Method for producing release agent, release agent and use of release agent

Abstract

The invention relates to a method for producing a release agent (2), said method comprising at least the following steps: a) providing a reactive mixture comprising a monomer component comprising a carboxylic acid, said component comprising itaconic acid and / or itaconic acid derivatives, preferably consisting of itaconic acid and / or itaconic acid derivatives; b) polymerizing the reactive mixture to form a polymer solution, where the polymer solution comprises a polymer at least partially dissolved in a solvent and containing the carboxylic acid-containing monomer component, c) obtaining a release agent (2) comprising the polymer solution, preferably, CO2 can be released in the polymer of the release agent through decarboxylation; and to a release agent (2) and to the use of a release agent (2).

Description

Technical Field

[0001] The present invention relates to a method for producing an improved mold release agent, an improved mold release agent and the use of the mold release agent. Background Art

[0002] Mineral building material mixtures, for example, which contain concrete, mortar and / or sand-lime bricks, are used, for example, in the manufacture of buildings, in the construction of tunnels, bridges and retaining walls or foundations or in the construction of individual walls, ceilings, columns or ring beams, and in the production of furniture or works of art.

[0003] For this purpose, a flowable or plastic mineral building material mixture is introduced into a mold element, preferably a formwork, which predefines the shape of the mineral molded body to be obtained therefrom. The mold element, preferably the formwork, is usually removed again after curing and / or hardening.

[0004] In order to achieve a non-destructive separation between the building material mixture and the mould element, preferably the formwork, a release agent can be arranged on at least one surface of the mould element, preferably on at least one surface of the formwork, before the mould element is brought into contact with the flowable or plastic building material mixture, for example fresh concrete. Due to the release agent, the adhesion between the building material mixture and the mould element, preferably the formwork, is reduced and damage to the mineral moulded body and to the at least one surface of the mould element, preferably the formwork, is prevented.

[0005] The at least one surface of the mould element, preferably the formwork, can be designed to be absorbent and / or non-absorbent, or provided as such. The at least one absorbent surface of the mould element, preferably the formwork, can be based on a biogenic material, in particular wood. Further, the at least one surface, in particular the absorbent surface, can be provided in a roughened manner, in particular rough chiseled, planed, flame-treated and / or sandblasted.

[0006] Alternatively, the at least one non-absorbent surface of the mold element, preferably the formwork, can be based on metal, in particular on steel, hardened and tempered wood, plastic, in particular hardened and tempered plastic, and / or formwork matting. Furthermore, the at least one surface, in particular the non-absorbent surface, can be heated or unheated, and / or coated and / or coated with plastic and / or rubber, or a combination thereof.

[0007] Different mold release agents are known from the prior art. These can be present, for example, in the form of water-insoluble template oils, template slurries, template waxes, chemically reactive mold release agents or mold release agent emulsions. Mold release agents usually contain at least one oil component. Oil components are various substance types or mixtures thereof. These substance types can, for example, contain mineral oils, waxes or fats and their derivatives. Relative to the weight of the mold release agent previously arranged on the mold element, preferably on the template, the oil component usually forms the largest proportion here.

[0008] Release agents in the form of aqueous emulsions usually contain, in addition to the oil component, an emulsifier, such as an ionic surfactant and / or a nonionic surfactant, which distributes the oil component in the form of droplets in the aqueous solvent.

[0009] The mold release agents known in the prior art have various disadvantages. For example, the mineral oil as the oil component is not biodegradable enough. In addition, mold release agents containing at least one oil component or an emulsifier are usually classified as being harmful to water and therefore have low environmental compatibility.

[0010] Furthermore, saponification of oil components or emulsifiers by alkaline components of the mineral building material mixture can lead to undesired precipitation of calcium soaps. This in turn leads to a failure of the setting and organization of the mineral building material mixture and to an error mode known as sanding. Sanding causes adhesion problems when the mineral building material mixture is further processed, for example in the adhesion of paints or plasters.

[0011] Furthermore, in the case of release agents in the form of aqueous emulsions, the emulsifiers used can cause re-emulsification at the interface with the alkaline mineral building material mixture. In this case, the release agent at least partially penetrates into the surface formed by the mineral building material mixture. The penetrated release agent can cause adhesion problems of the paint or plaster during subsequent further processing.

[0012] In the case of release agents with at least one oil component, more effort is required to clean the mineral molded body or the mold elements, preferably the mold plates, after demolding. This is because they can only be removed without residue with difficulty using water. In addition, the oil components of the release agent can discolor the surface of the mineral molded body and thus affect or impair the visual appearance in an undesirable manner. Summary of the invention

[0013] It is now an object of the present invention to provide a method for producing an improved release agent, an improved release agent and the use of the improved release agent, wherein the release agent has good environmental compatibility and good release properties.

[0014] This object is achieved by a method for producing a release agent, in particular according to one of claims 1 to 35, wherein the method comprises at least the following steps, wherein the steps are performed in particular in the specified order:

[0015] a) providing a reactive mixture comprising a carboxylic acid-containing monomer component, said component comprising, preferably consisting of, itaconic acid and / or itaconic acid derivatives,

[0016] b) polymerizing the reactive mixture to form a polymer solution, wherein the polymer solution comprises a polymer at least partially dissolved in a solvent and containing the carboxylic acid-containing monomer component,

[0017] c) obtaining a release agent comprising the polymer solution, wherein CO can be released from the release agent, preferably the polymer of the release agent, by decarboxylation 2 .

[0018] The object is further achieved by a release agent, preferably according to claim 36, wherein the release agent, in particular a release agent produced according to a process according to any of the preceding claims 1 to 35, contains a polymer at least partially dissolved in a solvent, wherein the polymer contains a carboxylic acid-containing monomer component which comprises itaconic acid and / or itaconic acid derivatives, and wherein CO can be released from the release agent, preferably the polymer of the release agent, by decarboxylation. 2 .

[0019] The object is further achieved by the use of a release agent, in particular a release agent prepared according to one of claims 1 to 35, for the production of a mineral molded body, in particular by claim 37, wherein the release agent is arranged on at least one surface of a mold element, preferably on at least one surface of a formwork, and is brought into contact with a flowable or plastically deformable mineral building material mixture, wherein the mineral building material mixture contains water and at least one mineral binder, and wherein CO can be released from the release agent, preferably a polymer of the release agent, by decarboxylation. 2 .

[0020] Furthermore, a method for producing a mineral molded body can be provided, wherein a release agent produced according to one of claims 1 to 35 is arranged on at least one surface of a mold element, preferably on at least one surface of a formwork, so that it comes into contact with the mineral building material mixture.

[0021] The process according to the invention makes it possible to provide a release agent containing at least partially dissolved polymers. However, the release agent according to the invention does not require additional emulsifiers or oil components. By omitting these emulsifiers or oil components in the release agent according to the invention, the disadvantages that the release agent may have, which have already been mentioned above, are avoided. In addition, any disposal costs that may be incurred are thereby reduced.

[0022] A further advantage is that, unlike the release agents known from the prior art, the polymer which is at least partially dissolved in the release agent according to the invention can be produced on the basis of biological raw materials. In other words, the amount of petroleum-based monomers can be reduced. Thus, for example, itaconic acid used as a monomer can be obtained biotechnologically by fermentation of molasses, or synthesized from pyruvic acid. This results in a more sustainable product. Due to the availability of the raw materials, a release agent comprising the polymer can also be produced cost-effectively.

[0023] The polymer contained in the release agent contains at least itaconic acid and / or itaconic acid derivatives. Due to the application of the release agent, for example by spraying, brushing or rolling, a layer is formed on the at least one surface of the mold element, preferably on the at least one surface of the template. The molecular structure of the polymer can be changed due to the preferably ion-catalyzed decarboxylation. Alternatively or additionally, the decarboxylation of the polymer can be thermally initiated. Decarboxylation refers to the addition of carbon dioxide (CO 2 ) dissociation. In particular, CO is dissociated from itaconic acid contained in the polymer 2 , in particular forming lactones and / or dissociating carboxylic acids.

[0024] In the following reaction equation (1), the decarboxylation of polyitaconic acid (left) and the resulting CO 2 Possible reaction pathways for release (right). Through this reaction, possible products (right) have closed rings within the molecule:

[0025]

[0026] The release agent according to the invention prevents an interaction between the mineral building material mixture and the mold element, preferably the formwork. Furthermore, the release agent leaves no or only a small amount of residue on the surface of the mold element, preferably on the surface of the formwork or on the mineral molded body after demolding. Any residues on the surface can be removed using only water (thus without using surfactants, solvents or chemical cleaning agents) and a common rag.

[0027] Further advantageous embodiments of the invention are described in the dependent claims.

[0028] In step a), a reactive mixture containing a carboxylic acid-containing monomer component is provided. The carboxylic acid-containing monomer component comprises itaconic acid and / or itaconic acid derivatives and / or consists of itaconic acid and / or itaconic acid derivatives. Step a) is carried out at the beginning of the process. The composition of the components of the reactive mixture is selected so that the sum of the components gives 100 Gew.-% (Gew.-%=weight percentage) relative to the total weight of the reactive materials.

[0029] The carboxylic acid-containing monomer component of the reactive mixture preferably contains and / or is provided together with itaconic acid and / or itaconic acid derivatives at least one further carboxylic acid-containing monomer component which is selected from acrylic acid, methacrylic acid and maleic acid, either alone or in combination.

[0030] Preferred itaconic acid derivatives of the carboxylic acid-containing monomer component are itaconic acid anhydride, itaconic acid methoxy ester and / or itaconic acid ethoxy ester. The itaconic acid derivative of the carboxylic acid-containing monomer component is preferably derivatized to the maximum extent on the carboxylic acid and is present, for example, as itaconic acid monoester.

[0031] It is possible that the proportion of the monomers of the carboxylic acid-containing monomer component, based on the total mass of the reactive mixture, has been selected and / or is selected from a range of 10 to 60% by weight, preferably 20 to 50% by weight, further preferably 30 to 40% by weight.

[0032] "Carboxylic acid-containing" preferably means the presence of molecules, such as monomers, which contain at least one functional unit of the -COOH type.

