Use of certain metal oxides for the photoconversion of organic compounds on keratinous materials.

Abstract

The present invention relates to a compound of formula A for reducing and / or removing the deposits of organic compounds on the surface of a keratinous material or on the surface of an object that comes into contact with said keratinous material. a B b O n-x The present invention relates to the use of solid particles comprising at least one metal oxide OM1 of the formula: (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 ranging from 1 to 4; b is an integer ranging from 1 to 10; n is an integer ranging from 3 to 6; and x is a decimal number smaller than n and ranging from 0.1 to 5). The present invention also relates to a method for cosmetically treating keratinous materials or the surfaces of objects that come into contact with keratinous materials, followed by exposure to light, using a cosmetic composition or article comprising such solid particles.

Description

[Technical field]

[0001] The present invention relates to the use of certain metal oxides for the photoconversion of undesirable organic compounds that may be present on keratinous materials, in particular human keratinous materials such as the skin, the scalp and keratinous fibers (such as hair), which particular use makes it possible to remove deposits of organic compounds on the surface of the keratinous materials or on the surface of objects that come into contact with said keratinous materials.

[0002] The present invention also relates to methods for the cosmetic treatment of keratinous materials or the surfaces of objects in contact with keratinous materials using certain such metal oxides.

[0003] The invention makes it possible in particular to reduce and / or slow down the phenomenon of oiling of keratinous materials. [Background technology]

[0004] Keratinous materials tend to lose some of their aesthetic properties over time due to the deposition or formation of undesirable organic compounds on their surface. This can be due to very diverse factors such as natural oiling (especially related to the secretion of sebum), sweat, dandruff shedding, pollution, humidity, etc. These can be compounds secreted by the human body (fatty substances such as sebum, protein derivatives, dead skin residues, etc.) or external compounds that deposit on the keratinous material, such as dirt, pollutants of automotive or industrial origin, etc.

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

[0006] Thus, for example, natural oiling tends to weigh down the hair and cause it to become caked, making it more difficult to style and giving it an unpleasant oily sheen and an unpleasant waxy feel.Similarly, the secretion of sebum by the skin gives the skin, especially on the face, an oily, shiny appearance that is considered to be particularly unattractive.

[0007] To remove undesirable organic compounds, detergent compositions such as soaps, shower gels, shampoos, etc. are commonly used, since washing keratinous materials with detergent compositions is very effective and makes it possible to remove both compounds secreted by the body and dirt from the external environment.

[0008] However, the beneficial effects of washing fade quickly, and the undesirable organic compounds are redeposited within days or even hours, recreating the problems mentioned above. As a result, those wishing to avoid these problems tend to increase the frequency of washing, which often has the effect of stimulating the body's secretions to increase its scum, and thus accelerating the rate of natural re-oiling of the keratinous materials after they have been washed.

[0009] Moreover, with these washes it is not possible to maintain the clean appearance of the keratinous materials with regular removal of the undesirable compounds as they appear. The general practice is to wait for a sufficient accumulation of undesirable compounds before washing the keratinous materials. Washing must be repeated periodically and it is common to be bothered by the presence of undesirable compounds between two washes.

[0010] Furthermore, to perform these washes, a source of water, preferably hot or warm water, is required. Detergent compositions often contain large amounts of surfactants that can cause stinging discomfort to the scalp, skin, or eyes.

[0011] In order to clean keratinous materials more quickly and without wetting them, it has already been proposed to use dry compositions such as "dry" shampoos or disposable wipes. Cleaning with dry shampoos consists of spraying absorbent particles onto the hair and then actively brushing the hair to remove the dirt. However, it is generally very difficult to completely remove the dirt. The result is not very satisfactory, as the hair becomes dull, lacks shine and feels rough to the touch. Furthermore, the use of disposable wipes containing detergent compositions deposited on a textile support causes environmental problems.

[0012] A similarly known solution is to remove all or part of the undesirable compounds (including sebum, pollutants, etc.) from the keratin materials by chemical oxidation. The principle is to combine an oxidizing agent with the compounds to be removed from the hair. However, this technique is unsatisfactory since its effect is immediate and cannot be continued for long periods of time, taking into account the lack of persistence of the oxidizing agent associated with its complete consumption during the reaction. Moreover, the oxidizing agents used may have a detrimental effect on the keratin materials.

[0013] It is also known that in the presence of a catalyst, such as titanium dioxide, photocatalysis in the presence of ultraviolet light can remove foreign or undesirable substances from keratinous materials, either in whole or in part. However, these photocatalysts have only limited activity under irradiation with visible light. The rate of photoconversion is often too slow. This means that undesirable compounds accumulate faster than they can be removed. Summary of the Invention [Means for solving the problem]

[0014] The object of the present invention is in particular to solve the above problems.

[0015] More specifically, the invention aims to provide a method for the cosmetic treatment of keratinous materials, in particular human keratinous materials, in order to reduce and / or slow the oiling associated with the deposition of both natural organic compounds, in particular those secreted by the body, and organic compounds from the external environment. The invention in particular makes it possible to prevent and / or reduce the deposition of sebum on the keratinous materials.

[0016] The present invention also makes it possible to remove organic compounds that may accumulate on the surfaces of objects that come into contact with keratinous materials.

[0017] After much research into this issue, applicants have discovered that these and other objectives may be achieved through the use of certain metal oxide particles as described above.

[0018] The present invention therefore relates to a compound of formula A for preventing, reducing and / or removing the deposition of organic compounds on the surface of keratinous materials, in particular human keratinous materials, or on the surface of objects that come into contact with said keratinous materials. a B b O n-x (In the formula, 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 ranging from 1 to 4; b is an integer ranging from 1 to 10; n is an integer ranging from 3 to 6; (x is a decimal number between 0.1 and 5, less than n) The present invention relates to the use of solid particles comprising at least one metal oxide OM1 of the above formula (I).

[0019] The Applicant has discovered that the particular OM1 oxides defined above are highly effective in catalysing the photodecomposition of organic compounds that may be present on keratinous materials at rates fast enough to allow both the removal of already deposited organic compounds and the decomposition of such compounds as they appear, thereby reducing the deposits and preventing the accumulation of new deposits.

[0020] The invention therefore makes it possible to prevent and / or reduce the deposition of undesirable organic compounds that may be present on keratinous materials, whether these are compounds originating from the external environment (such as stains, dirt, pollutants) or compounds secreted by the body, in particular proteins and fatty substances secreted by the body, in particular sebum. The invention therefore makes it possible to remove organic compounds as they appear and to maintain the continued cleanliness of the keratinous materials.

[0021] Furthermore, when keratinous materials are in contact with objects, the migration of organic compounds from the surface of the keratinous materials to the surface of the object often occurs to a greater or lesser extent. This can occur in particular in fabrics that come into contact with the skin, scalp, hair, and generally in any object that comes into contact with them. The present invention also makes it possible to prevent and / or reduce deposition on the surface of these objects.

