Composition for conditioning pores in building products in presence of sulfate-based superplasticizer

Abstract

The invention relates to an adhesive composition, which comprises a defoaming agent (a), the defoaming agent (a) is selected from the group consisting of mineral oils, vegetable oils, silicone oils, silicon-containing emulsions, fatty acids, fatty acid esters, organically modified polysiloxanes, borates, alkoxylates, polyoxyalkylene copolymers, ethylene oxide (EO)-propylene oxide (PO) block polymers, alkynediols, and phosphoric acid esters having the formula P (O) (O-R1) 3-x (O-R2) x, where P represents phosphorus, O represents oxygen, x represents oxygen, x represents oxygen, x represents oxygen, and x represents oxygen. And R1 and R2 are independently a C2-C20 alkyl or aryl group, the C2-C20 alkyl group preferably being a C2-C8 alkyl group, and x = 0, 1, 2; an inorganic binder (b); a blowing agent (c); and a dispersant (d) comprising at least 30% by weight, relative to the total weight of the dispersant (d), of a dispersant containing sulfonic acid groups.

Description

TECHNICAL FIELD

[0001] The present invention relates to an adhesive composition for adjusting the size of air pores in a building product in the presence of a superplasticizer in the adhesive composition. In particular, the present invention relates to an adhesive composition comprising: (a) an antifoam agent; (b) an inorganic binder; (c) a foaming agent; and (d) a dispersing agent. The present invention further relates to a method of producing a hardened gypsum product having pores of a predetermined pore size using said composition. BACKGROUND

[0002] Hardened gypsum products, such as gypsum building panels, are cost effective and provide a high performance product for the finishing of architectural spaces. Gypsum, also known as calcium sulfate dihydrate, is heated to drive off the water of crystallization, resulting in calcium sulfate anhydrite and / or calcium sulfate hemihydrate, which is also known as stucco, calcined gypsum, or plaster of Paris. Building panels are made by combining stucco with water. The calcined gypsum is combined with water and forms an interlocking matrix of gypsum crystals. After the calcined gypsum hydrates, excess water is driven off by heating. The resulting product is a relatively strong panel having a good surface for receiving a decorative finish such as paint or wallpaper.

[0003] Although gypsum building panels are cost effective, they are relatively heavy. Due to the weight, the panels must be moved in small batches. Installers become fatigued from lifting and holding the panels in place to be fastened while working on the panels. In addition, transporting heavy panels is expensive. One method of controlling the density of the product is by adding soap-based foam to the liquid slurry. The stucco then sets around the foam bubbles, creating voids in the gypsum matrix. It is important to control the size of the bubbles to avoid undesirable properties in the panel. If the bubbles are too small, a large number of small bubbles are needed to achieve the change in density. When there is a large number of bubbles in a limited space, the resulting gypsum matrix has low compressive strength. Bubbles that are too large tend to blister and, therefore, cannot hold air in the product to reduce the density of the gypsum product. In addition, blistering results in surface defects. Thus, it has been found that if the gypsum formed has voids that are not too small and uniform in size, a building panel can be produced that is both strong and free of surface defects (see US 5,643,510 A, US 5,085,929 A).

[0004] Various foaming agents produce bubbles with different properties. Some foaming agents form very strong and stable bubbles with little tendency to break down or coalesce. For the purposes of this discussion, a stable foaming agent is defined as one developed to maximize air entrainment and minimize its own use in the adhesive slurry. Other foaming agents are less stable, forming foam, but become even more unstable in the presence of the adhesive (especially gypsum). A combination of foaming agents that form stable and unstable foams allows for control over the formation of larger foam voids in the gypsum slurry. Therefore, it is generally desirable to control the average bubble size within a range that avoids foam formation and to achieve the desired compressive strength of the gypsum matrix at lower density gypsum slurries.

[0005] In addition, various types of organic compounds are typically applied to advantageously modify specific properties of wet hydraulic binder compositions. One class of components, collectively referred to as "high-efficiency water-reducing agents," fluidizes or plasticizes the wet binder composition to obtain a more fluid mixture. Controlled fluidity is desired so that aggregates used in mortars and concrete do not separate from the binder paste. Alternatively, high-efficiency water-reducing agents may allow (i.e.) the use of a lower water:binder ratio to prepare cementitious compositions in order to obtain compositions with a desired consistency. Such lower water:binder ratios generally result in higher compressive strength development in the hardened composition after setting.

[0006] A good high-efficiency water-reducing agent should not only fluidize the wet hydraulic binder composition it is added to, but also maintain that fluidity for a desired period of time. This time should be long enough to maintain the fluidity of the wet composition, for example, while it is en route to the work site in the ready-mix truck. Another important aspect involves the time it takes to unload the truck at the work site and the time required for the cement composition to work in the desired final form. On the other hand, the hydraulic mixture cannot remain fluid for too long, meaning that setting cannot be significantly delayed, as this will slow down the work process and negatively impact the characteristics of the final hardened product. Commonly used high-efficiency water-reducing agents include naphthalene sulfonate formaldehyde condensates, melamine sulfonate formaldehyde condensates, acetone formaldehyde condensates, and polycarboxylate ethers.

[0007] For example, US 2011 / 0213043 A1 discloses a gypsum building panel comprising a hydraulic material, foam, defoamer, and polycarboxylate dispersant.

[0008] Therefore, the flow behavior of adhesive mixtures can be improved by adding sulfate-based high-efficiency water-reducing agents, such as β-naphthalenesulfonate or ligninsulfonate. However, in the presence of a foaming agent, depending on the amount of high-efficiency water-reducing agent added, not only the flow rate changes, but also the air gap structure in the adhesive mixture.

[0009] For example, US 2011 / 0213043 A1 discloses a gypsum building panel comprising hydraulic materials, foam, defoamer, and polycarboxylate superplasticizer.

