FR2928265A1 - Treating human keratin materials e.g. hair, comprises applying composition having polymerizable liquid crystal of which color varies with temperature before its polymerization, on material and enhancing in situ liquid crystal polymerization - Google Patents

Abstract

Treating human keratinous material comprises applying cosmetic composition comprising at least one polymerizable liquid crystal of which color varies with temperature before its polymerization, where the polymerization is carried out under the action of external stimuli, on the keratinous material; and enhancing in situ liquid crystal polymerization on the keratin materials. An independent claim is included for a kit comprising the cosmetic composition comprising at least one polymerizable liquid crystal, and a mean for production of stimulus to induce the liquid crystal polymerization, e.g. stimulus from the sources of UV and/or heat including UV light, or chemicals, which triggers polymerization or produces exothermic reaction, in a single package.

Description

The present invention relates to the treatment of human keratin materials, including various makeup methods, kits and compositions for their implementation. BACKGROUND In a cholesteric liquid crystal, the elongated molecules are organized according to a helix that has the power to reflect light, the color being reflected at a particular wavelength depending on the amplitude of the pitch of this helix . These molecules make it possible to obtain colors depending on the temperature and the angle of observation.

Numerous attempts to use liquid crystals in the cosmetic field have been made, the liquid crystals being either in the form of encapsulated liquid or in the form of a pigment. In liquid form these molecules have the disadvantage of having a very poor resistance to keratin materials and have a color that can easily disappear during the addition of an ingredient or because of an external stimulus. US Pat. No. 6,346,237 describes a cosmetic composition comprising a liquid crystal pigment. US 6060042 discloses the use of a pigment made from liquid crystals so as to obtain protection of the skin against ultraviolet. Summary There is a need to produce new cosmetic effects, especially in terms of colors, and the invention aims to meet this need. According to one of its aspects, the subject of the invention is a process for the cosmetic treatment of human keratin materials, comprising the steps of: 1) Applying to the keratin materials a cosmetic composition comprising at least one polymerizable liquid crystal whose color varies according to the temperature before its polymerization, the polymerization taking place under the action of an external stimulus, 2) the composition being at a temperature corresponding to the desired appearance, subjecting it to the action of the stimulus to cause the polymerization of the liquid crystal in situ on keratin materials. According to another of its aspects, the subject of the invention is also a kit comprising, within the same package: a cosmetic composition comprising at least one polymerizable liquid crystal whose color varies as a function of its temperature before its polymerization, the polymerization taking place under the action of an external stimulus, - a means of producing the stimulus for causing the polymerization of the liquid crystal, chosen for example as a function of the stimulus among the sources of UV and / or heat, for example a UV lamp, or among chemical compounds triggering polymerization or producing an exothermic reaction.

The kit may optionally comprise a container containing a composition for forming a base layer and / or a container containing a composition for forming a covering layer. The aforementioned packaging can be any type of packaging or packaging device with multiple compartments.

Thanks to the invention, it is easy to obtain a deposit of relatively wide, colorful and attractive composition. In addition, the choice of the temperature at the time of the polymerization may allow the user to obtain several colors and / or effects from the same starting compounds, which gives an additional playfulness to the application. The effect of the polymerization is to fix the color but also to fix the colored liquid crystal on the support and to increase its durability. The invention can make it possible to form the composition deposit, for example over a thickness ranging from 2 to 2000 m, preferably between 10 and 500 m, directly on the keratin materials, without requiring encapsulation of the liquid crystals or the manufacture of liquid crystal pigments.

The composition may have a temperature for example between 10 ° C and 50 ° C during exposure to the stimulus. The composition may be brought to the desired temperature before application to the keratin materials, or alternatively after application to the keratin materials. The composition can be further brought to the desired temperature during application to keratin materials.

The stimulus may include ultraviolet radiation, especially UVA and / or UVB. This may allow, for example, to use already commercialized lamps to polymerize some nail polish. The stimulus may further include the application of heat or the combined application of heat and UV.

In general, the stimulus may be purely physical (heat, radiation) or chemical variant, being linked for example to the introduction into the composition of a polymerization initiator. The keratin materials may be chosen from keratinous fibers, in particular eyelashes or hair, skin, lips or nails. The same composition may for example be used with polymerization on certain regions of the body or face, for example the nails, and without polymerization on other regions, for example the skin, eyelashes or hair and lips. The composition may comprise at least one polymerizable liquid crystal (CLP) having a cholesteric phase at room temperature (20 ° C). The composition may be free of liquid crystal pigments and / or encapsulated liquid crystals. All the liquid crystals of the composition can be in solution during application. The composition may comprise at least a first polymerizable liquid crystal compound and a second polymerizable liquid crystal compound. The presence of a mixture of polymerizable liquid crystals within the composition can widen the range of temperatures making it possible to observe a color and may also allow the user, depending on the relative proportions of the different liquid crystals, to obtain easily different colors. Examples of mixtures are given below. According to another of its aspects, the subject of the invention is therefore a process for the cosmetic treatment, in particular of makeup, of human keratin materials, in which a deposit is formed on the keratin materials, this deposit comprising first and second crystals. polymerizable liquids in contact with each other, the contacting of these polymerizable liquid crystals being carried out by the user in selected proportions and / or in a sequence determined according to the desired result. The first and second polymerizable liquid crystals are, for example, mixed in proportions chosen by the user and the deposit formed from such a mixture. The first and second polymerizable liquid crystals may be present in respective first and second compositions and at least one of the polymerizable liquid crystals, preferably the two polymerizable liquid crystals, may exhibit color at room temperature (20 ° C), within the corresponding composition. The polymerizable liquid crystals may have different colors at room temperature within the corresponding compositions. The mixture can be formed extemporaneously and be applied by any means, for example using a single application member.

The composition may comprise, as polymerizable liquid crystals, a mixture of sterol derivatives, in particular plant-derived sterols, for example acrylic or methacrylic derivatives of sterols. The composition may comprise a polymerization initiator, in particular a photoinitiator. This polymerization initiator may be present in the composition proposed to the user or may be added by the latter to the composition, for example extemporaneously. The addition can be carried out, where appropriate, in a proportion chosen by the user so as to obtain for example different colors depending on the amount of polymerization initiator added, for example between 0.1 and 10% in mass relative to the total weight of the composition, preferably between 1 and 3%.

The composition may comprise an additional coloring agent, in particular a coloring agent chosen from: - dyes, in particular lipophilic dyes, - organic or inorganic pigments, - interferential pigments, metallic pigments and multilayer pigments. The additional coloring agent can create a specific optical effect perceptible to the naked eye, for example a point shine effect, a goniochromatic effect, a spotted effect, or any other desired optical effect. The additional coloring agent can create highlight points within the composition, contrasting with the surrounding color. These highlight points may be due to reflective particles, for example. The additional coloring agent (s) are, for example, in a total content ranging from 0.01% to 40% by weight relative to the total weight of the composition, preferably between 0.1% and 10%.

The coloring agent may be a coloring agent chosen, for example, from goniochromatic coloring agents, thermochromic, mechano-luminescent, piezochromic, photochromic coloring agents, reflective particles and interference pigments, especially diffracting pigments and pigments. interferential multilayer structure, such as nacres for example.

The coloring agent may also be a diffusing pigment or dye, generating a color by a color absorption phenomenon. The presence of a pigment in the composition can improve the visibility of the liquid crystal, and avoid having to deposit the composition on a dark background color. The presence of a pigment can also add color effects. The Applicant has found that the presence of a pigment does not prevent the polymerization to take place, even when it must be done by exposure to UV radiation. The pigment may for example be dark in color, for example black, being for example chosen from pigments based on black iron oxide, brown iron oxide, carbon black, iron, titanium oxide. reduced, sudan black, charcoal, caramel and melanin. The mass content of pigment is, for example, from 0.05 to 10% relative to the total weight of the composition, preferably from 0.1 to 2%. Such a proportion may be advantageous in that it improves the visibility of the liquid crystals, whereas too high a concentration can make disappear the color effect brought by the liquid crystals. By dark pigment is meant pigments whose average lightness L * and saturation C * measured in the mass (infinite thickness) in the CIE Lab 1976 color space are less than 40, preferably less than 30. reflectance expressed in colorimetric coordinates are measured using the Minolta 3700-d spectrocolorimeter (D65 / 10 °) in excluded specular component, small aperture mode. The presence within the composition of a thermochromic agent other than liquid crystals, changing color while becoming colorless below or above a certain temperature, may be useful for signaling to the user the moment at which the during the heating or cooling of the composition or subjecting the composition to the stimulus in order to obtain a given result with the liquid crystals. The composition may comprise at least one solvent, preferably an organic solvent, which can serve to dilute the composition and to improve the spreading thereof.

The evaporation of the solvent can also, if necessary bring about a color change of the composition. A slow evaporating solvent may then be preferable if it is desired to retard the color change due to evaporation.

