surface-loaded with carboxylic acids and with acidic polysaccharides, alone or as a mixture. By carboxylic acids, simple carboxylic acids are understood, as well as their salts. These acids are preferably chosen from uronic acids and are more particularly galacturonic acid and / or glucuronic acid. As acidic isaccharides, there may be mentioned pectins, more particularly polygalacturonic acids. These acid polysaccharides can be present in a mixture with hemicelluloses. In fact, these superficially charged nanofibrils do not result from a simple mixture between said nanofibrils and the acids and polysaccharides. It is more a close combination between these two types of compounds that are derived directly from the process used to prepare the nanofibrils. In fact, this preparation process can be such that the acids and polysaccharides are not completely separated from the fibers but rather lie on the surface of the latter, thus conferring them with very specific properties. It is important to emphasize that these same properties will not be reproduced if successively proceeds to a complete separation of the nanofibrils of these acids and / or polysaccharides, then to an addition of the latter, to the nanofibrils thus obtained. More precisely, the present invention contemplates the operation of these cellulose nanofibrils together with at least one polyhydroxylated organic compound (polyOH), under a redispersible solid form. Accordingly, the present invention aims at the use of essentially amorphous cellulose nanofibrils, having a crystallinity rate of less than or equal to 50% under a dispersible dry form, associated with at least one polyhydroxylated organic compound (polyOH), in a manner of texturizing and / or reinforcing agent in cosmetic formulations. In the sense of the present invention, a texturizing agent is an agent that has a stabilizing and thickening paper in the cosmetic composition that incorporates it.

Within the framework of the present invention, a reinforcing agent is an agent capable of improving the mechanical properties of the composition in which it is incorporated both in the wet state and in the dry state. It has also been observed that the associations according to the invention could optionally be used as an emulsifying and stabilizing agent in an aqueous medium containing surfactants. The use of cellulose nanofibrils associated with at least one (polyOH) in the dry or anhydrous form presents not only an economic advantage, both on the storage and transport plane for example, but also from the technical point of view, since with the redispersible dry or anhydrous form, aqueous suspensions with an important proportion of dry active substances can be prepared. Unexpectedly, the use of cellulose nanofibrils under this dry redispersible form as a texturizing and / or reinforcing agent in the cosmetic compositions is found to be advantageous at several degrees.

For example, in the particular case of cosmetic formulations intended for a cutaneous use of the cream type, for example, a significant improvement is noted in the level of cutaneous penetration of said formulations. No phenomenon of "sudsing" has been observed on the surface of the skin at the time of the application of these formulations Finally, the cellulose nanofibrils according to the invention rely on a very soft skin sensation as well as a tensor and protective effect of The skin surface, as well as a moisturizing effect As regards the particular case of hair formulations, the incorporation of cellulose nanofibrils associated with at least one polyhydroxylated organic compound reinforces the combing effect. a water-soluble film-forming polymer in solution, or a water-insoluble film-forming polymer in dispersion, leads to the production of a film-forming material which exhibits good adhesion on the keratin support with a tactile feel, neither fat nor sticky .

The water-soluble film-forming polymers used in accordance with the present invention can be: either a water-soluble polymer foxmator of synthetic film, low glass transition temperature Tg, preferably less than or equal to 20 ° C; - or a water-soluble, film-forming polymer of natural origin (polysaccharide derived from cellulose) of high Tg, generally greater than or equal to 40 ° C. Mention may be made, for example, of polyvinyl alcohol, hydroxyethyl cellulose, cellulose ethers in general used in cosmetics, guar gums, locust bean gums. Similarly, contrary to conventional thickening agents, the cellulose nanofibrils according to the invention do not affect the cosmetic properties of the formulations that incorporate them. Advantageously, no braking effect, no loss of brightness is observed and no decrease in the remanence to water of the compositions is observed. On the other hand, a reinforcing effect of the perfume has been evidenced.

