Inorganic foam based on ordinary Portland cement

Abstract

A method for preparing mineral foam includes: (a) providing a cementitious slurry comprising a cementitious binder, a foam stabilizer, and a hardening control agent; and (b) foaming the cementitious slurry, wherein the hardening control agent comprises (i) α-hydroxymonocarboxylic acid or a salt thereof, and (ii) an oxyanion source selected from the group consisting of a borate source and a carbonate source. An accelerator selected from the group consisting of an aluminum ion source, an aluminate source, and a silicate source may be added to the cementitious slurry. This method allows for ordinary Portland cement or limestone-calcined clay cement without impairing the final strength of the mineral foam.

Description

[Technical Field]

[0001] The present invention relates to a process for preparing inorganic foams based on a Portland cement clinker-based cementitious binder, the inorganic foams obtained thereby, and construction elements containing these inorganic foams. [Background technology]

[0002] Inorganic foams, also known as mineral foams or cement foams, possess advantageous properties such as a significantly lower specific weight compared to conventional concrete or other building materials. The foams contain gas pockets, which are somewhat separated air bubbles, contained within the solid sealant of the mineral binder. Due to the included cells or voids, the foams are considerably lighter than conventional concrete.

[0003] Inorganic foams, with their low density, can be used as insulating materials such as thermal insulation, soundproofing, or sound-absorbing materials, as well as as construction materials. Advantages of using inorganic foams include a reduced CO2 footprint compared to organic materials (PU, EPS) and other inorganic materials (AAC, mineral wool), good health and safety properties, no limitations on applications due to anticipated fire types, 100% recycling rate in the mineral material cycle, and high flexibility due to flexible density changes depending on the application. Furthermore, the low raw material and energy requirements for production reduce the impact on product costs when energy prices related to limited resources rise.

[0004] Currently, inorganic foams are mainly manufactured using surfactants or proteins as foam stabilizers. Because this type of foam stabilization is prone to defoaming and coagulation, fast-setting cements such as calcium sulfoaluminate (CSA), calcium aluminate (CA), or accelerated-curing standard cements are used. If hardening is slow, the instability of the foam stabilizer used leads to significant collapse of the foam structure and volume. This requirement for fast hardening affects the robustness of the foam against changing environmental conditions. High temperatures in summer can cause the cement to harden in the mixer, while low temperatures in winter delay hardening, resulting in a defoamed foam with properties far from the desired characteristics.

[0005] Particle stabilization enables the formation of a stable foam. Rapid hardening is not required to produce a homogeneous foam. Even today, special CSA cement is used, making it possible to accelerate the hardening of the cement to a level where air drying time is less than 30 minutes.

[0006] International Publication No. 2018 / 162381 relates to a process for preparing particle-stabilized inorganic foams based on calcium sulfoaluminate, particle-stabilized inorganic foams based on calcium sulfoaluminate, porous materials obtained by curing and optionally drying particle-stabilized inorganic foams based on calcium sulfoaluminate, and compositions for preparing inorganic foam formulations to provide particle-stabilized inorganic foams based on calcium sulfoaluminate.

[0007] Due to its high cost, CSA cement's applications are limited to low-density foams (primarily for thermal insulation), where only a minimal amount of binder is required. To expand its applications, OPC, as a less expensive binder, could be a viable alternative to CSA cement.

[0008] When ordinary Portland cement or calcined limestone clay cement (LC3 cement) is used, the demolding of the foam is slow due to the long curing time required to reach green strength. If common accelerators are used to shorten the curing time, the final strength of the mineral foam is substantially reduced. [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention aims to provide a method for preparing mineral foam that can overcome major obstacles such as high material costs, high cement clinker content, or low strength, thereby enabling the widespread application of mineral foam in the construction field. In a preferred embodiment, the present invention also addresses the problem of long air-drying times, enabling a reduction in turnover time. [Means for solving the problem]

[0010] The object of the present invention is solved by the method described in claim 1.

[0011] Further aspects of the present invention are the subject of the independent claims. Preferred embodiments are the subject of the dependent claims. [Modes for carrying out the invention]

[0012] This invention relates to a method for preparing mineral foam, the method being: a. cementite binder, Foam-stabilizer, and Curing control agent A step of providing an aqueous cementitious slurry containing; b. Step of foaming the cementitious slurry The curing control agent comprises (i) α-hydroxymonocarboxylic acid or a salt thereof, and (ii) an oxyanion source selected from the group consisting of a borate source and a carbonate source.

[0013] A hardening control agent is present in an aqueous cementitious slurry containing a cementitious binder and a foam stabilizer. The hardening control component controls the hydration process and ensures relatively constant rheological properties, preferably constant viscosity and yield stress. By incorporating the hardening control agent into the aqueous cement slurry, it is possible to obtain a mineral foam with improved final strength.

[0014] In a preferred embodiment, the method includes the step of adding an accelerator solution to a cementitious slurry. The accelerator comprises at least one agent selected from the group consisting of an aluminum ion source, an aluminate source, and a silicate source. This embodiment uses a curing regulator / accelerator combination to accelerate the curing time of formulations based on a sustainable binder. The curing regulator / accelerator combination enables rapid demolding and a reduction in turnover time. By dividing the process into two stages, the cementitious slurry, which typically has a long air-drying time, hardens rapidly when the accelerator solution is added. This reduces the cycle time and maximizes the use of the formwork. The addition of the accelerator solution ensures a rapid increase in strength and enables faster demolding in a short time after filling the formwork.

[0015] Curing control agent The curing control agent comprises (i) α-hydroxymonocarboxylic acid or a salt thereof, and (ii) an oxyanion source selected from the group consisting of a borate source and a carbonate source. The carbonate source is 0.1 g·L -1 The material is selected from the group consisting of inorganic carbonates, organic carbonates, and mixtures thereof, having the above-mentioned water solubility.

[0016] It is believed that a combination of (i) α-hydroxymonocarboxylic acid or a salt thereof and (ii) an oxyanion source selected from the group consisting of a borate source and a carbonate source delays the formation of ettringite from the aluminate phase derived from the cementitious binder.

[0017] Suitable α-hydroxymonocarboxylic acids and their salts include glycolic acid, gluconic acid, lactic acid, 2,3-dihydroxypropanoic acid, and salts and mixtures thereof. Hydroxymonocarboxylic acids are available as free acids or in partially or completely neutralized forms, i.e., as salts. The cation is not particularly limited and can be selected from the group consisting of alkali metals such as sodium or potassium, and ammonium cations. Sodium gluconate is particularly preferred.

[0018] The amount of α-hydroxymonocarboxylic acid or its salt may be in the range of 0.01 to 2.0% by weight, preferably 0.01 to 0.7% by weight, and more preferably 0.02 to 0.3% by weight, relative to the amount of cementitious binder.

[0019] The oxyanion source is selected from the group consisting of borate sources and carbonate sources.

[0020] The presence of a borate or carbonate source ensures that the mixed water is initially highly concentrated in borate or carbonate ions. The borate or carbonate ions are thought to adsorb onto the surface of the mineral phase along with α-hydroxymonocarboxylic acid or its salts. The latter also partially remains in the pore solution, preventing the formation of ettringites initially.

[0021] The amount of the oxyanion source may be in the range of 0.1 to 3% by weight, preferably 0.5 to 2.0% by weight, and more preferably 0.5 to 1% by weight, relative to the amount of cementitious binder.

[0022] Typically, borate sources are rapidly soluble and contain inexpensive borate compounds. Suitable borate sources include sodium borate, boric acid, borite, and hexahydroborate, as well as mixtures thereof.

[0023] To achieve the desired effect, only carbonate sources with sufficient water solubility are suitable. The carbonate source should be 0.1 g / L at 25°C. -1 The inorganic carbonate may have the above water solubility. The water solubility of the inorganic carbonate is preferably determined in water, starting at a pH of 7. It is understood that the pH value at the solubility limit is higher than the starting pH value.

[0024] Inorganic carbonates can be selected from the group consisting of alkali metal carbonates such as sodium carbonate, sodium bicarbonate, potassium carbonate, or lithium carbonate; alkaline earth metal carbonates that meet the required water solubility, such as magnesium carbonate; and mixtures thereof. Guanidine carbonate can also be used as an inorganic carbonate. Sodium carbonate and sodium bicarbonate, particularly sodium carbonate, are especially preferred.

[0025] Alternatively, the carbonate source is selected from the group consisting of organic carbonates. "Organic carbonate" refers to an ester of carbonic acid. Organic carbonates are hydrolyzed in the presence of a cementitious system to release carbonate ions. In one embodiment, the organic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, glycerol carbonate, dimethyl carbonate, di(hydroxyethyl) carbonate, and mixtures thereof. Ethylene carbonate, propylene carbonate, glycerol carbonate, and mixtures thereof, particularly ethylene carbonate and / or propylene carbonate, are preferred. Mixtures of inorganic carbonates and organic carbonates can also be used.

[0026] In a preferred embodiment, the curing control agent further comprises a high-molecular-weight polycarboxylic acid.

[0027] The term "high molecular weight polycarboxylic acid" includes polymer compounds composed of monomer units containing carboxylic acid functional groups, and optionally, further monomer units. High molecular weight polycarboxylic acids are available as free acids or in partially or completely neutralized forms, i.e., as salts. The cations are not particularly limited and may be selected from the group consisting of alkali metals such as sodium or potassium, and ammonium cations.

[0028] Preferably, the polycarboxylic acid has a carboxylic acid equivalent weight of 333 or less. The carboxylic acid equivalent weight can be determined by weighing a sample of the polymeric polycarboxylic acid and titrating the carboxylic acid groups. Alternatively, for polymeric polycarboxylic acids with a known carboxylic acid group density, the carboxylic acid equivalent weight of the polymeric polycarboxylic acid can be determined as the reciprocal of the carboxylic acid group density expressed as equivalents per gram of polymer. This means, for example, that a polymeric polycarboxylic acid with a milliequivalent number of 3.0 meq / g has a carboxylic acid equivalent weight of 1 / 0.003 = 333.

[0029] The molecular weight of the high molecular weight polycarboxylic acid is 25,000 g / mol or less, preferably in the range of 1,000 to 25,000 g / mol, and most preferably in the range of 1,000 to 5,000 g / mol.

