EP1814932A2

EP1814932A2 - Dried emulsion, method for preparing same and uses thereof

Info

Publication number: EP1814932A2
Application number: EP05821415A
Authority: EP
Inventors: Jean-Pierre Hecaen
Original assignee: Rhodia Chimie SAS
Current assignee: Rhodia Chimie SAS
Priority date: 2004-11-22
Filing date: 2005-11-22
Publication date: 2007-08-08
Also published as: US20080194709A1; CN101107295A; FR2878170B1; FR2878170A1; WO2006053999A3; WO2006053999A2; JP2008520794A

Abstract

The invention concerns a dried emulsion comprising a matrix including a water-soluble or water-dispersible polymer, wherein is dispersed a hydrophobic phase, characterized in that: the dried emulsion comprises a non-polyalkoxylated surfactant, the water-soluble or water-dispersible polymer comprised in the matrix is a polycarboxylate including hydrophobic units.

Description

Dried emulsion, process for its preparation and uses

The present invention relates to a dried emulsion comprising a matrix comprising a water-soluble or water-dispersible polymer, in which a hydrophobic phase is dispersed. The invention also relates to a process for preparing the dried emulsion, and uses of said emulsion.

The dried emulsions are compositions comprising a liquid hydrophobic phase dispersed in a solid matrix. They can be obtained by drying an emulsion comprising an aqueous phase in which the liquid hydrophobic phase is dispersed, generally with the aid of a surfactant, the aqueous phase comprising the water-soluble or water-dispersible compound which will constitute all or part of of the matrix after drying. Compositions in the form of dried emulsions and methods for their preparation are known to those skilled in the art. The dried emulsions are generally in the form of powder or granules.

Dried emulsions comprising a polyalkoxylated surfactant and a matrix comprising a polymer comprising hydrophilic units and units comprising hydrophobic groups or grafts are thus known. Such dried emulsions are for example described in WO 00/26280 (R 98145), WO 02/32563 (R 00137), and WO 03/006148 (R 01103).

The dried emulsions are generally intended to be dispersed in an aqueous composition to obtain an emulsion or a dispersion comprising the hydrophobic phase dispersed in the aqueous composition. The dried emulsions can thus facilitate or make economic the handling and / or the transport and / or the vectorization and / or the protection of the hydrophobic phase. The dried emulsions can thus be formulated with other solid compounds and be brought into the presence of water by the end user. For example, it is possible to produce powder mixtures. This is the case for example for certain phytosanitary compositions, and for detergent formulations in powders or granules. The dried emulsions may also be placed in the presence of water by an operator preparing an aqueous formulation comprising the hydrophobic phase. It is also noted that it may be interesting to trigger the re-dispersion by an external factor (for example a change in pH, temperature, chemical composition of the environment, by the release of aqueous substances such as urine or sweat ...) or to control the kinetics of the re-dispersion. Qualities of a dried emulsion include: easy re-dispersion in water, no coalescence of water-immiscible hydrophobic phase during drying and / or redispersion, good powder flowability, shape easily manipulated, for example non-oily, a control of a coalescence or droplet size of the hydrophobic phase before drying or after drying, redispersion.

We have now found new dried emulsions which may have improved qualities among those mentioned above.

Thus, the invention provides a dried emulsion comprising a matrix comprising a water-soluble or water-dispersible polymer, in which a hydrophobic phase is dispersed, characterized in that:

the dried emulsion comprises a non-polyalkoxylated surfactant,

the water-soluble or water-dispersible polymer included in the matrix is a polycarboxylate comprising hydrophobic units.

The invention also provides a process for preparing such emulsions, and uses.

The invention also proposes a surfactant mixture particularly suitable for the implementation of the dried emulsions according to the invention, or even for the implementation of emulsions in general.

Definitions

In the present application, the term "water-soluble or water-dispersible polymer" means a polymer which, at a concentration of 10% by weight in water at a temperature of 25 ° C., does not exhibit macroscopic phase separation. In the present application the water-soluble or water-dispersible quality refers to the preparation pH of the dried emulsion and / or the pH of use of the dried emulsion during the re-dispersion.

In the present application, hydrophobic phase means a compound or a composition comprising several compounds, immiscible with water (forming a macroscopic phase separation), at a concentration of 10% by weight, at a temperature of 25 ° C. vs. In the present application, the hydrophobic or water-dispersible phase quality refers to the preparation pH of the dried emulsion and / or the pH of use of the dried emulsion during the re-dispersion. In the present application, unless otherwise indicated, the amounts of ingredients and ratios are given by weight of dry matter.

