WO2018073401A1

WO2018073401A1 - Pulverulent pigment composition comprising polymethyl methacrylate particles

Info

Publication number: WO2018073401A1
Application number: PCT/EP2017/076820
Authority: WO
Inventors: Aurélie CREUZÉ MOREL; Thomas Luce; Virginie Boulier
Original assignee: Sensient Cosmetic Technologies
Priority date: 2016-10-20
Filing date: 2017-10-20
Publication date: 2018-04-26
Also published as: FR3057869B1; FR3057870B1; FR3057870A1; FR3057869A1

Abstract

The invention relates to a pulverulent pigment composition comprising spherical polymethyl methacrylate particles having a monomodal or bimodal size distribution where each mode has: - a volume median diameter Dv₅₀ ^PMMA measured by laser diffraction of from 1 to 80 µm, and - a coefficient of variation of the volume diameter CV_V ^PMMA of less than 10%, the surface of said spherical particles being at least partially covered with polysiloxane resin and particles of at least one pigment, to the process for preparing same, and to the use thereof for the preparation of a cosmetic composition.

Description

Pigmented pulverulent composition comprising polymethyl methacrylate particles

The present invention relates to a pulverulent pigment composition useful for the preparation of a cosmetic composition, especially a make-up composition.

The cosmetic compositions generally include a pigment to impart the desired color / hue.

Users particularly appreciate cosmetic compositions, especially makeup, which can color with good colonelle intensity while maintaining transparency. This avoids having to apply large amounts of makeup and maintain a natural effect. The application of the cosmetic composition must cause a pleasant sensory effect on the application area (skin or hair). A soft-focus effect that hides or fills imperfections, wrinkles and / or fine lines is also sought after. In addition, a makeup composition must have good coverage and good color homogeneity.

The development of pigment compositions which are easily dispersed in the cosmetic compositions and which make it possible to confer on them the above effects is therefore necessary.

For this purpose, according to a first object, the invention relates to a pigmentary powder composition comprising spherical particles of polymethyl methacrylate having a mono- or bimodal size distribution, wherein each mode has:

a median diameter in volume Dv ₅₀ ^PMMA measured by laser diffraction from 1 to 80 μηι, and a coefficient of variation of the volume diameter CV _V ^PMMA less than 10%, where C _VV PMMA is _{QBTEN U PAR} | _{A FORM U} | _E.

_CVV PMMA _{= 1 00} * σ _ν ™ ^ΜΑ / D _mean ^PMMA

in which :

σ _ν ^ΡΜΜΑ is the standard deviation of the volume distribution of diameters measured with a Coulter counter, and

D _{v avg} ^PMMA is the volume mean diameter measured with a Coulter Counter, the surface of said spherical particles being at least partially covered with polysiloxane resin and particles of at least one pigment.

By "powder composition" is meant that the composition is in powder form. Typically, it contains less than 5% by weight of water, or even less than 2% water, preferably less than 1% water. The proportion of water can be measured by a Karl Fisher type apparatus. More generally, the pulverulent pigment composition typically comprises less than 10% by weight, especially less than 6% by weight, preferably less than 5% by weight of liquid components at 20 ° C.

In the present application, the particle dimensions extracted from the volume distribution (Dv ₅₀ , Dv ₁₀ , Dv ₉₀ , span) are measured by laser diffraction, for example with a Horiba laser granulometer LA750v2, preferably on the product dispersed in a medium. aqueous, such as water), an alcoholic medium, such as ethanol or an aqueous-alcoholic medium (this product being, as the case may be, the spherical particles of polymethylmethacrylate, the particles of pigment or the particles of the powdery composition pigment).

The standard deviation σ _ν of volume distribution of diameter is the mean squared deviation from the mean.

σ _ν and D _vm0 yen are measured with a counter Counter ("Coulter Counter"). In this method, the particles are added to an electrolyte solution (e.g. 0.9% NaCl aqueous solution) and analyzed using a Multisizer 3, based on the Coulter principle, typically with 30,000 to 40,000 particles by measure. A prior dilution of the samples to be analyzed may be necessary so that the particles pass in the form of isolated particles through the orifice separating the two chambers of the Counter counter.

Within the meaning of the application, by ^"PMMA" denotes a characteristic of PMMA spherical particles, by ^'p' ^9ment "denotes a characteristic of the pigment particles and" ^com P ° ^sltlon ", a characteristic is designated to the powdery pigment composition. For example, Dv ₅₀ ^PMMA refers to the Dv ₅₀ of spherical particles of polymethyl methacrylate. ₅ o dv dv denotes the ^compositlon ₅₀ particles of the pigment powdery composition thus takes account of the pigment particles on the surface of spherical particles of polymethyl methacrylate. Dv ₅₀ ^p ^'9ment dv denotes the ₅₀ pigment particles.

The pigmentary powder composition comprises spherical particles of polymethylmethacrylate.

By "spherical particle" of polymethylmethacrylate is meant a particle for which the ^aspect ratio κ ^ΡΜΜΑ (ratio of length / thickness, where length is the highest diameter of the particles and thickness is the smallest diameter) (" aspect ratio "in English) for the spherical particles of polymethylmethacrylate is 1.0 to 1.1, especially 1.0 to 1.03, preferably 1.0. The report of shape (and thus the lengths and thicknesses) of the spherical particles of polymethyl methacrylate κ ^ΡΜΜΑ is measured by scanning electron microscopy (SEM), typically on a representative average of 10 particles.

A powdery pigment composition prepared from spherical polymethyl methacrylate particles is generally softer to the touch, more transparent and more intense in color than a powdery pigment composition prepared from hemispherical polymethylmethacrylate particles.

"Polymethyl methacrylate particles" means that the particles comprise at least 50% by weight, in particular at least 60% by weight, preferably at least 90% by weight, for example at least 95% by weight of polymethylmethacrylate. methyl.

The specific surface area of the spherical particles of polymethyl methacrylate, as measured by BET, is generally from 0.01 to 50 m ² / g, in particular from 0.05 to 10 m ² / g, preferably from 0.1 to 1 m ² / g.

The spherical particles of polymethylmethacrylate used in the powdery pigment composition have a mono- or bimodal size distribution, that is to say that there may be respectively one or two modes (or size populations). The curve obtained by plotting the quantity (or proportion) of particles as a function of diameter by volume comprises one or two peaks (one or two modes).

Each mode has a median diameter in volume Dv ₅₀ ^PMMA from 1 to 80 μηι, in particular from 1 to 50 μηι, preferably from 5 to 40 μηι.

Each mode has a coefficient of variation of the volume diameter CV _V ^PMMA less than 10%. A powdery pigment composition prepared from particles having a CV _V ^{PMMA of} less than 10% is generally softer to the touch, more transparent, more hydrophobic and more intense in color than a powdery pigment composition prepared from particles having a CV. _V ^PMMA greater than 10 o / o.

Preferably, each mode has a ^PMMA span:

(Dv ₉₀ ^PMMA - Dv ₁₀ ^PMMA ) / Dv ₅₀ ^PMMA

from 0.8 to 2.0, typically from 0.8 to 1.2, in particular from 0.9 to 1.1, preferably from 0.95 to 1.05 and more preferably equal to 1.0.

Preferably, the coefficient of variation of the CV _V ^PMMA diameter of each mode is less than 5%, especially less than 3% and more preferably less than 2%.

According to a first alternative, the spherical particles of polymethyl methacrylate used in the pulverulent pigment composition have a distribution of monomodal size. There is then only one population of size characterized by a single average size. The volume median diameter Dv ₅₀ ^PMMA , the coefficient of variation of the CV _V ^PMMA diameter and the ^PMMA span of the mode respectively correspond to the Dv ₅₀ ^PMMA , the coefficient of variation of the CV _V ^PMMA diameter and the ^PMMA span of the polymethacrylate spherical particles. of the pulverulent pigment composition.