As indicated above, the association with the cellulose nanofibrils of at least one (polyOH), operated at the time of the preparation process of the cellulose nanofibrils, has the advantage of allowing its formulation in a dry or anhydrous, dispersible form. This presents, of course, a potential interest for the preparation of the corresponding cosmetic formulations, mainly that of offering greater formulation flexibility due to the large proportion of active ingredient. The polyhydroxylated organic compound (polyOH) is preferably chosen from carbohydrates and their derivatives and polyalcohols. Representative of these carbohydrates are, in particular, linear or cyclic monosaccharides having 3 to 6 carbon atoms, and preferably 5 or 6 carbon atoms, for example fructose, mannose, galactose, sucrose. , the talose, the gulose, the allose, altrosa, idosa, arabinose, xylase, lixose and ribose, the oligosaccharides, for example the maltose and the lactose, the polysaccharides, for example the starch, the cellulose, the xanthan gum and the guar, and its fatty derivatives such as sucrose esters of fatty acids, carbohydrates of alcohols, for example sorbitol and mannitol, the carbohydrates of acids, for example gluconic, uronic, galacturonic acids, as well as their salts and the carbohydrates of ethers Examples are methyl-, ethyl-, carboxymethyl-, hydroxyethyl-, and hydroxypropyl ethers of cellulose. As far as polyalcohols are concerned, they can be, in particular, glycerol, pentaerythroline, propylene glycol, ethylene glycol and / or polyvinyl alcohols. In the particular case of carbohydrates and their derivatives, used in conjunction with the essentially amorphous cellulose nanofibrils, mention may be made more particularly of carboxylated celluloses and, preferably, carboxymethylated cellulose., designated even as CMC. Cellulose is a polymer made up of monomeric units of glucose: the degree of polymerization can vary within large limits. The carboxylated group is introduced in a manner known per se, by reacting the chloroacetic acid with the cellulose. Its degree of substitution corresponds therefore to the number of carboxymethylated groups per unit of glucose. The theoretical maximum substitution degree is 3. These carboxylated celluloses are denominated with a high degree of substitution for a value higher than 0.95, and low grade for a value lower than this. Thus, the carboxymethylated celluloses of high masses are suitable, the proportion of carboxylated cellulose in question is therefore greater than or equal to 5% by weight, and less than or equal to 30% by weight, or the carboxymethylated celluloses of small masses, the proportion of carboxylated cellulose is in this case, more particularly comprised between and 30% by weight. To an identical mass, it is verified on the other hand that it is still possible to reduce the proportion in relation to the nanofibrils, privileging the choice of a carboxymethylated cellulose of high degree of substitution. Such mixtures of cellulose nanofibrils and carboxylated cellulose are mainly described in PCT / FR 97 01291 applications published under WO 98/02487 and PCT / FR 97 01290 published under WO 98/02486. Preferably, this polyhydroxylated organic compound (polyOH) is chosen from carboxymethylcellulose, xanthan gum, guar, sorbitol, sucrose and mixtures thereof. The cosmetic formulations obtained according to the invention preferably comprise the polyhydroxy compound (s) and the cellulose nanofibrils in a weight ratio (polyOH) x 100 / [(polyOH) + (NFC)] greater than or equal to 5% and less than and equal to 50%, and preferably greater than or equal to 5%, and less than or equal to 30%. According to a preferred embodiment of the invention, these include cellulose nano fibers in a form associated with that of carboxymethylcellulose (CMC) of high degree of substitution in a weight ratio (CMC) x 100 / [(CMC) + ( NFC)] greater than or equal to 5% and less than or equal to 25%. It is also possible to associate another polyhydroxy derivative, such as sucrose, propylene glycol or polyethylene glycol, to the CMC, for example. In this particular case, the ratio by weight (CMC x 100 / [(polyOH) totai + (NFC)] is thus significantly decreased, as regards the amounts in cellulose and (polyOH) nanofibrils, which can be used for according to the invention, it is clear that these are a function of the type of galenic form considered and / or the effect sought at the level of the cosmetic formulation, for example reinforcing a moisturizing effect or even providing a protective effect of the epidermis as in the formulations Thus, in the galenic forms of the cream type, higher amounts of texturizing agent according to the invention will be present, comparatively to those put into operation in the fluid-type formulations, preferably the amount in the mixture of cellulose and cellulose nanofibrils. polyOH (s) is adjusted so that said nanofibrils are present at a ratio of about 0.1 to 20% and, more preferably of about 0.15 and 5% by weight of the cosmetic formulation. Illustratively, a concentration in cellulose and (polyOH) cellulose nanofibrils varying between 0.11 and 40% can be proposed for cream-type formulations, and for formulations of the fluid type, a concentration between 0.11 and 10%. The values are proposed for a weight ratio (polyOH) x 100 / [(polyOH) + (NFC)] greater than or equal to 5%, and less than or equal to 50%.

