Composite material of bismuth oxycarbonate and aluminum (hydr)oxide for ultraviolet radiation filtration

Abstract

Bismuth oxycarbonate and aluminum (hydr)oxide composite material for ultraviolet radiation filtration. The present invention relates to a composite material comprising at least one bismuth oxycarbonate particle of empirical formula (BiO)2-x(CO3), as well as its solvates, such as its hydrates, wherein -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm; and at least one aluminum (hydr)oxide particle of empirical formula [Al2O3.yH2O] wherein 0 ≤ y ≤ 10, their preparation process, as well as cosmetic compositions and uses employing said composite materials. Figure for the abstract: None

Description

Title of the invention: Composite material of bismuth oxycarbonate and aluminum (hydr)oxide for the filtration of ultraviolet radiation Technical field

[0001] The present invention relates to the field of sun protection and more particularly to composite materials of bismuth oxycarbonate, as well as its solvates, such as its hydrates, and aluminum (hydr)oxide, for their use in the filtration of ultraviolet radiation.

[0002] The invention also relates to a composition, in particular a cosmetic composition, comprising in particular composite materials of bismuth oxycarbonate, as well as its solvates, such as its hydrates, and aluminum (hydr)oxide.

[0003] Keratin materials are exposed to sunlight on a daily basis.

[0004] It is known that light radiation with wavelengths between 280 nm and 400 nm allows the tanning of human epidermis. However, rays with wavelengths between 280 and 320 nm, called UV-B rays, are detrimental to the development of a natural tan. This exposure is also likely to induce an alteration of the biomechanical properties of the epidermis which results in the appearance of wrinkles leading to premature aging of the skin.

[0005] It is also known that UV-A rays, with wavelengths between 320 and 400 nm, penetrate deeper into the skin than UV-B rays. UV-A rays promote rapid and persistent pigmentation of the skin. Daily exposure to UVA radiation, even for short periods, under normal conditions, can also generate a degradation of collagen and elastin fibers which results in a modification of the skin microrelief, the appearance of wrinkles and irregular pigmentation (i.e. brown spots, uneven skin tone, etc.).

[0006] Additionally, prolonged exposure to the sun can further dry out hair, making it brittle.

[0007] Consequently, protection of keratin materials, particularly human materials, such as skin, is essential. Prior art

[0008] To counter these undesirable effects, it is common practice to formulate organic and / or inorganic anti-UV-A and / or UV-B filters in compositions dedicated to providing sun protection.

[0009] Many photoprotective cosmetic compositions for the skin have been proposed to date. They generally contain organic UV filters and / or inorganic UV filters that act according to their own chemical nature and physical properties by absorbing, reflecting or scattering UV radiation. They generally contain combinations of oil-soluble organic UV filters and / or water-soluble organic UV filters combined with metal oxide pigments such as titanium dioxide (TiO2) or zinc oxide (ZnO).

[0010] As regards the usual organic filters, they must have acceptable cosmetic properties, good solubility in the usual solvents, in particular in oils, but also good photostability, alone and in combination. They must also be colorless or of a color that is cosmetically acceptable to consumers. These organic filters are generally used in mixtures and such combinations of filters can limit the formulatory field.

[0011] In addition, photoprotection from inorganic UV filters is today a very important expectation of consumers, as they consider mineral sunscreens safer.

[0012] TiO2 and ZnO are the most commonly used mineral UV filters.

[0013] However, one of the major drawbacks of such mineral filters lies in the fact that, once applied to the skin, they produce a whitening effect on the latter which is cosmetically undesirable and generally not appreciated by users.

[0014] This effect is all the more marked as the concentration of mineral filters in the composition is high, which limits their concentration in sunscreen formulations.

[0015] To avoid this problem, it would of course be possible to use reduced quantities of inorganic filter(s), but the resulting compositions, which would certainly lead to films having acceptable transparency on the skin, would then no longer offer suitable protection in the UV range, which greatly limits the interest of such an option.

[0016] Furthermore, the use of large quantities of these UV filters induces, in addition to significant whitening, unpleasant sensations after application to the skin, and in particular causes sensations of roughness and dryness on the skin in the case of significant and regular use of the products.

[0017] However, consumers are increasingly looking for products that are effective but also offer great ease of application, long-lasting comfort and satisfactory sensory properties. Statement of the invention

[0018] There therefore remains a need to have inorganic UV filters which are effective in photoprotection, and which do not have the drawbacks presented above. above.

[0019] In particular, there remains a need for inorganic UV filters capable of effectively blocking UV rays, particularly in the UV-B and UV-A range, and in particular UV-B rays, having high transparency to visible light, which do not bleach the keratin materials to which they are applied and having good cosmetic properties.

[0020] In particular, there remains a need for mineral UV filters, distinct from titanium dioxide or zinc oxide, which prove to be just as effective, which are transparent, which do not cause sensations of roughness and dryness on the skin, and which are easily formulated, particularly at high concentrations.

[0021] The present invention aims precisely to propose new mineral UV filters making it possible to meet these expectations. Summary of the invention

[0022] Thus, according to a first of its aspects, the present invention relates to a composite material comprising:

[0023] a) at least one particle of bismuth oxycarbonate of empirical formula (BiO)2 / CO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm; and

[0024] b) at least aluminum (hydr)oxide of empirical formula [Al2O3.yH2O] in which 0 < y < 10.

[0025] Preferably, the average size of the largest dimension of the composite material particle according to the invention is less than or equal to 1 μm, and more preferably less than or equal to 500 nm, even more preferably less than or equal to 450 nm.

[0026] Surprisingly, and as is apparent from the examples below, the inventors have discovered that the composite materials according to the invention have excellent efficiency for filtering ultraviolet radiation, and in particular UV-B rays, as well as high transparency in visible radiation, and make it possible to give the composition containing them cosmetic properties that are satisfactory for the consumer.

[0027] For the purposes of the present invention, the term “composite material” means a heterogeneous particulate solid material comprising at least two immiscible components, and the components of which are linked by physical and / or chemical interactions.

[0028] For the purposes of the present invention, the term “aluminum (hydr)oxide” means an aluminum oxide or an aluminum hydroxide.

[0029] For the purposes of the present invention, the term “high transparency in visible radiation” means particles having a high transmission of rays between 400 and 780 nm.

[0030] For the purposes of the present invention, the term "efficiency for filtering ultraviolet radiation" means particles having an absorbance threshold in the UV, in the dispersion medium comprising said particles at a mass fraction of 0.005%, greater than 0.25, preferably greater than or equal to 0.30, and more preferably still greater than or equal to 0.35. The higher the absorbance threshold, the greater the efficiency of filtering UV radiation.

[0031] UV-B radiation means the wavelength range from 280 to 320 nm. UV-A radiation means the wavelength range from 320 to 400 nm. Visible light means the wavelength range from 400 to 780 nm.

[0032] Thus, for the purposes of the present invention, the term "UV filter" is intended to denote any compound that filters ultraviolet (UV) radiation in the wavelength range from 280 nm to 400 nm. The term "UV-B filter" is intended to denote any compound that filters ultraviolet (UV) radiation in the wavelength range from 280 nm to 320 nm. The term "UV-A filter" is intended to denote any compound that filters ultraviolet (UV) radiation in the wavelength range from 320 nm to 400 nm.

[0033] This effectiveness of the composite materials according to the invention is, to the inventors' knowledge, characterized for the first time. It has never been proposed to use composite materials of bismuth oxycarbonate, as well as its solvates, such as its hydrates, and aluminum (hydr)oxide in cosmetic compositions intended for the effective filtration of UV radiation, in particular UV-B radiation.

[0034] The composite materials according to the invention are in particular intended to protect keratin materials, in particular the skin and hair, from UV radiation, in particular in cosmetic compositions for the fields of sun protection, care, hair treatment and makeup.

[0035] Thus, according to another aspect, the present invention also relates to the non-therapeutic cosmetic use of a composite material according to the invention, for filtering UV radiation, preferably UV-B, comprising at least the application to keratin materials of a composition comprising a composite material according to the invention.

[0036] The present invention also relates to a non-therapeutic cosmetic process for filtering UV radiation, preferably UV-B, comprising at least the application to keratin materials of a composition comprising composite materials of bismuth oxycarbonate, as well as its solvates, such as its hydrates, and aluminum (hydr)oxide as defined above.

[0037] The present invention also relates to methods for preparing the composite materials according to the invention.

[0038] By “keratin materials” is meant in particular the skin, including the scalp, the lips, and also keratin fibers such as the hair, the eyelashes, the eyebrows, in particular the skin and / or the hair, and preferably the skin.

[0039] The expression “at least one” is equivalent to “one or more”.

[0040] The expressions “between ... and ...”, “includes from ... to ...”, “formed from ... to ...”, and “ranging from ... to ...” must be understood inclusively, unless otherwise specified.

[0041] Other characteristics, variants and advantages of the compositions according to the invention will become more apparent on reading the description and examples which follow. Brief description of the drawings

[0042] [Fig.l] represents the absorbance spectrum obtained by UV-visible spectrophotometry on dispersions of composite A at 0.005% by mass in a Water / Propylene glycol / Tween 20 mixture.

[0043] [Fig.2] represents the absorbance spectrum obtained by UV-visible spectrophotometry on dispersions of composite B at 0.005% by mass in a Water / Propylene glycol / Tween 20 mixture.

[0044] [Fig.3] represents the absorbance spectrum obtained by UV-visible spectrophotometry on dispersions of composite C at 0.005% by mass in a Water / Propylene glycol / Tween 20 mixture.

[0045] [Fig.4] represents the absorbance spectrum obtained by UV-visible spectrophotometry on dispersions of composite D at 0.005% by mass in a Water / Propylene glycol / Tween 20 mixture. Detailed description

[0046] The invention relates to a composite material comprising a) bismuth oxycarbonate particles of empirical formula (BiO)2 / CO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm; and b) at least aluminum (hydr)oxide of empirical formula [Al2O3.yH2O] in which 0 < y < 10. Composite material

[0047] As indicated above, the composite material comprises at least a) a particle of bismuth oxycarbonate, as well as its solvates, such as its hydrates, and b) at least aluminum (hydr)oxide of empirical formula [Al2O3.yH2O] in which 0 < y < 10.

[0048] Thus, the composite material according to the invention can be represented according to the formula (BiO)2XCO3)-[Al2O3.yH2O] in which -0.4 < x < 0.6 and 0 < y < 10.

[0049] The composite materials according to the invention are of nanometric and / or micrometric size.

[0050] In particular, the average size of the largest dimension of the composite material particle varies from 0.005 pm to 10 pm.

[0051] Preferably, the average size of the largest dimension of the composite material particle varies from 0.01 pm to 1 pm.

[0052] Preferably, the average size of the largest dimension of the composite material particle varies from 30 nm to 500 nm.

[0053] Preferably, the average size of the largest dimension of the composite material particle varies from 30 nm to 450 nm.