[0022] The present invention does not require that the treated keratinous material or surface be exposed to strong light sources, including in the presence of weak or moderate light exposure sources, especially natural light, as long as the oxide according to the present invention remains effective. Furthermore, the metal oxide according to the present invention is effective in both exterior environments (including low levels of sunlight) and interior environments, including in the absence of direct exposure to light sources.

[0023] The invention makes it possible to destroy oily excretions, especially of keratinous materials such as sebum, and compounds resulting from the transformation of these excretions, such as aldehydes or ketones or peroxide derivatives resulting from oxidation by oxygen or ozone or microbial agents. The invention therefore makes it possible to reduce the disadvantages resulting from these oily excretions, such as a shiny, dirty appearance, or a greasy odor, or irritating compounds that may cause unpleasant reactions such as desquamation. The invention also makes it possible to destroy organic compounds resulting from aqueous body secretions, and compounds resulting from the transformation of organic compounds resulting from these aqueous excretions, such as acid derivatives resulting from oxidation by oxygen or ozone or microbial agents. Thus, disadvantages such as the stickiness, dirt, marks on clothes, or odor aspects of these aqueous excretions are reduced.

[0024] The present invention makes it possible to reduce the amount of undesirable compounds, which may be generated by secretions from the body, but may also be carried by the air or deposited by contact with keratinous materials, thus allowing the user to overcome the drawbacks of contamination, odor, bacteria, germs and other microorganisms that may accumulate on keratinous materials.

[0025] According to one variant, the oxide particles according to the invention are used to remove or reduce the amount of compounds that deposit on objects that come into contact with keratinous materials. This is especially the case for fatty substances, such as those that come into contact with the body during handling of the object, giving the object a dirty appearance. This also applies to volatile organic molecules, such as perfumes, or odors from humans and animals, or compounds that, after deposition, change to give malodorous compounds, giving the object a malodorous aspect. To address these inconveniences, the oxide particles according to the invention can be applied to the surface of the object or integrated therein.

[0026] The use according to the invention makes it possible in particular to remove fatty substances from keratinous materials or from the surfaces of objects in contact with them, which makes it possible to reduce the phenomenon of oiling of the keratinous materials, in particular their natural re-oiling due to the secretion of sebum.

[0027] The present invention relates to a method for the cosmetic treatment of keratinous materials or the surface of an object in contact with keratinous materials, comprising the steps of: (1) providing a compound represented by the formula A as defined above on said material or said surface; a B b O n-x applying a cosmetic composition comprising solid particles comprising at least one metal oxide OM1 of (2) exposing the material or surface to natural or artificial light; The present invention also relates to a method comprising the steps of:

[0028] According to a first preferred embodiment, the particles comprising metal oxide OM1 are prepared by the flame spray pyrolysis (FSP) method.

[0029] According to a second embodiment, which is also preferred, the metal oxide OM1 is used in combination with a second metal oxide OM2 different from the oxide OM1, said second oxide OM2 being able to be present in particles comprising the oxide OM1 or in different solid particles, as described below.

[0030] Other objects, characteristics, aspects and advantages of the present invention will become even more apparent on reading the following description and examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] In this specification, unless otherwise indicated, - the term "at least one" is equivalent to and may be replaced with the term "one or more"; - the expression "to the extent of" is equivalent to and may be substituted for the expression "to the extent of" and indicates that a limit is included; - the expression "human keratinous material" includes in particular human keratinous fibres, such as the skin, scalp and nails, but also hair, body hair, eyelashes and eyebrows; - "Alkyl" means "alkyl group", i.e. C1-C 10 is understood to mean in particular C1-C8, more in particular C1-C6 and preferentially C1-C4 linear or branched hydrocarbon-based radicals, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl or tert-butyl, an "aryl" group is understood to mean a monocyclic or fused or non-fused polycyclic carbon-based group containing 6 to 22 carbon atoms, at least one ring of which is aromatic, preferentially an aryl group is phenyl, biphenyl, naphthyl, indenyl, anthracenyl or tetrahydronaphthyl, preferably phenyl; - An "arylate" group is one or more -C(O)O groups, such as naphthalate or naphthenate. - is understood to mean an aryl group containing a carboxylate group, - "complexed metal" is understood to mean a metal forming a "metal complex" or "coordination compound" in which the metal ion corresponding to the central atom is chemically bound to one or more electron donors (ligands); - "ligand" is understood to mean a coordinating organic chemical group or compound, i.e. which contains at least one carbon atom, is capable of being coordinated to a metal and which, once coordinated or complexed, results in a metal compound (internal complex or chelate) which corresponds to the principle of a coordination sphere with a given number of electrons - see Ullmann's Encyclopedia of Industrial Chemistry, "Metal complex dyes", 2005, p. 1-42. More specifically, the ligand is an organic group which contains at least one group which is electron donating via inductive and / or mesomeric effects, more particularly an organic group which carries at least one amino, phosphino, hydroxy or thiol electron donating group, or the ligand is a persistent carbene, in particular of the "argengo" type (imidazol-2-ylidene) or which contains at least one carbonyl group.As ligands, mention may more particularly be made of: i) those containing at least one phosphorus atom -P< (i.e. phosphines, for example triphenylphosphine), ii) bidentate ligands of formula RC(X)-CR'R''-C(X)-R''', where R and R'''' are identical or different and represent a linear or branched (C1-C6) alkyl group, and R' and R'' are identical or different and represent a hydrogen atom or a linear or branched (C1-C6) alkyl group, preferentially R' and R'' represent a hydrogen atom and X represents an oxygen atom or a sulfur atom or an N(R) group, where R represents a hydrogen atom or a linear or branched (C1-C6) alkyl group), such as acetylacetone or β-diketones, iii) those of formula [HO-C(O)]AC(O)-OH and their deprotonated forms, where A represents a monovalent radical when n has the value zero, or a polyvalent radical when n is 1 or more, which is a saturated or unsaturated, cyclic or acyclic, aromatic or non-aromatic, based on a hydrocarbon comprising 1 to 20 carbon atoms, optionally interrupted by one or more heteroatoms and / or optionally substituted, inter alia, by one or more hydroxyl groups, preferably A represents a monovalent (C1-C6) alkyl group or a polyvalent (C1-C6) alkylene group, optionally substituted by one or more hydroxyl groups, and n represents an integer from 0 to 10 (both end values ​​inclusive), preferably n being 0 to 5, e.g. 0, 1 or 2) (poly)hydroxycarboxylic acid ligands, such as lactic acid, glycolic acid, tartaric acid, citric acid, maleic acid and arylates, e.g. naphthalates; and iv) C2-C containing 2 to 5 hydroxyl groups. 10 Polyol ligands, especially ethylene glycol, glycerol, even more especially the ligands have carboxy, carboxylate or amino groups, in particular the ligands are selected from acetate groups, (C1-C6)alkoxylate groups, (di)(C1-C6)alkylamino groups, and arylate groups, such as naphthalate or naphthenate groups.

