Gel-type cosmetic composition

The present invention is directed towards proposing for the field of caring for and making up keratin materials, especially the skin and/or the lips, and in particular the skin, a novel galenical form that is most particularly advantageous with regard to its technical performance and the sensations it affords the user during its application, in particular to the skin.

The term "keratin materials" especially means the skin, the lips and/or the eyelashes, in particular the skin and/or the lips, and preferably the skin.

Conventionally, a cosmetic composition formulator uses emulsified systems combining an aqueous phase for freshness and an oily phase for comfort. The strong point of these systems is also that they allow the combination, within the same composition, of cosmetic active agents that have different affinities with respect to these two aqueous and oily phases.

Unfortunately, these emulsifying systems do not lend themselves to rapid and easy production of an infinite range of compositions. Thus, for a given emulsifying system, it often proves complicated to functionalize the formulation by adding, for example, an antisun product, certain active agents, pigments, polymers, fragrances or fillers, etc. without impairing the stability, the sensory properties and the quality of the film deposited on the keratin materials and especially the skin. The formulation then needs to be readjusted. It is also difficult to reconcile, within the same composition, opposing technical performance qualities, for instance mattness (which may make the skin dry) and moisturization (which may make the skin shiny).

Furthermore, emulsified systems do not lend themselves to the formulation of all the ingredients or active agents liable to be considered in the field of care or makeup, or even to the formulation of high contents of certain cosmetic ingredients or active agents.

Non-compliance with these incompatibilities has the consequence of destabilizing the emulsified architecture, which then, inter alia, undergoes demixing.

Finally, these emulsified systems do not lend themselves to rapid and easy production of an infinite range of textures.

Moreover, in the case of making up the complexion, the preferred emulsifying systems are mainly reverse emulsions with regard to the good level of coverage and the homogeneous appearance they afford when compared with direct emulsions. On the other

hand, their weak point is a high greasy and tacky sensation, and thus a lack of lightness as regards the textures obtained.

Galenical formulations of gel/gel type partially meet these expectations (Almeida et al, Pharmaceutical Development and Technology, 2008, 13 :487, tables 1 and 2, page 488; WO 99/65455; PI 0405758-9; WO 99/62497; JP 2005-112834 and WO 2008/081 175). Formulations of this type combine a gelled aqueous phase with a gelled oily phase. In fact, these gel/gel formulations were essentially proposed as an advantageous alternative to emulsifying systems on the grounds that they make it possible to dispense with the use of the surfactants required for the stability and texturization of emulsions. Unfortunately, besides this advantage, the gel/gel formulations described hitherto do not essentially reveal any novel or improved technical performance qualities.

It therefore remains difficult for a person skilled in the art to propose homogeneous compositions that are capable of affording an immediate visual result on the skin with a light sensation on application, this expected immediate result preferentially being good coverage of colour imperfections and/or of relief imperfections, without, however, marking them. It is therefore necessary to find novel systems for distributing on the skin components such as water, fatty substances and solid particles.

These novel architectures must be entirely satisfactory to users as regards the sensation afforded, but must also be capable of affording improved cosmetic properties, or must even have an increased number of technical performance qualities such as freshness, lightness, emollience, comfort, coverage of imperfections, colour, unifying aspect, lightening, etc., and, on the other hand, must be free of the known side effects of oily and aqueous phases such as, respectively, a greasy feel, a tacky feel, a feeling of lack of glidance or alternatively a feeling of dragging on application.

The inventors have now found, unexpectedly, that such an objective can be achieved via the choice of a system of specific hydrophilic gelling agent(s)/lipophilic gelling agent(s) for the preparation of a cosmetic composition of the type such as a bi-continuous but on the other hand macroscopically homogeneous system which has a large number of technical performance qualities and which furthermore has optimized effects.

More precisely, the inventors have found that the choice of a system of specific hydrophilic gelling agent(s)/lipophilic gelling agent(s) makes it possible, contrary to all expectation, to combine in a single composition a significant number of technical

performance qualities, with the intensity of each performance quality advantageously not being attenuated by the manifestation of other associated performance qualities, or even being, for certain performance qualities, stimulated.

Thus, according to one of its aspects, the present invention relates to a cosmetic composition for making up and/or caring for keratin materials, in particular the skin and/or the lips, comprising:

- at least one aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent; and

- at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof;

the said phases forming therein a macroscopically homogeneous mixture.

According to one embodiment variant, a composition according to the invention consists of an aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent, and an oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof.

According to a preferred variant, a composition according to the invention also contains at least one dyestuff.

This dyestuff may be chosen from pigments, and water-soluble or liposoluble dyestuffs, especially as detailed below.

In particular, the dyestuffs are pigments.

According to an advantageous embodiment variant, the dyestuff is conveyed at least in the gelled oily phase.

As stated above, the inventors have found, contrary to all expectation, that the choice of particular hydrophilic gelling agent(s)/lipophilic gelling agent(s) couples for texturing a composition of gel/gel type makes it possible to significantly improve certain technical performance qualities, and to dispense with certain adverse effects inherent in the gelling agents under consideration, or even to reconcile within this composition properties which it was hitherto difficult to make coexist. Furthermore, as emerges from the examples below, the present invention moreover makes it possible, unexpectedly, to optimize some of the expected technical performance qualities.

For example, an aqueous phase textured according to the invention with an oily gelling agent of organopolysiloxane elastomer type, which is advantageous for its mattifying properties, makes it possible, when it is combined with an aqueous phase gelled with an acrylic polymer, to gain access to a cosmetic composition that is most particularly advantageous for caring for and making up greasy and combination skin since it has mattifying properties and a freshness effect, and for which the dragging effect, which is a known side effect of aqueous gelling agents, is unexpectedly found to be significantly attenuated.

Similarly, an oily phase gelled with a wax makes it possible, when it is combined with an aqueous phase gelled with an acrylic polymer, to gain access to a cosmetic composition that is most particularly advantageous for caring for and making up normal skin, since it has emollient properties and a freshness effect, but for which the greasy feel, which is a known side effect of waxes, is found to be significantly attenuated.

The inventors have also found, surprisingly, that the soft-focus performance quality of a composition according to the invention comprising aqueous and oily phases gelled, respectively, with a polymeric or particulate gelling agent with a soft-focus effect proves to be significantly improved. The gain in soft-focus effect proves to be greater than the sum of the respective optical effects of each of the two gelled phases in each of the two compositions. There is manifestly synergism.

In addition, the inventors have surpri singly found that compositions according to the invention allow obtaining pigmented "self- smoothing" formulations which are homogeneous and stable without requiring the presence of a surfactant, in particular when a nonionic associative polymer of polyurethane type is used as gelling agent of the aqueous phase. Moreover, such compositions have a homogeneous deposit upon application. In particular, the use of nonionic associative polymer of polyurethane type, such as nonionic fatty-chain polyurethane polyethers, allows to form composition having a dense and elastic texture, which enables to dose the grip of the composition.

In addition, by virtue of the associative polyurethane, the so-obtained compositions have the advantage of being "self-smoothing", whose surface regains its smoothness after use. After each use, a smooth and uniform surface reforms at the surface of the jar, as if the jar was new, and when the cream is taken up on a finger or any other means (sponge or spatula), the mark of this finger or of this means does not remain at all.

The compositions according to the invention also prove to be very stable and not subject to syneresis.

Besides the abovementioned unexpected advantages, the gelling system under consideration according to the invention affords a texture that is sufficiently thickened to be compatible with the formulation of a very wide diversity of ingredients or active agents. It combines in a single formulation a large number of functional active agents or ingredients (fillers, pigments, etc.).

In particular, the compositions according to the invention also prove to be very advantageous for formulating high amount of particulate materials, like pigments and fillers, as requested in conventional compositions dedicated to make-up.

It is known that compositions having high amounts of aqueous phase, like more than 30% by weight, are not always convenient for formulating solid materials in amount of more than 10%. However, such high amounts of particles are generally necessary to get the expected properties of make-up as coverage and/ or masking of skin imperfections.

The compositions according to the invention allow precisely formulating high amounts of solid materials while keeping the expected properties of a make-up composition, namely lightness, freshness and comfort. Moreover, the compositions according to the invention maintain the make-up properties, as good coverage, colored effect and relief masking.