[0033] "Carboxylic acid-free" preferably means that molecules, such as monomers, are present which do not contain functional units of the -COOH type. This definition therefore also includes, for example, carboxylic acid esters and carboxylic acid derivatives in addition to unsaturated hydrocarbons and / or unsaturated aromatics.

[0034] "Soluble" preferably means that a salt or a molecule, such as a monomer or a polymer, has a solubility of at least 60 g / l in the solvent present in the equilibrium state under standard atmospheric conditions. If the molecule has a lower solubility in standard atmospheric conditions in the equilibrium state, it is understood to be "insoluble". A salt or a molecule, such as a monomer or a polymer, may be "water-soluble" if the solubility is based on a solvent in the form of water. "Water-soluble" therefore preferably means that a salt or a molecule, such as a monomer or a polymer, has a solubility of at least 60 g / l in water in the equilibrium state under standard atmospheric conditions. If a molecule has a lower water solubility in standard atmospheric conditions in the equilibrium state, it is understood to be "water-insoluble". Standard atmospheric conditions refer to a temperature of 20° C. and an air pressure of 1 bar.

[0035] The reactive mixture may contain at least one carboxylic acid-free monomer component or be provided with it. Carboxylic acid-free monomer components are preferably selected from acrylamide and derivatives thereof, acrylic acid esters, methacrylic acid esters, itaconic acid esters, maleic acid esters, maleic anhydride, terpenes, preferably myrcene, styrene, isoprene, butadiene, vinyl ether and / or combinations thereof, alone or in combination. Carboxylic acid-free monomer components are preferably selected from acrylamide and derivatives thereof, acrylic acid esters, methacrylic acid esters, itaconic acid esters, terpenes or combinations thereof. Carboxylic acid-free monomer components are further preferably selected from acrylamide and derivatives thereof, itaconic acid esters, terpenes or combinations thereof.

[0036] The proportion of the monomers of the carboxylic acid-free monomer component, relative to the total mass of the reactive mixture, is preferably already selected and / or is selected from a range of greater than 0% to 30% by weight, preferably greater than 0% to 20% by weight, further preferably greater than 0% to 15% by weight.

[0037] It is possible for the carboxylic acid-free monomer component to comprise at least 80% by weight, preferably 100% by weight, of water-soluble monomers.

[0038] The carboxylic acid-containing monomer component and / or the carboxylic acid-free monomer component and / or the polymer and / or the release agent may contain and / or consist of bio-derived components and / or may be provided together with bio-derived components.

[0039] The carboxylic acid-containing monomer component and / or the carboxylic acid-free monomer component and / or the polymer and / or the release agent are preferably biodegradable. The carboxylic acid-containing monomer component and / or the carboxylic acid-free monomer component and / or the polymer and / or the release agent may be compostable.

[0040] "Biodegradable" means that chemical compounds or organic materials, for example carboxylic acid-containing monomer components and / or carboxylic acid-free monomer components and / or polymers and / or release agents, are broken down by microorganisms, for example fungi and / or bacteria in the presence of oxygen into carbon dioxide, water and salts of other elements present (mineralization) and in particular biomass, or in the absence of oxygen into carbon dioxide, methane, mineral salts and in particular biomass.

[0041] “Compostable” means in particular that the carboxylic acid-containing monomer components and / or carboxylic acid-free monomer components and / or polymers and / or release agents degrade in the composting process into carbon dioxide, water, salts of other elements present and in particular biomass at a rate that is compatible with other known compostable materials in the composting process, and in particular, apart from the biomass, no visible, recognizable and / or toxic residues are left. In particular, the carboxylic acid-containing monomer component and / or the carboxylic acid-free monomer component and / or the polymer and / or the release agent meets the requirements of DIN EN 13432:2000-12 (Date of Publication: 12.2000, "Verpackung-Anforderungen an die Verwertung von Verpackungen durch Kompostierung und biologischen Abbau-Prüfschema und Bewertungskriterien fürdie Einstufung von Verpackungen; Deutsche Fassung EN 13432:2000" (Packaging - Requirements for recycling packaging by composting and biodegradation - Test scheme and evaluation criteria for final acceptance of packaging, German version of EN 13432:2000) and / or the Australian Standard AS 4736:2006 (Date of Publication: 2006, "Biodegradable plastics - Biodegradable plastics suitable for composting and other microbialtreatment” (biodegradable plastics - biodegradable plastics suitable for composting and other microbial treatment) and / or the American standard ASTM D6400 (issue date: 05.1999, "Standard Specification for Compostable Plastic" and / or the ISO standard ISO17088:2008 (issue date: 06.2012, "Festlegungen für kompostierbare Kunststoffe" (Standard Specification for Compostable Plastics)).

[0042] The standards mentioned include chemical tests and disclosure of all ingredients. In particular, the release agent, preferably a polymer, meets the respective heavy metal thresholds. For the release agent, preferably a polymer, it can also be verified that at least 90% by weight of the organic material is converted into CO within 180 days. 2(or at least 60% by weight according to ASTM D6400). Furthermore, it is possible that after composting for 12 weeks under industrial and / or semi-industrial composting conditions and subsequent sieving through a sieve with a mesh size of 2 mm, the release agent, preferably not more than 10% by weight of dry material of the polymer, relative to the original weighed-in weight, remains. In particular, no negative impact should be exerted on the composting process. Finally, an ecotoxicity analysis is preferably carried out, wherein for a positive result, the produced compost should not have a significantly negative impact on plant growth compared to other composts (agronomic tests).

[0043] The reactive mixture may contain or be provided with a solvent, preferably an organic solvent, selected from ethanol, 1-propanol, 2-propanol, acetone, 2-butanone (MEK), acetates, in particular ethyl acetate and lactoacetate, alone or as a mixture. The organic solvent is miscible with water under standard atmospheric conditions, preferably miscible with water in a ratio of 1:1.

[0044] Alternatively or additionally, the reactive mixture may contain and / or be provided with a solvent comprising water and / or consisting of water. The solvent of the reactive mixture is preferably water.

[0045] The reactive mixture may have and / or be provided with a pH value selected from the range of 3 to 14, preferably 5 to 12, and further preferably 6 to 9. By means of the above pH value, the solubility of the monomer and / or polymer in the solvent is increased and polymerization is promoted. The reactive mixture may contain a dissolved hydroxide of an alkali metal of the first main group of the periodic table, preferably NaOH and / or KOH.

[0046] It is possible that the proportion of the solvent, based on the total mass of the reactive mixture, is already selected and / or is selected from a range of 10 to 90% by weight, preferably 30 to 80% by weight, further preferably 40 to 60% by weight.

[0047] The solvent refers to the medium in which the other ingredients of the reactive mixture, the polymer solution and / or the release agent are diluted. Preferably, the solvent is not consumed during the reaction of the ingredients of the reactive mixture to form the polymer of the polymer solution. The solvent preferably has a boiling point of at most 200° C. An organic solvent refers to a solvent having at least one carbon atom in its molecular structure.

[0048] The reactive mixture preferably contains and / or is provided together with an initiator, preferably an initiator for free-radical polymerization.

[0049] It is possible that the proportion of the initiator, based on the total mass of the reactive mixture, is already selected and / or is selected from a range of 0.05 to 2.5% by weight, preferably 0.1 to 1.5% by weight, further preferably 0.5 to 1.2% by weight.

[0050] The initiator is preferably already selected from or is selected from azo compounds, peroxides or mixtures thereof.

[0051] Additives are understood to be components which are added in order to have a defined effect and / or to provide properties, for example, to a mixture, a material and / or a solution, wherein the proportion of additives is 1.5% by weight or less, in each case relative to the total weight of the mixture, material or solution. Initiators, solvents, carboxylic acid-containing monomer components and / or carboxylic acid-free monomer components and / or polymers obtained therefrom are not to be understood as additives.

[0052] By using additives, the processability of the reactive mixture, polymer and / or release agent can be improved. In addition, the resistance of the release agent or the layer obtained therefrom to mechanical and chemical influences is thereby increased.

[0053] A reactive mixture suitable for the process according to the invention preferably has and / or is provided with the following composition, wherein the details about the individual components are in each case relative to the total mass of the reactive mixture and wherein the components are selected such that they give a total of 100% by weight:

[0054] Carboxylic acid-containing monomer component: 10 wt% - 60 wt%,

[0055] Monomer components not containing carboxylic acid: 0 wt% - 30 wt%,

[0056] Solvent: 10 wt% - 90 wt%,

[0057] Initiator: 0.05 wt% - 2.5 wt%,

[0058] Further preferably:

[0059] Carboxylic acid-containing monomer component: 20 wt% -50 wt%,

[0060] Monomer components not containing carboxylic acid: 0 wt% - 20 wt%,

[0061] Solvent: 30 wt% - 80 wt%,

[0062] Initiator: 0.1 wt% - 1.5 wt%,

[0063] Still more preferably:

[0064] Carboxylic acid-containing monomer component: 30 wt% -40 wt%,

[0065] Monomer components not containing carboxylic acid: 0 wt% - 15 wt%,

[0066] Solvent: 40 wt% - 60 wt%,

[0067] Initiator: 0.5 wt% - 1.2 wt%.

[0068] In step b), a polymer solution is obtained from the reactive mixture provided in step a). The polymer solution comprises a polymer containing at least a carboxylic acid-containing monomer component, in particular a monomer component of the reactive mixture provided in step a). The polymer contains at least itaconic acid and / or itaconic acid derivatives as monomer units, in particular as carboxylic acid-containing monomer units. In addition, the polymer solution contains a solvent. The polymer is at least partially dissolved in a solvent preferably in the form of water. The polymer may be dissolved in a solvent preferably in the form of water in a content of at least 30 g / l, preferably at least 60 g / l, in a solvent preferably in the form of water under standard atmospheric conditions in a state of equilibrium. Step b) is preferably carried out after step a).

[0069] Step b) may be carried out at a temperature of the reactive mixture selected from the range of 20°C to 110°C, preferably 40°C and 85°C, further preferably 50°C to 70°C.

