EP2181820A1 - Stable liquid oil-in-water or water-in-oil emulsions based on vegetal or mineral oils - Google Patents

Abstract

Water in oil or oil in water emulsion (I) comprises: an oily phase comprising one or more oils of vegetable, mineral and/or synthetic origin, at least one nonionic and/or anionic emulsifying surfactant; and an aqueous phase comprising water and at least one phyllosilicate (I). Water in oil or oil in water emulsion comprises: an oily phase comprising one or more oils of vegetable, mineral and/or synthetic origin, at least one nonionic and/or anionic emulsifying surfactant; and an aqueous phase comprising water and at least one phyllosilicate of formula (Na +> 0 . 7[(Si 8Mg 5 . 5Li 0 . 3)O 2 0(OH) 4] -> 0> 7>). Independent claims are included for: (1) concentrated water in oil or oil in water emulsion comprising at least one or more oils of vegetable, mineral and/or synthetic origin and a nonionic and/or anionic emulsifying surfactant and the phyllosilicate, previously dissolved in a minimum water to obtain a gel or fluid sol, where the dilution allows to obtain (I); (2) preparing (I) comprising: preparing the oily phase by mixing the components comprising at least one or more vegetable, mineral and/or synthetic oils and an anionic and/or ionic emulsifying surfactant in oily phase; preparing the aqueous phase by mixing the components comprising at least water and the phyllosilicate; and mixing continuously or in batch, the oily phase and the aqueous phase in a dissolver; and (3) preparing a concentrate by a water in oil or oil in water emulsion comprising: dissolving the phyllosilicate in a minimum of water to form a gel or fluid sol; mixing at least one or more vegetable and/or mineral and/or synthetic oils and a nonionic and/or anionic emulsifying surfactant of the oily phase; and mixing the mixtures.

Description

Field of the invention

The present invention relates to stable and fluid aqueous emulsions of one or more crude vegetable oils (i.e., purified, non-chemically modified vegetable oils) and / or one or more mineral oils previously refined or hydro-treated.

The present invention also relates to the process for manufacturing the abovementioned emulsions.

The present invention also relates to the use of these fluid and stable emulsions based on one or more crude vegetable oils and / or refined or hydro-treated mineral oils, for the stripping and demoulding of concrete parts, d clays, ceramics, rubber or plastics.

State of the art :

By definition, an emulsion is a mixture of two immiscible substances that can be emulsified according to different formulations and different production techniques. Each substance is called phase. In an emulsion, the microdroplet phase is the discontinuous phase, while the phase surrounding the microdroplets is called the continuous phase. Thus, a water-in-oil emulsion (w / h) is composed of an aqueous discontinuous phase dispersed in an oily continuous phase and, conversely, an oil-in-water emulsion (h / e) is composed of a discontinuous phase. Oily dispersed in a continuous aqueous phase.

Because of the chemical incompatibility of the two phases, as well as their difference in density (oily phase lighter than water), it is necessary to make the emulsion stable over time. The formation of the emulsion and its stability depend on the thermodynamic laws. In particular, it is known that reducing the droplet diameter is a favorable factor for stability. This reduction in diameter, on the other hand, requires energy. The method of manufacturing emulsions is therefore an important parameter. In general, high shear agitators or high pressure homogenizers are used.

To reduce the creation energy of the o / w or e / h interface, surfactants or emulsifiers that allow the lowering of this interfacial energy are also used.

However, despite the use of emulsifiers, it happens that emulsions e / h or h / e obtained lack stability. This lack of stability results in the appearance of a phenomenon of separation between the phases.

There are three main mechanisms of destabilization: creaming, which corresponds to the rise of the least dense phase; the coalescence which corresponds to the rupture of the film of surfactants separating two droplets, and the flocculation which corresponds to the aggregation of several droplets.

To avoid these undesirable phenomena, it is often necessary in emulsions to use thickeners. These thickening agents are indeed able to limit or even stop the internal movement of the droplets in the continuous phase. However, this addition of thickeners limits the possible galenic forms of the cosmetic products and excludes in particular very fluid compositions.

