Use of foamed mortar as an adhesive for flooring

Abstract

This invention relates to the use of foamed mortar as an adhesive for flooring, the foamed mortar comprising a polymer of protective colloidally stable olefinic unsaturated monomers.

Description

Technical Field

[0001] This invention relates to the use of foamed mortar as an adhesive for flooring, particularly as an adhesive for ceramic tiles, natural stone tiles or glass tiles, and to a method for laying flooring. Background Technology

[0002] In the construction industry, there is a growing need for more environmentally friendly building technologies, including, for example, the use of renewable building materials or those obtained through less energy-intensive methods, or the replacement of conventional building materials with those that are used in a resource-saving manner. At the same time, building products must continue to meet building material standards and possess advantageous performance characteristics. For example, flooring materials bonded to the floor with adhesives must adhere adequately to the substrate under normal exposure. For instance, cement brick adhesives need to meet the C1 standard, corresponding to at least 0.5 N / mm². 2 The adhesive exhibits high tensile bond strength. Furthermore, it possesses favorable processing qualities, such as a creamy consistency, which allows for easy ergonomic application and sufficient open time, so that flooring materials (such as tiles) laid on a mortar base can still be easily corrected. Summary of the Invention

[0003] In this context, the objective is to provide an adhesive for flooring that enables resource-efficient flooring installation while achieving desired performance characteristics, such as the adhesive's creamy consistency or open time, or favorable tensile adhesion strength of the flooring bonded with the adhesive. Particularly when using the adhesive as a tile adhesive, the laid tiles should meet the C1 standard according to DIN 12004, preferably corresponding to a minimum tensile strength of 0.5 N / mm². 2 The tensile bond strength.

[0004] Surprisingly, this theme has been achieved by using foam mortar as an adhesive for flooring, the foam mortar comprising a polymer of protective colloidally stable olefinic unsaturated monomers.

[0005] Foamed mortars typically contain binders with an increased proportion of porosity. Based on this porosity, the specific challenge involves achieving desired mechanical properties with foamed mortars, particularly tensile adhesion strength, while simultaneously achieving desired fresh mortar properties such as creamy consistency or open time.

[0006] Cement foam has been used in the construction industry as a thermal insulation material (for both thermal and sound insulation) or additionally as a fire-resistant material, and is known, for example, from CN 108484211 or CN 108529940. DE 4209897 and DE 3090083 describe gypsum-based foamed mortar. GB 20047636 relates to silicate foam. DE 2056255 discloses foam compositions for use in gypsum and cementitious materials. DE 4009967 teaches the use of a pore-forming agent in a mortar, the pore-forming agent being equipped with a deactivating coating, such that the pore-forming effect of the pore-forming agent in fresh concrete is delayed.

[0007] The subject of this invention is the use of foamed mortar as an adhesive for flooring, said foamed mortar comprising a polymer of protective colloidally stable olefinic unsaturated monomers.

[0008] Another subject of the invention is a method of laying flooring, wherein a foam mortar is used as an adhesive to bond the flooring to a substrate, the foam mortar comprising a polymer of protectively colloidally stable olefinic unsaturated monomers.

[0009] Foamed mortar is preferably based on a polymer of one or more protective colloidal stabilized olefinic unsaturated monomers in the form of one or more foam stabilizers, cement, water dispersions or water redispersible powders, one or more airentrainers, and optionally one or more additives.

[0010] Foamed mortar can be obtained, for example, by introducing air pores through one or more air-entraining agents, and optionally by introducing air into water-based mortar.

[0011] Air can be introduced into the water-based mortar, for example, through mechanical mixing. For this purpose, the water-based mortar can be agitated with the air mixed in. Mechanical mixing preferably occurs via mixing blades, mixing coils, paddle mixers, propeller mixers, or perforated plate mixers. Mixing coils and perforated plates are particularly preferred. Foam generators can also be used. Foam generators are commercially available machines for generating foam. Blowing air into the water-based mortar is another possibility. The air preferably has a temperature of 5°C to 35°C, and more particularly, ambient temperature.

[0012] Preferred aeration agents are bicarbonate or ammonium or alkali metal salts of carbonate, more particularly their ammonium, sodium, or potassium salts. Bicarbonate salts are particularly preferred. Sodium bicarbonate is most preferred. The aeration agent preferably does not contain alkaline earth metal carbonates. The aeration agent has a particle size preferably from 10 μm to 1 mm, more preferably from 100 μm to 800 μm, and most preferably from 200 μm to 700 μm.

[0013] The foamed mortar is preferably based on 0.01% to 10% by weight, more preferably 0.5% to 5% by weight, and most preferably 0.1% to 3% by weight of an air-entraining agent relative to the dry weight of the foamed mortar.

[0014] For example, foam stabilizers based on surfactants, polymers, proteins, or enzymes can be used.

