WO2017178489A1

WO2017178489A1 - Multiple emulsion

Info

Publication number: WO2017178489A1
Application number: PCT/EP2017/058683
Authority: WO
Inventors: Aurélie FIEVEZ; Hilde PEETERS
Original assignee: Oleon Nv
Priority date: 2016-04-12
Filing date: 2017-04-11
Publication date: 2017-10-19
Also published as: FR3049855A1

Abstract

The invention relates to a multiple emulsion comprising at least two surfactants having at least one negative charge, to the production method of the emulsion and to the use of same in the field of personal care and cosmetic products.

Description

MULTIPLE EMULSION

The present invention relates to a multiple emulsion, to a process for preparing this multiple emulsion and to the use of the multiple emulsion in the field of hygiene products and cosmetics.

An emulsion is a suspension of a liquid in the form of particles or droplets in another liquid, these two liquids being immiscible with each other. The two immiscible liquids of an emulsion are generally referred to as "aqueous phase" and "oily phase". However, it is possible to emulsify more than two phases. This is referred to as the general term multiple emulsion. The present multiple emulsion is a triple water-in-oil-in-water or "E / H / E" emulsion, and thus comprises three phases: two aqueous phases (E) and an oily phase (H). In such an emulsion Einteme / H / Eexteme, drops of an internal aqueous phase (External) are dispersed in an oily phase (H), to form a primary emulsion, said primary emulsion being itself dispersed in an external aqueous phase (e _ex dull) - The two aqueous phases (External and e _ex t _e rn) can be identical or different.

Such a multiple emulsion is particularly advantageous in the field of hygiene products and cosmetics. Indeed, it allows the formation of an oily film on the superficial part of the animal body, and more particularly human, on which the emulsion is applied and the progressive release of active (s) contained (s) in the aqueous phase internally dispersed in the oily film, for a prolonged effect over time.

These multiple emulsions are difficult to stabilize over time, especially when they contain one or more negative charge (s).

In particular, the invention relates to multiple W / O / W emulsions comprising at least one surfactant having at least one negative charge, in particular an anionic surfactant.

Surfactants having at least one negative charge, in particular anionic surfactants, have the disadvantage of destabilizing multiple emulsions, already more difficult to stabilize than emulsions comprising only two phases, aqueous and oily.

It is particularly advantageous to use a surfactant with at least a negative charge, in the field of hygiene products and cosmetics, in particular anionic surfactant, the latter may have a foaming function, appreciable in cleaning products.

US 6022547 discloses a W / O emulsion whose oily phase comprises a silicone, a hydrocarbon or mixtures thereof. However, such an emulsion, in the presence of 16.5% by weight of anionic surfactants, is only stable for 5 minutes (see Table 1, Example 29), the percentage by weight being given relative to the weight of the external aqueous phase. .

US4931210 discloses a method of preparing W / O / W emulsion using a polyglycerol polyricinoleate (PGPR). The latter would stabilize the emulsion over time. However, no stability period is indicated in this patent. In addition, the examples given do not contain a surfactant having at least one negative charge.

The work of the inventors has shown that the mere presence of PGPR is not sufficient to form and stabilize a multiple emulsion comprising a surfactant having at least one negative charge (see Example 2).

On the other hand, it made it possible to demonstrate that the use of particular hydrophobic substances made it possible to obtain W / O / W emulsions comprising a surfactant having at least one negative charge, stable for at least 1 month.

The invention thus relates to a multiple emulsion comprising an oily phase and two aqueous phases, which emulsion comprises:

at least 5% by weight of at least one triglyceride, relative to the weight of the multiple emulsion, the total amount of triglyceride (s) corresponding to at least 35% by weight of the oily phase,

at least one HLB emulsifying surfactant between 2 and 6 which is a polyglycerol polyricinoleate (PGPR), and

at least one surfactant having at least one negative charge.

It should be noted that in the context of the present application, and unless otherwise stated, the ranges of values indicated are inclusive.

The oily phase consists of one or more hydrophobic substance (s), of which at least one is a triglyceride.

Advantageously, the triglyceride is a mixture of triglycerides.

Preferably, the at least one triglyceride comprises acyl groups whose hydrocarbon chain contains from 6 to 24 carbon atoms, more preferably from 8 to 18 carbon atoms, more preferably still from 8 to 18 carbon atoms. 16 carbon atoms.

Preferably, the at least one triglyceride comprises acyl groups whose hydrocarbon chain is linear.

Advantageously, the at least one triglyceride comprises saturated linear hydrocarbon chains, in particular chains of 8 to 14 carbon atoms, more particularly chains of 8 to 10 carbon atoms.

Preferably, the triglyceride mixture is introduced into the emulsion via a substance chosen from the group consisting of vegetable oils, vegetable waxes, vegetable butters, animal oils and fats, a particular fraction of one of the substances mentioned above. before, or their mixtures. The particular substance or fraction consists of at least 90% by weight of triglycerides on the weight of the particular substance or fraction under consideration. A particular fraction of one of the above substances is obtained by any method known to those skilled in the art, in particular by distillation.

More preferably, the triglyceride is introduced into the emulsion via a vegetable oil, a vegetable wax, a vegetable butter, a particular fraction thereof, or mixtures thereof. More preferably still, the triglyceride is introduced into the emulsion via a vegetable oil, or a particular fraction of a vegetable oil.

By way of example of vegetable oil, mention may be made of coconut oil, palm kernel oil, palm oil, olive oil, walnut oil, rapeseed oil, corn oil, soybean oil, sunflower oil, grape oil, linseed oil, camphor oil, apricot kernel oil, olive oil avocado, macadamia nut oil, and sweet almond oil.

As an example of vegetable wax, mention may be made of soy wax.

Examples of vegetable butter include shea butter, cocoa butter, mango butter, olive butter and kokum butter.

As an example of oil and animal fat, there may be mentioned fish oil, and tallow.

Alternatively, the at least one triglyceride can be synthesized by esterification or trans-esterification using for example one or more particular fatty acid (s), such as capric acid and caprylic acid, in order to obtain a triglyceride or a mixture of triglycerides having acyl groups whose hydrocarbon chain has a particular number of carbon atoms. A mixture of triglycerides may for example be a mixture of glycerol triesters and caprylic and capric acids comprising acyl groups whose hydrocarbon chain has 8 and 10 carbon atoms respectively.

Preferably, the total amount of triglyceride (s) represents at least 5.3% by weight, more preferably at least 5.5% by weight relative to the weight of the multiple emulsion.

Preferably, the total amount of triglyceride (s) represents at least 38% by weight, more preferably at least 40% by weight, more preferably still, at least 45% by weight, relative to the weight of the oily phase.

Preferably, the total amount of triglyceride (s) represents at least 5.3% by weight relative to the weight of the multiple emulsion, and at least 38% by weight relative to the weight of the oily phase.

By total amount of triglyceride (s) is meant the total amount of triglyceride molecules (s).

The emulsion according to the invention comprises at least one emulsifying surfactant of HLB between 2 and 6 which is a polyglycerol polyricinoleate (PGPR). A PGPR of HLB between 2 and 6 is hydrophobic. It is dispersible in the oily phase.

By HLB (Hydrophilic-Lipophilic Balance) is meant the balance between the size and strength of the hydrophilic group and the size and strength of the lipophilic group of the surfactant. The HLB value according to GRIFFIN is defined in J. Soc. Cosm. Chem. 1954 (volume 5), pages 249-256.

