FR3150108A1 - Use of at least one particle of bismuth oxycarbonate, and at least one surfactant for the filtration of ultraviolet radiation - Google Patents

Abstract

The present invention relates to the field of sun protection and more particularly to the use of: at least one particle of bismuth oxycarbonate of empirical formula (I): (BiO)2-x(CO3), formula (I) as well as its solvates such as hydrates, in which -0.4 < x < 0.6, for the filtration of ultraviolet radiation, the largest average dimension of said particles being less than 400 nm; at least one surfactant; it being understood that: - the mass ratio R of the sum of i) the bismuth oxycarbonate particles to ii) the sum of the surfactants is greater than or equal to 1, preferably R > 1 - when the surfactant is polysorbate 20, then R is different from 2/0.29 for the filtration of UV rays, in particular UV-A and/or UV-B, in particular UV-B filters, in particular for the filtration of keratin materials, in particular human materials such as skin and/or fibres, in particular human materials such as hair. Figure for the abstract: None

Description

Use of at least one particle of bismuth oxycarbonate, and at least one surfactant for the filtration of ultraviolet radiation

The present invention relates to the field of sun protection and more particularly to the use of i) at least one specific particle of bismuth oxycarbonate, combined with ii) at least one surfactant in a mass ratio R i)/ii) greater than or equal to 1, for filtering ultraviolet radiation. The present invention also relates to a cosmetic composition comprising the ingredients i) and ii), and a method using the ingredients i) and ii) for filtering UV radiation, in particular UV-B radiation, in particular for protecting keratin materials, in particular human keratin materials, in particular the skin and/or keratin fibers, in particular human keratin fibers, such as hair.

Keratin materials are exposed to sunlight on a daily basis.

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.

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 cause degradation of collagen and elastin fibers, resulting in changes in the skin microrelief, the appearance of wrinkles and irregular pigmentation (i.e. brown spots, uneven skin tone, etc.).

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

Therefore, protection of keratin materials, particularly human ones, such as skin, is essential.

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

Many skin photoprotective cosmetic compositions have been proposed to date. They generally contain organic UV filters and/or inorganic UV filters which act according to their own chemical nature and according to their own physical properties by absorption, reflection or diffusion of UV radiation. They generally contain combinations of oil-soluble organic UV filters and/or water-soluble organic UV filters associated with metal oxide pigments such as titanium dioxide (TiO ₂ ) or zinc oxide (ZnO).

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

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

_TiO2 and ZnO are the most common mineral UV filters used.

However, one of the major drawbacks of such mineral filters is that, once applied to keratinous materials, particularly human ones such as skin, they produce a whitening effect on the skin which is cosmetically undesirable and generally not appreciated by users.

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

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 with 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.

In addition, 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.

Furthermore, the use of mineral filters requires that these filters can be formulated homogeneously in cosmetic compositions so that the protection provided is identical at all times and for all applications. It is therefore necessary to be able to formulate mineral filters without them settling and/or agglomerating within the formulations that implement them so that filtration is homogeneous.

In addition, the use of bismuth carbonate nanotubes in the presence of oleic acid for tumor-targeted chemotherapy combined with renal investigation in high-contrast computed tomography imaging has been described in the literature ( Nano Lett. , 18, 2, 1196–1204 Xi Hu et al. (2018)). This paper does not address the use of bismuth oxycarbonate particles with oleic acid for UV filtering.

However, consumers are increasingly looking for products that are effective but also easy to apply, provide long-lasting comfort and have satisfactory sensory properties.

There therefore remains a need for inorganic UV filters which are effective in photoprotection and which do not have the drawbacks presented above.

In particular, there remains a need for inorganic UV filters capable of effectively blocking UV rays, in particular in the UV-B and UV-A range, and in particular UV-B rays, having high transparency to visible light, which do not bleach keratin materials, in particular human materials such as skin and/or keratin fibres, in particular human materials such as hair, to which it is applied and having good cosmetic properties.

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

There is also a need for mineral filters capable of effectively blocking UV rays, particularly in the UV-B and/or UV-A range, including UV-B, without altering the performance linked to the agglomeration of said mineral filters and/or the deposition of said filters.

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

Thus, according to a first of its aspects, the present invention relates to the use of:

(i) at least one particle of bismuth oxycarbonate of formula (I): (BiO) _{2- x} (CO ₃ ),

formula (I) as well as its solvates such as hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm;

(ii) at least one surfactant;

it being understood that:

- the mass ratio R of the sum of i) the bismuth oxycarbonate particles to ii) the sum of the surfactants is greater than or equal to 1, preferably R >1; and

- when the surfactant is polysorbate 20:

then R is different from 2/0.29 for UV filtration, in particular UV-A and/or UV-B, in particular UV-B filters.

Another subject of the invention is a method for treating keratin materials, in particular human materials, such as skin, or keratin fibers, in particular human materials, such as hair, using the application

(i) at least one particle of bismuth oxycarbonate of empirical formula (I) as defined above, and

(ii) at least one surfactant; and

• le rapport massique R i)/ii) est supérieur ou égal à 1 de préférence R > 1, et
• lorsque le tensioactif est du polysorbate 20 alors R est différent de 2/0,29.

it being understood that:

• the mass ratio R i)/ii) is greater than or equal to 1, preferably R > 1, and
• when the surfactant is polysorbate 20 then R is different from 2/0.29.

Another object of the invention is a preferably cosmetic composition, comprising:

(i) at least one particle of bismuth oxycarbonate of empirical formula (I) as defined above;

(ii) at least one surfactant, and

• le rapport massique R i) / ii) est supérieur ou égal à 1 de préférence R > 1,
• lorsque la composition contient ii) de l’acide oléique alors la composition ne contient pas de polyvinylpyrrolidone, et
• lorsque le tensioactif est du polysorbate 20 alors R est différent de 2/0,29.

it being understood that

• the mass ratio R i) / ii) is greater than or equal to 1, preferably R > 1,
• where the composition contains ii) oleic acid then the composition does not contain polyvinylpyrrolidone, and
• when the surfactant is polysorbate 20 then R is different from 2/0.29.

Another subject of the invention is a method for treating keratin materials, in particular human materials, such as skin, or keratin fibers, in particular human materials, such as hair, implementing the application of the composition as defined above for the filtration of UV-A and/or UV-B, in particular UV-B.

Preferably, the largest average dimension of said particles i) is less than or equal to 300 nm.

Preferably, the particles i) of bismuth oxycarbonate are crystallized.

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

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.

For the purposes of the present invention, the term " efficiency for filtering ultraviolet radiation " means particles having a UV absorbance threshold, in the dispersion medium comprising said particles, greater than 0.5, preferably greater than or equal to 1.0, and more preferably still greater than or equal to 1.5. The higher the absorbance threshold, the greater the UV radiation filtration efficiency.

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.

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.

This effectiveness of bismuth oxycarbonate particles i) associated with at least one surfactant ii), in particular crystallized bismuth oxycarbonate particles i), is, to the knowledge of the inventors, characterized for the first time. It has never been proposed to use bismuth oxycarbonate particles associated with at least one surfactant ii) in cosmetic compositions intended for the effective filtration of UV radiation, in particular UV-B radiation.

The bismuth oxycarbonate particles i) required according to the invention combined with at least one surfactant ii) are in particular intended to protect keratin materials, in particular human materials, in particular the skin and/or keratin fibers, in particular human materials such as hair, from UV radiation, in particular in cosmetic compositions for the fields of sun protection, care, hair treatment and makeup.

Thus, according to another aspect, 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, in particular human materials such as the skin and/or keratin fibers, in particular human materials such as the hair, of a composition according to the invention comprising the bismuth oxycarbonate particles i) as defined below,.

For the purposes of the present invention, and unless otherwise indicated:

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

The expression " at least one " is equivalent to " one or more ".

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

For the purposes of the present invention, the term " fatty substance " means an organic compound which is immiscible in water at ordinary temperature (25°C) and at atmospheric pressure (760 mm Hg) (solubility less than 5%, and preferably 1%, even more preferably 0.1%); in addition, the fatty substances are miscible in particular in all proportions in organic solvents under the same temperature and pressure conditions, such as for example in halogenated solvents such as chloroform, dichloromethane, lower alcohols such as ethanol or aromatic solvents such as benzene or toluene.

By "organic or mineral acid salt " is meant more particularly the salts chosen from a salt derived from i) hydrochloric acid HCl, ii) hydrobromic acid HBr, iii) sulfuric acid H ₂ SO ₄ , iv) alkylsulfonic acids: Alk-S(O) ₂ OH such as methylsulfonic acid and ethylsulfonic acid; v) arylsulfonic acids: Ar-S(O) ₂ OH such as benzenesulfonic acid and toluenesulfonic acid; vi) citric acid; vii) succinic acid; viii) tartaric acid; ix) lactic acid, x) alkoxysulfinic acids: Alk-OS(O)OH such as methoxysulfinic acid and ethoxysulfinic acid; xi) aryloxysulfinic acids such as tolueneoxysulfinic acid and phenoxysulfinic acid; xii) phosphoric acid H ₃ PO ₄ ; xiii) acetic acid CH ₃ C(O)OH ; xiv) triflic acid CF ₃ SO ₃ H and xv) tetrafluoroboric acid HBF ₄ ; as well as salts of so-called "acidic" amino acids such as salts of glutamic acid, aspartic acid;

By " salts of organic or mineral bases " we mean salts of bases or alkaline agents as defined below as alkali metal hydroxides such as soda, potash, ammonia, amines or alkanolamines or salts of so-called "basic" amino acids such as lysine or arginine.

By " cationic counterion " is meant a cation or a cationic group derived from an organic or mineral base salt counterbalancing an anionic charge of at least one ingredient of the composition according to the invention; more particularly the cationic counterion is chosen from i) alkali metals such as sodium, potassium, preferably Na ⁺ , ii) alkaline earth metals such as calcium; iii) ammonium R ₄ N ⁺ with R, identical or different, representing a hydrogen atom, or a (C ₁ -C ₆ )alkyl group optionally substituted by one or more hydroxyl groups, preferably R represents a hydrogen atom or a (C ₁ -C ₄ )alkyl group such as methyl.

The invention also relates, according to another of its aspects, to a composition, in particular cosmetic, comprising:
(i) at least one particle of bismuth oxycarbonate as defined above and below;
(ii) at least one surfactant as defined below;

iii) optionally at least one solvent as defined below; and

iv) optionally at least one compound chosen from: a) UV filters distinct from bismuth oxycarbonate particles i); b) coloring matters; c) cosmetic active ingredients for the care of keratin materials; d) polymers distinct from said surfactant(s) ii); e) thickeners distinct from said polymer(s) d); and mixtures thereof;

it being understood that:

- the mass ratio R particles i) / surfactant(s) ii) is greater than or equal to 1, preferably the mass ratio R i) /ii) is between 1/1 and 1/0.001, preferably between 1/1 and 1/0.005, more preferably between 1/1 and 1/0.01; more particularly R i)/ii) is between 1 and 200, more particularly between 1 and 100; better still between 1.01 and 200, even better still between 1.1 and 100;

- where the composition contains ii) oleic acid then the composition does not contain polyvinylpyrrolidone, and

- when the surfactant is polysorbate 20 then R is different from 2/0.29.

