FR3147712A1 - Cosmetic dispersion stabilized by steric suspension - Google Patents

Abstract

Cosmetic dispersion stabilized by steric suspension The present invention relates to a composition, in particular a cosmetic composition, in the form of a dispersion comprising a dispersed phase in the form of capsules and a continuous aqueous phase, characterized in that: - the capsules represent a volume fraction of between 50% and 70% relative to the total volume of the composition; - the capsules comprise a shell and a core comprising at least one fatty phase comprising at least one perfuming agent; - the capsules comprise a Ri / Rc ratio of between 0.5 and 0.8, preferably between 0.6 and 0.8, and better still between 0.6 and 0.7, in which: - Ri corresponds to the radius of the core of the capsules; and - Rc corresponds to the radius of the capsule. Figure: none

Description

Cosmetic dispersion stabilized by steric suspension

The present invention relates to a composition in the form of a dispersion comprising a dispersed phase in the form of capsules and a continuous aqueous phase, in which the capsules represent a volume fraction of between 50% and 70% relative to the total volume of the composition, in particular for a cosmetic application.

The preparation of perfume compositions is mainly based on the dissolution of aromatic compounds in a hydroalcoholic solution (mixture of water and alcohol, typically ethanol). The use of an alcohol such as ethanol, thanks to its solvent properties, allows the solubilization of aromatic compounds which are generally insoluble or poorly soluble in water.

However, alcohol has many disadvantages; it is a skin sensitizer, drying agent, irritant. Furthermore, its use is not recommended for young children. What is more, environmental protection regulations have become stricter regarding volatile compounds such as ethanol.

Water-based, ethanol-free perfume compositions are known. Such compositions are an alternative to perfumes based on alcoholic solvents but have not, to date, met with the expected commercial success. This is explained in particular by the fact that these water-based, ethanol-free perfume compositions contain a high level of surfactants, which is recognized as being an irritant and can lead to a greasy or sticky sensation on application and to a tightening of the skin. In addition, surfactants can modify the olfactory profile of the perfume agents.

Thus, there is currently a need in the field of perfumery and more generally of cosmetics to replace hydroalcoholic compositions and provide alcohol-free perfuming compositions and/or comprising a reduced quantity, or even zero, of surfactants compared to current compositions.

A first solution to meet this need consists of nano/micro-emulsions, notably described in US5468725 or WO2021156521, the stability of which is based on very small dispersed phase drops and on the use of high surfactant contents. However, this technical solution is not entirely satisfactory, as nano/micro-emulsions have a milky appearance, and the presence of surfactants in high contents generally leads to a sticky feel. What is more, surfactants are often irritating and have a poor image with consumers.

A second solution consists of dispersions in which the dispersed phase is in the form of macroscopic capsules dispersed in a continuous aqueous phase in the form of a suspensive aqueous gel thanks to the presence of hydrophilic gelling agents, chosen for example from carbomers or polysaccharides. Such dispersions, notably described in WO2010/063937, are generally transparent and have an attractive visual appearance. However, it is known that certain active agents present in the dispersed phase, in particular perfuming agents, migrate towards the continuous phase and lead to opacification of the latter and/or interact with the hydrophilic gelling agents, leading to a drop in viscosity of this continuous aqueous phase. These degradations then give an opaque and/or non-suspensive finished product, potentially acidic and with an inappropriate texture. What is more, the use of a suspensive aqueous gel makes a formulation in the form of a spray difficult, if not impossible. Finally, this type of dispersion requires the implementation of capsules with a sufficiently robust shell to ensure satisfactory kinetic stability. However, this robustness is sometimes to the detriment of sensoriality since the application of such dispersions is generally accompanied by the presence of an undesirable residual membrane. It is also this drawback that led the applicant to develop packaging provided with a tangential filter to retain the shells, as described in WO2014/027039. What is more, it is this drawback that also makes this type of dispersion incompatible with packaging equipped with a spray-type dispensing pump.

The aim of the present invention is to provide new compositions in the form of stable dispersions in which the system ensuring the suspension of said capsules remains effective, including in the presence of high contents of perfuming agent(s).

Furthermore, the present invention aims to provide novel compositions in the form of stable dispersions with easy adjustment capacity in dispersed phase ratio.

The present invention further aims to provide novel compositions in the form of stable dispersions with improved sensoriality.

Finally, the present invention aims to provide new compositions in the form of stable sprayable dispersions, that is to say which offer great suitability for spraying.

Thus, the present invention relates to a composition, in particular cosmetic, in the form of a dispersion comprising a dispersed phase in the form of capsules and a continuous aqueous phase, characterized in that:

- the capsules represent a volume fraction of between 40% and 80%, and in particular between 50% and 70%, relative to the total volume of the composition;

- the capsules comprise a shell and a core comprising at least one fatty phase comprising at least one perfuming agent; and

- the capsules comprise a Ri / Rc ratio of between 0.5 and 0.8, preferably between 0.6 and 0.8, and better still between 0.6 and 0.7, in which:

- Ri corresponds to the radius of the core of the capsules; and

- Rc corresponds to the radius of the capsule.

Against all expectations, the inventors observed that a composition according to the invention ensures satisfactory suspension of the capsules, easy adjustment of the content of the core of the capsules, and even very good suitability for spraying, including in the presence of high contents of perfuming agent(s) in dispersed phase.

Without wishing to be bound by any theory, the inventors believe that the minimum volume fraction required in macroscopic capsules makes it possible to place the composition according to the invention in a regime close to close packing (or "compact stacking"), which minimizes, or even makes negligible, the instabilities linked to the phenomena of creaming or sedimentation, in particular creaming, of the capsules. We can therefore speak of "steric suspension" or "autonomous suspension", each macroscopic capsule participating in the suspension of the adjacent capsules.

This observation is all the more unexpected since a composition according to the invention, despite a high capsule volume fraction, has a very satisfactory sensoriality, resulting in particular in the absence of residual bark (or “residual membrane”) or in the ability of the residual membranes, when present, to (i) not have too much of an impact on the appearance of the composition applied to the material to be treated and (ii) to spread and disappear easily when spread.

This observation is even more unexpected since a composition according to the invention, despite a high capsule volume fraction, remains compatible with spraying, that is to say with a formulation in the form of a spray.

According to the invention, the pH of a composition is typically between 4.0 and 8.0, in particular between 5.0 and 7.0.

Unless otherwise indicated, in all that follows, we consider that we are at room temperature (for example T = 25°C ± 2°C) and atmospheric pressure (760 mm Hg, or 1,013.10 ⁵ Pa or 10 ¹³ mbar).

Continuous aqueous phase

According to the invention, the continuous aqueous phase comprises at least water. In addition to distilled or deionized water, water suitable for the invention may also be natural spring water or floral water.

The continuous aqueous phase can serve as a dispersion medium for the capsules and ensure permanent hydration of their shell.

According to a particular embodiment, the continuous aqueous phase may comprise at least water and optionally at least one hydrophilic gelling agent, and thus be described as an “aqueous gel”.

By "hydrophilic" is meant a gelling agent that is soluble or dispersible in water.

A hydrophilic gelling agent makes it possible in particular to modulate the fluidity of the continuous aqueous phase, and therefore the texture and/or sensoriality of the composition.

Preferably, the mass percentage of water in the continuous aqueous phase is at least 70%, in particular between 70% and 98%, preferably between 80% and 95%, relative to the total mass of the continuous aqueous phase.

Preferably, the continuous aqueous phase represents a volume fraction of less than 50%, preferably between 15% and 49%, and in particular between 30% and 40%, relative to the total volume of the composition.

As additional hydrophilic gelling agent, we can cite:

- natural gelling agents, in particular chosen from algae extracts, plant exudates, seed extracts, microorganism exudates, such as alcasealan (INCI: Alcaligenes Polysaccharides), and other natural agents, in particular hyaluronic acid,

- semi-synthetic gelling agents, in particular chosen from cellulose derivatives and modified starches,

- synthetic gelling agents, in particular chosen from homopolymers of (meth)acrylic acid or one of their esters, copolymers of (meth)acrylic acid or one of their esters, copolymers of AMPS (2-acrylamido-2-methylpropane sulfonic acid), associative polymers, for example those described in FR2999921,

- other gelling agents, notably chosen from clays, silicas such as those marketed under the names Aérosil® 90/130/150/200/300/380), and

- their mixtures.

