FR3085121A1 - DEVICE FOR PRODUCING A DISPERSION, ASSEMBLY AND ASSOCIATED METHOD - Google Patents

Abstract

Device (10) for producing a dispersion (12), comprising elements (14) dispersed in a continuous phase (18), the device (10) comprising at least one production nozzle (20) comprising: - a first conduit (30) suitable for conveying a first fluid (36), - a second conduit (32) suitable for conveying a second fluid (40), coaxially surrounding the first conduit (30), - an outlet (34) through which flows a fluid jet (22) comprising the first fluid (36) and the second fluid (40), - a chamber (26) for receiving the dispersion (12), the outlet (34) opening into the chamber (26 ), and - a mechanical fragmentation device (24) of the fluid jet (22), disposed in the receiving chamber (26), intended to mechanically fragment the fluid jet (22). The outlet (34) is movably mounted relative to the receiving chamber (26) and the fragmentation device (24).

Description

Device for producing a dispersion, assembly and associated method

The present invention relates to a device for producing a dispersion, comprising elements comprising at least a first phase, dispersed in a continuous phase substantially immiscible with the first phase at room temperature and atmospheric pressure, the device comprising at least one production nozzle. including:

a first conduit suitable for conveying a first fluid suitable for constituting the first phase,

a second conduit suitable for conveying a second fluid capable of constituting the continuous phase, the second conduit surrounding, preferably coaxially, at least part of the first conduit, and

- a nozzle outlet, the nozzle being capable of forming a fluid jet comprising the first fluid and the second fluid surrounding the first fluid, preferably coaxially, the fluid jet flowing through the outlet.

The invention also relates to a production assembly comprising at least one such device as well as to a process for producing a dispersion using such a device.

The Applicant manufactures and markets macroscopic dispersions comprising elements visible to the naked eye, for example with a diameter between 100 μm and 1500 μm, kinetically stable and optionally monodispersed.

The production of a dispersion comprising elements dispersed in a continuous phase, for example of macro-emulsions, generally consists in mixing between at least two phases which are substantially immiscible with each other, either directly in the manufacturing tank or in a reactor. online.

However, such methods make it very difficult, if not impossible, to obtain a homogeneous and reproducible distribution of the elements dispersed in the continuous phase. It is also difficult to obtain high dispersed phase concentrations, as well as to obtain macroscopic dispersed elements, in particular of millimeter or greater size. These difficulties are further increased when one of the phases has a high viscosity, or when it is desired to obtain a high production rate. What is more, it is known that such methods make it very difficult, if not impossible, to obtain dispersed elements exhibiting good monodispersity.

It is known to produce the elements of the dispersion in milli- or microfluidic devices, such as, for example, that described in WQ2012 / 120043, in order to precisely control their dimensions and the homogeneity of their distribution in the continuous phase.

These devices can be further improved. Indeed, they do not easily make it possible to obtain high production rates due to their hydrodynamic operation, the separation of the elements according to a drip-type process (or dripping in English).

These devices also impose limits in terms of rheology of the fluids, in particular of viscosity, or at least of the adaptations at the level of the raw materials and / or devices, the fluids having indeed to be able to flow in channels of very small section . These drawbacks de facto limit the dosage and / or the sensoriality of the dispersions capable of being obtained and / or complicate the dispersion production process.

An object of the invention is therefore to provide a production device making it possible to obtain a dispersion of elements, in particular macroscopic, with high production yields and efficient management of the phases of high viscosity, including in the presence of concentrations of significant dispersed phase.

Thus, the invention relates to a production device of the aforementioned type, comprising:

a dispersion receiving chamber, the outlet of the or each production nozzle opening into the chamber, and

a device for mechanical fragmentation of the fluid jet, arranged in the receiving chamber, in the vicinity of the outlet of the or each nozzle, intended to mechanically fragment the fluid jet into a plurality of elements dispersed in the continuous phase, each outlet nozzle being mounted movable relative to the receiving chamber and the fragmentation device.

According to particular embodiments, the device according to the invention has one or more of the following characteristics, taken separately or in any technically possible combination:

the production nozzle comprises a third conduit, at least part of which is surrounded, preferably coaxially, by at least part of the first conduit, the third conduit being suitable for conveying a third fluid, the fluid jet comprising the third fluid , the first fluid surrounding the third fluid, preferably coaxially, and the second fluid surrounding the first fluid, preferably coaxially, each element dispersed in the continuous phase comprising an external core formed by the first fluid, and at least a, preferably a single, inner heart formed by the third fluid disposed in the outer heart;

- The outlet of the or each nozzle is movable in rotation relative to the receiving chamber and to the fragmentation device;

- The fragmentation device is mounted fixed relative to the receiving chamber;

- The production nozzle comprises a tube extending the second conduit, movable in rotation about a central axis of the tube relative to the receiving chamber, the tube having a radial opening, preferably oriented perpendicular to the central axis, constituting the outlet of the nozzle and opening into the chamber, the fragmentation device circumferentially surrounding the tube opposite the radial opening;

- A static frame delimiting the first conduit and the second conduit, the first conduit and the second conduit opening into the tube, the tube being mounted movable in rotation relative to the frame;

- a rotary frame relative to the receiving chamber, the frame delimiting the first conduit and the second conduit concentrically, the first conduit and the second conduit opening at the outlet of the production nozzle by an opening in the frame;

- The device comprises at least one heating device capable of heating at least the first fluid, and optionally the second fluid and / or the third fluid, preferably at least in the production nozzle and / or upstream of the nozzle;

- Each element comprises a bark, preferably formed of a layer of coacervate, at the interface between the first phase and the continuous phase, and optionally also at the interface between the first phase and the third fluid; and

the first phase of the elements forms a layer comprising at least one gelling agent, in particular chosen from a heat-sensitive gelling agent which is solid at room temperature and atmospheric pressure, a polysaccharide, in particular a polyelectrolyte reactive with multivalent ions, and their mixtures, between the third fluid and the phase continues.

The invention also relates to an assembly for producing a dispersion, the assembly comprising a plurality of production devices and a fluid distribution system capable of supplying each device at least first fluid and second fluid and, optionally, third fluid, preferably the outputs of the nozzles opening into the same receiving chamber.