At last, the composition is easy to apply on the surface of the targeted keratin material. This performance is notably technically characterized by a good playtime.

According to another of its aspects, a subject of the invention is also a process for preparing a cosmetic composition for making up and/or caring for keratin materials, in particular the skin and/or the lips, comprising at least one step of mixing:

- at least one aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent; and

- at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof;

under conditions suitable for obtaining a macroscopically homogeneous mixture.

According to one embodiment variant, this process may advantageously comprise a step of mixing at least three or even more gelled phases.

For obvious reasons, the number of gelled aqueous phases and of gelled oily phases to be considered for forming a composition according to the invention may range for each of the two types of phase beyond two. It is especially conditioned by the number of expected technical performance qualities.

For example, this process may use a single gelled aqueous phase and two oily phases gelled with different lipophilic gelling agents.

Conversely, this process may also use a single gelled oily phase and two aqueous phases gelled with different hydrophilic gelling agents.

For example, the phases having the same architecture, namely aqueous or oily, may be precombined to form a premix, and it is this premix which is placed in contact with the phase or even with a premix of several phases having the other architecture.

The corresponding aqueous and oily gels may be prepared separately without heating, without requiring the necessary presence of surfactants in order to achieve the desired architecture. Thus, in addition to the advantages mentioned above, the claimed compositions may be readily prepared at reduced cost.

Advantageously, the mixing of the phases may be performed at room temperature.

However, the process of the invention may comprise, if necessary, a step of heating the mixture.

The process according to the invention thus offers the formulator a simple and rapid means for gaining access to a multitude of cosmetic compositions having common performance qualities but also performance qualities that are specific to each of its compositions.

The present invention also gives the user access to this faculty of mixing at least two phases of the same architecture with at least one phase of different architecture via the provision of a cosmetic kit for making up and/or caring for keratin materials.

Thus, according to another of its aspects, the present invention relates to a cosmetic kit for making up and/or caring for keratin materials, in particular the skin and/or the lips, comprising, in separate containers, at least one aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent; and at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof, and also to instructions for using the extemporaneous mixtures.

According to yet another of its aspects, the present invention relates to a device for making up and/or caring for keratin materials, in particular the skin and/or the lips, comprising at least:

- two separate containers containing, respectively, at least one aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent; and at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof;

- a distinct chamber for mixing the said containers, comprising an aperture configured to allow the introduction of the said phases to be mixed; and

- a means for distributing a macroscopically homogeneous mixture of the two phases.

According to an advantageous variant, the kits and devices according to the invention contain at least two, or even more, different gelled phases for each of the two types of aqueous and oily architecture.

According to a particular embodiment, the representative gelled phases of the same type of architecture are gelled with a different gelling agent.

Multi-phase formulations of "patchwork" type may thus be developed.

According to another particular embodiment, the representative gelled phases of the same type of architecture are different as regards their optical properties. For example, the kit or device may propose two oily gels phases textured by the same oily gelling agent, but one containing dyestuffs and the other not. The user thus has the possibility of exploiting or not exploiting makeup performance quality in addition to the other performance qualities.

A kit or device according to the invention also allows the user to modify the intensity of the colour effect by adjusting the proportion of the coloured gelled phase to be mixed.

Thus, the kits and devices according to the invention are particularly advantageous in so far as they afford the user the possibility of adjusting at will, by means of the choice of the gelled phases representative of the two types of oily and aqueous architecture, the desired makeup performance qualities, while at the same time ensuring convenience and ease of use.

The present invention especially makes it possible to afford the user a wider makeup range and also to give the makeup operation an appealing fun aspect. Moreover, the fact that the mixing of the phases may be performed at room temperature is of manifest interest as regards the convenience and thus gives satisfaction as regards the simplicity of use.

According to another of its aspects, a subject of the invention is also a process, especially a cosmetic process, for making up and/or caring for a keratin material, in particular the skin and/or the lips, comprising at least one step that consists in applying to the said keratin material a composition in accordance with the invention.

According to yet another of its aspects, the present invention relates to a process, especially a cosmetic process, for caring for and/or making up a keratin material, in particular the skin and/or the lips, comprising at least the application to the said material of a composition, in particular a macroscopically homogeneous composition obtained by extemporaneous mixing, before application or at the time of application to the said keratin material, of at least one aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent, and of at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof.

COSMETIC COMPOSITION

Firstly, it is important to note that a composition according to the invention is different from an emulsion.

An emulsion generally consists of an oily liquid phase and an aqueous liquid phase. It is a dispersion of droplets of one of the two liquid phases in the other. The size of the droplets forming the dispersed phase of the emulsion is typically about a micrometer (0.1 to 100 μιη). Furthermore, an emulsion requires the presence of a surfactant or of a silicone emulsifier to ensure its stability over time.

In contrast, a composition according to the invention consists of a macroscopically homogeneous mixture of two immiscible gelled phases. These two phases

both have a gel-type texture. This texture is especially reflected visually by a consistent, creamy appearance.

The terms "macroscopically homogeneous mixture" means a mixture in which each of the gelled phases cannot be individualized with the naked eye.

More precisely, in a composition according to the invention, the gelled aqueous phase and the gelled oily phase interpenetrate and thus form a stable and, consistent product. This consistency is achieved by mixing interpenetrated oily and aqueous gelled macrodomains. These interpenetrated macrodomains are not measurable objects. Thus, by microscope, the composition according to the invention is very different from an emulsion. It cannot be characterized either as having a "sense", i.e. an O/W or W/O sense.

Thus, a composition according to the invention has a consistency of gel type. Furthermore, the stability of the composition is long-lasting without surfactant. Consequently, a cosmetic composition according to the invention does not require any surfactant or silicone emulsifier to ensure its stability over time.

It is known from the state of the art to observe the intimate nature of the mixture of the aqueous and oily gels in a gel-type composition, for example, by introducing a dye substance into either the oily or aqueous gel phases before forming the gel-type composition. On visual inspection, the dye is seen to be uniformly dispersed, even though the dye is present in only one of the oily gel or aqueous gel. Indeed, if two different dyes of different colours are introduced into the oily and aqueous phases, respectively, before forming the gel-type composition, both colours can be observed uniformly dispersed throughout the gel-type composition. This is in contrast to an emulsion wherein if a dye that is either water-soluble or oil-soluble is introduced into the aqueous or oily phases, respectively, before forming an emulsion, only the colour of the dye in the external phase will be observed (Remington: The Science and Practice of Pharmacy, 19th Edition (1995) Chapter 21, page 282).

It is also known to distinguish a gel-type composition from an emulsion by performing a "drop test". This test consists to demonstrate the bi-continous nature of a gel-type composition. Indeed, as mentioned above, the composition's consistency is achieved by interpenetrating oily and aqueous gelled domains. Therefore, the bi-continous nature of a gel-type composition can be highlighted by a simple test with respectively hydrophilic and hydrophobic solvents. This test consists to deposit, on the one hand, a

droplet of a hydrophilic solvent on a first sample of the tested composition, and, on the other hand, a droplet of a hydrophobic solvent on a second sample of the same tested composition, and to analyze the behavior of both droplets of solvents. In the case of an O/W emulsion, a droplet of hydrophilic solvent diffuses in the sample and a droplet of hydrophobic solvent remains at the sample surface. In the case of a W/O emulsion, a droplet of hydrophilic solvent remains at the sample surface and a droplet of hydrophobic solvent diffuses throughout sample. Finally, in the case of a gel-type composition (bi-continuous system), the hydrophilic and hydrophobic droplets diffuse in the entire sample.

In particular, in the case of the present invention, the test which will be privileged for distinguishing a gel-type composition from an emulsion consists in a dilution test. Indeed, in a gel-type composition, the gelled aqueous domains and gel oily domains interpenetrate and form a stable and consistent product, whose dilution behavior in water and oil is different of emulsion's behavior. Therefore, the dilution behavior of a gel-type composition (bi-continuous system) can be compared to emulsions.

More specifically, the dilution test consists to put 40g of product plus 160g of dilution solvent (water or oil) in a 30 ml plastic beaker. The dilution is performed under controlled agitation to avoid any phenomenon of emulsification. In particular, it is done using a planetary mixer: Speed Mixer TM DAC400FVZ. The Speed Mixer is set to 1500 rpm for 4 minutes. Finally, observation of resulting sample is made with a light microscope at a magnification of x 100 (xlOxlO). It may be noticed that oils like Parleam® and Xiameter PMX-200 Silicone Fluid 5CS® from Dow Corning are convenient as dilution solvents.