[0054] KaKBy "average dimension" is meant the number-average value of the dimensions of the primary particles. The dimensions of the particles can be determined by transmission electron microscopy, for example using a Hitachi HT 7700 microscope, in particular at an acceleration voltage of 100 kV, by scanning electron microscopy, or from the measurement of the specific surface area by the BET method, or by means of a laser granulometer. Preferably, the dimensions of the particles are determined by transmission electron microscopy, for example using a Hitachi HT 7700 microscope, in particular at an acceleration voltage of 100 kV, or by scanning electron microscopy. Preferably, the measurement is made on the smallest individualized or individualizable objects. The number-average value can be calculated by analyzing the images obtained using software, such as the Image J software (CASchneider, WS Rasband, KW Eliceiri, NIH Image to ImageJ: 25 years of image analysis, Nat. Methods. 9 (2012) 671-675). .

[0055] The average dimension is chosen from the average length L, the average width 1, the average thickness e, or the average diameter d.

[0056] By "the average size of the largest dimension" or "the largest average dimension" of composite materials or particles is meant the largest average dimension of a surface, such as a face, that can be measured between two diametrically opposite points of an individual particle.

[0057] The “length” L of a composite material or of a particle is its largest dimension observable on a photograph taken in a direction perpendicular to the plane on which said composite material or said particle rests.

[0058] The “width” l and “thickness” e of a composite material or particle are the lengths of the major and minor axes, respectively, of the smallest possible ellipse in which the median cross-section of said composite material or particle can be inscribed.

[0059] The “diameter” d of a composite material or particle is the largest observable dimension along a straight line passing through the center of a circle or a sphere.

[0060] The composite materials according to the invention can be of various shapes and structures.

[0061] The composite materials according to the invention may in particular be spherical, cubic, platelet-like, cylindrical or tubular.

[0062] The shape of said composite materials will depend in particular on their preparation process and the operating conditions.

[0063] In particular, the composite materials according to the invention may be in the form of tubes, platelets, sheets, rods, spheres, flowers, pompoms, threads, filaments, fibers, needles, cubes or any of their mixtures.

[0064] The composite materials according to the invention can furthermore aggregate in the form of superstructures. For example, platelets, tubes and / or rods can aggregate in the form of spheres, flowers or even pompoms.

[0065] According to a particular embodiment, the composite materials according to the invention are in the form of spheres.

[0066] According to a particular embodiment, the composite materials according to the invention are in the form of tubes, plates and / or rods. Even more preferably, the composite materials according to the invention are in the form of plates and / or rods.

[0067] Composite materials in the form of plates or rods or tubes are therefore distinguished in particular from spherical, fibrous shapes, flowers, pompoms, threads, filaments, needles or cubes.

[0068] It is understood that the composite materials according to the invention can be used in the form of a mixture. In particular, the composite materials according to the invention can be used in a mixture in any proportion of platelets and / or rods and / or tubes.

[0069] According to a preferred embodiment, the composite materials used according to the invention are mainly or exclusively in the form of platelets.

[0070] A composite material in the form of a “platelet” has a length greater than its width and a width greater than its thickness.

[0071] According to a preferred embodiment, the composite materials are mainly or exclusively in the form of rods.

[0072] A composite material in the form of a “rod” has a solid cylindrical shape and its length L is greater than its diameter d, or has a prism shape whose base is solid polygonal, preferably triangular or hexagonal, and the diameter d of the circle circumscribed to this polygonal base is less than the length L of the prism.

[0073] According to a preferred embodiment, the composite materials are mainly or exclusively in the form of tubes.

[0074] A composite material in the form of a “tube” has a hollow cylindrical shape and its length L is greater than its diameter d.

[0075] By "predominantly in the form of platelets / rods / tubes" within the meaning of the present invention, it is meant that at least 50% by number, in particular at least 70% by number, or even at least 90% by number of the composite materials are in the form of platelets / rods / tubes respectively.

[0076] The bismuth oxycarbonate particle(s) a), as well as its solvates, such as its hydrates, and the aluminum (hydr)oxide species(s) b) can be arranged in different ways within the composite material.

[0077] According to one embodiment, the composite material may have at least one core and at least one coating in layer(s) surrounding said core.

[0078] Thus, they can comprise at least one coating in layer(s) surrounding a core chemically different from said coating.

[0079] The coating may be formed from one or more layers.

[0080] The core of the composite materials may consist of at least a) one or more particles of bismuth oxycarbonate of empirical formula (BiO)2XCO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm.

[0081] According to a particular embodiment, the core of the composite materials may consist of at least one species of aluminum (hydr)oxide b).

[0082] The composite material may contain bismuth oxycarbonate particles a) as defined above in the core and / or in the layer(s) forming the coating.

[0083] According to a particular embodiment, the material contains at least one particle of bismuth oxycarbonate a), as well as its solvates, such as its hydrates, as defined above in the core.

[0084] According to another particular embodiment, the material contains particles of bismuth oxycarbonate a), as well as its solvates, such as its hydrates, as defined above in the coating.

[0085] According to one embodiment, the aluminum (hydr)oxide species b) may cover all or part of at least one particle of bismuth oxycarbonate a), as well as its solvates, such as its hydrates.

[0086] According to another embodiment, the aluminum (hydr)oxide species b) may be covered in whole or in part by at least one particle of bismuth oxycarbonate a), as well as its solvates, such as its hydrates.

[0087] In particular, the molar ratio between the number of moles of coating compound(s) and the number of moles of core compound(s) varies from 0.0001 to 20, preferably varies from 0.005 to 15, more preferably varies from 0.01 to 10, and even more preferably varies from 0.05 to 5.

[0088] According to a particular embodiment, the composite materials according to the invention contain at least one layer surrounding the core.

[0089] Thus, according to a particular embodiment, the composite materials according to the invention comprise a core comprising at least a) at least one particle of bismuth oxycarbonate of empirical formula (BiO)2 / CO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm, said core being covered on the surface, continuously or discontinuously, by a coating comprising b) at least aluminum (hydr)oxide of empirical formula [Al2O3.yH2O] in which 0 < y < 10.

[0090] According to a first variant of the invention, the composite materials in accordance with the invention comprise a coating, also called a bark or envelope, which is continuous, namely surrounding the entire surface of the core.

[0091] According to a second variant of the invention, the composite materials in accordance with the invention comprise a coating, also called a bark or envelope, which is discontinuous, namely discontinuously surrounding the surface of the core.

[0092] Preferably, from 10% to 90%, more particularly from 10% to 70%, and even more particularly from 30% to 50% of the surface of the core is covered by the coating.

[0093] According to one embodiment, the coating is a multi-layer coating, i.e. comprising one or more internal layers and an external layer, in other words several superimposed layers for all or part of which each can be continuous or discontinuous.

[0094] In a multi-layer coating, the term "inner layer" means any layer that is not an outer layer. This may be the layer directly superimposed on the core or any intermediate layer between the core and the outer layer.

[0095] In a multi-layer coating, the term "outer layer" means the layer forming the last layer of the coating which is not contiguous to the core. The outer layer is separated from the core by at least one inner layer. The outer layer has no coating.

[0096] In a multi-layer coating formed of two layers, the inner layer is the layer contiguous to the core and the outer layer is the layer contiguous to the inner layer and not contiguous to the core.

[0097] In a multi-layer coating formed of more than two layers, the internal layers are the layer adjacent to the core and the intermediate layer(s) between the layer adjacent to the core and the outer layer.

[0098] The inner layer(s) forming the multi-layer coating of the composite material and the single outer layer of the composite material may be formed from identical or different compounds.

[0099] Each layer may consist of a single compound or a mixture of compounds.

[0100] The layer(s) may in particular extend concentrically relative to the core.

[0101] In particular, the composite materials according to the invention have a double layer surrounding the core, in other words an internal layer and an external layer.

[0102] According to a preferred embodiment, the composite materials according to the invention have at least one layer, preferably comprising at least b) at least aluminum (hydr)oxide of empirical formula [Al2O3.yH2O] in which 0 < y < 10.

[0103] According to a preferred embodiment, the composite materials according to the invention comprise: - a core comprising at least a) at least one particle of bismuth oxycarbonate of empirical formula (BiO)2XCO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm, and - at least one layer continuously or discontinuously surrounding said core and comprising b) at least aluminum (hydr)oxide of empirical formula [Al2O3.yH2O] in which 0 < y < 10.

[0104] Preferably, the composite materials according to the invention comprise: - a core comprising at least a) at least one particle of bismuth oxycarbonate of empirical formula (BiO)2XCO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm, - a single layer contiguous to said core and comprising b) at least aluminum (hydr)oxide of empirical formula [Al2O3.yH2O] in which 0 < y < 10. a) Bismuth oxycarbonate particles

[0105] The bismuth oxycarbonate particles a) according to the invention have the empirical formula (BiO)2 / CO3), as well as its solvates, such as its hydrates, with -0.4 < x < 0.6. The value of x can in particular be determined by elemental analysis.

[0106] Preferably, x is equal to 0 and the empirical formula of the bismuth oxycarbonate particles a) is (BiO)2(CO3).

[0107] The bismuth oxycarbonate particles a) according to the invention may be crystallized or amorphous.

[0108] According to one form of the invention, the bismuth oxycarbonate particles a) are amorphous.

[0109] According to a preferred form of the invention, the bismuth oxycarbonate particles a) are crystallized.

[0110] It is understood that the bismuth oxycarbonate particles a) may consist of a mixture of several bismuth oxycarbonate particles of different crude formulas and / or different shapes.

[0111] Thus, the bismuth oxycarbonate particles a) may be a mixture of amorphous particles and crystallized particles.

[0112] By "crystallized" as used herein is meant that the atoms constituting the bismuth oxycarbonate particles are arranged in an orderly manner. In other words, the crystallized bismuth oxycarbonate particles are organized materials.

[0113] In contrast, particles whose atoms are disordered are called "amorphous". The atoms of such particles have no organization in the microscopic state.

[0114] Preferably, the crystallized particles required according to the invention have the crystalline phase of the natural ore bismutite, designated as lamellar, and which has an alternation of [Bi2O2]2+ and [CO3]2 layers.

[0115] Such particles crystallize in an orthorhombic system of space group Imm2.

[0116] The bismutite crystal structure of bismuth oxycarbonate can have the following lattice parameters: a = 3.865 Å; b = 3.862 Å; c = 13.675 Å and Vmaiue = 0.204 nm3. This particular arrangement of atoms allows in particular the growth of anisotropic objects.

[0117] A particle is considered “anisotropic” when the elongation factor R between its length L and its thickness e, i.e. R = L / e, is greater than 2.

[0118] According to the invention, the largest average dimension of the crystallized or amorphous particles, preferably crystallized, of bismuth oxycarbonate a) of crude formula (BiO)2XCO3), as well as its solvates, such as its hydrates, in which -0.4 <x< 0,6 est inférieure à 400 nm.

[0119] Preferably, the largest average dimension of said particles is less than or equal to 300 nm.

[0120] According to the invention, the bismuth oxycarbonate particles of empirical formula (BiO)2^ (CO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, can be in any form.

[0121] The shape of said particles will depend in particular on their preparation process and the operating conditions.

[0122] In particular, the particles according to the invention may be in the form of tubes, plates, sheets, sticks, spheres, flowers, pompoms, threads, filaments, fibers, needles, cubes or any mixture thereof.

