CN1280486A - Use of substantially amorphous cellulose nanofibrils associated with a polyhydroxylated 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 substantially amorphous cellulose nanofibrils in combination with at least one polyhydroxylated organic compound in cosmetic preparations

The present invention relates to the use of substantially amorphous cellulose nanofibrils in a form dispersible in cosmetic preparations, having a degree of crystallinity less than or equal to 50%, and the preparations obtained therefrom.

The present invention relates more particularly to novel thickeners and/or fortifiers for cosmetic formulations.

Within the meaning of the present invention, the term "cosmetic preparations" refers to those types described in Annex I (Table of Cosmetics Scope Explanation) of European Directive No. 76/768/EEC of 25.07. any cosmetics.

Cosmetic compositions are generally formulated into a variety of product types that are either applied to the hair, such as foams, gels (especially hairsprays), conditioners, for hair styling or to facilitate detangling and/or detangling formulations, or rinse-off formulations, or applied to the skin, such as hand and body washes, skin moisture-regulating products, skin cleansers, make-up removal compositions, depilatory products, creams or washes for sun and UV radiation protection Lotions, care creams, anti-acne preparations, topical analgesics, cosmetic preparations of the mascara, foundation or nail polish type, products intended to be applied to the lips or other mucous membranes, lip balms, solid compositions of the soap type and the like other preparations.

Usually, these various formulations include, in addition to one or more active ingredients specific to the intended application, a certain amount of so-called more general compounds whose specific role is to confer long-term stability (e.g. preservatives) and /or special drug preparation form (such as gel, cream, milk or lotion type). They are generally surfactants and/or dispersants, stabilizers, emulsifiers, wetting agents, gelling agents or thickeners.

As representatives of universal stabilizing and/or thickening agents, mention may in particular be made of crosslinked polyacrylates, hydrocolloids obtained by fermentation such as Xanthane- ^Rhodicare® gums and succinoglycans such as ^Rhéozan® , cellulose derivatives such as hydroxy Propylcellulose or carboxymethylcellulose, or guar gum and derivatives thereof, alone or in combination.

One of the objects of the present invention is to provide novel thickeners and/or intensifiers having favorable properties with regard to the rheology of formulated cosmetic compositions. More specifically, it is an agent based on substantially amorphous cellulose nanofibrils having a crystallinity of less than or equal to 50% and which are dispersible in a medium containing dry form.

Natural cellulose is generally always in the form of fibrils. These fibrils are well known substances which have been specifically suggested for modifying the structure of the medium in which they are located. In the case of fluid media, they modify their viscosity and even their rheology.

Nanofibrils may be of various origins, such as from plants, bacteria, fungi or amoebae.

In plant fibers or cell walls, strong association forces generally exist between nanofibrils. Among the cell walls a distinction can be made between secondary walls mainly obtained from wood, primary walls typically exemplified by parenchyma. Examples of parenchyma consist of beet pulp, citrus (lemon, tangerine, grapefruit) and most fruits and vegetables. In the secondary wall, these fibrils are arranged in highly oriented sheets, forming inseparable fibers. They are usually in the form of aggregates ranging from tens of nanometers to several micrometers. These aggregates consist of monomeric fibrils that cannot be dislodged during homogenization under conditions that do not lead to fragmentation.

Cellulose fibrils considered within the meaning of the present invention are essentially amorphous cellulose nanofibrils (CNF), preferably obtained from cells with primary walls.

The cellulose nanofibrils of the invention are advantageously obtained from cells consisting of at least about 80%, preferably at least 85% by weight of primary walls.

The substantially amorphous cellulose nanofibrils used in the present invention thus preferably have at least 80% cells with primary walls.

In contrast to the secondary wall cellulose fibrils discussed above, the cellulose nanofibrils are at most a few nanometers in diameter and they have the appearance of filaments which proved to be dissolvable during the homogenization stage.

They preferably have cross-sections from about 2 to about 10 nm, more preferably from about 2 to about 4 nm.

Within the meaning of the present invention, the nanofibrils considered are so-called substantially amorphous nanofibrils, as opposed to so-called crystalline fibrils.

The term "substantially amorphous" means that the defined nanofibrils have a crystallinity of less than or equal to 50%. According to a particular alternative of the invention, this degree of crystallinity is between 15 and 50%, more preferably less than 50%.

These substantially amorphous cellulose nanofibrils are particularly advantageous over crystalline microfibrils because they are dispersible in aqueous media, giving them a highly specific shear-thinning type of Rheological and stable to heat or in media with high ionic loads. The high effectiveness exhibited by cellulose nanofibrils at lower quantities is in fact the result of their excellent rheological behavior in terms of pour point and shear thinning capacity.