In the case of a gel-type composition (bi-continuous system), when diluted either in oil or water, a heterogeneous aspect is always observed. When a gel-type composition (bi-continuous system) is diluted with water, one will observe lumps of oily gel in suspension and when a gel-type composition (bi-continuous system) is diluted with oil, one will observe lumps of aqueous gel in suspension.

On the contrary, upon dilution, emulsions display a different behavior. An O/W emulsion when it is diluted with an aqueous solvent will gradually thin up without presenting a heterogeneous and lumpy aspect. This same O/W emulsion when diluted with oil will present a heterogeneous appearance (lumps of O/W emulsion suspended in oil). A W/O emulsion when diluted with an aqueous solvent will present a heterogeneous

appearance (lumps of W/O emulsion is suspended in the water). This same W/O emulsion when diluted with oil will gradually thin up without presenting a heterogeneous and lumpy aspect.

In general, the aqueous gelled phase and the oily gelled phase forming a composition according to the invention are present in a weight ratio ranging from 95/5 to 5/95. More preferentially, the aqueous phase and the oily phase are present in a weight ratio ranging from 30/70 to 80/20.

The ratio between the two gelled phases is adjusted according to the desired cosmetic properties.

Thus, in the case of a composition intended for making up the skin and especially the face, it is advantageous to favour an aqueous phase/oily phase weight ratio greater than 1, especially ranging from 60/40 to 90/10, preferably ranging from 60/40 to 80/20, preferably from 60/40 to 70/30 and more preferably to favour an aqueous phase/oily phase weight ratio of 60/40 or 70/30.

These preferred ratios are particularly advantageous for obtaining fresh and light compositions.

Advantageously, a composition according to the invention is in the form of a creamy gel with a minimum stress below which it does not flow unless it has been subjected to an external mechanical stress.

As emerges from the text hereinbelow, a composition according to the invention may have a minimum threshold stress of 1.5 Pa and in particular greater than 10 Pa.

It also advantageously has a stiffness modulus G* at least equal to 400 Pa and preferably greater than 1000 Pa.

According to an advantageous embodiment variant, the gelled phases under consideration to form a composition according to the invention have, respectively, a threshold stress of greater than 1.5 Pa and preferably greater than 10 Pa.

Characterization of the threshold stresses is performed by oscillating rheology measurements. A method is proposed in the examples section of the present text.

In general, the corresponding measurements are taken at 25°C using a Haake

RS600 imposed-stress rheometer equipped with a plate-plate measuring body (60 mm diameter) fitted with an anti-evaporation device (bell jar). For each measurement, the sample is placed delicately in position and the measurements start 5 minutes after placing the sample in the air gap (2 mm). The composition is then subjected to a stress ramp from 10"2 to 103 Pa at a set frequency of 1 Hz.

A composition according to the invention may also have a certain elasticity. This elasticity may be characterized by a stiffness modulus G* which, under this minimum stress threshold, may be at least equal to 400 Pa and preferably greater than 1000 Pa. The value G* of a composition may be obtained by subjecting the composition under consideration to a stress ramp from 10"2 to 103 Pa at a set frequency of 1 Hz.

HYDROPHILIC GELLING AGENT

For the purposes of the present invention, the term "hydrophilic gelling agent" means a compound that is capable of gelling the aqueous phase of the compositions according to the invention.

The gelling agent is hydrophilic and is thus present in the aqueous phase of the composition.

The gelling agent may be water-soluble or water-dispersible.

As stated above, the aqueous phase of a composition according to the invention is gelled with at least one hydrophilic gelling agent chosen from synthetic polymeric gelling agents.

For the purposes of the invention, the term "synthetic" means that the polymer is neither naturally existing nor a derivative of a polymer of natural origin.

The synthetic polymeric hydrophilic gelling agent under consideration according to the invention may or may not be particulate.

For the purposes of the invention, the term "particulate" means that the polymer is in the form of particles, preferably spherical particles.

Advantageously, a composition according to the invention comprises a polymeric hydrophilic gelling agent chosen from crosslinked acrylic homopolymers or copolymers; associative polymers, in particular associative polymers of polyurethane type; polyacrylamides and crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid polymers and copolymers; modified or unmodified carboxy vinyl polymers, and mixtures thereof, especially as defined below.

A. Particulate synthetic polymeric gelling agents

They are preferably chosen from crosslinked polymers.

They may especially be crosslinked acrylic homopolymers or copolymers, which are preferably partially neutralized or neutralized, and which are in particulate form.

According to one embodiment, the particulate gelling agent according to the present invention is chosen from crosslinked sodium polyacrylates. Preferably, it has in the dry or non-hydrated state a mean size of less than or equal to 100 μιη and preferably less than or equal to 50 μιη. The mean size of the particles corresponds to the mass-average diameter (D50) measured by laser particle size analysis or another equivalent method known to those skilled in the art.

Thus, preferably, the particulate gelling agent according to the present invention is chosen from crosslinked sodium polyacrylates, preferably in the form of particles with a mean size (or mean diameter) of less than or equal to 100 microns, more preferably in the form of spherical particles.

As examples of crosslinked sodium polyacrylates, mention may be made of those sold under the brand names Octacare XI 00, XI 10 and RM100 by the company Avecia, those sold under the names Flocare GB300 and Flosorb 500 by the company S F, those sold under the names Luquasorb 1003, Luquasorb 1010, Luquasorb 1280 and Luquasorb 1110 by the company BASF, those sold under the names Water Lock G400 and G430 (INCI name: Acrylamide/Sodium acrylate copolymer) by the company Grain Processing.

Mention may also be made of crosslinked polyacrylate microspheres, for instance those sold under the name Aquakeep® 10 SH F by the company Sumitomo Seika.

Such gelling agents may be used in a proportion of from 0.1% to 5% by weight of solids relative to the total weight of the aqueous phase, especially from 0.5% to 2% by weight and in particular in a proportion of about from 0.8% to 1.7% by weight, relative to the total weight of the aqueous phase.

B. Non-particulate synthetic polymeric gelling agents

This family of gelling agents may be detailed under the following subfamilies: 1. Associative polymers,

2. Crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid polymers and copolymers, and

3. Modified or unmodified carboxyvinyl polymers.

B.l Associative polymers

For the purposes of the present invention, the term "associative polymer" means any amphiphilic polymer comprising in its structure at least one fatty chain and at least one hydrophilic portion. The associative polymers in accordance with the present invention may be anionic, cationic, nonionic or amphoteric.

Associative anionic polymers

Among the associative anionic polymers that may be mentioned are those comprising at least one hydrophilic unit, and at least one fatty-chain allyl ether unit, more particularly those whose hydrophilic unit is formed by an unsaturated ethylenic anionic monomer, advantageously by a vinylcarboxylic acid and most particularly by an acrylic acid or a methacrylic acid or mixtures thereof, and whose fatty-chain allyl ether unit corresponds to the monomer of formula (I) below:

CH2 = C(R')CH2 O Bn R (I)

in which R' denotes H or CH3, B denotes the ethylenoxy radical, n is zero or denotes an integer ranging from 1 to 100, R denotes a hydrocarbon-based radical chosen from alkyl, arylalkyl, aryl, alkylaryl and cycloalkyl radicals, comprising from 8 to 30 carbon atoms, preferably 10 to 24 and even more particularly from 12 to 18 carbon atoms.

Anionic amphiphilic polymers of this type are described and prepared, according to an emulsion polymerization process, in patent EP 0 216 479.

Among the associative anionic polymers that may also be mentioned are maleic anhydride/C3o-C3s a-olefin/alkyl maleate terpolymers, such as the product (maleic anhydride/C3o-C38 a-olefin/isopropyl maleate copolymer) sold under the name Performa V

1608 by the company Newphase Technologies.

Among the associative anionic polymers, it is possible, according to a preferred embodiment, to use copolymers comprising among their monomers an α,β-monoethylenically unsaturated carboxylic acid and an ester of an α,β-monoethylenically unsaturated carboxylic acid and of an oxyalkylenated fatty alcohol.

