EP2646211B1 - Mold release composition - Google Patents

Description

The present invention relates to a composition for demolding, particularly useful for the manufacture of molded parts of hydraulic setting material such as concrete.

When manufacturing parts by molding, it is important to control the demolding step in order to obtain an intact surface appearance (for example not bubbled) and homogeneous and to reduce nonconformities. In particular, hydraulically setting materials such as concrete tend to react with the surface of the mold. These reactions tend to decrease the quality of the molded part and the life of the mold.

In order to remedy this difficulty, it is known to coat the mold with a so-called stripping or demoulding composition. For demolding parts made of hydraulically setting materials, mold release oils can be used. The oil film thus deposited on the walls of the mold makes it possible to avoid direct contact between the hydraulically setting material and the surface of the mold, thus protecting the surface of the mold.

However, known mold release oils still have certain disadvantages. In particular, it remains difficult to obtain parts having a homogeneous surface appearance. In particular, the appearance of small bubbles on the surface and inhomogeneities of hue, such as whitish streaks or dark rings.

Thus, it remains difficult to obtain molded parts having a look and shade of sufficient homogeneity for certain applications, such as for uncoated facings after stripping.

The patent application WO2008 / 087298 discloses a mold release composition comprising at least one oil and at least one calcium salt. Although the molded parts obtained using the mold release compositions according to the examples described in this patent application have a homogeneous surface appearance, the stability of the mold release compositions is not always satisfactory.

Also the problem to be solved by the invention is to provide a demolding composition of molded parts of a hydraulically setting material to obtain a molded part having a homogeneous surface appearance and corresponding to an emulsion having a storage stability before use of at least one day, preferably at least 2 days.

The invention can be implemented in at least one of the industries such as the building industry, the chemical industry (preferably adjuvants) and the industry. cement, in the construction markets (building, civil engineering, roads or prefabrication plants), or in concrete plants.

Unexpectedly, the inventors have demonstrated that the introduction with specific proportions of a surfactant, a water repellent, an oil and a water-soluble calcium salt in a mold release composition can lead to obtaining a demolding composition whose performance in improving the surface appearance of the molded parts is maintained for at least one day when the mold release composition is left at rest.

The present invention aims to provide a composition that spreads easily when applied to the surface of a mold; which can be stored without agitation and substantially retains its mold release properties for at least one day at 25 ° C; which allows the production of molded objects having a homogeneous surface appearance; and / or which has a viscosity which allows it to be applied, for example, by spraying.

• de 10 à 20 % d'une huile ;
• de 1 à 5 % d'un agent hydrofuge ;
• de 0,1 à 1 % d'un sel de calcium hydrosoluble autre que le borate de calcium ou un sel de calcium d'un acide gras ;
• de 0,5 à 3 % d'un tensioactif non-ionique ou un mélange de tensioactifs ayant un rapport hydrophile-lipophile (HLB) de 8 à 20 ; et
• de l'eau, de préférence de l'eau déminéralisée.

For this purpose, the present invention proposes a demolding composition, intended for the manufacture of parts made of hydraulically setting material, the composition comprising, as a percentage by weight relative to the mass of the demolding composition:

• from 10 to 20% of an oil;
• from 1 to 5% of a water-repellent agent;
• 0.1 to 1% of a water-soluble calcium salt other than calcium borate or a calcium salt of a fatty acid;
• 0.5 to 3% of a nonionic surfactant or a mixture of surfactants having a hydrophilic-lipophilic (HLB) ratio of 8 to 20; and
• water, preferably deionized water.

The demolding composition according to the invention is preferably an emulsion. An emulsion is generally a substantially homogeneous mixture of at least two immiscible liquid substances, a first substance being dispersed in a second substance in the form of droplets. In the emulsions according to the invention, the mean diameter of the droplets is preferably less than about 10 micrometers.

Preferably, the stability of the demolding composition is at least about 1 day at 25 ° C, still more preferably greater than or equal to about 2 days, in particular greater than or equal to about 5 days. By "stability" of the demolding composition is meant that the demolding composition remains in the form of an emulsion, with substantially no agglomeration of the droplets; of preferably the average diameter of the droplets of the emulsion remains less than about 10 micrometers. Stability can also be assessed visually.

The release composition according to the invention may comprise an oil or a mixture of different oils. The oils used in the composition according to the invention are essentially hydrocarbonaceous materials that are liquid at room temperature and immiscible with water. The oils reduce the coefficient of friction and thus facilitate demolding. These oils include mineral, animal and vegetable oils. Animal and vegetable oils can also be synthetic, using fatty acids of animal or vegetable origin.

Preferably, the oil is a vegetable or animal oil. Indeed, they are more polar and it is found that the molded parts have a more homogeneous surface appearance, including a decrease in the appearance of bubbles. In addition, mineral oils are subject to strict regulations at their level of discharge.

Preferably, the oil is an oil of vegetable origin. Indeed, vegetable oils contain functions that are likely to be saponified in an alkaline medium to give an alcohol and a salt, for example a calcium salt.

