DESCRIPTION

The invention relates to a method for preparing a dispersion of a lipophilic compound in a hydrophilic continuous phase, the morphology of which is submicronic. During the preparation of this dispersion, is applied, by means of a device producing a shear gradient of less than 5,000 s 1 , a shear stress ranging from 100 to 5,000 Pa during the addition of the lipophilic compound in the mixture. continuous phase which comprises a rheology modifying compound chosen from anionic copolymers, preferably an anionic polymer, in particular an ASE polymer or a HASE polymer.

The dispersed lipophilic compound particles are nanometric particles whose size is less than 1 µm. The dispersion, in particular in the form of an emulsion, can be used in many fields.

Many areas require the combination of substances with properties that make them incompatible. In particular, it is important to be able to combine a lipophilic compound and a hydrophilic compound.

Thus, it is essential to be able to have methods of preparing the dispersion of a lipophilic compound in a hydrophilic phase.

Besides being able to prepare such dispersions, especially in the form of emulsions, it is also essential to provide methods leading to stable dispersions.

The emulsification of two incompatible substances is an out of equilibrium process which consists in breaking up macroscopic domains of the substance to be dispersed by input of mechanical energy and in stabilizing the dispersion obtained.

Generally, the methods for preparing a dispersion, in particular an emulsion, use a physical constraint when mixing the two phases to be combined. Applying shear stress during this combination is a very popular procedure. The value of the shear stress that is applied is an essential factor in controlling the size of the particles of lipophilic compound which are dispersed in the hydrophilic phase.

Most often, the hydrophilic phase is in gelled form, in particular to facilitate the preparation of the dispersion or to improve the stability of this dispersion.

A major drawback encountered during the preparation of the dispersions concerns the destabilization, or even the rupture, of the gel of the hydrophilic phase, in particular this destabilization or this rupture during the application of the shear stress.

When it occurs, this destabilization or disruption prevents the attainment of sub-micron or nanometric particle sizes.

The dispersions thus obtained do not comply with the desired aim and they are then generally unusable.

Indeed, many technical fields require the use of dispersions in which the lipophilic compound is in the form of particles of very small size and in particular of submicron size. It is therefore essential to have methods of preparing a dispersion of lipophilic compound in the form of nanometric particles. Furthermore, it is also essential to be able to prepare dispersions using conventional mechanical devices, in particular mixers or mixers widely available. In particular, it is particularly advantageous to be able to prepare dispersions by using mixers or mixers producing a low shear gradient, for example less than 5,000 s 1 , or even less than 2,000 s 1 or less.

Likewise, it is essential to be able to have methods of preparing a dispersion during which the hydrophilic continuous phase is stable, in particular is in the form of a stable gel and is not broken or fractured during the application of 'a mechanical stress.

Preferably, the dispersion preparation methods should make it possible to control the texture of the dispersions prepared.

Document WO 2015 155703 describes a nanodispersion comprising an aqueous dispersion medium, a dispersed phase, a surfactant and optionally an additive. This nanodispersion is self-emulsifying and does not include any anionic copolymer. Document EP 1951200 discloses a composition comprising a nanoemulsion which can be used for its anti-inflammatory activity. Document WO 2017 182265 discloses a nanoemulsion comprising a large amount of surfactant compound which is an N-acylated salt of an amino-monocarboxylic. Document EP 1172077 describes an oil-in-water nanoemulsion in which the oil droplets consist of a nonionic or anionic amphiphilic lipid. It does not include any anionic copolymer.

The prior art dispersion preparation methods do not make it possible to prepare dispersions in a satisfactory or efficient manner.

The method according to the invention makes it possible to provide a solution to all or part of the methods for preparing a dispersion of the state of the art.

Thus, the invention provides a method of preparing a dispersion (D) comprising:

• a continuous hydrophilic phase comprising at least one hydrophilic compound and at least one compound modifying the rheology of the hydrophilic compound, and chosen from anionic copolymers, and

• a lipophilic phase dispersed in the continuous phase in the form of nanometric particles,

comprising:

the preparation of a mixture (M) comprising the hydrophilic compound and the compound for modifying the rheology of the hydrophilic compound,

the addition of the lipophilic compound in the continuous phase by applying, by means of a device producing a shear gradient of less than 5,000 s 1 , a stress chosen from a shear stress ranging from 100 to 5,000 Pa and an elongation stress ranging from 100 to 5,000 Pa.

Preferably, the dispersion (D) is an emulsion. More preferably, the dispersion is an emulsion of the lipophilic dispersed phase in the hydrophilic continuous phase.

In a particularly advantageous manner, the method according to the invention makes it possible to prepare the dispersion (D) in the absence of a surface-active compound which generally serves to cause G self-emulsion of the lipophilic phase to be dispersed.

The method according to the invention makes it possible to easily prepare a dispersion (D) in which the lipophilic phase is dispersed in the hydrophilic continuous phase in the form of nanometric particles. According to the invention, the particles of lipophilic phase therefore have a size of less than 1 μm, therefore strictly less than 1000 nm. The method according to the invention therefore makes it possible to prepare a dispersion (D) for which the particles of dispersed lipophilic phase have an average size (measured by light diffraction) that is submicron.

Preferably, at least 30% by volume or at least 40% by volume, more preferably at least 50% by volume, of the dispersed lipophilic phase particles have an average nanometric or submicron size.

More preferably, at least 30% by volume or at least 40% by volume, more preferably at least 50% by volume, dispersed lipophilic phase particles have an average size ranging from 50 to 999 nm or from 100 to 999 nm. or else from 50 to 990 nm or from 500 to 990 nm.

The method according to the invention makes it possible to control the viscosity of the hydrophilic continuous phase prepared. According to the invention, the viscosity is measured by means of a rheometer, for example by means of a Mars III rheometer (Thermofisher).

Preferably according to the invention, the hydrophilic continuous phase has a viscosity ranging from 20 to 50,000 mPa.s. More preferably according to the invention, the hydrophilic continuous phase has a viscosity ranging from 100 to 50,000 mPa.s or from 100 to 20,000 mPa.s.

The method according to the invention also makes it possible to control the viscosity of the dispersion (D) prepared. Preferably according to the invention, the dispersion (D) has a viscosity ranging from 20 to 50,000 mPa.s. More preferably according to the invention, the dispersion (D) has a viscosity ranging from 100 to 50,000 mPa.s or from 100 to 20,000 mPa.s. According to the invention, the preparation of the dispersion (D) can comprise an additional step making it possible to increase its viscosity. Moreover, an additional step of reducing the pH can make it possible to lower the viscosity of the dispersion (D).