According to a second alternative, the spherical particles of polymethyl methacrylate used in the pulverulent pigment composition have a bimodal size distribution. There are then two populations of different particle sizes, each characterized by a Dv ₅₀ ^PMMA (Dv ₅₀ ^{mode1 PMMA} and Dv ₅₀ ^mode2PMMA) and a coefficient of variation of diameter cv _v ^PMMA (CV _v ^{mode1 PMMA} and cv _v ^mode2PMMA) with 1 μπι <Dv ₅₀ ^{mode1 PMMA} <80 μπι, 1 μπι <Dv ₅₀ ^mode2PMMA <80 μπι and Dv ₅₀ ^{mode1 PMMA} <Dv ₅₀ ^mode2PMMA (Dv ₅₀ ^{mode1 PMMA} is different from _Dv5o mode ₂ PMM _{A) and with}

< _{1 0} %. For example, _Dv5o modei PMMA _{can be between 1 μηΓ | and 2Q} ^ _for example equal to 5 μπι, and Dv ₅₀ ^mode2PMMA can be between 24 μm and 80 μηι, for example equal to 40 μηι. Preferably, the ratio _Dv5o mode ₂ PMMA /

PMMA _{is superior or equal} | _{at 1 2} , especially greater than or equal to 2, and more preferably greater than 5 and less than 10. _S p _an ^{mode1 PMMA} and _S p _an ^mode2PMMA may be identical or different, and are preferably from 0.8 to 1, 2, in particular from 0.9 to 1, 1, preferably from 0.95 to 1.05 and more preferably equal to 1.0. Preferably, the pigmentary powder composition having a bimodal size distribution comprises less than 40% by volume of mode 1 and at least 60% by volume of mode 2, with Dv ₅₀ ^{mode1 PMMA} <Dv ₅₀ ^mode2PMMA .

Generally, the viscosity of a cosmetic composition obtained from a bimodal powdered pigment composition is lower than that of a cosmetic composition obtained from a pigmented powder composition of monomodal distribution.

Generally, the composition comprises from 19.5 to 95% by weight, preferably from 29.5 to 90% by weight, more preferably from 39.5 to 85% by weight of spherical particles of polymethyl methacrylate relative to the total weight of the powdery pigment composition.

The powdery pigment composition comprises one or more pigments.

The pigment (s) present in the pulverulent pigment composition may (may independently) be an organic, inorganic or hybrid organic-inorganic pigment.

These are typically inorganic pigments, preferably a metal oxide. The inorganic pigment may, for example, be chosen from titanium dioxide, zinc oxide, zirconium or cerium oxides, aluminum oxide, as well as iron or chromium oxides, and manganese violet. ultramarine blue, chromium hydrate, ferric blue, and mixtures thereof. The pigments can be used as such or optionally surface-treated, in the form of surface-treated pigments or nanopigments surface-treated.

The preferred inorganic pigments are titanium dioxide, zinc oxide, zirconium dioxide, aluminum oxide and mixtures thereof, and preferably titanium dioxide or zinc oxide and mixtures thereof.

The specific surface area, as measured by BET, of the inorganic pigment is generally from 0.3 to 60 m ² / g and more generally from 0.3 to 17 m ² / g.

The organic pigment may for example be selected from carbon black, such as D & C black No. 2, red organic pigments, such as D & C Red No. 6, No. 7, No. 21, No. 27, No. ° 28, No. 30, No. 33, No. 36, No. 40, and Cochineal Carmine, blue organic pigments, such as copper phthalocyanine and FD & C Blue No. 1 lacquer, and organic pigments yellow, such as D & C Yellow No. 10, FD & C Yellow No. 5 and 6.

Generally, the composition comprises from 4.5 to 80% by weight, preferably from 9.5 to 70% by weight, more preferably from 14.5 to 60% by weight of pigment (s) relative to the total weight of the powdery pigment composition.

Generally, in the pigmentary powder composition, the mass ratio of pigment particles / spherical particles of polymethylmethacrylate is from 10/1 to 1/10, in particular from 10/1 to 4/5, in particular from 4/1 to 3 / 4, typically from 3/1 to 2/3, preferably 1/1. The mass ratio allowing optimum coverage of the surface of the spherical particles of polymethyl methacrylate by the pigment particles depends in particular on:

the shape of the pigment particles (the more the pigment particles are spherical, the more the mass ratio of pigment particles / spherical particles of polymethyl methacrylate making it possible to obtain an optimum coverage is low), and

- Dv ₅₀ ^PMMA (the higher the Dv ₅₀ ^PMMA , the lower the mass ratio of pigment particles / spherical particles of polymethyl methacrylate to obtain optimal recovery is low).

Typically, in the pigment powdery composition, the ratio of the volume median diameter Dv ₅₀ ^PMMA of polymethyl methacrylate spherical particles relative to the volume median diameter Dv ₅₀ ^p ^'9ment pigment particles (Dv ₅₀ ^PMMA ₅₀ ^parts ) is from 1 to 10,000, typically from 1 to 1,000, in particular from 1 to 100, more preferably from 1.5 to 40 and in particular from 1.8 to 25.

The smaller the spherical and small pigment particles (the lower the volume median diameter Dv ₅₀ ^% of the pigment is), the greater the surface ^coverage of the polymethylmethacrylate particles by the pigment particles, and hence more the hue of the cosmetic composition in which the powdery pigment composition is introduced is pronounced.

Each particle of the powdered pigment composition comprises a spherical particle of polymethylmethacrylate whose surface is at least partially coated with polysiloxane resin and pigment particles.

The particles of the pulverulent pigment composition have dimensions very close to those of the spherical particles of polymethyl methacrylate that it comprises, because the pigment particles have very small dimensions relative to the spherical particles of polymethyl methacrylate.

When the spherical particles of polymethyl methacrylate have a monomodal or bimodal size distribution, the particle size distribution of the powdery powder composition containing them is respectively monomodal or bimodal.

Generally, when polymethyl methacrylate spherical particles have a distribution of monomodal size, the volume median diameter Dv ₅ o ^compositlon of the pigment powdery composition is 60-1 10% of the volume median diameter Dv ₅₀ ^PMMA spherical particles polymethylmethacrylate it comprises. For example, a pulverulent pigment composition which comprises spherical particles of polymethyl methacrylate having a monomodal size distribution with Dv ₅₀ ^PMMA = 10 μπι has particles having a monomodal size distribution with 6 μπι <Dv ₅ o ^{mode1 composition} ≤ 1 1 μπη.

Generally, the _S pan ^composition :

composition composition ^ composition

particles of the pulverulent powder composition is 75% to 125% of the span ^PMMA of the polymethyl methacrylate spherical particles which it comprises.

Generally, the coefficient of variation of diameter by number of the particles of the pigment powdery composition cV ^composrtlon _n is less than or equal to 20%, which composition is obtained by the formula:

/ ~> composition composition /> composition

V _n - I UU U _n / U _n medium

in which : composition _is ^ y ^ ^ _ca deviation of the number distribution of diameters measured by scanning electron microscopy, and

Average D _number ^Compositlon is the number average diameter measured by scanning electron microscopy.

The _K- form ^ratio of each mode of the pulverulent powder composition is generally from 1.0 to 2.0, especially from ^1.0 to ^{1.8, preferably} from ^1.0 to ^1.6 , which also reflects the small proportion of aggregates in the pulverulent pigment composition, and therefore the good dispersibility properties of the pulverulent pigment composition in the cosmetic composition in which it will be introduced.

The aspect ratio (and therefore the lengths and thicknesses) of the pigment powder compositions _K ^composition, the diameter D _{n avg} in ^{com position} and the standard deviation a _n ∞ ^m ° ° ⁿ ^sili pigment powder compositions are measured by electron microscopy scanning (SEM), typically on a representative average of 10 particles. Due to the complexity of the powdery pigment composition (mono or bimodal distribution, presence of free pigment particles (not bound to spherical particles of polymethylmethacrylate) in small quantities), scanning electron microscopy is more suitable than laser diffraction. . For the same reason, it is more representative to determine the _{number of} ^compositions from diameter in number than diameter in volume.

Typically, the pulverulent pigment composition contains very few agglomerates, and less than 5% of the agglomerates have a size of more than twice the median diameter by volume. Dv ₅₀ ^PMMA of the spherical particles of polymethylmethacrylate (it being understood that when the distribution The size of the spherical particles of polymethylmethacrylate is bimodal, the Dv ₅₀ ^PMMA is the Dv ₅₀ ^mode2PMMA , ie the highest of the two Dv ₅₀ ^PMMA ). As used herein, "agglomerate" means a particle that comprises at least two spherical polymethacrylate particles bonded together by pigment particles and / or the polysiloxane resin. The less the pigmented powdery composition contains aggregates, the easier it will disperse in the cosmetic composition into which it will be introduced.

The pigmented powder composition comprises polysiloxane resin, which allows adhesion of the pigment particles to the surface of the spherical polymethyl methacrylate particles. Generally, the pulverulent pigment composition comprises from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight, of polysiloxane resin relative to the total weight of the pulverulent pigment composition.

The pulverulent pigment composition may comprise additives, for example:

an anti-caking agent (for example silica silylate) and / or

a hydrophilic agent that promotes the dispersibility of the pulverulent pigment composition in an aqueous cosmetic composition (for example phytic acid, dimethicone copolyol, sodium glycerophosphate, adipic acid or a mixture thereof, preferably phytic acid and / or dimethicone copolyol), or

a hydrophobic agent that promotes the dispersibility of the pulverulent pigment composition in an oily cosmetic composition (for example natural wax, lauroyl lysine, sodium cocoyl glutamate, L-cystine, lauroyl arginine or a mixture of these).