Ingredients of the Dried Emulsion The dried emulsion comprises a matrix comprising a water-soluble or water-dispersible polymer in which a hydrophobic phase is dispersed. The hydrophobic phase can be liquid or solid. It is preferably liquid. In the case where the hydrophobic phase is a solid phase, it may have been liquefied by heating and emulsified during the preparation of the emulsion of the dried emulsion. The hydrophobic phase is present in the form of inclusions (droplets if it is a liquid phase) in the matrix, advantageously of a mean size of between 0.1 and 50 μm, preferably between 1 and 10 μm. for example between 1 and 5 microns (determined using a HOR1BA laser diffraction granulometer). The average size may vary depending on the final application.

Below is described below various ingredients that can be used in the composition of the dry emulsion.

Hydrophobic Phase The hydrophobic phase may comprise all kinds of compounds, alone or in mixtures, optionally in solution or in dispersion in a hydrophobic solvent. Of course, the hydrophobic phase may consist only of a single hydrophobic liquid. The hydrophobic phase may be an active hydrophobic compound, or a mixture comprising an active hydrophobic compound in solution or a dispersion in a hydrophobic solvent.

Examples of hydrophobic phases or compounds included in the hydrophobic phase are:

silicones, for example silicone oils and gums, of the MD, MTD or MQ type, optionally solubilized in solvents, and optionally functionalized with groups such as amines, alcohols, polyols, etc. Such silicones are known to those skilled in the art.

- the perfumes.

organic, mineral or vegetable or mineral oils, and derivatives of these oils, said oils and derivatives being immiscible with water.

organic solvents immiscible with water. the non-water-soluble or water-dispersible active substances, optionally solubilized in a solvent.

- their mixtures, in solutions, dispersions, or emulsions.

In the field of agrochemistry, the phytosanitary active ingredients may be chosen from the family of α-cyano-phenoxybenzyl carboxylates or α-cyanohalogenophenoxy carboxylates, the family of N-methylcarbonates comprising aromatic substituents, the active ingredients such as that Aldrin, Azinphos-methyl, Benfluralin, Bifenthrin, Chlorphoxim, Chlorpyrifos, Fluchloralin, Fluroxypyr, Dichloruos, Malathion, Molinate, Parathion, Permethrin, Profenofos, Propiconazole, Prothiophos, Pyrifenox, Butachlor, Metolachlor, Chlorimephos, Diazinon, Fluazifop-P-butyl , Heptopargil, Mecarbam, Propargite, Prosulfocarb, Bromophos-ethyl, Carbophenothion, Cyhalothrin, Novaluron, Deltamethrin, Pendimethalin, Fluquinconazole, Tebuconazole, Alphamethrin, Chlothianidin, Betacyfluthrin, Cyfluthrin, Lambda-Cyhalothrin, Cyhalothrin, Fipronil, Thiacloprid, Imidacloprid, Phenmedipham, Desmedipham , Amidosulfuron, Ethofumesate. Phytosanitary active ingredients can be used in the presence of conventional additives, chosen for example from adjuvants for increasing the effectiveness of the active ingredient, anti-foaming agents, anti-caking agents, and water-soluble fillers. or not. These active substances may in solutions in a hydrophobic solvent, for example chosen from aromatic hydrocarbon solvents such as xylene, dibenzyltoluene, phosphate or phosphonate solvents such as tri-n-butyl phosphate (TBP), aliphatic hydrocarbon solvents such as that mineral or vegetable oils, alcohols such as cyclohexanol, ketones such as cyclohexanone, amides such as N, N-dimethylcaprylamide-capramid, pyrrolidones such as N-methylpyrrolidone, N-octylpyrrolidone, N dodecylpyrrolidone, N-cyclohexylpyrrolidone, alkyllactates, solvents.

The hydrophobic phase may in particular be a hydrophobic phase comprising deltamethrin and tri-n-butyl phosphate (TBP). It may, however, be different from a hydrophobic phase comprising both detlamethrin and TBP. The hydrophobic phase may in particular be a hydrophobic phase comprising deltamethrin and a xylene-based solvent such as Solvesso 200 or 200 ND. It may, however, be different from a hydrophobic phase comprising both detlamethrin and a xylene-based solvent such as Solvesso 200 or 200 ND. The hydrophobic phase may in particular be a hydrophobic phase comprising deltamethrin, a xylene-based solvent such as Solvesso 200 or 200 ND and trisamethrin. n-butyl phosphate (TBP). It may, however, be different from a hydrophobic phase comprising both detlamethrin, a xylene-based solvent such as Solvesso 200 or 200 ND, and TBP.

It is also possible to mention as suitable active materials in the field of phytosanitary formulations, vegetable oils, mineral oils, silicone oils, silicone anti-foams, etc.

