Stable amine defoamers for admixtures

Abstract

Antifoaming agents for reducing air entrainment in cement compositions. The antifoaming agents are polyalkoxylated alkylpolyamines having the structure of formula (1) or (2), and salts thereof. R 1 -(N(R 2 )-CH2-CH2-CH2) n -N-(R 3 )(R 4 )(1), R 1 -N(CH2-CH2-CH2-N(R 3 )(R 4 ))2(2)[where R 1 is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, and R 2 , R 3 , and R 4 each independently represents at least one of H, an alkylene oxide, or a polyalkylene oxide, and n is 1 to 50. The antifoaming agent can be used in combination with a superplasticizer in an admixture for a cement composition. The antifoaming agent increases the stability and solubility of the admixture under heat and aging.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application is based on and claims the benefit of priority to U.S. Patent Application No. 63 / 374,839, filed September 7, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] Background of the Invention The present invention relates to alkoxylated alkylpolyamine antifoam agents for controlling air entrainment in cement compositions.

[0003] 2. Description of Related Art The "Background" section set forth herein is intended to provide a general overview of the background to the present disclosure. The work of the named inventors, to the extent described in this Background section, along with aspects of the description that may not otherwise be admitted as prior art at the time of filing, is not admitted, expressly or impliedly, as prior art against the present invention.

[0004] The preparation of concrete requires mixing several ingredients, such as hydratable cement, sand, gravel, water, and additives, to form a homogeneous mixture. One of the additives often used is a superplasticizer, which is incorporated into the mixture to reduce the required water content, optimize initial flow and slump retention over time, and improve mechanical properties such as compressive strength. Air entrainment control agents are also desired to extend the freeze-thaw stability of hardened concrete. Superplasticizers often have a comb copolymer structure, where one monomer is composed of a carboxylate end group and another monomer is composed of ethylene oxide repeat units attached to the polymer chain. Specifically, comb copolymers derived from acrylic acid monomers are well-known superplasticizers.

[0005] One undesirable side effect of superplasticizers is the introduction of excess air into the finished concrete. This air entrainment can be beneficial in increasing the freeze-thaw stability of concrete, but proper control of the entrained air is necessary to prevent undesirable adverse effects on the physical properties (compressive strength) of the hardened concrete. A standard approach to reducing such adverse effects is to minimize air entrainment using antifoaming agents. These antifoaming agents are generally hydrophobic materials, such as nonionic surfactants with low HLB, silicone derivatives, di- and tributyl phosphates, and alkyl phthalates.

[0006] Due to their hydrophobic nature, antifoam agents are poorly soluble in water and cannot be incorporated into aqueous admixture solutions for long-term stability. Attempts to compatibilize antifoam agents into compatible polymers or disperse them in admixture (especially superplasticizer) solutions do not result in extended stability. Blended mixtures typically undergo rapid phase separation. This requires that the aqueous superplasticizer solution and antifoam agent be stored separately and mixed only immediately before use to ensure good air entrainment control. Alternatively, separation can be prevented by adding the antifoam agent, optionally with a stabilizing surfactant, to a constantly stirred superplasticizer solution. See U.S. Pat. No. 6,139,623, incorporated herein by reference in its entirety. The incompatibility of antifoam agents in aqueous superplasticizer solutions presents a clear disadvantage to users due to added cost, facility space, and use restrictions.

[0007] Prior art has been established to overcome the problem of hydrophobic incompatibility of antifoaming agents. By incorporating amine units into the antifoaming agent structure, ion pairs can be formed with the carboxylic acid functional groups of the superplasticizer polymer structure. Kuo, in U.S. Patent No. 8,187,376, disclosed polyalkoxylated polyalkylene polyamines as antifoaming agents. Like conventional defoamers, amine defoamers used to solve air entrainment problems can only be incorporated into superplasticizer solutions at relatively low concentrations. At higher concentrations, performance decreases, and the admixture formulation typically becomes unstable after a short time. In particular, exposure of these solutions to elevated temperatures results in separation of the defoamer from the aqueous superplasticizer solution. Therefore, there remains a need for a single storage-stable cement admixture that can be used at low and high concentrations and maintain stability over a wide range of environmental conditions. In view of the above, one object of the present invention is to provide a defoamer with improved stability, and its use in admixtures with superplasticizers for cement compositions. Summary of the Invention