Other characteristics, variants and advantages of the compositions according to the invention will emerge more clearly upon reading the description and examples which follow.

Detailed description

The invention relates to a composition, comprising:

(i) at least one particle of bismuth oxycarbonate of formula (I): (BiO) _{2- x} (CO ₃ ),

formula (I) and its solvates such as hydrates, in which -0.4 < x < 0.6, for the filtration of ultraviolet radiation, the largest average dimension of said particles being less than 400 nm; and

(ii) at least one surfactant;

it being understood that:

- the mass ratio R of the sum of the bismuth oxycarbonate particles i) to the sum of the surfactants ii) is greater than or equal to 1, preferably R > 1;

- where the composition contains ii) oleic acid then the composition does not contain polyvinylpyrrolidone, and

- when the surfactant is polysorbate 20 then R is different from 2/0.29.

The composition

The bismuth oxycarbonate particle(s) i) combined with one or more surfactants ii) are used in a composition, in particular in a cosmetic composition.

The present invention relates to a composition, in particular a cosmetic composition, comprising the ingredients i), and ii) in a particular ratio R as defined above.

i) Bismuth oxycarbonate particle(s)

As previously mentioned, the composition of the invention comprises i) one or more particles of bismuth oxycarbonate of formula (I) (BiO) _{2- x} (CO ₃ ), formula (I) as well as its solvates such as hydrates, with -0.4 < x < 0.6. The value of x can in particular be determined by elemental analysis.

Preferably, x is 0 and the empirical formula of bismuth oxycarbonate particles is (BiO) ₂ ( _CO3 ) as well as its solvates such as hydrates.

The particles may be identical or different from each other. The bismuth oxycarbonate particles according to the invention may be crystallized or amorphous.

According to one form of the invention, the bismuth oxycarbonate particles are amorphous.

According to a preferred form of the invention, the bismuth oxycarbonate particles are crystallized.

It is understood that the bismuth oxycarbonate particles may consist of a mixture of several bismuth oxycarbonate particles of different raw formulas and/or different shapes.

Thus, bismuth oxycarbonate particles can be a mixture of amorphous particles and crystalline particles.

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.

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

Preferably, the crystallized particles required according to the invention have the crystalline phase of the natural ore bismutite, referred to as lamellar, and which has an alternation of [Bi ₂ O ₂ ] ²⁺ and [CO ₃ ] ^2- layers.

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

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 V _lattice = 0.204 nm ³ . This particular arrangement of atoms allows in particular the growth of anisotropic objects.

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.

Particle size

According to the invention, the largest average dimension of the crystallized or amorphous particles, preferably crystallized, of bismuth oxycarbonate of formula (I) (BiO) _{2- x} (CO ₃ ), formula (I) as well as its solvates such as hydrates, in which -0.4 < x < 0.6 is less than 400 nm.

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

By " average size " is meant the number-average value of the particle dimensions. The particle dimensions 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 particle size analyzer. Preferably, the particle dimensions 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. For example, the average value in number can be determined by calculating it by analyzing images obtained by electron microscopy using software, such as ImageJ software (C.A. Schneider, W.S. Rasband, K.W. Eliceiri, NIH Image to ImageJ: 25 years of image analysis, Nat. Methods. 9 (2012) 671–675).

The average dimension is chosen from the average length L, the average width l, the average thickness e, or the average diameter d.

By " greatest average dimension " of 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.

The " length " L of a particle is its largest dimension observable on a picture taken in a direction perpendicular to the plane on which the said particle rests.

The " width " l and " thickness " e of a particle are the lengths of the major and minor axes, respectively, of the smallest possible ellipse in which the median cross-section of said particle can be inscribed.

The " diameter " d of a particle is the largest dimension observable along a line passing through the center of a circle or a sphere.

Particle shape

According to the invention, the bismuth oxycarbonate particle(s) of formula (I) (BiO) _{2- x} (CO ₃ ), formula (I) as well as its solvates such as hydrates, in which -0.4 < x < 0.6, can be in any form.

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

According to one embodiment, the particles i) are of identical morphology.

In particular, when the composition comprises particles i) of identical morphology, the composition of the invention consists of particles in the form of platelets or sheets or rods or spheres or flowers or pompoms or threads or filaments or fibers or needles, or cubes, preferably in the form of platelets or rods.

According to one embodiment, the particles i) are of different morphologies.

In particular, when the composition comprises particles i) of different morphologies, the composition of the invention comprises one or more particles chosen from particles in the form of tubes, platelets, sheets, rods, spheres, flowers, pompoms, threads, filaments, fibers, needles, cubes or any of their mixtures c

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.

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

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.

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, in particular in a mixture in any proportion of platelets and/or rods.

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

A particle in the form of a " platelet " has a length greater than its width and a width greater than its thickness.

In particular, when they are in the form of platelets, the particles according to the invention 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 < l < L .

According to one embodiment, the particles used according to the invention are mainly or exclusively in the form of rods or comprise particles in the form of rods.

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.

In particular, when they are in the form of rods, whether cylindrical or prismatic, the particles according to the invention 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 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.

According to one embodiment, the particles used according to the invention contain particles in the form of tubes.

A particle in the form of a " tube " has a hollow cylindrical shape and its length L is greater than its diameter d .

In particular, when they are in the form of tubes, the particles according to the invention 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 .

By " predominantly in the form of platelets/rods " for the purposes 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 respectively.

Particle doping

According to a particular embodiment, the composition comprises one or more doped bismuth oxycarbonate particles.

In particular, the bismuth oxycarbonate particles according to the invention can be doped with one or more chemical elements capable of being inserted into the structure or of partially replacing elements already present.

The particles can be doped via substitutions of all or part of the cations and/or all or part of the anions.

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.

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%.

In particular, the particles according to the invention may be doped with cations derived from elements chosen 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).

Preferably, the particles according to the invention can be doped with cations 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.

According to an alternative embodiment, the particles according to the invention are doped with cations derived from manganese, and the doping rate varies in particular from 0.5% to 2%.

According to another variant embodiment, the particles according to the invention are doped with cations derived from iron, and the doping rate varies in particular from 0.5% to 2%.

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.

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%.

In particular, the particles according to the invention 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 the sulfate ion (SO ₄ ^2- ), the sulfonate ion (S(=O) ₂ -O ^- ), the sulfite ion (SO ₃ ^2- ), the phosphate ion (PO ₄ ^3- ) and/or the iodate ion (IO ₃ ^- ).

Preferably, the particles according to the invention can be doped with S ^2- , SO ₃ ^2- , SO ₄ ^2- , Cl ^- and/or I ^- , more preferably with SO ₃ ^2- , SO ₄ ^2- and/or Cl ^- , and more preferably with Cl ^- or SO ₄ ^2- .

According to an alternative embodiment, the particles according to the invention are doped with anions derived from chlorine, and the doping rate varies in particular from 0.01% to 0.1%.

According to another variant embodiment, the particles according to the invention are doped with anions derived from iodine, and the doping rate varies in particular from 0.003% to 0.01%.

According to another variant embodiment, the particles according to the invention are doped with the sulfate ion, and the doping rate varies in particular from 0.005% to 0.1%.

According to another embodiment variant, the particles according to the invention are doped with cations preferably 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 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 (SO ₄ ^2- ), sulfonate ion (S(=O) ₂ -O ^- ), sulfite ion (SO ₃ ^2- ), phosphate ion (PO ₄ ^3- ) and/or iodate ion (IO ₃ ^- ), more preferably with S ^2- , SO ₃ ^2- , SO ₄ ^2- , Cl ^- and/or I ^- , even more preferably with SO ₃ ^2- , SO ₄ ^2- and/or Cl ^- , and particularly preferably with Cl ^- , I ^- or SO ₄ ^2- .

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

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

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

Process for preparing particles

The bismuth oxycarbonate particles according to the invention can be obtained by any preparation process known to those skilled in the art.

For example, the synthesis of bismuth oxycarbonate particles according to the invention is described in the article by Ni et al. (Fabrication, modification and application of (BiO) ₂ CO ₃ -based photocatalysts: A review, Applied Surface Science, 365, 314–335 (2016)).

In particular, the particles according to the invention can be prepared by solvothermal means, by electrochemical means, by co-precipitation, or by reflux, and preferably by solvothermal means or by reflux.

According to a first embodiment variant, the particles according to the invention are obtained by solvothermal means, in particular from bismuth nitrate and various carbonating agents such as sodium carbonate, ammonium carbonate or urea, in a polar protic 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.

The synthesis of particles by solvothermal means is notably described in the articles of Cheng, G. et al. (Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials, J. Solid State Chem . 183, 1878–1883 (2010)); Ruan, M. M. et al. (Facile Green Synthesis of Highly Monodisperse Bismuth Subcarbonate Micropompons Self-assembled by Nanosheets: Improved Photocatalytic Performance, Acta Physico-Chimica Sinica , 33, 1033–1042 (2017)); Quin et al. (Template‐Free Fabrication of Bi ₂ O ₃ and (BiO) ₂ CO ₃ Nanotubes and Their Application in Water Treatment, Chem. Eur. J., 18, 16491–16497 (2012)); Cheng, G. et al. (Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials, J. Solid State Chem., 183, 1878–1883, (2010)); Liu, YY et al. (Preparation, electronic structure, and photocatalytic properties of Bi ₂ O ₂ CO ₃ nanosheet, Appl. Surf. Sci., 257, 172–175 (2010)); Zheng et al. (Synthetic Bi ₂ O ₂ CO ₃ nanostructures: Novel photocatalyst with controlled special surface exposed, Journal of Molecular Catalysis A: Chemical, 317 (1-2), 34-40 (2010)); Liu, SQ et al. (The effects of citrate ion on morphology and photocatalytic activity of flower-like Bi ₂ O ₂ CO ₃ , Ceram. Int., 40, 2343–2348 (2014)); 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, 654–658 (2010)).

The synthesis of particles by electrochemical route is notably described in the article by Hu, Y. et al. (Simple hydrolysis route to synthesize Bi ₂ O ₂ CO ₃ nanoplate from Bi nanopowder and its photocatalytic application, Materials Letters, 170, 72–75 (2016)).

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, Bi ₁₂ O ₁₇ Cl ₂ , α-Bi ₂ O ₃ , and (BiO) ₂ CO ₃ ) by solution-phase methods, J. Solid State Chem. , 180, 2510–2516 (2007)).

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 ., 2265–2267 (2006)).

According to a preferred embodiment, the bismuth oxycarbonate particles required according to the invention are obtained solvothermally, for example according to the method described by Cheng et al. , or at reflux, for example according to the method described by Chen et al..

According to a preferred embodiment, the bismuth oxycarbonate particles 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.

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

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.

Bismuth(III) complex(es) can also be obtained from bismuth minerals, such as elemental bismuth and/or bismuth oxide and/or bismuth sulfide.

