WO2012042570A1 - A cosmetic method for hiding skin imperfections - Google Patents

Abstract

A cosmetic method for hiding skin imperfections and in particular pores and/or lines, in particular on skin face, the method comprising the steps of applying a cosmetic powder composition, in particular in a compact powder form, containing at least (i) fusiform particles being made of an organosilicone having a crosslinked polysiloxane structure, and having diameters along major axis L₁ between approximately 0.05 micro meters and approximately 20 micro meters, diameters along minor axes L₂ between approximately 0.03 micro meters and approximately 15 micro meters, and L₁/L₂ between approximately 1.1 and approximately 3.3 and (ii) hydrophobic surface treated filler and optionally (iii) a pigment and other cosmetically acceptable ingredients.

Description

A COSMETIC METHOD FOR HIDING SKIN IMPERFECTIONS

The present invention relates to a cosmetic method for hiding skin imperfections and in particular pores and/or lines, in particular on skin face. The cosmetic method comprises the steps of applying a cosmetic powder composition, in particular in a compact powder form, containing at least (i) fusiform particles being made of an organosilicone having a crosslinked polysiloxane structure, and (ii) hydrophobic surface treated filler and optionally (iii) a pigment and/or other cosmetically acceptable ingredients. The fusiform particles may have diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometers, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometers, and L₁/L₂ between approximately 1.1 and approximately 3.3.

Background

It is desired to provide an enhanced cosmetic method for hiding skin imperfections, in particular pores and/or lines on skin face. It is preferred that the cosmetic composition provides an improved transfer resistance and a smooth feel.

In view of the fact that the methods now available still require improved hiding or concealing yet providing simultaneously a good transfer resistance and smooth feel of the cosmetic compound to be used in the method, the inventors of the present invention have tested numerous methods wherein various cosmetic compositions are used. As a results, the inventors have discovered that application of a cosmetic composition can hide skin imperfections and in particular pores and/or lines, in particular on skin face, especially when the composition contains fusiform particles, hydrophobic surface treated filler and optionally a pigment and/or other cosmetically acceptable ingredients which will be specified later, and thereby completed the present invention.

According to an aspect of the present invention, the inventors propose a cosmetic method for hiding skin imperfections and in particular pores and/or lines, in particular on skin face, the method comprising the steps of applying a cosmetic powder composition, in particular in a compact powder form, containing at least (i) fusiform particles being made of an organosilicone having a crosslinked polysiloxane structure, and having diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometers, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometers, and L₁/L₂ between approximately 1.1 and approximately 3.3 and (ii) hydrophobic surface treated filler and optionally (iii) a pigment and/or other cosmetically acceptable ingredients.

In the present specification, unless otherwise specified, the term "cosmetic use" or "cosmetic method" includes uses and methods for so-called cosmeticpurposes as well as aesthetic purposes. The composition according to the invention can be a composition for making up or caring for the skin and can be provided in the form of a blusher, an eyeshadow, a face powder, a foundation, a concealer, a product for making up the body, a product for caring for the face, a product for caring for the body or an antisun product. More specifically, the invention relates to a foundation composition, in particular in a compact form.

A fusiform in this specification refers to such a shape that a sphere is extended in one direction so that there is a major axis along which the fusiform particle has the largest diameter L₁ which is between approximately 0.05 micrometer and approximately 20 micrometers and two minor aces L₂ perpendicular to the major axis and to each other along which the fusiform particle has the smallest diameter which is between approximately 0.03 micrometer and approximately 15 micrometers, and L₁/L₂ between approximately 1.1 and approximately 3.3.

The organosilicone material having a crosslinked polysiloxane structure preferably comprises, indeed even is composed of, units of formula (I): SiO₂, and of formula (II): R¹SiO_1.5,
in which R¹ denotes an organic group having a carbon atom directly connected to the silicon atom. The organic group can be a reactive organic group or an unreactive organic group and preferably an unreactive organic group.

The unreactive organic group can be a C₁-C₄ alkyl group, in particular a methyl, ethyl, propyl or butyl group, or a phenyl group and preferably a methyl group.
The reactive organic group can be an epoxy group, a (meth)acryloyloxy group, an alkenyl group, a mercaptoalkyl, aminoalkyl or haloalkyl group, a glyceroxy group, a ureido group or a cyano group. Preferably, the reactive organic group can be an epoxy group, a (meth)acryloyloxy group, an alkenyl group or a mercaptoalkyl or aminoalkyl group. The reactive organic group generally comprises from 2 to 6 carbon atoms, in particular from 2 to 4 carbon atoms.

Mention may be made, as epoxy group, of a 2-glycidoxyethyl group, a 3-glycidoxypropyl group or a 2-(3,4-epoxycyclohexyl)propyl group.
Mention may be made, as (meth)acryloyloxy group, of a 3-methacryloyloxypropyl group or a 3-acryloyloxypropyl group.
Mention may be made, as alkenyl group, of a vinyl, allyl or isopropenyl group.
Mention may be made, as mercaptoalkyl group, of a mercaptopropyl or mercaptoethyl group.

Mention may be made, as aminoalkyl group, of a 3-[(2-aminoethyl)amino]propyl group, a 3-aminopropyl group or an N,N-dimethylaminopropyl group.
Mention may be made, as haloalkyl group, of a 3-chloropropyl group or a trifluoropropyl group.
Mention may be made, as glyceroxy group, of a 3-glyceroxypropyl group or a 2-glyceroxyethyl group.
Mention may be made, as ureido group, of a 2-ureidoethyl group.
Mention may be made, as cyano group, of a cyanopropyl or cyanoethyl group.
Preferably, in the unit of formula (II), R1 denotes a methyl group.
Advantageously, the organosilicone material comprises the units (I) and (II) according to a unit (I)/unit (II) molar ratio ranging from 30/70 to 50/50, preferably ranging from 35/65 to 45/55.