[0008] The present invention provides the following: (1) A defoamer for reducing air entrainment, comprising a polyalkoxylated alkylpolyamine and its salt having a structure represented by formula (1) or (2) below: R 1 -(N(R 2 )-CH2-CH2-CH2) n -N-(R 3 )(R 4 ) (1), R 1 -N(CH2-CH2-CH2-N(R 3 )(R 4 ))2(2), [In the formula, R 1 is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, and R 2 , R 3 , and R 4 each independently represents H, an alkylene oxide, or a polyalkylene oxide, and n is 1 to 50. (2) A defoamer for reducing air entrainment, comprising a polyalkoxylated alkyldiamine and its salt having a structure represented by formula (3): R 1 -N(R 2 )-CH2-CH2-CH2-N-(R 3 )2(3), [In the formula, R 1 is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, and R 2 and R 3 each independently represents H, an alkylene oxide, or a polyalkylene oxide. (3) The defoaming agent according to (1) or (2), wherein the alkylene oxide is propylene oxide or ethylene oxide. (4) The defoaming agent according to any one of (1) to (3), wherein the polyalkylene oxide contains repeating groups of propylene oxide and / or ethylene oxide. (5)R 1 is a branched or unbranched hydrocarbon chain having a length of 12 to 18 carbon atoms. (6) The defoaming agent according to any one of (1) to (5), wherein the total weight percentage of propylene oxide and polypropylene oxide relative to the polyalkoxylated alkylpolyamine is in the range of 45 to 75% by weight. (7)R 1 The antifoaming agent according to any one of (1) to (6), wherein is a tallow alkyl. (8) An admixture comprising the antifoaming agent according to any one of (1) to (7) and an alkaline aqueous solution, suspension, or slurry. (9) An admixture for reducing air entrainment, comprising a dispersant, an antifoaming agent according to any one of (1) to (7), and water, wherein the dispersant and antifoaming agent are present in a combined concentration in the range of 25 to 35% by weight, based on the total weight of the admixture, and the antifoaming agent is present in a concentration of 0.1 to 20% by weight, based on the weight of the dispersant. (10) The admixture according to (9), wherein the antifoaming agent is present in a concentration of 4 to 15% by weight based on the total weight of the dispersant. (11) The admixture according to (9) or (10), having a pH in the range of 4.5 to 6.5. (12) The admixture according to any one of (9) to (11), wherein the dispersant is a superplasticizer selected from the group consisting of polycarboxylate ethers, sulfo-modified melamine-formaldehyde condensates, melamine-formaldehyde condensates, sulfonated melamine-formaldehyde condensates, lignin salts, naphthalene sulfonates, polycarboxylated acrylics, polycarboxylated ethers, carboxylate salts, casein, cocomide derivatives, and mixtures thereof. (13) The admixture according to any one of (9) to (12), wherein the dispersant is at least one selected from the group consisting of polycarboxylate ethers, ester-type dispersants, ether-type dispersants, and naphthalene-type dispersants. (14) The admixture according to any one of (9) to (13), wherein the dispersant is a polycarboxylate ether containing pendant polyethylene oxide groups. (15) An admixture, a dispersant; and The defoaming agent according to any one of (1) to (7), Water and Including, the dispersant and defoamer are present in a combined concentration ranging from 25 to 35% by weight based on the total weight of the admixture; the antifoaming agent is present in a concentration of 0.1 to 20% by weight based on the weight of the dispersant; The dispersant is a polycarboxylate ether copolymer including a structural unit (4) represented by the following formula (4) and a structural unit (5) represented by the following formula (5), [ka] [Wherein, the unit (4) is methacrylic acid or a salt thereof, The unit (5) is methoxypolyethylene glycol monomethacrylate, n1 is the average number of moles added, and represents a number of 15 or more and 30 or less. the proportion of the structural unit (4) in the total content of the structural units (4) to (5) is 65 mol% or more and 80 mol% or less; The weight average molecular weight (Mw) of the polycarboxylate ether copolymer is 35,000 or more and 60,000 or less; Admixture. (16) An admixture, a dispersant; and The defoaming agent according to any one of (1) to (7), water, the dispersant and defoamer are present in a combined concentration ranging from 25 to 35% by weight based on the total weight of the admixture; the antifoaming agent is present in a concentration of 0.1 to 20% by weight based on the weight of the dispersant; The dispersant is a polycarboxylate ether copolymer containing a structural unit (4') represented by the following formula (4') and a structural unit (5') represented by the following formula (5'), [ka] [Wherein, the unit (4') is methacrylic acid or a salt thereof, The unit (5') is methoxypolyethylene glycol monomethacrylate, n1' is the average number of moles added, and represents a number of 80 or more and 120 or less. the proportion of the structural unit (4') in the total content of the structural units (4') to (5') is 70 mol % or more and 90 mol % or less; The weight average molecular weight (Mw) of the polycarboxylate ether copolymer is 35,000 or more and 60,000 or less; Admixture. (17) A cement mixture comprising a particulate cementitious component, the admixture according to any one of (9) to (16), and water, wherein the admixture is present in the cement mixture at a concentration in the range of 0.05 to 1% by weight of cement. (18) The cement mixture according to (17), wherein the admixture is present in the cement mixture at a concentration ranging from 0.1 to 0.5% by weight of the cement. (19) The cement mixture according to (17) or (18), having a W / C ratio of 0.37 to 0.50. (20) A cement mixture comprising: A particulate cementitious component; The admixture according to any one of (9) to (16), Water and Including, The admixture solids are present in the cementitious mixture at a concentration ranging from 0.05 to 1% by weight of cement; The W / C ratio is in the range of 0.37 to 0.50. Cement mixture. (21) The cement mixture according to any one of (17) to (20), further comprising 45 to 60% by weight of sand based on the total weight of the cement mixture. (22) A method for forming an admixture, comprising the step of mixing an alkaline aqueous solution, suspension, or slurry with the defoaming agent according to any one of (1) to (7). (23) A method for forming a cement mixture, comprising the step of mixing a particulate cementitious component, the admixture according to any one of (9) to (16), and water, wherein the admixture is present in the cement mixture at a concentration ranging from 0.05 to 1% by weight of cement. (24) A method of forming a cement mixture, comprising: A particulate cementitious component; The admixture according to any one of (9) to (16), Water and mixing the The admixture is present in the cementitious mixture at a concentration ranging from 0.05 to 1% by weight of cement; The W / C ratio is in the range of 0.37 to 0.50. method. (twenty five) 1. A method for reducing air bubbles in a cement mixture, comprising: A method comprising a step of mixing the antifoaming agent according to any one of (1) to (7) and a dispersant with a cement mixture. (26) Use of a composition containing a polyalkoxylated alkylpolyamine having a structure represented by formula (1) or (2) and its salt as a deforming agent. R 1 -(N(R 2 )-CH2-CH2-CH2) n-N-(R 3 )(R 4 ) (1), R 1 -N(CH2-CH2-CH2-N(R 3 )(R 4 ))2(2), [In the formula, R 1 is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, and R 2 , R 3 , and R 4 each independently represents H, an alkylene oxide, or a polyalkylene oxide, and n is 1 to 50. (27) Use of the deforming agent according to embodiment (23) for an alkaline aqueous solution, suspension, or slurry. (28) Use of the deforming agent according to embodiment (23) for a hydraulic composition.

[0009] The foregoing paragraphs have been provided by way of general introduction and are not intended to limit the scope of the claims that follow. The described embodiments, together with further advantages, will best be understood by reference to the following detailed description when considered in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0010] A more complete understanding of the present disclosure and its advantages is readily obtained as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which: [Figure 1A] FIG. 1A shows the control superplasticizer M-1, which does not contain an antifoaming agent. [Figure 1B] FIG. 1B shows the thermal aging of M-1 superplasticizer neat and after one week at 50° C. pre-blended with ester antifoam (0.50 wt % antifoam loading / active PCE). [Figure 2] The long-term stability of antifoam S2 at various dosages (0.5 to 12.0% per active PCE) in M-2 superplasticizer after heating and aging is shown. [Figure 3]1 is a graph showing air bubble reduction in cement mortar mixtures with various antifoaming agent dosages. DETAILED DESCRIPTION OF THE INVENTION

[0011] Embodiments of the present disclosure now are described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the disclosure are shown.

[0012] The present disclosure is better understood with reference to the following definitions. As used herein, words such as "a" and "an" have the meaning "one or more." In describing the present disclosure, where numerical limits or ranges are set forth, the endpoints are included unless otherwise stated. It is further understood that the terms "comprises" and / or "comprising," as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0013] As used herein, the terms "about," "approximately," or "substantially similar," when describing magnitude and / or location, may be used to indicate that the stated value and / or location is within a reasonable expected range of values ​​and / or locations. For example, a numerical value may have a value that is + / -0.1% of the stated value (or range of values), + / -1% of the stated value (or range of values), + / -2% of the stated value (or range of values), + / -5% of the stated value (or range of values), + / -10% of the stated value (or range of values), + / -15% of the stated value (or range of values), or + / -20% of the stated value (or range of values). In describing this disclosure, when numerical limits or ranges are stated, the endpoints are included unless otherwise stated. Also, all values ​​and subranges within a numerical limit or range are specifically included as if explicitly set forth.

[0014] As used herein, "compound" is intended to refer to a chemical substance, whether solid, liquid, or gas, and whether in a crude mixture or isolated and purified.

[0015] As used herein, a "composite" refers to two or more distinct constituent materials combined together. The individual components remain separate and distinct within the completed structure at the atomic level. The materials may have different physical or chemical properties that, when combined, produce a material with properties different from those of the original components. In some embodiments, a composite may have at least two constituent materials that have the same empirical formula but are distinguished by different densities, crystalline phases, or the lack of a crystalline phase (i.e., an amorphous phase).