Preferably, the bismuth(III) complex(es) is(are) bismuth(III) nitrate and its hydrated forms of formula Bi( _NO3 ) ₃ · xH2O , and preferably is bismuth nitrate pentahydrate of formula Bi( _NO3 ) ₃ · _{5H2O .}

In particular, the carbonating agent(s) is (are) selected from Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , Rb ₂ CO ₃ , Cs ₂ CO ₃ , (NH ₄ ) ₂ CO ₃ , LiHCO ₃ , NaHCO ₃ , KHCO ₃ , RbHCO ₃ , CsHCO ₃ , (NH ₄ ) HCO ₃ , urea (NH ₂ ) ₂ CO and urea derivatives, CO ₂ , preferably from Na ₂ CO ₃ , K ₂ CO ₃ , (NH ₂ ) ₂ CO, (NH ₄ ) ₂ CO ₃ , and more preferably from (NH ₂ ) ₂ CO and/or (NH ₄ ) ₂ CO ₃ .

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.

According to one embodiment, the bismuth oxycarbonate particles required according to the invention are obtained by a preparation process using a polyol or a mixture of polyols.

According to a first embodiment variant, the polyol(s) may also be used as a solvent. The particles according to the invention may then be obtained, for example, according to the method described below.

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.

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

In case of doping with one or more cation(s) and/or 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 polyol mixture is not liquid at room temperature, all solids are mixed.

The resulting mixture is then heated to between 90°C 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.

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.

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

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

In the case where the polyol(s) are used as solvents, the bismuth oxycarbonate particles according to the invention 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.

According to another embodiment variant, the polyol(s) are used only as additives, and not as solvents. The particles according to the invention can then be obtained for example according to the process described below.

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.

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

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. 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.

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

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

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

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.

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; C ₁ -C ₆ alcohols such as ethanol or isopropanol; and mixtures thereof, and even more preferably the solvent is water.

In particular, when the polyol(s) are chosen solely as additives and water as solvent, the bismuth oxycarbonate particles according to the invention obtained are preferably in the form of platelets and/or in the form of rods.

According to a particular embodiment, the compositions of the invention contain at least 0.05% of particles i) by weight relative to the total weight of the composition.

According to a particular embodiment, the mass concentration of particles i) is between 0.05% and 80% relative to the total weight of the composition, preferably from 0.08% to 75%.

According to one embodiment, the mass concentration of particles i) is between 30% and 80% relative to the total weight of the composition, preferably from 35% to 75%.

According to one embodiment, the mass concentration of particles i) is between 1% and 60% relative to the total weight of the composition, preferably from 2% to 55%.

According to a particular embodiment of the invention, said particle(s) of bismuth oxycarbonate is (are) present in the composition, preferably cosmetic, in a content ranging from 0.5% to 40% by weight, preferably from 1% to 30% by weight, even better from 2% to 20% by weight relative to the total weight of the composition.

ii) Surfactant(s)

The second ingredient of the composition of the invention is ii) one or more surfactants.

By " surfactant " we mean a " surface agent " or " surfactant " which is a compound capable of modifying the surface tension between two surfaces, surfactants are amphiphilic molecules, i.e. which have two parts of different polarity, one lipophilic and apolar and the other hydrophilic and polar. Surfactants can be nonionic, anionic, amphoteric, cationic or nonionic active.

When there are several surfactants this implies that the surfactants ii) are chemically different and/or of different molar weight, and in this case are in a mixture.

It is understood that in the composition of the invention the mass ratio R of the sum of the bismuth oxycarbonate particles i) to the sum of the surfactants ii) is greater than or equal to 1, preferably greater than 1, and that when the surfactant is polysorbate 20 then R is different from 2/029.

According to one embodiment of the invention, when the surfactant(s) ii) are a single surfactant, this is different from polysorbate 20.

Preferably, the process of the invention and the composition of the invention do not use polysorbate 20.

According to one embodiment, the ratio R is greater than 1.

According to one embodiment, the mass ratio R i) /ii) is between 1/1 and 1/0.001, preferably between 1/1 and 1/0.005, more preferably between 1/1 and 1/0.01. According to a preferred embodiment, the ratio R is between 1 and 200, better between 1.01 and 200, more particularly between 1 and 100, better still the ratio R is between 1.1 and 100.

The surfactant(s) ii) of the composition of the invention may be chosen from nonionic, anionic, cationic, amphoteric or zwitterionic surfactants, and mixtures thereof. Reference may be made to the document “Encyclopedia of Chemical Technology, KIRK-OTHMER”, volume 22, p. 333-432, 3rd edition, 1979, WILEY, for the definition of the properties and emulsifying functions of surfactants, in particular p. 347-377 of this reference, for anionic, amphoteric and nonionic surfactants.

According to a preferred embodiment, the molar mass of the surfactant(s) ii) is less than 2000 g/mol.

According to another embodiment, the composition according to the invention comprises several surfactants and preferably at least one has a molar mass of less than 2000 g/mol.

According to one embodiment, the surfactant(s) ii) are hydrocarbon compounds comprising carbon, hydrogen, oxygen and optionally sulfur and phosphorus atoms.

According to a particular embodiment of the invention, the surfactant(s) ii) is (are) chosen from nonionic surfactants.

Among the nonionic surfactants according to the invention, mention may be made, alone or in mixtures, of a) fatty alcohols, b) alpha-diols, c) alkylphenols, these 3 types of compounds a) to c) being polyethoxylated, polypropoxylated and/or polyglycerolated, and having an aliphatic chain comprising for example 6 to 30 carbon atoms, in particular comprising 10 to 22 carbon atoms, the number of ethylene oxide or propylene oxide groups being able to range in particular from 2 to 200, in particular from 10 to 100 and the number of glycerol groups being able to range in particular from 2 to 200, in particular from 5 to 100, more particularly from 8 to 20 such as 10. Mention may also be made of copolymers of ethylene oxide (EO) and propylene oxide (PO), condensates of ethylene oxide and propylene oxide on fatty alcohols; polyethoxylated fatty amides preferably having from 2 to 30 moles EO, polyglycerolated fatty amides comprising on average 1 to 5 glycerol groups and in particular 1.5 to 4; oxyethylenated sorbitan fatty acid esters having from 2 to 200 moles EO, in particular from 10 to 100 EO; sucrose fatty acid esters, polyethylene glycol fatty acid esters, alkylpolyglycosides, N-alkylglucamine derivatives, amine oxides such as (C ₁₀ -C ₁₄ )alkylamine oxides or N-acylaminopropylmorpholine oxides.

Preferably, the nonionic surfactant is chosen from: (poly)ethoxylated fatty alcohols; glycerolated fatty alcohols; alkylpolyglycosides. Preferably the mono and diesters of oxyethylenated sorbitan fatty acids having from 2 to 200 moles EO, in particular from 10 to 100 EO.

More preferably, the surfactants are chosen from mono and diesters of oxyethylenated sorbitan fatty acids having from 2 to 200 moles EO, in particular from 10 to 100 EO such as propylene glycol stearate having from 10 to 30 EO such as 20 EO; glyceryl mono distearate/polyethylene glycol stearate (100 EO).

By fatty chain is meant a hydrocarbon chain comprising 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms, linear or branched, saturated or not, such as stearyl, oleyl, lauryl.

As regards alkylpolyglycosides, these compounds are well known and can be more particularly represented by the following general formula: R ₁ O-(R ₂ O) _t (G) _v (III) Formula (III) in which:

- R ₁ represents a linear or branched alkyl and/or alkenyl radical containing approximately 8 to 24 carbon atoms, an alkylphenyl radical whose linear or branched alkyl radical contains 8 to 24 carbon atoms;

- R₂represents an alkylene radical containing approximately 2 to 4 carbon atoms;

- G represents a sugar unit containing 5 to 6 carbon atoms;

- t denotes an integer between 0 and 10 inclusive, preferably between 0 and 4, preferably between 0 and 4; and

- v denotes an integer between 1 and 15 inclusive.

Preferred alkylpolyglycosides according to the present invention are compounds of formula (III) in which R ₁ more particularly denotes a saturated or unsaturated, linear or branched alkyl radical comprising from 8 to 18 carbon atoms, t denotes a value ranging from 0 to 3 and more particularly still equal to 0, G can denote glucose, fructose or galactose, preferably glucose. The degree of polymerization, i.e. the value of v in formula (III), can range from 1 to 15, preferably from 1 to 4. The average degree of polymerization is more particularly between 1 and 2 and even more preferably from 1.1 to 1.5.

The glycosidic bonds between the sugar units are of the 1-6 or 1-4 type and preferably 1-4.

Compounds of formula (III) are represented in particular by the products sold by the company COGNIS under the names PLANTAREN® (600 CS/U, 1200 and 2000) or PLANTACARE® (818, 1200 and 2000). It is also possible to use the products sold by the company SEPPIC under the names TRITON CG 110 (or ORAMIX CG 110) and TRITON CG 312 (or ORAMIX® NS 10), the products sold by the company B.A.S.F. under the name LUTENSOL GD 70 or those sold by the company CHEM Y under the name AG10 LK.

It is also possible to use, for example, _C8 / _C16 alkyl polyglucoside 1,4 in 53% aqueous solution marketed by COGNIS under the reference PLANTACARE® 818 UP.

With regard to mono or polyglycerolated surfactants, they preferably comprise on average from 1 to 40 glycerol groups, more particularly from 5 to 30 glycerol groups such as 10.

According to a particular embodiment of the invention, the surfactants are monoglycerolated or polyglycerolated and are preferably chosen from the compounds of the following formulas:

RO[CH ₂ CH(CH ₂ OH)O] _m H ,

RO[CH ₂ CH(OH)CH ₂ O] _m H or

RO[CH(CH ₂ OH)CH ₂ O] _m H ;

Formulas in which:

- R represents a saturated or unsaturated, linear or branched hydrocarbon radical, containing from 8 to 40 carbon atoms and preferably from 10 to 30 carbon atoms;

- m is a number between 1 and 30, preferably between 1 and 10, more particularly from 1.5 to 6. R may optionally comprise heteroatoms such as for example oxygen and nitrogen. In particular, R may optionally comprise one or more hydroxyl and/or ether and/or amide groups. R preferably denotes C ₁₀ -C ₂₀ alkyl and/or alkenyl radicals, optionally mono or polyhydroxylated.

Preferably, the composition of the invention comprises one or more (poly)ethoxylated fatty alcohols suitable for implementing the invention are more particularly chosen from alcohols comprising from 8 to 30 carbon atoms, and preferably from 12 to 22 carbon atoms.

The (poly)ethoxylated fatty alcohols more particularly have one or more linear or branched, saturated or unsaturated hydrocarbon groups, comprising 8 to 30 carbon atoms, optionally substituted, in particular by one or more hydroxyl groups (in particular 1 to 4). If they are unsaturated, these compounds may comprise one to three carbon-carbon double bonds, conjugated or not.

The (poly)ethoxylated fatty alcohol(s) preferably have the following formula:

R ^a -[O-CH ₂ -CH ₂ ] _n -OH

with

- R ^a representing a linear or branched C ₁ -C ₄₀ alkyl group, or linear or branched C ₂ -C ₃₀ alkenyl group (preferably C ₈ -C ₃₀ alkyl); and

- n represents an integer between 1 and 200 inclusive, preferably between 2 and 100, more particularly between 10 and 50 inclusive, even more particularly between 15 and 30 inclusive such as 100 or 20.