Particularly preferred is a mold release composition in which the vegetable oil comprises one or more compounds selected from fatty acid esters, and in particular fatty acid triglycerides, neopentyl polyol fatty acid esters, esters, of trimethylolpropane fatty acids and diglycerol esters. Vegetable oils can be oils obtained directly from vegetable sources or oils whose molecule comprises chemical groups, for example fatty acid residues, of plant origin.

According to an exemplary embodiment of the invention, the demolding composition comprises from 11 to 19%, preferably from 12 to 18%, even more preferably from 13 to 17%, by weight of oil relative to the mass of the demolding composition.

The demolding composition according to the invention may comprise a water-repellent agent or a mixture of different water-repellent agents. The water-repellent agent may be a hydrophobic agent, and is generally a water-repellent product, to reduce the penetration of water into the material. The demolding composition may in particular comprise, as a water-repellent agent, products based on silicones, silanes, siloxanes or metal salts of fatty acids. The water-repellent agent is preferably a product based on silicones, silanes, siloxanes, even more preferably a polydimethylsiloxane or a polydimethylsiloxane derivative.

According to an exemplary embodiment of the invention, the demolding composition comprises from 1.5 to 4%, preferably from 2.5 to 3% by weight of the water-repellent agent relative to the weight of the demolding composition. .

The surfactant used according to the invention is nonionic. A surfactant is a compound that lowers the surface tension of a liquid and / or lowers the interface voltage between two liquids or between a liquid and a solid. The HLB value of a surfactant can be obtained from manufacturers. Measurement of the HLB of a surfactant can be done experimentally at room temperature from a defined range of HLB solvents; by preparing their emulsions and examining the stabilities thereof.

où M est la masse de la molécule de tensioactif et M_h est la masse de la partie hydrophile de la molécule de tensioactif. Le HLB selon la méthode de Griffin varie de 0 à 20, 0 étant attribué à un produit totalement hydrophobe et 20 à un produit totalement hydrophile. Il est entendu que la valeur calculée selon la méthode de Griffin ne peut pas excéder 20. Cependant les valeurs HLB de certains tensioactifs, en particulier des tensioactifs anioniques, peuvent dépasser 20 quand elles sont mesurées expérimentalement.The HLB value of a nonionic surfactant having a simple molecular structure can be calculated according to the method of Griffin described in the document "Calculation of HLB Values of Non-Ionic Surfactants" Journal of the Society of Cosmetic Chemists 5 (1954): 259 . The HLB ratio for such a nonionic surfactant is given by the following relationship: $$\mathrm{HLB}={\mathrm{M}}_{\mathrm{h}}/\mathrm{M}\times \mathrm{20}$$

where M is the mass of the surfactant molecule and M _h is the mass of the hydrophilic portion of the surfactant molecule. HLB according to the Griffin method ranges from 0 to 20, 0 being assigned to a totally hydrophobic product and to a totally hydrophilic product. It is understood that the value calculated according to the Griffin method can not exceed 20. However, the HLB values of certain surfactants, in particular anionic surfactants, can exceed 20 when they are measured experimentally.

In the present description, including the accompanying claims, unless otherwise indicated, the HLB values are obtained from the surfactant manufacturer or are measured experimentally.

HLB values are also available in publications. For example, page 40 of "Surfactants: Fundamentals and Applications in the Petroleum Industry", Laurier Lincoln Schramm, Cambridge University Press 2000 , list multiple HLB values, including the following: Nonionic surfactants Sorbitan monolaurate (SPAN ™ 20) 9 Glycerol monostearate 11 Polyoxyethylene (10) cetyl ether (BRIJ ™ 56) 13 Polyoxyethylene sorbitan monooleate (TWEEN ™ 80) 15 Sodium octadecanoate 18 Sodium dodecanoate 21 Sodium octanoate 23 Dioctyl sodium sulphosuccinate 32 Sodium heptadecyl sulphate 38 Sodium dodecyl sulphate 40 Sodium octyl sulphate 42

HLB is a property that adds up; the HLB of a mixture of several surfactants is the average of the HLBs of these surfactants, taking into account the proportions of the mixture. A mixture of 20% of an HLB 6 product with 80% of an HLB 14 product has an HLB of: $$6\times 0,2+14\times 0,8=12,4$$

The HLB values of the nonionic surfactant or of the surfactant mixture used in the compositions according to the invention are from 8 to 20, preferably from 8 to 19, for example from 8 to 18.5. HLB values greater than 10 are preferred, more preferably greater than 13.

Nonionic surfactants can be classified according to the nature of the bond between the hydrophilic and hydrophobic parts of the molecule, for example esters and ethers.

Esters include glycol esters (for example esters with fatty acids, for example ethylene glycol stearate), glycerol esters (for example esters with fatty acids, for example glycerol stearate), polyoxyethylene glycol esters (obtained for example by the action of ethylene oxide on a fatty acid or a mixture of fatty acids) and sorbitan esters, for example polyoxyethylene sorbitan esters, called Tweens or polysorbates and esters glycosides (including sugar esters (eg sucrose)).