[0016] The present disclosure is intended to include all hydration states of a given compound or formula unless otherwise specified or when the material is heated. Additionally, the present disclosure is intended to include all isotopes of atoms present in the present compounds and complexes. Isotopes include atoms having the same atomic number but different mass numbers. By way of general example and without limitation, isotopes of hydrogen include deuterium and tritium. Isotopes of carbon include: 13 C and 14 C. Nitrogen isotopes include: 14 N and 15 N. Isotopes of oxygen include: 16 O. 17 O, and 18 Isotopically labeled compounds of the present disclosure can generally be prepared by conventional techniques known to those skilled in the art, or by processes analogous to those described herein, using an appropriate isotopically labeled reagent in place of the otherwise used non-labeled reagent.

[0017] A reference to a compound in its salt form may be understood to include a reference to its acid form, and vice versa, as this may be the case where both the acid and salt forms may coexist in an aqueous environment. Similarly, a reference to a compound in its amine form may be understood to include a reference to the ammonium form, and vice versa.

[0018] As used herein, the term "cementious" refers to a material that contains or consists of cement (e.g., Portland cement), or that otherwise functions as a binder holding together fine aggregate (e.g., sand), coarse aggregate (e.g., crushed gravel), or a mixture thereof. The cementitious component may be in particulate form. As used herein, the term "cement" encompasses hydratable cements made by finely grinding clinker composed of hydraulic calcium silicate with one or more forms of calcium sulfate (e.g., gypsum) as an intergrinding additive. Any type of cement or cement-containing material may be used in any of the embodiments disclosed herein. For example, the cement may include Type I, Type Ia, Type II, Type IIa, Type III, Type IIIa, Type IV, and Type V Portland cement (using either ASTM C150 or European EN-197 standards), hydraulic cement, non-hydraulic cement, Portland fly ash cement, Portland pozzolana cement, Portland silica fume cement, masonry cement, mortar, EMC cement, stucco, plastic cement, expansive cement, white blend cement, pozzolanic lime cement, lime slag cement, supersulfated cement, calcium aluminate cement, calcium sulfoaluminate cement, geopolymer cement, Rosendale cements, polymer cement mortar, lime mortar, and / or pozzolana mortar. The term "mortar" refers to a cement composition that includes one or more fine aggregates, such as sand or other finely particulate materials. In one embodiment, SiO may be present in the cement.

[0019] The cement may include SiO2-containing materials, including, but not limited to, belite (2CaO·SiO2), alite (3CaO·SiO2), celite (3CaO·Al2O3), or brownmillerite (4CaO·Al2O3·Fe2O3), which are commonly found in sand-free cements.

[0020] "Mortar" is a cement paste formed with water and further containing fine aggregate (e.g., sand), while "concrete" is mortar further containing coarse aggregate (e.g., crushed stone or gravel).

[0021] Typically, Portland cement is combined with one or more other supplemental cementitious materials ("SCMs") and provided as a blend. SCMs may include limestone, hydrated lime, fly ash, granulated blast furnace slag, and silica fume, or other materials commonly included in such cements. Thus, the cementitious material may include one or more SCMs, preferably in an amount of 0% to 100% by weight, more preferably 10% to 60% by weight, based on the total dry weight of the cementitious material.

[0022] As used herein, the term "hydratable" is intended to refer to cement or cementitious materials that harden through chemical interaction with water. Portland cement clinker is a partially molten mass composed primarily of hydratable calcium silicate. Calcium silicate is essentially a mixture of tricalcium silicate (3CaO·SiO2, or "C3S" in cement chemist's notation) and dicalcium silicate (2CaO·SiO2, "C2S"), the former being the predominant form, with smaller amounts of tricalcium aluminate (3CaO·Al2O3, "C3A") and tetracalcium aluminoferrite (4CaO·Al2O3·Fe2O3, "C4AF"). See, e.g., Dodson, Vance H., Concrete Admixtures (Van Nostrand Reinhold, New York NY 1990), page 1, incorporated by reference in its entirety.

[0023] The term "additive" shall be used herein to describe additives added at the cement manufacturing plant, and further to describe "admixtures" added to the cement, water, and optional aggregates used to make cement mortar, concrete, and other cementitious materials. Preferably, the additive composition is an aqueous liquid that can be dispensed in liquid form.

[0024] According to a first aspect, the present disclosure provides an antifoam agent for reducing air entrainment, where air entrainment refers to air, or any gas or any collection of gases, incorporated within a mixture. In reducing air entrainment, the antifoam agent, when added to a mixture, promotes the release of air from the mixture. The antifoam agent comprises a polyalkoxylated alkylpolyamine and a salt thereof having a structure represented by formula (1) or formula (2): R 1 -(N(R 2 )-CH2-CH2-CH2) n -N-(R 3 )(R 4 ) (1), R 1 -N(CH2-CH2-CH2-N(R 3 )(R 4 ))2(2), [In the formula, from the viewpoint of antifoaming property, R 1 is preferably a branched or unbranched hydrocarbon chain having a length of 1 to 20, 5 to 20, 10 to 20, 12 to 18, or 14 to 18 carbon atoms. 1 is more preferably tallow alkyl. From the viewpoint of solubility in water and antifoaming properties, R 2 and R 3 each independently represents at least one of H, alkylene oxide, or polyalkylene oxide, and n is preferably 1 to 50, 2 to 45, 3 to 40, 4 to 35, 5 to 30, 6 to 25, 7 to 20, or 8 to 15.

[0025] In another embodiment, the antifoam agent comprises a polyalkoxylated alkyldiamine having a structure represented by formula (3) and salts thereof. R 1 -N(R 2 )-CH2-CH2-CH2-N-(R 3 )2(3), [In the formula, from the viewpoint of antifoaming property, R 1 is preferably a branched or unbranched hydrocarbon chain having a length of 1 to 20, 5 to 20, 10 to 20, 12 to 18, or 14 to 18 carbon atoms. 1 is more preferably tallow alkyl, and R 2 and R 3 each independently represents H, an alkylene oxide, or a polyalkylene oxide.

[0026] In one embodiment, the alkylene oxide is propylene oxide and / or ethylene oxide. In one embodiment, the alkylene oxide is propylene oxide, and the polyalkylene oxide is polypropylene oxide. In one embodiment, the polyalkylene oxide contains repeating groups of propylene oxide and / or ethylene oxide. In view of solubility in water and defoaming properties, each polyalkylene oxide chain may contain an average of 1 to 15 propylene oxide and / or ethylene oxide groups, or preferably an average of 1 to 12, 1 to 10, 2 to 8, 2 to 7, or 3 to 5 propylene oxide and / or ethylene oxide groups. In one embodiment, when both propylene oxide and ethylene oxide are present in the alkylene oxide and / or polyalkylene oxide, from the viewpoint of defoaming property, the weight percentage of propylene oxide relative to the total weight of propylene oxide and ethylene oxide is preferably 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, or 100% by weight.

[0027] In one embodiment, when the alkylene oxide is propylene oxide and the polyalkylene oxide is polypropylene oxide, the total weight percentage of propylene oxide and polypropylene oxide to the polyalkoxylated alkylpolyamine is in the range of 45 to 75% by weight, preferably 50 to 70% by weight, and more preferably 60 to 70% by weight, from the viewpoint of defoaming property.