By PGPR, one targets a PGPR molecule or a mixture of different PGPR molecules.

Indeed, because of the multiplicity of hydroxyl functions present in glycerol and polyglycerol, and according to the process for obtaining PGPR, many reaction products are likely to form and a mixture of several PGPRs is generally formed. may differ from each other by:

the number of glycerol units forming the polyglycerol and the arrangement of these units,

the degree of esterification (that is to say the number of hydroxyl function esterified on the polyglycerol), and / or

the number of ricinoleic acid units forming the polyricinoleate.

Preferably, the PGPR of HLB between 2 and 6 comprises at least one non-esterified hydroxyl.

Preferably, the PGPR of HLB between 2 and 6 comprises predominantly (at least 50% by weight relative to the total weight of PGPR) a polyglycerol-3 polyricinoleate (PG-3-PR), a polyglyceryl-4 polyricinoleate (PG -4-PR), a polyricinoleate of polyglycerol-6 (PG-6-PR) and polyglycerol-7 polyricinoleate (PG-7-PR). More preferably, the PGPR predominantly comprises PG-3-PR or PG-4-PR.

The whole number following polyglycerol (or PG) represents the number of glycerol units forming polyglycerol.

Preferably, the PGPR of HLB between 2 and 6 comprises a number of ricinoleic acid unit forming the polyricinoleate (PR) of between 2 and 12, more preferably between 3 and 10, even more preferentially between 4 and 6, In particular, the number of ricinoleic acid units is 5.

More particularly, the polyglycerol polyricinoleate of HLB between 2 and 6 is linear and is represented by the following formula (I):

(II) in which m represents an integer between 2 and 12, preferably between 3 and 10, more preferably between 4 and 6,

and

n represents an integer between 3 and 7, preferentially between 3 and 4.

By "surfactant having at least one negative charge" is meant any surfactant which comprises at least one negative charge resulting from an ionic or ionizable group. By surfactant comprising a negative charge resulting from an ionizable group, a surfactant is targeted, which, when dissolved, will have an ionic group, the negative charge being borne by the part of the compound having the surfactant function. This is the case for example many surfactants said "Anionic" which are usually used in neutralized form, that is to say in the form of salts.

The at least one surfactant having at least one negative charge may be an anionic surfactant or an amphoteric surfactant. More particularly, the at least one surfactant having at least one negative charge in the emulsion according to the invention is an anionic foaming surfactant, an amphoteric foaming surfactant and / or an anionic self-emulsifiable surfactant.

By anionic foaming surfactant is thus more particularly meant a surfactant in the form of salts comprising an anionic foaming surfactant molecule, the sum of the charges of the ionic group (s) is negative and at least one counter-ion.

The counterion may advantageously be selected from the group consisting of sodium, potassium, ammonium and alkanolamine ions such as triethylamine, N-methylglucamine, lysine and arginine.

Preferably, the anionic foaming surfactant molecule is selected from the group consisting of carboxylates, sulphates, sulphonates, phosphates and mixtures thereof.

By way of example of anionic foaming surfactants comprising a carboxylate, mention may be made of the following carboxylate salts:

alkyl carboxylates;

ester carboxylates (comprising at least one carboxylate group and at least one ester group), including carboxylate esters of tartaric acid, citric acid and lactic acid;

ether carboxylates (comprising at least one carboxylate group and at least one ether group), including alkyl polyglycol ether carboxylates (such as oxyethylenated sodium lauryl ether carboxylate);

amide ether carboxylates (comprising at least one carboxylate group and at least one amide-ether group), such as sodium lauryl amido ether carboxylate;

anionic derivatives of acylamino acids (comprising at least one carboxylate group and at least one acylamino group), such as acylglutamates (comprising two carboxylate groups), such as triethanolamine mono-cocoyl glutamate, anionic derivatives of acyl- (poly) peptides, the anionic derivatives of proteins, in particular the hydrolysates of plant proteins such as hydrolysates of soybean, and acyl sarcosinates such as sodium lauroyl sarcosinate;

anionic derivatives of alkyl polyglucosides, such as the sodium salt of citric ester of cocoyl polyglucoside (1, 4).

By way of example of anionic foaming surfactants comprising a sulphate, mention may be made of the following sulphate salts:

alkyl sulphates, such as triethanolamine lauryl sulphate;

alkyl ether sulphates, such as sodium laureth sulfate (or sodium lauryl ether sulphate) and ammonium lauryl ether sulphate;

alkyl-aryl-polyether sulphates;

amide ether sulfates; and

- (alkyl) ester sulphates including sulphated triglycerides or sulphated oils, (alkyl) monoglyceride sulphates.

By way of example of anionic foaming surfactants comprising a sulphonate, mention may be made of the following sulphonate salts:

alkylsulphonates including alphaolefinosulphonates (such as C14-C16 sodium alpha-olefin sulphonate);

alkyl-aryl sulfonates;

sulphoesters (comprising at least one sulphonate group and at least one ester group), of which alkyl sulphoacetates, sulphosuccinates, such as dioctyl sodium sulphosuccinate and oxyethylenated lauric alcohol monosulfinate, and sulpho esters of fatty acids;

acyl taurates, including acyl methyltaurates, such as palmitoyl sodium methyltaurate; and

acyl isethionates, such as sodium cocoyl isethionate.

By way of example of anionic foaming surfactants comprising a phosphate, mention may be made of monoalkylphosphate salts, such as potassium cetylphosphate.

Amphoteric foaming surfactant is understood to mean a foaming surfactant comprising at least one negative charge and one positive charge, said charges being derived from ionic (s) or ionizable (s) group (s), the sum of the charges of said ionic group (s). (s) or ionizable (s) being neutral.

Preferably, the amphoteric foaming surfactant is chosen from the group consisting of the salts of the following compounds:

betaine derivatives, such as alkyl betaines such as cocobetaine, N-alkylamidobetaines, including amidopropylbetaines such as cocamidopropyl; Betal ^'does, alkyl ^betal' nes such as oxyethylenated laurylbétal ^'is oxyethylenated, and ^{phosphobétal'} nes;

imidazoline derivatives, such as alkyl-amphoacetates (such as N-cocoyl-N-hydroxyethyl-N-carboxymethyl-ethylenediamine N-sodium or sodium cocoamphoacetate), and amphodiacetates (such as N-cocoyl-N); - carboxymethoxyethyl-N-carboxymethyl-ethylenediamine N-di-sodium);

amino acid derivatives, such as N-alkylaminopropionates, and N-alkyliminodipropionates, alkylpolyaminocarboxylates (APACs) such as sodium cocoylpolyamino-carboxylate, sodium stearylpolyamidocarboxylate, and carboxymethyloleylpolypropylamine; sodium;

sultaines, such as hydroxylsultaines such as cocamidopropyl hydroxysultaine;

phosphitaines;

and their mixtures.

More preferably, the amphoteric foaming surfactant is chosen from the group consisting of the salts of the following compounds:

- the betaine derivatives such as alkyl-betal ^'nes as cocobetaine, N-alkylamidobetaines, including amidopropylbetaines them as cocamidopropyl ^Betal' does, alkyl betal ^'nes oxyethylenated like ^{laurylbétal'} is oxyethylenated, and phosphobétal ^'nes;

sultaines, such as hydroxylsultaines such as cocamidopropyl hydroxysultaine;

and their mixtures.