These hydrophilic gelling agents are described in more detail in FR3041251.

In particular, the hydrophilic gelling agents are preferably chosen from the group consisting of polysaccharides, galactomannans, polysaccharides, glycosaminoglycans, polyols, and mixtures thereof.

Advantageously, the hydrophilic gelling agents are chosen from the group consisting of xanthan, carrageenan, carob, guar, gellan, hyaluronic acid, cellulose derivatives, and mixtures thereof.

Of course, the person skilled in the art will take care to choose the possible hydrophilic gelling agents and/or their quantity in such a way that the advantageous properties of a composition according to the invention are not or are not substantially altered by the envisaged addition. These adjustments fall within the general knowledge of the person skilled in the art.

Preferably, a composition, particularly the continuous aqueous phase, does not comprise carbomer (or acrylic polymer).

Preferably, a composition, in particular the continuous aqueous phase, does not comprise a base, in particular alkali metal hydroxide, and in particular NaOH (or soda).

Preferably, the continuous aqueous phase is liquid and is non-suspending with respect to the capsules.

Preferably, the continuous aqueous phase has a high shear viscosity, as measured at 25°C and under a shear stress of 100 s ^-1 , of less than or equal to 100 mPa.s, preferably less than or equal to 50 mPa.s, in particular less than or equal to 25 mPa.s, and better still less than or equal to 10 mPa.s.

Preferably, a composition according to the invention is sprayable.

By “sprayable”, “spraying” or “sprayable”, within the meaning of the invention, is meant the capacity of a composition to be able to be sprayed in the form of fine droplets by means of spray-type delivery devices (pumps), or even pressurization (aerosols). In other words, a composition according to the invention is advantageously a vaporizable composition.

Advantageously, the continuous aqueous phase has a flow threshold value of less than or equal to 1 Pa, in particular less than or equal to 0.1 Pa, very particularly less than or equal to 0.01 Pa, or even has no flow threshold value. The flow threshold value is measured at 25°C, by the following method.

Viscosity and yield value are measured by the following method:

All measurements are performed with a Ta instrument DHR10 rheometer equipped with a 40mm diameter mobile forming a 1° cone - the measurement gap being 29µm. The rheometer is controlled by Trios software. The measurements are performed at 18°C, the temperature being controlled by a Peltier device. The rheological behavior is measured here using a shear sweep protocol (Flow sweep). Once the sample is in place and the temperature of 18°C is reached, the sample is left to rest for 60 seconds so that it can relax its constraints. It is then subjected to a logarithmic shear sweep between 0.01 and 500 s ^-1 with 5 points per decade. The viscosity (mPa.s) and stress (Pa) curves are plotted using Trios software. Analysis of the stress curve by software applying the Herschel-Bulkley model allows the rheological behavior to be expressed according to the following equation.

Or is the shear stress; is the flow threshold value; is the consistency coefficient; is the shear rate and is the flow index.

Preferably, a composition according to the invention comprises less than 10%, preferably less than 5%, in particular less than 2.5%, or even is free of alcohol(s), in particular ethanol, relative to the total weight of the composition.

The term “alcohol” is understood to mean, in particular, a lower alkyl alcohol, with the exception of any alcohol(s) present as a perfuming agent(s). A lower alkyl alcohol may be an aliphatic monoalcohol comprising from 2 to 6 carbon atoms. Such a lower alkyl alcohol may be ethanol.

The composition is preferably free of any lower alkyl alcohol.

For the purposes of the present invention, “ethanol-free” or “alcohol-free” may also refer to a cosmetic which is prepared by a preparation process preferably comprising no step of adding a lower alkyl alcohol and no step of mixing an alkyl alcohol with other ingredients.

However, it cannot be excluded that traces of lower alkyl alcohol, in particular traces of ethanol, may be present in some of the ingredients used in the preparation of the cosmetic of the invention, in particular in certain perfuming agents.

According to a particular embodiment, the continuous aqueous phase may further comprise at least one depolymerizing agent, in particular when the shell of the capsules comprises at least one polyelectrolyte in the gelled state, and in particular at least one polyelectrolyte reactive to multivalent ions, as described below.

In the context of the present description, the term “depolymerizing agent” means a compound capable of weakening the shell of the capsules to facilitate the application of the composition and in particular to prevent the appearance of residual shell (or “residual membrane”) during application. A depolymerizing agent is notably described in WO2013/132082. According to one embodiment, the polyelectrolyte of the capsules is chosen from polyelectrolytes reactive to calcium ions, such as a sodium alginate, and the depolymerizing agent is chosen from calcium chelating agents and salts capable of exchanging with calcium, such as EDTA.

Advantageously, the continuous aqueous phase is transparent so that the consumer can visualize the capsules.

Capsules

A composition according to the invention comprises macroscopic, and preferably monodisperse, capsules.

For the purposes of the present invention, the term “capsules” means a substantially spherical macroscopic element of the core/shell type, in which the shell completely encapsulates the core and the core comprises at least one drop of fatty phase, the fatty phase comprising at least one perfuming agent.

The capsules according to the invention form the “dispersed phase” or the “dispersed fatty phase”.

The bark can be referred to interchangeably by the terms “membrane” or “envelope”.

By “macroscopic”, “macroscopic capsule”, or “macroscopic dispersion” is meant, for the purposes of the present invention, capsules visible to the naked eye, as opposed to microscopic capsules not visible to the naked eye. Thus, preferably, the capsules have a diameter (or size) greater than or equal to 250 μm, or even greater than or equal to 500 μm, in particular between 250 μm and 3,000 μm, better still between 500 μm and 2,000 μm, and very particularly between 750 μm and 1,000 μm.

Bark

The bark completely encapsulating the core is advantageously a gelled envelope and/or an envelope deriving from a complex coacervation reaction.

Preferably, the bark is an aqueous phase.

Advantageously, the bark is transparent. This transparency of the bark is particularly advantageous insofar as it gives a composition according to the invention an impression according to which the drops (or core) of fatty phase do not touch each other and are perfectly suspended in the continuous aqueous phase.

Advantageously, the bark has a uniform thickness. By “uniform thickness”, for the purposes of the present invention, is meant capsules whose bark thickness varies according to a standard deviation of less than or equal to 10%, preferably less than or equal to 5%.

For the purposes of this description, the term “gelled shell” means an external phase surrounding the core of the capsules, and comprising at least one compound in the gelled state or in the form of a gel.

Typically, the shell is a hydrogel of at least one polyelectrolyte in the gelled state and/or of at least one thermosensitive hydrophilic gelling agent and/or is a shell which derives from a complex coacervation reaction between two oppositely charged polymers capable of coacervation.

Preferably, the shell comprises at least one polyelectrolyte in the gelled state and/or at least one thermosensitive hydrophilic gelling agent, and/or at least two oppositely charged polymers capable of coacerbating, and preferably at least one polyelectrolyte.

The gel coat is usually formed by a monolayer of a homogeneous material.

For obvious reasons, the thickness of the capsule shell according to the invention is advantageously adjusted to provide satisfaction in terms of mechanical strength, sprayability and sensoriality. This thickness of the capsule shell is further advantageous in that it intervenes in the Ri / Rc ratio, and gives a composition according to the invention the ability to easily modulate the fatty phase rate while retaining the required capsule volume fraction.

The invention is therefore based on an easy way of decorrelating the volume fraction of the capsules from the fatty phase rate, in particular by adjusting the thickness of the shell.

Thus, preferably, the shell of the capsules has a thickness of between 62.5 microns and 1200 microns, preferably between 100 microns and 1000 microns, better between 200 microns and 750 microns, particularly between 300 microns and 500 microns, or even between 100 microns and 200 microns.