Preferentially, these compounds also comprise as monomer an ester of an α,β-monoethylenically unsaturated carboxylic acid and of a C1-C4 alcohol.

Examples of compounds of this type that may be mentioned include Aculyn 22® sold by the company Rohm & Haas, which is a methacrylic acid/ethyl acrylate/oxyalkylenated stearyl methacrylate (comprising 20 OE units) terpolymer or Aculyn 28 (methacrylic acid/ethyl acrylate/oxyethylenated behenyl methacrylate (25 OE) terpolymer).

Examples of associative anionic polymers that may also be mentioned include anionic polymers comprising at least one hydrophilic unit of unsaturated olefinic carboxylic acid type, and at least one hydrophobic unit exclusively of the type such as a (C10-C30) alkyl ester of an unsaturated carboxylic acid. Examples that may be mentioned include the anionic polymers described and prepared according to patents US-3 915 921 and 4 509 949.

Associative anionic polymers that may also be mentioned include anionic terpolymers

The anionic terpolymer used according to the invention is a linear or branched and/or crosslinked terpolymer, of at least one monomer (1) bearing an acid function in free form, which is partially or totally salified with a nonionic monomer (2) chosen from N,N-dimethylacrylamide and 2-hydroxyethyl aciylate and at least one polyoxyethylenated alkyl aciylate monomer (3) of formula (I) below:

(I)

in which Rl represents a hydrogen atom, R represents a linear or branched C2-C8 alkyl radical and n represents a number ranging from 1 to 10.

The term "branched polymer" denotes a non-linear polymer which bears side chains so as to obtain, when this polymer is dissolved in water, a high degree of entanglement leading to very high viscosities, at a low speed gradient.

The term "crosslinked polymer" denotes a non-linear polymer which is in the form of a three-dimensional network that is insoluble in water but swellable in water, leading to the production of a chemical gel.

The acid function of the monomer (1) is especially a sulfonic acid or phosphonic acid function, the said functions being in free or partially or totally salified form.

The monomer (1) may be chosen from styrenesulfonic acid, ethylsulfonic acid and 2-methyl-2-[(l-oxo-2-propenyl)amino]-l-propanesulfonic acid (also known as acryloyldimethyl taurate), in free or partially or totally salified form. It is present in the anionic terpolymer preferably in molar proportions of between 5 mol% and 95 mol% and more particularly between 10 mol% and 90 mol%. The monomer (1) will more particularly be 2-methyl-2-[(l-oxo-2-propenyl)amino]-l-propanesulfonic acid in free or partially or totally salified form.

The acid function in partially or totally salified form will preferably be an alkali metal salt such as a sodium or potassium salt, an ammonium salt, an amino alcohol salt such as a monoethanolamine salt, or an amino acid salt such as a lysine salt.

The monomer (2) is preferably present in the anionic terpolymer in molar proportions of between 4.9 mol% and 90 mol%, more particularly between 9.5 mol% and 85 mol% and even more particularly between 19.5 mol% and 75 mol%.

In formula (I), examples of linear C8-Ci6 alkyl radicals that may be mentioned include octyl, decyl, undecyl, tridecyl, tetradecyl, pentadecyl and hexadecyl.

In formula (I), examples of branched C8-Ci6 alkyl radicals that may be mentioned include 2-ethylhexyl, 2-propylheptyl, 2-butyloctyl, 2-pentylnonyl, 2-hexyldecyl, 4-methylpentyl, 5-methylhexyl, 6-methylheptyl, 15-methylpentadecyl, 16-methylheptadecyl and 2-hexyloctyl.

According to a particular form of the invention, in formula (I), R denotes a C12-Ci6 alkyl radical.

According to a particular form of the invention, in formula (I), n ranges from 3 to 5.

Tetraethoxylated lauryl acrylate will more particularly be used as monomer of formula (I).

The monomer (3) of formula (I) is preferably present in the anionic terpolymer in molar proportions of between 0.1 mol% and 10 mol% and more particularly between 0.5 mol% and 5 mol%.

According to a particular mode of the invention, the anionic terpolymer is crosslinked and/or branched with a diethylenic or polyethylenic compound in the proportion expressed relative to the total amount of monomers used, from 0.005 mol% to 1 mol%, preferably from 0.01 mol% to 0.5 mol% and more particularly from 0.01 mol% to 0.25 mol%.

The crosslinking agent and/or branching agent is preferably chosen from ethylene glycol dimethacrylate, diallyloxyacetic acid or a salt thereof, such as sodium diallyloxyacetate, tetraallyloxyethane, ethylene glycol diacrylate, diallylurea, triallylamine, trimethylolpropane triacrylate and methylenebis(acrylamide), or mixtures thereof.

The anionic terpolymer may contain additives such as complexing agents, transfer agents or chain-limiting agents.

Use will be made more particularly of an anionic terpolymer of 2-methyl-2-[(l-oxo-2-propenyl)amino]-l-propanesulfonic acid partially or totally salified form of the ammonium salt, N,N-dimethylacrylamide and tetraethoxylated lauryl acrylate crosslinked with trimethylolpropane triacrylate, of INCI name Polyacrylate Crosspolymer-6, such as the product sold under the trade name Sepimax Zen® by the company SEPPIC.

Cationic associative polymers

Cationic associative polymers that may be mentioned include polyacrylates bearing amine side groups.

The polyacrylates bearing quaternized or non-quaternized amine side groups contain, for example, hydrophobic groups of the type such as steareth-20 (polyoxyethylenated (20) stearyl alcohol).

Examples of polyacrylates bearing amino side chains that may be mentioned are the polymers 8781-121B or 9492-103 from the company National Starch.

Nonionic associative polymers

The nonionic associative polymers may be chosen from:

- copolymers of vinylpyrrolidone and of fatty-chain hydrophobic

- copolymers of Ci-C6 alkyl methacrylates or acrylates and of amphiphilic monomers comprising at least one fatty chain;

- copolymers of hydrophilic methacrylates or acrylates and of hydrophobic monomers comprising at least one fatty chain, for instance the polyethylene glycol methaciylate/lauryl methacrylate copolymer;

- associative polyurethanes.

Associative polyurethanes are nonionic block copolymers comprising in the chain both hydrophilic blocks usually of polyoxyethylene nature (polyurethanes may also be referred to as polyurethane polyethers), and hydrophobic blocks that may be aliphatic sequences alone and/or cycloaliphatic and/or aromatic sequences.

In particular, these polymers comprise at least two hydrocarbon-based lipophilic chains containing from 6 to 30 carbon atoms, separated by a hydrophilic block, the hydrocarbon-based chains possibly being pendent chains or chains at the end of the hydrophilic block. In particular, it is possible for one or more pendent chains to be envisioned. In addition, the polymer may comprise a hydrocarbon-based chain at one end or at both ends of a hydrophilic block.

Associative polyurethanes may be block polymers, in triblock or multiblock form. The hydrophobic blocks may thus be at each end of the chain (for example: triblock copolymer containing a hydrophilic central block) or distributed both at the ends and in the chain (for example: multiblock copolymer). These polymers may also be graft polymers or star polymers. Preferably, the associative polyurethanes are triblock copolymers in which the hydrophilic block is a polyoxyethylene chain comprising from 50 to 1000 oxyethylene groups. In general, associative polyurethanes comprise a urethane bond between the hydrophilic blocks, whence arises the name.

According to a preferred embodiment, a nonionic associative polymer of polyurethane type is used as gelling agent.

As examples of nonionic fatty-chain polyurethane polyethers that may be used in the invention, it is also possible to use Rheolate® FX 1100 (Steareth-lOO/PEG 136/HDI (hexamethyl diisocyanate) copolymer), Rheolate® 205® containing a urea function, sold by the company Elementis, or Rheolate® 208, 204 or 212, and also Aery sol® RM 184 or Acrysol® RM 2020.

Mention may also be made of the product Elfacos® T210 containing a C12-C14 alkyl chain, and the product Elfacos® T212 containing a Ci6-i8 alkyl chain (PPG-14 Palmeth-60 Hexyl Dicarbamate), from Akzo.

The product DW 1206B® from Rohm & Haas containing a C20 alkyl chain and a urethane bond, sold at a solids content of 20% in water, may also be used.