The redispersible solid composition of cellulose nanofibrils, put into operation according to the invention, can also contain the polyhydroxylated organic compound (s) defined above, at least one co-additive chosen from: • The compounds of the formula (RXR2N) COA, in which R1 or R2 identical or different, represent hydrogen or an alkyl radical of 1 to 10 carbon atoms, preferably of 1 to 5 carbon atoms, A represents hydrogen, alkyl radical of 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, or even the group R '1R' 2N with R'1, R'2, identical or different, represents hydrogen or an alkyl radical of 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms; and • the anionic, nonionic or amphoteric surfactants, these co-additives being used alone or as a mixture. Representative of these surfactants are those identified later in the text. It is noted that the use of these coadditives allows, in combination with (polyOH) such as carboxymethylcellulose, to reinforce the reofluidising profile of cellulose nanofibrils, after the redispersion. As far as the compounds of the type (R1R2N) COA are concerned, it is preferred to use the compounds comprising two amide functional groups. Preferably, urea is used as the co-additive. According to a particular embodiment of the invention, these redispersible solid compositions of essentially amorphous cellulose nanofibrils comprise carboxylated cellulose with a high degree of substitution as an additive to at least one compound chosen from among the surfactants. When the cellulose nanofibrils put into operation according to the invention are associated with one or more polyhydroxy compounds and one or more coadditives indicated above, the proportion of polyhydroxy compound (s) and co-additive (s) is greater than or equal to 5% by weight and less than or equal to 30% by weight relative to the weight in nanofibrils, polyhydroxy compound (s) and co-additive (s). The nanofibrils used according to the invention can be obtained from different procedures, already described in the literature.

In particular, reference may be made to the process described in the European patent application EP-A-726, 356. The treatment is carried out on the pulp of vegetables with primary walls, namely the wet pulp, dehydrated, preserved by silage or partially deprecated, as for example of the beet pulp, after it has undergone a previous extraction stage of the sucrose, according to the methods known in the art. More precisely, this treatment puts into operation a first acid or basic extraction, at the outlet of which a first solid residue is recovered, followed eventually by a second extraction, carried out under alkaline conditions, of the first solid residue, the recovery of a second solid residue, the washing and then the bleaching of the two collected cellulosic material residues, the dilution of the third solid residue obtained at the exit of the whitening stage, then the dilution of the resulting suspension, in order to obtain a of dry materials comprised between 2 and 10% by weight, and finally a homogenization stage, comprising at least one cycle of the diluted suspension.