[0030] An effective high molecular weight polycarboxylic acid has a carboxylic acid group density within a certain range. Preferably, the milliequivalent is 3.0 meq / g or more, preferably 3.0 to 17.0 meq / g, more preferably 5.0 to 17.0 meq / g, and most preferably 5.0 to 14.0 meq / g.

[0031] High molecular weight polycarboxylic acids are available as free acids or in partially or completely neutralized forms, i.e., as salts. The cations are not particularly limited and may be selected from the group consisting of alkali metals such as sodium or potassium, and ammonium cations.

[0032] Preferably, the polymeric polycarboxylic acid or its salt is selected from the group consisting of homopolymers and copolymers of α,β-ethylenically unsaturated carboxylic acids; and copolymers of at least one α,β-ethylenically unsaturated carboxylic acid and at least one sulfo group-containing monomer.

[0033] Suitable α,β-ethylenically unsaturated carboxylic acids include acrylic acid, methacrylic acid, and polymaleic acid.

[0034] Suitable sulfo group-containing monomers include 2-propene-1-sulfonic acid (allyl sulfonic acid), 2-methyl-2-propene-1-sulfonic acid (methallyl sulfonic acid), vinyl sulfonic acid, styrene sulfonic acid, i.e., 2-styrene sulfonic acid, 3-styrene sulfonic acid, and 4-styrene sulfonic acid, as well as 2-acrylamido-2-methylpropane sulfonic acid (AMPS).

[0035] Preferably, the polymeric polycarboxylic acid is a homopolymer of acrylic acid, a homopolymer of methacrylic acid, a copolymer of acrylic acid and maleic acid, or a copolymer of methacrylic acid and maleic acid, most preferably a homopolymer of acrylic acid.

[0036] Examples of suitable polymer components are commercially available from BASF SE under the trade names SOKALAN®, such as SOKALAN® PA 20, SOKALAN® PA 15, SOKALAN® CP 10S, SOKALAN® PA 25 CL PN, SOKALAN® CP 12S, and SOKALAN® PA 40. "CP" generally indicates copolymer, while "PA" generally indicates polyacrylate.

[0037] If present, the amount of high molecular weight polycarboxylic acid or its salt may be in the range of 0.01 to 2% by weight, preferably 0.2 to 1.2% by weight, and more preferably 0.2 to 0.6% by weight, relative to the amount of cementitious binder.

[0038] The curing control agent is present in the mixed water and / or dry mixture. In actual embodiments, the curing control agent is dissolved in a portion of the mixed water, and a dry mixture containing a cementitious binder, optionally an external aluminate source, and optionally an external sulfate source is added to this mixture. The remainder of the water is then added to adjust the consistency.

[0039] In an alternative practical embodiment, the curing control agent is incorporated into the dry mixture before the addition of the mixed water.

[0040] Accelerator In a preferred embodiment, an accelerator solution containing at least one agent selected from the group consisting of an aluminum ion source, an aluminate source, and a silicate source is incorporated into the cementitious slurry. The addition of the accelerator solution may be performed before the foaming of the cementitious slurry, substantially simultaneously with the foaming of the cementitious slurry, or in a time overlap with the foaming of the cementitious slurry.

[0041] The present invention also envisions the use of combinations of accelerators, such as a combination of an aluminum ion source and a silicate source. To avoid undesirable interactions between accelerators, it is preferable to add individual accelerators to the cementitious slurry separately in time or space. For example, if the cementitious slurry is transported by pressure or pneumatic conveying through a tube or hose line, the introduction of accelerators into the cementitious slurry can be done by adding devices at different locations in the tube or hose line. Alternatively, the cementitious slurry flow can be divided into separate flows, accelerators can be added to each separate flow, and the separate flows can be recombined.

[0042] The accelerator acts to induce the formation of ettringite, a highly hydrated sulfoaluminate crystalline phase containing several water molecules in its structural units. During its formation, a considerable amount of mixed water is consumed, thus inducing a rapid increase in the viscosity of the cement mixture, resulting in a shorter curing time and the development of superior mechanical strength.

[0043] The accelerator is water-soluble. For the purposes of this invention, "water-soluble" means the solubility of the agent in water at 25°C, and atmospheric pressure is 0.1 g L. -1 Preferably 1 g L -1 Above, or more preferably 100g L -1 That's all.

[0044] According to one embodiment of the present invention, the accelerator solution includes an aluminum ion source. Preferably, the aluminum ion source is selected from the group consisting of aluminum salts, aluminum complexes, and mixtures thereof, and is preferably aluminum sulfate.

[0045] The source of aluminum ions may include, for example, aluminum salts and / or hydrates thereof such as sulfates, nitrates, and fluorides; aluminum oxide; and alkali-free accelerators based on aluminum compounds such as aluminum hydroxide. The source of aluminum ions can be selected from the group consisting of aluminum salts, aluminum complexes, and mixtures thereof. Preferably, the source of aluminum ions is selected from the group consisting of aluminum salts, and in particular aluminum sulfate.

[0046] Preferably, the amount of aluminum ions supplied in the hardening accelerator is in the range of 0.0005 to 0.05 mol, more preferably 0.004 to 0.012 mol, per 100 g of cementitious binder.

[0047] Preferably, the amount of sulfate in the aluminum ion source is in the range of 0.0008 to 0.075 mol, more preferably 0.006 to 0.02 mol, per 100 g of cementitious binder.

[0048] In addition to a source of aluminum ions, the accelerator may contain additives to provide storage stability and other desirable properties to the accelerator. The accelerator formulation can be stabilized by various chemicals. Examples of such stabilizers include organic acids such as carboxylic acids, dicarboxylic acids, hydroxycarboxylic acids, aminocarboxylic acids, phosphoric acid, phosphorous acid, phosphonic acid, and sulfamidic acid; inorganic acids such as sulfuric acid, nitrite, phosphoric acid, phosphorous acid, hydrofluoric acid, hexafluorosilicic acid, and mixtures thereof; urea; polymeric stabilizers such as polyacrylamide, polycarboxylate, polysulfonate, and copolymers, and mixtures thereof; aluminosilicates such as attapulgite, sepiolite, and bentonite; and colloidal silica. Furthermore, the curing accelerator may additionally contain calcium and magnesium compounds such as sulfate, and amines such as diethanolamine, triethanolamine, diisopropanolamine, and triisopropanolamine, and mixtures thereof.

[0049] Although not an essential component, a water-soluble magnesium salt may be included in the aluminum ion source system accelerator. Any of these salts may be used, but preferred salts are magnesium carbonate, magnesium sulfate, or a mixture of these salts. The magnesium sulfate used in the present invention may be any magnesium sulfate, but preferred magnesium is hydrated MgSO4·7H2O, which is known as the Epsom salt.

[0050] According to another embodiment of the present invention, the accelerator solution includes an aluminate source. As the aluminate source, alkali metal aluminates such as sodium aluminate are preferred.

[0051] According to another embodiment of the present invention, the accelerator solution includes a silicate source. The silicate source may be selected from the group consisting of water-soluble alkali metal silicates and quaternary ammonium silicates. A preferred silicate source is sodium silicate.

[0052] Alkali metal silicates are commercially available as water glass. Water glass can be obtained by the reaction of alkali metal carbonates with quartz sand (silicon dioxide). However, it can also be produced from a mixture of reactive silica and a suitable aqueous alkali metal hydroxide.

[0053] As water glass, alkali metal silicates of the following formula can be used. m SiO2·n M2O (In the formula, M is an alkali metal, preferably Li, Na, or K, or a mixture thereof, and the alkali metal silicate has a molar ratio m:n (also called the "coefficient") of 0.5 to 5, preferably 1 to 4, and more preferably 1.7 to 3.3).

[0054] The water glass is preferably sodium water glass, potassium water glass, or lithium water glass, and most preferably sodium water glass. However, it is also possible to use a mixture of the above water glasses.

[0055] Potassium water glass is highly hygroscopic and is therefore mainly sold as an aqueous solution, while sodium water glass with a favorable coefficient range is also sold as a solid. The solid content of commercially available aqueous water glass solutions is generally 20-60% by weight, preferably 40-60% by weight.

[0056] Alternatively, or in addition, the silicate source may be a quaternary ammonium silicate such as tetraalkylammonium silicate (generally including hydroxy-containing alkyl groups and alkoxy-containing alkyl groups having 1 to 4 carbon atoms in the alkyl or alkoxy group). The most preferred quaternary ammonium silicate is tetramethylammonium silicate.

[0057] From the viewpoint of ease of integration and efficiency, the curing accelerator preferably includes an aqueous solution of silicate source. The silicate is orthosilicate (SiO4) in an alkaline solution. 4- ), pyrosilicate (Si2O7 6- Numerous structures, including those containing ), as well as longer linear, cyclic, and branched structures, are all in dynamic equilibrium.

[0058] Preferably, the amount of silicate source introduced by the hardening accelerator is in the range of 0.03 to 10% by weight per 100 g of cementitious binder.

[0059] Foam stabilizer The aqueous cementitious slurry contains a foam stabilizer. Preferably, the foam stabilizer is selected from the group consisting of foam stabilizer inorganic particles, surfactants, proteins, and combinations thereof.

[0060] The foam stabilizer is present in the mixed water and / or dry mixture together with the hardening control agent and cementitious binder.

[0061] The term "foam-stabilized particles" is known in the art and may refer to pickering particles. Inorganic particles pretreated with a surface modifier may be used, including inorganic particles pretreated with an amphiphilic substance. In a preferred embodiment of the present invention, the foam-stabilized inorganic particles are inorganic particles treated with an amphiphilic compound.

[0062] The term "inorganic particles," as used herein, preferably refers to inorganic particles selected from the group consisting of the following: • Oxides containing pure and mixed metal oxides (especially aluminum oxide, silicon dioxide, spinel, cerium-gadolinium oxide, zirconium oxide, magnesium oxide, tin oxide, titanium oxide, and cerium oxide); • Hydroxides (especially aluminum hydroxide, calcium hydroxide, magnesium hydroxide, especially aluminum hydroxide); • Carbides (especially silicon carbide and boron carbide); • Nitrides (especially silicon nitride and boron nitride); • Phosphates (especially calcium phosphates such as tricalcium phosphate and hydroxyapatite); • Carbonates (especially nickel carbonate, calcium carbonate (crushed limestone or precipitated calcium carbonate), magnesium carbonate); • Silicates (especially silicon dioxide, silica fume, fly ash, quartz, crushed glass, slag, calcium silicate, mullite, cordierite, clay minerals such as kaolin or bentonite, zirconium silicate, zeolite, diatomaceous earth, especially silica fume, clay minerals, zirconium silicate; specifically clay minerals); Sulfates (especially calcium sulfate).