The organosilicone particles can in particular be capable of being obtained according to a process comprising:
(a) the introduction into an aqueous medium, in the presence of at least one hydrolysis catalyst and optionally of at least one surfactant, of a compound (III) of formula SiX₄ and of a compound (IV) of formula RSiY₃, where X and Y denote, independently of one another, a C₁-C₄ alkoxy group, an alkoxyethoxy group including a C₁-C₄ alkoxy group, a C₂-C₄ acyloxy group, an N,N-dialkylamino group including a C₁-C₄ alkyl group, a hydroxyl group, a halogen atom or a hydrogen atom and R denotes an organic group comprising a carbon atom connected directly to the silicon atom; and
(b) the operation in which the mixture resulting from stage (a) is brought into contact with an aqueous solution including at least one polymerization catalyst and optionally at least one surfactant, at a temperature of between 30 and 85 degrees Celsius, for at least two hours.

Stage (a) corresponds to a hydrolysis reaction and stage (b) corresponds to a condensation reaction.
In stage (a), the molar ratio of the compound (III) to the compound (IV) generally ranges from 30/70 to 50/50, advantageously from 35/65 to 45/45, and is preferentially 40/60. The ratio by weight of the water to the total of the compounds (III) and (IV) preferably ranges from 10/90 to 70/30. The order of introduction of the compounds (III) and (IV) generally depends on their rate of hydrolysis. The temperature of the hydrolysis reaction generally ranges from 0 to 40 degrees Celsius and usually does not exceed 30 degrees Celsius in order to prevent premature condensation of the compounds.

For the X and Y groups of the compounds (III) and (IV):
mention may be made, as C₁-C₄ alkoxy group, of the methoxy or ethoxy groups;
mention may be made, as alkoxyethoxy group including a C₁-C₄ alkoxy group, of the methoxyethoxy or butoxyethoxy groups;
mention may be made, as C₂-C₄ acyloxy group, of the acetoxy or propionyloxy groups;
mention may be made, as N,N-dialkylamino group including a C₁-C₄ alkyl group, of the dimethylamino or diethylamino groups;
mention may be made, as halogen atom, of the chlorine or bromine atoms.

Mention may be made, as compounds of formula (III), of tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, trimethoxyethoxysilane, tributoxyethoxysilane, tetraacetoxysilane, tetrapropioxysilane, tetra(dimethylamino)silane, tetra(diethylamino)silane, silanetetraol, chlorosilanetriol, dichlorodisilanol, tetrachlorosilane or chlorotrihydrosilane. Preferably, the compound of formula (III) is chosen from tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane and their mixtures.

The compound of formula (III) results, after the polymerization reaction, in the formation of the units of formula (I).
The compound of formula (IV) results, after the polymerization reaction, in the formation of the units of formula (II).
The R group in the compound of formula (IV) has the meaning as described for the R¹ group for the compound of formula (II).

Mention may be made, as examples of compounds of formula (IV) comprising an unreactive organic group R, of methyltrimethoxysilane, ethyltriethoxysilane, propyltributoxysilane, butyltributoxysilane, phenyltrimethoxyethoxysilane, methyltributoxyethoxysilane, methyltriacetoxysilane, methyltripropioxysilane, methyltri(dimethylamino)silane, methyltri(diethylamino)silane, methylsilanetriol, methylchlorodisilanol, methyltrichlorosilane or methyltrihydrosilane.

Mention may be made, as examples of compounds of formula (IV) comprising a reactive organic group R, of:
silanes having an epoxy group, such as (3-glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)triethoxysilane, [2-(3,4-epoxycyclohexyl)ethyl]trimethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane, (2-glycidoxyethyl)methyldimethoxysilane, (3-glycidoxypropyl)dimethylmethoxysilane or (2-glycidoxyethyl)dimethylmethoxysilane;
silanes having a (meth)acryloyloxy group, such as (3-methacryloyloxypropyl)trimethoxysilane or (3-acryloyloxypropyl)trimethoxysilane;
silanes having an alkenyl group, such as vinyltrimethoxysilane, allyltrimethoxysilane or isopropenyltrimethoxysilane;
silanes having a mercapto group, such as mercaptopropyltrimethoxysilane or mercaptoethyltrimethoxysilane;
silanes having an aminoalkyl group, such as (3-aminopropyl)trimethoxysilane, (3-[(2-aminoethyl)amino]propyl)trimethoxysilane, (N,N-dimethylaminopropyl)trimethoxysilane or (N,N-dimethylaminoethyl)trimethoxysilane;
silanes having a haloalkyl group, such as (3-chloropropyl)trimethoxysilane or trifluoropropyltrimethoxysilane;
silanes having a glyceroxy group, such as (3-glyceroxypropyl)trimethoxysilane or di(3-glyceroxypropyl)dimethoxysilane;
silanes having a ureido group, such as (3-ureidopropyl)trimethoxysilane, (3-ureidopropyl)methyldimethoxysilane or (3-ureidopropyl)dimethylmethoxysilane;
silanes having a cyano group, such as cyanopropyltrimethoxysilane, cyanopropylmethyldimethoxysilane or cyanopropyldimethylmethoxysilane.

Preferably, the compound of formula (IV) comprising a reactive organic group R is chosen from silanes having an epoxy group, silanes having a (meth)acryloyloxy group, silanes having an alkenyl group, silanes having a mercapto group or silanes having an aminoalkyl group.