[0032] The term "fuel" is understood to mean a liquid compound that burns in a chemical reaction that produces heat: combustion, using dioxygen and energy. In particular, liquid fuels are selected from aprotic solvents, in particular alcohols such as methanol, ethanol, isopropanol, n-butanol, glycols, esters such as those derived from methyl esters and acetates (such as 2-ethylhexyl acetate), acids (such as acetic acid, 2-ethylhexanoic acid (EHA)), acyclic ethers (such as ethyl ether, methyl tert-butyl ether (MTBE), methyl tert-amyl ether (TAME), methyl tert-hexyl ether (THEME), ethyl tert-butyl ether (ETBE), ether tert-amyl ether (TAEE), diisopropyl ether (DIPE)), cyclic ethers (such as tetrahydrofuran (THF)), aromatic hydrocarbons or arenes (such as xylene), non-aromatic hydrocarbons, and mixtures thereof. The fuel may optionally be selected from liquefied hydrocarbons such as acetylene, methane, propane or butane, and mixtures thereof.

[0033] First metal oxide OM1 The solid particles used in the present invention are represented by the formula A a B b O n-x : (In the formula, 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 ranging from 1 to 4; b is an integer ranging from 1 to 10; n is an integer ranging from 3 to 6; (x is a decimal number between 0.1 and 5, less than n) The metal oxide OM1 includes at least one metal oxide selected from the group consisting of:

[0034] A is preferably selected from bismuth and barium, more preferably A represents bismuth.

[0035] B is preferably selected from tungsten and vanadium, more preferably B represents tungsten.

[0036] The integers a, b and x depend on the nature of the metals A and B.

[0037] The decimal number x is preferably in the range of 0.1 to 1.9, more preferentially 0.2 to 1.5, and even more preferably 0.3 to 1. Particularly preferably, x is 0.5 or more and strictly less than 1.

[0038] According to a particularly preferred embodiment, the oxide OM1 has the formula Bi2WO 6-x where x is a decimal number in the range of 0.2 to 1.5, preferably 0.3 to 1; more preferably x is greater than or equal to 0.5 and strictly less than 1.

[0039] Preferably, the metal oxide OM1 is in a crystalline state.

[0040] Optional second metal oxide OM2 According to a preferred embodiment, the metal oxide OM1 has the formula M c O k : (In the formula, M represents a transition metal; c is an integer ranging from 1 to 3; k is a decimal number in the range of 0.1 to 4. is combined with a second metal oxide, denoted OM2, which corresponds to

[0041] The combined use of the two oxides OM1 and OM2 allows for a further increase in the rate of photoconversion of undesirable organic compounds, which allows for a higher removal efficiency of these compounds at the same light exposure, or even maintains a good effect, including in the presence of low-intensity light exposure, e.g., indoors or during winter use.

[0042] Preferably, M represents copper.

[0043] According to one particularly preferred embodiment, the oxide OM2 has the formula CuO.

[0044] Preferably, the metal oxide OM2 is in a crystalline state.

[0045] The metal oxide OM2 can be present in a particle comprising the metal oxide OM1 (designated particle P1) or in the form of a different particle P2, as described below.

[0046] Preferably, the metal oxide OM2 is used in an amount less than the 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 preferentially greater than or equal to 3, even more preferentially greater than or equal to 4, even more preferably greater than 4.

[0047] Metal oxide solid particles In the following, P1 denotes a particle comprising a metal oxide OM1.

[0048] Said particles P1 comprise a metal oxide OM1, either alone or in combination with other metal oxides, such as in particular the oxide OM2 mentioned above.

[0049] According to a preferred embodiment, the particles P1 do not comprise an upper coating layer.

[0050] According to one particularly preferred embodiment, the particles P1 are entirely composed of said oxide OM1.

[0051] The particles P1 preferably have a number average diameter in the range of 1 to 1000 nm, more preferably 10 to 200 nm.

[0052] According to an equally preferred embodiment, said second oxide OM2 is in the form of solid particles P2 different from said particles P1, which preferably have a number average diameter in the range from 1 to 300 nm, preferably from 2 to 20 nm and more preferentially from 2 to 10 nm.

[0053] In the latter embodiment, preferably the number average diameter of particles P1 is greater than the number average diameter of said particles P2, and more preferentially the number average diameter of particles P1 is at least twice the number average diameter of particles P2.

[0054] In the latter embodiment, preferably, the particles P2 comprising the oxide OM2 are connected to the particles P1 comprising the oxide OM1. The particles may in particular be in the form of clusters in which the particles P1 are connected to each other and / or to the particles P2 (each particle P1 may be in contact with either the particles P1 and the particles P2) or each of the particles P1 is connected only to the particles P2 (particles P2 are interposed between the particles P1 so that the particles P1 are not in direct contact with each other).

[0055] The number average diameter of the particles P1 and P2 according to the invention can be determined by transmission electron microscopy or by X-ray diffraction (XRD).

[0056] Preparation of solid particles According to one preferred embodiment, the solid particles P1 comprising said at least one metal oxide OM1 used in the present invention are obtained or are obtainable by flame spray pyrolysis (FSP).

[0057] Likewise, if particles P2 comprising a metal oxide OM2 are used, these particles P2 are preferably obtained or obtainable by flame spray pyrolysis.

[0058] According to a preferred embodiment, the oxides OM1 and OM2 are prepared in the same flame in a single FSP apparatus.

[0059] Flame spray pyrolysis or FSP is a well-known method essentially developed to synthesize ultrafine powders of single or mixed oxides of various metals (e.g. SiO2, Al2O3, BO, ZrO2, GeO2, WO3, Nb2O5, SnO2, MgO, ZnO) with controlled morphology and / or deposit them on various substrates, starting from various metal precursors, generally in the form of organic or inorganic, preferably flammable, sprayable liquids, which are sprayed into a flame, which, upon combustion, releases, among other things, nanoparticles of the metal oxides sprayed by the flame itself on these various substrates. This method has also been used for the production of oxide particles covered with a layer of silica. The principles of this method are recalled, for example, in a recent (2011) publication entitled "Flame Spray Pyrolysis: a Unique Facility for the Production of Nanopowders" by Johnson Matthey, Platinum Metals Rev., 2011, 55, (2), 149-151. Numerous variants of FSP processes and reactors are also described, for example, 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 7,211,236, WO 2004 / 056927, WO 2005 / 103900, WO 2006 / 023616, WO 2005 / 023628, WO 2005 / 023639, WO 2005 / 023641, WO 2005 / 023651, WO 2005 / 023662, WO 2005 / 023663, WO 2005 / 023664, WO 2005 / 023665, WO 2005 / 0236 ... No. 2007 / 028267 or U.S. Pat. No. 8,182,573, WO 2008 / 049954 or U.S. Pat. No. 8,231,369, WO 2008 / 019905, U.S. Patent Application Publication No. 2009 / 0123357, U.S. Patent Application Publication No. 2009 / 0126604, U.S. Patent Application Publication No. 2010 / 0055340, and WO 2011 / 020204.

