Use of specific metal oxides for organic compounds on photoconverting keratin materials

Abstract

This invention relates to a compound containing at least one formula A a B b O n‑x Solid particles of metal oxide OM1 are used to reduce and / or eliminate deposits of organic compounds on the surface of keratin materials or on the surface of objects in contact with said keratin materials, wherein: A represents a metal selected from bismuth, calcium, sodium, lanthanum, barium, copper, tin, magnesium, zinc, and silver; B represents a metal selected from tungsten, vanadium, gallium, niobium, and strontium; a is an integer in the range of 1 to 4; b is an integer in the range of 1 to 10; n is an integer in the range of 3 to 6; and x is a decimal less than n in the range of 0.1 to 5. The invention also relates to a method for cosmetically treating keratin materials or the surface of objects in contact with said keratin materials, using a cosmetic composition or article containing such solid particles, followed by exposure to light.

Description

[0001] This invention relates to the use of specific metal oxides for photoconversion of undesirable organic compounds that can be present on keratin materials, particularly human keratin materials such as skin, scalp, and keratin fibers such as hair. This specific use makes it possible to eliminate deposits of organic compounds on the surface of keratin materials or on the surface of objects in contact with said keratin materials.

[0002] The present invention also relates to a method of using such a metal oxide for cosmetic treatment of keratin materials or the surface of an object in contact with keratin materials.

[0003] This invention specifically enables the reduction and / or slowing down of oil exudation in keratin materials.

[0004] Keratin materials tend to lose some of their aesthetic qualities over time due to the deposition or formation of undesirable organic compounds on their surface. These compounds can originate from a wide variety of factors, such as natural oil secretion (especially related to sebum production), sweating, dandruff removal, pollution, and humidity. These may be compounds secreted by the body (fatty substances such as sebum, protein derivatives, and dead skin residue) or external compounds deposited on the keratin material, such as dirt, pollutants from vehicles or industry, etc.

[0005] The presence of these organic compounds on keratin materials can cause discomfort and / or aesthetic problems. In particular, these compounds are detrimental to the visual appearance and feel of keratin materials.

[0006] Therefore, for example, natural oil production exacerbates hair's condition, causing it to tend to clump together. This makes hair more difficult to style, resulting in an unpleasant greasy shine and an unpleasant waxy feel. Similarly, sebum secreted by the skin gives it a greasy and shiny appearance that is considered particularly unattractive, especially on the face.

[0007] To remove unwanted organic compounds, detergent compositions such as soap, shower gel, and shampoo are commonly used. This is because detergent compositions are very effective at washing keratin materials and can remove both compounds secreted by the body and dirt from the external environment.

[0008] However, the beneficial effects of washing quickly disappear, and unwanted organic compounds redeposit within days or even hours, causing the aforementioned problems again. Therefore, individuals wishing to avoid these issues tend to increase washing frequency, which often stimulates bodily secretions and increases scaling, thus accelerating the natural re-oiling of keratin material after washing.

[0009] Furthermore, these washes make it impossible to regularly remove unwanted compounds as they accumulate and to maintain the clean appearance of keratin materials. Typically, people wait for the unwanted compounds to accumulate sufficiently before washing the keratin material. Washing must be repeated periodically, and individuals often tolerate the presence of these unwanted compounds between washes.

[0010] In addition, a water source, preferably hot or warm water, is required for these washes. Detergent compositions typically contain large amounts of surfactants that can cause discomfort, such as stinging on the scalp, skin, or eyes.

[0011] To more quickly clean keratin materials and avoid wetting them, the use of dry compositions such as "dry" shampoos or disposable wipes has been proposed. Cleaning with a dry shampoo involves spraying absorbent particles onto the hair and then actively combing it to remove dirt. However, complete removal of dirt is often difficult to achieve. The results are not very satisfactory: hair is dry, not very shiny, and feels rough. Furthermore, the use of disposable wipes containing detergent compositions deposited on a textile carrier causes environmental problems.

[0012] Other known solutions include removing all or some unwanted compounds (including sebum, contaminants, etc.) from keratin materials through chemical oxidation. The principle is to bind the oxidant and the compounds to be removed together on the hair. However, this technique is not satisfactory because its effects are immediate, and it does not last over time due to the lack of persistence of the oxidant associated with its complete consumption during the reaction. Furthermore, the oxidant used may have harmful effects on keratin materials.

[0013] It is also known that, in the presence of UV light and a catalyst (such as titanium dioxide), photocatalysis can remove all or some foreign or unwanted substances from keratin materials. However, these photocatalysts exhibit only limited activity under visible light irradiation. The photoconversion kinetics are generally too slow, meaning that unwanted compounds accumulate faster than they are removed.

[0014] The purpose of this invention is, in particular, to solve the above-mentioned problems.

[0015] More specifically, the present invention aims to provide a method for cosmetic treatment of keratin materials, particularly human keratin materials, to reduce and / or slow down oil production associated with the deposition of both natural organic compounds (particularly those secreted by the body) and organic compounds from the external environment. The present invention particularly enables the prevention and / or reduction of sebum deposition on keratin materials.

[0016] This invention also makes it possible to eliminate organic compounds that can deposit on the surface of objects in contact with keratin materials.

[0017] After extensive research in this area, the applicant discovered that these and other objectives can be achieved by using particles of a specific metal oxide as described above.

[0018] Therefore, the present invention relates to a compound containing at least one formula A a B b O n-x The use of solid particles of metal oxide OM1 for preventing, reducing, and / or eliminating the deposition of organic compounds on the surface of keratin materials, particularly human keratin materials, or on the surface of objects in contact with said keratin materials, wherein:

[0019] A represents a metal selected from bismuth, calcium, sodium, lanthanum, barium, copper, tin, magnesium, zinc, and silver;

[0020] B indicates a metal selected from tungsten, vanadium, gallium, niobium, and strontium;

[0021] a is an integer in the range from 1 to 4;

[0022] b is an integer in the range from 1 to 10;

[0023] n is an integer in the range of 3 to 6; and

[0024] x is a decimal less than n in the range from 0.1 to 5.

[0025] The applicant has discovered that the specific OM1 oxide defined above is very effective at catalyzing the photodegradation of organic compounds that can be present on keratin materials, with kinetics high enough to eliminate already deposited organic compounds and degrade both when such compounds are present, which makes it possible to reduce deposits and prevent the accumulation of new deposits.

[0026] Therefore, this invention enables the prevention and / or reduction of deposits of undesirable organic compounds that can be present on keratin materials, whether these organic compounds are compounds originating from the external environment (e.g., stains, dirt, contaminants) or compounds secreted by the body, particularly proteins and fats, and especially sebum. Thus, this invention enables the elimination of organic compounds when they are present, and ensures the continued cleanliness of keratin materials.

[0027] Furthermore, when keratin materials come into contact with objects, more or less transfer of organic compounds often occurs from the surface of the keratin material to the surface of the object. This can occur particularly on textiles that come into contact with skin, scalp, and hair, and generally on any object that comes into contact with these. The present invention also makes it possible to prevent and / or reduce deposits on the surfaces of these objects.