[0015] An example of a surfactant used as a foam stabilizer is olefin sulfonic acid. The following are preferred fatty acids having 16-18 carbon atoms or their salts: fatty alcohols, preferably having 10 to 18 carbon atoms; alkylphenols or hydroxyalkylphenols, preferably alkyl chains having 10 to 18 carbon atoms; alkyl and alkylaryl ether sulfates having preferably 8 to 18 carbon atoms and preferably 1 to 50 ethylene oxide units in the hydrophobic group; sulfonates, especially alkyl sulfonates having preferably 8 to 18 carbon atoms, preferably alkylaryl sulfonates having alkyl groups having 8 to 18 carbon atoms, esters or monoesters of sulfosuccinic acid with monohydric alcohols or alkylphenols having preferably 4 to 15 carbon atoms in the alkyl group, wherein these alcohols or alkylphenols may also be ethoxylated by 1 to 40 ethylene oxide units; phosphate metaesters, especially alkyl or alkylaryl phosphates having 8 to 20 carbon atoms in the organic group, alkyl ethers and alkylaryl ethers having 8 to 20 carbon atoms and 1 to 50 EO units in the alkyl or alkylaryl group. Phosphate esters; preferably alkyl polyethylene glycol ethers having 8-40 EO units and alkyl groups having 8-20 carbon atoms; preferably alkylaryl polyethylene glycol ethers having 8 to 40 EO units and 8 to 20 carbon atoms in the alkyl and aryl groups; preferably ethylene oxide / propylene oxide (EO / PO) block copolymers having 8-40 EO and / or PO units; N-methyl taurine, preferably a higher fatty acid, preferably having 10 to 18 carbon atoms; fatty acid alkyl alcohols Amides, such as monoethanolamides or diethanolamides of fatty acids; amine oxides or phosphine oxides, such as cocodimethylamine oxide or cocodimethylphosphine oxide with the general formula RN(CH3)2=O or RP(CH3)2=O; amphoteric electrolytes, such as sodium cocoyl dimethylaminoacetate or sulfobetaine; phosphate esters, especially phosphate esters of long-chain alcohols having preferably 10 to 18 carbon atoms or alcohols having 8 to 10 carbon atoms in the molecule ethoxylated with 1 to 4 moles of ethylene oxide.

[0016] The preferred surfactants here are olefin sulfonic acids, fatty acids, fatty alcohols, alkyl and alkylaryl ether sulfates and sulfonates.

[0017] The EO unit represents an ethylene oxide unit, and the PO unit represents a propylene oxide unit. The above acids can also be in the form of their salts, especially ammonium salts, alkali metal salts, or alkaline earth metal salts. Olefin sulfonic acids preferably contain 10 to 20 carbon atoms. Olefin sulfonic acids preferably have one or two sulfonic acid or hydroxyalkyl sulfonic acid groups. In this case, α-olefin sulfonic acids are preferred.

[0018] Examples of polymers used as foam stabilizers include polyvinyl alcohol; polyvinyl acetal; polyvinylpyrrolidone; water-soluble forms of polysaccharides such as starch (amylose and amylopectin), cellulose and its derivatives such as carboxymethyl, methyl, hydroxyethyl and hydroxypropyl derivatives, dextrin and cyclodextrin; lignin sulfonates; poly(meth)acrylic acid; copolymers of (meth)acrylates with carboxyl-functionalized comonomer units; poly(meth)acrylamide; polyvinyl sulfonic acid and its water-soluble copolymers; melamine-formaldehyde sulfonate; naphthalene-formaldehyde sulfonate; styrene-maleic acid copolymers and vinyl ether-maleic acid copolymers.

[0019] Examples of proteins used as foam stabilizers include casein, caseinate, soy protein, or gelatin. Proteins can be obtained, for example, through protein hydrolysis, particularly animal proteins, such as horns, blood, bones, and similar waste products from cattle, pigs, and other animal carcasses. Enzymes used as foam stabilizers can be, for example, of biotechnological origin.

[0020] Preferred foam stabilizers are surfactants; polyvinyl alcohol; polyvinylpyrrolidone; cellulose and its derivatives, such as carboxymethyl, methyl, hydroxyethyl and hydroxypropyl derivatives; proteins such as casein or caseinate, soy protein and gelatin. Particularly preferred foam stabilizers are surfactants, especially olefin sulfonic acids.

[0021] A particularly preferred approach is to use a combination of surfactant foam stabilizers and polymer foam stabilizers.

[0022] These foam stabilizers have a molecular weight that is preferably ≤4000 g / mol, more preferably ≤3000 g / mol, even more preferably ≤2500 g / mol, very preferably ≤1500 g / mol, and most preferably ≤1000 g / mol.

[0023] Foam stabilizers and protective colloidal stabilizers typically exist side-by-side. Foam stabilizers are usually not components of protective colloidal stabilizers.