This homogenization stage corresponds to any operation of mixing, crushing or any high mechanical shearing operation, followed by one or more steps of the cell suspension through a small diameter orifice, subjecting the suspension to a pressure drop of at least 20 mPa and a high speed deceleration action, followed by a deceleration impact at high speed. The homogenization of cellulose suspension is obtained by a number of passages that can vary between 1 and 20, preferably between 2 and 5, until obtaining a stable suspension. As regards the detailed protocol of each of the stages of this treatment, reference will be made to the description of the previously identified application. The procedure to be described allows to obtain the nanofibrils that retain carboxylic acids and / or polysaccharides on their surface. In the case of the cellulose nanofibrils used according to the invention, a polyhydroxy compound of the type, for example, of carboxylated cellulose, is introduced into the preparation protocol described above, either before the start-up of the homogenization step or well after a homogenization cycle has been operated. It should be noted that this variant of the method is described in the international patent application PCT / FR 97/01291 published under the number WO 98/02487, to which reference may be made if necessary. The process for the preparation of the cellulose nanofibrils, added with polyhydroxy compound (s) consists, in a first stage, of adding to the suspension of nanofibrils, possibly having undergone at least one homogenization cycle, at least one part of the polyhydroxy compound considered and optionally of the additive (s). Then, in a second step, a drying step of the suspension added in this way is put into operation. In fact, the addition of at least a part of the polyhydroxy compound and optionally of the additive (s) can be carried out according to three variants: either at the exit of the homogenization stage and according to a privileged modality, after this The last has undergone at least one concentration stage, or the suspension from the homogenization stage, before the latter has undergone at least one concentration stage, or even, before or during the homogenization stage, the pulp which has undergone at least one cycle of the homogenization stage. The concentration stage or stages can be carried out by any conventional means, until obtaining a dry extract of approximately 35% by weight. More particularly, the dry extract is between 5 and 25% by weight. Prior to the actual drying step, it may be advantageous to effect a shaping, namely by extrusion or granulation, of the suspension that has been concentrated. The temperature of the drying step is of course controlled so as to limit any degradation of the carboxylic acids, the acid polysaccharides, the hemicelluloses, the polyhydroxy compounds and, where appropriate, the coadditives. This is more particularly comprised between 30 and 80 ° C, preferably between 30 and 60 ° C. The drying step, carried out by conventional means, is carried out so as to maintain at least 3% by weight of water relative to the weight of the solid manufactured. More particularly, the weight of the water maintained is between 10 and 30% by weight. Such an operation allows not to exceed the threshold beyond which the redispersion of the nanofibrils can not be completed. Advantageously, the suspension of cellulose nanofibrils obtained by redispersion in water of the mixture, obtained according to the protocol described above, has a level of viscosity corresponding to at least 50% for a shear rate of at least 1 s-1, of the viscosity level of a suspension of cellulose nanofibrils that has not undergone the drying step and that does not comprise the polyhydroxy compound or coadditives. Of course, essentially amorphous cellulose nanofibrils, preferably surface-charged with an acid, and associated with a polyhydroxy compound and optionally with a co-additive, are put into operation in the cosmetic formulations obtained according to the invention, in a mixture with at least a vehicle compatible with a capillary, cutaneous or solar application. The term "compatible" with an application on the hair and / or the skin means here that the veniculo does not spoil or has no negative effect on the appearance of the hair and / or the skin and does not create a skin irritation and The objective of the present invention is also to provide cosmetic formulations which put the essentially amorphous cellulose nanofibrils into operation as a texturizing and / or reinforcing agent, in a dispersible dry form, and associated with at least one polyhydroxylated organic compound as it is preferably defined These formulations may also contain an additive as defined above.Preferably, the cosmetic formulations according to the invention resort to a vehicle, or a mixture of several vehicles, present in said formulations in concentrations comprised between about 0.5 and 99.5%, and more preferably between about 5 and 90% .

The vehicles compatible with the formulations acing to the invention comprise, for example, those used in sprays, foams, tonics, gels, shampoos, or even rinsing lotions. Of course, the choice of the appropriate vehicle depends on the specific application considered by the formulation. A vehicle suitable for a formulation intended to remain on the surface from which it has been applied (for example spray, foam, lotion, tonic or gel), will not be the appropriate vehicle for a formulation that must be rinsed after use. (for example shampoo or conditioner, lotion or rinse). The vehicles that can be used can therefore be simple or complex and include a large number of products commonly used in cosmetic formulations intended for capillary, cutaneous or solar use. Water can thus be optionally supplemented with a solubilizer to dissolve or disperse the active ingredients used, such as alcohols having 1 to 6 carbon atoms, and mixtures thereof, in particular ethanol, isopropanol or propylene glycol, and mixtures thereof.