[0070] In step b), the solvent of the reactive mixture can be separated after obtaining the polymer, for example selected from filtration, suction, evaporation, vacuum drying, exposure to infrared radiation or cryo separation or a combination thereof. Further, the polymer can then be added to another solvent. In other words, the solvent of the reactive mixture can be a solvent different from the solvent of the polymer solution.

[0071] The solvent of the polymer solution preferably comprises water and / or consists essentially of water. In particular, the polymer is water-soluble.

[0072] The polymer, in particular before decarboxylation, may contain a carboxylic acid-containing monomer component selected from the range of 25 wt % to 99.95 wt %, preferably 40 wt % to 99.95 wt %, more preferably 55 wt % to 99.95 wt %, preferably itaconic acid and / or itaconic acid derivatives, more preferably itaconic acid. The carboxylic acid-containing monomer component preferably consists of itaconic acid and / or itaconic acid derivatives, preferably itaconic acid.

[0073] The polymer, in particular before decarboxylation, may contain a carboxylic acid-free monomer component selected from the range of greater than 0% to 75% by weight, preferably 0% to 60% by weight, and further preferably 0% to 45% by weight.

[0074] In particular, the polymer, in particular before decarboxylation, contains an initiator selected from the range of 0.05 to 2% by weight, preferably 0.1 to 1.5% by weight, further preferably 0.5 to 1.1% by weight.

[0075] The polymer, in particular before decarboxylation, preferably has a number average molar mass value selected from the range of 500 g / mol to 500,000 g / mol, preferably 750 g / mol to 100,000 g / mol, further preferably 1000 g / mol to 50,000 g / mol, still further preferably 1500 g / mol to 20,000 g / mol.

[0076] The carboxylic acid-containing monomer component contained in the polymer may contain at least one other carboxylic acid-containing monomer component in addition to itaconic acid and / or itaconic acid derivatives, which is selected from acrylic acid, methacrylic acid, maleic acid alone or in combination. The proportion of the carboxylic acid-containing monomer component, in particular itaconic acid and / or itaconic acid derivatives in the polymer is selected from the range of 2.5% by weight to 100% by weight, preferably 5% by weight to 80% by weight, further preferably 10% by weight to 50% by weight, in particular before decarboxylation, based on the total mass of the polymer.

[0077] The polymer preferably contains at least one carboxylic acid-free monomer component, whose components or derivatives are selected, alone or in combination, from acrylamide, acrylic acid esters, methacrylic acid esters, itaconic acid esters, maleic acid esters, maleic anhydride, terpenes, myrcene, styrene, isoprene, butadiene, vinyl ethers. The proportion of the carboxylic acid-free monomer component relative to the total mass of the polymer is preferably selected from the range of more than 0% by weight to 97.5% by weight, preferably 5% by weight to 90% by weight, further preferably 15% by weight to 85% by weight, in particular before decarboxylation.

[0078] The polymer, in particular before decarboxylation, may have a glass transition temperature value selected from the range of -20°C to 110°C, preferably -20°C to 50°C, further preferably -10°C to 25°C.

[0079] In step c), a release agent is obtained. The release agent comprises a polymer solution, which contains the polymer obtained in step b). Before its use, thus before it is arranged as a layer on at least one surface of a mold element, preferably on at least one surface of a template, the release agent, preferably the polymer, is preferably present in a state in which decarboxylation has not yet been completed and which is at least partially decarboxylable. In particular, CO is released from the polymer of the release agent during or after use of the release agent. 2 . CO is removed from the polymer by decarboxylation. 2 The amount of polymer released depends on the polymer structure. CO can be released at least partially from the carboxylic acid-containing monomer component, preferably itaconic acid and / or itaconic acid derivatives, by decarboxylation. 2 In this case, the polymer chain length and / or the polymer mass can be reduced.

[0080] The release agent preferably releases CO after and / or during contact with the mineral building material mixture. 2 The release agent further preferably releases CO during at least partial curing and / or hardening of the contacted mineral building material mixture. 2 The building material mixture is in particular flowable or plastically deformable. Furthermore, the building material mixture contains water and at least one mineral binder. Alternatively or additionally, the release agent, preferably a polymer, can also release CO after being arranged on at least one surface of the mold element, preferably the formwork, preferably before it comes into contact with the mineral building material mixture. 2 and / or decarboxylation.

[0081] The decarboxylation of the release agent, in particular the polymer, is preferably initiated by contacting the release agent with the flowable or plastically deformable mineral building material mixture.

[0082] Alternatively or additionally, the release agent can be brought into contact with a volume of a liquid containing the above-mentioned anions and / or cations and being alkaline, preferably by spraying and / or pouring.

[0083] It is possible that, in particular, the released CO 2 A first possible mode of action is the contact of the mineral building material mixture with the surface of the mould element (preferably a formwork) on which the release agent is arranged by CO 2 A porous matrix of a mineral moulding is produced.

[0084] Furthermore, the chain length and / or the mass of the polymer can be reduced by decarboxylation of the polymer. Thus, in particular the water-soluble fraction of the polymer can be diffused into the mineral building material mixture. The water-soluble fraction of the polymer can preferably promote the creation of a porous matrix in the mineral molding.

[0085] The porous matrix of the resulting mineral molded body has a lower strength than the standard strength of the mineral building material mixture. This reduces the adhesion between the formwork and the concrete, as a result of which the mineral molded body can be easily demoulded. Different concrete strength grades can be assigned a standard strength or a compressive strength, whereby different strength grades are obtained as required and, accordingly, different compressive strengths are obtained.

[0086] Alternatively or additionally, it is possible to use, in particular, as the released CO 2 The second mode of action of CO 2 At the surface of the mineral building material mixture, carbonic acid is formed. Carbonic acid can react in particular with Ca(OH) present in the liquid volume dissolved in the pores of the mineral building material mixture. 2 Reaction, wherein calcium carbonate precipitates. The above reaction is preferably referred to as carbonation.

[0087] The above-mentioned, especially the second mode of action, can be described by the sub-steps shown in equations (2), (3) and (4). These sub-steps are combined in equation (5):

[0088]

[0089] The volume of calcium hydroxide is greater than that of calcium carbonate, in particular an increase in volume of 11% can result. As a result, the pore volume of the mineral building material mixture can be reduced. In addition, an interface between the surfaces of the mold elements (preferably the formwork) can be obtained that has a more uniform and / or smoother surface than the mineral building material mixture before carbonation. In other words, a kind of rock skin is formed. Preferably, the contact surface area between the mineral building material mixture and the surface of the mold element (preferably the formwork) can be reduced, which improves the separation of the mold element, preferably the formwork, from the mineral molded body.

[0090] The mechanism of action of the release agent is therefore based in particular on the release of CO 2 .CO 2 As described above, a porous matrix can be produced in the mineral building material mixture on the surface of the mineral building material mixture facing the mould element, and / or the pore volume can be reduced and a smoother interface can be produced. The mould release agent preferably leaves no residues on the surface of the mould element, preferably on the surface of the moulding. If residues remain, these can be removed mechanically with water and a conventional rag. It is possible that CO released during the production of the mineral moulding is present. 2 All described modes of action of, and / or preferably one of the modes of action is present. For example, a porous matrix can be obtained on the side facing the smoother interface of the mold element, preferably the template, thereby achieving a particularly good demoulding effect.

[0091] In particular, the flowable or plastically deformable building material mixture contains at least one component which catalyzes a decarboxylation. The decarboxylation is preferably ionically catalyzed, in particular alkaline catalyzed. The decarboxylation may be thermally catalyzed.

[0092] The flowable or plastically deformable building material mixture preferably contains divalent or polyvalent cations of at least one metal, wherein the at least one metal is preferably selected from Mg, Ca, Sr, Ba, Al, Fe, Co or mixtures thereof. The cations are preferably present in the form of water-soluble salts.

[0093] The present inventors have surprisingly found that in the presence of divalent or higher valent cations, decarboxylation and CO 2The release of the polymer can be carried out particularly well. Divalent or polyvalent cations can preferably catalyze the decarboxylation of the polymer, preferably itaconic acid and / or itaconic acid derivatives. The presence of alkali metals of the first main group of the periodic table, such as sodium or potassium, and other monovalent ions such as ammonium, for example in alkaline solutions, has no significant effect on the decarboxylation. The corresponding itaconates can be formed which have a higher water solubility than itaconic acid. In other words, the release agent is stable to alkali metals of the first main group of the periodic table, since these do not trigger decarboxylation.

[0094] “Alkaline” preferably means that the flowable or plastically deformable mineral building material mixture and / or solution has a pH value selected from the range of 8 to 14, preferably 10 to 14, further preferably 12 to 14.

[0095] The mineral building material mixture preferably comprises concrete, mortar, lime sand brick, silicate ceramic or a combination thereof, or consists thereof. The at least one mineral binder preferably comprises a hydraulic binder, a non-hydraulic binder or a mixture thereof. In addition, the at least one mineral binder can be selected from hydrated calcium silicate, cement, lime, clay (Ton), gypsum, clay (Lehm), magnesium oxide binder and a combination thereof.

[0096] A method for producing a mineral molded body which can use a release agent comprises at least the following sub-steps, which are carried out in particular in the specified order:

[0097] i) providing at least one mould element, preferably a mould plate, on at least one surface of which a mould release agent according to the invention and / or a mould release agent obtained in step c) by the process according to the invention is arranged in the form of a layer,

[0098] ii) applying a flowable or plastically deformable mineral building material mixture comprising water and at least one mineral binder to the at least one surface of the mould element (preferably the formwork) coated with a release agent,

[0099] iii) at least partially curing the mineral building material mixture to obtain a dimensionally stable mineral green body, and hardening the mineral building material mixture, preferably the dimensionally stable mineral green body,

[0100] iv) Removing the mould element, preferably the shuttering, from the mineral building material mixture and obtaining a mineral moulded body.

[0101] The release agent preferably dissociates CO from the polymer structure after step i), in step ii) and / or in step iii). 2 .

[0102] The release agent is preferably applied to the at least one surface of the mould element, preferably to the at least one surface of the formwork, by a method selected from the group consisting of spraying, brushing or rolling or a combination thereof. The release agent is preferably applied to the at least one surface of the mould element, preferably to the at least one surface of the formwork, in full surface form. The release agent is preferably applied to all surfaces of the mould element, preferably to the at least one surface of the formwork, which are in contact with the mineral building material mixture.