The solvent may for example be introduced by the user in a proportion chosen according to the desired color, when the color depends on the proportion of solvent in the composition. Such a solvent is, for example, isododecane or isononyl isononanoate. An excessively high content of organic solvent can cause a disappearance of the visibility of the liquid crystals in the composition. A mass content of organic solvent of less than or equal to 25% may be preferred. A relatively low organic solvent content can cause a reversible change in the color of the liquid crystal, depending on the solvent content. The kit may comprise, if necessary, a container comprising the solvent without the liquid crystal, so as to allow the user to create a mixture of the solvent and the liquid crystal in selected proportions. The invention may comprise a step of observing the color change of the composition related to evaporation of the solvent (s) and subjecting the deposit to the stimulus, to cause polymerization when the desired color is reached. The color is then frozen after polymerization. In this example, the intensity of the stimulus can be chosen so that the polymerization can take place sufficiently rapidly between the moment when the desired color is reached and the polymerization is initiated and when the appearance of the composition is frozen due to of the polymerization. The invention may further comprise a step of creating an inhomogeneity of solvent concentration, by locally depositing an additional amount of solvent or by locally counteracting the evaporation of the solvent. A drop of solvent may for example be deposited on the composition deposit to cause a change in the color of the zone in contact with the drop of solvent. The polymerization can take place while said zone has a different color appearance from the rest of the deposit. The composition may comprise an additional compound, in particular a film-forming compound, for example polymerizable during the drying of the composition and / or under UV radiation or under the effect of heat, for example a polyfunctional acrylate, especially chosen from trimethacrylates, tetrametacrylates and pentamethacrylates, in the form of monomers or oligomers.

The additional compound can make it possible, by polymerizing, to reinforce the resistance of the deposit and to obtain a state of the non-sticky surface in the event that the polymerization of the liquid crystals is incomplete. The composition may comprise at least one surfactant, which may make it possible to improve the spreading on the keratin materials. The exposure to the stimulus can take place while the composition is present on the region to be treated in the form of a homogeneous temperature deposit. By "homogeneous temperature" it should be understood that the appearance of the deposit appears homogeneous due to the same temperature or a temperature difference sufficiently low to reveal a difference in appearance. Alternatively, the exposure to the stimulus can take place while the composition is present on the region to be treated in the form of inhomogeneous temperature deposition. If necessary, the heat can be applied locally to the composition deposition so as to locally change the appearance of the composition and create at least one pattern, for example an alphanumeric character or a gradient.

A covering layer may be applied to the composition after exposure to the stimulus. This can help protect the deposit, to obtain if necessary a perfectly dry and smooth surface, not sticky, and / or to give more shine and / or depth. This can still make it possible to change the apparent color, when the covering layer is colored.

A base layer may be applied to the region to be treated prior to the application of the composition, for example an opaque or reflective base layer, preferably colored, in particular of dark color, preferably of black color. The presence of such a base layer can improve the visibility of the liquid crystal deposit and / or change its appearance, including color. The base layer may be a layer of another makeup composition, for example a mascara, a foundation or a nail polish, among other examples. According to another of its aspects, the subject of the invention is therefore a process for treating human keratin materials, in particular make-up materials, comprising the steps of applying a base layer to the region to be treated and then forming on the base layer a deposit of a composition according to the invention, comprising at least one polymerizable liquid crystal. The base layer may comprise an organic solvent rather than an aqueous solvent, in order to improve the compatibility between the base layer and the deposit formed thereon. The base layer can thus be anhydrous.

The base layer may be applied uniformly or in at least one pattern, as may the deposit formed thereon. The composition deposition may extend over the keratin materials beyond the pattern, which may make it possible to obtain an aspect contrast between the deposition zone 5 covering the base layer and the rest of the deposit. The base layer can be applied manually or by means of a printer. The base layer may comprise, where appropriate, a liquid crystal, for example at least one polymerizable liquid crystal. In one example, a first deposit is made from a first composition according to the invention, the appearance of which is fixed in a first color state during the polymerization. A second deposit of a second composition according to the invention, which may be the same as the first or different, is formed on the first deposit, in total or partial recovery. This second deposit can be frozen with a color state different from the first, by polymerization. A wide variety of different color effects can thus be obtained. In exemplary embodiments of the invention, regardless of the presence or absence of a base layer, a first zone of the composition deposition is exposed to the stimulus while being in a first color state, a second zone of the deposition The composition is not exposed to the stimulus, and then the second area is exposed to the stimulus at a different temperature than the first area during the stimulus exposure, so as to be fixed in another color state. This can make it possible to create patterns with different colors. The exposure of the first zone can be effected through a mask avoiding the action of the stimulus on the second zone. This mask may, where appropriate, include at least one aperture corresponding to the stimulus to be performed. In a variant, the mask may comprise a support that is transparent to UV radiation and a print that is opaque to UV radiation. This printing can be preset or selected by the user, for example in an image bank, and printed on the medium, for example with an inkjet printer. The formation of the deposition of the composition on the keratin materials may be carried out with an inhomogeneity of thickness and / or concentration of at least one compound, especially a solvent. This can create at least one particular pattern or optical effect.

The stimulus-generating means may comprise both a source of UV radiation and heat, and be arranged to initiate polymerization under the effect of UV radiation once the color corresponding to the desired effect has been achieved, which color can be obtained by regulating the temperature of the composition, for example by blowing air at a controlled temperature on the composition deposition. Polymerizable liquid crystals Different polymerizable liquid crystals may be used, alone or in admixture. The polymerization may be a free radical induced polymerization produced by UV radiation or thermal excitation. methacrylic. The liquid crystals may comprise acrylic or polymerizable groups. A composition according to the invention comprises one or more liquid crystals which may be, for example, as described in the application US 2008 / 0001121A1 (or in the corresponding application FR 2903115). The composition can each comprise a mixture of two compounds polymerizable an optical activity, as is the case for example of the two compounds (1) and (2) below. with m = 5 or 10! 6 NR pz .p (2) and n = 3,4,6,7,8 or 9 R = Hou CH3 The compounds (1) have a cholesteric liquid crystal phase in the vicinity of room temperature, and when they are isolated, reflect a light whose color goes mainly from green to blue. Compounds (2), when isolated, crystallize readily in the vicinity of room temperature. By mixing the compounds (1) and (2) in a composition according to the invention, a composition which can have a cholesteric liquid crystal phase in a relatively wide range of temperatures near room temperature. The compound or compounds (1) are for example in a proportion ranging from 40 to 98% by weight, better still from 50 to 98% and the compound (s) (2) are for example in a mass proportion ranging from 2 to 60%, better 5 to 50%, relative to the total weight of the composition. The compounds (1) and (2) can be synthesized for example according to the method disclosed in FR 2 903115, page 20 et seq. Preferred examples correspond to the mixture of (1) with m = 5 and (2) with n = 3 and R = H or with the mixture of (1) with m = 5, (1) with m = 10 and (2) with n = 3 and R = H. The composition may comprise an additional compound chosen from the following structures (3), (4) and (10): with p = 5 or 10 q = 2, 4 or 6 t = 2, 3 or 4 R = H or CH 3 The presence of at least one compound (3), (4) or (10), which are each provided with optical activity and have a high helical twist ability, may reduce the risk of the composition crystallizing at room temperature. This may furthermore make it possible to adjust the color of the light reflected at a given temperature and in particular to obtain a cholesteric phase which reflects a red, orange, green or blue (violet) light in a relatively wide temperature range.

The compounds (3), (4) and (10) can each be in a mass proportion ranging from 5 to 60%, better 10 to 50%, relative to the total weight of the compounds (1), (2), ( 3), (4) and (10). Examples of synthesis of the compounds (3), (4), and (10) are given in FR 2 903115, from page 21 in particular.

The composition may comprise, in an alternative embodiment of the invention, a mixture of at least two liquid crystal polymers chosen from the following compounds (5) and (6): with r = 3-9 R = H 0 CH 3 and q = 2, 4 or 6 The mass proportion of the compound or compounds (5) ranges, for example, from 2 to 98%, better still from 50 to 98%, even more preferably from 60 to 95%, and the mass proportion of the compound (s) ( 6) is for example from 2 to 98%, better 2 to 40%, relative to the total weight of the composition. The mixture may comprise at least one additional compound chosen from R = H or CH 3 q = 2.4 or 60 s = 3,4,5,6,7,8 or 9, R = H or CH 3 In another example of implementation of the invention, the composition comprises at least one compound having the structure (5) r = 3 to 9 R = Hou CH 3 and at least one compound having the structure (10) t = 2, 3 or 4 R = Hou CH3 The mass proportion of compound (s) (5) ranges, for example, from 2 to 98%, better still from 50 to 98%, even more preferably from 60 to 95%, and the proportion by weight of compound (s) (10) ranges, for example, from 2 to 98%, better from 2 to 50%, even better 5 to 40%, relative to the total weight of the composition. The composition may further comprise at least one additional compound having the structure (4) q = 2.4 or 6, R = H or CH 3 The presence of a compound (4) in the composition may make it possible to adjust the color of the light reflected at a given color and obtain for example a cholesteric phase that reflects a light of red, orange, green or blue (violet) in a wide range of temperatures. The compound (4) may be in a mass content ranging for example from 2 to 30%, better still 5 to 20%, relative to the total weight of the compounds (4), (5) and (10).