[0060] According to a preferred embodiment, the solid particles P1 comprising at least one metal oxide OM1 are prepared by a process comprising at least the following steps: a. preparing a composition (C) by adding one or more metal A precursors and one or more metal B precursors to a flammable solvent or mixture of flammable solvents; then b. In a flame spray pyrolysis apparatus, the above-defined formula A a B b O n-x forming a flame by injecting the composition (C) and an oxygen-containing gas until particles P1 of the metal oxide OM1 are obtained.

[0061] The precursors of metals A and B and the combustible solvent that can be used according to the invention can be selected from the metal precursors and combustible solvents conventionally used in flame spray pyrolysis.

[0062] Preferably, the metal A precursor and metal B precursor contained in composition (C) comprise one or more atoms of A and B, respectively, optionally complexed with one or more ligands comprising at least one carbon atom.

[0063] More preferentially, said ligands are chosen from acetate groups, nitrate groups, ammonium groups, (C1-C6)alkoxylate groups, (di)(C1-C6)alkylamino groups, and arylate groups, such as naphthalate groups, or naphthenate groups.

[0064] Preferably, the flammable solvent is selected from protic flammable solvents, aprotic flammable solvents, and mixtures thereof; more preferentially from alcohols, esters, acids, acyclic ethers, cyclic ethers, aromatic hydrocarbons or arenes, non-aromatic hydrocarbons, and mixtures thereof; even more preferably from (C1-C8) alkyl carboxylic acids, such as acetic acid or 2-ethylhexanoic acid (EHA), (C1-C6) alkane (mono / di / tri)ols, such as ethylene glycol, (C1-C8) alkyl carbonyl (C1-C8) alkoxy, such as 2-ethylhexyl acetate, di(C1-C6) alkyl ethers, such as ethyl 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.

[0065] According to a preferred embodiment, the flammable solvent is chosen from aprotic flammable solvents containing at least 3 carbon atoms and mixtures thereof, and even more preferentially from xylene, tetrahydrofuran, 2-ethylhexyl acetate, and mixtures thereof.

[0066] According to another embodiment, the flammable solvent is selected from protic flammable solvents containing at least two carbon atoms and mixtures thereof, and even more preferentially from acetic acid, ethylene glycol, 2-ethylhexanoic acid (EHA), and mixtures thereof.

[0067] Advantageously, the total content of precursors of metals A and B in composition (C) is between 1% and 90% by weight, in particular between 5% and 80% by weight, preferably between 10% and 70% by weight and more preferentially between 25% and 60% by weight, relative to the total weight of composition (C).

[0068] The method for preparing particles P1 further comprises the step (b) of injecting the composition (C) and an oxygen-containing gas into a flame spray pyrolysis (FSP) device to form a flame.

[0069] In this step (b), the composition (C) and the oxygen-containing gas are advantageously injected into the flame spray pyrolysis device by two independent injections, in other words, the composition (C) and the oxygen-containing gas are injected separately, i.e., the composition (C) and the oxygen-containing gas are not injected using a single nozzle.

[0070] More specifically, composition (C) is transported through one tube and an oxygen-containing gas (also called "dispersed oxygen") is transported through the other tube. The inlets of the two tubes are positioned such that the oxygen-containing gas creates a negative pressure to suck up composition (C) by the Venturi effect and convert it into droplets.

[0071] Step (b) may optionally further comprise the injection of an additional "premix" mixture comprising oxygen and one or more combustible gases, also called "supporting flame oxygen", which allows the generation of a supporting flame intended to ignite and sustain the flame arising from composition (C) and the oxygen-containing gas (i.e., "dispersed oxygen").

[0072] Preferably, in step (b), composition (C), the oxygen-containing gas and, if optionally present, the "premix" mixture are injected into a reaction tube, also called "enveloping tube". Preferably, this reaction tube is made of metal or quartz. Advantageously, the reaction tube has a height of at least 20 cm, more preferentially at least 40 cm and even at least 50 cm. Advantageously, the length of said reaction tube is between 30 cm and 300 cm, preferably between 40 cm and 200 cm, more preferentially between 45 cm and 100 cm and even more preferably, this length is 50 cm.

[0073] The mass ratio of the solvent present in the composition (C) on the one hand to the oxygen-containing gas on the other hand is defined as follows:

[0074] That is, first, the amount of oxygen-containing gas (also called oxidizer compound) is calculated so that the aggregate formed by composition (C), i.e., the combustible solvent and zinc precursor on the one hand, and the oxygen-containing gas on the other hand, can react together in a combustion reaction in a stoichiometric ratio (so that there is no excess or deficiency of oxidizer compound).

[0075] Starting from this calculated amount of oxygen-containing gas, also called "calculated oxidant", a new calculation is carried out according to the following formula: Injected oxidant = calculated oxidant / φ, in which φ is preferably between 0.30 and 1.0, more preferentially between 0.7 and 1.0, in order to derive from this the amount of injected oxygen-containing gas, also called "injected oxidant".

[0076] This method is defined, inter alia, by Turns, S. R. in An Introduction to Combustion: Concepts and Applications, 3rd ed.; McGraw-Hill: New York, 2012.

[0077] Preferably the flame formed in step (b) is at a temperature of 2000°C or greater in at least a part of the flame.

[0078] The solid particles P2 comprising a metal oxide OM2 can be prepared according to the same principles as described above for the preparation of the particles P1.

[0079] According to a preferred embodiment, the solid particles P2 comprising at least one metal oxide OM2 are prepared by a method comprising at least the following steps: a. preparing a composition (C') by adding precursors of one or more metals M to a flammable solvent or mixture of flammable solvents; thereafter b. In a flame spray pyrolysis apparatus, the above-defined formula M c O kforming a flame by injecting the composition (C') and an oxygen-containing gas until particles P2 of the metal oxide OM2 are obtained.

[0080] Those skilled in the art will readily understand how to adapt the detailed description given above for the preparation of particles P1 to the preparation of particles P2.

[0081] According to a preferred embodiment, the solid particles P1 and P2 are prepared simultaneously in the same flame spray pyrolysis apparatus.

[0082] In this embodiment, solid particles P1 comprising said at least one metal oxide OM1 are prepared together with solid particles P2 comprising said at least one metal oxide OM2 by a method comprising at least the following steps: a. preparing a first composition (C) by adding, on the one hand, 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 preparing a second composition (C') by adding one or more metal M precursors to a flammable solvent or a mixture of flammable solvents; then b. In a flame spray pyrolysis apparatus, the above-defined formula A a B b O n-x Particles P1 of metal oxide OM1 and of formula M defined above c O k forming a flame by injecting compositions (C) and (C') and an oxygen-containing gas until particles P2 of metal oxide OM2 are obtained.