According to a preferred solution of the present invention, the surface of the cellulose nanofibrils used in the present invention is loaded with carboxylic acid and acidic polysaccharides present alone or in combination.

The term "carboxylic acid" refers to common carboxylic acids and their salts. These acids are preferably selected from uronic acids, more particularly galacturonic acid and/or glucuronic acid.

As acidic polysaccharides, mention may be made of pectin, including more particularly polygalacturonic acid. These acidic polysaccharides may be in admixture with hemicellulose.

In fact, these nanofibrils with surface loads are not obtained simply by mixing said nanofibrils with acids and polysaccharides. Rather, it involves an intimate association between these two types of compounds that results directly from the process used to make the nanofibrils. This is because this type of preparation can be such that the acids and polysaccharides may not be completely separated from the fibers, but remain on the surface of the fibers, giving them very specific properties. It is important to emphasize that these same properties cannot be reproduced if the nanofibrils are then completely separated from these acids and/or polysaccharides and then added to the nanofibrils thus obtained. of.

More specifically, the present invention aims to use these cellulose nanofibrils in solid redispersible form together with at least one polyhydroxylated (polyOH) organic compound.

The subject of the present invention is thus substantially amorphous cellulose nanofibers in dry dispersible form, in combination with at least one polyhydroxylated (polyOH) organic compound, with a degree of crystallinity less than or equal to 50%. Use of silk as thickener and/or strengthening agent in cosmetic preparations.

A thickener within the meaning of the present invention is an agent which has a stabilizing and thickening effect in the cosmetic composition comprising it.

Within the scope of the present invention, a reinforcing agent is an agent capable of improving the mechanical properties of a composition to which the agent is added in wet or dry form.

Furthermore, it has also been observed that the compositions of the present invention act as emulsifiers and stabilizers even in aqueous media containing surfactants.

The use of cellulose nanofibrils combined with at least one (polyOH) in dry form is not only economically advantageous with respect to e.g. storage and transport, but also from a technical point of view, because, Using the dry redispersible form it is possible to prepare aqueous suspensions with a high content of dry active substance.

The use of such cellulose nanofibrils in dry redispersible form as thickener and/or strengthening agent in cosmetic compositions has surprisingly proven to be advantageous in many respects.

For example, in the particular case of cosmetic preparations for dermal application of the cream type, for example, a marked increase in the skin penetration of said preparations is noted. During the application of these formulations, no "soaping" was observed on the surface of the skin. Finally, the cellulose nanofibrils of the present invention impart a very soft skin feel, and have the effect of tightening and protecting the skin surface, and also have a moisturizing effect.

In the particular case of hair cosmetic preparations, the addition of cellulose nanofibrils in combination with at least one polyhydroxy organic compound enhances the styling action.

The use of said composition with dissolved water-soluble film-forming polymers or dispersed water-insoluble film-forming polymers results in a film-forming substance which exhibits good adhesion to the keratinous substrate, has both Cosmetic feel that is not greasy or sticky.

The water-soluble film-forming polymer used in the present invention can be:

- synthetic water-soluble film-forming polymers with a low glass transition temperature Tg (preferably lower than or equal to 20° C.);

- Water-soluble film-forming polymers of natural origin (polysaccharides derived from cellulose), generally having a Tg greater than or equal to 40°C.

Mention may be made, for example, of poly(vinyl alcohol), hydroxyethylcellulose, cellulose ethers commonly used in cosmetics, guar gum or carob gum.

Also, in contrast to common thickeners, the cellulose nanofibrils of the invention do not affect the cosmetic properties of the formulations to which they are added. Advantageously, no curbing effect or loss of gloss is observed for said compositions, and no decrease in water resistance is seen.

Furthermore, it has been confirmed that it has a fragrance-enhancing effect.

As mentioned above, the incorporation of said cellulose nanofibrils with at least one (polyOH) carried out during the preparation of said cellulose nanofibrils has the advantage that they can be formulated in a dry dispersible form. This is of course a potential advantage for the preparation of corresponding cosmetic preparations, in particular the greater flexibility afforded for formulation due to the high content of active ingredient.

The polyhydroxylated (polyOH) organic compounds are preferably selected from carbohydrates and their derivatives and polyols.

As representatives of these carbohydrates, mention may in particular be made of C _3-6 , preferably C ₅ or C ₆ cyclic or linear monosaccharides, such as fructose, mannose, galactose, sucrose, talose, gulose, Allose, altrose, idose, arabinose, xylose, lyxose and ribose, oligosaccharides such as maltose and lactose, polysaccharides such as starch, cellulose, xanthan gum and guar gum, and Their fatty derivatives, such as fatty acid sugar esters, alcohol sugars such as sorbitol and mannitol, acid sugars such as gluconic acid, uronic acid and galacturonic acid and their salts, and ether sugars such as cellulose Base-, ethyl-, carboxymethyl-, hydroxyethyl- and hydroxypropyl-ethers.