[0028] In one embodiment, from the viewpoint of antifoaming properties and water solubility, the weight percentage of propylene oxide is preferably in the range of 45 to 75 wt %, 50 to 70 wt %, or 55 to 65 wt %, based on the total mass of the polyalkoxylated alkylpolyamine and propylene oxide.

[0029] In one embodiment, from the standpoint of antifoaming properties and economic efficiency, the antifoam agent is preferably produced by reacting N-(tallow alkyl)dipropylene triamine with propylene oxide, and the weight percentage of propylene oxide is in the range of 45 to 75 wt %, 50 to 70 wt %, or 55 to 65 wt %, based on the total mass of the N-(tallow alkyl)dipropylene triamine and propylene oxide.

[0030] In one embodiment, from the viewpoint of defoaming properties, the defoaming agent preferably has a number average molecular weight or weight average molecular weight in the range of 350 to 5,000 g / mol, 400 to 4,000 g / mol, 500 to 2,000 g / mol, 600 to 1,000 g / mol, or 700 to 800 g / mol.

[0031] The average molecular weight was determined from the quantitative total amine value of the defoamer of the present invention. The total amine value is obtained by neutralizing the amines present in the defoamer with a known acid and converting the amount of acid to potassium hydroxide units. The measurement was performed in accordance with ASTM D 2073.

[0032] In other embodiments, the antifoam agent is not made from tallow alkylamines, but rather from alkylamines derived from coconut oil, soybean oil, palm kernel oil, or mixtures thereof.

[0033] In other embodiments, defoamers may be used in a wide range of applications, including any aqueous mixture where it is desirable to control the specific air content of the mixture, particularly mixtures containing amphiphilic molecules. Non-limiting examples of such applications include, but are not limited to, building materials, coatings, and adhesives, especially pressure-sensitive adhesives.

[0034] Specific examples of building materials include self-leveling mortar, cement, grout, overlayers, and screeds. The present invention may also be used in other building materials, such as insulating wall mortar tiles, autocatalytic mortar tiles, self-compacting concrete compositions, wet plaster, rendering compositions, offshore cementitious compositions, oilfield cementitious compositions, and pigment slurries. The present invention is useful in the manufacture of cementitious products, including as a grinding aid. In particular, the present invention is useful in the preparation of admixtures. Such admixtures include, but are not limited to, superplasticizers, superplasticizers, retarders, sprayed concrete admixtures, foamed concrete admixtures, and strength-enhancing admixtures. Specific examples of coatings in which the present invention can be used include overprint varnishes, plastic coatings, and clear coats. Further non-limiting examples of uses for the de-airentrainer compositions of the present invention include ink formulations and production, inkjet ink formulations and production, metalworking fluids, and industrial and institutional cleaning compositions.

[0035] Without being bound by theory, it is believed that the amine units present in the antifoam structure of the present invention are ionized by the acidic species present in the superplasticizer, thereby solubilizing it and providing a stable, homogeneous mixture. The solubility of the antifoam in low pH formulations achieved with the degree of propylene oxide incorporation is not observed with other similar structures. When the antifoam is added to high pH cement, the antifoam of the present invention is neutralized to more hydrophobic species, which cause disruption of the lipid bilayer. The antifoam has a relatively hydrophilic head group at the propylene oxide end of the molecule and a branched or unbranched hydrophobic hydrocarbon chain (R 1 ) has a highly hydrophobic, surfactant structure. The hypothesis is that the antifoaming agent is transported into the foam lamellae, destabilizing and dehumidifying them, thereby suppressing foaming upon application.

[0036] According to a second aspect, the present disclosure provides an admixture, for example for reducing air entrainment in a mortar or cement composition.

[0037] In one embodiment, the admixture comprises the antifoaming agent of the first aspect of the present disclosure and an alkaline aqueous solution, suspension, or slurry. Examples of alkaline aqueous solutions, suspensions, or slurries include, but are not limited to, combustion ash suspensions, hydraulic compositions, and cementitious compositions, preferably cementitious compositions.

[0038] In one embodiment, the admixture comprises a dispersant, an antifoaming agent according to the first aspect of the present disclosure, and water. From the viewpoint of antifoaming and storage stability, the dispersant and antifoaming agent may be present at a combined concentration of preferably 25-35 wt %, 27-33 wt %, 29-31 wt %, or about 30 wt %, based on the total weight of the admixture. From the viewpoint of antifoaming and storage stability, the antifoaming agent is preferably present at a concentration of 0.1-20 wt %, 0.2-18 wt %, 0.4-16 wt %, 0.5-15 wt %, 0.7-13 wt %, 1-12 wt %, 3-10 wt %, 4-9 wt %, or 5-8 wt %, based on the weight of the dispersant.

[0039] In one embodiment, from the viewpoint of storage stability, the pH of the admixture is preferably in the range of 4.5 to 6.5, 4.6 to 6.4, 4.8 to 6.2, or 5.0 to 6.0.

[0040] In one embodiment, the dispersant is a superplasticizer. As used herein, the term "superplasticizer" refers to one or more materials that can provide improved flow properties and performance efficiency to mixtures, such as cementitious compositions, mortars and mortar tiles, grouts, screeds, pigment slurries, plasters, overprint varnishes, coatings, and adhesives, and other hardening compounds. As used herein, the term "superplasticizer" refers to both plasticizer and superplasticizer chemicals. In one embodiment, the superplasticizer is selected from the group consisting of polycarboxylate ethers, sulfo-modified melamine-formaldehyde condensates, melamine-formaldehyde condensates, sulfonated melamine-formaldehyde condensates, lignin salts, naphthalene sulfonates, polycarboxylated acrylics, polycarboxylated ethers, cocomide derivatives, and mixtures thereof.

[0041] In one embodiment, the superplasticizer is a sulfo-modified melamine-formaldehyde condensate, such as melamine formaldehyde sulfonate (MFS) or a sulfonated melamine-formaldehyde condensate. In one embodiment, from a processability standpoint, the dispersant is preferably a polycarboxylate ether, and in a further embodiment, the dispersant may contain pendant polyethylene oxide groups.

[0042] Superplasticizer; Polycarboxylate ether copolymer In one embodiment, the superplasticizer is a polycarboxylate ether copolymer comprising a structural unit (4) represented by the following formula (4) and a structural unit (5) represented by the following formula (5):

[0043] [ka] [In the formula, R 5 and R 7 are the same or different and each represents a hydrogen atom or a methyl group, and R 6 and R 8 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; M represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an organic ammonium; p represents a number of 0 to 2; q represents a number of 0 or 1; and n1 represents the average number of moles added and is a number of 5 to 150.

[0044] For the structural unit (4) represented by formula (4), R 5 is a hydrogen atom or a methyl group, and preferably contains a methyl group. M is a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an organic ammonium, preferably an alkali metal or an alkaline earth metal. There may be two or more structural units (4). Examples of monomers that can be structural units (4) include monomers selected from acrylic acid, methacrylic acid, and salts thereof. From the viewpoints of storage stability and antifoaming properties, methacrylic acid and salts thereof are preferred.