Examples of compounds (III) and (IV) which are preferred for the implementation of this invention are respectively tetraethoxysilane and methyltrimethoxysilane.
Use may independently be made, as hydrolysis and polymerization catalysts, of basic catalysts, such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogencarbonate or amines (such as ammonia, trimethylamine, triethylamine or tetramethylammonium hydroxide), or acidic catalysts chosen from organic acids, such as citric acid, acetic acid, methanesulphonic acid, p-toluenesulphonic acid, dodecylbenzenesulphonic acid or dodecylsulphonic acid, or inorganic acids, such as hydrochloric acid, sulphuric acid or phosphoric acid. When it is present, the surfactant used is preferably a nonionic or anionic surfactant or a mixture of the two. Sodium dodecylbenzenesulphonate can be used as anionic surfactant. The end of the hydrolysis is marked by the disappearance of the products (III) and (IV), which are insoluble in water, and the production of a homogeneous liquid layer.

The condensation stage (b) can use the same catalyst as the hydrolysis stage or another catalyst chosen from those mentioned above.
On conclusion of this process, a suspension in water of fine organosilicone particles is obtained, which particles can optionally be separated subsequently from their medium. The process described above can thus comprise an additional stage of filtration, for example on a membrane filter, of the product resulting from stage (b), optionally followed by a stage of centrifuging the filtrate, intended to separate the particles from the liquid medium, and then by a stage of drying the particles. Other separation methods can, of course, be employed.
The fusiform particles used according to the invention are the ones described in JP2003-171465 and in particular the fusiform particles are the those similar to the ones examplified as P1, P2 and P10 therein.

The filler may be one of more of talc, mica, silica, kaolin, powders formed of polyamide, of poly-beta-alanine and of polyethylene, powders formed of tetrafluoroethylene polymers, lauryllysine, starch, boron nitride, polymeric hollow microspheres of poly(vinylidene chloride)/acrylonitrile or of acrylic acid copolymers, silicone resin microbeads, particles formed of polyorganosiloxane elastomers, precipitated calcium carbonate, magnesium carbonate, basic magnesium carbonate, hydroxyapatite, barium sulphate, aluminium oxides, polyurethane powders, composite fillers, hollow silica microspheres, glass or ceramic microcapsules, or metal soaps derived from organic carboxylic acids having from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, for example zinc stearate, magnesium stearate, lithium stearate, zinc laurate or magnesium myristate.
According to a particular embodiment, the filler is a lamellar filler chosen from talc, mica, kaolin, silica, and mixtures thereof.
In a preferred embodiment, the composition according to the invention contains at least hydrophobic treated talc or mica or both of them.
In a preferred embodiment, the composition according to the invention contains at least silicone treated talc or mica or both of them.
The hydrophobic treatment agent can be chosen form silicone, amino-acids and/or fluorinated treatment.

The hydrophobic treatment agent can be chosen from silicones, such as methicones, dimethicones or perfluoroalkylsilanes, fatty acids, such as stearic acid, metal soaps, such as aluminum dimyristate or the aluminum salt of hydrogenated tallow glutamate, perfluoroalkyl phosphates, perfluoroalkylsilanes, perfluoroalkylsilazanes, poly(hexafluoropropylene oxide)s, polyorganosiloxanes comprising perfluoroalkylperfluoropolyether groups, amino acids,
N-acylated amino acids or their salts, lecithin, isopropyl triisostearyl titanate and their mixtures.
The N-acylated amino acids can comprise an acyl group having from 8 to 22 carbon atoms, such as, for example, a 2-ethylhexanoyl, caproyl, lauroyl, myristoyl, palmitoyl, stearoyl or cocoyl group. The salts of these compounds can be the aluminium, magnesium, calcium, zirconium, zinc, sodium or potassium salts. The amino acid can, for example, be lysine, glutamic acid or alanine.
The term "alkyl" mentioned in the abovementioned compounds denotes in particular an alkyl group having from 1 to 30 carbon atoms, preferably having from 5 to 16 carbon atoms.
In a particular embodiment, the hydrophobic treatment to be performed on the filler may be silicone treatment, amino acid treatment or both to be performed on the filler surface.
In a preferred embodiment, the hydrophobic treatment to be performed on the filler is silicone treatment.

In a preferred embodiment, the composition contains at least a dimethicone treated talc, in particular the talc sold under the names SI-2 TALC JA-46R by DAITO KASEI KOGYO (INCI Name Talc (and) dimethicone 98/2). As an alternative, we can use the talc sold under the name SA-TA-46R by Miyoshi Kasei (INCI Name Talc (and) dimethicone 98/2).
In another embodiment, the composition contains at least a dimethicone treated mica, such as the mica sold under the name SA-S-200 by Miyoshi Kasei (INCI Name Mica (and) Dimethicone 97/3).
In another embodiment, the composition contains at least an amino acid treated mica (sericite), such as the mica sold under the name LP-S-100 by Miyoshi Kasei (INCI Name mica (and) palmitoyl prolone (and) sodium palmitoyl sarcosinate (and) magnesium palmitoyl glutamate (and) aluminium hydroxide (and) palmitic acid).
In another embodiment, the composition contains at least an amino acid talc, such as the talc sold under the name LP-TA-46R by Miyoshi Kasei (INCI name TALC (and) Palmitoyl Proline (and) Palmitic Acid (and) Aluminum Hydroxide (and) Sodium Palmitoyl Sarcosinate (and) Magnesium Palmitoyl Glutamate)
The composition might contain mixtures thereof.
In a preferred embodiment, the hydrophobic treated filler represents generally between 5 and 90 % by weight with respect to the total weight of the composition, preferably from 10 to 85% by weight and more preferably from 20 to 80% by weight, and more preferably from 60 to 80% by weight.
In a preferred embodiment, the composition according to the invention contains:
(i) at least 5% to 20% of fusiform particles by weight of total composition and
(ii) at least 5%to 20%, preferably from 10 to 15% of hydrophobic treated fillers by weight of total composition, and
(iii) optionally a pigments and/or other cosmetic ingredients.