(Poly)ethoxylated fatty alcohols are more particularly fatty alcohols containing 8 to 22 carbon atoms and oxyethylenated by 1 to 30 moles of ethylene oxide (1 to 100 EO). Among them, we can cite more particularly lauryl alcohol 20 EO, lauryl alcohol 30 EO, decyl alcohol 3 EO, decyl alcohol 5 EO and oleyl alcohol 20 EO.

Mixtures of these (poly)oxyethylenated fatty alcohols can also be used.

According to another advantageous variant, the nonionic surfactant(s) ii) of the invention are chosen from those comprising one or more ester groups, one or more hydroxyl groups, and comprising from 10 to 50 carbon atoms, more particularly between 20 and 42 carbon atoms and more than 4 hydroxyl groups, preferably between 10 and 25 hydroxyl groups. According to this variant, the fatty acid and polyglycerol esters such as POLYGLYCERYL-5 LAURATE or polyglyceryl-10-laurate, in particular polyglyceryl-10-laurate, will be chosen in particular.

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-esters, 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.

Among the nonionic surfactants, _C6 - _C24 alkyl polyglucosides and (poly)ethoxylated fatty alcohols are preferably used, and _C8 - _C16 alkyl polyglucosides are more particularly used.

According to another particular embodiment of the invention, the composition comprises one or more anionic surfactants.

The term “ anionic surfactant ” means a surfactant containing only anionic groups as ionic or ionizable groups. These anionic groups are preferably chosen from the groups –C(O)OH, –C(O)O ^- , -SO ₃ H, -S(O) ₂ O ^- , -OS(O) ₂ OH, -OS(O) ₂ O ^- , -P(O) ₂ OH, -P(O) ₂ O ^- , -P(O)O ₂ ^- , -P(OH) ₂ , =P(O)OH, -P(OH)O ^- , =P(O)O ^- , =POH, =PO ^- , the anionic parts comprising a cationic counterion such as an alkali metal, an alkaline earth metal, or an ammonium, more preferably the groups are chosen from –C(O)OH, –C(O)O ^- , -SO ₃ H, -S(O) ₂ O ^- , -OS(O) ₂ OH, and -OS(O) ₂ O ^- .

As examples of anionic surfactants that can be used in the composition according to the invention, mention may be made of alkylcarboxylic acids, alkylcarboxylates, alkyl sulfates, alkyl ether sulfates, alkyl ester sulfonates or sulfonic acids, alkylamidoether sulfates, alkylarylpolyether sulfates, monoglyceride sulfates, alkylsulfonates, alkylamidesulfonates, alpha-olefin sulfonates, paraffin sulfonates, alkylsulfosuccinates, alkylethersulfosuccinates, alkylamidesulfosuccinates, alkylsulfoacetates, acylsarcosinates, acylglutamates, alkylsulfosuccinamates, acyl isethionates and N-acyltaurates, salts of alkyl monoesters and acids polyglycoside-polycarboxylic acids, salts of alkyl diesters and polyglycoside-polycarboxylic acids, acyllactylates, salts of D-galactoside-uronic acids, salts of alkyl ether-carboxylic acids, salts of alkylaryl ether-carboxylic acids, salts of alkyl amidoether-carboxylic acids, and the corresponding non-salified forms of all these compounds, the alkyl and acyl groups of all these compounds comprising from 8 to 30 carbon atoms, preferably from 10 to 22 carbon atoms and the aryl group denoting a phenyl group. It is understood that the alkyl groups of the surfactants can be linear or branched, interrupted by one or more heteroatoms or groups chosen from O, S, N, C(O) or their combination such as the ester group. According to one embodiment, the surfactant(s) ii) are or comprise at least one anionic surfactant preferably chosen from alkyl sulfonate or sulfonic esters, more preferably from alkyl sulfosuccinates such as docusates. For example, docusates, in particular of alkali or alkaline earth metals, including sodium docusate, may be mentioned.

According to one embodiment, the surfactant(s) ii) are or comprise at least one anionic surfactant preferably chosen from alkyl sulfates, alkyl ether sulfates, said alkyl sulfates or alkyl ether sulfates being optionally oxyethylenated or oxypropylenated. These anionic surfactants may in particular be oxyethylenated and then preferably comprise from 1 to 50 ethylene oxide units. Examples that may be mentioned include alkyl ether sulfates such as lauryl ether sulfates, in particular of alkali or alkaline earth metals, including sodium lauryl ether sulfate.

These anionic surfactants can be alkyl sulfates such as alkali or alkaline earth metal salts including sodium lauryl sulfate.

According to a particular embodiment of the invention, the anionic surfactants which carry one or more carboxy –C(O)OH, or carboxylate–C(O)O ^- groups (i.e. alkyl (poly)carboxylic acids, or alkyl(poly)carboxylates) are non-oxyethylenated.

More particularly, the anionic surfactants of the invention are chosen from saturated or unsaturated fatty acids, the hydrocarbon chain being able to be linear or branched, preferably comprising from 6 to 30 carbon atoms, particularly from 10 to 20 carbon atoms, more particularly from 12 to 18 carbon atoms such as stearic, oleic and lauric acids.

The salts of C ₆ -C ₂₄ alkyl monoesters and polyglycoside-polycarboxylic acids may be selected from C ₆ -C ₂₄ alkyl polyglycoside citrates, C ₆ -C ₂₄ alkyl polyglycoside tartrates and C ₆ -C ₂₄ alkyl polyglycoside sulfosuccinates.

When the anionic surfactant(s) are in salt form, they may be chosen from alkali metal salts such as sodium or potassium salt and preferably sodium salt, ammonium salts, amine salts and in particular amino alcohol salts or alkaline earth metal salts such as magnesium salts.

Examples of amino alcohol salts include mono-, di- and triethanolamine salts, mono-, di- or triisopropanolamine salts, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol and tris(hydroxymethyl)amino methane salts.

Preferably, salts of alkali or alkaline earth metals are used, particularly sodium or magnesium salts.

Among the anionic surfactants mentioned, it is preferred to use alkyl(C ₆ -C ₂₄ )carboxylic acids, in particular alkyl(C ₁₀ -C ₂₀ )carboxylic acids, preferably of natural origin, in particular plant origin, such as stearic acid, oleic acid and lauric acid; more preferably oleic acid and lauric acid may be in the form of salts of alkali metals, ammonium, amino alcohols and alkaline earth metals, or a mixture of these compounds.

According to another embodiment of the invention, the surfactant(s) are zwitterionic, betaine or amphoteric.

The term " zwitterionic, betaine or amphoteric surfactant " means a surfactant comprising as ionic or ionizable groups at least one anionic group and at least one cationic group. The anionic groups being as defined above. The cationic group being more particularly chosen from ammonium and phosphonium groups. Each anionic or cationic group can carry a cationic or anionic counterion respectively or else said groups do not carry a counterion, and the anionic group counterbalances the charge by the presence of a cationic group within the same surfactant so that the electroneutralite of said surfactant is respected. 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 cocamidopropyl betaine, lauramidopropyl betaine and N-carboxyethoxyethyl N-cocoylamidoethyl aminoacetate N-disodium; sultaines, in particular cocoyl amidopropylhydroxy sultaine; and mixtures thereof.

According to another embodiment of the invention, the surfactant(s) are cationic.

The term " cationic surfactant " means a surfactant comprising as ionic or ionizable groups only cationic or cationizable groups. These cationic groups are preferably chosen from amines, ammonium and phosphonium, the cationic parts optionally comprising an anionic counterion such as halide such as chloride Cl ^- , alkyl sulfate or sulfonates such as mesylate, and alkylcarboxylates such as citrate, preferably halides such as chloride.

The cationic surfactants may be chosen from alkylimidazolidiniums, such as isostearylethylimidonium ethosulfate, ammonium salts, such as (C _12-30 alkyl)-tri(C _1-4 alkyl)ammonium halides such as N,N,N-trimethyl-1-docosaminium chloride (or Behentrimonium chloride).

Silicone surfactants can be chosen from dimethicone copolyols or silicone elastomers.

According to one embodiment, the surfactant(s) ii) of the invention is (are) non-silicone.

Preferably, the surfactant(s) of the invention ii) are chosen from nonionic surfactants and anionic surfactants.

More particularly, the surfactant(s) of the invention ii) are chosen from:

ii-1) nonionic surfactants chosen from those comprising one or more ester groups, one or more hydroxy groups, and comprising from 10 to 50 carbon atoms, more particularly between 20 and 42 carbon atoms and more than 4 hydroxy groups, preferably between 10 and 25 hydroxy groups such as polyglyceryl-10 laurate;

ii-2) anionic surfactants chosen from saturated or unsaturated fatty acids, the hydrocarbon chain being able to be linear or branched, preferably comprising from 6 to 24 carbon atoms, particularly from 10 to 20 carbon atoms, more particularly from 12 to 18 carbon atoms such as stearic, oleic and lauric acids, preferably of natural origin, in particular plant origin such as stearic acid, oleic acid and lauric acid; more preferably oleic acid and lauric acid being able to be in the form of salts of alkali metals, ammonium, amino alcohols, and alkaline earth metals, or a mixture of these compounds;

ii-3) the anionic surfactants chosen from alkyl sulfates, alkyl ether sulfates the alkyl groups of the surfactants can be linear or branched, interrupted by one or more heteroatoms or groups chosen from O, S, N, C(O) or their association such as esters such as docusates in particular of alkali or alkaline earth metals including sodium docusate, these surfactants can in particular be oxyethylenated and then preferably comprise from 1 to 50 ethylene oxide units more particularly alkyl ether sulfates such as lauryl ether sulfates in particular of alkali or alkaline earth metals including sodium lauryl ether sulfate.

The amount of surfactants ii) preferably ranges from 0.001% to 10% by weight, in particular from 0.01% to 5% by weight, and more particularly from 0.05 to 3% by weight, more preferably between 0.5% and 1% relative to the total weight of the composition of the invention.

iii) Aqueous phase

The composition, in particular cosmetic, according to the invention may comprise iii) at least one aqueous phase. Preferably the composition is aqueous i.e. comprises water and optionally one or more water-miscible solvents.

According to a particular embodiment, the composition according to the invention is devoid of aqueous phase.

The aqueous phase may comprise water and optionally at least one water-miscible solvent.

The composition may comprise water without a water-miscible solvent.

According to another variant, the aqueous phase comprises water and at least one water-miscible solvent.

In the present invention, the term " water-miscible solvent " means a compound which is liquid at room temperature and whose miscibility in water is greater than 50% by weight at 25°C and atmospheric pressure.

The water-miscible solvents that can be used in a composition according to the invention can also be volatile.

Among the water-miscible solvents which may be used in a composition in accordance with the invention, mention may be made in particular of lower monoalcohols having from 1 to 5 carbon atoms such as ethanol and isopropanol, C ₂ -C ₃₂ polyols, C ₃ and C ₄ ketones and C ₂ -C ₄ aldehydes.