Anionic self-emulsifiable surfactant is understood to mean an anionic surfactant capable of being emulsified instantaneously (that is to say in less than 10 seconds) in an aqueous phase, under the effect of slight agitation, such as from a stirring of 150 revolutions per minute.

It is typically a surfactant in neutralized form that is to say in the form of salts, such as a sodium salt or a potassium salt.

More particularly, the anionic self-emulsifiable surfactant may be chosen from the group consisting of the salts of: self-emulsifiable waxes such as the mixture of cetostearyl alcohol and sodium cetyl stearyl sulphate;

partial self-emulsifiable glycerol esters, such as glycerol stearate (glyceryl stearate SE), glycerol stearate citrate (glyceryl stearate citrate SE), glycerol monooleate;

propylene glycol esters, such as propylene glycol stearate;

and their mixtures.

Preferably, the total amount of surfactants having at least one negative charge represents at least 5% by weight, more preferably at least 7% by weight, more preferably still at least 9% by weight, more particularly at least 10% by weight, relative to the weight of the multiple emulsion.

More particularly, by total amount of surfactants having at least one negative charge, it is meant the total amount of anionic surfactant (s) molecules, amphoteric foaming surfactant (s) and of anionic self-emulsifying surfactant (s).

According to a first embodiment of the multiple emulsion according to the invention, the at least one surfactant having at least one negative charge is a foaming, anionic and / or amphoteric surfactant.

The emulsion may comprise one or more anionic foaming surfactant (s) and / or one or more amphoteric surfactant (s).

In addition to their ability to produce foam, foaming surfactants are able to clean a superficial part of the animal body, and more particularly human, especially the skin.

Preferably, the total amount of surfactant (s) foaming (s) represents at least 5% by weight, more preferably at least 8% by weight, more preferably still, at least 9% by weight, more particularly at least 10% by weight. weight, the percentages by weight being given with respect to the weight of the multiple emulsion.

By total amount of foaming surfactant (s) is meant the total amount of anionic foaming surfactant (s) molecules and amphoteric foaming surfactant (s) in the multiple emulsion.

According to a particular embodiment of the first embodiment of the multiple emulsion according to the invention, it comprises at least two surfactants having at least one negative charge: an anionic foaming surfactant and an amphoteric foaming surfactant. In this case, the total amount of anionic foaming surfactant (s) and amphoteric foaming surfactant (s) present in the multiple emulsion according to the invention preferably represents, at least 7% by weight, more preferably at least 9% by weight, more preferably still at least 10% by weight relative to the weight of the multiple emulsion.

According to a second embodiment of the emulsion according to the invention, the at least one surfactant having at least one negative charge, is an anionic self-emulsifiable surfactant.

The emulsion may comprise one or more anionic self-emulsifiable surfactant (s).

Preferably, the total amount of anionic self-emulsifying surfactant (s) present in the multiple emulsion according to the invention represents at least 2% by weight, more preferably at least 2.5% by weight, more preferably still, at least 3% by weight, relative to the weight of the multiple emulsion. Preferably, the total amount of anionic self-emulsifying surfactant (s) present in the emulsion according to the invention represents between 2 and 5% by weight relative to the weight of the emulsion.

According to a third embodiment of the multiple emulsion according to the invention, it comprises at least two surfactants having at least one negative charge: an anionic foaming surfactant and / or an amphoteric foaming surfactant, and an anionic self-emulsifiable surfactant. .

The invention therefore relates more particularly to a multiple emulsion comprising an oily phase and two aqueous phases, which emulsion comprises:

at least one HLB emulsifying surfactant of from 2 to 6 which is a polyglycerol polyricinoleate (PGPR), and

at least two surfactants having at least one negative charge, these being an anionic foaming surfactant and / or an amphoteric foaming surfactant, and an anionic self-emulsifiable surfactant. Preferably, the total amount of anionic foaming surfactant (s) and / or amphoteric foaming surfactant (s) represents at least 5% by weight, more preferably at least 8% by weight. weight, more preferably still, at less 9% by weight, more particularly at least 10% by weight, the percentages by weight being given relative to the weight of the multiple emulsion.

Preferably, the total amount of anionic self-emulsifying surfactant (s) present in the multiple emulsion according to the invention represents at least 2% by weight, more preferably at least 2.5% by weight, more preferably still, at least 3% by weight, relative to the weight of the multiple emulsion. Preferably, the total amount of anionic self-emulsifying surfactant (s) present in the multiple emulsion according to the invention represents between 2 and 5% by weight relative to the weight of the multiple emulsion.

According to a particular embodiment of the third embodiment of the multiple emulsion according to the invention, it comprises at least three surfactants having at least one negative charge: an anionic foaming surfactant and an amphoteric foaming surfactant and an autosurfactant. anionic emulsifiable.

Preferably, the total amount of anionic foaming surfactant (s) and / or amphoteric foaming surfactant (s) represents at least 7% by weight, more preferably at least 9% by weight. weight, more preferably still at least 10% by weight relative to the weight of the multiple emulsion.

Preferably, the total amount of anionic self-emulsifying surfactant (s) present in the emulsion according to the invention represents at least 2% by weight, more preferably at least 2.5% by weight, more preferably still at least 3% by weight, relative to the weight of the multiple emulsion. Preferably, the total amount of anionic self-emulsifying surfactant (s) present in the multiple emulsion according to the invention represents between 2 and 5% by weight relative to the weight of the multiple emulsion.

Preferably, and whatever the embodiment, the multiple emulsion according to the invention comprises a total amount of surfactant (s) having at least one negative charge, at most 25% by weight, more preferably, of at most 20% by weight, more preferably still, of at most 18% by weight, relative to the weight of the multiple emulsion.

Preferably, and regardless of the embodiment, the multiple emulsion according to the invention comprises an emulsifying surfactant of HLB between 7 and 15 and / or a gelling agent.

An HLB emulsifying surfactant of between 7 and 15 is hydrophilic and is dispersible in an aqueous phase.

Preferably, such a surfactant is selected from the group consisting of polyglycerol esters, sorbitan esters, ethoxylated sorbitan esters, sucroesters, and mixtures thereof.

By way of example of polyglycerol esters of HLB between 7 and 15, mention may be made of polyglycerol-2 stearate, polyglycerol-3 stearate, polyglycerol-10 isostearate and polyglycerol-6 isostearate. , polyglycerol-2 caprylate, polyglycerol-3 caprylate, polyglycerol-2 caprate, and polyglycerol-3 caprate.

As an example of sorbitan esters of HLB between 7 and 15, mention may be made of sorbitan stearate, sorbitan laurate, and sorbitan palmitate.

By way of example of ethoxylated sorbitan esters of HLB between 7 and 15, mention may be made of polyoxyethylene (polysorbate 40) sorbitan monopalmitate, polyoxyethylene (polysorbate 60) sorbitan monostearate, polyoxyethylene (polysorbate 80) sorbitan monooleate ), and polyoxyethylene sorbitan trioleate (polysorbate 85).

By way of example of HLB sucroesters of between 7 and 15, mention may be made of sucrose stearate (sucrose stearate), sucrose laurate, and sucrose palmitate.

Preferably, the HLB emulsifying surfactant of between 7 and 15 is selected from the group consisting of polyglycerol esters, sorbitan esters, ethoxylated sorbitan esters and mixtures thereof.

