FR3117867A1 - Natural wax microdispersion - Google Patents

Abstract

Microdispersion of natural wax The present invention relates to a composition comprising a microdispersion of particles of natural wax with a volume-average diameter D[4;3] of less than 500 nm, characterized in that it comprises: - from 0.1 to 30% by weight of at least one wax of natural origin with a melting point Tm in the range from 50 to 100° C., - from 3 to 15% by weight of at least one nonionic surfactant chosen from esters of C8-C16 fatty acid and sugar, - at least 40% by weight of water, - at least 12% by weight of at least one polyol comprising at least three hydroxyls, on the total weight of the composition representing 100% . The present invention also relates to a method of making a natural wax microdispersion; as well as a non-therapeutic process for the cosmetic treatment of keratin materials, in particular for making up or removing make-up from the skin, including the scalp, the hair and/or the lips, comprising the application to the skin, the hair and/ or the lips, of a composition as defined according to the invention. Figure for abstract: Figure 3

Description

Natural wax microdispersion

Technical field of the invention

The subject of the present invention is fluid cosmetic compositions containing a microdispersion of wax, as well as a process for preparing these compositions, and their use, in particular in hairstyling or make-up products,

Background of the invention

The technology of wax microdispersions consists in transforming a wax in solid form into a liquid which can either be implemented directly in a formula by simple dilution in water, without a prior heating step, or directly applied as a cosmetic on materials. keratins.

Wax microdispersions are stable dispersions of colloidal particles

of wax, and are described in particular in "Microemulsions Theory and Practice",

15 L.M. Prince Ed., Academic Press (1977) pp. 21-32. In particular, these wax microdispersions can be obtained by melting the wax in the presence of a surfactant, and optionally of part of the water, then gradually adding hot water with stirring. The intermediate formation of an emulsion of the water-in-oil type is observed, followed by a phase inversion with final production of a microemulsion of the oil-in-water type. On cooling, a stable microdispersion of solid colloidal particles of wax is obtained. The wax microdispersions can also be obtained by stirring the mixture of wax, surfactant and water using stirring means such as ultrasound, a high pressure homogenizer, or turbines.

In the cosmetics field, such wax microdispersions can be used in particular as styling lotions giving volume to the hairstyle, more thickness to the hair; these lotions make it possible to obtain disciplined and sheathed hair up to their ends, which they make smooth. They also have the surprising property of not giving the hair a greasy appearance but on the contrary of delaying its appearance, although they contain a wax as their main active ingredient, i.e. a substance classified among the fat.

Thus, patent document EP394078B1 describes a stable microdispersion of particles with dimensions less than 500 nm, said particles consisting essentially of a wax with a melting point greater than 60° C., from 0.01 to 25% of at least a nonionic or anionic surfactant and at least 35% water, the wax/surfactant weight ratio possibly varying from 1 to 30. The surfactant used is most often nonionic, generally chosen from polyalkoxylated surfactants and/or polyglycerols, such as PEG-30-glyceryl stearate. Patent document EP446094B1 describes microdispersions, in which the anionic or nonionic surfactant is replaced by a cationic surfactant.

The formulation of cosmetic products that respect the environment is a major challenge today, in particular that of eco-designed, natural and/or of natural origin products. However, if the wax used in the microdispersions mentioned above is very natural, this is not the case for the surfactants currently used.

In addition, consumers expect these same cosmetic compositions to contain no, or as little as possible, preservatives or surfactants that are supposed to be irritating to the skin, such as those based on polyethylene glycol (PEG).

The object of the present invention is therefore to propose compositions of wax microdispersions which use the mildest and most natural ingredients possible, including as regards the surfactant, and this without compromising the stability performance of the microdispersions.

The Applicant has now found that the use of a particular nonionic surfactant according to a particular ratio with the wax, combined with the addition of at least one specific polyol in the wax microdispersion, makes it possible to obtain wax microdispersions stable. Surprisingly, the use of particular polyol(s) in a specific quantity of at least 12% by weight in combination with these microdispersions of natural waxes in the composition according to the invention, makes it possible both to effectively stabilize the microstructure of the composition and to protect it from microbial attack.

A subject of the present invention is therefore a composition comprising a microdispersion of natural wax particles with a volume-average diameter D[4;3] of less than 500 nm, characterized in that it comprises:

• from 0.1 to 30% by weight of at least one wax of natural origin with a melting point Tm in the range of 50 to 100°C,
• from 3 to 15% by weight of at least one nonionic surfactant chosen from C8-C16 fatty acid esters and sugar,
• at least 40% by weight of water,
• at least 12% by weight of at least one polyol comprising at least three hydroxyls,

on the total weight of the composition representing 100%.

The present invention also relates to a process for manufacturing a microdispersion of natural wax according to the invention, characterized in that it comprises at least the steps of:

- heating of said wax in the presence of said surfactant to a sufficient temperature Ts, preferably to a temperature Ts greater than or equal to the melting point of the mixture of wax and surfactant, optionally added with oil and/or fat-soluble substances, preferably at a temperature Ts comprised in the range from Tf to Tf+10° C., Tf being the melting temperature of the wax, to allow the wax to completely melt in the presence of the surfactant, then

- gradual addition of the aqueous phase at a temperature in the range from Tf-5°C to Tf+10°C, preferably from Tf-5°C to Tf+5°C, preferably from Tf-2°C to Tm+2°C, with stirring, preferably at a stirring speed comprised in the range of 100 to 1000 rpm, so that a microemulsion of molten wax in a continuous aqueous phase is obtained, then

- cooling the microemulsion until an aqueous microdispersion of wax particles is formed, preferably to room temperature, then

- addition, preferably at room temperature, of at least one polyol comprising at least three hydroxyls, according to a content of at least 12%, preferably comprised in the range of 12 to 20% by weight on the total weight of the composition.

A further subject of the present invention is a non-therapeutic process for the cosmetic treatment of keratin materials, in particular for making up or removing make-up from the skin, including the scalp, the hair and/or the lips, comprising the application to the skin, the hair and/or the lips, of a composition as defined according to the invention.

The composition in the form of a wax microdispersion according to the invention is stable even when it contains only a minimum number of ingredients, according to specific ratios, namely: water, a natural wax of high melting temperature (>50° C.) at a rate of 30% by weight, on the total weight of the composition, a natural surfactant, the latter ideally representing 1/4 of the wax rate, and at least 12% of a polyol.

In addition, the composition of the invention is advantageously of fluid texture, that is to say of viscosity generally less than or equal to 30 Pa.s, which is made possible by the size of the objects (average diameter by volume of the wax particles) less than or equal to 500 nm in the composition of the invention.

In addition, the composition of the invention has a fine and homogeneous film-forming effect, with an atypical sensory signature with a “grip” effect, a dry feel and therefore a natural rendering on keratin materials such as the skin or the hair. Such a composition finds applications in particular in the hair field where it is now sought to achieve extreme levels of fixation, volume, a "corporizing" effect, good definition of curls and better hold over time, or still in make-up products for its fine and homogeneous film-forming effect. The composition of the invention also makes it possible to respond to ecological issues, thanks to a selection of the most natural possible ingredients, and to safety issues, in particular thanks to the use of the most natural surfactant(s) and the sweetest possible. In the line of styling products as in the line of make-up products, a film-forming effect is obtained without the addition of fixing polymers.

The invention can be better understood on reading the detailed description that follows, non-limiting examples of implementation thereof, and on examining Figures 1 to 3.

is a photograph taken with SEM of a part of the hair, on which a lacquer (outside the invention) based on fillers has been applied, this having led to a coarse deposit, that is to say with an unsmooth surface .

is a photograph taken with SEM of a part of the hair, on which a lacquer (outside the invention) based on fillers (12.5%) and polymers (5%) has been applied, the latter having led to a deposit heterogeneous.

is a photograph taken with SEM of a part of the hair, on which a milk corresponding to the microdispersion of wax according to the invention has been applied, the latter having led to a fine and regular deposit on the hair.

detailed description

Within the meaning of the present invention, and unless a different indication is given:

The expression "at least one" is equivalent to "one or more" and, unless otherwise indicated (such as "more than...", "less than" or "between X and Y ”), the limits of a range of values are included in this range (for example “in the range from X to Y”).

Within the meaning of the invention, and in the rest of the description, the contents are generally measured and expressed in% by weight.

By "stable composition" is meant within the meaning of the invention a composition which, after 2 months of storage at 4° C., 25° C. and 45° C., shows no macroscopic change in color, odor, or viscosity, but which on the contrary remains homogeneous and regular, and which does not phase out (no separation of the aqueous phase and the oily or waxy phase) nor does it release oil or wax.

The compositions according to the invention can be cosmetic or dermatological compositions. Preferably, they are cosmetic compositions.

The composition according to the invention contains a physiologically acceptable medium.

The term "physiologically acceptable medium" in the present invention means a non-toxic medium, compatible with the skin (including the inside of the eyelids), the mucous membranes, the hair or the lips of human beings. A cosmetic composition is a product having a pleasant appearance, smell and feel, and intended for topical application.

By “made natural”, is meant in the sense of the invention a fine and homogeneous film-forming effect having a dry touch, that is to say a touch that is not wet, not greasy or sticky.

By "high" melting temperature is meant a melting temperature Tm "greater than 50° C.".

By “objects” in the microdispersion of wax, is meant within the meaning of the present invention, the drops of wax placed in suspension and solidified in the form of particles of wax.

By "natural compound" is meant a compound that is obtained directly from the earth or the soil, or from plants or animals, via, where appropriate, one or more physical processes, such as for example grinding , pressure, extraction, refining, distillation, purification or filtration.

By compounds "of natural origin", we mean a natural compound having undergone one or more chemical or industrial treatments, generating modifications that do not affect the essential qualities of this compound and / or a compound mainly comprising natural constituents having or not undergone transformations, as indicated above.

By way of non-limiting example of ancillary chemical or industrial treatment causing modifications that do not affect the essential qualities of a natural compound, mention may be made of those authorized by control bodies such as Ecocert (Reference of organic cosmetic products and ecological, January 2003) or defined in recognized manuals in the field, such as “Cosmetics and Toiletries Magazine”, 2005, vol. 120, 9:10.

Raincoats)

The wax(es) is (are) generally a lipophilic compound, solid at room temperature (25°C), with a reversible solid/liquid state change, having a melting point greater than or equal to at 30°C up to 200°C, most often up to 120°C.

Within the meaning of the invention, the melting temperature corresponds to the temperature of the most endothermic peak observed in thermal analysis (DSC) as described in standard ISO 11357-3; 1999. The melting point of the wax can be measured using a differential scanning calorimeter (DSC), for example the calorimeter sold under the name "DSC Q2000" by the company TA Instruments.

Preferably, the waxes that can be used in the composition of the present invention have an enthalpy of fusion ΔHf greater than or equal to 70 J/g.

Preferably, the waxes comprise at least one crystallizable part, visible by X-ray observations.

