WO2011045746A2 - A composition comprising a dispersion of photonic particles; methods of treating various materials - Google Patents

Abstract

Exemplary embodiments of the invention provide a composition, in particular cosmetic, comprising a dispersion of photonic particles each having a form factor of less than 2, said particles comprising a diffracting arrangement of voids or monodisperse nanoparticles in a thermo-, electro- or photo- crosslinkable matrix. The present invention also provides a method of photo-protecting a material solar UV radiation, comprising treating said material with a composition as defined above or comprising integrating said composition into said material. More particularly, exemplary embodiments of the invention provide methods of photo-protecting materials such as paints, inks, coatings, materials manufactured from polymers, fibrous materials such as textiles, or papers, or organic or mineral glasses. Exemplary embodiments of the invention also provide a method of photo-protecting human keratinous material against solar UV radiation, a method of coloring and/or lightening human keratinous material and a method of modifying the spectral reflectance of human keratinous materials employing said composition.

Description

A COMPOSITION COMPRISING A DISPERSION OF PHOTONIC PARTICLES; METHODS OF TREATING VARIOUS MATERIALS

The invention relates to compositions comprising photonic particles as well as to methods of treating various materials with said photonic particles. Further, the invention relates to compositions and methods of treating human keratinous materials.

Prior art

Current photoprotective compositions use

combinations of various screening agents, especially soluble or insoluble organic screens. The absorption spectrum of each of said screens is rarely broad enough to cover the whole UV spectrum, and combinations are necessary.

Further, a large number of soluble organic screens may cause compatibility problems with the ingredients usually contained in them, especially as a result of interactions with other organic screens or with active molecules such as antioxidants or vitamins, and their photostability may not be entirely satisfactory. Many patents are concerned with solving this problem,

indicating that this problem is recurrent.

Many non-cosmetic industry sectors also use UV screens to photoprotect various materials against the effects of UV radiation, in particular solar radiation.

This applies in particular with paint, ink, or protective coating formulations for applying to

substances that are permanently exposed to UV radiation, such as building materials, materials used in the

automobile industry, or plastic packaging materials. In particular, UV screens are being developed for colorant formulations, which screens need to be transparent, photostable, compatible with the usual ingredients contained in said formulations, and effective in

providing the color with the desired resistance to light. This also applies with polymer compositions used in particular in the manufacture of plastics materials that are stable in storage; they need the development of UV light screens that are particularly adapted to methods of manufacturing and transforming polymers, and in

particular they have to be able to tolerate the high temperatures used in extrusion.

In the natural fiber, artificial fiber or synthetic fiber industry, broad spectrum photostable UV screens are being developed that are compatible with methods of manufacturing said fibers, in particular in the context of the manufacture of polyamide fibers such as nylon, which filters are resistant to high temperatures and enable UV protection to be incorporated during extrusion. Further, UV screens are being developed that have good affinity, good adhesion to fibers, and thus in particular that provide good resistance to frequent washing. The UV screens being developed must also provide both good protection of the textile fibers and also of the skin and other human keratinous material in contact with said fibers .

Similar problems also arise in the manufacture of paper, generally formed from cellulose fibers, where the UV screens used must be photostable, transparent, and compatible with the other usual ingredients, and also adapted to the various paper manufacturing techniques.

The mineral or organic glass industry, in particular glass used in ophthalmology, is developing UV screens that are to have a broad spectrum (active in the UVA and in the UVB regions) , and that are photostable,

transparent, and compatible with the various techniques for treating glass such as methods of keying onto the glass matrix or applying a photoprotective coating, for example with polycarbonate glass.

Application WO 06/136724 shows that it is known to use monodisperse particles that are capable of forming a lattice and that have optical screening properties in the UVB, UVA and infrared. In that application, the

particles have to become organized on the skin.

In the publication by J. Wang, Polym Int 57:509 - 514, 2008, the authors produced monodisperse PMMA spheres with various diameters (95 nm, 114 nm, 134 nm, 142 nm and 150 nm) . Each diameter corresponded to a reflection maximum (250 nm, 280 nm, 330 nm, 350 nm, 380 nm) when the particles are organized into a lattice.

Application WO 08/007267 describes the use of hollow particles that are capable of becoming organized into a photonic crystal for makeup and UV photoprotection applications .

Applications US 2003/0116062 and US 2006/0002875 describe photonic particles.

Patent US 6 894 086 describes photonic particles comprising a matrix, said particles in particular being colored or reflecting electromagnetic radiation outside the visible spectrum.

The publication by A. Stein (Chem. Mater. 2002, 14, 3305 - 3315) discloses photonic particles having a reflection band in the long UVA spectrum (374 nm) .

There is a need to benefit from non-soluble

screening materials that can be used to cover the UVA and/or UVB spectrum, that are completely harmless, inert towards the environment, photostable, and not

photoreactive, and that do not have compatibility

problems with the other constituents of the compositions containing them, do not modify the mechanical properties of the materials of the packaging in a negative manner, and do not release nanoparticles , and that are

transparent to visible light.

There is also a need to develop novel materials that screen UV radiation and that are adapted to

photoprotecting materials such as those mentioned above.

The invention aims to achieve all or some of these obj ects . Exemplary embodiments of the invention provide a composition comprising a dispersion of photonic particles each having a form factor of less than 2, said particles comprising a diffracting arrangement of voids or

monodisperse nanoparticles in a thermo-, electro- or photo-crosslinkable matrix.

More particularly, exemplary embodiments of the invention provide a cosmetic composition comprising, in a cosmetically acceptable medium, at least one dispersion of photonic particles each having a form factor of less than 2, said particles comprising a diffracting

arrangement of voids or monodisperse nanoparticles in a thermo-, electro- or photocrosslinkable matrix.

Furthermore, other exemplary embodiments of the invention provide a method of photoprotecting a material against solar UV radiation, comprising treating said material with a composition comprising a dispersion of photonic particles as defined above or comprising

integrating at least said composition into said material.

More particularly, exemplary embodiments of the invention provide:

• a method of photoprotecting an ink, a paint, or a coating, comprising incorporating at least one

composition comprising a dispersion of photonic particles as defined above into said ink or paint or said coating;

• a method of photoprotecting a material

manufactured from at least one synthetic or natural polymer, comprising treating said polymer with a

composition comprising a dispersion of photonic particles as defined above or comprising integrating at least said composition into said material;

• a method of photoprotecting an organic or mineral glass, comprising treating said glass with at least one composition comprising a dispersion of photonic particles as defined above or comprising integrating at least said composition into said glass; • a method of photoprotecting a material comprising at least natural fibers and/or artificial fibers and/or synthetic fibers such as textiles or papers, comprising treating said fibers with at least one composition comprising a dispersion of photonic particles as defined above or comprising integrating at least said composition into said material.

The polymeric materials of the invention are, in particular plastic materials that are capable of being molded or worked, in general hot and under pressure, in order to result in a semimanufactured product or an article .

The polymers used for said materials are preferably selected from three major categories:

(i) thermoplastics such as, for example:

^• acrylonitrile-butadiene-styrene (ABS) copolymers;

^• cellulose acetate (CA) polymers;

^• expanded polystyrenes (EPS) ;

^• polystyrenes (PS) ;

· polyamides (PA) ;

^• polybutylene terephthalate (PBT) ;

^• polyethylene terephthalate (PET) ;

^• polycarbonates (PC) ;

^• polyethylenes (PE) ;

· polypropylenes (PP) ;

^• polymethyl methacrylate (PMMA) ;

^• polyformaldehydes (POM) ;

^• polyvinyl acetates (PVAC) ;

^• polyvinyl chlorides (PVC) ;

· styrene-acrylonitrile (SAN) copolymers;

( ii ) thermosets, such as:

^• polyepoxides (EP) ;

^• melamine-formaldehyde (MF) copolymers;

^• phenol-formaldehyde (PF) copolymers;

· cured polyurethanes (PUR) ;

^• urea-formaldehyde (UF) copolymers;

^• unsaturated polyesters. (iii) technical plastics such as:

^• polytetrafluoroethylene (PTFE) .

Examples of natural fibers that may be mentioned, for example, are:

· plant fibers such as cotton, linseed, hemp, jute, straw, or latex;

• animal fibers such as wool, silk, mohair, angora, cashmere or alpaca.

Artificial fibers are generally obtained by chemical treatment (dissolution then precipitation) of natural substances such as milk caseins for lanital, or cellulose from various plants (pine bark, bamboo, soya, birch) for viscose. These chemical treatments are intended to produce a product that can be spun (capable of passing through the small holes of a die) . At the die outlet, the filaments obtained are either combined to form continuous filaments in the manner of a silk thread, or are cut into discontinuous fibers in the manner of wool.

Examples of artificial fibers that may, for example, be mentioned are:

cellulose acetate;

cellulose triacetate; and

viscose .