According to a particular embodiment, the assembly according to the invention has the following characteristic:

the nozzles are arranged in a centrifugal circle, the outputs of the nozzles being oriented towards the outside of the circle, the fragmentation device and the receiving chamber circumferentially surrounding the nozzles, the nozzles being mounted so as to be able to rotate about a central axis of the circle.

The invention further relates to a method for manufacturing a dispersion comprising elements comprising at least a first phase, the elements being dispersed in a continuous phase, the method comprising at least the following steps:

- supply of a production device and at least a first fluid and a second fluid that is substantially immiscible with the first fluid at ambient temperature and at atmospheric pressure;

- flow of the first fluid in the first conduit, the first fluid forming the first phase and flow of the second fluid in the second conduit surrounding, preferably coaxially, the first conduit;

- formation of a fluid jet at the outlet of the nozzle, the fluid jet, formed by co-extrusion, comprising at least the first fluid and the second fluid surrounding the first fluid (36), preferably coaxially;

- displacement of the outlet of the nozzle relative to the fragmentation device, to fragment the fluid jet and obtain elements comprising at least the first fluid dispersed in the second fluid; and

- recovery of the dispersion in the recovery chamber.

According to a particular embodiment, the method according to the invention has the following characteristic:

- The method further comprises a step of flowing a third fluid, in a third conduit, the first conduit surrounding, preferably coaxially, the third conduit;

the fluid jet formed by co-extrusion also comprising the third fluid, the first fluid surrounding, preferably coaxially, the third fluid, each element of the dispersion comprising an external core formed by the first fluid and at least one, preferably a single, internal heart formed by the third fluid, disposed in the external heart.

According to a particular embodiment, the phases of the dispersion form a macroscopically inhomogeneous mixture. This is particularly the case when the dispersed elements have a macroscopic character.

In the context of the present invention, the above-mentioned dispersions can be designated either by the term emulsions.

According to one embodiment, the dispersions according to the invention do not comprise a surfactant.

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

Finally, the invention relates to a composition, in particular a cosmetic composition, comprising at least one dispersion as described above and, optionally, a physiologically acceptable medium.

The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the appended drawings, among which:

- Figure 1 is a schematic view in longitudinal section of a production device according to the invention;

- Figure 2 is a schematic cross-sectional view of the production device of Figure 1;

- Figure 3 is a perspective view of a production assembly according to the invention comprising a plurality of production devices;

- Figure 4 is a view similar to Figure 1 of a production device according to another embodiment of the invention;

- Figure 5 is a view of an example of dispersion according to the invention where the elements of the dispersion are in the form of drops formed by a device according to the invention;

- Figure 6 is a view of an example of a dispersion according to the invention where the elements of the dispersion are in the form of capsules formed by a device according to the invention.

Definitions

Throughout the description, the expression “comprising a” should be understood as being synonymous with “comprising at least one”, unless otherwise specified.

The terms "between ... and ...", "ranging from ... to ..." and "ranging from ... to ..." must be understood including limits, unless otherwise specified.

The expressions "substantially parallel", "substantially perpendicular" (or "substantially orthogonal"), and "substantially oriented" must be interpreted respectively as parallel, perpendicular and oriented with an angular tolerance of 10 ° or less, preferably 5 ° or less.

The expressions “substantially miscible” and “substantially immiscible” must be understood as having a solubility respectively greater than 95% and less than 5%, by mass. Solubility is always considered at room temperature and under atmospheric pressure.

Temperature and pressure

Unless otherwise indicated, in all that follows, we consider that we are at ambient temperature (for example T = 25 ° C ± 2 ° C) and atmospheric pressure (760 mm of Hg, i.e. 1.013.10 ⁵ Pa or 1013 mbar ).

Viscosity

The viscosity of the dispersions according to the invention can vary significantly, which makes it possible to obtain various textures.

According to one embodiment, each of the phases forming a dispersion according to the invention and / or the dispersion according to the invention has a viscosity ranging from 1 mPa.s to 500,000 mPa.s, preferably from 10 mPa.s to 300 000 mPa.s, better from 400 mPa.s to 200,000 mPa.s, in particular from 1,000 mPa.s to 100,000 mPa.s, and more particularly from 2,000 mPa.s to 10,000 mPa.s, such as measured at 25 ° C, vore from 1 mPa.s to 10 000 mPa.s.

The viscosity is measured at ambient temperature and at ambient pressure, by the method described in WO2016 / 096995.

Referring to FIG. 1, a device 10 for producing a dispersion 12 according to a first embodiment of the invention is described, the dispersion 12 comprising elements 14 comprising a first phase 16, dispersed in a continuous phase 18.

Dispersion 12

The dispersion 12 according to the invention may be:

- a simple dispersion, that is to say direct (i.e. of oil-in-water type) or reverse (i.e. of water-in-oil type), even of oil-in-oil type; or

- A multiple dispersion, in particular double, and in particular of the water-in-oil-in-water, oil-in-water-in-oil or oil-in-oil-in-water type.

The dispersion 12 obtained is advantageously stable (or "kinetically stable"), in particular over time and during transport. By “stable”, within the meaning of the present invention, is meant for example that the dispersion is stable for at least two weeks, or even a month, preferably three months, and better still six months. By "stable" is meant that the dispersion retains a satisfactory visual homogeneity, that is to say without phase shift or creaming perceptible to the eye, the absence of clouding of the continuous phase, the absence of aggregation elements between them, and in particular the absence of coalescence or Oswald ripening of the elements between them, and the absence of leakage of materials from the dispersed phase to the continuous phase, or vice versa.

The first phase 16 is aqueous or oily, preferably oily, and immiscible with the continuous phase 18 at room temperature and at atmospheric pressure.

The continuous phase 18 is oily or aqueous, preferably aqueous, and in particular of a different nature from the first phase 16.

Within the meaning of the present invention, the dispersed phase of a dispersion 12 is represented by the first phase 16 and the third fluid 72 when present.

As oils which can be used in the present invention, mention may be made of those described in the patent application filed under the number FR1759183.

The elements 14 are advantageously substantially spherical and preferably macroscopic.