The measurement protocol is as follows:

A sample of 5 mg of wax placed in a crucible is subjected to an initial rise in temperature ranging from -20°C to 120°C, at a heating rate of 10°C/minute, then is cooled from 120°C to -20°C at a cooling rate of 10°C per minute and finally subjected to a second temperature rise ranging from -20°C to 120°C at a heating rate of 5°C per minute. During the second temperature rise, the following parameters are measured:

- the melting point or melting temperature (Tm) of the wax, as previously mentioned corresponding to the temperature of the most endothermic peak of the melting curve observed, representing the variation of the difference in power absorbed as a function of temperature ,

- ∆Hf: the melting enthalpy of the wax corresponding to the integral of the entire melting curve obtained. This wax melting enthalpy is the amount of energy required to change the compound from solid to liquid state. It is expressed in J/g.

The wax(es) may (may) be present in a total content greater than or equal to 10% by weight relative to the total weight of the composition, better still in a total content greater than or equal to 15% by weight relative to the total weight of the composition. Preferably, they are present in a content ranging from 10 to 30% by weight relative to the total weight of the composition, better still from 15 to 30% by weight relative to the total weight of the composition. .

Hard wax(es)

According to the invention, the composition more specifically comprises at least one hard wax. in the form of an aqueous dispersion of wax particle(s).

By “hard wax” within the meaning of the present invention, is meant a wax having a melting point greater than or equal to 50° C., in particular ranging from 50 to 100° C., more preferably between 50 and 90° C.

Advantageously, by “hard” wax within the meaning of the present invention, is meant a wax having, at 20° C., a hardness greater than 5 MPa, in particular ranging from 5 to 30 MPa, preferably greater than 6 MPa, better still ranging from 6 to 25 MPa.

To perform these hardness measurements, the wax is melted at a temperature equal to the melting point of the wax +20°C. For this, 30g of wax is placed in a 100ml beaker with a diameter of 50mm, itself positioned on a heated magnetic stirring plate.

A quantity of approximately 15g of molten wax is poured into a stainless steel container 80mm in diameter and 15mm deep, previously heated to 45°C in an oven. The wax is then left to recrystallize in a room thermostated at 20° C. for 24 hours before taking the measurement.

The mechanical properties of the wax or mixture of waxes are determined in a room thermostated at 20° C. using the texturometer sold under the name TA-XT2i by the company Swantech, equipped with a stainless steel cylinder with a diameter 2mm.

The measurement comprises 3 steps: a first step after automatic detection of the surface of the sample where the mobile moves at the measurement speed of 0.1 mm/s, and penetrates the wax at a penetration depth of 0, 3 mm, the software notes the value of the maximum force reached; a second so-called relaxation stage where the mobile remains in this position for one second and where the force is noted after 1 second of relaxation; finally a 3rd stage called withdrawal where the mobile returns to its initial position at the speed of 1 mm/s and we note the energy of withdrawal of the probe (negative force).

The hardness value corresponds to the maximum compression force measured in Newtons divided by the surface area of the texturometer cylinder expressed in mm2 in contact with the wax. The hardness value obtained is expressed in mega-pascals or MPa.

As examples of hard wax, mention may in particular be made of carnauba wax, candelilla wax, hydrogenated jojoba oil, hydrogenated palm oil, rice bran wax, sumac wax, sunflower wax, macadamia wax, hydrogenated olive oil such as Waxolive from SOLIANCE, waxes obtained by hydrogenation of olive oil esterified with C12 to C18 chain fatty alcohols such as those sold by SOPHIM under the trade names Phytowax Olive 16L55 and 18L57, the waxes obtained by hydrogenation of castor oil esterified with cetyl or behenic alcohol, such as those sold under the names Phytowax Ricin 16 L 64 and Phytowax Ricin 22 L 73 by SOPHIM.

Preferably, waxes of plant origin are used, such as carnauba wax, candelilla wax, hydrogenated jojoba wax, sumac wax, waxes obtained by hydrogenation of olive oil esterified with fatty alcohols C12 to C18 chain, rice bran wax.

Preferably, the hard wax(es) used in a composition in accordance with the present invention are introduced in the form of a powder, or a solid fatty substance. However, the final composition can be defined as comprising an aqueous dispersion of hard wax(es). Indeed, according to the present manufacturing process, the dispersion of hard wax(es) is produced in situ, allowing, surprisingly and advantageously, to achieve high dry extracts and hard wax(es) contents. , unattainable if a microdispersion of pre-prepared hard waxes were introduced as such to manufacture a cosmetic composition according to the invention. Indeed, in the present invention, the water resulting from the aqueous dispersion of the film-forming polymer(s) is used to achieve the dispersion of the hard wax(es).

The hard wax(es) is (are) preferably polar.

“Polar” wax means a wax whose solubility parameter calculated beyond its melting point δa is different from 0 (J/cm3)½.

In particular, by "polar" wax is meant a wax whose chemical structure is essentially formed, or even constituted, of carbon and hydrogen atoms, and comprising at least one strongly electronegative heteroatom such as an oxygen atom , nitrogen, silicon or phosphorus.

The definition and calculation of solubility parameters in HANSEN's three-dimensional solubility space are described in the article by C. M. HANSEN: "The three dimensional solubility parameters" J. Paint Technol. 39, 105 (1967).

According to this Hansen space:

- δD characterizes the LONDON dispersion forces resulting from the formation of dipoles induced during molecular shocks;

- δp characterizes the DEBYE interaction forces between permanent dipoles as well as the KEESOM interaction forces between induced dipoles and permanent dipoles;

- δh characterizes the forces of specific interactions (type hydrogen bonds, acid/base, donor/acceptor, etc.);

- δa is determined by the equation: δa = (δp² + δh²)½

The parameters δp, δh, δD and δa are expressed in (J/cm3)½.

Advantageously, the composition according to the invention comprises a content of hard wax(es), preferably present(s) in the form of an aqueous dispersion, preferably greater than or equal to 10% by weight relative to the total weight of the composition. , better still at 15% by weight, relative to the total weight of the composition.

The composition according to the invention advantageously comprises a total content of hard wax(es), preferably present(s) in the form of an aqueous dispersion, ranging from 10 to 30% by weight, better still from 15 to 30% by weight, relative to the total weight of the composition.

According to an advantageous embodiment, the composition according to the invention comprises a total content of particles of hard wax(es), preferably present(s) in the form of an aqueous dispersion, as they represent(s) ) at least 80% by weight, preferably at least 90% by weight, and even more preferably 100% by weight, relative to the total weight of the wax(es).

Preferably, the total content of hard wax(es), present in the form of an aqueous microdispersion, is greater than or equal to 30% by weight, preferably 40% by weight, relative to the total weight of the particles. solid.

According to an advantageous embodiment, the total content of hard wax(es), preferably present in the form of an aqueous dispersion, represents at least 80% by weight, preferably at least 90% by weight, more preferably still 100% by weight, relative to the total fat body weight.

Additionally, a composition according to the invention may comprise at least one soft wax, present in the form of an aqueous dispersion of wax particles or not, that is to say whose melting point is strictly lower than 50° C., and possibly whose hardness is strictly less than 5 MPa.

However, a composition according to the invention preferably comprises less than 5% by weight of soft wax(es), preferably less than 2% by weight of soft wax(es), more preferably still is free of of soft wax(es).

The particles of the wax microdispersion according to the invention preferably have average dimensions of less than 0.5 μm (less than 500 nm), in particular ranging from 0.06 μm to 0.5 μm. These particles consist essentially of a wax or a mixture of waxes.

They may, however, comprise a minor proportion of oily and/or pasty fatty additives, a surfactant and/or a usual fat-soluble additive/active agent.

This microdispersion of natural hard wax in liquid form with a percentage of wax less than or equal to 30% by weight, stabilized by a natural surfactant can advantageously be used in the composition of cosmetic products, in particular: mascara, foundation, anti-wrinkle, and / or styling products.

Nonionic surfactants in accordance with the invention

The composition according to the invention comprises at least one nonionic surfactant chosen from fatty acid and sugar mono-esters, preferably of a disaccharide, more preferably still sucrose also called sucrose.

Preferably, the composition according to the invention comprises at least one nonionic surfactant with an HLB value, in the sense of Griffin, at 25° C., greater than 15, preferably comprised in the range from 16 to 20.

The term HLB (from the English “Hydrophilic Lipophilic Balance”) is well known to those skilled in the art, and designates the hydrophilic-lipophilic balance of a surfactant. The HLB or hydrophilic-lipophilic balance of the surfactant(s) used according to the invention can be determined by the GRIFFIN method or the DAVIES method.

The scale varies from 0 to 20 (limits excluded otherwise the molecules are no longer surfactants). The higher the value, the greater the solubility in water and conversely, the lower the value, the more affinity the surfactant will have for oil.

The HLB according to GRIFFIN is defined in the publication J. Soc. Cosm. Chem. 1954 (Volume 5), pages 249-256 or the HLB determined experimentally and as described in the work by authors F. PUISIEUX and M. SEILLER, entitled "GALENICA 5: Dispersed systems - Volume I - Surface agents and emulsions - Chapter IV - Concepts of HLB and critical HLB, pages 153-194 - paragraph 1.1.2 Determination of HLB experimentally, pages 164-180.

Preferably, it is the value of the calculated HLBs which must be taken into account according to the present invention.

The calculated HLB is defined as the following coefficient:

Calculated HLB = 20 x molar mass hydrophilic part / total molar mass.

The HLB according to DAVIES considers the hydrophilic and lipophilic contributions made by each of the structural groups of the surfactant, according to the following calculation method:

HLB = ∑ HLB of hydrophilic groups - ∑ HLB of hydrophobic groups + 7

Thus, the HLB of the surfactant is equal to the sum of the HLBs of the hydrophilic groups minus the sum of the HLBs of the hydrophobic groups plus 7.

There are HLB tables for the different classic groups that can be found in particular in the following collection: Surfactants in cosmetics, second edition, surfactant science series volume 68, edited by Martin M.Rieger & Linda D.Rhein, p. 134, table 4.

According to a particular embodiment of the invention, the surfactant(s) comprise(s) one or more hydrocarbon chains, linear or branched, saturated or unsaturated, comprising from 8 to 22 carbon atoms, preferably from 10 to 22 carbon atoms, and even more preferentially from 12 to 20 carbon atoms, and even better, from 12 to 18 carbon atoms.

By “hydrocarbon chain”, is meant a group essentially formed, or even constituted, of carbon and hydrogen atoms, and optionally of oxygen and nitrogen atoms, and not containing any silicon or fluorine; it may contain ester, ether, amine or amide groups.

Fatty acid and sugar esters

The ester or esters of fatty acid and sugar are advantageously monoesters of fatty acid and sugar.

They can be chosen in particular from the group comprising esters or mixtures of fatty acid esters, C8-C22, preferably C10-C20, preferably C12-C18, even C12-C16, or better still C12-C14, optionally with one or more unsaturations, and sucrose (sucrose), maltose, glucose, fructose, xylose, and C8-C22 fatty acid esters or esters, preferably C10-C20, preferably C12-C18, or even C12-C16, or better still C12-C14, optionally with one or more unsaturations, and (C1-C4 alkyl) glucose such as methyl glucose, and mixtures thereof.