The preparation method according to the invention makes it possible to use very varied lipophilic compounds. Preferably, the lipophilic compound used according to the invention is a lipophilic compound useful in a field chosen from cosmetics, painting, dyeing, printing, inks, construction, fuels, lubricants, anti-foam agents, metallurgy, fertilizers, pharmaceuticals, agrochemicals, phytosanitary products, detergents, food, leather, coating, in particular textile coating.

More preferably according to the invention, the lipophilic compound is a compound immiscible in water at room temperature or else miscible in water at room temperature in an amount by weight of less than 0.1% by weight relative to to the amount of water.

In a particularly advantageous manner, within the dispersion (D) the respective amounts of hydrophilic and lipophilic phases can vary quite widely. Preferably, the dispersion (D) comprises from 0.1 to 75% by weight or from 0.3 to 75% by weight or from 1 to 75% by weight of dispersed lipophilic phase relative to the total amount by weight of phase continuous hydrophilic and dispersed lipophilic phase.

Also preferably, the dispersion (D) comprises from 0.1 to 70% by weight or from 0.3 to 70% by weight or from 1 to 70% by weight of dispersed lipophilic phase relative to the total amount by weight of continuous hydrophilic phase and dispersed lipophilic phase.

More preferably the dispersion (D) comprises from 0.1 to 65% by weight or from 0.3 to 65% by weight or from 1 to 65% by weight of dispersed lipophilic phase relative to the total amount by weight of hydrophilic phase continuous and dispersed lipophilic phase.

Also more preferably, the dispersion (D) comprises from 0.1 to 60% by weight or from 0.3 to 60% by weight or from 1 to 60% by weight, of dispersed lipophilic phase relative to the total amount by weight continuous hydrophilic phase and dispersed lipophilic phase. Preferably according to the invention, the hydrophilic compound is water. The hydrophilic compound can also be water mixed with at least one other compound. Preferably, this mixture comprises water and a compound chosen from glycerol, polyglycerols, glycols, for example propylene glycol, butylene glycol, humectant compounds, for example humectant compounds for cosmetic composition, derivatives of sugars, for example xylytol, maltilol, agents. coalescence, for example low molecular weight polyalkylene glycols, especially polyethylene glycol, butyldiglycol.

According to the invention, the preferred humectant compounds are water-soluble or hydrophilic. Preferably, they are chosen from a water-soluble compound of synthetic origin, a water-soluble compound of natural origin and their combinations, in particular a water-soluble compound of plant origin; for example a water-soluble compound (a) chosen from diols, triols, sugars, modified sugars, ethers, protein compounds, amino acids, triglycerides and their combinations; in particular a water-soluble compound (a) chosen from pidolic acid (PCA; CAS number 98-79-3 L or S (-) form; 4042-36-8 D or R (+) form; 149-87-1 racemic form) ; PCA derivatives, in particular arginine PCA, chitosan PCA, copper derivative of PCA, ethylhexyl PCA, lauryl PCA, magnesium derivative of PCA, sodium derivative of PCA, zinc derivative of PCA; butylene glycol, pentylene glycol; calcium gluconate; fructose; glucose; isomalt; lactose; maltitol; mannitol; polydextrose; sorbitol; sucrose; sucrose; xylitol; glycerol; glycerin; glycyrrhizic acid; glycyrrhizic acid derivatives; histidine; hyaluronic acid ; salts of hyaluronic acid, in particular sodium hyaluronate; silk hydrolyzate; keratin hydrolyzate; soybean hydrolyzate; PEG -7; PEG -8; PEG -10; PEG -12; PEG -14; phytantriol; propylene glycol ; silk (serica); urea; propylene glycol-1,2,6; hexanetriol; butylene glycol; capryl glycol; dipropylene glycol; erythritol; triethylene glycol; hexylene glycol; phytantriol hexanediol; beeswax triol; humectants of biological origin; panthenol; provitamin B5; inositol glycogen; sugars and modified sugars polyglyceryl; sorbitol; honey; polymeric polyols; inositol; vitamin B7; liquorice saponin with high sweetening power; ethers; isoceteth-x; isolaureth-x; dill-x; laureth-x; steareth-x; polyethyleneglycols; polyethylene glycol derivatives; trideceth- (5-50); polyethylene glycol ether of tridecyl alcohol; silicone copolyols; protein humectants; hydrolyzed casein cocodimonium hydroxypropyl; hydrolyzed collagen cocodimonium hydroxypropyl; hydrolyzed keratin cocodimonium hydroxypropyl; hydrolyzed rice protein cocodimonium hydroxypropyl; hydrolyzed silk protein cocodimonium hydroxypropyl; cocodimonium hydroxypropyl from hydrolyzed soy protein; hydroxypropyl cocodimonium from hydrolyzed wheat protein; silk amino acids cocodimonium hydroxypropyl; hydrolyzed collagen cocoyl; hydrolyzed keratin cocoyl; keratin; hydrolyzed keratin; hydrolyzed oat protein; hydrolyzed quinoa protein; potassium cocoyl from hydrolyzed collagen; hydrolyzed triethanolamine-cocoyl from collagen; triethanolamine-cocoyl from hydrolyzed soy protein; histidine; amino acids ; triglycerides; glyceryl triacetate; glyceryl triacetate obtained by esterification of natural glycerin; alpha hydroxy acids; fruit sugar derivatives; sugar derivatives of milk fruit; fruit acids; Lactic acid ; neoagarobiosis; Aloe vera. glyceryl triacetate; glyceryl triacetate obtained by esterification of natural glycerin; alpha hydroxy acids; fruit sugar derivatives; sugar derivatives of milk fruit; fruit acids; Lactic acid ; neoagarobiosis; Aloe vera. glyceryl triacetate; glyceryl triacetate obtained by esterification of natural glycerin; alpha hydroxy acids; fruit sugar derivatives; sugar derivatives of milk fruit; fruit acids; Lactic acid ; neoagarobiosis; Aloe vera.

Essentially, the method according to the invention uses at least one compound for modifying the rheology of the hydrophilic compound chosen from anionic copolymers. According to the invention, the concentration of the rheology modifier compound in the mixture (M) also comprising the hydrophilic compound can vary quite widely, in particular to allow effective control of the viscosity of the mixture (M).

Preferably, the concentration by weight of rheology modifying compound in the mixture (M) ranges from 4 to 14% by weight of mixture (M) and the viscosity of the mixture (M) ranges from 300 to 5000 mPa.s.

Also preferably, the concentration by weight of rheology modifying compound in the mixture (M) ranges from 4 to 12% by weight of mixture (M) and the viscosity of the mixture (M) ranges from 300 to 2000 mPa.s .

Also preferably, the concentration by weight of rheology modifier compound in the mixture (M) ranges from 4 to 11% by weight of the mixture (M) and the viscosity of the mixture (M) ranges from 300 to 1000 mPa.s .