In particular, the shell of the capsules has a thickness greater than 80 microns, preferably greater than 120 microns, and most particularly greater than 170 microns.

The presence of a shell of minimal thickness advantageously makes it possible to adjust, in particular to reduce, the content of polyelectrolyte(s) in the gelled state, thermosensitive hydrophilic gelling agent(s) and/or oppositely charged polymers capable of coacerbating. This makes it possible to obtain compositions according to the invention with optimized properties in terms of sprayability and sensoriality, while guaranteeing satisfactory mechanical strength of the capsules.

When transparent, the presence of a minimally thick shell is further advantageous in that it also contributes to the aforementioned visual impression that the drops (or core) of fatty phase do not touch each other and are perfectly suspended in the continuous aqueous phase.

Preferably, the shell of the capsules has a thickness different from the values between 80 microns and 200 microns, preferably between 100 microns and 180 microns, better between 120 microns and 170 microns.

Preferably, the capsule shell is a gelled envelope comprising a gel containing water and at least one polyelectrolyte advantageously chosen from proteins, natural polysaccharides and polyelectrolytes reactive to multivalent ions, and mixtures thereof.

For the purposes of the present invention, the term “polyelectrolyte reactive to polyvalent ions” means a polyelectrolyte capable of passing from a liquid state in an aqueous solution to a gelled state under the effect of contact with a gelling solution containing multivalent ions such as ions of an alkaline earth metal chosen for example from calcium ions, barium ions, magnesium ions.

In the liquid state, the individual polyelectrolyte chains are substantially free to flow relative to each other. An aqueous solution of 2% by mass of polyelectrolyte then exhibits purely viscous behavior at the shear gradients characteristic of the forming process. The viscosity of this solution at zero shear is between 50 mPa.s and 10,000 mPa.s, advantageously between 3,000 mPa.s and 7,000 mPa.s. This viscosity at the shear gradients characteristic of the flows involved during the manufacture of the capsules is for example measured using a stress or strain rheometer imposed at the manufacturing temperature, 25°C for example. For the measurements, a cone-plate geometry with a diameter of 10 to 50 mm and a cone angle of 1° maximum will be used.

The individual polyelectrolyte chains in the liquid state advantageously have a molar mass greater than 65000 g/mol.

In the gelled state, the individual polyelectrolyte chains form, together with the multivalent ions, a coherent three-dimensional network that holds the liquid core and prevents its flow. The individual chains are held relative to each other and cannot flow freely relative to each other. In this state, the viscosity of the gel formed is infinite.

The three-dimensional polyelectrolyte gel contained in the envelope traps water and the surfactant when present.

Advantageously, the polyelectrolyte is chosen from polysaccharides, synthetic polyelectrolytes based on acrylates (sodium, lithium, potassium or ammonium polyacrylate, or polyacrylamide), synthetic polyelectrolytes based on sulfonates (sodium poly(styrene sulfonate), for example). More particularly, the polyelectrolyte is chosen from alkaline earth alginates, such as a sodium alginate or a potassium alginate, a gellan or a pectin.

Preferably, the polyelectrolyte is selected from a protein such as collagen; a natural polysaccharide such as heparan sulfate; a polyelectrolyte reactive to multivalent ions, in particular a polysaccharide reactive to multivalent ions such as alginate, pectin, in particular Low Methoxyl pectin, carrageenan, in particular kappa and iota-carrageenan, gellan gum, diutan gum, furcellaran, or a derivative thereof, and mixtures thereof; and preferably a polyelectrolyte reactive to multivalent ions.

According to one embodiment of the invention, the polyelectrolyte is a sodium alginate.

Alginates are produced from brown algae called “laminaria”, also known as “sea weed”.

By “heat-sensitive gelling agent” is meant a gelling agent which reacts to heat, and in particular is a gelling agent which is solid at room temperature and liquid at a temperature above 40°C, preferably above 50°C.

Preferably, the thermosensitive hydrophilic gelling agent is selected from agar, kappa carrageenan, konjac, gelatin, and mixtures thereof.

Preferably, the thermosensitive hydrophilic gelling agent is not a hydrophilic gelling agent capable of gelling in the presence of at least one salt.

The oppositely charged and coacerbable polymers comprise at least one first cationic polymer and at least one second anionic polymer.

In view of the above, these oppositely charged and coacerbated polymers are advantageously hydrophilic.

According to a particular embodiment, the anionic polymer is hydrophilic and the cationic polymer is lipophilic, and therefore present in the fatty phase, or vice versa. This embodiment is notably illustrated in WO2012120043.

The oppositely charged polymers capable of coacerbating can be chosen from the pairs “gum arabic (or acacia gum) / gelatin”, “albumin / alginate” or “gelatin / alginate”.

Of course, the person skilled in the art will take care to choose the polyelectrolyte(s) and/or thermosensitive hydrophilic gelling agent(s) and/or oppositely charged polymers capable of coacerbating and/or their quantity in such a way that the advantageous properties of a composition according to the invention are not or are not substantially altered by the envisaged addition. These adjustments fall within the general knowledge of the person skilled in the art.

A composition according to the invention may advantageously comprise between 0.25% and 5%, preferably between 0.5% and 3%, and better still between 0.75% and 1%, by weight of polyelectrolyte(s) and/or thermosensitive hydrophilic gelling agent(s) and/or oppositely charged polymers capable of coacerbating, relative to the total weight of the bark.

Advantageously, the bark, in particular when represented by a gelled envelope as described above, can also comprise at least one surfactant.

The surfactant is advantageously an anionic surfactant, a nonionic surfactant, a cationic surfactant, or a mixture thereof. The molecular weight of the surfactant is advantageously between 150 g/mol and 10,000 g/mol, preferably between 250 g/mol and 1,500 g/mol.

In the case where the surfactant is an anionic surfactant, it is for example chosen from alkyl sulfates, alkyl sulfonates, alkylaryl sulfonates, alkali metal alkyl phosphates, dialkyl sulfosuccinates, alkaline earth salts of saturated or unsaturated fatty acids, or a mixture thereof. These surfactants advantageously have at least one hydrophobic hydrocarbon chain having a number of carbons greater than 5, or even 10, and at least one hydrophilic anionic group, such as a sulfate, a sulfonate or a carboxylate linked to one end of the hydrophobic chain.

In the case where the surfactant is a cationic surfactant, it is for example chosen from alkylpyridium or alkylammonium halide salts such as n-ethyldodecylammonium chloride or bromide, cetylammonium chloride or bromide (CTAB), or a mixture thereof. These surfactants advantageously have at least one hydrophobic hydrocarbon chain having a number of carbon atoms greater than 5, or even 10, and at least one hydrophilic cationic group, such as a quaternary ammonium cation.

In the case where the surfactant is a nonionic surfactant, it is for example chosen from polyoxyethylenated and/or polyoxypropylenated derivatives of fatty alcohols, fatty acids, or alkylphenols, arylphenols, or from alkylglucosides, polysorbates, cocamides, or a mixture thereof.

According to one embodiment of the invention, the surfactant is sodium lauryl sulfate (SLS or SDS) or sodium lauryl glutamate.

The mass content of surfactant(s) in the bark is advantageously greater than 0.001%, preferably greater than 0.1%, in particular between 0.001% and 1%, and better still between 0.01% and 0.5%, relative to the total weight of the bark.

Heart

The capsules comprise a liquid or at least partly gelled or at least partly thixotropic core, and preferably liquid.

According to a first particular embodiment, the fatty phase of the core of the capsules according to the invention is single-phase and therefore comprises only one fatty phase.

According to a second particular embodiment, the fatty phase of the core of the capsules according to the invention is at least biphasic; such a fatty phase is therefore in the form of an inverse emulsion (or “water-in-oil emulsion”) in which the dispersed phase is in the form of microscopic drops.

According to a first embodiment, the capsule is a so-called “simple” capsule, meaning that the core is monophasic, i.e. consisting of a single fatty phase, the fatty phase being placed in whole or in part in contact with the shell. A simple capsule is for example a capsule as described in WO2010/063937.