[0063] Preferably, the inorganic particles are selected from the group consisting of silica particles, alumina particles, zirconia particles, calcium carbonate particles, and mixtures thereof.

[0064] The particle size of inorganic particles can vary within a wide range. For powders (primary particles), a suitable median particle size D 50 The particle size range is 30 nm to 300 μm, preferably 100 nm to 250 μm, more preferably 100 nm to 150 μm, and even more preferably 100 nm to 100 μm. In further embodiments, a suitable particle size range is 100 nm to 10 μm, preferably 100 nm to 2 μm. It has been found that the particle size distribution is not very important. Good foams can be obtained with both narrow and wide particle size distributions.

[0065] In a preferred embodiment of the present invention, at least one group of inorganic particles has a median particle diameter D within the range of 30 nm to 300 μm in measurement by the dynamic light scattering method. 50 It has.

[0066] The term "particle diameter (D x )" refers to the diameter of a particle distribution in which x% of the particles have a smaller diameter. Therefore, D 50 The particle diameter is the median particle diameter. D x The particle diameter can be measured, for example, by laser diffraction or dynamic light scattering method (DLS). According to the present invention, it is preferable to use the dynamic light scattering method (DLS) conforming to ISO 22412: 2008. The dynamic light scattering method (DLS), sometimes referred to as the quasi-elastic light scattering method (QELS), is a non-invasive and established technique for measuring the size and size distribution of molecules and particles, typically in the submicron region. In the present invention, particles dispersed in a liquid such as water or ethanol were preferably characterized. Due to the Brownian motion of the particles or molecules in the suspension, the laser light is scattered at different intensities. By analyzing these intensity fluctuations, the velocity of Brownian motion, and thus the particle diameter, can be obtained using the Stokes-Einstein relation. The distribution can be a volume distribution (D v ), surface distribution (D s ) or number distribution (D n ). In the context of the present application, the D x value refers to the number distribution, where x (number)% of the particles have a smaller diameter.

[0067] The term "amphiphilic compound" is known in the art and relates to an organic compound having a non-polar part (also identified as a tail or group R) and a polar part (also identified as a head group). Therefore, suitable amphiphilic molecules typically contain a tail bonded to the head group by a covalent bond. Such amphiphilic molecules typically contain one tail and one head group, but may contain two or more head groups.

[0068] The tail can be aliphatic (straight or branched) or cyclic (alicyclic or aromatic) and can have substituents. Such substituents include, for example, -C n H 2n+1 (n≦8), secondary-OH, secondary-NH2, etc. The preferred tail is a linear carbon chain having 2 to 8 carbon atoms, which may be optionally substituted, more preferably a linear carbon chain having 3 to 8, 4 to 8, or 5 to 8 carbon atoms. Throughout this specification, “secondary-OH” and “secondary-NH2” mean that the resulting substituted tail group constitutes a secondary alcohol or secondary amine. The head group attached to the tail is preferably an ionic group, an ionic group, and / or a polar group. Examples of possible head groups and their corresponding salts are shown in Table 1 below (where the tail is denoted as R).

[0069] [Table 1]

[0070] [Table 2]

[0071] [Table 3]

[0072] The preferred head group is selected from the group consisting of carboxylic acid groups, gallates, amines, and sulfonates. Particularly preferred head groups are selected from the group consisting of carboxylic acid groups (i.e., -C(O)OH groups), gallates, and amine groups (where X preferably represents H or methyl). The preferred carboxylic acid is enanthic acid (heptanoic acid). The preferred gallate is butyl gallate. The preferred amine is heptylamine. The carboxylic acid group is the most preferred.

[0073] Amphiphilic molecules reduce the surface tension of the air-water interface to a value of 65 mN / m or less at a concentration of 0.5 mol / l or less.

[0074] Preferably, the amphiphilic molecules have a limiting micelle concentration (CMC) greater than 10 μmol / l, and / or they have a solubility greater than 1 μmol / l.

[0075] The amphiphilic compound comprises at least one polar head group and at least one nonpolar tail group, wherein the at least one head group is selected from the group consisting of phosphates, phosphonates, sulfates, sulfonates, alcohols, amines, amides, pyrrolidines, gallates, and carboxylic acids; and wherein the at least one tail group is selected from the group consisting of aliphatic or aromatic groups, or cyclic groups having 2 to 8 carbon atoms, wherein the carbon atoms may be optionally substituted with one or more identical or different substituents selected from the group consisting of C1 to C6-alkyl, secondary-OH, and secondary-NH2.

[0076] In preferred embodiments of the present invention, the amphiphilic compound comprises at least one head group selected from the group consisting of a carboxylic acid group, a 3,4,5-trihydroxybenzoyloxy group, and an amino group, and at least one tail group selected from an aliphatic group having 2 to 8 carbon atoms.

[0077] It is understood that hydrophobic inorganic particles are formed by combining inorganic particles as defined herein with amphiphilic compounds as defined herein. The term “hydrophobic inorganic particles” refers to inorganic particles whose surface has been modified with amphiphilic molecules so that the hydrophilic properties of the inorganic particles are reduced. In this context, surface modification means that the amphiphilic compound is adsorbed onto the surface of the particles.

[0078] The amount of amphiphilic compounds per surface area of ​​inorganic particles (BET) is 0.5 to 160 μmol / m². 2 Preferably 10-140 μmol / m³ 2 More preferably 20-120 μmol / m³ 2In short, the BET multipoint method may include the steps of introducing a suitable amount of inorganic particles into a BET tube, and then degassing the sample using a nitrogen stream at a temperature of 60°C for approximately 5.0 hours before analysis. The multipoint surface area can be determined using nitrogen as the adsorbent gas at 77.350 Kelvin. The cross-sectional area of ​​a nitrogen adsorbent of 16.200 square angstroms can be used to calculate the surface area. Various instruments are commercially available for performing this analysis and determining the BET of particles. One example of such an instrument is the Nova 800 (Quantachrome Instruments).

[0079] Alternatively, or in addition, a surfactant may be used as a foam stabilizer. Examples of surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0080] Examples of nonionic surfactants include aliphatic alcohols, cetyl alcohol, stearyl alcohol, and cetos-stearyl alcohol (mainly containing cetyl and stearyl alcohols), as well as oleyl alcohol. Further examples include polyethylene glycol alkyl ethers such as octaethylene glycol monododecyl ether or pentaethylene glycol monododecyl ether (Brij)CH3-(CH2). 10-16 -(O-C2H4) 1-25 -OH; polypropylene glycol alkyl ether CH3-(CH2) 10-16 -(O-C3H6) 1-25 -OH; Glucoside alkyl ethers such as decyl glucoside, lauryl glucoside, and octyl glucoside CH3-(CH2) 10-16 -(O-glucoside) 1-3 -OH; Polyethylene glycol octylphenyl ether C8H such as Triton X-100 17 -(C6H4)-(O-C2H4) 1-25 -OH; Polyethylene glycol alkylphenyl ether C9H such as Nonoxynol-9 19 -(C6H4)-(O-C2H4) 1-25Examples include -OH; glycerol alkyl esters such as glyceryl laurate; polyoxyethylene glycol sorbitan alkyl esters such as polysorbate; sorbitan alkyl esters such as span; cocamide MEA, cocamide DEA; dodecyldimethylamine oxide; block copolymers of polyethylene glycol and polypropylene glycol such as poloxamer; and polyethoxylated tallow amines (POEA). Another preferred nonionic surfactant is alkyl polyglucoside. Alkyl polyglucosides generally have the formula H-(C6H 10 O5) m -OR 1 It has, in the formula, (C6H 10 O5) is a glucose unit, and also, R 1 is C6~C 22 - Alkyl alkyl group, preferably C8-C 16 - Alkyl groups, and especially C8~C 12 -It is an alkyl group, and m = 1 to 5.

[0081] Anionic surfactants contain anionic functional groups such as sulfates, sulfonates, phosphates, and carboxylates in their head structure. Major alkyl sulfates include ammonium lauryl sulfate, sodium lauryl sulfate (sodium dodecyl sulfate, SLS, or SDS), and related alkyl ether sulfates such as sodium laureth sulfate (sodium lauryl ether sulfate or SLES) and sodium myreth sulfate. Other examples include docusate (sodium dioctyl sulfosuccinate), perfluorooctanesulfonate (PFOS), perfluorobutanesulfonate, alkyl aryl ether phosphates, and alkyl ether phosphates. Preferred carboxylates include alkyl carboxylates such as sodium stearate. More specific species include sodium lauroyl sarcosinate and carboxylate-based fluorinated surfactants such as perfluorononanoate and perfluorooctanoate (PFOA or PFO).

[0082] Cationic surfactants include primary, secondary, or tertiary amines, depending on the pH, with primary and secondary amines exhibiting a positive charge at pH levels below 10. One example is octenidine dihydrochloride. Furthermore, cationic surfactants include permanently charged quaternary ammonium salts such as cetrimonium bromide (CTAB), cetylpyridinium chloride (CPC), benzalkonium chloride (BAC), benzethonium chloride (BZT), dimethyldioctadecylammonium chloride, and dioctadecyldimethylammonium bromide (DODAB).

[0083] Amphoteric surfactants have both a cationic and anionic center in the same molecule. The cationic moiety is based on a primary, secondary, or tertiary amine, or a quaternary ammonium cation. The anionic moiety can be more diverse and includes sulfonates such as sultaine CHAPS (3-[(3-coramidopropyl)dimethylammonio]-1-propanesulfonate) and cocamidopropyl hydroxysultaine. Betaines such as cocamidopropyl betaine have a carboxylate with ammonium. The most common biological amphoteric surfactants have phosphate anions with amines or ammonium, such as phospholipids like phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine, and sphingomyelin.

[0084] The proportion of surfactant can vary over a wide range. The surfactant may be present in an amount of 5% by weight or less, preferably 1.5% by weight or less.