Also preferably, the concentration by weight of rheology modifier compound in the mixture (M) ranges from 2.5 to 12% by weight of mixture (M) and the viscosity of the mixture (M) ranges from 100 to 2000 mPa .s.

Also preferably, the concentration by weight of rheology modifier compound in the mixture (M) ranges from 2.5 to 11% by weight of mixture (M) and the viscosity of the mixture (M) ranges from 100 to 1000 mPa .s.

According to the invention, the rheology modifying compound generally has a pH greater than 5, preferably greater than 5.5. More preferably, the pH is greater than 6.

According to the invention, the rheology-modifying compound is chosen from ASE copolymers, HASE copolymers and their combinations.

According to the invention, the preferred anionic copolymers are prepared by polymerization reaction:

(al) at least one anionic monomer comprising at least one polymerizable olefinic unsaturation, preferably an anionic monomer comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function, preferably the anionic monomer is chosen from acrylic acid , methacrylic acid, maleic acid, maleic anhydride, itaconic acid, crotonic acid, a salt of acrylic acid, a salt of methacrylic acid, a salt of maleic acid, a salt of maleic anhydride, a salt of itaconic acid, a salt of crotonic acid and their combinations, much more preferably acrylic acid or methacrylic acid and

(a2) at least one ester of a compound derived from an acid chosen from acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid and crotonic acid, preferably an ester of acrylic acid or an ester of methacrylic acid, preferably chosen from methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, ethylhexyl acrylate, methyl methacrylate, methacrylate ethyl, propyl methacrylate, butyl methacrylate, ethylhexyl methacrylate, and combinations thereof.

Also preferably, the anionic copolymers are prepared by a polymerization reaction which also implements:

(a3) at least one compound of formula (I):

R 1 - (OE) m - (OP) „- R 2 (I)

in which :

m and n, identical or different, independently represent 0 or an integer or decimal less than 150, m or n is different from 0,

EO independently represents a CH2CH2O group,

OP independently represents a group selected from CH (CH 3 ) CH 2 0 and CH 2 CH (CH 3 ) 0,

R 1 represents a group comprising at least one polymerizable olefinic unsaturation, preferably an acrylate group or a methacrylate group and

R 2 represents a linear or branched C 6 -C 4 o-alkyl group, a phenyl group, a polyphenyl group, preferably a linear or branched Cio-C 3 o-alkyl group, more preferably a C12-C22- group. alkyl, linear or branched, or a group comprising 2 to 5 phenyls or a tristyrylphenyl group or a pentastyrylcumylphenyl group.

Also preferably, the anionic copolymers are prepared by a polymerization reaction which also implements:

(a4) at least one compound selected from 2-acrylamido-2-methylpropanesulfonic acid, ethoxymethacrylate sulfonic acid, sodium methallyl sulfonate, styrene sulfonate, phosphated hydroxyethyl-acrylate, phosphated hydroxypropyl-acrylate, phosphated hydroxyethylhexyl-acrylate, phosphated hydroxyethyl methacrylate, phosphated hydroxypropyl methacrylate, phosphated hydroxyethylhexyl methacrylate, their salts and combinations thereof.

Also preferably, the anionic copolymers are prepared by a polymerization reaction which also implements:

(a5) at least one compound chosen from hydroxyethyl-acrylate, hydroxypropyl-acrylate, hydroxyethylhexyl-acrylate, hydroxyethyl-methacrylate, hydroxypropyl-methacrylate, hydroxyethylhexyl-methacrylate.

Also preferably, the anionic copolymers are prepared by a polymerization reaction which also implements:

(a6) at least one crosslinking monomer or at least one monomer comprising at least two olefinic unsaturations.

The particularly preferred anionic copolymers according to the invention are prepared by a polymerization reaction which implements:

(al) acrylic acid, methacrylic acid or alternatively acrylic acid and methacrylic acid,

(a2) methyl acrylate, methyl methacrylate or else methyl acrylate and methyl methacrylate,

(a3) of at least one compound of formula (I):

R 1 - (OE) m - (OP) „- R 2 (I)

in which :

m and n, identical or different, independently represent 0 or an integer or decimal less than 150, m or n is different from 0,

EO independently represents a CH2CH2O group,

OP independently represents a group selected from CH (CH 3 ) CH 2 0 and CH 2 CH (CH 3 ) 0,

R 1 represents a group, an acrylate group or a methacrylate group and

R 2 represents a linear or branched C 6 -C 4 o-alkyl group, a phenyl group, a polyphenyl group, preferably a linear or branched Cio-C 3 o-alkyl group, more preferably a C12-C22- group. alkyl, linear or branched, or a group comprising 2 to 5 phenyls or a tristyrylphenyl group or a pentastyrylcumylphenyl group.

Other particularly preferred anionic copolymers according to the invention are prepared by a polymerization reaction which also implements:

(al) acrylic acid, methacrylic acid or alternatively acrylic acid and methacrylic acid,

(a2) G methyl acrylate, methyl methacrylate or else G methyl acrylate and methyl methacrylate,

(a3) of at least one compound of formula (I):

- R 1 - (OE) m - (OP) n -R 2 (I)

in which :

m and n, identical or different, independently represent 0 or an integer or decimal less than 150, m or n is different from 0,

EO independently represents a CH2CH2O group,

OP independently represents a group selected from CH (CH 3 ) CH 2 0 and CH 2 CH (CH 3 ) 0,

R 1 represents a group, an acrylate group or a methacrylate group and

R 2 represents a linear or branched C 6 -C 4 o-alkyl group, a phenyl group, a polyphenyl group, preferably a linear or branched Cio-C 3 o-alkyl group, more preferably a C12-C22- group. alkyl, linear or branched, or a group comprising 2 to 5 phenyls or a tristyrylphenyl group or a pentastyrylcumylphenyl group and

(a4) 2-acrylamido-2-methylpropanesulfonic acid.

Other particularly preferred anionic copolymers according to the invention are prepared by a polymerization reaction which also implements:

(al) acrylic acid, methacrylic acid or alternatively acrylic acid and methacrylic acid,

(a2) G methyl acrylate, methyl methacrylate or else G methyl acrylate and methyl methacrylate,

(a4) 2-acrylamido-2-methylpropanesulfonic acid.

When preparing the rheology modifier compound used according to the invention, it is possible to use at least one chain transfer agent, preferably chosen from mercaptan compounds, in particular mercaptan compounds comprising at least four atoms. carbon such as butylmercaptan, n-octylmercaptan, n-dodecylmercaptan, ieri-dodecylmercaptan.

Preferably according to the invention, the mixture (M) comprises from 0.5 to 15% by weight, preferably from 1 to 15% by weight or from 2 to 12% by weight, of rheology modifier. More preferably according to the invention, the mixture (M) comprises from 1 to 15% by weight or from 2 to 12% by weight, of rheology modifier.

