FR2919801A1 - Composition, useful to obtain varnish film deposited on the nails, comprises medium, thixotropic thickener, and coloring agent comprising magnetic bodies, diffracting pigments, interferential pigments and/or light-reflecting particles - Google Patents

Abstract

Nail varnish composition comprises a medium, a thixotropic thickener, and a coloring agent (>= 2 wt.%) comprising magnetic bodies, diffracting pigments, interferential pigments and/or light-reflecting particles, where the composition has a viscosity of 0.6 Pa.s at 25[deg] C.

Description

The present invention relates to a nail varnish of high viscosity and

  of gelled texture comprising particular coloring agents and a method of coating the nails.

  The nail varnish composition, colored or transparent, can be used as a base for nail polish or "base-coat" in English terminology, as a nail makeup product, as a finishing composition, also called "top-coat", to be applied to the nail makeup product or even as a cosmetic nail care product.

  Conventional nail polishes are in liquid or fluid form and are generally packaged in vials. They generally comprise coloring agents which are solid particles such as pigments, nacres, fillers, which are dispersed in the aqueous continuous medium or the organic solvent medium of the composition. This fluid form imposes a good dispersion of the solid particles so as to preserve the homogeneity of the color of the liquid varnish and the varnish film once applied to the nails. However, these particles tend to sediment over time, because of their density which is greater than that of the continuous medium in which they are dispersed. This sedimentation results in a modification of the macroscopic appearance of the composition, and in particular, in the case of colored nail polishes, by a heterogeneity of the color of the varnish. The incorporation of this type of particles, in particular nacres and magnetic pigments is therefore limited (of the order of 1 to 2% maximum depending on the type of particles) in conventional nail varnishes in liquid form.

  It is therefore sought to obtain nail polishes having a good dispersion of solid particles such as magnetic particles and pearlescent agents and thus good stability and good color homogeneity over time, said varnish making it possible to obtain color effects. satisfactory, not limited. In addition from a practical point of view, it would be interesting to have varnish with new textures that are easy to handle (without problems of spill or drop).

  The Applicant has found that these advantages can be obtained by the implementation of a nail varnish composition in non-liquid form, high viscosity and gelled texture allowing a homogeneous dispersion of the pigments when they are present in a content greater than or equal to 2% by weight of the composition. In addition, this gelled texture allows a better organization and orientation of the coloring particles (in particular nacres) in the composition when it is applied to the nails and then during the drying of the varnish film, thus making it possible to obtain a color effect and higher gloss than conventional fluid nail polish films in which the coloring particles do not follow a preferred orientation.

  In addition, this composition, unlike conventional nail polish, does not run, does not drip and provides, after application to the nails, a film that dries quickly while being homogeneous and smooth; and which has good tint and gloss properties.

  The subject of the present invention is therefore a nail polish composition comprising a cosmetically acceptable medium, at least one thixotropic thickening agent, at least one coloring agent chosen from magnetic substances, diffractive pigments, interference pigments, reflecting particles and their mixtures, said coloring agent being present in a content greater than or equal to 2% by weight relative to the total weight of the composition, said composition having a viscosity at 25 C of at least 0.6 Pa.s.

  In particular, the nature and / or the amount of said thickening agent are such that, in response to a non-chemical action, especially a mechanical action, prior to or simultaneously with the application of the composition to the nails, the viscosity of the composition can be reversibly lowered to a value not exceeding 0.4 Pa.s, preferably to a value not exceeding 0.3 Pa.s.

Viscosity measurement

  The viscosity of the composition is measured at 25 ° C. using a Rhéomat 180 (Company LAMY) equipped with a mobile MS-R1, MS-R2, MS-R3, MS-R4 or MS-R5 chosen according to the consistency of the composition, rotating at a speed of rotation of 200 t.min-1. The measurement is taken after 10 minutes of rotation. The viscosity measurements are carried out at most 1 week after manufacture.

  The nail polish of the invention may have a viscosity ranging from 0.6 to 20 Pa.s, preferably from 0.7 to 15 Pa.s and better still from 0.75 to 10 Pa.s.

  The invention also relates to a cosmetic nail makeup method of applying to the nails a composition as defined above.

  The invention also relates to the use of a composition as defined above to obtain a film of varnish deposited on the nails, homogeneous and having good gloss properties and / or good coverage.

  By cosmetically acceptable medium is meant a non-toxic medium that can be applied to the keratin materials of human beings, in particular the nails.

  The composition according to the invention advantageously has a thixotropic character. By composition having a thixotropic character, or thixotropic composition, is meant, in the sense of the invention, a structured composition that fluidifies (especially its viscosity decreases) when it applies a non-chemical action, particularly mechanical, and which recovers any or part of its initial viscosity after a sufficient rest time which may be longer or shorter, at room temperature. In particular, the composition according to the invention has the following properties: the composition has a rheofluidifying character, that is to say that the viscosity of the composition decreases when increasing shears are applied to the composition; - The composition after the application of intense shear fluidifies (especially its viscosity decreases). The viscosity, the consistency and the elasticity of the composition, after its destructuration, in particular after a rest period of one minute after having applied the shear, are lower than those of the composition before the application of the intense shearing. ; - The composition regenerates partially or completely its initial structure after a sufficient rest time and the restructuring of the composition is delayed in time .. The restructuring of the composition does not therefore occur instantly but deferred manner over time. A definition of thixotropic composition is particularly indicated in the book "Understanding rheology - From the circulation of blood to the setting of concrete" by P. Coussot and J. L. Grossiord, EDP Science, 2002, pages 16 and 17.

  The thixotropic behavior of the composition can in particular be characterized by measuring the viscosity of the composition at low shear rate and then at high shear rate, as described below: These measurements are carried out on an imposed stress rheometer, Haake RheoS. tress RS 600 from ThermoRhéo, equipped with a thermostatic bath and a stainless steel mobile with cone / plane geometry, diameter 35 mm and angle 2, with a gap of 0.104 mm. Both surfaces are sandblasted to limit slippage to the walls. An anti-evaporation device (solvent bell) is used.