To obtain fine, fluid and stable O / W emulsions, it has been described as stabilizing, especially in the document EP0864320 ionic polymers (cationic or anionic) of the phthalate sulfoisophthalate glycol co-polymer type sold under the Eastman AQ Polymer® trademark of Eastman chemical.

The document WO 1995 031898 discloses concentrated pesticidal compositions useful in agriculture and intended to be emulsified with water just prior to use. In order to viscosify the final formula, silicic derivatives, such as precipitated or pyrogenic colloidal silicas, are added. As an additional thickening agent, mention is made of products known to those skilled in the art, such as mineral derivatives such as silicates (attapulgite, bentonites, etc.), magnesium aluminosilicates, organic derivatives such as cellulose derivatives (cellulose ethers, carboxymethylcellulose, hydroxypropylcellulose ...) or polymers such as gums arabic or xanthan. Thus, this document proposes to mix the oily compound with water just before use.

For creams or cosmetic milks, the document EP 0737508 proposes as stabilizer emulsions of 2-F-octyl ethyl hexanoate hydro-fluoro-carbon compounds.

For galenic forms in the cosmetic and pharmaceutical fields, the document EP 0711539 As stabilizer there are provided o / w emulsions, salts of salicylic acid derivatives such as n-octanoyl-5-salicylic acid.

In the field of building, civil engineering, concrete release agents are used to facilitate the stripping after concrete hardening.

Conventional compositions are made either from aromatic petroleum derivatives (gas oil) or from solvent recycle oils to lower the viscosity and facilitate their application (in cold weather in particular) by spraying.

The use of such non-biodegradable and toxic compounds in general leads to a high health risk for building workers who must spray the product, as well as environmental pollution.

In order to reduce the viscosity of these compounds and to fluidize them, it has been proposed to use pure or modified solvent-based vegetable oils. Despite improved biodegradability, these new release agents based on solvented vegetable oils are flammable and toxic by the presence of their solvent. In addition, in terms of the appearance of the concrete facing after demolding, there are still bubbling defects and superficial heterogeneities.

The document EP 1900702 discloses a biodegradable mold release composition containing an aqueous emulsion of a mineral oil or ester derivatives. The emulsion comprises an organic acid, an ester surfactant, such as lower alkanoic acid monoglycerides, another polyethylene glycol ester, an oleic acid, and a surfactant ether. The composition also comprises colloidal silica, the colloidal silica being silicon dioxide in a colloidal state.

As mentioned above, previous attempts to produce emulsions of pure vegetable oils such as rapeseed or soya, from different emulsifying systems, thickeners or conventional organic stabilizers (gum xanthan ..) or minerals (silicas, bentonites ...), proved to be insufficient when the aim was to obtain fluid emulsions, low viscosity and with storage stability over 6 months to 1 year.

In addition, for each type of vegetable oil (rapeseed, soybean, etc.), because of their different chemical composition (variable oleic fatty acid, linoleic, palmitic acid content), it was necessary to modify the systems for each formulation. emulsifiers, as well as the choice of the thickening agent.

These difficulties have led many manufacturers of concrete mold release agents to give up the development of low viscosity, ready-to-use emulsions of w / o or e / h from vegetable oils.

The document EP 1 785 250 discloses an aqueous dispersion intended in particular for molding polyurethane comprising water, anionic or nonionic emulsifiers (0.1 to 10%), an anti-caking agent (0.5 to 40%) chosen from: soaps, oils , waxes and silicones, and talc or mica (0.1 to 10%).

The document WO 02/16096 discloses a release agent comprising organic acid amine soaps, nonionic emulsifiers ("sorbitan monooleate") and phyllosilicates (talc Mg ₃ Si ₄ O ₁₀ (OH) ₂ ; polygorskite: Mg ₅ Si ₈ O ₂₀ (HO) ₂ (OH _{2) 4} • _{4H 2} O; or clays of the smectite group) in a deionized aqueous phase. Phyllosilicates comprising magnesium silicate and / or aluminum are preferred.