As regards the polyols, these may in particular be glycerol, pentaerythritol, propylene glycol, ethylene glycol and/or poly(vinyl alcohol).

In the particular case of the use of carbohydrates and their derivatives together with substantially amorphous cellulose nanofibrils, more particular mention may be made of carboxylated cellulose, preferably carboxymethylated cellulose, the latter also Expressed in CMC.

Cellulose is a polymer composed of glucose monomer units: the degree of polymerization can vary over a wide range. The carboxylated groups are introduced into the cellulose in a manner known per se by reacting chloroacetic acid with the cellulose. The degree of substitution then corresponds to the number of carboxymethyl groups per glucose unit. The theoretical maximum degree of substitution is 3. These carboxylated celluloses are considered to have a high degree of substitution when their degree of substitution value is greater than 0.95, and are considered to have a low degree of substitution when their degree of substitution is below this value.

Thus, suitable are high-quality carboxymethylated celluloses in which the carboxylated cellulose content is greater than or equal to 5% by weight and less than or equal to 30% by weight, or low-quality carboxymethylated celluloses in which the carboxylated cellulose content is more particularly 10 to 30% by weight. methylated cellulose.

For the same mass, it has also been shown that its proportion relative to the nanofibrils can be further reduced by favoring the selection of carboxymethylated cellulose with a high degree of substitution.

Such mixtures of cellulose nanofibrils and carboxylated cellulose are disclosed in particular in applications PCT/FR9701291 (publication number WO98/02487) and PCT/FR9701290 (publication number WO98/02486).

Such polyhydroxylated (polyOH) organic compounds are preferably selected from carboxymethylcellulose, xanthan gum, guar, sorbitol, sucrose and mixtures thereof.

The cosmetic preparation obtained by the present invention is preferably greater than or equal to 5% and less than or equal to 50%, preferably greater than or equal to 5% and less than or equal to 30% consisted of polyhydroxylated compound(s) and cellulose nanofibrils.

According to an advantageous form of the invention, they comprise cellulose nanofibrils in combination with highly substituted carboxymethyl cellulose (CMC) with a weight ratio of (CMC)×100/[(CMC)+(CNF)] greater than Or equal to 5% and less than or equal to 25%.

Another polyhydroxylated derivative such as sucrose, propylene glycol or poly(ethylene glycol), for example, can also be combined with CMC. In this particular case, the (CMC) x 100/[(multi-OH) _total +(CNF)] weight ratio drops significantly.

With regard to the amounts of cellulose nanofibrils and (polyOH) which can be used according to the invention, they obviously depend on the targeted effect of the pharmaceutical dosage form and/or cosmetic preparation, for example, a moisturizing effect or, as in depilatory preparations, Protective effect of the epidermis.

Thus, the thickener of the present invention is present in a greater amount in cream-type pharmaceutical formulations compared to the amount employed in liquid formulations.

The amount of the mixture of cellulose nanofibrils and polyOH is preferably adjusted such that said nanofibrils are present in a ratio of about 0.1 to 20% by weight of the cosmetic formulation, more preferably about 0.15 to 5% by weight.

As an illustration, concentrations of cellulose nanofibrils and (poly-OH) can be suggested in the range of 0.11 to 40% for the preparation of cream type formulations and 0.11 to 10% for the preparation of liquid type formulations . Suggested values for the weight ratio of (poly-OH) x 100/[(poly-OH)+(CNF)] are greater than or equal to 5% and less than or equal to 50%.

The cellulose nanofibril redispersible solid composition used in the present invention can also include at least one auxiliary additive selected from the following materials in addition to the polyhydroxylated organic compounds defined above:

A compound of general formula (R ¹ R ² N)COA, wherein R ¹ or R ² are the same or different, represent hydrogen or C _1-10 , preferably C _1-5 alkyl, A represents hydrogen, C _1-10 , Preferably a C _1-5 alkyl or group R ^{`1</sup> R <sup>`2} N, wherein R ^{`1</sup> or R <sup>`2} are the same or different and represent hydrogen or C _1-10 , preferably C _1-5 alkyl; and

·Anionic, nonionic or amphoteric surfactants, these two auxiliary additives can be used alone or in combination.

As representatives of these surfactants, mention may in particular be made of those indicated herein below.

It should be noted that the use of these co-additives in combination with (polyOH) such as carboxymethylcellulose can enhance the shear thinning properties of cellulose nanofibrils after redispersion.

With regard to compounds of the (R ¹ R ² N)COA type, preference is given to using compounds comprising two amide functions. Preference is given to using urea as co-additive.