The composition may also, in another example of implementation of the invention, comprise at least one compound having the structure (4) and at least one compound having the structure (10) 10 q = 2, 4 or 6 t = 2, 3 or 4 R = Hou CH3 The mass content within the composition of compound (s) (4) is for example from 5 to 70% preferably from 20 to 60%, and the proportion by mass of compound (s) (10) is for example 30 to 95%, more preferably 40 to 80%, relative to the total weight of the composition. Examples of liquid crystal mixtures (taken from US 2008 / 0001121A1) Examples Compound (1), Compound (2) Color of light m = 5 n = 3, R = H reflected% weight% weight 22 ° C 40 ° C A5 67 33 Orange + Green Green Veronese A6 62 38 Orange Green (Vermilion) A7 57 43 Sanguine Greenish yellow A8 50 50 Ruby red Greenish yellow Compound (1) Compound Compound Color of light (2) (4) Reflected Examples m = 5 m = 10 n = 3, R = H q = 2, R = H% weight% weight% weight% weight 22 ° C 40 ° C B1 44 11 44 -Red Green B2 40 20 40 - Orange Green Veronese B3 36 27 36 - Green Blue Other polymerizable liquid crystals may be used, ie (this list not being limiting): (LC1) (LC2) (LC3) (LC4) O4CH2 0

-O 4 CH 2) -O 0 6 CN 7 (LC 5) ~ O (CH 2) _O 6 O- (CH 2 O -CH 2 O) O (CH 6) O-CH 2) -O 6 O- (CH 2 O) These compounds can be used alone or as a mixture, preferably in a mass content ranging from 2 to 30%, better still from 2 to 15% by weight. %, relative to the total weight of the composition. Polymerization initiators The composition may comprise at least one polymerization initiator, in particular a photoinitiator. The latter is chosen for example from those known under the trade names Irgacure 184, 651, 819, 500, 1000, 295, 907, 369, Darocure 1173, 4265, 1116 from CIBA GEIGY, benzophenone or acetophenone.

The amount of photoinitiator may range, for example, from 0.01% to 10% by weight relative to the total weight of the radically polymerizable compounds, especially having a saturated ethylenic bond. The composition may contain other compounds than the polymerizable liquid crystals, insofar as these compounds do not interfere with obtaining the desired optical effects or the polymerization, when this is desired. This may include other coloring agents. Other Coloring Agents The composition may comprise at least one coloring agent, in addition to polymerizable liquid crystals, which is a goniochromatic coloring agent.

2ONIOCHROMATIC COLORING AGENTS For the purposes of the present invention, a goniochromatic coloring agent is intended to mean a coloring agent which makes it possible, when the composition is spread on a support, to obtain a color path in the plane a * b * of the CIE 1976 color space which corresponds to a variation Dh of the h angle angle of at least 20 ° when the angle of observation is varied from 0 ° to 80 °, for an angle incidence of light 45 °. The color path can be measured for example by means of an INSTRUMENT SYSTEMS brand spectrogoniorflectometer and GON 360 GONIOMETER reference, after the first composition has been spread in the fluid state with a thickness of 300 m by means of a automatic spreader on an ERICHSEN brand contrast card and Typ 24/5, the measurement being made on the black background of the card. The goniochromatic coloring agent may be selected for example from the multilayer interference structures and liquid crystal coloring agents other than the liquid crystal discussed above. The presence of multilayer interference structures may make it possible to extend the color range of the composition. It may also make it possible to add colored highlight points in the middle of the colored continuous background constituted by the liquid crystal or crystals. In the case of a multilayer structure, this may comprise for example at least two layers, each layer being made for example from at least one material selected from the group consisting of the following materials: MgF2, CeF3, ZnS , ZnSe, Si, SiO2, Ge, Te, Fe2O3, Pt, Va, Al2O3, MgO, Y2O3, S2O3, SiO, HfO2, ZrO2, CeO2, Nb2O5, Ta2O5, TiO2, Ag, Al, Au, Cu, Rb, Ti , Ta, W, Zn, MoS2, cryolite, alloys, polymers and their combinations. The multilayer structure may or may not have, with respect to a central layer, a symmetry at the chemical nature of the stacked layers. Depending on the thickness and nature of the different layers, different effects are obtained.

Examples of symmetrical interferential multilayer structures are for example the following structures: Fe2O3 / SiO2 / Fe2O3 / SiO2 / Fe2O3, a pigment having this structure being marketed under the name SICOPEARL by the company BASF; Fe2O3 / SiO2 / titanium oxide or iron mica / titanium oxide or iron oxide / SiO2 / Fe2O3; TiO2 / SiO2 / TiO2 and TiO2 / Al2O3 / TiO2, pigments having these structures being marketed under the name XIRONA by the company Merck (Darmstadt). The optional liquid crystal coloring agents, other than the polymerizable liquid crystal polymers mentioned above, are for example in the form of pigments and comprise, for example, silicones or cellulose ethers onto which mesomorphic groups are grafted. Examples of goniochromatic liquid crystal particles that may be used are those sold by the company Chenix and those sold under the name HELICONE HC by the company Wacker. As goniochromatic coloring agent, it is also possible to use certain nacres, pigments having effects on a synthetic substrate, in particular substrate such as alumina, silica, borosilicate, iron oxide, aluminum, or interferential holographic flakes, especially originating from a polyterephthalate film. . The amount of goniochromatic coloring agent may vary, by weight relative to the total weight of the composition, for example from 0.1 to 30%.

The size of the goniochromatic coloring agent may be for example between 5 and 200 m, better between 5 and 100 m. The composition may also comprise at least one diffractive pigment. Diffracting peppers For the purposes of the present invention, the term "diffractive pigment" denotes a pigment capable of producing a color variation according to the angle of observation when illuminated by white light, because of the presence of a diffracting structure. the light. A diffractive pigment may comprise a diffraction grating, capable of, for example, diffracting in defined directions an incident monochromatic ray of light. The diffraction grating may comprise a periodic pattern, in particular a line, the distance between two adjacent patterns being of the same order of magnitude as the wavelength of the incident light. When the incident light is polychromatic, the diffraction grating will separate the different spectral components of the light and produce a rainbow effect. The structure of diffractive pigments can be usefully referred to in the article Pigments Exhibiting Diffractive Effects by Alberto Argoitia and Matt Witzman, 2002, Society of Vacuum coaters, 45th Annual Technical Conference 20 Proceedings 2002. The diffractive pigment can be produced with patterns having different profiles, in particular triangular, symmetrical or not, in crenellations, of constant width or not, sinusoidal. The spatial frequency of the grating and the depth of the patterns will be selected according to the degree of separation of the different orders desired. The frequency can vary for example between 500 and 3000 lines per mm. Preferably, the particles of the diffractive pigment each have a flattened shape, and in particular are platelet-shaped. The same pigment particle may comprise two crossed diffraction gratings, perpendicular or otherwise. The diffractive pigment may have a multilayer structure comprising a layer of a reflective material, covered at least on one side with a layer of a dielectric material. The latter can impart better rigidity and durability to the diffractive pigment. The dielectric material may then be chosen for example from the following materials: MgF 2, SiO 2, Al 2 O 3, AlF 3, CeF 3, LaF 3, NdF 3, SmF 2, BaF 2, CaF 2, LiF and their combinations. The reflective material may be chosen for example from metals and their alloys and also from non-metallic reflective materials. Among the metals that can be used include Al, Ag, Cu, Au, Pt, Sn, Ti, Pd, Ni, Co, Rd, Nb, Cr and their materials, combinations or alloys. Such a reflective material may alone constitute the diffractive pigment which will then be monolayer. Alternatively, the diffractive pigment may comprise a multilayer structure comprising a core of a dielectric material covered with a reflective layer at least on one side, or even completely encapsulating the core. A layer of a dielectric material may also cover the reflective layer (s). The dielectric material used is then preferably inorganic, and may be chosen for example from metal fluorides, metal oxides, metal sulfides, metal nitrides, metal carbides and their combinations. The dielectric material may be in the crystalline, semicrystalline or amorphous state. The dielectric material, in this configuration, may for example be selected from the following materials: MgF 2, SiO 2, SiO 2, Al 2 O 3, TiO 2, WO, AlN, BN, B 4 C, WC, TiC, TiN, N 4 Si 3, ZnS, glass particles , diamond-like carbons and their combinations. Alternatively, the diffractive pigment may be composed of a preformed dielectric or ceramic material such as a natural lamella mineral, for example peroskovite mica or talc, or synthetic lamellae formed from glass, alumina, SiO2, carbon, iron oxide / mica, mica coated with BN, BC, graphite, bismuth oxychloride, and their combinations. In place of a layer of dielectric material, other materials improving the mechanical properties may be suitable. Such materials may include silicone, metal silicides, semiconductor materials formed from Group III, IV and V elements, metals having a centered cubic crystal structure, cermet compositions or materials, semi-conductors -conductors, and their varied associations. The diffractive pigment used may in particular be chosen from those described in US patent application US 2003/0031870 published on February 13, 2003. A diffractive pigment may comprise, for example, the following structure: MgF 2 / Al / MgF 2, a diffractive pigment having this structure being marketed under the name SPECTRAFLAIR 1400 Pigment Silver by the company FLEX PRODUCTS, or SPECTRAFLAIR 1400 Pigment Silver FG. The proportion by weight of the MgF 2 can be between 80 and 95% of the total weight of the pigment. The amount of diffractive pigment may vary, by weight relative to the total weight of the composition, for example from 0.1 to 5%.