According to a particular embodiment, the C8-C22 fatty acids (preferably C10-C20, and even more preferably C12-C18, even C12-C16, or better still C12-C14) forming the fatty unit of the esters which can be used according to the invention comprise a linear or branched, saturated or unsaturated hydrocarbon chain, comprising from 8 to 22 carbon atoms (preferably from 10 to 20 carbon atoms, and even more preferably from 12 to 18 carbon atoms, or even from 12 to 16 carbon atoms, or better still from 12 to 14 carbon atoms.

The fatty unit of the esters can be chosen in particular from stearates, behenates, cocoates, arachidonates, palmitates, myristates, laurates, caprates, oleates, and mixtures thereof. The laurates are preferably used.

The sugar unit of the sugar fatty acid ester(s) may or may not include a C1-C4 alkyl group. It is advantageously chosen from sucrose, maltose, glucose, fructose, mannose, galactose, arabinose, xylose, lactose, trehalose, methylglucose. Preferably sucrose, glucose and methylglucose are used, even more preferably sucrose.

According to a preferred embodiment of the invention, the C8-C22 fatty acids (preferably C10-C20, and even more preferably C12-C18, and better still C12-C14) forming the fatty unit of the esters which can be used according to the invention comprise a linear and saturated hydrocarbon chain, comprising from 8 to 22 carbon atoms, preferably 10 to 20, and even more preferably 12 to 18, or even 12 to 16 carbon atoms, or better still 12 to 14 carbon atoms , preferably 12 carbon atoms, such as lauric acid.

According to a preferred embodiment, the fatty acid and sugar ester(s) result from the reaction of a fatty acid whose fatty unit comprises a linear and saturated hydrocarbon chain, comprising from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, and a sugar.

More preferably the sugar is a disaccharide, more preferably still sucrose.

Consequently, a surfactant in accordance with the invention advantageously comprises, as sugar fatty acid ester, and preferably is, sucrose laurate, also called sucrose laurate, or else sucrose laurate (according to its INCI name).

Sucrose laurate is a particularly mild nonionic surfactant. It is a sugar (sucrose) ester of lauric acid, which is also often used in light cleansing formulas, in particular make-up removers or baby wipes. It acts as a surfactant and thickener in natural cleansing oils. At 25° C., its HLB in the sense of Griffin is 16 and its pH such that 5<pH<7.

Preferably, the surfactant according to the invention is used in a content comprised in the range of 5 to 10%, preferably 6 to 8%, preferably 7 to 8%, preferably substantially equal to 7.5%, this for a maximum wax content of 30% by weight on the total weight of the composition.

Preferably, the ratio of the content by weight of said at least one wax to the content by weight of nonionic surfactant is in the range from 2 to 8, preferably from 2 to 6, preferably from 3 to 5.

Advantageously, the composition of the invention comprises less than 2% by weight, preferably less than 1% by weight, of surfactant other than said nonionic surfactant, on the total weight of the composition, and preferably is free of surfactant other than said nonionic surfactant.

In a particularly advantageous embodiment of the invention, the microdispersion consists of water, natural waxes with a high melting point above 50° C. at a maximum rate of 30% by weight and a natural surfactant representing 1/4 the rate of wax to stabilize the system.

Aqueous phase

In the composition of the invention, the aqueous phase consists mainly of water, which means that it comprises at least 50% by weight of water on the total weight of aqueous phase, and it also comprises at least one polyol containing at least three hydroxyls.

Advantageously, the wax microdispersion of the invention comprises at least 40% water and at least 12% of at least one polyol comprising at least three hydroxyls, on the total weight of the composition representing 100%.

The water used can be sterile demineralised water and/or floral water such as rose water, cornflower water, chamomile water or linden water, and/ or natural thermal or mineral water, such as: Vittel water, water from the Vichy basin, Uriage water, water from Roche Posay, water from La Bourboule, water water from Enghien-les-Bains, water from Saint Gervais-les-Bains, water from Néris-les-Bains, water from Allevar-les-Bains, water from Digne, water from Maizières, water from Neyrac-les-Bains, water from Lons-le-Saunier, Eaux Bonnes, water from Rochefort, water from Saint Christau, water from Fumades and water from Tercis -les-bains, water from Avene. The aqueous phase can also comprise reconstituted thermal water, that is to say water containing trace elements such as zinc, copper, magnesium, etc., reconstituting the characteristics of thermal water.

Preferably, the composition according to the invention comprises at least 45%, preferably at least 50%, preferably at least 55%, preferably at least 60% of water, preferably at least 65% of water, on the total weight of the composition.

By “polyol comprising at least three hydroxyl functions” according to the invention, is meant a hydrocarbon chain comprising at least 2 carbon atoms, preferably from 2 to 50 carbon atoms, preferably from 2 to 20 carbon atoms, preferably having from 2 to 10 carbon atoms, and preferably from 2 to 6 carbon atoms, and carrying at least three hydroxyl groups. Preferably, the polyols used in the present invention have an average molecular weight of less than or equal to 1000 g/mol, preferably comprised in the range of 85 to 500 g/mol.

Advantageously, the polyol comprising at least three hydroxyl functions is a natural or synthetic polyol, and has a linear, branched or cyclic molecular structure.

The polyol comprising at least three hydroxyl functions is advantageously chosen from glycerin and derivatives thereof, and glycols comprising at least three hydroxyl functions and derivatives thereof.

The polyol comprising at least three hydroxyl functions is preferably chosen from glycerin (or glycerol), diglycerin (or diglycerol), sugars such as sorbitol, and mixtures thereof.

Said polyol is advantageously chosen from polyols having symmetry of the hydroxyls in the polyol molecule. Preferably said at least one polyol comprises glycerin, and preferably is glycerin.

Preferably, said polyol comprising at least three hydroxyls is present in the composition of the invention in a content of 12 to 20%, preferably 10 to 15%, by weight relative to the total weight of the composition.

The aqueous phase may also contain hydrophilic adjuvants, including polyols other than those having at least three hydroxyl functions, such as propanediol; glycols such as pentylene glycol, propylene glycol, butylene glycol, isoprene glycol; and their mixtures.

The aqueous composition according to the invention may also comprise a monoalcohol having from 2 to 6 carbon atoms such as ethanol or isopropanol.

Advantageously, the composition of the invention comprises less than 5%, preferably less than 2%, by weight of monoalcohol or diol, over the total weight of the composition, and preferably is free of monoalcohol or diol, which have a destabilizing effect of the wax microdispersion of the invention.

Film-forming polymer(s)

Preferably, the composition of the invention comprises less than 2% by weight, preferably less than 1% by weight, on the total weight of the composition, preferably is free, of polymer of synthetic origin, and in particular is free film-forming polymer of synthetic origin.

The composition according to the invention may nevertheless comprise at least one aqueous dispersion of particles of film-forming polymer(s) and optionally at least one additional film-forming polymer (not present in the form of an aqueous dispersion of particles, such as a film-forming polymer water soluble).

In the present application, the term "film-forming polymer" means a polymer capable of forming, on its own or in the presence of an auxiliary film-forming agent, a macroscopically continuous deposit, and preferably a cohesive deposit, and better still a deposit whose the cohesion and the mechanical properties are such that said deposit can be isolated and manipulated in isolation, for example when said deposit is made by pouring onto a non-stick surface such as a Teflon-coated or silicone-coated surface.

According to a particular and non-preferred embodiment, a composition according to the invention comprises a total dry matter content of film-forming polymer(s) greater than or equal to 5% by weight, relative to the total weight of the composition. The composition according to the invention optionally comprises at least one aqueous dispersion of particles formed from one or more film-forming polymers.

It may also comprise at least one water-soluble film-forming polymer. Thus, a composition may comprise at least one additional film-forming polymer, distinct from particles of film-forming polymer(s) present in the form of an aqueous dispersion. The content of this (these) additional film-forming polymer(s), referred to as water-soluble, is preferably less than or equal to 10% by weight relative to the total weight of the composition, more preferably still to 5 % by weight, better still 2% by weight, relative to the total weight of the composition.

Film-forming polymer(s) in aqueous dispersion

Such a film-forming polymer present in said preparation of the composition in the form of particles in aqueous dispersion, generally bears the name of (pseudo)latex, that is to say latex or pseudolatex. The techniques for preparing these dispersions are well known to those skilled in the art. Such a dispersion can comprise one or more types of particles, these particles possibly varying by their size, by their structure and/or by their chemical nature.

According to a particular, but not preferred, embodiment, a composition according to the invention comprises a total dry matter content of particles of film-forming polymer(s) ranging from 10 to 30% by weight relative to the total weight of the composition, better still from 12 to 25% by weight. These particles can be of anionic, cationic or neutral nature and can constitute a mixture of particles of different natures.

Among the film-forming polymers that can be used in the composition of the present invention, mention may be made of synthetic polymers, of radical type or of polycondensate type, polymers of natural origin and mixtures thereof. In general, these polymers can be random polymers, block copolymers of the A-B type, multi-block A-B-A or even ABCD…, or even graft polymers.

Free radical film-forming polymer

By “radical polymer”, we mean a polymer obtained by polymerization of monomers with in particular ethylenic unsaturation, each monomer being capable of homopolymerizing (unlike polycondensates).

The film-forming polymers of radical type may in particular be acrylic and/or vinyl homopolymers or copolymers.

The vinyl film-forming 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 acid monomers.

As ethylenically unsaturated monomers having at least one acid group or monomer bearing an acid group, it is possible to use αβ-ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic, itaconic acid. In particular, (meth)acrylic acid and crotonic acid, and more particularly (meth)acrylic acid, are used.

The esters of acid monomers are advantageously chosen from esters of (meth)acrylic acid (also called (meth)acrylates), in particular alkyl (meth)acrylates, in particular C1-C20 alkyl, plus particularly C1-C8, aryl (meth)acrylates, in particular C6-C10 aryl, hydroxyalkyl (meth)acrylates, in particular C2-C6 hydroxyalkyl. Among the alkyl (meth)acrylates, mention may be made of methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate. Among the hydroxyalkyl (meth)acrylates, mention may be made of hydroxyethyl acrylate, 2-hydroxypropyl acrylate, hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate. Among the aryl (meth)acrylates, mention may be made of benzyl acrylate and phenyl acrylate. The esters of (meth)acrylic acid are in particular alkyl (meth)acrylates.

According to the present invention, the alkyl group of the esters can be either fluorinated or perfluorinated, that is to say that some or all of the hydrogen atoms of the alkyl group are substituted by fluorine atoms. As amides of acid monomers, mention may for example be made of (meth)acrylamides, and in particular N-alkyl (meth)acrylamides, in particular of C2-C12 alkyl. Among the N-alkyl (meth)acrylamides, mention may be made of N-ethyl acrylamide, N-t-butyl acrylamide and N-t-octyl acrylamide.

The vinyl film-forming polymers can also result from the homopolymerization or the copolymerization of monomers chosen from vinyl esters and styrene monomers. In particular, these monomers can be polymerized with acid monomers and/or their esters and/or their amides, such as those mentioned above.

Examples of vinyl esters include vinyl acetate, vinyl neodecanoate, vinyl pivalate, vinyl benzoate, and vinyl t-butyl benzoate.

As styrene monomers, mention may be made of styrene of alpha-methyl styrene.