As examples of active materials that can be used in the field of cosmetics, mention may be made of silicone oils belonging in particular to the family of dimethicones; lipophilic vitamins, such as vitamin A and its derivatives, vitamin B2, pantothenic acid, vitamin D and vitamin E; mono-, di- and triglycerides; the perfumes ; bactericides; UV-absorbing agents, such as aminobenzoate derivatives of PABA and PARA type, salicylates, cinnamates, anthranilates, dibenzoylmethanes, camphor derivatives and mixtures thereof. Anti-aging agents can likewise be used. Examples of such agents that may be mentioned include retinoids, α- and β-hydroxy acids, their salts and esters, fat-soluble vitamins, ascorbyl palmitate, ceramides, pseudo-ceramides, phospholipids, fatty acids, fatty alcohols, cholesterol, sterols and their mixtures. Preferred fatty acids and alcohols include, for example, those having linear or branched alkyl chains containing from 12 to 20 carbon atoms. It may in particular be linoleic acid.

It is likewise possible to use anti-cellulite agents, such as in particular isobutylmethylxanthine and theophylline; as well as anti-acne agents, such as resorcinol, resorcinol acetate, benzoyl peroxide and many natural compounds.

Aromas, perfumes, essential oils, essences can also be used as hydrophobic active material. By way of example, mention may be made of oils and / or essences of mint, spearmint, peppermint, menthol, vanilla, cinnamon, laurel, anise, eucalyptus, thyme, sage, cedar leaf, nutmeg, citrus (lemon, lime, grapefruit, orange), fruit (apple, pear, peach, cherry, plum, strawberry, raspberry, apricot, pineapple, grape, etc.). ), alone or in mixtures.

The antimicrobial agents may be selected from thymol, menthol, triclosan, 4-hexylresorcinol, phenol, eucalyptol, benzoic acid, benzoic peroxide, butyl paraben, and mixtures thereof. As examples of suitable active materials for use in the field of paints include alkyd resins, epoxy resins, isocyanates blocked or not.

In the field of paper, mention may be made, inter alia, of resins such as alkylketene dimer (AKD) or alkenyl succinic anhydride (ASA).

In the field of detergency, there may be mentioned as possible active ingredient, amino silicones as a softening agent, silicone anti-foams, antimicrobial agents, perfumes, oils and essences, etc. As such, we can refer to the list of compounds of this type, indicated in the context of active ingredients for the field of cosmetics.

Among the suitable hydrophobic active substances, mention may also be made of:

- oils / fats / organic waxes of animal origin or of vegetable origin;

- mineral oils / waxes; products derived from the alcoholysis of the aforementioned oils;

mono-, di- and triglycerides;

saturated or unsaturated fatty acids comprising 10 to 40 carbon atoms; esters of such acids and of alcohol containing 1 to 6 carbon atoms;

saturated or unsaturated monoalcohols comprising 8 to 40 carbon atoms; these compounds being used alone or in a mixture.

As organic oils / fats / waxes of animal origin, there may be mentioned, in particular, sperm whale oil, whale oil, seal oil, shark oil, cod liver oil, pork, mutton fat, perhydrosqualene, beeswax, alone or in a mixture. Examples of organic oils / fats / waxes of vegetable origin include rapeseed oil, sunflower oil, peanut oil, olive oil and others. , walnut oil, corn oil, soybean oil, avocado oil, linseed oil, hemp oil, grape seed oil, coconut oil, palm oil, cottonseed oil, palm kernel oil, babassu oil, jojoba oil, sesame oil, castor oil, macadamia, sweet almond oil, camauba wax, shea butter, cocoa butter, peanut butter, alone or mixed.

As regards mineral oils / waxes, mention may be made, inter alia, of naphthenic, paraffinic (petroleum), isoparaffinic and paraffinic waxes, alone or as a mixture.

Products derived from alcoholysis of the above-mentioned oils can also be used.

Regarding the fatty acids, the latter, saturated or not, comprise 10 to 40 carbon atoms, more particularly 18 to 40 carbon atoms, and can include one or more ethylenic unsaturations, conjugated or not. It should be noted that said acids may comprise one or more hydroxyl groups.

Examples of saturated fatty acids include palmitic, stearic, isostearic and behenic acids.

Examples of unsaturated fatty acids that may be mentioned include myristoleic, palmitoleic, oleic, erucic, linoleic, linolenic, arachidonic and ricinoleic acids, as well as their mixtures.

With regard to the fatty acid esters, mention may be made of the esters of the acids previously listed, for which the portion derived from the alcohol comprises 1 to 6 carbon atoms, such as methyl, ethyl, propyl, and isopropyl esters. etc.

It is mentioned that the hydrophobic phase may comprise an immiscible intermediate phase with water in which is dispersed an internal phase immiscible or insoluble in the intermediate phase. In this case we can speak of dried multiple emulsion.

Of course, it is not excluded that the dried emulsion comprises several different hydrophobic phase dispersed matrix, consisting of two populations of inclusions.

Water-soluble or water-dispersible polymer

The water-soluble or water-dispersible polymer of the matrix is a polycarboxylate comprising hydrophobic units.