[0028] This invention does not require the treated keratin material or surface to be exposed to a strong light source, provided that the oxides according to the invention remain effective, including under weak or moderate light exposure sources, particularly natural light. Furthermore, the metal oxides according to the invention are effective in both external environments (including under low levels of sunlight) and internal environments, in the absence of direct exposure to a light source.

[0029] This invention enables the destruction of oily secretions of keratin materials (especially sebum) and compounds generated from the transformation of these secretions, such as aldehydes, ketones, or peroxide derivatives produced by oxidation with oxygen, ozone, or microbial agents. Therefore, this invention reduces the inconveniences caused by these oily secretions, such as a shiny, soiled appearance, oily odor, or irritating compounds that may cause adverse reactions (such as peeling). This invention also enables the destruction of organic compounds generated from aqueous bodily secretions and compounds generated from the transformation of these organic compounds, such as acidic derivatives produced by oxidation with oxygen, ozone, or microbial agents. Therefore, the inconveniences of these aqueous secretions (such as stickiness, staining, clothing marks, or odor) are reduced.

[0030] Undesirable compounds can be produced through bodily secretions, but can also be deposited on keratin materials through airborne transport or contact. This invention allows for a reduction in their quantity, and thus enables users to overcome the drawbacks of contamination, odor, bacteria, germs, and other microorganisms that can accumulate on keratin materials.

[0031] According to one variant, the oxide particles according to the invention are used to eliminate or reduce the amount of compounds deposited on objects in contact with keratin materials. This is particularly true for fatty substances, such as those produced during contact with the body during handling and giving the object a stained appearance. This also applies to volatile organic molecules (such as fragrances or odors from humans and animals) that gradually produce malodorous compounds after deposition and impart an unpleasant odor to the object. To overcome these inconveniences, the oxide particles according to the invention can be applied to or integrated into the surface of the object.

[0032] The application according to the invention enables the removal of fatty substances, particularly from the surface of keratin materials or objects in contact with them. It reduces oil production in keratin materials, and especially reduces their natural re-oiling due to sebum secretion.

[0033] The present invention also relates to a method for cosmetically treating keratin materials or surfaces of objects in contact with keratin materials, the method comprising:

[0034] (1) Applying a cosmetic composition comprising solid particles to the material or the surface, said solid particles comprising at least one of the formula A as defined above. a B b O n-x The metal oxide OM1; then

[0035] (2) Expose the material or the surface to natural or artificial light.

[0036] According to a first preferred embodiment, particles containing metal oxide OM1 are prepared by flame spray pyrolysis (FSP).

[0037] According to the second embodiment, which is also preferred, metal oxide OM1 is used in combination with a second metal oxide OM2 that is different from oxide OM1, and as described below, the second oxide OM2 may be present in the particles containing oxide OM1 or in different solid particles.

[0038] Other subjects, features, aspects, and advantages of the invention will become even clearer and more apparent after reading the following description and examples.

[0039] In this specification and unless otherwise indicated:

[0040] - The expression "at least one / kind" is equivalent to the expression "one / kind or more / kinds" and can be replaced by it;

[0041] The expression "between" is equivalent to the expression "ranging from..." and can be replaced by it, and implies that the limit value is included;

[0042] - The term "keratin material" specifically includes skin, scalp, nails, and keratin fibers such as hair, body hair, eyelashes, and eyebrows;

[0043] - "alkyl" should be understood as referring to "alkyl group", that is, C1 to C2. 10 In particular, straight-chain or branched hydrocarbon groups of C1 to C8, more particularly C1 to C6, and preferably C1 to C4, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl or tert-butyl;

[0044] - The term "aryl" should be understood to mean a monocyclic or fused or non-fused polycyclic carbonyl group comprising 6 to 22 carbon atoms, wherein at least one ring is aromatic; preferably, the aryl group is phenyl, biphenyl, naphthyl, indenyl, anthraceneyl or tetrahydronaphthyl, preferably phenyl;

[0045] - The "arylate" group should be understood to mean that it contains one or more -C(O)O groups. -Aryl groups of carboxylic acid groups (such as naphthalene dicarboxylate or cycloalkanoate);

[0046] - "Complex metal" should be understood as meaning that metals form "metal complexes" or "coordination compounds", in which the metal ion corresponding to the central atom is chemically bonded to one or more electron donors (ligands);

[0047] - "Ligand" should be understood to mean a coordinating organic chemical group or compound, that is, one that contains at least one carbon atom and is capable of coordinating with a metal, and once coordinated or complexed, produces a metal compound (internal complex or chelate) with a predetermined number of electrons corresponding to the coordination layer principle - see Ullmann's Encyclopedia of Industrial Chemistry, "Metal complex dyes", 2005, pp. 1-42. More specifically, a ligand is an organic group that contains at least one electron-donating group via an induced and / or mediating effect, more particularly having at least one amino, phosphine, hydroxyl, or thiol electron-donating group, or the ligand is a stable carbene, particularly an "Arduengo" type (imidazolium-2-yl) stable carbene, or contains at least one carbonyl group. As ligands, more specific references may be made to: i) those containing at least one phosphorus atom -P<, i.e., phosphine, such as triphenylphosphine; ii) bidentate ligands of the formula RC(X)-CR'R”-C(X)-R”', wherein R and R”” are the same or different, representing straight-chain or branched (C1-C6) alkyl groups, and R' and R” are the same or different, representing hydrogen atoms or straight-chain or branched (C1-C6) alkyl groups, preferably R' and R” representing hydrogen atoms, X representing oxygen or sulfur atoms, or an N(R) group, wherein R represents hydrogen atoms or straight-chain or branched (C1-C6) alkyl groups, such as acetylacetone or β-diketone; iii) (poly)hydroxycarboxylic acid ligands of the formula [HO-C(O)]nAC(O)-OH and their deprotonated forms, wherein when n When n has a value of zero, A represents a monovalent group, or when n is greater than or equal to 1, A represents a polyvalent group, which is saturated or unsaturated, cyclic or acyclic, and aromatic or non-aromatic, based on a hydrocarbon containing 1 to 20 carbon atoms, optionally with one or more heteroatoms inserted and / or optionally substituted (especially substituted with one or more hydroxyl groups); preferably, A represents a monovalent (C1-C6) alkyl or polyvalent (C1-C6) alkylene group optionally substituted with one or more hydroxyl groups; and n represents an integer between 0 and 10 including end values; preferably, n is between 0 and 5, for example in 0, 1, or 2; such as lactic acid, glycolic acid, tartaric acid, citric acid, and maleic acid, and aryl groups such as naphthalene dicarboxylate; and iv) C2 to C 10Polyol ligands containing 2 to 5 hydroxyl groups, especially ethylene glycol and glycerol, and more particularly, ligands having carboxyl, carboxylate or amino groups, especially selected from acetate, (C1-C6) alkoxylate, (di)(C1-C6) alkylamino and aryl groups, such as naphthalene dicarboxylate or cycloalkanoate groups;

[0048] The term "fuel" should be understood to mean a liquid compound that burns in a chemical reaction with molecular oxygen and energy, producing heat: combustion. Specifically, liquid fuels are selected from: protic solvents, particularly alcohols such as methanol, ethanol, isopropanol, n-butanol, and glycols; aprotic solvents, particularly selected from esters such as methyl esters and those derived from acetate esters such as 2-ethylhexyl acetate; acids such as acetic acid and 2-ethylhexanoic acid (EHA); acyclic ethers such as diethyl ether, methyl tert-butyl ether (MTBE), methyl tert-amyl ether (TAME), methyl tert-hexyl ether (THEME), ethyl tert-butyl ether (ETBE), ethyl tert-amyl ether (TAEE), diisopropyl ether (DIPE); cyclic ethers such as tetrahydrofuran (THF); aromatic hydrocarbons or aromatic hydrocarbons such as xylene; non-aromatic hydrocarbons; and mixtures thereof. Fuels may optionally be selected from liquefied hydrocarbons such as acetylene, methane, propane, or butane; and mixtures thereof.