According to a first variant, a single capsule comprises two distinct phases, namely a fatty phase in the form of a single drop and an external phase in the gelled state surrounding the fatty phase. This first variant of a single capsule is illustrated in (10: capsule; 14: bark; 12: fatty phase).

According to a second variant, a single capsule comprises two distinct phases, namely a fatty phase in the form of several drops and an external phase in the gelled state surrounding all the drops of fatty phase. This second variant of a single capsule is illustrated in (10: capsule; 14: bark; 12: fatty phase).

Alternatively, in the simple capsules described above, the fatty phase may itself be in the form of an inverse emulsion.

According to another embodiment, the capsule is a so-called “complex” capsule, meaning that the core comprises an intermediate fatty phase, the intermediate fatty phase being placed in whole or in part in contact with the shell, and at least one internal drop of an internal phase arranged in the intermediate fatty phase.

According to a first variant, a complex capsule is such that the core comprises a single intermediate drop of an intermediate fatty phase, the intermediate fatty phase being placed in whole or in part in contact with the shell, and at least one internal drop of an internal phase arranged in the intermediate drop and immiscible with the intermediate drop. This second variant of a simple capsule is illustrated in (10: capsule; 14: bark; 12: fatty phase; 16: internal phase).

According to a second variant (not illustrated), a complex capsule is such that the core comprises several intermediate drops of intermediate fatty phase, the intermediate fatty phase being placed in whole or in part in contact with the shell, and each intermediate drop comprises at least one internal drop of an internal phase arranged in each intermediate drop and immiscible with the intermediate drop.

The core of such complex capsules can thus comprise an intermediate fatty phase within which there is a single drop of internal phase or a plurality of drops of internal phase(s).

Alternatively, in the complex capsules described above, the fatty phase may itself be in the form of an inverse emulsion.

For obvious reasons, the continuous aqueous phase and the fatty phase are immiscible. By “immiscible” or “non-miscible” within the meaning of the present invention, it is meant that the solubility of a first phase in a second phase is advantageously less than 5% by mass, and vice versa.

For obvious reasons, in complex capsules the intermediate fat phase and the internal phase are immiscible.

Thus, according to a first variant of complex capsules, the intermediate phase is a fatty phase and the internal phase is an aqueous phase. According to a second variant, the intermediate phase is a first fatty phase and the internal phase is a second fatty phase immiscible with the first fatty phase. Pairs of immiscible oils are notably described in FR3063893.

Each internal drop of a complex capsule advantageously has a substantially spherical shape. Alternatively, the shape of the internal drop is different from a spherical shape, for example elliptical or lenticular.

The internal drops of complex capsules are advantageously macroscopic. The internal drops of complex capsules advantageously have a size (or diameter) greater than 150 µm, and in particular greater than or equal to 100 µm, preferably greater than or equal to 200 µm, but in all cases necessarily less than the diameter of the core of the capsules. Determining the size of the capsules or drops falls within the general knowledge of a person skilled in the art, and can in particular be measured by a method using the image processing software “Image J”.

The sum of the volumes of the or each internal drop is advantageously between 5% and 65% of the total volume of the core, and preferably between 10% and 55% of the volume of the core.

In view of the above, in a composition according to the invention, the capsules may comprise a liquid core or at least partly gelled or at least partly thixotropic, the core being single-phase or comprising an intermediate drop of fatty phase, and at least one, preferably a single, internal drop of an internal phase arranged in the intermediate drop.

The minimum volume of the core is advantageously between 5% and 80%, preferably between 10% and 70%, better between 20% and 60%, and particularly between 30% and 50%, relative to the total volume of the capsule.

Preferably, the core of the capsules has a diameter between 125 μm and 1,500 μm, better between 250 μm and 1,200 μm, and very particularly between 500 μm and 1,000 μm.

In the case of complex capsules, the core is understood to be the intermediate phase and the internal phase.

The capsules of a composition according to the invention represent a volume fraction of between 50% and 70% relative to the total volume of the composition.

As previously indicated, it is this high volume fraction in capsules which ensures their suspension in the continuous aqueous phase.

Preferably, the volume fraction of the capsules is between 55% and 65%, and preferably between 57% and 63% relative to the total volume of the composition.

In particular, the inventors have observed that the nature and/or content of polyelectrolyte(s) and/or thermosensitive hydrophilic gelling agent(s) forming the shell of the capsules makes it possible to modulate the mechanical resistance (or resistance to compression), and therefore the deformability, of the capsules, thus making it possible to further increase the volume fraction of the capsules relative to the total volume of the composition.

Thus, and as indicated above, the capsules of a composition according to the invention capsules comprise a Ri / Rc ratio of between 0.5 and 0.8, preferably between 0.6 and 0.8, and better between 0.6 and 0.7, in which:

- Ri corresponds to the radius of the core of the capsules; and

- Rc corresponds to the radius of the capsule, namely resulting from the sum of the radius of the core of the capsules and the thickness of the bark.

In cases where the capsules are complex capsules, Rc also includes the radius of the internal phase internal drops.

Preferably, the capsules according to the invention comprise a ratio (e) / Ri of between 0.2 and 1, preferably between 0.3 and 0.8, and very particularly between 0.4 and 0.7, in which:

- (e) corresponds to the thickness of the bark; and

- Ri corresponds to the radius of the core of the capsules.

As can be seen from example 4 below, these values of the Ri/Rc ratio or the (e)/Ri ratio correspond to a satisfactory and non-obvious compromise between mechanical resistance, sprayability and sensoriality.

According to a particular embodiment, a composition according to the invention may comprise between 45% and 85%, preferably between 50% and 75%, and better between 55% and 70%, by weight of capsules relative to the total weight of the composition.

Advantageously, a composition according to the invention may comprise between 5% and 40%, preferably between 10% and 30%, and better between 15% and 20%, by weight of fatty phase relative to the total weight of the composition.

Fragrances

The core of the capsules includes at least one perfuming agent.

For obvious reasons, a perfuming agent according to the invention is a lipophilic agent, that is to say soluble or dispersible in an organic solvent, in particular an oil.

A “perfuming agent”, also indifferently referred to as “perfume”, “perfume juice” or “perfume concentrate”, within the meaning of the present invention, may be chosen from compounds having the INCI name “Perfume” or “Fragrance”. Thus, within the meaning of the present invention, the term “perfume” does not designate a mixture comprising a perfume concentrate and alcohol.

The perfuming agents that can be used according to the invention are ingredients commonly used in perfumery. Their nature does not require a more detailed description here, which cannot be exhaustive, since a person skilled in the art is able to choose them based on his general knowledge and according to the desired olfactory effect. These perfuming agents belong to chemical classes as varied as alcohols, aldehydes, ketones, esters, ethers, acetates, nitriles, terpene hydrocarbons, nitrogenous or sulfurous heterocyclic compounds, as well as essential oils of natural or synthetic origin. Many of these ingredients are also listed in reference texts such as the book by S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, New Jersey, USA, or its more recent versions, or in other works of a similar nature, as well as in the more recent scientific and patent literature relating to the art of perfumery.

For example, a fragrance agent is a compound or mixture of compounds that is at least partially volatile at room temperature and whose odor can be detected. A fragrance agent composed of essential oils is generally diluted in order to express its full olfactory potential, i.e. a perception that evolves during the day after application to the surface to be treated, thanks to the presence of several odorous organic compounds having different volatilities from each other. The development of a perfume includes a step of combining several fragrance raw materials to give a top note, a heart note and a base note to the fragrance composition.

A fragrance agent can be prepared from natural or synthetic organic fragrance materials.

Examples of natural fragrance materials are extracts of flowers, leaf stems, fruits, barks, roots, woods, herbs, grasses, resins, balms, and mixtures thereof.

These plant fragrance materials may be essential oils, such as bergamot, rose, lavender, sandalwood, cardamom, sage, chamomile, clove, lemon balm, mint, cinnamon leaf, juniper, vetiver, olibanum, galbanum, labdanum, and mixtures thereof.