[0103] The amount of release agent applied relative to the non-absorbent template is preferably selected from 50 g / m 2 Up to 400g / m 2 , preferably 100g / m 2 Up to 250g / m 2 , further preferably 125g / m 2 Up to 175g / m 2 range.

[0104] The release agent can act as a release agent in the form of a layer, i.e., has a release effect, regardless of the water content of the release agent. In other words, decarboxylation of the release agent (preferably a polymer) can be achieved regardless of the water content of the release agent, and / or CO can be released from the release agent (preferably a polymer) regardless of the water content. 2 The release agent is therefore effective both in the dry state and in the wet state.

[0105] The dry state refers to a dry layer, preferably after placement, which preferably contains components with a boiling point below 110° C. in a proportion selected from the range of 0% to 10% by weight, preferably 0% to 8% by weight, further preferably 0% to 5% by weight, relative to the total mass of the components of the layer. Drying is preferably carried out until the components of the layer have a constant mass. The wet state refers to the release agent before use, preferably as provided in step c), wherein the release agent contains a polymer solution.

[0106] The release agent preferably contains or is provided with an indicator, whereby the release agent has a different color impression in the dry state than in the moist state.

[0107] The release agent before use, which contains a polymer solution, therefore has a different color impression compared to the dry layer. For example, it is possible that the indicator has a color impression in the wet state of the release agent and the indicator is colorless in the dry state of the release agent. Thus, in the dry state, the indicator is preferably not discernible to an observer.

[0108] Suitable indicators are preferably selected from one or more leuco dyes.

[0109] The indicator provides the advantage that when the layer is arranged on the at least one surface of the mold element, preferably on the at least one surface of the mold plate, it can be recognized where the release agent has been applied. This allows a particularly uniform application.

[0110] The release agent may contain and / or be provided with a leveling additive, preferably selected from the range of more than 0% to 10% by weight, further preferably more than 0% to 7.5% by weight, still further preferably more than 0% to 5.5% by weight, in each case relative to the total weight of the release agent. Leveling additives enable the formation of uniform films and layers.

[0111] The total weight of the release agent refers to the wet state and / or the total weight of the release agent obtained in step c) before its use.

[0112] The release agent may also contain and / or be provided with a thickener, preferably selected from the range of more than 0% by weight to 2% by weight, further preferably more than 0% by weight to 1.5% by weight, still further preferably more than 0% by weight to 1.2% by weight, in each case relative to the total weight of the release agent. The thickener enables a uniform layer thickness of the layer to be achieved even on vertical surfaces.

[0113] The release agent from step c) contains the polymer solution from step b). The release agent preferably comprises the polymer solution selected from the range of 0.01% to 100% by weight, preferably 0.01% to 50% by weight, further preferably 0.01% to 20% by weight, and / or is provided as such, in each case relative to the total weight of the release agent.

[0114] The release agent from step c) contains in particular the polymer solution from step b). In a preferred embodiment, the polymer solution preferably comprises a polymer selected from the range of 0.005% by weight to 50% by weight, preferably 0.005% by weight to 25% by weight, further preferably 0.005% by weight to 10% by weight, and / or is provided as such, in each case relative to the total weight of the release agent.

[0115] The solvent of the mold release agent preferably comprises water and / or consists essentially of water.

[0116] The release agent preferably contains and / or is provided with a solvent, preferably in the form of water, selected from the range of more than 0% to 99.99% by weight, preferably 50% to 99.99% by weight, further preferably 80% to 99.99% by weight, in each case relative to the total weight of the release agent.

[0117] The release agent according to the invention preferably has and / or is provided with the following composition, wherein the data on the individual components are in each case relative to the total weight of the release agent and / or are provided, and wherein the components are selected so that they give a total of 100% by weight:

[0118] Polymer solution: 0.01 wt% - 100 wt%,

[0119] Solvent: 0 wt% - 99.99 wt%,

[0120] Leveling additive: 0 wt% -10 wt%,

[0121] Thickener: 0 wt% - 2 wt%,

[0122] Further preferably:

[0123] Polymer solution: 0.01 wt% - 50 wt%,

[0124] Solvent: 50 wt% - 99.99 wt%,

[0125] Leveling additive: 0 wt% -7.5 wt%,

[0126] Thickener: 0 wt% -1.5 wt%,

[0127] Still more preferably:

[0128] Polymer solution: 0.01 wt% - 20 wt%,

[0129] Solvent: 80 wt% - 99.99 wt%,

[0130] Leveling additive: 0 wt% -5.5 wt%,

[0131] Thickener: 0 wt% - 1.2 wt%.

[0132] The dynamic viscosity is already and / or preferably selected from the range of 1 mPas to 300 Pas, preferably 2 mPas to 200 mPas, further preferably 3 mPas to 150 mPas, still further preferably 3 mPas to 100 mPas.

[0133] In particular, in the case of arrangement on a vertical surface, the dynamic viscosity of the release agent is selected from the range of 50 mPas to 300 mPas, preferably 75 mPas to 200 mPas, further preferably 100 mPas to 150 mPas.

[0134] In particular, when applied to a horizontal surface, the dynamic viscosity of the release agent is selected from the range of 1 mPas to 300 mPas, preferably 2 mPas to 200 mPas, and more preferably 3 mPas to 100 mPas.

[0135] The dynamic viscosity is preferably in each case determined in accordance with DIN EN ISO 2884-1:2006-09 (date of publication: 2006-09, "Beschichtungsstoffe-Bestimmung der mit Rotationsviskosimetern-Teil 1:Kegel-Platte-Viskosimeter bei hohem The viscosity determination method using a rotational viscometer as described in (ISO 2884-1: 1999); Deutsche Fassung EN ISO 2884-1: 2006) (Coatings - Determination of viscosity using a rotational viscometer - Part 1: Cone and plate viscometer at high shear rates (ISO 2884-1: 1999); German version of EN ISO 2884-1: 2006), in particular using a cone and plate viscometer with cone and plate measuring geometry from ThermoScientific, Haake Mars 60 model.

[0136] The cone and plate viscometer is a measuring device for determining viscosity, in particular dynamic viscosity, and consists essentially of a measuring head and a fixed support for the medium to be measured. In addition, an upper temperature control module and a measuring shaft for receiving a rotor are located in the measuring head, wherein the rotor is shaped to receive different cone plates. A cone plate is essentially a circular measuring plate, which is provided with a small tip in its center. The cone diameter is typically 24 mm and the cone angle is 0.5° (+ / -2'), in particular from the tip to the measuring plate. In addition, a lower temperature control module is located in the fixed support. The upper and lower temperature control modules ensure that the rotor has the same temperature as the medium to be measured. The medium to be measured is introduced into the fixed support. The fixed support can have a plate. The cone plate rests on the medium, forms a certain gap size, and can therefore move freely in the medium. The gap size refers to the distance from the tip of the cone plate to the lower fixed support. The cone and plate viscometer is operated with an electric motor, which drives the cone plate at a constant number of revolutions so that its tip contacts a rigid, temperature-controlled plate. The torque can be measured mechanically or electronically. Cone and plate viscometers are usually used for routine viscosity measurements at high shear rates. The device is designed so that the unit consisting of cone, plate and electric motor can be easily raised, first when the test liquid is placed on the plate and later in order to enable thorough cleaning after each measurement. When a liquid is used, preferably the medium to be measured, it only fills the small gap between plate and cone. The cone and plate viscometer is preferably operated at a speed of 750 rpm (+ / - 10 rpm) in the viscosity range of 0 Pas to 1 Pas. Here, the medium to be measured is preferably at 9000 s -1 Up to 12,000s-1 Specifically, the above data show that 9000s -1 The shear rate must be the same when comparing the viscosities of coatings. Unless otherwise agreed, the determination must be carried out in particular at (23±0.2)° C. The values ​​obtained provide information on the resistance of substances (especially release agents) when applied by painting, spraying and rolling.

[0137] After the at least partial solidification and / or hardening of the mineral molded body, the surface of the mineral molded body in contact with the release agent is preferably designed so that the surface area of ​​shrinkage pores is less than 5%, preferably less than 3%, particularly preferably less than 1.5% relative to the total surface area.

[0138] A mineral molded body is considered to be at least partially cured when it has reached at least 50% of its nominal strength. For example, a mineral molded body based on cement paste is preferably cured over a period of 12 hours. A mineral molded body is preferably at least partially cured when it has reached 95% of its nominal strength. The hardening of concrete takes place over several days. During the hardening phase, for example in concrete or mortar, the transition from cement paste to cement paste occurs. Under normal temperature and humidity conditions, cement preferably reaches standard strength after 28 days.

[0139] Shrinkage pores are holes in the surface of a mineral molded body. Air pockets and / or defects, preferably when viewed perpendicularly to the plane formed by the surface of the molded body. Shrinkage cavities can form, for example, as a result of the mold release agent being applied too thickly or as a result of the mold release agent penetrating into the molded body.

[0140] The desired shaped body surface is characterized by the presence of as few shrinkage pores as possible and / or shrinkage pores that are as small as possible. The number and size of the shrinkage pores can be considered as a quality indicator for the shaped body surface and can be analyzed.

[0141] The above-mentioned surface area of ​​shrinkage pores is determined as follows. A mold element, preferably a mold plate, is provided in the form of a plastic cube with a side length of 150 mm. A spray gun is used to spray the plastic cube at 150 g / m 2 The release agent is placed on the surface of the mold element, preferably on the surface of the template, by an applied weight of , and then dried.

[0142] As a mineral building material mixture, 1935 g of gravel (grain size fraction: 2 mm to 8 mm), 2565 g of sand (grain size fraction: 0 mm to 2 mm) and 900 g of CEMII / A-LL 42.5N (Portland limestone cement) were mixed with each other, and this mixture was stirred with 450 g of water to form a homogeneous concrete mixture.