[0085] Alternatively, or in addition, proteins may be used as foam stabilizers. Non-limiting examples of proteins include animal-derived proteins such as bovine serum albumin, egg ovalbumin, milk casein, β-lactoglobulin, or keratin, or plant-derived proteins such as soybean-derived proteins. Proteins having a molecular weight of 1,000 to 50,000 daltons can be suitably used.

[0086] polyol The method of the present invention may include a polyol as an optional component. In a preferred embodiment, at least one of the curing control agent and the curing accelerator contains a polyol.

[0087] The polyol is used in an amount of 0.05 to 2.5% by weight, preferably 0.15 to 0.5% by weight, relative to the amount of cementitious binder.

[0088] It is believed that polyols such as glycerol chelate calcium ions, for example, calcium sulfate or C3A. As a result, the dissociation of calcium ions is promoted. Chelation of calcium ions stabilizes the calcium in the solution and also promotes the dissociation of the calcium aluminate phase, making the aluminates derived from these calcium aluminate phases more readily available.

[0089] The term "polyol" is intended to refer to a compound having at least two alcoholic hydroxyl groups in its molecule. Useful polyols have at least three alcoholic hydroxyl groups in their molecule, for example, three, four, five, or six alcoholic hydroxyl groups. Polyols having vicinal hydroxyl groups are preferred. Most preferred are polyols having at least three hydroxyl groups bonded to three consecutive carbon atoms.

[0090] The ability of polyols to chelate calcium ions and thereby stabilize calcium in solution can be evaluated by a calcium aluminate precipitation test. In one embodiment, in a calcium aluminate precipitation test in which a test solution obtained by adding 20 mL of 1 mol / L NaOH aqueous solution and 50 mL of 25 mmol / L NaAlO2 aqueous solution to 400 mL of 1 wt% aqueous solution of polyol is titrated with a 0.5 mol / L CaCl2 aqueous solution at 20°C, the polyol inhibits the precipitation of calcium aluminate up to a calcium concentration of 75 ppm, preferably 90 ppm.

[0091] The test detects the precipitation of calcium aluminate by turbidity. Initially, the test solution is clear. The clear test solution is titrated with an aqueous CaCl2 solution at a constant rate, for example, 2 mL / min, as described above. Continuous addition of CaCl2 leads to the precipitation of calcium aluminate, resulting in a change in the optical properties of the test solution due to turbidity. The maximum calcium concentration (Ca) before turbidity occurs is measured. 2+ The titration endpoint, expressed as (as), can be calculated from the elapsed time until the point of occurrence.

[0092] In a preferred embodiment, the polyol is selected from the group consisting of compounds composed only of carbon, hydrogen, and oxygen, and which do not contain a carboxyl group (C(O)OH) in their molecule.

[0093] In one embodiment, the polyol is a monosaccharide, oligosaccharide, water-soluble polysaccharide, a compound of general formula (PI), or a compound of general formula (PI): [ka] (In the formula, X is [ka] (In the formula, R is -CH2OH, -NH2. n is an integer from 1 to 4. (m is an integer between 1 and 8) (is) It is selected from the group consisting of dimers or trimers.

[0094] In one embodiment, the polyol is selected from saccharides. Useful saccharides include monosaccharides such as glucose and fructose; disaccharides such as lactose and sucrose; trisaccharides such as raffinose; and water-soluble polysaccharides such as amylose and maltodextrin. Monosaccharides and disaccharides, particularly sucrose, are especially preferred.

[0095] In other preferred embodiments, the polyol is selected from the group of compounds consisting only of carbon, hydrogen, and oxygen, and which do not contain either a carboxyl group (C(O)OH) or a carbonyl group (C=O) in their molecule. The term “carbonyl group” is understood to include tautomerized forms of the C=O group, i.e., a pair of double-bonded carbon atoms adjacent to a hydroxyl group (-C=C(OH)-).

[0096] Compounds of formula (PI) where X is (P-Ia) are generally called sugar alcohols. Sugar alcohols are typically organic compounds derived from carbohydrates and containing one hydroxyl group (-OH) bonded to each carbon atom. Useful sugar alcohols include mannitol, sorbitol, xylitol, arabitol, erythritol, and glycerol. Of these, glycerol is particularly preferred. It is assumed that polyhydric alcohol carbonates, such as glycerol carbonate, can act as polyol sources.

[0097] Examples of compounds of formula (PI) where X is (P-Ib) include pentaerythritol and tris(hydroxymethyl)aminomethane.

[0098] Triethanolamine is an example of a compound of formula (PI) where X is (P-Ic).

[0099] Dimers or trimers refer to compounds derived from a condensation reaction in which two or three molecules of general formula (PI) are linked via ether crosslinks, and formally involve the elimination of one or two water molecules. Examples of dimers and trimers of compounds of formula (PI) include dipentaerythritol and tripentaerythritol.

[0100] cementite binder The method of the present invention can be used with a variety of cementitious binders comprising one or more silicate mineral phases and one or more calcium aluminate mineral phases.

[0101] Typically, the calcium silicate mineral phase and the calcium aluminate mineral phase constitute at least 90% by weight of the cementitious binder. Furthermore, the calcium silicate mineral phase preferably constitutes at least 60% by weight, more preferably at least 65% by weight, and most preferably 65-75% by weight of the cementitious binder.

[0102] For convenience, the mineralogical phases are shown in this specification using cement notation. In cement notation, the main compounds are represented by oxide species: CaO is denoted by C, MgO by M, SiO2 by S, Al2O3 by A, SO3 by $, Fe2O3 by F, and H2O by H.

[0103] Appropriately, the calcium silicate mineral phase is selected from the group consisting of C3S (alite) and C2S (belite). The calcium silicate mineral phase is primarily responsible for the final strength characteristics.

[0104] Appropriately, the calcium aluminate mineral phase is selected from the group consisting of C3A, C4AF, and C12A7, particularly C3A and C4AF.

[0105] In a preferred embodiment, the cementitious binder comprises a Portland cement clinker binder. The term “Portland cement clinker binder” refers to any cement compound containing Portland clinker, particularly CEM I, within the meaning of section 5.2 of the standard EN 197-1. The preferred cement is ordinary Portland cement (OPC) in accordance with DIN EN 197-1. The phases constituting Portland cement are mainly alite (C3S), belite (C2S), calcium aluminate (C3A), calcium ferroaluminate (C4AF), and other non-major phases. Commercially available OPC may contain calcium sulfate (<7% by weight) or may be substantially calcium sulfate-free (<1% by weight).

[0106] In a preferred embodiment of the present invention, the cementitious binder is Al(OH)4- The available aluminate content, calculated as such, is controlled. Typically, the approximate proportion of the main minerals in Portland cement is calculated using the Bogue formula, based on the elemental composition of the clinker, determined, for example, by X-ray fluorescence analysis (XRF). Such methods yield the oxide composition of the elements. This means that the amount of Al is reported as Al2O3. It has been found that cements with the same apparent Al2O3 content exhibit very different properties in terms of early strength and controllability through hydration control. Cement contains Al sources with greatly different mineralogical properties and solubility. It has been found that not all Al is available or readily available for ettringite formation. Only Al-containing mineral phases with appropriate solubility in the aqueous environment of cement paste are involved in ettringite formation. Other Al-containing minerals, such as crystalline aluminum oxide like corundum, do not form aluminates in an aqueous environment due to their limited solubility. Therefore, elemental analysis alone cannot provide a reliable value for available aluminates.

[0107] Therefore, the present invention relates to Al(OH)4 - It depends on the available aluminate calculated as follows. "Available aluminate" is Al(OH)4 in an alkaline aqueous environment. - This means that it contains a mineral phase and Al-containing compounds that can generate Al(OH)4. Calcium aluminate phases such as C3A (Ca3Al2O6) dissolve in an alkaline aqueous environment to form Al(OH)4. - and Ca 2+ It yields ions. In this specification, Al(OH)4 - The concentration of the mineral phase and Al-containing compound that can generate this is Al(OH)4 per 100g of cementitious binder. - It is expressed as the number of moles.

[0108] The common calcium aluminate mineral phase (as opposed to crystalline aluminum oxide) is considered a source of available aluminate. Therefore, the amount of available aluminate in a given cementitious binder can be determined by a method that can identify the mineral phases constituting the cementitious binder. A useful method for this purpose is Rietveld refinement of X-ray diffraction (XRD) powder patterns. This software technique is used to refine various parameters, including lattice parameters, peak positions, intensities, and shapes. This allows for the calculation of a theoretical diffraction pattern. When the calculated diffraction pattern closely matches the data from the tested sample, accurate quantitative information about the contained mineral phases can be determined.

[0109] Generally, in an alkaline aqueous environment, Al(OH)4 - The calcium aluminate mineral phases capable of generating are tricalcium aluminate (C3A), monocalcium aluminate (CA), meienite (C12A7), grocite (CA2), Q phase (C20A13M3S3), or tetracalcium aluminoferrite (C4AF). In practice, when the cementitious binder is Portland cement, generally only the following mineral phases need to be evaluated: tricalcium aluminate (C3A), monocalcium aluminate (CA), meienite (C12A7), and tetracalcium aluminoferrite (C4AF), especially tricalcium aluminate (C3A) and tetracalcium aluminoferrite (C4AF).

[0110] Alternatively, the amount of usable aluminate can be determined from the elemental composition of the cementitious binder by, for example, determining the total amount of Al by XRF, and then subtracting the amount of crystalline aluminum compounds that cannot produce usable aluminate, as determined by XRD and Rietveld refinement. This method also considers soluble amorphous aluminum compounds that can produce usable aluminate. Examples of such crystalline aluminum compounds that cannot produce usable aluminate include, for example, compounds of the melilite group such as gaylanite (C2AS), compounds of the spinel group such as spinel (MA), and mullite (Al2Al 2+2x Si 2-2x O 10-x Examples include ) and corundum (Al2O3).

[0111] In one embodiment, the present invention utilizes a cementitious binder containing 0.05 to 0.2 mol of available aluminate derived from a calcium aluminate mineral phase, as determined, for example, by XRD analysis.

[0112] Alternatively, if the cementitious binder does not inherently contain a sufficient concentration of aluminate per 100g of cementitious binder, an external aluminate source can be added. Therefore, in some embodiments, the cementitious slurry contains an external aluminate source.