Tweens include Tweens 20, 60, 80 wherein the numbers represent the fatty acid present in the molecule. Monolaurate is identified by 20, monostearate by 60 and monooleate by 80. The sugar esters comprise a hydrophilic (glucosidic) glycidyl group and a hydrophobic fatty chain. The ethers include ethers of fatty alcohols and polyoxyethylene glycol.

• sur un alcool gras (linéaire ou ramifié, saturé, insaturé ou polyinsaturé, de préférence linéaire) ; ou
• sur un polypropylène glycol ou polybutylène glycol (par exemple les polymères par blocs EO-PO-EO et les polymères PO-EO dans lesquelles le symbole EO signifie l'éthylèneoxy et le symbole PO signifie le propylèneoxy) ; ou le tensioactif est, par exemple un ester de sucre (incluant un dérivé de sucre) ; le sucre est de préférence le sucrose (saccharose);

The surfactant is, for example, an alkoxylated alkyl derivative whose alkyl chains are preferably based:

• on a fatty alcohol (linear or branched, saturated, unsaturated or polyunsaturated, preferably linear); or
• on a polypropylene glycol or polybutylene glycol (for example, EO-PO-EO block polymers and PO-EO polymers in which the symbol EO signifies ethyleneoxy and the symbol PO signifies propyleneoxy); or the surfactant is, for example, a sugar ester (including a sugar derivative); the sugar is preferably sucrose (sucrose);

The surfactant is preferably an alkoxylated alkyl derivative, for example an ethoxylated fatty alcohol which comprises at least one alkyl chain combined with a few ethylene oxide units. The ethoxylated fatty alcohol preferably comprises an alkyl chain of 6 to 22 carbon atoms and more preferably 10 to 14 carbon atoms.

The polyalkoxy groups, for example EO and PEO, preferably comprise at one end a C1-C4 alkyl group, for example methyl or butyl.

According to another embodiment of the invention, the composition according to the invention comprises a mixture of nonionic and anionic surfactants having an HLB value of greater than 8.

Anionic surfactants release a negative charge (anion) in aqueous solution. They have a relatively high Hydrophilic / Lipophilic Balance (HLB) (8 to 45). They orient the emulsion in the Oil / Water (O / W) direction. Anionic surfactants are generally compatible with nonionic surfactants. They are generally not compatible with cationic surfactants.

Anionic surfactants include soaps, sulfated derivatives, and sulfonated derivatives. They are salts of fatty acids of general formula RCOOM (R = a long hydrocarbon chain, M = a metal, for example an alkali metal, an alkaline earth metal or an organic base). Depending on the nature of the group M, these surfactants comprise alkaline soaps (for example Na +, K + or NH ₄ + soaps), metal soaps (for example calcium) and organic soaps (triethanolamine soap for example), triethanolamine stearate).

Sulphated derivatives include fatty acid sulphates, for example sodium lauryl sulphate and triethanolamine lauryl sulphate, which are widely used as emulsifiers.

The sulfonated derivatives include sodium dioctylsulfosuccinate.

In the present description, including the accompanying claims: the fatty alcohols and the fatty acids comprise a lipophilic group generally comprising from 6 to 32 carbon atoms, preferably 8 to 22 carbon atoms, more preferably 8 to 18 carbon atoms. carbon atoms; and

the alkoxylated groups generally comprise from 1 to 100 alkoxy groups, preferably 3 to 30 alkoxy groups, more preferably 8 to 18 alkoxy groups, in which the alkoxy group is preferably propyleneoxy or more preferably ethyleneoxy.

Preferably, the demolding composition comprises at least 1% of the surfactant relative to the weight of the demolding composition. The inventors have indeed demonstrated that when the demolding composition comprises at least 1% of the surfactant relative to the mass of the demolding composition, the stability of the demolding composition is generally at least 2 days. Preferably, the demolding composition comprises at least 1.2% of the surfactant relative to the weight of the demolding composition. The inventors have in fact demonstrated that when the demolding composition comprises at least 1.2% of the surfactant relative to the weight of the demolding composition, the stability of the demolding composition is generally at least 5 days. According to an exemplary embodiment of the invention, the demolding composition comprises from 1 to 2%, preferably from 1.2 to 1.5% by weight of the surfactant relative to the weight of the demolding composition.

A calcium salt is a compound that comprises a calcium ion and an inorganic or organic counterion. The calcium salts used according to the invention are water-soluble; the water solubility is preferably greater than 2 g / 100 ml at 20 ° C. Particularly targeted are calcium halides such as chloride or bromide; calcium thiocyanate; salts of nitrogenous ions such as calcium nitrate or nitrite; sulphurous ion salts such as sulphate, sulphite or calcium bisulphite; or salts of carboxylic or hydroxycarboxylic acids such as lactates. The calcium salt is preferably selected from chloride, bromide, nitrite and calcium thiocyanate. The calcium salt is preferably calcium thiocyanate. Generally, a low concentration of calcium salts, of the order of 0.1% by weight relative to the weight of the demolding composition, is sufficient to improve the surface appearance of the molded parts. Also, the demolding composition will generally contain 0.1 to 1% by weight of calcium salt expressed in terms of anhydrous salt.