[0083] According to a preferred embodiment, instead of the two separate compositions (C) and (C'), a single composition (C'') is used which comprises one or more metal A precursors, one or more metal B precursors and one or more metal M precursors in a flammable solvent or in a mixture of flammable solvents.

[0084] use The use according to the invention of said solid particles P1 comprising at least one metal oxide OM1 is aimed at reducing and even removing the deposits of undesirable organic compounds on the surface of keratinous materials, in particular human keratinous materials, or on the surface of objects coming into contact with said materials.

[0085] Preferably, said keratinous material is selected from the skin, the scalp and the hair.

[0086] Preferably, the undesirable organic compounds are selected from proteins and fatty substances secreted by the body.The present invention is particularly aimed at preventing, reducing and / or eliminating the deposition of sebum on the surface of keratinous materials or on the surface of objects in contact with keratinous materials.

[0087] For the implementation of the present invention, the particles P1 and optional particles P2 described above are brought into contact with the keratinous material or surface to be treated. The keratinous material or surface to be treated is then exposed to light.

[0088] According to one embodiment of the present invention, the above-mentioned particles P1 and, optionally, particles P2 are applied directly to the keratin material or to the surface to be treated. The particles can be applied as such, in powder form or dispersed in a cosmetic composition.

[0089] According to another embodiment of the invention, the above-mentioned particles P1 and optional particles P2 are incorporated into an article intended to be applied to keratinous materials. The particles can be incorporated into said article, in particular in the case of an absorbent article, or can be impregnated into the surface of the article, in particular in the case of a non-absorbent article (such as, for example, an article made of leather).

[0090] The article may be of textile type, for example a piece of cloth which may be absorbent such as a towel or tea towel, absorbent paper such as kitchen roll, or non-absorbent.

[0091] The impregnation of the article with the particles can be carried out by dusting using a powder of said particles, optionally followed and / or preceded by a fixing step, or by applying a composition comprising said particles dispersed in a solvent, which is then evaporated.

[0092] The article may in particular be a brush for keratin fibres, 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, which is combed one or more times with the brush. The brush is then preferably exposed to natural or artificial light. In particular, the brush is exposed to very intense light (>0.1 W / cm2) in a chamber designed so that light does not escape therefrom. 2 ). The treated keratin fibers may be treated again as many times as necessary with said brush exposed to natural or artificial light. The brush is thus kept clean in the sense that the organic compounds absorbed by the brush during contact are removed during exposure to light. It is possible to wash the brush from time to time, typically once every 10 uses, by applying water or a cleaning composition.

[0093] According to one variant, the brush further comprises at least one means for generating artificial light. According to one particular embodiment, the particles are arranged at the base of the bristles of the brush and the artificial light generator is arranged at the other end of the bristles. After the brush has passed one or more times through the keratin fibers, the sebum is rapidly destroyed.

[0094] According to another variant of the invention, the particles P1 and optional particles P2 are used in a recovery device. Recovery device is understood to mean a device that allows the recovery of organic compounds such as sebum after friction with keratinous materials. The recovery device may be a system that does not require handling of cloth, shells, clothes or hats. The recovery device can then be placed in natural or artificial light to remove the recovered organic compounds.

[0095] Treatment According to a first embodiment, the present invention relates to a method for the cosmetic treatment of keratinous materials or of the surface of an object in contact with keratinous materials, comprising: (1) The substance or surface is treated with the formula A a B b O n-x applying a cosmetic composition comprising solid particles comprising at least one metal oxide OM1 of (2) exposing the material or surface to natural or artificial light; The present invention relates to a method comprising the steps of:

[0096] Preferably, the cosmetic composition used in step (1) comprises the above-mentioned M, present in the above-mentioned particles P1 or in different solid particles P2. c O k The metal oxide further comprises at least one metal oxide OM2.

[0097] Said cosmetic composition may be in various galenic forms. Thus, the composition of the invention may be in the form of a (dusty) powder comprising the particles P1 and, optionally, the particles P2, alone or in a mixture with a powder carrier.

[0098] The cosmetic composition may be in the form of a more or less mobile liquid, for example in the form of a simple or complex emulsion such as a cream, milk or cream gel (abbreviated as oil-in-water or O / W, water-in-oil or W / O, oil-in-water-in-oil or O / W / O or water-in-oil-in-water or W / O / W), or in the form of a gel, a paste or a spray composition.

[0099] The cosmetic composition preferably comprises particles of the metal oxide according to the invention dispersed in a cosmetic medium, "cosmetic medium" being understood to mean a medium suitable for application to body materials.

[0100] According to a preferred embodiment, the cosmetic medium comprises water and / or one or more organic solvents. Preferably, the composition comprises water in a content ranging from 5% to 95% by weight relative to the total weight of the composition.

[0101] The term "organic solvent" refers to an organic substance that can dissolve another substance without chemically modifying it. Examples of organic solvents that can be used in the composition of the present invention include 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.

[0102] When present, the organic solvent is preferably present in a proportion of from about 0.1% to 40% by weight, more preferentially from about 1% to 30% by weight, and even more preferentially from 5% to 25% by weight, relative to the total weight of the composition.

[0103] The compositions of the invention may further comprise a fatty phase and may be in the form of a direct or inverse emulsion.

[0104] According to a particular embodiment, the cosmetic composition may be in the form of an anhydrous composition, for example in the form of an oil or alcohol solution.The term "anhydrous composition" is intended to mean a composition that contains less than 2% by weight of water, preferably less than 1% by weight of water, and even more preferentially less than 0.5% by weight of water relative to the total weight of the composition, or even a composition that does not contain water.In this type of composition, the water that may be present is not added during the preparation of the composition, but corresponds to the residual water brought by the mixed components.

[0105] The compositions according to the invention may be prepared according to techniques well known to those skilled in the art.

[0106] The content of metal oxide OM1 in the cosmetic composition is preferably in the range of 0.4% to 40% by weight, more preferentially 0.5% to 20% by weight, even better still 1% to 10% by weight and even more preferentially 1.5% to 5% by weight, relative to the total weight of the composition.

[0107] If a metal oxide OM2 is also present, its content ranges from 0.1 to 10% by weight, preferably from 0.15 to 5% by weight, and more preferably from 0.25 to 1.5% by weight, relative to the total weight of the composition.

[0108] According to a preferred embodiment, the cosmetic composition comprises the two metal oxides OM1 and OM2, and the molar ratio of the content of metal oxide OM1 to the content of metal oxide OM2 is 1 or more, preferably 2 or more, more preferentially 3 or more, even more preferentially 4 or more, and even more preferably greater than 4.