  The measurements are made at 20 ° C. At first, the sample is warmed to 20 ° C. for 300 seconds (without any shear applied).

  a) Increasing stresses are applied to the sample starting from an initial stress of 0 Pa to arrive at a final stress of 500 Pa, the stresses being applied only once (which corresponds to a ramp in shearing ranging from 10-1 s -1 to 400 s -1). The evolution of the viscosity ri is then plotted as a function of the shearing gradient Y. The measurement is carried out on 40 logarithmically distributed points. It is expected to obtain a stable value between each constraint, the waiting time between each constraint being 30 s. b) The composition is then de-structured by applying a continuous shear corresponding to a stress of 500 Pa (corresponding to a shear of 400 s -1) for 30 seconds. c) We apply to the sample decreasing stresses starting from an initial stress of 500 Pa to arrive at a final stress of 0 Pa, the stresses being applied only once. We take the measurement on 40 points distributed logarithmically. It is expected to obtain a stable value between each constraint, the waiting time between each constraint being 30 s. The shear gradient range is from 400 s -1 to 10 3 s -1. In the range considered, the maximum value of 400 s -1 must be taken into account with an uncertainty of measurement of 10 s'. The evolution of the viscosity II is then plotted as a function of the shear gradient. The sample is then subjected to a constraint imposed by 10 Pa for 1000 s, and the evolution of the viscosity as a function of time is measured. e) Again applying increasing stresses to the sample starting from an initial stress of 0 Pa to arrive at a final stress of 500 Pa, the stresses being applied only once (which corresponds to a shear gradient ranging from 102 s -1 to 300 s -1). The analysis of the results is done through the graphical representation of the evolution of the viscosity, noted as a function of the shear gradient, noted. The viscosity r 1, the shear gradient and the imposed stress T being connected to each other by the relationship r Y = - 17 The composition is such that it has a viscosity, as measured during step e), at a shear rate of 4.10-2 s-1, ranging from 102 to 104 Pa.s, more preferably from 5.102 to 5.103 Pa.s, more preferably from 600 to 4000 Pa.s. The rheofluidifying character of the composition is characterized in particular by a difference (viscosity measured in step e), at a shear rate of 100 s-1-viscosity measured in step e), at a shear rate of 4.10. 2 s-1), ranging from 10 to 105 Pa.s, more preferably from 102 to 104 Pa.s. The thixotropic behavior of the composition is characterized by a viscosity difference measured at a shear rate of 1 s 1 between step c) and step e) (viscosity measured during step c) at a rate of shear of 1 s-1 - viscosity measured during step e) of at least 1 Pa.s, preferably at least 10 Pa.s, better still at least 20 Pa.s, still better at least 30 Pa.s, preferably at least 40 Pa.s. In particular, the difference in viscosity measured at a shear rate of 1 s' between step c) and step e) is the difference (viscosity measured during step c) at a shear rate of 1 s-1 - viscosity measured during step e) ranging from 1 to 1000 Pa.s, better still from 20 to 500 Pa.s, in particular from 40 to 200 Pa.s. Y-d) Measurement of viscoelastic characteristics

  The compositions in accordance with the invention advantageously have a viscoelastic behavior, with a predominant elastic nature. In general terms, a material is said to be viscoelastic when, under the effect of shearing, it has both the characteristics of an elastic material, ie capable of storing energy and the characteristics of a material viscous, ie able to dissipate energy.

  More particularly, the viscoelastic behavior of the compositions according to the invention can be characterized by its stiffness modulus G *, its elasticity S and its flow threshold Tc; these parameters are defined in particular in the book Initiation to rheology, G. Couarraze and J.L. Grossiord, 2nd edition, 1991, Edition Lavoisier-Tec 1 Doc.

  The measurements are carried out on an imposed stress rheometer, Haake RheoS-tress 600 from ThermoRhéo, equipped with a thermostatic bath and a stainless steel mobile with plane / plane geometry, the plane having a diameter of 20 mm and an entre-fer (distance between the lower plane-called stator plane - on which is deposited the composition and the upper plane - called rotor plane) of 1 mm. The 2 planes are striated to limit sliding phenomena on the walls of the planes. An anti-evaporation device (solvent bell) is used.

  The measurements are made at 20.degree. C. The composition is subjected to a harmonic shear according to a stress T (t) varying sinusoidally according to a pulse w (w = 2f-Iv), where v is the frequency of the shear applied. . The stress T (t) and the strain y (t) are respectively defined by the following relations: z (t) = ro cos (wt) 7 (t) = yo cos (w • t ù 8). maximum amplitude of the stress and yo being the maximum amplitude of the deformation. est is the phase shift angle between the stress and the strain and G * corresponds to the ratio To on yo. The measurements are made at a fixed frequency of 1 Hz (v = 1 Hz).

  In a first step, the sample is brought to temperature at 20 ° C. for 300 seconds. Then increasing stresses are applied to the sample starting from an initial stress equal to 0.01 Pa to arrive at a final stress of 1000 Pa, to go up to the destruction of the sample (the constraints not being applied only once). We measure the evolution of the modulus of rigidity G * (corresponding to the ratio of To on y0.) And the phase shift 8 (corresponding to the phase angle of the applied stress with respect to the measured strain) as a function of the stress T (t) applied. In particular, the deformation of the composition is measured for the stress zone in which the variation of modulus of rigidity G * and of elasticity 8 is less than 7% (area of microdeformations) and the parameters known as plateaux Gp and 8p. The threshold stress Tc (the composition not flowing under its own weight, the threshold stress corresponding to the minimum force that it is necessary to apply to the composition to cause its flow) is determined from the curve G * = f (T). It is defined as the value of T at the intersection of the two tangents to the curve G * = f (T) for the low values of T and for the high values of T.

  The viscoelastic behavior of the compositions according to the invention is characterized in particular by a plateau rigidity modulus Gp greater than 100 Pa, preferably greater than 500 Pa. Therefore, the subject of the invention is also a nail polish composition comprising a cosmetically acceptable medium and at least one thixotropic thickening agent, said composition having a plateau rigidity modulus Gp greater than 100 Pa.

  In particular, the compositions according to the invention have a plateau modulus of stiffness Gp ranging from 100 to 2 × 10 6 Pa.s, preferably from 5 × 10 to 104 Pa.s, better still from 800 to 4000 Pa.s, and in particular from 1000 to 3000 Pa.s.

  The compositions in accordance with the invention may also have an elasticity 8p ranging from 2 to 30, and in particular ranging from 15 to 25 and a flow threshold T ,, ranging from 10 Pa to 3.104 Pa, and in particular ranging from 30 Pa at 500 Pa and better 50 to 200 Pa.