[0010] However, unlike sulfonate-based high-efficiency water-reducing agents, polycarboxylate high-efficiency water-reducing agents have the disadvantage that they do not improve the early compressive strength of the corresponding adhesive compositions (Wu et al., Materials, 14, p. 662, 2021).

[0011] Another disadvantage is that when a highly effective water-reducing agent is present in the composition, foam is formed during the preparation of the adhesive system.

[0012] WO 2011 / 029711 A1 relates to a gypsum slurry containing a compound having dispersing properties, characterized in that the slurry contains a condensation product as a dispersant, the condensation product containing (I) at least one structural unit having an aromatic or heteroaromatic subunit and a polyether side chain, and (II) at least one phosphorylated structural unit having an aromatic or heteroaromatic subunit, and preferably additionally (III) at least one structural unit having an aromatic or heteroaromatic subunit.

[0013] WO 2012 / 049077 A1 discloses a formulation containing at least one component having dispersing properties, selected from the group consisting of: a compound containing at least a branched comb polymer having a polyether side chain, a naphthalene sulfonate-formaldehyde condensate (“NSF”), and a melamine sulfonate-formaldehyde condensate (“MSF”), and b) a condensation product containing (I) at least one structural unit having an aromatic or heteroaromatic subunit and at least one polyether side chain, and (II) at least one phosphorylated structural unit having an aromatic or heteroaromatic subunit, and (III) at least one structural unit having an aromatic or heteroaromatic subunit. The formulation is suitable as an additive for compositions used in hydraulic adhesives and preferably calcium sulfate-containing adhesive systems.

[0014] However, both solutions use dispersants with polyether side chains. These dispersants tend to form low pore sizes, which results in lower compressive strength.

[0015] US 8,344,084 B2 relates to liquid admixture compositions for use in compositions containing calcium sulfate binder systems, comprising an aqueous composition comprising a) a copolymer dispersion component, b) an antifoaming component, c) a surfactant component, and d) water. However, US 8,344,084 B2 does not relate to foamed products at all. Summary of the Invention

[0016] Therefore, one object of the present invention is to provide an adhesive composition adapted to adjust the optimal size of air bubbles in a slurry of water and adhesive composition, thereby adjusting the pore size of the hardened adhesive composition (independent of the amount of highly effective water-reducing agent present in the composition), and having improved early compressive strength.

[0017] Surprisingly, the above objective can be achieved by an adhesive composition comprising: (a) A defoamer selected from the group consisting of: mineral oils, vegetable oils, silicone oils, silicone-containing emulsions, fatty acids, fatty acid esters, organically modified polysiloxanes, borate esters, alkoxylates, polyoxyethylene copolymers, ethylene oxide (EO)-propylene oxide (PO) block polymers, acetylacetonate, and substances having the formula P(O) (OR) 1 ) 3-x (OR 2 ) x Phosphate ester, where P represents phosphorus, O represents oxygen, and R 1 and R 2 Independently for C2-C 20 Alkyl or aryl groups, C2-C 20 The alkyl group is preferably a C2-C8 alkyl group, and x = 0, 1, 2; (b) Inorganic adhesives; (c) foaming agents; and (d) A dispersant comprising at least 30% by weight of a sulfonic acid group relative to the total weight of the dispersant (d).

[0018] It was further surprising to discover that the above objective can be achieved by a method for producing a hardened adhesive product with holes of a predetermined hole size, the method comprising the following steps: (I) Mix water, inorganic binder and dispersant to prepare binder slurry; (II) Provide foaming agents; (III) Add the defoamer to the adhesive slurry of step (I) and / or the foaming agent of step (II); (IV) Combining the adhesive slurry with a foaming agent to form a foamed adhesive slurry; (V) Forming a foamed adhesive slurry into an article; and (VI) To solidify the product. A certain amount of defoamer is added to adjust the pore size of the foamed adhesive product to a predetermined size; The defoamer is selected from the group consisting of: mineral oil, vegetable oil, silicone oil, silicone-containing emulsion, fatty acids, fatty acid esters, organically modified polysiloxanes, borate esters, alkoxylates, polyoxyethylene copolymers, ethylene oxide (EO)-propylene oxide (PO) block polymers, acetylacetonate, and substances having the formula P(O) (OR). 1 ) 3-x (OR 2 ) x Phosphate ester, where P represents phosphorus, O represents oxygen, and R 1 and R 2 Independently for C2-C 20 Alkyl or aryl groups, C2-C 20 The alkyl group is preferably a C2-C8 alkyl group, and x = 0, 1, 2; and The dispersant comprises at least 30% by weight of a dispersant containing sulfonic acid groups relative to the total weight of the dispersant.

[0019] The inventors have surprisingly discovered that by using defoamers and dispersants as defined above, an adhesive composition can be provided in which the bubble size in the slurry of water and adhesive composition can be adjusted regardless of the amount of dispersant present in the adhesive composition. This is essential, among other things, for the good strength of the constructed product obtained from the slurry of water and adhesive composition. Furthermore, a suitable defoamer emulsion allows for the adjustment of raw material fluctuations, such as in the production process of gypsum board equipment, as needed (compensation for changes in pore size due to gypsum). Attached Figure Description

[0020] Figure 1 shows an image of the pore structure of the hardened gypsum mixture of Embodiment 1 of the present invention.

[0021] Figure 2 shows an image of the pore structure of the hardened gypsum mixture of Comparative Example 1.

[0022] Figure 3 shows an image of the pore structure of the hardened gypsum mixture of Comparative Example 2.

[0023] Figure 4 shows an image of the pore structure of the hardened gypsum mixture of Embodiment 2 of the present invention.

[0024] Figure 5 shows an image of the pore structure of the hardened gypsum mixture of Comparative Example 3.