The list of monomers given is not exhaustive and it is possible to use any monomer known to those skilled in the art falling within the categories of acrylic and vinyl monomers (including monomers modified by a silicone chain).

As vinyl polymer, silicone acrylic polymers can also be used.

Mention may also be made of polymers resulting from the radical polymerization of one or more radical monomers, inside and/or partially on the surface of pre-existing particles of at least one polymer chosen from the group consisting of polyurethanes, polyureas , polyesters, polyesteramides and/or alkyds. These polymers are generally referred to as "hybrid polymers".

Polycondensate

As film-forming polymer of polycondensate type, mention may be made of anionic, cationic, nonionic or amphoteric polyurethanes, polyurethane-acrylics, polyurethane-polyvinylpyrrolidones, polyester-polyurethanes, polyether-polyurethanes, polyureas, polyurea/polyurethanes, silicone polyurethanes, and mixtures thereof.

The film-forming polyurethane may be, for example, a polyurethane, polyurea/urethane, or polyurea, aliphatic, cycloaliphatic or aromatic copolymer, comprising alone or as a mixture at least one sequence chosen from: a sequence of aliphatic and/or cycloaliphatic polyester origin and / or aromatic, and/or a silicone block, branched or not, for example polydimethylsiloxane or polymethylphenylsiloxane, and/or a block comprising fluorinated groups.

The film-forming polyurethanes as defined in the invention can also be obtained from polyesters, branched or not, or from alkyds comprising mobile hydrogens which are modified by reaction with a diisocyanate and a bifunctional organic compound (for example dihydro , diamino or hydroxyamino), additionally comprising either a carboxylic acid or carboxylate group, or a sulfonic acid or sulfonate group, or even a neutralizable tertiary amine group or a quaternary ammonium group.

Among the film-forming polycondensates, mention may also be made of polyesters, polyester amides, fatty-chain polyesters, polyamides, and epoxy ester resins.

The polyesters can be obtained, in known manner, by polycondensation of dicarboxylic acids with polyols, in particular diols.

The dicarboxylic acid can be aliphatic, alicyclic or aromatic. Mention may be made, as examples of such acids, of: oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, 2,2 -dimethylgluratic, azelaic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, phthalic acid, dodecanedioic acid, 1,3-acid cyclohexanedicarbocylic acid, 1,4-cyclohexa-nedicarboxylic acid, isophthalic acid, terephthalic acid, 2,5-norborane dicarboxylic acid, diglycolic acid, thiodipropionic acid,

2,5-naphthalenedicarboxylic acid, 2,6-naphthalene-dicarboxylic acid. These dicarboxylic acid monomers can be used alone or in combination of two or more dicarboxylic acid monomers. Among these monomers, phthalic acid, isophthalic acid and terephthalic acid are chosen in particular.

The diol can be chosen from aliphatic, alicyclic or aromatic diols. In particular, a diol chosen from among: ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, cyclohexane dimethanol, 4-butanediol is used. As other polyols, it is possible to use glycerol, pentaerythritol, sorbitol, trimethylol propane.

Polyester amides can be obtained analogously to polyesters, by polycondensation of diacids with diamines or amino alcohols. As the diamine, ethylenediamine, hexamethylenediamine, meta- or para-phenylenediamine can be used. As aminoalcohol, monoethanolamine can be used.

Polymer of natural origin

This type of polymer is of course preferred in the composition of the invention.

It is possible to use in the present invention polymers of natural origin, optionally modified, such as shellac resin, sandarac gum, dammars, elemis, copals, water-insoluble cellulosic polymers such as nitrocellulose, modified cellulose esters including in particular carboxyalkyl cellulose esters such as those described in patent application US 2003/185774, and mixtures thereof.

According to a particular embodiment of the invention, said at least one film-forming polymer in the dispersed state is chosen from acrylic polymer dispersions, polyurethane dispersions, sulfopolyester dispersions, vinyl dispersions, polyvinyl acetate dispersions , vinyl pyrrolidone, dimethylaminopropyl methacrylamide and lauryldimethylpropylmethacrylamidoammonium chloride terpolymer dispersions, polyurethane/polyacrylic hybrid polymer dispersions, dispersions of core-shell type particles and mixtures thereof.

Detailed below are various types of aqueous dispersions, in particular commercial ones, suitable for the preparation of the composition in accordance with the present invention.

1/ Thus, according to a preferred embodiment of the invention, the aqueous dispersion of polymer particles is an aqueous dispersion of acrylic polymer.

The acrylic polymer can be a styrene/acrylate copolymer, and in particular a polymer chosen from copolymers resulting from the polymerization of at least one styrene monomer and at least one C1-C18 alkyl (meth)acrylate monomer.

As styrene monomer that can be used in the invention, mention may be made, for example, of styrene or alpha-methylstyrene, and in particular styrene.

The C1-C18 alkyl (meth)acrylate monomer is in particular a C1-C12 alkyl (meth)acrylate and more particularly a C1-C10 alkyl (meth)acrylate. The C1-C18 alkyl (meth)acrylate monomer can be chosen from methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, 2-ethyl hexyl acrylate, lauryl (meth)acrylate and stearyl (meth)acrylate.

As acrylic polymer in aqueous dispersion, it is possible to use according to the invention the styrene/acrylate copolymer marketed under the name "Joncryl SCX-8211®" by the company BASF or "SYNTRAN 5760CG" by the company Interpolymer, the acrylic polymer marketed under the reference “Acronal® DS – 6250” by the company BASF, the acrylic copolymer “Joncryl® 95” by the company BASF.

2/ according to a variant embodiment of the invention, the aqueous dispersion of polymer particles is an aqueous dispersion of polyester-polyurethane and/or polyether-polyurethane particles, in particular anionic.

The anionic character of the polyester-polyurethanes and of the polyether-polyurethanes used according to the invention is due to the presence in their constituent units of groups with a carboxylic acid or sulphonic acid function. The polyester-polyurethane or polyether-polyurethane particles used according to the invention are generally marketed in the form of aqueous dispersions.

The particle content of said dispersions currently available on the market ranges from about 20% to about 60% by weight relative to the total weight of the dispersion.

Among the anionic polyester-polyurethane dispersions which can be used in the compositions according to the invention, mention may be made in particular of that marketed under the name “Avalure UR 405®” by the company NOVEON or “Baycusan C1004” by the company BAYER MATERIAL SCIENCE.

Among the dispersions of anionic polyether-polyurethane particles that can be used according to the invention, mention may be made in particular of those marketed under the name "Avalure UR 450®" by the company NOVEON, and under the name "Neorez R 970®" by the DSM company.

According to a particular embodiment of the invention, it is possible to use a mixture of commercial dispersions consisting of particles of anionic polyester-polyurethane as defined above and particles of anionic polyether-polyurethane also defined above.

For example, it is possible to use a mixture consisting of the dispersion marketed under the name of “Sancure 861®” or a mixture of that marketed under the name of “Avalure UR 405®” and of that marketed under the name of “Avalure UR 450 ®”, these dispersions being marketed by the company NOVEON.

3/ According to another particular embodiment of the invention, the aqueous dispersion used comprises a mixture of at least two film-forming polymers in the form of particles distinct by their respective glass transition temperatures (Tg).

In particular, according to one embodiment of the invention, the composition in accordance with the invention may comprise at least one first film-forming polymer in the dispersed state and at least one second film-forming polymer in the dispersed state, said first and second polymers having different Tgs and preferably the Tg of the first polymer (Tg1) is greater than the Tg of the second polymer (Tg2). In particular, the difference between Tg1 and Tg2 is, in absolute value, at least 10°C, preferably at least 20°C.

More specifically, it comprises in an acceptable aqueous medium:

a) particles dispersed in the aqueous medium of a first film-forming polymer having at least one glass transition temperature Tg1 greater than or equal to 20°C, and

b) particles dispersed in the aqueous medium of a second film-forming polymer having at least a glass transition temperature Tg2 less than or equal to 70°C,

This dispersion generally results from a mixture of two aqueous dispersions of film-forming polymer.

The first film-forming polymer has at least one, in particular has a glass transition temperature Tg1 greater than or equal to 20°C, in particular ranging from 20°C to 150°C, and advantageously greater than or equal to 40°C, in particular ranging from 40 °C to 150°C, and in particular greater than or equal to 50°C, in particular ranging from 50°C to 150°C.

The second film-forming polymer has at least one, in particular has a glass transition temperature Tg2 of less than or equal to 70°C, in particular ranging from -120°C to 70°C, and in particular less than 50°C, in particular ranging from - 60°C to +50°C, and more particularly ranging from -30°C to 30°C.

Measurement of the glass transition temperature (Tg) of a polymer is performed by DMTA (Dynamic and Mechanical Temperature Analysis) as described below.

To measure the glass transition temperature (Tg) of a polymer, viscoelasticimetry tests are carried out with a DMTA device from “Polymer laboratories”, on a sample of film. This film is prepared by casting the aqueous dispersion of film-forming polymer in a Teflon-coated matrix and then dried at 120° C. for 24 hours. A film is then obtained from which the specimens are cut (for example with a cookie cutter). These typically have a thickness of around 150 µm, a width of 5 to 10 mm and a useful length of around 10 to 15 mm. A tensile stress is imposed on this sample. The sample is subjected to a static force of 0.01 N on which is superimposed a sinusoidal displacement of ± 8 µm at a frequency of 1 Hz. This works in the linear domain, under low levels of deformation. This tensile stress is performed on the sample at temperatures varying from -150°C to +200°C, with a temperature variation of 3°C per minute.

The complex modulus E* = E' + iE'' of the polymer tested is then measured as a function of temperature.

From these measurements, we deduce the dynamic moduli E', E'' and the damping power: tgδ = E''/E'.

Then the curve of the values of tgδ is plotted as a function of the temperature; this curve has at least one peak. The glass transition temperature Tg of the polymer corresponds to the temperature at which the apex of this peak is located.

When the curve presents at least 2 peaks (in this case, the polymer presents at least 2 Tg), the value of the Tg of the polymer tested is taken as the temperature for which the curve presents a peak of greater amplitude (i.e. corresponding to the highest value of tgδ; in this case, only the "majority" Tg is considered as the Tg value of the polymer tested).

In the present invention, the transition temperature Tg1 corresponds to the “main” Tg (in the sense defined above) of the first film-forming polymer when the latter has at least 2 Tg; the glass transition temperature Tg2 corresponds to the “main” Tg of the second film-forming polymer when the latter has at least 2 Tg.

The first film-forming polymer and the second film-forming polymer can be chosen, independently of each other, from radical polymers, polycondensates and polymers of natural origin as defined above having the glass transition temperature characteristics defined above .

As first film-forming polymer in aqueous dispersion, it is possible to use the aqueous polymer dispersions sold under the names “NeoRez R-989®” by the company DSM, “Joncryl 95” and “Joncryl® 8211” by the company BASF.

As second film-forming polymer in aqueous dispersion, it is possible to use, for example, the aqueous polymer dispersions sold under the names "Avalure® UR-405", "Avalure® UR-460" by the company NOVEON or "Acrilem IC89RT®" by the company ICAP, Neocryl A-45 by DSM.