[0123] The particles according to the invention can further aggregate in the form of superstructures. For example, platelets, tubes and / or rods can aggregate in the form of spheres, flowers or even pompoms.

[0124] According to a preferred embodiment, the particles according to the invention are in the form of tubes, platelets and / or rods. Even more preferably, the particles according to the invention are in the form of platelets and / or rods.

[0125] Particles in the form of platelets or rods or tubes are therefore distinguished in particular from spherical, fibrous forms, flowers, pompoms, threads, filaments, needles or cubes.

[0126] It is understood that the particles according to the invention can be used in the form of a mixture. In particular, the particles according to the invention can be used in a mixture in any proportion of platelets and / or rods and / or tubes.

[0127] According to a preferred embodiment, the particles used according to the invention are mainly or exclusively in the form of platelets.

[0128] A particle in the form of a “platelet” has a length greater than its width and a width greater than its thickness.

[0129] In particular, when they are in the form of platelets, the bismuth oxycarbonate particles a), as well as its solvates, such as its hydrates, have: - an average length L ranging from 15 to 300 nm, in particular ranging from 30 to 250 nm, preferably ranging from 50 to 200 nm, more preferably ranging from 70 to 150 nm; - an average width l ranging from 10 to 250 nm, in particular ranging from 20 to 200 nm, preferably ranging from 30 to 150 nm, more preferably ranging from 50 to 120 nm; - an average thickness e ranging from 2 to 120 nm, in particular ranging from 5 to 100 nm, preferably ranging from 10 to 80 nm, more preferably ranging from 20 to 50 nm; and - with e <1 <L.

[0130] According to a preferred embodiment, the bismuth oxycarbonate particles a), as well as its solvates, such as its hydrates, are found mainly or exclusively in the form of rods.

[0131] A particle in the form of a “rod” has a solid cylindrical shape and its length L is greater than its diameter d, or has a prism shape whose base is solid polygonal, preferably triangular or hexagonal, and the diameter d of the circle circumscribed to this polygonal base is less than the length L of the prism.

[0132] In particular, when they are in the form of rods, whether cylindrical or prismatic, the particles of bismuth oxycarbonate, as well as its solvated, such as its hydrates, have: - an average length L ranging from 30 to 300 nm, in particular ranging from 50 to 250 nm, preferably ranging from 70 to 230 nm, more preferably ranging from 70 to 140 nm; - an average diameter d ranging from 15 to 150 nm, in particular ranging from 20 to 130 nm, preferably ranging from 25 to 120 nm, more preferably ranging from 25 to 100 nm, and even more preferably ranging from 25 to 60 nm, and - with L> d.

[0133] According to a preferred embodiment, the bismuth oxycarbonate particles a), as well as its solvates, such as its hydrates, are found mainly or exclusively in the form of tubes.

[0134] A particle in the form of a “tube” has a hollow cylindrical shape and its length L is greater than its diameter d.

[0135] In particular, when in the form of tubes, bismuth oxycarbonate particles, as well as its solvates, such as its hydrates, have: - an average length L ranging from 10 to 300 nm, in particular ranging from 20 to 250 nm, preferably ranging from 40 to 200 nm, more preferably ranging from 60 to 200 nm; - an average diameter d ranging from 2 to 30 nm, in particular ranging from 3 to 20 nm, and preferably ranging from 5 to 15 nm; and - with L> d.

[0136] By "predominantly in the form of platelets / rods / tubes" within the meaning of the present invention, it is meant that at least 50% by number, in particular at least 70% by number, or even at least 90% by number of the particles are in the form of platelets / rods / tubes respectively. Doping of particles a)

[0137] According to a particular embodiment, the bismuth oxycarbonate particles a), as well as its solvates, such as its hydrates, can be doped.

[0138] In particular, the bismuth oxycarbonate particles may be doped with one or more chemical elements capable of being inserted into the structure or of partially replacing elements already present.

[0139] The particles may be doped via substitutions of all or part of the cations and / or all or part of the anions.

[0140] According to a particular embodiment, the doping partly concerns cations in insertion or substitution of bismuth within the limit of 20% of the bismuth composition.

[0141] According to this variant, the doping rate varies in particular from 0.005% to 15%, preferably from 0.05% to 12%, more preferably from 0.1% to 10%, and even more preferably from 0.5% to 6%.

[0142] In particular, the bismuth oxycarbonate particles may be doped with cations derived from elements selected from aluminum (Al), silicon (Si), scandium (Sc), titanium (Ti), vanadium (V), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), silver (Ag), indium (In), lanthanum (La), cerium (Ce), tantalum (Ta), tungsten (W) and / or gold (Au).

[0143] Preferably, the bismuth oxycarbonate particles may be doped with cations derived from elements chosen from titanium, vanadium, manganese, iron, copper, zinc, lanthanum, and / or cerium, more preferably from manganese, iron and / or cerium, and even more preferably from manganese or iron.

[0144] According to an alternative embodiment, the bismuth oxycarbonate particles are doped with cations derived from manganese, and the doping rate varies in particular from 0.5% to 2%.

[0145] According to another embodiment variant, the bismuth oxycarbonate particles are doped with cations derived from iron, and the doping rate varies in particular from 0.5% to 2%.

[0146] According to another particular embodiment, the doping concerns in part or in total anions in insertion or in substitution of the carbonate group within the limit of 20% of the carbonate composition.

[0147] According to this variant, the doping rate varies in particular from 0.001% to 1%, preferably from 0.002% to 0.5%, more preferably from 0.003% to 0.2%, and even more preferably from 0.005% to 0.1%.

[0148] In particular, the bismuth oxycarbonate particles may be doped with anions derived from elements chosen from fluorine (F), sulfur (S), chlorine (Cl), bromine (Br), iodine (I), and / or with polyatomic anions, in particular chosen from sulfate ion (SO42), sulfonate ion (S(=0)2-0), sulfite ion (SO32), phosphate ion (PO43) and / or iodate ion (IO3).

[0149] Preferably, the bismuth oxycarbonate particles may be doped with S2, SO32, SO42, Cl and / or I, more preferably with SO32, SO42 and / or Cl, and more preferably with Cl or SO42.

[0150] According to an alternative embodiment, the bismuth oxycarbonate particles are doped with anions derived from chlorine, and the doping rate varies in particular from 0.01% to 0.1%.

[0151] According to another embodiment variant, the bismuth oxycarbonate particles are doped with anions derived from iodine, and the doping rate varies in particular from 0.003% to 0.01%.

[0152] According to another embodiment variant, the bismuth oxycarbonate particles are doped with sulfate ion, and the doping rate varies in particular from 0.005% to 0.1%.

[0153] According to another embodiment variant, the bismuth oxycarbonate particles are doped with cations preferably derived from elements chosen from titanium, vanadium, manganese, iron, copper, zinc, lanthanum, and / or cerium, more preferably chosen from manganese, iron and / or cerium, and even more preferably chosen from manganese or iron, and with anions preferably derived from elements chosen from fluorine (F), sulfur (S), chlorine (Cl), bromine (Br), iodine (I), and / or with polyatomic anions, in particular chosen from the sulfate ion (SO42), the sulfonate ion (S(=0)2-0), the sulfite ion (SO32), the phosphate ion (PO43) and / or the iodate ion (IO3), more preferably with S2, SO32, SO42, Cl and / or I, even more preferably with SO32, SO42 and / or Cl, and particularly preferably with Cl, I or SO42.

[0154] According to a preferred embodiment, the bismuth oxycarbonate particles required according to the invention are undoped.

[0155] According to another preferred embodiment, the bismuth oxycarbonate particles required according to the invention are doped.

[0156] According to another preferred embodiment, the bismuth oxycarbonate particles required according to the invention are a mixture of doped particles and undoped particles.

[0157] Process for the preparation of bismuth oxycarbonate particles a)

[0158] The bismuth oxycarbonate particles a), as well as its solvates, such as its hydrates, can be obtained by any preparation process known to those skilled in the art.

[0159] For example, the synthesis of bismuth oxycarbonate particles is described in the article by Ni et al. (Fabrication, modification and application of (BiO)2CO3-based photocatalysts: A review, Applied Surface Science, 365, 2016, 314-335).

[0160] In particular, bismuth oxycarbonate particles, as well as its solvates, such as its hydrates, can be prepared solvothermally, electrochemically, by co-precipitation, or even at reflux, and preferably solvothermally or at reflux.

[0161] According to a first embodiment variant, the bismuth oxycarbonate particles, as well as its solvates, such as its hydrates, are obtained by solvothermal means, in particular from bismuth nitrate and various carbonating agents such as sodium carbonate, ammonium carbonate or urea, in a protic polar solvent in the presence of polyols. Such a synthesis makes it possible to obtain bismuth oxycarbonate particles in the form of platelets and / or rods, the largest dimension of which varies from 50 to 300 nm.

[0162] The synthesis of particles by solvothermal means is notably described in the articles de Cheng, G. et al. (Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials, J. Solid State Chem. 183, 1878-1883 (2010)) ; Ruan, MM et al. (Facile Green Synthesis of Highly Monodisperse Bismuth Subcarbonate Micropompons Self-assembled by Nanosheets: Improved Photocatalytic Performance, Acta Physico-Chimica Sinica, 33, 2017, 1033-1042) ; Quin et al. (Template-Free Fabrication of Bi2O3 and (BiO)2CO3 Nanotubes and Their Application in Water Treatment, Chem. Eur. J., 18, 2012, 16491-16497) ; Cheng, G. et al. (Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials, J. Solid State Chem., 183, 2010, 1878-1883) ; Liu, YY et al. (Préparation, electronic structure, and photocatalytic properties of Bi2O2CO3 nanosheet, Appl. Surf. Sci., 257, 2010, 172-175) ; Zheng et al.(Synthetic Bi2O2CO3 nanostructures: Novel photocatalyst with controlled special surface exposed, Journal of Molecular Catalysis A: Chemical, 2010, 317 (1-2), 34-40); Liu, SQ et al. (The effects of citrate ion on morphology and photocatalytic activity of flower-like Bi2O2CO3, Ceram. Int., 40, 2014, 2343-2348); or Chen, R. et al. (Bismuth subcarbonate nanoparticles fabricated by water-in-oil microemulsion-assisted hydrothermal process exhibit anti-Helicobacterpylori properties, Mater. Res. Bull., 45, 2010, 654-658). .

[0163] The synthesis of particles by electrochemical means is notably described in the article by Hu, Y. et al. (Simple hydrolysis route to synthesize Bi2O2CO3 nanoplate from Bi nanopowder and its photocatalytic application, Materials Letters, 170, 2016, 72-75).

[0164] The synthesis of particles by co-precipitation is notably described in the article by Chen, XY et al. (Controlled synthesis of bismuth oxo nanoscalecrystals (BiOCl, Bii2O i7Cl2, a-Bi2O3, and (BiO)2CO3) by solution-phase methods, J. Solid State Chem., 180, 2007,2510-2516).

[0165] The synthesis of particles by reflux is notably described in the article by Chen et al. (Fabrication of bismuth subcarbonate nanotube arrays from bismuth citrate, Chem. Commun., 2006, 2265-2267).