[0049] First metal oxide OM1

[0050] The solid particles used in this invention contain at least one formula A a B b O n-x The metal oxide OM1, wherein:

[0051] A represents a metal selected from bismuth, calcium, sodium, lanthanum, barium, copper, tin, magnesium, zinc, and silver;

[0052] B indicates a metal selected from tungsten, vanadium, gallium, niobium, and strontium;

[0053] a is an integer in the range from 1 to 4;

[0054] b is an integer in the range from 1 to 10;

[0055] n is an integer in the range of 3 to 6; and

[0056] x is a decimal less than n in the range from 0.1 to 5.

[0057] A is preferably selected from bismuth and barium, and more preferably A represents bismuth.

[0058] B is preferably selected from tungsten and vanadium, and more preferably B represents tungsten.

[0059] Integers a and b, as well as x, depend on the properties of metals A and B.

[0060] The decimal x is preferably in the range of 0.1 to 1.9, more preferably from 0.2 to 1.5, and even more preferably from 0.3 to 1. Particularly preferably, x is greater than or equal to 0.5 and strictly less than 1.

[0061] According to a particularly preferred embodiment, oxide OM1 has the formula Bi2WO 6-x , where x is a decimal in the range of 0.2 to 1.5, preferably from 0.3 to 1; and even better, x is greater than or equal to 0.5 and strictly less than 1.

[0062] Preferably, the metal oxide OM1 is in a crystalline state.

[0063] Optional second metal oxide OM2

[0064] According to a preferred embodiment, a metal oxide OM1 is combined with a second metal oxide denoted as OM2, the second metal oxide corresponding to formula M. c O k ,in:

[0065] M represents a transition metal;

[0066] c is an integer in the range from 1 to 3; and

[0067] k is a decimal in the range of 0.1 to 4.

[0068] The combined use of the two types of oxides, OM1 and OM2, allows for further enhancement of the photoconversion kinetics of undesirable organic compounds. This enables increased efficacy in eliminating these compounds, provided there is equal light exposure, or good efficacy is maintained, including in the presence of low-intensity light exposure, such as during indoor or winter use.

[0069] Preferably, M represents copper.

[0070] According to a particularly preferred embodiment, the oxide OM2 has the formula CuO.

[0071] Preferably, the metal oxide OM2 is in a crystalline state.

[0072] Metal oxide OM2 can exist in particles containing metal oxide OM1 (denoted as particle P1), or in the form of different particles P2 as described below.

[0073] Preferably, the amount of metal oxide OM2 is less than the amount of metal oxide OM1. More preferably, the molar ratio of the amount of metal oxide OM1 to the amount of metal oxide OM2 is greater than or equal to 1, preferably greater than or equal to 2, more preferably greater than or equal to 3, even more preferably greater than or equal to 4, and even more preferably greater than 4.

[0074] Solid particles of metal oxides

[0075] In the following text, P1 refers to particles containing the metal oxide OM1.

[0076] The particle P1 comprises a metal oxide OM1 alone or in combination with another metal oxide (such as, in particular, the aforementioned oxide OM2).

[0077] According to a preferred embodiment, particle P1 does not include an upper coating.

[0078] According to a particularly preferred embodiment, particle P1 is composed entirely of the oxide OM1.

[0079] Particle P1 preferably has a number-average diameter ranging from 1 to 1000 nm, more preferably from 10 to 200 nm.

[0080] According to another preferred embodiment, the second oxide OM2 is in the form of a solid particle P2, different from the particle P1, and preferably has a number-average diameter ranging from 1 to 300 nm, preferably from 2 to 20 nm, and even more preferably from 2 to 10 nm.

[0081] In a later embodiment, preferably, the number-average diameter of particle P1 is greater than the number-average diameter of particle P2, and more preferably, the number-average diameter of particle P1 is greater than or equal to twice the number-average diameter of particle P2.

[0082] In a later embodiment, it is preferable to combine particles P2 containing oxide OM2 with particles P1 containing oxide OM1. The particles may be in the form of clusters, wherein particles P1 are combined with each other and / or with particles P2 (each particle P1 may be in contact with both particles P1 and P2), or each particle P1 is combined with only particles P2 (particles P2 are inserted between particles P1 such that particles P1 do not directly contact each other).

[0083] The number-average diameters of particles P1 and P2 according to the present invention can be determined by transmission electron microscopy or by X-ray diffraction (XRD).

[0084] Preparation of solid particles

[0085] According to a preferred embodiment, the solid particles P1 comprising at least one metal oxide OM1 used in the present invention are obtained by flame spray pyrolysis (FSP) or can be obtained by flame spray pyrolysis.

[0086] Similarly, when using particles P2 containing metal oxide OM2, these particles P2 are preferably obtained by flame spray pyrolysis or can be obtained by flame spray pyrolysis.

[0087] According to a preferred embodiment, oxides OM1 and OM2 are prepared in the same flame in a single FSP device.

[0088] Flame spray pyrolysis, or FSP, is a well-known method that essentially involves developing ultrafine powders (with controlled morphologies) of single or mixed oxides of various metals (e.g., SiO2, Al2O3, B2O3, ZrO2, GeO2, WO3, Nb2O5, SnO2, MgO, ZnO) and / or their deposition on various substrates. This is achieved by starting with a wide variety of metal precursors, typically in organic or inorganic, preferably flammable, aerosolizable liquid form. The liquid, sprayed into a flame, releases metal oxide nanoparticles, particularly through combustion, which are then atomized onto these diverse substrates by the flame itself. This method has also been used to fabricate oxide particles coated with a silica layer. For example, the principles of this method are reviewed in Johnson Matthey’s recent (2011) publication, “Flame Spray Pyrolysis: a Unique Facility for the Production of Nanopowders”, Platinum Metals Rev., 2011, 55, (2), 149-151. For example, many variations of the FSP process and reactor are described in the following patents or patent applications: US 5 958 361, US 2 268 337, WO 01 / 36332 or US 6 887 566, WO 2004 / 005184 or US 7 211236, WO 2004 / 056927, WO 2005 / 103900, WO 2007 / 028267 or US 8 182 573, WO 2008 / 049954 or US 8 231 369, WO 2008 / 019905, US 2009 / 0123357, US 2009 / 0126604, US 2010 / 0055340, WO 2011 / 020204.