Particular examples of textile fibers are:

· polylactic acid;

acrylic;

aramides ;

elasthane: ©Lycra;

chlorofiber ;

· modacrylic;

polyamide ;

polybenzimidazole ;

polyester;

polyethylene ;

· polyphenolic; and

polyurea: polyurethane . Examples of glasses that are suitable for use in the invention that may be mentioned are conventional mineral glasses based on silicates, glasses used for optics, glasses used for ophthalmology, especially organic glasses such as polycarbonates, for example bisphenol A polycarbonate or allyl polycarbonate, those used in the automobile industry (windshields), etc.

In particular, exemplary embodiments of the

invention provide a non-therapeutic, and in particular cosmetic, method of photoprotecting human keratinous material against solar UV radiation, comprising applying to the keratinous material a cosmetic composition

comprising a dispersion of photonic particles each having a form factor of less than 2, said particles comprising a diffracting arrangement of voids or monodisperse

nanoparticles in a thermo-, electro- or

photocrosslinkable matrix.

Other exemplary embodiments of the invention provide a composition for use in a method of photoprotection of human keratinous material against solar UV radiation, in particular in a method of reducing the risk of apparition of a skin cancer,

wherein said composition comprises a dispersion of photonic particles each having a form factor of less than 2, said particles comprising a diffracting arrangement of voids or monodisperse nanoparticles in a thermo-,

electro- or photocrosslinkable matrix.

This composition may present, unless the contrary is specified, all the properties of the cosmetic

compositions according to the invention described below.

Exemplary embodiments of the invention also provide:

• a method of coloring and/or lightening human keratinous material;

• a method of modifying the spectral reflectance of human keratinous material,

comprising applying to said keratinous material a

cosmetic composition comprising a dispersion of photonic particles each having a form factor of less than 2, said particles comprising a diffracting arrangement of voids or monodisperse nanoparticles in a thermo-, electro- or photocrosslinkable matrix.

In the context of the invention, the term

"diffracting arrangement" means a set of particles or voids diffracting incident light in a manner that screens UV and/or produces a coloration and/or modifies the spectral reflectance, depending on the application.

By way of example, the composition used in the photoprotection method in accordance with the invention has an SPF index of at least 10, preferably 15, more preferably at least 30, 45 or 60. The SPF index

(Sunscreen Protection Factor) is defined in the article "A new substrate to measure sunscreen protection factors throughout the ultraviolet spectrum", J. Soc. Cosmet. Chem., 40, 127 - 133 (May/June 1989).

The formulation of the composition is, for example, selected such that the composition has a transmission factor of 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5% or less, or preferably of 1% or less, for at least one wavelength in the range 250 nm to 400 nm, preferably over the whole of said range. Screening is much better when the

transmission factor is low in the range 250 nm to 400 nm.

Photonic particles

In the context of the invention, photonic particles are also known as opals.

The photonic particles may have a form factor of less than 2, especially less than 1.75. When the

particle is oblong, the form factor denotes the ratio of its largest longitudinal dimension to its largest

transverse dimension. The photonic particles may be spherical, then having a form factor of 1.

A form factor of less than 2 may have an advantage in terms of surface coverage compared with flat particles that may become superimposed. The mean size of the photonic particles may be in the range 1 ym to 500 ym, for example in the range 1 ym to 300 ym. The term "mean size" denotes the statistical grain-size dimension at half the population, termed D(0.5) .

The content by weight of photonic particles may be in the range 0.1% to 20%, preferably in the range 1% to 10%, relative to the total composition weight, before application .

The photonic particles of the invention comprise nanoparticles dispersed in any type of thermo-, electro- or photo-crosslinkable matrix.

The photonic particles of the invention may be categorized, according to the different embodiments of the invention, as direct, inverse or pseudo inverse opals, as described below.

The photonic particles may be solid or hollow.

Direct opals

Photonic particles of the "direct opal" type employ an arrangement of solid, optionally composite

nanoparticles .

The photonic particles 1 of the "direct opal" type comprise nanoparticles 10 dispersed, as shown in

Figure 1, in a thermo-, electro- or photo-crosslinkable matrix 20.

The advantage of using an organic photo-, electro- or thermocrosslinkable, especially photocrosslinkable or thermocrosslinkable, matrix is because it is possible to adjust the distance between the nanoparticles contained in the matrix in order to vary the optical properties of the photonic particle. This distance may be a function of the fraction by weight of the nanoparticles dispersed in the organic matrix, before photo-, electro- or thermocrosslinking, especially before photocrosslinking or thermocrosslinking. Said weight fraction is equal to the ratio of the weight of nanoparticles divided by the weight of matrix before thermocrosslinking, electro- crosslinking or photocrosslinking .

In a preferred implementation of the invention, this fraction of nanoparticles is in the range 1% to 90% by weight, preferably in the to 60% by weight.

This type of photonic particle may be obtained using several emulsification methods, for example those

described in the publication by S-H Kim et al, Adv.

Mater. 2008, 9999, 1 - 7, which employs silica particles dispersed in a photocrosslinkable ETPTA (ethoxylated trimethylolpropane triacrylate) resin that can be

photopolymerized under UV, or in the publication "Ordered macroporous titania photonic balls by micrometer-scale spherical assembly templating" by Li et al, J. Mater. Chem., 2005, 15, 2551 - 2556.

In certain implementational examples, the photonic particles comprise nanoparticles of polystyrene (PS) dispersed in a thermo-, electro- or photo-crosslinkable silicone matrix.

Inverse opals

Photonic particles of the "inverse opal" type comprise holes instead of nanoparticles.

They may be obtained from direct opals after

destroying nanoparticles, for example by calcining or acid hydrolysis, for example with 5% hydrofluoric acid, therewith leaving empty spaces in the place of all or part of the nanoparticles. The destruction step may possibly cause a reduction in the size of the imprint of the nanoparticle in the thermo-, electro- or photo^¬ crosslinkable matrix, of up to 50%.

Calcining (500°C or 1000°C) may be carried out on direct opals based on organic nanoparticles and an inorganic matrix.

Acid hydrolysis, for example with a hydrofluoric acid solution, may be carried out on opals based on inorganic nanoparticles and an organic thermo-, electro- or photo-crosslinkable matrix.

With inverse opals, the ratio of the volume occupied by the nanoparticles divided by the volume occupied by the thermo-, electro- or photo-crosslinkable matrix may vary over the range 99/1 to 80/20, thereby having the effect of causing the surface porosity of the inverse opals to vary. Such a variation is presented in the publication by D. Pine, F. Lange, Langmuir 2005, 21, 6669 - 6674. The inverse opals may be produced using the methods described above for direct opals comprising nanoparticles dispersed in a thermo-, electro- or photo- crosslinkable matrix, followed by a step of destroying nanoparticles, for example by calcining or acid

hydrolysis, for example as described in the following publications :

• A. Stein: Chem. Mater. 2002,14, 3305 - 3315, wherein opals are produced from monodisperse particles in zirconium acetate matrixes for ZrO articles, from Ti propoxide for T1O₂ opals, or from tetramethoxysilane (TMOS) for silica opals. After calcining, the PS

particles give way to voids. The final material is then milled to produce opal powder;

• D. Pine, F. F. Lange: Langmuir, Vol 21, 15,

2005,6669 - 6674, describing the production of opals in the form of spheres using a method of emulsification followed by a step of calcining PMMA particles. The porosity of the opal is controlled by the ratio: Ti alkoxides divided by the amount of PMMA particles;

· F. F. Lange, Colloid Polym. Sci. (2003) 282, 7 -

13, describing the emulsification of particles of PMMA in the presence of Ti butoxide then calcining the PMMA particles .

By their nature, inverse opals are, in the absence of an additional treatment, porous materials having optical properties that vary as a function of the medium, which can fill the holes in the opals. In order to guarantee their optical properties in any medium, photonic particles with an inverse opal structure may be coated and sealed against the medium into which they are immersed.

Said coating may, for example, be carried out using polymers or waxes.

Several methods are possible:

• spray drying: the principle is to dissolve or disperse (for latexes) the material that is to coat the photonic particles in a volatile solvent with an

evaporation point of 100°C or less (ethanol, acetone, isopropanol, water, etc, or mixtures thereof) . Spraying the ensemble into a chamber heated to a temperature that allows evaporation of the solvent or the mixture, results in the material being deposited to coat the particles.

These are entrained in a stream of air in a container at ambient temperature, for collection therefrom. An example that may be mentioned is the publication "Effects of fabrication conditions on the characteristics of etamidazole spray dried microspheres": Wang et al, J. Microencapsulation, 2002, vol. 19, No 4, 495 - 510;

• bed of fluidized air: the fluidized air bed method is a method that is frequently used to dry and

manufacture granules. A temperate stream of air is introduced via the bottom of a reactor. The suspension, sprayed by an atomizer into the production chamber, makes the particles in suspension bigger and they fall to the bottom whereupon they cannot be lifted by the stream of air .