Advantageously, the method according to the invention uses a mixture (M) which also comprises a base. Preferably, it is a mineral base, in particular a base chosen from NaOH, KOH, ammonium derivatives, ammonia and their

combinations. Also preferably, it is a base chosen from amino bases, for example triethanolamine, aminomethylpropanol or 2-amino-2-methyl-propanol (AMP) and their combinations.

Also advantageously, the method according to the invention uses a mixture (M) which has a pH greater than 5, preferably greater than 5.5, more preferably greater than 6. Also advantageously, the method according to 1 The invention uses a mixture (M) which has a pH below 12.

More advantageously, the method according to the invention uses a mixture (M) which has a pH ranging from 5 to 12, preferably from 5.5 to 12, more preferably from 6 to 12. Generally according to the invention , the mixture (M) does not comprise a surface-active compound or else comprises a quantity of surface-active compound, preferably nonionic, which is small. Then, the amount of surfactant compound, preferably nonionic, can range from 0.05 to 10% by weight or from 0.05 to 5% by weight, of the weight of the mixture (M).

Advantageously according to the invention, the preparation temperature is below the boiling point of the hydrophilic phase and below the boiling point of the lipophilic phase. Also advantageously according to the invention, the preparation temperature is above the melting point of the hydrophilic phase and above the melting point of the lipophilic phase.

Preferably, the preparation temperature is below the boiling point of the hydrophilic phase and below the boiling point of the lipophilic phase while being above the melting point of the hydrophilic phase and above the melting point of the hydrophilic phase. lipophilic phase.

The method according to the invention comprises the addition of the lipophilic compound in the continuous phase by applying a stress chosen from among a shear stress and an elongation stress. Preferably, it is a shear stress. Advantageously, the shear stress or the elongation stress can be applied during the preparation of the mixture (M), preferably at a value equal to or less than that applied during the addition of the lipophilic compound.

Preferably according to the invention, the shear stress or the elongation stress ranges from 300 to 5000 Pa.

Also preferably according to the invention, the shear stress or the elongation stress ranges from 100 to 2000 Pa or from 300 to 2000 Pa.

More preferably according to the invention, the shear stress or the elongation stress ranges from 100 to 1700 Pa or from 300 to 1700 Pa.

According to the invention, the stress is applied by means of a device producing a shear gradient of less than 5,000 s 1 .

Preferably, the device used can produce a shear gradient of less than 2000 s 1 or less than 1000 s 1 . Also preferably, the device used can produce a shear gradient ranging from 100 to 5000 s 1 or ranging from 100 to 2000 s 1 or even ranging from 100 to 1000 s 1 .

More preferably, the device used can produce a shear gradient ranging from 200 to 5000 s 1 or ranging from 200 to 2000 s 1 or even ranging from 200 to 1000 s 1 , in particular ranging from 200 at 800 s 1 ,

In a particularly advantageous manner, the device used is a mixer, in particular a VMI Rayneri mixer, an Ika mixer or a PC Labor System mixer.

The method of preparation according to the invention comprises the preparation of a continuous phase in the form of the mixture (M) and then the addition of the lipophilic compound in the continuous phase by applying a shear stress. Other additional steps can also be implemented during the preparation method according to the invention.

Thus, advantageously, the method of preparation according to the invention can also comprise the neutralization of the dispersion (D). Preferably, the neutralization is carried out using at least one compound chosen from NaOH, KOH, ammonium derivatives, ammonia, amino bases, for example triethanolamine, aminomethylpropanol or 2-amino-2-methyl-propanol (AMP) and their combinations. .

Also advantageously, the preparation method according to the invention can also comprise the partial coacervation of the rheology modifier compound. Preferably, the partial coacervation of the rheology modifying compound is carried out by reducing the pH of the dispersion (D), for example by reducing the pH to a value less than 6.5. The reduction of the pH can be carried out by means of an acidic compound, in particular by means of at least one organic or mineral acidic compound, in particular an acidic compound chosen from phosphoric acid, citric acid, glucono-lactone, lactic acid, acid salicylic, glycolic acid, ascorbic acid, glutamic acid, hydrochloric acid, acetic acid, D-gluconic acid, sulfonic acid, methanesulfonic acid, benzimidazolesulfonic acid, tartaric acid,

sulfonic acid, benzylidene camphor sulfonic acid, terephthalylidene dicamphor sulfonic acid.

Also preferably, the partial coacervation of the rheology modifier compound is carried out by increasing the ionic strength of the dispersion (D). The increase in the ionic strength of the dispersion (D) can be carried out by adding at least one ionized compound or at least one salt, in particular NaCl, KC1, MgCl 2 , CaCl 2 , MgS0 4 , CaS0 4 .

Also preferably, the partial coacervation of the rheology modifier compound is achieved by reducing the solubility of the rheology modifier compound in the hydrophilic phase. The reduction in solubility can be carried out by adding at least one cationic polymer, in particular by adding at least one cationic polymer, in particular a cationic polymer chosen from polyquaternium 1 to polyquaternium 47 and quaternized guars, in particular hydroxypropyl chloride. guar triammonium, polydiallyldimethylammonium chloride (polyDADMAC or polyDDA), poly-2- (methacryloyloxy) ethyl-trimethyl-ammonium chloride (polyMAD quat).

The method according to the invention can combine one or other of these additional steps. For example, the method according to the invention can also comprise the neutralization of the dispersion (D) and the partial coacervation of the rheology modifier compound.

The method according to the invention makes it possible to prepare a dispersion (D) which is particularly advantageous as such. Thus, the invention also relates to a dispersion (D) capable of being prepared according to the invention.

The dispersion (D) according to the invention can be used in many products which are then particularly advantageous as such. The invention therefore also relates to a product comprising at least one dispersion (D) according to the invention.

Due to the fact that they comprise a lipophilic phase dispersed in a continuous hydrophilic phase in the form of nanometric particles, the dispersion (D) according to the invention and the product according to the invention can be used in a very large number of technical fields.

Thus, the invention relates to the use of a dispersion (D) in a field chosen from cosmetics, painting, dyeing, printing, inks, construction, fuels, lubricants, anti- foam, metallurgy, fertilizers, pharmaceuticals, agrochemicals, phytosanitary products, detergents, food, leather, coating, in particular textile coating.

The invention also relates to the use of a product according to the invention in a field selected from cosmetics, painting, dyeing, printing, inks, construction, fuels, lubricants, anti-foam agents, metallurgy, fertilizers, pharmaceuticals, agrochemicals, phytosanitary products, detergents, food, leather, coating, in particular textile coating.

The examples which follow make it possible to illustrate the various aspects of the invention.