The proportion of this (these) additive (s) is generally less than 5% by weight relative to the weight of the pulverulent pigment composition.

Typically, the pulverulent pigment composition comprises (consists of):

from 4.5 to 80% by weight, preferably from 9.5 to 70% by weight, more preferably from 14.5 to 60% by weight, of pigment,

from 19.5 to 95% by weight, preferably from 29.5 to 90% by weight, more preferably from 39.5 to 85% by weight, of spherical particles of polymethyl methacrylate as defined above,

from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight of polysiloxane resin,

from 0 to 5% by weight of additives.

The pulverulent pigment composition is advantageously stable on storage. No degradation was observed after 6 months of storage at 20 ° C.

According to a second subject, the invention relates to a process for the preparation of the above-mentioned pulverulent powder composition, comprising a step of dry mixing of spherical particles of polymethyl methacrylate as defined above, particles of at least one pigment and polysiloxane resin or a polysiloxane resin precursor. By "dry mixing" is meant a mixture produced in the presence of less than 5% by weight, especially less than 3% by weight, for example less than 2% by weight of water relative to the mixture. The mixture is generally produced in the absence of an organic solvent, or even in the absence of a liquid compound at 20 ° C. (other than water).

This dry mix is typically carried out in a mixer-granulator with horizontal or vertical stirring shaft. For example, one can use a Lodige type device or a Guedu De Dietrich respectively. Using a mixer-granulator allows a homogeneous coating of the surface of the polymethyl methacrylate spherical particles by the pigment particles and minimizes the presence of agglomerates in the pulverulent pigment composition and their sizes.

The mixer-granulator may be provided with one or more lopper (s) to prevent the formation of agglomerates.

This dry mix usually lasts 5 minutes to 3 hours. The stirring speed is usually 50 rpm at 450 rpm. The temperature during dry mixing is typically 10 to 90 ° C.

It is possible to introduce into the dry blender:

spherical particles of polymethyl methacrylate,

- the pigment particles and

the polysiloxane resin or the polysiloxane resin precursor.

However, this embodiment where the three components are introduced at the same time generally leads to the formation of more aggregates than by introducing the polysiloxane resin or the polysiloxane resin precursor in a step of premixing with one other components. This is why the multi-step preparation process as detailed below is preferred.

According to a first alternative, the method comprises:

a step a1) of mixing the pigment particles and a polysiloxane resin precursor or polysiloxane resin to obtain a treated pigment, and then

optionally, a step b1) of grinding the treated pigment obtained in step a1), then

a step c1) of dry mixing of the treated pigment and spherical particles of polymethyl methacrylate.

According to a second alternative, the method comprises:

a step a2) of mixing the spherical particles of polymethyl methacrylate and a precursor of polysiloxane resin or of polysiloxane resin to obtain spherical particles of polymethyl methacrylate treated, then a step b2) of dry mixing of the spherical particles of polymethyl methacrylate treated and pigment particles.

According to a third alternative, the method comprises:

a step a3) of mixing the spherical particles of polymethyl methacrylate and a precursor P1 of polysiloxane resin or of polysiloxane resin to obtain spherical particles of polymethyl methacrylate treated,

a step b3) of mixing the pigment particles and a precursor P2 of polysiloxane resin or of polysiloxane resin to obtain a treated pigment,

optionally a step c3) of grinding the treated pigment obtained in step b3), then a step c3) of dry mixing the spherical particles of polymethyl methacrylate treated and the treated pigment,

the precursors P1 and P2 may be of identical or different natures,

steps a3) and b3) can be performed simultaneously or successively, and in any order.

Grinding of steps b1) and c3) defined above is preferably micronization. These grinding steps advantageously make it possible to significantly reduce the value of the ^composition Dv ₁₀ . The grinding thus makes it possible to shift the size distribution of particles to smaller sizes and to increase the proportion of small particles, which makes it possible to better coat the surface of the polymethyl methacrylate particles.

As used herein, "spherical particles of treated polymethyl methacrylate" or "treated pigment" means spherical particles of polymethyl methacrylate or pigment particles of which at least a portion of the surface is coated with polysiloxane resin. or a precursor of polysiloxane resin (or a mixture of precursor and resin).

In order to prepare a pulverulent pigment composition whose spherical particle size distribution of polymethylmethacrylate is bimodal, typically:

either the dry mixture, or the steps c1), a2) or a3) is carried out with spherical particles of polymethyl methacrylate whose size distribution is bimodal,

or two powdery pigment compositions are separately prepared by following the method described above, wherein the size distribution of the spherical polymethyl methacrylate particles of each powdery pigment composition is monomodal, each of these powdery pigment compositions having a Dv ₅₀ different ^PMMA , then mixing the two pulverulent pigment compositions obtained.

The method may comprise, after the dry mixing step of spherical particles of polymethyl methacrylate as defined above, particles of at least one pigment and polysiloxane resin or a polysiloxane resin precursor ( that is to say after step c1) of the method according to the first alternative after step b2) of the method according to the second alternative or after step c3) of the method according to the third alternative), a step d) surface treatment with an additive, especially as defined above.

The method employs a polysiloxane resin or a polysiloxane resin precursor.

In the case of polysiloxane resin, this can for example be applied by spraying.

When it is a polysiloxane resin precursor, the mixture with the other component (s), in particular the mixture of the steps a1), a2), a3) and b3) ci- above, can be done dry or wet. By "wet" is meant with more than 5% by weight of water relative to the weight of the mixture. The dry route is preferred to avoid the formation of aggregates.

The polysiloxane resin precursor is generally an alkylalkoxysilane, an alkoxysilane, an alkylalkyloxysilane or an acyloxysilane, wherein the alkyl, alkoxy and acyloxy groups generally independently contain 1 to 13 carbon atoms. Typically, the polysiloxane resin precursor has the following formula (I):

(R ¹ ) _n -Si - (XR ² ) ₄ - _n (I)

in which :

each X independently represents -O- or O- (C = O) -,

n represents an integer of 0 to 3,

each R ² independently represents a linear, branched or cyclic alkyl comprising from 1 to 12 carbon atoms, a linear, branched or cyclic alkenyl comprising from 1 to 12 carbon atoms, an aryl comprising from 6 to 12 carbon atoms or a alkylaryl comprising from 7 to 12 carbon atoms,

each R ¹ independently represents a linear, branched or cyclic alkyl comprising from 1 to 12 carbon atoms, a linear, branched or cyclic alkenyl comprising from 1 to 12 carbon atoms, an aryl comprising from 6 to 12 carbon atoms or a alkylaryl comprising 7 to 12 carbon atoms, said alkyl, alkenyl, aryl or arylalkyl being optionally substituted by one or more groups selected from -OH, -NR ³ R ⁴ R ⁵ , - (OCH ₂ -CH ₂ ) p R ⁸ , oxiranyl and / or said alkyl, alkenyl or arylalkyl being optionally interrupted by one or more groups selected from S, O, - (C = O) -O-, -O- (C = O) - and -NR ⁶ R ⁷ -,

R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ independently represent H, linear, branched or cyclic alkyl comprising from 1 to 6 carbon atoms, linear, branched or cyclic alkenyl comprising from 1 to 6 carbon atoms,

R ⁸ represents OH or a linear, branched or cyclic alkyl comprising from 1 to 6 carbon atoms,

p represents an integer from 1 to 50.

Preferably, in formula (I):

- all Xs represent O, and / or

- n represents 3, and / or

each R ² independently represents a linear, branched or cyclic alkyl comprising from 1 to 12 carbon atoms or a linear, branched or cyclic alkenyl comprising from 1 to 12 carbon atoms, preferably a linear or branched alkyl comprising from 1 to 6 carbon atoms,

each R ¹ independently represents a linear, branched or cyclic alkyl comprising from 1 to 12 carbon atoms, a linear, branched or cyclic alkenyl comprising from 1 to 12 carbon atoms, an aryl comprising from 6 to 12 carbon atoms or a alkylaryl comprising from 7 to 12 carbon atoms, preferably a linear or branched alkyl comprising from 1 to 6 carbon atoms,

or

each R ¹ independently represents a linear or branched alkyl substituted with one or more groups selected from -OH, -NR ³ R ⁴ R ⁵ , - (OCH ₂ -CH ₂ ) _p -R ⁸ , oxiranyl and said alkyl being optionally interrupted by one or more groups selected from S, O, - (C = O) -O-, -O- (C = O) - and -NR ⁶ R ⁷ -, and / or

p represents an integer from 2 to 25, for example 12.