[0109] The composition may contain a thickener, a fragrance, a pearlescent agent, a preservative, a sunscreen, an anionic or nonionic or amphoteric or cationic surfactant, an anionic or nonionic or amphoteric polymer, a cationic polymer, a protein, a protein hydrolysate, a ceramide, a pseudoceramide, a linear or branched C 16 ~C 40 The composition may also contain one or more additives selected from fatty acids having a chain length (such as 18-methyleicosanoic acid), hydroxy acids, vitamins, provitamins (such as panthenol), silicones, vegetable oils, mineral oils, synthetic oils, antidandruff agents, and other additives conventionally used in the cosmetic field and which do not adversely affect the stability and properties of the composition according to the invention.

[0110] These additives are optionally present in the composition according to the invention in a proportion that may range from 0.001% to 50% by weight relative to the total weight of the composition. The exact amount of each additive can be easily determined by those skilled in the art depending on its nature and function.

[0111] Application of the composition to the keratinous material or surface to be treated can be effected by hand, with a sprayer, with an aerosol, with an applicator end piece, with a dispenser comb, or with a towel (or wipe) impregnated with the composition.

[0112] Following this application, the keratinous material or the surface to be treated may be dried. The drying step may optionally be carried out by heating using a hair dryer, a heating hood, a straightening iron, a curling iron, a heating comb, or by any other heating device.

[0113] After the above-described compositions have been applied to the keratinous materials or surfaces to be treated, they are exposed to light.

[0114] The term light means electromagnetic radiation which may be of the ultraviolet (UV) and / or visible and / or near infrared (NIR) type. It may be natural light (especially for use in outdoor or indoor environments, for example near a window) or artificial light, in particular light from a lamp emitting ultraviolet and / or visible light (e.g. for use in indoor environments).

[0115] Preferably, step (2) of the cosmetic treatment method is carried out by photoirradiation using a light source (or lamp) that emits one or more electromagnetic waves having wavelengths from 200 nm in the ultraviolet (UV) range to 3000 nm in the infrared (IR) range.

[0116] The term "light irradiation" is understood to mean any exposure of keratinous materials to artificial light waves, i.e. light waves emitted by a lamp. The spectrum of light may include wavelengths in the UV region (200-400 nm), the visible region (400-750 nm) and the infrared region (745 nm-3 μm).

[0117] As lamps emitting in the UV region, those described in Ullmann's Encyclopedia "Ultraviolet and Visible Spectroscopy", 2008, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 10.1002 / 14356007.b05 383.pub2, point 3.2 can be mentioned. As for lamps in general, those described in Ullmann's Encyclopedia "Lamps" 2005, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002 / 14356007.a15 115 and Ullmann's Encyclopedia "Photochemistry" 2005, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002 / 14356007.a19 573, point 3.2 "light sources" can be mentioned.

[0118] The lamps used in the method of the invention may in particular be incandescent, halogen or fluorescent lamps; low pressure lamps, such as sodium or neon lamps, high pressure lamps, such as mercury lamps, halide lamps, flash lamps, such as xenon flash lamps, fluorescent excimer lamps, such as xenon fluorescent excimer lamps, light emitting diodes of 50 to 1000 mW, i.e. LED lamps, lamps emitting black light or Wood's light, and lasers.

[0119] According to a preferred embodiment, LED lamps are used as light sources, emitting radiation having wavelengths in the visible range (400-745 nm).

[0120] According to one variant which is also preferred, step (2) of the cosmetic treatment method is carried out by exposing the keratinous material to natural sunlight or daylight.

[0121] The exposure of the keratin material or of the surface to be treated to light is preferably carried out for a period ranging from 10 minutes to 180 minutes, more preferentially from 30 minutes to 90 minutes.

[0122] According to a second embodiment, the present invention relates to a method for the cosmetic treatment of keratinous materials, comprising: (1) The substance is treated with a compound represented by formula A as defined above. a B b O n-x with an article comprising solid particles comprising at least one metal oxide OM1; thereafter (2) exposing the article to natural or artificial light; The present invention relates to a method comprising the steps of:

[0123] Preferably, the product used in step (1) is a solid particle having the above-mentioned formula M c O k The metal oxide further comprises at least one metal oxide OM2.

[0124] The article used in step (1) may be any object capable of being applied to keratinous materials, in particular a fabric or a brush as mentioned above. During step (1), undesirable organic compounds are deposited by migration onto the surface of said article.

[0125] Step (2) is carried out by exposing the article to light, the conditions of such exposure being as described above with respect to the first embodiment, which allows the destruction of undesirable organic compounds by photolysis.

[0126] The following examples serve to illustrate the invention but are not limiting in nature. EXAMPLES

[0127] In the following examples, the particles are prepared in a flame spray pyrolysis apparatus (or FSP apparatus) where the liquid is fed to a burner through a capillary nozzle (capillary with a diameter of 500 μm). The resulting flame is enclosed in a tube that surrounds the pyrolysis flame. The tube is placed above the nozzle of the FSP device. The tube is a metal or quartz cylinder with a length of 20 cm to 60 cm, in particular 30 cm to 50 cm, for example 40 cm. The flame usually has a length between 5 cm and 15 cm and is at a temperature of 500 ° C to 2000 ° C. The sprayed metal precursors (Bi, W, Cu, etc.) are burned in the flame and particles are formed. The particles are then collected upstream on a glass fiber filter, preferably maintained at a temperature of 350 ° C to 420 ° C. The distance between the FSP nozzle and the filter for collecting the particles is 40 cm to 80 cm, preferably 55 cm to 65 cm.

[0128] Example 1: Preparation of particle powder by FSP Composition C1 is prepared by dissolving 250 mM ammonium metatungstate hydrate and 500 mM bismuth nitrate in an organic solvent composed of a diethylene glycol monobutyl ether / absolute ethanol / acetic acid mixture.

[0129] This composition C1, plus pure oxygen, is then injected into the FSP device.

[0130] 1.1.Bi2WO 6-x Preparation of particles (present invention) The flow rates used for injection are 7 ml / min for composition C1 and 4 l / min for gas (O2).

[0131] The powder thus obtained is subjected to a thermal post-treatment by exposure to a temperature of 300° C. for 1 hour, which allows improving its crystallinity.

[0132] The powder is yellow-green and is Bi2WO 6-x particles (where x is a decimal number greater than 0.1 and strictly less than 1).

[0133] The number average size of the particles is 25 nm (measured by X-ray diffraction or XRD).

[0134] 1.2. Preparation of Bi2WO6 particles (comparison) The flow rates used for injection are 7 ml / min for composition C1 and 5 l / min for gas (O2).

[0135] The powder thus obtained is subjected to a thermal post-treatment by exposure to a temperature of 300° C. for 1 hour.

[0136] The powder is yellow-green in color and contains Bi2WO6 particles. 。

[0137] The number average size of the particles is 25 nm (measured by X-ray diffraction or XRD).

[0138] 1.3.Particle characterization Bi2WO prepared in 1.1 and 1.2 above 6-x and Bi2WO6 particles were identified by Raman spectroscopy in the visible region of 400-500 nm, especially Bi2WO 6-x The Bi2WO6 particles are distinguished by their higher absorbance (typically about 20% higher) compared to the Bi2WO6 particles.