It is also possible to use solutions or dispersions of these polymers, in particular in water or in aqueous-alcoholic medium. Examples of such polymers that may

® ® ®

be mentioned are Rheolate 255, Rheolate 278 and Rheolate 244 sold by the company

Elementis. Use may also be made of the products DW 1206F and DW 1206J sold by the company Rohm & Haas.

The associative polyurethanes that may be used according to the invention are in particular those described in the article by G. Fonnum, J. Bakke and Fk. Hansen - Colloid Polym. Sci., 271, 380-389 (1993).

Even more particularly, according to the invention, use may also be made of an associative polyurethane that may be obtained by poly condensation of at least three compounds comprising (i) at least one polyethylene glycol comprising from 150 to 180 mol of ethylene oxide, (ii) steaiyl alcohol or decyl alcohol, and (iii) at least one diisocyanate.

Such polyurethane polyethers are sold especially by the company Rohm & Haas under the names Aculyn® 46 and Aculyn® 44; Aculyn 46® is a polycondensate of polyethylene glycol containing 150 or 180 mol of ethylene oxide, of steaiyl alcohol and of methylenebis(4-cyclohexyl isocyanate) (SMDI), at 15% by weight in a matrix of maltodextrin (4%) and water (81%), and Aculyn® 44 is a polycondensate of polyethylene glycol containing 150 or 180 mol of ethylene oxide, of decyl alcohol and of methylenebis(4-cyclohexyl isocyanate) (SMDI), at 35% by weight in a mixture of propylene glycol (39%) and water (26%).

Use may also be made of solutions or dispersions of these polymers, especially in water or in aqueous-alcoholic medium. Examples of such polymers that may be mentioned include SER AD FX1010, SER AD FX1035 and SER AD 1070 from the

® ® ®

company Elementis, and Rheolate 255, Rheolate 278 and Rheolate 244 sold by the company Elementis. Use may also be made of the products Aculyn® 44, Aculyn® 46, DW

1206F and DW 1206J, and also Acrysol® RM 184 from the company Rohm & Haas, or alternatively Borchi Gel LW 44 from the company Borchers, and mixtures thereof.

Amphoteric associative polymers

Among the associative amphoteric polymers of the invention, mention may be made of crosslinked or non-crosslinked, branched or unbranched amphoteric polymers, which may be obtained by copolymerization:

1) of at least one monomer of formula (IVa) or (IVb):

c- - C - (CnH2n) - NT (IVa)

H I

o FL

/ Re

R4- g =j- C - Z - (CnH2n) N (ivb)

R5 O R7

in which R4 and R5, which may be identical or different, represent a hydrogen atom or a methyl radical;

Rs, R7 and R8, which may be identical or different, represent a linear or branched alkyl radical containing from 1 to 30 carbon atoms;

Z represents an H group or an oxygen atom;

n is an integer from 2 to 5;

A" is an anion derived from an organic or mineral acid, such as a methosulfate anion or a halide such as chloride or bromide;

2) of at least one monomer of formula (V):

R - C = CR1fl-CO-Z1 (V)

9 H 10 1

in which R9 and RIO, which may be identical or different, represent a hydrogen atom or a methyl radical;

Zi represents a group OH or a group HC(CH3)2CH2S03H;

3) of at least one monomer of formula (VI):

R9- C = CR10- COXR11 (VI)

in which R9 and RIO, which may be identical or different, represent a hydrogen atom or a methyl radical, X denotes an oxygen or nitrogen atom and Rl l denotes a linear or branched alkyl radical containing from 1 to 30 carbon atoms;

4) optionally at least one crosslinking or branching agent; at least one of the monomers of formula (IVa), (IVb) or (VI) comprising at least one fatty chain containing from 8 to 30 carbon atoms and said compounds of the monomers of formulae (IVa), (IVb), (V) and (VI) possibly being quaternized, for example with a C1-C4 alkyl halide or a C1-C4 dialkyl sulfate.

The monomers of formulae (IVa) and (IVb) of the present invention are preferably chosen from the group formed by:

- dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate,

- diethylaminoethyl methacrylate, diethylaminoethyl acrylate,

- dimethylaminopropyl methacrylate, dimethylaminopropyl acrylate,

- dimethylaminopropylmethacrylamide or dimethylaminopropylacrylamide, optionally quaternized, for example with a C1-C4 alkyl halide or a C1-C4 dialkyl sulfate.

More particularly, the monomer of formula (IVa) is chosen from acrylamidopropyltrimethylammonium chloride and methacrylamidopropyl-trimethylammonium chloride.

The compounds of formula (V) of the present invention are preferably chosen from the group formed by acrylic acid, methacrylic acid, crotonic acid, 2-methylcrotonic acid, 2-acrylamido-2-methylpropanesulfonic acid and 2-methacrylamido-2-methylpropanesulfonic acid. More particularly, the monomer of formula (V) is acrylic acid.

The monomers of formula (VI) of the present invention are preferably chosen from the group formed by C12-C22 and more particularly C16-C18 alkyl acrylates or methacrylates.

The crosslinking or branching agent is preferably chosen from Ν,Ν'-methylenebisacrylamide, triallylmethylammonium chloride, allyl methacrylate, n-methylolacrylamide, polyethylene glycol dimethacrylates, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate and allyl sucrose.

The polymers according to the invention may also contain other monomers such as nonionic monomers and in particular C1-C4 alkyl acrylates or methacrylates.

The ratio of the number of cationic charges/anionic charges in these amphoteric polymers is preferably equal to about 1.

The weight-average molecular weights of the associative amphoteric polymers have a weight-average molecular mass of greater than 500, preferably between 10 000 and 10 000 000 and even more preferentially between 100 000 and 8 000 000.

Preferably, the associative amphoteric polymers of the invention contain from 1 mol% to 99 mol%, more preferentially from 20 mol% to 95 mol% and even more preferentially from 25 mol% to 75 mol% of compound(s) of formula (IVa) or (IVb). They also preferably contain from 1 mol% to 80 mol%, more preferentially from 5 mol% to 80 mol% and even more preferentially from 25 mol% to 75 mol% of compound(s) of formula (V). The content of compound(s) of formula (VI) is preferably between 0.1 mol% and 70 mol%, more preferentially between 1 mol% and 50 mol% and even more preferentially between 1 mol% and 10 mol%. The crosslinking or branching agent, when it is present, is preferably between 0.0001 mol% and 1 mol% and even more preferentially between 0.0001 mol% and 0.1 mol% .

Preferably, the mole ratio between the compound(s) of formula (IVa) or (IVb) and the compound(s) of formula (V) ranges from 20/80 to 95/5 and more preferentially from 25/75 to 75/25.

The associative amphoteric polymers according to the invention are described, for example, in patent application WO 98/44012.

The amphoteric polymers that are particularly preferred according to the invention are chosen from acrylic acid/acrylamidopropyltrimethylammonium chloride/stearyl methacrylate copolymers.

According to a preferred embodiment, the associative polymer is chosen from nonionic associative polymers and more particularly from associative polyurethanes, such as Steareth-100/PEG-136/HDI Copolymer sold under the name Rheolate FX 1100 by Elementis.

Such an associative polymer is advantageously used in a proportion of from 0.1% to 8% by weight of solids and preferably about 3% by weight, relative to the total weight of the aqueous phase.

B.2 Polyacrylamides and crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid polymers and copolymers

The polymers used that are suitable as aqueous gelling agent for the invention may be crosslinked or non-crosslinked homopolymers or copolymers comprising at least the 2-acrylamidomethylpropanesulfonic acid (AMPS®) monomer, in a form partially or totally neutralized with a mineral base other than aqueous ammonia, such as sodium hydroxide or potassium hydroxide.

They are preferably totally or almost totally neutralized, i.e. at least 90% neutralized.

These AMPS® polymers according to the invention may be crosslinked or non-crosslinked.

When the polymers are crosslinked, the crosslinking agents may be chosen from the polyolefinically unsaturated compounds commonly used for crosslinking polymers obtained by radical polymerization.