Advantageously, it is a copolymer comprising units deriving from the following monomers:

- (I) linear or branched, ethylenically unsaturated, linear or branched, monocarboxylic or polycarboxylic acid, or anhydride, aliphatic, cyclic or aromatic,

- (II) monomer of formula (R ² ) (R ² ) C = CH (R ³ ) in which - R ³ is a hydrogen atom or a methyl group, and

- R ² , which may be identical or different, represent a hydrogen atom, a linear or branched, optionally cyclic, saturated or ethylenically unsaturated, aliphatic or aromatic radical, at C ² -C ⁶ O, with the proviso that the two radicals R 2 are not hydrogen atoms, and optionally (III) polyoxyalkylene ester of ethylenically unsaturated carboxylic acid. The monomer (I) advantageously has the formula:

(R ³ ) HC = C (R ¹ ) -COOX (la), in which:

- R ³ is a hydrogen atom or a methyl group, - R ¹ is a hydrogen atom, a hydrocarbon radical C-] - C-] o optionally comprising a group - COOX, or a -COOX group, forming optionally with the group - COOX an anhydride group -CO-O-OC-, and

X is a hydrogen atom or a cation, for example the cation of sodium, of potassium, or the ammonium cation. For example, the monomer (I) is advantageously chosen from acrylic, methacrylic, citraconic, maleic, fumaric, itaconic or crotonic acids or anhydrides, in acid form or in the form of salts, for example in the form of sodium or potassium salt.

Advantageously, the monomer (II) is chosen from 1-butene, isobutylene, n-1-pentene, 2-methyl-1-butene, n-1-hexene, 2-methyl-1-pentene, 4-methyl-pentene, 2-ethyl-1-butene, diisobutylene (or 2,4,4-trimethyl-1-pentene), 2-methyl-3,3-dimethyl-1-pentene.

The monomer (III) may correspond to the following formula:

CH 2 = C (R 3) -C (O) -O- [CH 2 CH (R 4) O] _m - [CH (R 5) -CH 2 O] _n -R ⁶ in which formula:

R3 is a hydrogen atom or a methyl radical,

R4 and R5, which may be identical or different, represent a hydrogen atom or an alkyl radical containing from 1 to 4 carbon atoms,

Rδ is an alkyl, aryl, alkylaryl or arylalkyl radical containing from 1 to 30, preferably from 8 to 30 carbon atoms, n is between 2 and 100, preferably between 6 and 10O m is between 0 and 50, under reserve that n is greater than or equal to m and their sum between 2 and

100, preferably between 6 and 100.

Preferably, monomers of formula (M1) are used, for which R6 is an alkyl radical containing from 8 to 30 carbon atoms, or a phenyl radical substituted with one to three 1-phenylethyl groups, or an alkylphenyl radical whose alkyl radical. contains from 8 to 16 carbon atoms.

Among the monomers of this type that may be used include those described in patents EP 705 854, US 4 138 381 or US 4 384 096. The copolymer may further comprise units derived from an optional monomer (IV) selected from the following monomers:

vinyl aromatic monomers such as styrene, vinyltoluene, C 1 -C 20 alkyl esters of ethylenically unsaturated acids such as methyl, ethyl and butyl acrylates or methacrylates,

vinyl or allyl esters of ethylenically unsaturated acids such as vinyl or allyl acetates or propionates,

vinyl or vinylidene halides such as vinyl chloride or vinylidene,

ethylenically unsaturated nitriles such as acrylonitrile,

hydroxyalkyl esters of ethylenically unsaturated acids such as hydroxyethyl or hydroxypropyl acrylates or methacrylates,

ethylenically unsaturated amides, such as acrylamide and methacrylamide.

According to an advantageous embodiment, the polycarboxylate comprising hydrophobic units is a copolymer derived from maleic anhydride or from a maleic anhydride salt and from diisobutylene. Such a polymer is, for example, marketed by Rhodia under the name Geropon® EGPM (in solution, in sodium carboxylate form).

It is noted that the copolymers can be obtained in a manner known to those skilled in the art, for example by radical polymerization.

Non-polyalkoxylated surfactant

The non-polyalkoxylated surfactant may be a non-polyalkoxylated nonionic surfactant, a non-polyalkoxylated anionic surfactant, a non-polyalkoxylated amphoteric surfactant, or a mixture of these surfactants.

As examples of non-polyalkoxylated amphoteric surfactants, mention may be made of amphoacetates, amphodiacetates, betaines (carboxybetaines such as alkylbetaines and alkylamidoalkyl betaines), amine oxides, sultaines (sulfobetaines), and mixtures thereof.

By way of examples of non-polyalkoxylated surfactants, mention may be made of alkyl sulphates, alkyl sulphonates, alkylarylsulphonates and alkylphosphates, and mixtures thereof.