[0025] Figure 6 shows an image of the pore structure of the hardened gypsum mixture of Comparative Example 4. Detailed Implementation

[0026] The adhesive composition of the present invention comprises: (a) A defoamer selected from the group consisting of: mineral oils, vegetable oils, silicone oils, silicone-containing emulsions, fatty acids, fatty acid esters, organically modified polysiloxanes, borate esters, alkoxylates, polyoxyethylene copolymers, ethylene oxide (EO)-propylene oxide (PO) block polymers, acetylacetonate, and substances having the formula P(O) (OR) 1 ) 3-x (OR 2 ) x Phosphate ester, where P represents phosphorus, O represents oxygen, and R 1 and R 2 Independently for C2-C 20 Alkyl or aryl groups, C2-C 20 The alkyl group is preferably a C2-C8 alkyl group, and x = 0, 1, 2; (b) Inorganic adhesives; (c) foaming agents; and (d) A dispersant comprising at least 30% by weight of a sulfonic acid group relative to the total weight of the dispersant (d).

[0027] In a preferred embodiment, the defoamer (a) comprises at least one compound selected from the group consisting of: trialkyl phosphate, polyoxypropylene copolymer, acetate, ethylene oxide (EO)-propylene oxide (PO) block polymer, or mixtures thereof. More preferably, the defoamer (a) comprises a trialkyl phosphate.

[0028] Preferred trialkyl phosphates are triisobutyl phosphate, tri-n-butyl phosphate, triphenyl phosphate, triethyl phosphate, and tripropyl phosphate. Most preferably, the defoamer (a) comprises triisobutyl phosphate, and more preferably consists of triisobutyl phosphate.

[0029] The defoamer (a) present in the adhesive composition of the present invention results in larger bubbles in the adhesive slurry with a small amount of dispersant (d). Furthermore, by adding the defoamer (a) to the adhesive composition of the present invention, the bubble size in the slurry of water and adhesive composition can be advantageously adjusted with a constant amount of foaming agent (c) and independently of the amount of dispersant (d).

[0030] In a preferred embodiment, the inorganic binder (b) is selected from the group consisting of cement, gypsum, and mixtures thereof.

[0031] As used herein, the term "cement" refers to cement classified according to, for example, the CEM classification listed in DIN EN 197-1. Preferred cement is ordinary Portland cement (OPC) according to DIN EN 197-1, which may contain calcium sulfate (<7% by weight) or be substantially free of calcium sulfate (<1% by weight). Another preferred cement is sulfoaluminate cement (calcium sulfoaluminate cement, CSA) or high-alumina cement (HAC) according to DIN EN 14647, or a mixture of ordinary Portland cement and aluminate cement, particularly a mixture of ordinary Portland cement and high-alumina cement, or a mixture of ordinary Portland cement and sulfoaluminate cement, or a mixture of ordinary Portland cement, high-alumina cement, and sulfoaluminate cement.

[0032] In the context of this invention, the term "gypsum" refers to calcium sulfate in its anhydrous or hydrated form, such as gypsum rock composed of the compound in crystalline form, and corresponding building materials such as calcium sulfate hemihydrate, calcium sulfate dihydrate, or anhydrous calcium sulfate of the formula CaSO4×H2O (where x is 0, ½, or 2), or mixtures thereof.

[0033] In a preferred embodiment, the gypsum is selected from the group consisting of: natural gypsum, calcium sulfate, calcined gypsum, calcium sulfate hemihydrate, anhydrous calcium sulfate, calcined gypsum, synthetic gypsum, or recycled gypsum, wherein the synthetic gypsum is preferably formed as a byproduct of flue gas desulfurization.

[0034] In the context of this invention, the term "recycled gypsum" refers to gypsum that has been used in the production of gypsum-containing articles and has been recovered from said articles.

[0035] In a preferred embodiment, the recycled gypsum is recycled from at least one compound selected from the group consisting of: stucco gypsum, mortar gypsum, machine gypsum plaster, plastering gypsum, bonding gypsum, jointing gypsum, filling gypsum, insulating gypsum, flooring gypsum, premixed gypsum mortar, imitation marble, and gypsum-containing prefabricated structural components. Additionally, the recycled gypsum may contain siloxanes, wax emulsions, or combinations thereof.

[0036] Based on the total gypsum content, the recycled gypsum content of the gypsum used according to the present invention is at least 0.5% by weight, more preferably at least 2.0% by weight, and particularly preferably at least 5.0% by weight.

[0037] Recycled gypsum typically contains additives present in gypsum-containing products, which are integrated into the production process. For example, hydrophobic gypsum plasterboard panels used for wet chamber finishing include siloxanes or wax emulsions.

[0038] Therefore, recycled gypsum preferably contains siloxanes. Siloxanes are straight-chain or cyclic compounds according to formula (I).

[0039] R 3 2-3 R 4 0-1 Si-[O-SiR 4 ] n -O-SiR 3 2-3 (I) Where R 3 It is a hydrogen or alkyl radical, and R 4 (If it exists) is at the end R 3 2-3 R 4 0-1 Si- and SiR 3 2-3 The groups form a closed-loop -O- group, and n can have a value from 0 to 100. If R 3 If it is an alkyl radical, then it is preferably a straight-chain or branched C1-C radical. 10 -alkyl radical. Preferably, R 3 It is methyl, ethyl, n-propyl, n-butyl, isobutyl, or n-hexyl. More preferably, R 3 It is a methyl group.

[0040] Specifically, based on the total weight of the recycled gypsum, the recycled gypsum contains at least 0.01% by weight of siloxane, more preferably 0.02% to 5.0% by weight of siloxane, and particularly preferably 0.05% to 2.0% by weight of siloxane.