Among the usable precursors include methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, trimethoxysilane, isobutyltrimethoxysilane, phenyltrimethoxysilane, n-octyltriethoxysilane, aminopropyltriethoxysilane, aminoethylaminopropyltrimethoxysilane the aminoethylaminopropyltrimethoxysilane benzyl, the γ-methacryloxypropyltrimethoxysilane, v-glycidoxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, v-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, mercaptopropyltriethoxysilane, γ-ureidopropyltriethoxysilane. Such compounds are commercially available, for example from Dow Chemical or can easily be prepared.

According to a third object, the invention relates to the pigmentary powder composition that can be obtained by the process described above.

According to a fourth subject, the invention relates to the use of the powdery pigment composition for introduction into a cosmetic composition (or for the preparation of a cosmetic composition), as well as a cosmetic composition comprising the powdery pigment composition defined hereinbelow. above.

The pulverulent pigment composition according to the invention corresponds to a

"All-in-one product" adapted to be introduced into a cosmetic composition. The pulverulent pigment composition according to the invention can be easily dispersed in a cosmetic composition, without the formation of agglomerates, and therefore without it being necessary to grind the cosmetic composition. The pulverulent pigment composition according to the invention has a very hydrophobic character which makes it particularly suitable for the preparation of cosmetic compositions comprising an oily continuous phase.

Cosmetic compositions, especially make-up compositions, prepared from the pulverulent pigment composition make it possible to color with good colonelle intensity while maintaining transparency. The spherical particles of polymethylmethacrylate it contains have a ball rolling effect during application, which causes a pleasant sensory effect on the area of application. The use of spherical particles of polymethyl methacrylate having a ^PMMA span as defined above (monodisperse particles or mixture of monodisperse particles) induces not only a soft-focus effect which makes it possible to attenuate the imperfections present. on the area of application (hide wrinkles and / or fill in fine lines for example), but also an increase in brightness and colonelle intensity.

A cosmetic composition prepared from a pulverulent pigment composition according to the invention generally has:

i. a softer feel and is smooth, and / or

ii. a more transparent appearance due to the fact that the pigment particles are distributed homogeneously on the surface of the spherical particles of polymethylmethacrylate, and / or

iii. higher brightness and color intensity, and / or

iv. color homogeneity, and / or

v. improved coverage, relative to a cosmetic composition prepared by separately introducing spherical particles of polymethylmethacrylate and pigment particles. The coverage can be evaluated by comparing the transmittance, the haze (also called "haze") and the brightness measured by a haze meter (Haze-gard i 4775 (BYK).) The homogeneity of color can notably be evaluated with a microscope or by colorimetric measurements by CIE L ^* a ^* b ^*. the invention also relates to the use of a pigment pulverulent composition according to the invention to improve the opacity and / or color uniformity of a cosmetic composition comprising particles spherical polymethylmethacrylate and particles of at least one pigment.

The cosmetic composition typically comprises the pulverulent pigment composition as defined above and at least one cosmetically acceptable excipient. The weight ratio of the powdery composition relative to the weight of the cosmetic composition is, for example, from 0.1 to 20%, and preferably from 5 to 15%.

The cosmetic composition may be in the form of a monophasic or biphasic lotion, a water-in-oil or oil-in-water emulsion, a hydrophilic or lipophilic gel or a powder.

Typically, the cosmetic composition is a makeup composition, preferably chosen from a foundation, a colored cosmetic composition for the skin, a lipstick, a nail polish, or an eyeshadow, a hair make-up, or a dry shampoo.

The examples and figures below illustrate the invention.

Figure 1: Photo taken in SEM (JEOL JSM-6010 PLUS / LA, with an acceleration voltage of 10 keV, and electron beam size of 40) of the composition 3b (Example 1 .5).

FIG. 2: Brookfield viscosities (in cPs) as a function of the speed of rotation (in revolutions / minutes) for the foundation FDT1 according to the invention (diamonds) and FDT2 (comparative) (round) (example 2). For each foundation, there are two viscosity values per speed, one corresponding to the measurement when the speed of rotation is increased and the other to the measurement when the speed of rotation is decreased.

In the following tables, the proportions are by weight relative to the total weight of the composition in question. Example 1: Powdery component compositions

1.1. Preparation of pigmentary powder compositions

The spherical particles of polymethyl methacrylate (in the tables below, PMMA means spherical particles of polymethyl methacrylate) (Sensient Cosmetic Technologies) have a median diameter in volume Dv ₅₀ ^PMMA of:

- 20 μηι (only for the powdery pigment compositions 7a, 7b, 7c and 7d, and CV20 below), or

10 μηι (for all other examples, except particles "Covabead PMMA" of paragraph 1 .9 below),

and a coefficient of variation of the CV _V ^PMMA diameter strictly less than 5%. They contain between 60 and 100% by weight of polymethyl methacrylate and less than 100 ppm of residual methyl methacrylate.

The pigments are provided by Sensient Cosmetic Technologies.

The osmosis water is produced using filter cartridges ranging from 10 μηι to 0.2 μηι from Hycoma.

The polysiloxane resin precursor (hereinafter P) used is octyltriethoxysilane (DYNASYLAN OCTEO) which comes either from Univar or from Safic Alcan with a purity greater than 98% by weight.

Silica Silylate VM2270 (anti-caking agent) comes from Univar.

The nature and the process for preparing the pigments used in the following experiments are described in Table 1.

Pigment Color Nature Preparation process

LC987

pigment as it is

(comparative)

LC987EM Oxide

White micronized pigment

(comparative) Titanium

LC987ASE pigment treated with P then

(pigment treated) micronized

LC182

pigment as it is

(comparative)

Yellow

LC182ASE

Treated by P then micronized

(processed pigment)

LC381 EM

micronized

(comparative)

Red Iron Oxide

LC381 ASE

Treated by P then micronized

(processed pigment)

LC990

pigment as it is

(for comparative)

Black

LC990ASE

Treated by P then micronized

(processed pigment)

Table 1: Nature and process for the preparation of the pigments used in the experiments

Steps a1), b1) and c1) described above were used to prepare the pigmentary powder compositions according to the invention.

Step a1): mixing the pigment and a polysiloxane resin precursor to obtain a treated pigment

The pigments treated with P were obtained as follows:

The surface treatment of the pigments with the precursor P-octyltriethoxysilane was carried out in the dry or wet process.

The pigment was introduced into a mixer-granulator type Lodige. Osmosis water was then added dropwise (at 1% by weight relative to the total mixture). The mixture was stirred at a speed of 17 rpm / min + stirrers for 5 minutes. The octyltriethoxysilane precursor P was slowly introduced at 2% by weight compared to the total mixture. The mixture was stirred at a speed of 1 17 rpm in the presence of coulters and swimmers for 10 minutes.

The reactor was inerted with nitrogen and then heated at 90 ° C. for 3 hours, except for the yellow pigment LC182 for which the process was adjusted over a period of 6 hours. During this heating phase, agitation was at 60 rpm, and the swimmers were cut. Step b1): micronization

The micronization of the pigments to obtain the EM and ASE grades was carried out using the air jet micronizer (OM15 Micronizer from Sturtevant).

The feed rate was adjusted to prevent clogging by adjusting the motor driving the worm between 50 and 600 revolutions / min. Chamber pressure was adjusted between 6 and 8 bar depending on the pigment. The pressure on the supply side was set at 5 bars.

Step c1): dry mixing of the treated pigment and the spherical particles of polymethyl methacrylate

Powdery pigment compositions were obtained after 30 minutes of mixing the treated pigment and the spherical particles of polymethyl methacrylate in a Lôdige apparatus, set at a speed of 1 17 rev / min in the presence of coulters and swimmers.

1.2. 1.2. Methods used for the physico-chemical characterization of powdery pigment compositions

Electron Scanning Microscopy (SEM)

Samples of powdery pigment compositions were metallized with a gold / palladium source under vacuum for 10 minutes with an intensity of 10 mA and a voltage of 1.2 kV.

They were then analyzed with a JEOL scanning electron microscope

JSM-6010 PLUS / LA, with an acceleration voltage of 10 keV, and electron beam size of 40.

Granulometre Analysis

1) By laser granulometry

Granulometric analyzes of the liquid-phase compositions were carried out with a Horiba LA750v2 laser granulometer for all the examples, except for those of paragraph 1 .9 where the granulometer was a Horiba LA920v2. The measuring medium was ethanol, the particles being hydrophobic.