EXAMPLES

Example 1: preparation of rheology modifying compounds according to the invention

474.9 g of bipermuted water, 6.51 g of sodium dodecyl sulfate (SDS) and 5.45 g of triethoxylated tridecyl alcohol (Rhodasurf ID 030, Solvay) are introduced into a polymerization reactor. The reactor is placed under stirring and heated to 76 ° C.

Separately, in a beaker are weighed 153 g of bipermuted water, 2.28 g of sodium dodecyl sulfate, 0.163 g of n-dodecyl mercaptan, 109.04 of ethyl acrylate (EA) as compound (a2), 112 , 5 g of methacrylic acid (AMA) as compound (al), 45.31 g of methyl methacrylate as other compound (a2), 13.445 g of branched methacrylate- (EO) 25-Cl6 as compound (a3) ​​of formula (I) in which R 1 represents a methacrylate group, R 2 represents a Ci 6 -branched alkyl group, m = 25 and n = 0.13.445 g of branched methacrylate- (EO) 30-Ci 2 as other compound (a3) of formula (I) in which R 1 represents a methacrylate group, R 2 represents a Ci 2 group-branched alkyl, m = 30 and n = 0. This mixture is placed with stirring using a bar magnet.

A mixture containing 0.925 g of ammonium persulfate and 4.07 g of bipermuted water and a second mixture composed of 0.093 g of sodium bisulfite and 4.88 g of bipermuted water are simultaneously added to the reactor. Then, the injection of the mixture is started, which lasts 2 hours. The temperature is maintained at 76 ° C.

The polymer (P1) is obtained according to the proportions presented in Table 1 in which the values ​​are proportions by weight.

In an analogous manner, the polymers (P2), (P3) are prepared, for which (a3) ​​is a compound of formula (I) in which R 1 represents a methacrylate group, R 2 represents a tristyrylphenyl (TSP) group, m = 25 and n = 0, and (P4) according to the proportions (in g dry for dryness) presented in Table 1. The total amount of monomers is 100% by weight and the amount of chain transfer agent is relative to the total amount by weight of monomers.

Table 1

Example 2: preparation of dispersions according to the invention

A mixture (M) of hydrophilic continuous phase is prepared from rheology modifying polymer, water and optionally of an additional hydrophilic compound and optionally of a nonionic surfactant compound (TA) chosen from Plantaren 2000 N UP (Basf), Sensient LRI (Sensient Cosmetic Technologies), Rhodasurf ID 030 (Solvay), Polysorbate 20 (Sigma-Aldrich) and Availability G625 (Basf).

A base is added and the mixture is stirred until a homogeneous aqueous mixture is obtained. Separately, the lipophilic compound to be dispersed is prepared.

Then, with stirring carried out by means of a mixer, the lipophilic phase is introduced into the continuous hydrophilic phase to produce an emulsion.

If necessary, an acid or saline coacervation agent (acid diluent or saline diluent) is added.

Dispersions of different lipophilic compounds or of mixtures of lipophilic compounds were prepared: alkyd resin 1 (viscosity at 70 ° C of 500,000 mPa.s), alkyd resin 2 (viscosity at 70 ° C of 6550 mPa.s), alkyd resin 3 (viscosity at 70 ° C of 230 mPa.s), mixture of alkyd resin 1 and linoleic acid (viscosity at 70 ° C of 8,000 mPa.s), sunflower oil (viscosity at room temperature of 560 mPa.s ), n-octyltriethoxysilane (viscosity at room temperature of 16.7 mPa.s).

Dispersions according to the invention are obtained according to the quantities (g) and the characteristics presented in Tables 2 to 7 and the size of the particles of dispersed lipophilic compound of which is less than 1 μm.

Table 2

* without alkyd resin, gradual addition

Table 3

* without alkyd resin, gradual addition

Table 4

* without alkyd resin, gradual addition

Table 5

* without alkyd resin, gradual addition

Table 6

* without alkyd resin, gradual addition

Table 7

The method according to the invention makes it possible to easily prepare, by means of a conventional mixer producing a low shear gradient, emulsions of various lipophilic compounds dispersed in a hydrophilic continuous phase for which the size of the particles of lipophilic compound is much less than 1 pm

CLAIMS

1. Method for preparing a dispersion (D) comprising:

• a continuous hydrophilic phase comprising at least one hydrophilic compound and at least one compound modifying the rheology of the hydrophilic compound, and chosen from anionic copolymers, and

• a lipophilic phase dispersed in the continuous phase in the form of nanometric particles,

comprising:

the preparation of a mixture (M) comprising the hydrophilic compound and the compound for modifying the rheology of the hydrophilic compound,

G addition of the lipophilic compound in the continuous phase by applying, by means of a device producing a shear gradient of less than 5000 s 1 , a stress chosen from a shear stress ranging from 100 to 5000 Pa and an elongation stress ranging from 100 to 5,000 Pa.

2. Method according to claim 1 for which:

• the hydrophilic continuous phase has a viscosity ranging from 20 to 50,000 mPa.s, preferably from 100 to 50,000 mPa.s or from 100 to 20,000 mPa.s or

• the dispersion (D):

o has a viscosity ranging from 20 to 50,000 mPa.s, preferably from 100 to 50,000 mPa.s or from 100 to 20,000 mPa.s or

o is an emulsion or

o comprises from 0.1 to 75% by weight or from 0.3 to 75% by weight or from 1 to 75% by weight, preferably from 0.1 to 70% by weight or from 0.3 to 70% by weight weight or from 1 to 70% by weight, more preferably from 0.1 to 65% by weight or from 0.3 to 65% by weight or from 1 to 65% by weight, also more preferably from 0.1 to 60% by weight or from 0.3 to 60% by weight or from 1 to 60% by weight, of dispersed lipophilic phase relative to the total amount by weight of continuous hydrophilic phase and of dispersed lipophilic phase.

3. Method according to one of claims 1 or 2 for which the hydrophilic compound is chosen from water alone or as a mixture with at least one compound chosen from glycerol, polyglycerols, glycols, for example propylene glycol, butylene glycol, humectant compounds, by example of humectant compounds for cosmetic composition, derivatives of sugars, for example xylytol, maltilol, coalescing agents, for example polyalkylene glycols of low molecular mass, in particular polyethylene glycol, butyldiglycol.