Advantageously, a good compatibility of the cellulose nanofibrils associated with at least one polyhydroxylated organic compound with respect to the alcohol-type solubilizers is noted. The texturizing properties of these cellulose nanofibrils are not altered in hydroalcoholic media. Likewise, these retain their properties in so-called more aggressive media, either very acid such as creams with a-hydroxy acids or alkaline media such as depilatory formulations or lotions for permanents. Examples 2 and 3 presented below take into account this advantageous behavior of the cellulose nanofibrils associated with at least one polyOH in cosmetic application. Advantageously, NFC formulated acing to the invention prove to be excellent structuring agents of cosmetic media and retain their properties over time. Its viscosifying power is superior to that of the micromecrystalline celluloses. It can also be associated, in a fat phase different from the aqueous phase of the NFC of 2.1 Acing to the invention, one or more emollients chosen from: mineral oils (such as Marcol 82®), vegetable or marine oils, halogenated hydrocarbons, linalool, esters (such as isopropyl myristate), and silicones compatible with a cosmetic application (in particular cyclodimethicones and dimethicones and derivatives and hexamidildyl) and their derivatives or mixtures. When the cosmetic formulations are presented in the form of sprays, tonics, gels, or foams, the preferred solvents comprise water, ethanol, volatile silicone derivatives, and mixtures thereof. The solvents used in these mixtures can be miscible or immiscible with each other. Sprays and aerosol sprays can also use no matter which propeller capable of generating products in the form of fine, even foam or sprays. By way of examples, mention may be made of dimethyl ether, propane, n-butane or isobutane. In the case where the cosmetic formulations are intended for local topical application, the vehicles must have good Edenic properties, be compatible with all other components, and present a perfect harmlessness. These vehicles can take a large number of forms, emulsion type, foams, dew, etc. For example, vehicles in the form of emulsions include emulsions of water in silicone, water in oil, oil in water, and oil in water in silicone. These emulsions cover a large viscosity range, for example from IDO to 2Q, 0Q0 mPa.s at 25 ° C. These emulsions can also be supplied in the form of sprays using either a mechanical pump-type device or pressurized by the use of a propellant gas. These vehicles can also be distributed in the form of foam. Parallel to the vehicles identified above, the cosmetic formulations according to the invention may contain surfactants, put into operation to disperse, emulsify, solubilize, stabilize various compounds used mainly for their emollient or moisturizing property. These may be of the anionic, nonionic, cationic, or amphoteric type. Illustrative of these compounds are more particularly: anionic surfactants such as alkyl sulfonates, alkyl sulfates, alkylamide sulfates and salts of saturated or unsaturated fatty acids; nonionic surfactants such as polyoxyalkylenated alkylphenols, glucosamides, glucamides, glycerolamides derived from N-alkylamines, polyoxyalkylenated aliphatic alcohols of 8 to 22 carbon atoms, the products resulting from the condensation of ethylene oxide with a hydrophobic compound or resulting from the condensation of propylene oxide with propylene glycol, amine oxides, alkyl polyglycosides and their polyoxyalkylenated derivatives, fatty amides of 8 to 20 carbon atoms and fatty acids, amides, amines, ethoxylated amidoates; amphoteric and zwitterionic surfactants such as those of betaine type, such as betaines, sulfo-betaines, amidoalkylbetaines and sulfo-betaines, alkylsultains, condensation products of fatty acids and protein hydroxylates, cocoamphoacetates and the cocoamphodiacetates, the alkylampho-propionates or -dipropionates, the amphoteric derivatives of the alkylpolyamines. Conditioning agents may also be present. Among these, we can mention those of synthetic origin better known under the name polyquaternium, such as polyquaterniums -2, -7 and -10, cationic derivatives of polysaccharides, such as cocodimony-dihydroxyethyl-cellulose, guar-hydroxypropyl chloride triammonium, hydroxypropyl-guar-nid-oxydropyl-triammonium chloride, non-volatile derivatives of silicones such as amodimethicone, cyclomethicones, non-water-soluble and non-volatile organopolysiloxanes such as oils, resins or gums such as diphenyldimethicone rubbers. The cosmetic formulations may also contain polymers having film-forming properties that can be used to provide a fixing functional group. These polymers are generally present at concentrations comprised between 0.01 and 10%, preferably between 0.5 and 5%. These are preferably of the polyvinylpyrrolidone type, copolymers of polyvinylpyrrolidone and methyl methacrylate, polyvinylpyrrolidone and vinyl acetate copolymer, polyethylene glycol polyterephthalate / polyethylene glycol copolymers, sulfonated terephthalic copolyester polymers. The cosmetic formulations may also contain polymeric derivatives that exert a protective function, in amounts of the order of 0.01 to 10%, preferably of approximately 0.1 to 5% by weight, derivatives such as the cellulose derivatives, the polyvinyl esters grafted onto the polyalkylene skeletons. , polyvinyl alcohols, sulfonated terephthalic copolyester copolymers, ethoxylated monoamines or polyamines and ethoxylated amine polymers. Moisturizing agents can also be incorporated into cosmetic formulations. Illustrative of the latter are glycerol, propylene glycol, urea, collagen, gelatin, and emollients, which are generally chosen from alkyl monoglycerides, alkyldiglycerides, triglycerides, and oils extracted from plants. Vegetables or their hydrogenated derivatives, mineral oils or paraffinic oils, diols, fatty esters, silicones, etc. To these compounds, one or more perfumes, coloring agents and / or opacifying agents such as pigments are generally added. To protect the skin and / or hair from the sun's aggressions and ultraviolet rays, you can add to these formulations sunscreens that are either organic compounds that strongly absorb ultraviolet radiation, or mineral particles in the nanoparticle state, such as zinc oxide, titanium dioxide or cerium oxides. The active ingredients, such as vitamins, a-hydroxy acids, plant derivatives, marine extracts, with purely cosmetic properties, can be incorporated into the formulations containing the NFC with a view to a treatment action. Likewise, NFCs are privileged texturizing agents of depilatory formulations, such as means based on calcium thioglycolate, for example. Conservative agents such as esters of p-hydroxybenzoic acid, sodium benzoate, or any chemical agent that prevents bacterial or fungal proliferation, and traditionally used in cosmetic compositions, are generally introduced in these compositions to more than 0.01 to 3% by weight, according to Annex VII of the cosmetic regulation. Finally, the cosmetic formulations may also contain viscosifying or gelling polymers such as the crosslinked poly-acrylates of CARBOPOL® type marketed by GOODRICH, the cellulose derivatives such as hydroxypropylcellulose, carboxymethylcellulose, the guares and their derivatives as hydroxypropylguar such as Jaguar HP®. , carob, tara or cassia gum, xanthan gum, such as Rhodicare®, succinoglycans, alginates, carrageenans, chitin derivatives or any other polysaccharide with texturizing function. It is clear that the choice of the so-called conventional compounds, and the appreciation of their respective amounts are directly linked to the type of formulation considered, namely gel, cream, milk, spray, lotion, etc. and the desired edonian character. These adjustments actually involve routine operations for the cosmetic formulator. The cosmetic formulations according to the invention can advantageously be put into operation in the capillary, solar, body cleansing and make-up domains. The examples described below are presented simply by way of illustration and not limitation of the present invention.