The film-forming polymer of the "Avalure® UR-460" aqueous dispersion is a polyurethane obtained by the polycondensation of tetramethylene polyoxide, tetramethylxylylene diisocyanate, isophorone diisocyanate and dimethylol propionic acid.

According to one embodiment of the invention, the combination of a styrene/acrylate polymer dispersion such as the dispersion marketed under the reference "Joncryl 8211®" by BASF and a dispersion of acrylic polymer such as the dispersion marketed under the reference “Neocryl A-45®” by DSM.

According to another preferred embodiment of this particular embodiment of point 3/ above of the invention, the first film-forming polymer in aqueous dispersion is used as an acrylic polymer dispersion such as the dispersion marketed under the reference “Joncryl 95 ®” by BASF and as second film-forming polymer an anionic polyurethane polymer dispersion marketed under the reference “Avalure UR405®” by DSM.

As aqueous dispersions of film-forming polymer, it is possible to use:

- the acrylic dispersions sold under the names “Acronal DS-6250®” by the company BASF, “Neocryl A-45Ò”, “Neocryl XK-90Ò”, “Neocryl A-1070Ò”, “Neocryl A-1090Ò”, “Neocryl BT-62Ò”, “Neocryl A-1079Ò” and “Neocryl A-523Ò” by DSM, “Joncryl 95®”, “Joncryl 8211®” by BASF, “Daitosol 5000 ADÒ” or “Daitosol 5000 SJ” by the company DAITO KASEY KOGYO; "Syntran 5760 CG" by Interpolymer,

- aqueous polyurethane dispersions sold under the names “Neorez R-981Ò” and “Neorez R-974Ò” by the company DSM, “Avalure UR-405Ò”, “Avalure UR-410Ò”, “Avalure UR-425Ò”, “Avalure UR-450Ò”, “Sancure 875Ò”, “Avalure UR 445Ò”, “Avalure UR 450Ò” by the company NOVEON, “Impranil 85Ò” by the company BAYER, “Baycusan C1004Ò” by the company BAYER MATERIAL SCIENCE,

- the sulfopolyesters sold under the brand name “Eastman AQÒ” by the company EASTMAN CHEMICAL PRODUCTS,

- vinyl dispersions such as “Mexomer PAM”, aqueous dispersions of polyvinyl acetate such as “VinybranÒ” from the company Nisshin Chemical or those marketed by the company UNION CARBIDE, aqueous dispersions of vinyl pyrrolidone terpolymer, dimethylaminopropyl methacrylamide and lauryldimethylpropylmethacrylamidoammonium chloride such as the “Styleze W Ò”-from ISP,

- aqueous dispersions of polyurethane/polyacrylic hybrid polymers such as those marketed under the references “Hybridur Ò” by the company AIR PRODUCTS or “Duromer Ò” from NATIONAL STARCH,

- dispersions of particles of the core-shell type such as those marketed by the company ARKEMA under the reference "Kynar Ò" (core: fluorinated - shell: acrylic) or those described in US Pat. No. 5,188,899 (core: silica - shell: silicone) and mixtures thereof.

According to a particular embodiment, a composition in accordance with the invention comprises an aqueous dispersion of particles chosen from aqueous dispersions of acrylic film-forming polymer(s) and derivatives, in particular of styrene-acrylic and derivatives, and dispersions aqueous polymer(s) of polyurethane(s), in particular of polyester-polyurethane, and their derivatives, and their mixture(s).

According to one embodiment, the total content of hard wax(es) and the total content of particles of film-forming polymer(s) are such that the weight ratio of the hard wax(es)( s) on the particles of film-forming polymer(s) is between 1/2 and 2, more preferably still between 2/3 and 3/2.

According to an advantageous embodiment, the total content of hard wax(es) and the total content of particles of film-forming polymer(s), both preferentially present in the form of particles in aqueous dispersion, with the ( the) film-forming polymer(s) chosen from aqueous dispersions of acrylic film-forming polymer(s) and derivatives, in particular styrene-acrylic and derivatives, and aqueous dispersions of polyester-polyurethane hybrid polymer(s), and their mixture, are such that the weight ratio of particles of hard wax(es) to said particles of film-forming polymer(s) is greater than or equal to 1/2, better still 2/ 3.

Preferably, this ratio is inclusively between 1/2 and 2, more preferably still between 2/3 and 3/2.

Water-soluble film-forming polymer

The compositions according to the present invention comprise at least one water-soluble film-forming polymer.

Preferably, a composition according to the invention is free of water-soluble film-forming polymer. However, the total dry matter content of "water-soluble film-forming polymer(s)" can range from 0.1 to 10%, preferably from 0.5 to 8% and better still from 1 to 5% by weight, relative to the total weight of the composition.

Examples of water-soluble film-forming polymers include:

- proteins such as proteins of plant origin such as wheat or soy proteins; proteins of animal origin such as keratins, for example keratin hydrolysates and sulphonic keratins;

- cellulose polymers such as hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylhydroxyethylcellulose, carboxymethylcellulose, as well as quaternized derivatives of cellulose;

- acrylic polymers or copolymers, such as polyacrylates or polymethacrylates;

- vinyl polymers, such as polyvinylpyrrolidones, copolymers of methylvinyl ether and malic anhydride, copolymer of vinyl acetate and crotonic acid, copolymers of vinylpyrrolidone and vinyl acetate; copolymers of vinylpyrrolidone and caprolactam; polyvinyl alcohol;

- anionic, cationic, amphoteric or non-ionic chitin or chitosan polymers,

- Arabic gums, guar gum, xanthan derivatives, karaya gum, acacia gum;

- alginates and carrageenans;

- glycoaminoglycans, hyaluronic acid and its derivatives;

- deoxyribonucleic acid;

- muccopolysaccharides such as chondroitin sulphate,

and their mixtures.

Preferably, the composition according to the invention contains less than 2%, preferably less than 1%, by weight relative to the total weight of the composition, preferably is free, of ingredient(s) chosen from: gelling agents and/or thickeners and/or preservatives.

According to a non-preferred embodiment, it may nevertheless contain some, in which case the following definitions may apply:

gelling agents

Hydrophilic gelling agents

The compositions according to the present invention may also contain at least one hydrophilic or water-soluble gelling agent, they may be chosen from:

- homo- or copolymers of acrylic or methacrylic acids or their salts and their esters and in particular the products sold under the names VERSICOL FÒ or VERSICOL KÒ by the company ALLIED COLLOID, UTRAHOLD 8Ò by the company CIBA-GEIGY, polyacrylic acids of the SYNTHALEN K type,

- copolymers of acrylic acid and acrylamide sold in the form of their sodium salt under the names RETENÒ by the company HERCULES, the sodium salts of polyhydroxycarboxylic acids sold under the name HYDAGEN FÒ by the company HENKEL,

- polyacrylic acid/alkyl acrylate copolymers of the PEMULEN type,

- AMPS (polyacrylamidomethyl propane sulphonic acid partially neutralized with ammonia and highly cross-linked) marketed by CLARIANT,

- AMPS/acrylamide copolymers of the SEPIGELÒ or SIMULGELÒ type marketed by the company SEPPIC, and

- AMPS/polyoxyethylenated alkyl methacrylate copolymers (crosslinked or not), and mixtures thereof.

- associative polymers and in particular associative polyurethanes such as the C16-OE120-C16 polymer from the company ELEMENTIS (marketed under the name RHEOLATE FX1100, molecule with a urethane function and average molecular weight by weight of 1300), OE being an oxyethylenated unit , Rheolate 205 with a urea function sold by RHEOX or Rheolate 208 or 204 (these polymers being sold in pure form) or DW 1206B from RHOM & HAAS with a C20 alkyl chain and urethane bond, sold at 20 % active ingredient in water. It is also possible to use solutions or dispersions of these associative polyurethanes, in particular in water or in a hydroalcoholic medium. By way of example, such polymers include RHEOLATE fx1010, RHEOLATE FX1035 and RHEOLATE 1070, Rheolate 255, Rheolate 278 and Rheolate 244 sold by the company ELEMENTIS. You can also use the product DW 1206F and DW 1206J, as well as Acrysol RM 184 or Acrysol 44 from RHOM & HAAS, or even Borchigel LW 44 from BORCHERS,

- and mixtures thereof.

Certain water-soluble film-forming polymers also act as water-soluble gelling agents.

The hydrophilic gelling agents may be present in the compositions according to the invention in a content ranging from 0.05 to 10% by weight relative to the total weight of the composition, preferably from 0.1 to 5% and better still from 0.5 at 2% by weight.

A composition according to the invention advantageously comprises one of the aforementioned gelling agents, preferably chosen from AMPS (polyacrylamidomethyl propane sulfonic acid partially neutralized with ammonia and highly crosslinked), AMPS/acrylamide copolymers, and mixtures thereof.

Lipophilic gelling agents

A composition according to the invention may comprise at least one lipophilic or fat-soluble gelling agent. The gelling agent(s) that can be used can be organic or inorganic, polymeric or molecular lipophilic gelling agents. As inorganic lipophilic gelling agents, mention may be made of clays, modified clays, such as Bentone 38 VCG by the company ELEMENTIS, and fumed silica optionally treated hydrophobic on the surface

Polymeric organic lipophilic gelling agents are, for example, partially or totally crosslinked elastomeric organopolysiloxanes, of three-dimensional structure, such as those sold under the names KSG6Ò, KSG16Ò and KSG18Ò by the company SHIN-ETSU, Trefil E-505CÒ and Trefil E-506CÒ by DOW-CORNING, Gransil SR-CYCÒ, SR DMF10Ò, SR-DC556Ò, SR 5CYC gelÒ, SR DMF 10 gelÒ and SR DC 556 gelÒ by GRANT INDUSTRIES, SF 1204Ò and JK 113Ò by GENERAL ELECTRIC; ethylcellulose such as that sold under the name Ethocel® by the company DOW CHEMICAL; polycondensates of the polyamide type resulting from the condensation between (a) at least one acid chosen from dicarboxylic acids comprising at least 32 carbon atoms such as dimer fatty acids and (b) an alkylene diamine and in particular ethylene diamine, in which the polyamide polymer comprises at least one terminal carboxylic acid group esterified or amidated with at least one mono alcohol or one mono amine comprising from 12 to 30 linear and saturated carbon atoms, and in particular, ethylene diamine/dilinoleate copolymers stearyl such as that marketed under the name Uniclear 100 VGâ by the company ARIZONA CHEMICAL; silicone polyamides of the polyorganosiloxane type such as those described in the documents US A 5,874,069, US A 5,919,441, US A 6,051,216 and US A 5,981,680 such as for example those marketed under the reference Dow Corning 2-8179 and Dow Corning 2-8178 Gellant by the DOW CORNING Company. Block copolymers of the "diblock", "triblock" or "radial" type of the polystyrene/polyisoprene, polystyrene/polybutadiene type such as those marketed under the name Luvitol HSB® by the company BASF, of the polystyrene/copoly(ethylene-propylene) type such as those marketed under the name Kraton® by the company SHELL CHEMICAL CO or else of the polystyrene/copoly(ethylene-butylene) type, mixtures of triblock and radial (star) copolymers in isododecane such as those marketed by the company PENRECO under the name Versagel® such as for example the mixture of butylene/ethylene/styrene triblock copolymer and ethylene/propylene/styrene star copolymer in isododecane (Versagel M 5960).