In a non-limiting manner, the materials for coating the particles may be selected from the following:

• waxes and fats with a melting point of more than 45°C, especially carnauba wax, beeswax, stearyl stearate, polyethylene wax, DI 18/22 adipate, pentaerythrityl tetrastearate, tetracontanyl stearate, or dioctadecyl carbonate ; • cellulose and cellulose derivatives, in particular ethylcellulose, hydroxypropyl cellulose,

hydroxypropylmethyl cellulose, hydroxybutyl cellulose, or polymers sold under the trademark Ethocel®;

· polycaprolactone having a molecular weight in the range 10000 g/mol [gram/mole] to 80000 g/mol;

• polylactic acid (PLA) and polylactic acid-glycolic acid (PLAGA) at a ratio lying in the range 90/10 to

50/50;

· polyvinyl alcohol;

• copolymers of polyvinylpyrrolidone and vinyl acetate; and copolymers of acrylic acid and methyl methacrylate sold under the trademark Eudragit® L100.

The weight ratio between the core of the photonic particle and the shell produced therewith may be in the range 99.9/0.1 to 80/20, and preferably in the range 99/1 to 90/10.

Pseudo-inverse opals

"Pseudo-inverse opal" type photonic particles comprise hollow nanoparticles dispersed in a thermo-, electro- or photo-crosslinkable matrix.

Producing direct opals from hollow nanoparticles, also termed "pseudo-inverse opals", has the advantages of amplifying the optical effects by a higher index

difference compared with direct opals not using hollow nanoparticles, and of offering a zero porosity compared with uncoated inverse opals, of optical properties that are dependent on the medium in which they are dispersed.

The hollow nanoparticles may be as described below.

Janus type photonic particles

The photonic particles may be of the Janus type, i.e. comprising at least one other diffracting

arrangement of nanoparticles, or even at least two other diffracting arrangements, the arrangements each having their own optical properties, especially different diffraction spectra.

In first exemplary embodiments, one arrangement may comprise solid nanoparticles and another arrangement may comprise solid or hollow nanoparticles.

In a variation, one arrangement may comprise hollow nanoparticles and another arrangement may comprise hollow nanoparticles .

When the photonic particles comprise a plurality of arrangements, each arrangement may, for example, cover a different part of the UV spectrum, in order to obtain broader photoprotection .

The photonic particles comprising a plurality of diffracting arrangements may be obtained as taught in the publication by S-H Kim et al, Adv. Mater. 2008, 9999,

1 - 7 or in the publication "Patterned colloidal photonic domes and balls derived from viscous photocurable

suspensions" from Kim et al, Adv. Mater. 2008, 20,

3211 - 3217.

When the photonic particles are used at least in part for their coloring properties, in particular to make the complexion uniform, the arrangements of

nanoparticles, when illuminated with white light, may produce different respective colors; the arrangements may in particular produce a red, green and/or blue color, thereby enabling a large number of shades to be obtained, in particular white by additive synthesis of reflected light .

An arrangement presents a reflected red color, for example, when the reflectance in the visible spectrum is at least 50% in the wavelength range 620 nm to 700 nm, for an angle of observation in the range 30° to 150°. For green, the wavelength range under consideration is 490 nm to 550 nm, and for blue, it is 410 nm to 490 nm.

The arrangements may diffract light through the various respective zones of the photonic particle, for example two opposed zones, for example two diametrically opposed hemispherical zones for a photonic particle that is spherical.

Mixture of photonic particles

The composition of the invention may comprise a single type of photonic particle or a mixture of at least two different types of photonic particle, for example having reflection peaks centered on different wavelengths located in the visible or UV region.

The composition may, for example, comprise a mixture of one type of photonic particle comprising solid

nanoparticles and another type of photonic particles comprising nanoparticles that may be solid or hollow.

The composition may, for example, comprise a mixture of one type of photonic particle comprising hollow nanoparticles and another type of photonic particle comprising nanoparticles that may be hollow.

The composition may, for example, comprise one type of photonic particle comprising a thermo-, electro- or photo-crosslinkable matrix and another type of photonic particle not comprising a thermo-, electro- or photo- crosslinkable matrix.

Nanoparticles

The photonic particle nanoparticles may have a mean size in the range 100 nm to 500 nm, preferably in the range 100 nm to 300 nm. The term "mean size" denotes the statistical granulometric dimension at half the

population, termed D(0.5).

The nanoparticles may be spherical in shape.

The nanoparticles may be 15% monodisperse or better. The term "x% monodisperse" as used in the invention means particles with a mean size having a coefficient of variation, CV, of x% or less. The coefficient of

variation CV is defined by the relationship CV=— , s_ being the standard deviation of the particle size distribution and D being the mean size thereof. The mean size D and the standard deviation s_ may be measured for 250 particles by analyzing an image obtained using a scanning electron microscope, for example that with reference S-4 500 from the supplier HITACHI. Image analysis software may be used to facilitate this

measurement, for example Winroof® software, from the supplier Mitani Corporation. Preferably, the coefficient of variation of the monodisperse nanoparticles is 10% or less, more preferably 7% or less, or even more preferably 5% or less, for example substantially of the order of 3.5% or less .

The nanoparticles may be solid or hollow, organic or inorganic .

The nanoparticles may be monolithic or composite.

When the monodisperse nanoparticles are composites, they may, for example, comprise a core and a shell produced from different substances, for example organic and/or mineral substances.

Inorganic nanoparticles

The nanoparticles may comprise an inorganic

compound, or even be entirely mineral.

When the nanoparticles are inorganic, they may comprise at least one oxide, especially a metallic oxide, selected from silica, oxides of silica, iron, titanium, aluminum, chromium, zinc, copper, zirconium and cerium, and mixtures thereof. The nanoparticles may also include a metal, especially titanium, silver, gold, aluminum, zinc, iron, copper and mixtures and alloys thereof.

Organic nanoparticles

The nanoparticles may include an organic compound, or even be entirely organic.

Materials that may be suitable for producing organic nanoparticles that may be mentioned are polymers, in particular with a carbon or silicone chain, for example polystyrene (PS) , polymethyl methacrylate (PMMA) ,

polyacrylamide (PAM) , silicone polymers, NADs ("non aqueous dispersions") such as rigid NADs for example, e.g. constituted by 96.7% methyl methacrylate and 3.3% ethylene glycol dimethacrylate 20% cured in isododecane, particle diameter: 141 nm (polydispersity Q = 0.14); or 90% methyl methacrylate and 10% allyl methacrylate, particle diameter: 170 nm; or 100% methyl dimethacrylate, particle diameter: 138 nm (polydispersity Q = 0.15); or poly (methyl methacrylate/ allyl methacrylate), polylactic acid (PLA) , the polylactic acid-glycolic acid (PLAGA) , celluloses and derivatives thereof, polyurethane,

polycaprolactone, latex form, chitin, or composite chitin materials .

The glass transition temperature (T_g) of the organic nanoparticles may be greater than 40°C, and preferably greater than 60°C.

Hollow nanoparticles

These nanoparticles comprise a core and a shell.

The shell may be organic or inorganic.

The shell of the nanoparticles may, for example, be formed from PS and the particles may, for example, be dispersed in a thermo-, electro- or photo-crosslinkable organic matrix.

The core of said hollow nanoparticles may be

constituted by air or a gas other than air in order to benefit from a different refractive index, for example CO2, N₂, butane, or isobutane.

The presence of air or another gas inside the hollow nanoparticles may be used to obtain a large difference in the refractive index between the nanoparticles and the surrounding medium, which is favorable in terms of the intensity of the diffraction peak.

When the nanoparticles are hollow, the difference in refractive index at a wavelength diffracted between the core and the shell may be 0.4 or more. Said diffracted wavelength may be in the range 250 nm to 800 nm, for example in the range 250 nm to 400 nm. When the

nanoparticles are hollow, the ratio between a largest dimension of the core and a largest dimension of the nanoparticle may be in the range 0.5 to 0.8.

When the nanoparticles are hollow, the volume of the core represents in the range 10% to 80%, preferably in the range 20% to 60% of the total volume of the

nanoparticle .

The thickness of the shell of the hollow

nanoparticles, equal to half the difference between the largest dimension of the nanoparticle and the largest dimension of the core of the nanoparticle, may be in the range 50 nm to 200 nm, for example in the range 30 nm to 100 nm.

An example of hollow nanoparticles that may be mentioned are 280 nm nanoparticles from the supplier JSR SX866 (B) .

The core of the nanoparticles may optionally comprise a sunscreen or a mixture of sunscreens.

Thermo-, electro- or photo-crosslinkable matrix

The term "photocrosslinkable matrix" means a matrix in which crosslinking is induced and/or assisted by light, especially UV.

The term "thermocrosslinkable matrix" means a matrix in which crosslinking is induced and/or assisted by adding heat, for example bringing the matrix to a temperature of more than 60 °C.

The term "electrocrosslinkable matrix" means a matrix in which crosslinking is induced and/or assisted by applying an electric field.

A matrix may be both thermocrosslinkable and

photocrosslinkable .

As mentioned above, the photonic particles comprise solid or hollow nanoparticles, dispersed in a thermo-, electro- or photo-crosslinkable matrix, or voids dispersed in a thermo-, electro- or photo-crosslinkable matrix .