A pigment may be one or more of titanium dioxide, optionally surface treated, zirconium or cerium oxides, as well as zinc, iron or chromium oxides, manganese violet, ultramarine blue, chromium hydrate and ferric blue, or aluminium powder or copper powder or nanopigments formed of titanium dioxide, zinc oxide, iron oxide, zirconium oxide, cerium oxide and their mixtures. In a preferred embodiment, the composition contains hydrophobic treated pigments, and in particular hydrophobic treated titanium dioxide, such as lauroyl lysine treated titanium dioxide.

The term pigments should be understood to mean particles of any shape, white or colored, inorganic or organic, which are insoluble in the physiological medium and which are intended to color the composition. The pigments can be white and/or colored and inorganic and/or organic.

According to a specific embodiment, the composition according to the invention can comprise at least one pigment chosen from inorganic pigments. These inorganic pigments can in particular be chosen from metal oxide pigments.

Mention may be made, among inorganic pigments, of titanium dioxide, optionally surface treated, zirconium or cerium oxides, and also zinc, iron (black, yellow or red) or chromium oxides, manganese violet, ultramarine blue, chromium hydrate and ferric blue, and metal powders, such as aluminium powder or copper powder.

According to a preferred embodiment, the inorganic pigments, in particular metal oxide pigments, present in the composition according to the invention are chosen from titanium dioxide, zinc oxide and/or iron oxide.

According to a specific embodiment, the composition may comprise at least two different pigments. According to an embodiment which is also preferred, the composition may comprise at least one first pigment chosen from iron oxides and at least one second titanium dioxide pigment.

In addition to inorganic pigments, the composition according to the invention can comprise organic pigments. Mention may be made, among organic pigments, of carbon black, pigments of D and C type and lakes based on cochineal carmine, barium, strontium, calcium or aluminium.

The pigment can also comprise goniochromatic pigments. These pigments exhibit a relatively large change in color with the angle of observation. The goniochromatic pigment can be chosen, for example, from pigments comprising a multilayer interference structure and liquid crystal pigments.

In the case of a multilayer structure, the latter can comprise, for example, at least two layers, each layer, independently or not of the other layer(s), being produced, for example, from at least one material chosen from the group consisting of the following materials: MgF₂, CeF₃, ZnS, ZnSe, Si, SiO₂, Ge, Te, Fe₂O₃, Pt, Va, Al₂O₃, MgO, Y₂O₃, S₂O₃, SiO, HfO₂, ZrO₂, CeO₂, Nb₂O₅, Ta₂O₅, TiO₂, Ag, Al, Au, Cu, Rb, Ti, Ta, W, Zn, MoS₂, cryolite, alloys, polymers and their combinations.

The goniochromatic agents comprising multilayer structures are in particular those described in the following documents: US-A 3,438,796, EPA 227 423, US-A 5,135,812, EP-A 170 439, EP-A 341 002, US-A 4,930,866, US-A 5,641,719, EP-A 472 371, EP-A 395 410, EP-A 753 545, EP-A 768 343, EP-A 571 836, EP-A 708 154, EP-A 579 091, US-A 5,411,586, US-A 5,364,467, WO-A 97/39066, DE-A 4,225,031, WO-9517479 (BASF) and DE-A 196 14 637. They are provided in the form of flakes with a metallic color.

The multilayer structures which can be used in the invention are, for example, the following structures: Al/SiO₂/Al/SiO₂/Al; Cr/MgF₂/Al/MgF₂/Al; MoS₂/SiO₂/Al/SiO₂/MoS₂; Fe₂O₃/SiO₂/Al/SiO₂/Fe₂O₃; Fe₂O₃/SiO₂/Fe₂O₃/SiO₂/Fe₂O₃; MoS₂/SiO₂/mica oxide/SiO₂/MoS₂; Fe₂O₃/SiO₂/mica oxide/SiO₂/Fe₂O₃. Different colors are obtained depending on the thicknesses of the different layers. Thus, with the structure Fe₂O₃/SiO₂/Al/SiO₂/Fe₂O₃, the color changes from golden-green to grey-red for SiO₂ layers with a thickness of 320 to 350 nm; from red to golden for SiO₂ layers with a thickness of 380 to 400 nm; from purple to green for SiO₂ layers with a thickness of 410 to 420 nm; and from copper to red for SiO₂ layers with a thickness of 430 to 440 nm.

Consequently, the multilayer structure can be essentially inorganic or organic. Different colors are obtained depending on the thickness of each of the different layers. The goniochromatic pigments comprising a multilayer interference structure according to the invention are in particular those described in the following documents: US-A 3,438,796, EP-A 227 423, US-A 5,135,812, EP-A 170,439, EP-A 341 002, US-A 4,930,866, US-A 5,641,719, EP-A 472 371, EP-A 395 410, EP-A 753 545, EP-A 768 343, EP-A 571 836, EP-A 708 154, EP-A 579 091, US-A 5,411,586, US-A 5,364,467, WO-A 97/39066, DE-A 4,225,031, WO-9517479 (BASF) and DE-A 196 14 637, and their combinations. They are provided in the form of flakes with a metallic color.