4. Method according to one of claims 1 to 3 for which the rheology modifying compound:

• has a pH greater than 5, preferably greater than 5.5, more preferably greater than 6 or

• is chosen from ASE copolymers, HASE copolymers and their combinations, preferably from anionic copolymers prepared by polymerization reaction:

(al) of at least one anionic monomer comprising at least one polymerizable olefinic unsaturation, preferably an anionic monomer comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function, preferably the anionic monomer is chosen from acrylic acid , methacrylic acid, maleic acid, maleic anhydride, itaconic acid, crotonic acid, a salt of acrylic acid, a salt of methacrylic acid, a salt of maleic acid, a salt of maleic anhydride, a salt of itaconic acid, a salt of crotonic acid and their combinations, much more preferably acrylic acid or methacrylic acid and

(a2) at least one ester of a compound derived from an acid chosen from acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid and crotonic acid, preferably an ester of acrylic acid or an ester of methacrylic acid, preferably chosen from methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, ethylhexyl acrylate, methyl methacrylate, methacrylate 'ethyl, propyl methacrylate, butyl methacrylate, ethylhexyl methacrylate and their combinations, optionally

(a3) of at least one compound of formula (I):

R 1 - (OE) m - (OP) n -R 2 (I)

in which :

m and n, identical or different, independently represent 0 or an integer or decimal less than 150, m or n is different from 0,

EO independently represents a CH2CH2O group,

OP independently represents a group selected from CH (CH 3 ) CH 2 0 and CH 2 CH (CH 3 ) 0,

R 1 represents a group comprising at least one polymerizable olefinic unsaturation, preferably an acrylate group or a methacrylate group and

R 2 represents a linear or branched C 6 -C 4 o-alkyl group, a phenyl group, a polyphenyl group, preferably a Cio-C 3 groupo-alkyl, linear or branched, more preferably a C12-C22-alkyl group, linear or branched, or a group comprising 2 to 5 phenyls or a tristyrylphenyl group or a pentastyrylcumylphenyl group, optionally (a4) of at least one chosen compound from 2-acrylamido-2-methylpropanesulphonic acid, ethoxymethacrylate sulphonic acid, sodium methallyl sulphonate, styrene sulphonate phosphated hydroxyethyl-acrylate, phosphated hydroxypropyl-acrylate, phosphated hydroxyethylhexyl-acrylate, phosphated hydroxyethyl-methacrylate methacrylate-phosphated hydroxypropyl-acrylate , phosphated hydroxyethylhexylmethacrylate, their salts and their combinations, optionally

(a5) of at least one compound chosen from hydroxyethyl-acrylate, hydroxypropyl-acrylate, hydroxyethylhexyl-acrylate, hydroxyethyl-methacrylate, hydroxypropyl-methacrylate, hydroxyethylhexyl-methacrylate and also optionally (a6) of at least one crosslinking monomer or of ' at least one monomer comprising at least two olefinic unsaturations.

5. Method according to one of claims 1 to 4 for which the mixture (M):

• also comprises a base, preferably an inorganic base, in particular a base chosen from NaOH, KOH, ammonium derivatives, ammonia, amino bases, for example triethanolamine, aminomethylpropanol or

2-amino-2-methyl-propanol (AMP) and combinations thereof or

• has a pH greater than 5, preferably greater than 5.5, more preferably greater than 6 or

• has a pH below 12 or

• has a pH ranging from 5 to 12, preferably from 5.5 to 12, more preferably from 6 to 12 or

• does not contain a surface-active compound or else comprises a small amount, for example an amount of surface-active compound ranging from 0.05 to 10% by weight or ranging from 0.05 to 5% by weight, of the weight of the mixture (M) or else an amount of nonionic surfactant compound ranging from 0.05 to 10% by weight or ranging from 0.05 to 5% by weight, of the weight of the mixture (M).

6. Method according to one of claims 1 to 5 for which the mixture (M) comprises from 0.5 to 15% by weight, preferably from 1 to 15% by weight or from 2 to 12% by weight, of modifier. of rheology.

7. Method according to one of claims 1 to 6 for which:

• the preparation temperature is below the boiling point of the hydrophilic phase and below the boiling point of the lipophilic phase or

• the preparation temperature is above the melting point of the hydrophilic phase and above the melting point of the lipophilic phase or

• the preparation temperature is lower than the boiling point of the hydrophilic phase and lower than the boiling point of the lipophilic phase while being higher than the melting point of the hydrophilic phase and higher than the melting point of the lipophilic phase.

8. Method according to one of claims 1 to 7 for which the dispersion is an emulsion of the lipophilic dispersed phase in the hydrophilic continuous phase.

9. Method according to one of claims 1 to 8 for which the shear stress or the elongational stress:

• ranges from 300 to 5,000 Pa, preferably from 100 to 2,000 Pa or from 300 to 2,000 Pa, more preferably from 100 to 1,700 Pa or from 300 to 1,700 Pa or

• is also applied during the preparation of the mixture (M), preferably at a value equal to or less than that applied during the addition of the lipophilic compound or

• the stress is applied by means of a device producing a shear gradient of less than 2000 s 1 or less than 1000 s 1 or by means of a device producing a shear gradient ranging from 100 to 5000 s 1 or ranging from 100 to 2000 s 1 or even ranging from 100 to 1000 s 1 , preferably ranging from 200 to 5000 s 1 or from 200 to 2000 s 1 or else from 200 to 1000 s 1 , in particular from 200 to 800 s 1 .

10. Method according to one of claims 1 to 9 for which the dispersed lipophilic phase particles have an average size (measured by light diffraction) submicron, preferably at least 30% by volume or at least 40% by volume, preferably at least 50% by volume, dispersed lipophilic phase particles have an average nanometric or submicron size, more preferably at least 30% by volume or at least 40% by volume, more preferably at least 50% by volume, particles of dispersed lipophilic phase have an average size ranging from 50 to 999 nm or from 100 to 999 nm or even from 50 to 990 nm or from 500 to 990 nm.

11. Method according to one of claims 1 to 10 also comprising:

• neutralization of the dispersion (D), preferably by means of at least one compound chosen from NaOH, KOH, ammonium derivatives, ammonia, amino bases, for example triethanolamine, aminomethylpropanol or 2-amino-2-methyl-propanol ( AMP) and their combinations or

• partial coacervation of the rheology modifying compound, preferably: by reducing the pH of the dispersion (D), for example by reducing the pH to a value below 6.5, in particular using an acidic compound, in particular by means of at least one organic or inorganic acidic compound, in particular an acidic compound chosen from phosphoric acid, citric acid, glucono-lactone, lactic acid, salicylic acid, glycolic acid, ascorbic acid, glutamic acid, hydrochloric acid, acetic acid , D-gluconic acid, sulfonic acid, methanesulfonic acid, benzimidazole-sulfonic acid, tartaric acid, 4-aminobenzoic acid, benzoic acid, sorbic acid, phenylbenzimidazole sulfonic acid, benzylidene camphor sulfonic acid, terephthalylidene dicamphor sulfonic acid or

o by increasing the ionic strength of the dispersion (D), for example by adding at least one ionized compound or at least one salt, in particular NaCl, KC1, MgCl 2 , CaCl 2 , MgS0 4 , CaS0 4 or

o by reducing the solubility of the rheology modifying compound in the hydrophilic phase, for example by adding at least one cationic polymer, in particular by adding at least one cationic polymer, in particular a cationic polymer chosen from polyquaternium 1 to polyquaternium 47 and quaternized guars, in particular hydroxypropyl-guar triammonium chloride, polydiallyldimethylammonium chloride (polyDADMAC or polyDDA), poly-2- (methacryloyloxy) ethyl-trimethyl-ammonium chloride (polyMAD quat).