By way of examples of non-polyalkoxylated nonionic surfactants, mention may be made of the following surfactants: the alkylpolyglucosides,

the non-polyalkoxylated sorbitan esters,

fatty acids,

- their mixtures.

The dried emulsion may be a dried emulsion comprising, as sole non-polyacyloxylated surfactant, a sorbitan ester such as the surfactant Alkamuls S80 marketed by Rhodia. It may, however, be a dried emulsion comprising in addition another surfactant. It may in particular be different from a dried emulsion comprising, as sole non-polyacyloxylated surfactant, a sorbitan ester such as the surfactant Alkamuls S80 marketed by Rhodia. The dried emulsion may be a dried emulsion comprising, as sole non-polyacyloxylated surfactant, a sorbitan ester such as the surfactant Alkamuls S80 marketed by Rhodia and as a solvent for the active ingredient a xylene-based solvent such as Solvesso 200 or 200 ND or tri-n-butyl phosphate (TBP), or a mixture of these solvents. It may, however, be different from a dried emulsion comprising, as sole non-polyacrylated surfactant, a sorbitan ester such as the surfactant Alkamuls S80 marketed by Rhodia and as a solvent for active ingredient a xylene-based solvent such as Solvesso 200 or 200 ND or tri-n-butyl phosphate (TBP), or a mixture of these solvents.

According to an advantageous embodiment, the non-polyalkoxylated surfactant is:

a sorbitan ester derived from a C ₈ -C ₃₀ , preferably C ₁₆ -C ₂₂ , fatty acid, or

- a mixture of a sorbitan ester derived from a fatty acid C ₈ -C _30, preferably C ₆ -C ₂₂ fatty acid and of a C ₈ -C _30, preferably C ₆ - C ₂₂ , or a salt of the fatty acid.

Preferably, the mixture of the sorbitan ester and the fatty acid comprises, in dry matter, from 2 to 20% by weight of the fatty acid or salt.

The mixture of the sorbitan ester and the fatty acid is a surfactant (surfactant composition, or "blend" of surfactants) which makes it possible to control the emulsification of hydrophobic phases, especially the size of the droplets of an emulsion comprising a hydrophobic phase dispersed in an aqueous phase. Thus, the invention also relates to this surfactant (this surfactant composition, or "blend" of surfactants) as such, in particular a mixture comprising the sorbitan ester and the fatty acid or its salt, where appropriate with water, at a solids concentration greater than 20% or 30% or 50% or 75%. The invention also relates to emulsions, dried or not, comprising this surfactant (and the hydrophobic phase and the aqueous phase), or the use of the surfactant in the emulsions.

Quantities of ingredients Advantageously, the weight ratio between the hydrophobic phase and the matrix is between 50% and 80%.

Advantageously, the weight ratio between the non-polyalkoxylated surfactant and the hydrophobic phase is between 0.003 and 0.3, preferably between 0.01 and 0.06.

Advantageously, the weight ratio between the non-polyalkoxylated surfactant and the matrix is between 0.006 and 0.6, preferably between 0.02 and 1.2.

Advantageously, the matrix comprises at least 90% by weight of the water-soluble or water-dispersible polymer.

Other Compounds The dried emulsion may comprise other ingredients, which may be useful in its preparation, or which may be useful in modulating its properties or applications.

It may especially be active ingredients (ie ingredients having a function during use, for example in a liquid formulation), included in the matrix, and formulated in an aqueous phase.

It may also be antifoam agents, daring as described in the document WO 03/055584 (R 01186), or complexing agents comprising at least one of the elements of columns HA, IVA, VA, VIII, IB, and IHB, to more easily control the release of the hydrophobic phase during a redispersion in water, as described in WO 03/006148 (R 01103).

The dried emulsion may optionally contain residual water. The water content is advantageously less than 10% by weight, still more preferably less than 3%.

Process

The dried emulsion according to the invention may be carried out according to a process comprising the following steps: a) preparing an emulsion comprising an aqueous phase in which the hydrophobic phase dispersed in liquid form is dispersed in water, the emulsion comprising the copolymer water-soluble or water-dispersible matrix of the non-polyalkoxylated surfactant, where appropriate by heating the hydrophobic phase above its melting point, b) removing the water, to obtain a dried emulsion, c) optionally putting the dried emulsion in the form of powder or granules, d) recovering the dried emulsion,

Step a) preparation of the emulsion

In a first step of the process, an emulsion comprising the hydrophobic phase dispersed in the aqueous phase is prepared. The hydrophobic phase, during this step, is in liquid form. If necessary, it is heated for this purpose. The emulsion comprises the water-soluble or water-dispersible polymer, and the surfactant. All methods of preparing an emulsion can be used. They are known to those skilled in the art. Methods are described, for example, in "ENCYCLOPEDIA of EMULSIONS TECHNOLOGY", volumes 1 to 3 by Paul BECHER edited by MARCEL DEKKER INC, 1983, and may be implemented within the scope of the present invention. Thus, the so-called direct phase emulsification method can be used. It is briefly recalled that this method consists of preparing a mixture containing water and emulsifiers, including the water-soluble or water-dispersible polymer, and then introducing the hydrophobic phase in liquid form, with stirring.