The thermocrosslinkable or photocrosslinkable matrix may be organic.

Non-limiting examples of crosslinkable organic matrixes that may be mentioned are:

• photocrosslinkable polymers such as ETPA

(ethoxylated trimethylolpropanetriacrylate) , PEGDA

(polyethyleneglycol diacrylate) , acrylic resins, PEG diacrylates, or materials described in FR 2 833 487;

• copolymers, described in FR 2 848 428, which crosslink by polycycloaddition, of PVA (polyvinyl

acetate) or PVEA (polyvinylethyl acetate) and

styrylpyridinium with the following formulae:

where R represents a hydrogen atom, an alkyl group or a hydroxyalkyl group, and R' represents a hydrogen atom or an alkyl group;

• cinnamic derivatives such as polyvinylcinnamate and PDMS cinnamate;

• reactive silicones described in patent

FR 2 910 286, i.e. :

• polyorganosiloxanes comprising siloxane units with formula:

m i—m

2

where R is a linear or cyclic monovalent hydrocarbon group containing 1 to 30 carbon atoms, m is equal to 1 or 2 and R' is an unsaturated aliphatic hydrocarbon group containing 2 to 10 carbon atoms or an unsaturated cyclic hydrocarbon group containing 5 to 8 carbon atoms; and/or

• polyorganosiloxanes comprising at least one alkylhydrogenosiloxane unit with formula: R_pHSiO^,

2

where R is a linear or cyclic monovalent hydrocarbon group containing 1 to 30 carbon atoms or a phenyl group and p is equal to 1 to 2; and

· thermoplastic, thermocrosslinkable polymers.

The matrix crosslinking may be chemical

crosslinking, for example using succinimides as described in application WO 2007/082061 A2.

For photocrosslinkable matrixes requiring a

photoinitiator, the photoinitiator is selected, for example, from the following list: DMPA (dimethoxy 2- phenyl acetophenone) , 2-benzyl-2- (dimethylamino) -1- [4- (4- morpholino phenyl ] -1-butanone sold under the trademark Irgacure^® 369 by Ciba^®, 4 , 4 ' -bis (diethylamino) benzophenone sold by Sigma-Aldrich^®, 2-hydroxy-4 ' - (2-hydroxyethoxy) -2- methylpropiophenone sold by Sigma-Aldrich^®, 2-benzyl-2- (dimethylamino) -4 ' -morpholinobutyrophenone sold by Sigma- Aldrich^®, phenylbis (2,4, 6-trimethylbenzoyl ) -phosphine oxide sold by Sigma-Aldrich^®, isopropyl-thioxanthone sold by Sigma-Aldrich^®, and camphorolactone .

The PEG diacrylates may, for example, be crosslinked using a photoinitiator such as camphorolactone.

Medium containing photonic particles

The photonic particles may be contained in a

cosmetically acceptable medium, i.e. a non-toxic medium suitable for application to human keratinous materials, in particular the skin, mucous membranes, or the hair or the nails.

Said medium is adapted to the nature of the support onto which the composition is to be applied and to the form in which the composition is to be packaged.

The medium may comprise a phase that is liquid at 25°C, containing photonic particles.

The medium may be selected so as to encourage dispersion of the photonic particles in the medium before application thereof, in order to prevent the photonic particles from becoming aggregated. As an example, it may be possible to use one or more agents that reduce the surface tension of the medium containing the photonic particles to less than 35 mN/m [millinewtons per meter] .

The medium may be aqueous, with the photonic

particles contained in an aqueous phase. The term

"aqueous medium" denotes a medium that is liquid at ambient temperature and atmospheric pressure and contains a large fraction of water relative to the total weight of the medium. The complementary fraction may contain or be constituted by physiologically acceptable organic

solvents, miscible with water, for example alcohols or alkylene glycols. The quantity of water in the aqueous medium is, for example, 30% by weight or more, preferably 40% or more preferably 50%.

The medium may be monophase or multiphase.

The medium may comprise an alcohol, such as ethanol or isopropanol, for example, or a glycol derivative, in particular ethylene glycol or propylene glycol.

The medium may be transparent or translucent, and colored or not colored. The medium containing the photonic particles may contain no pigment or colorant. The coloration of the medium may be due to adding an additional coloring agent.

The medium may comprise a volatile solvant. The term "volatile solvant" as used in the context of the invention means any liquid capable of evaporating in contact with keratinous materials, at ambient temperature and at atmospheric pressure.

The medium may in particular be selected such that the composition contains at least 5%, or even at least 30% of volatile solvant.

The medium may comprise a film-forming polymer improving protection persistence. Film-forming polymer

In the present invention, the term "film-forming polymer" means a polymer that, by itself or in the presence of an auxiliary film-forming agent, is capable of forming a macroscopically continuous film that adheres to keratinous material, preferably a cohesive film, and more preferably a film of cohesion and mechanical

properties that are such that said film can be isolated and manipulated in isolation, for example when said film is produced by casting over a non-stick surface such as a Teflon or silicone surface.

The composition may comprise an aqueous phase and the film-forming polymer may be present in said aqueous phase. It is then preferably a polymer in dispersion or an amphiphilic or associative polymer.

The term "polymer in dispersion" means polymers that are insoluble in water, in the form of particles of various sizes. The polymer may optionally be cured. The mean particle size is typically in the range 25 nm to 500 nm, preferably in the range 50 nm to 200 nm. The following polymers in aqueous dispersion may be used:

Ultrasol 2075® from Ganz Chemical, Daitosol 5000AD® from Daito Kasei, Avalure UR 450® from Noveon, DYNAMX® from National Starch, Syntran 5760® from Interpolymer, Acusol OP 301® from Rohm&Haas, and Neocryl A 1090® from Avecia.

Acrylic dispersions sold under the names Neocryl XK-90®, Neocryl A-1070®, Neocryl A-1090®, Neocryl

BT-62®, Neocryl A-1079® and Neocryl A-523® by the supplier AVECIA-NEORESINS, Dow Latex 432® by the supplier DOW CHEMICAL, Daitosol 5000 AD® or Daitosol 5000 SJ® by the supplier DAITO KASEY KOGYO, Syntran 5760® by the supplier Interpolymer, Allianz OPT by the supplier ROHM & HAAS, aqueous dispersions of acrylic or styrene/acrylic polymers sold under the trade name JONCRYL® by the supplier JOHNSON POLYMER, or aqueous dispersions of polyurethane sold under the names Neorez R-981® and

Neorez R-974® by the supplier AVECIA-NEORESINS, Avalure UR-405®, Avalure UR-410®, Avalure UR-425®, Avalure

UR-450®, Sancure 875®, Sancure 861®, Sancure 878® and Sancure 2060® by the supplier GOODRICH, Impranil 85® by the supplier BAYER, Aquamere H-1511® by the supplier HYDROMER, sulfopolyesters sold under the trade name

Eastman AQ® by the supplier Eastman Chemical Products, vinyl dispersions such as Mexomere PAM® from the supplier CHIMEX and mixtures thereof, are other examples of aqueous dispersions of particles of hydrodispersible film-forming polymers.

The term "amphiphilic or associative polymers" means polymers comprising one or more hydrophilic portions that render them partially soluble in water and one or more hydrophobic portions via which the polymers associate or interact. The following associative polymers may be used: Nuvis FX1100® from Elementis, Aculyn 22®, Aculyn 44®, Aculyn 46® from Rohm&Haas, and Viscophobe DB1000® from Amerchol. Diblock copolymers constituted by a hydrophilic block (polyacrylate, polyethylene glycol) and a hydrophobic block (polystyrene, polysiloxane) may also be used.

The composition may comprise an oily phase and the film-forming polymer may be present in said oily phase. The polymer may then be in dispersion or in solution.

NAD type polymers or microgels (for example KSGs) may be used, as well as polymers of the PS-PA type or copolymers based on styrene (Kraton, Regalite) .

Examples of non-aqueous dispersions of polymer particles in one or more silicone and/or hydrocarbon oils that can be stabilized at their surface by at least one stabilizing agent, in particular a block, graft or random polymer and that may be mentioned are acrylic dispersions in isododecane, such as Mexomere PAP® from the supplier CHIMEX, and dispersions of particles of a graft ethylenic polymer, preferably acrylic, in a liquid fatty phase, the ethylenic polymer advantageously being dispersed in the absence of additional stabilizer on the surface of particles such as that described in particular in the document WO 04/055081.

Film-forming polymers that may be used in the composition of the present invention and that may be mentioned are synthetic polymers of the radical or polycondensation type, polymers of natural origin, and mixtures thereof.

In particular, the radical type film-forming

polymers may be polymers or copolymers, which are vinyls, especially acrylic polymers.

Vinyl film-forming polymers may result from

polymerizing monomers containing an ethylenically

unsaturated bond having at least one acid group and/or esters of said acid monomers and/or amides of said acid monomers, such as unsaturated a, β-ethylenically

unsaturated carboxylic acids, e.g. acrylic acid,

methacrylic acid, crotonic acid, maleic acid or itaconic acid .