The emulsifying surfactant of HLB between 7 and 15 makes it possible to increase the viscosity of the aqueous phase in which it is dispersed. Consequently, the viscosity of the emulsion comprising this aqueous phase is increased.

Advantageously, the emulsifying surfactant of HLB between 7 and 15 allows the formation of a gelled lamellar aqueous phase.

Preferably, the emulsifying surfactant has an HLB of between 7 and 10, more preferably between 8 and 9.

By gelling agent is meant a compound which allows the gelling of the aqueous phase, that is to say the formation of a three-dimensional network of a solid in a liquid.

By way of examples of gelling agents, mention may be made of gums, such as gum arabic, gum tragacanth and xanthan gum, alginates, cellulose derivatives, such as methylcellulose, hydroxyethylcellulose and cetyl. hydroxyethylcellulose, carboxyvinyl polymers, acrylic acid polymers, magnesium aluminum silicate, carrageenans, glucomannan and starch.

In order to facilitate the use of the gelling agent, it may be dispersed in glycerine, for example. In particular, it is possible to disperse the xanthan gum in glycerine at a weight ratio of xanthan gum / glycerin, ranging from 1/8 to 1/15, preferably from 1/10 to 1/14.

Preferably, the total amount of HLB emulsifying surfactant (s) between 7 and 15 and / or gelling agent (s) present in the emulsion according to the invention represents between 0.1 and 8% by weight relative to the weight of the multiple emulsion.

According to a preferred embodiment of the first embodiment of the multiple emulsion according to the invention, the latter comprises an anionic foaming surfactant and / or an amphoteric foaming surfactant, and an emulsifying surfactant of HLB between 7 and 15 and / or gelling agent.

In this case, the total amount of HLB emulsifying surfactant (s) between 7 and 15 and / or gelling agent (s) present in the multiple emulsion according to the invention represents between 0.1 and 8% by weight relative to the weight of the multiple emulsion.

If an HLB emulsifying surfactant of between 7 and 15 is present in the multiple emulsion, then preferably, the total amount of HLB emulsifying surfactant (s) of between 7 and 15 is between 2 and 8% by weight. more preferably between 2 and 7% by weight, more preferably between 3 and 6% by weight, relative to the weight of the multiple emulsion.

If a gelling agent is present in the multiple emulsion, then preferably, the total amount of gelling agent (s) is between 0.1 and 1% by weight, more preferably between 0.1 and 0.5. % by weight, more preferably still between 0.1 and 0.4% by weight, relative to the weight of the multiple emulsion.

According to a preferred embodiment of the second embodiment of the multiple emulsion according to the invention, it comprises an anionic self-emulsifiable surfactant and an HLB emulsifying surfactant of between 7 and 15 and / or a gelling agent.

If an emulsifying surfactant of HLB between 7 and 15 is present in the multiple emulsion, then preferably, the ratio by weight, total amount of anionic self-emulsifiable surfactant (s) / total amount of surfactant (s) HLB emulsifier (s) between 7 and 15, varies between 25/75 and 75/25, more preferably between 35/65 and 65/35, more preferably between 45/55 and 55/45.

Advantageously, the ratio by weight, total amount of anionic self-emulsifiable surfactant (s) / total amount of emulsifying surfactant (s) of HLB between 7 and 15, is 50/50.

Preferably, the total amount of HLB emulsifying surfactant (s) between 7 and 15 present in the multiple emulsion represents between 2 and 8% by weight, more preferably between 2 and 7% by weight, more preferably still between 3 and 6% by weight, based on the weight of the multiple emulsion.

If a gelling agent is present in the multiple emulsion, then, preferably, the total amount of gelling agent (s) present in the multiple emulsion is between 0.1 and 2% by weight, more preferably between 0.1 and 0.5% by weight, more preferably still between 0.1 and 0.4% by weight, relative to the weight of the multiple emulsion.

More particularly, the multiple emulsion according to the invention comprises an anionic self-emulsifiable surfactant, an HLB emulsifying surfactant of between 7 and 15 and a gelling agent.

In this case, the total amount of emulsifying surfactant (s) of HLB between 7 and 15 present in the multiple emulsion represents between 2 and 7% by weight, preferably between 2 and 6% by weight relative to the weight of the multiple emulsion, the ratio by weight, total amount of anionic self-emulsifiable surfactant (s) / total amount of HLB emulsifying surfactant (s) between 7 and 15 is as described above, and the total amount of gelling agent (s) present in the multiple emulsion is between 0.10 and 0.40% by weight, preferably between 0.10 and 0.35% by weight multiple emulsion.

Advantageously, the multiple emulsion according to the invention also comprises an emulsifying surfactant of HLB between 2 and 6, other than a PGPR.

In addition to the PGPR, the emulsion may comprise one or more other surfactant (s) emulsifying (s) of HLB between 2 and 6. Such a surfactant has the effect of prolonging the stability of the emulsion according to the invention . The multiple emulsion according to the invention can thus be stable for at least three months at 20 ° C. +/- 5 ° C. and at atmospheric pressure. The multiple emulsion is also stable for at least three months at 4 ° C, 42 ° C and 50 ° C. These temperatures are commonly used for accelerated aging studies in cosmetics.

An emulsifying surfactant of HLB between 2 and 6 being lipophilic, it is dispersible in the oily phase. Preferably, the HLB emulsifying surfactant between 2 and 6 other than a PGPR is selected from the group consisting of polyglycerol esters other than PGPR, sorbitan esters, sucroesters and mixtures thereof.

By way of example of polyglycerol esters (other than PGPR) of HLB of between 2 and 6, mention may be made of polyglycerol-3 diisostearate, polyglycerol-4 isostearate, polyglycerol-2 diisostearate, and the like. polyglycerol-3 oleate, and polyglycerol-2 isostearate.

By way of example of sorbitan esters of HLB between 2 and 6, mention may be made of sorbitan diisostearate, sorbitan oleate, sorbitan sesquioleate, sorbitan trioleate, and sorbitan dioleate.

By way of example of HLB sucroesters of between 2 and 6, mention may be made of sucrose polystearate and sucrose distearate.

Preferably, the HLB emulsifying surfactant between 2 and 6 other than a PGPR is selected from the group consisting of polyglycerol esters (other than PGPR), sorbitan esters and mixtures thereof.

Advantageously, the emulsifying surfactant of HLB between 2 and 6 is a polyglycerol-4 isostearate obtained according to the production process described in the patent application FR1556521, the content of which is incorporated in the present application.

Thus, the process for producing polyglycerol-4 isostearate comprises reacting isostearic acid and glycerol carbonate, wherein:

the molar ratio of the glycerol carbonate to the isostearic acid used in the reaction is at least 2, and

the reaction is initiated in the presence of a compatibilizing agent which is a polyglycerol ester.

Such a polyglycerol-4 isostearate is dispersible in water. A multiple emulsion according to the invention containing this surfactant is more easily removed with water. Indeed, the surfactant being dispersible in water, unlike other polyglycerol esters which are insoluble in water, the polyglycerol-4 isostearate thus prepared is more easily driven by water.

Preferably, in the multiple emulsion according to the invention, the total amount of surfactant (s) emulsifying (s) of HLB between 2 and 6 represents between 1, 6% and 3.2% by weight relative to the weight of the multiple emulsion.