[0089] According to a preferred embodiment, solid particles P1 comprising at least one metal oxide OM1 are prepared by a method comprising at least the following steps:

[0090] a. To prepare composition (C) by adding one or more metal A precursors and one or more metal B precursors to a flammable solvent or a mixture of flammable solvents; then

[0091] b. In a flame spray pyrolysis apparatus, a flame is formed by injecting composition (C) and oxygen-containing gas until formula A as defined above is obtained. a B b O n-x Particles of metal oxide OM1 P1.

[0092] The precursors of metals A and B and the combustible solvents that can be used according to the present invention can be selected from metal precursors and combustible solvents conventionally used for flame spray pyrolysis.

[0093] Preferably, the metal A precursor and metal B precursor contained in the composition (C) each contain one or more A and B atoms (which optionally are complexed with one or more ligands containing at least one carbon atom).

[0094] More preferably, the ligand is selected from acetate, nitrate, ammonium, (C1-C6) alcohol, (bis(C1-C6) alkylamino), and aryl groups (such as naphthalene dicarboxylate or cycloalkanoate).

[0095] Preferably, the flammable solvent is selected from proton flammable solvents, non-proton flammable solvents, and mixtures thereof; more preferably, it is selected from alcohols, esters, acids, acyclic ethers, cyclic ethers, aromatic hydrocarbons or aromatic hydrocarbons, non-aromatic hydrocarbons, and mixtures thereof; and even more preferably, it is selected from (C1-C8)alkylcarboxylic acids such as acetic acid or 2-ethylhexanoic acid (EHA), (C1-C6)alkane (mono / di / tri)ols such as ethylene glycol, (C1-C8)alkylcarbonyl (C1-C8)alkoxy such as 2-ethylhexyl acetate, di(C1-C6)alkyl ethers such as diethyl ether, methyl tert-butyl ether (MTBE), methyl tert-amyl ether (TAME), methyl tert-hexyl ether (THEME), ethyl tert-butyl ether (ETBE), ethyl tert-amyl ether (TAEE), diisopropyl ether (DIPE), tetrahydrofuran (THF), xylene, and mixtures thereof.

[0096] According to a preferred embodiment, the flammable solvent is selected from aprotic flammable solvents containing at least three carbon atoms and mixtures thereof; more preferably, it is selected from xylene, tetrahydrofuran, 2-ethylhexyl acetate and mixtures thereof.

[0097] According to another embodiment, the flammable solvent is selected from proton flammable solvents containing at least two carbon atoms and mixtures thereof; more preferably selected from acetic acid, ethylene glycol, 2-ethylhexanoic acid (EHA) and mixtures thereof.

[0098] Advantageously, the total content of the precursors of metals A and B in composition (C) is between 1% and 90% by weight, particularly between 5% and 80% by weight, preferably between 10% and 70% by weight, and more preferably between 25% and 60% by weight, relative to the total weight of composition (C).

[0099] The method for preparing particles P1 further includes step (b): injecting the composition (C) and oxygen-containing gas into a flame spray pyrolysis (FSP) apparatus to form a flame.

[0100] During step (b), composition (C) and oxygen-containing gas are advantageously injected into the flame spray pyrolysis apparatus through two separate syringes. In other words, composition (C) and oxygen-containing gas are injected separately, i.e., they are not injected through a single nozzle.

[0101] More specifically, composition (C) is delivered through one tube, while oxygen-containing gas (also known as "dispersed oxygen") is delivered through another tube. The inlets of the two tubes are arranged to create a negative pressure on the oxygen-containing gas, and the composition (C) is drawn in and converted into droplets by the Venturi effect.

[0102] Step (b) may optionally further include an additional injection of a “premixed” mixture containing oxygen and one or more combustible gases. This “premixed” mixture is also known as “support flame oxygen” and is capable of producing a support flame designed to ignite and sustain the flame generated by the composition (C) and the oxygen-containing gas (i.e., “dispersed oxygen”).

[0103] Preferably, during step (b), the composition (C), oxygen-containing gas, and optionally a "premixed" mixture (if present) are injected into a reaction tube, also referred to as a "closed tube." Preferably, the reaction tube is made of metal or quartz. Advantageously, the reaction tube has a height greater than or equal to 20 cm, more preferably greater than or equal to 40 cm, and even more preferably greater than or equal to 50 cm. Advantageously, the length of the reaction tube is between 30 cm and 300 cm, preferably between 40 cm and 200 cm, more preferably between 45 cm and 100 cm, and even more preferably equal to 50 cm.

[0104] The weight ratio of the mass of the solvent present in composition (C) to the mass of the oxygen-containing gas is defined as follows:

[0105] First, the amount of oxygen-containing gas (also known as oxidant compound) is calculated so that the combination formed by the composition (C) (i.e., combustible solvent and metal precursor) and the oxygen-containing gas on the other hand can react together in the combustion reaction in stoichiometric proportions (therefore there is no excess or deficiency of oxidant compound).

[0106] Starting with the calculated oxygen content (also known as the "calculated oxidant"), a new calculation is performed to deduce the amount of oxygen to be injected (also known as the "oxidant to be injected") from it, based on the following formula: [Formula to be injected]

[0107]

[0108] in Preferably between 0.30 and 1.0, and more preferably between 0.7 and 1.0.

[0109] This method is specifically defined by Turns, SR in An Introduction to Combustion: Concepts and Applications, 3rd Edition; McGraw-Hill: New York, 2012.

[0110] Preferably, the flame formed during step (b) has a temperature of 2000°C or higher in at least a portion of the flame.

[0111] Solid particles P2 containing metal oxide OM2 can be prepared by following the same principle as that used to prepare particles P1 described above.

[0112] According to a preferred embodiment, solid particles P2 comprising at least one metal oxide OM2 are prepared by a method comprising at least the following steps:

[0113] a. A composition (C') is prepared by adding one or more metal M precursors to a flammable solvent or a mixture of flammable solvents; then

[0114] b. In a flame spray pyrolysis apparatus, a flame is formed by injecting a composition (C') and an oxygen-containing gas until formula M as defined above is obtained. c O k Particles of metal oxide OM2.

[0115] Those skilled in the art will readily understand how to adapt the above detailed description of the preparation of particle P1 to the preparation of particle P2.

[0116] According to a preferred embodiment, solid particles P1 and P2 are prepared simultaneously in the same flame spray pyrolysis apparatus.

[0117] In this embodiment, solid particles P1 containing at least one metal oxide OM1 and solid particles P2 containing at least one metal oxide OM2 are prepared by combining them through a method comprising at least the following steps:

[0118] a. On the one hand, a first composition (C) is prepared by adding one or more metal A precursors and one or more metal B precursors to a flammable solvent or a mixture of flammable solvents; and on the other hand, a second composition (C') is prepared by adding one or more metal M precursors to a flammable solvent or a mixture of flammable solvents; then

[0119] b. In a flame spray pyrolysis apparatus, a flame is formed by injecting compositions (C) and (C') along with oxygen-containing gas until formula A as defined above is obtained. a B b O n-x The metal oxide OM1 particles P1 and the formula M as defined above c O k Particles of metal oxide OM2.