G.Lagaly's "smectite as colloidal stabilizers of emulsions I" and "smectite as colloidal stabilizers of emulsions II" publications describe smectites used as an emulsion stabilizer comprising surfactants, such as nonionic surfactants. ionic. In particular, the second publication describes oil-in-water emulsions prepared by dispersing an aqueous phase comprising bentonites (Al ₂ O ₃ 4SiO ₂ H ₂ O), montmorillonites (Na, Ca) _0.33 (Al, Mg) ₂ Si ₄ O ₁₀ (OH) _{2 · n} H 2 O) or hectorite (Na _0.3 (Mg, Li) ₃ Si ₄ O ₁₀ (F, OH) ₂₎ in paraffin oil comprising emulsifiers.

In conclusion, the state of the art does not describe any emulsion w / e or e / h liquid at ambient temperature and stable over time, that is to say for at least 6 months to 1 year.

The object of the invention is to propose a new emulsion w / h or h / e that avoids all or some of the aforementioned disadvantages.

Description of the invention

For this purpose, the invention relates to a water-in-oil (w / o) or oil-in-water (o / w) emulsion composed of an oily phase comprising one or more oils of plant and / or mineral origin and / or or of synthesis, at least one nonionic and / or anionic emulsifying surfactant, and an aqueous phase comprising water, characterized in that the aqueous phase comprises at least one phyllosilicate, so as to obtain a stable and stable emulsion in time.

The present applicant has found, unexpectedly, that the addition of certain specific clays presented in sheet form and more particularly belonging to the family of phyllosilicates, made it possible to easily stabilize w / o or e / h emulsions based on vegetable oils and / or mineral oils and / or synthetic oils, while maintaining a low viscosity and whatever the temperature. Thus, the emulsions based on vegetable / mineral / synthetic oils according to the invention have a sufficient fluidity to be easily applicable on site, using sprayers for example, or pre-production by simply spraying on the walls of mussels. In addition, these phyllosilicates make it possible to obtain an emulsion w / h or h / e homogeneous and stable over time (8 months to 1 year), which constitutes a real progress compared to emulsions currently on the market.

Because of their mineral nature, phyllosilicate clays are inert and compatible with most conventional nonionic, anionic or amphoteric emulsifying surfactants.

Preferably, the phyllosilicate corresponds to the formula below:

Na ⁺ _0.7 [(Si ₈ Mg _5.5 Li _0.3 ) O ₂₀ (OH) ₄ ] ^-07

Indeed, it has been found that the stabilizing efficacy of phyllosilicates is related not only to their special chemical and crystallographic composition, but also to their overall negative ionic polarity after dispersion in water. In particular, the stability is improved with a phyllosilicate having insufficient charge 0.7 mesh per mesh as the phyllosilicate of the formula above.

Therefore, thanks to the crystallographic and ionic properties of phyllosilicates, it is now possible to obtain emulsions from pure vegetable / mineral or synthetic oils which are fluid, stable over time and have a rapid shear thinning during the process. use of emulsions by spraying. In addition, unlike emulsions containing conventional organic thickeners such as xanthan, etc., the stabilization of emulsions according to the present invention is not affected by temperature variations.

In order to control the quality of this type of phyllosilicates, it is preferable to obtain them synthetically from pure and regular basic components. The synthesized leaflets will preferably be milled to obtain a powdery, dry, easy-to-store phyllosilicate product.

Moreover, at the level of the process for preparing the emulsions, this powdery phyllosilicate product may be mixed with water (preferably deionized or softened) and may be previously in the form of a gel or a fluid sol. For example, a polyphosphate type pepter dispersant may be used to produce the gel or fluid soil.

Advantageously, the vegetable oil or oils are crude and the mineral oils are refined or hydro-treated.

By crude vegetable oil is meant that the vegetable oil has been purified and is chemically unmodified. An oil is purified when it has been previously filtered at least.

According to one characteristic of the invention, the water of the aqueous phase is deionized or softened.

Preferably, the nonionic and / or anionic emulsifying surfactant is liquid at room temperature (20-25 ° C.), biodegradable and produced on a vegetable basis.