By total amount of surfactant (s) emulsifier (s) of HLB between 2 and 6 is meant the sum of the molecules of the different surfactant (s) emulsifier (s) of HLB between 2 and 6, that is to say say, of the at least one PGPR and optionally surfactant (s) emulsifier (s) of HLB between 2 and 6 other (s) that PGPR, expressed as a percentage by weight relative to the weight of the multiple emulsion.

More preferably, the total amount of emulsifying surfactant (s) of HLB between 2 and 6 represents between 2% and 2.8% by weight, in particular, it represents 2.4% by weight, the weights being relative to the weight of the multiple emulsion.

Preferably, the ratio by weight, total amount of PGPR of HLB between 2 and 6 / total amount of surfactant (s) emulsifier (s) of HLB between 2 and 6 other (s) that PGPR, varies between 50/50 and 90/10, more preferably between 70/30 and 80/20. Advantageously, the ratio by weight, total amount of PGPR of HLB between 2 and 6 / total amount of surfactant (s) emulsifier (s) of HLB between 2 and 6 other (s) that PGPR is 75/25.

A multiple emulsion comprising an oily phase and two aqueous phases according to the invention, which is particularly preferred, comprises:

^■ at least one emulsifying surfactant having an HLB of between 2 and 6 which is a PGPR,

At least 5% by weight relative to the weight of the multiple emulsion of an anionic foaming surfactant and / or an amphoteric foaming surfactant,

^■ at least 2% by weight based on the weight of the multiple emulsion of an anionic self-emulsifiable,

Between 0.1 and 8% by weight relative to the weight of the multiple emulsion of an HLB emulsifying surfactant of between 7 and 15 and / or of a gelling agent,

^■ optionally, an emulsifying surfactant having an HLB of between 2 and 6 other than polyglycerol polyricinoleate, wherein the total amount of surfactant (s) emulsifier (s) having an HLB of between 2 and 6 (polyricinoleate (s) polyglycerol and optionally surfactant (s) emulsifier (s) of HLB between 2 and 6 other (s) a PGPR) is between 1, 6% and 3.2% by weight relative to the weight of the multiple emulsion.

In particular, the multiple emulsion according to the invention comprises:

At least 5% by weight, preferably at least 5.3% by weight, at least one triglyceride, relative to the weight of the multiple emulsion, the total amount of triglyceride (s) corresponding to at least 35% by weight, preferably at least 38% by weight, of the oily phase,

^■ from 1, 6% and 3.2% by weight based on the weight of the multiple emulsion of at least two emulsifying surfactants having an HLB of between 2 and 6, one of the two being a PGPR and other non , the ratio by weight, total amount of PGPR of HLB between 2 and 6 / total amount of surfactant (s) emulsifier (s) of HLB between 2 and 6 other (s) that PGPR, being between 50/50 and 90/10, preferably between 70/30 and 80/20,

^■ at least 5% by weight of an anionic lathering surfactant and an amphoteric lathering surfactant, preferably at least 7% by weight, based on the weight of the multiple emulsion,

^■ at least 2% by weight of an anionic self-emulsifiable, preferably between 2 and 5% by weight based on weight of the multiple emulsion,

^■ between 2 and 8% by weight based on weight of the multiple emulsion of a surfactant emulsifier of HLB between 7 and 15,

^■ from 0.1 to 0.4% by weight based on weight of the multiple emulsion of a gelling agent,

in which,

the ratio by weight, total amount of anionic self-emulsifying surfactant (s) / total amount of HLB emulsifying surfactant (s) between 7 and 15, varies between 25/75 and 75/75. 25, more preferably between 35/65 and 65/35, and

the ratio by weight, total amount of PGPR of HLB between 2 and 6 / total amount of surfactant (s) emulsifier (s) of HLB between 2 and 6 other (s) that PGPR, varies between 50/50 and 90 / 10, more preferably between 70/30 and 80/20.

The multiple emulsion thus obtained is in the form of a cream, white and shiny.

Advantageously, in the multiple emulsion according to the invention, the sum of the aqueous phases, that is to say the internal aqueous phase and the external aqueous phase, represents between 80 and 92% by weight relative to the weight of the multiple emulsion. The multiple emulsion according to the invention preferably has a pH of between 4 and 9. The pH can be adjusted by adding citric acid for example, depending on the desired use of the multiple emulsion.

Preferably, in the multiple emulsions according to the invention, the oily phase represents at least 8% by weight, preferably at least 10% by weight, relative to the weight of the multiple emulsion.

Preferably, the oily phase represents between 8 and 20% by weight, more preferably between 10 and 18% by weight, more preferably between 12 and 16% by weight, the percentages by weight being given relative to the weight of the emulsion. multiple.

In addition to the triglyceride and the emulsifying surfactant (s) of HLB between 2 and 6, the oily phase may also comprise one or more other hydrophobic substance (s).

Preferably, the hydrophobic substance has a Hansen solubility parameter relating to the polarity δΡ less than or equal to 3 (J / cm ³ ) ^1/2 at 25 ° C.

The calculation of the Hansen solubility parameter is described in Solubility Parameters, Kirk-Othmer Encyclopedia of Chemical Technology, Suppl. Vol., 2nd ed., Standen, A., Ed., Interscience, New York, 1971, 889-910.

This hydrophobic substance may be chosen from the group consisting of mineral oils, silicones, fatty acids, fatty alcohols, esters other than triglycerides and the emulsifying surfactants of HLB comprising 2 and 6, their ethoxylated derivatives and their mixtures. .

More particularly, the mineral oil is liquid paraffin.

More particularly, the silicone is chosen from dimethicones and cyclopentasiloxane.

More particularly, the fatty acid is selected from stearic acid, cetyl acid and cetearyl acid.

More particularly, the fatty alcohol is chosen from stearic alcohol, cetyl alcohol and cetearyl alcohol.

More particularly, the ester other than a triglyceride and an emulsifying surfactant of HLB 2 and 6, is chosen from the group consisting of:

monoesters obtained from a monoalcohol, such as butanol, isopropanol, octanol, heptanol, ethylhaxanol, stearyl alcohol, isostearyl alcohol, dodecanol, isodecanol isononanol, isooctanol, and a monocarboxylic acid, such as caprylic acid, capric acid, heptanoic acid, palmitic acid, myristic acid, lauric acid and isostearic acid;

diesters obtained from a monoalcohol, as previously described, and a dicarboxylic acid, such as fumaric acid, adipic acid, succinic acid and sebacic acid;

diesters obtained from monopropylene glycol and a monocarboxylic acid as described above;

tetraesters obtained from a tetra-alcohol, such as pentaerythritol, and a monocarboxylic acid as described above;

and their mixtures.

Advantageously, the multiple emulsion according to the invention does not comprise a silicone substance.

Preferably, the hydrophobic substance other than triglyceride (s) and surfactant (s) emulsifying (s) of HLB between 2 and 6, is selected from esters, more preferably from the group of esters described above, more preferably still, among the diesters, the tetraesters and their mixtures.

In particular, the hydrophobic substance is chosen from diisostearyl succinate, pentaerythritol tetraoctanoate, pentaerythritol tetraisostearate, monopropylene glycol diheptanoate, ethylhexyl laurate, and mixtures thereof.

Advantageously, the multiple emulsion according to the invention comprises a tetraester, such as pentaerythritol tetraoctanoate and / or pentaerythritol tetraisostearate. Such an ester has the effect of further stabilizing the multiple emulsion.

Preferably, the content of tetraester represents at least 2% by weight, more preferably at least 3% by weight, more preferably still at least 3.5% by weight, relative to the weight of the multiple emulsion.