[0143] The concrete is then filled into the mould element, preferably into the formwork. The filling level is preferably at least 9 cm. The side parts of the mineral moulding, ie the vertical surfaces, and not the bottom side of the mineral moulding, ie the horizontal surface, are used for the analysis.

[0144] To determine the size and number of shrinkage pores, the image processing program Fiji (version ImageJ 1.53c) is used. In a first step, an image of the surface area to be analyzed is recorded. The recorded surface area is preferably at least 15 cm×9 cm. An inner partial surface area is then created from the recorded surface area by removing at least 2 cm from the edge at least at each edge of the recorded surface area. Edge effects such as flaking or shrinkage pores located at the edge are thereby excluded from the analysis. The inner partial surface area is preferably at least 7 cm×7 cm.

[0145] In an image processing program, a binary color image of the partial surface area of ​​the interior is first created. The color values ​​of this image are then set so that closed surface areas, i.e. surface areas without shrinkage pores, are monochrome and the shrinkage pores are displayed colorless. The image processing program then determines the area proportion of the colorless portion and thereby the total surface area of ​​all shrinkage pores. The surface area of ​​the shrinkage pores is relative to the total surface area, preferably relative to the partial surface area of ​​the interior, and is given as a percentage.

[0146] The release agent is in particular free of polychlorinated biphenyls. The release agent contains no dispersing additives and / or emulsion additives and / or is not provided with these. It is possible that the polymer has an emulsifying effect.

[0147] The mold release agent does not contain refined oils and / or fats, oils and / or fats of biological origin, and / or is not provided together with these. The carboxylic acid-containing monomer components and optionally carboxylic acid-free monomer components from step a) and the polymer obtained in step b) are not to be understood as refined oils and / or fats, oils and / or fats of biological origin.

[0148] Of course, the product features listed above may equally apply to the method, or the method features listed may apply to the product.

[0149] The present invention will be described below by way of example with reference to the accompanying drawings using several embodiments. Therefore, the embodiments shown should not be understood as limiting. BRIEF DESCRIPTION OF THE DRAWINGS

[0150] Figure 1 A method for producing a release agent is schematically shown.

[0151] Figure 2 Schematic diagram showing the use of a release agent.

[0152] Figure 1The method for producing a release agent 2 according to the invention is schematically shown. The method has at least the following steps a), b) and c).

[0153] exist Figure 1 In step a), a reactive mixture is provided which contains a carboxylic acid-containing monomer component, wherein this carboxylic acid-containing monomer component comprises itaconic acid and / or itaconic acid derivatives and / or consists of itaconic acid and / or itaconic acid derivatives. Step a) is carried out at the beginning of the process. The composition of the components of the reactive mixture is selected so that the sum of the components gives 100 Gew.-% (Gew.-%=weight percentage) relative to the total weight of the reactive mass.

[0154] according to Figure 1 The carboxylic acid-containing monomer component of the reactive mixture preferably contains and / or is provided with, in addition to itaconic acid and / or itaconic acid derivatives, at least one further carboxylic acid-containing monomer component which is selected, alone or in combination, from acrylic acid, methacrylic acid and maleic acid.

[0155] Preferred itaconic acid derivatives of the carboxylic acid-containing monomer component are itaconic acid anhydride, itaconic acid methoxy ester and / or itaconic acid ethoxy ester. The itaconic acid derivative of the carboxylic acid-containing monomer component is preferably derivatized to the maximum extent on the carboxylic acid and is present, for example, as itaconic acid monoester.

[0156] The proportion of the monomers of the carboxylic acid-containing monomer component relative to the total mass of the reactive mixture can be and / or has been selected from the range of 10 to 60% by weight, preferably 20 to 50% by weight, further preferably 30 to 40% by weight.

[0157] according to Figure 1 The reactive mixture of the method may contain or be provided with at least one carboxylic acid-free monomer component, which is selected from acrylamide and its derivatives, esters of acrylic acid, esters of methacrylic acid, esters of itaconic acid, esters of maleic acid, maleic anhydride, terpenes, preferably myrcene, styrene, isoprene, butadiene, vinyl ether and / or combinations thereof, alone or in combination. The carboxylic acid-free monomer component is preferably selected from acrylamide and its derivatives, esters of acrylic acid, esters of methacrylic acid, esters of itaconic acid, terpenes or combinations thereof. The carboxylic acid-free monomer component is further preferably selected from acrylamide and its derivatives, esters of itaconic acid, terpenes or combinations thereof.

[0158] The proportion of the monomers of the carboxylic acid-free monomer component, relative to the total mass of the reactive mixture, is preferably already selected and / or is selected from a range of greater than 0% to 30% by weight, preferably greater than 0% to 20% by weight, further preferably greater than 0% to 15% by weight.

[0159] The carboxylic acid-free monomer component may contain at least 80% by weight, preferably 100% by weight, of water-soluble monomers.

[0160] The carboxylic acid-containing monomer component and / or the carboxylic acid-free monomer component and / or the polymer and / or the release agent 2 may contain and / or consist of biogenic components and / or may be provided together with biogenic components.

[0161] The carboxylic acid-containing monomer component and / or the carboxylic acid-free monomer component and / or the polymer and / or the release agent 2 is preferably biodegradable. The carboxylic acid-containing monomer component and / or the carboxylic acid-free monomer component and / or the polymer and / or the release agent 2 may be compostable.

[0162] according to Figure 1 The reactive mixture of the method may contain or be provided with a solvent, preferably an organic solvent, which is selected from ethanol, 1-propanol, 2-propanol, acetone, 2-butanone (MEK), acetate, in particular ethyl acetate and lactoacetate, alone or as a mixture. The organic solvent is miscible with water under standard atmospheric conditions, preferably miscible with water in a ratio of 1:1.

[0163] Alternatively or additionally, the reactive mixture can contain and / or be provided with a solvent which contains water and / or consists of water. The solvent of the reactive mixture is preferably water.

[0164] The reactive mixture may have and / or be provided with a pH value selected from the range of 3 to 14, preferably 5 to 12, further preferably 6 to 9. The reactive mixture may contain dissolved hydroxide of an alkali metal of main group 1 of the periodic table, preferably NaOH and / or KOH.

[0165] The proportion of the solvent relative to the total mass of the reactive mixture can be and / or has been selected from the range of 10% to 90% by weight, preferably 30% to 80% by weight, further preferably 40% to 60% by weight.

[0166] according to Figure 1 The reactive mixture of the process preferably contains and / or is provided with an initiator, preferably an initiator for free-radical polymerization.

[0167] The proportion of the initiator, relative to the total mass of the reactive mixture, can be and / or has been selected from a range of 0.05% to 2.5% by weight, preferably 0.1% to 1.5% by weight, further preferably 0.5% to 1.2% by weight.

[0168] The initiator is preferably selected and / or has been selected from azo compounds, peroxides or mixtures thereof.

[0169] according to Figure 1The reactive mixture of the process preferably has and / or is provided with the following composition, wherein the data on the individual components are in each case relative to the total mass of the reactive mixture and wherein the components are selected such that they give a total of 100% by weight:

[0170] Carboxylic acid-containing monomer component: 10 wt% - 60 wt%,

[0171] Monomer components not containing carboxylic acid: 0 wt% - 30 wt%,

[0172] Solvent: 10 wt% - 90 wt%,

[0173] Initiator: 0.05 wt% - 2.5 wt%,

[0174] Further preferably:

[0175] Carboxylic acid-containing monomer component: 20 wt% -50 wt%,

[0176] Monomer components not containing carboxylic acid: 0 wt% - 20 wt%,

[0177] Solvent: 30 wt% - 80 wt%,

[0178] Initiator: 0.1 wt% - 1.5 wt%,

[0179] Still more preferably:

[0180] Carboxylic acid-containing monomer component: 30 wt% -40 wt%,

[0181] Monomer components not containing carboxylic acid: 0 wt% - 15 wt%,

[0182] Solvent: 40 wt% - 60 wt%,

[0183] Initiator: 0.5 wt% - 1.2 wt%.

[0184] In accordance with Figure 1 In step b) of the method, a polymer solution is obtained from the reactive mixture provided in step a). The polymer solution comprises a polymer containing at least a monomer component containing a carboxylic acid, in particular a monomer component of the reactive mixture provided in step a). In addition, the polymer solution contains a solvent. The polymer is at least partially dissolved in a solvent preferably in the form of water. The polymer can be dissolved in a solvent preferably in the form of water in a content of at least 30 g / l, preferably at least 60 g / l in a solvent preferably in the form of water under standard atmospheric conditions under equilibrium conditions. Step b) is preferably carried out after step a).

[0185] Step b) may be carried out at a temperature of the reactive mixture selected from the range of 20°C to 110°C, preferably 40°C and 85°C, further preferably 50°C to 70°C.

[0186] In accordance with Figure 1 In step b) of the method, the solvent of the reactive mixture can be separated after obtaining the polymer, for example selected from filtration, suction, evaporation, vacuum drying, exposure to infrared radiation or cryo separation or a combination thereof. In addition, the polymer can then be added to a further solvent. In other words, the solvent of the reactive mixture can be a different solvent compared to the solvent of the polymer solution.

[0187] It is further possible in step b) to wash the polymer with a further solvent, preferably an organic solvent, which has a boiling point lower than the boiling point of the solvent which is or has been comprised in the reactive mixture.

[0188] The solvent of the polymer solution preferably comprises water and / or consists essentially of water. In particular, the polymer is water-soluble.

[0189] The polymer, in particular before decarboxylation, may contain a carboxylic acid-containing monomer component selected from the range of 25 wt % to 99.95 wt %, preferably 40 wt % to 99.95 wt %, more preferably 55 wt % to 99.95 wt %, preferably itaconic acid and / or itaconic acid derivatives, more preferably itaconic acid. The carboxylic acid-containing monomer component preferably consists of itaconic acid and / or itaconic acid derivatives, preferably itaconic acid.

[0190] The polymer, in particular before decarboxylation, may contain carboxylic acid-free monomer components, in particular selected from the range of greater than 0% to 75%, preferably greater than 0% to 60%, further preferably greater than 0% to 45%.