[0041] The presence of siloxanes or other additives in an adhesive composition can negatively impact the resulting foam, or even completely destroy it. Therefore, this invention provides an adhesive composition and a method for foaming and curing adhesive articles thereof, which can produce recycled plaster or other inorganic adhesives containing siloxanes or similar additives without increasing foam quality (see WO 2019 / 081344 A2).

[0042] In a preferred embodiment, the foaming agent (c) comprises at least one compound selected from the group consisting of: nonionic surfactants, desalting bleaching agents, cationic surfactants, and amphoteric surfactants. More preferably, the foaming agent (c) comprises at least one compound selected from the group consisting of: alkyl polyglycosides, betaine, glutamate, sulfonyl ketones, alkyl sulfates, alkyl aryl groups, alkyl ethers, alkyl aryl ethers, alkyl ether hydroxyethyl sulfonates, N-acyl amino acid compounds, sulfoacetates, sulfonates, sulfosuccinates, taurines, alkanolamides, amine oxides, carboxylates, cationic polymers, organosilicones, alcohols, protein derivatives, and mixtures thereof.

[0043] The preferred alkyl polyglycosides are compounds according to formula (II).

[0044] R 5 -O-[G] p (II) Where R 5 It is a straight-chain or branched alkyl and / or alkylene radical having 8 to 18 carbon atoms, G is a sugar residue having 5 or 6 carbon atoms, preferably G is glucose, and p is a number from 1 to 10.

[0045] The preferred alkylamide betaine is a compound according to formula (III).

[0046] R 6 -CO-NH-(CH2) y -N + (CH3)2-CH2-COO - (III) Where R 6 It is a straight-chain or branched alkyl or alkylene radical having 7 to 19 carbon atoms, and y is an integer in the range of 2 to 4.

[0047] The preferred betaine is alkylamido betaine. Also preferred are alkyl ethoxylates.

[0048] Preferably, the alkyl ether is selected from the group consisting of: polyethylene oxide alkyl ether, polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene ((ethylene oxide)) alkyl ether and polyoxypropylene alkyl ether.

[0049] The N-acyl amino acid compound is preferably an N-acylglutamic acid compound according to formula (IV).

[0050] M 1 OOC-CH2-CH2-CH(NH-CO-R 7 )-COOM 2 (IV) Where R 7 It is a straight-chain or branched alkyl or alkylene radical having 7 to 19 carbon atoms, and M 1 and M 2 The free radicals are independently selected from the group consisting of H, Li, Na, K, Ca / 2, Mg / 2, ammonium, and alkanolamines.

[0051] The protein derivative is preferably a protein hydrolysis product.

[0052] Alkyl sulfates include straight-chain or branched alkyl sulfates. Straight-chain or branched alkyl sulfates are known in the art.

[0053] Exemplary embodiments of straight-chain or branched alkyl sulfates are compounds represented by formula (V): R 8 -OSO3 - M + (V) Where R 8 It is a straight-chain and / or branched hydrocarbon moiety with a maximum molecular weight of 253, preferably containing 2 to 20 carbon atoms, more preferably 6 to 18 carbon atoms of a straight-chain or branched alkyl group; and M is a monovalent cation comprising at least one selected from sodium, potassium, lithium, magnesium, ammonium and mixtures thereof.

[0054] Preferably, the alkyl sulfate is an α-sulfonyl fatty acid disalt. More preferably, the α-sulfonyl fatty acid disalt is a compound of formula (VI). R 9 CH(SO3M 3 COOM 4 (VI) Where R 9 It is a straight-chain or branched alkyl or alkylene radical having 6 to 16 carbon atoms, and M 3 and M 4 It can be H, Li, Na, K, Ca / 2, Mg / 2, ammonium, or an alkanolamine. Particularly preferred alkanolamines are monoethanolamine, diethanolamine, triethanolamine, and monoisopropanolamine.

[0055] A further applicable prerequisite is that, based on the total weight of the α-sulfonic fatty acid salt, the α-sulfonic fatty acid disalt contains 3% by weight or less of the compound according to formula (VI), wherein R 9 The free radical is an alkylene free radical.

[0056] Preferably, R 9 It is a saturated straight-chain alkyl radical having 8 to 16 carbon atoms, more preferably 9 to 16 carbon atoms, and particularly preferably 10 to 12 carbon atoms.

[0057] More preferably, the applicable prerequisite is that, based on the total weight of the α-sulfonyl fatty acid salt, the α-sulfonyl fatty acid disalt comprises 90% by weight or more of the compound according to formula (VI), wherein R 9 The free radicals are decyl and / or dodecyl free radicals.

[0058] More preferably, M 3 and M 4 Yes.

[0059] Therefore, the α-sulfonyl fatty acid disalt is particularly preferably a disodium salt of 2-sulfonadodecanoic acid, a disodium salt of 2-sulfonotetradecanoic acid, or a mixture thereof. Most preferably, the α-sulfonyl fatty acid disalt is a mixture of a disodium salt of 2-sulfonadodecanoic acid and a disodium salt of 2-sulfonotetradecanoic acid.

[0060] Compounds of formula (VI) can be prepared by any relevant method known to those skilled in the art. A particularly preferred method is the sulfonation of the corresponding carboxylic acid. Such a method involves reacting the corresponding carboxylic acid (especially the corresponding fatty acid) with gaseous sulfur trioxide, preferably in a molar ratio of SO3 to fatty acid of 1.0:1 to 1.1:1. The crude product thus obtained (which is an acidic sulfonated product) is then partially or completely neutralized, preferably completely neutralized with an aqueous solution of NaOH.

[0061] In a preferred embodiment, the foaming agent (c) comprises at least 50% by weight, preferably 60% by weight, and more preferably 70% by weight of a compound relative to the total weight of the foaming agent (c), the compound being selected from the group consisting of alkyl sulfates, alkyl polyglycosides, and mixtures thereof.