According to an exemplary embodiment of the invention, the demolding composition comprises from 0.2 to 0.6%, preferably from 0.25 to 0.5%, by weight of water-soluble calcium salt relative to the mass of the demolding composition.

According to one embodiment of the invention, the demolding composition comprises from 71 to 88%, preferably from 75 to 85%, even more preferably from 77 to 83% by weight of water, in particular demineralized water, relative to the mass of the demolding composition.

The demolding composition may further comprise other materials, for example one or more compounds selected from a stabilizer, a dispersant, a preservative, a solvent, a thickener, a thixotropic agent, a biocidal agent or a pigment.

Among the pigments, mention may in particular be made of inorganic pigments such as, in particular, oxides or hydroxides of metals such as iron, chromium, titanium, cobalt, aluminum or manganese, their mixtures and mixed compounds, as well as carbon black. Titanium dioxide and / or iron, cobalt or chromium oxides are preferably used. These inorganic pigments and their mixtures are known per se and sold in particular by the company Chryso, France.

Titanium dioxide, by virtue of its photocatalytic properties, can also be used as a depollution agent.

The hydraulically setting material can be tinted also with organic pigments such as catechol or bromothymol blue.

However, inorganic pigments will preferably be chosen.

These pigments may be added in varying amounts, but generally in the range of 2 to 70%, preferably 5 to 40% by weight, based on the final mold release composition.

The present invention also relates to a method for preparing a release composition according to the invention, the process comprising a step of contacting a water-repellent agent, an oil, a nonionic surfactant and a calcium salt other than as calcium borate or a calcium salt of a fatty acid, and water.

• former une première émulsion de l'agent hydrofuge, la première émulsion comprenant une partie du tensioactif ;
• former une deuxième émulsion de l'huile, la seconde émulsion comprenant le reste du tensioactif ;
• former une solution du sel de calcium ; et
• mélanger la solution du sel de calcium, la première émulsion et la deuxième émulsion.

The present invention also relates to a method of manufacturing the demolding composition as defined above comprising the following steps:

• forming a first emulsion of the water-repellent agent, the first emulsion comprising a portion of the surfactant;
• forming a second emulsion of the oil, the second emulsion comprising the remainder of the surfactant;
• form a solution of the calcium salt; and
• mix the calcium salt solution, the first emulsion and the second emulsion.

Preferably, the calcium salt solution is first mixed with the first emulsion of the water repellent agent to obtain a third emulsion. The second emulsion of the oil is then mixed with the third emulsion.

The first emulsion of the water-repellent agent can be obtained by mixing water and said part of the surfactant, then introducing the water-repellent agent.

The second oil emulsion can be obtained by mixing water and said remainder of the surfactant and then introducing the oil. The whole is then diluted with water.

Since the calcium salt is generally poorly soluble in oil, it is preferably introduced in the form of a solution, in particular an aqueous solution.

The mixture of constituents is preferably subjected to an additional emulsification step to reduce the size of the droplets, for example to less than 10 microns. This emulsification may be carried out by known methods, for example using a high pressure emulsifier using a high pressure dynamic emulsification. This can be achieved using, for example, an Emulsiflex C3. More than one passage in the emulsifier can be achieved; in this case, the emulsion is preferably cooled to a temperature below 25 ° C before each pass. The emulsion according to the invention preferably comprises droplets having a narrow particle size distribution, for example a distribution that can be obtained using an Emulsiflex C3.

• enduire les parois d'un moule avec la composition de démoulage selon l'invention ;
• introduire dans le moule le matériau à prise hydraulique à l'état frais ; et
• retirer la pièce du moule après durcissement du matériau à prise hydraulique.

The release composition according to the present invention can be used for the preparation of moldings made of hydraulically setting material, comprising the step comprising:

• coating the walls of a mold with the release composition according to the invention;
• introducing into the mold the hydraulic setting material in the fresh state; and
• remove the mold part after curing the hydraulically setting material.

The setting material is a mixture of at least one hydraulic binder, with water, optionally aggregates, optionally adjuvants, for example adjuvants according to EN 934-2, and optionally mineral additions. A hydraulic binder is a compound that takes and cures after hydration including water binders. The hydraulic binder used may in particular be a plaster, cement or hydraulic lime. Preferably, the hydraulic binder is a cement, for example a Portland cement.

The hydraulically setting material comprises a fresh or hardened material. The hydraulic setting material used may be, for example, a cement slurry, a mortar, a concrete or a hydraulic lime slurry. Preferably, the hydraulically setting material is a cement slurry, a mortar or a concrete. The hydraulically setting material can be for example a concrete such as high performance concrete (BHP), ultra high performance concrete (BUHP), self-compacting concrete, self-leveling concrete, self-compacting concrete, fiber concrete, ready-mix concrete. construction concrete, foamed concrete, lightweight concrete, precast concrete, heavy concrete, extruded concrete, calendered concrete, colored concrete or prestressed concrete. Concretes also include concretes that have undergone a finishing operation such as bush-hammered concrete, deactivated or washed concrete, or polished concrete. Ready-mix concrete includes concrete with an open time of sufficient workability to allow concrete to be transported to the site where it will be poured. Concrete includes mortars; in this case the concrete comprises a mixture of a hydraulic binder, sand, water and possibly additives and possibly mineral additions. Concrete includes fresh concrete or hardened concrete.