COLORING AGENT

  The coloring agent is chosen from magnetic substances, diffractive pigments, interference pigments, reflecting particles and their mixtures.

  The coloring agent may be present in a content greater than or equal to 2.5% by weight, preferably greater than or equal to 3% by weight, better still, greater than or equal to 3.5% by weight, and even better, greater than or equal to 4% by weight, up to 20%, preferably up to 15% by weight, and more preferably up to 10% by weight relative to the total weight of the composition.

Al Magnetic particles

  By magnetic particles, also called magnetic bodies, are meant particles having a magnetic susceptibility, that is to say sensitive to the action of a magnetic field and tending for example to align with the field lines.

  The magnetic particles may comprise any magnetic material having sensitivity to the lines of a magnetic field, whether produced by a permanent magnet or from an induction, this material being for example chosen from nickel, cobalt, iron , their alloys and oxides, especially Fe3O4, and also gadolinium, terbium, dysprosium, erbium, their alloys and oxides. The magnetic material may be soft or hard type. The magnetic particles may or may not have a multilayer structure, comprising at least one layer of a magnetic material, such as, for example, iron, nickel, cobalt, their alloys and oxides, especially Fe3O4. The magnetic particles preferably have an anisotropic character. The magnetic particles are preferably aspherical, having for example an elongate shape. Thus, when these particles are subjected to a magnetic field, they tend to orient themselves with their longitudinal axis in the alignment of the field lines, and undergo a change of orientation which results in a change of appearance from of the anisotropy and creating the pattern (s). When the magnetic particles are substantially spherical, preferably their appearance is inhomogeneous, so that a change of orientation induces a change in appearance. The composition may take a state preventing any further change of orientation of the magnetic particles under the effect of a magnetic field after a given drying time.

  The size of the magnetic particles is for example between 1 nm and 700 μm, for example between 1 μm and 500 μm, more preferably between approximately 10 μm and approximately 150 μm. By dimension, we denote the dimension given by the statistical size distribution to half of the population, called D50.

  The magnetic particles may comprise magnetic pigments. Particularly suitable pigments are pearlescent agents containing Fe304 iron oxide. Pigments having magnetic properties are, for example, those sold under the trade names Colorona Blackstar Blue, Colorona Blackstar Green, Colorona Blackstar Gold, Colorona Blackstar Red, Microna Matte Black (17437), Mica Black (17260), Colorona Patina Silver (17289) and Colorona Patina Gold (17288) from Merck, Gemtone Moonstone (G004) or Chroma-Lite Black (4498) from Engelhard. As another example of a magnetic pigment that may be included in the formulation of the composition, mention may be made of black iron oxide particles, for example those marketed under the name SICOVIT black E172 by the company BASF. The magnetic pigments may also comprise metal iron, in particular mild passivated iron, for example obtained from carbonyl iron by implementing the process described in US Pat. No. 6,589,331, the contents of which are incorporated by reference. These particles may comprise a layer of an oxide on the surface.

BI Interference Pigment

  The expression "interference pigment" denotes a pigment capable of producing a color by an interference phenomenon, for example between the light reflected by a plurality of superimposed layers of different refractive indices, in particular a high-layer layer-transfer. and low refractive indices. An interference pigment may for example have more than four layers of different refractive indices. The layers of the interference pigment may or may not surround a core, which may have a flattened shape or not. Nacres are examples of interferential pigments.

nacres

  By nacre, it is necessary to understand colored particles of any shape, iridescent or not, in particular produced by certain shellfish in their shell or else synthesized and which exhibit a color effect by optical interference. Examples of pearlescent agents that may be mentioned are pearlescent pigments such as iron oxide-coated titanium mica, bismuth oxychloride-coated mica, titanium mica coated with chromium oxide, titanium mica coated with a organic dye including the aforementioned type 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. As an illustration of nacres that can be introduced as interference pigment in the first composition, mention may be made of gold-colored pearlescent agents marketed 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); black nacres with a gold glint sold especially by ENGELHARD under the name Nu antique bronze 240 AB (Timica), blue nacres sold especially by MERCK under the name Matte blue (17433) (Microna), white nacres to silvery reflection sold especially by the company Merck under the name Xirona Silver and the golden-green orange-colored mother-of-pearl sold by Merck under the name Indian Summer (Xirona) and their mixtures. Interferential Reflective Particles These particles may be chosen from particles with a synthetic substrate at least partially coated with at least one layer of at least one metal oxide, chosen, for example, from titanium oxides, in particular TiO 2, in particular iron Fe 2 O 3, tin, chromium, barium sulfate and the following materials: MgF 2, CrF 3, ZnS, ZnSe, SiO 2, Al 2 O 3, MgO, Y 2 O 3, SeO 3, SiO, HfO 2, ZrO 2, CeO 2, Nb 2 O 5, Ta 2 O 5, MoS 2 and mixtures thereof or alloys.

  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. Particles with a glass substrate coated with a metal oxide, in particular TiO 2, are sold by the company Nippon Sheet Glass under the name Methashine. Goniochromatic Pigment For the purposes of the present invention, the term "goniochromatic pigment" denotes a pigment which makes it possible, when the composition is spread on a support, to obtain a color path in the plane a * b * of the corresponding CIE 1976 color space. a variation Dh of the hue angle h of at least 20 when the angle of view is varied from normal between 0 and 80, for a light incidence angle of 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 μm 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 pigment may be chosen, for example, from interferential multilayer structures and liquid crystal coloring agents. 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, SiO 2, Ge, Te, Fe 2 O 3, Pt, Va, Al 2 O 3, MgO, Y 2 O 3, S 2 O 3, SiO, HfO 2, ZrO 2, CeO 2, Nb 2 O 5, Ta 2 O 5, TiO 2, 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: Fe 2 O 3 / SiO 2 / Fe 2 O 3 / SiO 2 / Fe 2 O 3, a pigment having this structure being marketed under the name SICOPEARL by the company BASF; MoS2 / SiO2 / mica-oxide / SiO2 / MoS2; Fe 2 O 3 / SiO 2 / mica-oxide / SiO 2 / Fe 2 O 3; TiO 2 / SiO 2 / TiO 2 and TiO 2 / Al 2 O 3 / TiO 2, pigments having these structures being sold under the name XIRONA by the company Merck (Darmstadt). The liquid crystal coloring agents 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 pigment, it is also possible to use certain nacres, pigments with effects on synthetic substrate, in particular substrate type alumina, silica, borosilicate, iron oxide, aluminum, or interference flakes from a polyterephthalate film. The material may further comprise dispersed goniochromatic fibers. Such fibers may have a length less than 80 pm, for example.