Examples of fragrance materials of synthetic origin are hedione, ethylene brassilate, habanolide, benzyl acetate, benzyl benzoate, phenoxyethyl isobutyrate, p-tert-butylcyclohexyl acetate, citronellyl acetate, citronellyl formate, geranyl acetate, linalyl acetate, dimethylbenzylcarbinyl acetate, phenylethyl acetate, linalyl benzoate. , benzyl formate, ethyl methyl phenyl glycinate alkylcyclohexyl propionate, styralyl propionate and benzyl salicylate, benzyl ethyl ether, linear alkanals of 8 to 18 carbon atoms, citral, citronellal, citronellyloxyacetaldehyde, cyclamenaldehyde, hydroxycitronellal, ionones such as alpha-isomethylionone, methyl cedrylketone, anethole, citronellol, eugenol, isoeugenol, geraniol, linalool, phenylethyl alcohol, terpineol, terpenes, and mixtures thereof.

These compounds often occur as a mixture of two or more of these odorous substances.

The characteristics of a composition according to the invention, in particular those of the capsules, are such that they allow high contents of perfuming agent(s), without prejudice to the kinetic stability of the composition and in particular without prejudice to the suspension of the capsules in the continuous aqueous phase.

Thus, the fatty phase of a composition according to the invention can advantageously comprise from 5% to 30%, and preferably from 10% to 20%, by weight of perfuming agent(s) relative to the total weight of the composition.

Also, the composition may advantageously comprise from 5% to 100%, preferably from 10% to 90%, in particular from 25% to 80%, or even from 50% to 70%, by weight of perfuming agent(s) relative to the total weight of the fatty phase of the capsules.

Oils

According to a particular embodiment, the core of the capsules can further comprise at least one oil.

The term "oil" means a fatty substance that is liquid at room temperature.

As oils which can be used in a dispersion of the invention, we can cite for example:

- hydrocarbon oils of vegetable origin, such as hydrogenated jojoba oil, hydrogenated sunflower oil, hydrogenated castor oil, hydrogenated copra oil;

- hydrocarbon oils of animal origin, such as perhydrosqualene and squalane;

- synthetic esters and ethers, in particular of fatty acids, such as oils of formulas R1COOR2 and R1OR2 in which R1 represents the residue of a C8 to C29 fatty acid, and R2 represents a branched or unbranched C3 to C30 hydrocarbon chain, such as for example Purcellin oil, isononyl isononanoate, isodecyl neopentanoate, isopropyl myristate, 2-ethylhexyl palmitate, 2-octyldodecyl stearate, 2-octyldodecyl erucate, isostearyl isostearate; hydroxylated esters such as isostearyl lactate, octylhydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate, triisocetyl citrate, fatty alcohol heptanoates, octanoates, decanoates; polyol esters, such as propylene glycol dioctanoate, neopentyl glycol diheptanoate and diethylene glycol diisononanoate; and pentaerythritol esters such as pentaerythrityl tetrabehenate (DUB PTB) or pentaerythrityl tetraisostearate (Prisorine 3631);

- linear or branched hydrocarbons, of mineral or synthetic origin, such as paraffin oils, volatile or not, and their derivatives, petroleum jelly, polydecenes, hydrogenated polyisobutene such as Parléam oil;

- silicone oils, such as volatile or non-volatile polymethylsiloxanes (PDMS) with a linear or cyclic silicone chain, liquid or pasty at room temperature, in particular cyclopolydimethylsiloxanes (cyclomethicones) such as cyclohexasiloxane and cyclopentasiloxane; polydimethylsiloxanes (or dimethicones) comprising alkyl, alkoxy or phenyl groups, pendant or at the end of the silicone chain, groups having from 2 to 24 carbon atoms; phenylated silicones such as phenyltrimethicones, phenyldimethicones, phenyltrimethylsiloxydiphenylsiloxanes, diphenyldimethicones, diphenylmethyldiphenyl trisiloxanes, 2-phenylethyltrimethylsiloxysilicates, and polymethylphenylsiloxanes;

- fatty alcohols with 8 to 26 carbon atoms, such as cetyl alcohol, stearyl alcohol and their mixture (cetylstearyl alcohol), or octyldodecanol;

- partially hydrocarbon and/or silicone fluorinated oils such as those described in document JP-A-2-295912;

- and their mixtures.

According to another preferred embodiment, the fatty phase does not comprise silicone oil, and preferably does not comprise polydimethylsiloxane (PDMS).

Of course, the person skilled in the art will take care to choose the possible oils and/or their quantity in such a way that the advantageous properties of a composition according to the invention are not or are not substantially altered by the envisaged addition. These adjustments fall within the general knowledge of the person skilled in the art.

According to one embodiment, a dispersion according to the invention comprises between 0% and 95%, in particular between 10% and 90%, preferably between 20% and 75%, and in particular between 30% and 50%, by weight of oil(s) relative to the total weight of the fatty phase.

Lipophilic gelling agents

According to a particular embodiment, the core of the capsules may further comprise at least one lipophilic gelling agent, in particular when the core is at least partly gelled or at least partly thixotropic.

A lipophilic gelling agent, i.e. soluble or dispersible in the fatty phase, may be chosen from organic or mineral, polymeric or molecular gelling agents; fatty substances that are solid at room temperature and pressure, in particular chosen from waxes, pasty fatty substances, butters; and mixtures thereof, and preferably from polymeric gelling agents. Such lipophilic gelling agents are described in particular in WO2019002308.

Among the lipophilic gelling agents that can be used in the present invention, mention may be made of dextrin and fatty acid esters, such as dextrin palmitates. Among the dextrin and fatty acid esters, mention may be made, for example, of dextrin palmitates, dextrin myristates, dextrin palmitates/ethylhexanoates and mixtures thereof. Mention may in particular be made of the dextrin and fatty acid esters marketed under the names Rheopearl® KL2 (INCI name: dextrin palmitate), Rheopearl® TT2 (INCI name: dextrin palmitate ethylhexanoate), and Rheopearl® MKL2 (INCI name: dextrin myristate) by the company Miyoshi Europe, also dextrin palmitate marketed by The Innovation Company.

Other examples include THIXCIN® R from Elementis Specialties (INCI: Trihydroxystearin), OILKEMIA™ 5S polymer from Lubrizol (INCI: Caprylic/Capric Triglyceride (and) Polyurethane-79), Oilkemia™ 5S CC polymer, (INCI: Caprylic/Capric Triglyceride (and) Hydrogenated Poly(C6-20 Olefin) (and) HDI/Trimethylol Hexyllactone Crosspolymer), Estogel M from PolymerExpert (INCI: CASTOR OIL / IPDI COPOLYMER & CAPRYLIC / CAPRIC TRIGLYCERIDE), EMC30 (INCI: Caprylic/Capric Triglyceride (and) Castor Oil/IPDI Copolymer), Hydrogenated Castor Oil/Sebacic Acid Copolymer and its derivatives, notably marketed respectively under the names Estogel Green (or Estogel G) and Estogel Green 40 by PolymerExpert, and their mixtures.

Advantageously, a lipophilic gelling agent is a heat-sensitive gelling agent.

According to the invention, a composition according to the invention may comprise from 0.5% to 30%, preferably from 1% to 25%, in particular from 1.5% to 20%, better still from 2% to 15%, and very particularly from 5% to 12%, by weight of lipophilic gelling agent(s) relative to the total weight of the fatty phase.

Of course, the person skilled in the art will take care to choose the possible lipophilic gelling agent(s) and/or their quantity in such a way that the advantageous properties of a composition according to the invention are not or are not substantially altered by the envisaged addition. These adjustments fall within the general knowledge of the person skilled in the art.

Monodispersity

Preferably, the capsules have a monodisperse distribution.