For the purposes of the present invention, the term “ polyol ” means any organic molecule comprising at least two free hydroxyl groups.

A polyol suitable for the invention may be a compound of the alkyl type, linear, branched or cyclic, saturated or unsaturated, carrying on the alkyl chain at least two –OH functions.

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.

Advantageously, the polyol may be chosen, for example, from propylene glycol, pentaerythritol, trimethylolpropane, caprylyl glycol, glycerol, polyglycerols, such as glycerol oligomers such as diglycerol, polyethylene glycols, and mixtures thereof.

According to a particular embodiment, the composition comprises water and is free of water-soluble solvent.

iv) Fatty phase

The composition, in particular cosmetic, according to the invention may further comprise v) at least one fatty phase, in particular an oily phase.

For the purposes of the invention, the term “ fatty phase ” means a phase comprising at least one fatty substance - other than anionic surfactant fatty acids ii).

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

By " oil " we mean a fatty substance, liquid at room temperature (25°C) and atmospheric pressure (760 mm Hg).

The fatty phase may comprise at least a) a hydrocarbon or silicone or fluorinated oil, preferably hydrocarbon, said oil(s) being volatile or non-volatile and/or b) at least one fatty substance different from the surfactants ii).

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 fatty acids in C ₁₂ -C ₂₂ , carbonates, and mixtures thereof.

Examples of volatile hydrocarbon oils include hydrocarbon oils with 8 to 16 carbon atoms.

Non-volatile silicone oils may be chosen in particular from non-volatile polydimethylsiloxanes (PDMS) and phenylated silicones. As volatile silicone oils, examples that may be mentioned are volatile linear or cyclic silicone oils.

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

According to one embodiment, the composition according to the invention comprises at least one oil, preferably hydrocarbon-based.

According to a preferred embodiment, the hydrocarbon oils are chosen from triglycerides consisting of fatty acid esters and glycerol, in particular the fatty acids of which may have chain lengths varying from C4 to C36, and in particular from _C18 to _C36 , these oils being able to be linear or branched, saturated or unsaturated; as examples, mention may in particular be made of heptanoic or octanoic triglycerides, caprylic/capric acid triglycerides; vegetable oils such as wheat germ, sunflower, grape seed, sesame, corn, apricot kernel, castor, shea, avocado, olive, soybean, sweet almond, palm, rapeseed, cottonseed, hazelnut, macadamia, jojoba, alfalfa, poppy, pumpkin, squash, blackcurrant, evening primrose, millet, barley, quinoa, rye, safflower, candlenut, passionflower, musk rose, peanut, coconut, argan, passionflower, kaya; the liquid fraction of shea butter, and the liquid fraction of cocoa butter; and their mixtures According to one embodiment, the non-volatile hydrocarbon oil(s) comprise or consist of at least one non-volatile oil chosen from triglycerides consisting of fatty acid esters and glycerol, in particular the fatty acids of which may have chain lengths varying from C4 to C36, and in particular from C8 to C36, these oils possibly being linear or branched, saturated or unsaturated as described above, preferably chosen from heptanoic or octanoic triglycerides, caprylic/capric acid triglycerides and their mixtures and in addition preferentially caprylic/capric acid triglycerides such as the reference PALMESTER 3585 marketed by KLK OLEO.

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 wax, a gum, a pasty compound, or mixtures thereof.

v) Additional UV filters

According to a particular embodiment, a composition according to the invention comprises vi) at least one complementary UV filter distinct from the bismuth oxycarbonate particles required according to the invention and defined above.

By " complementary UV filter distinct from the bismuth oxycarbonate particles " is meant, for the purposes of the present invention, any UV filter whose chemical nature differs from that of the bismuth oxycarbonate particles required according to the invention i) and defined above.

The bismuth oxycarbonate particles i) according to the invention can therefore be used alone or in combination with vi) at least one other complementary UV filter distinct from i), in particular chosen from organic and/or inorganic UV filters.

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 distinct from the bismuth oxycarbonate particles i) according to the invention.

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.

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.

By " insoluble UV filter " is meant any organic or inorganic cosmetic or dermatological compound distinct from the particles i) according to the invention and filtering UV radiation and 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.

Complementary organic UV filters are chosen in particular from:
- cinnamic compounds, in particular Ethylhexyl Methoxycinnamate,
- anthranilate compounds, in particular Menthyl anthranilate,
- salicylic compounds, in particular Homosalate and Ethylhexyl Salicylate,
- dibenzoylmethane compounds, in particular Butyl Methoxydibenzoylmethane,
- benzylidene camphor compounds, in particular 3-Benzylidene camphor, 4-Methylbenzylidene camphor, Benzylidene Camphor Sulfonic Acid and Terephthalylidene Dicamphor Sulfonic Acid,
- benzophenone compounds, in particular oxybenzone and n-hexyl 2-(4-diethylamino-2-hydroxybenzoyl)-benzoate,
- β,β-diphenylacrylate compounds, in particular octocrylene,
- triazine compounds, in particular Phenylene Bis-Diphenyl triazine, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Ethylhexyl Triazone and Diethylhexyl Butamido Triazone,
- benzotriazole compounds, in particular Drometrizole Trisiloxane,
- benzalmalonate compounds, in particular those cited in US patent 5624663, in particular Polysilicone-15,
- benzimidazole derivatives, in particular Phenylbenzimidazole Sulfonic Acid,
- imidazoline compounds, in particular Ethylhexyl Dimethoxybenzylidene Dioxoimidazoline Propionate,
- bis-benzoazolyl compounds, as described in patents EP 0669323 and US 2463264, in particular Disodium Phenyl Dibenzimidazole Tetra-sulfonate,
- para-aminobenzoic compounds, in particular PABA, Ethylhexyl Dimethyl PABA and PEG-25 PABA,
- 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,
- benzoxazole compounds, as described in patent applications EP 0832642, EP 1027883, EP 1300137 and DE 10162844, in particular 2,4-bis-[5-1(dimethylpropyl)benzoxazol-2-yl-(4-phenyl)-imino]-6-(2-ethylhexyl)-imino-1,3,5-triazine,
- filter polymers and filter silicones, such as those described in particular in application WO 93/04665,
- dimers derived from α-alkylstyrene, such as those described in patent application DE 19855649,
- 4,4-diarylbutadienes 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.

Complementary inorganic UV filters (vi) are generally mineral UV filters, in particular chosen from metal oxides.

The metal oxides vi) may in particular be chosen from titanium, zinc, iron, zirconium and cerium oxides, and their mixtures.

The metal oxide particles (vi) may be coated or uncoated.

The coated particles (vi) are more particularly titanium oxides coated with silica, silica and iron oxide, silica and alumina, alumina, alumina and aluminium stearate, silica, alumina and alginic acid, alumina and aluminium laurate, iron oxide and iron stearate, zinc oxide and zinc stearate, silica and alumina and treated with a silicone, silica, alumina, aluminium stearate and treated with a silicone, silica and treated with a silicone, alumina and treated with a silicone, triethanolamine, stearic acid, sodium hexametaphosphate, or TiO ₂ treated with octyl trimethyl silane, TiO ₂ treated with a polydimethylsiloxane, polydimethylhydrogensiloxane-treated anatase/rutile TiO ₂ , TiO ₂ coated with triethylhexanoin, aluminum stearate and alumina, TiO ₂ coated with aluminum stearate, alumina and silicone, TiO ₂ coated with lauroyl lysine, or TiO ₂ coated with C _9-15 fluoroalcohol phosphate and aluminum hydroxide.

Metal oxides (vi) may optionally be doped.

In this respect, we can cite _TiO2 particles doped with at least one transition metal such as iron, zinc, manganese, and more particularly manganese.

The doped particles vi) 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 be made more particularly of the oily dispersion of manganese-doped TiO ₂ particles in capric/caprylic acid triglyceride in the presence of tri-PPG-3 myristyl ether citrate and polyglyceryl-3-polyricinoleate and sorbitan isostearate.

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.

(vi) Colouring matters

According to a particular embodiment, a composition according to the invention comprises vii) at least one coloring material.

According to one embodiment, the composition does not contain Basic Red 51, more preferably does not contain a dye with an imidazolium group, more particularly does not contain a cationic dye with an imidazolium and azo group (azo dye), more particularly does not contain basic dye (cationic dye). In one embodiment, the method of the invention and the use of the invention do not use Basic Red 51, more preferably do not use a dye with an imidazolium group, more particularly do not use a cationic dye with an imidazolium and azo group (azo dye), more particularly do not use basic dye (cationic dye).

Generally speaking, a “coloring matter” 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 as a color such as yellow, orange, red, violet, blue or green.

Preferably, a composition according to the invention comprises at least one pigment different from the bismuth oxycarbonate particles i) according to the invention.

By " pigments " is meant white or colored particles, mineral or organic, insoluble in liquid hydrophilic and lipophilic phases, intended to color and/or opacify the composition containing them, said particles being distinct from the bismuth oxycarbonate particles i) according to the invention. More particularly, the pigments are slightly or not at all soluble in hydroalcoholic media.

The pigments that can be used are in particular chosen from organic and/or mineral pigments known in the art, in particular those described in Kirk-Othmer's Encyclopedia of Chemical Technology and in Ullmann's 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 and ibid, "Pigments, Inorganic, 1. General” 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim10.1002/14356007.a20_243.pub3), said pigments being different from i).

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

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

The pigment may be a mineral pigment. By mineral pigment is meant any pigment that meets the definition of the Ullmann encyclopedia in the inorganic pigment chapter and different from the particles i) according to the invention. 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.

The pigment may be an organic pigment.

By organic pigment is meant any pigment that meets the definition of the Ullmann encyclopedia in the organic pigment chapter.

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.

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.

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.

According to a particular embodiment of the invention, the quantity of pigments distinct from the bismuth oxycarbonate particles i) according to the invention varies from 0.5% to 40%, and preferably from 1 to 20% relative to the weight of the composition of the invention comprising them.

vii) Cosmetic active ingredient

According to a particular embodiment, a composition according to the invention comprises viii) at least one cosmetic active ingredient for the care of keratin materials, in particular human materials, such as the skin and/or keratin fibers, in particular human fibers, such as hair, preferably for skin care.

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

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

Cosmetic active ingredients include, for example, moisturizing agents, depigmenting agents, desquamating agents, humectants, anti-aging agents, mattifying agents, healing agents, antibacterial 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, myorelaxant agents, refreshing agents, tensor agents, pro-pigmenting agents, keratolytic agents, slimming agents, agents acting on the energy metabolism of cells, repellent agents against insects, antagonists of substances P or CRGP, anti-hair loss agents, and their mixtures.

The asset(s) may in particular be chosen from:
- 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),
- humectants or moisturizers such as urea, hydroxyureas, glycerol, polyglycerols, glycerolglucoside, diglycerolglucoside, polyglycerylglucosides, xylitylglycoside and plant extracts (in particular tea, mint, orchid, soya, aloe vera, honey), and in particular glycerol;
- C-glycoside compounds, and preferably hydroxypropyl tetrahydropyrantiol (or proxylane);
- antioxidant compounds;
- 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;

- keratolytic agents such as lactic acid or glycolic acid; and
- their mixtures.