The samples were prepared as follows. 0.50 g of dry particles were weighed, then 50 g of ethanol was added, except for the examples of by. Where 0.20 g of particles were weighed and then 50 ml of ethanol was added. The sample thus obtained was stirred with a magnetic bar for about 5 minutes. The vat of the granulometer was filled with ethanol, then the sample was introduced with a pipette pasteur drip until obtaining a blue laser transmission (corresponding to the finest particles) equal to 90 ± 1%. The actual part of the refractive index was entered by the user into the software and taken equal to the refractive index measured on the pigment. The imaginary part of the refractive index has been determined experimentally by adjusting the following parameters:

Use or no ultrasound (up to 2 minutes),

Variation of the imaginary index, taking the following values: 0.01, 0.1 or 1, so as to obtain the best fit between the theoretical response curve and the measured one.

2) By Coulter Method

The particles were added in 0.9% aqueous NaCl solution (electrolate) and analyzed using a Coulter-based Multisizer 3, counting from 30,000 to 40,000 particles per measurement. A prior dilution of the samples to be analyzed was carried out so that the particles pass in the form of isolated particles through the orifice separating the two chambers of the Counter counter.

Apparent density

The bulk density of the particles was measured using a controlled scale to an accuracy of ± 0.01 g and a graduated cylinder of 50 or 100 ml. The test specimen was calibrated and then filled with 20 to 30 g powder. The volume of powder thus obtained was measured. The density has finally been calculated by making the ratio of mass to volume.

The packed apparent density was measured using a tamping volumeter and a specimen. After 400 normalized packings of the powdery composition in the test tube, the volume occupied by the powder was measured. The density has finally been calculated by making the ratio of mass to volume.

Varnish film color measurement comprising powdery pigment compositions on contrast map (i.e. black and white parts)

The pulverulent pigment composition was mixed with the speedmixer for

3min at 1500 revolutions per minute with KF-7312-J: DC245 50:50 where KF7312-J is Shin etsu's "film forming silicone" and DC245 is silicone oil. The film was then shot using a 6mils thick applicator (152.4 μηι) BYK biko micro-applicator drive. Three measurements per result were made on each part of the contrast card (black part and white part). The colorimetric analyzes were then carried out with a Konica Minolta CM-5 reflectance spectrophotometer and a BYK microtrigloss gloss meter.

To observe the transparency of the films, the dE ^* ab was measured between the measurements on the black part and the white part.

Compact color measurement consisting of 100% powdery pigment composition

A compact 100% powdery pigment composition was prepared. The powdery pigment composition was placed in a bucket and subjected to a pressure of 50 bar for 15 seconds.

The color measurement of the compact was then directly carried out with a portable spectrophotometer (Spectrocolorimeter BYK spectro-guide sphere gloss), with 3 measurements per compact.

1.3. Influence of the presence of the precursor P / polysiloxane resin

By way of comparison, pigmentary powder compositions were prepared without the use of precursor P, that is by mixing in the Cyclomix 500L spherical particles of PMMA and an untreated pigment. The compositions obtained were therefore free of polysiloxane resin.

The pulverulent pigment compositions obtained are given in Table 2:

Table 2: Composition of pigment-free powder compositions containing polysiloxane resin (comparative) and mixer used to prepare them

The four compositions 1a to 1d were analyzed by SEM. The photos obtained show that the coverage of the surface of the spherical particles of polymethylmethacrylate by the pigment is heterogeneous and very weak. Other pigmentary powder compositions were prepared using either a treated and micronized pigment or an untreated micronized pigment (Table 3).

Table 3: Composition of pigmentary powder compositions prepared from LC987 pigment and mixer used to prepare them

Compositions 5a and 5b were analyzed by SEM. The photos obtained show that the surface of the PMMA particles of the pulverulent pigment composition 5b (obtained from an alkylalkoxysilane-treated pigment) according to the invention is much more pigment-coated than that of the PMMA particles of the composition. pigmentary powder 5a (obtained from an untreated pigment).

These experiments show that the presence of polysiloxane resin is important to have a good surface coverage of spherical PMMA particles by the pigment.

1.4. Influence of the type of mixer in step c1)

For comparison, in step c1), the dry mixer Lodige was replaced by a high shear granulator type Cyclomix 500L from Hosokawa Micron (Netherlands) (Cyclomix mixer, which is not a mixer-granulator with horizontal or vertical stirring shaft). Powdery pigment compositions were obtained after 5 minutes of mixing in this granulator, set at a speed of 515 rpm for the first 20 seconds, 1000 rpm for the next 40 seconds and finally at 1668 rpm for 4 minutes (Table 1). 4).

Pigmented pulverulent compositions

2a 2b 2c 2d (according to the invention)

LC987ASE 70 70 50 50

PMMA 30 30 50 50

Cyclomix Granulator 5 L Lodige 5 L Cyclomix 5 L Lodige 5 L Table 4: Composition of the pigmentary powder compositions according to the invention comprising different mass ratios treated pigment / PMMA and mixer used to prepare them

The different powdery pigment compositions 2a to 2d were made with the same batches of raw material. Only the type of mixer (Cyclomix 5 L vs. lodge 5 L) varies.

All compositions 2a to 2d were analyzed in SEM. From the SEM photos obtained, regardless of the type of mixer-granulator (i.e. Cyclomix vs. Lodige), the surface coverage of the PMMA particles by the pigment is equivalent.

All compositions 2a to 2d were subjected to volume particle size analyzes. The results for compositions 2c and 2d are provided in Table 5.

TABLE 5 Result of the Granulometric Analysis of the Powdered Powder Compositions 2c and 2d According to the Invention

The analysis of the particle size of the powdery pigment compositions reveals a significantly more monodisperse (therefore better controlled) particle size distribution with Lodige than that obtained with Cyclomix. 1.5. Influence of the weight ratio pigment / PMMA particles, and Dv ₅₀ ^PMMA on this ratio

Two mass ratios of different pigment / PMMA particles: 70/30 or 50/50 were used in the experiments (Table 6).

Table 6: Composition of pigmentary powder compositions comprising different pigments treated with different mass ratios of pigment / PMMA according to the invention and mixer used to prepare them

All compositions 3a to 3h were analyzed in SEM. By way of illustration, FIG. 1 is an SEM photograph of composition 3b. The PMMA particles whose surface is covered with pigment particles are well visualized.

According to the SEM photos obtained, the adhesion of the treated pigments on the surface of the spherical particles of PMMA is strong. The adhesion of the needle-shaped yellow pigment is substantially lower than that of the other three pigments.

From the SEM photos obtained, which is the pigment, the surface coating of the spherical particles of PMMA in treated pigment is improved by reducing the mass ratio pigment / PMMA spherical particles from 70/30 to 50/50.

The yellow pigment used has a needle shape which could explain the poorer adhesion of the pigment to the spherical particles of PMMA. Additional experiments were performed with this yellow pigment (Table 7).

TABLE 7 Composition of the Pigmented Pigmentary Compositions According to the Invention Comprising the Needle-Shaped Yellow Pigment and Mixer Used to Prepare Them The powdery pigment compositions 6a to 6c were analyzed in SEM. According to the SEM photos obtained, the surface of spherical particles of coated PMMA is more important for the powdery pigment composition 6c than for the 6b, and even more so for the 6a for which the surface is the least coated.

The reduction of the yellow pigment / spherical PMMA mass ratio thus makes it possible to limit the level of free pigment and to promote the adhesion of the pigment to the surface of the spherical PMMA particles.

These results are corroborated by volume particle size analyzes, summarized in Table 8. A tightening of the particle size distributions (that is to say the reduction of the quantity of free pigments and consequently of their ability to form agglomerates) is observed by reducing the mass ratio pigment / spherical particles of PMMA from 70/30 to 50/50.

^* measured by SEM measured on a representative average of 10 particles

Table 8: Result of the granulometric analysis of the pigmentary powder compositions 3b, 3d and 3f according to the invention and starting materials: PMMA and treated pigments. These powdery pigment compositions were used to prepare a liquid foundation composition (Examples 2, 3 and 4 hereinafter).

The pigment / particulate ratio of PMMA was furthermore optimized by using spherical particles of polymethyl methacrylate with a median diameter in volume Dv ₅₀ ^PMMA twice as high, ie 20 μηι, following the same protocols as described above. The ratios allowing an optimized recovery (according to the SEM photos) of the surface of the spherical particles of PMMA in treated pigment are reported in Table 9.

Table 9: Composition of the pigmentary powder compositions comprising different pigments treated with different mass ratios pigment / PMMA according to the invention and mixer used to prepare them.