The size of the diffractive pigment may be for example between 5 and 200 m, better between 5 and 100 m. The thickness of the diffractive pigment particles may be less than or equal to 3 m, more preferably 2 m, for example of the order of 1 m. The composition may also include reflective particles.

Reflective Particles For the purposes of the present invention, the term "reflective particles" denotes particles whose size, structure, in particular the thickness of the layer or layers which constitute it and their physical and chemical natures, and the surface condition, their allow to reflect the incident light. This reflection may, if necessary, have sufficient intensity to create on the surface of the composition, when it is applied to the support to make up, highlight points visible to the naked eye, that is to say say brighter points that contrast with their surroundings by appearing to shine. The reflective particles may be selected so as not to significantly alter the coloring effect generated by the coloring agents associated with them and more particularly so as to optimize this effect in terms of color rendering. They may more particularly have a color or a yellow, pink, red, bronze, orange, brown, gold and / or coppery reflection. The presence of these particles may make it possible to extend the color range of the composition. It may also make it possible to add colored highlight points in the middle of the colored continuous background constituted by the liquid crystal or crystals. The presence of reflective particles within the composition can also improve the visibility of the liquid crystal polymer (s). The reflective particles may be present in the composition at a content ranging from 0.1% to 50% relative to the total weight of the composition, in particular from 1% to 30% by weight, in particular from 3% to 10% by weight. weight. The reflective particles may have various shapes, in particular be in the form of platelets or globular, in particular spherical. The reflective particles, whatever their shape, may have a multilayer structure or not and, in the case of a multilayer structure, for example at least one layer of uniform thickness, especially a reflective material. When the reflective particles do not have a multilayer structure, they may be composed for example of metal oxides, including synthetically obtained titanium or iron oxides.

When the reflective particles have a multilayer structure, these may for example comprise a natural or synthetic substrate, in particular a synthetic substrate at least partially coated with at least one layer of a reflective material, in particular at least one metal or metal material. . The substrate may be monomaterial, multimaterial, organic and / or inorganic.

More particularly, it may be chosen from glasses, ceramics, graphite, metal oxides, aluminas, silicas, silicates, in particular aluminosilicates and borosilicates, synthetic mica and mixtures thereof, this list not being limiting. The reflective material may include a layer of metal or a metallic material. Reflective particles are described in particular in JP-A-09188830, JP-A-10158450, JP-A-10158541, JP-A-07258460 and JP-A-05017710. Still another example of reflective particles having a mineral substrate coated with a metal layer are also particles having a silver coated borosilicate substrate. Particles with a silver-coated glass substrate, in the form of platelets, are sold under the name MICROGLASS METASHINE REFSX 2025 PS by the company TOYAL. Particles with a glass substrate coated with nickel / chromium / molybdenum alloy are sold under the name CRYSTAL STAR GF 550, 25 GF 2525 by the same company. The reflective particles, whatever their shape, can also be chosen from particles with a synthetic substrate at least partially coated with at least one layer of at least one metallic material, in particular a metal oxide, chosen, for example, from oxides of titanium, especially TiO2, iron including Fe2O3, tin, chromium, barium sulfate and the following materials: MgF2, CrF3, ZnS, ZnSe, SiO2, Al2O3, MgO, Y2O3, SeO3, SiO, HfO2, ZrO2 , CeO 2, Nb 2 O 5, Ta 2 O 5, MoS 2 and mixtures or alloys thereof. By way of example of such particles, mention may be made, for example, of particles comprising a synthetic mica substrate coated with titanium dioxide, or particles of coated glass of brown iron oxide, of titanium oxide, of tin oxide or a mixture thereof such as those sold under the trade name REFLECKS by ENGELHARD. The composition according to the invention may comprise at least one mother-of-pearl.

Nacres By nacre, we must understand colored particles of any shape, iridescent or not, especially produced by some shellfish in their shell or synthesized and which exhibit a color effect by optical interference. The nacres may be chosen from pearlescent pigments such as iron oxide-coated titanium mica, bismuth oxychloride-coated mica, titanium mica coated with chromium oxide, titanium mica coated with an organic dye. as well as pearlescent pigments based on bismuth oxychloride. It may also be mica particles on the surface of which are superimposed at least two successive layers of metal oxides and / or organic dyestuffs.

The nacres may more particularly have a color or a yellow, pink, red, bronze, orange, brown, gold and / or coppery reflection. The incorporation of nacres in the composition can be done without canceling the color due to (x) liquid crystals. The presence of nacres can extend the color range of the composition. It may also make it possible to add colored highlight points in the middle of the colored continuous background constituted by the liquid crystal or crystals. The mother of pearl may be chosen so that its color path is complementary to that of the liquid crystal or crystals, so as to better highlight these highlight points. As an illustration of the nacres that may be introduced into the composition, mention may especially be made of gold-colored mother-of-pearl sold in particular by ENGELHARD under the name Brillant gold 212G (Timica), Gold 222C (Cloisonne), Sparkle gold (Timica), Gold 4504 (Chromalite) and Monarch gold 233X (Cloisonne); bronze nacres sold especially by the company Merck under the name Bronze Fine (17384) (Colorona) and Bronze (17353) (Colorona) and by Engelhard under the name Super Bronze (Cloisonne); orange nacres sold especially by the company Engelhard under the name Orange 363C (Cloisonne) and Orange MCR 101 (Cosmica) and by the company Merck under the name Passion Orange (Colorona) and Matte Orange (17449) (Microna); brown-colored pearlescent agents marketed by Engelhard under the name Nu-antique copper 340XB (Cloisonne) and Brown CL4509 (Chromalite); nacres with a copper sheen sold especially by Engelhard under the name Copper 340A (Timica); the nacres with a red glint sold especially by MERCK under the name Sienna fine (17386) (Colorona); yellow-colored pearlescent agents marketed by ENGELHARD under the name Yellow (4502) (Chromalite); the red-colored pearlescent agents with a gold glint sold especially by ENGELHARD under the name Sunstone G012 (Gemtone); pink nacres sold especially by Engelhard under the name Tan opal G005 (Gemtone); the black nacres with gold reflection sold by the company Engelhard under the name Nu antique bronze 240 AB (Timica), the blue nacres sold especially by the company Merck under the name Matte Blue (17433) (Microna), the white nacres with reflection silver sold in particular by the company Merck under the name Xirona Silver and the golden-green orange-colored mother-of-pearl marketed by Merck under the name Indian summer (Xirona) and their mixtures. The composition may also comprise dyes, organic pigments or lacquers. Dyes, Organic Peppers and Lacquers Dyes may be fat soluble. Liposoluble dyes are, for example, Sudan Red, DC Red 17, DC Green 6, (3-carotene, soybean oil, Sudan Brown, DC Yellow 11, DC Violet 2, Orange DC 5 The dyes may, for example, represent from 0.01 to 20% of the weight of the composition, or even from 0.1 to 6%, when present, The organic lakes or pigments may be chosen from the materials mentioned below. below and mixtures thereof: - cochineal carmine, - organic pigments of azo, anthraquinone, indigo, xanthene, pyrenic, quinoline, triphenylmethane, fluoran dyes, - organic lakes or insoluble salts of sodium, potassium, calcium, barium, aluminum, zirconium, strontium, titanium, acid dyes such as azo, anthraquinone, indigo, xanthene, pyrenic, quinoline, triphenylmethane, fluoran dyes, these dyes may comprise at least one grou carboxylic acid or sulfonic acid. Among the organic pigments, mention may be made of those known under the following names: D & C Blue No. 4, D & C Brown No. 1, D & C Green No. 5, D & C Green No. 6, D & C Orange No. 4, D & C Orange No. 5, D & C Orange No. 10, D & C Orange No. 11, D & C Red No. 6, D & C Red No. 7, D & C Red No. 17, D & C Red No. 21, D & C Red No. 22, D & C Red No. 27, D & C Red No. 28, D & C Red No. 30, D & C Red No. 31, D & C Red No. 33, D & C Red No. 34, D & C Red No. 36, D & C Violet No. 2, D & C Yellow No. 7, D & C Yellow No. 8, D & C Yellow No. 10, D & C Yellow No. 11, FD & C Blue No. 1, FD & C Green No. 3, FD & C Red No. 40, FD & C Yellow No. 5, FD & C Yellow No. 6. Organic Coloring Matter may comprise an organic lacquer supported by an organic support such as rosin or aluminum benzoate, for example. Among the organic lakes, mention may be made in particular of the following denominations: D & C Red No. 2 Aluminum Lake, D & C Red No. 3 Aluminum Lake, D & C Red No. 4 Aluminum Lake, D & C Red No. 6 Aluminum Lake, D & C Red # 6 Barium Lake, D & C Red # 6 Barium / Strontium Lake, D & C Red # 6 Strontium Lake, D & C Red # 6 Potassium Lake, D & C Red # 7 Aluminum Lake, D & C Red # 7 Barium Lake, D & C Red # 7 Calcium Lake, D & C Red # 7 Calcium / Strontium Lake, D & C Red # 7 Zirconium Lake, D & C Red # 8 Sodium Lake, D & C Red # 9 Aluminum Lake, D & C Red # 9 Barium Lake, D & C Red # 9 Barium / Strontium Lake, D & C Red # 9 Zirconium Lake, D & C Red # 10 Sodium Lake, D & C Red # 19 Aluminum Lake, D & C Red # 19 Barium Lake, D & C Red # 19 Zirconium Lake, D & C Red # 21 Aluminum Lake, D & C Red # 21 Zirconium Lake, D & C Red # 22 Aluminum Lake, D & C Red # 27 Aluminum Lake, D & C Red # 27 Aluminum / Titanium / Zirconium Lake, D & C Red # 27 Barium Lake , D & C Red # 27 Calcium Lake, D & C Red # 27 Zirconium Lake, D & C Red # 28 Aluminum Lake, D & C Red # 30 Lake, D & C Red # 31 Calcium Lake, D & C Red # 33 Aluminum Lake, D & C Red # 34 Calcium Lake, D & C Red # 36 Lake, D & C Red # 40 Aluminum Lake, D & C Blue # 1 Aluminum Lake, D & C Green # 3 Aluminum Lake, D & C Orange # 4 Aluminum Lake, D & C Orange # 5 Aluminum Lake, D & C Orange # 5 Zirconium Lake, D & C Orange # 10 Aluminum Lake, D & C Orange # 17 Barium Lake, D & C Yellow # 5 Aluminum Lake, D & C Yellow # 5 Zirconium Lake, D & C Yellow # 6 Aluminum Lake, D & C Yellow # 7 Zirconium Lake, D & C Yellow # 10 Aluminum Lake, FD & C Blue # 1 Aluminum Lake, FD & C Red # 4 Aluminum Lake, FD & C Red # 40 Aluminum Lake, FD & C Yellow # 5 Aluminum Lake, FD & C Yellow # 6 Aluminum Lake.