[0166] According to a preferred embodiment, the bismuth oxycarbonate particles, as well as its solvates, such as its hydrates, required according to the invention are obtained by solvothermal means, for example according to the process described by Cheng et al., or at reflux, for example according to the process described by Chen et al..

[0167] According to a preferred embodiment, the bismuth oxycarbonate particles, as well as its solvates, such as its hydrates, required according to the invention are obtained by a preparation process using one or more bismuth (III) complexes, one or more carbonating agents, one or more polyols and optionally one or more polar solvents, distinct from the polyols.

[0168] When the particles used according to the invention are doped, one or more reagents additional elements including doping elements can be added.

[0169] In particular, the bismuth (III) complex(es) is (are) chosen from bismuth nitrate and its hydrated forms, bismuth citrate and its hydrated forms, bismuth sulfate and its hydrated forms and bismuth chloride and its hydrated forms.

[0170] The bismuth(III) complex(es) may also be obtained from bismuth minerals, such as elemental bismuth and / or bismuth oxide and / or bismuth sulfide.

[0171] Preferably, the bismuth(III) complex(es) is(are) bismuth(III) nitrate and its hydrated forms of formula Bi(NO3)3œH2O, and preferably is bismuth nitrate pentahydrate of formula Bi(NO3)3-5H2O.

[0172] In particular, the carbonating agent(s) is (are) chosen from Li2CO3, Na2CO3, K2CO3, Rb2CO3, Cs2CO3, (NH4)2CO3, LiHCO3, NaHCO3, KHCO3, RbHCO3, CsHCO3, (NH4)HCO3, urea (NH2)2CO and urea derivatives, CO2, preferably from Na2CO3, K2CO3, (NH2)2CO, (NH4)2CO3, and more preferably from (NH2)2CO and / or (NH4)2CO3.

[0173] Polyols are compounds having several hydroxyl functions. They can in particular be chosen from glycols, in particular ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol; short or long polymers of glycols, for example polyethylene glycol, polypropylene glycol, polybutylene glycol; glycerol and its derivatives; or for example sugars, in particular glucose, fructose, sucrose, xylitol, mannitol, such as D-mannitol, sorbitol or maltitol.

[0174] According to one embodiment, the bismuth oxycarbonate particles, as well as its solvates, such as its hydrates, required according to the invention are obtained by a preparation process using a polyol or a mixture of polyols.

[0175] According to a first embodiment variant, the polyol(s) may also be used as a solvent. The bismuth oxycarbonate particles, as well as its solvates, such as its hydrates, may then be obtained for example according to the process described below.

[0176] A solution A is formed from the dissolution of the bismuth (III) complex, preferably at a concentration of 0.001 to 0.5 M, in the polyol or polyol mixture. A solution B is formed by the partial or complete dissolution of the carbonating agent, preferably from 1 to 100 equivalents relative to bismuth, in the polyol or polyol mixture or in a polyol or polyol mixture different from that(those) used in solution A.

[0177] In the case of doping by a cation, the doping agent is preferably integrated into solution A. In the case of doping by an anion, the doping agent is preferably integrated into the solution B.

[0178] In the case of doping by one or more cation(s) and / or by one or more anion(s), the cationic doping agent(s) is / are preferably integrated into solution A and the anionic doping agent(s) is / are preferably integrated into solution B. Solution A is then added at room temperature to solution B. If the polyol or the mixture of polyols is not liquid at room temperature, all the solids are mixed.

[0179] The resulting mixture is then heated between 90 and 250°C for a reaction time of between 10 minutes and 48 hours. If the desired reaction temperature is greater than or equal to the boiling point of the solvent, a solvothermal synthesis is carried out using an autoclave.

[0180] Preferably, the reaction temperature is between 95°C and 200°C and the reaction time is between 1 and 24 hours, and more preferably the reaction temperature is between 100°C and 180°C and the reaction time is between 2 and 16 hours.

[0181] The particles obtained are isolated from the reaction medium by centrifugation and washed by successive cycles of dispersion and centrifugation.

[0182] After drying under vacuum at a temperature between 40°C and 60°C, a white powder is obtained.

[0183] In the case where the polyol(s) are used as solvents, the particles of bismuth oxycarbonate, as well as its solvates, such as its hydrates, obtained are in the form of platelets, preferably with an average thickness e of between 2 and 15 nm, and / or in the form of tubes.

[0184] According to another embodiment variant, the polyol(s) are used solely as additives, and not as solvents. The bismuth oxycarbonate particles, as well as its solvates, such as its hydrates, can then be obtained for example according to the process described below.

[0185] A solution A is formed from the dissolution of the bismuth complex, preferably at a concentration of 0.001 to 0.5 M, and the polyol(s) preferably at a total concentration of polyols, preferably 0.01 to 5 M, in a solvent, preferably polar. A solution B is formed by the partial or complete dissolution of the carbonating agent, preferably 1 to 100 equivalents relative to the bismuth complex, in the polar solvent identical or different (miscible with the solvent of A) from that of solution A, preferably identical.

[0186] In the case of doping by a cation, the doping agent is preferably integrated into solution A. In the case of doping by an anion, the doping agent is preferably integrated into solution B.

[0187] In the case of doping by one or more cation(s) and / or by one or more anion(s), the cationic doping agent(s) is / are preferably integrated into solution A and the anionic doping agent(s) is / are preferably integrated into solution B.

[0188] Solution A is then added at room temperature to solution B. The resulting mixture is then heated between 90°C and 250°C for 10 minutes to 48 hours. If the desired reaction temperature is greater than or equal to the boiling point of the solvent, a solvothermal synthesis is carried out using an autoclave.

[0189] Preferably, the reaction temperature is between 90°C and 150°C and the reaction time is between 4 and 16 hours.

[0190] The particles obtained are isolated from the reaction medium by centrifugation and washed by successive cycles of dispersion and centrifugation.

[0191] After drying under vacuum at a temperature between 40°C and 60°C, a white powder is obtained.

[0192] When the polyol(s) are used solely as additives, they may in particular be chosen from ethylene glycol, propylene glycol, glycerol and / or a sugar, preferably a sugar, more preferably D-mannitol.

[0193] According to this variant, the synthesis process further uses a solvent distinct from the polyols, or a mixture of solvents distinct from the polyols. In particular, the solvent or the mixture of solvents is chosen from polar solvents, preferably from polar and protic solvents, such as water; C1-C6 alcohols such as ethanol or isopropanol; and mixtures thereof, and even more preferably the solvent is water.

[0194] In particular, when the polyol(s) are chosen solely as additives and water as solvent, the particles of bismuth oxycarbonate, as well as its solvates, such as its hydrates, obtained are preferably in the form of platelets and / or in the form of rods. (hydr)aluminium oxide b)

[0195] As mentioned previously, the composite material according to the invention comprises at least aluminum (hydr)oxide b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10.

[0196] The chemical species of aluminum (hydr)oxide in accordance with the invention may be amorphous or crystalline forms, hydrated or non-hydrated.

[0197] In particular, in the gross formula [Al2O3.yH2O] in which 0 < y < 10, y represents an integer or a decimal number.

[0198] Preferably, y is an integer.

[0199] Preferably, the aluminum (hydr)oxide b) has the empirical formula [Al2O3.yH2O] in which 0 < y < 5.

[0200] According to a particular embodiment, y is equal to 0, and the aluminum (hydr)oxide b) is of formula (A12O3).

[0201] According to a particular embodiment, y is equal to 1, and the aluminum (hydr)oxide b) is of formula (AIO(OH)).

[0202] According to a particular embodiment, y is equal to 3, and the aluminum (hydr)oxide b) is of formula (A1(OH)3).

[0203] According to a preferred embodiment, the aluminum (hydr)oxide b) is chosen from (A12O3), (AIO(OH)), (A1(OH)3) and their mixtures.

[0204] According to a preferred embodiment, the aluminum (hydr)oxide b) has the empirical formula [Al2O3.yH2O] in which y is an integer equal to 0, 1 or 3, preferably 3.

[0205] According to a particular embodiment, the molar ratio between the aluminum (hydr)oxide b) and the particle(s) of bismuth oxycarbonate a), as well as its solvates, such as its hydrates, according to the invention is between 0.0001 and 20, preferably between 0.005 and 15, more preferably between 0.01 and 10, and even more preferably between 0.05 and 5. Process for preparing the composite material

[0206] The composite materials according to the invention can in particular be obtained according to the preparation methods described below.

[0207] In particular, the composite materials according to the invention can be obtained by chemical grafting or physical adsorption between one or more aluminum (hydr)oxide(s) b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10, and at least one particle of bismuth oxycarbonate a), as well as its solvates, such as its hydrates, as defined above.

[0208] According to one embodiment, the composite materials according to the invention can be obtained by chemical grafting or physical adsorption of at least one particle of bismuth oxycarbonate a), as well as its solvates, such as its hydrates, as defined previously, on the surface of at least one species of aluminum (hydr)oxide b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10 as defined previously.

[0209] In particular, the composite materials according to the invention can be obtained by chemical grafting or physical adsorption of the species(s) of aluminum (hydr)oxide(s) b), directly on the surface of the particles of bismuth oxycarbonate a), as well as its solvates, such as its hydrates, as defined previously.

[0210] In particular, the composite materials according to the invention as defined above can be obtained in one or more stages.

[0211] Preferably, the process for preparing the composite materials according to the invention uses:

[0212] - bismuth oxycarbonate particles a) of empirical formula (BiO)2 / CO3), as well as that its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm;

[0213] - one or more precursors intended to form the (hydr)oxide species(s) of aluminum b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10 and / or one or more species of aluminum (hydr)oxide b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10 as defined previously;

[0214] - optionally one or more additives; and

[0215] - optionally one or more solvents.

[0216] According to a particular embodiment, the process for preparing the composite materials according to the invention may comprise one or more separation steps.

[0217] In particular, the precursor(s) intended to form the species(s) of aluminum (hydr)oxide b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10 and which make it possible to obtain by chemical reaction or physical adsorption particles of bismuth oxycarbonate a), as well as its solvates, such as its hydrates, and of aluminum (hydr)oxide b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10, are chosen from organic or inorganic, acidic and / or basic, hydrated and / or non-hydrated compounds.

[0218] Preferably, said precursor(s) may be chosen from sodium aluminate, potassium aluminate, aluminum chloride, aluminum nitrate, aluminum sulfate, aluminum acetylacetonate, and mixtures thereof.

[0219] Preferably, said precursor is sodium aluminate.

[0220] According to a particular embodiment, the process for preparing the composite materials according to the invention uses at least one solvent.

[0221] The choice of solvent(s) may in particular depend on the precursor(s) and additive(s) used in the process.

[0222] In particular, the solvent(s) may be chosen from polar and / or apolar, protic and / or aprotic solvents.

[0223] Preferably, the solvent used is a polar and protic solvent, in particular chosen from water, alcohols, polyols and their mixtures.

[0224] Preferably, the solvent used is water.

[0225] According to a particular embodiment, the method for preparing the materials composites according to the invention use at least one additive.