[0113] The external aluminate source provides the available aluminate as defined above. Generally, the external aluminate source provides, for example, 0.05 g L at 25°C and atmospheric pressure. -1 The following is preferably 0.005 g L -1 The following is a poorly soluble aluminate source having the following water solubility. The limited solubility of the external aluminate source acts to prevent premature hardening of the uncontrolled cementitious slurry. The external aluminate source is included in the cementitious slurry in an undissolved form (e.g., powder) or in a partially dissolved form.

[0114] Appropriately, the external aluminate source is selected from the group consisting of non-calcareous aluminate sources such as amorphous aluminum hydroxide, and calcareous aluminate sources such as high-alumina cement, sulfoaluminate cement, or synthetic calcium aluminate mineral phase.

[0115] Preferably, amorphous aluminum hydroxide is used as an external aluminate source.

[0116] High-aluminate cement refers to cement containing a calcium aluminate phase at a high concentration, such as at least 30% by weight. More precisely, the aluminate-type mineralogical phase includes tricalcium aluminate (C3A), monocalcium aluminate (CA), meienite (C12A7), tetracalcium aluminoferrite (C4AF), or several combinations of these phases.

[0117] Sulfoaluminate cement typically contains more than 15% by weight of e-limite (chemical formula 4CaO.3Al2O3.SO3 or C4A3$ in cement notation).

[0118] A suitable synthetic calcium aluminate mineral phase is amorphous myenite (C12A7).

[0119] Preferably, the cementitious slurry contains a calcium aluminate mineral phase and 0.02 to 0.20 mol of total available aluminate (Al(OH)4) per 100 g of cementitious binder, derived from an optional external aluminate source. - It contains (calculated as follows). Preferably, the cementitious slurry contains at least 0.065 mol, and more particularly at least 0.072 mol, of total available aluminate per 100 g of cementitious binder.

[0120] It was found that cementitious slurry containing at least 0.05 mol of total available aluminate per 100 g of cementitious binder exhibits optimal performance in terms of pre-curing air-drying time and early strength development. In other cases, if the cementitious binder contains more than 0.2 mol of total available aluminate per 100 g of cementitious binder, the air-drying time is shortened due to excessively rapid early strength development.

[0121] In a preferred embodiment, the cementitious slurry further includes an external sulfate source, preferably selected from the group consisting of gypsum, hemihydrate gypsum, anhydrous gypsum, and mixtures thereof.

[0122] After incorporating the accelerator, the total molar ratio of available aluminate to sulfate (including aluminate and sulfate inherently contained in the cement, any external aluminate, and / or sulfate sources, as well as aluminum and sulfate contained in the hardening accelerator) is 0.4 to 3.5.

[0123] A sulfate source is a compound capable of providing sulfate ions in an alkaline aqueous environment. Generally, a sulfate source has water solubility at a temperature of 30°C and at least 0.6 mmol g·L. -1 This results in a sulfate ion concentration. The water solubility of the sulfate source is preferably determined in water, starting from a pH value of 7.

[0124] Specifically, the molar ratio of total available aluminate to sulfate (including aluminate and sulfate essentially contained in the cement, any external aluminate, and / or sulfate sources, and aluminum and sulfate contained in the hardening accelerator) is in the range of 0.4 to 3.5, preferably 0.57 to 0.8, and particularly about 0.67. This means that the mixing ratio in the composition is adjusted so that the highest possible proportion of ettringite is formed from the available aluminate.

[0125] As previously mentioned, commercially available Portland cement typically contains small amounts of sulfate sources. If the intrinsic amount of sulfate is unknown, it can be determined by methods well known to those skilled in the art, such as elemental analysis by XRF. Common sulfate sources used in cement production, such as alkaline earth metal sulfates, alkali metal sulfates, or mixtures thereof (gypsum, hemihydrate gypsum, anhydrous gypsum, alkanite, thenardite, singenite, langbainite, etc.), are typically crystalline, and their amounts can also be determined by XRD. Both the intrinsic amount of sulfate and any added external sulfate sources are taken into consideration when calculating the molar ratio of total available aluminate to sulfate.

[0126] Typically, the external sulfate source can be selected from the group consisting of calcium sulfate dihydrate, anhydrous gypsum, α- and β-hemihydrate gypsum, i.e., α-basanite and β-basanite, or mixtures thereof. Preferably, the calcium sulfate source is α-basanite and / or β-basanite. The sulfate source is not particularly limited, and other possible sulfate sources are alkali metal sulfates such as potassium sulfate or sodium sulfate.

[0127] The additive is expected to act as a source of both aluminate and sulfate, such as aluminum sulfate hexahydrate or aluminum sulfate octahydrate. Preferably, the sulfate source is calcium sulfate.

[0128] Preferably, the mineral foam contains sulfate in an amount ranging from 0.025 to 0.5 mol per 100 g of cementitious binder, including the intrinsic SO4 content of the binder and any added external sulfate source.

[0129] Auxiliary cementitious material In one embodiment, the mineral foam further comprises at least one of a latent hydraulic binder, a pozzolanic binder, and a filler material.

[0130] In this specification, “latent hydraulic binder” is preferably a binder having a molar ratio (CaO+MgO):SiO2 of 0.8 to 2.5, particularly 1.0 to 2.0. Generally, the above latent hydraulic binder can be selected from industrial and / or synthetic slags, particularly from the group consisting of blast furnace slag, electroheated rinsing slag, steel slag and mixtures thereof. “Pozzolann binder” can generally be selected from the group consisting of amorphous silica, preferably precipitated silica, fumed silica and microsilica, fly ash such as crushed glass, metakaolin, aluminosilicate, preferably lignite fly ash and hard carbon fly ash, natural pozzolann such as tuff, volcanic soil and volcanic ash, calcined clay, calcined shale, rice husk ash, natural and synthetic zeolites, and mixtures thereof.

[0131] Slag can be industrial slag (i.e., waste from industrial processes) or synthetic slag. Since industrial slag is not always available in consistent quantities and quality, the latter can be advantageous.

[0132] Blast furnace slag (BFS) is a waste product of the glass furnace process. Other materials include granular blast furnace slag (GBFS) and finely ground granular blast furnace slag (GGBFS). Finely ground blast furnace slag varies in terms of fineness and particle size distribution depending on its origin and processing method, where fineness affects reactivity. The Blaine value is used as a parameter for fineness, typically ranging from 200 to 1000 mm. 2 kg -1 Preferably 300-500m 2 kg -1 It has the order of [order of magnitude]. Finer grinding results in higher reactivity.

[0133] In this specification, however, the term “blast furnace slag” is intended to include materials resulting from all of the above levels of processing, grinding, and quality (i.e., BFS, GBFS, and GGBFS). Blast furnace slag generally contains 30–45 wt% CaO, about 4–17 wt% MgO, about 30–45 wt% SiO2, and about 5–15 wt% Al2O3, typically about 40 wt% CaO, about 10 wt% MgO, about 35 wt% SiO2, and about 12 wt% Al2O3.

[0134] Electrothermal phosphorus slag is a waste product from the production of electrothermal phosphorus. It is less reactive than blast furnace slag and contains approximately 45-50 wt% CaO, approximately 0.5-3 wt% MgO, approximately 38-43 wt% SiO2, approximately 2-5 wt% Al2O3, and approximately 0.2-3 wt% Fe2O3, as well as fluorides and phosphates. Steel slag is a waste product from various steelmaking processes and its composition varies greatly.

[0135] Amorphous silica is preferably X-ray amorphous silica, i.e., silica whose degree of crystallinity is not revealed by powder diffraction. The SiO2 content in amorphous silica is advantageously at least 80% by weight, preferably at least 90% by weight. Precipitated silica is obtained on an industrial scale by a precipitation process starting from water glass. Precipitated silica derived from some manufacturing processes is also called silica gel.

[0136] Fumed silica is produced by the reaction of chlorosilanes, such as silicon tetrachloride, in a hydrogen / oxygen flame. Fumed silica is produced in 50-600 m 2 This is an amorphous SiO2 powder with a specific surface area of ​​5-50 nm and a particle size of 5-50 nm.

[0137] Microsilica is a by-product of silicon or ferrosilicon production and is similarly composed mostly of amorphous SiO2 powder. The particles have a diameter on the order of 0.1 μm. The specific surface area is 15–30 m². 2 g -1 This is the order.

[0138] Metakaolin is produced when kaolin is dehydrated. At 100-200°C, kaolin releases physically bound water, while at 500-800°C, dehydroxylation occurs, accompanied by the breakdown of the lattice structure and the formation of metakaolin (Al2Si2O7). Therefore, pure metakaolin contains approximately 54% by weight of SiO2 and approximately 46% by weight of Al2O3.

[0139] Fly ash is produced, in particular, during the combustion of coal in power plants. Class C fly ash (lignite fly ash) contains about 10 wt% CaO, according to International Publication No. 08 / 012438, while Class F fly ash (hard coal fly ash) contains less than 8 wt%, preferably less than 4 wt%, and typically about 2 wt% CaO.

[0140] Preferably, the cementite binder contains less than 5% by weight, more preferably less than 3.5% by weight, and most preferably less than 2% by weight of cementite hydrate products, based on the total weight of the cementite binder, before being mixed with water in the presence of a hardening control agent. Generally, the following cementite hydrate products should be evaluated: ettringite, portlandite, and singenite. The presence and concentration of these cementite hydrate products can be determined by Rietveld refinement of the X-ray diffraction (XRD) powder pattern. This means that the cementite binder has no history of being stored in a high-humidity environment. The inventors believe that ettringite, among other cementite hydrate products, is otherwise already formed in the powdered composition. These ettringite crystals are crushed when the cementite binder is mixed with water at the time of use, but the control of ettringite formation provided by the present invention is less effective. Therefore, storage of cementite binder in a high-humidity environment should be avoided.

[0141] Dispersant In a preferred embodiment, the cementitious slurry further contains a dispersant.

[0142] To achieve the above-mentioned transportability or pumpability, it is preferable to add a water-reducing agent, particularly a fluidizer or high-performance fluidizer, preferably a polyoxypolycarboxylate or phosphonate-based fluidizer, to the construction material before the transport step.

[0143] Water-reducing agents can typically reduce the amount of mixed water by 10–15% for a given workability. Examples of water-reducing agents include lignosulfonates, hydroxycarboxylic acids, carbohydrates, and other specific organic compounds, such as glycerol, polyvinyl alcohol, sodium aluminomethylsilicate, and sulfanilic acid, as described in the Concrete Admixtures Handbook, Properties Science and Technology, VSRamachhandran, Noyes Publications, 1984.