According to a particular embodiment of the present invention, these solid redispersible compositions of substantially amorphous cellulose nanofibrils comprise carboxylated cellulose with a high degree of substitution and at least one surfactant selected from the group consisting of compound of.

When the cellulose nanofibrils used in the present invention are combined with one or more polyhydroxylated compounds and one or more of the above-mentioned auxiliary additives, the content of the polyhydroxylated compounds and auxiliary additives is greater than or equal to that of the nanofibrils, polyhydroxylated compounds 5wt% and less than or equal to 30wt% of the hydroxylated compound and co-additives.

The nanofibrils used in the present invention can be obtained by various methods disclosed in the literature.

Particular mention may be made of the process disclosed in European patent application EP-A-726356.

Wherein slurries obtained from plants with primary walls, ie dehydrated, silage-preserved or partially depectinized wet slurries such as sugar beet pulp, are subjected to this process after pre-extraction of sucrose according to methods known in the art. More specifically, this treatment employs a first step of acidic or basic extraction, at the end of which a first solid residue is recovered, which can also be followed by a second step under basic conditions extraction, recovery of the second solid residue, washing of the combined two residues consisting of cellulosic material followed by bleaching, dilution of the third solid residue obtained at the end of the bleaching stage, and subsequent dilution of the resulting suspension , to achieve a dry matter amount of 2 to 10% by weight, and finally, a homogenization step comprising at least one cycle of said diluted suspension.

This homogenization step corresponds to any mixing, grinding operation or any operation of high mechanical shear followed by passing the cell suspension one or more times through small diameter orifices, subjecting the suspension to a pressure drop of at least 20 mPa and high velocity Shearing action, followed by a high-speed deceleration impact. Homogenization of the cellulosic suspension is obtained by several passes, which may be from 1 to 20, preferably from 2 to 5, until a stable suspension is obtained.

For detailed procedures of the various stages of this process, reference is made to the specification of the above-mentioned application.

The method just described makes it possible to obtain nanofibrils having carboxylic acids and/or polysaccharides retained on their surface.

In the case of the cellulose nanofibrils used according to the invention, polyhydroxylated compounds, for example of the carboxylated cellulose type, are introduced into the above-mentioned production procedure before the homogenization stage or after the homogenization cycle has been carried out.

It should be noted that this alternative method form is disclosed in International Patent Application No. PCT/FR 97/01291 (published as WO 98/02487), and reference may be made to this document if necessary.

Process for the preparation of polyhydroxylated cellulose nanofibrils comprising, in a first stage, adding at least a portion of the polyhydroxylated compound under consideration and also Co-additive(s) may be added. Then, in a second stage, a stage of drying the suspension thus added is carried out.

In fact, at least a part of the polyhydroxylated compound and possibly the auxiliary additive(s) may be added in three alternative forms:

- can be added to said suspension at the end of the homogenization phase and preferably after at least one concentration step,

- or to the suspension at the end of the homogenization stage before the suspension is subjected to at least one concentration step, or

- Addition before or during the homogenization stage, when the slurry has passed through at least one cycle of the homogenization stage.

The concentration stage(s) can be carried out by any common means until a dry extract of about 35% by weight is obtained. More specifically, the content of the dry extract is 5 to 25 wt%.

Before the drying stage in the strict sense, it is advantageous to shape the already concentrated suspension, ie by extrusion or granulation. The temperature of the drying stage is of course chosen such that the decomposition of carboxylic acids, acidic polysaccharides, hemicelluloses, polyhydroxylated compounds and, if appropriate, co-additives is limited. More particularly from 30 to 80°C, preferably from 30 to 60°C.

The drying stage is carried out by common means to maintain a minimum moisture of 3% by weight relative to the weight of the solids produced. More particularly, the weight of water retained is from 10 to 30% by weight. Such an embodiment does not allow exceeding the limit at which the nanofibrils will not be fully redispersible.

The cellulose nanofibril suspension obtained by redispersing in water the mixture obtained according to the above procedure advantageously exhibits a viscosity value corresponding to the undried stage and both for a shear rate of at least 1 s ⁻¹ At least 50% of the viscosity value of the suspension of cellulose nanofibrils without polyhydroxylated compounds and co-additives.

Of course, the substantially amorphous surface is loaded with substances (preferably acid), with polyhydroxylated compounds and possibly with co-additives in combination with cellulose nanofibrils for at least one combination with hair, skin or sunscreen applications. Compatible carrier mixtures are used in the cosmetic preparations obtained according to the invention.

The term "compatible with application on the hair and/or skin" means here that the carrier does not spoil or negatively affect the appearance of the hair and/or skin, does not irritate the skin and/or the eyes and/or the scalp effect.