[0226] In particular, the additive(s) may be chosen from acids, in particular mineral acids, such as hydrochloric acid or sulfuric acid, and bases, preferably mineral bases, such as sodium hydroxide or potassium hydroxide.

[0227] The species(s) of aluminum (hydr)oxide b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10 or their precursors, as defined previously, can be used pure or as a mixture.

[0228] According to a particular embodiment, the present invention relates to a process for preparing composite materials as defined above comprising the steps consisting of:

[0229] (i) having a dispersion of bismuth oxycarbonate particles a) of formula crude (BiO)2 / CO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm, in at least one solvent, in particular in an amount ranging from 0.05 g / L to 500 g / L;

[0230] (ii) having a solution of at least one species of aluminum (hydr)oxide b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10, or one of its precursors, optionally in a mixture with at least one solvent, in particular in a molar ratio of aluminum (hydr)oxide b) or precursor of aluminum (hydr)oxide b) / bismuth oxycarbonate a), as well as its solvates, such as its hydrates, varying from 0.0001 to 20;

[0231] (iii) bringing together said dispersion (i) and said solution (ii) to form the composite material;

[0232] (iv) insulating said composite material.

[0233] According to a particular embodiment, the bismuth oxycarbonate particles a), as well as its solvates, such as its hydrates, are used in the dispersion (i) in a content ranging from 0.05 to 500 g / L, preferably from 10 to 250 g / L, and more preferably from 50 to 150 g / L.

[0234] In particular, the solvent(s) of steps (i) and (ii) may be identical or different, and preferably chosen from polar and protic solvents, more preferably from water, alcohols, polyols and their mixtures, and even more preferably is water.

[0235] According to a particular embodiment, the medium of the dispersion (i) can be heated to a temperature varying from 40°C to 200°C, preferably from 50°C to 100°C, in particular for a duration varying from 1 minute to 24 h, preferably from 20 minutes to 2 h.

[0236] According to a particular embodiment, when the solvent or mixture of solvents of step (i) contains water, the pH can be adjusted between 5 and 10, preferably between 6 and 8, for example by adding sodium hydroxide.

[0237] According to a particular embodiment, the molar ratio in step (iii) aluminum (hydr)oxide b) or aluminum (hydr)oxide precursor b) / bismuth oxycarbonate a), as well as its solvates, such as its hydrates, varies from 0.0001 to 20, preferably varies from 0.005 to 15, more preferably varies from 0.01 to 10, and even more preferably from 0.05 to 5.

[0238] According to a particular embodiment, step (iii) is carried out with stirring.

[0239] According to a particular embodiment, step (iii) is carried out for a duration ranging from 1 minute to 24 hours, preferably from 20 minutes to 8 hours.

[0240] According to a preferred embodiment, step (iii) is carried out at a temperature ranging from 60°C to 70°C.

[0241] According to a particular embodiment, the pH in step (iii) is adjusted to 6.5, for example by adding sulfuric acid.

[0242] According to a particular embodiment, a cooling step can be carried out between steps (iii) and (iv).

[0243] According to a particular embodiment, step (iv) can be carried out by centrifugation.

[0244] According to a particular embodiment, step (iv) is followed by a washing step, in particular by successive cycles, and optionally by drying, such as drying in an oven, for example at a temperature ranging from 40°C to 100°C, and optionally under vacuum (pressure less than 100 mbar).

[0245] According to a preferred embodiment, the present invention relates to a process for preparing composite materials as defined above comprising the steps consisting of:

[0246] (i) having a dispersion of bismuth oxycarbonate particles a) of formula crude (BiOMCOj), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm, in at least one solvent, in particular in an amount ranging from 0.05 g / L to 500 g / L;

[0247] (ii) having an aqueous solution of sodium aluminate;

[0248] (iii) bringing together said dispersion (i) and said solution (ii) to form particles of bismuth oxycarbonate and aluminum (hydr)oxide;

[0249] (iv) isolating said composite material of bismuth oxycarbonate and aluminum (hydr)oxide.

[0250] According to one embodiment, a calcination step is carried out after step iv). Cosmetic composition

[0251] The composite materials according to the invention can in particular be used in a composition, in particular in a cosmetic composition.

[0252] Thus, the present invention also relates to a composition, in particular a cosmetic composition, comprising at least one composite material as defined above.

[0253] According to a preferred embodiment, the present invention also relates to a composition, in particular a cosmetic composition, comprising at least:

[0254] i) at least one composite material as defined above;

[0255] ii) at least one aqueous phase and / or at least one fatty phase; and

[0256] iii) at least one compound chosen from: 1) UV filters distinct from the composite materials i); 2) coloring materials; 3) cosmetic active ingredients for the care of keratin materials; 4) surfactants; 5) thickeners; and mixtures thereof.

[0257] Said composite materials may be present in the composition, preferably cosmetic, in a content ranging from 0.5% to 70% by weight, preferably from 1% to 50% by weight, even better from 2% to 40% by weight relative to the total weight of the composition. Aqueous phase

[0258] A composition, in particular a cosmetic composition, according to the invention may comprise at least one aqueous phase.

[0259] The aqueous phase may comprise water and optionally a water-soluble solvent.

[0260] In the present invention, the term "water-soluble solvent" means a compound that is liquid at room temperature and miscible with water (miscibility in water greater than 50% by weight at 25°C and atmospheric pressure).

[0261] The water-soluble solvents that can be used in a composition according to the invention can also be volatile.

[0262] Among the water-soluble solvents which may be used in a composition in accordance with the invention, mention may in particular be made of lower monoalcohols having from 1 to 5 carbon atoms such as ethanol and isopropanol, C2-C32 polyols, C3 and C4 ketones and C2-C4 aldehydes.

[0263] Among the water-soluble solvents that can be used in a composition in accordance with the invention, mention may in particular be made of polyols. For the purposes of the present invention, the term "polyol" means any organic molecule comprising at least two free hydroxyl groups.

[0264] A polyol suitable for the invention may be a compound of alkyl type, linear, branched or cyclic, saturated or unsaturated, carrying on the alkyl chain at least two -OH functions, in particular at least three -OH functions.

[0265] The polyols advantageously suitable for the formulation of a composition according to the present invention are those having in particular from 2 to 32 carbon atoms, preferably 3 to 16 carbon atoms.

[0266] Advantageously, the polyol may be chosen, for example, from pentaerythritol, trimethylolpropane, caprylyl glycol, glycerol, polyglycerols, such as glycerol oligomers such as diglycerol, polyethylene glycols, polypropylene glycols, and mixtures thereof. Fat phase

[0267] A composition, in particular a cosmetic composition, according to the invention may comprise in in addition to at least one fatty phase, in particular an oily phase.

[0268] For the purposes of the invention, the term “fatty phase” means a phase comprising at least one fatty substance and all of the liposoluble and lipophilic ingredients used for the formulation of the compositions of the invention.

[0269] Preferably, the fatty phase comprises at least one oil, in particular a cosmetic oil.

[0270] By "oil" is meant a non-aqueous compound, immiscible with water, liquid at room temperature (25°C) and atmospheric pressure (760 mm Hg).

[0271] The fatty phase may comprise at least one volatile or non-volatile hydrocarbon oil and / or a fatty substance.

[0272] As non-volatile hydrocarbon oils, mention may in particular be made of hydrocarbon oils of vegetable origin, synthetic ethers having from 10 to 40 carbon atoms, linear or branched hydrocarbons, of mineral or synthetic origin, synthetic esters, fatty alcohols which are liquid at room temperature with a branched and / or unsaturated carbon chain having from 12 to 26 carbon atoms, higher C12-C22 fatty acids, carbonates, and mixtures thereof.

[0273] As volatile hydrocarbon oils, mention may in particular be made of hydrocarbon oils having from 8 to 16 carbon atoms.

[0274] The non-volatile silicone oils may be chosen in particular from non-volatile polydimethylsiloxanes (PDMS) and phenyl silicones. As volatile silicone oils, mention may be made, for example, of volatile linear or cyclic silicone oils.

[0275] Fluorinated volatile oils, such as nonafluoromethoxybutane, nonafluoromethoxybutane, decafluoropentane, tetradecafluorohexane, dodecafluoropentane and mixtures thereof, may also be used.

[0276] The oily phase may further comprise, mixed with or dissolved in the oil, other fatty substances. Another fatty substance that may be present in the oily phase may be, for example, a fatty acid, a wax, a gum, a pasty compound, or mixtures thereof. 1) Additional UV filters

[0277] According to a particular embodiment, a composition according to the invention comprises 1) at least one complementary UV filter distinct from the composite materials required according to the invention and defined above.

[0278] By "complementary UV filter distinct from the composite materials" is meant, within the meaning of the present invention, any UV filter whose chemical nature differs from that of the composite materials required according to the invention and defined above.

[0279] The composite materials according to the invention can therefore be used alone or in association with 1) other UV filters, in particular chosen from UV filters or- organic and / or inorganic.

[0280] Thus, the cosmetic composition may also contain one or more complementary UV filters chosen from hydrophilic, lipophilic or insoluble organic UV filters and / or mineral UV filters, different from the composite materials according to the invention.

[0281] By "hydrophilic UV filter" is meant any organic or inorganic cosmetic or dermatological compound filtering UV radiation capable of being completely dissolved in the molecular state in a liquid aqueous phase or of being in colloidal suspension (for example in micellar form) in a liquid aqueous phase.

[0282] By "lipophilic UV filter" is meant any organic or inorganic cosmetic or dermatological compound filtering UV radiation capable of being completely dissolved in the molecular state in a liquid fatty phase or of being in colloidal suspension (for example in micellar form) in a liquid fatty phase.

[0283] By "insoluble UV filter" is meant any organic or inorganic cosmetic or dermatological compound filtering UV radiation having a solubility in water of less than 0.5% by weight and a solubility of less than 0.5% by weight in most organic solvents such as paraffin oil, fatty alcohol benzoates and fatty acid triglycerides, for example Miglyol 812®. This solubility, achieved at 70°C, is defined as the quantity of product in solution in the solvent at equilibrium with an excess of suspended solid after returning to room temperature. It can easily be evaluated in the laboratory.