The compositions according to the invention may also comprise, as lipophilic gelling agent, a non-emulsifying silicone elastomer. Mention may also be made, among the lipophilic gelling agents, of organogelators.

A composition according to the invention is preferably free of lipophilic gelling agent.

Dyestuffs

The compositions in accordance with the invention comprise at least one dyestuff.

This (or these) dyestuff(s) is (or are) preferably chosen from pulverulent materials, fat-soluble dyes, water-soluble dyes, and mixtures thereof.

Preferably, the compositions according to the invention comprise at least one powdery dyestuff. The pulverulent dyestuffs can be chosen from pigments and nacres, preferably from pigments.

The pigments can be white or colored, mineral and/or organic, coated or not. Mention may be made, among the mineral pigments, of metal oxides, in particular titanium dioxide, optionally surface-treated, zirconium, zinc or cerium oxides, as well as iron, titanium or chromium oxides, manganese violet, ultramarine blue, chromium hydrate and ferric blue. Among the organic pigments, mention may be made of carbon black, D & C type pigments, and lakes based on cochineal carmine, barium, strontium, calcium, aluminum.

The nacres can be chosen from white pearlescent pigments such as mica covered with titanium or bismuth oxychloride, colored pearlescent pigments such as titanium mica with iron oxides, titanium mica with in particular ferric blue or chromium oxide, titanium mica with an organic pigment of the aforementioned type as well as pearlescent pigments based on bismuth oxychloride.

Examples of fat-soluble dyes are Sudan Red, D&C Red 17, D&C Green 6, β-carotene, soybean oil, Sudan Brown, D&C Yellow 11, D&C Violet 2, D&C Orange 5, quinoline yellow, annatto.

Preferably, the pigments contained in the compositions according to the invention are chosen from metal oxides.

These dyestuffs may be present in a content ranging from 0.01 to 30% by weight relative to the total weight of the composition, in particular from 3 to 22% by weight relative to the total weight of the composition.

Preferably, the dyestuff(s) is (are) chosen from one or more metal oxide(s) present at a content greater than or equal to 2% by weight relative to the total weight of the composition, advantageously inclusive between 3 and 22% by weight relative to the total weight of the composition.

Expenses

The compositions in accordance with the invention may also comprise at least one filler.

The fillers can be chosen from those well known to those skilled in the art and commonly used in cosmetic compositions. The fillers can be mineral or organic, lamellar or spherical. Mention may be made of talc, mica, silica, kaolin, polyamide powders such as Nylon® marketed under the name Orgasol® by the company Atochem, poly-β-alanine and polyethylene, powders of tetrafluoroethylene polymers such as Teflon®, lauroyl-lysine, starch, boron nitride, expanded polymeric hollow microspheres such as those of polyvinylidene chloride/acrylonitrile such as those sold under the name Expancel® by the company Nobel Industrie, acrylic powders such as those sold under the name Polytrap® by Dow Corning, polymethyl methacrylate particles and silicone resin microbeads (Tospearls® from Toshiba, for example), precipitated calcium carbonate, carbonate and magnesium hydro-carbonate, hydroxyapatite, hollow silica microspheres (Silica Beads® from MAPRECOS), glass or ceramic microcapsules, metal soaps derived s of organic carboxylic acids having from 8 to 22 carbon atoms, and in particular from 12 to 18 carbon atoms, for example zinc, magnesium or lithium stearate, zinc laurate, magnesium myristate.

The fillers can represent from 0.1 to 15%, in particular from 0.5 to 10% by weight relative to the total weight of the composition.

Cosmetic active ingredients

The compositions in accordance with the invention may also comprise at least one cosmetic active ingredient.

As cosmetic active agents which can be used in the compositions in accordance with the invention, mention may in particular be made of antioxidants, preservatives, perfumes, neutralizers, emollients, coalescence agents, moisturizers, vitamins and filters, in particular sunscreens. , and mixtures thereof.

Of course, those skilled in the art will take care to choose the possible additional additives and/or their quantity in such a way that the advantageous properties of the composition according to the invention are not, or substantially not, altered by the addition envisaged.

Preferably, the composition according to the invention is not rinsed out. Advantageously, the composition is a makeup composition and in particular a mascara.

Oil or organic solvent

The compositions according to the invention may comprise at least one oil or organic solvent.

The compositions according to the invention may in particular comprise at least one oil chosen from at least one non-volatile oil, at least one volatile oil, and a mixture thereof.

Non-volatile oil

By “oil” is meant a fatty substance that is liquid at ambient temperature and atmospheric pressure.

By “non-volatile oil”, is meant an oil remaining on the skin or the keratin fiber at ambient temperature and pressure. More precisely, a non-volatile oil has an evaporation rate strictly lower than 0.01 mg/cm2/min.

To measure this evaporation rate, we introduce into a crystallizer, 7 cm in diameter, placed on a balance located in a large enclosure of about 0.3m3 regulated in temperature, at a temperature of 25°C, and in hygrometry, at 50% relative humidity, 15g of oil or oil blend to be tested. The liquid is allowed to evaporate freely, without stirring it, providing ventilation by a fan (PAPST-MOTOREN, reference 8550 N, rotating at 2700 revolutions per minute) placed in a vertical position above the crystallizer containing said oil or said mixture, the blades being directed towards the crystallizer and at a distance of 20cm from the bottom of the crystallizer. The mass of oil remaining in the crystallizer is measured at regular intervals. Evaporation rates are expressed in mg of oil evaporated per unit area (cm2) and per unit time (minute).

Said at least one non-volatile oil can be chosen from hydrocarbon oils and silicone oils, and mixtures thereof, preferably from hydrocarbon oils.

The non-volatile hydrocarbon oils suitable for the present invention may in particular be chosen from:

- hydrocarbon oils of plant origin such as triglycerides consisting of esters of fatty acids and glycerol, the fatty acids of which may have chain lengths varying from C4 to C28, the latter possibly being linear or branched, saturated or unsaturated ; these oils are in particular wheat germ, sunflower, grapeseed, sesame, corn, apricot, castor, shea, avocado, olive, soybean oil, sweet almond, rapeseed, cotton, hazelnut, macadamia, jojoba, palm, alfalfa, poppy, pumpkin, sesame, squash, rapeseed, blackcurrant, evening primrose, millet, barley, quinoa, rye, safflower, bankoulier, passionflower, muscat rose; or alternatively caprylic/capric acid triglycerides such as those sold by the company Stéarineries Dubois or those sold under the names of Miglyol 810®, 812® and 818® by the company Sasol;

- synthetic ethers having 10 to 40 carbon atoms;

- linear or branched hydrocarbons, of mineral or synthetic origin other than the polymers according to the invention, such as petroleum jelly, polybutenes, polydecenes, squalane, and mixtures thereof;

- synthetic esters such as oils of formula R1COOR2 in which R1 represents the residue of a linear or branched fatty acid containing from 1 to 40 carbon atoms and R2 represents a hydrocarbon chain in particular branched containing from 1 to 40 carbon atoms at provided that R1 + R2 is ≥ 10, such as Purcellin's oil (cetostearyl octanoate), isopropyl myristate, isopropyl palmitate, C12 to C15 alcohol benzoate, hexyl laurate , diisopropyl adipate, isononyl isononanoate, 2-ethyl-hexyl palmitate, isostearate isostearate, octanoates, decanoates or ricinoleates of alcohols or polyalcohols such as propylene glycol dioctanoate; hydroxylated esters such as isostearyl lactate, di-isostearyl malate; and pentaerythritol esters

- fatty alcohols that are liquid at room temperature with a branched and/or unsaturated carbon chain having from 12 to 26 carbon atoms, such as octyl dodecanol, isostearyl alcohol, oleic alcohol, 2-hexyldecanol, 2-butyloctanol, 2-undecylpentadecanol;

- higher fatty acids such as oleic acid, linoleic acid, linolenic acid and mixtures thereof.

The non-volatile silicone oils suitable for the present invention may in particular be chosen from:

- the non-volatile silicone oils which can be used in the composition in accordance with the invention may be non-volatile polydimethylsiloxanes (PDMS), polydimethylsiloxanes comprising alkyl or alkoxy groups, pendent and/or at the end of the silicone chain, groups each having 2 with 24 carbon atoms, phenyl silicones such as phenyl trimethicones, phenyl dimethicones, phenyl trimethylsiloxy diphenylsiloxanes, diphenyl dimethicones, diphenyl methyldiphenyl trisiloxanes, 2-phenylethyl trimethylsiloxysilicates.

A composition according to the invention optionally comprises at least one non-volatile hydrocarbon oil of plant origin, such as triglycerides consisting of esters of fatty acids and glycerol, the fatty acids of which may have chain lengths varying from C4 to C28. , in particular hydrogenated palm and jojoba oil. A composition according to the invention is preferably free of non-volatile silicone oil(s).

A composition according to the invention is preferably free of non-volatile oil. However, the total content of non-volatile oil(s) in a composition in accordance with the invention can range from 0.01 to 10% by weight, in particular from 0.1 to 8% by weight, and preferably from 0.25 to 5% by weight relative to the total weight of the composition.

According to a preferred embodiment, a composition according to the invention comprises less than 5% by weight of non-volatile oil(s) relative to the total weight of the composition.

volatile oil

The composition according to the invention may comprise at least one volatile oil.

By "volatile oil" is meant an oil (or non-aqueous medium) capable of evaporating on contact with the skin in less than one hour, at ambient temperature and atmospheric pressure. Volatile oil is a volatile cosmetic oil, liquid at room temperature. More precisely, a volatile oil has an evaporation rate between 0.01 and 200 mg/cm2/min, limits included.

This volatile oil can be hydrocarbon.

The volatile hydrocarbon-based oil can be chosen from hydrocarbon-based oils having from 7 to 16 carbon atoms.

The composition according to the invention may contain one or more volatile branched alkane(s). By “one or more volatile branched alkane(s)”, is meant “one or more volatile branched alkane oil(s)”.

As volatile hydrocarbon oil having from 7 to 16 carbon atoms, mention may in particular be made of branched C8-C16 alkanes such as C8-C16 iso-alkanes (also called isoparaffins), isododecane, isodecane, isohexadecane and for example the oils sold under the trade names Isopars or Permetyls, branched C8-C16 esters such as iso-hexyl neopentanoate, and mixtures thereof. Preferably, the hydrocarbon-based volatile oil having from 8 to 16 carbon atoms is chosen from isododecane, isodecane, isohexadecane and mixtures thereof, and is in particular isododecane.

The composition according to the invention may contain one or more volatile linear alkane(s). By “one or more volatile linear alkane(s)”, is meant “one or more volatile linear alkane oil(s)”.

A volatile linear alkane suitable for the invention is liquid at room temperature (about 25° C.) and at atmospheric pressure (760 mm Hg).

By “volatile linear alkane” suitable for the invention, is meant a cosmetic linear alkane, capable of evaporating on contact with the skin in less than one hour, at ambient temperature (25° C.) and atmospheric pressure (760 mm Hg, i.e. 101,325 Pa), liquid at room temperature, having in particular an evaporation rate ranging from 0.01 to 15 mg/cm²/min, at room temperature (25°C) and atmospheric pressure (760mm Hg).