[0191] In particular, the polymer, in particular before decarboxylation, contains an initiator selected from the range of 0.05 to 2% by weight, preferably 0.1 to 1.5% by weight, further preferably 0.5 to 1.1% by weight.

[0192] The polymer, in particular before decarboxylation, preferably has a number average molar mass value selected from the range of 500 g / mol to 500,000 g / mol, preferably 750 g / mol to 100,000 g / mol, further preferably 1000 g / mol to 50,000 g / mol, still further preferably 1500 g / mol to 20,000 g / mol.

[0193] The carboxylic acid-containing monomer component contained in the polymer may contain at least one other carboxylic acid-containing monomer component in addition to itaconic acid and / or itaconic acid derivatives, which is selected from acrylic acid, methacrylic acid, maleic acid alone or in combination. The proportion of the carboxylic acid-containing monomer component, in particular itaconic acid and / or itaconic acid derivatives in the polymer is selected from the range of 2.5% by weight to 100% by weight, preferably 5% by weight to 80% by weight, further preferably 10% by weight to 50% by weight, in particular before decarboxylation, based on the total mass of the polymer.

[0194] The polymer preferably contains at least one carboxylic acid-free monomer component, whose components or derivatives are selected, alone or in combination, from acrylamide, acrylic acid esters, methacrylic acid esters, itaconic acid esters, maleic acid esters, maleic anhydride, terpenes, myrcene, styrene, isoprene, butadiene, vinyl ethers. The proportion of the carboxylic acid-free monomer component relative to the total mass of the polymer is preferably selected from the range of more than 0% by weight to 97.5% by weight, preferably 5% by weight to 90% by weight, further preferably 15% by weight to 85% by weight, in particular before decarboxylation.

[0195] The polymer, in particular before decarboxylation, may have a glass transition temperature value selected from the range of -20°C to 110°C, preferably -20°C to 50°C, further preferably -10°C to 25°C.

[0196] according to Figure 1 The release agent 2 is obtained in step c). The release agent 2 comprises a polymer solution, which contains the polymer obtained in step b). Before its use, thus before it is arranged as a layer on at least one surface of the mold element 1, preferably on at least one surface of the template, the release agent 2, preferably the polymer, is preferably present in a state in which decarboxylation has not yet been completed and is at least partially decarboxylable. In particular, CO is released from the polymer of the release agent 2 during or after use of the release agent 2. 2 . By decarboxylation, it dissociates from the polymer and releases CO 2 The amount of polymer released depends on the polymer structure. CO can be released at least partially from the carboxylic acid-containing monomer components, preferably itaconic acid and / or itaconic acid derivatives, by decarboxylation. 2 .

[0197] The release agent 2 preferably releases CO after and / or during contact with the mineral building material mixture 3. 2 The release agent 2 further preferably releases CO during the at least partial curing and / or hardening of the contacted mineral building material mixture 3. 2The building material mixture 3 is in particular flowable or plastically deformable. Furthermore, the building material mixture 3 contains water and at least one mineral binder. Alternatively or additionally, the release agent 2, preferably a polymer, can also release CO after being arranged on at least one surface of the mold element 1, preferably a template, preferably before it comes into contact with the mineral building material mixture 3. 2 and / or decarboxylation.

[0198] The release agent 2 can act as a release agent 2 in the form of a layer, regardless of the water content of the release agent 2. In other words, the decarboxylation of the release agent 2 (preferably a polymer) can be achieved regardless of the water content of the release agent 2, and / or CO can be released from the release agent 2 (preferably a polymer) regardless of the water content. 2 The release agent 2 is therefore effective both in the dry state and in the wet state.

[0199] The release agent 2 preferably contains or is provided with an indicator, whereby the release agent 2 has a different color impression in the dry state compared to the wet state. The release agent 2 before use, which contains the polymer solution, therefore has a different color impression compared to the dry layer.

[0200] For example, it is possible that the indicator has a color impression in the moist state of the release agent 2 and that the indicator is colorless in the dry state of the release agent 2. In the dry state, the indicator is therefore preferably not perceptible to an observer.

[0201] Suitable indicators are preferably selected from one or more leuco dyes.

[0202] The release agent 2 can contain and / or be provided with a leveling additive, preferably selected from the range of greater than 0% to 10% by weight, further preferably greater than 0% to 7.5% by weight, still further preferably greater than 0% to 5.5% by weight, in each case relative to the total weight of the release agent 2.

[0203] The total weight of the release agent 2 refers to the wet state and / or the total weight of the release agent 2 used to obtain the release agent in step c) and before its use.

[0204] The release agent 2 may also contain and / or be provided with a thickener, preferably selected from the range of greater than 0% to 2% by weight, further preferably greater than 0% to 1.5% by weight, still further preferably greater than 0% to 1.2% by weight, in each case relative to the total weight of the release agent 2.

[0205] The release agent 2 from step c) contains the polymer solution from step b). The release agent 2 preferably contains the polymer solution selected from the range of 0.01% by weight to 100% by weight, preferably 0.01% by weight to 50% by weight, further preferably 0.01% by weight to 20% by weight, and / or is provided as such, in each case relative to the total weight of the release agent 2.

[0206] The release agent 2 from step c) contains in particular the polymer solution from step b). In a preferred embodiment, the polymer solution preferably comprises a polymer selected from the range of 0.005% by weight to 50% by weight, preferably 0.005% by weight to 25% by weight, further preferably 0.005% by weight to 10% by weight, and / or is provided as such, in each case relative to the total weight of the release agent 2.

[0207] The solvent of the release agent 2 preferably contains water and / or consists essentially of water.

[0208] according to Figure 1 The release agent 2 of the method preferably contains and / or is provided with a solvent, preferably in the form of water, selected from the range of more than 0% by weight to 99.99% by weight, preferably 50% by weight to 99.99% by weight, further preferably 80% by weight to 99.99% by weight, in each case relative to the total weight of the release agent 2.

[0209] The release agent 2 according to the invention preferably has and / or is provided with the following composition, wherein the data on the individual components are in each case relative to the total weight of the release agent 2 and wherein the components are selected such that they give a total of 100% by weight:

[0210] Polymer solution: 0.01 wt% - 100 wt%,

[0211] Solvent: 0 wt% - 99.99 wt%,

[0212] Leveling additive: 0 wt% -10 wt%,

[0213] Thickener: 0 wt% - 2 wt%,

[0214] Further preferably:

[0215] Polymer solution: 0.01 wt% - 50 wt%,

[0216] Solvent: 50 wt% - 99.99 wt%,

[0217] Leveling additive: 0 wt% -7.5 wt%,

[0218] Thickener: 0 wt% -1.5 wt%,

[0219] Still more preferably:

[0220] Polymer solution: 0.01 wt% - 20 wt%,

[0221] Solvent: 80 wt% - 99.99 wt%,

[0222] Leveling additive: 0 wt% -5.5 wt%,

[0223] Thickener: 0 wt% - 1.2 wt%.

[0224] The dynamic viscosity is already and / or preferably selected from the range of 1 mPas to 300 Pas, preferably 2 mPas to 200 mPas, further preferably 3 mPas to 150 mPas, still further preferably 3 mPas to 100 mPas.

[0225] Particularly in the case of arrangement on a vertical surface, the dynamic viscosity of the release agent 2 is selected from the range of 50 mPas to 300 mPas, preferably 75 mPas to 200 mPas, further preferably 100 mPas to 150 mPas.

[0226] Particularly in the case of application to a horizontal surface, the dynamic viscosity of the release agent 2 is selected from the range of 1 mPas to 300 mPas, preferably 2 mPas to 200 mPas, further preferably 3 mPas to 100 mPas.

[0227] The dynamic viscosity is preferably in each case determined in accordance with DIN EN ISO 2884-1:2006-09 (date of publication: 2006-09, "Beschichtungsstoffe-Bestimmung der mit Rotationsviskosimetern-Teil 1:Kegel-Platte-Viskosimeter bei hohem The viscosity determination method using a rotational viscometer as described in (ISO 2884-1: 1999); Deutsche Fassung EN ISO 2884-1: 2006) (Coatings - Determination of viscosity using a rotational viscometer - Part 1: Cone and plate viscometer at high shear rates (ISO 2884-1: 1999); German version of EN ISO 2884-1: 2006), in particular using a cone and plate viscometer with cone and plate measuring geometry from ThermoScientific, Haake Mars 60 model.

[0228] After the at least partial solidification and / or hardening of the mineral molded body 4, the surface of the mineral molded body 4 in contact with the release agent 2 is preferably designed so that the surface area of ​​the shrinkage pores is less than 5%, preferably less than 3%, particularly preferably less than 1.5% relative to the total surface area.

[0229] The release agent 2 is in particular free of polychlorinated biphenyls. The release agent 2 is free of dispersing additives and / or emulsion additives and / or is not provided with these. The polymer may have an emulsifying effect.

[0230] The release agent 2 does not contain refined oils and / or fats, oils and / or fats of biological origin, and / or is not provided together with these. The carboxylic acid-containing monomer components and optionally carboxylic acid-free monomer components from step a) and the polymer obtained in step b) are not to be understood as refined oils and / or fats, oils and / or fats of biological origin.

[0231] Figure 2 Schematic diagram showing the use of a mold release agent 2 according to the invention or a mold release agent 2 produced according to claim 1 in a method for obtaining a mineral molded body 4 .

[0232] In step i), at least one mold element 1, preferably a template, is provided. A release agent 2 according to the invention or a release agent 2 obtained in step c) according to the process according to the invention is arranged in the form of a layer on at least one surface of the mold element 1, preferably a template.

[0233] The release agent 2 is preferably arranged on the at least one surface of the mold element 1, preferably on the at least one surface of the formwork, by a method selected from the group consisting of spraying, brushing or rolling, or a combination thereof. The release agent 2 is preferably arranged on the at least one surface of the mold element 1, preferably on the at least one surface of the formwork, in the form of the entire surface. The release agent 2 is preferably arranged on all surfaces of the mold element 1 that are in contact with the mineral building material mix 3, preferably on the at least one surface of the formwork, in the form of the entire surface.