[0139] The two types of particles can also be distinguished by electron paramagnetic resonance spectroscopy (or EPR spectroscopy). 6-x The EPR spectrum of the particles typically has a signal at g = 2.002 characteristic of oxygen vacancies in the crystal lattice of Bi2WO6. The method is very sensitive and confirms the actual presence of suboxides with x > 0.1.

[0140] In contrast, Bi2WO 6-x Particles of Bi2WO6 are usually not distinguished by the position of the XRD peaks.

[0141] Typically, the metal oxide particles according to the invention are made of a suboxide (e.g., of the formula BiWO 6-x ) and: 1) have similar peak positions in X-ray diffraction (XRD) as their stoichiometrically oxidized homologues (e.g., Bi2WO6); 2) has a Raman spectroscopic profile with an absorbance in the 400-500 nm region that is at least 5%, preferably at least 10%, lower than the absorbance of its stoichiometrically oxidized homologue (e.g., Bi2WO6); and / or 3) It has an EPR spectroscopic profile that contains signals in the region of 2, specifically at g=2.002, which its stoichiometrically oxidized homologues (especially Bi2WO6) do not have.

[0142] Example 2: Preparation of particle mixtures by FSP Composition C2 is prepared by dissolving 25 mM copper nitrate, 250 mM ammonium metatungstate hydrate, and 500 mM bismuth nitrate in an organic solvent composed of a diethylene glycol monobutyl ether / absolute ethanol / acetic acid mixture.

[0143] This composition C2, plus pure oxygen, is then injected into the FSP device.

[0144] 2.1.Bi2WO 6-x Preparation of a mixture of particles and CuO particles (present invention) The flow rates used for injection are 7 ml / min for composition C2 and 4 l / min for gas (O2).

[0145] The powder thus obtained is subjected to a thermal post-treatment by exposure to a temperature of 300 °C for 1 h. The powder is light brown in colour and is Bi2WO 6-x The nanotube is formed from a mixture of SiO particles (where x is a decimal number greater than 0.1 and strictly less than 1) and CuO particles.

[0146] The EPR spectrum of the obtained powder has a signal at g=2.002 characteristic of oxygen atom vacancies compared to the crystal lattice of Bi2WO6.

[0147] The number average size of the particles is Bi2WO 6-xThe particles are 20 nm (measured by XRD) and the CuO particles are 2.5 nm (measured by XRD).

[0148] Bi2WO versus the amount of CuO in the powder 6-x The molar ratio of the amounts is 20.

[0149] 2.2. Preparation of a mixture of Bi2WO6 particles and CuO particles (comparison) The flow rates used for injection are 7 ml / min for composition C2 and 7 l / min for gas (O2).

[0150] The powder thus obtained is subjected to a thermal post-treatment by exposure to a temperature of 300° C. for 1 hour.

[0151] The powder is light brown in color and is formed of a mixture of Bi2WO6 and CuO particles.

[0152] The number average size of the particles is 20 nm for the Bi2WO6 particles (measured by XRD) and 2.5 nm for the CuO particles (measured by XRD).

[0153] The molar ratio of the amount of Bi2WO6 to the amount of CuO in the powder is 20.

[0154] Example 3: Sebum removal test with a thin layer under natural light irradiation Approximately 10cm 2 Prepare five identical plates by spreading each time a layer of artificial sebum (33 mg) composed of oleic acid on a glass plate with a surface area of ​​100 μm.

[0155] Then, on the surface of each plate, 10 mg of one of the following powders is deposited: On plate 1 and plate 5: BiWO from example 1.1 (invention) 6-x The powder formed from the particles is deposited; On plate 2: a powder formed of Bi2WO6 particles from example 1.2 (comparative) is deposited; On plate 3: BiWO from example 2.1 (invention) 6-x A powder formed from a mixture of particles and CuO particles is deposited; On plate 4: a powder formed of a mixture of Bi2WO6 particles and CuO particles from example 2.2 (comparative) is deposited.

[0156] Plates 1–4 were then placed in moderate sunlight (38 mW / cm 2 ) for a total of 60 minutes. The plate is then weighed to estimate the amount of sebum that has disappeared from the plate after 30 minutes and then 60 minutes of exposure to light.

[0157] The results obtained in terms of the percentage by weight of sebum disappeared are detailed in Table 1 below.

[0158] [Table 1]

[0159] To serve as a control, plate 5 (identical to plate 1) was not exposed to light. No loss of sebum was observed at t=60 min (the extent of loss was measured to be less than 5% by weight).

[0160] The above results show that the use of the particles according to the invention allows the removal of sebum much more effectively than the use of the comparative particles. 6-x Powders formed from particles give excellent results, Bi2WO 6-x Powders formed from a mixture of CuO particles can further enhance the effect.

[0161] Example 4: Test for removing sebum from hair A scalp hair containing 1000 mg of sebum is considered. Half of the scalp hair is visible, i.e. 1000 cm 2 Therefore, the visible surface area is 1 cm 2There is 0.5 mg of sebum per 100g of hair. This amount is enough to give hair a dirty, partially soiled appearance. In particular, when the hair is combed, the teeth of the comb tend to form furrows and hold the hair in place.

[0162] Test 1: In the first test, Bi2WO from Example 1.1 6-x The composition is prepared by dispersing 1000 mg of powder formed from the particles in 50 ml of ethanol. 12 grams of this composition is applied to the hair, and then the hair is left to dry for 10 minutes.

[0163] Next, 20mW / cm 2 The hair is exposed to natural light (sunlight) in an indoor environment that is assumed to be indoors (behind a window). It is observed that it takes one hour for the surface sebum to be sufficiently removed to reach a level where it is no longer visible.

[0164] In particular, it is observed that the treated hair is shiny and that the separation of the hair strands after combing is significantly better than before combing. The treated hair looks clean, as if it had just been washed, and unlike the untreated hair which looked very oily due to the presence of sebum, oil is no longer present in the hair.

[0165] Test 2: BiWO from Example 2.1 6-x Test 1 is repeated using a composition obtained by dispersing 1000 mg of a powder formed from a mixture of particles and CuO particles in 50 ml of ethanol.

[0166] It is observed that 28 minutes is required for surface sebum to be sufficiently removed to reach a level where it is no longer visible.

[0167] Test 3: Repeat test 1 using 12 grams of ethanol (no particles).

[0168] There is no change in the appearance of the hair and it still looks oily.

[0169] Test 4: Test 1 is repeated using a composition obtained by dispersing 1000 mg of a powder formed from a mixture of Bi2WO6 particles from example 2.2 and particles of Cu in 50 ml of ethanol.

[0170] After an hour, the hair appears less oily but not clean, due to insufficient removal efficiency and approximately 35%-40% of the sebum remaining on the visible surface of the hair.

[0171] Test 5: Test 2 is repeated but the hair is left in the dark after drying for 10 minutes.