The chemical materials corresponding to each of the organic dyestuffs mentioned above are mentioned in the International Cosmetic Ingredient Dictionary and Handbook, Edition 1997, pages 371 to 386 and 524 to 528, published by The Cosmetic, Toiletry, and Fragrance Association, whose Content is incorporated herein by reference. The composition may comprise a composite pigment. Composite peppers The composite pigment may be composed in particular of particles comprising: an inorganic core, magnetic or not, at least one at least partial coating of at least one organic dyestuff. At least one binder can advantageously contribute to the fixing of the organic dyestuff on the inorganic nucleus. The composite pigment particles may have various shapes. These particles may in particular be platelet-shaped or globular, in particular spherical, and may be hollow or solid. Platelet-shaped means particles whose ratio of the largest dimension to the thickness is greater than or equal to 5. A composite pigment may have, for example, a specific surface area of between 1 and 1000 m 2 / g, especially between 10 and 600 m2 / g, and in particular between 20 and 400 m2 / g. The specific surface is the value measured by the BET method. The inorganic core of the composite pigment may be of any form suitable for fixing particles of organic dyestuff, for example spherical, globular, granular, polyhedral, acicular, fusiform, flattened in the form of flakes, grains of rice, tortoiseshell as well as a combination of these forms, this list not being limiting. The ratio of the largest dimension of the core to its smallest dimension can be between 1 and 50.

The inorganic core may have a size of between about 1 nm and about 100 nm, or even between about 5 nm and about 75 nm, for example between about 10 nm and about 50 nm. The inorganic nucleus may be made of a material chosen from the nonlimiting list comprising metal salts and metal oxides, in particular oxides of titanium, zirconium, cerium, zinc, iron, ferric blue, aluminum and aluminum. chromium, alumina, glasses, ceramics, graphite, silicas, silicates, especially aluminosilicates and borosilicates, synthetic mica, and mixtures thereof. The oxides of titanium, in particular TiO 2, of iron, in particular Fe 2 O 3, of cerium, of zinc and of aluminum, the silicates, in particular the aluminosilicates and the borosilicates, are very particularly suitable. The inorganic core may have a specific surface area, measured by the BET method, for example between about 1 m 2 / g and about 1000 m 2 / g, more preferably between about 10 m 2 / g and about 600 m 2 / g, for example between about 20 m 2 / g m2 / g and about 400 m2 / g. The inorganic core can be colored, if necessary. The organic dyestuff may be as defined above. The binder of the composite pigment can be of any type since it allows the organic dyestuff to adhere to the surface of the inorganic core.

The binder can in particular be chosen from a non-limiting list comprising silicone materials, polymeric, oligomeric or similar materials, and in particular from organosilanes, fluoroalkylated organosilanes and polysiloxanes, for example polymethylhydrogenosiloxane, as well as various coupling agents, such as coupling agents based on silanes, titanates, aluminates, zirconates and mixtures thereof. The composition may further comprise a photochromic or thermochromic coloring agent. Photochromic Agents In general, a photochromic coloring agent is a coloring agent having the property of changing color when illuminated by ultraviolet light and restoring its original color when it is no longer illuminated by this light. or to go from an uncolored state to a colored state and vice versa. In other words, such an agent has different hues depending on whether it is illuminated by light containing a certain amount of UV radiation as in sunlight or artificial light. It will be useful to refer to the examples of photochromic agents described in EP 1 410 786. The photochromic agent will be chosen so as not to prevent photopolymerization when this is desired.

Thermochromic Agents It is possible, for example, to use encapsulated or microencapsulated thermochromic dyes marketed by Color Change Corporation, Chromatic Technologies and Matsui International.

Such thermochromic dyes can change color precisely as a function of temperature and become colorless beyond or below a certain temperature and thus indicate to the user the moment to apply an external stimulus to the composition. The composition may further comprise piezochromic compounds, in particular tribochromic compounds, or mechano luminescent compounds. Piezochromic or mechanoluminescent agent A piezochromic agent may change color in the presence of a mechanical force. As an example of a piezochromic agent, mention may be made of diphenylflavylene. A mechanoluminescent agent is capable of emitting a color when it receives a mechanical stress. Examples of luminescent materials include lanthanide complexes and chelates, aluminates, silicates and aluminosilicates doped with rare earth ions, zinc sulphide, manganese sulphide, cadmium sulphide or lithium oxide. zinc doped with ions of transition metals or rare earths. Other components Typically, the cosmetic composition comprises a cosmetically acceptable medium. By cosmetically acceptable medium is meant a non-toxic medium that can be applied to the skin, integuments or lips of human beings. The cosmetically acceptable medium is generally adapted to the nature of the support to which the composition is to be applied and to the form in which the composition is packaged. The composition may comprise other ingredients than those described above, in particular at least one filler, a solvent, a fatty phase, a film-forming polymer and / or a dermatological or cosmetic active agent, in particular depending on the galenic form. The composition may comprise, for example, at least one filler. Charges By charge means particles of any form, insoluble in the medium of the composition, regardless of the temperature at which the composition is manufactured. A filler can serve in particular to modify the rheology or the texture of the composition. The nature and quantity of the particles may depend on the desired mechanical properties and textures. Examples of fillers that may be mentioned include talc, mica, silica, kaolin, sericite, polyamide, polyolefin powders, for example polyethylene, polytetrafluoroethylene, polymethyl methacrylate , polyurethane, starch powders and silicone resin beads. The fillers may be intended to create, inter alia, a blur effect, especially in the case of a foundation, in order to hide skin imperfections.

Solvents and Oils The composition may comprise at least one organic solvent or an oil. The composition may advantageously comprise a volatile solvent, in particular a volatile organic solvent. For the purposes of the present invention, the term "volatile solvent" is intended to mean a solvent which is liquid at ambient temperature, in particular having a non-zero vapor pressure, at ambient temperature and atmospheric pressure, in particular having a vapor pressure of 0.13 Pa. at 40,000 Pa (10-3 at 300 mm Hg), and preferably ranging from 1.3 Pa to 13 000 Pa (0.01 to 100 mm Hg), and preferably ranging from 1.3 Pa to 1300 Pa (0. , 01 to 10 mmHg).

When the composition comprises one or more organic solvents, these solvents may be present in a content ranging from 0.1% to 30%, relative to the total weight of the composition. In general, the amount of solvent (s), in particular organic (s), will depend on the nature of the support on which the composition is intended to be applied.