Preferably, the elements 14 having a diameter greater than or equal to 100 μm represent a volume greater than or equal to 60%, or even greater than or equal to 70%, preferably greater than or equal to 80%, and better still greater than or equal to 90% of the total volume of the dispersed phase and / or at least 60%, or even at least 70%, preferably at least 80%, and better still at least 90%, of the elements 14 have a diameter greater than or equal to 100 μm, preferably greater than or equal to 150 μm, better greater than or equal to 200 μm, in particular greater than or equal to 250 μm, preferably greater than or equal to 300 μm, in particular greater than or equal to 400 μm and better still greater than or equal to 500 μm.

The elements 14 advantageously have an apparent monodispersity (that is to say that they are perceived to the eye as identical spheres in diameter).

By “apparent monodispersity” is meant, for a given population of elements 14, a coefficient of variation Cv of the mean diameter D q _es elements 14 of between 10% and 30%, and better still between 15% and 20%.

The average diameter D of the elements 14 is for example measured by analysis of a photograph of a batch consisting of N elements 14, by image processing software. Typically, according to this method, the diameter is measured in pixels, then reported in pm, depending on the size of the container containing the elements 14 of the dispersion 12.

Preferably, the value of N is chosen to be greater than or equal to 30, so that this analysis statistically significantly reflects the distribution of diameters of the elements of said emulsion. N is advantageously greater than or equal to 100, in particular in the case where the dispersion is polydispersed.

We measure the diameter Di of each element 14, then we get the average diameter

D by calculating the arithmetic mean of these values:

From these values Di, one can also obtain the standard deviation σ of the diameters of the elements 14 of the dispersion 12:

The standard deviation σ of a dispersion reflects the distribution of the diameters Di of the elements of the dispersion 12 around the mean diameter D.

By knowing the mean diameter D _e t the standard deviation σ of a Gaussian dispersion, we can determine that 95.4% of the population of elements 14 is found in the range of diameters | p ^_ 2σ, £> + 2σ] _and q _{ue ρ} οη _is 53.2% of the population in the range ^{"σ; D +} .

To characterize the monodispersity of the dispersion 12 according to this mode of the invention, the coefficient of variation can be calculated:

This parameter reflects the distribution of the diameters of the elements 14 as a function of the average diameter of these.

The coefficient of variation Cv of the diameters of the elements 14 is advantageously less than 30%, preferably less than 20%, and better still less than 10%, or even less than 5%.

Alternatively, the monodispersity can be demonstrated by placing a sample of a dispersion according to the invention in a bottle with a constant circular section. A gentle agitation by rotation of a quarter of a turn for half a second around the axis of symmetry crossing the flask, followed by a rest of half a second is carried out, before repeating the operation in reverse, and this four times in a row.

The elements 14 of the dispersed phase are organized in a crystalline form when they are monodispersed. Thus, they have a stack in a pattern repeating in three dimensions. It is then possible to observe, a regular stack which indicates a good monodispersity, an irregular stack reflecting the polydispersity of the dispersion 12. If necessary, the skilled person will be able to adjust the viscosity of the phases, in particular of the continuous phase 18, for a satisfactory implementation of this method of characterizing monodispersity.

A dispersion 12 according to the invention can advantageously comprise from 0.5% to 80%, preferably from 1% to 70%, better still from 2.5% to 60%, in particular from 5% to 50%, preferably from 7.5% to 40%, better still from 10% to 30%, and very particularly from 15% to 20%, by weight of dispersed phase, in particular of oil (s), relative to the total weight of the dispersion 12 .

On the contrary, with a drip process of the prior art, the maximum achievable fraction in the dispersed phase, in particular of oil (s) in direct dispersion, is approximately 15%.

In the embodiment shown in FIG. 1, each element 14 of the dispersion is formed from a drop of first phase 16.

According to an alternative embodiment, each element 14 of the dispersion comprises at least one bark. A person skilled in the art will know how to make the adaptations and / or adjustments necessary to ensure the formation of this bark, taking into account, in particular, the characteristics of the device according to the invention.

For example, the shell can be formed from a coacervate layer at the interface between the first phase 16 and the continuous phase 18. This coacervate layer is advantageously formed by interaction between at least one first precursor polymer of the coacervate initially contained. in the first phase 16 and at least one second precursor polymer of the coacervate initially contained in the continuous phase 18. Thus, the first polymer is a hydrophilic polymer and the second precursor polymer is a lipophilic polymer, or vice versa. A pair "first coacervate precursor polymer / second coacervate precursor polymer" is in particular a "carbomer / amodimethicone" pair. Examples of elements of this type are described in WO2012120043.

The device 10 according to the invention is also advantageous in that it makes it possible to form a dispersion 12 by dispensing with the use of an intermediate liquid generally used to retard the migration of one of the two polymers involved in the coacervation reaction towards the interface between the first phase 16 and the continuous phase 18 and this, without fouling.

According to a second variant, each element 14 of the dispersion 12 comprises at least a first gelling agent in the first phase 16 and optionally at least a second gelling agent in the continuous phase 18, different from the first gelling agent. In other words, the elements 14 of the dispersion 12 according to this second variant have improved kinetic stability and mechanical strength despite the absence of bark. The first phase 16 and / or the continuous phase 18 are for example gelled. Examples of hydrophilic or lipophilic gelling agents are described in the application filed under the number FR1752208.

According to a third alternative embodiment, the dispersion 12 comprises at least a first gelling agent in the first phase 16 and / or at least a second gelling agent in the continuous phase 18, different from the first gelling agent, each element 14 further comprising a bark, in particular formed of a coacervate layer at the interface between the first phase 16 and the continuous phase 18 by interaction between at least one first polymer initially contained in the first phase 16 and at least one second polymer initially contained in the continuous phase 18. This variant is advantageous in that it leads to further improved kinetic stability of the dispersion 12.

Production device 10

As shown in FIGS. 1 and 2, the device 10 comprises a production nozzle 20 capable of forming a fluid jet 22, a mechanical fragmentation device 24 intended to mechanically fragment the fluid jet 22 to form the dispersion 12, and a chamber 26 intended to contain and evacuate the dispersion 12.

The nozzle 20 comprises at least a first conduit 30 and a second conduit 32, defined in a frame 35 carrying the nozzle 20, as well as an outlet 34 through which the fluid jet 22 flows. By the expression "fluid jet ”Means the flow of several fluids in laminar regime in a common direction, and in particular a flow in which the fluids flow by forming successive concentric cylindrical layers arranged around one another.