[0024] The foamed mortar is based on a foam stabilizer, preferably from 0.01% to 35% by weight, more preferably from 0.05% to 20% by weight, and most preferably from 0.1% to 10% by weight. The surfactant or polymer used as the foam stabilizer is preferably included in the form of a foam stabilizer at 0.01% to 10% by weight, more preferably from 0.05% to 5% by weight, and most preferably from 0.1% to 3% by weight. The protein or enzyme used as the foam stabilizer is preferably included in the form of a foam stabilizer at 10% to 35% by weight, more preferably from 15% to 30% by weight, and most preferably from 20% to 25% by weight. The figures expressed as % by weight refer to the dry weight of the foamed mortar.

[0025] Relative to the dry weight of the foam mortar, the foam mortar is based on a polymer of protective colloidally stable olefinic unsaturated monomers, preferably 0.5% to 40% by weight, more preferably 5% to 30% by weight, and most preferably 10% to 20% by weight.

[0026] Polymers of olefinic unsaturated monomers, for example, are based on one or more monomers selected from the group consisting of vinyl esters, (meth)acrylates, vinyl aromatic compounds, alkenes, 1,3-dienes and vinyl halides.

[0027] Suitable vinyl esters are, for example, vinyl esters of carboxylic acids having 1 to 15 carbon atoms. Preferred are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurylate, 1-methyl vinyl acetate, vinyl neopentanoate, and vinyl esters of branched monocarboxylic acids having 9 to 11 carbon atoms, such as VeoVa9R or VeoVa10R (trade names of Resolution). Vinyl acetate is particularly preferred.

[0028] Suitable monomers from the group consisting of acrylates or methacrylates are, for example, esters of unbranched or branched alcohols having 1 to 15 carbon atoms. Preferred methacrylates or acrylates are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, and 2-ethylhexyl acrylate. Particularly preferred are methyl acrylate, methyl methacrylate, n-butyl acrylate, tert-butyl acrylate, and 2-ethylhexyl acrylate.

[0029] Preferred vinyl aromatic compounds are styrene, methylstyrene, and vinyltoluene. Preferred ethylene halohalides are vinyl chloride. Preferred olefins are ethylene and propylene, and preferred dienes are 1,3-butadiene and isoprene.

[0030] Optionally, the auxiliary monomers may copolymerize at 0% to 10% by weight, preferably 0.1% to 5% by weight, relative to the total weight of the monomers. Examples of auxiliary monomers are olefinic unsaturated monocarboxylic acids and dicarboxylic acids, preferably acrylic acid, methacrylic acid, fumaric acid, and maleic acid; olefinic unsaturated carboxamides and nitriles, preferably acrylamide and acrylonitrile; monoesters and diesters of fumaric acid and maleic acid, such as diethyl ester and diisopropyl ester, and maleic anhydride; olefinic unsaturated sulfonic acids and their salts, preferably vinyl sulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid. Other examples are pre-crosslinked comonomers, such as polyolefin unsaturated comonomers, examples being diallyl phthalate, divinyl adipate, diallyl maleate, allyl methacrylate, or triallyl cyanurate; or post-crosslinked comonomers, examples being acrylamide glycolic acid (AGA), methyl methacrylamide glycolate (MAGME), N-hydroxymethylacrylamide (NMA), N-hydroxymethyl methacrylamide, N-hydroxymethyl allyl carbamate; alkyl ethers, such as isobutoxy ethers or esters of N-hydroxymethylacrylamide, N-hydroxymethyl methacrylamide, and N-hydroxymethyl allyl carbamate. Also suitable are epoxy-functionalized comonomers, such as glycidyl methacrylate and glycidyl acrylate. Other examples are silicon-functionalized comonomers such as acryloyloxypropyltris(alkoxy)silane and methacryloxypropyltris(alkoxy)silane, vinyltrialkoxysilane and vinylmethyldialkoxysilane, wherein the alkoxy groups present can be, for example, ethoxy and ethoxypropylene glycol ether groups. Monomers having hydroxyl or CO groups may also be mentioned, examples being hydroxyalkyl methacrylates and hydroxyalkyl acrylates, such as hydroxyethyl esters, hydroxypropyl esters or hydroxybutyl esters of acrylic acid or methacrylic acid, and compounds such as diacetone acrylamide and acetylacetoxyethyl esters of acrylic acid or methacrylic acid.