This monodispersity advantageously contributes to the aforementioned steric suspension and sprayability. Indeed, the inventors have observed that with a composition comprising polydisperse capsules, the smaller capsules tend to occupy the spaces between the larger capsules. This phenomenon leads to a local increase in the capsule density and therefore mechanically to a creaming of the capsules. These drawbacks impact the visual appearance of the composition and the homogeneity during application, or even the sprayability of the composition. A solution to counteract these drawbacks would consist in adding in a continuous aqueous phase at least one hydrophilic gelling agent such as those described above for the purpose of increasing the viscosity. However, this solution is not optimal in view of the aforementioned drawbacks with the dispersions of the prior art.

For the purposes of the present invention, the term "monodisperse" means a composition whose polydispersity in capsule size, measured by the coefficient of variation C _v consisting of the ratio of the standard deviation to the mean, is less than 10%, and in particular between 1% and 10%.

This ratio can be measured, for example, on the basis of the diameters measured on at least seven capsules using the image processing software “Image J”, based on a top-view photograph of the capsules taken with a digital camera.

Alternatively, the mass polydispersity of the capsules can be calculated, based on at least fifty measurements of the mass of fifty complex capsules made using a Mettler-Toledo type balance with an accuracy of 0.1 mg.

Additional compound(s)

According to the invention, a dispersion according to the invention, in particular the continuous phase and/or the constituent phase of the bark and/or the fatty phase, may further comprise at least one additional compound other than the oils, hydrophilic and lipophilic gelling agents, and the aforementioned perfuming agents.

The dispersions according to the invention may thus also comprise powders; reflective particles, in particular flakes, in particular as defined in FR3082731; coloring agents, in particular chosen from water-soluble or non-water-soluble, fat-soluble or non-fat-soluble, organic or inorganic coloring agents, materials with an optical effect, liquid crystals, and mixtures thereof; fillers, in particular as described in FR1755907; emulsifying and/or non-emulsifying silicone elastomers, in particular as described in EP2353577; “soft focus” fillers; texturizing agents, in particular polyethylene glycols (e.g. marketed under the name Carbowax) or glycerin; preservatives; humectants; stabilizers; chelating agents; emollients; pH modifying agents, osmotic force modifying agents and/or refractive index modifiers, etc. or any usual cosmetic additive; and their mixtures.

Additional dispersed phase

A composition according to the invention may further comprise:

- capsules comprising a shell and a core comprising at least one aqueous phase, optionally the aqueous core further comprises at least one hydrophilic active agent; and/or

- macroscopic solid (or matrix) beads.

For the purposes of the present invention, the term “pearls” means a substantially spherical macroscopic element devoid of bark, the constituent phase being also able to comprise at least one active agent, in particular at least one perfuming agent.

In the context of the present invention, the solid beads may indifferently be designated by the expression “beads”, “balls”, “spheres” or “additional dispersed phase”.

A composition according to the invention may further comprise hydrophilic or lipophilic macroscopic solid pearls.

A composition according to the invention may further comprise macroscopic solid pearls whose constituent phase is a direct or reverse emulsion.

A hydrophilic macroscopic solid bead comprises water and at least one polyelectrolyte in the gelled state and/or at least one thermosensitive hydrophilic gelling agent, in particular as described above.

A lipophilic macroscopic solid pearl comprises at least one lipophilic gelling agent and optionally at least one oil, in particular as described above.

Such pearls allow the presence in a composition according to the invention of a hydrophilic or lipophilic active agent incompatible with other ingredients present in the composition.

As lipophilic active agent, we can cite those described previously.

As hydrophilic active agent, we can cite proteins or protein hydrolysates, amino acids, polyols in particular C2 to C10, urea, allantoin, sugars and sugar derivatives, water-soluble vitamins, starch, bacterial or plant extracts such as those of Aloe Vera, and their mixtures.

Special embodiments

A composition according to the invention may comprise a single population of capsules among the different variants of simple and complex capsules described above.

Alternatively, a composition according to the invention may comprise at least two different populations of capsules chosen from the different variants of simple and complex capsules described above.

Thus, according to a first variant embodiment, a composition according to the invention can comprise at least two populations of capsules with different Ri/Rc ratios, of identical or different sizes, as illustrated in example 5 below.

According to a second variant embodiment, a composition according to the invention may comprise a first population of simple capsules and a second population of complex capsules, of identical or different sizes.

Such alternative embodiments may further comprise solid beads as described above.

All these variants are advantageous in that they allow in particular access to compositions comprising macroscopic elements of different densities and/or sizes and/or mechanical resistance, thus being able to lead to different visual/aesthetic effects and/or cosmetic effects and/or sensory effects.

Preparation process

The preparation of a continuous aqueous phase of a composition according to the invention falls within the general knowledge of those skilled in the art.

The preparation of the capsules of a composition according to the invention also falls within the general knowledge of a person skilled in the art. By way of illustration, the capsules of a composition according to the invention may be obtained by means of non-micro/millifluidic manufacturing processes, such as for example by stirring with a Rayneri, or by means of micro/millifluidic manufacturing processes, for example those described in WO2010063937, FR2964017, WO2012089820, WO2021037999, WO2022106361, EP2292752, EP0525731, EP1020177, EP1025842.

The preparation of solid pearls also falls within the general knowledge of a person skilled in the art. By way of illustration, the pearls can be obtained using any method known to a person skilled in the art, for example those described in BRPI1001438 or FR2645439.

Uses

Preferably, a composition according to the invention can be used directly, following the aforementioned preparation processes, as a composition, in particular a cosmetic composition.

The compositions according to the invention can therefore be used in particular in the cosmetic field.

They may include, in addition to the above-mentioned ingredients or compounds, at least one physiologically acceptable medium.

The physiologically acceptable medium is generally adapted to the nature of the support on which the composition is to be applied, as well as to the aspect in which the composition is to be packaged.

According to one embodiment, the physiologically acceptable medium is represented directly by the aqueous continuous phase as described above.

In the context of the invention, and unless otherwise stated, the term "physiologically acceptable medium" means a medium suitable for cosmetic applications, and particularly suitable for the application of a composition of the invention to a keratin material, particularly the skin and/or hair, and more particularly the skin.

A cosmetic composition according to the invention may be an eau de toilette, an eau de Cologne, a perfume extract, a spirit of perfume, a veil of perfume, an eau de parfum or an eau de parfum.

Thus, a cosmetic composition according to the invention is advantageously a perfume composition, in particular an alcohol-free perfume composition, in liquid form comprising macroscopic capsules intended to perfume an individual after spraying or application to the skin, hair and/or clothing. Such a product is not rinsed after application.

A perfume composition will thus be distinguished from a scented composition. Indeed, a cosmetic composition can be perfumed without being perfumed.

Thus, preferably, a composition according to the invention is not dedicated to the care and/or makeup of a keratin material.

The invention also relates to a bottle provided with an application means and a packaging means, said packaging means containing a composition as described above.

A composition according to the invention is oral or topical, preferably topical.

The present invention also relates to a non-therapeutic cosmetic treatment process, in particular for perfuming a keratin material or a garment, comprising at least one step of applying to the keratin material and/or said garment at least one composition according to the invention.

The present invention also relates to the use of at least one composition according to the invention, for perfuming a keratin material or a garment.

The composition will preferably be applied/used by means of a spraying device (or means).

Throughout the description, the expression “comprising a” shall be understood as being synonymous with “comprising at least one”, unless otherwise specified. The expressions “between … and …”, “from … to …” and “ranging from … to …” shall be understood inclusively, unless otherwise specified.

EXAMPLES

Example 1 : Preparation of a continuous aqueous phase

The table below indicates the composition of an aqueous phase, dedicated to representing the continuous aqueous phase of the compositions described in examples 3 to 5 below. Compound %mass Water QSP* Glycerol 19.0 Propanediol (Zemea, Dupont Tate) 7.0 Microcare PE (Phenoxyethanol) 0.89 Microcare emollient PTG (Pentylene
Glycol) 2.22 Total 100

* Sufficient Quantity For

The preservatives were first dispersed in the glycols (glycerol and propanediol) by stirring with a paddle stirrer. Finally, water was added and the mixture was mixed with a paddle stirrer for 1 hour.

The aqueous phase obtained is transparent and has a viscosity of less than 15 mPa.s.