The first conduit 30 and the second conduit 32 each comprise a succession of at least one substantially cylindrical conduit segment in the frame 35.

The first conduit 30 is intended to convey a first fluid 36, suitable for forming the first phase 16, from a first channel 38 for supplying the first fluid 36.

The first conduit 30 opens into the second conduit 32, for example at half the length of the second conduit 32. The segment of the first conduit 30 opening into the second conduit 32 extends along a flow axis X-X ’.

The second conduit 32 is intended to convey a second fluid 40, capable of forming the continuous phase 18, from a second channel 42 for supplying the second fluid 40.

The second conduit 32 opens along the flow axis X-X ’, and surrounds, preferably coaxially, at least part of the first conduit 30 over at least part of the length of the second conduit 32.

According to a particular embodiment (not shown), the second conduit 32 and the first conduit 30 open into the same plane.

In the example shown in FIGS. 1 and 2, the nozzle 20 comprises a substantially cylindrical rotary tube 44, extending parallel to the flow axis X-X ’and extending the second conduit 32.

The rotary tube 44 is mounted movable in rotation relative to the frame 35 and to the chamber 26, around a central axis. The central axis of the rotary tube 44 is advantageously coincident with the flow axis X-X ’.

The rotary tube 44 is for example in sliding contact with the frame 35 at a first end 46, and is fixed by a second end 48 to an actuator 50.

As a variant, the nozzle 20 comprises a rotary joint disposed between the rotary tube 44 and the frame 35.

The rotary tube 44 defines a central duct 52 oriented along the flow axis XX ‘, which opens at the first end 46 through an axial opening 54, and in the vicinity of the second end through a radial opening 56.

The second conduit 32 of the nozzle opens into the axial opening 54.

The radial opening 56, which opens into the chamber 26, constitutes the outlet 34 of the nozzle 20.

The axial opening 54 is oriented substantially parallel to the flow axis X-X ’, and the radial opening 56 is preferably oriented substantially orthogonal to the flow axis X-X’.

Advantageously, the central duct 52 defines a bend opposite the radial opening 54, capable of deflecting the flow of the first fluid 36 and the second fluid 40 towards the radial opening 56.

The actuator 50 is configured to impose on the rotary tube 44 a rotational movement around the flow axis X-X ’, in particular with a constant angular speed.

As a variant, the actuator 50 is configured to impose an oscillating movement on the rotary tube.

The actuator 50 is for example an electric motor.

The nozzle 20 is thus able to form the fluid jet 22 by coextrusion of the first fluid 36 and the second fluid 40 from the first conduit 30 and the second conduit 32, the second fluid 40 surrounding, preferably coaxially, the first fluid 36 in the fluid jet 22.

The fluid jet 22 is formed at the outlet of the second conduit 32, and flows through the rotary tube 44 to the radial opening 56, along the flow axis X-X ’.

The fluid jet 22 then flows from the radial opening 56 into the receiving chamber 26, along an outlet axis Y-Y ’substantially orthogonal to the flow axis XX’.

During the movement of the rotary tube 44, the outlet axis Y-Y ’moves in a plane orthogonal to the flow axis X-X’, when the actuator 50 moves the rotary tube 44.

A person skilled in the art will know how to make the necessary adjustments, in particular at the level of the first fluid 36 and second fluid 40 flow rates, to ensure the formation of the fluid jet 22 by the nozzle 20.

The mechanical fragmentation device 24 is placed in the chamber 26, in the vicinity of the outlet 34 of the nozzle 30.

In particular, in the example shown in FIGS. 1 and 2, the fragmentation device 24 circumferentially surrounds the rotary tube 44 opposite the radial opening 56.

The fragmentation device 24 is therefore arranged opposite the radial opening 56 for all the positions taken by the radial opening 56 during its rotational movement.

The fragmentation device 24 comprises a plurality of windows 58 distributed cironferentially around the rotary tube 44, allowing the passage of the fluid jet 22, as well as a plurality of bars 60 alternated with the windows 58, which block the passage of the fluid jet 22.

For example, the fragmentation device 24 has the shape of a cylindrical grid, comprising alternating bars 60, in particular of metal, and windows 58.

The windows 58 are through and open into the chamber 26. They are advantageously regularly distributed angularly around the flow axis XX ’.

Each window 58 advantageously has a transverse extent substantially equal to a transverse extent of the radial opening 56, in a plane orthogonal to the outlet axis Y-Y ’. Thus, the window 58 is adapted to disturb the flow of the fluid jet 22 as little as possible when it is opposite the radial opening 56.

The movement of the rotary tube 44 relative to the mechanical fragmentation device 24 is capable of fractionating the fluid jet 22 mechanically, that is to say that the fragmentation device 24 cuts the fluid jet 22 regularly to divide it mechanically, for example with a frequency between 1 Hz and 350 Hz, and preferably between 50 Hz and 200 Hz.

The fractionation of the fluid jet 22 takes place at one time, and over a very short period, for example between 2.5 ms and 50 ms, preferably between 5 ms and 20 ms, which makes it possible to control the action mechanical fragmentation as well as the size of the elements 14.

The chamber 26 is intended to receive the dispersion 12 resulting from the fragmentation of the fluid jet 22 and to evacuate the dispersion 12 for distribution.

The chamber 26 is located directly around the outlet 34 of the nozzle 20, so that the nozzle 20 opens directly into the receptacle 26 through the fragmentation device 24.

Preferably, the chamber 26 contains a liquid extending at least around the outlet 34. Advantageously, the chamber 26 is completely filled with the liquid.

The liquid is in particular the second fluid 40 or the dispersion 12.

The size of the elements 14 mainly depends on the speed (or frequency) of movement of the rotary tube 44, on the viscosity of the first fluid 36 and of the second fluid 40, of the dimensions of the radial opening 56 and of the windows 58, of the spacing between the radial opening 56 the fragmentation device 24, and / or the flow rates imposed on the first fluid 36 and on the second fluid 40.

In particular, the volume ratio of the elements 14 and of the continuous phase 18 depends on the ratio of the flow rates of the first fluid 36 and of the second fluid 40 at the outlet 34 of the nozzle 20.

Adjustments to these various parameters are the general knowledge of those skilled in the art. In other words, a person skilled in the art will know how to make the necessary adjustments to form elements 14 of the desired size.