It is also observed that the adhesion of the yellow needle-shaped pigment is appreciably lower than that of the other three pigments and that the ratio of yellow pigment to spherical particle of PMMA should be reduced in order to limit the level of free yellow pigment and of promote the adhesion of the yellow pigment to the surface of the spherical particles of PMMA.

Comparison of optimized PM ₅₀ ^PMMA ratios shows that by using larger size PMMA spherical particles, the pigment coating of the PMMA particles is optimal for lower pigment / spherical PMMA mass ratios.

1.6. Influence of mixing times and temperatures in step c1)

The influence of the duration and temperature of the dry mix in the device

Lodige has been tested. Two different pigment / PMMA particle ratios: 70/30 or 50/50 were used in the experiments (Table 10). powdery pigment composition

4a 4b 4c 4d

(according to the invention)

LC987ASE 50 50 70 70

PMMA 50 50 30 30

1 = 30 min at room temperature (20 ° C) X X

Process 11 = 30 min at 20 ° C then 30 min at 50 ° C X X

Lodige Mixer-Granulator 5 L

Table 10: Composition of the pulverulent pigment compositions according to the invention with different pigment / PMMA ratios, different dry mixing times and different temperatures during dry mixing.

The pulverulent powder compositions 4a to 4d were analyzed in SEM. According to the SEM photos obtained, the increase in temperature from 20 ° C to 50 ° C does not significantly affect the amount of pigment attached to the surface of the PMMA spherical particles.

1.7. Evaluation of the hydrophobicity of pigmentary powder compositions

2.2 g of powdery pigmentary compositions 3b, 3d, 3f or 3h were introduced into:

i. 19.8 g of water,

ii. 19.8 g of DC 245 silicone oil (INCI: CYCLOPENTASILOXANE;

Supplier: Dow Corning),

iii. 19.8 g of fluid mineral oil,

iv. 19.8 g of water and 10 g of fluid mineral oil,

and the mixture was stirred 10 times in all four cases.

In experiments i and iv, the water has no color and is not pigmented. In experiment i, the powdery pigment composition was deposited on the walls of the flask, above the aqueous phase. In experiments ii, iii and iv, the powdery pigment composition is suspended in the oily phase. These results are observed whatever the nature of the pigment (3b, 3d, 3f or 3h).

A thin layer of compact powder of powdery pigment composition 3f was deposited on a surface, and a drop of water was deposited thereon. The contact angle measured with a Kruss DSA 30 goniometer was more than 145 °, which again shows the highly hydrophobic character of the powdery pigment composition according to the invention. These experiments demonstrate the highly hydrophobic nature of the powdery pigment compositions according to the invention.

1.8. Influence of particle geometry PMMA: spherical vs. hemispherical

The influence of particle geometry of PMMA: spherical vs. hemispherical was tested following the preparation method described in 1 .1. The compositions prepared are given in Table 11.

CV _n : coefficient of variation of the number diameter of spherical PMMA particles

^PMMA CV _n = 100 _n ^* a ^PMMA / D _n _r î medium or ^PMMA:

σ _η is the standard deviation of the distribution in number of diameters measured by SEM, and

D _n ^MMA medium ^P is the number average diameter measured by SEM.

. _ra pp _0RT (d _e f _elm _are uncoated PMMA spherical particles measured by SEM on an average of 10 particles

composition. _ra pp _0RT (d _e f _elm _es PMMA spherical particles at least partially covered by the LC990 pigment measured by SEM on an average of 10 particles Table 1 1: The composition of the powder compositions prepared from spherical or hemispherical PMMA particles and mixer used to prepare them.

The two powdery pigment compositions were deposited on a perfectly flat carbon double-sided tape. It was metallized with a current of 10mA, 1.2kV and an Au / Pd source (80/20). The samples were then observed at SEM, which validated the composite structure: in both cases, the surface of the PMMA particles is partially coated with pigment (the polysiloxane resin is not observable in SEM). Sensory tests were then performed. 0.025 g of each powdery pigment composition was spread in circles on a forearm. In order to more effectively compare the color and the coverage, the test was carried out crosswise (the spread of each composition was therefore done twice).

These tests have shown that the pulverulent pigment composition 8a according to the invention, obtained from spherical PMMA particles, is:

- much softer and very slippery (i.e. no brake on the application),

- more transparent, less covering,

more saturated in color

more satin, less matte,

- has a better hold on the skin

that the comparative powdery pigmentary composition 8b, obtained from hemispherical PMMA particles

Color measurements:

in varnished film printing on the one hand, and

- in compact on the other hand,

pulverulent powder compositions according to the invention or comparative comprising the hemispherical particles have also been made.

The results in lacquer film print are provided in paragraph 1 .9 - Table 16 below and show that:

the powdery pigment composition according to the invention (prepared from spherical PMMA particles) is as clear, but brighter, than a comparative powdery pigment composition prepared from hemispherical PMMA particles,

the powdery pigment compositions according to the invention are more transparent than the comparative powdery powder composition (with hemispherical PMMA particles).

The results in compact are given in paragraph 1 .9 - Table 17 (compact) below and show that the powdery pigment composition made with PMMA particles according to the invention is lighter than the comparative powdery powder composition prepared from PMMA particles hemispherical. 1.9. Influence of granulometry and monodisperse character of the PMMA particles used

Three types of monomodal size PMMA particles with particle size distributions as described in the following Tables 12 and 13 were used.

^* : CV = Covabead Velvet

Table 12: Results of granulometric analyzes by Coulter counter of the three types of spherical PMMA particles used

*: CV = Covabead Velvet

Table 13: Results of particle size analysis by laser granulometry of the three types of spherical PMMA particles used Granulometric measurements show that CV10 is much more monodisperse than Covabead PMMA. Both measurement methods (eg Coulter vs. laser) show this same trend.

Powdery pigment compositions were prepared from these three types of particles following the preparation method described in 1. with 50% by weight of PMMA particles and 50% by weight of LC990ASE pigment using a Lodige. The powdery pigment compositions were analyzed to investigate the influence of the monodisperse character of the PMMA particles.

• Granulometric analyzes of powdery pigment compositions

^* : CV = Covabead Velvet

Table 14: Results of particle size analysis by laser granulometry of the three pulverulent pigment compositions

The comparison of the results of the granulometric analyzes of the particles of

"Free" PMMA (Table 13) and powdery pigment compositions (Table 14) show that the particles of the powdery pigment compositions do not include little or no free pigment. Photos by SEM of the powdery pigment composition (according to the invention) prepared from CV10 and that (comparative) prepared from Covabead PMMA were taken. In the microscopy photos, length and thickness were measured on partially pigmented particles to determine the aspect ratio. The results are provided in Table 15. MEB measurements pigment composition composition pigment composition

pulverulent (comparative) pulverulent pigment (according to the invention)

prepared from pulverulent Covabead prepared from CV10

PMMA

Shape report

composition U 1, 1

Q composition

7.8 34.5

Dmoyen (μΠΊ) 1 1, 4 ± 0.4 8.6 ± 0.4

Table 15: Results of SEM analyzes of 10 particles of two powdery pigment compositions

These results show that the particles of the pulverulent pigment composition (according to the invention) prepared from CV10 are more monodisperse than those of the pulverulent (comparative) pigment composition prepared from Covabead PMMA.

• Evaluation of hydrophobicity

0.2 g of pulverulent pigment composition (according to the invention) prepared from CV10 or from that (comparative) prepared from Covabead PMMA were introduced into 19.8 g of distilled water, and each of the two mixtures was stirred 10 times. Visual observation has shown that the pulverulent pigment composition (according to the invention) prepared from CV10 has a better hydrophobicity compared to that (comparative) prepared from Covabead PMMA of CV _v ^PMMA of 25.6.

• Sensory analysis: Touch

Powdery pigment compositions were spread over a smooth area of the skin to assess softness. The powdery pigment composition (according to the invention) prepared from CV10 has a softer and more slippery feel than that (comparative) prepared from Covabead PMMA of CV _v ^PMMA of 25.6. • Sensory analysis: Color

Small piles of powdery pigment compositions were crushed with a sheet of paper and then visually observed. The pulverulent pigment composition (according to the invention) prepared from CV10 has a more intense color than that (comparative) prepared from Covabead PMMA of CV _v ^PMMA of 25.6.

• Color measurements in glossy film printing comprising pulverulent pigment compositions

Color measurements in varnish film printing were carried out in order to study the influence:

- CV _v ^PMMA and

- spherical or hemispherical geometry,

PMMA particles used as starting material on the color of the powdery pigment compositions.