12. Dispersion (D) capable of being prepared according to one of claims 1 to 11.

13. Product comprising at least one dispersion according to claim 12.

14. Use of a dispersion (D) according to claim 12 or of a product according to claim 13 in a field chosen from cosmetics, painting, dyeing, printing, inks, construction, fuels, lubricants, anti-foam agents, metallurgy, fertilizers, pharmaceuticals, agrochemicals, phytosanitary products, detergents, food, leather, coating, in particular textile coating

REVENDICATIONS

1. Méthode de préparation d’une dispersion (D) comprenant :

• une phase continue hydrophile comprenant au moins un composé hydrophile et au moins un composé modificateur de rhéologie du composé hydrophile, et choisi parmi les copolymères anioniques, et

• une phase lipophile dispersée dans la phase continue sous la forme de particules nanométriques,

comprenant :

la préparation d’un mélange (M) comprenant le composé hydrophile et le composé modificateur de rhéologie du composé hydrophile,

G addition du composé lipophile dans la phase continue en appliquant, au moyen d’un dispositif produisant un gradient de cisaillement inférieur à 5 000 s 1, une contrainte choisie parmi une contrainte de cisaillement allant de 100 à 5 000 Pa et une contrainte élongationnelle allant de 100 à 5 000 Pa.

2. Méthode selon la revendication 1 pour laquelle :

• la phase continue hydrophile a une viscosité allant de 20 à 50 000 mPa.s, de préférence de 100 à 50 000 mPa.s ou de 100 à 20 000 mPa.s ou

• la dispersion (D) :

o a une viscosité allant de 20 à 50 000 mPa.s, de préférence de 100 à 50 000 mPa.s ou de 100 à 20 000 mPa.s ou

o est une émulsion ou

o comprend de 0,1 à 75 % en poids ou de 0,3 à 75 % en poids ou de 1 à 75 % en poids, de préférence de 0,1 à 70 % en poids ou de 0,3 à 70 % en poids ou de 1 à 70 % en poids, plus préférentiellement de 0,1 à 65 % en poids ou de 0,3 à 65 % en poids ou de 1 à 65 % en poids, également plus préférentiellement de 0,1 à 60 % en poids ou de 0,3 à 60 % en poids ou de 1 à 60 % en poids, de phase lipophile dispersée par rapport à la quantité totale en poids de phase hydrophile continue et de phase lipophile dispersée.

3. Méthode selon l’une des revendications 1 ou 2 pour laquelle le composé hydrophile est choisi parmi l’eau seule ou en mélange avec au moins un composé choisi parmi glycérol, polyglycérols, glycols, par exemple propylèneglycol, butylèneglycol, composés humectants, par exemple des composés humectants pour composition cosmétique, dérivés de sucres, par exemple xylytol, maltilol, agents de coalescence, par exemple des polyalkylène-glycols de faible masse moléculaire, notamment polyéthylèneglycol, butyldiglycol.

4. Méthode selon l’une des revendications 1 à 3 pour laquelle le composé modificateur de rhéologie :

• a un pH supérieur à 5, de préférence supérieur à 5,5, plus préférentiellement supérieur à 6 ou

• est choisi parmi les copolymères ASE, les copolymères HASE et leurs combinaisons, de préférence parmi les copolymères anioniques préparés par réaction de polymérisation :

(al) d’au moins un monomère anionique comprenant au moins une insaturation oléfinique polymérisable, de préférence un monomère anionique comprenant au moins une insaturation oléfinique polymérisable et au moins une fonction acide carboxylique, de préférence le monomère anionique est choisi parmi l’acide acrylique, l’acide méthacrylique, l’acide maléique, l’anhydride maléique, l’acide itaconique, l’acide crotonique, un sel d’acide acrylique, un sel d’acide méthacrylique, un sel d’acide maléique, un sel d’anhydride maléique, un sel d’acide itaconique, un sel d’acide crotonique et leurs combinaisons, bien plus préférentiellement l’acide acrylique ou l’acide méthacrylique et

(a2) d’au moins un ester d’un composé dérivé d’un acide choisi parmi l’acide acrylique, l’acide méthacrylique, l’acide maléique, l’anhydride maléique, l’acide itaconique et l’acide crotonique, de préférence un ester de l’acide acrylique ou un ester de l’acide méthacrylique, de préférence choisi parmi acrylate de méthyle, acrylate d’éthyle, acrylate de propyle, acrylate de butyle, acrylate d’éthylhexyle, méthacrylate de méthyle, méthacrylate d’éthyle, méthacrylate de propyle, méthacrylate de butyle, méthacrylate d’éthylhexyle et leurs combinaisons, éventuellement

(a3) d’au moins un composé de formule (I) :

R1-(OE)m-(OP)n-R2 (I)

dans laquelle :

m et n, identiques ou différents, représentent indépendamment 0 ou un nombre entier ou décimal inférieur à 150, m ou n est différent de 0,

OE représente indépendamment un groupement CH2CH2O,

OP représente indépendamment un groupement choisi parmi CH(CH3)CH20 et CH2CH(CH3)0,

R1 représente un groupement comprenant au moins une insaturation oléfinique polymérisable, de préférence un groupement acrylate ou un groupement méthacrylate et

R2 représente un groupement C6-C4o-alkyl, linéaire ou ramifié, un groupement phényl, un groupement polyphényl, de préférence un groupement Cio-C3o-alkyl, linéaire ou ramifié, plus préférentiellement un groupement Ci2-C22-alkyl, linéaire ou ramifié, ou un groupement comprenant 2 à 5 phényls ou un groupement tristyrylphényl ou un groupement pentastyrylcumylphényl, éventuellement (a4) d’au moins un composé choisi parmi l’acide 2-acrylamido-2-méthylpropane sulfonique, l’acide éthoxyméthacrylate sulfonique, méthallyl sulfonate de sodium, styrène sulfonate hydroxyéthyl-acrylate phosphaté, hydroxypropyl-acrylate phosphaté, hydroxyéthylhexyl-acrylate phosphaté, hydroxyéthyl-méthacrylate phosphaté, hydroxypropyl-méthacrylate phosphaté, hydroxyéthylhexyl- méthacrylate phosphaté, leurs sels et leurs combinaisons, éventuellement

(a5) d’au moins un composé choisi parmi hydroxyéthyl-acrylate, hydroxypropyl- acrylate, hydroxyéthylhexyl-acrylate, hydroxyéthyl-méthacrylate, hydroxypropyl- méthacrylate, hydroxyéthylhexyl-méthacrylate et également éventuellement (a6) d’au moins un monomère réticulant ou d’au moins un monomère comprenant au moins deux insaturations oléfiniques.