[0045] For the structural unit (5) represented by formula (5), R 6 and R 8 are the same or different, and from the viewpoint of reactivity, each represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and from the viewpoint of storage stability, each preferably represents an alkyl group having 1 carbon atom, i.e., a methyl group. 7 represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom from the viewpoint of storage stability. There may be two or more structural units (5). p represents a number of 0 or more and 2 or less, and is preferably 0 or more and 1 or less, from the viewpoint of storage stability, more preferably 0. q represents a number of 0 or 1, and is preferably 1 from the viewpoint of storage stability.

[0046] n1 is the average number of moles added and represents a number of 5 or more and 150 or less. From the viewpoint of storage stability, n1 is preferably 15 or more, and n1 is preferably 140 or less, more preferably 130 or less, and even more preferably 120 or less.

[0047] In another aspect of the present invention, from the viewpoint of storage stability and cement dispersibility, n1 is preferably 15 or more, and n1 is preferably 140 or less, more preferably 130 or less, even more preferably 120 or less, even more preferably 100 or less, even more preferably 80 or less, even more preferably 70 or less, even more preferably 60 or less, even more preferably 50 or less, even more preferably 40 or less, and even more preferably 30 or less.

[0048] In another embodiment of the present invention, from the viewpoint of storage stability and strength of the hydraulic composition, n1 may be in the range of 80 or more and 150 or less, preferably 140 or less, more preferably 130 or less, and more preferably 120 or less.

[0049] In one embodiment, the structural unit (5) may be a monomer selected from the group consisting of methoxypolyethylene glycol monomethacrylate, polyoxyethylene methallyl ether, polyoxyethylene isoprenyl ether, and polyoxyethylene vinyl ether. From the viewpoints of storage stability and defoaming properties, methoxypolyethylene glycol monomethacrylate is preferred.

[0050] In one embodiment, the polycarboxylate ether copolymer includes a structural unit (6) represented by the following formula (6) in terms of fluidity retention performance.

[0051] [ka] [In the formula, R 9 represents a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom.

[0052] R in equation (6) 9represents a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom, and is preferably a hydroxyethyl group or a methyl group.

[0053] The structural unit (6) is preferably a structural unit having a monomer selected from alkyl (having 1 to 4 carbon atoms) acrylate and alkyl (having 1 to 4 carbon atoms) methacrylate.

[0054] The polycarboxylate ether copolymer is preferably a copolymer containing the structural unit (4), the structural unit (5), and optionally the structural unit (6). In one embodiment, from the viewpoint of cement dispersibility, the proportion of the structural unit (4) is 45 mol% or more and 95 mol% or less, the proportion of the structural unit (5) is 5 mol% or more and 30 mol% or less, and the proportion of the structural unit (6) is 0 mol% or more and 35 mol% or less, based on the total number of moles of the structural units (4) to (6).

[0055] In one embodiment, from the viewpoint of cement dispersibility and storage stability, the proportion of the structural unit (4) as a monomer in the copolymer is 55 mol% or more, preferably 65 mol% or more, more preferably 70 mol% or more, and 90 mol% or less, more preferably 85 mol% or less, more preferably 80 mol% or less, based on the total number of moles of the structural units (4) to (6).

[0056] In one embodiment, the proportion of the monomer structural unit (5) in the copolymer is preferably 10 mol% or more, more preferably 15 mol% or more, and 25 mol% or less, more preferably 20 mol% or less, relative to the total number of moles of the structural units (4) to (6).

[0057] In one embodiment, the proportion of the monomer structural unit (6) in the copolymer is preferably 5 mol% or more, more preferably 10 mol% or more, and 25 mol% or less, preferably 15 mol% or less, based on the total number of moles of the structural units (4) to (6).

[0058] In one embodiment, from the viewpoint of cement dispersibility, the molar ratio of the structural unit (4) to the structural unit (5) in the polycarboxylate ether copolymer (structural unit (4) / structural unit (5)) is preferably 1 or more, more preferably 3 or more, and preferably 20 or less, more preferably 10 or less.

[0059] In one embodiment, the ratio of the total number of moles of the structural units (4) and (5) to all structural units of the polycarboxylate ether copolymer is preferably 80 mol% or more, more preferably 90 mol% or more, and preferably 100 mol% or less, preferably 100 mol%.

[0060] In one embodiment, the ratio of the total number of moles of the structural units (4), (5), and (6) to all structural units of the polycarboxylate ether copolymer is preferably 80 mol% or more, more preferably 90 mol% or more, and preferably 100 mol% or less, preferably 100 mol%.

[0061] In one embodiment, from the viewpoint of cement dispersibility, the weight average molecular weight (Mw) of the polycarboxylate ether copolymer is preferably 20,000 or more, more preferably 25,000 or more, even more preferably 30,000 or more, even more preferably 35,000 or more, and preferably 70,000 or less, more preferably 60,000 or less, even more preferably 55,000 or less. This weight average molecular weight is measured by gel permeation chromatography (GPC) under the following conditions. GPC conditions Equipment: GPC (HLC-8320GPC) manufactured by Tosoh Corporation Column: G4000PWXL + G2500PWXL (Tosoh) Eluent: 0.2M phosphate buffer / CH3CN=9 / 1 Flow rate: 1.0mL / min Column temperature: 40℃ Detection: RI Sample size: 0.2 mg / mL Standard substance: Expressed in polyethylene glycol equivalent (monodisperse polyethylene glycol: molecular weight 87,500, 250,000, 145,000, 46,000, 24,000)

[0062] In one embodiment, the admixture is a clear, homogeneous solution that does not undergo phase separation when formed and does not develop haze or turbidity over time. In other words, the solution does not develop cloudiness or significant levels of precipitated solids, and may have a turbidity of 100 or less, 80 or less, 60 or less, 50 or less, or 40 or less as measured in Nephelometric Turbidity Units (NTU) per USEPA Method 180.1. A lower NTU represents less turbidity and greater clarity.

[0063] In one embodiment, the admixture can remain free from separation or from developing haze or cloudiness for at least 7 days, at least 10 days, at least 14 days, at least 15 days, at least 20 days, at least 25 days, at least 30 days, at least 35 days, or at least 40 days. In further embodiments, the admixture can remain free from separation or from developing haze or cloudiness over the above periods even when held at temperatures of at least 20°C, at least 30°C, at least 35°C, at least 40°C, at least 50°C, at least 55°C, and / or less than 60°C, or less than 50°C.

[0064] According to a third aspect, the present disclosure provides a cement mixture comprising a particulate cementitious component, the admixture of the second aspect of the disclosure, and water. From the viewpoint of workability, the solids content of the admixture is preferably present in the cement mixture in the range of 0.05-1 wt%, 0.08-0.8 wt%, 0.1-0.5 wt%, or 0.2-0.4 wt% of the weight of the cement.

[0065] In one embodiment, the cement mixture has a W / C ratio (water / cement mass ratio) of 0.37 to 0.50, 0.38 to 0.48, 0.39 to 0.46, 0.40 to 0.45, or 0.42 to 0.44.

[0066] In one embodiment, the cement mixture further comprises 45-60 wt%, 48-58 wt%, 50-57 wt%, 52-56 wt%, or about 55 wt% sand based on the total weight of the cement mixture, or the cement mixture further comprises sand at a concentration of 140-180 wt%, 150-175 wt%, or 160-170 wt% of the cement.