Another suitable method is phase inversion emulsification. According to this route, the hydrophobic phase is mixed with an emulsifier and water which can contain the other constituents, such as the water-soluble or water-dispersible polymer for example, is introduced dropwise and with stirring. From a certain amount of introduced water, an inversion of the emulsion occurs. A direct oil-in-water emulsion is then obtained. The resulting emulsion is then diluted in water to obtain a suitable dispersed phase volume fraction.

Finally, the emulsion can be prepared by using colloid mills such as MANTON GAULIN and MICROFLUIDIZER (MICROFLUIDICS).

The average size of the hydrophobic phase droplets dispersed in the aqueous phase is generally between 0.1 and 50 μm, often between 1 and 10 microns and preferably between 0.2 and 5 microns (expressed relative to the volume of particles; by means of a laser diffraction granulometer of the type

HORIBA).

The emulsification can be carried out at a temperature close to room temperature, although lower or higher temperatures are possible.

The quantity of water present in the emulsion, before drying, may be between 5 and 99% by weight, preferably between 20% and 70% by weight. So Generally it is preferred to use small amounts of water since it must be removed later. Controlling the amount of water can be a way to manage the viscosity.

Steps b) c) d) drying, shaping The method used to remove water from the emulsion and obtain the dried emulsion may be carried out by any means known to those skilled in the art.

This operation takes place so that the various constituent elements of the mixture are subjected to temperatures lower than those of their degradation.

According to a first embodiment of the invention, drying in an oven can be envisaged. This drying preferably takes place in a thin layer. More particularly, the temperature at which the drying is carried out is less than or equal to 100 ^° C., preferably between 30 and 90 ^° C., preferably between 50 and 90 ^° C.

According to another particular embodiment of the invention, the so-called rapid drying of the mixture (or emulsion) is carried out. Suitable for this purpose is spray drying in a fluidized bed, using Duprat® drums, or freeze-drying (freezing-sublimation).

Spray drying, for example using an NIRO apparatus, or in a fluidized bed, for example using an AEROMATIC apparatus, may be carried out in the usual manner in any known apparatus such as, for example, a tower atomization device associating a spray produced by a nozzle or a turbine with a stream of hot gas. The inlet temperature of the hot gas (generally air) at the top of the column is preferably between 50 ^° C. and 250 ^° C. and the outlet temperature is preferably lower than the degradation temperature of the elements. constituents of the granule obtained. In the case of drying operations of the mixture (or emulsion) carried out by means of Duprat® drum, or any means making it possible rapidly to obtain a dry film which is separated from the drying support by a scraping operation, for example particles are obtained which can optionally be ground. If necessary, these particles may be further shaped, such as an agglomeration step, so as to obtain granules.

It should be noted that additives, such as anti-caking agents may be incorporated into the granules at the time of this drying step.

By way of example, it is recommended to use a filler chosen in particular from calcium carbonate, barium sulfate, kaolin, silica, bentonite, titanium oxide, talc, hydrated alumina and calcium sulfoaluminate. Preferably, the drying is carried out such that at least 90% by weight of the external aqueous phase is removed, preferably between 90 and 95% by weight. The amount of residual water is preferably less than 3% by weight.

uses:

The dried emulsion can be used:

- in phytosanitary formulations,

in formulations for the care of laundry, for example in powdered or tablet detergents, for the formulation of softeners, the vectorization of perfumes, the formulation of defoamers, or silicones for example for a deposit on fibers ,

in formulations for automatic dishwashers, in the form of powders or tablets,

in cosmetic formulations,

- in wipes for household care, - in wipes or for skincare

- in wipes for the care of babies,

- in diapers

- in cleansing wipes,

in formulations of bath salts, in formulations of building materials and / or public works, for example for the formulation of retarders or accelerators for setting cement,

in surface coating formulations, for example in paints.

to formulate in solid form silicone oils, for example defoamers.

In more detail, the dried emulsion can be used in phytosanitary formulations, the hydrophobic phase being a phytosanitary active compound, or a mixture comprising a hydrophobic active phytosanitary compound, in solution or dispersion in a hydrophobic solvent. The dried emulsion may optionally be used with other phytosanitary products (association of phytosanitary products), for example in combination with a fertilizer. The dried emulsion and the fertilizer may in particular be mixed in the same tank with water.

Other details or advantages of the invention may appear in light of the examples below, without limitation. Dried emulsions whose hydrophobic phase is metolachlor are prepared by preparing an emulsion comprising metolachlor, a surfactant, water and the polymer (Geropon® EGPM marketed by Rhodia), followed by drying. The compositions (ingredients and quantities) of the emulsions and dried emulsions are given in the tables below.