Other embodiments of the device 10

In a second embodiment of the production device 10, illustrated in FIG. 4, the device 10 comprises a nozzle 20 comprising the first conduit 30 and the second conduit 32 as well as a third conduit 70.

At least a portion of the third conduit 70 is surrounded, preferably coaxially, by at least a portion of the first conduit 30. The third conduit 70 is adapted to convey a third fluid 72, supplied by a third channel 74 for supplying third fluid 72.

The fluid jet 22 then comprises the first fluid 36, the second fluid 40 surrounding the first fluid 36, preferably coaxially, and the third fluid 72 surrounded by the first fluid 36, preferably coaxially, the fluid jet 22 being formed by co-extrusion at the outlet of the second conduit 32.

Each of the elements 14 formed after fragmentation of the fluid jet 22 then comprises, at least temporarily, an external core 76 formed by the first fluid 36, and at least one, preferably a single, internal core 78 formed by the third fluid 72, disposed in the outer heart 76.

According to a first variant, the third fluid 72 and the first fluid 36 are substantially miscible. This variant is advantageous in that it allows the encapsulation of raw materials which are not compatible with each other but which are soluble in the same phase.

Thus, by way of illustration of this first variant, in the case where the elements 14 comprise a coacervate bark, the third fluid 72 comprises high contents of vegetable oils and the first fluid 36 comprises at least one cationic lipophilic polymer precursor of the coarcervate, in particular an amodimethicone, as described above, in an oil known to be a good solvent for the cationic polymer. Thus, any possible incompatibility between said cationic polymer and vegetable oil occurs after the formation of the coacervate bark.

This makes it possible to encapsulate active agents capable of reacting with each other without altering the formation of elements 14. Thus, these active agents govern together after the formation of elements 14.

According to a second variant, the third fluid 72 and the first fluid 36 are substantially immiscible. The dispersion 12 is thus multiple, in particular double, and in particular of the water-in-oil-in-water, oil-in-water-in-oil or oil-in-oil-in-water type. This makes it possible to form two-phase elements 14.

According to a first example, illustrated in FIG. 5, the two-phase elements 14 form drops endowed with a multicomponent heart, that is to say comprising an internal heart 78 formed by the third fluid 72 and an external heart 76 formed of the first fluid 36 completely surrounding the internal heart 78. Optionally, these drops comprise a bark, in particular of coacervate, as described above at the interface between the external heart 76 and the continuous phase 18, or even between the external heart 76 and the internal heart 78.

According to another example (not shown), the two-phase elements 14 of the dispersion 12 comprise at least a first gelling agent in the first phase 16 and optionally at least a second gelling agent in the continuous phase 18 different from the first gelling agent. In other words, the two-phase elements 14 according to this second example exhibit improved kinetic stability and mechanical resistance despite the absence of bark and the gelation of the external heart 76 makes it possible to prevent creaming or sedimentation of the internal heart 78. Examples of gelling agents are described in the application filed under the number FR1752208.

According to a third example, the elements 14 form drops comprising both a bark, in particular of coacervate, disposed around the external heart 76 as described above, and at least one gelling agent in the first phase 16 and / or the continuous phase 18 .

According to a fourth example, shown in FIG. 6, the elements 14 form capsules comprising an internal core 78 formed by the third fluid and a shell 82 formed by the first fluid 36 disposed around the internal core 78.

The bark 82 can be produced from at least one gelling agent.

Such a gelling agent may for example be chosen from a thermosensitive gelling agent which is solid at room temperature and atmospheric pressure, such as for example agar.

Such a gelling agent may for example be chosen from a polysaccharide, in particular a polyelectrolyte reactive with multivalent ions, such as for example an alginate.

The gelation of the polyelectrolyte requires the presence in the second fluid 40 of at least one reagent capable of reacting with the polyelectrolyte to make it pass from a liquid state to a gelled state. Such a reagent is typically a solution comprising multivalent ions such as ions of an alkaline earth metal chosen for example from calcium ions, barium ions, magnesium ions, and their mixtures. Examples of gelling agents, in particular heat-sensitive agents, of polysaccharides, in particular of polyelectrolytes reactive with multivalent ions, and of reagents capable of reacting with the polyelectrolyte to bring it from a liquid state to a gelled state are described in WO2010063937.

Preferably, when the second fluid 40 comprises at least one reagent capable of reacting with the polyelectrolyte present in the first fluid 36 to make it pass from a liquid state to a gelled state, the first fluid 36 and / or the second fluid 40 comprises in addition at least gelling retardant, such as for example a tetrasodium pyrophosphate.

In a third embodiment of the production device 10, shown in FIG. 3, the production nozzle 20 does not include a rotary tube 44, but it is the frame 35 which is rotatable around an axis of rotation Z- Z 'orthogonal to the flow axis X-X'.

The outlet 34 of the nozzle 20 is then an opening inscribed in a plane substantially orthogonal to the flow axis X-X ’.

The fragmentation device 24 is positioned around the frame 35, facing the outlet 34. The windows are then oriented along the flow axis X-X ‘.

According to a variant not shown, the device 10 further comprises at least one heating device suitable for heating at least the first fluid 36 and / or the second fluid 40 in the nozzle 20. The heating device is for example placed in the vicinity of the first conduit 30 and / or second conduit 32, and in particular surrounds the first conduit 30 and / or the second conduit 32, preferably in a coaxial manner.

For example, the heating device comprises a heating resistor and an electric generator, and is capable of heating the first fluid 36 by the Joule effect. Alternatively, the heating device comprises a heat exchanger.

Optionally, the heating device is suitable for heating the third fluid 72, and is arranged in the vicinity of the third conduit 70, or else is suitable for heating both the first fluid 36, the second fluid 40 and the third fluid 72 and located in the vicinity of the first conduit 30, the second conduit 32 and the third conduit 70.

As a variant, the heating device is arranged upstream of the production nozzle 20, for example in the vicinity of the first supply channel 38, and / or in the vicinity of the second channel 42, and optionally in the vicinity of the third channel 74.

According to one embodiment (not shown), the production device 10 also comprises at least one duct independent of the nozzle 20 and opening directly into the chamber 26, intended to convey to the dispersion 12 an additional fluid comprising at least one solution of increase in the viscosity of the continuous phase 18. The second fluid 40 is therefore miscible with the additional fluid. Such a solution for increasing the viscosity is for example a solution containing a base, in particular an alkali hydroxide, such as sodium hydroxide, and is in particular described in WO2015055748.