C / Diffractive pigment

  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 structure which diffracts light. . Such a pigment is still sometimes called holographic pigment. A diffractive pigment may comprise a diffraction grating, capable of

  for example, to diffract in a defined direction a ray of incident monochromatic 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. We can usefully refer to the structure of diffracting pigments in the article Pigments Exhibiting Diffractive Effects by Alberto Argoitia and Matt Witzman, 2002, Society of Vacuum Coaters, 45th Annual Technical Conference Proceedings 2002. The diffractive pigment can be made with patterns having different profiles, in particular triangular, symmetrical or not, in crenellations, of constant width or not, sinusoidal, in staircase. The spatial frequency of the network and the depth of the patterns will be chosen 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 not, of the same linearization or not. 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, there may be mentioned Al, Ag, Cu, Au, Pt, Sn, Ti, Pd, Ni, Co, Rd, Nb, Cr, Fe and their materials, combinations, alloys and their doping by land. rare. 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 chosen 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. Other diffracting pigments are marketed under the names Metalure Prismatic by the company ECKART. Other possible structures are Fe / Al / Fe or Al / Fe / Al. The size of the diffractive pigment may be, for example, between 5 and 200 μm, more preferably between 5 and 100 μm, for example between 5 and 30 μm. The thickness of the diffractive pigment particles may be less than or equal to 3 μm, more preferably 2 μm, for example of the order of 1 μm. D / Piqments or Reflective Particles Reflective particles are particles whose size, structure, including the thickness of the layer or layers that constitute it and their physical and chemical nature, and the surface state, allow them to reflect the incident light. This reflection may, if necessary, have sufficient intensity to create on the surface of the composition or mixture, when it is applied to the support to make up, highlight points visible to the naked eye is ie brighter points that contrast with their surroundings while 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. These particles may have various forms, 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, they 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 including 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 as an example of reflective particles comprising a mineral substrate coated with a metal layer, there may also be mentioned particles comprising a borosilicate substrate coated with silver.

  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 a nickel / chromium / molybdenum alloy are sold under the name CRYSTAL STAR GF 550, GF 2525 by the same company. Particles comprising a metal substrate such as silver, aluminum, iron, chromium, nickel, molybdenum, gold, copper, zinc, tin, magnesium steel, bronze, titanium, said substrate being coated with at least one layer of at least one metal oxide such as titanium oxide, aluminum oxide, iron oxide, oxide cerium, chromium oxide, silicon oxides and mixtures thereof. By way of example, mention may be made of aluminum, bronze or copper powders coated with SiO 2 sold under the name VISIONAIRE by the company ECKART.

THICKENING AGENT

  The composition according to the invention comprises a thixotropic thickening agent in an amount sufficient to give the composition a viscosity at rest sufficient to give it its texture, and a thixotropic behavior. In particular, the nature and / or the amount of said thickening agent are such that, in response to a non-chemical action, especially a mechanical action, prior to or simultaneously with the application of the composition to the nails, the viscosity of the composition can be reversibly lowered to a value not exceeding 0.4 Pa.s, preferably to a value not exceeding 0.3 Pa.s.

  The thixotropic thickening agent may be present in a content greater than or equal to 1.7% by weight, for example ranging from 1.7% to 15% by weight, relative to the total weight of the composition, preferably greater than or equal to at 2% by weight, ranging for example from 2% to 10% by weight, preferably ranging from 2% to 7.5% by weight. The thickening agent may be chosen from hydrophilic or organophilic clays, hydrophilic or hydrophobic pyrogenic silicas, elastomeric organopolysiloxanes and mixtures thereof.

  The clays are silicates containing a cation which may be chosen from calcium, magnesium, aluminum, sodium, potassium and lithium cations and their mixtures. By hydrophilic clay is meant a clay capable of swelling in water; this clay swells in water and forms after hydration a colloidal dispersion.

  Examples of such products include clays of the smectite family such as montmorillonites, hectorites, bentonites, beidellites, saponites, as well as the family of vermiculites, stevensite, chlorites . These clays can be of natural or synthetic origin.

  As hydrophilic clay, there may be mentioned smectites such as saponites, hectorites, montmorillonites, bentonites, beidellite and in particular synthetic hectorites (also called laponites) such as the products sold by Laporte under the name Laponite XLG, Laponite RD, Laponite RDS (these products are sodium and magnesium silicates and in particular sodium, lithium and magnesium silicates); bentonites, such as the product sold under the name Bentone HC by Rheox; magnesium and aluminum silicates, in particular hydrated silicates, such as the products sold by Vanderbilt Company under the name Veegum ultra, Veegum HS and Veegum DGT, or else calcium silicates and in particular the synthetic form sold by the company under the name The organophilic clays are clays modified with chemical compounds making the clay swellable in the solvent media.

  The clay may be selected from montmorillonite, bentonite, hectorite, attapulgite, sepiolite, and mixtures thereof. The clay is preferably a bentonite or a hectorite.

  The organophilic clays are clays modified with a chemical compound chosen from quaternary amines, tertiary amines, amino acetates, imidazolines, amine soaps, fatty sulphates, alkyl aryl sulphonates, amine oxides, and mixtures thereof.

  As organophilic clays, mention may be made of quaternium-18 bentonites such as those sold under the names Bentone 3, Bentone 38, Bentone 38V by Elementis, Tixogel VP by United catalyst, Claytone 34, Claytone 40, Claytone XL by the company Southern Clay Company; stearalkonium bentonites such as those sold under the names Bentone 27V by Elementis, Tixogel LG by United Catalyst, Claytone AF, Claytone APA by Southern Clay; quaternium-18 / benzalkonium bentonite such as those sold under the names Claytone HT, Claytone PS by Southern Clay.