[0067] In one embodiment, the cement mixture has an 80% or greater reduction in air bubbles when compared to a substantially similar cement mixture without an antifoaming agent. For example, the air bubble reduction can be 85% or greater, 90% or greater, 95% or greater, 97% or greater, or 98% or greater. In one embodiment, the cement mixture can have a 100% reduction in air bubbles, meaning no air bubbles are detectable.

[0068] In one embodiment, air bubbles as measured in a cementitious mixture by ASTM D 3203-94 may be present at a concentration of 0.10% or less, 0.08% or less, 0.06% or less, 0.05% or less, 0.04% or less, or 0.03% or less.

[0069] According to another aspect, the present disclosure relates to a method of forming an admixture comprising mixing an alkaline aqueous solution, suspension, or slurry with an antifoaming agent described herein.

[0070] According to another aspect, the present disclosure relates to a method of forming a cement mixture comprising mixing a particulate cementitious component, an admixture of the second aspect, and water.

[0071] According to another aspect, the present disclosure relates to a method of forming a cement mixture comprising mixing a particulate cementitious component, an antifoaming agent of the first aspect, a dispersant, and water.

[0072] According to another aspect, the present disclosure provides a method for reducing air bubbles in a cementitious mixture, comprising mixing an admixture of the second aspect with a cementitious mixture having air bubbles, wherein the amount of air bubbles measured by ASTM D 3203-94 is reduced by at least 80%, at least 85%, at least 90%, at least 95%, or at least 97% compared to a substantially similar cementitious mixture mixed with the admixture of the first aspect but without the antifoaming agent.

[0073] According to another aspect, the present disclosure relates to a method of reducing air bubbles in a cement mixture, comprising mixing the antifoaming agent of the first aspect and a dispersant with the cement mixture.

[0074] According to another aspect, the present disclosure relates to the use of an antifoam agent comprising a polyalkoxylated alkylpolyamine having a structure represented by formula (2) and salts thereof. R 1 -N(CH2-CH2-CH2-N(R 3 )(R 4 ))2(2), [In the formula, R 1 is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, and R 2 , R 3 , and R 4 each independently represents H, an alkylene oxide, or a polyalkylene oxide.

[0075] According to a further aspect, the present disclosure relates to the use of an antifoaming agent for an alkaline aqueous solution, suspension, or slurry.

[0076] According to a further aspect, the present disclosure relates to the use of an antifoaming agent for a hydraulic composition.

[0077] In other embodiments, the antifoaming agent may be combined with additional ingredients, and the resulting composition may be incorporated into cement, mortar, concrete compositions, overprint varnishes, plastic coatings, clear coats, inks, dyes, or other suitable applications. Examples of suitable additional ingredients include wetting agents, flow and leveling agents, shrinkage-reducing agents, naphthalene sulfonates, polystyrene sulfonates, phosphates, phosphonates, crosslinked homopolymers or copolymers of acrylic acid and its salts, calcium salts of organic acids, preferably having from 1 to about 4 carbon atoms, alkanoic acids and their salts, aluminum sulfate, metallic aluminum, bentonite, montmorillonite, sepiolite, polyamide fibers, polypropylene fibers, polyvinyl alcohol, and homopolymers, copolymers, or terpolymers based on vinyl acetate, maleate esters, ethylene, styrene, butadiene, vinyl versatate, and acrylic monomers, as well as redispersible dispersion powders, such as polyvinyl acetate, polyethylene-polyvinyl acetate, polyvinyl alcohol, and homopolymers, copolymers, or terpolymers based on vinyl acetate, maleate esters, ethylene, styrene, butadiene, vinyl versatate, and acrylic monomers. Other suitable ingredients include short and long fibers, such as steel fibers, glass fibers, carbon fibers, polyolefin fibers, polyester fibers, and polyamide fibers. Rheology modifiers (including cellulose-containing polysaccharide additives, starch, xanthan gum, and other biopolymers) and alkali-swellable acrylic associative thickeners (containing cellulose and / or meth(acrylic) functional groups) can also be used, as well as fillers such as fine and / or coarse aggregates and / or sand or clay. Other inorganic cement components, such as gypsum, blast furnace slag, fly ash, aluminum sulfate, metallic aluminum, bentonite, montmorillonite, and sepiolite, as well as dyes, pigments, and finely divided colorants, may also be included. Other functional additives include set accelerators and / or set retarders, water repellents, hydrophobic agents, rust inhibitors, flame retardants, biocides, and fungicides.

[0078] The following are exemplary embodiments of the present disclosure.

[0079] Embodiment (1): A defoamer for reducing air entrainment in an alkaline aqueous solution, suspension, or slurry, comprising a polyalkoxylated alkylpolyamine and salts thereof having a structure represented by formula (1) or (2): R 1 -(N(R 2 )-CH2-CH2-CH2) n -N-(R 3 )(R 4 )(1), R 1 -N(CH2-CH2-CH2-N(R 3 )(R 4 ))2(2), [In the formula, R 1 is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, and R 2 , R 3 , and R 4 each independently represents at least one of H, alkylene oxide, or polyalkylene oxide, and n is 1 to 50.

[0080] Embodiment (2): A defoamer for reducing air entrainment, comprising a polyalkoxylated alkyldiamine and a salt thereof having a structure represented by formula (3): R 1 -N(R 2 )-CH2-CH2-CH2-N-(R 3 )2(3), [In the formula, R 1 is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, and R 2 and R 3 each independently represents H, an alkylene oxide, or a polyalkylene oxide.

[0081] Embodiment (3): The defoamer of embodiment (1) or (2), wherein the alkylene oxide is propylene oxide or ethylene oxide.

[0082] Embodiment (4): The defoaming agent according to any one of embodiments (1) to (3), wherein the polyalkylene oxide comprises repeating groups of propylene oxide and / or ethylene oxide.

[0083] Embodiment (5): The defoaming agent according to any one of embodiments (1) to (4), wherein the alkylene oxide is propylene oxide and the polyalkylene oxide is polypropylene oxide.

[0084] Embodiment (6): R 1 is a branched or unbranched hydrocarbon chain having a length of 12 to 18 carbon atoms.

[0085] Embodiment (7): The defoaming agent according to any one of embodiments (1) to (6), wherein the total weight percentage of propylene oxide and polypropylene oxide relative to the polyalkoxylated alkylpolyamine is in the range of 45 to 75% by weight.

[0086] Embodiment (8): An admixture comprising the defoaming agent according to any one of embodiments (1) to (7) and an alkaline aqueous solution, suspension, or slurry.

[0087] Embodiment (9): An admixture for reducing air entrainment, the admixture comprising a dispersant, an antifoaming agent according to any one of embodiments (1) to (7), and water, wherein the dispersant and antifoaming agent are present in a combined concentration in the range of 25 to 35 wt.%, based on the total weight of the admixture, and the antifoaming agent is present in a concentration of 0.1 to 20 wt.%, based on the weight of the dispersant.

[0088] Embodiment (10): The admixture of embodiment (9), wherein the antifoaming agent is present in a concentration of 4 to 15 wt. % based on the total weight of the dispersant.

[0089] Embodiment (11): The admixture according to embodiment (9) or (10), having a pH in the range of 4.5 to 6.5.