EXAMPLE 1 Preparation of a mixture of cellulose and carboxymethylcellulose nanofibrils A carboxymethylcellulose, with a degree of substitution equal to 1.2 (CMC BLANOSE® 12M8P from AQUALON) is placed in solution in distilled water. The solution is then added to the mother dispersion of nanofibrils at 2.3% in cellulose nanofibrils and prehomogenized in the Ultra-Turrax at 14,000 revolutions / min (1 minute for 100 g of suspension). The whole is shaken with a deflocculating shovel at 1,000 rpm for 30 minutes.

The amount of carboxymethylcellulose added is 15% by weight, based on the weight of the cellulose nanofibrils and carboxymethylcellulose. The mixture is then poured into the cups and then dried either in a ventilated oven at 40 ° C, up to a dry extract of 92%, controlled by water dosing by the KARL-FISCHER method. The dry mixture is then crushed, then sieved on a 500 μm sieve. The powder obtained is redispersed at a rate of 0.43% by weight of cellulose nanofibrils and carboxymethylcellulose in distilled water. The agitation is carried out with the deflocculating paddle at 1000 rpm for 5 minutes or 30 minutes. This dispersion is put into operation in the following examples.

EXAMPLE 2 Behavior of NFCs associated with CMC in alcoholic medium To do this, the NFC / CMC mixture prepared in Example 1 is dispersed in water, under shear, then the alcohol considered is added or not. Table I presented below accounts for the composition of two hydroalcoholic media prepared in this way. The viscosities of these media and a control medium (water) are evaluated with the help of a BROOKFIELD LVT type viscometer. The results are shown in Table I.

TABLE I EXAMPLE 3 Behavior of NFCs associated with CMC in acid or alkaline media The NFC mixture prepared according to Example 1 is introduced in buffered water at a pH of 4 or 9. The rheological behavior of this medium is appreciated with respect to a control medium comprising 1% of microcrystalline celluloses added with CMC. Table II accounts for the evaluation of viscosity over time.