  The hydrophilic pyrogenic silicas can be obtained by high temperature hydrolysis of a volatile silicon compound in an oxyhydrogen flame, producing a finely divided silica. Hydrophilic silicas have a large number of silanol groups on their surface. Such hydrophilic silicas are for example sold under the names "AEROSIL 130", "AEROSIL 200", "AEROSIL 255", "AEROSIL 300", "AEROSIL 380" by the company Degussa, "CAB-O-SIL HS-5, "CAB-0-SIL EH-5", "CAB-O-SIL LM-1300", "CAB-O-SIL MS-550", "CAB-O-SIL M-5e" by Cabot.

  Hydrophobic pyrogenic silicas may be obtained by modifying the surface of the silica by a chemical reaction generating a decrease in the number of silanol groups, these groups possibly being in particular substituted with hydrophobic groups.

  The hydrophobic groups may be: trimethylsiloxyl groups, which are especially obtained by treatment of fumed silica in the presence of hexamethyldisilazane. Silicas thus treated are called "silica silylate" according to the CTFA (6th edition, 1995). They are for example marketed under the references "AEROSIL R812" by the company Degussa, "CAB-O-SIL TS-530" by the company Cabot. dimethylsilyloxyl or polydimethylsiloxane groups, which are especially obtained by treating fumed silica in the presence of polydimethylsiloxane or dimethyldichlorosilane. Silicas thus treated are called "Silica dimethyl silylate" according to the CTFA (6th edition, 1995). They are for example sold under the references "AEROSIL R972", "AEROSIL R974" by the company Degussa, "CAB-O-SIL TS-610", "CAB-O-SIL TS-720" by Cabot.

  The elastomeric organopolysiloxanes are generally partially or completely crosslinked and optionally of three-dimensional structure. The elastomeric organopolysiloxanes associated with a fatty phase are generally in the form of a gel consisting of an elastomeric organopolysiloxane associated with a fatty phase, included in at least one hydrocarbon oil and / or a silicone oil.

  They may be chosen in particular from the crosslinked polymers described in claim EP-A-0295886. According to this application, the organopolysiloxane elastomers are obtained by reaction of addition and crosslinking of at least: (a) an organopolysiloxane having at least two lower alkenyl groups per molecule

  (b) an organopolysiloxane having at least two hydrogen atoms bonded to one silicon atom per molecule; and (c) and a platinum catalyst.

  The elastomeric organopolysiloxanes associated with a fatty phase may also be chosen from those described in US Pat. No. 5,266,321, in particular from polyorganopolysiloxanes comprising R2SiO and RSiO1,5 units and optionally R3SiOo, 5 and / or SiO2 units in which the R radicals, independently of each other, denote a hydrogen, an alkyl such as methyl, ethyl or propyl, an aryl such as phenyl or tolyl, an unsaturated aliphatic group such as vinyl and where the ratio by weight of the units R2SiO on the units RSiO1.5 varies from 1/1 to 30/1;

  According to a preferred embodiment, the thixotropic thickening agent is chosen from organophilic modified clays such as hectorite modified with benzyl dimethyl ammonium stearate. According to an advantageous embodiment, the thixotropic thickening agent comprises, in addition to an organophilic modified clay, a hydrophilic fumed silica.

Additional thickening agent

  The composition according to the invention may further comprise an additional thickening agent other than the thixotropic thickening agents described above. This additional thickening agent is not able on its own to render the composition thixotropic (non-thixotropic thickener); it allows in particular to adjust the viscosity of the composition to obtain a homogeneous flow.

  The additional thickening agent may be chosen, according to the cosmetically acceptable medium of the composition, from: hydrophilic thickening agents such as guar gum, quaternized guar gum, nonionic guar gums, xanthan gums carob, scleroglucan, gellan, rhamsan, karaya, alginates, maltodextrin, starch and its derivatives, hyaluronic acid and its salts, poly (metha) crylates of glyceryl - polyvinylpyrrolidone polyvinyl alcohol, crosslinked polymers and copolymers of acrylamide, associative polymers and in particular associative polyurethanes, and organophilic thickening agents such as: alkylated guar gums (with C1-C6 alkyl group) as described in EP-A-708114; oil-forming polymers such as triblock or star polymers resulting from the polymerization or copolymerization of at least one monomer containing an ethylenic group, such as the polymers sold under the name Kraton; polyamide resins comprising alkyl groups having from 12 to 22 carbon atoms, such as those described in US-A-5783657. hydrophobic thickening agents, such as alkyl ethers of polysaccharides (in particular of which the alkyl group contains from 1 to 24 carbon atoms, preferably from 1 to 10, better still from 1 to 6, and more particularly from 1 to 3), such as those described in EP-A-898958.

  The additional thickening agent may be present in a content ranging from 0.1% to 20% by weight, relative to the total weight of the composition, and preferably ranging from 0.1% to 10% by weight.

Organic solvent medium

  The composition according to the invention may comprise an organic solvent medium comprising at least one organic solvent chosen from: ketones that are liquid at ambient temperature, such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone, acetone; alcohols which are liquid at room temperature, such as ethanol, isopropanol, diacetone alcohol, 2-butoxyethanol or cyclohexanol; 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; cyclic ethers such as γ-butyrolactone; short-chain esters (having from 3 to 8 carbon atoms in total) such as ethyl acetate, butyl acetate, methyl acetate, propyl acetate, isopropyl acetate isopentyl acetate, methoxypropyl acetate, butyl lactate; ethers which are liquid at ambient temperature, such as diethyl ether, dimethyl ether or dichiorodiethyl ether; alkanes which are liquid at ambient temperature, such as decane, heptane, dodecane or cyclohexane; alkyl sulphoxides such as dimethyl sulphoxide; aldehydes that are liquid at room temperature, such as benzaldehyde or acetaldehyde; ethyl 3-ethoxypropionate; carbonates such as propylene carbonate, dimethyl carbonate, acetals such as methylal; and their mixtures.

  The organic solvent medium may represent from 30 to 97% by weight and especially from 50 to 95% by weight relative to the total weight of the composition.

  The composition according to the invention may comprise an aqueous medium. The aqueous content of the composition may range from 5 to 95% by weight relative to the total weight of the composition, preferably from 50 to 70% by weight. Film-forming polymer The composition advantageously comprises at least one film-forming polymer. According to the present invention, the term "film-forming polymer" means a polymer capable of forming on its own or in the presence of an auxiliary film-forming agent, a continuous and adherent film on a support, in particular on keratin materials.