[0062] In a preferred embodiment, the defoamer (a) and the foaming agent (c) are present in the composition in a ratio (a):(c) of 1:2000 to 1:1, preferably 1:1800 to 1:5, more preferably 1:1500 to 1:7, even more preferably 1:1200 to 1:8, and particularly preferably 1:1000 to 1:10.

[0063] The compositions of the present invention comprise a dispersant (d), wherein the amount of the dispersant containing sulfonic acid groups is at least 30% of the total weight of the dispersant.

[0064] Preferably, the dispersant (d) comprises at least 40% by weight, more preferably at least 60% by weight, more preferably at least 80% by weight, and even more preferably at least 90% by weight of a dispersant containing sulfonic acid groups relative to the total weight of the dispersant (d).

[0065] In a particularly preferred embodiment, the dispersant (d) consists of a dispersant containing sulfonic acid groups.

[0066] The presence of dispersant (d) in the adhesive composition of the present invention affects the size distribution of bubbles in the slurry of water and adhesive composition. Higher amounts of dispersant (d) result in larger bubbles in the slurry. In the adhesive composition of the present invention, higher amounts of dispersant (d) enable further water reduction at the same flow rate.

[0067] In a preferred embodiment, the dispersant (d) containing sulfonic acid groups is selected from the group consisting of: polynaphthalene sulfonates, ketone resins, melamine resins, lignin sulfonates, and mixtures thereof, preferably naphthalene sulfonate-formaldehyde condensates. Preferably, the polynaphthalene sulfonate is neutralized by calcium ions. Particularly preferred polynaphthalene sulfonate is β-naphthalene sulfonate formaldehyde (BNS). A commercially available product is Flube CA 40 (a calcium salt of a polymer of naphthalene sulfonic acid condensed with formaldehyde), available from Bozetto.

[0068] Preferably, the ketone resin is synthesized from cyclohexanone or acetone and / or mixtures thereof, formaldehyde, and sulfite, more preferably from cyclohexanone, formaldehyde, and sulfite (CFS) as monomers. Preferably, the CFS-based ketone resin has a molecular weight between 10,000 g / mol and 40,000 g / mol, more specifically between 15,000 g / mol and 25,000 g / mol.

[0069] Lignosulfonates are preferably water-soluble anionic polyelectrolyte polymers. Generally, lignin sulfonates are understood to be a byproduct of wood pulp production using sulfite pulp, and this is known to those skilled in the art.

[0070] Polynaphthalene sulfonates are sulfonic acid derivatives containing naphthalene functional units and are commonly used as water-reducing agents in inorganic adhesives. They are mass-produced by the condensation of naphthalene sulfonates or alkylnaphthalene sulfonates with formaldehyde.

[0071] Melamine resin is a resin in which the melamine ring is capped with multiple hydroxyl groups derived from formaldehyde. Preferred melamine resins are melamine sulfonate / formaldehyde condensation products.

[0072] In a preferred embodiment, the composition further comprises a surfactant (e) selected from the group consisting of: styrene / maleic acid copolymers, alcohol alkoxylates, alkynyl glycols, monoalkyl polyalkylene oxides, alkyl ether sulfonates, and alkyl ether carboxylates.

[0073] Preferably, the alcohol alkoxylate is an alcohol ethoxylate R 10 -(EO)-H, where R10 It is ethoxylated nonylphenol or an aliphatic hydrocarbon group having 1 to 25 carbon atoms.

[0074] Preferably, the surfactant (e) is present in an amount of 0.00002% by weight to 0.20% by weight, more preferably 0.0001% by weight to 0.10% by weight, based on the total weight of the adhesive composition.

[0075] When a surfactant (e) is present in the adhesive composition of the present invention, the bubble size of the adhesive composition can be further advantageously adjusted. Furthermore, the defoamer is stabilized by the presence of the surfactant (e).

[0076] The adhesive composition of the present invention may further comprise additives selected from the group consisting of: accelerators, retarders, anti-sagging agents, binders, dust removers, reinforcing materials, biocides, and combinations thereof.

[0077] The adhesive composition of the present invention may further comprise at least one compound selected from the group consisting of low-charge polymers, neutral polymers, and mixtures thereof. Preferably, the adhesive composition may further comprise polyvinyl alcohol.

[0078] Preferably, the low-charge polymer is branched, and one of the side chains is preferably a polyether.

[0079] The present invention further relates to a method for preparing a hardened adhesive product having pores of a predetermined size distributed therein, the method comprising the following steps: (I) Mix water, inorganic binder and dispersant to prepare binder slurry; (II) Provide foaming agents; (III) Add the defoamer to the adhesive slurry of step (I) and / or the foaming agent of step (II); (IV) Combine the adhesive slurry obtained in step (I) with the foaming agent in step (II) to prepare a foamed adhesive slurry; (V) Forming a foamed adhesive slurry into an article; and (VI) To solidify the product. A certain amount of defoamer is added to adjust the pore size in the foamed adhesive product to a predetermined size; The defoamer is selected from the group consisting of: mineral oil, vegetable oil, silicone oil, silicone-containing emulsion, fatty acids, fatty acid esters, organically modified polysiloxanes, borate esters, alkoxylates, polyoxyethylene copolymers, ethylene oxide (EO)-propylene oxide (PO) block polymers, acetylacetonate, and substances having the formula P(O) (OR). 1 ) 3-x (OR 2 )x Phosphate ester, where P represents phosphorus, O represents oxygen, and R 1 and R 2 Independently for C2-C 20 Alkyl or aryl groups, C2-C 20 The alkyl group is preferably a C2-C8 alkyl group, and x = 0, 1, 2; and The dispersant comprises at least 30% by weight of a dispersant containing sulfonic acid groups relative to the total weight of the dispersant.

[0080] The adhesive and dispersant in the method of the present invention are the adhesive and dispersant as described above (d).