[0172] No change in the appearance of the hair is observed and the hair still looks greasy.

[0173] Example 5: Test for maintaining hair cleanliness BiWO from Example 1.1 6-x A cosmetic composition is prepared by dispersing 400 mg of the powder formed from the particles in 50 ml of ethanol.

[0174] The test is carried out on a model with freshly washed medium-length hair at 22:00 in the evening. The hair is sufficiently cleaned of sebum so that the hair looks clean. After the hair is dry, 12 grams of the above cosmetic composition is applied and the roots are massaged with the fingertips, targeting the roots. Overnight, the scalp of the model produces approximately 500 mg of sebum, which is dispersed over time by various contacts (pillow). Then, during the day (considered here to be the range from 10:00 to 22:00), another 500 mg of sebum is produced. During this second period, the sebum is also distributed along the length of the hair through various contacts (hands, combs, etc.).

[0175] The model's hair was irradiated with 10mW / cm in the morning. 2The composition containing the particles according to the invention was applied the night before, and thus 500 mg of sebum produced during the night was destroyed in one hour, between 08:00 and 09:00.

[0176] For the rest of the day, the particles according to the invention continue to break down the sebum that appears on the scalp, then move to the roots before being removed by touch or other movements. At the end of the day, it is observed that the hair remains overall clean. Thus, the model does not feel the need to wash her hair in the evening.

[0177] The next day, when you wake up, your hair will be a little dirty, but will return to a clean appearance while morning light is still present.

[0178] Example 6: Test using a brush The brush is made by adhesively bonding a series of 80 bristles made from absorbent foam, 3 mm wide and 1 cm long, to a metal substrate. Then, 12 ml of the composition from Example 4-Test 2 (Bi2WO in 50 ml of ethanol) is applied. 6-x 1000 mg of a powder formed from a mixture of particles and CuO particles) is sprayed onto the brush and then dried.

[0179] The brush is passed through the hair and roots, absorbing some of the sebum while retaining the particles on the foam surface. This property is due to the fact that the contact point is dry (solvent-free). The brush is then placed (bristles down) 5cm above a light source (a series of four 1W LED lamps) until the sebum is removed.

[0180] One variant consists of using a Plexiglas substrate and a series of diodes placed under the substrate, which can then be brushed over the hair to collect the sebum and begin removing it from the moment of contact, after which, when the user places the brush down, the irradiation continues to complete the removal of the sebum collected in the foam bristles.

[0181] Example 7: Testing on Packages The tests use two identical copies of a brown cardboard package intended to cover boxes containing perfume or other cosmetic products.

[0182] In the first test, a tester places a finger on the package and, because the tester's finger is covered with a thin layer of skin oil, a visible mark is left on the package.

[0183] In a second test, the packaging is pretreated by spraying an ethanolic dispersion of the particles according to the invention onto cardboard. 6-x 10 mg of powder formed from a mixture of particles and CuO particles (Example 2.1) is dispersed in 10 ml of absolute ethanol, then this dispersion is sprayed onto a cardboard and allowed to dry. When a tester places his finger on this package, it is observed that the finger is covered with a thin layer of sebum, so that a visible mark is left on the package.

[0184] The two packages are then placed under light provided by a 20 cm 1 W yellow spotlight, typical of shop lighting.

[0185] After 10 minutes, the finger mark on the package of the second test is observed to gradually disappear until it is no longer visible after 1 hour. This disappearance is not observed on the package of the first test.

Claims

1. For preventing, reducing and / or removing the deposition of proteins and fatty substances secreted by the body on the surface of a keratinous material or on the surface of an object in contact with the keratinous material, ２ WO ６－ｘ : (In the formula, x is a decimal number ranging from 0.2 to 1.

5.

2. Use of solid particles comprising at least one metal oxide OM1 of the formula:

2. 2. The use according to claim 1, wherein x is a decimal number in the range of 0.3 to 1.

3. 2. The use according to claim 1, wherein x is a decimal number greater than or equal to 0.5 and strictly less than 1.

4. The metal oxide OM1 is represented by the formula M ｃ O ｋ : (In the formula, M represents a transition metal; c is an integer ranging from 1 to 3; k is a decimal number ranging from 0.1 to 4.

4. The use according to claim 1, in combination with a second metal oxide OM2 of

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

6. 6. Use according to claim 4 or 5, wherein the molar ratio of the amount of said metal oxide OM1 to the amount of said metal oxide OM2 is ≧1.

7. 7. The use according to claim 6, wherein the molar ratio of the amount of said metal oxide OM1 to the amount of said metal oxide OM2 is 4 or more.

8. The use according to any one of the preceding claims, wherein the solid particles comprising the at least one metal oxide OM1 have a number average diameter in the range from 1 to 1000 nm.

9. The use according to any one of the preceding claims, wherein the solid particles comprising the at least one metal oxide OM1 have a number average diameter in the range from 10 to 200 nm.

10. Use according to any one of claims 1 to 9 for preventing, reducing and / or removing sebum deposits.

11. A method for preventing, reducing and / or removing deposits of proteinaceous and fatty substances secreted by the body on a surface of a keratinous material or on a surface of an object in contact with the keratinous material, comprising: (1) applying to the surface of the keratinous material or the object a compound represented by the formula Bi ２ WO ６－ｘ applying a cosmetic composition comprising solid particles comprising at least one metal oxide OM1 of (2) exposing the keratinous material or the surface of the object to natural or artificial light; The method includes:

12. The cosmetic composition used in step (1) is a composition of formula M according to any one of claims 4 to 7, wherein the composition is present in the particles comprising at least one metal oxide OM1 or in different solid particles. ｃ O ｋ 12. The method according to claim 11, further comprising at least one metal oxide OM2 of the formula:

13. The method according to claim 11 or 12, characterized in that the content of the metal oxide OM1 in the cosmetic composition ranges from 0.4% by weight to 40% by weight relative to the total weight of the composition.

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

15. A method for preventing, reducing and / or removing deposits of proteinaceous and fatty substances secreted by the body on the surface of keratinous materials, comprising: (1) The keratinous material is treated with a compound of the formula Bi ２ WO ６－ｘ with solid particles comprising at least one metal oxide OM1 of (2) exposing the solid particles to natural or artificial light; The method includes:

16. The at least one metal oxide OM1 used in step (1) is a metal oxide of formula M ｃ O ｋ 16. The method according to claim 15, characterized in that it is combined with at least one metal oxide OM2 of the formula:

17. 17. The method according to claim 12 or 16, wherein the molar ratio of the amount of said metal oxide OM1 to the amount of said metal oxide OM2 is 1 or more.

18. 18. The method according to any one of claims 11 to 17, characterized in that step (2) is carried out by photoirradiation using a light source emitting one or more electromagnetic waves having wavelengths from 200 nm in the ultraviolet range to 3000 nm in the infrared range.

19. 20. The method of claim 18, wherein the light source is an LED lamp emitting radiation having wavelengths in the visible range.

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