The goniochromatic pigment comprising a multilayer interference structure can be chosen from the group consisting of the following commercial goniochromatic pigments: Infinite Colors from Shiseido, Sicopearl Fantastico from BASF, Colorstream, Xirallic and Xirona from Merck, Colorglitter from Flex, and their mixtures.

Liquid crystal pigments are described in particular in Application EP-A 1 046 692. Use may in particular be made, as liquid crystal particles, of those known under the CTFA name Polyacrylate-4 and sold under the names "Helicone (registered trademark) HC Sapphire", "Helicone (registered trademark) HC Scarabeus", "Helicone (registered trademark) HC Jade", "Helicone (registered trademark) HC Maple", "Helicone (registered trademark) HC XL Sapphire", "Helicone (registered trademark) HC XL Scarabeus", "Helicone (registered trademark) HC XL Jade" and "Helicone (registered trademark) HC XL Maple" by Wacker.

The pigments can be present in the composition according to the invention in a content ranging from 1 to 30% by weight, with respect to the total weight of the composition, preferably from 5 to 20% by weight and more preferably from 5 to 15% by weight. According to a preferred embodiment, the lamellar particles and the pigments are present in the composition in a content such that the ratio by weight of the lamellar particles to the pigments ranges from 0.1 to 20, preferably from 5 to 15.

Cosmetically acceptable other ingredients are, for example, waxes, preservatives, cosmetic active principles, moisturizing agents, UV screening agents, thickeners, water, surfactants, binders or fragrances. The cosmetically acceptable other ingredients may be one or more of pulverulent phases including spherical solid particles, boron nitride particles, lamellar particles, additional particles, fatty binders, waxes, pasty fatty substances, and other additives.

Additional Particles
In addition to the lamellar particles described above, the composition according to the invention can comprise at least one additional nonlamellar particle of any shape, for example spherical or oblong.

Mention may be made of spherical silica, polyamide (Nylon (registered trademark)) powders, poly-beta-alanine powders, polyethylene powders, polyurethane powders, such as the powder formed of hexamethylene diisocyanate and trimethylol hexyllactone copolymer sold under the name "Plastic Powder D-400" by Toshiki, the powders formed of tetrafluoroethylene polymers (Teflon (registered trademark)), lauroyllysine, starch, boron nitride, polymeric hollow microspheres, such as those of polyvinylidene chloride/acrylonitrile, for example Expancel (registered trademark) (Nobel Industrie), or of acrylic acid copolymers, silicone resin powders, in particular silsesquioxane powders (silicone resin powders described in particular in Patent EP 293 795; for example Tospearls (registered trademark) from Toshiba), polyorganosiloxane elastomer particles, polymethyl methacrylate particles, precipitated calcium carbonate, magnesium carbonate, basic magnesium carbonate, hydroxyapatite, hollow silica microspheres, glass or ceramic microcapsules, metal soaps derived from organic carboxylic acids having from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, for example zinc stearate, magnesium stearate, lithium stearate, zinc laurate or magnesium myristate; barium sulphate, and their mixtures.

Fatty binder
The composition according to the invention may comprise at least one fatty binder. The term fatty binder is understood to mean, within the meaning of the present application, a fatty phase which generally comprises at least one oil. This type of fatty phase is used in particular as dispersing medium for the pulverulent phase. Advantageously, the fatty binder can comprise at least one oil.

The oil can be chosen from the oils conventionally used as binder in loose or compact powders. These oils can in particular be chosen from:
- mink oil, turtle oil, soybean oil, grape seed oil, sesame oil, corn oil, rapeseed oil, sunflower oil, cottonseed oil, avocado oil, olive oil, castor oil, jojoba oil or peanut oil;
- hydrocarbon oils, such as liquid paraffins, squalane or liquid petrolatum;
- fatty esters, such as isopropyl myristate, isopropyl palmitate, butyl stearate, isodecyl stearate, isocetyl stearate, hexyl laurate, isononyl isononanoate, 2-ethylhexyl palmitate, 2-hexyldecyl laurate, 2-octyldecyl palmitate, 2-octyldodecyl myristate, 2-octyldodecyl lactate, di(2-ethylhexyl) succinate, diisostearyl malate, glyceryl triisostearate or diglyceryl triisostearate;
- silicone oils, such as polymethylsiloxanes, polymethylphenylsiloxanes, polysiloxanes modified by fatty acids, fatty alcohols or polyoxyalkylenes, fluorosilicones or perfluorinated oils;
- higher fatty acids, such as myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid, linolenic acid or isostearic acid;
- higher fatty alcohols, such as ketanol, stearyl alcohol or oleyl alcohol;
- poly(methylfluoroalkyl)(dimethyl)siloxanes of formula (I):

in which:
- n represents an integer varying from 5 to 90, in particular from 30 to 80 and especially from 50 to 80,
- m represents an integer varying from 1 to 150, in particular from 1 to 80 and especially from 1 to 40,
- a represents an integer varying from 0 to 5, and
- Rf denotes a perfluoroalkyl radical comprising from 1 to 8 carbon atoms;
and
- their mixtures.

According to a preferred embodiment, the oil is chosen from fatty esters, such as isopropyl myristate, isopropyl palmitate, butyl stearate, isodecyl stearate, isocetyl stearate, hexyl laurate, isononyl isononanoate, 2-ethylhexyl palmitate, 2-hexyldecyl laurate, 2-octyl-decyl palmitate, 2-octyldodecyl myristate, 2-octyl-dodecyl lactate, di(2-ethylhexyl) succinate, diisostearyl malate, glyceryl triisostearate or diglyceryl triisostearate.