Advantageously, the hydrophobic substance is chosen from substances intended to be brought into contact with the superficial parts of the animal body, and more particularly, human.

The multiple emulsion according to the invention may also comprise one or more additive (s) and / or one or more active (s), soluble and / or dispersible in an aqueous phase.

Preferably, the additive and / or the active agent are chosen from substances intended to be brought into contact with the superficial parts of the animal body, and more particularly human, in particular, from those usually used in the field of animal and human hygiene and cosmetics. More generally, all the ingredients making up the multiple emulsion according to the invention are selected from the ingredients having a good safety with respect to the animal body, more particularly human.

Indeed, the multiple emulsion according to the invention can be used as a hygiene product and / or cosmetic product.

By hygiene product and / or cosmetic product, any mixture intended to be placed in contact with the superficial parts of the human body (epidermis, hair and hair systems, nails, lips and external genital organs) or with the teeth and oral mucosa, in view, exclusively or mainly, to clean, perfume, modify the appearance, protect, maintain or repair body odors.

Preferably, the multiple emulsion according to the invention is used as a hygiene product.

The invention therefore also relates to a hygiene product and / or a cosmetic product comprising the multiple emulsion according to the invention, optionally with an additive and / or an active ingredient, such as a cosmetic additive and / or a cosmetic active agent.

By way of example of such products, mention may be made of cleansing products for the skin, mucous membranes and / or hair, shower gels or creams, shampoos, shaving products and make-up remover products. skin, conditioners, rinsing masks and exfoliating products.

The cosmetic additive is preferably chosen from the group consisting of preservatives, humectants, stabilizers, perfumes, sequestering agents (EDTA), pigments, especially exfoliating fillers, soluble dyes, sunscreens and their mixtures.

The cosmetic active agent is preferably chosen from the group consisting of moisturizers, such as hyaluronic acid; ceramides; water-soluble vitamins; antiseptics; antiseborrhoeic; antimicrobials such as benzoyl peroxide, salicylic acid, triclosan and azelaic acid; optical brighteners; and their mixtures.

The amount of each additive or active ingredient is that conventionally used in the field under consideration, and for example from 0.01 to 5% by weight relative to the weight of the multiple emulsion.

The multiple emulsion according to the invention can also be used as an hygiene product of an animal such as an animal shampoo. Such an animal hygiene product can be used on any superficial part of the animal body such as hair, claws, mucosa and may include additives and / or cosmetic active agents such as mentioned above, and / or veterinary assets such as those against pests.

The invention also relates to a method for cleaning a superficial part of the animal or human body, such as the skin, scalp, hair, hair, eyelashes, eyebrows, nails, claws and mucous membranes, comprising a step of applying a multiple emulsion according to the invention to the surface portion, and a step of rinsing the surface portion.

During cleaning, the emulsion gives a very smooth foam.

The foam formed during the spreading of the multiple emulsion according to the invention on the superficial part of the animal body, and more particularly human is dense and very lubricating. A spreading rate of 400 s ^{-1 is} sufficient to obtain the formation of a foam.

Rinsing is easy.

The superficial part of the animal or human body is left clean, soft and hydrated.

Preferably, the superficial part of the animal body, and more particularly the human body, is the skin.

However, the uses of the multiple emulsion according to the invention are numerous and are not limited to the fields of cosmetic and veterinary hygiene.

Advantageously, the multiple emulsion according to the invention comprises components of renewable origin, such as vegetable oil derivatives.

The invention also relates to a method for preparing a multiple emulsion such as according to the invention, comprising:

(i) a 1 ^st stage emulsion

an internal aqueous phase

in

an oily phase comprising:

^■ at least 5% by weight of at least one triglyceride, based on the weight of the multiple emulsion, the total amount of triglyceride (s) corresponding to at least 35% by weight of the oil phase, and ■ at least one an HLB emulsifying surfactant of from 2 to 6 which is a polyglycerol polyricinoleate (PGPR) to provide a water-in-oil primary emulsion;

(ii) a 2 ^nd stage emulsion

of the primary emulsion thus obtained

in an external aqueous phase comprising at least one surfactant having at least one negative charge.

The triglyceride, the polyglycerol polyricinoleate of HLB between 2 and 6, and the surfactant having at least one negative charge, are as described above, including the advantageous and preferential modes.

Preferably, the total amount of surfactant (s) having at least one negative charge represents at least 3% by weight, more preferably at least 8% by weight, more preferably still at least 11% by weight, more particularly at least 20% by weight. % by weight, based on the weight of the external aqueous phase.

Preferably, in the process according to the invention, the at least one surfactant having at least one negative charge of the external aqueous phase, is an anionic foaming surfactant, an amphoteric foaming surfactant and / or an anionic self-emulsifiable surfactant.

The anionic foaming surfactant, the amphoteric foaming surfactant and the anionic self-emulsifiable surfactant are as described above, including the preferred, alternative and preferred modes.

The invention more particularly relates to a method for preparing a multiple emulsion, comprising:

(i) a 1 ^st stage emulsion

an internal aqueous phase

in

an oily phase comprising

^■ at least 5% by weight of at least one triglyceride, based on the weight of the multiple emulsion, the total amount of triglyceride (s) corresponding to at least 35% by weight of the oily phase, and

^■ at least one emulsifying surfactant having an HLB of between 2 and 6 which is a polyglycerol polyricinoleate (PGPR),

to obtain a primary water-in-oil emulsion;

(ii) a 2 ^nd stage emulsion

of the primary emulsion thus obtained

in

an external aqueous phase comprising at least two surfactants having at least one negative charge, these being an anionic foaming surfactant and / or a foaming surfactant amphoteric, and an anionic self-emulsifiable surfactant.

In the process according to the invention, if there is presence of anionic foaming surfactant and / or an amphoteric foaming surfactant, then preferably, the total amount of foaming surfactant (s) anionic (s) and / or Amphoteric foaming surfactant (s) represents at least 5% by weight, more preferably at least 7% by weight, more preferably still, at least 9% by weight relative to the weight of the multiple emulsion.

In the process according to the invention, if anionic self-emulsifiable surfactant is present, then preferably the total amount of anionic self-emulsifying surfactant (s) is at least 2% by weight. more preferably at least 3% by weight, based on the weight of the multiple emulsion. Preferably, the total amount of anionic self-emulsifying surfactant (s) represents between 2 and 5% by weight relative to the weight of the multiple emulsion.

Preferably, in the process according to the invention, the external aqueous phase comprises an HLB emulsifying surfactant of between 7 and 15 and / or a gelling agent.

The emulsifying surfactant of HLB between 7 and 15 and the gelling agent are as described above, including advantageous and preferred modes.

Preferably, the total amount of HLB emulsifying surfactant (s) of between 7 and 15 represents between 3 and 14% by weight, more preferably between 4 and 10% by weight, relative to the weight of the external aqueous phase.

Preferably, the total amount of gelling agent (s) represents between 0.1 and 1, 6% by weight, more preferably between 0.1 and 0.8% by weight, relative to the weight of the aqueous phase. external.

Preferably, in the process according to the invention, the oily phase comprises an emulsifying surfactant of HLB between 2 and 6 other than a polyglycerol polyricinoleate.

The emulsifying surfactant of HLB between 2 and 6 other than a polyglycerol polyricinoleate is as described above, including advantageous and preferred modes.