[0234] The amount of release agent 2 applied relative to the non-absorbent template is preferably selected from 50 g / m 2 Up to 400g / m 2 , preferably 100g / m 2 Up to 250g / m 2 , further preferably 125g / m 2 Up to 175g / m 2 range.

[0235] In step ii), a particularly flowable or plastically deformable mineral building material mixture 3 comprising water and at least one mineral binder is then arranged on the at least one surface of the mould element 1 , preferably the formwork, coated with the release agent 2 .

[0236] The mineral building material mixture 3 preferably comprises concrete, mortar, lime sand brick, silicate ceramic or a combination thereof, or consists thereof. The at least one mineral binder preferably comprises a hydraulic binder, a non-hydraulic binder or a mixture thereof. In addition, the at least one mineral binder can be selected from hydrated calcium silicate, cement, lime, clay, gypsum, clay, magnesium oxide binder and a combination thereof.

[0237] In accordance with Figure 2 In step iii), the mineral building material mixture 3 is at least partially cured and a dimensionally stable mineral green body is obtained. Further, the mineral building material mixture 3, preferably the dimensionally stable mineral green body, is hardened.

[0238] In step iv) the mould element 1 , preferably a shuttering, is shown removed from the mineral building material mixture 3 . A mineral moulded body 4 is obtained.

[0239] The release agent 2 preferably releases CO from the polymer structure after step i), in step ii) and / or in step iii). 2 In other words, the release agent 2 releases CO after and / or during contact with the mineral building material mixture 3. 2 The release agent 2 further preferably releases CO during the at least partial curing and / or hardening of the contacted mineral building material mixture 3. 2 .

[0240] The decarboxylation of the release agent 2 , in particular of the porous structure, is preferably initiated by contacting the release agent 2 with the flowable or plastically deformable mineral building material mixture 3 .

[0241] Alternatively or additionally, the release agent 2 can be brought into contact with a volume of a liquid containing the above-mentioned anions and / or cations and being alkaline, preferably by spraying and / or pouring.

[0242] In particular, the flowable or plastically deformable building material mixture 3 contains at least one component that catalyzes decarboxylation. The decarboxylation is preferably ionically catalyzed, in particular alkaline catalyzed. The decarboxylation can be thermally catalyzed.

[0243] The flowable or plastically deformable building material mixture 3 preferably contains divalent or polyvalent cations of at least one metal, wherein the at least one metal is preferably selected from Mg, Ca, Sr, Ba, Al, Fe, Co or mixtures thereof. The cations are preferably present in the form of water-soluble salts.

[0244] Divalent or higher valent cations may preferably catalyze the decarboxylation of polyitaconic acid.

[0245] It is possible that, in particular, the released CO 2A first possible mode of action is achieved by the CO at the contact points between the mineral building material mix 3 and the surface of the mould element 1 (preferably a formwork) on which the release agent 2 is arranged. 2 A porous matrix of the mineral molded body 4 is produced.

[0246] Furthermore, the chain length and / or the mass of the polymer can be reduced by decarboxylation of the polymer. In particular, the water-soluble fraction of the polymer can thus be diffused into the mineral building material mixture 3. The water-soluble fraction of the polymer can preferably promote the creation of a porous matrix in the mineral molding.

[0247] The porous matrix of the resulting mineral molded body 4 has a lower strength than the standard strength of the mineral building material mixture 3. This reduces the adhesion between the formwork and the concrete, as a result of which the mineral molded body 4 can be easily demoulded.

[0248] Alternatively or additionally, in particular as CO 2 The second mode of action of CO 2 The reaction at the surface of the mineral building material mixture 3 to form carbonic acid can occur, and as described above, carbonation occurs, for example, in equations (2) to (5). The pore volume of the mineral building material mixture 3 can thereby be reduced, and an interface between the surface of the mold element 1 (preferably the template) having a more uniform and / or smoother surface than the mineral building material mixture 3 before carbonation can be obtained. Preferably, the contact surface area between the mineral building material mixture 3 and the surface of the mold element 1 (preferably the template) can be reduced, which improves the separation of the mold element 1 (preferably the template) from the mineral molded body 4.

[0249] It is possible that all described modes of action are present in the production of the mineral molded body 4 and / or one of the modes of action is preferably present. In this case, the release agent 2 preferably leaves no residues on the surface of the mold element 1, preferably on the surface of the template. If residues remain, these can be removed mechanically with water and a conventional rag. For example, a porous matrix can be obtained on the side facing the smoother interface of the mold element 1, preferably the template, whereby a particularly good demoulding effect is achieved. DETAILED DESCRIPTION

[0250] Example 1

[0251] To obtain the reactive mixture according to step a), 50 g of distilled water were placed in a round bottom flask and 15.8 g of potassium hydroxide (KOH, Carl Roth, 85%) were dissolved at room temperature (20° C.) under constant stirring. The alkaline pH was adjusted. 36.65 g of itaconic acid (Thermo Scientific Chemicals, 99+%) were slowly added to this solution as the carboxylic acid-containing monomer component. The solubility of itaconic acid was improved by the alkaline pH of the solution. Once the itaconic acid had completely dissolved in the solution, 13.35 g of acrylamide (Sigma Aldrich, 99+%) were added as the carboxylic acid-free monomer component. The solution was then purged with argon for 5 minutes.

[0252] Thereafter, the resulting reactive mixture was heated from room temperature to 50° C. with stirring, and 1.12 g of initiator (Fujifilm Wako Chemicals Europe GmbH, azo polymerization initiator V-50 (free radical initiator)) was added. The reactive mixture according to step a) was obtained.

[0253] The reaction mixture was further heated to 60° C. and stirred for 12 hours with further stirring. After cooling to room temperature, an aqueous polymer solution according to step b) was obtained. The solid content of the polymer solution was 50% by weight, relative to the dry weight of the polymer solution.

[0254] From the polymer solution according to step b), the release agent 2 according to step c) is admixed. The composition of the release agent 2 corresponds to 1.84 g of polymer solution (2% by weight), 0.184 g of leveling additive (1% by weight, BYK-Chemie GmbH, Wesel, BYK-Dynwet 800N), 1.38 g of thickener (7% by weight, Dow Chemical, Midland, Walocell MW 40000) and 90.16 g of distilled water (90% by weight). The components of the release agent 2 are stirred until a homogeneous solution is formed.

[0255] Comparative Example

[0256] As a comparative example, an oil-containing release agent Master Finish RL 419 (MasterBuilders Solutions, Staβfurt) was provided.

[0257] Application of release agent

[0258] In order to evaluate the effectiveness and properties of the release agent 2, a mineral molded body 4 was produced. For this purpose, a mold element 1, preferably a template, was provided in the form of a plastic cube with a side length of 150 mm. The mold element 1 was sprayed with a spray gun (Einhell, Landau / Isar) at 120 g / m 2 The mold release agent 2 of the present invention according to Example 1 and the oil-containing mold release agent according to the comparative example were applied on the surface of the mold member 1, preferably on the surface of the template, and then dried.

[0259] As mineral building material mixture 3, 1935 g of gravel (particle size fraction: 2 mm to 8 mm), 2565 g of sand (particle size fraction: 0 mm to 2 mm) and 900 g of CEMII / A-LL 42.5N (Portland limestone cement) were mixed with each other, and this mixture was stirred with 450 g of water to form a homogeneous concrete mixture.

[0260] The plastic cube is then filled with the mineral building material mixture 3 or concrete. The filling height is at least 9 cm. Only the side parts of the cube (i.e. the vertical surfaces), but not the bottom side of the cube (i.e. the horizontal surface), are used for the analysis.

[0261] result

[0262] The desired molded body surface is characterized by the presence of as few shrinkage pores as possible and / or shrinkage pores that are as small as possible. The number and size of shrinkage pores can be considered as a quality indicator for the molded body surface and analyzed. The size and number of shrinkage pores are determined as already described further above.

[0263] The results are shown in Table 1. It has been shown that in the case of the release agent according to Example 1, a much smaller number of shrinkage pores (voids) is obtained compared to the comparative example, and in addition, the diameter of the pores is much smaller. In addition, the absolute surface area of ​​the shrinkage pores is also reduced. This can be explained by the penetration of the oil-containing release agent into the concrete that has not yet solidified, and therefore the formation of shrinkage pores increases. In addition, the release agent 2 according to the invention can reduce the size and / or number of shrinkage pores by carbonation.

[0264] Table 1: Analysis results of shrinkage pore formation of the release agent according to Example 1 and the release agent according to the comparative example

[0265] Release agent Example 1 Comparative Example Surface area of ​​holes / pixel 1144 7797 Surface area of ​​holes / % 0.311 2.024 <![CDATA[Surface area of the hole / cm 2 > 0.375 2.553 <![CDATA[Total surface area of the sample / cm 2 > 120.53 126.15 Number of holes / - 312 905 Hole diameter / pixel 3.667 8.615 <![CDATA[Holes per unit surface area / 1 / cm 2 > 2.59 7.17

[0266] The cleanliness of the mold surface is an important point, since it reveals how much effort is required to clean the surface of the mold element 1 after the mineral molded body 4 has been demoulded. In order to find out the cleanliness of the surfaces of the cube-shaped mold elements 1 used, they were wiped off with a damp rag. The residues of the mold release agent 2 according to Example 1 could be easily removed with a rag, while the mold release agent of the comparative example remained on the surface of the mold element 1.

[0267] The surface of the molded body was checked for sanding, i.e. the detachment of fine particles from the surface of the mineral molded body due to low structural bonding, with the aid of an adhesion test tape (Tesa company). In the adhesion test, a Tesa film 4104 with a width of 14 mm was used, which was pressed onto the surface of the molded body without bubbles by applying it three times with the tip of the thumb. After application, the Tesa film was quickly peeled off from the molded body manually at an angle of 45° to 60°. The angle was measured in particular between the planes formed by the Tesa film. The tape was then applied to a piece of white paper in order to visually determine the degree of sanding. It has been shown that a smaller number of particles can be visually detected on the tape from the molded body surface obtained by the release agent according to Example 1 than on the molded body surface obtained by the release agent of the comparative example. This can probably be explained by the penetration of the oil-containing release agent into the mineral building material mixture 3, which leads to setting failure and structural failure here. In addition, a smoother interface can be obtained by the release agent 2 according to the invention, which can be described as a kind of skin, for example.