Example 2: Preparation of capsules

The table below shows the composition of single capsules comprising a gelled alginate shell and a core of a perfumed fatty phase. Trade name INCI %mass/phase %mass /capsule OF Water
Water 98.36 80.14 Protanal LF 200S Sodium alginate 1.5 1.22 SDS Sodium lauryl sulfate 0.14 0.11 IF Scent Fragrance 90 16.67 DUB MCT55/45 MB Caprylic/Capric triglyceride 10 1.85 Total 100.00%

A. Preparation of the first liquid solution (IF)

The perfume and the oil are mixed and stirring is continued until homogenized.

B. Preparation of the second liquid solution (OF)

SDS and sodium alginate were added to water under magnetic stirring. The solution was kept stirring for 24 hours to ensure that the alginate was completely dissolved and the solution was homogeneous.

C. Preparation of the gelling solution

200 g of calcium chloride were dissolved in 1000 g of water.

D. Obtaining the capsules

• convoyage séparé dans une buse sous forme d’une double enveloppe de la première solution liquide (IF) et de la deuxième solution liquide (OF) ;
• formation, à la sortie de la double enveloppe, d’une série de gouttes, chaque goutte comprenant un noyau central formé de première solution (IF) et une pellicule périphérique formée de deuxième solution (OF), recouvrant totalement le noyau central ; l’étape de formation de la série de gouttes comprend une étape de formation d’un jet liquide à la sortie de la double enveloppe et une étape de fragmentation du jet liquide en gouttes ;
• immersion de chaque goutte dans la solution gélifiante de manière à faire passer l’alginate de sodium de la seconde solution liquide (OF) d’un état liquide à un état gélifié et former l’enveloppe gélifiée, le noyau central formant le cœur liquide, ce par quoi on obtient des capsules ; et
• récupération des capsules formées.

The capsule manufacturing process is based on the concentric co-extrusion of two solutions, notably described in FR2964017, implemented with the flow rates described in the table below. The capsules were therefore obtained according to the following steps:

• separate conveying in a nozzle in the form of a double envelope of the first liquid solution (IF) and the second liquid solution (OF);
• formation, at the outlet of the double envelope, of a series of drops, each drop comprising a central core formed of first solution (IF) and a peripheral film formed of second solution (OF), completely covering the central core; the step of forming the series of drops comprises a step of forming a liquid jet at the outlet of the double envelope and a step of fragmenting the liquid jet into drops;
• immersing each drop in the gelling solution so as to cause the sodium alginate of the second liquid solution (OF) to pass from a liquid state to a gelled state and form the gelled shell, the central core forming the liquid heart, whereby capsules are obtained; and
• recovery of the formed capsules.

The flow rates are as follows: Phase Flow rate per nozzle (in ml/hr) OF 40.74 IF 9.26

Simple macroscopic and monodisperse capsules with a size (or diameter) of 800 μm are obtained.

Example 3: Influence of volume fraction

Example 3 consists of bringing into contact and mixing the capsules of Example 2 with the continuous aqueous phase of Example 1 in a 100 ml package equipped with a spray-type dispensing pump, in different “continuous aqueous phase/capsules” ratios as described below.

Scoring criteria:

0 1 2 Suspensivity Zero suspension; strong creaming in less than 1 min. at RT* Partial suspension; slight creaming after 1 hour at RT* Satisfactory suspension;
no creaming after 1 month at RT* Sprayability Poor sprayability and/or delivery Average sprayability and/or inhomogeneous delivery Good sprayability with homogeneous delivery Brilliance Composition that does not reflect light Composition that reflects light without shining Composition that reflects light and shines

* TA: Room Temperature

Tests and results:

Tests φ PAC ⁽¹⁾ φ capsules ⁽²⁾ Suspensivity Sprayability Brilliance Perfume rate 3.1 70 30 0 NA ⁽³⁾ 0 5 3.2 60 40 1 NA ⁽³⁾ 0 6.67 3.3 50 50 2 1 1 8.33 3.4 40 60 2 2 2 10 3.5 30 70 2 1 2 11.67 3.6 20 80 2 0 2 13.33

⁽¹⁾ φ PAC: volume fraction of the Continuous Aqueous Phase according to example 1 relative to the total volume of the composition.

⁽²⁾ φ Capsules: volume fraction of the capsules according to example 2 relative to the total volume of the composition.

⁽³⁾ NA: Not Applicable

From the above results, it is observed that a capsule volume fraction of less than 50% does not allow a satisfactory steric suspension due to too rapid creaming of the capsules. During use, a preferential distribution of the continuous aqueous phase is observed, leading to an increase in the capsule concentration as the product is used. Mechanically, the formulation of the dispensed composition is inhomogeneous, i.e. mainly composed of the continuous aqueous phase at the start of use and then increasingly concentrated in the dispersed phase as use progresses. An exact and constant formulation of the product delivered throughout its use is therefore impossible to guarantee. This increase in capsule concentration even leads, after a while, to the suction/delivery device becoming blocked. This explains the “NA” rating for tests 3.1 and 3.2.

From a volume fraction in capsules of 50%, a composition capable of ensuring a suspension of the capsules in the continuous aqueous phase is achieved. Consequently, an exact and constant formulation of the product delivered is observed throughout the use of the product, as well as the absence of obstruction phenomena, or even blockages, at the level of the suction/delivery device, which is particularly unexpected given the high concentration of capsules.

Finally, from a volume fraction in capsules of 70%, we observe that the product becomes less and less fluid to be homogeneously pumped. A significant degradation of the sprayable character of the composition occurs from a volume fraction in capsules of 80%.

It should be noted that all samples have very interesting aesthetic properties in the packaging. Indeed, in these samples, the macroscopic capsules are clearly visible, and in particular the core of the capsules, which is all the easier since the continuous aqueous phase and the shell are transparent. Furthermore, it should be noted that the volume fraction, in addition to the suspension of the capsules and the sprayability, also impacts the more or less shiny character of the composition.

Finally, it is observed that tests 3.3 to 3.5 relate to alcohol-free perfume compositions which offer high sprayability whilst maintaining the stability and olfactory properties of the perfume agent.

Example 4: Influence of the Ri / Rc ratio

Example 4 consists of contacting and mixing, in the continuous aqueous phase described in Example 1, capsules in a volume fraction of 60% relative to the total volume of the composition. These capsules differ from Example 2 in terms of flow rates, as indicated in the table below.

The compositions obtained are packaged in 100 ml packaging with a spray-type dispensing pump.

There illustrates the evolution of the Ri / Rc ratio and the (e) / Ri ratio for these tests 4.1 to 4.6. Tests 4.1 4.2 4.3 4.4 4.5 4.6 Comp. Inv. Inv. Inv. Inv. Comp. OF flow ⁽⁴⁾ 46.67 43.33 38.33 32.5 25 13.11 IF Flow ⁽⁴⁾ 3.33 6.67 11.67 17.5 25 36.89 Ri (in microns) 162 204 246 282 317 361 (e) (in microns) 238 196 154 118 83 39 Rc (in microns) 400 400 400 400 400 400 Size (in microns) 800 800 800 800 800 800 % fat phase / composition 4 8 14 21 30 45 Ri / Rc ratio ⁽⁵⁾ 0.41 0.51 0.62 0.71 0.79 0.90 Report (e) / Ri ⁽⁵⁾ 1.47 0.96 0.62 0.42 0.26 0.11

⁽⁴⁾ Flow rate per nozzle (in ml/hr)

⁽⁵⁾ Ri corresponds to the radius of the core of the capsules; Rc corresponds to the radius of the capsule (i.e. resulting from the sum of the radius of the core of the capsules and the thickness of the bark); (e) corresponds to the thickness of the bark.