CV = Covabead Velvet

ς: dE ^* (D65) = square root [(dl_ ^* (D65)) ² + (da (D65)) ² + (db (D65)) ² ] with dl_ ^* (D65) = L ^* (D65) _white c - L ^* (D65) _noi r; da ^* (D65) = a ^* (D65) _blan c - a ^* (D65) black; dL ^* (D65) = b ^* (D65) _b ianc - b ^* (D65) _n0 ir- The more dE ^* ab is important, the more transparent the print. The weaker it is, the more opaque it is. Table 16: Results of Color Measurements in Varnish Film Printing Comprising Powdery Pigmenting Compositions

The results in Table 16 above show that:

L ^* (powdery pigment composition comprising CV10 (according to the invention)) is slightly greater than L ^* (powdery pigment composition comprising Covabead PMMA (polydisperse) (comparative))

L ^* (pulverulent pigment composition comprising CV10 (according to the invention) is equivalent to L ^* (pulverulent powder composition comprising 3D tech (hemispherical particles))

Gloss 20 ° (pulverulent pigment composition comprising CV10 (according to the invention)) is substantially less than Gloss 20 ° (powdered pigment composition comprising Covabead PMMA (polydisperse) (comparative))

Gloss 20 ° (pulverulent pigment composition comprising CV10 (according to the invention)) is substantially greater than Gloss 20 ° (powdery pigment composition comprising 3D tech (hemispherical particles)),

the opacity is such that 3D Tech OTS IOB-30 (comparative powdery pigment composition with hemispherical particles) Covabead PMMA (comparative powdery pigment composition with polydisperse particles) CV10 (powdery pigment composition according to the invention)> CV20 ( powdery pigment composition according to the invention),

which implies :

- the pulverulent pigment composition according to the invention is lighter, but duller, a pulverulent pigment composition prepared from spherical PMMA particles polydisperse ^(PMMA _V CV of 25.6, well over 10%), and

the pulverulent pigment composition according to the invention is as clear, but brighter, than a pulverulent pigment composition prepared from hemispherical PMMA particles,

the powdery pigment compositions according to the invention (comprising CV10 or CV20) are more transparent than the comparative powdery powder compositions (with hemispherical PMMA particles, or spherical particles but CV _V ^PMMA of 25.6).

Color measurements in compact consisting of powdery pigment compositions

Compact color measurements were made to study the influence of: - CV _v ^PMMA and - spherical or hemispherical geometry,

PMMA particles used as starting material on the color of the powdery pigment compositions. The results are shown in Table 17:

Table 17: Results of compact color measurements made of powdery pigment compositions

The results in Table 17 show that the powdery pigment composition according to the invention is lighter than the comparative powdery pigment compositions (with hemispherical PMMA particles, or spherical particles but CV _V ^PMMA of 25.6). Example 2: Cosmetic Composition: Foundation Formulation (FDT) .1. Preparation of a foundation formulation

The simplified foundation formulation formulation tested (water-in-oil emulsion) is shown in Table 18.

FDT1

FDT2 (according to

(comparative)

Components providing the invention)

Proportions Proportions

(% w / w) (% w / w)

SILAMER HC Sensient 16.07

Dow

CETYL DIMETH ICON DC2502 2,04

Corning Phase

A HEXYL LAURATE BASF 2,89

CYCLOPENTASILOXANE Dow

10.71

DC245 Corning

Deionized water VWR 50,73

NaCI Sensient phase 0.64

B Butylene Glycol Sensient 6.43

Microcare PM3 Thor 0.48

pigmentary composition

1, 25

powdery 3h

pigmentary composition

0.45

powdery 3f

pigmentary composition

0.25

powdery 3b

Phase

pigmentary composition

C, 8.05

powdery 3d

LC 182 ASE 0.625

LC 381 ASE 0.225

LC 990 ASE 0.125

LC 987 ASE 4.025

PMMA 5

%

100 100 total Table 18: Composition of the phases used to prepare the foundations

Phase A was heated to 85 ° C. Phase C was then added to phase A after stopping the heating. When the temperature was below 50 ° C, phase B was finally added.

The mixture of the phases A + B + C was made with a medium deflocculating Rayneri in beaker of 100 mL for 10 minutes at 3000 rpm.

For comparison, a foundation (FDT2) was prepared by adding the treated pigments on the one hand and spherical particles of PMMA on the other hand in the foundation composition.

2.2. Comparison of FDT1 and FDT2 foundations

Dispersibility test of the pigmentary powdery compositions in the foundation

A drop of foundation FDT1 obtained from the powdery pigment composition according to the invention was deposited between two glass plates (by crushing the dispersion). The experiment was reproduced with a drop of foundation FDT2 prepared by adding the treated pigment on the one hand and spherical particles of PMMA on the other hand.

In the case where color spots were observed, the pigment was said to be "poorly dispersed" and therefore considered non-dispersible. In the opposite case, the material is said to be "dispersed".

In both cases, no pigment agglomerates can be distinguished. Thus, the dispersion of the powdery pigment composition in the foundation is of good quality. Similarly, the dispersion of the treated pigment in the foundation is of good quality.

Colorimetric measurement

The equipment used was Konica from Minolta.

The colorimetric measurements by CIE L ^* a ^* b ^* of the foundations obtained are shown in Table 19. Origin of

Foundation L ^* (D65) a ^* (D65) b ^* (D65) C ^* (D65) h ^* (D65) pigment

compositions Average 63.66 1 1, 87 21, 27 24.41 60.78

FDT1 powdery

(according to pigments Ecart-

0.06 0.05 0.05 0.06 0.08 the invention) according to type

the invention

pigment Average 62.67 1 1, 37 21, 07 24.02 61, 64 treated with one

share and

FDT2

particles Ecart- (comparative) 0.02 0.02 0.05 0.04 0.08 spherical type

from PMMA

on the other hand

Table 19: Result of colorimetric measurements by CIE L ^* a ^* b ^* of foundation funds

The foundation FDT1 obtained from the powdery pigment composition according to the invention has a significantly higher luminance and chromaticity for an equivalent shade compared to the foundation FDT2 made with the separated compounds.

Viscosity measurements

The comparison of the Brookfield viscosity measurements on the two foundations at ambient temperature (20 ° C.) and with a Brookfield DV2T viscometer (expressed in cPs as a function of the rotational speed in revolutions / minutes) is represented in FIG. 2.

The FDT1 foundation obtained from the powdery pigment compositions was more viscous than the FDT2. Without wishing to be bound by any particular theory, the viscosity increase observed could be related to the surface irregularity of the spherical PMMA particles whose surface is coated with treated pigment compared to the mixture of the two constituents. This surface irregularity would induce greater friction and therefore a higher viscosity.

Preliminary Sensory Evaluation of Foundation Formulations

The foundations were evaluated sensitively by three operators in comparison 2 to 2. The FDT1 foundation according to the invention prepared from the pigmentary powder compositions 3b, 3d, 3f and 3h gives a makeup result: brighter

more transparent

more homogeneous

Its texture is:

more creamy, thicker

easier to apply, works better

softer,

than the foundation FDT2. Example 3 Cosmetic Composition: Other Foundation Formulations (FDT)

3.1. Preparation of foundation formulations

Foundation foundations were prepared using 10% by weight:

v. either of a pulverulent pigment composition according to the invention (FDT3),

i. either a 50/50 mixture by weight of pigment treated on the one hand and PMMA on the other hand (FDT4),

with the compositions shown in Table 20.

Table 20: Composition of the phases used to prepare the foundations

Phase A was mixed with the spatula before addition to phase B. Phase B was stirred at 500 rpm and after the addition of phase C, stirring was increased to 700 rpm. The agitator used was a 4-limb Ika. These agitations are given as an indication for 100 g of foundation, they are flexible depending on the amount of the batch.

3.2. Comparison of FDT3 and FDT4 Foundations

Visual aspect of the foundations obtained

The two foundations obtained visually have a similar appearance.

Dispersibility test of the pigmentary powdery compositions in the foundation

A drop of the foundation FDT4 obtained from the powdery pigment composition according to the invention was deposited between two plastic films 25.4 thick. μηι (BYK provider) by overwriting the dispersion with a byko-drive device. The experiment was reproduced with a drop of foundation FDT3 prepared by adding the treated pigment on the one hand and spherical particles of PMMA on the other hand.

Evaluation of the color homogeneity of films under a microscope

The analyzes of the films formed by placing a drop of foundation between two glass plates by Olympus BX53F optical microscope under polarized or unpolarized light show a higher color homogeneity for the FDT4 foundation than for the comparative FDT3.