In particular, the nonionic emulsifying surfactant is chosen from an ethoxylated fatty alcohol, an ester of fatty acids and polyols, a sorbitan ester, a polyethoxylated sorbitan ester, an ethoxylated castor oil, an alkoxylated fatty alcohol, a alkyl polyglucoside, a polymeric surfactant and the anionic emulsifier surfactant is selected from an alkaline salt of fatty and rosin acids, an alkylarylsulfonate, a alkylsulfosuccinate, alkyl sulfate, alkyl ether sulfate, ether sulfate amide, dodecylbenzene sulfonic acid derivative, amide ether sulfate.

Advantageously, the oil or oils represent, by weight, 10% to 80%, the emulsifying surfactant represents, by weight, 0.5% to 20%, the water represents, by weight, 10% to 90% and the phyllosilicate represents, by weight, from 0.01% to 20%, relative to the total weight of the emulsion water-in-oil (w / h) or oil in water (h / e).

Even more advantageously, the oil or oils represent, by weight, 20% to 50%, the emulsifying surfactant represents, by weight, 2% to 8%, the water represents, by weight, 30% to 80% and the phyllosilicate is 0.1% to 5% by weight, based on the total weight of the water-in-oil emulsion (w / o) or oil in water (h / e).

Preferably, the oily phase comprises at least one oleophilic adjuvant.

It is possible to add to the oily phase and at low dose, for example of the order of 0.01% to 2% by weight relative to the total weight of the emulsion, oleophilic adjuvants such as defoamers, antifreezes, anti-corrosion, anti-oxidation agents, color tracers, etc.

Advantageously, the aqueous phase comprises a hydrophilic adjuvant.

Similarly, it is possible to add to the aqueous phase and also at low dose (of the order of 0.01% to 2% by weight relative to the total weight of the emulsion), hydrophilic adjuvants such as biocides, dispersants, chelants, antioxidants, viscosity reducers, thickeners, etc.

The adjuvants used are preferably biodegradable and liquid at room temperature (20-25 ° C).

• l'huile d'origine végétale est choisie parmi l'huile de colza, de soja, de tournesol, d'olive, de palme, d'arachide, de jojoba, de coprah ou un de leurs mélanges ;
• l'huile d'origine minérale est choisie parmi la paraffine, l'isoparaffine, la naphténique hydrotraitée, la polyisobutène ou un de leurs mélanges ;
• l'huile de synthèse est choisie parmi les esters d'acides gras comme l'ester méthylique de soja ou de colza ou un de leurs mélanges.

According to one characteristic of the invention:

• the vegetable oil is selected from rapeseed, soybean, sunflower, olive, palm, peanut, jojoba, coconut oil or a mixture thereof;
• the oil of mineral origin is chosen from paraffin, isoparaffin, hydrotreated naphthenic, polyisobutene or a mixture thereof;
• the synthesis oil is chosen from fatty acid esters such as the soy or rapeseed methyl ester or a mixture thereof.

These oils are preferably liquid at room temperature (20-25 ° C).

The emulsions produced according to the invention can be classified as biodegradable (or totally biodegradable depending on the adjuvant used), non-toxic, non-flammable and environmentally friendly.

The present invention therefore provides low viscosity emulsions and without the use of solvents or volatile organic compounds (VOCs).

The subject of the present invention is also a concentrate of a water-in-oil (w / o) or oil-in-water (w / w) emulsion comprising at least one or more oils of plant and / or mineral origin and / or synthetic material and a nonionic and / or anionic emulsifying surfactant and at least one phyllosilicate in pulverulent form and / or previously dissolved in a minimum of water so as to obtain a gel or a fluid sol, characterized in that its dilution allows to obtain an emulsion w / h or h / e according to the characteristics of the emulsion water in oil (W / h) or oil in water (W / W) as described above.

The concentrate may further comprise the other components included in the composition of the w / o or h / e emulsion ready for use as oleophilic, hydrophilic adjuvants as described above.

Since the emulsion according to the present invention is in the form of a concentrate, it has the advantage of being more easily transportable and thus of reducing the cost of long distance transport.

It is also an object of the present invention to use the water-in-oil (w / o) or oil-in-water (w / w) emulsion according to any of the above characteristics as a release agent and / or stripping.

In particular, the present invention relates to the use of the water-in-oil (w / o) or oil-in-water (w / w) emulsion as described above for demolding and / or stripping of parts in water. concrete.