[0284] The complementary organic UV filters are notably chosen from:

[0285] - cinnamic compounds, in particular Ethylhexyl Methoxycinnamate,

[0286] - anthranilate compounds, in particular Menthyl anthranilate,

[0287] - salicylic compounds, in particular Homosalate and Ethylhexyl Salicylate,

[0288] - dibenzoylmethane compounds, in particular Butyl Methoxydibenzoylmethane,

[0289] - benzylidene camphor compounds, in particular 3-Benzylidene camphor, 4-Methylbenzylidene camphor, Benzylidene Camphor Sulfonic Acid and Tereph-thalylidene Dicamphor Sulfonic Acid,

[0290] - benzophenone compounds, in particular oxybenzone and n-hexyl 2-(4-diethylamino-2-hydroxybenzoyl)-benzoate,

[0291] - [3,[3-diphenylacrylate] compounds, in particular octocrylene,

[0292] - triazine compounds, in particular Phenylene Bis-Diphenyl triazine, Bis- Ethylhexyloxyphenol Methoxyphenyl Triazine, Ethylhexyl Triazone and Di-thylhexyl Butamido Triazone,

[0293] - benzotriazole compounds, in particular Drometrizole Trisiloxane,

[0294] - benzalmalonate compounds, in particular those cited in US patent 5624663, in especially Polysilicone-15,

[0295] - benzimidazole derivatives, in particular Phenylbenzimidazole Sulfonic Acid,

[0296] - imidazoline compounds, in particular Ethylhexyl Dimethoxybenzylidene Dioxoimidazoline Propionate,

[0297] - bis-benzoazolyl compounds, as described in patents EP 0669323 and US 2463264, in particular Disodium Phenyl Dibenzimidazole Tetra-sulfonate,

[0298] - para-aminobenzoic compounds, in particular PABA, Ethylhexyl Dimethyl PABA and PEG-25 PABA,

[0299] - methylene bis-(hydroxyphenyl benzotriazole) compounds, as described in applications US 5237071, US 5166355, GB 2303549, DE 19726184 and EP 0893119, in particular Methylene bis-Benzotriazolyl Tetramethylbutylphenol,

[0300] - benzoxazole compounds, as described in patent applications EP 0832642, EP 1027883, EP 1300137 and DE 10162844, in particular 2,4-bis-[5-l(dimethylpropyl)benzoxazol-2-yl-(4-phenyl)-imino]-6-(2-ethylhexyl)-imin ol,3,5-triazine,

[0301] - filter polymers and filter silicones, such as those described in particular in the application WO 93 / 04665,

[0302] - dimers derived from α-alkylstyrene, such as those described in the application of patent DE 19855649,

[0303] - 4,4-diarylbutadiene compounds, as described in applications EP 0967200, DE 19746654, DE 19755649, EP 1008586, EP 1133980 and EP 0133981, in particular 1,1-dicarboxy(2,2'-dimethyl-propyl)-4,4-diphenylbutadiene, and - their mixtures.

[0304] The complementary inorganic UV filters are generally mineral UV filters, in particular chosen from metal oxides.

[0305] The metal oxides may in particular be chosen from titanium, zinc, iron, zirconium, cerium oxides, and mixtures thereof.

[0306] The metal oxide particles may be coated or uncoated.

[0307] The coated particles are more particularly titanium oxides coated with silica, silica and iron oxide, silica and alumina, alumina, alumina and aluminum stearate, silica, alumina and alginic acid, alumina and aluminum laurate, iron oxide and iron stearate, zinc oxide and zinc stearate, silica and alumina and treated with a silicone, silica, alumina, aluminum stearate and treated with a silicone, silica and treated with a silicone, alumina and treated with a silicone, triethanolamine, stearic acid, sodium hexametaphosphate, or TiO2 treated with octyl trimethyl silane, TiO2 treated with a polydimethylsiloxane, TiO2 anatase / rutile treated with a polydimethylhydrogeno- siloxane, TiO2 coated with triethylhexanoin, aluminum stearate and alumina, TiO2 coated with aluminum stearate, alumina and silicone, TiO2 coated with lauroyl lysine, or TiO2 coated with C9.15 fluoroalcohol phosphate and aluminum hydroxide.

[0308] The metal oxides may optionally be doped.

[0309] In this respect, mention may be made of TiO2 particles doped with at least one transition metal such as iron, zinc, manganese, and more particularly manganese.

[0310] The doped particles may be in the form of a dispersion, preferably an oily dispersion. The oil present in the oily dispersion is preferably chosen from triglycerides, including those of capric / caprylic acids. The oily dispersion of titanium oxide particles may additionally comprise one or more dispersing agents, for example a sorbitan ester or a polyoxyalkylenated fatty acid and glycerol ester. Mention may more particularly be made of the oily dispersion of manganese-doped TiO2 particles in capric / caprylic acid triglyceride in the presence of tri-PPG-3 myristylether citrate and polyglyceryl-3-polyricinoleate and sorbitan isostearate.

[0311] Mention may also be made of mixtures of metal oxides, in particular titanium dioxide and cerium dioxide, including the equal-weight mixture of titanium dioxide and cerium dioxide coated with silica, as well as the mixture of titanium dioxide and zinc dioxide coated with alumina, silica and silicone or coated with alumina, silica and glycerin. 2) Coloring matters

[0312] According to a particular embodiment, a composition according to the invention comprises 2) at least one coloring material.

[0313] Generally speaking, a “coloring material” is intended to designate any compound capable of coloring a composition, that is to say which absorbs in the visible spectrum, in particular so as to appear to the human eye in a color such as yellow, orange, red, violet, blue or green.

[0314] Preferably, a composition according to the invention comprises at least one pigment.

[0315] By "pigments" we mean white or colored, mineral particles or organic, insoluble in liquid hydrophilic and lipophilic phases, intended to color and / or opacify the composition containing them, and different from the composite materials according to the invention. More particularly, the pigments are slightly or not at all soluble in hydroalcoholic media.

[0316] The pigments which can be used are in particular chosen from organic and / or mineral pigments known in the art, in particular those which are described in the Kirk-Othmer encyclopedia of chemical technology and in the Ullmann encyclopedia of industrial chemistry (Ullmann's Encyclopedia of Industrial Chemistry “Pigment organics”, 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002 / 14356007.a20 371 etibid, “Pigments, Inorganic, 1. General” 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheiml0.1002 / 14356007.a20_243.pub3).

[0317] These pigments can be in the form of powder or pigment paste. They can be coated or uncoated.

[0318] The pigments may for example be chosen from mineral pigments, organic pigments, lakes, special effect pigments such as mother-of-pearl or glitter, and mixtures thereof.

[0319] The pigment may be a mineral pigment. By mineral pigment is meant any pigment which meets the definition of the Ullmann encyclopedia in the inorganic pigment chapter. Among the mineral pigments useful in the present invention, mention may be made of iron or chromium oxides, manganese violet, ultramarine blue, chromium hydrate, ferric blue and titanium oxide.

[0320] The pigment may be an organic pigment.

[0321] By organic pigment is meant any pigment which meets the definition of the Ullmann encyclopedia in the organic pigment chapter.

[0322] The organic pigment may in particular be chosen from nitroso, nitro, azo, xanthene, quinoline, anthraquinone, phthalocyanine, metal complex type compounds, isoindolinone, isoindoline, quinacridone, perinone, perylene, diketopyrrolopyrrole, thioindigo, dioxazine, triphenylmethane, quinophthalone.

[0323] Preferably, the pigment(s) suitable for the invention are chosen from carbon black, iron oxides, in particular red, brown or black, micas coated with iron oxide, triarylmethane pigments, in particular blue and violet, such as BLUE 1 LAKE, azo pigments, in particular red, such as D&C RED 7, alkali metal salts of lithol red, such as the calcium salt of lithol red B, more preferably the pigment(s) used are chosen from red iron oxides and azo pigments, in particular red, such as D&C RED 7.

[0324] The coloring matter(s) may be present in a composition according to the invention in a content ranging from 0.001 to 10% by weight, preferably from 0.005% to 5% by weight, relative to the total weight of the composition.

[0325] According to a particular embodiment of the invention, the quantity of pigments varies from 0.5% up to 40%, and preferably from 1% to 20% relative to the weight of the composition of the invention comprising them. 3) Cosmetic active ingredient

[0326] According to a particular embodiment, a composition according to the invention comprises 3) at least one cosmetic active ingredient for caring for keratin materials, preferably for caring for the skin.

[0327] In particular, the cosmetic active ingredient may be at least one hydrophilic active ingredient and / or one active ingredient lipophilic, preferably hydrophilic.

[0328] The term “hydrophilic active” means a water-soluble or water-dispersible active agent capable of forming hydrogen bonds.

[0329] As cosmetic active ingredients 3), mention may be made, for example, of moisturizing agents, depigmenting agents, desquamating agents, humectants, anti-aging agents, mattifying agents, healing agents, anti-bacterial agents, vitamins and their derivatives or precursors, antioxidant compounds, anti-radical agents, anti-polluting agents, self-tanning agents, anti-glycation agents, soothing agents, deodorant agents, essential oils, NO-synthase inhibitors, agents stimulating the synthesis of dermal or epidermal macromolecules and / or preventing their degradation, agents stimulating the proliferation of fibroblasts, agents stimulating the proliferation of keratinocytes, muscle relaxants, refreshing agents, tightening agents, depigmenting agents, propigmenting agents, keratolytic agents, slimming agents, agents acting on the energy metabolism of cells,insect repellents, substance P or CRGP antagonists, anti-hair loss agents, and mixtures thereof,

[0330] The active ingredient(s) may in particular be chosen from:

[0331] - vitamins and their derivatives, in particular their esters, such as niacinamide (3-pyridinecarboxamide) nicotinamide (vitamin B3), tocopherol (vitamin E) and its esters (such as tocopheryl acetate), ascorbic acid and its derivatives (vitamin C), retinol (vitamin A),

[0332] - humectants or moisturizers such as urea, hydroxyureas, glycerol, poly- glycerols, glycerolglucoside, diglycerolglucoside, polyglycerylglucosides, xylitylglucoside and plant extracts (in particular tea, mint, orchid, soy, aloe vera, honey, and in particular glycerol;

[0333] - C-glycoside compounds, and preferably hydroxypropyl tetrahydropyrantiol (INCI name) (or proxylane);

[0334] - antioxidant compounds;

[0335] - anti-aging active ingredients, such as hyaluronic acid compounds, and in particular sodium hyaluronate, salicylic acid compounds and in particular n-octanoyl-5-salycilic acid (capryloyl salicylic acid), adenosine, and the sodium salt of 3-hydroxy-2-pentylcyclopentyl)acetic acid;

[0336] - keratolytic agents such as lactic acid or glycolic acid; and

[0337] - their mixtures.

[0338] Such active ingredients may be present in a composition according to the invention in a content ranging from 0.05% to 10% by weight, preferably from 1.0% to 8.0% by weight, relative to the total weight of the composition. 4) Surfactant

[0339] According to a particular embodiment, a composition according to the invention comprises 4) at least one surfactant.

[0340] The surfactants may be chosen from nonionic, anionic, cationic, amphoteric surfactants, and mixtures thereof. Reference may be made to the document “Encyclopedia of Chemical Technology, KIRK-OTHMER”, volume 22, pp. 333-432, 3rd edition, 1979, WILEY, for the definition of the emulsifying properties and functions of the surfactants, in particular pp. 347-377 of this reference, for anionic, amphoteric and nonionic surfactants.

[0341] Examples of amphoteric surfactants suitable for the invention are in particular chosen from betaines, preferably chosen from alkyl betaines, in particular lauryl betaine; N-alkylamido betaines and their derivatives, in particular co-camidopropylbetaine, lauramidopropylbetaine and N-carboxyethoxyethyl N-cocoylamidoethyl aminoacetate N-disodium; sultaines, in particular cocoyl amidopropylhydroxy sultaine; and mixtures thereof.