According to a more preferred form, the oil is isononyl isononanoate. The oil of the binder can represent from 10 to 100% by weight, with respect to the total weight of the binder. The binder can be present in the composition according to the invention in a content ranging from 0.5 to 15% by weight, with respect to the total weight of the composition, in particular from 1 to 10% by weight and more preferably from 1.5 to 5% by weight.

Waxes and pasty fatty substances
The composition according to the invention can also comprise a wax and/or a pasty fatty substance. The term "wax" is understood to mean, within the meaning of the present invention, a lipophilic fatty compound which is solid at ambient temperature (25 degrees Celsius) and atmospheric pressure (760 mmHg, i.e. 10⁵ Pa), which exhibits a reversible solid/liquid change in state and which has in particular a melting point of greater than or equal to 30 degrees Celsius, especially of greater than or equal to 55 degrees Celsius and which can range up to 250 degrees Celsius, in particular up to 230 degrees Celsius and especially up to 120 degrees Celsius.

On bringing the wax to its melting point, it is possible to render it miscible with the oils and to form a microscopically homogeneous mixture but, on reestablishing the temperature of the mixture at ambient temperature, the wax recrystallizes from the oils of the mixture.

The melting point values correspond, according to the invention, to the melting peak measured using a differential scanning calorimeter (DSC), for example the calorimeter sold under the name DSC 30 by Metler, with a rise in temperature of 5 or 10 degrees Celsius per minute.

The waxes, within the meaning of the invention, can be those generally used in the cosmetic or dermatological fields. They can in particular be hydrocarbon, silicone and/or fluorinated waxes optionally comprising ester or hydroxyl functional groups. They can also be of natural or synthetic origin.

Mention may in particular be made, without implied limitation, of the following waxes:
- beeswax, lanolin wax and Chinese insect waxes; rice wax, carnauba wax, candelilla wax, ouricury wax, cork fibre wax, sugarcane wax, Japan wax and sumac wax; montan wax, microcrystalline waxes, paraffin waxes, ozokerites, ceresin wax, lignite wax, polyethylene waxes, the waxes obtained by the Fischer-Tropsch synthesis, and fatty acid esters and glycerides which are solid at 40 degrees Celsius and in particular at more than 55 degrees Celsius,
- waxes obtained by catalytic hydrogenation of animal or vegetable oils having linear or branched C₈-C₃₂ fatty chains, in particular hydrogenated jojoba oil, hydrogenated sunflower oil, hydrogenated castor oil, hydrogenated coconut oil and hydrogenated lanolin oil,
- silicone waxes or fluorinated waxes, and
- their mixtures.

According to a specific alternative form of the invention, the solid fatty phase can comprise at least one wax chosen from carnauba waxes, paraffin waxes and their mixtures.

According to a preferred embodiment, the wax present in the composition according to the invention can be completely or partially in the powder form, in particular the micronized form, in order to facilitate the use thereof in the preparation of the cosmetic composition.

Mention may in particular be made, among the waxes which can be used in the powder form, of the carnauba wax microbeads sold under the name "Microcare 350 (registered trademark)" by Micro Powders and the paraffin wax microbeads sold under the name "Microease 114S (registered tradmark)" by Micro Powders. Such additional micronized waxes make it possible in particular to improve the properties when the composition is applied to the skin.

The waxes and/or pasty fatty substances can be present in the composition in a content ranging from 0.1 to 8% by weight, with respect to the total weight of the composition, preferably from 0.5 to 5% by weight.

Additives
The composition according to the invention can comprise at lest one other conventional cosmetic ingredient which can be chosen in particular from lipophilic gelling and/or thickening agents, antioxidants, fragrances, preservatives, neutralizing agents, sunscreens, vitamins, moisturizing agents, self-tanning compounds, antiwrinkle active agents, emollients, hydrophilic or lipophilic active principles, agents for combating pollution or free radicals, sequestering agents, film-forming agents, nonelastomeric surfactants, dermo-decontracting active agents, soothing agents, agents which stimulate the synthesis of dermal or epidermal macromolecules and/or which prevent their decomposition, antiglycation agents, agents which combat irritation, desquamating agents, depigmenting, antipigmenting or propigmenting agents, NO synthase inhibitors, agents which stimulate the proliferation of fibroblasts or keratinocytes and/or the differentiation of keratinocytes, agents which act on the microcirculation, agents which act on the energy metabolism of the cells, healing agents, and their mixtures.

According to a preferred embodiment, the composition according to the invention can be an anhydrous composition. The term "anhydrous composition" is understood to mean a composition comprising less than 2% by weight of water, indeed even less than 0.5% by weight of water, and which in particular is devoid of water, the water not being added during the preparation of the composition but corresponding to the residual water contributed by the mixed ingredients.

The fusiform particles may have slits along their major axes. Also, the fusiform particles are less than 40 wt%, preferably between approximately 5 wt% and approximately 20 wt%, more preferably between approximately 10 wt% and approximately 15 wt% of the powder foundation. The surfactant includes zinc stearate, the binder includes a mineral oil or phenyl trimethicone, and the preservative includes phenoxyethanol. T crosslinked polysiloxane comprises first, second and third siloxane units which are SiO₂, R¹SiO_1.5 and R²R³SiO, respectively, wherein R¹, R² and R³ are any one of organic groups, same or different, having a carbon atom directly linked to a silicon atom. The molar ratio of the third siloxane unit with respect to the molar sum of the first, second and third siloxane units is between 1 to 50 percent, approximately.

The molar ratio of the first siloxane unit with respect to the second siloxane unit is between 23:77 and 50:60, approximately. In the powder composition according to the present invention, R¹ and at least one of R² and R³ may preferably selected from the group consisting of epoxy group, (meta) acryloxy group, mercaptoalkyl group, aminoalkyl group and organic groups having any one of preceding groups. According to the present invention, the powder composition may be one of foundation, make-up, loose powder, cheek, eyebrow, mascara, concealer and high-light.