Procedure: a) Realization of the emulsion

The polymer is weighed down with an antifoam if necessary. The stirring is carried out at 500 rpm with a paddle frame.

- Add all or part of the water

- A mixture of metolachlor and surfactant is added.

- Homogenize and acidify with HCl 2N (drop by drop)

- It is stirred at 500 revolutions / minutes 15 minutes - If necessary the rest of the water is added

- Let stir 30 minutes

- The particle size (Horiba) is measured as a function of time b) Drying

- Dry on a tray in an oven at 75 ⁰ C overnight - Coarsely ground.

The particle size is measured during re-dispersion (1 g of powder in 50 ml of tap water, with an electromagnetic stirrer, at 500 rpm for 5 minutes at room temperature.

Example 1 (Comparative)

Polyethoxylated tristyrylphenol

Emulsion before drying

- Metolachlor / sec: 63.7%

- Sec clip: 34.9%

- Surfactant / (Metolachlor + surfactant): 6.8%

- Surfactant / Polymer: 13.2%

The emulsion is coarse. It is not dried afterwards.

Example 2 (Comparative)

(1) Polyethoxylated tristyrylphenol

Emulsion before drying

- Sec clip: 34.9%

- Surfactant / (Metolachlor + surfactant): 3%

- Surfactant / (surfactant + dry polymer): 6.0%

Granulometry before drying:

D10 = 0.54 μm

D50 = 1, 30 μm

D90 = 3.35 μm

(D90-D10) / D50 = 2.16

The emulsion is not dried subsequently.

Example 3

(2) Sorbitan Ester

Emulsion before drying

- Dry extract: 35.3%

- Surfactant / (Metolachlor + surfactant): 3%

- Surfactant / (surfactant + dry polymer): 6.0%

Granulometry before drying:

D10 = 0.228 μm bipopulated 21, 156 μm

D50 = 0.329 μm bipopulated 28.625 μm

D90 = 0.453 μm bipopulated 38.645 μm

(D90-D10) / D50 = 0.684 bipopulated 0.611

The emulsion is not dried subsequently. Example 4

(3) A mixture comprising an ester of oleic acid and sorbitan and 15% by weight of oleic acid.

Emulsion before drying

- Dry extract: 35.3%

- Surfactant / (Metolachlor + surfactant): 3%

- Surfactant / (surfactant + dry polymer): 6.0%

Granulometry before drying:

D10 = 0.233 μm

D50 = 0.303 μm

D90 = 0.42 μm

(D90-D10) / D50 = 0.617 The emulsion is not dried subsequently. Example 5 (Comparative)

(4) oleic acid.

Emulsion before drying

- Extract Sec: 36.4

The emulsion is coarse. It is not dried afterwards.

Example 6

(5) A mixture comprising an ester of oleic acid and sorbitan and 8% by weight of oleic acid.

Emulsion before drying - Dry extract: 35,3% - Surfactant / (Metolachlor + surfactant): 3%

- Surfactant / (surfactant + dry polymer): 6.0%

Particle size before drying: D10 = 0.124 μm D50 = 0.168 μm D90 = 0.226 μm (D90-D10) / D50 = 0.607

Granulometry after re-dispersion:

D10 = 0.258 μm

D50 = 0.396 μm

D90 = 0.591 μm

(D90-D10) / D50 = 0.841

The granulometries before drying and after re-dispersion are remarkable.

Claims

A dried emulsion comprising a matrix comprising a water-soluble or water-dispersible polymer, in which a hydrophobic phase is dispersed, characterized in that:

the dried emulsion comprises a non-polyalkoxylated surfactant,

2. Dried emulsion according to claim 1, characterized in that the hydrophobic phase is a liquid hydrophobic phase, or a solid hydrophobic phase.

3. Dried emulsion according to one of the preceding claims, characterized in that the hydrophobic phase is an active hydrophobic compound, or a mixture comprising a hydrophobic active compound in solution or dispersion in a hydrophobic solvent.

4. Dried emulsion according to one of the preceding claims, characterized in that the polycarboxylate comprising hydrophobic units is a copolymer comprising units deriving from the following monomers: - (I) monocarboxylic or polycarboxylic acid, or anhydride, aliphatic, cyclic or aromatic , linear or branched, ethylenically unsaturated,

- (II) monomer of formula (R ² ) (R ² ) C = CH (R ³ ) in which

- R ³ is a hydrogen atom or a methyl group, and - R ² , identical or different, represent a hydrogen atom, a linear or branched, optionally cyclic, saturated or ethylenically unsaturated, aliphatic or aromatic radical, in C2 - C10, with the proviso that the two radicals R2 are not hydrogen atoms, and

optionally (III) polyoxyalkylene ester of ethylenically unsaturated carboxylic acid.