Examples of crosslinking agents that may be mentioned include divinylbenzene, diallyl ether, dipropylene glycol diallyl ether, polyglycol diallyl ethers, triethylene glycol divinyl ether, hydroquinone diallyl ether, ethylene glycol or tetraethylene glycol di(meth)acrylate, trimethylolpropane triacrylate, methylenebisacrylamide, methylenebismethacrylamide, triallylamine, triallyl cyanurate, diallyl maleate, tetraallylethylenediamine, tetraallyloxyethane, trimethylolpropane diallyl ether, allyl (meth)acrylate, allylic ethers of alcohols of the sugar series, or other allyl or vinyl ethers of polyfunctional alcohols, and also the allylic esters of phosphoric and/or vinylphosphonic acid derivatives, or mixtures of these compounds.

According to one preferred embodiment of the invention, the crosslinking agent is chosen from methylenebisacrylamide, allyl methacrylate and trimethylolpropane triacrylate (TMPTA). The degree of crosslinking generally ranges from 0.01 mol% to 10 mol% and more particularly from 0.2 mol% to 2 mol% relative to the polymer.

The AMPS® polymers that are suitable for use in the invention are water-soluble or water-dispersible. They are in this case:

-either "homopolymers" comprising only AMPS monomers and, if they are crosslinked, one or more crosslinking agents such as those defined above;

- or copolymers obtained from AMPS and from one or more hydrophilic or hydrophobic ethylenically unsaturated monomers and, if they are crosslinked, one or more crosslinking agents such as those defined above. When said copolymers comprise hydrophobic ethylenically unsaturated monomers, the latter do not comprise a fatty chain and are preferably present in small amounts.

For the purpose of the present invention, the term "fatty chain" is intended to mean any hydrocarbon-based chain containing at least 7 carbon atoms.

The term "water-soluble or water-dispersible" means polymers which, when introduced into an aqueous phase at 25°C, at a mass concentration equal to 1%, make it possible to obtain a macroscopically homogeneous and transparent solution, i.e. a solution with a maximum light transmittance value, at a wavelength equal to 500 nm, through a sample 1 cm thick, of at least 60% and preferably of at least 70%.

The "homopolymers" according to the invention are preferably crosslinked and neutralized, and they may be obtained according to the preparation process comprising the following steps:

(a) the monomer such as AMPS in free form is dispersed or dissolved in a solution of tert-butanol or of water and tert-butanol;

(b) the monomer solution or dispersion obtained in (a) is neutralized with one or more mineral or organic bases, preferably aqueous ammonia ¾, in an amount making it possible to obtain a degree of neutralization of the sulfonic acid functions of the polymer ranging from 90% to 100%;

(c) the crosslinking monomer(s) are added to the solution or dispersion obtained in (b);

(d) a standard free-radical polymerization is performed in the presence of firee-radical initiators at a temperature ranging from 10 to 150°C; the polymer precipitates in the tert-butanol-based solution or dispersion.

The water-soluble or water-dispersible AMPS® copolymers according to the invention contain water-soluble ethylenically unsaturated monomers, hydrophobic monomers, or mixtures thereof.

The water-soluble co-monomers may be ionic or nonionic.

Among the ionic water-soluble co-monomers, mention may be made, for example, of the following compounds and salts thereof:

- (meth)acrylic acid,

- styrenesulfonic acid,

- vinylsulfonic acid and (meth)allylsulfonic acid,

- vinylphosphonic acid,

- maleic acid,

- itaconic acid,

- crotonic acid,

- water-soluble vinyl monomers of formula (A) below:

in which:

- R1 is chosen from H, -CH3, -C2H5 and -C3H7;

- Xi is chosen from:

- alkyl oxides of type -OR2 where R2 is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbon atoms, substituted with at least one sulfonic (-S03-) and/or sulfate (-SO4-) and/or phosphate (-PO4H2-) group.

Among the nonionic water-soluble co-monomers, mention may be made, for example, of:

- (meth)acryl amide,

- N-vinylacetamide and N-methyl-N-vinylacetamide,

- N-vinylformamide and N-methyl-N-vinylformamide,

- maleic anhydride,

- vinylamine,

- N-vinyllactams comprising a cyclic alkyl group containing from 4 to 9 carbon atoms, such as N-vinylpyrrolidone, N-butyrolactam and N-vinylcaprolactam,

- vinyl alcohol of formula CH2=CHOH,

- water-soluble vinyl monomers of formula (B) below:

H,C=C ,

C I O

v

A2

in which:

- R3 is chosen from H, -CH3, -C2H5 and -C3H7;

- X2 is chosen from:

- alkyl oxides of the type -OR4 where R4 is a linear or branched, saturated or unsaturated hydrocarbon-based radical having from 1 to 6 carbon atoms, optionally substituted with a halogen (iodine, bromine, chlorine or fluorine) atom; a hydroxyl (-OH) group; ether.

Mention is made, for example, of glycidyl (meth)acrylate, hydroxyethyl methacrylate, and (meth)acrylates of ethylene glycol, of diethylene glycol or of polyalkylene glycol.

Among the hydrophobic co-monomers without a fatty chain, mention may be made, for example, of:

- styrene and derivatives thereof, such as 4-butylstyrene, a-methylstyrene and vinyltoluene;

- vinyl acetate of formula CH2=CH-OCOCH3;

- vinyl ethers of formula CH2=CHOR in which R is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbons;

- acrylonitrile;

- caprolactone;

- vinyl chloride and vinylidene chloride;

- silicone derivatives, which, after polymerization, result in silicone polymers such as methacryloxypropyltris(trimethylsiloxy)silane and silicone methacrylamides;

- hydrophobic vinyl monomers of formula (C) below:

H-.0— R .

I 4 (C)

CO ·

X

3

in which:

- R4 is chosen from H, -CH3, -C2H5 and -C3H7;

- X3 is chosen from:

- alkyl oxides of the type -OR5 where R5 is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbon atoms.

Mention may be made, for example, of methyl methacrylate, ethyl methacrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl acrylate, isobornyl acrylate and 2-ethylhexyl acrylate.

The water-soluble or water-dispersible AMPS® polymers of the invention preferably have a molar mass ranging from 50 000 g/mol to 10 000 000 g/mol, preferably from 80 000 g/mol to 8 000 000 g/mol, and even more preferably from 100 000 g/mol to 7 000 000 g/mol.

As water-soluble or water-dispersible AMPS homopolymers in accordance with the invention, mention may be made, for example, of crosslinked or non-crosslinked polymers of sodium acrylamido-2-methylpropanesulfonate, such as that used in the commercial product Simulgel 800 (CTFA name: Sodium Polyacryloyldimethyl Taurate), crosslinked ammonium acrylamido-2-methylpropanesulfonate polymers (INCI name: Ammonium polydimethyltauramide) such as those described in patent EP 0 815 928 Bl and such as the product sold under the trade name Hostacerin AMPS® by the company Clariant.

As water-soluble or water-dispersible AMPS copolymers in accordance with the invention, examples that may be mentioned include:

- crosslinked acrylamide/sodium acrylamido-2-methylpropanesulfonate copolymers, such as that used in the commercial product Sepigel 305 (CTFA name: Polyacrylamide/Ci3-Ci4 Isoparaffin/ Laureth-7) or that used in the commercial product sold under the name Simulgel 600 (CTFA name: Acrylamide/Sodium Acryloyldimethyltaurate/Isohexadecane/Polysorbate-80) by the company SEPPIC;

- copolymers of AMPS® and of vinylpyrrolidone or vinylformamide, such as that used in the commercial product sold under the name Aristoflex AVC® by the company Clariant (CTFA name: Ammonium acryloyldimethyltaurate/VP copolymer) but neutralized with sodium hydroxide or potassium hydroxide;

- copolymers of AMPS® and of sodium acrylate, for instance the AMPS/sodium acrylate copolymer, such as that used in the commercial product sold under the name Simulgel EG® by the company SEPPIC or under the trade name Sepinov EM (CTFA name: Hydroxyethyl acrylate/sodium acryloyldimethyl taurate copolymer);

- copolymers of AMPS® and of hydroxyethyl acrylate, for instance the AMPS®/hydroxyethyl acrylate copolymer, such as that used in the commercial product sold under the name Simulgel NS® by the company SEPPIC (CTFA name: Hydroxyethyl acrylate/sodium acryloyldimethyltaurate copolymer (and) squalane (and) polysorbate 60), or such as the product sold under the name Sodium acrylamido-2-

methylpropanesulfonate/hydroxyethyl acrylate copolymer, such as the commercial product Sepinov EMT 10 (INCI name: Hydroxyethyl acrylate/sodium acryloyldimethyl taurate copolymer).