The polymers of natural origin, optionally modified, may be selected from shellac resin, sandarac gum,

dammars, elemis, copals, and cellulose polymers such as nitrocellulose, ethylcellulose or nitrocellulose esters selected, for example, from cellulose acetate, cellulose acetobutyrate, cellulose acetopropionate, and mixtures thereof.

The film-forming polymer may be present in the form of solid particles in aqueous or oily dispersion,

generally known as a latex or pseudolatex. The film- forming polymer may comprise one or more stable

dispersions of particles of generally spherical polymers of one or more polymers, in a physiologically acceptable liquid fatty phase. These dispersions are generally termed polymer NADs, as opposed to latexes that are aqueous polymer dispersions. These dispersions may be in the form of nanoparticles of polymers in stable

dispersion in said fatty phase. The nanoparticle size is preferably in the range 5 nm to 600 nm. The techniques for preparing said dispersions are well known to the skilled person.

The composition may comprise at least one film- forming polymer that is a linear, block, ethylenic film- forming polymer. Said polymer may comprise at least one first sequence (block) and at least one second sequence having different glass transition temperatures (Tg) , said first and second sequences being connected together via an intermediate sequence comprising at least one

constitutive monomer of the first sequence and at least one constitutive monomer of the second sequence. As an example, the first and second sequences and the block polymer may be incompatible with each other. Such polymers, for example, are described in the documents EP 1 411 069 or WO 04/028488, which are herewith

incorporated by reference.

Fatty Phase

Although the composition containing the photonic particles may be free of oil, in some implementations the composition of the invention may include a fatty phase. The photonic particles may optionally be contained in said fatty phase.

The fatty phase may in particular be volatile.

The composition may comprise an oil such as, for example, synthesized esters or ethers, linear or branched hydrocarbons of mineral or synthetic origin, fatty alcohols containing 8 to 26 carbon atoms, partially fluorinated hydrocarbon and/or silicone oils, silicone oils such as polymethylsiloxanes (PDMS) , which may optionally be volatile, with a linear or cyclic silicone chain, which may be liquid or pasty at ambient

temperature, and mixtures thereof; other examples are given below.

A composition in accordance with the invention may thus comprise at least one volatile oil. Volatile oils

In the context of the present invention, the term "volatile oil" means an oil (or non-aqueous medium) that is capable of evaporating on contact with skin in less than one hour, at ambient temperature and at atmospheric pressure .

The volatile oil is a volatile cosmetic oil, liquid at ambient temperature, in particular having a non-zero vapor pressure, at ambient temperature and atmospheric pressure, in particular having a vapor pressure in the range 0.13 Pa to 40000 Pa (10^~3 mmHg to 300 mmHg) , in particular in the range 1.3 Pa to 13000 Pa (0.01 mmHg to 100 mmHg), and more particularly in the range 1.3 Pa to 1300 Pa (0.01 mmHg to 10 mmHg) .

The volatile hydrocarbon oils may be selected from hydrocarbon oils of animal or vegetable origin containing 8 to 16 carbon atoms, and in particular branched Cs-Ci₆ alkanes (also termed isoparaffins ) , such as isododecane (also termed 2 , 2 , 4 , 4 , 6-pentamethylheptane) , isodecane, isohexadecane, and, for example, oils sold under the trade names Isopars^® or Permethyls^®.

Examples of volatile oils that may also be used are volatile silicones, for example linear or cyclic volatile silicone oils, especially those with a viscosity

of <8 centistokes (8 x 10^~6 m²/s), especially containing 2 to 10 silicon atoms, in particular 2 to 7 silicon atoms, said silicones optionally comprising alkyl or alkoxy groups containing 1 to 10 carbon atoms. Examples of volatile silicone oils that may be used in the invention that may be mentioned are dimethicones with a viscosity of 5 cSt to 6 cSt, octamethyl cyclotetrasiloxane, decamethyl cyclopentasiloxane, dodecamethyl

cyclohexasiloxane, heptamethyl hexyltrisiloxane,

heptamethyloctyl trisiloxane, hexamethyl disiloxane, octamethyl trisiloxane, decamethyl tetrasiloxane, dodecamethyl pentasiloxane, and mixtures thereof. It is also possible to use fluorinated volatile such as nonafluoromethoxybutane or

perfluoromethylcyclopentane, and mixtures thereof.

It is also possible to use a mixture of the oils mentioned above.

Non-volatile oils

A composition of the invention may comprise a nonvolatile oil.

Within the context of the present invention, the term "non-volatile oil" means an oil having a vapor pressure of less than 0.13 Pa, in particular high

molecular mass oils.

The non-volatile oils may in particular be selected from hydrocarbon oils, fluorinated where appropriate, and/or non-volatile silicone oils.

Examples of non-volatile hydrocarbon oils that may be suitable for implementing the invention that may in particular be mentioned are:

· hydrocarbon oils of animal origin;

• hydrocarbon oils of vegetable origin, such as phytostearyl esters, for example phytostearyl oleate, physostearyl isostearate or lauroyl / octyldodecyl / phytostearyl glutamate sold, for example, under the name ELDEW PS203 by AJINOMOTO, triglycerides constituted by esters of fatty acids and glycerol in which the fatty acids may have chain lengths in the range C4 to C24, and may be linear or branched, saturated or unsaturated; said oils are in particular heptanoic or octanoic

triglycerides, or wheatgerm, sunflower, grapeseed, sesame, corn, apricot, castor, shea, avocado, olive, soya, sweet almond, palm, rape, cottonseed, hazelnut, macadamia nut, jojoba, alfalfa, poppy, Hokaido squash, gourd, blackcurrant, evening primrose, millet, barley, quinoa, rye, carthame, bancoulier, passiflora, or musk rose oils; shea butter; or caprylic / capric acid

triglycerides such as those sold by the supplier STEARINERIES DUBOIS OR those sold under the names MIGLYOL 810^®, 812^® and 818^® by the supplier DYNAMIT NOBEL;

• hydrocarbon oils of mineral or synthetic origin such as, for example:

o synthesized ethers containing 10 to 40 carbon atoms ;

o linear or branched hydrocarbons of mineral or synthetic origin, such as vaseline, polydecenes,

hydrogenated polyisobutene such as parleam, squalane and mixtures thereof, and in particular hydrogenated

polyisobutene; and

o synthesized esters such as oils with formula R₁COOR₂, wherein Ri represents the residue of a linear or branched fatty acid containing 1 to 40 carbon atoms and R₂ represents a hydrocarbon chain, especially branched, containing 1 to 40 carbon atoms, provided that Ri + R₂ ≥ 10.

The esters may be in particular be selected from esters, in particular of fatty acids such as, for

example:

• cetostearyl octanoate, esters of isopropyl alcohol such as isopropyl myristate, isopropyl palmitate, ethyl palmitate, 2-ethyl-hexyl palmitate, isopropyl stearate or isostearate, isostearyl isostearate, octyl stearate, hydroxyl esters such as isostearyl lactate, octyl

hydroxystearate, diisopropyl adipate, heptanoates, in particular isostearyl heptanoate, octanoates, decanoates or ricinoleates of alcohols or polyalcohols , such as propylene glycol dioctanoate, cetyl octanoate, tridecyl octanoate, 2-ethylhexyl 4-diheptanoate and palmitate, alkyl benzoate, polyethylene glycol diheptanoate,

propyleneglycol 2-diethyl hexanoate and mixtures thereof, Ci₂ ^_Ci₅ alcohol benzoates, hexyl laurate, neopentanoic acid esters such as isodecyl neopentanoate, isotridecyl neopentanoate, isostearyl neopentanoate, octyldodecyl neopentanoate, isononanoic acid esters such as isononyl isononanoate, isotridecyl isononanoate, octyl isononanoate, or hydroxyl esters such as isostearyl lactate, or di-isostearyl malate;

• esters of polyols, and pentaetrythritol esters, such as dipentaerythritol tetrahydroxystearat /

tetraisostearate ;

• esters of diol dimers and diacid dimers, such as Lusplan DD-DA5® and Lusplan DD-DA7®, sold by the supplier NIPPON FINE CHEMICAL and described in application FR 03 02809;

· fatty alcohols that are liquid at ambient

temperature having a branched and/or unsaturated carbon chain containing 12 to 26 carbon atoms, such as 2- octyldodecanol , isostearyl alcohol, oleic alcohol, 2- hexyldecanol , 2-butyloctanol, or 2-undecylpentadecanol ;

· higher fatty acids such as oleic acid, linoleic acid, linolenic acid and mixtures thereof; and

• dialkyl carbonates, the 2 alkyl chains possibly being identical or different, such as dicaprylyl

carbonate sold under the name Cetiol CC®, by Cognis;

· non-volatile silicone oils such as, for example, non-volatile polydimethylsiloxanes (PDMS) ,

polydimethylsiloxanes comprising pendant alkyl or alkoxy groups and/or with silicone chain ends, groups each containing 2 to 24 carbon atoms, phenyl silicones such as phenyl trimethicones , phenyl dimethicones , phenyl

trimethylsiloxy diphenylsiloxanes , diphenyl dimethicones, diphenyl methyldiphenyl trisiloxanes , or 2-phenylethyl trimethylsiloxysilicates , or dimethicones or

phenyltrimethicone with a viscosity less than or equal to 100 cSt, and mixtures thereof;

• and mixtures thereof.