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.

viii) Thickener

According to a particular embodiment, a composition according to the invention comprises ix) at least one thickener different from the surfactant(s) ii), also sometimes called gelling agent or viscosity modifying agent.

Thickeners can be synthetic, natural or naturally derived, preferably natural or naturally derived.

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

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

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, locust bean gum, konjac gum, galactomannans 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 gum, mucopolysaccharides, carboxyvinyl polymers, polyacrylamides, polymers and copolymers of 2-acrylamido-2-methylpropanesulfonic 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.

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.

ix) Adjuvants

A composition according to the invention may also comprise at least one adjuvant customary 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, anti-foaming agents, fillers, trace elements, propellants, and mixtures thereof.

Of course, the 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.

.

As stated above, a composition according to the invention may be cosmetic, and preferably is cosmetic.

A composition according to the invention is generally suitable for topical application to keratin materials, in particular human materials, preferably to the skin, and therefore generally comprises a physiologically acceptable medium, i.e. compatible with the keratin materials, preferably the skin.

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 dissuade the user from applying this composition.

Galenic forms of the compositions

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

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

Cosmetic compositions can be presented in the form of an aqueous or hydroalcoholic gel.

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.

They can also be present in anhydrous form, for example in the form of an oil.

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.

Cosmetic compositions can, for example, be used as make-up products.

The cosmetic compositions can for example be used as a care product and/or sun protection for the face and/or body. The compositions according to the invention can be 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 can optionally be applied to the skin in the form of an aerosol. It can also be in solid form, and for example in the form of a stick.

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, lips, hands, feet, anatomical folds or body (for example day creams, night creams, day serums, night serums, make-up remover creams, make-up bases, protective or care body milk, after-sun milk, lotion, gel or foam for skin or scalp care, serum, mask or after-shave composition).

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

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

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 required to obtain a sunburn (erythematogenic) with a sun protection composition and the minimum time without a sun protection composition to obtain said sunburn. More specifically, 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).

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 to be ideal.

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)”.

- "UVAPF" means: the index characterizing protection against UVA radiation. In particular, this index could be measured in vivo using the PPD (Persistent Pigment Darkening) method: "PPD" measures the skin color observed 2 to 4 hours after exposure to UVA. This method has been adopted since 1996 by the Japan Cosmetic Industry Association (JCIA) as the official test procedure 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 the effectiveness of UVA protection issued on November 21, 1995 and in force since January 1, 1996). The evaluation of UVA protection can also be measured in vitro with the Labsphere® spectrophotometer. The plate is the material on which the sunscreen composition is applied. For this protocol, polymethyl methacrylate (PMMA) sheets have proven to be ideal. The ISO 24443 protocol describes such an in vitro method.

Cosmetic processes and uses

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, in particular human materials such as the skin, and/or fibers, in particular human materials such as the hair, of a composition according to the invention comprising the bismuth oxycarbonate particles i) as defined above.

According to yet another of its aspects, the present invention also relates to the non-therapeutic cosmetic use of a cosmetic composition according to the invention comprising the bismuth oxycarbonate particles i) defined above, to prevent the appearance on the skin, in particular on the face, neckline, arms, hands and/or shoulders, of darker and/or more colored spots giving the skin a color heterogeneity.

The present invention also relates to a non-therapeutic cosmetic process for limiting the darkening of the skin and/or improving the color and/or uniformity of the complexion comprising the application to the surface of the keratin material of at least one cosmetic composition according to the invention comprising the bismuth oxycarbonate particles i) defined above.

The present invention further relates to the non-therapeutic cosmetic use of a cosmetic composition according to the invention comprising the bismuth oxycarbonate particles i) defined above, to prevent premature aging of the skin, in particular the skin of the face, décolleté, arms, hands and/or shoulders.

It also relates to a non-therapeutic cosmetic process for preventing and/or treating the signs of aging of a keratin material comprising the application to the surface of the keratin material of at least one cosmetic composition according to the invention comprising the bismuth oxycarbonate particles i) defined above.

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 or the appearance on the skin of darker and/or more colored spots giving the skin a heterogeneity of color and/or premature aging of the skin. In the description and examples, the percentages are percentages by weight. The ingredients are mixed, in the order and under the conditions easily determined by a person skilled in the art.

The invention will now be described by means of the following examples given of course as illustrations and not as limitations of the invention.

represents the UV-visible absorbance spectra of the composition of Example 1, (dispersion A1 of i) bismuth oxycarbonate particles and ii) polyglyceryl-10 laurate with a mass ratio R (BiO) ₂ CO ₃ /polyglyceryl-10 laurate equal to 1), and of polyglyceryl-10 laurate alone, in water.

represents the UV-visible absorbance spectra of the composition of Example 2, (dispersion A2 of i) bismuth oxycarbonate particles and ii) polyglyceryl-10 laurate with a mass ratio R (BiO) ₂ CO ₃ /polyglyceryl-10 laurate equal to 2), and of polyglyceryl-10 laurate alone, in water.

represents the UV-visible absorbance spectrum of the composition of Example 3, (dispersion B1 of i) bismuth oxycarbonate particles and ii) sodium lauryl ether sulfate with a mass ratio R (BiO) ₂ CO ₃ /sodium lauryl ether sulfate equal to 1), and sodium lauryl ether sulfate alone, in water.

represents the UV-visible absorbance spectra of the composition of Example 4, (dispersion B2 of i) bismuth oxycarbonate particles and ii) sodium lauryl ether sulfate with a mass ratio R (BiO) ₂ CO ₃ /sodium lauryl ether sulfate equal to 2), and sodium lauryl ether sulfate alone, in water.

represents the UV-visible absorbance spectra of the composition of Example 5, (dispersion C1 of i) bismuth oxycarbonate particles and ii) sodium docusate with a mass ratio R (BiO) ₂ CO ₃ / sodium docusate equal to 1) and sodium docusate alone, in water.

represents the UV-visible absorbance spectra of the composition of Example 6, (dispersion C2 of i) bismuth oxycarbonate particles and ii) sodium docusate with a mass ratio R (BiO) ₂ CO ₃ / sodium docusate equal to 2) and sodium docusate alone, in water.

represents the UV-visible absorbance spectra of the composition of Example 7, (dispersion G1 of i) bismuth oxycarbonate particles and ii) oleic acid with a mass ratio R (BiO) ₂ CO ₃ /oleic acid equal to 1), and of oleic acid alone, in caprylic/capric triglyceride.

represents the UV-visible absorbance spectra of the composition of Example 8, (dispersion G2 of i) bismuth oxycarbonate particles and ii) oleic acid with a mass ratio R (BiO) ₂ CO ₃ /oleic acid equal to 100), and of oleic acid alone, in caprylic/capric triglyceride.

represents the UV-visible absorbance spectra of the composition of Example 9, (dispersion H1 of i) bismuth oxycarbonate particles and ii) lauric acid with a mass ratio R (BiO) ₂ CO ₃ /lauric acid equal to 1), and of lauric acid alone, in caprylic/capric triglyceride.

represents the UV-visible absorbance spectra of the composition of Example 10, (H2 dispersion of i) bismuth oxycarbonate particles and ii) lauric acid with a mass ratio R (BiO) ₂ CO ₃ /lauric acid equal to 20), and of lauric acid alone, in caprylic/capric triglyceride.

represents the UV-visible absorbance spectra of the composition of Example 11, (dispersion I1 of i) bismuth oxycarbonate particles and ii) sodium docusate with a mass ratio R (BiO) ₂ CO ₃ / sodium docusate equal to 1), and of sodium docusate alone, in caprylic/capric triglyceride.

represents the UV-visible absorbance spectrum of the composition of Example 12, (dispersion I2 of i) bismuth oxycarbonate particles and ii) sodium docusate with a mass ratio R (BiO) ₂ CO ₃ / sodium docusate equal to 20).

EXAMPLES

Preparation of bismuth oxycarbonate powder i):

The bismuth oxycarbonate particles used in the compositions according to the invention described below are prepared by solvothermal synthesis, according to the following processes:

Protocol No. 1:

A solution of bismuth nitrate pentahydrate Bi(NO ₃ ) ₃ ·5H ₂ O (0.04 M) and D-mannitol (0.25 M) is prepared in 50 mL of water and stirred until the reagents are completely dissolved.

10 mL of a saturated solution of ammonium carbonate (21 equivalents relative to bismuth) is then added. A white solid precipitates. This mixture is then transferred to a Teflon autoclave reactor and heated for 12 hours at 100 °C.

The product obtained is isolated by centrifugation and washed 5 times alternately with water and ethanol, before being dried in an oven at 60°C.

The product is isolated as a white powder

Protocol No. 2:

A solution of bismuth nitrate pentahydrate Bi(NO ₃ ) ₃ ·5H ₂ O (0.40 M) and D-mannitol (2.0 M) is prepared in 800 mL of water and stirred until the reagents are completely dissolved.

160mL of an ammonium carbonate solution (2.1 equivalents relative to bismuth) are then added. A white solid precipitates. After 30 minutes, this mixture is then transferred to a Teflon autoclave type reactor and heated for 12 hours at 150°C.

The product obtained is isolated by centrifugation and washed 3 times with water before being dried in an oven at 60°C.

The product is isolated as a white powder.

Morphology and size of bismuth oxycarbonate particles i) in accordance with the invention

The particle morphology for each product prepared according to protocol 1 or 2 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 carbon surface layer) and dried in ambient air.

The observation was carried out with a Hitachi HT 7700 transmission electron microscope at an accelerating voltage of 100 kV.

Mean dimensions are obtained via particle size measurement by image analysis using ImageJ software ( CA Schneider, WS Rasband, KW Eliceiri, NIH Image to ImageJ: 25 years of image analysis, Nat. Methods. 9 671–675 (2012) ).

The results are grouped in the following Table 1.
particle i)
Morphology Average Dimensions (nm) Average length L Average width l Average thickness e Protocol 1 Platelets 106 66 41 Protocol 2 Platelets 85 52 28

The largest average dimension of particles prepared according to protocols 1 and 2 is less than 400 nm.

Examples of aqueous compositions according to the invention

Preparation of the compositions according to the invention:

A stock solution of surfactant ii) with a mass concentration of 1.0% is prepared in the aqueous phase iii) indicated in the tables below by stirring until completely dissolved (the temperature and/or pH being adjusted beforehand if necessary). The necessary mass (or weight) of this solution is taken and diluted in the same phase to reach the desired final concentration.

The powder of bismuth oxycarbonate particles i) prepared previously is then added at a mass concentration of 0.1% in the diluted surfactant solution ii) in the solvent S. The mixture is homogenized then placed under ultrasound (Prolabo TP 680/DH) at 100% power continuously for 15 minutes, and finally placed under magnetic stirring at 600 rpm for approximately 24 hours.