Another subject-matter of the present invention is a cosmetic preparation in which essentially amorphous cellulose nanoparticles in dry dispersible form in combination with at least one polyhydroxylated organic compound as defined above are used as thickener and/or strengthening agent. Fibril. These formulations may also include the additives defined above.

The cosmetic preparations according to the invention preferably contain one carrier or a mixture of several carriers, which are present in the preparation at a concentration of about 0.5 to 99.5%, more preferably about 5 to 90%.

Carriers compatible with the formulations of the invention include, for example, those employed in sprays, foams, tonics, gels, shampoos or emulsion-type hair treatments.

The selection of an appropriate carrier will of course depend on the particular application for which the formulation is intended. Carriers suitable in formulations to remain on the surface to which they are applied (e.g. sprays, foams, lotions, tonics or gels) for formulations to be rinsed off after use (e.g. conditioners, emulsion hair conditioners) ) is not appropriate.

The carriers that can thus be used may be simple or complex and may include a large number of products commonly used in cosmetic preparations for hair, skin or sun protection.

It is thus possible to add solubilizers to dissolve or disperse the active components used, such as C _1-6 alcohols and mixtures thereof, in particular ethanol, isopropanol or propylene glycol and mixtures thereof.

Advantageously, the cellulose nanofibrils combined with at least one polyhydroxy organic compound exhibit good compatibility with alcohol solubilizers. The structure-modifying properties of these cellulose nanofibrils were not adversely affected in aqueous/alcoholic media.

Also, they retain their properties in so-called more aggressive media, i.e. very acidic media, such as creams with alpha-hydroxy acids, or alkaline media, such as depilatory preparations or Perm solution.

Examples 2 and 3 given herein below illustrate the advantageous properties exhibited by cellulose nanofibrils in combination with at least one polyOH in cosmetic applications.

The CNFs formulated according to the invention advantageously prove to be excellent structurants for cosmetic vehicles and retain their properties over time. Their thickening ability is greater than that of microcrystalline cellulose.

One or more emollients selected from the group consisting of mineral oils (such as Marcol 82 ^® ), vegetable oils or oils of marine origin, halogenated hydrocarbons can also be mixed in the fatty phase separated from the aqueous phase of the CNF according to the invention , linalool, esters (such as isopropyl myristate) and polysiloxanes compatible with cosmetic applications (especially cyclomethicone and dimethicone and derivatives and hexamethicone Methyldisiloxane) and its derivatives or mixtures.

When the cosmetic formulation is in the form of a spray, tonic lotion, gel or foam, preferred solvents include water, ethanol, volatile silicone derivatives, and mixtures thereof. The solvents used in these mixtures may be miscible or immiscible with each other. Aerosol sprays and foams can also employ any propellant that produces the product in the form of a uniform finely divided spray or foam. By way of example, mention may be made of dimethyl ether, propane, n-butane or isobutane.

In the case of cosmetic preparations intended for surface topical application, the carrier must have good comfort properties, be compatible with all other components and be completely harmless.

These carriers can take many forms, such as emulsion, foam or spray type. For example, carriers in the form of emulsions include water-in-silicone, water-in-oil, oil-in-water and oil-in-water-in-silicone emulsions. These emulsions cover a wide range of viscosities, eg from 100 to 20000 mPa.s at 25°C. These emulsions can also be delivered in the form of aerosols by use of mechanical pump-like devices or pressurization with a propellant gas.

These carriers can also be delivered in the form of foams.

In addition to the aforementioned carriers, the cosmetic preparations according to the invention may also comprise surfactants for dispersing, emulsifying, dissolving or stabilizing the various compounds used which are required especially for softening or wetting properties. They may be anionic, nonionic, cationic, zwitterionic or amphoteric. As examples of such compounds, more particular mention may be made of:

- anionic surfactants, such as alkyl sulfonates, alkyl sulfates, alkylamide sulfates and saturated or unsaturated fatty acid salts;

- nonionic surfactants such as polyoxyalkylene alkylphenols, glucosamides, glucamides or glyceramides derived from N-alkylamines, polyoxyalkylene _C8-22 fatty alcohols, Products obtained from the condensation of ethylene oxide with hydrophobic compounds or from the condensation of propylene oxide with propylene glycol, amine oxides, alkyl polyglycosides and their polyoxyalkylene derivatives, _C8-20 fatty amides and ethoxylates Sylated fatty acids, amides, amines or amidoamines;

- Amphoteric or zwitterionic surfactants, such as those of the betaine type, such as betaines, sultaines, amidoalkylbetaines and sultaines, alkylsultaines, fatty acids and protein hydrolysates Condensation products, cocoamphoacetates and cocoamphodiacetates, alkylamphopropionates or amphodipropionates, or amphoteric derivatives of alkylpolyamines.

Conditioning agents may also be present.