[0120] According to a preferred embodiment, a single composition (C”) containing one or more metal A precursors, one or more metal B precursors and one or more metal M precursors in a flammable solvent or a mixture of flammable solvents is used instead of two separate compositions (C) and (C’).

[0121] use

[0122] The use of the solid particles P1 comprising at least one metal oxide OM1 according to the present invention is intended to reduce or even eliminate the deposition of unwanted organic compounds on the surface of keratin materials, particularly human keratin materials, or on the surface of objects in contact with said materials.

[0123] Preferably, the keratin material is selected from skin, scalp, and hair.

[0124] Preferably, the undesirable organic compounds are selected from proteins and fats secreted by the body. This invention is particularly aimed at preventing, reducing, and / or eliminating sebum deposits on the surface of keratin materials or on the surface of objects in contact with keratin materials.

[0125] To carry out the present invention, the aforementioned particles P1 and optionally P2 are brought into contact with keratin material or the surface to be treated. The keratin material or the surface to be treated is then exposed to light.

[0126] According to one embodiment of the invention, the aforementioned particles P1 and optionally particles P2 are applied directly to the keratin material or the surface to be treated. The particles may be applied as is, either in powder form or dispersed in a cosmetic composition.

[0127] According to another embodiment of the invention, the aforementioned particles P1 and optionally P2 are integrated into an article intended to be applied to a keratin material. Particularly in the case of absorbent articles, the particles can be introduced into said article, or particularly if the article is not absorbent (such as articles made of, for example, leather), the particles can be impregnated into the surface of the article.

[0128] The product can be a type of textile, such as absorbent fabric sheets like towels, tea towels, absorbent paper like kitchen paper rolls, or non-absorbent.

[0129] Impregnating the article with particles can be done by spraying with a powder of the particles, optionally after and / or before a fixing step; or by applying a composition comprising the particles dispersed in a solvent, followed by evaporation of the solvent.

[0130] The product can be a brush, particularly a brush for keratin fibers (such as a hairbrush), said brush comprising a coating of particles according to the invention. The brush is then applied to the keratin material to be treated, for example, in the case of hair, by combing it once or multiple times. The brush is then preferably exposed to natural or artificial light. In particular, the brush can be exposed to very strong light (>0.1 W / cm²) in a chamber designed to prevent light escape. 2 The treated keratin fibers can then be treated multiple times as needed with the brush, exposed to natural or artificial light. Thus, the brush remains clean because any organic compounds absorbed during contact are eliminated during light exposure. The brush can be washed periodically by applying water or a washing composition, typically once every 10 uses.

[0131] According to one variant, the brush further includes at least one device for generating artificial light. According to a particular embodiment, particles are located at the base of the brush bristles, and an artificial light emitter is positioned at the other end of the bristles. After the brush sweeps across the keratin fibers once or multiple times, the sebum is rapidly broken down.

[0132] According to another variation of the invention, particles P1 and optionally P2 are used in the collector device. The collector should be understood to mean a device that, after friction with a keratinous material, allows the collection of organic compounds (such as sebum). The collector device can be a system that does not require treatment, such as a cloth, shell, garment, or hat. The collector device can then be placed under natural or artificial light to remove the collected organic compounds.

[0133] processing method

[0134] According to a first embodiment, the present invention relates to a method for cosmetically treating keratin materials or object surfaces in contact with keratin materials, the method comprising:

[0135] (1) Applying a cosmetic composition comprising solid particles to the material or the surface, said solid particles comprising at least one of the formula A as described above. a B b O n-x The metal oxide OM1; then

[0136] (2) Expose the material or the surface to natural or artificial light.

[0137] Preferably, the cosmetic composition used in step (1) further comprises at least one of the formulas M as described above. c O k The metal oxide OM2 exists in particles P1 as described above or in different solid particles P2.

[0138] The cosmetic composition can be in various galen formulations. Therefore, the composition of the present invention can be in the form of a (powdered) powder comprising particles P1 alone or as a mixture with a powder carrier and optionally particles P2.

[0139] Cosmetic compounds can also be in the form of more or less fluid liquids, such as simple or complex emulsions (oil-in-water, or abbreviated as O / W, water-in-oil or W / O, water-in-oil or O / W / O, or water-in-oil-in-water or W / O / W), such as creams, emulsions or cream gels, or in the form of gels, pastes or compositions for use in aerosol devices.

[0140] The cosmetic composition comprises particles of the metal oxide according to the invention, preferably dispersed in a cosmetic medium. "Cosmetic medium" should be understood to mean a medium suitable for application to human materials.

[0141] According to a preferred embodiment, the cosmetic medium comprises water and / or one or more organic solvents. Preferably, the composition comprises water, in particular in an amount between 5% and 95% by weight relative to the total weight of the composition.

[0142] The term "organic solvent" refers to an organic substance that can dissolve another substance without chemically altering it. Examples of organic solvents that can be used in the compositions of the present invention include, for example, lower C2-C6 alkanols such as ethanol and isopropanol; polyols and polyol ethers such as 2-butoxyethanol, propylene glycol, propylene glycol monomethyl ether, and diethylene glycol monoethyl ether and monomethyl ether; and aromatic alcohols such as benzyl alcohol or phenoxyethanol, and mixtures thereof.

[0143] When they are present, the organic solvent is present in the following proportions: preferably between 0.1% and 40% by weight, more preferably between 1% and 30% by weight, and even more particularly between 5% and 25% by weight, relative to the total weight of the composition.

[0144] The compositions according to the invention may further contain a fatty phase and may be in the form of a direct or reverse emulsion.

[0145] According to a particular embodiment, the cosmetic composition may also be in the form of an anhydrous composition, such as in the form of an oil or an alcohol solution. The term "anhydrous composition" is intended to mean a composition containing less than 2% water by weight, preferably less than 1% water by weight, and even more preferably less than 0.5% water by weight, or even a composition that contains no water, relative to the total weight of the composition. In this type of composition, any water present is not added during the preparation of the composition, but corresponds to residual water provided by the mixed ingredients.

[0146] The compositions according to the present invention can be prepared according to techniques well known to those skilled in the art.

[0147] The content of metal oxide OM1 in the cosmetic composition is preferably from 0.4% to 40% by weight relative to the total weight of the composition, more preferably from 0.5% to 20% by weight, even more preferably from 1% to 10% by weight, and even more preferably from 1.5% to 5% by weight.

[0148] When the metal oxide OM2 is also present, its content relative to the total weight of the composition is preferably from 0.1% to 10% by weight, more preferably from 0.15% to 5% by weight, and even more preferably from 0.25% to 1.5% by weight.

[0149] According to a preferred embodiment, the cosmetic composition comprises the two metal oxides OM1 and OM2 described above, wherein the molar ratio of the content of metal oxide OM1 to the content of metal oxide OM2 is greater than or equal to 1, preferably greater than or equal to 2, more preferably greater than or equal to 3, even more preferably greater than or equal to 4, and even more preferably greater than 4.