[0081] A certain amount of water is added to the slurry to obtain a flowable slurry. The amount of water used varies significantly depending on the application, the nature of the dispersant, the characteristics of the binder (i.e., plaster), and the additives used. The water-to-binder ratio (“WSR”) used in the production of gypsum wall panels is preferably from about 0.40 to about 1.20 based on the dry weight of the binder. Often, a WSR of about 0.50 to about 0.90 is preferred.

[0082] The water used to obtain the slurry should be as pure as possible to optimally control the properties of both the slurry and the setting gypsum. It is well known that salts and organic compounds can alter the setting time of the slurry, varying greatly from accelerators to setting inhibitors. Some impurities lead to irregularities in the structure of the interlocking matrix during the formation of the two crystals, thereby reducing the strength of the set product. Therefore, using water that is as free of contaminants as possible in practice enhances the product's strength and consistency. Preferably, the water is distilled water.

[0083] The foaming agent in the method of the present invention is the foaming agent (c) as described above.

[0084] In a preferred embodiment, in step (II), the foaming agent is provided in the form of pre-formed foam. The foam is pre-generated from an aqueous foaming agent solution. One method of preparing the foam is to use a foam generator that mixes the foaming agent solution with air. Any mixing method can be used to combine the foaming agent with the solution air that causes bubble formation, including stirring, turbulence, or mixing. The amounts of water and air are controlled to generate foam of a specific density. Adjustment of the foam volume is used to control the total dry product weight.

[0085] In a preferred embodiment, the pore size regulator comprises a surfactant. Preferably, the surfactant in the method of the present invention is the surfactant (e) described above.

[0086] The method of the present invention includes the step (VI) of forming a foamed adhesive slurry into an article. Forming an article from a foamed adhesive slurry is known to those skilled in the art.

[0087] The method of the present invention includes a step (V) of solidifying the article. This step is known to those skilled in the art.

[0088] Preferably, the pore size of the foamed adhesive product is measured to be in the range of 150 μm to 2000 μm, more preferably 200 μm to 800 μm. The defoamer is preferably added in an amount of 0.00002% to 0.20% by weight, more preferably 0.0001% to 0.10% by weight, relative to the total weight of the adhesive.

[0089] The present invention will be further illustrated by the accompanying drawings and the following embodiments.

[0090] Measurement method a) wet density To determine the wet density of a gypsum composition, the ratio between weight and volume is determined by introducing the composition into a beaker of known volume and then weighing it.

[0091] b) Foam density To determine the density of foam, the ratio between weight and volume is determined by introducing the corresponding foam into a beaker of known volume and then weighing it.

[0092] c) slump test Measure the flowability after 60 seconds. After adding the powder components to the liquid, the plaster must soak for 15 seconds. Then mix the slurry with a Hobart mixer for 30 seconds. After a total of 45 seconds, fill the ASTM ring with plaster slurry up to the top edge and lift it after 60 seconds. Finally, measure the diameter of the cake on both vertical axes with calipers.

[0093] d) Hardening time Initial solidification is determined using the so-called knife-cut method (similar to DIN EN 13279-2).

[0094] e) Flexural strength and compressive strength Prepare test specimens (4×4×16cm) for studying strength development according to DIN 196-1. 3 Prism). Before testing flexural and compressive strength, all samples were dried until uniform in mass as follows: After the gypsum mortar had set, all test specimens were stored at 20°C / 65% relative humidity for one day. Afterward, all samples were removed from the mortar and subsequently dried at 40°C until uniform in mass. Measurements were taken by weighing and by volume (256 cm³). 3 To calculate the dry density (δT), we use ).

[0095] Examples Foam 1 Preparation To this end, 7g of BASF SE's commercially available Vinapor GYP 3711 (based on alkyl sulfates) with 36% active compounds was dissolved in 1 liter of water and converted into foam using a rotor / stator-based foam generator with added compressed air. The foam density was 75g / L.

[0096] Emulsions 1 ( 50% Preparation of active substances For this purpose, 10g of commercially available defoamer Polyglycol P-3000E from Dow Chemical and 15g of commercially available defoamer Degressal SD 40 (phosphate ester) from BASF SE were mixed with 50g of deionized water and 25g of styrene / maleic acid copolymer prepared according to Example 5 of EP 0 306 449 A2 to prepare emulsion 1.

[0097] Comparative Example 1 ( CE1 ) To produce gypsum slurry, 400 g of β-hemihydrate (obtained from natural gypsum) was homogenized with 0.5 g of finely ground dihydrate, and then introduced into 306.5 g of water containing 0.50 g of an aqueous solution of 40% β-naphthalenesulfonate superplasticizer (NSF) and soaked for 15 seconds. The mixture was then placed in a mixing vessel (stirred according to DIN EN 196-1) and sheared for 30 seconds. During this time, foam 1 (27.2 g, density 75 g / L) was added. The resulting comparative mixture 1 had a fresh density of 888 g / dm³. 3 The measured flowability was 18.8 cm, and the initial solidification time was 2:15 min:s.

[0098] Comparative Example 2 (Comparative Example 1) CE2 ) To produce gypsum slurry, 400 g of β-hemihydrate (obtained from natural gypsum) was homogenized with 0.4 g of finely ground dihydrate, and then introduced into 278.7 g of water containing 3.0 g of an aqueous solution of 40% β-naphthalenesulfonate superplasticizer (NSF) and soaked for 15 seconds. The mixture was then placed in a mixing vessel (stirred according to DIN EN 196-1) and sheared for 30 seconds. During this time, foam 1 (29.5 g, density 75 g / L) was added. The resulting comparative mixture 2 had a fresh density of 873 g / dm³. 3 The measured flowability was 19 cm, and the initial solidification time was 2:15 min:s.