The amount of solvent (s) will be chosen so as not to cancel the color effect related to the liquid crystals. The composition may comprise at least one volatile solvent consisting of a volatile oil. The oil may be a silicone oil or a hydrocarbon oil, or comprise a mixture of such oils. For the purposes of the present invention, the term "silicone oil" means an oil comprising at least one silicon atom, and in particular at least one Si-O group. The term "hydrocarbon-based oil" means an oil containing mainly hydrogen and carbon atoms and optionally oxygen, nitrogen, sulfur and / or phosphorus atoms. The volatile hydrocarbon oils may be chosen from hydrocarbon-based oils containing from 8 to 16 carbon atoms, and especially branched C8-C16 alkanes (also known as isoparaffins), such as isododecane (also called 2,2,4,4,6 - pentamethylheptane), isodecane, isohexadecane, and for example the oils sold under the trade names ISOPARS or PERMETHYLS. Volatile silicones can also be used as volatile oils, for example volatile linear or cyclic silicone oils, in particular those having a viscosity of 8 centistokes (8 × 10 -6 m 2 / s), and having in particular from 2 to 10 atoms. silicon, and in particular from 2 to 7 silicon atoms, these silicones optionally comprising alkyl or alkoxy groups having from 1 to 10 carbon atoms. As volatile silicone oil that may be used in the invention, mention may be made in particular of dimethicones of viscosity 5 and 6 cSt, octamethyl cyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, heptamethylhexyltrisiloxane, heptamethyloctyltrisiloxane and hexamethyl. disiloxane, octamethyl trisiloxane, decamethyl tetrasiloxane, dodecamethyl pentasiloxane, and mixtures thereof. Fluorinated volatile oils such as nonafluoromethoxybutane or perfluoromethylcyclopentane and mixtures thereof can also be used. The composition may comprise between 0.01% and 30% by weight of volatile oil, relative to the total weight of the composition, better still between 1% and 10% by weight. The composition may comprise at least one organic solvent chosen from the following list: ketones that are liquid at ambient temperature, such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone or acetone; glycols that are liquid at room temperature, such as ethylene glycol, propylene glycol, pentylene glycol or glycerol; propylene glycol ethers which are liquid at ambient temperature, such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate or dipropylene glycol mono-butyl ether; short-chain esters (having from 3 to 8 carbon atoms in total) such as ethyl acetate, methyl acetate, propyl acetate, n-butyl acetate, acetate isopentyl; alkanes which are liquid at ambient temperature, such as decane, heptane, dodecane and cyclohexane.

The composition may also comprise water or a mixture of water and hydrophilic organic solvents commonly used in cosmetics such as alcohols and in particular linear or branched lower monoalcohols having from 2 to 5 carbon atoms, such as ethanol, isopropanol or n-propanol, polyols such as glycerine, diglycerine, propylene glycol, sorbitol, penthylene glycol, polyethylene glycols. The composition may further contain C 2 ethers and C 2 -C 4 hydrophilic aldehydes. The water or the mixture of water and hydrophilic organic solvents may be present in the composition in a content ranging for example from 0% to 10%, in particular from 0.1% to 5% by weight, relative to the total weight of the composition. the composition. Grime phase The composition, for example when it is intended to be applied to the lips, may comprise a fatty phase, and in particular at least one fatty substance that is liquid at room temperature (25 ° C.). The fatty phase may further contain lipophilic organic solvents. The composition may for example have a continuous fat phase, which may contain less than 5% water, especially less than 1% water relative to its total weight and in particular be in anhydrous form. As liquid fatty substances at room temperature, often called oils, mention may be made of: vegetable hydrocarbon-based oils such as liquid triglycerides of fatty acids with 4 to 10 carbon atoms, for instance triglycerides of heptanoic or octanoic acids, or oils sunflower, maize, soya, grape seed, sesame, apricot, macadamia, castor oil, avocado, caprylic / capric acid triglycerides, jojoba oil, shea butter, lanolin, acetylated lanolin; linear or branched hydrocarbons of mineral or synthetic origin, such as liquid paraffins and derivatives thereof, petroleum jelly, polydecenes, hydrogenated polyisobutene such as parleam; esters and synthetic ethers, in particular of fatty acids, for example purcellin oil, isopropyl myristate, 2-ethylhexyl palmitate, octyl-2-dodecyl stearate, erucate octyl-2-dodecyl, isostearyl isostearate; hydroxylated esters such as isostearyl lactate, octyl hydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate, triisocetyl citrate, heptanoates, octanoates, decanoates of fatty alcohols; isononyl isonanoate, isopropyl lanolate, tridecyl trimellilate, diisostearyl malate; polyol esters such as propylene glycol dioctanoate, neopentyl glycol diheptanoate, diethylene glycol diisononanoate; and pentaerythritol esters; fatty alcohols having 12 to 26 carbon atoms such as octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol, oleyl alcohol; partially hydrocarbon and / or silicone fluorinated oils; silicone oils, such as volatile or nonvolatile polymethylsiloxanes (PDMS), linear or cyclic, liquid or pasty at room temperature, such as cyclomethicones, dimethicones, optionally comprising a phenyl group, such as phenyl trimethicones, phenyltrimethylsiloxydiphenylsiloxanes or diphenylmethyldimethyltrisiloxanes, diphenyl dimethicones, phenyl dimethicones, polymethylphenyl siloxanes; their mixtures. The oils may be present in a content ranging from 0.01 to 30%, and better still from 0.1 to 15% by weight, relative to the total weight of the composition. Filmo2ene Polymers The composition may also comprise, in addition to the liquid crystal or crystals, a film-forming polymer which may be without optical activity, in particular in the case of a mascara or a nail polish. "Film-forming polymer" means a polymer capable of forming, by itself or in the presence of an auxiliary film-forming agent, a continuous and adherent film on a support, in particular on keratin materials. Among the film-forming polymers that may be used in the composition according to the invention, mention may be made, inter alia, of synthetic polymers, of radical type or of polycondensate type, polymers of natural origin, such as nitrocellulose or cellulose esters, and their mixtures . The radical-type film-forming polymers may in particular be vinyl polymers or copolymers, in particular acrylic polymers. The vinyl film-forming polymers may result from the polymerization of ethylenically unsaturated monomers having at least one acidic group and / or esters of these acidic monomers and / or amides of these acidic monomers, such as α, β-ethylenically unsaturated carboxylic acids. acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, vinyl film-forming polymers may also result from the homopolymerization or copolymerization of monomers chosen from vinyl esters such as vinyl acetate, vinyl neodecanoate, vinyl pivalate, vinyl benzoate and vinyl t-butyl benzoate and styrene monomers such as styrene and alpha-methyl styrene.

Among the film-forming polycondensates, there may be mentioned polyurethanes, polyesters, polyesters amides, polyamides, and polyureas, this list not being limiting. The composition may comprise a polymerizable film-forming compound during drying of the composition and / or under UV radiation or under the effect of heat, for example a polyfunctional acrylate, especially chosen from trimethacrylates, tetramethacrylates and pentamethacrylates, in particular in the form of oligomers. The composition according to the invention may also comprise an auxiliary film-forming agent promoting the formation of a film with the film-forming polymer.

Active ingredients The composition may comprise at least one cosmetic or dermatological active agent. As cosmetic, dermatological, hygienic or pharmaceutical active agents that can be used in the compositions of the invention, mention may be made of moisturizers (polyol as glycerol), vitamins (C, A, E, F, B, or PP), essential fatty acids, essential oils, ceramides, sphingolipids, liposoluble sunscreens or in the form of nano-particles, the specific active agents of the skin treatment (protection agents, anti-bacterial agents, anti-wrinkles, etc.), self-tanning agents. These active agents may be used, for example, at concentrations of 0 to 20% and especially from 0.001 to 10% relative to the total weight of the composition.

The composition may also contain ingredients commonly used in cosmetics, such as, for example, surfactants, trace elements, perfumes, preservatives, antioxidants or mixtures thereof. The composition according to the invention may comprise, depending on the type of application envisaged, the constituents conventionally used in the fields under consideration, which are present in an amount appropriate to the desired dosage form. Galenic forms The composition can take various forms, depending on its purpose. The composition may thus be in any galenical form normally used for topical application and in particular in anhydrous form, in the form of an oily solution, an oily gel, an oil-in-water emulsion, water-in-oil, or an oil dispersion in water through vesicles at the oil / water interface. Base layer According to one aspect of the invention, a base layer is applied to the keratin materials before application of the composition comprising the polymerizable liquid crystals. The base layer may be intended to improve the visibility of the liquid crystal composition and / or the holding of this composition and / or to create an additional optical effect. The base layer may comprise at least one compound for producing an exothermic or endothermic reaction. Such a reaction can be used to bring the liquid crystal (s) to the desired temperature before the polymerization process or to release the heat useful for the polymerization, when the external stimulus causing the polymerization is a thermal stimulus. The basecoat may also include a coloring agent selected from those mentioned in the above list of coloring agents.

The basecoat can stain the support to bring out or change the color produced by the liquid crystal. For this purpose, the base layer may comprise at least one coloring agent making it possible to reduce the clarity of the support. The base layer may for example comprise a pigment or a black dye, or a different color, to create a colored background for adding an additional color to a given color by the liquid crystal; The base layer may comprise a volatile phase. The volatile phase may be an aqueous phase or an anhydrous phase. In the case of an aqueous phase it is constituted, preferably water, alcohol and glycol.

In the case of an anhydrous phase, it is preferably composed of at least one volatile oil. For the purposes of the present invention, the term "volatile oil" means an oil (or non-aqueous medium) capable of evaporating on contact with the skin in less than one hour, at ambient temperature and at atmospheric pressure. The volatile oil is a volatile cosmetic oil which is liquid at ambient temperature, in particular having a non-zero vapor pressure, at ambient temperature and atmospheric pressure, in particular having a vapor pressure ranging from 0.13 Pa to 40 000 Pa (10 3 to 300 mmHg), in particular ranging from 1.3 Pa to 13 000 Pa (0.01 to 100 mmHg), and more particularly ranging from 1.3 Pa to 1300 Pa (0.01 to 10 mmHg). ).