[0031] Preferred copolymers are vinyl acetate with 1% to 50% by weight of ethylene; copolymers of vinyl acetate with 1% to 50% by weight of ethylene and 1% to 50% by weight of one or more other comonomers from the group consisting of vinyl esters having 1 to 12 carbon atoms in the carboxyl group, such as vinyl propionate, vinyl laurate, and vinyl esters of α-branched carboxylic acids having 9 to 13 carbon atoms, such as VeoVa9, VeoVa10, VeoVa11; and copolymers of vinyl acetate, 1% to 50% by weight of ethylene, and preferably 1% to 60% by weight of unbranched or branched alcohols having 1 to 15 carbon atoms, particularly n-butyl acrylate or 2-ethylhexyl acrylate. The copolymer comprises, by weight, 30% to 75% vinyl acetate, 1% to 30% vinyl laurate or vinyl ester of α-branched carboxylic acid having 9 to 11 carbon atoms, and 1% to 30% by weight unbranched or branched alcohols of (meth)acrylate having 1 to 15 carbon atoms, especially n-butyl acrylate or 2-ethylhexyl acrylate, further comprising 1% to 40% ethylene by weight; or a copolymer comprising vinyl acetate, 1% to 50% ethylene by weight and 1% to 60% vinyl chloride by weight; wherein the polymer may further comprise a specified amount of the auxiliary monomers, and wherein, in each case, the total percentage by weight is 100% by weight.

[0032] Also preferred are (meth)acrylate polymers, such as copolymers of n-butyl acrylate or 2-ethylhexyl acrylate, or copolymers of methyl methacrylate with n-butyl acrylate and / or 2-ethylhexyl acrylate; styrene-acrylate copolymers having one or more monomers from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate; vinyl acetate-acrylate copolymers having one or more monomers from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and optionally ethylene; styrene-1,3-butadiene copolymers; wherein the polymer may additionally contain a specified amount of the auxiliary monomers, and wherein, in each case, the total percentage by weight is 100% by weight.

[0033] Most preferably, a copolymer comprising vinyl acetate and 5% to 50% ethylene by weight; or a copolymer comprising vinyl acetate, 1% to 50% ethylene by weight and 1% to 50% vinyl ester of an α-branched monocarboxylic acid having 9 to 11 carbon atoms; or a copolymer comprising 30% to 75% vinyl acetate, 1% to 30% vinyl laurate or vinyl ester of an α-branched carboxylic acid having 9 to 11 carbon atoms, and 1% to 30% unbranched or branched alcohol (meth)acrylate having 1 to 15 carbon atoms, further comprising 1% to 40% ethylene by weight; or a copolymer comprising vinyl acetate, 5% to 50% ethylene by weight and 1% to 60% vinyl chloride by weight.

[0034] The weight fractions of these monomers and / or comonomers are selected to result in a glass transition temperature (Tg) of -25°C to +35°C, preferably -10°C to +25°C, and more preferably -10°C to +20°C. The glass transition temperature (Tg) of the polymer can be determined in a known manner by differential scanning calorimetry (DSC). Tg can also be approximately calculated in advance using Fox's equation. According to Fox T.G., Bull. Am. Physics Soc. 1, 3, page 123 (1956): 1 / Tg = x1 / Tg1 + x2 / Tg2 + ... + xn / Tgn, where xn is the mass fraction of monomer n (by weight % / 100), and Tgn is the glass transition temperature of the homopolymer of monomer n in Kelvin. The Tg values ​​for the homopolymer are listed in Polymer Handbook, 2nd edition, J. Wiley & Sons, New York (1975).

[0035] Polymers are typically prepared in aqueous media and preferably by emulsion or suspension polymerization methods, as described in, for example, DE-A102008043988. Polymerization can be carried out using common protective colloids and / or emulsifiers, as described in DE-A102008043988. Polymers in aqueous dispersion form can be converted into the corresponding water-redispersible powders as described in DE-A102008043988. In this case, drying aids are typically used, preferably the aforementioned polyvinyl alcohol.

[0036] The polymer can be, for example, an aqueous dispersion, and more specifically, an aqueous dispersion with protective colloidal stability. A preferred protective colloid is polyvinyl alcohol, such as partially or completely hydrolyzed polyvinyl alcohol, more specifically having a degree of hydrolysis of 80 mol% to 100 mol%. Particularly preferred are those having a degree of hydrolysis of 80 mol% to 94 mol% and, particularly, a degree of hydrolysis of 1 mPas to 30 mPas in a 4% aqueous solution. Viscosity (at 20°C) The method (DIN 53015) involves the partial hydrolysis of polyvinyl alcohol. The protective colloid can be obtained by methods known to those skilled in the art. The protective colloid is typically included in an amount totaling 1% to 20% by weight relative to the total weight of the polymer.

[0037] The polymer is preferably in the form of a protective colloidal stabilized, water-redispersible powder. The dispersion of the protective colloidal stabilized, water-redispersible polymer powder results in water redispersibility. These powders preferably contain 3% to 30% by weight, more preferably 5% to 20% by weight, of polyvinyl alcohol, and more particularly, the aforementioned polyvinyl alcohol, relative to the dry weight of the powder.

[0038] Protective colloidal stabilized polymers are typically present separately from aeration agents and / or foam stabilizers. Aeration agents and / or foam stabilizers are generally not coated with protective colloidal stabilized polymers. The protective colloidal stabilized polymer or the polymer itself is typically different from the foam stabilizer and any thickener.