The setting comprises the solid state transition of the hydraulic binder by hydration reaction. The setting is usually followed by the hardening period. Before setting, concrete is said to be fresh, or fresh.

Aggregates can be gravel, chippings and / or sand. The Portland cement may be, for example a CEM I, CEM II, CEM III, CEM IV or CEM V cement according to the "Cement" NF EN 197-1 standard. Mineral additions can be a finely divided mineral material used in concrete or cement to improve certain properties or to confer particular properties. It is, for example, fly ash (for example as defined in the standard "Cement" NF EN 197-1 paragraph 5.2.4 or as defined in the standard "Concrete" EN 450), pozzolanic materials ( for example, as defined in the "Cement" standard NF EN 197-1 paragraph 5.2.3), silica fumes (for example as defined in the "Cement" standard NF EN 197-1 paragraph 5.2.7 or such as defined in the "Concrete" standard prEN 13263: 1998 or NF P 18-502), slags (for example as defined in the standard "Cement" NF EN 197-1 paragraph 5.2.2 or as defined in the standard " Concrete »NF P 18-506), calcined schists (for example as defined in the" Cement "standard NF EN 197-1 paragraph 5.2.5), calcareous additions (for example as defined in the" Cement "standard). NF EN 197-1 paragraph 5.2.6 or as defined in the "Concrete" standard NF P 18-508) and siliceous additions (for example as defined in the "Concrete" standard) NF P 18-509) or mixtures thereof.

Preferably, the coating of the mold is carried out by spraying.

The coating of the mold with the demolding composition may be carried out by means known per se, for example by application with a brush, a cloth, or a roll, by dipping or else by spraying, this latter mode of application being preferred.

The amount of mold release composition to be applied is generally chosen to be sufficient to form a continuous film over the entire mold surface intended to be in contact with the hydraulic setting material. The thickness of the oil film formed is generally sufficient to produce a dry film having a thickness in the range of 1 to 15 microns.

Thus, the amount of demolding composition depends on its viscosity and thus its formulation. The material and topology of the mold may also be factors to consider.

As an indication, it is generally sufficient to apply 5 to 30 g / m ² , preferably 5 to 20 g / m ² , for example 5 to 15 g / m ² of a mold release composition having, for example a viscosity less than or equal to 50 mPa.s at room temperature on a mold, for example a metal mold. The amount applied will be greater on absorbent molds, for example of wood, or for a higher viscosity formulation.

The mold release composition on the mold is generally allowed to dry. The drying time depends on the ambient conditions, but is usually 10 hours or more.

The demolding composition is effective on molds of different materials. We can thus particularly include metal molds, wood, bakelized wood or polymer.

• une bonne homogénéité de teinte ;
• une coloration plus durable ;
• une diminution des bulles visibles en surface ; et /ou
• la possibilité de conférer des propriétés hydrofugeantes.

The molded parts from molds thus treated are generally easily demolded and generally have homogeneous surface aspects. In particular, we generally find:

• a good homogeneity of hue;
• a more durable color;
• a decrease in visible bubbles on the surface; and or
• the possibility of conferring water-repellent properties.

The use of the mold release composition described thus allows access to molded parts of aesthetic appearance compatible with a demanding application, for example for uncovered facings after stripping.

The method as described above can provide a molded part, in particular wherein the hydraulic setting material is a cementitious material, including a concrete. The castings may be elements for the field of construction, for example a wall, a partition wall, a bulkhead, a ceiling, a beam, a worktop, a pillar, a bridge stack, a block, a cellular concrete block, pipe, pipe, post, staircase, panel, cornice, mold, road element (eg curb), tile, extruded concrete element and tile plaster.

In the present description, including the claims which accompany it: the percentages are expressed in mass, unless otherwise indicated.

The size and size distribution of the droplets are measured using a Malvern MS2000 laser granulometer. The measurement is carried out in the water. The light source consists of a red He-Ne laser (632 nm) and a blue diode (466 nm). The optical model is that of Mie and the calculation matrix is of the polydisperse type.

The device is checked before each use by means of a standard sample (Sifraco C10 silica), for which the particle size distribution is known.

The measurements are made with the following parameters: pump speed of 2300 rpm and stirring speed of 800 rpm. The sample is introduced to obscure between 10 and 20%. The measurement is performed after stabilization of the darkening. A measurement is made for 15 seconds (15000 images analyzed). Without emptying the cell, the measurement is repeated at least twice to check the stability of the results and the elimination of any bubbles.

The invention will be described in more detail in the following non-limiting examples.