The volatile hydrocarbon-based oils may be chosen from hydrocarbon-based oils containing from 8 to 16 carbon atoms, and especially branched C 8 -C 16 alkanes (also known as isoparaffins), such as isododecane (also called 2,2,4,4,6). -pentamethylheptane), isodecane, isohexadecane, and for example the oils sold under the trade names of Isopars or Permethyls. As volatile oils, it is also possible to use volatile silicones, for example volatile linear or cyclic silicone oils, in particular those having a viscosity of 8 centistokes (8 × 10 -6 m 2 / s), and especially having from 2 to 10 silicon atoms, and in particular from 2 to 7 silicon atoms, these silicones optionally containing alkyl or alkoxy groups having from 1 to 10 carbon atoms. As volatile silicone oil that may be used in the invention, mention may be made in particular of dimethicones of viscosity 5 and 6 cSt, octamethyl cyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, heptamethylhexyltrisiloxane, heptamethyloctyltrisiloxane and hexamethyl. disiloxane, octamethyl trisiloxane, decamethyl tetrasiloxane, dodecamethyl pentasiloxane, and mixtures thereof. Fluorinated volatile oils such as nonafluoromethoxybutane or perfluoromethylcyclopentane and mixtures thereof can also be used. It is also possible to use a mixture of the above-mentioned oils. The base layer may comprise a polymer chosen in particular from film-forming polymers. The polymer is preferably capable of forming a film after application and drying of the composition. The formation of the film can be done with the aid of a coalescing agent. The polymer may be in dispersion or in solution in an aqueous or anhydrous phase. The polymer will preferably be insoluble in contact with an aqueous phase or an oily phase after application and drying. It is also possible to use according to this process in the base layer monomers or prepolymers which are also able to polymerize after application to the skin, either by UV action, heat or the presence of water for example. Mention may be made, for example, of cyanoacrylate monomers or of low-molecular-weight silicone polymers carrying reactive functional groups, monomeric or multifunctional acrylate or methacrylate monomers. The basecoat may contain other solid components (fillers, effect pigments) or other nonvolatile liquid components. These will preferably be in small quantities.

The base layer may be for example a solvent-based nail polish, an aqueous nail polish, a lipstick or a mascara comprising a proportion of volatile phase greater than 30% by weight, preferably greater than 50%. Overcoat Once the composition has been applied and after any polymerization, the composition may be covered with a covering layer, constituted for example by a varnish, in order to protect it. This varnish can be a varnish that cures by drying or alternatively a varnish that hardens under the effect of an external stimulus, for example UV radiation.

For example, the same UV light source is used to cause polymerization of the composition comprising the polymerizable liquid crystals and to polymerize the protective varnish. The covering layer may comprise polymerizable compounds selected from those indicated above as well as coloring agents, if appropriate. Proposed Examples Examples of compositions (% by weight relative to the total weight of the composition) Mixture A Mixture B Compound (1) with m = 5 ... 60% Compound (1) with m = 5 ... 33.3% Compound (2) with n = 3, R = H .. 40% Compound (1) with m = 10 33.3% Compound (2) with n = 3, R = H .33.4% where (1) and (2) are the compounds previously described under (1) and (2).

Examples of nail polish Example 1 Blend A 92% Irgacure 184 3% Benzophenone 3% Black iron oxide 2%

Example 2 Blend A 84% Irgacure 184 3% Benzophenone 3% Nacres 10% Example 3 Blend A 88.7% Irgacure 184 3% Benzophenone 3% DCRed7 0.2% PEG 20 Dimethicone 0.1% Particles of PMMA (51um) 2 % 2% blue nacre The compositions of Examples 1, 2 and 3 are applied to the nails and then exposed to UV radiation for 2 minutes with a lamp having a power of 50mW / cm 2. Red compositions are obtained when the exposure is at 20 ° C and green at 40 ° C. Patterns can be obtained when the temperature of the deposit is not uniform.

Nail kits Example 4 First composition red nail polish Second composition varnish of Example 2 Third compositionVulis UV brand Clear Veil, Natural Field, Japan.

The first composition is applied and allowed to dry. The second composition is applied to this first deposit and cured with a UV lamp. Any unpolymerized areas are removed with ethanol and the third composition is applied and then cured under a UV lamp. EXAMPLE 5 First Composition X 94% Irgacure Blend 184 3% Benzophenone 3% Second Composition Y Blend B 94% Irgacure 184 3% Benzophenone 3% Tests are carried out with the following ratios and then cured by exposure to a UV lamp of 50 mW / cm2 for 2 minutes.

X = 100 Y = 0 Mixture red (at 20 ° C) X = 75 Y = 25 Mix orange / yellow (at 20 ° C) X = 30 Y = 70 X = 0 Y = 100 Mixture green / blue (at 20 ° C) C) Blue mixture (at 20 ° C.) Formation of the mixture The mixture of the polymerizable liquid crystals may be proposed to the user while the compounds of the mixture are already mixed or, alternatively, the compounds to be mixed are proposed separately to the user and mixed in proportions chosen by the user according to the desired result, for example extemporaneously. When the composition is proposed to the user with the liquid crystals already mixed, the composition is for example packaged in a packaging and application device which may comprise, as illustrated in FIG. 1, a container 10 and an applicator 11. The container 10 may be made of any material compatible with the composition to be contained, for example a glass or thermoplastic container. When the composition comprises at least one photoinitiator, the container may be opaque to light, or at least ultraviolet radiation. The packaging and application device may comprise any type of applicator 11 and the latter is for example designed to serve not only the application but also to close the container 10 in the absence of use. The applicator 11 comprises, for example, a rod 12 provided at one end with an applicator member 13 and at the other end with a gripping means which can constitute a closing cap of the container 10. The body Application 13 may be of any type, depending on the region to be treated, and comprises for example a brush, a flocked tip, a capillary tip, a felt, a brush, a comb or a foam.

The packaging and application device may comprise a support on which at least one sample 14 reproducing the appearance of the composition is present. In an exemplary implementation of the invention, the packaging and application device comprises at least two samples 14 respectively indicating the appearance of the composition for different temperatures, to allow the user to choose the temperature to perform the polymerization, depending on the desired appearance. In exemplary embodiments of the invention, the applicator is separable from the container that contains the composition, but in variants, the applicator member 10 remains integral with the container during application. The composition may also be proposed to the user with at least two compounds to be mixed, for example extemporaneously. In such a case, the compounds to be blended are, for example, contained in respective containers 20 and 30 and these containers may be provided, if appropriate, with another container 40 for mixing. The container 40 is for example equipped with an applicator 50 which can also be used to close it in the absence of use. Alternatively, one of the containers 20 or 30 serves to accommodate the contents of the other container to achieve mixing. Each of the containers 20 and 30 may comprise graduations 21 and 31 which make it possible to dose each compound when poured into the container 40. The latter may also be provided, if necessary, with graduations 41. The containers 20 and 30 as well as the container 40 for receiving the mixture may be contained within a common package 60, for example as illustrated in Figure 3, which may be provided with a carrier bearing samples 61 representing the appearance mixture for different proportions of the compounds to be mixed. If appropriate, these samples 61 may have an appearance that varies with temperature. In a variant, the support comprises representations of the appearance of the mixture for different proportions of the compounds and for several temperatures. The container in which the mixing is carried out can be provided with any mixer such as, for example, a dispensing ball or cannula provided with baffles, so that during the distribution of the mixture, the compounds are intimately mixed. When the composition comprises at least two compounds to be mixed by the user, the latter can add to the mixture before use, if necessary, at least one polymerization initiator.

The polymerizable liquid crystal or crystals may be contained in one or more containers whose capacity ranges, for example, from 0.5 ml to 500 ml. Formation of a deposit on keratin materials When the composition comprises all the compounds that come into its formulation, the application of the composition can be done by any means that makes it possible to apply a composition to the keratin materials, for example by contact thereof an application member responsible for the composition, for example a brush, a foam, a wipe, a flocked tip or a felt, among other application members. The application can still be done on the finger.

The application of the composition may also be carried out by spraying on the region to be treated, this sputtering being for example obtained by means of a piezoelectric, electrostatic or airbrush spraying device. The application of the composition may also be carried out for example by an ink jet printing technique or by transfer.

When the composition comprises several compounds to be mixed, the mixture can be made before the application of the composition or alternatively, at least two compounds can be applied successively to one another and / or mix during application . In an exemplary embodiment of the invention, the composition comprises at least two compounds that can be used either separately or mixed at the user's choice. When each compound can be used separately, this compound can be applied and then its polymerization can be triggered by exposure to a stimulus. If desired, after polymerization of this compound, the other compound can be applied and then polymerized, also by being subjected to the action of the stimulus. A covering composition may be further applied, for example to protect the underlying composition. The choice of the order of application of the compounds can make it possible to create different effects. Polymerization Temperature According to one aspect of the invention, the composition can be brought to a temperature selected by the user depending on the desired appearance, before its polymerization.

For example, the composition may be heated prior to application so that its color (when viewed at a predefined incidence angle) matches the desired effect. The composition may for example change color between 20 ° C and 40 ° C and be brought to a temperature between these values depending on the desired color. The heating or cooling of the composition to bring it to the desired temperature can be carried out while the composition is contained in a conditioning device or, alternatively, can take place while the composition is already in the form of a deposit on keratin materials.