[0039] Cement may include, for example, Portland cement (CEM I), Portland composite cement (CEM II), blast furnace cement (CEM III), pozzolanic cement (CEM IV), composite cement (CEM V), Portland silicate dust cement, Portland slate cement, Portland limestone cement, volcanic rock cement, magnesium oxide cement, phosphate cement, blended cement, filler cement, or fast-setting cement. Examples of fast-setting cement are aluminate cement, calcium sulfoaluminate cement, and high-alumina cement. Preferred types include Portland cement CEM I, Portland composite cement CEMII / AS, CEMII / BS, Portland limestone cement CEMII / A-LL, Portland fly ash cement CEMII / AV, Portland fly ash composite cement CEMII / B-SV, or blast furnace cement CEMIII / A, CEMIII / B, CEMIII / B, and aluminate cement.

[0040] The foamed mortar is based on cement, preferably 40% to 95% by weight, more preferably 50% to 92% by weight, very preferably 60% to 91% by weight, and most preferably 70% to 90% by weight, relative to its dry weight.

[0041] In a preferred embodiment, the foamed mortar comprises fast-setting cement, such as aluminate cement, and one or more cements other than fast-setting cement, more specifically Portland cement. Fast-setting cement is particularly advantageous for achieving the objectives of the invention.

[0042] Relative to the dry weight of the foamed mortar, the foamed mortar is based on preferably 1% to 30% by weight, more preferably 5% to 20% by weight, and most preferably 10% to 15% by weight of fast-setting cement. Relative to the total weight of all cement used, the foamed mortar is based on preferably 1% to 40% by weight, more preferably 5% to 30% by weight, and most preferably 10% to 20% by weight of fast-setting cement.

[0043] Foamed mortar may also contain one or more thickeners, examples of which are polysaccharides such as cellulose ethers and modified cellulose ethers, cellulose esters, starch ethers, guar gum, xanthan gum, polycarboxylic acids such as polyacrylic acid and its esters, casein, and associative thickeners. Preferred cellulose ethers are methylcellulose ethers. Thickeners are generally different from foam stabilizers. These thickeners have a molecular weight preferably >4000 g / mol, more preferably ≥10000 g / mol, and most preferably ≥20000 g / mol. The foamed mortar is based on a thickener at a concentration preferably ≤5% by weight, more preferably 0.1% to 3% by weight, and most preferably 0.5% to 1.5% by weight, relative to the dry weight of the foamed mortar.

[0044] In addition, foamed mortar may contain accelerators, such as aluminum compounds, silicates, alkali metal or alkaline earth metal hydroxides, nitrates, nitrites, sulfates, borates or carboxylic acids. Preferred accelerators are aluminum salts, aluminates, alkali metal silicates such as water glass, alkali metal formates, potassium hydroxide or calcium hydroxide (Ca(OH)2).

[0045] The foamed mortar is based on a settling accelerator, preferably 0.1% to 5% by weight, more preferably 0.2% to 2% by weight, and most preferably 0.3% to 1% by weight, relative to the dry weight of the foamed mortar.

[0046] Foamed mortar may also contain one or more types of volcanic ash, such as kaolin, microsilica, diatomaceous earth, fly ash, tuff powder, ground blast furnace slag, glass powder, precipitated silica, and fumed silica. Preferred volcanic ash is kaolin, microsilica, fly ash, ground blast furnace slag, especially metakaolin. The foamed mortar is based on, for example, 0% to 10% by weight, preferably 0.5% to 5% by weight, of volcanic ash relative to its dry weight. Most preferably, the foamed mortar does not contain volcanic ash.

[0047] The foamed mortar is based on a paste, preferably ≤30% by weight, more preferably ≤20% by weight, even more preferably ≤10% by weight, and very preferably ≤5% by weight, relative to the dry weight of the components used to produce the foamed mortar. Most preferably, the foamed mortar does not contain gypsum. The absence of gypsum results in an improvement in the water resistance of the solidified foamed mortar. Illustrative examples of gypsum are α- or β-hemihydrate (CaSO41 / 2H2O), dihydrate, anhydrite, or calcium sulfate (FGD gypsum) from flue gas desulfurization.

[0048] Foamed mortar may also contain one or more fillers. Examples of fillers are quartz sand, quartz powder, sand, limestone powder, dolomite, clay, chalk, slag sand powder, quicklime, talc or mica, rubber granules, or hard fillers such as aluminum silicate, corundum, basalt, and carbides such as silicon carbide or titanium carbide. Preferred fillers are quartz sand, quartz powder, limestone powder, calcium carbonate, calcium magnesium carbonate (dolomite), chalk, or quicklime. The fillers preferably have a particle size of ≤2 mm, more preferably ≤1 mm.

[0049] The foamed mortar contains, relative to its dry weight, preferably ≤10% by weight, and more preferably ≤5% by weight, filler. Most preferably, the foamed mortar does not contain filler.