Preferably, the total amount of emulsifying surfactant (s) of HLB between 2 and 6 represents between 1 1% and 23% by weight relative to the weight of the oily phase.

More preferably, the total amount of surfactant (s) emulsifying (s) of HLB between 2 and 6 represents between 14% and 20% by weight, in particular, it represents 17% by weight, the weights being given relative to the weight of the oily phase.

More particularly, the process according to the invention aims at preparing the particularly preferred multiple emulsions described above.

Preferably, the oily phase represents at least 8% by weight, preferably at least 10% by weight, relative to the weight of the multiple emulsion.

The hydrophobic substance is as described above, including advantageous and preferential modes.

In the process according to the invention, the 1 ^st emulsion step is carried out at a temperature between 15 and 80 ° C, preferably between 20 ° and 30 ° C, more preferably between 20 ° and 25 ° C with stirring moderate, such as stirring at 500 to 900 rpm, preferably with stirring at 600 to 800 rpm.

Preferably, once emulsified, the primary water-in-oil emulsion is stirred for at least 1 minute under very vigorous agitation, such as stirring at 8,000 to 12,000 rpm, more preferably 8,000 to 10,000 rpm. . This step of very strong stirring makes it possible to reduce the size of the droplets of the emulsified aqueous phase in the oily phase in the primary emulsion. In order not to break the emulsion, this very strong agitation does not last more than 10 minutes, preferably not more than 7 minutes.

Prior to the 1 ^st step of emulsion, the internal aqueous phase and the oily phase are prepared by the component substances these phases. These Preparations may require heating to homogenize the phase at a temperature equivalent to the highest melting temperature of the melting temperatures of the substances present.

Advantageously, the substances constituting the phases are liquid and it is therefore not necessary to heat to homogenize the internal and oily aqueous phases.

The ^2nd emulsion stage is carried out at a temperature of between 30 and 50.degree. C., preferably between 35 and 45.degree. C., in particular at 40.degree. C., with moderate stirring, such as stirring between 500 and 1000 rpm. per minute, preferably between 600 and 750 rpm.

Prior to the 2 ^nd stage emulsion, the external aqueous phase is prepared according to the substances composing the multiple emulsion according to the invention. For exemple :

a possible step of preparing an optional premix comprising the anionic self-emulsifying surfactant and the emulsifying surfactant of HLB between 7 and 15, and heating this optional premix at a temperature of between 70 and 90; ° C, preferably at a temperature of about 80 ° C,

a step of preparing an aqueous premix comprising water, the anionic foaming surfactant and / or the amphoteric foaming surfactant, and optionally the gelling agent, and of heating this aqueous premix at a temperature comprised between between 70 and 90 ° C, preferably at a temperature of about 80 ° C, and

a step of mixing the aqueous premix with the anionic self-emulsifying surfactant (optionally in the form of an optional premix) above, at a temperature of between 70 and 90 ° C., preferably at a temperature of approximately 80 ° C.

This last mixing step is carried out with moderate stirring, such as stirring at 400 to 1000 rpm, preferably 850 to 950 rpm, more preferably 900 rpm.

The addition rate during the mixing step is about 5% w / w, based on the weight of anionic self-emulsifying surfactant or premix if the presence of the HLB emulsifying surfactant between 7 and 15.

At the end of the mixing step, the stirring is slowed down by 500 to 700 rpm, preferably at 600 rpm, and the temperature of the aqueous phase external is allowed to cool down to 40 ° C +/- 5 ° C.

Advantageously, one or more additive (s) and / or one or more active (s) such (s) as those usually used in the field of hygiene products and cosmetics, dispersible in an aqueous phase, preferably chosen among the substances intended to be brought into contact with the superficial parts of the animal body, and more particularly human, are added to the internal aqueous phase and / or to the external aqueous phase.

The additive and the active agent are as described above, including advantageous and preferential modes.

The amount of each additive or active agent is that conventionally used in the field under consideration, and for example from 0.01 to 6% by weight relative to the weight of the internal and external aqueous phases.

Advantageously, the internal and external aqueous phases are different in composition.

The external aqueous phase represents between 60 and 90% by weight of the multiple emulsion according to the invention.

The external aqueous phase preferably comprises, in addition to the surfactant (s) comprising at least one negative charge, one or more additive (s) and / or active (s) as described above.

The internal aqueous phase represents between 2 and 20% by weight of the multiple emulsion according to the invention.

It may comprise one or more additive (s) and / or active (s) as described above. Preferably, the additive is selected from the group consisting of preservatives, humectants, stabilizers, fragrances, sequestering agents (EDTA) and mixtures thereof.

The active ingredients in the internal phase will gradually release on the material, such as for example the skin, the scalp, the hair, the hairs, the eyelashes, the eyebrows, the nails, the claws and the mucous membranes, on which the Multiple emulsion according to the invention has been applied.

Additives and actives may be temperature and / or air sensitive.

When the additive and / or the active ingredient is / are added in the internal aqueous phase, the additive is protected by the oily phase.

The addition of an additive and / or active in the external aqueous phase may be carried out prior to the ^2nd stage emulsion. Alternatively, it is performed after the ^2nd step of emulsion. The additive and / or active is added to the end of the ^2nd stage emulsion when the temperature is less than or equal to 30 ° C.

Preferably, the additives are added one after the other.

A method for preparing a multiple emulsion according to the invention which is particularly preferred comprises:

(i) a 1 ^st step of emulsion carried out at a temperature between

15 and 80 ° C, preferably between 20 and 30 ° C, with stirring of 500 to 900 rpm, preferably 600 to 800 rpm,

an internal aqueous phase

in

an oily phase comprising

^■ at least 5% by weight of at least one triglyceride, based on the weight of the multiple emulsion, the total amount of triglyceride (s) corresponding to at least 38% by weight of the oil phase, and between 1 ■, 6% and 3.2% by weight of at least one HLB emulsifying surfactant of from 2 to 6 which is a polyglycerol polyricinoleate and optionally an HLB emulsifying surfactant of between 2 and 6 other than a polyglycerol polyricinoleate, based on the weight of the multiple emulsion, to obtain a primary emulsion;

(ii) a 2 ^nd emulsion step, carried out at a temperature between 30 and 50 ° C, preferably between 35 and 45 ° C with stirring at 500 to 1000 rpm, preferably 600 to 750 revolutions per minute,

- the primary emulsion

in

an external aqueous phase comprising, in addition to water:

^■ at least 5% by weight of an anionic lathering surfactant and / or an amphoteric lathering surfactant,

Between 2 and 5% by weight relative to the weight of the multiple emulsion of an anionic self-emulsifiable surfactant,

^■ from 0.1 to 8% by weight based on weight of the multiple emulsion of an emulsifying surfactant having an HLB of between 7 and 15 and / or a gelling agent,

the constituents of the external aqueous phase being premixed with a temperature of between 70 and 90 ° C.

In particular, this method also has the following characteristics:

the ratio by weight, total amount of PGPR of HLB between 2 and 6 / total amount of emulsifying surfactant (s) of HLB between 2 and 6 other (s) than PGPR, varies between 50/50 and 90 / 10, more preferably between 70/30 and 80/20,

the ratio by weight, total amount of anionic self-emulsifying surfactant (s) / total amount of HLB emulsifying surfactant (s) between 7 and 15, varies between 25/75 and 75; / 25, more preferably between 35/65 and 65/35, more preferably between 45/55 and 55/45.