[0150] The composition may also contain one or more additives selected from thickeners, fragrances, pearlescent agents, preservatives, sunscreens, anionic, nonionic, amphoteric or cationic surfactants, anionic or nonionic or amphoteric polymers, cationic polymers, proteins, protein hydrolysates, ceramides, pseudoceramides, and compounds having linear or branched C4 chains. 16 -C 40 Chain fatty acids such as 18-methyleicosanoic acid, hydroxy acids, vitamins, provitamins such as panthenol, silicones, vegetable oils, mineral oils and synthetic oils, anti-dandruff agents and any other additives commonly used in the cosmetic field without adversely affecting the stability and properties of the compositions according to the invention.

[0151] These additives are optionally present in the compositions according to the invention in a proportion ranging from 0.001% to 50% by weight relative to the total weight of the composition. Those skilled in the art can readily determine the precise amount of each additive based on its properties and functions.

[0152] The composition can be applied to keratin material or the surface to be treated by hand, sprayer, aerosol, applicator end, dispenser comb or towel (or wipe) soaked in the composition.

[0153] After this application, the keratin material or the surface to be treated can be dried. The drying stage can optionally be performed using a hair dryer, heating pad, straightener or curling iron, heated comb, or any other heating device.

[0154] After the above composition is applied to the keratin material or the surface to be treated, they are exposed to light.

[0155] The term light refers to electromagnetic radiation, which can be of the ultraviolet (UV) and / or visible and / or near-infrared (NIR) types. It can be natural light (especially in cases used in external or internal environments (e.g., near windows)) or artificial light, particularly light from lamps that emit UV and / or visible radiation (e.g., in cases used in internal environments).

[0156] Preferably, step (2) of the cosmetic treatment method is performed by light irradiation using a light source (or lamp) that emits one or more electromagnetic waves with wavelengths between 200 nm in the ultraviolet (UV) range and 3000 nm in the infrared (IR) range.

[0157] The term "light irradiation" should be understood as referring to the exposure of keratin materials to artificial light waves, that is, any light waves emitted by a lamp. The spectrum can include wavelengths in the UV region (200-400 nm), the visible light region (400-750 nm), and the infrared region (745 nm to 3 μm).

[0158] For lamps emitting in the UV region, those described in Ullmann's Encyclopedia "Ultraviolet and Visible Spectroscopy", 2008, Wiley-VCHVerlag GmbH & Co. KGaA, Weinheim, 10.1002 / 14356007.b05 383.pub2, point 3.2 can be mentioned. Regarding lamps, those that are commonly mentioned are those in Ullmann's Encyclopedia "Lamps" 2005, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002 / 14356007.a15 115 and those mentioned in Ullmann's Encyclopedia "Photochemistry" 2005, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002 / 14356007.a19 573, point 3.2 "light sources".

[0159] The lamps used in the methods of the present invention may in particular be incandescent lamps, halogen lamps or fluorescent lamps; low-pressure lamps, such as sodium lamps or neon lamps; high-pressure lamps, such as mercury lamps or halide lamps; flash lamps, such as xenon flash lamps; fluorescent excimer lamps, such as xenon fluorescent excimer lamps; light-emitting diodes or LEDs of 50 to 1000 mW; lamps emitting black light or Wood's light; and lasers.

[0160] According to a preferred embodiment, an LED lamp that emits radiation in the visible light region (400-745nm) is used as the light source.

[0161] According to a similarly preferred variant, step (2) of the cosmetic treatment is performed by exposing the keratin material to natural sunlight or daylight.

[0162] The light exposure of the keratin material or the surface to be treated is preferably for a period of time ranging from 10 minutes to 180 minutes, more preferably from 30 minutes to 90 minutes.

[0163] According to a second embodiment, the present invention relates to a method for cosmetic treatment of keratin materials, the method comprising:

[0164] (1) Contact the material with an article comprising solid particles, the solid particles comprising at least one of the formula A as defined above. a B b O n-xThe metal oxide OM1; then

[0165] (2) Expose the article to natural or artificial light.

[0166] Preferably, the article used in step (1) further comprises at least one of the formula M as described above. c O k The metal oxide OM2 exists in particles P1 as described above or in different solid particles P2.

[0167] The article used in step (1) can be any object that can be applied to keratin material, and in particular textiles or brushes, as described above. During step (1), unwanted organic compounds are deposited on the surface of the article by transfer.

[0168] Step (2) is performed by exposing the article to light. The conditions of this exposure are those described above with respect to the first embodiment. This light exposure is capable of destroying undesirable organic compounds through photodegradation.

[0169] The following examples are used to illustrate the invention, but are not restrictive in nature.

[0170] Example

[0171] In the following example, particles are prepared in a flame spray pyrolysis apparatus (or FSP apparatus), wherein liquid is supplied to the burner via a capillary nozzle (a capillary tube with a diameter of 500 μm). The resulting flame is enclosed in a tube surrounding the pyrolysis flame. The tube is positioned above the nozzle of the FSP apparatus. The tube is a cylinder made of metal or quartz with a length between 20 and 60 cm, particularly between 30 and 50 cm, for example, 40 cm. The flame typically has a length between 5 and 15 cm and a temperature between 500°C and 2000°C. The precursor of the sprayed metal (such as Bi, W, Cu) burns in the flame, resulting in the formation of particles. The particles are then collected upstream on a glass fiber filter, which is preferably maintained at a temperature between 350°C and 420°C. The distance between the FSP nozzle and the filter used to collect the particles is between 40 and 80 cm, preferably between 55 and 65 cm.

[0172] Example 1: Powder preparation by FSP

[0173] Composition C1 was prepared by dissolving 250 mM ammonium metatungstate hydrate and 500 mM bismuth nitrate in an organic solvent consisting of a mixture of diethylene glycol monobutyl ether / anhydrous ethanol / acetic acid.

[0174] Next, the composition C1, along with pure oxygen, is injected into the FSP device.

[0175] 1.1.Bi2WO 6-x Preparation of particles (this invention)

[0176] The injection was performed at a flow rate of 7 ml / min for composition C1 and 4 l / min for gas (O2).

[0177] The resulting powder was then subjected to a heat treatment by exposing it to a temperature of 300°C for 1 hour, which improved its crystallinity.

[0178] The powder is yellowish-green and contains Bi2WO3. 6-x Particles, where x is a decimal greater than 0.1 and strictly less than 1.

[0179] The number-average size of the particles was 25 nm (measured by X-ray diffraction or XRD).

[0180] 1.2. Preparation of Bi2WO6 particles (comparative)

[0181] The injection was performed at a flow rate of 7 ml / min for composition C1 and 5 l / min for gas (O2).

[0182] The resulting powder was then subjected to a heat treatment process by exposing it to a temperature of 300°C for 1 hour.

[0183] The powder is yellowish-green and contains Bi2WO6 particles.

[0184] The number-average size of the particles was 25 nm (measured by X-ray diffraction or XRD).