[0099] Comparative Example 3 ( CE3 ) To produce gypsum slurry, 400 g of β-hemihydrate (obtained from natural gypsum) was homogenized with 0.5 g of finely ground dihydrate and then introduced into 289.3 g of water containing 0.50 g of an aqueous solution of 40% β-naphthalenesulfonate superplasticizer (NSF) and soaked for 15 seconds. The mixture was then placed in a mixing vessel (stirred according to DIN EN 196-1) and sheared for 30 seconds. During this time, foam 1 (20.4 g, density 75 g / L) based on Vinapor GYP 3711 was added. The resulting comparative mixture 3 had a fresh density of 982 g / dm³. 3 The measured flowability was 19.2 cm, and the initial solidification time was 2:15 min:s.

[0100] Comparative Example 4 (Comparative Example 1) CE4 ) To produce gypsum slurry, 400 g of β-hemihydrate (obtained from natural gypsum) was homogenized with 0.4 g of finely ground dihydrate, and then introduced into 265.9 g of water containing 3.0 g of an aqueous solution of 40% β-naphthalenesulfonate superplasticizer (NSF) and soaked for 15 seconds. The mixture was then placed in a mixing vessel (stirring according to DIN EN 196-1) and sheared for 30 seconds. During this time, foam 1 (20.4 g, density 75 g / L) was added. The resulting comparative mixture 4 had a fresh density of 985 g / dm³. 3 The measured flowability was 19.1 cm, and the initial solidification time was 2:05 min:s.

[0101] Embodiments of the invention 1 ( IE1 ) To produce the gypsum slurry, 400 g of β-hemihydrate (obtained from natural gypsum) was homogenized with 0.4 g of finely ground dihydrate and then introduced into 292.2 g of water containing 0.50 g of an aqueous solution of 40% β-naphthalenesulfonate superplasticizer (NSF) and soaked for 15 seconds. In addition to Comparative Mixture 1, 0.06 g of defoamer (Pluronic RPE3110 from BASF) was premixed in water. The mixture was then placed in a mixing vessel (stirred according to DIN EN 196-1) and sheared for 30 seconds. During this time, Foam 1 (29.5 g, density 75 g / L) was added. The resulting Example Mixture 1 had a fresh density of 852 g / dm³. 3 The measured flowability was 19.1 cm, and the initial solidification time was 2:10 min:s.

[0102] Table 1 : Summary of application test results Table 1 shows the mixtures of IE1, CE1, and CE2 established with similar fluidity, initial set, and wet slurry density by using different additives. Higher amounts of β-naphthalenesulfonate (NSF) (dispersant (d)) enabled further water reduction at the same fluidity.

[0103] Table 2: Summary of strength study Comparing the results for IE1 and CE1 in Table 2, it can be seen that, under the same density, fluidity, and setting time, adding defoamer (to IE1) can achieve higher strength values ​​compared to CE1, especially at the same NSF dosage level. At a defoamer dosage of 0.015% by weight in the mortar, the flexural strength can even be improved to the CE2 level, which is much higher than CE1.

[0104] The comparison of CE1 and CE2 results in Table 2 shows that the amount of NSF used affects the pore structure (bubble size). It can be seen that at higher NSF doses, the pores are larger.

[0105] The addition of defoamer (a) can increase pore size at lower NSF dosages, as established by IE1 (Figure 1). Therefore, pore size can be adjusted at a constant foaming agent (a) dosage, independent of the NSF dosage, by adding an appropriate amount of defoamer. Larger pores provide higher compressive strength values ​​in calcium sulfate-based adhesives.

[0106] Embodiments of the invention 2 ( IE2 ) To produce the gypsum slurry, 400 g of β-hemihydrate (obtained from natural gypsum) was homogenized with 0.4 g of finely ground dihydrate and then introduced into 273.3 g of water containing 0.50 g of an aqueous solution of 40% β-naphthalenesulfonate superplasticizer (NSF) and soaked for 15 seconds. In addition to comparative mixture 3, 0.015 g of emulsion 1 was premixed in water. The mixture was then placed in a stirring vessel (stirred according to DIN EN 196-1) and sheared for 30 seconds. During this time, foam 1 (20.4 g, density 75 g / L) was added. The resulting example mixture 1 had a fresh density of 988 g / dm³. 3 The measured flowability was 19.1 cm, and the initial solidification time was 2:05 min:s.

[0107] Table 3: Summary of application test results Table 3 shows the mixtures of IE2, CE3, and CE4 established with similar fluidity, initial set, and wet slurry density by using different additives. Higher amounts of β-naphthalenesulfonate (NSF) (dispersant (d)) enabled further water reduction at the same fluidity.

[0108] Table 4: Summary of strength study Comparing the results of IE2 and CE3 in Table 4, it can be seen that, under the same density, fluidity, and setting time, adding emulsion 1 (to IE2) can achieve higher strength values ​​compared to CE3, especially at the same NSF dosage level. With a defoaming dosage of 0.00375% by weight of the plaster (based on 0.001875% by weight of the active plaster), the flexural strength can even be improved to the CE4 level, far exceeding CE3.

[0109] The comparison of CE3 and CE3 results in Table 4 shows that the amount of NSF used affects the pore structure (bubble size). It can be seen that at higher NSF doses, the pores are larger.

[0110] The addition of emulsion 1 can increase pore size at lower NSF dosages, as established by IE2 (Figure 4). Therefore, pore size can be adjusted independently of NSF dosage by adding appropriate amounts of emulsion 1 at a constant foaming agent (a) dosage. Larger pores provide higher compressive strength values ​​in calcium sulfate-based adhesives.