The multiple emulsion thus obtained is in the form of a cream, white and shiny.

The invention will be better understood from the following examples, given for illustrative purposes.

Example 1 Preparation of a Water-in-Oil-in-Water Emulsion According to the Invention

a) Products used in the emulsion

International nomenclature%

Phases of cosmetic ingredients Function in

(INCI) weight ^*

surfactant

Polyglyceryl-4 isostearate 0.60

emulsifier from HLB 4

surfactant

Polyglyceryl-3 polyricinoleate 1, 80

HLB emulsifier 4

Caprylic / capric triglycerides Emollient 5.60

Pentaerythrityl tetraoctanoate Emollient 3.60

Diisostearyl succinate Emollient 2.40

Water (demineralized) Solvent 25.72

Ei magnesium sulfate

Additive (stabilizer) 0.28 heptahydrated

Emulsifying surfactant

Polyglyceryl-3-stearate 3.00

HLB 9

vs

Self emulsifiable surfactant

Glyceryl stearate citrate SE 3.00

anionic

E ₂

Sodium laureth sulfate

Anionic foaming surfactant 12.85 70% active solution

d

Cocamidopropyl betaine

Amphoteric foaming surfactant 10,00 30% active solution Xanthan gum + Glycerin Gelling Agent + Additive

3.25 (ratio: 1/12) (humectant)

Water Solvent 26.90

Phenoxyethanol Additive (preservative) 1, 00

^* on the total weight of the emulsion

Table 1: composition of the emulsion b) Preparation of the primary emulsion water-in-oil Ei / H

The oily phase H is prepared by mixing the five compounds mentioned in Table 1 above and in the amounts indicated.

In parallel, the internal aqueous phase E _1; is prepared by introducing the magnesium sulphate heptahydrate into a container containing deionized water.

The primary emulsion Ε ^ Η is carried out at 20 ° +/- 3 ° C with moderate stirring (700 rpm). The aqueous phase Ei is added very slowly to the oily phase H, in a dropwise manner for 6 minutes. Once the addition is complete, the emulsion is stirred for 1 minute under very vigorous agitation at 8000 rpm.

Such a primary emulsion E ^ H is stable for at least 3 months at 20 ° +/-

c) Preparation of the external aqueous phase E?

Phase E _2c is prepared by heating polyglycerol-3 stearate and glyceryl stearate citrate SE at 80 ° C. according to the amounts indicated in Table 1 above.

The aqueous phase E _2c i is prepared by adding to the quantity of water present in a container, the xanthan gum previously dispersed in glycerin according to the ratio indicated in Table 1. The foaming surfactants are then added, starting with sodium lauryl ether sulfate followed by cocamidopropyl betaine, according to the amounts indicated in Table 1 above. Phase E _2d is then heated to 80 ° C.

Phase E _2c is then added slowly to phase E _2d , over a time interval of one minute, with vigorous stirring (900 rpm). At the end of the addition, the external aqueous phase E ₂ is allowed to cool to a temperature of 40 ° C with moderate stirring (600 rpm). d) Preparation of the Emulsion According to the Invention

The water-in-oil primary emulsion Ei / H is heated to 40 ° C.

When the aqueous phase E ₂ is also at 40 ° C., the primary water-in-oil emulsion Ei / H is added slowly to the external aqueous phase E ₂ over a time interval of 4 min, with moderate stirring (700 turns per minute).

At the end of the addition, the triple emulsion E ₁ / H / E ₂ obtained is cooled to room temperature with gentle stirring (250 rpm).

When a temperature of less than or equal to 30 ° C. is reached, the preservative, according to the amount indicated in Table 1 above, is added to the emulsion E ₁ / H / E ₂ , with moderate agitation (600 rpm per minute).

Obtaining a multiple emulsion is observed under a microscope.

The multiple emulsion obtained can be used as a shower cream. This emulsion is indeed obtained in the form of cream, white and shiny appearance that gives a very creamy foam during washing.

The foam is dense and very lubricating.

Rinsing with water is easy and leaves a clean feeling on the skin.

Finally, after a few minutes of drying, the skin is very soft and hydrated. e) Stability of the Ei / H / E emulsion?

The emulsion E ₁ / H / E ₂ thus obtained is stable for at least 3 months at 23 ° C.

The emulsion E ₁ / H / E ₂ is also stable for at least 3 months at 4 ° C., 42 ° C. and 50 ° C. f) Stability of the multiple emulsion

The multiple emulsion thus obtained is stable for at least 3 months at 23 ° C.

The multiple emulsion is also stable for at least 3 months at 4 ° C, 42 ° C and 50 ° C.

In addition, no microbial growth is observed. This makes it a product suitable for use in cosmetics.

Example 2 Comparative Test for the Preparation of an Ei / H / E Emulsion

The products and amounts used are those described in Table 1, with the exception of the triester of glycerol and caprylic and capric acids (triglycerides), replaced by isopropyl myristate.

The process for preparing the triple emulsion E ₁ / H / E ₂ is identical to that described in Example 1. After formation of the primary emulsion Ε ^ Η, it is added to the external phase E ₂ . But during this addition, it is not an emulsion multiple which is formed but an oil-in-water emulsion, the two internal and external aqueous phases forming only one aqueous phase.

Without triglyceride, it is therefore impossible to form an emulsion.

Claims

Multiple emulsion comprising an oily phase and two aqueous phases, which emulsion comprises:

at least two surfactants having at least one negative charge, these being an anionic foaming surfactant and / or an amphoteric foaming surfactant, and an anionic self-emulsifiable surfactant.

Multiple emulsion according to claim 1, comprising an HLB emulsifying surfactant of between 7 and 15 and / or a gelling agent.

Multiple emulsion according to claim 1 or 2, comprising an HLB emulsifying surfactant of between 2 and 6, other than PGPR.

Multiple emulsion according to any one of claims 1 to 3, wherein the total amount of emulsifying surfactant (s) of HLB between 2 and 6 is between 1.6% and 3.2% by weight relative to weight of the emulsion.

A multiple emulsion according to any one of claims 1 to 4, further comprising a tetraester.

Process for the preparation of a multiple emulsion, comprising:

(i) a 1 ^st stage emulsion

an internal aqueous phase

in

an oily phase comprising

^■ at least 5% by weight of at least one triglyceride, based on the weight of the multiple emulsion, the total amount of triglyceride (s) corresponding to at least 35% by weight of the oily phase, and ^■ at least one emulsifying surfactant having an HLB of between 2 and 6 which is a polyglycerol polyricinoleate (PGPR),

to obtain a primary water-in-oil emulsion;

(ii) a 2 ^nd stage emulsion

- the primary emulsion thus obtained

in

an external aqueous phase comprising at least two surfactants having at least one negative charge, these being an anionic foaming surfactant and / or an amphoteric foaming surfactant, and an anionic self-emulsifiable surfactant.

The method of claim 6, wherein the external aqueous phase comprises an HLB emulsifying surfactant of between 7 and 15 and / or a gelling agent.

The process of any one of claims 6 or 7, wherein the oily phase comprises an HLB emulsifying surfactant of from 2 to 6 other than a polyglycerol polyricinoleate.

Use of the emulsion according to any one of the claims as a hygiene product and / or cosmetic product.

10. Cosmetic product comprising the emulsion according to claims 1 to 5, and a cosmetic additive and / or a cosmetic active.