Preferably, the product sold under the name Sodium acrylamido-2-methylpropanesulfonate/hydroxyethyl acrylate copolymer, such as the commercial product Sepinov EMT 10 (INCI name: Hydroxyethyl acrylate/sodium acryloyldimethyl taurate copolymer) is used as water-soluble or water-dispersible AMPS copolymers in accordance with the invention.

In general, an aqueous phase according to the invention may comprise from

0.1% to 8% by weight of solids, preferably 0.2% to 5% by weight, and more preferentially from 0.7%) to 2.5% by weight of polyacrylamide(s) and of crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid polymer(s) and copolymer(s) relative to its total weight.

B.3 Modified or unmodified carboxyvinyl polymers

The modified or unmodified carboxyvinyl polymers may be copolymers derived from the polymerization of at least one monomer (a) chosen from α,β-ethylenically unsaturated carboxylic acids or esters thereof, with at least one ethylenically unsaturated monomer (b) comprising a hydrophobic group.

The term "copolymers" means both copolymers obtained from two types of monomer and those obtained from more than two types of monomer, such as terpolymers obtained from three types of monomer.

Their chemical structure more particularly comprises at least one hydrophilic unit and at least one hydrophobic unit. The term "hydrophobic group or unit" means a radical with a saturated or unsaturated, linear or branched hydrocarbon-based chain, comprising at least 8 carbon atoms, preferably from 10 to 30 carbon atoms, in particular from 12 to 30 carbon atoms and more preferentially from 18 to 30 carbon atoms.

Preferably, these copolymers are chosen from copolymers derived from the polymerization:

- of at least one monomer of formula (1) below:

CH, = C— C— OH

1 I I

R 0 (1)

in which Rl denotes H or CH3 or C2H5, i.e. acrylic acid, methacrylic acid or ethacrylic acid monomers, and

- of at least one monomer of unsaturated carboxylic acid (Cio-C3o)alkyl ester type corresponding to the monomer of formula (2) below:

CH ~ C— C— OR- I I I R O

2 (2)

in which R2 denotes H or CH3 or C2H5 (i.e. acrylate, methacrylate or ethacrylate units) and preferably H (acrylate units) or CH3 (methacrylate units), R3 denoting a Cio-C30 and preferably Ci2-C22 alkyl radical.

The unsaturated carboxylic acid (Cio-C3o)alkyl esters are preferably chosen from lauryl acrylate, stearyl acrylate, decyl acrylate, isodecyl acrylate and dodecyl acrylate, and the corresponding methacrylates, such as lauryl methacrylate, stearyl methacrylate, decyl methacrylate, isodecyl methacrylate and dodecyl methacrylate, and mixtures thereof.

According to a preferred embodiment, these polymers are crosslinked.

Among the copolymers of this type that will be used more particularly are polymers derived from the polymerization of a monomer mixture comprising:

- essentially acrylic acid,

- an ester of formula (2) described above in which R2 denotes H or CH3, R3 denoting an alkyl radical containing from 12 to 22 carbon atoms,

- (iii) and a crosslinking agent, which is a well-known copolymerizable polyethylenic unsaturated monomer, such as diallyl phthalate, allyl (meth)acrylate, divinylbenzene, (poly)ethylene glycol dimethacrylate or methylenebisacrylamide.

Among the copolymers of this type, use will more particularly be made of those consisting of from 95% to 60% by weight of acrylic acid (hydrophilic unit), 4% to 40% by weight of Cio-C30 alkyl acrylate (hydrophobic unit) and 0 to 6% by weight of crosslinking polymerizable monomer, or alternatively those consisting of from 98% to 96%) by weight of acrylic acid (hydrophilic unit), 1%> to 4% by weight of Cio-C30 alkyl acrylate (hydrophobic unit) and 0.1% to 0.6% by weight of crosslinking polymerizable monomer such as those described previously.

Among the abovementioned polymers, the ones that are most particularly preferred according to the present invention are acrylate/Cio-C3o-alkyl acrylate copolymers (INCI name: Acrylates/Cio-30 Alkyl acrylate Crosspolymer) such as the products sold by the company Lubrizol under the trade names Pemulen TR-1, Pemulen TR-2, Carbopol 1382, Carbopol EDT 2020 and Carbopol Ultrez 20 Polymer, and even more preferentially Pemulen TR-2.

Among the modified or unmodified carboxyvinyl polymers, mention may also be made of sodium polyacrylates such as those sold under the name Cosmedia SP® containing 90% solids and 10% water, or Cosmedia SPL® as an inverse emulsion containing about 60% solids, an oil (hydrogenated polydecene) and a surfactant (PPG-5 Laureth-5), both sold by the company Cognis.

Mention may also be made of partially neutralized sodium polyacrylates that are in the form of a reverse emulsion comprising at least one polar oil, for example the product sold under the name Luvigel® EM sold by the company BASF.

The modified or unmodified carboxyvinyl polymers may also be chosen from crosslinked (meth)acrylic acid homopolymers.

For the purposes of the present patent application, the term " (meth) acrylic" means "acrylic or methacrylic" .

Examples that may be mentioned include the products sold by Lubrizol under the names Carbopol 910, 934, 940, 941, 934 P, 980, 981, 2984, 5984 and Carbopol Ultrez 10 Polymer, or by 3V-Sigma under the name Synthalen K, Synthalen L or Synthalen M.

Among the modified or unmodified carboxyvinyl polymers, mention may be made in particular of Carbopol (INCI name: carbomer) and Pemulen (CTFA name: Acrylates/ClO-30 alkyl acrylate crosspolymer) sold by the company Lubrizol.

The modified or unmodified carboxyvinyl polymers may be present in a proportion of from 0.1% to 5% by weight of solids relative to the weight of the aqueous phase, in particular from 0.3% to 1% by weight and preferably in a proportion of about 1% by weight, relative to the weight of the aqueous phase.

According to a preferred variant, the hydrophilic gelling agent is chosen from crosslinked acrylic homopolymers or copolymers; associative polymers, in particular associative polymers of polyurethane type; polyacrylamides and crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid polymers and copolymers; modified or unmodified carboxyvinyl polymers, and mixtures thereof.

Advantageously, use is made, as synthetic polymeric hydrophilic gelling agent, of at least one gelling agent chosen from crosslinked acrylic homopolymers or copolymers; polyacrylamides and crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid polymers and copolymers; modified or unmodified carboxyvinyl polymers, and mixtures thereof, and preferentially at least one 2-acrylamido-2-methylpropanesulfonic acid polymer or copolymer, an associative polyurethane and/or a crosslinked sodium polyacrylate.

LIPOPHILIC GELLING AGENT

For the purposes of the present patent application, the term "lipophilic gelling agent" means a compound that is capable of gelling the oily phase of the compositions according to the invention.

The gelling agent is lipophilic and is thus present in the oily phase of the composition.

The gelling agent is liposoluble or lipodispersible.

As emerges from the foregoing, the lipophilic gelling agent is advantageously chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof.

I. Particulate gelling agents

The particulate gelling agent used in the composition according to the invention is in the form of particles, preferably spherical particles.

As representative lipophilic particulate gelling agents that are suitable for use in the invention, mention may be made most particularly of polar and apolar waxes, modified clays, and silicas such as fumed silicas and hydrophobic silica aerogels.

Waxes

The choice of a wax as lipophilic gelling agent is particularly advantageous for giving a composition according to the invention good emollience and comfort properties. Its combination with an aqueous phase gelled with a compound such as synthetic polymers gives access to compositions that have emollience and comfort with a fresh effect and advantageously an attenuated greasy feel. Compositions of this type are more particularly advantageous for dry to normal skin types.

The term "wax" under consideration in the context of the present invention generally means a lipophilic compound that is solid at room temperature (25°C), with a solid/liquid reversible change of state, having a melting point of greater than or equal to 30°C, which may be up to 200°C and in particular up to 120°C.

For the purposes of the invention, the melting point corresponds to the temperature of the most endothermic peak observed on thermal analysis (DSC) as described in standard ISO 11357-3; 1999. The melting point of the wax may be measured using a differential scanning calorimeter (DSC), for example the calorimeter sold under the name MDSC 2920 by the company TA Instruments.