According to the cosmetic method of the present invention:
the filler which is treated with hydrophobic treatment may be at least one filler having a plate or lamellar form, such as lauroyl lysine, mica, talc, boron nitride, kaolin, oxychloride bismuth, barium sulfate, perlite, PTFE, and their mixtures.
the pigment may be one or more of titanium dioxide, optionally surface treated, zirconium or cerium oxides, and also zinc, iron (black, yellow or red) or chromium oxides, manganese violet, ultramarine blue, chromium hydrate and ferric blue, and metal powders, such as aluminium powder or copper powder, and their mixtures; and
the other cosmetically acceptable ingredients may be one or more of waxes, preservatives, cosmetic active principles, moisturizing agents, UV screening agents, thickeners, water, surfactants, binders or fragrances.

The present invention also proposes a powder composition, in particular in a compact powder form, for cosmetic use for providing an improved transfer resistance and hiding capability, the composition containing fusiform particles in addition to a filler on which hydrophobic treatment has been performed and optionally a pigment and other cosmetically acceptable ingredients, the fusiform particles being made of an organosilicone having a crosslinked polysiloxane structure, and having diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometers, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometers, and L₁/L₂ between approximately 1.1 and approximately 3.3.
In a preferred embodiment, the composition according to the invention contains:
(i) at least 5% to 20% of fusiform particles by weight of total composition and
(ii) at least 5%to 20%, preferably from 10 to 15% of hydrophobic treated fillers by weight of total composition, and
(iii) optionally a pigments and/or other cosmetic ingredients.

The present invention also proposes a method for making a powder composition, in particular in a compact powder form, for cosmetic use the composition providing an improved transfer resistance and hiding capability, the method comprising the steps of mixing fusiform particles, a filler on which hydrophobic treatment has been performed and optionally a pigment and other cosmetically acceptable ingredients, the fusiform particles being made of an organosilicone having a crosslinked polysiloxane structure, and having diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometers, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometers, and L₁/L₂ between approximately 1.1 and approximately 3.3.

Fig. 1 is a diagram schematically showing the shape of a fusiform particle Fig. 2 is a diagram showing the color coverage of the method according to the present invention. Fig. 3 is a diagram showing the method for measuring transfer resistance. Fig. 4 shows the results of transfer measurements for different combinations of treatment of fillers and whether or not fusiform particles are added. Fig. 5 shows transfer quantification results. Fig. 6 shows the method of friction coefficent measurement. Fig. 7 shows the results of friction coefficient measurements.

Embodiments of the present invention will be described herebelow. It should be noted that the embodiments and descriptions thereof are provided solely to assist in understanding the present invention and should not be construed as limiting the present invention in any way to the embodiments described below.

Fig. 1 schematically shows the shape of a fusiform particle. The particle has a rugby ball shape, that is, a major axis along which the diameter is larger than any other diameters, and two minor axes which are perpendicular to the major axis and which are perpendicular to each other. In fact the two minor axes may be defined in any direction as long as the axes are in the plane perpendicular to the major axes. The diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometers, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometers, and L₁/L₂ between approximately 1.1 and approximately 3.3. As may be understood from Fig. 1, there is a groove on the surface along the major axis, in the particles used in the experiments described below. However, the groove is not necessary.

Table 1 below shows morphology of the particles according to the present invention (SP9) which have fusiform shapes, and the comparative particles which have a bowl (Chawan) shape (SP10), spherical shapes (SP11 - SP15). Their particle sizes and oil and water absorption are also shown in Table 1.

* Fusiform Silicon particles similar to those disclosed by Japanese Patent Application, Publication No. 2003-171465. Same definition applies to other appearances unless otherwise specified.

Table 2 shows the ingredients of each one of the compositions. The compositions include the elements which are typical in a cosmetic composition.

Table 3 below shows the results of sensorial evaluation of the compositions. The compositions were applied on 11 models, and the models evaluated several criteria (fit to skin, homogeneity, coverage, hiding pores and lines, lasting). The results of SP9 is distinguished by the evaluation that it provides more feel "fit to the skin" and "coverage" than other compositions wherein spherical fillers are used.

The coverage of the composition, when it is applied on the skin surface which may have imperfections in particular pores and/or lines in particular on skin face, has been determined according to the contrast ratio calculated by the formula as follows:

wherein L_black and L_white designate lightness of black and white specimen, respectively, to which the composition is applied.

The inventors also made additional comparative tests with non treated fillers, confirming the importance in the invention of hydrophobic treated fillers as shown by Table 4. With respect to the total weight of the composition, fillers are preferably from 10 to 85% by weight and more preferably from 20 to 80% by weight.

Fig. 4 shows the transfer characteristics of compositions containing either hydrophobic treated or non treated fillers. As shown in Fig. 4, the best results are obtained with hydrophobic treated fillers in association with fusiform particles.

The inventors also tested different % of fusiform particles (5%, 10% and 15%) and obtained the good results either with 5%, 10% and 15% of fusiform particles as shown by Table 05.

* Fusiform Silicon particles as disclosed by Japanese Patent Application, Publication No. 2003-171465.

Fig 5 shows the transfer characteristics of compositions containing 5%, 10%, 25% of fusiform particles in association with hydrophobic treated particles. According to this result, the compositions of 5-15% rugby ball (Fusiform silicon particles) in hydrophobic treatment formula are effective to resist transfer, and better results with 10 and 15% in term of transfer resistance as shown by Fig. 05

Fig. 2 shows that SP9 wherein fusiform particles are contained depict good hiding or conceal capacity even compared with SP8 wherein no fusiform particles are added but the amount of surface treated talc is increased instead and SP11 wherein silicone gum with silicone resin is added in the place of fusiform particles. The results of other compositions are inferior.