[0342] The nonionic surfactants may be chosen in particular from poly(ethylene oxide) alkyl- and polyalkyl-esters, oxyalkylenated alcohols, poly(ethylene oxide) alkyl- and polyalkyl-ethers, polyoxyethylenated or non-polyoxyethylenated sorbitan alkyl- and polyalkyl-ethers, polyoxyethylenated or non-polyoxyethylenated sorbitan alkyl- and polyalkyl-ethers, in particular sucrose alkyl- and polyalkyl-esters, polyoxyethylenated or non-polyoxyethylenated glycerol alkyl- and polyalkyl-ethers, polyoxyethylenated or non-polyoxyethylenated glycerol alkyl- and polyalkyl-ethers, geminal surfactants, cetyl alcohol, stearyl alcohol, and mixtures thereof.

[0343] The anionic surfactants may be chosen from alkyl ether sulfates, carboxylates, amino acid derivatives, sulfonates, isethionates, taurates, sulfosuccinates, alkylsulfoacetates, phosphates and alkylphosphates, polypeptides, metal salts of C10-C30 fatty acids, in particular C16-C25, in particular metal stearates and behenates and mixtures thereof.

[0344] The cationic surfactants may be chosen from alkylimidazolidiniums, such as isostearylethylimidonium ethosulfate, ammonium salts, such as (C1210)-tri(C1400)alkylammonium halides such as N,N,N-trimethyl-1-docosaminium chloride (or Behentrimonium chloride).

[0345] The silicone surfactants can be chosen from dimethicone copolyols or silicone elastomers.

[0346] A composition according to the invention may comprise between 0.01% and 2.0% by weight of surfactant, preferably between 0.05% and 1.5% by weight, more preferably between 0.1% and 1.0% by weight, relative to the total weight of the composition. 5) Thickener

[0347] According to a particular embodiment, a composition according to the invention comprises 5) at least one thickener, also sometimes called gelling agent or viscosity modifying agent.

[0348] Thickeners may be synthetic, natural or of natural origin, preferably natural or of natural origin.

[0349] Such thickeners may more particularly be chosen from natural polymers or polymers of natural origin, in particular of plant origin.

[0350] These thickeners are preferably hydrophilic, that is to say soluble or dispersible in water.

[0351] Advantageously, the thickener(s) are chosen from polysaccharides, modified or native, in particular modified or unmodified starches, fructans, gellans, glucans, amylose, amylopectin, glycogen, pullulan, dextrans, celluloses and their derivatives, in particular methylcelluloses, hydroxyalkylcelluloses, ethylhydroxyethylcelluloses, and carboxymethylcelluloses, mannans, xylans, lignins, arabans, galactans, galacturonans, alginate-based compounds, chitin, chitosans, glucuronoxylans, arabinoxylans, xyloglucans, glucomannans, pectic acids and pectins, arabinogalactans, carrageenans, agars, glycosaminoglucans, gum arabic, sclerotium gum, Tragacanth gum, Ghatti gum, Karaya gum, carob gum, konjac gum, galacto-mannans such as guar gum and their non-ionic derivatives,in particular hydroxypropyl guar, and ionic, biopolysaccharide gums of microbial origin, in particular scleroglucan or xanthan gums, mucopolysaccharides, carboxyvinyl polymers, polyacrylamides, polymers and copolymers of 2-acrylamido 2-methylpropane sulfonic acid, optionally crosslinked and / or neutralized, water-soluble or water-dispersible silicone derivatives, such as acrylic silicones, polyether silicones and cationic silicones, and mixtures thereof.

[0352] The thickener(s) may be present in a composition according to the invention in a content ranging from 0.05 to 5.0% by weight, in particular from 0.3% to 4.0% by weight, more particularly from 0.4% to 2.5% by weight, relative to the total weight of the composition. Adjuvants

[0353] A composition according to the invention may further comprise at least one adjuvant usual in the cosmetic field chosen from perfumes, film-forming polymers, pH adjusters (acids or bases), for example citric acid, tartaric acid or oxalic acid, chelating agents, preservatives, softeners, sweeteners, antifoaming agents, fillers, trace elements, propellants, and mixtures thereof.

[0354] Of course, a person skilled in the art will take care to choose this or these possible additional compounds and / or their quantity in such a way that the advantageous properties of a composition according to the invention are not, or not substantially, altered by the envisaged addition.

[0355] Of course, those skilled in the art will take care to choose this or these possible complementary compounds, and / or their quantity, in such a way that the advantageous properties of the particles according to the invention are not, or not substantially, altered by the envisaged addition.

[0356] As stated previously, a composition according to the invention may be cosmetic, and preferably is cosmetic.

[0357] A composition according to the invention is generally suitable for topical application to the skin and therefore generally comprises a physiologically acceptable medium, i.e. compatible with the skin.

[0358] It is preferably a cosmetically acceptable medium, that is to say which has a pleasant color, odor and feel and does not generate unacceptable discomfort, that is to say tingling, tightness, likely to discourage the user from applying this composition. Galenic forms of the compositions

[0359] The compositions, in particular cosmetic compositions, containing the particles according to the invention can be prepared according to techniques well known to those skilled in the art.

[0360] They can be presented in all conventional galenic forms depending on the applications envisaged and are suitable for topical application, that is to say for application to the surface of the keratin materials considered.

[0361] The cosmetic compositions may be in the form of an aqueous or hydroalcoholic gel.

[0362] They can be presented in the form of an emulsion, simple or complex (O / W, W / O, O / W / O or W / O / W), such as a cream, a milk, or a cream gel.

[0363] They can also be in anhydrous form, for example in the form of an oil.

[0364] The term “anhydrous composition” means a composition containing less than 5% by weight of water, or even less than 2% water, better still less than 1% water and in particular free of water, the water not being added during the preparation of the composition but corresponding to the residual water provided by the mixed ingredients.

[0365] The cosmetic compositions can for example be used as a makeup product.

[0366] The cosmetic compositions may, for example, be used as a care and / or sun protection product for the face and / or body of liquid to semi-liquid consistency, and have the appearance of a white or colored cream, more or less creamy, an ointment, a milk, a gel-cream, a lotion, a serum, a paste or a mousse. It may optionally be applied to the skin in the form of an aerosol. It may also be in solid form, for example in the form of a stick.

[0367] The cosmetic compositions may be in the form of skin or semi-mucous membrane care products, such as a protective composition, cosmetic care for the face, for the lips, for the hands, for the feet, for anatomical folds or for the body (for example day creams, night cream, day serum, night serum, make-up remover cream, make-up base, protective or care body milk, after-sun milk, lotion, gel or mousse for skin or scalp care, serum, mask or after-shave composition).

[0368] The composition can be applied by hand or using an applicator.

[0369] In particular, the cosmetic compositions have an SPF value of greater than 5 and preferably greater than 10.

[0370] For the purposes of the invention, the term "SPF" (Sun Protection Factor) means: the sun protection factor which measures the level of protection against UV radiation. The SPF value corresponds to the ratio between the minimum time necessary to obtain a sunburn (erythematogenic) with a sun protection composition and the minimum time without a sun protection composition to obtain said sunburn. More precisely, the term "SPF" is defined in the article A new substrate to measure sunscreen protection factor across the ultraviolet spectrum, J. Soc. Cosmet. Chem., 40, 127-133 (May / June 1989).

[0371] The SPF (Sun Protection Factor) assessment can be performed in vitro with a Labsphere® spectrophotometer. The plate is the material on which the sunscreen composition is applied. For this protocol, poly(methyl methacrylate) (PMMA) plates have proven ideal.

[0372] The evaluation of the Sun Protection Factor (SPF) of the compositions can also be carried out in vivo according to the ISO 24444 protocol “Cosmetics - Sun protection test methods - In vivo determination of the sun protection factor (SPF) (2010)”.

[0373] By "UVAPF" is meant: the index characterizing protection against UVA radiation. In particular, this index could be measured in vivo according to the PPD (Persistent Pigment Darkening) method: the "PPD" measures the color of the skin observed 2 to 4 hours after exposure to UVA. This method has been adopted since 1996 by the Japan Cosmetic Industry Association (JCIA) as a procedure for official test for UVA labeling of products and is frequently used by testing laboratories in Europe and the United States (Japan Cosmetic Industry Association Technical Bulletin. Measurement Standards for UVA Protection Effectiveness issued on November 21, 1995 and effective since January 1, 1996). UVA protection can also be measured in vitro using the Labsphere® spectrophotometer. The plate is the material on which the sunscreen composition is applied. Polymethyl methacrylate (PMMA) sheets have proven ideal for this protocol. ISO 24443 describes such an in vitro method. Cosmetic processes and uses

[0374] The present invention also relates to the non-therapeutic cosmetic use of the composite materials according to the invention for filtering UV radiation, preferably UV-B, comprising at least the application to keratin materials of a composition comprising at least one composite material as defined above.

[0375] The present invention also relates to a non-therapeutic cosmetic process for filtering UV radiation, in particular UV-B, comprising at least the application to keratin materials of a composition comprising at least one composite material as defined above.

[0376] According to yet another of its aspects, the present invention also relates to the non-therapeutic cosmetic use of a cosmetic composition comprising at least one composite material defined above, to prevent the appearance on the skin, in particular on the face, décolleté, arms, hands and / or shoulders, of darker and / or more colored spots giving the skin a heterogeneity of color.

[0377] The present invention also relates to a non-therapeutic cosmetic process for limiting the darkening of keratin materials, in particular human, such as the skin, and / or keratin fibers, in particular human, such as the hair and / or improving the color and / or the homogeneity of the complexion or of the keratin fibers comprising the application to the surface of said keratin materials and / or of said keratin fibers of at least one cosmetic composition comprising at least one composite material defined above.

[0378] The present invention further relates to the non-therapeutic cosmetic use of a cosmetic composition comprising at least one composite material defined above, to prevent premature aging of keratin materials, in particular human keratin materials, such as the skin, in particular the skin of the face, décolleté, arms, hands and / or shoulders.

[0379] It also relates to a non-therapeutic cosmetic process for preventing and / or treating the signs of aging of a keratin material, in particular human, in particular the skin, comprising the application to the surface of the keratin material of at least one cosmetic composition comprising at least one composite material defined previously.

[0380] According to one of its aspects, the present invention relates to composite materials as defined above, for their use as agents for the filtration of UV radiation, in particular UV-B.

[0381] For the purposes of the present invention, the term "prevent" or "prevention" means reducing, at least in part, the risk of occurrence of a given phenomenon, for example the signs of aging of a keratin material, in particular human, such as the skin, or the appearance on said keratin material, in particular human, such as the skin of darker and / or more colored spots giving the skin a heterogeneity of color and / or premature aging of the skin.

[0382] In the description and examples, the percentages are weight or molar percentages. The ingredients are mixed, in the order and under the conditions easily determined by those skilled in the art.

[0383] The invention will now be described by means of the following examples given of course by way of illustration and not limitation of the invention. Examples

[0384] Example 1: Preparation of bismuth oxycarbonate particles according to the invention

[0385] Bismuth oxycarbonate particles 1 are synthesized according to the preparation method described below.