[0144] High-performance fluidizers belong to a new class of water-reducing agents and can reduce the water content of mixed water by approximately 30% by mass for a given workability. An example of a high-performance fluidizer is a PCP high-performance fluidizer. The terms "PCP" or "polyoxypolycarboxylate" are understood herein to refer to copolymers of acrylic acid or methacrylic acid and polyoxyethylene (POE) or its esters.

[0145] It will be recognized that many useful dispersants contain carboxyl groups, salts thereof, or hydrolyzable groups that release carboxyl groups upon hydrolysis. Preferably, the milliequivalent number of carboxyl groups contained in these dispersants (or carboxyl groups that can be released by hydrolysis of hydrolyzable groups contained in the dispersant) is less than 3.0 meq / g, assuming that all carboxyl groups are in a non-neutralized form.

[0146] Examples of useful dispersants include: -Pendant cement- A comb-shaped polymer having a carbon-containing main chain to which stationary groups and polyether side chains are bonded; - A nonionic comb-shaped polymer having a carbon-containing main chain to which pendant hydrolyzable groups and polyether side chains are bonded, wherein the hydrolyzable groups release cement-fixing groups upon hydrolysis; -Al 3+ Fe 3+ or Fe 2+ A colloidal dispersion preparation comprising a polyvalent metal cation and a polymeric dispersant containing anionic and / or anion-generating groups and a polyether side chain, wherein the polyvalent metal cation exists in a hyperstoichiometric amount calculated as the cation equivalent based on the sum of the anionic and anion-generating groups of the polymeric dispersant; -Sulfonated melamine-formaldehyde condensate; -Lignosulfonate; -Sulfonated ketone-formaldehyde condensate; -Sulfonated naphthalene-formaldehyde condensate; - A phosphonate-containing dispersant, preferably a phosphonate-containing dispersant comprising at least one polyalkylene glycol unit; and - These mixtures These are some examples.

[0147] Preferably, the dispersant is present in a weight percentage of 0.005 to 1.0, preferably 0.05 to 0.5, and more preferably 0.02 to 0.15, relative to the cementitious binder.

[0148] A comb-shaped polymer having a carbon-containing main chain to which pendant cement-fixing groups and polyether side chains are bonded is particularly preferred. The cement-fixing groups are anionic and / or anion-generating groups such as carboxylic acid groups, phosphonic acid groups, or phosphate groups or their anions. The anion-generating groups are acidic groups present in the polymer dispersant that can be converted to their respective anionic groups under alkaline conditions.

[0149] Preferably, the structural unit containing anionic and / or anion-generating groups has the general formula (Ia), (Ib), (Ic), and / or (Id): [ka] (In the formula, R 1 is H, C1-C4 alkyl, preferably H or methyl; X is NH-(C n1 H 2n1 ) or O-(C n1 H 2n1 ) where n1 = 1, 2, 3, or 4, or a chemical bond, with a nitrogen atom or oxygen atom bonded to the CO group; R 2 is OM, PO3M2, or O-PO3M2; however, R 2 If OM is true, then X is a chemical bond. [ka] (In the formula, R 3 is H or C1-C4 alkyl, preferably H or methyl; n is 0, 1, 2, 3, or 4; R 4 It is PO3M2 or O-PO3M2); [ka] (In the formula, R 5 is H or C1-C4 alkyl, preferably H; Z is O or NR 7 and; R 7 H, (C n1 H 2n1 )-OH, (C n1 H 2n1 )-PO3M2, (C n1 H 2n1 )-OPO3M2, (C6H4)-PO3M2, or (C6H4)-OPO3M2; and n1 is 1, 2, 3, or 4; [ka] (In the formula, R 6is H or C1-C4 alkyl, preferably H; Q is NR 7 or O; R 7 is H, (C n1 H 2n1 )-OH, (C n1 H 2n1 )-PO3M2, (C n1 H 2n1 )-OPO3M2, (C6H4)-PO3M2, or (C6H4)-OPO3M2; n1 is 1, 2, 3 or 4; and where each M is, independently, H or a cation equivalent) is one of these.

[0150] Preferably, the structural unit containing a polyether side chain is of the general formula (IIa), (IIb), (IIc) and / or (IId):

Chemical formula

[0151] The molar ratio of structural unit (I) to structural unit (II) varies from 1:3 to about 10:1, preferably 1:1 to 10:1, and more preferably 3:1 to 6:1. Polymeric dispersants containing structural units (I) and (II) can be prepared by conventional methods, for example, by free radical polymerization or controlled radical polymerization. Preparations of dispersants are described, for example, in European Patent No. 0894811, European Patent No. 1851256, European Patent No. 2463314, and European Patent No. 0753488.

[0152] More preferably, the dispersant is selected from the group of polycarboxylate ethers (PCEs). In PCEs, the anionic group is a carboxylic acid group and / or a carboxylate group. PCEs can preferably be obtained by radical copolymerization of a polyether macromonomer and a monomer containing anionic and / or anion-generating groups. It is preferable that at least 45 mol%, preferably at least 80 mol%, of all structural units constituting the copolymer are structural units of a polyether macromonomer or a monomer containing anionic and / or anion-generating groups.

[0153] Further classes of suitable pendant cement-fixing groups and comb-like polymers having a carbon-containing main chain to which polyether side chains are bonded are structural unit (III) [ka] (In the formula, T is a phenyl, naphthyl, or heteroaryl having 5 to 10 ring atoms (of which one or two atoms are heteroatoms selected from the group consisting of N, O, and S); n3 is either 1 or 2; B is N, NH, or O, where n3 is 2 if B is N, and 1 if B is NH or O; A is a C2-C5 alkylene or CH2CH(C6H5), preferably a C2-C3 alkylene; a2 is an integer between 1 and 300; R 26 H, C1~C 10 Alkyl, C5-C8 cycloalkyl, aryl, or heteroaryl having 5-10 ring atoms (of which one or two atoms are heteroatoms selected from the group consisting of N, O, and S). and (IV), where structural unit (IV) is structural unit (IVa) and (IVb): [ka] (In the formula, D is a phenyl, naphthyl, or heteroaryl having 5 to 10 ring atoms (of which one or two atoms are heteroatoms selected from the group consisting of N, O, and S); E 3 is N, NH, or O, where m is E 3 If N, then 2, and m is E 3 If it is NH or O, it is 1; A is a C2-C5 alkylene or CH2CH(C6H5), preferably a C2-C3 alkylene; b is an integer between 0 and 300; M is independently H or a cationic equivalent. [ka] (In the formula, V 2 is phenyl or naphthyl, and R 8 , OH, OR 8 (CO)R 8 COOM, COOR 8 SO3R 8 It may be optionally substituted with one or two groups selected from the group consisting of NO2; R 7A These are COOM, OCH2COOM, SO3M, or OPO3M2; M is H or a cationic equivalent; and R 8 (These are C1-C4 alkyl, phenyl, naphthyl, phenyl-C1-C4 alkyl, or C1-C4 alkylphenyl.) It is selected from the group consisting of the following.

[0154] Polymers containing structural units (III) and (IV) can be obtained by polycondensation of aromatic or aromatic heterocyclic compounds having a polyoxyalkylene group bonded to an aromatic or aromatic heterocyclic core, aromatic compounds having a carboxyl moiety, a sulfone moiety, or a phosphate moiety, and aldehyde compounds such as formaldehyde.

[0155] In one embodiment, the dispersant is a nonionic comb-shaped polymer having a carbon-containing main chain to which a pendant hydrolyzable group and a polyether side chain are bonded, and the hydrolyzable group releases a cement-fixing group upon hydrolysis. For convenience, the structural unit containing the polyether side chain is one of the above general formulas (IIa), (IIb), (IIc), and / or (IId). The structural unit having the pendant hydrolyzable group is preferably derived from an acrylic acid ester monomer, more preferably from a hydroxyalkyl acrylic monoester and / or hydroxyalkyl diester, and most preferably from a hydroxypropyl acrylate and / or hydroxyethyl acrylate. The ester functional group is hydrolyzed to an acid group (deprotonated) upon exposure to water, preferably at an alkaline pH (by mixing the cementite binder with water), and the resulting acid functional group then forms a composite with the cement components.

[0156] In one embodiment, the dispersant is Al 3+ Fe 3+ or Fe 2+ The group consists of colloidal dispersion preparations of polyvalent metal cations and polymeric dispersants containing anionic and / or anion-generating groups and polyether side chains. The polyvalent metal cations are present in hyperstoichiometric amounts calculated as cation equivalents based on the sum of the anionic and anion-generating groups of the polymeric dispersant. Such dispersants are described in more detail in International Publication No. 2014 / 013077A1, which is incorporated herein by reference.

[0157] Preferred sulfonated melamine-formaldehyde condensates are of the type frequently used as fluidizers for hydraulic binders (also known as MFS resins). Sulfonated melamine-formaldehyde condensates and their preparations are described, for example, in Canadian Patent No. 2172004A1, German Patent No. 4411797A1, U.S. Patent No. 4,430,469, U.S. Patent No. 6,555,683, and Swiss Patent No. 686186, as well as in Ullmann's Encyclopedia of Industrial Chemistry, 5th Ed., vol. A2, page 131, and Concrete Admixtures Handbook - Properties, Science and Technology, 2nd Ed., pages 411, 412. Preferred sulfonated melamine-formaldehyde condensates are of the formula [ka] The product includes units (which are greatly simplified and idealized), where n4 generally represents 10 to 300. The molar weight is preferably in the range of 2500 to 80000. In addition to sulfonated melamine units, other monomers can be incorporated by condensation. Urea is particularly preferred. Furthermore, additional aromatic units such as gallic acid, aminobenzenesulfonic acid, sulfanilic acid, phenolsulfonic acid, aniline, ammoniabenzoic acid, dialkoxybenzenesulfonic acid, dialkoxybenzoic acid, pyridine, pyridinemonosulfonic acid, pyridinedisulfonic acid, pyridinecarboxylic acid, and pyridinedicarboxylic acid can also be incorporated by condensation. An example of a melamine sulfonate-formaldehyde condensate is the Melment® product sold by Master Builders Solutions Deutschland GmbH.