[0090] Embodiment (12): The admixture of any one of embodiments (9) to (11), wherein the dispersing agent is a superplasticizer selected from the group consisting of polycarboxylate ethers, sulfo-modified melamine-formaldehyde condensates, melamine-formaldehyde condensates, sulfonated melamine-formaldehyde condensates, lignin salts, naphthalene sulfonates, polycarboxylated acrylics, polycarboxylated ethers, carboxylate salts, casein, cocomide derivatives, and mixtures thereof.

[0091] Embodiment (13): The admixture according to any one of (9) to (12), wherein the dispersant is at least one selected from the group consisting of polycarboxylate ethers, ester-type dispersants, ether-type dispersants, and naphthalene-type dispersants.

[0092] Embodiment (14): The admixture of any one of embodiments (9) to (13), wherein the dispersing agent is a polycarboxylate ether containing pendant polyethylene oxide groups.

[0093] Embodiment (15): A cement mixture comprising a particulate cementitious component, the admixture of any one of embodiments (9) to (14), and water, wherein the admixture solids are present in the cement mixture at a concentration ranging from 0.05 to 1% by weight of cement.

[0094] Embodiment (16): The cementitious mixture of embodiment (15), wherein the admixture solids are present in the cementitious mixture at a concentration ranging from 0.1 to 0.5% by weight of the cement.

[0095] Embodiment (17): The cement mixture according to embodiment (15) or (16), wherein the W / C ratio is 0.37 to 0.50.

[0096] Embodiment (18): The cement mixture of any one of embodiments (15) to (17), further comprising 45 to 60 wt. % sand, based on the total weight of the cement mixture.

[0097] Embodiment (19): A method of forming an admixture, comprising mixing an alkaline aqueous solution, suspension, or slurry with the defoamer of any one of embodiments (1) to (7).

[0098] Embodiment (20): A method of forming a cement mixture, comprising the step of mixing a particulate cementitious component, the antifoaming agent of any one of embodiments (1) to (7), a dispersant, and water, wherein the admixture is present in the cement mixture at a solids concentration ranging from 0.05 to 1% by weight of cement.

[0099] Embodiment (21): A method of forming a cement mixture, comprising mixing a particulate cementitious component, the admixture of any one of embodiments (9) to (14), and water, wherein the admixture is present in the cement mixture at a solids concentration ranging from 0.05 to 1% by weight of cement.

[0100] Embodiment (22): 1. A method for reducing air bubbles in a cement mixture, comprising: A method comprising the step of mixing the claimed antifoaming agent according to any one of embodiments (1) to (7) and a dispersant with a cement mixture.

[0101] Embodiment (23): Use of a defoaming agent having a composition comprising a polyalkoxylated alkylpolyamine having a structure represented by formula (1) or (2) and a salt thereof. R 1 -(N(R 2 )-CH2-CH2-CH2) n -N-(R 3 )(R 4 ) (1), R 1 -N(CH2-CH2-CH2-N(R 3 )(R 4 ))2(2), [In the formula, R 1 is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, and R 2 , R 3 , and R 4each independently represents H, an alkylene oxide, or a polyalkylene oxide, and n is 1 to 50.

[0102] Embodiment (24): Use of the defoamer according to embodiment (23) for an alkaline aqueous solution, suspension, or slurry.

[0103] Embodiment (25): Use of the defoamer according to embodiment (23) for a hydraulic composition.

[0104] The following examples are intended to further illustrate protocols for preparing the antifoam agents and admixtures, and their uses, and are not intended to limit the scope of the claims. [Example]

[0105] Aqueous dispersion and antifoam blends were prepared with varying antifoam loadings while keeping the total actives content constant at 30 wt%. Polymers M-1, M-2, and M-3 are superplasticizers for ester-type polycarboxylate dispersants and are commercially available from Kao Specialties Americas (High Point, NC). Specifically, Polymer M-1 consisted of a 40% solids aqueous copolymer of sodium methacrylate and methoxypolyoxyethylene (100) methacrylate (80 / 20 mol%) with a Mw of 50,000. Polymer M-2 consisted of a 50% solids aqueous copolymer of sodium methacrylate and methoxypolyoxyethylene (20) methacrylate (70 / 30 mol%) with a Mw of 50,000. Polymer M-3 consisted of a 40% solids aqueous copolymer of sodium methacrylate and methoxypolyoxyethylene (100) methacrylate (90 / 10 mol%) with a Mw of 40,000. Polymer M-4 is a commercially available naphthalenesulfonic acid-formaldehyde condensate superplasticizer (e.g., Mighty 150 manufactured by Kao Corporation, Tokyo). Polymer M-5 is an ether-type polycarboxylate dispersant consisting of a 50% solids aqueous copolymer of sodium acrylate and polyoxyethylene (50) methallyl ether (85 / 15 mol%) with a Mw of 40,000.

[0106] Defoamers widely accepted in the industry, with different functional groups such as esters, silicones, and nonionic alkoxylates, all separated into two phases after storage at 50°C for 2-3 days, as shown in Table 4 and Figure 1. Amine-based defoamers disclosed in the prior art, such as ethylenediamine-block polyoxyethers and alkyl ether amines, provided stable solutions, while tertiary alkyl amines were unstable. All aqueous dispersant solutions containing the amine defoamers of the present invention were relatively stable at 50°C for extended periods, as shown in Tables 4 and 5.

[0107] [Table 1]

[0108] A homogeneous solution can be observed in Figure 2. One typical limitation of blends of aqueous defoamers with polycarboxylates is that the hydrophobic defoamer can only be incorporated at limited concentrations to avoid separation. It can be clearly seen from the inventive defoamer S2 that this defoamer can be incorporated at, but not limited to, 12% (addition based on active PCE) of the dispersant formulation. At both low and high addition levels of the inventive defoamer, blends with dispersants produce clear, stable solutions.

[0109] The antifoaming properties of various polyalkoxylated alkyl polyamine additives were evaluated in a standard mortar test for air bubble content. Ordinary Portland cement, Type I, was used in a sand / cement / water ratio of 2.2 / 1.3 / 0.5. All tests were performed in the presence of a superplasticizer dispersant. The dispersant dosage was 0.10% active by weight of cement, and the antifoam to dispersant ratio was 0.10% active by weight. Air bubble content was measured in accordance with ASTM D 3203-94 using a 400 ml measuring tube with a 3-inch inside diameter according to ASTM C-185.

[0110] Various polyalkoxylated alkylpolyamines were compared with comparative industry-wide defoamers using ester-type polycarboxylate dispersant M-1, as shown in Table 2. The defoaming ability of inventive defoamer S2 was compared with that of an ether-type polycarboxylate dispersant composed of a 50% solids aqueous copolymer of sodium acrylate and polyoxyethylene (50) methallyl ether (85 / 15 mole %), as shown in Table 3.

[0111] [Table 2]

[0112] [Table 3]

[0113] [Table 4]

[0114] [Table 5]

[0115] The reduced foaming of the inventive additives, which are the subject of this invention, compared to the control mixture without antifoaming agent, clearly demonstrates that the polyalkoxylated alkylpolyamine antifoaming agents S1-S6 function effectively as foam control agents and are superior to the comparative industry standard antifoaming agents in reducing foam in mortar mixtures. This result demonstrates that the functionality of the antifoaming agents described in this invention is superior to conventional antifoaming agents and amine antifoaming agents known in the art.