  Among the film-forming polymers that can be used in the composition of the present invention, mention may be made of synthetic polymers, of free radical type or of polycondensate type, polymers of natural origin, and mixtures thereof.

  The film-forming polymer may be chosen in particular from cellulose polymers such as nitrocellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, ethyl cellulose, or even polyurethanes, acrylic polymers, vinyl polymers, polyvinyl butyrals, alkyd resins, resins derived from aldehyde condensation products such as arylsulfonamide formaldehyde resins such as toluene sulfonamide formaldehyde resin, epoxy arylsulfonamide resins or ethyl tosylamide resins.

  As the film-forming polymer, RS 1/8 nitrocellulose can be used in particular; RS sec. ; 'Dried up. ; RS 5 sec. ; RS 15 sec. ; RS 35 sec. ; RS 75 sec .; RS 150 sec; AS 'A dry. ; AS '/ 2 sec. ; SSsec. ; SS '/ 2 sec. ; SS 5 sec., In particular marketed by the company HERCULES; the toluene sulfonamide formaldehyde resin "Ketjentflex MS80" from the company AKZO or "Santolite MHP", "Santolite MS 80" from the company Fontronno or "Resimpol 80" from the company PAN AMERICANA, the alkyd resin "BECKOSOL ODE 230-70-E "of the company DAINIPPON, the acrylic resin" ACRYLOID B66 "of the company ROHM & HAAS, the polyurethane resin" TRIXENE PR 4127 "from the company BAXENDEN.

  According to one embodiment of the invention, the film-forming polymer is a film-forming linear ethylenic block polymer, which preferably comprises at least a first block and at least a second block having different glass transition temperatures (Tg), said first and second sequences being interconnected by an intermediate sequence comprising at least one constituent monomer of the first block and at least one constituent monomer of the second block. Advantageously, the first and second sequences and the block polymer are incompatible with each other. Such polymers are described for example in EP 1411069 or WO04 / 028488.

  The film-forming polymer may be present in the composition according to the invention in a solids content ranging from 0.1% to 60% by weight, relative to the total weight of the composition, preferably ranging from 2% to 40% by weight. weight, and better from 5% to 25% by weight.

Auxiliary filming agent

  To improve the film-forming properties of the nail polish composition, an auxiliary film-forming agent may be provided. Such an auxiliary film-forming agent may be chosen from all the compounds known to those skilled in the art, as being capable of fulfilling the desired function, and in particular be chosen from plasticizers and coalescers of the polymer (s). film (s). Thus, the composition may further comprise at least one plasticizer and / or a coalescing agent. In particular, mention may be made, alone or as a mixture, of the usual plasticizers and coalescence agents, such as: glycols and their derivatives, such as diethylene glycol ethyl ether, diethylene glycol methyl ether, diethylene glycol butyl ether or else diethylene glycol hexyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol hexyl ether; glycol esters; propylene glycol derivatives and in particular propylene glycol phenyl ether, propylene glycol diacetate, dipropylene glycol ethyl ether, tripropylene glycol methyl ether and diethylene glycol methyl ether, propylene glycol butyl ether; esters of acids, in particular carboxylic acids, such as citrates, phthalates, adipates, carbonates, tartrates, phosphates, sebacates; oxyethylenated derivatives, such as oxyethylenated oils, especially vegetable oils, such as castor oil; and - their mixtures. The type and amount of plasticizing and / or coalescing agent may be selected by those skilled in the art based on their general knowledge. For example, the content of plasticizer and / or coalescence can range from 0.01% to 20% and in particular from 0.5% to 10% by weight relative to the total weight of the composition.

Spreading agent

  According to one embodiment, the composition according to the invention comprises a spreading agent chosen to promote the application of the composition to the nails. It can be chosen from linear or cyclic silicone oils, in particular those having a viscosities of 6 centistokes (6.10-6 m 2 / s), and having in particular 3 to 6 silicon atoms, these silicones possibly comprising one or more alkyl groups. or alkoxy having 1 or 2 carbon atoms. As silicone oil that can be used in the invention, mention may in particular be made of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, heptamethylhexyltrisiloxane, heptamethyloctyltrisiloxane, hexamethylisiloxane, octamethyltrisiloxane and decamethyltetrasiloxane. dodecamethyl pentasiloxane and mixtures thereof.

  The spreading agent may represent from 0.1 to 15% by weight relative to the total weight of the composition, preferably from 0.5 to 10% by weight and better still from 1 to 5% by weight.

Additional coloring matter

  The composition according to the invention may comprise, in addition to the coloring agents chosen from magnetic substances, diffractive pigments, interferential pigments, reflecting particles, at least one additional coloring agent, in particular which produces a color by absorption of at least part of the visible spectrum. coloring. These additional dyestuffs may be selected from water-soluble or liposoluble dyes, organic or inorganic pigments or hybrids. The dyeing agent may be a particulate compound or not. Fat-soluble dyes are, for example, Sudan Red, DC Red 17, DC Green 6, E3-carotene, soybean oil, Sudan Brown, DC Yellow 11, DC Violet 2, Orange DC 5, yellow quinoline. The water-soluble dyes are, for example, beet juice and methylene blue. The coloring agent may also be a lacquer or an organic pigment chosen from the materials below and their mixtures: cochineal carmine, organic pigments of azo, anthraquinone, indigo, xanthene, pyrenic, quinoline dyes triphenylmethane, fluoran, in particular D & C type pigments, organic lakes or insoluble salts of sodium, potassium, calcium, barium, aluminum, zirconium, strontium, titanium, acid dyes such as azo, anthraquinone, indigo, xanthene, pyrenic, quinolinic, triphenylmethane and fluoran dyes, these dyes possibly comprising at least one carboxylic or sulphonic acid group. 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 additional coloring agents may be present in a content ranging from 0.01% to 30% by weight, based on the weight of the composition, preferably from 1% to 10% by weight.