Among these may be mentioned those of synthetic origin better known by the name quaternized hydroxyethyl cellulose, such as quaternized hydroxyethyl cellulose-2, quaternized hydroxyethyl cellulose-7 and quaternized hydroxyethyl cellulose cellulose-10, cationic derivatives of polysaccharides such as cocodimonium hydroxyethyl cellulose, guar hydroxypropyl trimonium chloride or hydroxypropyl guar hydroxypropyl trimonium chloride, or non-volatile polysiloxanes Derivatives such as amodimethicone, cyclomethicone or water-insoluble and non-volatile organopolysiloxanes such as oils, resins or gums such as diphenyl dimethicone gum.

The cosmetic preparations may also comprise polymers having film-forming properties, which act as fixatives. These polymers are generally present in concentrations of 0.01 to 10%, preferably 0.5 to 5%. They are preferably of the following types: polyvinylpyrrolidone, copolymers of polyvinylpyrrolidone and methyl methacrylate, copolymers of polyvinylpyrrolidone and vinyl acetate, poly(ethylene terephthalate)/poly(ethylene diol) copolymer or sulfonated terephthalic acid copolyester polymer.

The cosmetic preparations may also contain polymeric derivatives, such as cellulose derivatives, polyvinyl esters grafted onto polyolefin backbones, polyethylene Alcohols, sulfonated terephthalate copolyester polymers, ethoxylated monoamines or polyamines, and ethoxylated amine polymers.

Wetting agents may also be incorporated into the cosmetic preparations. Mention may especially be made, by way of example, of glycerol, propylene glycol, urea, collagen, gelatin and emollients, usually selected from the group consisting of alkyl monoglycerides, alkyl diglycerides, or triglycerides, Such as oils extracted from plants and vegetables or their hydrogenated derivatives, mineral oil or paraffin oil, glycols, fatty acid esters or polysiloxanes.

Also usually added to these compounds is one or more fragrances, colorants and/or opacifiers such as pigments.

To protect the skin and/or hair from the sun and UV radiation, sunscreens can be added to these formulations, which can be organic compounds that strongly absorb UV radiation or inorganic particles in the form of nanoparticles, such as zinc oxide, titanium dioxide or cerium oxide.

Active ingredients having purely cosmetic properties, such as vitamins, alpha-hydroxy acids, plant derivatives or seafood extracts, can be incorporated into said preparations comprising CNF for therapeutic purposes.

Likewise, CNF is a preferred thickener for depilatory formulations, such as calcium thioglycolate based vehicles.

According to Annex VII of the Cosmetic Regulations, preservatives such as parabens, sodium benzoate or common in cosmetic compositions to prevent bacteria or Any chemical agent for the growth of mold.

Finally, the cosmetic preparations may also contain thickening or gelling polymers, such as crosslinked polyacrylates of the ^Garbopol® type sold by Goodrich, cellulose derivatives, such as hydroxypropylcellulose or carboxymethylcellulose, Guar gum and its derivatives, such as hydroxypropyl guar gum, e.g. ^JaguarHP® , carob gum, thorn extract or cassia gum, xanthan gum, e.g. ^Rhodicare® , succinoglycans, alginates, carobium Carrageenan, chitin derivatives or any other polysaccharide with thickening effect.

Obviously, the choice of these said so-called universal compounds and the estimation of their corresponding quantities are directly related to the type of formulation designed, ie gel, cream, lotion, spray, lotion, etc., and the desired comfort. These adjustments are in fact just routine operational issues for cosmetics blenders.

The cosmetic product of the present invention can be advantageously used in the fields of hairdressing, sun protection, skin care and makeup.

The examples given below are for illustrative purposes only and are not meant to limit the invention.

Example 1

Preparation of a mixture of cellulose nanofibrils and carboxymethyl cellulose

Carboxymethylcellulose with a degree of substitution of 1.2 (CMC ^Blanose® 12M8P from Aqualon) was dissolved in distilled water.

Said solution was then added to a nanofibril dispersion mother liquor prehomogenized with an Ultra-Turrax at 14000 rpm (1 min per 100 g of dispersion) containing 2.3% cellulose nanofibrils. The combined mixture was stirred at 1000 rpm for 30 minutes with a defatting paddle.

The added amount of carboxymethyl cellulose is 15wt% of the total weight of cellulose nanofibrils and carboxymethyl cellulose.

The mixture is then poured into pans and dried, ie in a vented oven at 40° C. to a solids content of 92%, monitored by the Karl-Fischer method for water determination.

The dried mixture is subsequently ground and then sieved through a 500 μm sieve.

The resulting powder was redispersed in distilled water at a ratio of cellulose nanofibrils and carboxymethylcellulose at a ratio of 0.43 wt%. Stir for 5 minutes or 30 minutes at 1000 rpm with a defatting paddle. This dispersion was used in the following examples.