Scoring criteria:

0 1 2 Mechanical resistance

(Rm) ⁽⁶⁾ Low Rm
Capsule rupture in the packaging -> opacification -> significant visual alteration and creaming Average Rm
Leakage of fatty phase into the aqueous phase continues -> shrivelled or empty capsules, with opacification -> visual impairment Good Rm
Capsules/stable composition(s), no opacification Sprayability Poor sprayability, even clogging
(capsules too robust) Average sprayability and/or inhomogeneous delivery Good sprayability with homogeneous delivery Sensoriality ⁽⁷⁾ Very uncomfortable application; hard and persistent residual membranes on application Uncomfortable application; residual membranes hard and difficult to remove upon application Comfortable application with little or no residual membranes that disappear easily and quickly upon application

⁽⁶⁾ Rm = Mechanical resistance, also called "compressive resistance". The principle is to exert a stress at constant speed on a capsule and measure the force required to rupture the capsule. A method for measuring this mechanical resistance is described in particular in WO2015075074.

⁽⁷⁾ The sensoriality is reflected in particular by an easy and comfortable application of the composition on the material to be treated, and in particular by the absence of residual membrane, at least the ability of these residual membranes, when present, to (i) not have too much of an impact on the visual aspect of the composition applied to the material to be treated and (ii) to spread and disappear easily when spread.

Tests and results:

Tests Mechanical resistance Sprayability Sensoriality 4.1 2 0 0 4.2 2 1 1 4.3 2 2 2 4.4 2 2 2 4.5 1 2 2 4.6 0 2 2

Test 4.1 is characterized by capsules with a very thick shell. Such capsules provide a very stable composition but with unsatisfactory sprayability and sensoriality.

Test 4.6 is characterized by capsules with a very large fatty phase core. Such capsules allow access to a composition very loaded with perfume but their robustness is insufficient.

Interesting results are obtained with tests 4.2 to 4.5, for which the Ri / Rc ratio is between 0.5 and 0.8. The best results are obtained with tests 4.3 and 4.5, and even 4.3 and 4.4, corresponding to a Ri / Rc ratio between 0.6 and 0.8, and particularly between 0.6 and 0.7. These Ri / Rc ratio values therefore correspond to the best non-obvious compromises between mechanical resistance, sprayability and sensoriality.

Finally, it is observed that tests 4.2 to 4.5 relate to alcohol-free perfume compositions which offer high sprayability whilst maintaining the stability and olfactory properties of the perfume agent.

Example 5: composition according to the invention with a double population of capsules

Example 5 consists of bringing into contact and mixing, in a continuous aqueous phase according to example 1, capsules according to examples 4.3 and 4.5 above and according to the volume fractions described in the table below.

The capsules differ, however, from examples 4.3 and 4.5 by the addition, in the fatty phase, of coloring agents, namely a red coloring agent (i.e. D&C Red No. 17 K7007 (INCI: CI 26100 – 0.001%) for the capsules according to example 4.3 and a blue coloring agent (i.e. Phat Blue DC 6204 (INCI: CI 61565 / CI 60725 – 0.001%) for the capsules according to example 4.5. Volume fraction (in %) Capsules according to example 4.3 25 Capsules according to example 4.5 30 Aqueous phase according to example 1 45 Total 100

The resulting composition is packaged in 100 ml packaging with a spray-type dispensing pump.

This produces a cosmetic product comprising a volume fraction in capsules greater than 50%, and therefore capable of sterically suspending the capsules.

The double population of capsules, identical in size but of different densities, gives the product an unexpected visual/aesthetic effect.

Thus, when stirred, the composition appears as a dispersion in which the red capsules and the blue capsules are uniformly mixed, giving the overall impression of a purple product (i.e. State 1).

At rest, a reorganization of the capsules is observed resulting in creaming of the capsules 4.5 of lower density and sedimentation of the capsules 4.3 which are denser (i.e. State 2). This color change of the composition according to the invention is all the more unexpected since it occurs without altering the suspension of the capsules in the continuous aqueous phase. After a certain time, the composition exhibits a color gradient between red capsules at the lower level and blue capsules at the upper level.

Further agitation leads to a return to a composition in the form of State 1 described above.

Claims (20)

Composition, in particular cosmetic, in the form of a dispersion comprising a dispersed phase in the form of capsules and a continuous aqueous phase, characterized in that:
- the capsules represent a volume fraction of between 50% and 70% compared to the total volume of the composition;
- the capsules comprise a shell and a core comprising at least one fatty phase comprising at least one perfuming agent; and
- the capsules comprise a Ri / Rc ratio of between 0.5 and 0.8, preferably between 0.6 and 0.8, and better still between 0.6 and 0.7, in which:
- Ri corresponds to the radius of the core of the capsules; and
- Rc corresponds to the radius of the capsule. Composition according to claim 1, in which the capsules have a diameter greater than or equal to 250 μm, or even greater than or equal to 500 μm, in particular between 250 μm and 3,000 μm, better still between 500 μm and 2,000 μm, and very particularly between 750 μm and 1,000 μm. Composition according to claim 1 or 2, in which the capsules are monodisperse. Composition according to any one of the preceding claims, in which the volume fraction of the capsules is between 55% and 65%, and preferably between 57% and 63%, relative to the total volume of the composition. A composition according to any preceding claim, wherein the bark is:
- a gelled envelope completely encapsulating the core, said gelled envelope comprising at least one polyelectrolyte in the gelled state and/or at least one thermosensitive hydrophilic gelling agent; and/or
- an envelope that derives from a complex coacervation reaction between two oppositely charged polymers capable of coacervation. Composition according to the preceding claim, in which the composition comprises between 0.25% and 5%, preferably between 0.5% and 3%, and better still between 0.75% and 1%, by weight of polyelectrolyte(s) and/or thermosensitive hydrophilic gelling agent(s) and/or oppositely charged polymers capable of coacerbating, relative to the total weight of the bark. A composition according to any preceding claim, wherein the bark further comprises at least one surfactant. Composition according to any one of the preceding claims, in which the capsules comprise a liquid or at least partly gelled or at least partly thixotropic core, the core being single-phase or comprising an intermediate drop of fatty phase, and at least one, preferably a single, internal drop of an internal phase arranged in the intermediate drop. Composition according to any one of the preceding claims, in which the composition comprises between 5% and 40%, preferably between 10% and 30%, and better between 15% and 20%, by weight of fatty phase relative to the total weight of the composition. Composition according to any one of the preceding claims, in which the fatty phase comprises from 5% to 30%, and preferably from 10% to 20%, by weight of perfuming agent(s) relative to the total weight of the composition. Composition according to any one of the preceding claims, in which the composition comprises from 5% to 100%, preferably from 10% to 90%, in particular from 25% to 80%, or even from 50% to 70%, by weight of active agent(s), in particular perfuming agent(s), relative to the total weight of the fatty phase. Composition according to any one of the preceding claims, in which the fatty phase further comprises at least one oil. A composition according to any preceding claim, wherein the continuous aqueous phase does not comprise carbomer. A composition according to any preceding claim, wherein the continuous aqueous phase is liquid and is non-suspensive with respect to the capsules. Composition according to any one of the preceding claims, in which the continuous aqueous phase has a high shear viscosity, as measured at 25°C and under a shear stress of 100 s ^-1 , of less than or equal to 100 mPa.s, preferably less than or equal to 50 mPa.s., in particular less than or equal to 25 mPa.s., and more preferably less than or equal to 10 mPa.s. Composition according to any one of the preceding claims, in which the composition is sprayable, and preferably the continuous aqueous phase has a flow threshold value of less than or equal to 1 Pa, in particular less than or equal to 0.1 Pa, very particularly less than or equal to 0.01 Pa, or even has no flow threshold value. Composition according to any one of the preceding claims, in which the composition comprises less than 10%, preferably less than 5%, in particular less than 2.5%, or even is free of alcohol(s), in particular ethanol, relative to the total weight of the composition. A composition according to any preceding claim, wherein the composition is a perfuming composition. Non-therapeutic cosmetic treatment process, in particular for perfuming a keratin material or a garment, comprising at least one step of applying to the keratin material and/or said garment at least one composition according to any one of claims 1 to 18. Use of at least one composition according to any one of claims 1 to 18, for perfuming a keratin material or a garment.