5. Dried emulsion according to claim 4, characterized in that the monomer (I) has the formula

(R ³ ) HC = C (R ¹ ) - COOX (la) in which:

R ³ is a hydrogen atom or a methyl group, R ¹ is a hydrogen atom, a C 1 -C 10 hydrocarbon radical optionally comprising a COOX group, or a -COOX group, optionally forming, with the group COOX, an anhydride group -CO-O-OC; -, and

X is a hydrogen atom or a cation.

6. Dried emulsion according to claim 5, characterized in that the monomer (I) is chosen from acrylic, methacrylic, citraconic, maleic, fumaric, itaconic and crotonic acids or anhydrides.

7. Dried emulsion according to one of claims 4 to 6, characterized in that the monomer (11) is selected from 1-butene, isobutylene, n-1-pentene, 2-methyl-1-butene, n-1-hexene, 2-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-butene, diisobutylene, 2-methyl-3, 3-dimethyl-1-pentene.

8. Dried emulsions according to one of the preceding claims, characterized in that the polycarboxylate comprising hydrophobic units is a copolymer derived from maleic anhydride or a maleic anhydride salt, and diisobutylene.

9. Dried emulsions according to one of the preceding claims, characterized in that the non-polyalkoxylated surfactant is a non-polyalkoxylated nonionic surfactant, a non-polyalkoxylated anionic surfactant, a non-polyalkoxylated amphoteric surfactant, or a mixture of these surfactants.

10. Dried emulsion according to claim 9, characterized in that the non-polyalkoxylated nonionic surfactant is chosen from the following surfactants:

the alkylpolyglucosides,

the non-polyalkoxylated sorbitan esters,

fatty acids,

- their mixtures.

Dried emulsion according to claim 9, characterized in that the non-polyalkoxylated surfactant is:

a sorbitan ester derived from a C ₈ -C ₃₀ fatty acid, preferably a C ₆ -C ₂ 2 fatty acid, or

a mixture of a sorbitan ester derived from a C ₈ -C ₃₀ fatty acid, preferably a C ₆ -C ₂₂ fatty acid, and a C ₈ -C ₃₀ fatty acid, preferably a C ₁₆ -C ₂₀ fatty acid; C ₂₂ , or a salt of the fatty acid.

12. Dried emulsion according to claim 11, characterized in that the mixture of the sorbitan ester and the fatty acid comprises, in dry matter, 2 to 20% by weight of the fatty acid or salt.

13. Dried emulsion according to one of the preceding claims characterized in that the weight ratio between the hydrophobic phase and the matrix is between 50% and 80%.

14. Dried emulsion according to one of the preceding claims characterized in that the weight ratio between the non-polyalkoxylated surfactant and the hydrophobic phase is between 0.003 and 0.3, preferably between 0.01 and 0.06.

15. Dried emulsion according to one of the preceding claims, characterized in that the weight ratio between the non-polyalkoxylated surfactant and the matrix is between 0.006 and 0.6, preferably between 0.02 and 1, 2.

16. Dried emulsion according to one of the preceding claims characterized in that the matrix comprises at least 90% by weight of the water-soluble or water-dispersible polymer.

17. Process for the preparation of a dried emulsion according to one of the preceding claims, comprising the following steps: a) preparing an emulsion comprising an aqueous phase in which is dispersed the hydrophobic phase dispersed in liquid form in water, the an emulsion comprising the water-soluble or water-dispersible copolymer of the matrix, the non-polyalkoxylated surfactant, where appropriate by heating the hydrophobic phase above its melting point, b) removing the water, to obtain a dried emulsion, c) optionally adding the dried emulsion in the form of powder or granules, d) recovering the dried emulsion.

18. The method of claim 17, characterized in that during step b) the water is removed by evaporation in a thin layer, lyophilization, or by atomization of the emulsion.

19. Method according to one of claims 17 or 18, characterized in that the weight ratio between the aqueous phase and the hydrophobic phase is between 5 and 99%.

20. Use of the dried emulsion according to one of claims 1 to 16 or prepared by the method according to one of claims 17 to 19, in phytosanitary formulations, in formulations for the care of laundry, in formulations for dishwashers, in cosmetic formulations, in household or skin care or baby care wipes, in diapers, in building material formulations and / or public works, in surface coating formulations, for example in paints.

21. Use of the dried emulsion according to claim 20, in phytosanitary formulations, the hydrophobic phase being a phytosanitary active compound, or a mixture comprising a hydrophobic compound active phytosanitary, in solution or dispersion in a hydrophobic solvent, the emulsion. dried being optionally used in combination with a fertilizer.

22. Use according to claim 21, in combination with a fertilizer, the dried emulsion and the fertilizer being mixed in the same tank with water.