The composition containing photonic particles may be free of oil, and in particular may contain no nonvolatile oil.

Complementary screens and additives

The composition comprising photonic particles may comprise at least one additive selected from adjuvants that are normal in the cosmetics field, such as fillers, coloring agents, hydrophilic or lipophilic gelling agents, active ingredients, either hydrosoluble or liposoluble, preservatives, moisturizers such as polyols and in particular glycerin, sequestrating agents, antioxidants, solvents, fragrances, physical and chemical sunscreens, especially against UVA and/or UVB, odor absorbers, pH adjusting agents (acids or bases) , and mixtures thereof.

The composition may contain at least one active ingredient having a complementary activity in the solar protection field, such as antioxidants, whitening agents in the context of anti-pigmentation and depigmentation, or anti-ageing active ingredients.

The additional organic screens, either hydrophobic, hydrophilic or insoluble in the usual solvents, may be selected from various categories of chemical compounds. In particular, the organic screens are selected from dibenzoylmethane derivatives; anthranilates ; cinnamic derivatives; salicylic derivatives, camphor derivatives; benzophenone derivatives; β , β-diphenylacrylate

derivatives; triazine derivatives other than those with formula (I); benzalmalonate derivatives, in particular those mentioned in patent US 5 624 663; benzimidazole derivatives; imidazolines; p-aminobenzoic acid (PABA) derivatives; benzotriazole derivatives; methylene bis- (hydroxyphenyl benzotriazole) derivatives such as those described in applications US 5 237 071, US 5 166 355, GB 2 303 549, DE 197 26 184 and EP 0 893 119; benzoxazole derivatives such as those described in patent

applications EP 0 832 642, EP 1 027 883, EP 1 300 137 and DE 01 62 844; polymer screens and silicone screens such as those described in particular in application

WO 93/04665; dimers derived from CC-alkylstyrene, such as those described in patent application DE 198 55 649; 4,4- diarylbutadienes such as those described in applications EP 0 967 200, DE 197 46 654, DE 197 55 649,

EP A 1 008 586, EP 1 133 980 and EP 0 133 981; or

merocyanin derivatives such as those described in

applications WO 04/006878, WO 05/058269 and WO 06/032741, and mixtures thereof.

The screen or screens may be selected from the following screens:

Hydrophobic screens capable of absorbing UV in the range 320 nm to 400 nm (UVA)

Dibenzoylmethane derivatives

^• butyl methoxydibenzoylmethane sold in particular under the trade name "PARSOL 1789" by DSM Nutritional Products, Inc;

^• isopropyl dibenzoylmethane.

Aminobenzophenones

n-hexyl 2- (4-diethylamino-2-hydroxybenzoyl) -benzoate sold under the trade name "UVINUL A+" by BASF.

Anthranilic derivatives

menthyl anthranilate sold under the trade name "NEO HELIOPAN MA" by SYMRISE.

4 , 4-diarylbutadiene derivatives

1, 1-dicarboxy (2,2' -dimethyl-propyl ) -4, 4- diphenylbutadiene .

Preferred screens are butyl methoxydibenzoylmethane and n-hexyl 2- (4-diethylamino-2-hydroxybenzoyl) -benzoate .

Hydrophobic screens capable of absorbing UV in the range 280 nm to 320 nm (UVB)

Para-aminobenzoates

^• ethyl PABA;

^• ethyl dihydroxypropyl PABA;

^• ethylhexyl dimethyl PABA (ESCALOL 507 from ISP) . Salicylic derivatives

^• homosalate sold under the name "Eusolex HMS" by Rona/EM Industries;

· ethylhexyl salicylate sold under the name "NEO

HELIOPAN OS" by SYMRISE;

^• dipropyleneglycol salicylate sold under the name "DIPSAL" by SCHER;

^• TEA salicylate, sold under the name "NEO HELIOPAN TS" by SYMRISE.

Cinnamates

^• ethylhexyl methoxycinnamate sold in particular under the trade name "PARSOL MCX" by DSM Nutritional Products, Inc;

^• isopropyl methoxy cinnamate;

^• isoamyl methoxy cinnamate sold under the trade name "NEO HELIOPAN E 1000" by SYMRISE;

^• diisopropyl methylcinnamate ;

· cinoxate;

^• glyceryl ethylhexanoate dimethoxycinnamate . β , β ' -diphenylacrylate derivatives

^• octocrylene, sold in particular under the trade name "UVINUL N539" by BASF;

^• etocrylene, sold in particular under the trade name "UVINUL N35" by BASF.

Benzylidene camphor derivatives

· 3-Benzylidene camphor manufactured under the trade name "MEXORYL SD" by CHIMEX;

^• methylbenzylidene camphor sold under the trade name "EUSOLEX 6300" by MERCK;

^• polyacrylamidomethyl benzylidene camphor

manufactured under the name "MEXORYL SW" by CHIMEX. Triazine derivatives

^• ethylhexyl triazone sold in particular under the trade name "UVINUL T150" by BASF;

^• diethylhexyl butamido triazone sold under the trade name "UVASORB HEB" by SIGMA 3V;

^• 2 , 4 , 6-tris (dineopentyl 4 ' -amino benzalmalonate) -s- triazine ;

^• 2 , 4 , 6-tris- (diisobutyl 4 ' -amino benzalmalonate) -s- triazine ;

^• 2 , 4-bis (dineopentyl 4 ' -amino benzalmalonate) -6- (4'- n-butyl aminobenzoate) -s-triazine;

^• 2 , 4-bis (n-butyl 4 ' -amino benzoate)-6- (aminopropyltrisiloxane) -s-triazine;

^• symmetrical triazine screens described in patent US 6 225 467, application WO 2004/085412 (see compounds 6 to 9) or the document "Symmetrical Triazine Derivatives", IP.COM Journal, IP.COM INC WEST HENRIETTA, NY, US (20 September 2004), in particular 2,4,6-tris- (biphenyl) -1, 3, 5-triazine (in particular 2,4,6- tris (biphenyl-4-yl-l, 3, 5-triazine) and 2,4,6- tris (terphenyl) -1, 3, 5-triazine that is discussed in applications by BEIERSDORF, numbers WO 06/035000,

WO 06/034982, WO 06/034991, WO 06/035007, WO 2006/034992, WO 2006/034985.

Imidazoline derivatives

Ethylhexyl dimethoxybenzylidene dioxoimidazoline propionate .

Benzalmalonate derivatives

^• polyorganosiloxanes having a benzalmalonate function, such as Polysilicone-15 sold under the trade name "PARSOL SLX" by DSM Nutritional Products, Inc;

^• di-neopentyl 4 ' -methoxybenzalmalonate . Merocyanin derivatives

Octyl-5-N, -diethylamino-2 -phenysuIfonyl-2 , 4- pentadienoate .

Preferred screens are homosalate,

ethylhexylsalicylate, octocrylene, ethylhexyl,

methoxycinnamate v, isoamyl methoxycinnamate, ethylhexyl triazone, and diethylhexyl butamido triazone.

The most preferred compounds are

ethylhexylsalicylate, octocrylene, ethylhexyl triazone and ethylhexyl methoxycinnamate.

Mixed hydrophobic screens capable of absorbing both UVA and UVB Benzophenone derivatives

^• benzophenone-1 sold under the trade name "UVINUL 400" by BASF;

^• benzophenone-2 sold under the trade name "UVINUL D50" by BASF;

· benzophenone-3 or oxybenzone, sold under the trade name "UVINUL M40" by BASF;

^• benzophenone-5 ;

^• benzophenone- 6 sold under the trade name "Helisorb 11" by Norquay

benzophenone-8 sold under the trade name "Spectra-Sorb UV-24" by American Cyanamid;

^• benzophenone-10 ;

^• benzophenone-11 ;

^• benzophenone-12.

Phenyl benzotriazole derivatives

^• drometrizole trisiloxane sold under the name

"Silatrizole" by RHODIA CHIMIE;

^• methylene bis-benzotriazolyl

tetramethylbutylphenol , sold in the solid form under the trade name "MIXXIM BB/100" by FAIRMOUNT CHEMICAL or in micronized form in aqueous dispersion under the trade name "TINOSORB M" by CIBA SPECIALTY CHEMICALS.

Bis-resorcinyl triazine derivatives

bis-ethylhexyloxyphenol methoxyphenyl triazine sold under the trade name "TINOSORB S" by CIBA GEIGY .

Benzoxazole derivatives

2,4-bis-[5 - 1 (dimethylpropyl) benzoxazol-2-yl- (4- phenyl) -imino] -6- (2-ethylhexyl) -imino-1, 3, 5-triazine sold under the name Uvasorb K2A by Sigma 3V.