According to one embodiment (not shown), the device 10 further comprises at least one mixer into which the dispersion 12 is injected, suitable for exerting a controlled and homogeneous shearing on the elements 14. The mixer comprises at least one shearing cell .

The mixer is capable of improving the monodispersity of the elements 14, the elements 14 being subjected to shearing capable of fragmenting them into elements 14 of homogeneous and controlled diameters, as described in more detail in EP3144058. According to this embodiment, the dispersion 12 obtained comprises elements 14 endowed with an homogeneity of improved size.

The shear cell is advantageously a Couette type cell, comprising at least two coaxial rotary cylinders. The cylinders comprise for example an external cylinder having an internal radius Ro and an internal cylinder having an external radius Ri, with Ro> Ri. The outer cylinder is for example fixed, and the inner cylinder is for example driven by a rotation movement at constant angular speed ω. Dispersion 12 is arranged between the outer cylinder and the inner cylinder, and sheared by the differential movement of the two cylinders.

Alternatively, the shear cell comprises two parallel rotating discs, or two parallel oscillating plates.

Production set

With reference to FIG. 3, a production assembly 90 is described comprising a plurality of production devices 10 in which the production nozzle 20 does not comprise a rotary tube 44.

The outlet 34 of the nozzle 20 of each device 10 is then an opening inscribed in a plane substantially orthogonal to the flow axis X-X ’relating to the nozzle 20.

The production devices 10 are arranged around at least one centrifugal circle, with their respective flow axes X-X ’diverging from the center of the circle.

The frame 35 is common to all the production devices 10, and is mounted movable in rotation, about an axis of rotation Z-Z ’, relative to the same shared receiving chamber 26.

In the example shown in Figure 3, the production devices 10 are arranged in a single centrifugal circle, the center of which is located on an axis of rotation Z-Z 'orthogonal to each of the flow axes X-X'.

According to an embodiment not shown, the production devices 10 are arranged in at least two superimposed centrifugal circles, the centers of which are aligned along the central axis Z-Z ’. Such an embodiment is advantageous in that it makes it possible to easily increase the production yields in dispersion 12 according to the invention, if necessary without multiplying the first channels 38, second channels 42 and optionally third supply channels 74 , respectively, first fluids 36, second fluid 40 and third fluid 72.

The outlets 34 of the devices 10 open into the chamber 26, intended to receive the dispersion 12 produced by each of the devices 10. The chamber 26 has a substantially annular shape, and circumferentially surrounds the frame 35.

The production assembly 90 comprises a fluid distribution system capable of supplying each production device 10 with the first fluid 36 with the second fluid 40, and optionally with the third fluid 72, via the first channels 38 and the second channels respectively. 42 and optionally third channels 74.

Advantageously, the devices 10 share the same first channel 38 and the same second channel 42 and optionally the same third channel 74.

Advantageously, each first channel 38 opens into the first conduit (s) 30 and each second channel 42 opens into the second conduit (s) 32, or even each third channel 74 opens into the (s) third (s) conduit (s) 70 through at least one pressure drop, for example formed by a channel portion 91 of reduced section. The pressure drop causes a slowdown in the flow of the first fluid 36, respectively of the second fluid 40, or even of the third fluid 72 upstream of the nozzle 20.

The channel portions 91 have a section in a plane transverse to the direction of flow of the first fluid 36, respectively of the second fluid 40, or even of the third fluid 72, with a smaller area than the cross sections of the first channel 38 and the first conduit 30, respectively of the second channel 42 and of the second conduit 32, or even of the third channel 74 and of the third conduit 70. Thanks to the pressure drop produced, it is possible to regulate the flow of the first fluid 36, respectively of the second fluid 40, or even the third fluid 72 downstream of the pressure drop and thus homogenize the fluid (s) injected into the production device 10.

The first channel 38 and the second channel 42 and optionally the third channel 74 extend annularly and concentrically along the central axis Z-Z ’. They present, in a plane orthogonal to the central axis Z-Z ’, sections in the form of concentric rings. The first channel 38, the second channel 42 and optionally the third channel 74 are supplied through a rotating joint (not shown).

The fluid distribution system comprises, for example, a first pump fluidly connected to the first channel 38 by the rotary joint, and to a reservoir of first fluid 36. The first pump is capable of circulating the first fluid 36 in the first channel 38 and supplying the devices 10 with the first fluid 36 with a predetermined flow rate.

The fluid distribution system also comprises a second pump fluidly connected to the second channel 42 by the rotary joint, and to a reservoir of second fluid 40. The second pump is adapted to circulate the second fluid 40 in the second channel 42 and to supplying the devices 10 with second fluid 40 at a predetermined flow rate, equal or not to the flow rate of the first fluid 36.

Optionally, the fluid distribution system also includes a third pump fluidly connected to the third channel 74 by the rotary joint, and to a reservoir of third fluid 72. The third pump is suitable for circulating the third fluid 72 in the third channel 74 and supplying the devices 10 with third fluid 72 at a predetermined flow rate, equal or not to the flow rate of the first fluid 36 and / or of the second fluid 40.

The devices 10 advantageously share the same fragmentation device 24, which includes a scraper 92 defining the windows 58 as described above.

The scraper 92 is arranged around an external contour 94 of the frame 35 and is thus substantially tangent to the opening plane of each of the outlets 34 of the devices 10.

The external contour 94 of the frame 35 and an internal contour 96 of the scraper 92 are advantageously separated by a distance less than or equal to 1 mm, preferably less than or equal to 0.5 mm, and better still less than or equal to 0.2 mm .

The windows 58 of the scraper 92 are advantageously regularly angularly spaced, the scraper 92 is therefore suitable for fragmenting the fluid jets 22 formed at the outlet 34 of each of the nozzles 20 at the same predetermined frequency and thus forming the elements 14 identically.

Production process

A method for producing the dispersion 12 using the device 10 shown in FIG. 1 will now be described. The production process comprises a preliminary step of supplying the production device 10, as well as a first fluid 36 and a second fluid 40 substantially immiscible with the first fluid 36.