TABLE II Agent Viscosity Pa.s Texturizer 1 s "1 100 s" 1 J pH = 4 pH = 9 pH = 4 pH = 9 0. 43% of added NFC ij 0.35 0.55 0.015 0.02 85/15 CMC 5j 0.35 0.65 0.015 0.02 1% of Celluloses ij 0.02 0.03 microcrystalline added- with CMC 5j 0.02 0.03 It is noted that NFC formulated according to the invention prove to be excellent structuring agents of cosmetic media and retain their properties over time. Its viscosifying power is superior to that of the microcrystalline celluloses.

EXAMPLE 4 Cosmetic formulations according to the invention These formulations contain the NFC / CMC mixture prepared in the Example. 1. 1) Cream with a-hydroxy acids Ingredients% by weight Phase A • Cetearyl alcohol 8 • Diethylamine cetyl phosphate 2 • Eicosene / PVP 2 copolymer • Octyldodecyl neopentanoate 10 • Mirasil® DM 300: Dimethicone 1 Phase B • NFC / CMC 0.2 • Propylene glycol 5 • Water c.b.p. 100 Phase C • Alpha hydroxy acids Phase D • Triethanolamine 1.8 Phase E • Conservative c. s. s 2) Gentle body scrub Ingredients% by weight Phase A • Water c.b. p. 100 Phase B • NFC / CMC Phase C • Magnesium Lauryl Sulfate 8.5 • Cocoilsarcosinate sodium 1.0 • 55% sodium hydroxide 0.50 • Diethylamine Lauramide 2.0 • Stearic acid 1.0 • Géropon AC78® sodium 13 cocoyl isethionate Phase D • Polyethylene oxide 20 Conservative Phase E c. s. s Perfume and coloring c. s. s 3) Epilator lotion Ingredients% by weight Phase A • NFC / CMC 0.5 • Water c.b.p. 100 Phase B • Propylene glycol Phase C • Mineral oil and lanolin alcohol • Polysorbate 80 and cetyl acetate and acetylated lanolin alcohol • PEG-100 stearate and glyceryl stearate Phase D • Calcium thioglycollate 5 • Calcium hydroxide 6 Phase E • Preservative, coloring, perfume c.b.p. 100 EXAMPLE 5 Behavior of NFC bound to CMC as a reinforcing agent of a film-forming polymer dispersion The purpose of this example is to show that the association of nanofibrils with at least one (polyOH) can also be a reinforcing agent. The tests were carried out with a film-forming latex Rhodopas DS 1003 marketed by Rhodia- (aqueous dispersion of acrylic polymer), whose vitreous transition temperature Tg is 12 ° C, the film forming temperature TMF lower than 5 ° C , the dry extract of the dispersion is 50%, and the granulometry of said latex is 0.1 μm. The dispersion has a pH equal to about 8. The dispersion of cellulose nanofibrils obtained in Example 1 from the dry powder is used in this example.

Formulation that can serve as a base for aqueous nail varnish Two formulations based on latex DS 1003 are prepared as defined above: Fl (comparative): 30% by weight of latex 1003 + 70% by weight of water, based on the total weight of the formulation; F2 (according to the invention: 30% by weight of latex 1003 + 1% by weight of NFC obtained in Example 1 + 69% by weight of water, based on the total weight of the formulation.) The pH of the medium is adjusted a 7. Fl has a viscosity lower than 10 mPa.s while - the viscosity of F2 is approximately 4500 mPa.s. The viscosities are evaluated with the aid of a viscosimeter of the type BROOKFIELD LVT (needle 3, 10 rpm). Results are described in Table III.

TABLE III The Persoz hardness is determined according to the NFT 30-016 standard: the hardnesses are measured after more than 8 days of drying to the environment in 3 different places of the plate. Each measurement corresponds to the average of 3 measurements. The results indicate the time (in seconds) it takes for the pendulum to decrease its oscillation from an angle of 12 ° to an angle of 4 °. The time is so much longer when the film is "hard". Adhesion on the support is determined by a grid test according to the standard ISO 2409: films have been shot on a steel plate. The test consists of using a cutter to graph the film of 2 series of 6 perpendicular strokes spaced 1 mm apart and to tear off this grid with adhesive tape. The rating goes from 0 (without tearing) to 4 (tearing off approximately 50% of the grid). The formulation F2 comprising the added NFCs of the invention thus corresponds to a material that can serve as a base for aqueous varnishes. The formulation F2 obtained is stable. Of pseudoplasic character, it spreads easily on the supports. The film has a good adhesion, and a good flexibility with a touch feeling neither greasy nor sticky.