[0050] Foamed mortar may also contain lightweight fillers. Lightweight fillers are generally a term for fillers with a low bulk weight (typically less than 500 g / L). Lightweight fillers are preferably different from the fillers described above. Particularly preferably, the foamed mortar contains no filler other than lightweight fillers. Typical lightweight fillers, on a synthetic or natural basis, include: hollow glass microspheres, polymers such as polystyrene beads, aluminosilicates, silica, aluminosilicate, hydrated calcium silicate, silica, aluminum silicate, magnesium silicate, hydrated aluminum silicate, calcium aluminum silicate, hydrated calcium silicate, aluminum iron magnesium silicate, calcium silicate metal silicates, and / or volcanic slag. Preferred lightweight fillers are perlite, Celite, Cabosil, Circosil, Eurocell, Filite, Promaxon, Vermex, and / or wollastonite, as well as polystyrene.

[0051] Relative to the dry weight of the foamed mortar, the foamed mortar is based on preferably 0% to 10% by weight, more preferably 0.5% to 5% by weight, and very preferably 1% to 3% by weight of lightweight filler. Most preferably, the foamed mortar does not contain lightweight filler.

[0052] Foamed mortar may optionally contain additives, examples of which are plasticizers, superplasticizers, flame retardants, film-forming aids, dispersants, hydrophobic agents, pigments, preservatives, flame retardants (e.g., aluminum hydroxide), and finely crushed silica. Preferred additives are plasticizers and superplasticizers. The additives are preferably present in an amount of 0% to 20% by weight, more preferably 0.1% to 10% by weight, and most preferably 0.5% to 7% by weight, relative to the dry weight of the foamed mortar.

[0053] Foamed mortar preferably does not contain hexafluorosilicic acid, and more particularly does not contain salts of hexafluorosilicic acid, such as calcium, magnesium, zinc or ammonium salts.

[0054] Water-based foamed mortar is preferably produced using 4% to 30% by weight, more preferably 6% to 20% by weight, and most preferably 8% to 15% by weight, relative to the dry weight of the foamed mortar.

[0055] Water-based foamed mortars can be produced by mixing their individual components in common mixing equipment, such as mortar mixing components, mechanical drilling mixers, dissolvers, or mixing coil mixers, particularly at high speeds, preferably >150 rpm, more preferably 150 to 1000 rpm. In this case, air pores are generally incorporated into the foamed mortar using an air-entraining agent and / or by introducing air, as described above.

[0056] Foamed mortar is preferably a one-component system, meaning that all components of the foamed mortar are preferably mixed in a mixing device. More preferably, the foamed mortar is first produced as a dry mixture, and water is then added.

[0057] When adding water, the foamed mortar should be mixed for 1 to 10 minutes, more preferably 2 to 5 minutes. Mixing is preferably carried out at 5°C to 35°C, more preferably 15°C to 25°C.

[0058] Foamed mortar typically contains air pockets. Foamed mortar preferably has a creamy or buttery consistency. The density of the foamed mortar is preferably 0.1-1 g / cm³. 3 More preferably 0.2-0.9 g / cm³ 3 The optimal value is 0.5-0.8 g / cm³. 3 Density can be determined in conventional ways, such as by filling a container with a defined volume of foam and weighing it.

[0059] Generally, the resulting foamed mortars are applied immediately after they have been produced, and in particular, no further processing steps are required.

[0060] Foamed mortar is used as an adhesive for flooring. It is commonly used to bond flooring to a substrate. The flooring is specifically laid on a level surface or a surface with a slight gradient. Foamed mortar itself can be applied when using conventional construction adhesives. Therefore, water-based foamed mortar can be applied to the substrate by machine, such as using a sprayer, or preferably manually, such as using a squeegee, and spread using, for example, a notched squeegee. The flooring can then be laid on the applied layer of foamed mortar and bonded to the substrate.

[0061] The foamed mortar layer applied to the substrate has a thickness of preferably 0.5 mm to 8 mm, more specifically 2 mm to 4 mm.

[0062] After the foam mortar layer has cured, any joints can be filled with, for example, conventional joint fillers.

[0063] Foamed mortar can be used to lay conventional flooring on a common substrate. Examples of substrates are aerated concrete, concrete, gypsum, or floor filling compounds. Examples of flooring are natural stone flooring, ceramic flooring, or plastic flooring, especially in the form of tiles, such as vinyl tiles, preferably ceramic tiles, natural stone tiles, or glass tiles, for example, exterior or particularly interior use. Particularly preferred tiles are terracotta tiles, stone tiles, porcelain tiles, ceramic tiles, or natural tiles, especially large tiles.

[0064] After 28 days under standard conditions (23°C, 50% relative humidity), the solidified foamed mortar preferably has a strength of 10 to 1000 kg / m³. 3 More preferably 100 to 800 kg / m 3 Dry bulk density (determination method: based on EN 1015-6).