When the composition is heated or cooled while present in the conditioning device, any heating means can be used, this heating means possibly forming part of the conditioning device. When the composition is deposited on the keratin materials and must be brought to a particular temperature, for example the heating of the hot air or the heat generated by a light bulb is used for heating. The heating or cooling can also be brought about by the deposition on the keratin materials of an endothermic or exothermic composition. This composition is for example deposited on the keratin materials before the composition comprising the liquid crystals. The composition deposition may be uniformly heated or cooled, or not, depending on the desired effect. If necessary, the heating of the composition can be carried out so as to create a temperature gradient to form a color gradient. A mask may be interposed between the composition deposition and the heat source so as to raise the temperature of the composition locally and thereby create a pattern. For example, a mask 70 may be used which comprises, as illustrated in FIG. 4, an opening 71 having the shape of the pattern to be produced. When such a mask is placed between the heat source, for example an incandescent lamp, and the composition deposit, a pattern corresponding to the aperture 71 may be formed by local reheating of the deposit, and it is possible to proceed. at the polymerization in this state. The mask can also be made with a support that is transparent to infrared radiation and a printing of a reflective ink.

If necessary, a device 100 may be used to carry out the polymerization, which comprises not only a UV source but also a thermal device making it possible to send hot or cold air or thermal radiation to the composition deposit, for example to form a pattern locally by raising or lowering the temperature. Alternatively, the device 100 may be arranged to cool or uniformly heat the deposit to a temperature selected by the user depending on the color he wishes to obtain. The device 100 is for example arranged to heat the deposition of composition formed on the nail at a controlled temperature and initiate the polymerization once this temperature reached, maintaining the temperature substantially constant during the polymerization time. The device 100 may for example comprise a housing 101 for receiving one or more nails and, where appropriate, one or more buttons 102 for turning on or off the device and selecting a temperature. Stimulus exposure Polymerization may be by UV radiation, which is emitted by any suitable light source, for example a discharge lamp, a UV light-emitting diode or a flash tube. The polymerization can still take place, if the composition allows, under the effect of natural or artificial light, without requiring a specific light source. The polymerization can also be carried out by a polymerization reaction in the presence of the humidity of the air, according to the compounds which enter into the formulation of the composition. The polymerization can also be carried out hot and can be triggered for example by the blowing of hot air on the deposit or by an exothermic reaction. The polymerization can also be triggered by mixing at least two substances, one of which contains a polymerization initiator or by adding such an initiator in the composition. The polymerization can be carried out on the whole or only a part of the composition deposit. Partial polymerization may be useful for making a pattern. In this case, it is possible to place a mask, such as for example one of those illustrated in FIG. 4, between the source causing the polymerization and the composition deposition, so that only the zone situated in line with the The opening of the mask receives the stimulus causing its polymerization. Once the polymerization has been carried out, the composition which has not polymerized can be removed by means of a solvent, such as for example an alcohol. A pattern is obtained corresponding to the composition portion which has polymerized. This pattern can be left as is or alternatively be covered with a new layer of at least one composition, the latter being for example intended to protect the pattern or to bring a new optical effect. The polymerization can be carried out while the temperature of the deposit is controlled, as described above.

The invention is not limited to the examples which have just been described. The expression "having one" should be understood as being synonymous with "having at least one".

Claims (13)

1. A process for the cosmetic treatment of human keratin materials comprising the steps of: 1) applying to the keratin materials a cosmetic composition comprising at least one polymerizable liquid crystal whose color varies as a function of the temperature before its polymerization, the polymerization taking place under the action of an external stimulus, 2) the composition being at a temperature corresponding to the desired aspect, subjecting it to the action of the stimulus in order to cause the polymerization of the liquid crystal in situ on the keratin materials. 2. Method according to claim 1, the composition being brought to the desired temperature before application to the keratin materials. 3. The method of claim 1, the composition being brought to the desired temperature after application to keratin materials. 15 4. The method of claim 1, the composition being brought to the desired temperature during application on keratin materials. 5. Method according to any one of the preceding claims, the stimulus comprising ultraviolet radiation, in particular UVA and / or UVB. 6. A process according to any one of the preceding claims, wherein the composition comprises at least one liquid crystal having a cholesteric phase at room temperature. 7. Method according to any one of the preceding claims, the composition being a temperature between 10 ° C and 50 ° C during exposure to the stimulus. 25 8. Method according to any one of the preceding claims, wherein the keratin materials are chosen from keratinous fibers, in particular eyelashes or hair. 9. A method according to any one of claims 1 to 7, the keratin materials being chosen from skin and lips. 30 10. Process according to any one of claims 1 to 7, the keratin materials being formed by the nails. 11. A method according to any one of the preceding claims, the composition comprising polymerizable liquid crystals comprising a mixture of acrylic or methacrylic derivatives of sterols. 12. Process according to any one of the preceding claims, the composition comprising a polymerization photoinitiator. 13. Method according to any one of the preceding claims, the composition comprising an additional coloring agent, in particular a coloring agent chosen from: - dyes, in particular lipophilic dyes, - organic or inorganic pigments, - interferential pigments, pigments metallic and multilayer pigments. 17. Process according to any one of the preceding claims, the composition comprising an additional polyfunctional acrylate, especially chosen from trimethacrylates, tetrametacrylates and pentamethacrylates, in the form of monomers or oligomers. 18. Process according to any one of the preceding claims, the composition comprising at least one surfactant. The method of any of the preceding claims, wherein the stimulus exposure occurs while the composition is present on the region to be treated as a homogeneous temperature layer. 17. A method according to any one of claims 1 to 15, wherein the stimulus exposure occurs while the composition is present on the region to be treated as an inhomogeneous temperature layer. 18. A method according to any one of claims 1 to 15, wherein heat is applied locally to the composition deposition so as to locally change the appearance of the composition and create at least one pattern. 19. A method according to any one of the preceding claims, a covering layer being applied to the composition after exposure to the stimulus. 20. A method according to any one of the preceding claims, a base layer being applied to the region to be treated prior to the application of the composition 21. The method of claim 20, the base layer being opaque. 22. Method according to one of claims 20 and 21, the base layer being colored, in particular of dark color, preferably of black color. 23. A method according to any one of the preceding claims, wherein a first zone of the composition deposition is exposed to the stimulus while being in a first color state, a second zone of the composition deposition not being exposed to austimulus, then the second The zone is exposed to the stimulus by being at a temperature different from that of the first zone during the exposure to the stimulus, so as to be fixed in another color state. 24. The method of claim 23, the exposure of the first zone being effected through a mask avoiding the action of the stimulus on the second zone. 25. Process according to any one of the preceding claims, in which the formation of the deposition of the composition on the keratin materials takes place with an inhomogeneity of thickness and / or concentration of at least one compound, in particular a solvent. 26. Process according to any one of claims 1 to 25, the composition comprising a mixture of at least two compounds chosen from structures (1) and (2). with m = 5 or 10! 6 N e: e and n = 3,4,6,7,8 or 9 R = H 0 CH 3, preferably a mixture of compounds (1) and (2) with m = 5, n = 3, R = H or a mixture of compounds (1) with m = 5 and m = 10 and a compound (2) with n = 3 and R = H 27. The process according to the preceding claim, the mixture comprising an additional compound chosen from the structures ( 3), (4) and (10): with p = 5 or 10 q = 2, 4 or 6 t = 2, 3 or 4 R = H or CH 3 (I C 10 28. Process according to any one of claims 1 to at 25, the composition comprising a mixture of at least two compounds chosen from the following compounds (5) and (6): with r = 3-9 R = H 0 CH 3 and H 3 q = 2, 4 or 6 29. Method according to the preceding claim, the mixture comprising at least one additional compound selected from R = H or CH3154a., Q = 2,4 or 6 s = 3,4,5,6,7,8 or 9, R = H or CH3 30. A process according to any one of claims 1 to 25, the composition comprising at least one compound having the structure (5) r = 3-9 R = Hou CH3 and at least one compound having the stru (10) t 10t = 2, 3 or 4 R = Hou CH3 31. The process according to the preceding claim, the substance additionally comprising at least one additional compound having the structure (4) 32. Process according to any one of Claims 1 to 25, the composition comprising at least one compound having the structure (4) and at least one compound having the structure (10). 15p = 5 or 10 q = 2, 4 or 6 t = 2, 3 or 4 R = Hou CH3 33. A method according to any one of the preceding claims, the thickness of the deposit ranging from 2 to 2000 m, preferably from 10 to 500 m. 34. Kit comprising within the same package: a cosmetic composition comprising at least one polymerizable liquid crystal whose color varies as a function of its temperature before its polymerization, the polymerization taking place under the action of an external stimulus, a means of producing the stimulus for causing the polymerization of the liquid crystal, chosen for example as a function of the stimulus from the sources of UV and / or heat, for example a UV lamp, or from chemical compounds which trigger polymerization or producing an exothermic reaction. 35. Kit according to the preceding claim, the composition comprising one or more of the liquid crystals defined in claims 26 to 32.