The emulsions of the present invention can also be used for demolding other materials such as clay, ceramic, rubber or plastic parts.

1. (i) préparer la phase huileuse en mélangeant les composés rentrant dans la phase huileuse comme au moins une ou plusieurs huiles d'origine végétale et/ou minérale et/ou de synthèse et un tensio-actif émulgateur non ionique et/ou anionique,
2. (ii) préparer la phase aqueuse en mélangeant les composés rentrant dans la phase aqueuse comme au moins l'eau et le phyllosilicate,
3. (iii) mélanger en continu ou en discontinu, la phase huileuse et la phase aqueuse dans un disperseur.

The present invention also relates to a process for preparing a water-in-oil (w / o) or oil-in-water (w / w) emulsion as described above, comprising the steps of:

1. (i) preparing the oily phase by mixing the compounds entering the oily phase as at least one or more oils of plant and / or mineral origin and / or synthesis and a nonionic and / or anionic emulsifying surfactant,
2. (ii) preparing the aqueous phase by mixing the compounds entering the aqueous phase as at least water and phyllosilicate,
3. (iii) continuously or batch mixing the oily phase and the aqueous phase in a disperser.

By disperser is meant a device for effectively mixing, shearing, emulsifying the emulsions, so as to obtain fine-cell emulsions.

The process for preparing the emulsions according to the invention thus has the advantages of being simple and economical. Indeed, it is useless for example to perform phase inversions that require heating at high temperature (around 90 ° C) oil and water phases, and thus increase manufacturing costs.

This is why the mixing of the phases is carried out at ambient temperature. There is no phase inversion.

Even more particularly, the mixing of the phases takes place at about 20 to 25 ° C.

As mentioned above, the phyllosilicate or phyllosilicates may be previously packaged in the form of gel or fluid soil.

1. (i) préparer un premier mélange à base d'au moins un phyllosilicate sous forme pulvérulente et/ou à base d'au moins un phyllosilicate préalablement dissous dans un minimum d'eau de sorte à obtenir un gel ou un sol fluide,
2. (ii) mélanger au moins une ou plusieurs huiles d'origine végétale et/ou minérale et/ou de synthèse avec un tensio-actif émulgateur non ionique et/ou anionique, de sorte à former une phase huileuse,
3. (iii) mélanger dans un disperseur le mélange obtenu à l'étape (i) avec celui obtenu à l'étape (ii).

The present invention also relates to a process for preparing a concentrate of a water-in-oil or oil-in-water emulsion according to the above characteristic, characterized in that it comprises the steps of:

1. (I) preparing a first mixture based on at least one phyllosilicate in pulverulent form and / or based on at least one phyllosilicate previously dissolved in a minimum of water so as to obtain a gel or a fluid sol,
2. (ii) mixing at least one or more oils of vegetable and / or mineral origin and / or of synthesis with a nonionic and / or anionic emulsifying surfactant, so as to form an oily phase,
3. (iii) mixing in a disperser the mixture obtained in step (i) with that obtained in step (ii).

Step (iii) above can be carried out continuously or discontinuously, continuous mixing being preferred in order to obtain a more homogeneous concentrate.

Examples of a method of preparation and emulsion compositions according to the invention and comparative test :

To better understand the object of the invention, an apparatus capable of obtaining the emulsions according to the invention will be described, on the one hand, and on the other hand, exemplary embodiments of said emulsions will be described. . Finally, comparative concrete demoulding tests will be presented. The following descriptions are given as purely illustrative and non-limiting examples; the drawing of the emulsifying apparatus is a schematic drawing intended solely to illustrate the principle of the apparatus used for carrying out the examples of the emulsions according to the invention.

• la figure 1 représente, en coupe axiale, un appareil émulsionneur permettant d'obtenir les compositions selon l'invention ;
• la figure 2 est une représentation partielle et schématique des palettes du rotor et du stator, palettes dont la coopération permet l'obtention d'un fort taux de cisaillement et, en conséquence, d'une émulsion suffisamment fine pour entrer dans le cadre de la présente invention ;
• la figure 3 est une photographie montrant l'état de la surface d'un moule après décoffrage béton en utilisant une composition de démoulage selon l'art antérieur, dite composition X ;
• la figure 4 est une photographie montrant l'état de la surface d'un moule après décoffrage béton en utilisant l'émulsion selon la présente invention ;
• la figure 5 est une photographie montrant la finition du béton après démoulage lorsque la composition X a été utilisée en tant qu'agent de démoulage ;
• la figure 6 est une photographie montrant la finition du béton après démoulage lorsque l'émulsion selon la présente invention a été utilisée en tant qu'agent de démoulage.