Claims (16)

1. Use of essentially amorphous cellulose nanofibrils having a crystallinity ratio or ratio of less than or equal to 50% under a dispersible dry form, associated with at least one polyhydroxylated organic compound (polyOH), as a texturizing and / or reinforcing agent in cosmetic formulations.

2. Use in accordance with the claim 1, characterized in that the polyhydroxylated organic compound (polyOH) is chosen from carbohydrates and their derivatives and polyalcohols.

3. Use in accordance with the claim 2, characterized in that the carbohydrates are preferably chosen from the linear or cyclic onosaccharides of 3 to 6 carbon atoms, the oligosaccharides, the polysaccharides and their fatty derivatives such as the sucrose esters of fatty acids, the carbohydrates of alcohol, acids and ethers.

4. Use according to any of claims 1 to 3, characterized in that the polyhydroxylated organic compound (polyOH.) Is preferably chosen from carboxymethylcellulose, xanthan gum, guar, sorbitol, sucrose and mixtures thereof.

5. Use according to any of claims 1 to 4, characterized in that the crystallinity ratio is between 15 and 50% and preferably less than 50%.

6. Use according to any of claims 1 to 5, characterized in that the cellulose nanofibrils have at least 80% of cells with primary walls.

7. Use according to any of claims 1 to 6, characterized in that the cellulose nanofibrils are from cells preferably consisting of at least about 80% of primary walls.

8. Use according to any of claims 1 to 7, characterized in that the cellulose nanofibrils are loaded with carboxylic acids and acidic polysaccharides, alone or as a mixture.

9. Use according to any of claims 1 to 8, characterized in that the polyhydroxylated organic compound is associated with the cellulose nanofibrils in a weight ratio (polyOH) x 100 / [(polyOH) + (NFC)] greater than or equal to 5%. % and less than or equal to 50%.

10. Use according to claim 9, characterized in that the weight ratio (polyOH) x 100 / [(polyOH) + (NFC)] is greater than or equal to 5% and less than or equal to 30%.

11. Use according to any of claims 4 to 10, characterized in that the cellulose nanofibrils are associated with those of carboxymethylcellulose (CMC), with a high degree of substitution in a weight ratio (CMC) x 100 / [(CMC) + (NFC)] greater than or equal to 5% and less than or equal to 25%.

12. Use according to any of the preceding claims, characterized in that the amount of mixture of cellulose nanofibrils and (polyOH) (s) is adjusted so that said nanofibrils are used in a proportion of 0.1 to 20% by weight of the cosmetic formulation .

13. Use according to claim 12, characterized in that the nansfibrils are used at a ratio of 0.15% to 5% by weight.

14. Use according to any of the preceding claims, characterized in that the cellulose nanofibrils and the (polyOH) are associated to at least one coaddit selected from: • the compounds of the formula (R1R2N) COA, in which R1 or R2 identical or different , represent hydrogen or an alkyl radical of 1 to 10 carbon atoms, preferably of 1 to 5 carbon atoms, A represents hydrogen, an alkyl radical of 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms; carbon, or even the group R 'XR' 2N with R'1, R'2, identical or different, representing hydrogen or an alkyl radical of 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms; and • the anionic, non-anionic or amphoteric surfactants, these co-additives being used alone or as a mixture.

15. Use according to claim 14, characterized in that the proportion of the compound (s) polyhodroxylate (s) and coadjutor (s) is greater than or equal to 5% by weight and less than or equal to 30% by weight relative to the weight of the nanofibrils, polyhydroxylated compound (s) and co-additive (s).

16. Cosmetic formulation, characterized in that it comprises as a texturizing and / or reinforcing agent nanofibril essentially amorphous cellulose under a dispersible dry form, and associated with at least one polyhydroxylated organic compound, as defined according to claims 1 to 13 and according to the case at least one additive according to claim 14 or 15.