[0116] The mortar test procedure described in the previous example was repeated, except that the ratio of defoamer to active dispersant was 0.10 wt.% or 0.50 wt.%. The data in Table 2 show that inventive defoamers S1-S6 all exhibit significant foam reduction below the threshold of the control (ester defoamer). Foam reduction is further improved by increasing the defoamer concentration to 0.50 wt.%. All three inventive examples outperformed the comparative industrial standard defoamer and amine-based defoamer used in this example. The results are also shown graphically in Figure 3.

[0117] Preparation of antifoam / PCE solutions with various antifoam loadings Aqueous mixtures of polycarboxylate dispersants and polyalkoxylated alkylpolyamines of the present invention were prepared to yield solutions with a solids content of 30% by total weight. The two components were blended at room temperature for 30 minutes to a final pH of 5-6. The resulting solutions were clear and showed no separation or defoamer segregation after extended storage at room temperature and 50°C for a period of one month (Figure 2). The polymeric dispersants contained a backbone with polycarboxylate groups and pendant polyethylene oxide groups. The alkylpolyamines were derived from N-(tallow alkyl)trimethylenediamine, N-(oleyl)trimethylenediamine, N-(coco)trimethylenediamine, or N-(tallow alkyl)dipropylenetriamine, or varied in degree of polypropoxylation (indicated by the weight percent of propylene oxide in the total molecular weight), as shown in Table 1.

Claims

1. 1. A defoamer for reducing air entrainment in alkaline aqueous solutions, suspensions, or slurries, the defoamer comprising a polyalkoxylated alkylpolyamine and salts thereof having a structure represented by formula (1) or (2): R １ -(N(R ２ )-CH ２ -CH ２ -CH ２ ) ｎ -N-(R ３ )(R ４ ) (1)、 R １ -N(CH ２ -CH ２ -CH ２ -N(R ３ )(R ４ )) ２ (2)、 [During the ceremony R １ is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, R ２ , R ３ and R ４ each independently represents at least one of H, alkylene oxide, or polyalkylene oxide; n is 1 to 50.

2. 1. A defoamer for reducing air entrainment in an alkaline aqueous solution, suspension, or slurry, the defoamer comprising a polyalkoxylated alkyldiamine and salts thereof having a structure represented by formula (3): R １ -N(R ２ )-CH ２ -CH ２ -CH ２ -N-(R ３ ) ２ (3)、 [During the ceremony R １ is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, R ２ and R ３ each independently represents H, an alkylene oxide, or a polyalkylene oxide.

3. 2. The defoamer of claim 1, wherein the alkylene oxide is propylene oxide or ethylene oxide.

4. 2. The defoamer of claim 1, wherein said alkylene oxide is propylene oxide and said polyalkylene oxide is polypropylene oxide.

5. R １ 2. The defoamer of claim 1, wherein is a branched or unbranched hydrocarbon chain having a length of 12 to 18 carbon atoms.

6. 5. The defoamer according to claim 4, wherein the combined weight percentage of propylene oxide and polypropylene oxide to the polyalkoxylated alkylpolyamine ranges from 45 to 75% by weight.

7. An admixture comprising: The defoaming agent according to claim 1; an alkaline aqueous solution, suspension, or slurry; Admixtures, including:

8. 1. An admixture for reducing air entrainment, comprising: a dispersant; and The defoaming agent according to claim 1; Water and Including, the dispersant and the defoamer are present in a combined concentration ranging from 25 to 35% by weight, based on the total weight of the admixture; the antifoaming agent is present in a concentration of 0.1 to 20% by weight based on the weight of the dispersant; Admixture.

9. 9. The admixture of claim 8, wherein the antifoaming agent is present in a concentration of 4 to 15% by weight based on the total weight of the dispersant.

10. 9. The admixture of claim 8 having a pH in the range of 4.5 to 6.

5.

11. 9. The admixture of claim 8, wherein the dispersing agent is a superplasticizer selected from the group consisting of polycarboxylate ethers, sulfo-modified melamine-formaldehyde condensates, melamine formaldehyde condensates, sulfonated melamine-formaldehyde condensates, lignin salts, naphthalene sulfonates, polycarboxylated acrylics, polycarboxylated ethers, carboxylate salts, casein, cocomide derivatives, and mixtures thereof.

12. 9. The admixture of claim 8, wherein the dispersant is at least one selected from the group consisting of polycarboxylate ethers, ester-type dispersants, ether-type dispersants, and naphthalene-type dispersants.

13. 9. The admixture of claim 8, wherein the dispersing agent is a polycarboxylate ether containing pendant polyethylene oxide groups.

14. 1. A cement mixture comprising: A particulate cementitious component; The admixture according to claim 8; Water and Including, The admixture solids are present in the cement mix at a concentration ranging from 0.05 to 1% by weight of cement; Cement mixture.

15. 15. The cement mixture of claim 14, wherein the admixture solids are present in the cement mixture at a concentration in the range of 0.1 to 0.5% by weight of cement.

16. 15. The cement mixture of claim 14, having a W / C ratio of 0.37 to 0.

50.

17. 15. The cement mixture of claim 14, further comprising 45 to 60 weight percent sand, based on the total weight of the cement mixture.

18. 1. A method of forming an admixture, comprising:

10. A method comprising the step of mixing an alkaline aqueous solution, suspension, or slurry with the defoamer of claim 1.

19. 1. A method of forming a cement mixture, comprising: A particulate cementitious component; The admixture according to claim 8; Water and mixing the The method wherein the solids of the admixture are present in the cement mixture at a concentration ranging from 0.05 to 1% by weight of cement.

20. 1. A method of forming a cement mixture, comprising: A particulate cementitious component; The defoaming agent according to claim 1; a dispersant; and Water and mixing the The method wherein the solids of the admixture are present in the cement mixture at a concentration ranging from 0.05 to 1% by weight of cement.

21. 1. A method for reducing air bubbles in a cement mixture, comprising:

10. A method comprising the step of mixing the admixture of claim 8 with a cement mixture.

22. 1. A method for reducing air bubbles in a cement mixture, comprising:

10. A method comprising the step of mixing the antifoaming agent of claim 1 and a dispersant with a cement mixture.

23. Use of a defoaming agent comprising a polyalkoxylated alkyltriamine having a structure represented by formula (1) or (2) and a salt thereof. R １ -(N(R ２ )-CH ２ -CH ２ -CH ２ ) ｎ -N-(R ３ )(R ４ ) (1)、 R １ -N(CH ２ -CH ２ -CH ２ -N(R ３ )(R ４ )) ２ (2)、 [In the formula, R １ is a branched or unbranched hydrocarbon chain having a length of 1 to 20 carbon atoms, R ２ , R ３ , and R ４ each independently represents H, an alkylene oxide, or a polyalkylene oxide; n is 1 to 50.

24. 24. Use of the defoamer according to claim 23 for an alkaline aqueous solution, suspension or slurry.

25. Use of the defoaming agent according to claim 23 for hydraulic compositions.

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