The preferred screens are:

^• drometrizole trisiloxane;

^• methylene bis-benzotriazolyl

tetramethylbutylphenol ;

^• bis-ethylhexyloxyphenol methoxyphenyl triazine; and

^• benzophenone-3 or oxybenzone.

The most preferred are:

· drometrizole trisiloxane; and

^• bis-ethylhexyloxyphenol methoxyphenyl triazine

Hydrosoluble screens capable of absorbing UV in the range

320 nm to 400 nm (UVA)

Terephthalylidene dicamphor acid sulfonic acid manufactured under the name "MEXORYL SX" by CHIMEX.

Bis-benzoazolyl derivatives as described in patents

EP 0 669 323 and US 2 463 264, more particularly the compound disodium phenyl dibenzimidazole tetrasulfonate sold under the trade name "NEO HELIOPAN AP" by Haarmann and REIMER .

The preferred screen is terephthalylidene dicamphor acid sulfonic acid. Hydrosoluble screens capable of absorbing UV in the range 280 nm to 320 nm (UVB) p-aminobenzoic derivatives (PABA)

^• PABA;

^• glyceryl PABA; and

^• PEG-25 PABA sold under the name "UVINUL P25" by BASF;

^• phenylbenzimidazole sulfonic acid sold in

particular under the trade name "EUSOLEX 232" by MERCK;

^• ferulic acid;

^• salicylic acid;

· DEA methoxycinnamate ;

^• benzylidene camphor sulfonic acid manufactured under the name "MEXORYL SL" by CHIMEX; and

^• camphor benzalkonium methosulfate manufactured under the name "MEXORYL SO" by CHIMEX; and

The preferred screen is phenylbenzimidazole sulfonic acid .

Mixed UVA and UVB hydrosoluble screens Benzophenone derivatives comprising at least one sulfonic radical

^• benzophenone-4 sold under the trade name "UVINUL MS40" by BASF;

^• benzophenone-5 ; and

· benzophenone- 9.

The preferred screen is benzophenone-4.

The organic screen or screens of the invention may be present in the compositions of the invention in a concentration in the range 0.1% to 15%, preferably in the range 0.2% to 10%, by weight relative to the total composition weight.

Inorganic sunscreens or photoprotectors

The inorganic photoprotective agents are selected from metallic oxide pigments that may optionally be coated (mean size of primary particles: generally in the range 5 nm to 100 nm, preferably in the range 10 nm to 50 nm) , such as titanium oxide pigments (amorphous or crystalline in the form of rutile and/or anatase) , iron, zinc, zirconium, or cerium, which are all UV

photoprotectors that are well known per se.

The pigments may optionally be coated.

The coated pigments are pigments that have undergone one or more surface treatments of a chemical, electronic, or chemical-mechanical nature with compounds such as those described in Cosmetics & Toiletries, February 1990, Vol 105, pp. 53 - 64, such as amino acids, beeswax, fatty acids, fatty alcohols, anionic surfactants,

lecithins, sodium, potassium, zinc, iron, or aluminum salts of fatty acids, metallic (titanium or aluminum) alkoxides, polyethylene, silicones, proteins (collagen, elastin) , alkanolamines , oxides of silicon, metallic oxides or sodium hexametaphosphate .

In known manner, the silicones are organo-silicon polymers or oligomers with a linear or cyclic, branched or cured structure, with a variable molecular weight obtained by polymerization and/or polycondensation of suitably functionalized silanes and essentially

constituted by repeated principal motifs in which the silicon atoms are connected together via oxygen atoms (siloxane linkage) , with hydrocarbon radicals that may be substituted being directly bonded via a carbon atom to said silicon atoms.

The term "silicones" also encompasses pigments that are necessary for their preparation, in particular alkylsilanes .

The silicones that are used for coating pigments for suitable use in the present invention are preferably selected from the group containing alkyl silanes,

polydialkylsiloxanes and polyalkylhydrogenosiloxanes . Still more preferably, the silicones are selected from the group containing octyl trimethyl silane,

polydimethylsiloxanes and polymethylhydrogenosiloxanes . Clearly, prior to treating them with silicones, the metallic oxide pigments may have been treated with other surface agents, in particular with cerium oxide, alumina, silica, aluminum compounds, silicon compounds, or

mixtures thereof.

More particularly, the coated pigments are titanium oxides coated with the following:

• silica, such as the product "SUNVEIL" from the supplier IKEDA;

· silica and iron oxide, such as the product

"SUNVEIL F" from the supplier IKEDA;

• silica and alumina, such as the products

"MICROTITA IUM DIOXIDE MT 500 SA" and "MICROTITANIUM DIOXIDE MT 100 SA" from the supplier TAYCA, or "TIOVEIL" from the supplier TIOXIDE;

• alumina, such as the products "TIPAQUE TTO-55 (B) " or "TIPAQUE TTO-55 (A) " from the supplier I SHIHARA, and "UVT 14/4" from the supplier KEMIRA;

• alumina and aluminum stearate, such as the

products "MICROTITANIUM DIOXIDE MT 100 T, MT 100 TX, MT 100 Z, MT-01" from the supplier TAYCA, the product

"Solaveil CT-10 W" and "Solaveil CT 100" from the

supplier UNIQEMA and the product "Eusolex T-AVO" from the supplier MERCK;

· silica, alumina and alginic acid, such as the product "MT-100 AQ" from the supplier TAYCA;

• alumina and aluminum laurate, such as the product "MICROTITANIUM DIOXIDE MT 100 S" from the supplier TAYCA;

• iron oxide and iron stearate, such as the product "MICROTITANIUM DIOXIDE MT 100 F" from the supplier TAYCA;

• zinc oxide and zinc stearate, such as the product "BR 351" from the supplier TAYCA;

• silica and alumina treated with a silicone, such as the product "MICROTITANIUM DIOXIDE MT 600 SAS",

"MICROTITANIUM DIOXIDE MT 500 SAS", or "MICROTITANIUM DIOXIDE MT 100 SAS" from the supplier TAYCA; • silica, alumina, and aluminum stearate treated with a silicone, such as the products "STT-30-DS" from the supplier TITAN KOGYO;

• silica treated with a silicone, such as the product "UV-TITAN X 195" from the supplier KEMIRA;

• alumina treated with a silicone, such as the products "TIPAQUE TTO-55 (S)" from the supplier I SHIHARA, or "UV TITAN M 262" from the supplier KEMIRA;

• triethanolamine, such as the product "STT-65-S" from the supplier TITAN KOGYO;

• stearic acid, such as the product "TIPAQUE TTO-55 (C) " from the supplier ISHIHARA;

• sodium hexametaphosphate, such as the product

"MICROTITANIUM DIOXIDE MT 150 W" from the supplier TAYCA;

· T1O₂ treated with octyl trimethyl silane, sold under the trade name "T 805" by the supplier DEGUSSA SILICES;

• T1O₂ treated with a polydimethylsiloxane, sold under the trade name "70250 Cardre UF Ti02SI3" by the supplier CARDRE;

• T1O₂ anatase/rutile treated with a

polydimethylhydrogenosiloxane sold under the trade name "MICRO TITANIUM DIOXIDE USP GRADE HYDROPHOBIC" by the supplier COLOR TECHNIQUES.

Uncoated titanium oxide pigments are, for example, sold by the supplier TAYCA under the trade names

"MICROTITANIUM DIOXIDE MT 500 B" or "MICROTITANIUM

DIOXIDE MT600 B", by the supplier DEGUSSA under the name "P 25", by the supplier WACKER under the name

"Transparent titanium oxide PW", by the supplier MIYOSHI KASEI under the name "UFTR" , by the supplier TOMEN under the name "ITS" and by the supplier TIOXIDE under the name "TIOVEIL AQ".

Examples of uncoated zinc oxide pigments are:

· those sold under the name "Z-cote" by the supplier

Sunsmart ; • those sold under the name "Nanox" by the supplier Elementis ;

• those sold under the name "Nanogard WCD 2025" by the supplier Nanophase Technologies.

Examples of coated zinc oxide pigments are:

• those sold under the name "Zinc oxide CS-5" by the supplier Toshibi (ZnO coated with

polymethylhydrogenosiloxane) ;

• those sold under the name "Nanogard Zinc Oxide FN" by the supplier Nanophase Technologies (40% dispersion in

Finsolv TN, C12-C15 alcohol benzoate) ;

• those sold under the name "DAITOPERSION ZN-30" and "DAITOPERSION Zn-50" by the supplier Daito (dispersions in cyclopolymethylsiloxane / oxyethylenated

polydimethylsiloxane, containing 30% to 50% of nano-zinc oxides coated with silica and

polymethylhydrogenosiloxane) ;

• those sold under the name "NFD Ultrafine ZnO" by the supplier Daikin (ZnO coated with perfluoroalkyl phosphate and copolymer based on perfluoroalkylethyl in dispersion in cyclopentasiloxane) ;

• those sold under the name "SPD-Z1" by the supplier Shin-Etsu (ZnO coated with silicone-grafted acrylic polymer, dispersed in cyclodimethylsiloxane) ;

· those sold under the name "Escalol Z100" by the supplier ISP (ZnO-treated alumina dispersed in an

ethylhexyl methoxycinnamate / PVP-hexadecene copolymer / methicone mixture) ;

• those sold under the name "Fuji ZnO-SMS-10" by the supplier Fuji Pigment (ZnO coated with silica and

polymethylsilsesquioxane) ;

• those sold under the name "Nanox Gel TN" by the supplier Elementis (ZnO dispersed in a concentration of 55% in C12-C15 alcohol benzoate with polycondensate of hydroxystearic acid) . Uncoated cerium oxide pigments are sold under the name "COLLOIDAL CERIUM OXIDE" by the supplier RHONE

POULENC.