The dispersion thus obtained is noted X_nin the table below: Dispersion according to the invention Protocol for the preparation of bismuth oxycarbonate particles i)
Surfactant ii)
iii) aqueous phase
Ratio R i) / ii) A1 1 Polyglyceryl-10-laurate Water 1 A2 1 Polyglyceryl-10-laurate Water 2 B1 1 Sodium lauryl ether sulfate Water 1 B2 1 Sodium lauryl ether sulfate Water 2 C1 2 Docusate sodium Water 1 C2 2 Docusate sodium Water 2

The X _n dispersions thus prepared were characterized by UV/Visible spectrophotometry, by dynamic light scattering, and by analytical centrifugation.

Characterizations by UV/Visible spectrophotometry of aqueous compositions A1, A2, B1, B2, C1, C2 according to the invention

Method

Each of the dispersions A1, A2, B1, B2, C1 and C2 is diluted by adding deionized water so that the final mass concentration of bismuth oxycarbonate is equal to 0.01%, then placed under magnetic stirring at 600 rpm for 20 min before carrying out the absorbance measurement.

The quartz cell used for the measurements is 1 cm on each side. The absorbance spectra are recorded using a UV-2600 UV-Vis Spectrophotometer (Shimadzu). The baseline determination is carried out beforehand on a quartz cell containing water.

For each dispersion, the absorbance spectrum obtained is compared to the spectrum of the surfactant ii) alone, solubilized in water at the same concentration as in the dispersion.

The absorbance spectra are given in the figures at 6.

It appears according to the spectrum that the aqueous composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 1.5 around 300 nm.

It appears according to the spectrum that the aqueous composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 1.5 around 300 nm.

It appears according to the spectrum that the aqueous composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 1.5 around 300 nm.

It appears according to the spectrum that the aqueous composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 1.5 around 300 nm.

It appears according to the spectrum that the aqueous composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 1.5 around 300 nm.

It appears according to the spectrum that the aqueous composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 1 around 300 nm.

Size measurements by dynamic light scattering (DLS) of aqueous compositions A1, A2, B1, B2, C1, C2 according to the invention

Method

The particle size distribution of the dispersions is determined by dynamic light scattering using a ZetaSizer Nano-ZS device (model ZEN3600) marketed by Malvern Panalytical, the detection angle being set at 173°. The technique is particularly suitable for the characterization of submicron-sized objects.

For each of the aqueous dispersions A1, A2, B1, B2, C1 and C2, an aliquot is taken and diluted in water until reaching a mass concentration of bismuth oxycarbonate particles i) close to 10 ^-4 %. The diluted sample is introduced into a single-use cuvette (DTS0012 from Malvern) and placed in the measuring compartment. After temperature equilibration for 10 minutes at 25 °C, 6 consecutive measurements are carried out. The viscosity of water at 25 °C is considered equal to 0.8872 cP.

• le paramètre « Z-average » correspond au diamètre hydrodynamique moyen des objets pondéré par l’intensité, en d’autres termes, il correspond au « diamètre » moyen des particules ;
• l’indice de polydispersité (PDI) qui est associé au calcul du Z-average et estime la largeur de la distribution de taille.

The CUMULANTS algorithm included in Zetasizer Software 7.13 (Malvern Panalytical) is used for raw data analysis. It allows to determine:

• the “Z-average” parameter corresponds to the average hydrodynamic diameter of the objects weighted by the intensity, in other words, it corresponds to the average “diameter” of the particles;
• the polydispersity index (PDI) which is associated with the calculation of the Z-average and estimates the width of the size distribution.

The results obtained are averaged over the 6 measurements.

Z-average and polydispersity index of dispersions A1, A2, B1, B2, C1 and C2 Dispersion Surfactant ii) Ratio R i) /ii) Z-average (nm) PDI A1 Polyglyceryl-10 laurate
1/1 154 0.15 A2 Polyglyceryl-10 laurate
1/0.5 156 0.14 B1 Sodium lauryl ether sulfate
1/1 176 0.18 B2 Sodium lauryl ether sulfate 1/0.5 207 0.25 C1 Docusate sodium 1/1 243 0.36 C2 Docusate sodium 1/0.5 254 0.35

The results show that the particles are well dispersed in the compositions according to the invention, and that the average size of the objects is less than 400 nm.

Thus, the results show that the particles form little or no agglomerates within the compositions according to the invention. The compositions according to the invention limit bleaching.

Evaluation of the stability by analytical centrifugation of aqueous compositions A1, A2, B1, B2, C1, C2 according to the invention

Method

An analytical centrifuge LUMiSizer (model 651) marketed by LUM GmbH is used to analyze the stability of dispersions with respect to sedimentation. The operation of the LUMiSizer is based on the combination of centrifugation and STEP technology (Space and Time resolved Extinction Profiles), which consists of measuring the light transmitted over the entire height of the tube containing the sample over time. The wavelength of the light source is set at 410 nm.

Dispersions A1, A2, B1, B2, C1 and C2 with a mass concentration of 0.1% bismuth oxycarbonate are introduced into 10 mm thick polycarbonate tubes (reference 110-132xx, LUM GmbH), and centrifuged at a rotation speed of 2000 rpm (corresponding to an average relative centrifugal acceleration of 520*g) and a temperature of 25°C for 5 minutes. During the measurement, the transmission profiles along the longitudinal direction of the tubes are recorded every 10 seconds.

The data are analyzed using SEPView 6 software (LUM GmbH). The amplitude of the sedimentation phenomena involved in the different dispersions is quantified by determining the instability index, the definition of which is given in the technical document: "Instability Index", T. Detloff, T. Sobisch, D. Lerche - Dispersion Letters Technical, T4 (2013) 1-4, Update 2014. This index is a dimensionless number, between 0 and 1. It is equal to 0 when the sample is stable, i.e. the transmission profiles remain unchanged over time. On the contrary, it is equal to 1 when the particles have completely sedimented. The instability indices of dispersions A1, A2, B1, B2, C1 and C2 after 5 minutes of centrifugation at 2000 rpm are calculated over the region of interest ranging from longitudinal positions 107 to 125 mm.

Dispersion instability indices A1, A2, B1, B2, C1 and C2 Dispersion Surfactant ii) Ratio R i)/ii) Instability index Reference Bismutite without additives Not applicable 0.97 A1 Polyglyceryl-10-laurate 1/1 0.28 A2 Polyglyceryl-10-laurate 1/0.5 0.29 B1 Sodium lauryl ether sulfate 1/1 0.34 B2 Sodium lauryl ether sulfate 1/0.5 0.35 C1 Docusate sodium 1/1 0.35 C2 Docusate sodium 1/0.5 0.45

It appears from the results recorded in Table 4 that the instability indices of the compositions according to the invention are significantly lower than that of the bismutite dispersion without surfactant, which shows that the presence of the surfactant makes it possible to reduce sedimentation phenomena and therefore improve the stability of the compositions.

Examples of oily compositions according to the invention

The compositions are prepared as previously described for the aqueous compositions, replacing the aqueous phase iii) with the fatty phase iv) which is caprylic/capric triglyceride.

The dispersions thus obtained are noted X_nin table 5 below: Dispersion according to the invention Particle preparation protocol i) Surfactant ii) Fatty phase iv) - fatty substances Ratio R i) / ii) G1 2 Oleic acid caprylic/capric triglyceride 1 G2 2 Oleic acid caprylic/capric triglyceride 100 H1 2 Lauric acid caprylic/capric triglyceride 1 H2 2 Lauric acid caprylic/capric triglyceride 20 I1 2 Docusate sodium caprylic/capric triglyceride 1 I2 2 Docusate sodium caprylic/capric triglyceride 20

The Xn dispersions thus prepared were characterized by UV/Visible spectrophotometry, by dynamic light scattering, and by analytical centrifugation.

Characterizations by UV/Visible spectrophotometry of the oily compositions according to the invention G1, G2, H1, H2, I1, I2

Method

Each of the dispersions G1, G2, H1, H2, I1 and I2 is diluted by adding caprylic/capric triglyceride so that the final mass concentration of bismuth oxycarbonate i) is equal to 0.01%, then placed under magnetic stirring at 600 rpm for 20 min before carrying out the absorbance measurement.

The quartz cell used for the measurements is 1 cm on each side. The absorbance spectra are recorded using a UV-2600 UV-Vis Spectrophotometer (Shimadzu). The baseline determination is carried out beforehand on a quartz cell containing caprylic/capric triglyceride.

For each dispersion, the absorbance spectrum obtained is compared to the spectrum of the surfactant ii) alone, solubilized in caprylic/capric triglyceride at the same concentration as in the dispersion.

Absorbance spectra of associations G1, G2, H1, H2, I1 and I2

The absorbance spectra are given in the figures has .

It appears according to the spectrum that the oily composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 0.5 around 300 nm.

It appears according to the spectrum that the oily composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 0.5 around 300 nm.

It appears according to the spectrum that the oily composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 0.5 around 300 nm.

It appears according to the spectrum that the oily composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 0.5 around 300 nm.

It appears according to the spectrum that the oily composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 0.5 around 300 nm.

It appears according to the spectrum that the oily composition effectively absorbs UV between 200 and 550 nm with an absorbance threshold greater than 0.5 around 300 nm.

Dynamic light scattering (DLS) size measurements of associations G1, G2, H1, H2, I1 and I2

Method

The particle size distribution of the dispersions is determined by dynamic light scattering using a ZetaSizer Nano-ZS device (model ZEN3600) marketed by Malvern Panalytical, the detection angle being set at 173°. The technique is particularly suitable for the characterization of submicron-sized objects.

For each of the dispersions G to I, an aliquot is taken and diluted in caprylic/capric triglyceride until a mass concentration of bismuth oxycarbonate particles i) close to 10 ^-4 % is reached. The diluted sample is introduced into a glass cuvette (model 100-OS, Hellma) and placed in the measuring compartment. After temperature equilibration for 10 minutes at 25°C, 6 consecutive measurements are carried out. The viscosity of caprylic/capric triglyceride at 25°C is considered equal to 20 cP.

• le paramètre « Z-average »correspond au diamètre hydrodynamique moyen des objets pondéré par l’intensité,
• l’indice de polydispersité (PDI) qui est associé au calcul du Z-average et estime la largeur de la distribution de taille.

The CUMULANTS algorithm included in Zetasizer Software 7.13 (Malvern Panalytical) is used for raw data analysis. It allows to determine:

• the “Z-average” parameter corresponds to the average hydrodynamic diameter of the objects weighted by the intensity,
• the polydispersity index (PDI) which is associated with the calculation of the Z-average and estimates the width of the size distribution.

The results obtained are averaged over the 6 measurements. The results are recorded in Table 6 below. Z-average and polydispersity index of dispersions G to I. Dispersion Surfactants ii) Ratio i)/ii) Z-average (nm) PDI G1 Oleic acid 1/1 408 0.18 G2 Oleic acid 1/0.01 259 0.23 H1 Lauric acid 1/1 365 0.25 H2 Lauric acid 1/0.05 335 0.27 I1 Docusate sodium 1/1 276 0.29 I2 Docusate sodium 1/0.05 294 0.30

The results show that the particles are well dispersed in the compositions according to the invention, and that the average size of the objects is less than 400 nm.

Thus, the results show that the particles form little or no agglomerates within the compositions according to the invention. The compositions according to the invention limit bleaching.