On the drawing :

• the figure 1 represents, in axial section, an emulsifier apparatus making it possible to obtain the compositions according to the invention;
• the figure 2 is a partial and schematic representation of the vanes of the rotor and the stator, pallets whose cooperation makes it possible to obtain a high shear rate and, consequently, an emulsion sufficiently fine to fall within the scope of the present invention;
• the figure 3 is a photograph showing the state of the surface of a mold after concrete stripping using a demolding composition according to the prior art, said composition X;
• the figure 4 is a photograph showing the state of the surface of a mold after concrete stripping using the emulsion according to the present invention;
• the figure 5 is a photograph showing the finish of the concrete after demolding when the composition X was used as a release agent;
• the figure 6 is a photograph showing the finish of the concrete after demolding when the emulsion according to the present invention has been used as a release agent.

Although the emulsifying apparatus shown on the Figures 1 and 2 is not part of the invention, we will give below a quick description. The stator of the emulsifier has been designated as 1 as a whole. The stator 1 consists essentially of two parts 1a and 1b joined to one another by means of bolts 2. The stator 1 receives a rotor designated by 3 as a whole, the rotor 3 is rotated with respect to the stator by a shaft 4. The rotation of the rotor 3 and the shaft 4 with respect to the stator 1 is permitted thanks to a system of sealed bearings 5.

The part 1 b of the stator comprises the arrival pipes of the products intended to constitute the emulsion: for example the aqueous phase is sent according to the arrow F1 and the oily phase of the emulsion is sent according to the arrow F2 (or conversely) . The assembly enters the stator comprises a circular blade holder 6 fixed by screws to the part 1b of the stator, the blades 6a of the blade holder 6 being radial and directed toward the rotor 3, that is that is to say on the opposite side to the arrival of the products to be emulsified. The end of the rotor 3 which vis-à-vis the blade carrier 6 has the form of a plate which carries radial blades 3 a. The blades 3a and 6a are arranged in concentric circles, the blades 3 a is located in the circular annular spaces that exist between two successive circles of blades 6a.

The products to be emulsified come into the zone between the blade carrier 6 and the rotor 3 via a central circular orifice of the blade carrier 6, centrifugally cross the space between the blade carrier 6 and the rotor 3 and are ejected at the periphery of said space to be discharged out of the apparatus according to the arrow F3. It is clear that the flow of incoming products undergoes successive shearing between the stationary blades 6a and the blades 3 is rotated by the shaft 4. In known manner, the fineness of the emulsion obtained is a function in particular of the number of concentric circles of blades 3a and 6a, the radial space between the edges of said blades and shaft rotation speed 4. in other words, for a given device and a given flow rate, the characteristics of the emulsion obtained are a function of the speed of rotation of the rotor.

Preferably, a rotation speed of the order of 6,500 rpm is suitable for obtaining fluid emulsions according to the present invention.

The process as described above makes it possible to obtain homogeneous and regular emulsions continuously, however, it is also possible to produce the emulsions according to the invention batchwise (batch process).

Now, examples of emulsion according to the invention purely illustrative and not limiting the scope of the invention will be described.