Claims

1. An adhesive composition comprising: (a) An antifoaming agent selected from the group consisting of: mineral oils, vegetable oils, silicone oils, silicone-containing emulsions, fatty acids, fatty acid esters, organically modified polysiloxanes, borate esters, alkoxylates, polyoxyethylene copolymers, ethylene oxide (EO)-propylene oxide (PO) block polymers, acetylacetonate, and substances having the formula P(O) (OR). 1 ) 3-x (OR 2 ) x Phosphate ester, where P represents phosphorus, O represents oxygen, and R 1 and R 2 Independently for C2-C 20 alkyl or aryl groups, the C2-C 20 The alkyl group is preferably a C2-C8 alkyl group, and x = 0, 1, 2; (b) Inorganic adhesives; (c) foaming agents; and (d) A dispersant comprising at least 30% by weight of a sulfonic acid group relative to the total weight of the dispersant.

2. The adhesive composition according to claim 1, wherein the defoamer (a) comprises at least one compound selected from the group consisting of: trialkyl phosphate, polyoxypropylene copolymer, glycerol acetate / alcohol ester, ethylene oxide (EO)-propylene oxide (PO) block polymer or mixtures thereof.

3. The adhesive composition according to claim 1 or 2, wherein the adhesive composition comprises a surfactant (e) selected from the group consisting of: styrene / maleic acid copolymers, alcohol alkoxylates, alkynyl glycols, monoalkyl polyalkylene oxides, alkyl ether sulfonates, and alkyl ether carboxylates.

4. The adhesive composition according to any one of the preceding claims, wherein the foaming agent (c) comprises at least one compound selected from the group consisting of: alkyl polyglycosides, betaine, glutamate, sulfonyl ketones, alkyl sulfates, alkyl aryl groups, alkyl ethers, alkyl aryl ethers, alkyl ether hydroxyethyl sulfonates, N-acyl amino acid compounds, sulfoacetates, sulfonates, sulfosuccinates, taurines, alkanolamides, amine oxides, carboxylates, cationic polymers, organosilicones, alcohols, protein derivatives, and mixtures thereof.

5. The adhesive composition according to any one of the preceding claims, wherein the defoamer (a) and the foaming agent (c) are present in a ratio of 1:2000 to 1:1 ((a):(c)).

6. The adhesive composition according to any one of the preceding claims, wherein the foaming agent (c) comprises at least 50% by weight of a compound selected from the group consisting of alkyl sulfates, alkyl polyglycosides, and mixtures thereof.

7. The adhesive composition according to any one of the preceding claims, wherein the dispersant comprising the sulfonic acid group in the dispersant (d) is selected from the group consisting of: polynaphthalene sulfonate, ketone resin, melamine resin, lignin sulfonate and mixtures thereof, preferably naphthalene sulfonate-formaldehyde condensate.

8. The adhesive composition according to any one of the preceding claims, wherein the inorganic adhesive (b) is selected from the group consisting of cement, gypsum, and mixtures thereof.

9. The adhesive composition according to claim 8, wherein the gypsum is selected from the group consisting of: natural gypsum, calcium sulfate, calcined gypsum, calcium sulfate hemihydrate, anhydrous calcium sulfate, calcined gypsum, synthetic gypsum, or recycled gypsum, wherein the synthetic gypsum is preferably formed as a byproduct of flue gas desulfurization.

10. The adhesive composition according to claim 9, wherein the recycled plaster is - Select from the group consisting of: plaster, mortar plaster, mechanical plaster, plastering plaster, bonding plaster, jointing plaster, filling plaster, insulating plaster, flooring plaster, premixed gypsum mortar, imitation marble, gypsum-containing prefabricated structural components, and mixtures thereof; and / or - Contains siloxanes, wax emulsions, or combinations thereof.

11. The adhesive composition according to any one of the preceding claims, wherein the dispersant (d) comprises the dispersant containing the sulfonic acid group.

12. A method for preparing a hardened adhesive product with pores having a predetermined pore size, the method comprising the steps of: (I) Mix water, inorganic binder and dispersant to prepare binder slurry; (II) Provide foaming agents; (III) Add the defoamer to the adhesive slurry of step (I) and / or the foaming agent of step (II); (IV) Combine the adhesive slurry from step (I) with the foaming agent to prepare a foamed adhesive slurry. (V) Forming the foamed adhesive slurry into an article; as well as (VI) Solidify the product. A certain amount of the defoamer is added to adjust the pore size of the pores in the foamed adhesive product to a predetermined size; The defoamer mentioned above is selected from the group consisting of: mineral oil, vegetable oil, silicone oil, silicone-containing emulsion, fatty acid, fatty acid ester, organically modified polysiloxane, borate ester, alkoxylate, polyoxyethylene copolymer, ethylene oxide (EO)-propylene oxide (PO) block polymer, acetylacetonate, and having the formula P(O) (OR). 1 ) 3-x (OR 2 ) x Phosphate ester, where P represents phosphorus, O represents oxygen, and R 1 and R 2 Independently for C2-C 20 alkyl or aryl groups, the C2-C 20 The alkyl group is preferably a C2-C8 alkyl group, and x = 0, 1, 2, and The dispersant comprises at least 30% by weight of a dispersant containing sulfonic acid groups relative to the total weight of the dispersant.

13. The method of claim 12, wherein - In step (II), the foaming agent is provided in the form of a pre-formed foam produced by the foaming agent; and / or - In step (I), the dispersant is selected from the group consisting of: polynaphthalene sulfonate, ketone resin, melamine resin, lignin sulfonate and mixtures thereof, preferably naphthalene sulfonate-formaldehyde condensate.

14. The method according to claim 12 or 13, wherein the inorganic binder is selected from the group consisting of cement, gypsum, and mixtures thereof.

15. The method according to claim 14, wherein the adhesive is selected from the group consisting of: natural gypsum, calcium sulfate, calcined gypsum, calcium sulfate hemihydrate, anhydrous calcium sulfate, calcined gypsum, synthetic gypsum, or recycled gypsum, wherein the synthetic gypsum is preferably formed as a byproduct of flue gas desulfurization.

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