[0386] A solution of bismuth nitrate pentahydrate Bi(NO3)3-5H2O (0.40 M) and D-mannitol (2 M) is prepared in 800 mL of water and stirred until the reagents are completely dissolved. 160 mL of an ammonium carbonate solution (2.1 equivalents relative to bismuth) is then added. A white solid precipitates. After 30 minutes, this mixture is then transferred to a Teflon autoclave reactor and heated for 12 hours at 150 °C. The bismuth oxycarbonate particles 1 are isolated by centrifugation and washed 3 times with water before being dried in an oven at 60 °C.

[0387] The morphology of bismuth oxycarbonate particles was determined by direct observation by transmission electron microscopy. 1 to 5 milligrams of dry particles are dispersed in 10 mL of absolute ethanol and treated in an ultrasonic bath for two minutes. 5 μL of dispersion are then placed on an observation grid (copper with a carbon surface layer) and dried in ambient air.

[0388] The observation is carried out with a Hitachi HT 7700 transmission electron microscope at an accelerating voltage of 100 kV. The average dimensions are obtained via measurement of particle dimensions by image analysis using ImageJ software (CA Schneider, WS Rasband, KW Eliceiri, NIH Image to ImageJ: 25 years of image analysis, Nat. Methods. 9 (2012) 671-675).

[0389] Bismuth oxycarbonate particles 1 are platelets of the following average dimensions:

[0390] Average length L: 85 nm

[0391] Average width 1: 52 nm

[0392] Average thickness e: 28 nm

[0393] Example 2: Syntheses of composite materials according to the invention

[0394] Example 2.A: Synthesis of composite materials A bismuth oxycarbonate - aluminum hydroxide

[0395] The bismuth oxycarbonate particles according to Example 1 are stirred in water at a concentration of 100 g / L at room temperature. The temperature of the medium is then brought to 70°C for 30 minutes.

[0396] A 0.5 M sodium aluminate solution in water is added dropwise in such an amount that the sodium aluminate / bismuth oxycarbonate molar ratio is equal to 0.13. After the addition is complete, the reaction medium is kept stirring for 1 h at 70 °C. The pH is adjusted to 6.5 with the addition of sulfuric acid.

[0397] After cooling, the composite material A is isolated by centrifugation, washed three times with water and then left to dry in an oven at 50°C.

[0398] Composite material A is obtained in the form of a white powder and is characterized by UV / Vis spectrophotometry.

[0399] Example 2.B: Synthesis of composite materials B bismuth oxycarbonate - aluminum hydroxide

[0400] The bismuth oxycarbonate particles according to Example 1 are stirred in water at a concentration of 100 g / L at room temperature. The temperature of the medium is then brought to 70°C for 30 minutes. The pH is adjusted to 8 with the addition of sodium hydroxide.

[0401] A 0.5 M sodium aluminate solution in water is added dropwise in such an amount that the sodium aluminate / bismuth oxycarbonate molar ratio is equal to 0.13. After the addition is complete, the reaction medium is kept stirring for 1 h at 70 °C. The pH is adjusted to 6.5 with the addition of sulfuric acid.

[0402] After cooling, the composite material B is isolated by centrifugation, washed three times with water and then left to dry in an oven at 50°C.

[0403] Composite material B is obtained in the form of a white powder and is characterized by UV / Vis spectrophotometry.

[0404] Example 2.C: Synthesis of composite materials C bismuth oxycarbonate - aluminum hydroxide

[0405] The bismuth oxycarbonate particles according to Example 1 are stirred in water at a concentration of 100 g / L at room temperature. The temperature of the medium is then brought to 70°C for 30 minutes. The pH is adjusted to 8 with the addition of sodium hydroxide.

[0406] A 0.5 M sodium aluminate solution in water is added dropwise in such an amount that the sodium aluminate / bismuth oxycarbonate molar ratio is equal to 0.065. After the addition is complete, the reaction medium is kept stirring for 1 h at 70 °C. The pH is adjusted to 6.5 with the addition of sulfuric acid.

[0407] After cooling, the composite material C is isolated by centrifugation, washed three times with water and then left to dry in an oven at 50°C.

[0408] Composite material C is obtained in the form of a white powder and is characterized by UV / Vis spectrophotometry.

[0409] Example 2.D: Synthesis of composite materials D bismuth oxycarbonate - aluminum hydroxide

[0410] The bismuth oxycarbonate particles according to Example 1 are stirred in water at a concentration of 100 g / L at room temperature. The temperature of the medium is then brought to 70°C for 30 minutes. The pH is adjusted to 8 with the addition of sodium hydroxide.

[0411] A 0.5 M sodium aluminate solution in water is added dropwise in such an amount that the sodium aluminate / bismuth oxycarbonate molar ratio is equal to 1. After the addition is complete, the reaction medium is kept stirring for 1 h at 70°C. The pH is adjusted to 6.5 with the addition of sulfuric acid.

[0412] After cooling, the composite material D is isolated by centrifugation, washed three times with water and then left to dry in an oven at 50°C.

[0413] Composite material D is obtained in the form of a white powder and is characterized by UV / Vis spectrophotometry.

[0414] Example 3: Absorbance spectra of bismuth oxycarbonate composite materials in accordance with the invention

[0415] The absorbance spectra by UV-visible spectrophotometry of the composite materials in accordance with the invention and prepared according to example 2 were carried out.

[0416] They were obtained by UV-visible spectrophotometry on dispersions at 0.005% by mass of composite in a mixture of water, propylene glycol and polysorbate 20 (Tween 20).

[0417] The quartz cell used for absorbance measurements is 1 cm on each side. The spectrophotometer used is the Genesys 10S from Thermo Fischer Scientific.

[0418] The dispersion of composite materials of bismuth oxycarbonate and aluminum (hydr)oxide A to D, at 0.1% by mass is exposed to ultrasound for 15 minutes and then stirred with a mechanical stirrer for 16 hours at room temperature. It is then diluted to 0.005% by mass and mechanically stirred again for 20 minutes before carrying out the absorbance measurement.

[0419] Beyond a predetermined threshold value for measuring UV absorbance, the filtration of UV radiation is considered effective. In particular, composite materials having a UV absorbance threshold, in the dispersion medium comprising said composite materials, at a mass fraction of 0.005%, greater than 0.25 are considered effective for the filtration of UV radiation.

[0420] The absorbance spectra are shown in Figures 1 to 4.

[0421] The results are grouped in the following Table 1.

[0422] [Tables 1] Absorbance Composite A Composite B Composite C Composite D Absorbance at 220 nm 0.58 0.6 0.57 0.38 Absorbance at 300 nm 0.72 0.72 0.74 0.48 Absorbance at 400 nm 0.42 0.4 0.4 0.28 Absorbance at 620 nm 0.12 0.12 0.12 0.1

[0423] The composite materials in accordance with the invention show good absorbance of UV rays and consequently effective filtration of UV rays.

Claims

Claims

1. Composite material comprising: a. at least one particle of bismuth oxycarbonate of empirical formula (BiO)2 / CO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm; and b. at least aluminum (hydr)oxide of empirical formula [Al2 O3.yH2O] in which 0 < y < 10.

2. Composite material according to claim 1, characterized in that it has an average size of the largest dimension of composite material particle varying from 0.005 pm to 10 pm, in particular from 0.01 pm to 1 pm, preferably from 30 nm to 500 nm, and more preferably from 30 nm to 450 nm.

3. Composite material according to any one of the preceding claims, comprising: - a core comprising at least a) at least one particle of bismuth oxycarbonate of empirical formula (BiO)2 / CO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm, and - at least one layer continuously or discontinuously surrounding said core and comprising b) at least aluminum (hydr)oxide of empirical formula [Al2O3.yH2O] in which 0 < y < 10.

4. Composite material according to any one of claims 4 or 5, the molar ratio between the number of moles of coating compound(s) and the number of moles of core compound(s) varying from 0.0001 to 20, preferably varying from 0.005 to 15, more preferably varying from 0.01 to 10, and even more preferably varying from 0.05 to 5.

5. A composite material according to any preceding claim, said bismuth oxycarbonate particles being crystallized.

6. A composite material according to any one of the preceding claims- preceding, said bismuth oxycarbonate particles being of formula (BiO)2(CO3).

7. A composite material according to any preceding claim, the largest average dimension of said bismuth oxycarbonate particles being less than or equal to 300 nm.

8. Composite material according to any one of the preceding claims, said bismuth oxycarbonate particles being in the form of tubes, platelets and / or rods, preferably in the form of platelets and / or rods.

9. Composite material according to any one of the preceding claims, said species(s) of aluminium (hydr)oxide b) being chosen from (A12O3), (A10(OH)), (A1(OH)3) and mixtures thereof.

10. Process for preparing a composite material according to any one of the preceding claims, comprising a step of chemical grafting or physical adsorption between one or more aluminum (hydr)oxide(s) b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10, and at least one particle of bismuth oxycarbonate of empirical formula (BiO)2.x(CO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm.

11. A method for preparing a composite material according to any one of claims 1 to 9, comprising the steps of: i. providing a dispersion of bismuth oxycarbonate particles a) of empirical formula (BiO)2 / CO3), as well as its solvates, such as its hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm, in at least one solvent, in particular in an amount ranging from 0.05 g / L to 500 g / L; ii. providing a solution of at least one species of aluminum (hydr)oxide b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10, or one of its precursors, optionally in a mixture with at least one solvent; iii. bringing together said dispersion (i) and said solution (ii) to form the composite material; iv. isolate said composite material.

12. Preparation process according to claim 11, said one or more solvents of steps (i) and (ii) being identical or different, preferably chosen from polar and protic solvents, more preferably from water, alcohols, polyols and their mixtures, and even more preferably is water.

13. Preparation process according to any one of claims 11 or 12, said solution (ii) comprising at least one precursor of aluminum (hydr)oxide b) of empirical formula [Al2O3.yH2O] in which 0 < y < 10, in particular chosen from sodium aluminate, potassium aluminate, aluminum chloride, aluminum nitrate, aluminum sulfate, aluminum acetylacetonate, and mixtures thereof, and preferably being sodium aluminate.

14. Composition, in particular cosmetic, comprising at least one composite material according to any one of claims 1 to 9.

15. Composition according to the preceding claim comprising at least: i) at least one composite material according to any one of claims 1 to 9; ii) at least one aqueous phase and / or at least one fatty phase; and iii) at least one compound chosen from: 1) UV filters distinct from the composite materials i); 2) coloring materials; 3) cosmetic active ingredients for the care of keratin materials; 4) surfactants; 5) thickeners; and mixtures thereof.

16. Composition according to any one of claims 14 or 15, said composite materials being present in a content ranging from 0.5% to 70% by weight, preferably from 1% to 50% by weight, even better from 2% to 40% by weight, relative to the total weight of the composition.

17. Non-therapeutic cosmetic use of a composite material according to any one of claims 1 to 9, for filtering UV radiation, preferably UV-B, comprising at least the application to keratin materials of a composition comprising a composite material according to any one of claims 1 to 9, in particular of a composition according to any one of claims 14 to 16.

18. d 1U. Non-therapeutic cosmetic process for filtering UV radiation, preferably UV-B, comprising at least the application to keratin materials, in particular human materials, such as the skin and / or to keratin fibers, in particular human materials, such as the hair, of a composition comprising a composite material according to any one of claims 1 to 9, in particular of a composition according to any one of claims 14 to 16.

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