[0065] After 28 days under standard conditions (23°C, 50% relative humidity), the foamed mortar (solid mortar) exhibits a thermal conductivity preferably of 50 to 200 mW / mK, more preferably 30 to 100 mW / mK. The thermal conductivity was measured using an HFM 436 thermal conductivity instrument from Netzsch according to DIN EN 13163. Measurements were performed using a Lambda 10°C setting, with the lower plate set at 2.5°C and the upper plate at 17.5°C. The test substrate was clamped in the center, and measurements were taken until the test substrate reached its core temperature of 10°C.

[0066] By using the foam mortar according to the invention as an adhesive for laying floors, significant savings in adhesive can be achieved, for example, up to 70%, compared to the corresponding use of conventional adhesives. This is a considerable environmental and economic advantage, and it also reduces the cost and complexity involved in transporting construction adhesives to and processing them at the construction site, thus enabling a substantial increase in overall productivity. Advantageously, the foam mortar is readily accessible and can be processed like conventional adhesive mortars used for laying floors.

[0067] Surprisingly, the flooring laid according to the present invention exhibits unexpectedly good mechanical properties, particularly tensile adhesion strength. Therefore, the floor tiles laid according to the present invention also meet the C1 standard according to DIN 12004, thus achieving at least 0.5 N / mm² after dry storage or wet storage. 2 The tensile bond strength.

[0068] Furthermore, the foamed mortar of the present invention exhibits advantageous fresh mortar properties and has, for example, a creamy consistency, which is highly valued by users when applying the adhesive for ergonomic reasons. The open time of the foamed mortar is sufficient to allow for corrections to the laid floor. Detailed Implementation

[0069] The following examples are provided to explain the invention in detail and should not be construed as imposing any limitations.

[0070] Production of foamed mortar as an adhesive for floor tiles:

[0071] Add the amount of water indicated in Table 1 to the dry mixture of the components listed in Table 1, and after stirring with a Toni mixer (level 2) for 30 minutes, obtain a ready-to-use foam mortar with a creamy consistency.

[0072] The resulting foamed mortar was used as an adhesive for floor tiles.

[0073] To lay the floor tiles, use a notched trowel (6×6×6 comb application, layer thickness: approximately 4mm) to spread the foamed mortar onto the concrete slab. Lay the glass bricks (measured 40cm×40cm) into the foamed mortar bed with a joint width of 6mm.

[0074] Table 1: Tile adhesive formulation, Example 1:

[0075]

[0076]

[0077] Components of a tile adhesive formula:

[0078] -Polymer powder:

[0079] Polymer powder of polyvinyl alcohol-stabilized water-redispersible vinyl acetate-ethylene copolymer with a glass transition temperature of 16°C.

[0080] -Tylose MH 60010P4 (a product name belonging to Shin Etsu):

[0081] Etherified methyl hydroxyethyl cellulose (thickener);

[0082] -Hostapur OSB (a product name belonging to Shin Etsu):

[0083] Sodium salts of C14 / C16-α-olefin sulfonic acids;

[0084] -Milke CEM I 52, 5R: Portland Cement;

[0085] -Fondu Lafarge (a product name belonging to Imerys):

[0086] Calcium aluminum cement (quick-setting cement);

[0087] -Walhalla fine hydrate:

[0088] Calcium hydroxide (Ca(OH)2) (latent hydraulic adhesive).

[0089] Test of the floor tile assembly in Example 1:

[0090] Use a density measuring cup to determine the wet density of the foamed mortar.

[0091] Opening times are determined according to EN1348 after 5, 20 and 30 minutes.

[0092] Tensile bond strength was determined according to EN1348 after the storage conditions indicated in Table 2.

[0093] The test results are summarized in Table 2.

[0094] Table 2: Results of tests on foamed mortar and floor tile components in Example 1:

[0095]

[0096] a) 28dSC: Tested after 28 days of storage under standard conditions;

[0097] b) 7dSC / 21dWS: Tested after 7 days of storage under standard conditions and 21 days of wet storage (in water at 23°C);

[0098] c) 14dSC / 14dDS: Tested after 14 days of storage under standard conditions and 14 days of dry storage at 70°C;

[0099] d)7dSC / 21dWS / 25* Freeze-thaw: Tested after 7 days of storage under standard conditions, 21 days of wet storage (in water at 23°C), and 25 days of freeze-thaw storage.

Claims

1. Use of a foamed mortar as an adhesive for flooring, the foamed mortar comprising a protective colloid-stabilized polymer of ethylenically unsaturated monomers and one or more air entraining agents selected from the group comprising ammonium and alkali metal salts of bicarbonate and carbonate, with the proviso that the foamed mortar does not comprise a filler.

2. Use of the foam mortar according to claim 1 as an adhesive for floors, characterized in that, The foamed mortar is based on one or more protective colloid-stabilized polymers of ethylenically unsaturated monomers in the form of one or more of a foam stabilizer, a cement, a water dispersion or a water redispersible powder, one or more air entraining agents, and optionally one or more additives.