EXAMPLES

In the examples, the products and materials used are available from the following suppliers: Product or material Provider (1) Portland cement Lafarge-France, Le Havre site (2) Sand 0/4 mm Lafarge France website St Bonnet Little Craz (3) GLENIUM® 27 Superplasticizer BASF (4) ACTICIDE® MBS Biocide THOR (5) SLOVASOL® 2411 Surfactant (HLB = 13.8) SASOL (6) DOW CORNING® 230 Fluid Silicone DOW CORNING (7) RESINOLINE E 500 ™ Oil DRT (8) LUTENSOL® TO 109 surfactant (HLB = 14.2) BASF (9) DISPONIL® FES 61 Surfactant (HLB = 42.5) BASF (10) TEGOSIVIN® HL 250 Degussa

Portland cement is a CEM I 52.5N CE CP2 NF. Adjuvant GLENIUM® 27 is a superplasticizer of the polycarboxylate type of polyalkylene oxide. ACTICIDE® MBS is a biocidal agent that comprises a mixture of methylisothiazolinone and benzyl isothiazolinone. SLOVASOL® 2411 is a surfactant which comprises a dodecyl- and tetradecyl-polyethylene glycol mixture. Dow Corning® 230 Fluid is a silicone that includes a polydimethylsiloxane. RESINOLINE E 500 ™ is a plant-based oil that includes a pentaerythritol ester of tall oil fatty acid. LUTENSOL® TO 109 is a surfactant which comprises an ethoxylated fatty alcohol with 10 ethylene oxide groups. DISPONIL® FES 61 is a surfactant comprising an alkyl ether sulfate having 50 ethylene oxide groups. Dow Corning® 230 Fluid is a hydrophobic agent based on functionalized silanes and siloxanes. TEGOSIVIN® HL 250 is a solvent-free water-based formulation based on functional silanes and siloxanes.

EXAMPLE 1 Release composition according to the invention No. 1

On the one hand, a silicone emulsion has been produced. To do this, a first aqueous solution was made by mixing 91.95 parts by mass of demineralized water relative to the mass of the silicone emulsion, 0.05 parts by weight, relative to the mass of the silicone emulsion, ACTICIDE® MBS biocidal agent and 1 part by weight, based on the weight of the silicone emulsion, of the nonionic surfactant. Ionic SLOVASOL® 2411. To the solution obtained was added little by little for 5 minutes 7 parts by weight, relative to the mass of the silicone emulsion, of Dow Corning® 230 Fluid silicone, the mixture being agitated by means of an Ultra-Turrax mixer equipped with a rotor / stator geometry dispersing tool rotating at a speed of rotation of 17,000 rpm (with two identical stirring blades S25N-18G which are referenced under the same number: MALX- 173-2006 / 08). The coarse emulsion obtained was refined in an Emulsiflex C3 model high pressure homogenizer (HHP) at a pressure of 1500 bar according to the following sequence: first pass, first cooling at a temperature below 25 ° C to reach an average temperature of emulsion less than 25 ° C, second pass and second cooling at a temperature below 25 ° C.

On the other hand, an emulsion of vegetable oil has been produced. To do this, a second solution was carried out by mixing 1.5 parts by weight, relative to the weight of the vegetable oil emulsion, demineralized water, 0.05 parts by weight, relative to the mass. of the vegetable oil emulsion, the ACTICIDE® MBS biocidal agent and 1.5 parts by weight, based on the weight of the vegetable oil emulsion, of a nonionic SLOVASOL® 2411 surfactant. second solution was agitated with a Rayneri mixer equipped with a circular blade fin beveled at a speed set by the position 4 of the variable speed drive during which are added little by little 25 parts by weight, relative to the mass of the Vegetable oil emulsion, vegetable oil RESINOLINE E 500 ™. The product obtained was diluted by adding 71.95 parts by weight, based on the mass of the vegetable oil emulsion, of demineralized water, while maintaining the stirring with a Rayneri mixer.

The demolding composition according to the invention was produced by successively mixing 38.3 parts by weight, relative to the weight of the demolding composition, of the silicone emulsion and 0.4 parts by weight relative to the mass. of the demolding composition, a solution of calcium thiocyanate salt (product sold by BALLU CHIMIE and 50% calcium thiocyanate by mass), and then adding to the assembly 61.3 parts by weight, relative to the mass of the demolding composition, the emulsion of vegetable oil. The mixture was made with magnetic stirring

The stability of the demolding composition according to the present embodiment is 10 days. Stability was observed visually leaving the mold release composition resting in a clear container. The demolding composition is considered stable until it is observed the beginning of formation of at least two distinct phases one on the other.