5. Méthode selon l’une des revendications 1 à 4 pour laquelle le mélange (M) :

• comprend également une base, de préférence une base minérale, en particulier une base choisie parmi NaOH, KOH, dérivés ammonium, ammoniaque, bases aminées, par exemples triéthanolamine, aminométhylpropanol ou

2-amino-2-méthyl-propanol (AMP) et leurs combinaisons ou

• a un pH supérieur à 5, de préférence supérieur à 5,5, plus préférentiellement supérieur à 6 ou

• a un pH inférieur à 12 ou

• a un pH allant de 5 à 12, de préférence de 5,5 à 12, plus préférentiellement de 6 à 12 ou

• ne comprend pas de composé tensio-actif ou bien comprend une faible quantité, par exemple une quantité de composé tensio-actif allant de 0,05 à 10 % en poids ou allant de 0,05 à 5 % en poids, du poids du mélange (M) ou bien une quantité de composé tensio-actif non-ionique allant de 0,05 à 10 % en poids ou allant de 0,05 à 5 % en poids, du poids du mélange (M).

6. Méthode selon l’une des revendications 1 à 5 pour laquelle le mélange (M) comprend de 0,5 à 15 % en poids, de préférence de 1 à 15 % en poids ou de 2 à 12 % en poids, de modificateur de rhéologie.

7. Méthode selon l’une des revendications 1 à 6 pour laquelle :

• la température de préparation est inférieure au point d’ébullition de la phase hydrophile et inférieure au point d’ébullition de la phase lipophile ou

• la température de préparation est supérieure au point de fusion de la phase hydrophile et supérieure au point de fusion de la phase lipophile ou

• la température de préparation est inférieure au point d’ébullition de la phase hydrophile et inférieure au point d’ébullition de la phase lipophile tout en étant supérieure au point de fusion de la phase hydrophile et supérieure au point de fusion de la phase lipophile.

8. Méthode selon l’une des revendications 1 à 7 pour laquelle la dispersion est une émulsion de la phase dispersée lipophile dans la phase continue hydrophile.

9. Méthode selon l’une des revendications 1 à 8 pour laquelle la contrainte de cisaillement ou la contrainte élongationnelle :

• va de 300 à 5 000 Pa, de préférence de 100 à 2 000 Pa ou de 300 à 2 000 Pa, plus préférentiellement de 100 à 1 700 Pa ou de 300 à 1 700 Pa ou

• est également appliquée lors de la préparation du mélange (M), de préférence a une valeur égale ou inférieure à celle appliquée lors de l’addition du composé lipophile ou

• la contrainte est appliquée au moyen d’un dispositif produisant un gradient de cisaillement inférieur à 2 000 s 1 ou inférieur à 1 000 s 1 ou au moyen d’un dispositif produisant un gradient de cisaillement allant de 100 à 5 000 s 1 ou allant de 100 à 2 000 s 1 ou bien encore allant de 100 à 1 000 s 1, de préférence allant de 200 à 5 000 s 1 ou de 200 à 2 000 s 1 ou bien de 200 à 1 000 s 1, en particulier allant de 200 à 800 s 1.

10. Méthode selon l’une des revendications 1 à 9 pour laquelle les particules de phase lipophile dispersées ont une taille moyenne (mesurée par diffraction de la lumière) submicronique, de préférence au moins 30 % en volume ou au moins 40 % en volume, de préférence au moins 50 % en volume, des particules de phase lipophile dispersée ont une taille moyenne nanométrique ou submicronique, de manière plus préférée au moins 30 % en volume ou au moins 40 % en volume, plus préférentiellement au moins 50 % en volume, des particules de phase lipophile dispersée ont une taille moyenne allant de 50 à 999 nm ou de 100 à 999 nm ou encore de 50 à 990 nm ou de 500 à 990 nm.

11. Méthode selon l’une des revendications 1 à 10 comprenant également :

• la neutralisation de la dispersion (D), de préférence au moyen d’au moins un composé choisi parmi NaOH, KOH, dérivés ammonium, ammoniaque, bases aminées, par exemples triéthanolamine, aminométhylpropanol ou 2-amino-2-méthyl-propanol (AMP) et leurs combinaisons ou

• la coacervation partielle du composé modificateur de rhéologie, de préférence : o par réduction du pH de la dispersion (D), par exemple par réduction du pH à une valeur inférieure à 6,5, notamment au moyen d’un composé acide, en particulier au moyen d’au moins un composé acide organique ou minéral, notamment un composé acide choisi parmi acide phosphorique, acide citrique, glucono-lactone, acide lactique, acide salicylique, acide glycolique, acide ascorbique, acide glutamique, acide hydrochlorique, acide acétique, acide D-gluconique, acide sulfonique, acide méthane-sulfonique, acide benzimidazole-sulfonique, acide tartrique, acide 4-aminobenzoique, acide benzoïque, acide sorbique, acide phenylbenzimidazole sulfonique, acide benzylidene camphor sulfonique, acide terephthalylidene dicamphor sulfonique ou

o par augmentation de la force ionique de la dispersion (D), par exemple par addition d’au moins un composé ionisé ou d’au moins un sel, en particulier NaCl, KC1, MgCl2, CaCl2, MgS04, CaS04 ou

o par réduction de la solubilité du composé modificateur de rhéologie dans la phase hydrophile, par exemple par addition d’au moins un polymère cationique, en particulier par addition d’au moins un polymère cationique, notamment un polymère cationique choisi parmi polyquaternium 1 à polyquatemium 47 et guars quatemisées, notamment chlorure d’hydroxypropyl-guar triammonium, chlorure de polydiallyldiméthylammonium (polyDADMAC ou polyDDA), chlorure de poly-2-(méthacryloyloxy)éthyl-triméthyl-ammonium (polyMAD quat).

12. Dispersion (D) susceptible d’être préparée selon l’une des revendications 1 à 11.

13. Produit comprenant au moins une dispersion selon la revendication 12.

14. Utilisation d’une dispersion (D) selon la revendication 12 ou d’un produit selon la revendication 13 dans un domaine choisi parmi la cosmétique, la peinture, la teinture, l’imprimerie, les encres, la construction, les combustibles, les lubrifiants, les agents anti-mousse, la métallurgie, les fertilisants, la pharmacie, l'agrochimie, les produits phytosanitaires, la détergence, l'alimentation, le cuir, l'enduction, notamment l’enduction textile.