[0185] 1.3. Characterization of Particles

[0186] Bi2WO prepared in 1.1 and 1.2 above 6-x Bi2WO6 particles were distinguished from Bi2WO6 particles by Raman spectroscopy in the visible light region between 400 and 500 nm, particularly by their similarity to Bi2WO6. 6-x Compared to the absorbance of other particles, Bi2WO6 particles have a higher absorbance (typically about 20% higher) to distinguish them.

[0187] The two types of particles were also distinguished by electron paramagnetic resonance spectroscopy (or EPR spectroscopy). The Bi₂WO₄ prepared in 1.1 above... 6-x The EPR spectra of the particles typically show a signal at g = 2.002, which is characteristic of oxygen atom vacancies in the Bi₂WO₆ lattice. This method is highly sensitive and ensures the presence of low-grade oxides with x greater than 0.1.

[0188] In comparison, Bi2WO 6-x Bi2WO6 particles are not typically distinguished by the location of peaks in XRD.

[0189] Typically, the metal oxide particles according to the invention are low oxides (e.g., having the formula Bi2WO). 6-x ):

[0190] 1) In X-ray diffraction (XRD), it has peak positioning similar to that of its stoichiometric oxidative homologues (e.g., Bi2WO6);

[0191] 2) They possess Raman spectra such that their absorbance in the 400-500 nm region is at least 5% lower, and preferably at least 10% lower, than that of their stoichiometric oxidative homologues (e.g., Bi₂WO₆); and / or

[0192] 3) It has an EPR spectrum containing a signal of about 2, in particular g = 2.002, which is not present in its stoichiometric oxidative homologues (especially Bi2WO6).

[0193] Example 2: Preparation of particulate mixtures via FSP

[0194] Composition C2 was prepared by dissolving 25 mM copper nitrate, 250 mM ammonium metatungstate hydrate and 500 mM bismuth nitrate together in an organic solvent consisting of a mixture of diethylene glycol monobutyl ether / anhydrous ethanol / acetic acid.

[0195] Next, the composition C2, along with pure oxygen, is injected into the FSP device.

[0196] 2.1.Bi2WO 6-x Preparation of a mixture of particles and CuO particles (this invention)

[0197] The injection was performed at a flow rate of 7 ml / min for composition C2 and 4 l / min for gas (O2).

[0198] The resulting powder was subjected to heat post-treatment by exposing it to a temperature of 300°C for 1 hour. The powder is light brown and consists of Bi2WO3. 6-x A mixture of particles (where x is a decimal greater than 0.1 and strictly less than 1) and CuO particles is formed.

[0199] The obtained powder's EPR spectrum showed a signal at g = 2.002, which is characteristic of oxygen atom vacancies compared to the Bi2WO6 lattice.

[0200] The number-average particle size is for Bi2WO3 6-x The particle size is 20 nm (measured by XRD) and for CuO particles it is 2.5 nm (measured by XRD).

[0201] Bi2WO in powder 6-x The molar ratio of the amount of CuO to the amount of CuO is 20.

[0202] 2.2. Preparation of a mixture of Bi₂WO₆ particles and CuO particles (comparative)

[0203] The injection was performed at a flow rate of 7 ml / min for composition C2 and 7 l / min for gas (O2).

[0204] The resulting powder was then subjected to a heat treatment process by exposing it to a temperature of 300°C for 1 hour.

[0205] The powder is light brown and is formed from a mixture of Bi2WO6 particles and CuO particles.

[0206] The number-average particle size was 20 nm for Bi2WO6 particles (measured by XRD) and 2.5 nm for CuO particles (measured by XRD).

[0207] The molar ratio of Bi2WO6 to CuO in the powder is 20.

[0208] Example 3: Tests for eliminating thin layers of sebum under natural light.

[0209] Each time, the surface area is approximately 10 cm². 2 Five identical plates were prepared by spreading a layer of artificial sebum (33 mg) composed of oleic acid on a glass plate.

[0210] Next, deposit 10 mg of one of the following powders onto the surface of each plate:

[0211] On plates 1 and 5: Bi2WO3 of Example 1.1 (the present invention) is deposited. 6-x Powder formed from particles;

[0212] On plate 2: Powder formed from Bi2WO6 particles of Example 1.2 (comparison) is deposited;

[0213] On plate 3: Bi2WO3 of Example 2.1 (the present invention) is deposited. 6-x A powder formed by mixing CuO particles;

[0214] On plate 4: a powder formed by depositing a mixture of Bi2WO6 and CuO particles from Example 2.2 (comparison) was deposited.

[0215] Next, expose panels 1 to 4 to mild sunlight (38 mW / cm²). 2 The total duration was 60 minutes. The plate was then weighed to estimate the amount of sebum that disappeared after 30 minutes and then after 60 minutes of light exposure.

[0216] The results obtained are detailed in Table 1 below (in terms of the percentage of sebum lost by weight).

[0217] [Table 1]

[0218]

[0219]

[0220] For control purposes, plate 5 (same as plate 1) was not exposed to light. No sebum loss was observed at t = 60 min (the measured degree of loss was less than 5% by weight).

[0221] The above results show that, compared with the use of comparative particles, the use of particles according to the present invention allows for significantly more effective elimination of sebum. (By Bi2WO) 6-x The powder formed from the particles yielded excellent results, and was produced by Bi2WO3. 6-x The powder formed by the mixture of CuO particles allows for further improvement in efficiency.

[0222] Example 4: Tests to remove sebum from hair

[0223] Consider hair containing 1000mg of sebum. Half of this is in the visible area of ​​the hair, i.e., within 1000cm. 2 On the surface area. Therefore, on the visible surface area, per cm 2 It contains 0.5mg of sebum. This amount is sufficient to give the hair a partially dirty appearance. In particular, when combed, the hair tends to remain clumped together, revealing grooves where the comb teeth pass through.

[0224] Test 1:

[0225] In the first test, 1000 mg was obtained from Bi2WO3 from Example 1.1. 6-x The powder formed from the particles was dispersed in 50 ml of ethanol to produce the composition. 12 grams of the composition was applied to the hair and then left for 10 minutes to allow the hair to dry.

[0226] Then, the hair was subjected to an estimated 20 mW / cm² in an indoor environment (behind a window). 2 Natural sunlight. It was observed that it takes 1 hour to fully remove sebum from the surface and reach a level that makes it invisible.

[0227] In particular, the treated hair was observed to be shiny, and showed significantly better strand separation after combing compared to before the treatment. The treated hair looked clean, as if it had just been washed, and no longer showed any oiliness, unlike the untreated hair, which looked very greasy due to the presence of sebum.

[0228] Test 2:

[0229] Using 1000 mg of Bi2WO3 from Example 2.1 6-x The composition obtained by dispersing the powder formed by the mixture of CuO particles in 50 ml of ethanol was tested repeatedly.

[0230] It was observed that 28 minutes were required to fully remove sebum from the surface and reach a level that made it invisible.

[0231] Test 3:

[0232] Repeat test 1 using 12 grams of ethanol (particle-free).

[0233] No change was observed in the appearance of the hair; it still looked oily.

[0234] Test 4:

[0235] Test 1 was repeated using a composition obtained by dispersing 1000 mg of a powder formed from a mixture of Bi2WO6 and CuO particles from Example 2.2 in 50 ml of ethanol.