Advantageously, the first fluid 36 is supplied via a first channel 38 for supplying the first fluid 36 fluidly connected to a first conduit 30 and the second fluid 40 is supplied via a second channel 42 d supply of second fluid 40 fluidly connected to a second conduit 32 of a nozzle 20 of the device 10.

The method comprises at least one flow step, in the direction of an outlet 34 of the nozzle 20 in a flow direction XX ′, of the first fluid 36 in a first conduit 30 and of the second fluid 40 in a second conduit 32, said second conduit 32 surrounding, preferably coaxially, at least part of the first conduit 30.

The method then comprises a step of flowing the first fluid 36 and the second fluid 40 into the rotary tube 44, the second fluid surrounding, preferably coaxially, the first fluid 36.

The method then comprises a step of forming a fluid jet 22, the fluid jet 22 being formed by co-extrusion through the first conduit 32 and the second conduit 32, and flowing through the rotary tube 44 to the radial opening 56, in the flow direction X-X '. The fluid jet 22 comprises the first fluid 36 and the second fluid 40 surrounding the first fluid 36, preferably coaxially.

The fluid jet 22 then flows through the radial opening 56 in an exit direction Y-Y ′ orthogonal to the flow axis X-X '.

The method comprises a step of moving the rotary tube 44, in rotation relative to the chamber 26, and of moving the radial opening 56 opposite a fragmentation device 24 of the production device 10, to fragment the fluid jet 22 and obtain the dispersion 12.

Advantageously, the rotary tube 44 is moved by an actuator 50 at a predetermined fixed speed so as to form the elements 14. The elements 14 are advantageously substantially identical to each other. Preferably, the dispersion 12 obtained is monodisperse.

The method finally comprises a stage of recovery in a chamber 26 of the dispersion 12 comprising the elements 14 dispersed in the continuous phase 18.

In another embodiment, the method comprises the step of flowing the first fluid 36 and second fluid 40 as described above, as well as a third fluid 72 in a third conduit 70 surrounded at least in part by preferably coaxially, by at least part of the first conduit 30.

According to a first variant, the third fluid 72 is substantially miscible with the first fluid 36.

According to a second variant, the third fluid 72 is substantially immiscible with the first fluid 36.

The fluid jet 22 thus formed by co-extrusion then comprises the first fluid 36, the second fluid 40 and the third fluid 102, in which the second fluid 40 surrounds the first fluid 36, preferably coaxially, and the first fluid 36 surrounds the third fluid 72, preferably coaxially.

In the dispersion 12 thus obtained and according to the miscible or immiscible nature of the first fluid 36 and third fluid 102 therebetween, the elements 14 are single-phase or two-phase.

In another embodiment, the method further comprises a step of refining the size of the elements 14, during which a controlled and homogeneous shear is applied to the elements 14 in a mixer, the mixer being in particular as described above.

In another embodiment, the method further comprises a step of filtering the dispersion 12 to collect only the elements 14.

Additional compounds

A dispersion 12 according to the invention, in particular the first phase 16 and / or the continuous phase 18 and / or the third fluid 72, can also (at least) comprise at least one additional compound different from the precursor polymers of the coacervate, gelling agents, polysaccharides and oils mentioned above.

A dispersion 12 according to the invention, in particular the first phase 16 and / or the continuous phase 18 and / or the third fluid 72, may (may) also further comprise as additional compound (s) powders , flakes, coloring agents, in particular chosen from coloring agents which are water-soluble or not, liposoluble or not, organic or inorganic, pigments, materials with optical effect, liquid crystals, and their mixtures, particulate agents which are insoluble in the phase fatty, emulsifying and / or non-emulsifying silicone elastomers, preservatives, humectants, stabilizers, chelators, emollients, modifiers chosen from pH, osmotic force agents and / or modifiers of index refraction etc ... or any usual cosmetic additive, and mixtures thereof.

A dispersion 12 according to the invention, in particular the first phase 16 and / or the continuous phase 18 and / or the third fluid 72, can also be included as additional compound (s) at least an active, in particular biological or cosmetic, preferably chosen from hydrating agents, healing agents, depigmenting agents, UV filters, desquamating agents, antioxidant agents, active agents stimulating the synthesis of dermal and / or epidermal macromoleculars, dermodecontracting agents, antiperspirant agents, soothing agents, antiaging agents, perfuming agents and their mixtures. Such assets are described in particular in FR 1,558,849.

Of course, the person skilled in the art will take care to choose any additional compound (s) mentioned above and / or their respective amounts so that the device and / or the advantageous properties of a dispersion according to the invention are not not or substantially not altered by the proposed addition. In particular, the nature and / or the amount of the additional compound (s) depends on the aqueous or oily (or fatty) nature of the phase in question of the dispersion according to the invention. These adjustments fall within the competence of a person skilled in the art.

Uses

A dispersion according to the invention can be a topical composition, and therefore not an oral composition, or a food composition.

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

The dispersions according to the invention can comprise, in addition to the abovementioned ingredients, at least one physiologically acceptable medium.

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

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 appearance under which the composition is to be packaged.

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

The cosmetic compositions of the invention may for example be a cream, an emulsion, a lotion, a serum, a gel and an oil for the skin (hands, face, 5 feet, etc.), a foundation (liquid, paste) a preparation for baths and showers (salts, foams, oils, gels, etc.), a hair care product (hair dyes and bleaches), a cleaning product (lotions, powders, shampoos), a cleaning product for the hair (lotions, creams, oils), a styling product (lotions, lacquers, brilliants), a shaving product (soaps, mousses, lotions, etc.), a product intended to be applied to the lips, a sunscreen product, a sunless tanning product, a product for whitening the skin, an anti-wrinkle product. In particular, the cosmetic compositions of the invention can be an anti-aging serum, a youth serum, a hydrating serum or a scented water.

The present invention also relates to a non-therapeutic method for cosmetic treatment of a keratinous material, in particular the skin and / or the hair, and more particularly the skin, comprising a step of applying to said keratinous material at least one composition. or at least one layer of a cosmetic composition mentioned above.