3. Use of the foam slurry according to claim 1 or 2 as an adhesive for a floor, characterized in that, The foamed mortar comprises sodium bicarbonate as an air entraining agent.

4. Use of the foam mortar according to claim 2 as an adhesive for floors, characterized in that, The selected foam stabilizer is one or more surfactants selected from the group comprising olefin sulfonic acids; fatty acids or salts thereof; fatty alcohols; alkyl and hydroxyalkyl phenols; alkyl and alkyl aryl ether sulfates; alkyl sulfonates, alkyl aryl sulfonates; esters of sulfosuccinic acids; partial esters of phosphoric acid; alkyl polyglycol ether; alkyl aryl polyglycol ether; ethylene oxide / propylene oxide (EO / PO) block copolymers; N-methyl taurine; fatty acid alkylol amides; amine oxides; or phosphine oxides; sodium cocodimethylaminoacetate; sulfobetaines and phosphate esters; and / or one or more polymers selected from the group comprising polyvinyl alcohol; polyvinyl acetals; polyvinyl pyrrolidone; polysaccharides in water-soluble form; lignin sulfonates; poly(meth)acrylic acid; copolymers of (meth)acrylic acid esters with carboxy-functional comonomer units; poly(meth)acrylamide; polyvinylsulfonic acid and water-soluble copolymers thereof; melamine-formaldehyde sulfonates; naphthalene-formaldehyde sulfonates; styrene-maleic acid copolymers; and vinyl ether-maleic acid copolymers; and / or one or more proteins selected from the group comprising casein, caseinate, soy protein; gelatin; and other proteins obtainable by proteolysis of animal proteins; and / or enzymes of biotechnological origin.

5. Use of the foam mortar according to claim 1 as an adhesive for floors, characterized in that, The foamed mortar comprises one or more foam stabilizers selected from the group comprising olefin sulfonic acids; fatty acids or salts thereof having 16 to 18 carbon atoms; fatty alcohols having 10 to 18 carbon atoms; alkyl phenols or hydroxyalkyl phenols having an alkyl chain of 10 to 18 carbon atoms; alkyl and alkyl aryl ether sulfates having 8 to 18 carbon atoms in the hydrophobic group and 1 to 50 ethylene oxide units; alkyl sulfonates having 8 to 18 carbon atoms; alkyl aryl sulfonates having an alkyl group of 8 to 18 carbon atoms; and esters of sulfosuccinic acids.

6. Use of the foam mortar according to claim 1 as an adhesive for floors, characterized in that, The foamed mortar is based on 5% to 40% by weight of the protective colloid-stabilized polymer of ethylenically unsaturated monomers relative to the dry weight of the foamed mortar.

7. Use of the foam slurry according to claim 1 as an adhesive for floors, characterized in that, The polymer of ethylenically unsaturated monomers is based on one or more monomers selected from the group comprising vinyl esters, (meth)acrylic acid esters, vinyl aromatic compounds, olefins and vinyl halides.

8. Use of the foam slurry according to claim 1 as an adhesive for floors, characterized in that, The polymer of ethylenically unsaturated monomers selected is one or more copolymers selected from the group comprising: copolymers with vinyl acetate and 5% to 50% by weight of ethylene; copolymers with vinyl acetate, 1% to 50% by weight of ethylene and 1% to 50% by weight of a vinyl ester of an alpha-branched monocarboxylic acid with 9 to 11 carbon atoms; copolymers with 30% to 75% by weight of vinyl acetate, 1% to 30% by weight of vinyl laurate or a vinyl ester of an alpha-branched carboxylic acid with 9 to 11 carbon atoms, and 1% to 30% by weight of a (meth)acrylic ester of an unbranched or branched alcohol with 1 to 15 carbon atoms, the copolymers additionally comprising 1% to 40% by weight of ethylene.

9. Use of the foam slurry according to claim 1 as an adhesive for floors, characterized in that, The foam mortar is based on 1% to 40% by weight of a rapid setting cement selected from the group comprising calcium sulfoaluminate cement and high alumina cement, relative to the total weight of the total cement contained.

10. Use of the foam slurry according to claim 1 as an adhesive for floors, characterized in that, The floor is selected from the group comprising natural stone floor, ceramic floor, glass floor and vinyl floor.

11. Use of the foam slurry according to claim 1 as an adhesive for floors, characterized in that, The floor is selected from the group comprising ceramic tile and natural stone tile.

12. Use of the foam slurry according to claim 9 as an adhesive for floors, characterized in that, The rapid setting cement is an aluminate cement.

13. A method for laying a floor, wherein a floor is adhered to a substrate with a foam mortar as an adhesive, the foam mortar comprising a protective colloid-stabilized polymer of ethylenically unsaturated monomers and one or more air entraining agents selected from the group comprising ammonium and alkali metal salts of bicarbonate and carbonate, with the proviso that the foam mortar does not comprise a filler.

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