[0158] Suitable lignosulfonates are products obtained as by-products in the paper industry. These are described in Ullmann's Encyclopedia of Industrial Chemistry, 5th Ed., vol. A8, pages 586, 587. These are represented by greatly simplified and idealized formulas. [ka] Includes units of.

[0159] Lignosulfonates have a molar weight of 2,000 to 100,000 g / mol. They typically exist in the form of their sodium, calcium, and / or magnesium salts. A suitable example of a lignosulfonate is the Borresperse product, sold by Borregaard LignoTech, Norway.

[0160] Preferred sulfonated ketone-formaldehyde condensates are products incorporating a monoketone or diketone, preferably acetone, butanone, pentanone, hexanone, or cyclohexanone, as the ketone component. These main condensates are known and, for example, described in International Publication No. 2009 / 103579. Sulfonated acetone-formaldehyde condensates are preferred. These are generally represented by formula (according to J. Plank et al., J. Appl. Poly. Sci. 2009, 2018-2024): [ka] The formula includes units, where m² and n� are generally 10 to 250, and M 2 is Na +These are alkali metal ions such as , and the ratio m2:n5 is usually in the range of about 3:1 to about 1:3, more specifically about 1.2:1 to 1:1.2. Furthermore, it is possible to incorporate other aromatic units by condensation, such as gallic acid, aminobenzenesulfonic acid, sulfanilic acid, phenolsulfonic acid, aniline, ammoniabenzoic acid, dialkoxybenzenesulfonic acid, dialkoxybenzoic acid, pyridine, pyridinemonosulfonic acid, pyridinedisulfonic acid, pyridinecarboxylic acid, and pyridinedicarboxylic acid. A suitable example of a sulfonated acetone-formaldehyde condensate is the Melcret K1L product sold by Master Builders Solutions Deutschland GmbH.

[0161] Suitable sulfonated naphthalene-formaldehyde condensates are products obtained by sulfonation of naphthalene and subsequent polycondensation with formaldehyde. These are described in literature including Concrete Admixtures Handbook-Properties, Science and Technology, 2nd Ed., pages 411-413, and Ullmann's Encyclopedia of Industrial Chemistry, 5th Ed., vol. A8, pages 587, 588. These are defined by formula [ka] Includes units of.

[0162] Typically, molar weights (Mw) of 1,000 to 50,000 g / mol are obtained. Furthermore, it is possible to incorporate other aromatic units by condensation, such as gallic acid, aminobenzenesulfonic acid, sulfanilic acid, phenolsulfonic acid, aniline, ammoniabenzoic acid, dialkoxybenzenesulfonic acid, dialkoxybenzoic acid, pyridine, pyridinemonosulfonic acid, pyridinedisulfonic acid, pyridinecarboxylic acid, and pyridinedicarboxylic acid. A suitable example of a sulfonated β-naphthalene-formaldehyde condensate is the Melcret 500 L product sold by Master Builders Solutions Deutschland GmbH.

[0163] Generally, phosphonate-containing dispersants incorporate phosphonic acid groups and polyether side groups.

[0164] A suitable phosphonate-containing dispersant is given by the following formula: R-(OA 2 ) n6 -N-[CH2-PO(OM 3 2)2]2 (In the formula, R is H or hydrocarbon residue, preferably C1-C 15 It is an alkyl group, A 2 These are, independently, C2~C 18 Alkylene, preferably ethylene and / or propylene, most preferably ethylene, n6 is an integer between 5 and 500, preferably between 10 and 200, most preferably between 10 and 100, and M 3 (These are H, alkali metals, 1 / 2 alkaline earth metals and / or amines.) This is due to...

[0165] Foam The cementitious slurry is foamed. Foaming means that, by injecting an inert gas into the slurry or generating an inert gas in the slurry, a ternary system is formed in which one phase is gaseous, one phase is liquid, and one phase is solid.

[0166] The gas phase exists as fine gas bubbles separated by cell walls obtained from the liquid and solid phases. The cell walls are in contact with each other at their edges, and the edges are in contact with each other at nodal points, thereby forming a frame structure. The gas phase content in the inorganic foam can vary within the range of 40 to 99 volume%, preferably 90 to 95 volume%.

[0167] The gaseous phase present in the foam can be introduced or generated by chemical foaming, mechanical foaming, and combinations thereof. Non-limiting examples of gases include air, nitrogen, noble gases, carbon dioxide, hydrocarbons, hydrogen, oxygen, and mixtures thereof.

[0168] Mechanical foaming can be carried out, for example, by using a mixer, by a vibration process, or by a stator-rotor process.

[0169] The gas phase can also be introduced into the foam by chemical foaming, where the chemical foaming process is preferred for releasing the gas. Preferably, a leavening agent is used that releases gas by evaporation, decomposition, or reaction with water and / or acid. Non-limiting examples of leavening agents include peroxides such as hydrogen peroxide, dibenzyl peroxide, peroxobenzoic acid, peroxoacetic acid, alkali metal peroxides, perchloric acid, peroxomonosulfuric acid, dicumyl peroxide, or cumyl hydroperoxide; carbonates and bicarbonates such as isocyanates, CaCO3, Na2CO3, and NaHCO3 (these are preferably used in combination with acids such as mineral acids); metal powders such as aluminum powder; azides such as methyl azide; hydrazides such as p-toluenesulfonyl hydrazide; and hydrazines.

[0170] In a preferred embodiment, the chemical foaming includes catalytic decomposition of peroxides. A preferred catalyst is Mn 2+ Mn 4+ Mn 7+ or Fe 3+It is preferably cation-containing. Alternatively, enzyme catalase can be used as a catalyst. Non-limiting examples of suitable catalysts are MnO2 and KMnO4. Such catalysts are preferably used in combination with a peroxide blowing agent. Further details regarding the components used in the preparation process of particle-stabilized inorganic foams based on Portland cement clinker-based cementitious binders, the inorganic foams obtained thereby, and construction elements containing these inorganic foams are shown below in this specification.

[0171] Use of the foam In a preferred embodiment, the present invention includes the steps of casting a cementitious slurry, either foamed or unfoamed, into a mold, foaming the unfoamed cementitious slurry, curing the foamed cementitious slurry, and demolding.

[0172] In other preferred embodiments, the present invention includes the steps of applying a cementitious slurry, either foamed or unfoamed, onto a support and / or introducing a cementitious slurry, either foamed or unfoamed, into a void space, foaming the unfoamed cementitious slurry, and curing the foamed cementitious slurry.

[0173] In one embodiment, the present invention includes a mineral foam obtainable by the method according to the present invention for preparing a mineral foam.

[0174] The mineral foam according to the present invention may have an open-cell or closed-cell structure.

[0175] In other embodiments, the present invention includes the use of the mineral foam according to the present invention as a heat insulating material, a sound insulating material or a sound absorbing material, for fireproof applications and / or as a construction material. In other embodiments, a mineral foam having an open-cell structure is used as a sound insulating material or a sound absorbing material, while a mineral foam having a closed-cell structure is used as a heat insulating material, for fireproof applications and / or as a construction material.

[0176] In a further aspect, the present invention provides a method for manufacturing a building material, comprising the step of forming the mineral foam according to the present invention into a material selected from the group consisting of a heat insulating material, a sound insulating material, a sound absorbing material, a fireproof element and a construction material.

[0177] The present invention can be further described and illustrated based on the following drawings and examples.

Example

[0178] Method Initial and final Vicat curing times after addition of the curing accelerator. Apparatus: TonyMIX mixer, manual Vicat needle Using a Vicat needle composed of a cylindrical part with a weight of 300 ± 1 g and a needle tip with a diameter of 1.13 ± 0.05 mm, in accordance with DIN EN 196-3, the initial and final curing times are measured. The initial curing time is defined as the time when the paste or mortar placed in the mold begins to show resistance to the penetration of the Vicat needle. In practice, the Vicat needle is dropped by gravity. If the needle does not touch the bottom of the mold due to the resistance of the material, curing has started. On the other hand, when the Vicat needle in contact with the upper surface of the material does not destroy its structure and only leaves a trace due to the pressure of the needle tip, final curing is defined to have occurred.

[0179] The curing time of the comparative sample is determined using a fully automatic Vicat measurement system manufactured by DETTKI equipped with a Vicat needle and two different loads (300 g and 1000 g). The measurement was carried out in accordance with DIN EN 196-3.

[0180] Dry density measurement The foam block was prepared by pouring a mixture of a suspension and hydrogen peroxide into a mold and expanding the foam. After expansion (for about 30 minutes), the surface of the foam was covered with plastic wrap to prevent surface drying and cured for 24 hours under indoor conditions. The next day, the plastic wrap was removed and the cured foam block was demolded. After demolding, the foam prism (16 / 4 / 4 cm 3A sample was cut from the foam block, and after foaming, it was dried at 23°C and 50% relative humidity for 21 days to obtain a hardened and dry foam prism. The sample was weighed using an experimental balance, and the dry density was measured by dividing the weight by the volume.

[0181] Compressive strength measurement Each of the foam samples obtained for density measurement was measured to approximately 8 / 4 / 4 cm². 3 The material was cut into two prisms, and its compressive strength (=comp. strength) was measured in accordance with DIN EN 826 using a universal testing machine (Inspekt Blue, Hegewald & Peschke) equipped with a 5kN load cell.

[0182] Experiment 1 Standard foams and two foam mixtures containing curing control / accelerator combinations were prepared as shown in Table 2. First, the foam powder was dispersed in water. Next, cement, sand, fly ash, microsilica, anhydrous gypsum, amorphous aluminum oxide, and a dry mixture of the solid components of the curing control, namely sodium gluconate and potassium carbonate, were added and homogenized for 15 minutes. 14 minutes and 30 seconds after mixing, the liquid components of the curing control, namely Sokalan PA 15 and glycerin, were added to the suspension. 15 seconds before the end of mixing, the accelerator, namely MasterRoc SA 160, was added. Foaming of the suspension was initiated by adding hydrogen peroxide and mixing. The resulting slurry was poured into a mold, where the foam expansion was allowed to proceed until the decomposition of hydrogen peroxide was complete.

[0183] [Table 4]

[0184] The initial and final curing times were determined using aliquots of the suspension taken before the addition of hydrogen peroxide. After 21 days, the density and compressive strength of the cured and dried foam samples were measured. The results are shown in Table 3.