The formulation of the demolding composition according to the present embodiment of the invention is detailed in Table 1 below: <b><u> Table 1: Mold Release Composition of the Invention No. 1 </ u></b> Product Quantity (% by mass of raw materials per 100g of the mold release composition) DOW CORNING® Hydrophobic Agent 230 Fluid 2,681 Vegetable oil RESINOLINE E 500 ™ 15.325 SLOVASOL® 2411 Surfactant 1.3025 ACTICIDE® MBS biocidal agent 0.05 Calcium thiocyanate (expressed as dry material) 0.2 Demineralized Water 80.4417

EXAMPLE 2 Release composition according to the invention No. 2

The demolding composition according to the invention No. 2 has a formulation similar to the formulation of the demolding composition according to Example No. 1 except that the surfactant is a mixture of LUTENSOL® TO 109 and DISPONIL® FES 61 in proportions of 85/15 by total mass of surfactant and that the hydrophobic agent is the product TEGOSIVIN® HL 250. The stability of the demolding composition is 1 day at room temperature. <u><b> Table 2 </ b>: <b> Release composition according to the invention No. 2 </ b></u> Product Quantity (% by mass of raw materials per 100g of the mold release composition) Hydrophobic agent TEGOSIVIN® HL 250 1.7 Vegetable oil RESINOLINE E 500 ™ 15 LUTENSOL® TO 109 Surfactant 0.954 Surfactant DISPONIL® FES 61 0.17 ACTICIDE® MBS biocidal agent 0.05 Calcium thiocyanate (expressed as dry material) 0,125 Demineralized Water 82.011

• 81,77 parties en masse, par rapport à la masse de l'émulsion finale, d'eau déminéralisée ;
• 0,05 partie en masse, par rapport à la masse de l'émulsion de l'émulsion finale, de l'agent biocide ACTICIDE® MBS (THOR) ;
• 0,25 partie en masse, par rapport à la masse de l'émulsion de l'émulsion finale, d'une solution de sel de thiocyanate de calcium commercialisée par la société BALLU CHIMIE et à 50 % de thiocyanate de calcium en masse ;
• 0,954 partie en masse, par rapport à la masse de l'émulsion finale, du tensioactif non ionique LUTENSOL® TO 109 (BASF) ; et
• 0,17 partie en masse, par rapport à la masse de l'émulsion finale, du tensioactif DISPONIL® FES 61 (BASF).

For the manufacture of the final emulsion, a first aqueous solution was made, with stirring with Ultra-Turrax, rotating at a speed of rotation of 5000 revolutions / min, by mixing:

• 81.77 parts by weight, based on the mass of the final emulsion, of demineralized water;
• 0.05 parts by weight, based on the weight of the emulsion of the final emulsion, of the biocidal agent ACTICIDE® MBS (THOR);
• 0.25 part by weight, relative to the mass of the emulsion of the final emulsion, of a calcium thiocyanate salt solution marketed by BALLU CHIMIE and 50% of calcium thiocyanate by mass;
• 0.954 parts by weight, based on the weight of the final emulsion, of the nonionic surfactant LUTENSOL® TO 109 (BASF); and
• 0.17 parts by weight, based on the weight of the final emulsion, of the surfactant DISPONIL® FES 61 (BASF).

• 15 parties en masse, par rapport à la masse de l'émulsion de l'émulsion finale, de l'huile végétale RESINOLINE E 500™ (DRT) ; et
• 1,7 parties en masse, par rapport à la masse de l'émulsion de l'émulsion finale, du silicone TEGOSIVIN® HL 250 (DEGUSSA).

To this aqueous solution were added successively, with stirring Ultra-Turrax, rotating at a speed of 10000 rpm:

• 15 parts by weight, based on the weight of the emulsion of the final emulsion, vegetable oil RESINOLINE E 500 ™ (DRT); and
• 1.7 parts by weight, based on the weight of the emulsion of the final emulsion, of TEGOSIVIN® HL 250 (DEGUSSA) silicone.

The HLB value of the 85/15 surfactant mixture used is: $$\left(0.85\times 14.2\right)+\left(0.15\times 42.5\right)=18.5$$

The coarse emulsion obtained was refined in an Emulsiflex C3 high pressure homogenizer (HHP) at a pressure of 1500 bar according to the following sequence: first pass, first cooling at a temperature below 25 ° C, to reach an average temperature of emulsion less than 25 ° C, second pass and second cooling at a temperature below 25 ° C.

EXAMPLE 3 Comparison mold release composition

In a suitable container, 30 parts by weight of vegetable mold release oil (product marketed by CHRYSO under the name CHRYSO®Dem ECO2) were introduced and then 35 parts by weight of an aqueous solution of chloride were allowed to flow. of calcium (at 75 g / L) and 35 parts by weight of an emulsion of anti-efflorescence, water-repellent agent (product marketed by BASF under the name RHEOMIX® 791). The 3 phases were mixed with the mixer Ultra-Turrax and we got a mixture. The stability of the demoulding composition according to the present comparative example is 0.5 hours (and not several hours as indicated in Example 3 of WO2008 / 087298 ).

EXAMPLE 4

The demolding behavior of the release compositions prepared according to Examples 1 to 3 was evaluated for mortars in the following manner.

An appropriate amount (20 g / m ² ) of mold release composition was applied after being allowed to stand for 2 hours after manufacture of the mold release composition on metal molds using a cloth. After drying for about 10 hours, a mortar according to the formulation of Table 3 below was introduced into the mold. The part was then demolded after hardening of the mortar. The same test was carried out using a demolding composition after being left standing for 2 days after the manufacture of the mold release composition. <u><b> Table 3 </ b>: <b> Mortar Formulation </ b></u> components Mass [g] Cement 540 Sand 1350 Total water 297 Adjuvant (GLENIUM® 27 from BASF) in mass of dry matter compared to the mass of the cement 0.648

The effectiveness of the demolding composition was assessed in terms of ease of application, ease of demolding, surface appearance of the molded part, presence of surface defects and appearance of the mold. mold surface when the demolding composition was used 2 hours after its manufacture and 2 days after its manufacture. The results are summarized in Table 4 below.