  The composition according to the invention may also comprise, in addition, one or more fillers, in particular in a content ranging from 0.01% to 50% by weight, relative to the total weight of the composition, preferably ranging from 0.01%. at 30% by weight. By fillers, it is necessary to include particles of any form, colorless or white, mineral or synthetic, insoluble in the medium of the composition regardless of the temperature at which the composition is manufactured. These fillers serve in particular to modify the rheology or the texture of the composition. The fillers can be mineral or organic of any shape, platelet, spherical or oblong, irrespective of the crystallographic form (for example sheet, cubic, hexagonal, orthorhombic, etc.). Mention may be made of talc, mica, silica, kaolin, polyamide (nylon) (Orgasol from Atochem), poly-R-alanine and polyethylene powders, tetrafluoroethylene (Teflon) polymer powders, lauroyllysine, starch, boron nitride, polymeric hollow microspheres such as those of polyvinylidene chloride / acrylonitrile such as Expancel (Nobel Industrie), acrylic acid copolymers (Polytrap from Dow Corning) and microbeads silicone resins (for example Toshiba's Tospearls), elastomeric polyorganosiloxane particles, precipitated calcium carbonate, magnesium carbonate and hydrocarbonate, hydroxyapatite, hollow silica microspheres (Silica Beads from Maprecos), microcapsules of glass or ceramic, metal soaps derived from organic carboxylic acids having from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, for example stearic acid zinc, magnesium or lithium ate, zinc laurate, magnesium myristate.

Other additives

  The composition may further include other ingredients commonly used in cosmetic compositions. Such ingredients may be chosen from spreading agents, wetting agents, dispersing agents, defoamers, preservatives, UV filters, active agents, surfactants, moisturizing agents, perfumes, neutralizers, stabilizers, antioxidants.

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

Process

  According to another aspect, the subject of the invention is a cosmetic nail-making process consisting in lowering the viscosity of a nail polish composition as described above, by means of a non-chemical action, simultaneously or prior to the application on the nails of said composition

  According to one embodiment, the method consists in applying to the composition in gel form packaged in a container, a non-chemical action, in particular a mechanical action, so as to thin and reduce the viscosity of said composition and allow its application to the nails . When the application stops the action, the composition in its conditioning, after a rest period, covers its initial texture of gel. According to another embodiment, the method consists in taking a sample of the composition in its packaging and then applying to said sample the non-chemical action so as to fluidize said composition simultaneously with its application to the nails.

  The non-chemical action may be chosen from thermal actions such as, for example, a heat source, mechanical actions such as an object via which a mechanical stress or shear is applied to the composition, and their associations. In particular, this object may be an applicator in the form of a brush, a spatula or a tip. Preferably, the non-chemical action is a mechanical action. The nail polish composition of the invention may be packaged in a container defining at least one compartment, said container being closed by a closure member. The container may be in any suitable form and may be, at least in part, of a material such as glass. However, materials other than glass can be used such as thermoplastic materials such as PP or PE or as a metal.

  The closure element can be coupled to the compartment by screwing in the closed position of the container. Alternatively, the coupling between the closure element and the container can be done other than by screwing, in particular by snapping.

  The container may be associated with an applicator which may be in the form of a brush consisting of at least one tuft of bristles. Alternatively, the applicator is in form other than a brush, for example in the form of a spatula or a foam tip.

  The examples which follow illustrate the invention in a nonlimiting manner. Unless otherwise indicated, the quantities indicated are percentages by mass.

  Example 1 Synthesis of pentaerythrityl benzoatelisophthalatelisostearate

  In a reactor equipped with mechanical stirring, an argon inlet and a distillation system, 227.5 g of benzoic acid, 72.8 g of isostearic acid and 118.3 g of pentaerythritol, and then heated gradually, under a gentle stream of argon, to 110-130 C to obtain a homogeneous solution. The temperature is then gradually increased to 180 ° C and held for about 2 hours. The temperature is again raised to 220 ° C. and maintained until an acid number of less than or equal to 1 is obtained, which takes about 18 hours. It is cooled to a temperature of between 100 and 130 ° C., then 91 g of isophthalic acid are introduced and heated again gradually to 220 ° C. for about 11 hours. 430 g of pentaerythrityl benzoate / isophthalate / isostearate polycondensate are thus obtained in the form of a thick oil which solidifies at room temperature.

  The polycondensate has the following characteristics: - Acid number = 12.7 - Hydroxyl value = 49 - -1.0o c = 25.4 Poises (ie 2540 mPa. $) - ratio between the number of moles of monocarboxylic acid aromatic and the number of moles of nonaromatic monocarboxylic acid: 7.28. 420 g of polycondensate obtained above are taken off, heated to 100-120 ° C. and 180 g of butyl acetate are slowly poured while stirring and then clarified by hot filtration on sintered n 2. After cooling to room temperature 600 g of 70% polycondensate solution in butyl acetate, in the form of a pale yellow viscous liquid and having a viscosity at 25 ° C of about 800 centipoise (mPa). Examples 2 and 3 : Nail varnish A gelled texture nail varnish (example 2 according to the invention) having a viscosity, measured according to the protocol indicated in the description, greater than 0.6 Pa.s and a nail polish are prepared: in liquid form according to the prior art (Comparative Example 3) whose viscosity is not measurable according to the protocol indicated above. The varnishes have the following composition (% by weight): Example 2 Example 3 (Invention) (Comparative)

  70% dry solution of the polymer 12,18 - of Example 1 in butyl acetate Nitrocellulose with isopropyl alcohol (visco-4,18 12,37 sity: E22 - 1/2 S) Nitrocellulose 30% isopropyl alcohol 12.7 - (IDYL E27 from Bergerac) Nitrocellulose 30% isopropyl alcohol (viscosity: E28 - 1/8 S) Nitrocellulose 30% isopropyl alcohol 0.004 1.63 (Azur E80 from Bergerac) 1.42 15.53 Glycerophthalic acid ester esterified with branched fatty acids in ethyl acetate at 2-70% (Beckosol ODE 230 70E from Dainippon Ink and Chemicals) Cyclopentadimethylsiloxane (DC245 fluid from Dow Corning ) 0.47-Polydimethylsiloxane 5 cSt (DC200 Dow Corning fluid) 3.3 1.23 Hectorite modified stearyl benzyl dimethyl ammonium (Elementis BENTONE 27 V) 0.4 - Hydrophilic fumed silica (Degussa Aerosil 200) 1.5 1.5 Nippon Sheet Glass (Metashine MC104ORY Titanium Coated Glass Particles) 1.5 1.5 Coated Glass Particles of titanium oxide (Nippon Sheet Glass Metashine MC104ORS) 0.8 0.8 Mica Titanium Oxide (Merck Timiron Super Gold) 0.0045 0.0045 Red 34 Lacquer Red 6 Lacquer 0.005 0.005 Ferric Blue 0.00009 0 , 00009 Isopropyl alcohol 1.23 3.58 Ethyl acetate 14.27 22.51 Acetyl tributyl citrate 7.31 1.73 Butyl acetate Qsp 100 Qsp 100 N-ethyl 0, P-toluenesulfonamide 4.85 Citric acid , 1 H2O 0.13 0.05 The stability of the formulas over time can be evaluated by placing one vial of each formula in an oven at 45 C for 2 months, then visually observing the evolution of the homogeneity of the formula in time. The observer assigns a score ranging from 0 to 5 after 2 months at 45 C, (0 = maximum sedimentation, 5 = no sedimentation).