Linear alkanes, preferably of vegetable origin, comprising from 7 to 15 carbon atoms, in particular from 9 to 14 carbon atoms, and more particularly from 11 to 13 carbon atoms.

As an example of a linear alkane suitable for the invention, mention may be made of the alkanes described in the patent applications of the company Cognis WO 2007/068371, or WO2008/155059 (mixtures of distinct alkanes and differing from at minus one carbon). These alkanes are obtained from fatty alcohols, themselves obtained from copra or palm oil.

By way of example of a linear alkane suitable for the invention, mention may be made of n-heptane (C7), n-octane (C8), n-nonane (C9), n-decane (C10), n-undecane (C11), n-dodecane (C12), n-tridecane (C13), n-tetradecane (C14), -pentadecane (C15), and mixtures thereof, and in particular the mixture of n -undecane (C11) and n-tridecane (C13) described in example 1 of application WO2008/155059 from Cognis. Mention may also be made of n-dodecane (C12) and n-tetradecane (C14) sold by Sasol respectively under the references PARAFOL 12-97 and PARAFOL 14-97, as well as their mixtures.

The linear alkane may be used alone or as a mixture of at least two distinct alkanes and differing from each other by a carbon number of at least 1, and in particular a mixture of at least two linear alkanes comprising from 10 to 14 carbon atoms which are distinct and differ from each other by a carbon number of at least 2, and in particular a mixture of volatile linear C11/C13 alkanes or a mixture of linear C12/C14 alkanes, in particular a mixture n- undecane/n-tridecane (such a mixture can be obtained according to example 1 or example 2 of WO 2008/155059).

As a variant or additionally, the composition produced can comprise at least one volatile silicone oil or solvent, compatible with cosmetic use.

By silicone oil is meant an oil containing at least one silicon atom, and in particular containing Si—O groups. According to one embodiment, said composition comprises less than 10% by weight of non-volatile silicone oil(s), relative to the total weight of the composition, better still less than 5% by weight, or even is free of silicone oil.

As volatile silicone oil, mention may be made of cyclic polysiloxanes, linear polysiloxanes and mixtures thereof. As linear volatile polysiloxanes, mention may be made of hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, tetradecamethylhexasiloxane and hexadecamethylheptasiloxane. As volatile cyclic polysiloxanes, mention may be made of hexamethylcyclotrisiloxane, octamethylcylotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane.

As a variant or additionally, the composition produced can comprise at least one fluorinated volatile oil.

By fluorinated oil is meant an oil containing at least one fluorine atom.

As fluorinated volatile oil, mention may be made of nonafluoromethoxybutane or perfluoromethylcyclopentane, and mixtures thereof.

A composition according to the invention is preferably free of non-volatile oil. However, at least volatile oil may be present in a total content ranging from 0.1% to 10% by weight. In particular, the volatile oil may be present in the composition in a content ranging from 0.5 to 5% by weight relative to the total weight of the composition.

According to a preferred embodiment, a composition according to the invention comprises less than 5% by weight of volatile oil(s) relative to the total weight of the composition.

Process

The microdispersions are implemented according to a thermodynamic process or in a conventional tank using the mechanical and kinetic energy of a rotor-stator. The crucial step is the total melting of the wax in the presence of the surfactant then the very gradual addition of the aqueous phase at the same temperature so as to cross the phase diagram to achieve a fine dispersion of the objects in the form of wax particles of volume average diameter less than 500 nm.

The subject of the present invention is thus a process for the manufacture of a microdispersion of natural wax according to the invention, characterized in that it comprises at least the steps of:

- heating of said wax in the presence of said surfactant to a temperature Ts sufficient to allow the complete melting of the wax in the presence of the surfactant, preferably at a temperature Ts greater than or equal to the melting temperature Tf of the wax, preferably at a temperature Ts comprised in the range of Tf to Tf+10°C, to allow complete melting of the wax in the presence of the surfactant, then

- gradual addition of the aqueous phase at a temperature in the range from Tf-5°C to Tf+10°C, preferably from Tf-5°C to Tf+5°C, preferably from Tf-2°C to Tm+2°C with stirring, preferably at a stirring speed comprised in the range of 100 to 1000 rpm, so that a microemulsion of molten wax in an aqueous continuous phase is obtained, then

- cooling the microemulsion until an aqueous microdispersion of wax particles is formed, preferably down to room temperature, and

- addition at room temperature (25°C) of at least one polyol comprising at least three hydroxyls, according to a content of at least 12%, preferably comprised in the range of 12 to 20% by weight on the total weight of the composition.

The term “progressive addition” of the aqueous phase means a rate of addition of the aqueous phase that is slow enough to allow or observe:

- first the production of an inverse water-in-wax emulsion,

- then the transition from this inverse emulsion to a direct emulsion of microdroplets of wax in water.

Advantageously, the gradual addition of the aqueous phase is carried out for a time comprised in the range of 5 to 45 minutes, preferably for a time comprised in the range of 10 to 30 minutes, preferably 10 to 15 minutes.

At the end of the process according to the invention, a microdispersion of particles of natural wax with a volume-average diameter D[4;3] of less than 500 nm is obtained.

Advantageously, said wax particles have a volume-average diameter D[4,3] comprised between 30 and 500 nm, preferably comprised in the range of 50 to 300 nm, and preferably comprised in the range of 60 to 200 nm.

Preferably, the sizes and size distributions of the particles of the compositions according to the invention are measured by static light scattering using a commercial particle sizer of the MasterSizer 2000 type from Malvern. The data is processed based on Mie scattering theory. This theory, exact for isotropic particles, makes it possible to determine in the case of non-spherical particles, an "effective" particle diameter. This theory is notably described in the work of Van de Hulst, H.C., “Light Scattering by Small Particles”, Chapters 9 and 10, Wiley, New York, 1957.

In the context of the present invention, volume-average diameter D[4;3] is expressed as volume-average “effective” diameter D[4.3], defined as follows:

where Vi represents the volume of the particles of effective diameter di. This parameter is described in particular in the technical documentation of the particle size analyzer. The measurements are carried out at 25°C, on a dispersion of diluted particles. The "effective" diameter is obtained by taking a refractive index of 1.33 for water and an average refractive index of 1.45 for particles.

The composition in the form of a microdispersion of wax according to the invention advantageously has a fluid, liquid texture, with a viscosity at 25° C. of less than 30 Pa.s, preferably comprised in the range of 5 to 25 Pa.s, and preferably it has the macroscopic appearance of milk.

The waxes, at the end of the process of the invention, thus find themselves frozen in an aqueous dispersion, and their dispersion remains stable over time, in the form of a milk.

Advantageously, this milk can either be used as it is and applied directly to keratin materials, or also very easy to incorporate directly into cosmetic formulas, in order to provide them in particular with the benefit of a homogeneous, smooth, and natural film-forming deposit with a grip effect. all the more present as the concentration of wax microdispersion is high in the cosmetic formula.

The compositions according to the invention equally well include:

- the microdispersions concentrated in wax particles as described above containing essentially, or even only, the wax, the surfactant, the water, and the polyol, as defined above, possibly to be diluted at the time of use,

that

- non-concentrated microdispersions, that is to say containing at least the wax, the surfactant, the water, and the polyol, as defined above, to which are added, for example at the time of use or more conventionally during the manufacture of the final composition, one or more secondary ingredient(s).

By secondary ingredient is meant here any ingredient conventionally used in cosmetics, and in particular any cosmetic adjuvant.

Such a cosmetic adjuvant is advantageously chosen from cosmetic or dermatological active agents, preservatives, antioxidants, perfumes, fillers, pigments, UV filters, odor absorbers, dyestuffs, and mixtures thereof.

Where appropriate, this or these secondary ingredients are present in the composition according to the invention in contents ranging from 0.01 to 20% by weight, preferably from 0.05 to 10%, preferably from 1 to 5%, and even more preferably from 0.1 to 1% by weight relative to the total weight of the composition.

These ingredients and/or active agents as well as their concentrations must be such that they do not modify the property sought for the wax microdispersion of the invention.

Preferably, ingredients and/or active ingredients of natural origin are used.

A further subject of the present invention is a non-therapeutic process for the cosmetic treatment of keratin materials, in particular for making up or removing make-up from the skin, including the scalp, the hair and/or the lips, comprising the application to the skin, the hair and/or the lips, of a composition according to the present invention.

The subject of the present invention is in particular a process for the cosmetic treatment of the hair, intended in particular to improve the hold and/or the volume of the hairstyle and/or to eliminate or delay the appearance of the greasy appearance of the hair, in which applies, at least to the part of the hair close to the root, a composition as defined above, in sufficient quantity to impregnate the hair or parts of hair to be treated.

Examples

Example 1

Feasibility study of a microdispersion of carnauba wax according to the surfactant used

The surfactant used for each test is indicated in Table 1 below.

Composition-type compared:

In the tests, only the nature of the surfactant changes in the following standard composition, the contents of active matter of the various ingredients remain identical.

The carnauba wax used in the tests has a melting point of 81.5° C. and a hardness of 6.8 MPa.

INCI Typical composition Carnauba wax 30 surfactant 7.5 Water 52.5 Glycerine 10

Materials:

Beaker on hot plate (Maxilab 3L) equipped with a stirring system.

Procedure:

- heating of the carnauba wax in the presence of the surfactant to a temperature Ts of 90-100°C (higher than the melting temperature Tf of the carnauba wax (Tf = 85°C), to allow the total melting of the wax in the presence of the surfactant, then

- gradual addition of water at a temperature substantially equal to 90°C (Ts) with stirring at a stirring speed of 200 rpm, so that a fine dispersion of waxes is obtained, then

- cooling the dispersion to room temperature (25°C), and

- addition of glycerin at room temperature.

Results :

Table 1 below shows the state of the formula obtained according to the surfactant used in the standard composition.

For the formula obtained to be qualified as "microdispersion of wax in accordance with the invention", it must have:

• a macroscopic milk appearance checked 24 hours after formulation;
• a monodisperse microscopic appearance, with wax particles with a volume-average diameter D[4;3] of less than 500 nm in the milk.

Surfactant used in the Standard Composition
(INCI name) Common chemical name Nature/HLB/pH Macroscopic appearance 24h D[4;3] Cp1 PEG-30-glyceryl stearate Oxyethylenated Glyceryl Monostearate (30 EO) Nonionic/16/5.5 beige milk 118nm Ex1 Sucrose laurate (C24H44O12) Sucrose laurate Nonionic/16/5.7 beige milk 243nm Cp2 Sodium stearate Sodium Stearate Anionic Heterogeneous 17mm Cp3 Sucrose stearate Sucrose Stearate Nonionic/15/9.8 Liquid
biphase / paste N / A Cp4 Stearamidopropyl dimethyl amine Stearyl amidopropyl dimethylamine Cationic Heterogeneous appearance
liquid/paste N / A Cp5 POLYGLYCERYL-6 DISTEARATE (and) POLYGLYCERYL-6 BEHENATE DIGLYCERYL STEARATE AND DIGLYCERYL BEHENATE Nonionic /13/9.3 Heterogeneous appearance
liquid/paste N / A Cp6 Glyceryl stearate citrate GLYCEROL STEARATE CITRIC ESTER Anionic/11/4.5-6.8 Liquid + solid
biphase N / A Cp7 Polyglyceryl 2 stearate MONO-STEARATE POLYGLYCEROLE (2 MOLES) Nonionic/10/? Dough N / A

Of the various surfactants tested of natural origin, only sucrose laurate made it possible to obtain a microdispersion of wax in accordance with the invention.