Fig. 3 shows how the transfer characteristics of compositions are measured. The composition to be tested is applied on the surface of Bio Skin, another layer such as Supplare is attached and pressed on to the Bio Skin surface to which the composition has been applied with a predetermined weight of 1,424 g, and then the amount of the composition transferred from Bio Skin to Supplare is measured.

Fig. 4 shows the results of this measurement. The three columns on the left side of the graph depict the amount of transferred composition (difference from bare supplare) by the vertical axis, the composition containing neither spherical particles nor fusiform particles (SP8). Delta E shown by the vertical axis is defined by the equation as follows:

The three columns correspond to the compounds which contain non-treaded fillers, silicone treated fillers and amino acid treated fillers, respectively, the latter two being hydrophobic surface treatments. The three columns at the center of the graph depict the amount of transferred composition for the compositions containing spherical particles (SP11), and the right end columns correspond to the amount of transferred composition for the compositions containing fusiform particles (SP9: the composition according to the present invention). It is clearly observed that a combination of fusiform particles and hydrophobic surface treated filler (silicone treated or amino acid treated fillers) represented by the rightmost two columns depict the lowest transfer. Therefore, the test data indicates that combination of fusiform particles and hydrophobic treated fillers provides the best non-transfer performance.

Fig. 5 shows how the non-transfer characteristics of the composition relates to the amount of fusiform particles contained in the composition. It is observed that the amount of transferred composition decreases as the proportion of fusiform particles increase from 5 wt% to 15 wt% of the compound.

Fig. 6 shows how friction coefficients of compositions containing various particles and not containing a particle have been measured. A 2 mm thick Bio Skin to which the compositions to be tested are applied is laid on a slide glass and another Bio Skin is pressed onto the first Bio Skin so that the surface on which the compositions are applied are between the first and the second Bio Skins. Then, fixing the first Bio Skin to the slide glass and pull the second Bio Skin to measure the friction force acting between the two Bio Skin surfaces.

Fig. 7 shows the results of the above-described friction coefficient measurements. SP9 which is a composition according to the present invention depicts the smallest friction coefficient next to SP12 and SP15 both containing spherical silica particles instead of fusiform particles.

As may be clear now from the above-described test data, cosmetic composition containing fusiform particles and fillers on which hydrophobic surface treatment such as silicone treatment or amino acid treatment has been performed depicts enhanced characteristics with regard to hiding of skin imperfections such as pores and/or lines yet depicting the features which are desirable for cosmetic applications such as resistance against transfer and smoothness when applied.

Claims (11)

1. A cosmetic method for hiding skin imperfections and in particular pores and/or lines, in particular on skin face, the method comprising the steps of applying a cosmetic powder composition, in particular in a compact powder form, containing at least (i) fusiform particles being made of an organosilicone having a crosslinked polysiloxane structure, and having diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometers, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometers, and L₁/L₂ between approximately 1.1 and approximately 3.3 and (ii) hydrophobic surface treated filler and optionally (iii) a pigment and other cosmetically acceptable ingredients.
2. A cosmetic method according to claim 1, wherein the fusiform particles have slits along their major axes.
3. A cosmetic method according to one of claims 1 and 2, wherein the fusiform particles are between 5 wt% and 20 wt%, more preferably between 10 wt% and 15 wt% of the powder composition.
4. A cosmetic method according to one of claims 1 to 3 wherein the filler is a non-spherical filler having a plate or lamellar form, such as lauroyl lysine, mica, talc, boron nitride, kaolin, oxychloride bismuth, barium sulfate, perlite, PTFE, and their mixtures.
5. A cosmetic method according to one of claims 1 to 4wherein the filler is mica, talc, and their mixture
6. A cosmetic method according to one of claims 1 to 5 wherein the filler represents between 5 and 90 % by weight with respect to the total weight of the composition, preferably from 10 to 85% by weight and more preferably from 20 to 80% by weight, and more preferably from 60 to 80% by weight.
7. A cosmetic method according to one of claims 1 to 6 wherein the hydrophobic treatment on the filler is silicone treatment, amino acid, fluorinated treatment, preferably silicone or amino acid treatment or both performed on the filler surface.
8. A cosmetic method according to one of claims 1 to 7 wherein:
   the pigment includes one or more of titanium dioxide, optionally surface treated, zirconium or cerium oxides, and also zinc, iron (black, yellow or red) or chromium oxides, manganese violet, ultramarine blue, chromium hydrate and ferric blue, and metal powders, such as aluminium powder or copper powder, and their mixtures; and
   the other cosmetically acceptable ingredients include one or more of waxes, preservatives, cosmetic active principles, moisturizing agents, UV screening agents, thickeners, water, surfactants, binders or fragrances.
9. A cosmetic method according to one of claims 1 and 5, wherein the crosslinked polysiloxane comprises first, second and third siloxane units which are SiO₂, R¹SiO_1.5 and R²R³SiO, respectively, wherein R¹, R² and R³ are any one of organic groups, same or different, having a carbon atom directly linked to a silicon atom.
10. A cosmetic method according to any one of claims 1 to 12 wherein the powder composition is a make-up or caring product for the skin in the form of a blusher, an eyeshadow, a face powder, a foundation, a concealer, a product for making up the body, a product for caring for the face, a product for caring for the body or an antisun product.
11. A cosmetic method according to previous claims wherein the composition is applied on skin of persons having skin imperfections, in particular pores and/or lines.

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