  The stability of the nail polish according to the invention did not change after 2 months at 45 ° C. (no sedimentation of the pigments), whereas the conventional nail polish in liquid form has a sedimentation of the pigments at the bottom of the flask and a non-homogeneous color.

Claims (8)

  1. A nail polish composition comprising a cosmetically acceptable medium, at least one thixotropic thickening agent, at least one coloring agent chosen from magnetic substances, diffractive pigments, interference pigments, reflecting particles and their mixtures, said agent coloring being present in a content greater than or equal to 2% by weight relative to the total weight of the composition, said composition having a viscosity at 25 C of at least 0.6 Pa.s.   2. Composition according to claim 1, characterized in that it has a viscosity ranging from 0.6 to 20 Pa.s, preferably from 0.7 to 15 Pa.s and better still from 0.75 to 10 Pa. s.   3. Composition according to one of the preceding claims, characterized in that the diffractive pigments are chosen from: - monolayer pigments comprising a reflective material selected from metals and their alloys, - the pigments having a multilayer structure comprising a layer of a reflective material selected from metals and their alloys and also from nonmetallic reflective materials, covered at least on one side with a layer of a dielectric material. pigments composed of a preformed dielectric or ceramic material such as a natural lamella mineral, or synthetic lamellae, and mixtures thereof.   4. Composition according to one of the preceding claims, characterized in that the interference pigments are selected from nacres, interferential reflective particles, goniochromatic pigments and mixtures thereof.   5. Composition according to the preceding claim, characterized in that the goniochromatic pigments are selected from interferential multilayer structures and liquid crystal coloring agents.   6. Composition according to claim 4, characterized in that the nacres are chosen from pearlescent pigments such as titanium mica coated with iron oxide, mica coated with bismuth oxychloride, titanium mica coated with aluminum oxide. chromium, titanium mica coated with an organic dye, pearlescent pigments based on bismuth oxychloride, mica particles on the surface of which are superimposed at least two successive layers of metal oxides and / or organic dyestuffs and their mixtures.   7. Composition according to claim 4, characterized in that the interferential reflective particles are chosen from particles with a synthetic substrate at least partially coated with at least one layer of at least one metal oxide.   8. Composition according to one of the preceding claims, characterized in that the reflective pigments are selected from - metal oxides, including synthetically obtained titanium or iron oxides, - multilayer structures comprising a natural or synthetic substrate, at less partially coated with at least one layer of a reflective material including at least one metal or metal material. 11. Composition according to any one of the preceding claims, characterized in that the magnetic bodies or particles comprise a magnetic material selected from the group consisting of: iron, nickel, cobalt, their alloys and oxides, in particular Fe304 . 12. Composition according to any one of the preceding claims, characterized in that the magnetic particles are aspherical. 13. Composition according to any one of the preceding claims, characterized in that the coloring agent is present in a content greater than or equal to 2.5% by weight, preferably greater than or equal to 3% by weight, more preferably greater than or equal to 3.5% by weight, and more preferably greater than or equal to 4% by weight relative to the total weight of the composition. 14. Composition according to any one of the preceding claims, characterized in that the coloring agent is present in a content of up to 20%, preferably up to 15% by weight, and better up to 10%. by weight relative to the total weight of the composition. 13. Composition according to one of the preceding claims, characterized in that the thixotropic thickening agent is selected from hydrophilic or organophilic clays, hydrophilic or hydrophobic pyrogenic silicas, elastomeric organopolysiloxanes and mixtures thereof. 14. Composition according to any one of the preceding claims, characterized in that the thixotropic thickening agent is chosen from organophilic modified clays such as hectorite modified with benzyl dimethyl ammonium stearate. 15. Composition according to any one of the preceding claims, characterized in that the thixotropic thickening agent further comprises a hydrophilic fumed silica. 16. Composition according to any one of the preceding claims, characterized in that the thickening thixotropic agent is present in a content ranging from 1.7% to 15% by weight, relative to the total weight of the composition, preferably ranging from from 2% to 10% by weight, preferably from 2% to 7.5% by weight. 17. Composition according to any one of the preceding claims, characterized in that it comprises at least one film-forming polymer. 18. Composition according to the preceding claim, characterized in that the film-forming polymer is present in a content ranging from 0.1% to 60% by weight, relative to the total weight of the composition, preferably ranging from 2% to 40%. by weight, and better still from 5% to 25% by weight. 19. Composition according to any one of the preceding claims, characterized in that it comprises at least one organic solvent. Composition according to the preceding claim, characterized in that the organic solvent represents from 30 to 97% by weight and especially from 50 to 95% by weight relative to the total weight of the composition. 21. Composition according to any one of the preceding claims, characterized in that it comprises at least one spreading agent chosen from linear or cyclic silicone oils, especially having a viscosity <6 centistokes (6.10-6 m2 / s). ). 22. Composition according to claim 21, characterized in that the spreading agent represents from 0.1 to 15% by weight relative to the total weight of the composition, preferably from 0.5 to 10% by weight and better from 1 to 5% by weight 23. Composition according to any one of the preceding claims, characterized in that it comprises at least one coloring material chosen from water-soluble dyes, pigments, pearlescent agents, flakes and their mixtures. 24. Composition according to the preceding claim, characterized in that the dyestuffs are present in a content ranging from 0.01% to 60% by weight, relative to the weight of the composition, preferably from 1% to 40% by weight. . 25. Use of a composition according to one of claims 1 to 24, to obtain a varnish film deposited on the nails, having good gloss properties and / or good coverage. 26. Cosmetic nail makeup method of applying to the nails a composition according to any one of claims 1 to 24.