Evaluation of stability by analytical centrifugation

Method

An analytical centrifuge LUMiSizer (model 651) marketed by LUM GmbH is used to analyze the stability of dispersions with respect to sedimentation. The operation of the LUMiSizer is based on the combination of centrifugation and STEP technology (Space and Time resolved Extinction Profiles), which consists of measuring the light transmitted over the entire height of the tube containing the sample over time. The wavelength of the light source is set at 410 nm.

Dispersions G to I with a mass concentration of 0.1% bismuth oxycarbonate are introduced into 10 mm thick polyamide tubes (reference 110-135xx, LUM GmbH), and centrifuged at a rotation speed of 2000 rpm (corresponding to an average relative centrifugal acceleration of 520*g) and a temperature of 25°C for 30 minutes. During the measurement, the transmission profiles along the longitudinal direction of the tubes are recorded every 10 seconds.

The data are analyzed using SEPView 6 software (LUM GmbH). The amplitude of the sedimentation phenomena involved in the different dispersions is quantified by determining the instability index, the definition of which is given in the technical note: "Instability Index", T. Detloff, T. Sobisch, D. Lerche - Dispersion Letters Technical, T4 (2013) 1-4, Update 2014. This index is a dimensionless number, between 0 and 1. It is equal to 0 when the sample is stable, i.e. the transmission profiles remain unchanged over time. On the contrary, it is equal to 1 when the particles have completely sedimented. The instability indices of dispersions G to I after 30 minutes of centrifugation at 2000 rpm are calculated on the region of interest ranging from longitudinal positions 107 to 125 mm.

Dispersion instability index G to I Example Dispersion Surfactant ii) Ratio i)/ii) Instability index 7 Reference Bismutite without additives Not applicable 0.62 8 G1 Oleic acid 1/1 0.46 9 G2 Oleic acid 1/0.01 0.48 10 H1 Lauric acid 1/1 0.62 11 H2 Lauric acid 1/0.05 0.54 12 I1 Docusate sodium 1/1 0.34 13 I2 Docusate sodium 1/0.05 0.34

It appears from the results recorded in Table 7 that the instability indices of the compositions according to the invention are significantly lower than those of bismutite dispersion without surfactant. The presence of surfactant(s) therefore makes it possible to significantly reduce sedimentation phenomena and improve the stability of the compositions.

Claims (19)

Use of:
(i) one or more particles of bismuth oxycarbonate of formula (I): (BiO) _{2- x} (CO ₃ ), formula (I) as well as its solvates such as hydrates, in which -0.4 < x < 0.6, the largest average dimension of said particles being less than 400 nm;
(ii) at least one surfactant;
it being understood that:
- the mass ratio R of the sum of i) the bismuth oxycarbonate particles to ii) the sum of the surfactants is greater than or equal to 1, preferably R > 1
- when the surfactant is polysorbate 20:
then R is different from 2/0.29; for UV filtration, in particular UV-A and/or UV-B, in particular UV-B filters. Use according to the preceding claim in which i) the particle(s) of bismuth oxycarbonate of empirical formula (I) is (are) crystallized. Use according to any one of the preceding claims, wherein i) the bismuth oxycarbonate particle(s) is(are) of formula (BiO) ₂ (CO ₃ ). Use according to any one of the preceding claims, in which the largest average dimension of i) the particle(s) of bismuth oxycarbonate of empirical formula (I) is (are) less than or equal to 300 nm. Use according to any one of the preceding claims wherein i) the bismuth oxycarbonate particle(s) of empirical formula (I) is (are) in the form of tubes, platelets and/or rods, particularly platelets and/or rods;
preferentially, said particle(s) i) is/are predominantly or exclusively in the form of platelets, and has/have an average length L ranging from 15 to 300 nm, in particular ranging from 30 to 250 nm; an average width l ranging from 10 to 250 nm, in particular ranging from 20 to 200 nm, and an average thickness e ranging from 2 to 120 nm, in particular ranging from 5 to 100 nm; and with e < l <L;
or else the said particle(s) i) is/are predominantly or exclusively in the form of rods, and has/have an average length L ranging from 30 to 300 nm, in particular ranging from 50 to 250 nm; a diameter d ranging from 15 to 150 nm, in particular ranging from 20 to 130 nm; and with L >d;
or else the said particle(s) i) is/are predominantly or exclusively in the form of tubes, and has/have an average length L ranging from 10 to 300 nm; in particular ranging from 20 to 250 nm; a diameter d ranging from 2 to 30 nm, in particular ranging from 3 to 20 nm; and with L > d . Use according to any one of the preceding claims, in which ii) the surfactant(s) is (are) chosen from nonionic and anionic surfactants. Use according to any one of the preceding claims, in which ii) the surfactant(s) is (are) chosen from:
ii-1) nonionic surfactants chosen from those comprising one or more ester groups, one or more hydroxy groups, and comprising from 10 to 50 carbon atoms, more particularly between 20 and 42 carbon atoms and more than 4 hydroxy groups, preferably between 10 and 25 hydroxy groups such as polyglyceryl-10 laurate;
ii-2) anionic surfactants chosen from saturated or unsaturated fatty acids, the hydrocarbon chain possibly being linear or branched, preferably comprising from 6 to 24 carbon atoms, particularly from 10 to 20 carbon atoms, more particularly from 12 to 18 carbon atoms such as stearic, oleic and lauric acids, preferably of natural origin, particularly plant-based, such as stearic acid, oleic acid and lauric acid; more preferably oleic acid and lauric acid possibly being in the form of salts of alkali metals, ammonium, amino alcohols and alkaline earth metals, or a mixture of these compounds;
ii-3) the anionic surfactants chosen from alkyl sulfates, alkyl ether sulfates the alkyl groups of the surfactants can be linear or branched, interrupted by one or more heteroatoms or groups chosen from O, S, N, C(O) or their association such as esters such as docusates in particular of alkali or alkaline earth metals including sodium docusate, these surfactants can in particular be oxyethylenated and then preferably comprise from 1 to 50 ethylene oxide units more particularly alkyl ether sulfates such as lauryl ether sulfates in particular of alkali or alkaline earth metals including sodium lauryl ether sulfate. Use according to any one of the preceding claims, in which the mass ratio R i) /ii) is between 1/1 and 1/0.001, preferably between 1/1 and 1/0.005, more preferably between 1/1 and 1/0.01; more particularly is between 1 and 200, more particularly between 1 and 100, better still between 1.01 and 200, even better still between 1.1 and 100. Use according to any one of the preceding claims, for the protection of keratin materials, in particular human materials such as skin and/or keratin fibers, in particular human materials such as hair. Composition, in particular cosmetic, comprising:
(i) one or more bismuth oxycarbonate particles as defined in any one of claims 1 to 5;
ii) one or more surfactants as defined in any one of claims 6 or 7;
it being understood that:
- the mass ratio R particles i) / surfactant(s) ii) is greater than or equal to 1, preferably the mass ratio R i) /ii) is between 1/1 and 1/0.001, more preferably between 1/1 and 1/0.005, even more preferably between 1/1 and 1/0.01, more particularly is between 1 and 200, better still between 1.01 and 200, even more particularly between 1 and 100; even better still between 1.1 and 100;
- where the composition contains ii) oleic acid then the composition does not contain polyvinylpyrrolidone, and
- when the surfactant is polysorbate 20 then R is different from 2/0.29. Composition according to the preceding claim in which i) the particle(s) of bismuth oxycarbonate is (are) present in the composition, in a content greater than or equal to 0.05% by weight, relative to the total weight of the composition, particularly in a content of between 0.05% and 80% by weight relative to the total weight of the composition, preferably from 0.08% to 75%, more particularly between 0.5% to 40% by weight, preferably from 1% to 30% by weight, more preferably from 2% to 20% by weight relative to the total weight of the composition. Composition according to claim 10 or 11, in which the amount of surfactant(s) ii) ranges from 0.001% to 10% by weight, in particular from 0.01% to 5% by weight, and more particularly from 0.05 to 3% by weight, more preferably between 0.5% and 1% by weight relative to the total weight of the composition. Composition according to any one of claims 10 to 12, which comprises iii) at least one aqueous phase, preferably the composition is aqueous i.e. comprises water and optionally one or more water-miscible solvents. Composition according to any one of claims 10 to 13, which comprises iv) at least one fatty phase, i.e. which comprises one or more fatty substances different from the anionic surfactant fatty acid(s) ii); in particular the fatty phase is an oily phase; preferably the fatty phase comprises one or more oil(s). Composition according to any one of claims 10 to 14 which comprises one or more oil(s) chosen from hydrocarbon oils chosen from triglycerides consisting of esters of fatty acids and glycerol, in particular the fatty acids of which may have chain lengths varying from C ₄ to C ₃₆ , and in particular from C ₁₈ to C ₃₆ , these oils being able to be linear or branched, saturated or unsaturated; particularly heptanoic or octanoic triglycerides, caprylic/capric acid triglycerides; vegetable oils such as wheat germ, sunflower, grape seed, sesame, corn, apricot kernel, castor, shea, avocado, olive, soybean, sweet almond, palm, rapeseed, cottonseed, hazelnut, macadamia, jojoba, alfalfa, poppy, pumpkin, squash, blackcurrant, evening primrose, millet, barley, quinoa, rye, safflower, candlenut, passionflower, musk rose, peanut, coconut, argan, passionflower, kaya; the liquid fraction of shea butter, and the liquid fraction of cocoa butter; and their mixtures According to one embodiment, the non-volatile hydrocarbon oil(s) comprise or consist of at least one non-volatile oil chosen from triglycerides consisting of fatty acid esters and glycerol, in particular the fatty acids of which may have chain lengths varying from C ₄ to C ₃₆ , and in particular from C ₈ to C ₃₆ , these oils possibly being linear or branched, saturated or unsaturated as described above, preferably chosen from heptanoic or octanoic triglycerides, caprylic/capric acid triglycerides and their mixtures and in addition preferentially the oil(s) is (are) chosen from caprylic/capric acid triglycerides. A composition according to any one of claims 10 to 15, which comprises
at least one compound selected from: v) UV filters distinct from bismuth oxycarbonate particles i); vi) coloring matters; vii) cosmetic active ingredients for the care of keratin materials; viii) thickeners and ix) adjuvants; and mixtures thereof. Process for treating keratin materials, in particular human materials, such as skin, and/or keratin fibers, in particular human materials, such as hair, implementing the application:
(i) at least one particle of bismuth oxycarbonate of empirical formula (I) as defined in any one of claims 1 to 5, and
ii) at least one surfactant as defined in any one of claims 6 to 8; it being understood that:

• the mass ratio R i)/ii) is greater than or equal to 1, preferably R > 1, particularly as defined in claim 8; and
• when the surfactant is polysorbate 20 then R is different from 2/0.29.

Cosmetic process according to the preceding claim comprising the application to keratin materials, in particular human materials such as the skin and/or keratin fibers, in particular human materials such as the hair, of at least one cosmetic composition as defined in any one of claims 10 to 16. Method according to claim 17 or 18 for filtering UV radiation, in particular UV-B, in particular for the protection of keratin materials, in particular human, in particular skin and/or keratin fibers, in particular human, such as hair.