Claims (15)

1. - Device (10) for producing a dispersion (12), comprising elements (14) comprising at least a first phase (16), dispersed in a continuous phase (18) substantially immiscible with the first phase (16) at ambient temperature and atmospheric pressure, the device (10) comprising at least one production nozzle (20) comprising: a first conduit (30) capable of conveying a first fluid (36) capable of constituting the first phase (16), - A second conduit (32) suitable for conveying a second fluid (40) suitable for constituting the continuous phase (18), the second conduit (32) surrounding, preferably coaxially, at least part of the first conduit (30) , and - a nozzle outlet (34) (20), the nozzle (20) being able to form a fluid jet (22) comprising the first fluid (36) and the second fluid (40) surrounding the first fluid (36), preferably coaxially, the fluid jet (22) flowing through the outlet (34), characterized in that the device (10) comprises: a chamber (26) for receiving the dispersion (12), the outlet (34) of the or each production nozzle (20) opening into the chamber (26), and - a mechanical fragmentation device (24) of the fluid jet (22), disposed in the receiving chamber (26), in the vicinity of the outlet (34) of the or each nozzle (20), intended to mechanically fragment the jet fluid (22) in a plurality of elements (14) dispersed in the continuous phase (18), each outlet (34) of nozzle (20) being mounted movable relative to the receiving chamber (26) and to the fragmentation device (24). 2, - Device (10) according to claim 1, wherein the production nozzle (20) comprises a third conduit (70) at least part of which is surrounded, preferably coaxially, by at least part of the first conduit (30), the third conduit (70) being able to convey a third fluid (72), the fluid jet (22) comprising the third fluid (72), the first fluid (36) surrounding the third fluid (72), preferably coaxially, and the second fluid (40) surrounding the first fluid (36), preferably coaxially, each element (14) dispersed in the continuous phase (18) comprising an outer core (76) formed by the first fluid (36), and at least one, preferably a single, inner core (78) formed by the third fluid (72) disposed in the outer core (76). 3. - Device (10) according to claim 1 or 2, wherein the outlet (34) of the or each nozzle (20) is movable in rotation relative to the receiving chamber (26) and to the fragmentation device ( 24). 4. - Device (10) according to any one of claims 1 to 3, wherein the fragmentation device (24) is mounted fixed relative to the receiving chamber (26). 5. - Device (10) according to any one of claims 1 to 4, wherein the production nozzle (20) comprises a tube (44) extending the second conduit (32), movable in rotation about a central axis (X-Xj of the tube (44) relative to the receiving chamber (26), the tube (44) having a radial opening (56), preferably oriented perpendicular to the central axis (X-Xj, constituting the outlet (34) of the nozzle (20) and opening into the chamber (26), the fragmentation device (24) circumferentially surrounding the tube (44) opposite the radial opening (56). 6. - Device (10) according to claim 5, comprising a static frame (35) delimiting the first conduit (30) and the second conduit (32), the first conduit (30) and the second conduit (32) opening into the tube (44), the tube (44) being mounted movable in rotation relative to the frame (35). 7. - Device (10) according to any one of claims 1 to 4, comprising a frame (35) rotatable relative to the receiving chamber (26), the frame (35) delimiting the first conduit (30) and the second conduit (32) concentrically, the first conduit (30) and the second conduit (32) opening at the outlet (34) of the production nozzle (20) through an opening in the frame (35). 8. - Device (10) according to any one of claims 1 to 7, wherein the device (10) comprises at least one heating device capable of heating at least the first fluid (36), and optionally the second fluid ( 40) and / or the third fluid (72), preferably at least in the production nozzle (20) and / or upstream of the nozzle (20). 9. - Device (10) according to any one of claims 1 to 8, in which each element (14) comprises a bark, preferably formed of a layer of coacervate, at the interface between the first phase (16) and the continuous phase (18), and 26 optionally also at the interface between the first phase (16) and the third fluid (72). 10. - Device (10) according to any one of claims 2 to 9, in which the first phase (16) of the elements (14) forms a layer (82) comprising at least one gelling agent, in particular chosen from an agent solid thermosensitive gelling agent at room temperature and atmospheric pressure, a polysaccharide, in particular a polyelectrolyte reactive with multivalent ions, and their mixtures, between the third fluid (72) and the continuous phase (18). 11. assembly (90) for producing a dispersion (12), the assembly (90) comprising a plurality of devices (10) for production according to any one of claims 1 to 10 and a clean fluid distribution system supplying each device (10) with at least the first fluid (36) and the second fluid (40) and, optionally, the third fluid (72), preferably the outlets (34) of the nozzles (20) opening into the same chamber (26) reception. 12. - assembly (90) according to claim 11, wherein the nozzles (20) are arranged in a centrifugal circle, the outlets (34) of the nozzles (20) being oriented towards the outside of the circle, the fragmentation device ( 24) and the receiving chamber (26) circumferentially surrounding the nozzles (20), the nozzles (20) being mounted movable in rotation about a central axis (ZZ j of the circle. 13. - Method for manufacturing a dispersion (12) comprising elements (14) comprising at least a first phase (16), the elements (14) being dispersed in a continuous phase (18), the method comprising at least the following steps : - Supply of a device (10) for production according to any one of claims 1 to 10 and of at least a first fluid (36) and a second fluid (40) substantially immiscible with the first fluid (36) at temperature ambient and at atmospheric pressure; - flow of the first fluid (36) in the first conduit (30), the first fluid (36) forming the first phase (16) and flow of the second fluid (40) in the second conduit (32) surrounding, preferably so coaxial, the first conduit (30); - formation of a fluid jet (22) at the outlet (34) of the nozzle (20), the fluid jet (22), formed by co-extrusion, comprising at least the first fluid (36) and the second fluid (40 ) surrounding the first fluid (36), preferably coaxially; - displacement of the outlet (34) of the nozzle (20) relative to the device 5 fragmentation (24), to fragment the fluid jet (24) and obtain elements (14) comprising at least the first fluid (36) dispersed in the second fluid (40); and - recovery of the dispersion (12) in the recovery chamber (26). 14, - Method according to claim 13, comprising the following step: 10 - flow of a third fluid (72), in a third conduit (70), the first conduit (30) surrounding, preferably coaxially, the third conduit (70); the fluid jet (22) formed by co-extrusion also comprising the third fluid (72), the first fluid (36) surrounding, preferably coaxially, the third fluid (72), Each element (14) of the dispersion (12) comprising an outer core (76) formed by the first fluid (36) and at least one, preferably a single, inner core (78) formed by the third fluid (72) , located in the outer heart (76).