EXAMPLE 1 Emulsion Based on Pure Rapeseed Oil and Biodegradable Components and Adjuvants

Composition % (by weight) relative to the total weight of the emulsion Oily phase - crude rapeseed oil: 350 kg 34.99% fatty acid esters (polyethylenated): 55 kg 5.5% - ethoxylated vegetable base emulsifiers: 25 kg 2.5% Aqueous phase - water: 564 kg 56.38% - Ionized phyllosilicate type clay answering for example the formula 0.60% Na ⁺ _0.7 [(Si ₈ Mg _5.5 Li _0.3 ) O ₂₀ (OH) ₄ ] ^-07 : 6 kg - preservative: 0.4 kg (dispersed in water) 0.04%

EXAMPLE 2 Emulsion Based on Pure Soybean Oil and Biodegradable Components and Adjuvants

Composition % (by weight) relative to the total weight of the emulsion Oily phase - crude soybean oil: 350 kg 34.9 9% - alkoxylated fatty alcohols: 50 kg 5.50% - Vegetable base emulsifiers ethoxylated: 15 kg 1.50% Aqueous phase - water: 579 kg 57.88% - Ionized phyllosilicate type clay answering for example the formula 0.60% Na ⁺ _0.7 [(Si ₈ Mg _5.5 Li _0.3 ) O ₂₀ (OH) ₄ ] ^-07 : 6 kg - preservative: 0.4 kg (dispersed in water) 0.04%

Comparative tests of concrete release on building site exterior between an emulsion according to the present invention and a demolding composition according to the prior art (composition X) will be presented below.

For these tests, the emulsion according to Example 1 was reproduced.

Composition X according to the prior art is a solvent-based mineral oil which according to the security label is harmful and flammable.

The emulsion according to the invention as well as the composition X were sprayed onto metal molds (it is also possible to do it on wood) under a pressure of at least 6 bar using a sprayer. With the composition according to Example 1, it is noted the presence of a uniform and stable film of oil deposited on the entire surface.

Then, the mussels are left to air dry for about an hour (until no water).

A molding is then carried out, one side with the emulsion according to the invention (Example 1) and the other with the composition X and this, according to the practice known to those skilled in the art.

Then, the demolding is carried out and as illustrated in the photographs 5 and 6, it is found that the concrete finish, when the emulsion according to Example 1 of the invention is used, is better than with the composition X. Indeed, when the concrete facing is demolded with the composition X of the prior art, the surface of the concrete comprises bubbles ( figure 5 ). It will therefore be necessary to carry out an additional step of patching so that the surface of the concrete is uniform. Whereas, when the concrete is demolded with the emulsion of Example 1 ( figure 6 ), the concrete is of good quality and there is no (or almost no) bubbling, in this case the patch is not necessary. In addition, when an emulsion according to Example 1 is used as a release agent, it is noted that the fouling of the mold surfaces is minimized with respect to fouling of the mold when the composition X is used as a mold release agent. as demolding agent.

Therefore, the emulsions according to the invention, stabilized by one or more phyllosilicates, have proven to be as much if not more effective than the mold release oils currently on the market.

Although the invention has been described in connection with a particular embodiment, it is obvious that it is not limited thereto and that it comprises all the technical equivalents of the means described and their combinations if they are within the scope of the invention.

Claims (17)

Water-in-oil (w / o) or oil-in-water (o / w) emulsion composed of an oily phase comprising one or more oils of vegetable and / or mineral origin and / or of synthesis, at least one surfactant nonionic and / or anionic emulsifying active agent, and an aqueous phase comprising water, the aqueous phase comprising at least one phyllosilicate, so as to obtain a fluid emulsion that is stable over time, characterized in that the phyllosilicate corresponds to the formula below:

Na ⁺ _0.7 [(Si ₈ Mg _5.5 Li _0.3 ) O ₂₀ (OH) ₄ ] ^-07

The water-in-oil (w / o) or oil-in-water (w / w) emulsion of claim 1, wherein the one or more vegetable and / or mineral oils are crude or purified and chemically unmodified. The water-in-oil (w / o) or oil-in-water (w / w) emulsion according to one of the preceding claims, wherein the water of the aqueous phase is deionized or softened. Water-in-oil (w / o) or oil-in-water (h / e) emulsion according to one of the preceding claims, wherein the nonionic and / or anionic emulsifying surfactant is liquid at room temperature, biodegradable and produced. on vegetable basis. The water-in-oil (w / o) or oil-in-water (w / w) emulsion of claim 4, wherein the nonionic emulsifying surfactant is selected from an ethoxylated fatty alcohol, an ester of fatty acids and polyols a sorbitan ester, a polyethoxylated sorbitan ester, an ethoxylated castor oil, an alkoxylated fatty alcohol, an alkyl polyglucoside, a polymeric surfactant and the anionic emulsifier surfactant is selected from an alkaline salt of fatty and rosin acids, an alkylarylsulfonate, an alkylsulfosuccinate, an alkyl sulphate, an alkyl ether sulphate, a sulphate ether amide, a dodecylbenzene sulphonic derivative. Water-in-oil (w / o) or oil-in-water (h / e) emulsion according to one of the preceding claims, in which, relative to the total weight of the water-in-oil emulsion (w / h) or oil in water (h / e), the oil or oils represent, by weight, 10% to 80%, the emulsifying surfactant represents, by weight, 0.5% to 20%, water represents, in weight, weight, 10% to 90% and the phyllosilicate represents by weight 00.1% to 20%. The water-in-oil (w / o) or oil-in-water (h / e) emulsion according to claim 6, in which, relative to the total weight of the water-in-oil emulsion (w / h) or oil in water (h / e), the oil or oils represent, by weight, 20% to 40%, the emulsifying surfactant represents, by weight, 2% to 8%, the water represents, by weight, 30% to 80% and the phyllosilicate is 0.1% to 5% by weight. The water-in-oil (w / o) or oil-in-water (w / w) emulsion according to one of the preceding claims, wherein the oily phase comprises at least one oleophilic adjuvant. The water-in-oil (w / o) or oil-in-water (w / w) emulsion according to one of the preceding claims, wherein the aqueous phase comprises a hydrophilic adjuvant. Water-in-oil (w / o) or oil-in-water (w / w) emulsion according to one of the preceding claims, in which: the oil of vegetable origin is chosen from rapeseed, soya, sunflower, olive, palm, peanut, jojoba, coconut oil or a mixture thereof; the oil of mineral origin is chosen from paraffin, isoparaffin, hydrotreated naphthenic, polyisobutene or a mixture thereof; the synthesis oil is chosen from esters of fatty acids, such as the methyl ester of soya or rapeseed, or a mixture thereof. Concentrate of a water-in-oil (w / o) or oil-in-water (w / w) emulsion comprising at least one or more oils of plant and / or mineral and / or synthetic origin and an emulsifying surfactant nonionic and / or anionic and a phyllosilicate of formula Na ⁺ _0.7 [(Si ₈ Mg _5.5 Li _0.3 ) O ₂₀ (OH) ₄ ] ^-07 previously dissolved in a minimum of water so as to obtain a gel or a fluid floor, characterized in that its dilution makes it possible to obtain an emulsion w / h or h / e according to claim 1. Use of the water-in-oil (w / o) or oil-in-water (w / w) emulsion according to one of claims 1 to 10 as mold release agent and / or stripping agent. Use according to claim 12 of the water-in-oil emulsion (w / o) or oil in water (m / e) for demolding and / or removing concrete parts. A process for preparing a water-in-oil (w / o) or oil-in-water (w / w) emulsion according to one of claims 1 to 10 comprising the steps of: (i) preparing the oily phase by mixing the compounds entering the oily phase as at least one or more oils of plant and / or mineral origin and / or synthesis and a nonionic and / or anionic emulsifying surfactant, (ii) preparing the aqueous phase by mixing the compounds entering the aqueous phase as at least water and phyllosilicate, (iii) continuously or batch mixing the oily phase and the aqueous phase in a disperser. A process for preparing a water-in-oil (w / o) or oil-in-water (w / w) emulsion according to claim 14, wherein the mixing of the phases is carried out at room temperature. A process for preparing a water-in-oil (w / o) or oil-in-water (w / w) emulsion according to claim 15, wherein the mixing of the phases is carried out at about 20 to 25 ° C. Process for the preparation of a concentrate of a water-in-oil or oil-in-water emulsion according to claim 11, characterized in that it comprises the steps of: (i) dissolving the phyllosilicate in a minimum of water so as to form a gel or a fluid sol, (ii) mixing at least one or more oils of plant and / or mineral and / or synthetic origin and a nonionic and / or anionic emulsifying surfactant of the oily phase, (iii) mixing the mixture obtained in step (i) with that obtained in step (ii).

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