[0268] In summary, by means of the method according to the invention, an improved mold release agent 2 can be provided which has, on the one hand, improved environmental compatibility and, on the other hand, a good mold release agent action.

[0269] Of course, the listed embodiment variants can be combined with one another as desired and do not represent a limitation.

[0270] Reference numerals list

[0271] 1 Mold components

[0272] 2 Release agent

[0273] 2'Release agent containing decarboxylation polymer

[0274] 3 Mineral building material mixtures

[0275] 4 Mineral molded body

Claims

1. A method for producing a release agent (2), Features The method comprises at least the following steps: a) providing a reactive mixture comprising a carboxylic acid-containing monomer component, said component comprising, preferably consisting of, itaconic acid and / or itaconic acid derivatives, b) polymerizing the reactive mixture to form a polymer solution, wherein the polymer solution comprises a polymer at least partially dissolved in a solvent and containing the carboxylic acid-containing monomer component, c) obtaining a release agent (2) comprising the polymer solution, wherein CO2 can be released from the release agent (2), preferably the polymer of the release agent (2), by decarboxylation.

2. The method according to the preceding claim, It is characterized in that The polymer solution and / or the release agent (2), in particular the polymer, contains and / or consists of biogenic components and / or is biodegradable and / or compostable.

3. The method according to any one of the preceding claims, It is characterized in that After the release agent (2) is arranged on at least one surface of the mold element (1), preferably on at least one surface of the mold plate, and preferably after contact with a flowable or plastically deformable mineral building material mixture (3) comprising water and at least one mineral binder, and further preferably during at least partial solidification and / or hardening of the flowable or plastically deformable mineral building material mixture (3), CO2 is formed.

4. The method according to claim 1, It is characterized in that The carboxylic acid-containing monomer component of the reactive mixture contains, in addition to itaconic acid and / or itaconic acid derivatives, at least one further carboxylic acid-containing monomer component selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid and maleic acid, either alone or in combination.

5. The method according to any one of the preceding claims, It is characterized in that The proportion of the monomer of the carboxylic acid-containing monomer component relative to the total mass of the reactive mixture is selected from the range of 2.5 to 65 wt %, preferably 5 to 50 wt %, and further preferably 10 to 35 wt %.

6. The method according to any one of the preceding claims, It is characterized in that The reactive mixture contains at least one carboxylic acid-free monomer component selected from acrylamide, esters of acrylic acid, esters of methacrylic acid, esters of itaconic acid, esters of maleic acid, maleic anhydride, terpenes, preferably myrcene, styrene, isoprene, butadiene, vinyl ethers and / or combinations thereof, alone or in combination.

7. The method according to any one of the preceding claims, It is characterized in that The proportion of the monomer of the carboxylic acid-free monomer component relative to the total mass of the reactive mixture is selected from the range of 5 to 50 wt %, preferably 10 to 35 wt %, and more preferably 15 to 30 wt %.

8. The method according to any one of the preceding claims, It is characterized in that The carboxylic acid-containing monomer component and / or the carboxylic acid-free monomer component comprises and / or consists of biogenic components and / or is biodegradable and / or compostable.

9. The method according to any one of the preceding claims, It is characterized in that The reactive mixture contains a solvent, preferably an organic solvent, which is selected from ethanol, 1-propanol, 2-propanol, acetone, 2-butanone (MEK), acetates, in particular ethyl acetate and lactoacetate, alone or as a mixture.

10. The method according to any one of the preceding claims, It is characterized in that The reactive mixture contains a solvent which comprises water and / or consists of water.

11. The method according to any one of the preceding claims, It is characterized in that The proportion of the solvent relative to the total mass of the reactive mixture is selected from the range of 15 to 95 wt %, preferably 30 to 85 wt %, more preferably 40 to 70 wt %, and even more preferably 45 to 55 wt %.

12. The method according to any one of the preceding claims, It is characterized in that The reactive mixture comprises an initiator, preferably an initiator for free radical polymerization.

13. The method according to any one of the preceding claims, It is characterized in that The proportion of the initiator relative to the total mass of the reactive mixture is selected from the range of 0.05% by weight to 1.5% by weight, preferably 0.1% by weight to 1% by weight, and more preferably 0.25% by weight to 0.5% by weight.

14. The method according to any one of the preceding claims, Features The initiator is selected from azo compounds, peroxides or mixtures thereof.

15. The method according to any one of the preceding claims, It is characterized in that Step b) is carried out at a temperature of the reactive mixture selected from the range of 20°C to 110°C, preferably 40°C and 85°C, further preferably 50°C to 70°C.

16. The method according to any one of the preceding claims, It is characterized in that The solvent of the polymer solution comprises water and / or consists essentially of water.

17. The method according to any one of the preceding claims, It is characterized in that The polymer is water-soluble, in particular wherein at least 30 g / l polymer, preferably at least 60 g / l polymer, is soluble in water in equilibrium under standard atmospheric conditions.

18. The method according to any one of the preceding claims, It is characterized in that The polymer contains a carboxylic acid-containing monomer component selected from the range of 25 to 100 wt %, preferably 40 to 100 wt %, and more preferably 55 to 100 wt %, preferably itaconic acid and / or an itaconic acid derivative, and more preferably itaconic acid.

19. The method according to any one of the preceding claims, It is characterized in that The polymer contains a carboxylic acid-free monomer component selected from the range of greater than 0% to 75% by weight, preferably greater than 0% to 60% by weight, and more preferably greater than 0% to 45% by weight.

20. The method according to any one of the preceding claims, It is characterized in that The polymer contains an initiator in an amount selected from the range of 0.05 wt % to 2 wt %, preferably 0.1 wt % to 1.5 wt %, and more preferably 0.5 wt % to 1.1 wt %.

21. The method according to any one of the preceding claims, It is characterized in that The polymer has a glass transition temperature value selected from the range of -20°C to 110°C, preferably -20°C to 50°C, and more preferably -10°C to 25°C.

22. The method according to any one of the preceding claims, Features CO 2 can be released from the release agent ( 2 ) independently of its water content.

23. The method according to any one of the preceding claims, It is characterized in that The release agent (2) contains an indicator, so that the release agent (2) has a different color impression in the dry state compared to the moist state.

24. The method according to any one of the preceding claims, It is characterized in that The indicator has a color impression in the moist state of the release agent (2) and is colorless in the dry state of the release agent (2).

25. The method according to any one of the preceding claims, Features The indicator is selected from one or more leuco dyes.

26. The method according to any one of the preceding claims, Features The release agent (2) contains a leveling additive, preferably selected from the range of greater than 0% to 10% by weight, further preferably greater than 0% to 7.5% by weight, still further preferably greater than 0% to 5.5% by weight, in each case relative to the total weight of the release agent (2).

27. The method according to any one of the preceding claims, It is characterized in that The release agent (2) contains a thickener, preferably selected from the range of greater than 0% to 2% by weight, further preferably greater than 0% to 1.5% by weight, still further preferably greater than 0% to 1.2% by weight, in each case relative to the total weight of the release agent (2).

28. The method according to any one of the preceding claims, It is characterized in that The release agent (2) comprises the polymer solution selected from the range of 0.01 to 100 wt. %, preferably 0.01 to 50 wt. %, further preferably 0.01 to 20 wt. %, in each case relative to the total weight of the release agent (2).

29. The method according to any one of the preceding claims, It is characterized in that The solvent of the release agent (2) contains water and / or consists essentially of water.

30. The method according to any one of the preceding claims, It is characterized in that The release agent (2) contains a solvent, preferably in the form of water, selected from the range of more than 0% by weight to 99.99% by weight, preferably 50% by weight to 99.99% by weight, further preferably 80% by weight to 99.99% by weight, in each case relative to the total weight of the release agent (2).

31. The method according to any one of the preceding claims, It is characterized in that The dynamic viscosity of the release agent (2) is selected from the range of 1 mPas to 300 Pas, preferably 2 mPas to 200 mPas, more preferably 3 mPas to 150 mPas, and even more preferably 3 mPas to 100 mPas, in particular measured according to the viscosity measurement method using a rotational viscometer described in DIN EN ISO 2884-1:2006-09.

32. The method according to any one of the preceding claims, It is characterized in that The release agent (2) does not contain dispersing additives and / or emulsion additives, and / or the release agent (2) does not contain polychlorinated biphenyls, and / or the release agent (2) does not contain refined oils and / or fats, oils and / or fats of biological origin.

33. The method according to any one of the preceding claims, It is characterized in that After the at least partial solidification and / or hardening of the mineral molded body (4), the surface of the mineral molded body (4) in contact with the release agent (2) is designed so that the surface area of ​​the pores and / or shrinkage pores is less than 5%, preferably less than 3%, particularly preferably less than 1.5% relative to the total surface area.

34. The method according to any one of the preceding claims, It is characterized in that The decarboxylation of the release agent (2) is initiated by contacting the release agent (2) with a flowable or plastically deformable mineral building material mixture (3), in particular the flowable or plastically deformable mineral building material mixture (3) contains at least one component which catalyzes the decarboxylation.

35. The method according to any one of the preceding claims, It is characterized in that The decarboxylation is ionically catalyzed, in particular alkaline catalyzed.

36. A release agent (2), in particular a release agent (2) produced according to the method of one of the preceding claims, It is characterized in that The release agent (2) contains a polymer at least partially dissolved in a solvent, wherein the polymer contains a carboxylic acid-containing monomer component, which includes itaconic acid and / or an itaconic acid derivative, and wherein CO2 can be released from the release agent (2) by decarboxylation.

37. Use of a release agent (2), in particular a release agent (2) produced according to a method according to one of claims 1 to 35, in the production of mineral mouldings (4). Features The release agent (2) is arranged on at least one surface of a mould element (1), preferably on at least one surface of a formwork, and is brought into contact with a flowable or plastically deformable mineral building material mixture (3), wherein the mineral building material mixture (3) contains water and at least one mineral binder and wherein CO2 can be released from the release agent (2) by decarboxylation.

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