Evaluation of the FDToar's creep measurement of the haze with a hazemeter

Foundation films between a contrast card and a plastic film have been prepared. After their preparation, the films were dried for two hours before measurements on a hazemeter (Haze-gard i 4775 (BYK) - geometry when measuring: 0 ° - measuring area 18.0 mm). On the self-applicator are successively put: the contrast card, the plastic film and the applicator. The applicator has 8 different thicknesses in mils (thousandths of an inch) and the part allowing to have the desired thickness is put in contact with the part of the apparatus which will push the applicator. The foundation is put inside the applicator to the desired thickness (x mils). The auto-byko-drive applicator is used to pull the contrast card at constant speed and force. The foundation is drawn on the plastic film.

The haze is the percentage of transmitted light that deviates more than 2.5 ° from the incident beam.

Table 21: Transmittance, Haze and Clarity Measured by a Foundation Hazemeter FDT3 and FDT4 (The values shown are an average of three measurements).

The FDT4 foundation film prepared from the powdery pigment composition according to the invention has a lower total transmittance and a higher haze than the film obtained from the comparative FDT3, which demonstrates that the foundation prepared in from the pulverulent pigment composition according to the invention has improved coverage. EXAMPLE 4 Cosmetic Composition: Formulation of Eyeshadow

4.1. Preparation of eye shadow formulations

Eyeshadows were prepared using 50% by weight:

i. either of a pulverulent pigment composition according to the invention (FP1), i. either a 50/50 mixture by weight of pigment treated on the one hand and PMMA part (FP2),

with the compositions shown in Table 22.

Table 22: Composition of the phases used to prepare eye shadows Eyeshadows were prepared as follows:

Phases A and B were fed into a coffee grinder and mixed with 10 beats, then the mill vessel rims were scraped, and the mixture was again mixed with 10 beats. Phase C was then added dropwise, the whole was mixed with 50 pulses, then the mill vessel rims were scraped, and the mixture was again mixed with 50 pulses. The powder obtained was sieved and then pressed at 50 bar for 10 seconds in a cup with a tissue inducing specific surface effects (PROV 581 Taffetas Polyamide, drawing strikes, base 54796 - THIOLLIER).

4.2. Comparison of FP1 and FP2 Eyeshadow

Visual appearance of the obtained eyeshadows and sensory during the application

The foundation comprising the powdery pigment composition 3b has a full solid tone. When applied to the skin, a pleasing multisensory effect is observed, notably thanks to the pleasant ball rolling effect induced by the decorated PMMA beads or no pigments. The eye shadow is easy to apply without the applied layer being too thick, the color is more homogeneous and more intense than FP2 comparative eye shadow.

Colorimetric measurements

The equipment used was a portable spectrophotocolorimeter (Spectro Sphere Guide Gloss - BYK Additives & Instruments). The colorimetric parameters on the skin were made in 15 measurements on two different people, comparing, for each foundation, the difference between the bare skin and the skin provided with eyeshadow.

The colorimetric measurements by CIE L ^* a ^* b ^* eyeshadow are reported in Table 23 below:

FP1 (according to the invention) FP2 (comparative) dL 26.63666667 23.43066667

to 2.095333333 1, 809333333

db 9,393333333 8.1 12

standard deviation STD (dL) 0,646546862 1, 503256515 standard deviation STD (da) 0,139551786 0,255364802 standard deviation STD (db) 0,507104267 0,422220489 Table 23: Results of colorimetric measurements by CIE L ^* a ^* b ^* eyeshadow FP1 and FP2 (average of 15 measurements on two different people).

These results show that eyeshadow FP1 confers:

- a standard deviation of the lower brightness,

a difference in luminosity between the bare skin and the skin with a greater appearance,

Comparative FP2 eyeshadow, which implies that FP1 eye shadow provides better color consistency and better coverage than FP2 comparative eye shadow.

Claims

1. Powdered pulverulent composition comprising spherical particles of polymethyl methacrylate having a mono- or bimodal size distribution, wherein each mode has:

a median diameter in volume Dv ₅₀ ^PMMA measured by laser diffraction of 1 to 80 μηι, and

- a coefficient of variation of the volume diameter CV _V ^PMMA less than 10%, where C _VV PMMA _{IS QBTEN U PAR} | _{A FORM U} | _E.

_CVV PMMA _{= 1 00} * σ _ν ™ ^ΜΑ / D _mean ^PMMA

in which :

D _{v avg} ^{P MMA} is the volume mean diameter measured with a Coulter Counter, the surface of said spherical particles being at least partially covered with polysiloxane resin and particles of at least one pigment.

2. - pigment powder composition according to claim 1, wherein the ratio of the volume median diameter Dv ₅₀ ^PMMA measured by laser diffraction of polymethyl methacrylate spherical particles relative to the volume median diameter Dv ₅₀ ^p ^'9ment measured by laser diffraction the pigment is from 1 to 10,000, typically from 1 to 1000, in particular from 1 to 100, more preferably from 1.5 to 40 and in particular from 1.8 to 25.

3.- powdered pigment composition according to any one of claims 1 to 2, wherein the mass ratio of the pigment particles relative to the spherical particles of polymethyl methacrylate is from 10/1 to 1/10, in particular 4/1 at 3/4, typically from 3/1 to 2/3, preferably 1/1.

4.- pigment powdery composition according to any one of claims 1 to 3, wherein the coefficient of variation of diameter by number of the particles of the pigment powdery composition cv ^composrtlon _n is less than or equal to 20%, where _n cv ^composition is obtained by the formula:

composition_ * _ composition / composition

n I UU U _n / LJ _n medium

in which : ^ compos ⁱ t ⁱ on _is y ^ _ca ^ deviation of the number distribution of diameters measured by scanning electron microscopy, and

5. - Powdery pulverulent composition according to any one of claims 1 to 4, wherein the form ratio _K ^composrtlon of each mode is from 1.0 to 2.0, especially from 1, 0 to 1, 8, preferably from 1, 0 to 1, 6, where the tax form ratio _∞t , _{e ratjo de} | _ength / thickness, wherein:

- length is the highest diameter measured by scanning electron microscopy on an average of ten spherical particles of polymethylmethacrylate, the surface of which is at least partially covered,

- thickness is the smallest diameter measured by scanning electron microscopy on an average of ten spherical particles of polymethylmethacrylate, the surface of which is at least partially covered.

6. - A process for preparing a powdery pigment composition according to any one of claims 1 to 5 comprising a step of dry mixing of spherical particles of polymethyl methacrylate as defined in claim 1, pigment particles and polysiloxane resin or a polysiloxane resin precursor.

7. - A method of preparation according to claim 6, wherein the mixture is produced in a mixer-granulator with horizontal or vertical shaking shaft.

8. - Preparation process according to claim 6 or 7, comprising:

- Optionally a step b1) grinding the treated pigment obtained in step a1), and - a step c1) of dry mixing of the treated pigment and spherical particles of polymethyl methacrylate.

9. Preparation process according to claim 6 or 7, comprising a step a2) of mixing the spherical particles of polymethyl methacrylate and a precursor of polysiloxane resin or of polysiloxane resin to obtain spherical particles of polymethyl methacrylate treated, then

a step b2) of dry mixing of the spherical particles of polymethyl methacrylate treated and pigment particles.

10. Preparation process according to any one of claims 6 to 9, wherein the polysiloxane resin precursor is an alkylaikoxysilane, aikoxysilane, alkylcyloxysilane or acyloxysilane.

1 1. A preparation process according to claim 10, wherein the polysiloxane resin precursor has the following formula (I):

in which :

each X independently represents -O- or O- (C = O) -,

n represents an integer of 0 to 3,

each R ¹ independently represents a linear, branched or cyclic alkyl comprising from 1 to 12 carbon atoms, a linear, branched or cyclic alkenyl comprising from 1 to 12 carbon atoms, an aryl comprising from 6 to 12 carbon atoms or a alkylaryl comprising 7 to 12 carbon atoms, said alkyl, alkenyl, aryl or arylalkyl being optionally substituted by one or more groups selected from -OH, -NR ³ R ⁴ R ⁵ , - (OCH ₂ -CH ₂ ) pR ⁸ , oxiranyl and / or said alkyl, alkenyl, or arylalkyl being optionally interrupted by one or more groups selected from S, O, - (C = O) -O-, -O- (C = O) - and -NR ⁶ R ⁷ -

p represents an integer from 1 to 50.

12. - Cosmetic composition comprising a powdery pigment composition according to any one of claims 1 to 5.

13. - Cosmetic composition according to claim 12, said composition being a makeup composition, preferably chosen from a foundation, a colored cosmetic composition for the skin, a lipstick, a nail polish, an eyeshadow, hair makeup, or dry shampoo.

14. Use of a powdery pigment composition according to any one of claims 1 to 5 for improving the coverage and / or color homogeneity of a cosmetic composition comprising spherical particles of polymethyl methacrylate and particles of less a pigment.