• (+) meilleur
• (o) équivalent
• (-) Moins bon

Tableau 4 : Evaluation des compositions de démoulage Exemple 1 Exemple 2 Exemple 3 Facilité d'application : cas 2 heures (+) (+) (o) Facilité d'application : cas 2 jours (+) (o) (-) Facilité de démoulage : cas 2 heures (+) (+) (o) Facilité de démoulage : cas 2 jours (+) (o) (-) Aspect pièce : cas 2 heures (+) (+) (o) Aspect pièce : cas 2 jours (+) (o) (o) Défauts de surface : cas 2 heures (+) (+) (o) Défauts de surface : cas 2 jours (+) (o) (o) Aspect moule : cas 2 heures (+) (+) (o) Aspect moule : cas 2 jours (+) (o) (o) The results are compared with those obtained with the demolding composition according to Example 3 and evaluated as follows:

• (+) better
• (o) equivalent
• (-) Less good

<b><u> Table 4: Evaluation of release compositions </ u></b> Example 1 Example 2 Example 3 Easy to apply: 2 hours (+) (+) (O) Ease of application: 2 days case (+) (O) (-) Easy demolding: case 2 hours (+) (+) (O) Easy demolding: 2 days case (+) (O) (-) Part appearance: 2 hours case (+) (+) (O) Room aspect: 2 days case (+) (O) (O) Surface defects: case 2 hours (+) (+) (O) Surface defects: case 2 days (+) (O) (O) Mold appearance: 2 hours case (+) (+) (O) Mold appearance: 2 days case (+) (O) (O)

When the demolding composition was used 2 hours after its manufacture, it was found that the demolding composition according to Example 1 and the demolding composition according to Example 2 lead to an improvement in the surface appearance of the parts and a decrease in surface defects such as surface bubbles. Furthermore, it has been found that the pieces have a more homogeneous hue. On the other hand, the mortars made were easily removed. Finally, the appearance of the molds after demolding has been improved (less dusting).

However, when the demolding composition was used 2 days after its manufacture, there was an improvement in the parameters observed only for the demolding composition according to Example 1.

Claims (15)

1. A mold release composition for the manufacture of elements made of hydraulically setting material, comprising, in mass percent relative to the mass of the mold release composition, at least:

   - from 10% to 20% of an oil;

   - from 1% to 5% of a water-repellent agent;

   - from 0.1% to 1% of a hydrosoluble calcium salt;

   - from 0.5% to 3% of a nonionic surfactant or a mixture of surfactants having an HLB value from 8 to 20; and

   - water.
2. The mold release composition according to claim 1, wherein the oil comprises a plant oil.
3. The mold release composition according to claim 1 or 2, wherein the oil comprises a fatty acid ester.
4. The mold release composition according to any one of claims 1 to 3, comprising from 11% to 19% by mass of the oil relative to the mass of the mold release composition.
5. The mold release composition according to any one of claims 1 to 4, wherein the water-repellent agent comprises a polydimethylsiloxane or a polydimethylsiloxane derivative.
6. The mold release composition according to any one of claims 1 to 5, comprising from 1.5% to 4% by mass of the water-repellent agent relative to the mass of the mold release composition.
7. The mold release composition according to any one of claims 1 to 6, wherein the water solubility of the calcium salt is greater than 2 g/100 ml at 20°C.
8. The mold release composition according to any one of claims 1 to 7, wherein the calcium salt is calcium thiocyanate.
9. The mold release composition according to any one of claims 1 to 8, comprising from 0.2% to 0.6% by mass of the calcium salt relative to the mass of the mold release composition.
10. The mold release composition according to any one of claims 1 to 9, wherein the surfactant comprises an alkyl alkoxylated derivative, the alkyl chains of which are based on a fatty alcohol or a polypropylene or polybutylene glycol, or comprises a sugar ester.
11. The mold release composition according to any one of claims 1 to 10, wherein the surfactant comprises an ethoxylated fatty alcohol comprising an alkylated chain from 6 to 22 carbon atoms.
12. The mold release composition according to any one of claims 1 to 11, wherein the surfactant comprises an anionic surfactant.
13. The mold release composition according to any one of claims 1 to 12, comprising from 1% to 2% by mass of the surfactant relative to the mass of the mold release composition.
14. The mold release composition according to any one of claims 1 to 13, formulated as an emulsion.
15. A method for producing the mold release composition according to any one of claims 1 to 14, comprising the following steps:

    - forming a first emulsion of the water-repellent agent, the first emulsion comprising part of the surfactant;

    - forming a second emulsion of the oil, the second emulsion comprising the rest of the surfactant;

    - forming a calcium salt solution; and

    - mixing the calcium salt solution, the first emulsion and the second emulsion.