Example 2

Behavior of CNF mixed with CMC in alcoholic medium

To this end, the CNF/CMC mixture prepared in Example 1 was dispersed in water under shear, with or without the addition of the alcohol in question.

The compositions of the two aqueous/alcoholic media thus prepared are listed in Table I below. The viscosity of these media and a control medium (water) was evaluated using a Brookfield LVT type viscometer.

The results are shown in Table I.

Table I Added CNF 85/15 CMC 0.43% Viscosity, Pa.s 10% ethanol 10% propylene glycol distilled water 1s ^-1 0.8 0.85 0.60 100s ^-1 0.04 0.04 0.035

Example 3

Behavior of CNF mixed with CMC in acidic or basic media

The CNF mixture prepared in Example 1 was introduced into water buffered at pH 4 or 9. The rheological behavior of this medium was evaluated relative to a buffered medium containing 1% of microcrystalline cellulose with added CMC. The viscosity as a function of time is given in Table II.

Table II thickener Viscosity, Pa.s1s ^-1 100s ^-1 day pH＝4 pH＝9 pH＝4 pH＝9 0.43% adducted CNF85/15CMC 1 day 5 days 0.350.35 0.550.65 0.0150.015 0.020.02 1% microcrystalline cellulose with added CMC 1 day 5 days 0.020.02 0.030.03

It was noted that the CNF formulated according to the invention proved to be an excellent thickener for cosmetic media and maintained its properties unchanged over time. Their thickening ability is greater than that of microcrystalline cellulose.

Example 4

Cosmetic preparations according to the invention

These formulations contained the CNF/CMC mixture prepared in Example 1.

1) Creams with alpha-hydroxy acids

Component wt%

Phase A

□cetearyl alcohol 8

□Diethylamine hexadecyl phosphate 2

□Eicosene/PVP Copolymer 2

□Octyldodecyl pivalate 10

□ ^Mirasil® DM300: Dimethicone 1

Phase B

□CNF/CMC 0.2

□Propylene Glycol 5

□Water Appropriate amount to 100

Phase C

□α-hydroxy acid 5

D phase

□Triethanolamine 1.8

Phase E

□Preservatives Appropriate amount

2) Mild exfoliator for the body

Component wt%

Phase A

□Water Appropriate amount to 100

Phase B

□CNF/CMC 1

Phase C

□Magnesium lauryl sulfate 8.5

□Sodium cocoyl sarcosinate 1.0

□55% Sodium Hydroxide 0.50

□Diethylamine lauramide 2.0

□Stearic acid 1.0

□Geropon AC78 ^® : Sodium cocoyl isethionate 13

D phase

□Poly(ethylene oxide) 20

Phase E

□Preservatives Appropriate amount

□ Fragrance and coloring agent Appropriate amount

3) Hair removal solution

Component wt%

Phase A

□CNF/CMC 0.5

□Water Appropriate amount to 100

Phase B

□Propylene Glycol 5

Phase C

□Mineral oil and lanolin alcohol 5

□Polysorbate 80 and cetyl acetate and acetylated 2

lanolin alcohol

□PEG-100 stearate and glyceryl stearate 2

D phase

□Calcium Thioglycolate 5

□Calcium Hydroxide 6

Phase E

□Preservatives, coloring agents, fragrances The appropriate amount up to 100

Example 5

Behavior of CNF mixed with CMC as a film-forming polymer dispersion enhancer

The purpose of this example is to show that nanofibrils combined with at least one (poly-OH) can also be used as reinforcement.

The test was carried out with Rhodopas DS1003 film-forming latex (aqueous dispersion of acrylic polymer) sold by Rhodia, said latex having a glass transition temperature Tg of 12°C, a film-forming temperature TMF below 5°C, and a dispersion of The solids content was 50%, and the particle size of the latex was 0.1 μm. The pH of the dispersion is about 8.

The cellulose nanofibril dispersion obtained from the dry powder in Example 1 was used in this example.

Formulations that can be used as bases for aqueous nail polishes

Two formulations based on DS 1003 latex defined below were prepared:

F1 (contrast): 30wt% 1003 latex+70wt% water, based on the total weight of the preparation;

F2 (present invention): 30wt% 1003 latex + 1wt% CNF obtained in Example 1 + 69wt% water, based on the total weight of the preparation.

Adjust the pH of the medium to 7.

F1 exhibits a viscosity of less than 10 mPa.s, while F2 has a viscosity of approximately 4500 mPa.s. The viscosity is evaluated using a Brookfield LVT type viscometer (spindle 3, 10 rpm).

The results are listed in Table III.