The measuring protocol is as follows:

A 5 mg sample of wax placed in a crucible is subjected to a first temperature increase ranging from -20°C to 100°C, at a heating rate of 10°C/minute, it is then cooled from 100°C to -20°C at a cooling rate of 10°C/minute and is finally subjected to a second temperature increase ranging from -20°C to 100°C at a heating rate of 5°C/minute. During the second temperature increase, the variation in the difference in power absorbed by the empty crucible and by the crucible containing the sample of wax is measured as a function of the temperature. The melting point of the compound is the temperature value corresponding to the top of the peak of the curve representing the variation in the difference in power absorbed as a function of the temperature.

The waxes that may be used in the compositions according to the invention are chosen from waxes that are solid at room temperature of animal, vegetable, mineral or synthetic origin, and mixtures thereof.

For the purposes of the invention, the waxes may be those generally used in cosmetics or dermatology. They may especially be polar or apolar, and hydrocarbon-based, silicone and/or fluoro waxes, optionally comprising ester or hydroxyl functions. They may also be of natural or synthetic origin.

CLAIMS

1. Cosmetic composition for making up and/or caring for keratin materials, in particular the skin and/or the lips, comprising:

- at least one aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent; and

- at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof;

the said phases forming therein a macroscopically homogeneous mixture.

2. Composition according to the preceding claim, containing at least one dyestuff, preferably present at least in the gelled oily phase.

3. Composition according to either of the preceding claims, comprising as synthetic polymeric hydrophilic gelling agent at least one gelling agent chosen from crosslinked acrylic homopolymers or copolymers; associative polymers, in particular associative polymers of polyurethane type; polyacrylamides and crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid polymers and copolymers; modified or unmodified carboxyvinyl polymers, and mixtures thereof.

4. Composition according to any one of the preceding claims, comprising as synthetic polymeric hydrophilic gelling agent at least one gelling agent chosen from crosslinked acrylic homopolymers or copolymers; polyacrylamides and crosslinked and/or neutralized 2-acrylamido-2-methylpropanesulfonic acid polymers and copolymers; modified or unmodified carboxyvinyl polymers, and mixtures thereof.

5. Composition according to any one of the preceding claims, comprising as synthetic polymeric hydrophilic gelling agent at least one 2-acrylamido-2-methylpropanesulfonic acid polymer or copolymer, an associative polyurethane and/or a crosslinked sodium polyacrylate.

6. Composition according to any one of the preceding claims, in which the said lipophilic gelling agent is chosen from modified clays and especially bentonites and preferably hectorites; waxes, in particular polar waxes especially including ester waxes and preferably candelilla wax; hydrophobic silica, in particular hydrophobic silica aerogels and preferably silica silylates; dextrin esters and preferably dextrin palmitate, organopolysiloxane elastomers, and mixtures thereof.

7. Composition according to any one of the preceding claims, comprising, as lipophilic gelling agent, at least one organopolysiloxane elastomer or a dextrin ester and/or a particulate gelling agent, in particular chosen from a hydrophobic silica, a modified clay and a wax, and mixtures thereof.

8. Composition according to any one of the preceding claims, containing, as hydrophilic gelling agent(s)/lipophilic gelling agent(s) system, a system chosen from:

- copolymer of 2-acrylamido-2-methylpropanesulfonic acid and of hydroxyethyl acrylate/organopolysiloxane elastomer;

- polymer of 2-acrylamido-2-methylpropanesulfonic acid combined with a crosslinked sodium polyacrylate/hydrophobic silica combined with an organopolysiloxane elastomer;

- copolymer of 2-acrylamido-2-methylpropanesulfonic acid and of hydroxyethyl acrylate/modified clay;

- copolymer of 2-acrylamido-2-methylpropanesulfonic acid and of hydroxyethyl acrylate/dextrin ester and wax;

- associative polyurethane/modified clay;

- copolymer of 2-acrylamido-2-methylpropanesulfonic acid and of hydroxyethyl acrylate/polar wax;

- associative polyurethane/wax;

- acrylate/Cio-C3o-alkyl acrylate copolymer combined with an associative polyurethane/modified clay;

- copolymer of 2-acrylamido-2-methylpropanesulfonic acid and of hydroxyethyl acrylate combined with an associative polyurethane/organopolysiloxane elastomer; - copolymer of 2-acrylamido-2-methylpropanesulfonic acid and of hydroxyethyl acrylate/hydrophobic silica combined with an organopolysiloxane elastomer-

polymer of 2-acrylamido-2-methylpropanesulfonic acid/organopolysiloxane elastomer;

- polymer of 2-acrylamido-2-methylpropanesulfonic acid/modified clay;

modified or unmodified carboxyvinyl polymers made of sodium polyacrylates/organopolysiloxane elastomer; and

- modified or unmodified carboxyvinyl polymers made of sodium polyacrylates/ modified clay.

9. Composition according to any one of Claims 6 to 8, in which the organopolysiloxane elastomer is chosen from Dimethicone Crosspolymer, Dimethicone (and) Dimethicone Crosspolymer, Vinyl Dimethicone Crosspolymer, Dimethicone/Vinyl Dimethicone Crosspolymer and Dimethicone Crosspolymer-3.

10. Composition according to any one of the preceding claims, containing the aqueous and oily phases in an aqueous phase/oily phase weight ratio of from 95/5 to 5/95, preferably from 30/70 to 80/20, especially ranging from 60/40 to 80/20, preferably ranging from 60/40 to 70/30 and more preferably 60/40 or 70/30.

11. Composition according to any one of the preceding claims, which is in the form of a foundation, a face powder, an eyeshadow, a lipstick, a mascara and/or a care composition.

12. Composition according to any one of the preceding claims, further comprising solid particles such as pigments and/or fillers.

13. Composition according to the preceding claim, comprising from 0.01% to 25%) by weight, especially from 0.1%> to 25% by weight, in particular from 1%> to 20% by weight and preferably from 5% to 15%> by weight of solid particles relative to the total weight of the said composition.

14. Composition according to any one of the preceding claims, further comprising volatile and/or non volatile silicone oils.

15. Composition according to any one of the preceding claims, further comprising a moisturizer, and preferably glycerol.

16. Process for preparing a cosmetic composition for making up and/or caring for keratin materials, in particular the skin and/or the lips, comprising at least one step of mixing:

- at least one aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent as defined in Claims 1 and 3 to 5; and

- at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof as defined in Claims 1, 6, 7 and 9;

under conditions suitable for obtaining a macroscopically homogeneous mixture.

17. Process according to the preceding claim, comprising a step of mixing at least three or even more gelled phases.

18. Process according to either of Claims 16 and 17, in which the mixing is performed at room temperature.

19. Cosmetic kit for making up and/or caring for keratin materials, in particular the skin and/or the lips, comprising, in separate containers, at least one aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent as defined in Claims 1 and 3 to 5, and at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof, as defined in Claims 1, 6, 7 and 9, and also instructions for using the extemporaneous mixtures.

20. Device for making up and/or caring for keratin materials, in particular the skin and/or the lips, comprising at least:

- two separate containers containing, respectively, an aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent as defined in Claims 1 and 3 to 5, and at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi- crystalline polymers and dextrin esters, and mixtures thereof, as defined in Claims 1, 6, 7 and 9;

- a distinct chamber for mixing the said containers, comprising an aperture configured to allow the introduction of the said phases to be mixed; and

- a means for distributing a macroscopically homogeneous mixture of the two phases.

21. Cosmetic process for making up and/or caring for keratin materials, in particular the skin and/or the lips, comprising at least one step which consists in applying to the said keratin material a composition as defined according to any one of Claims 1 to 15.

22. Cosmetic process for making up and/or caring for a keratin material, in particular the skin and/or the lips, comprising at least the application to the said material of a composition, in particular a macroscopically homogeneous composition obtained by extemporaneous mixing, before application or at the time of application to the said keratin material, of at least one aqueous phase gelled with at least one synthetic polymeric hydrophilic gelling agent as defined in Claims 1 and 3 to 5, and at least one oily phase gelled with at least one lipophilic gelling agent chosen from particulate gelling agents, organopolysiloxane elastomers, semi-crystalline polymers and dextrin esters, and mixtures thereof, as defined in Claims 1, 6, 7 and 9.