Example 2

Impact of Sucrose Laurate Surfactant Content

INCI Ex1 Cp8 Carnauba wax 30 27 Sucrose Laurate 7.5 2.5 Water 52.5 60.5 Glycerine 10 10 Formula status monodisperse polydisperse D[4.3] <500nm >500nm

The minimum surfactant content to obtain a stable aqueous microdispersion of natural wax, for a high wax content (content of about 30%) is 3%. Beyond 15% of surfactant, no improvement was observed in the dispersion obtained. A content of surfactant comprised in the range of 3 to 15%, preferably 5 to 10%, proves to be optimal for the composition according to the invention.

Example 3

Impact of the nature of the polyol on the state of the final formula

INCI Ex2 Cp9 Cp10 Carnauba wax 27 27 27 Glycerine 15 Octane-1,2-Diol 1 Pentane-1,2-Diol 10 SUCROSE LAURATE 7.5 7.5 7.5 Water 50.5 55.5 64.5 State of the final formula :
monodisperse / polydisperse
stable / unstable
Monodisperse Compliant
D[4;3] < 500nm
stable at 2 months Improper
monodisperse
not stable at 2 months Not compliant with T0 polydisperse

Glycerin, used in a content of between 0.1 and 10% by weight on the total weight of the formula has a nutritive power.

Used in a content of at least 12%, here 15% by weight of the total weight of the composition, in example Ex2 according to the invention, glycerin also provides a protective power to the formula both in terms stability and as an antimicrobial agent: the composition of example Ex2 is stable for at least 2 months at any temperature within the range of 4 to 45°C.

On the contrary, the presence of alcohol comprising less than three hydroxyl functions, in particular diol(s), whatever its (their) content, destabilizes the wax dispersion of the comparatives Cp9 and Cp10.

It has also been observed that the presence of monoalcohol, such as ethanol, modifies the affinities of sucrose laurate (C12): its fatty chains are attracted by the continuous phase, and there is a reorganization within the formula into aggregates thick wax, and one or more cracks may appear within the resulting thick formula.

Example 4

Sensory evaluation – Vitro test

Material :

Malleable artificial head used: Karen head ref: 772708 brown, caucasian, india hair (eurotex quality supplier)

Spray: PUMP C14547.3 PMP APTAR PZ2 DL 190µl nozzle 3527 neck 24.410 jt triseal 1mm

BOTTLE C540 BTL EDP PET 2013 – Fla. Vita 150ml pet cleartuff high neck

Protocol

Apply the product by spraying 20 cm from the hair in a circular motion for 3 seconds for an even distribution over the entire targeted area. This corresponds to a quantity of product of the order of 0.5g per half-head.

INCI Cp11 Ex2 Carnauba wax 30 27 Alcohol 10 Glycerine 15 PEG-30 GLYCERYL STEARATE 7.5 SUCROSE LAURATE 7.5 Water 52.5 50.5 Evaluation - Texture Rating from 0 to 5 Rating from 0 to 5 Ease of grip 4 4 Spreadability 1.5 2 hand brake 4 3.5 Sticky in hand 1 1 Easy hand rinsing 4 4 Evaluation - Application on dry hair Ease of distribution 2.5 2.5 Brake 4.5 4 Instant shaping 4.5 4 Coating 3 3 Transfer in the fingers 4.5 4.5

There are no significant differences observed between the 2 formulas on a rating scale of 0 to 5. There is no negative impact of the natural surfactant according to the invention according to the sensory evaluations carried out.

Example 5

Characterization of the deposit on the hair

Hair is sprayed under the same conditions and then compared, after drying, the deposit formed on the hair, by each of the following hair fixing lacquers (commercial formulas) with the microdispersion of wax in the form of milk from Example Ex according to the invention. :

- Lacquer based on fillers (Ca, kaolin, silica) gives a coarse deposit ( ),

- The lacquer based on fillers (12.5%) and polymers (5%) gives a heterogeneous deposit ( ).

- A milk corresponding to the microdispersion of wax according to the invention (Ex ) gives a fine and regular deposit on the hair ( ).

The milk according to the invention has a regular and homogeneous deposit, which promotes a sheathing film-forming effect and fixation over the entire length of the fiber with a differentiating "grip effect" signature, unlike the other technologies tested which create glue points. heterogeneous for the supply of fixation.

Claims (21)

Composition comprising a microdispersion of natural wax particles with a volume-average diameter D[4;3] of less than 500 nm, characterized in that it comprises:

• from 0.1 to 30% by weight of at least one wax of natural origin with a melting point Tm in the range from 50 to 100° C.,
• from 3 to 15% by weight of at least one nonionic surfactant chosen from C8-C16 fatty acid esters and sugar,
• at least 40% by weight of water,
• at least 12% by weight of at least one polyol comprising at least three hydroxyls,

on the total weight of the composition representing 100%. Composition according to Claim 1, in which the wax is chosen from waxes of natural origin with a Tm of between 50 and 100°C, preferably between 50 and 90°C. Composition according to any one of the preceding claims, in which the wax has, at 20°C, a hardness greater than 5 MPa, in particular ranging from 5 to 30 MPa, preferably greater than 6 MPa, better still ranging from 6 to 25 MPa . Composition according to any one of the preceding claims, in which the wax is chosen from at least one of the following waxes: carnauba wax, candelilla wax, hydrogenated jojoba oil, hydrogenated palm oil, rice bran wax, Sumac wax, sunflower wax, macadamia wax, hydrogenated olive oil, waxes obtained by hydrogenation of olive oil esterified with C12 chain fatty alcohols at C18, hydrogenated castor oils, waxes obtained by hydrogenation of castor oil esterified with cetyl or behenic alcohol, and mixtures of these waxes; the wax is preferably chosen from: carnauba wax, rice bran wax, sunflower wax, hydrogenated castor oil, hydrogenated castor oil esterified with cetyl or behenic alcohol, and mixtures of these waxes. Composition according to any one of the preceding claims, in which the said surfactant is chosen from fatty acid and sugar esters, in which the fatty acid is C10-C16, preferably C12-C16, or even C12- C14, more preferably C12, preferably said surfactant is chosen from fatty acid and sugar monoesters, in which the fatty acid is C10-C16, preferably C12-C16, or even C12-C14, plus preferentially in C12. Composition according to any one of the preceding claims, in which the said surfactant is chosen from fatty acid and sugar esters, in which the sugar is chosen from sucrose, maltose, glucose, fructose, mannose, galactose, arabinose, xylose, lactose, trehalose, methylglucose; preferably chosen from sucrose, glucose and methylglucose; even more preferably sucrose. A composition according to any preceding claim, wherein said surfactant comprises, and preferably is, sucrose laurate. Composition according to any one of the preceding claims, in which the said surfactant represents a content of 5 to 10%, on the total weight of the composition. Composition according to any one of the preceding claims, characterized in that the ratio of the content by weight of the said at least one wax to the content by weight of nonionic surfactant is included in the range from 2 to 8, preferably from 2 to 6, preferably 3 to 5. Composition according to any one of the preceding claims, characterized in that it comprises less than 2% by weight, preferably less than 1% by weight, of surfactant other than the said nonionic surfactant, on the total weight of the composition, and preferably is free of surfactant other than said nonionic surfactant. Composition according to any one of the preceding claims, characterized in that it comprises less than 2% by weight, preferably less than 1% by weight, on the total weight of the composition, preferably is free, of polymer of synthetic origin, in particular free of film-forming polymer of synthetic origin. Composition according to any one of the preceding claims, characterized in that it contains less than 2%, preferably less than 1%, by weight relative to the total weight of the composition, preferably is free, of ingredient(s) chosen from: gelling agents and/or thickeners and/or preservatives. Composition according to any one of the preceding claims, in which the said polyol comprising at least three hydroxyls is present in the composition according to a content of 12 to 20%, preferably of 12 to 15%, by weight on the total weight of the composition . A composition according to any preceding claim, wherein said polyol is selected from polyols exhibiting hydroxyl symmetry in the polyol molecule, preferably said at least one polyol comprises glycerin, and preferably is glycerin. Composition according to any one of the preceding claims, characterized in that it comprises less than 5%, preferably less than 2%, by weight of monoalcohol or diol, on the total weight of the composition, and preferably is free monoalcohol or diol. Composition according to any one of the preceding claims, characterized in that the wax particles have a volume-average diameter D[4,3] of between 30 and 500 nm, preferably comprised in the range of 50 to 300 nm, of preferably in the range of 60 to 200 nm. Composition according to any one of the preceding claims, characterized in that it has a liquid texture with a viscosity at 25°C of less than 30 Pa.s, preferably comprised in the range from 5 to 25 Pa.s, preferably present the macroscopic appearance of milk. Composition according to any one of the preceding claims, characterized in that it additionally comprises at least one cosmetic adjuvant chosen from cosmetic or dermatological active agents, preservatives, antioxidants, perfumes, fillers, pigments, UV filters , odor absorbers, dyestuffs, and mixtures thereof. Process for the manufacture of a microdispersion of natural wax according to any one of the preceding claims, characterized in that it comprises at least the steps of:
- heating of said wax in the presence of said surfactant to a sufficient temperature Ts, preferably to a temperature Ts greater than or equal to the melting point of the mixture of wax and surfactant, optionally added with oil and/or fat-soluble substances, preferably at a temperature Ts comprised in the range from Tf to Tf+10° C., Tf being the melting temperature of the wax, to allow the wax to completely melt in the presence of the surfactant, then
- gradual addition of the aqueous phase at a temperature in the range from Tf-5°C to Tf+10°C, preferably from Tf-5°C to Tf+5°C, preferably from Tf-2°C to Tm+2°C, with stirring, preferably at a stirring speed comprised in the range of 100 to 1000 rpm, so that a microemulsion of molten wax in a continuous aqueous phase is obtained, then
- cooling the microemulsion until an aqueous microdispersion of wax particles is formed, preferably down to room temperature, then
- addition, preferably at room temperature, of at least one polyol comprising at least three hydroxyls, according to a content of at least 12%, preferably comprised in the range of 12 to 20% by weight on the total weight of the composition. Non-therapeutic process for the cosmetic treatment of keratin materials, in particular for making up or removing make-up from the skin, including the scalp, the hair and/or the lips, comprising the application to the skin, the hair and/or the lips, of a composition as defined according to any one of Claims 1 to 18. Process according to Claim 20, for the cosmetic treatment of the hair, intended in particular to improve the hold and/or the volume of the hairstyle and/or to eliminate or delay the appearance of the greasy appearance of the hair, in which one applies, least on the part of the hair close to the root, a composition as defined in any one of Claims 1 to 18, in an amount sufficient to impregnate the hair or parts of hair to be treated.