[0236] An hour later, the oiliness of the hair was reduced, but it didn't look clean. This is due to insufficient removal efficiency, leaving about 35% to 40% of the sebum on the visible surface of the hair.

[0237] Test 5:

[0238] Repeat test 2, but leave the hair in the dark for 10 minutes after drying.

[0239] No change was observed in the appearance of the hair; it still looked oily.

[0240] Example 5: Tests used to maintain hair cleanliness

[0241] By using 400 mg of Bi2WO3 from Example 1.1 6-x The powder formed by the particles is dispersed in 50 ml of ethanol to produce a cosmetic composition.

[0242] The test was conducted on models with medium-length hair, which had just been washed at 10:00 PM. The hair was thoroughly cleaned to remove sebum. Once dry, 12 grams of the cosmetic composition described above were applied, targeting the roots and massaging with fingertips. At night, the models' scalps produced approximately 500 mg of sebum, which was distributed over several hours after various contacts (pillows). Then, during the day (considered to be from 10:00 AM to 10:00 PM), another 500 mg of sebum was produced. During this second time period, the sebum was also distributed along the length of the hair with various contacts (hands, combs, etc.).

[0243] In the morning at 10mW / cm 2 The model's hair was illuminated at a relatively low level. From 08:00 to 09:00, 500 mg of sebum produced overnight was destroyed within 1 hour due to the application of the composition containing particles according to the invention the previous night.

[0244] Throughout the rest of the day, the particles according to the invention continue to break down sebum that appears on the scalp and then migrates to the roots, where it is subsequently removed by contact and other movements. At the end of the day, the hair was observed to generally remain clean. Therefore, the models did not feel the need to wash their hair at night.

[0245] The next day, my hair was slightly dirty when I woke up, but it regained its clean appearance in the presence of light during the morning.

[0246] Example 6: Test using a brush

[0247] A brush was made by adhesively bonding a series of 80 bristles, each 3 mm wide and 1 cm long, made of absorbent foam, to a metal substrate. Then, 12 ml of the composition from Example 4-Test 2 (1000 mg of Bi2WO3) was used. 6-x The powder formed by the mixture of CuO particles (dispersion in 50 ml of ethanol) is sprayed onto a brush and then dried.

[0248] As the brush passes through the hair and roots, it absorbs some of the sebum while keeping the particles on the surface of the foam. This property stems from the fact that the contact is dry (solvent-free). Next, the brush is placed (bristles down) 5cm above a light source (a series of four 1W LEDs) until the sebum is removed.

[0249] One variation involves using a base made of resin glass and a series of diodes placed beneath the base. Thus, from the moment of contact, the hair can be combed, sebum collected, and the process of removing sebum begins. Afterward, as the user puts down the brush, the illumination continues to complete the removal of the sebum collected by the foam bristles.

[0250] Example 7: Testing on packaging

[0251] For these tests, two identical copies of packaging made of brown cardboard were used, designed to cover boxes containing cosmetics such as perfumes.

[0252] In the first test, the test subjects placed their fingers on the packaging, and because the test subjects' fingers were covered by a thin layer of sebum, visible marks were left on the packaging.

[0253] In the second test, the packaging was pretreated by spraying an ethanol dispersion of the particles according to the invention onto cardboard. For this purpose, 10 mg of Bi2WO3 was used. 6-x The powder formed by the mixture of CuO particles (Example 2.1) was dispersed in 10 ml of anhydrous ethanol, and then the dispersion was sprayed onto cardstock and allowed to dry. It was observed that when test subjects placed their fingers on the packaging, visible marks remained on the packaging due to the fingers being covered by a thin layer of sebum.

[0254] Then, place the two packages under light obtained from a 1W yellow spotlight at 20cm (representing store lighting).

[0255] Ten minutes later, the fingerprints on the second test packaging were observed to gradually disappear until they became invisible after one hour. This disappearance was not observed on the packaging from the first test.

Claims

1. Containing at least one of the formulas Bi2WO 6-x Solid particles of metal oxide OM1 are used to prevent, reduce and / or eliminate deposits of organic compounds on the surface of keratin materials or on the surface of objects in contact with said keratin materials, wherein x is a decimal in the range of 0.2 to 1.

5.

2. The use according to claim 1, wherein x is in the range from 0.3 to 1.

3. The use according to claim 1, wherein, The metal oxide OM1 is combined with formula M c O k The second metal oxide OM2 combination, wherein: M represents a transition metal; c is an integer in the range from 1 to 3; and k is a decimal in the range of 0.1 to 4.

4. The use according to claim 3, wherein, The oxide OM2 has the formula CuO.

5. The use according to any one of claims 3 and 4, wherein, The molar ratio of the amount of metal oxide OM1 to the amount of metal oxide OM2 is greater than or equal to 1.

6. The use according to claim 1, wherein, The solid particles containing at least one metal oxide OM1 are obtained by flame spray pyrolysis.

7. The use according to claim 1, wherein, The solid particles comprising at least one metal oxide OM1 have a number-average diameter ranging from 1 to 1000 nm.

8. The use according to claim 1, for preventing, reducing and / or eliminating deposits of protein and fat substances secreted by the body.

9. A method for cosmetically treating a keratin material or a surface of an object in contact with said keratin material, the method comprising: (1) Applying a cosmetic composition comprising solid particles to the material or the surface, said solid particles comprising at least one of the formula Bi2WO 6-x The metal oxide OM1, where x is a decimal in the range of 0.2 to 1.5; then (2) Expose the material or the surface to natural or artificial light.

10. The method according to claim 9, characterized in that, The cosmetic composition used in step (1) further comprises at least one of the formulas M as defined in any one of claims 3 to 5. c O k The metal oxide OM2 is present in the particles containing at least one metal oxide OM1 or in different solid particles.

11. The method according to claim 9, characterized in that, The content of metal oxide OM1 in the cosmetic composition ranges from 0.4% to 40% by weight relative to the total weight of the composition.

12. The method according to claim 10, characterized in that, The content of the metal oxide OM2 relative to the total weight of the composition ranges from 0.1% to 10% by weight.

13. A method for cosmetically treating keratin materials, the method comprising: (1) Contact the material with an article comprising solid particles, the solid particles comprising at least one of the formula Bi2WO 6-x The metal oxide OM1, where x is a decimal in the range of 0.2 to 1.5; then (2) Expose the article to natural or artificial light.

14. The method according to claim 13, characterized in that, The article used in step (1) further comprises at least one of the formulas M as defined in any one of claims 3 to 5. c O k The metal oxide OM2 is present in the particles containing at least one metal oxide OM1 or in different solid particles.

15. The method according to any one of claims 10 and 14, wherein, The molar ratio of the amount of metal oxide OM1 to the amount of metal oxide OM2 is greater than or equal to 1.

16. The method according to any one of claims 9 to 14, characterized in that, Step (2) is performed by light irradiation using a light source that emits one or more electromagnetic waves with wavelengths between 200 nm in the ultraviolet range and 3000 nm in the infrared range.

17. The method according to claim 16, characterized in that, The light source is an LED lamp that emits radiation with wavelengths in the visible light range.

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