[0185] [Table 5]

[0186] In Examples 1-3, CEM I cement, which is inherently low in aluminate, was supplemented with available external sources of aluminate and sulfate. The compressive strengths obtained in Examples 1 and 2 were significantly higher than those obtained with both supplemented binders in Example 3. Example 2 demonstrates that initial and final curing times can be improved by first adjusting the cement composition (if necessary) and by using curing control and accelerator formulations.

[0187] Experiment 2 Two additional cements were tested to verify the compatibility of the hardening control technique with different cement types. The addition of anhydrous gypsum and amorphous aluminum oxide was unnecessary due to the more favorable available aluminate content. The preparation method was the same as in Experiment 1. The composition of the foam is shown in Table 4. Initial and final hardening times were determined using aliquots of the suspension taken before the addition of hydrogen peroxide. After 21 days, the density and compressive strength of the hardened and dried foam samples were measured. The results are shown in Table 5.

[0188] [Table 6]

[0189] [Table 7]

[0190] In both examples, stable foams were obtained, indicating the applicability of the hardening control technology for different cements. By simply using the hardening control agent, higher strengths were obtained in Examples 4 and 5 compared to the reference example (Example 3). Karlstadt CEM II C-M(S-LL)42.5 N is a slow-hardening Portland composite cement, and for Example 5, no hardening was observed during the measurement time of 700 minutes. After 21 days of hardening, a lower compressive strength was measured compared to Milke CEM I (Example 1), which is a rapid-hardening cement, but the compressive strength was still higher than that of the reference example (Example 3) without the hardening control agent.

[0191] Experiment 3 Water glass was tested as an alternative accelerator for MasterRoc SA 160. In this experiment, sodium water glass (36 wt% aqueous sodium water glass, coefficient 3.2) was used. The amount of water glass was adjusted so that the same air-drying time as for Milke CEM I 52.5 R was obtained. The compatibility with different cements was tested using Milke CEM I 52.5 R and Karlstadt CEM II C-M(S-LL)42.5 N. The preparation method was the same as in Experiment 1. The composition of the foam is shown in Table 6. The initial hardening time and final hardening time were determined using aliquots of the suspension taken before the addition of hydrogen peroxide. After 21 days, the density and compressive strength of the hardened and dried foam samples were measured. The results are shown in Table 7.

[0192] [Table 8]

[0194]

[0195] [Table 9]

[0196] By using water glass, it is possible to achieve equivalent curing time with a smaller amount of accelerator (compare curing times 2 and 6). After curing for 21 days, it is possible to achieve equivalent strength (compare strengths 2 and 6). It is also possible to accelerate the curing of slower-hardening cements (compare curing times 5 and 7), resulting in a significant increase in strength at 21 days compared to non-accelerated foams (compare strengths 5 and 7).

[0195] Experiment 4 In this experiment, curing control agents that do not contain high-molecular-weight polycarboxylic acid (Sokalan PA 15) were investigated. Samples were prepared without Sokalan using Milke CEM I without accelerator (8), the accelerator MasterRoc (9), and the accelerator aqueous sodium water glass (10). The preparation method was the same as in Experiment 1. The composition of the foam is shown in Table 8. The initial curing time and final curing time were determined using aliquots of the suspension taken before the addition of hydrogen peroxide. After 21 days, the density and compressive strength of the cured and dried foam samples were measured. The results are shown in Table 9. Because the air-drying time was significantly reduced, the mixing time had to be shortened from 15 minutes to 2 minutes.

[0196] [Table 10]

[0197] [Table 11]

[0198] After adjusting the mixing time, it was possible to produce foams with comparable density. The curing of the curing control agent was reduced, resulting in a shorter curing time. The accelerator functioned as expected, further shortening the curing time. The compressive strength of all samples was reduced compared to foams using Sokalan (compare 8 with 1, 9 with 2, and 10 with 6).

[0199] Experiment 5 In this experiment, curing control agents that do not contain polyols (glycerin) were investigated. Samples were prepared using Milke CEM I, which uses only curing control, MasterRoc as an accelerator, or aqueous sodium water glass as an accelerator, omitting glycerin. The preparation method was the same as in Experiment 1. The composition of the foam is shown in Table 10. The initial curing time and final curing time were determined using aliquots of the suspension taken before the addition of hydrogen peroxide. After 21 days, the density and compressive strength of the cured and dried foam samples were measured. The results are shown in Table 11.

[0200] [Table 12]

[0201] [Table 13]

[0202] It was possible to produce foams with equivalent density. The air-drying time and compressive strength with and without the accelerator were within the same range as the foam containing glycerin (compare 11 with 1, 12 with 2, and 13 with 10).

[0203] Example 11 was repeated using citric acid (tricarboxylic acid) or tartaric acid (dicarboxylic acid) instead of sodium gluconate. Table 10a below shows the respective foam compositions 11a and 11b.

[0204] [Table 14]

[0205] Because premature hardening was observed, it was impossible to homogenize compositions 11a and 11b for 15 minutes. Therefore, the time during which homogenization was possible to generate foam was shortened to 5 minutes. Even in the latter case, some degree of hardening occurred in compositions 11a and 11b before foaming. This could be observed by the increase in viscosity of the still-unfoamed suspension (9740 mPa for 11a).* For s and 11b, the pressure is 8300 mPa. * s, in contrast, for 11, it is 1260 mPa * s). The foam structures obtained from compositions 11a and 11b exhibited higher heterogeneity and lower cell structure homogeneity compared to the foam from composition 11. In addition, compositions 11a and 11b had significantly less rise during foaming than composition 11 (7 cm for 11a and 8.5 cm for 11b, compared to 13 cm for 11).

[0206] Experiment 6 In this experiment, foam stabilizers other than foam stabilizing particles were investigated. A foam containing a surfactant as an air stabilizer was produced. The preparation method was the same as in Experiment 1. The composition of the foam is shown in Table 12. The initial curing time and final curing time were determined using aliquots of the suspension taken before the addition of hydrogen peroxide. After 21 days, the density and compressive strength of the cured and dried foam samples were measured. The results are shown in Table 13.

[0207] [Table 15]

[0208] [Table 16]

[0209] When common surfactants are used, it is possible to achieve equivalent foam densities (compare densities 14 and 2). The air-drying time is also within the same range as for particle-stabilized foams (compare initial and final curing times 14 and 2). The strength is significantly lower than that of particle-stabilized foams due to the open, porous nature of the foam. Particle-stabilized foams result in a closed-cell structure, while defoaming and curing with surfactants results in open cells, which can significantly reduce the strength of the foam structure. The degree of open cells, and therefore the foam strength, varies greatly depending on the properties of the surfactant / protein used to stabilize the foam and its compatibility with the additives used.

Claims

1. a. cementitious binder, Foam - stabilizer and Curing control agent A step of providing an aqueous cementitious slurry containing; b. Step of foaming the cementitious slurry. A method for preparing a mineral foam containing, The method comprising (i) an α-hydroxymonocarboxylic acid or a salt thereof, and (ii) an oxyanion source selected from the group consisting of a borate source and a carbonate source.

2. The method according to claim 1, wherein the curing control agent further comprises a polymeric polycarboxylic acid.

3. The method according to claim 1 or 2, comprising the step of adding an accelerator solution to the cementitious slurry, wherein the accelerator comprises at least one agent selected from the group consisting of an aluminum ion source, an aluminate source, and a silicate source.

4. The method according to any one of claims 1 to 3, wherein the cementitious binder includes a Portland cement clinker-based binder.

5. The method according to any one of claims 1 to 4, wherein the foam-stabilizer is selected from the group consisting of foam-stabilizing inorganic particles, surfactants, and proteins.

6. The method according to claim 5, wherein the foam-stabilized inorganic particles are inorganic particles treated with an amphiphilic compound.

7. The method according to claim 6, wherein the amphiphilic compound comprises at least one head group selected from the group consisting of a carboxylic acid group, a 3,4,5-trihydroxybenzoyloxy group, and an amino group, and at least one tail group selected from the group consisting of an aliphatic group having 2 to 8 carbon atoms.

8. The method according to claim 6 or 7, wherein the inorganic particles are selected from the group consisting of silica particles, alumina particles, zirconia particles, calcium carbonate particles, and mixtures thereof.

9. The method according to any one of claims 1 to 8, wherein the cementitious slurry further comprises an external sulfate source, preferably a sulfate source selected from the group consisting of gypsum, hemihydrate gypsum, anhydrous gypsum and mixtures thereof.

10. The method according to any one of claims 1 to 9, wherein the cementitious slurry further comprises an external aluminate supply source.

11. The method according to any one of claims 1 to 10, wherein the foaming step is selected from the group consisting of chemical foaming, mechanical foaming and combinations thereof.

12. The method according to claim 10, wherein the chemical foaming includes catalytic decomposition of a peroxide.

13. The method according to any one of claims 1 to 12, wherein the aluminum ion source is selected from the group consisting of aluminum salts, aluminum complexes, and mixtures thereof, and is preferably aluminum sulfate.

14. The method according to any one of claims 1 to 13, wherein the silicate source is sodium silicate.

15. The method according to any one of claims 1 to 14, wherein at least one of the curing control agent and the curing accelerator contains a polyol.

16. The method according to any one of claims 1 to 15, wherein the cementitious slurry further comprises a dispersant.

17. c. The steps of pouring the foamed or unfoamed cementitious slurry into a mold, foaming the unfoamed cementitious slurry, hardening the foamed cementitious slurry, and demolding the mold. The method according to any one of claims 1 to 16, including the method described in any one of claims 1 to 16.

18. c. The steps of applying the foamed or unfoamed cementitious slurry onto a support, and / or introducing the foamed or unfoamed cementitious slurry into a void space to foam the unfoamed cementitious slurry and harden the foamed cementitious slurry. The method according to any one of claims 1 to 16, including the method described in any one of claims 1 to 16.

19. A mineral foam obtainable by the method described in any one of claims 1 to 18.

20. Use of the mineral foam according to claim 19 as an insulating material, soundproofing material or sound-absorbing material, fire-resistant material and / or construction material.

21. A method for manufacturing building materials, comprising the step of forming the mineral foam described in claim 19 into a material selected from the group consisting of thermal insulation materials, soundproofing materials, sound-absorbing materials, fire-resistant elements, and construction materials.

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