Uncoated iron oxide pigments are sold, for example, by the supplier ARNAUD under the names "NANOGARD WCD 2002 (FE 45B)", "NANOGARD IRON FE 45 BL AQ", "NANOGARD FE 45R AQ", "NANOGARD WCD 2006 (FE 45R)", or by the supplier MITSUBISHI under the name "TY-220".

Coated iron oxide pigments are, for example, sold by the supplier ARNAUD under the names "NANOGARD WCD 2008

(FE 45B FN)", "NANOGARD WCD 2009 (FE 45B 556)", "NANOGARD FE 45 BL 345", "NANOGARD FE 45 BL", or by the supplier BASF under the name "TRANSPARENT IRON OXIDE".

Mention may also be made of mixtures of metallic oxides, in particular of titanium dioxide and of cerium dioxide, including the mixture of equal weights of titanium dioxide and cerium dioxide coated with silica, sold by the supplier IKEDA under the name "SUNVEIL A", as well as a mixture of titanium dioxide and zinc dioxide coated with alumina, silica and silicone, such as the product "M 261" sold by the supplier KEMIRA, or coated with alumina, silica and glycerin, such as the product "M 211" sold by the supplier KEMIRA.

The inorganic screen or screens may be present in the compositions of the invention in a concentration in the range 0.1% to 15%, preferably in the range 0.2% to 10%, by weight relative to the total composition weight.

The additive or additives may be selected from those mentioned in the CTFA Cosmetic Ingredient Handbook, 10^th Edition, Cosmetic and Fragrance Assn, Inc., Washington DC (2004), herewith incorporated by reference.

Galenical forms

The photonic particles may be used in lotions, creams, milks, pommades, gels, films, patches, sticks, powder, pastes, for the skin, the lips, the hair or the nails . Modes of application

The composition comprising photonic particles may be applied by hand or using an applicator.

Application may also be carried out by spraying or projection using a piezoelectric device, for example, or by transferring a layer of composition that has been deposited on an intermediate support. Packaging

The composition may be packaged in any packaging device, especially formed from thermoplastic material, or on any support provided for that purpose.

The packaging device may be a bottle, a pump bottle, an aerosol bottle, a tube, a sachet or a pot.

Unless specified otherwise, the expression

"comprising a" should be construed as meaning "comprising at least one".

Claims

A composition comprising a dispersion of photonic particles each having a form factor of less than 2, said particles comprising a diffracting arrangement voids or monodisperse nanoparticles in a thermo-, electro- or photo-crosslinkable matrix.

A composition according to claim 1, wherein the photonic particles are substantially spherical in shape .

A composition according to either one of claims 1 or 2, wherein the nanoparticles are dispersed in the matrix .

A composition according to the preceding claim, wherein the fraction of nanoparticles dispersed in the matrix before thermo-, electro- or photo-crosslinking is in the range 1% to 90% by weight, for example in the range 5% to 60% by weight.

A composition according to any preceding claim, wherein the mean size of the photonic particles is the range 1 ym to 500 ym, for example in the range 1 ym to 300 ym.

A composition according to any preceding claim, wherein the nanoparticles are substantially spherical in shape.

A composition according to any one of claims 3 to 6, wherein the matrix is selected from crosslinkable organic matrixes selected from: · photocrosslinkable polymers such as ETPA

(ethoxylated trimethylolpropanetriacrylate) , PEGDA (polyethyleneglycol diacrylate) , acrylic resins, PEG diacrylates ,

• copolymers of polyvinyl acetate or polyvinylethyl acetate and styrylpyridiniums with the following

formulae:

where R represents a hydrogen atom, an alkyl group or a hydroxyalkyl group, and R' represents a hydrogen atom or an alkyl group;

· cinnamic derivatives such as polyvinylcinnamate and PDMS cinnamate;

• polyorganosiloxanes comprising siloxane units with formula :

2

where R is a linear or cyclic monovalent hydrocarbon group containing 1 to 30 carbon atoms, m is equal to 1 or 2 and R' is an unsaturated aliphatic hydrocarbon group containing 2 to 10 carbon atoms or an unsaturated cyclic hydrocarbon group containing 5 to 8 carbon atoms;

· polyorganosiloxanes comprising at least one alkylhydrogenosiloxane unit with formula:

2

where R is a linear or cyclic monovalent hydrocarbon group containing 1 to 30 carbon atoms or a phenyl group and p is equal to 1 to 2; and

• thermoplastic, thermocrosslinkable or

electrocrosslinkable polymers.

8. A composition according to any preceding claim,

wherein the photonic particles comprise at least one other diffracting arrangement of nanoparticles, in particular two other diffracting arrangements, the arrangements having different diffracting spectra.

9. A composition according to the preceding claim,

wherein the different arrangements diffract light through different respective zones of the photonic particle .

10. A composition according to either of the two preceding claims, wherein the arrangements of nanoparticles produce different respective colors, the arrangements in particular producing red, green and blue, when illuminated with white light.

11. A composition according to any preceding claim,

comprising a single type of photonic particle.

12. A composition according to any one of claims 1 to 10, comprising at least two different types of photonic particles.

13. A composition according to any one of claims 1 to 12, wherein the photonic particles have a reflection peak in the wavelength range 250 nm to 400 nm.

14. A composition according to any preceding claim,

wherein the nanoparticles (10) have a mean size having a coefficient of variation lying in the range 5 % to 15 %.

15. A composition according to any preceding claim,

wherein the photonic particles each have a mean size lying in the range 1 to 50 ym, better 1 to 40 ym, better 1 to 20 ym.

16. A composition according to any preceding claim,

wherein the nanoparticles have a mean size lying in the range 1 to 500 nm, in particular 1 to 350 nm, in particular 1 to 300 nm.

17. A composition according to any preceding claim,

wherein the nanoparticles are inorganic and, in particular, comprise silica.

18. A composition according to any preceding claim,

wherein the photonic particles are of the direct opal type .

19. A composition according to any one of claims 1 to 17, wherein the photonic particles are of the inverse opal type .

20. A composition according to any preceding claim,

wherein the matrix does not comprise additional nanoparticles, in particular of metal or metal oxide type, different from the nanoparticles constituting the diffracting arrangement.

21. A cosmetic composition comprising, in a cosmetically acceptable medium, at least one dispersion of photonic particles as defined in one of claims 1 to 20.

22. A method of photoprotecting a material against solar UV radiation, comprising treating said material with a composition as defined in claims 1 to 20 or comprising integrating said composition into said material.

23. A non-therapeutic, and in particular cosmetic,

photoprotection method of human keratinous material against solar UV radiation, comprising at least one step of applying a composition according to claim 21.

24. A method of coloring and/or lightening human

keratinous material, comprising a step of applying a composition according to claim 21.

25. A method of modifying the spectral reflectance of human keratinous material, comprising a step of applying a composition according to claim 21.

26. A method of photoprotecting an ink, a paint or a

coating, comprising incorporating at least one composition comprising a dispersion of photonic particles as defined in claims 1 to 20 into said ink or paint or said coating.

27. A method of photoprotecting a material manufactured from at least one synthetic or natural polymer, comprising treating said polymer with at least one composition comprising a dispersion of photonic particles as defined in claims 1 to 20 or comprising integrating said composition into said material.

. A method of photoprotecting an organic or mineral glass, comprising treating said glass with at least one composition comprising a dispersion of photonic particles as defined in claims 1 to 20 or comprising integrating said composition into said glass.

29. A method of photoprotecting a material comprising at least natural fibers and/or artificial fibers and/or synthetic fibers such as textiles or papers,

comprising treating said fibers with at least one composition comprising a dispersion of photonic particles as defined in claims 1 to 20 or comprising integrating said composition into said material.

30. A composition, in particular a cosmetic composition, comprising a dispersion of photonic particles each having a form factor of less than 2, said particles comprising a diffracting arrangement of voids or monodisperse nanoparticles in a thermo-, electro- or photo-crosslinkable matrix,

wherein said photonic particles are of the direct opal type and are substantially spherical in shape.

A composition, in particular a cosmetic composition, comprising a dispersion of photonic particles each having a form factor of less than 2, said particles comprising a diffracting arrangement of voids or monodisperse nanoparticles in a thermo-, electro- or photo-crosslinkable matrix,

wherein said photonic particles are of the inverse opal type.