Table III

F1 F2

Appearance of Film Formed Without Film Formed Translucent Film

Persoz hardness (seconds) - 49

Adhesion 0 (no separation)

Persoz hardness is determined according to NFT standard 30-016: Hardness is measured at three different points on the plate after drying at room temperature for more than 8 days. Each measurement corresponds to the average of 3 measurements. The results show the time (in seconds) required for the pendulum vibration to damp from an angle of 12° to an angle of 4°.

This time increases as the "hardness" of the film increases.

Adhesion to the substrate was determined by cross-hatch test according to ISO standard 2409: Films were produced on steel plates. The test consists of using a knife to cross-hatch in 2 columns of 6 vertical lines spaced 1 mm apart, and tearing off this square with adhesive tape. Grading ranges from 0 (no separation) to 4 (squares separated by approximately 50%).

Formulation F2 comprises the additive-containing CNFs according to the invention and thus corresponds to substances which can be used as aqueous binders. The formulation F2 obtained was stable. Pseudoplastic formulations are readily coated on substrates. The film has good adhesion and good elasticity, and it feels neither greasy nor sticky.

Claims (16)

1. Essentially amorphous cellulose nanofibrils in dry dispersible form, in combination with at least one polyhydroxylated (polyOH) organic compound, with a degree of crystallinity less than or equal to 50%, for use in cosmetic preparations as an enhancer Use of Thickeners and/or Strengthening Agents. 2. Use according to claim 1, characterized in that the polyhydroxylated (polyOH) organic compounds are selected from sugars and their derivatives and polyols. 3. The purposes of claim 2, it is characterized in that said sugar is preferably selected from C _3-6 cyclic or linear monosaccharides, oligosaccharides, polysaccharides and fatty acid derivatives thereof such as fatty acid sugar esters, alcohol sugars, acid sugars and ether sugar. 4. Use according to any one of claims 1 to 3, characterized in that the polyhydroxylated (polyOH) organic compound is preferably selected from carboxymethylcellulose, xanthan gum, guar gum, sorbitol, sucrose and mixtures thereof. 5. Use according to any one of claims 1 to 4, characterized in that the degree of crystallinity is from 15 to 50%, preferably less than 50%. 6. Use according to any one of claims 1 to 5, characterized in that the cellulose nanofibrils have at least 80% cells with primary walls. 7. Use according to any one of claims 1 to 6, characterized in that the cellulose nanofibrils are derived from cells preferably consisting of at least about 80% primary walls. 8. Use according to any one of claims 1 to 7, characterized in that the cellulose nanofibrils are loaded with carboxylic acids and acidic polysaccharides alone or in mixture. 9. The purposes of any one of claims 1 to 8, characterized in that the polyhydroxylated organic compound and sodium cellulose fibrils are greater than (multi-OH) × 100/[(multi-OH)+(CNF)] weight Or equal to 5% and less than or equal to 50% mixed. 10. Use according to claim 9, characterized in that the weight ratio of (poly-OH) x 100/[(poly-OH)+(CNF)] is greater than or equal to 5% and less than or equal to 30%. 11. The purposes of any one of claims 4 to 10, characterized in that the cellulose nanofibrils and high degree of substitution carboxymethyl cellulose (CMC) in (CMC) × 100/[(CMC)+( CNF)] weight ratio greater than or equal to 5% and less than or equal to 25% mixed. 12. Use according to any one of the preceding claims, characterized in that the amounts of cellulose nanofibrils and (polyOH) mixture are adjusted such that said nanofibrils are used in proportions of 0.1 to 20% by weight of the cosmetic preparation. 13. The use according to claim 12, characterized in that the nanofibrils are used in a proportion of 0.15 to 5 wt%. 14. Use according to any one of the preceding claims, characterized in that the cellulose nanofibrils and (polyOH) are mixed with at least one co-additive selected from: A compound of general formula (R ¹ R ² N)COA, wherein R ¹ or R ² are the same or different, represent hydrogen or C _1-10 , preferably C _1-5 alkyl, A represents hydrogen, C _1-10 , Preferably C _1-5 alkyl or R ^{`1</sup> R <sup>`2} N, wherein R ^{`1</sup> or R <sup>`2} are the same or different, represent hydrogen or C _1-10 , preferably C _1-5 alkyl; and ·Anionic, nonionic or amphoteric surfactants, these auxiliary additives can be used alone or in combination. 15. Use according to claim 14, characterized in that the content of polyhydroxylated compounds and co-additives is greater than or equal to 5 wt% and less than or equal to 30 wt%, based on the weight of nanofibrils, polyhydroxylated compounds and co-additives. 16. Cosmetic preparation, characterized in that it comprises, as thickener and/or intensifier, the substantially amorphous, dry The cellulose nanofibrils may be in dispersible form and, if appropriate, also mixed with at least one additive according to claim 14 or 15.