Bubble-containing hydraulic composition

Abstract

To provide a bubble-containing hydraulic composition, wherein a cured product of the bubble-containing hydraulic composition has a low specific gravity and the diameter of bubbles in the cured product of the bubble-containing hydraulic composition is large; and a method for producing the same.SOLUTION: A bubble-containing hydraulic composition contains a hydraulic powder, water and (A) an alkyl or alkenyl sulfate ester or a salt thereof (hereinafter referred to as component (A)). Component (A) includes (A1) an alkyl or alkenyl sulfate ester having an alkyl group or alkenyl group with 10 carbon atoms, or a salt thereof (hereinafter referred to as component (A1)) and (A2) an alkyl or alkenyl sulfate ester having an alkyl group or alkenyl group with 12 carbon atoms, or a salt thereof (hereinafter referred to as component (A2)). The total content of component (A1) and component (A2) in component (A) is 99 mass% or more. The mass ratio (A1) / (A2) of the content of component (A1) and the content of component (A2) is 0.2-2.4 inclusive.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a bubble-containing hydraulic composition, a method for producing the same, and a foaming agent for a hydraulic composition. [Background technology]

[0002] Air bubbles are introduced into hydraulic compositions using cement or gypsum as a hardening agent to reduce their weight. Usually, a foamed liquid composition containing a foaming agent and water is foamed, and the foam is mixed with the hydraulic composition, or with fine aggregate or various admixtures to produce a lightweight air bubble-containing hydraulic composition.

[0003] Patent Document 1 discloses a surfactant composition for gypsum board, which contains a branched alkyl sulfate having 8 to 12 carbon atoms, optionally a linear alkyl sulfate having 8 to 12 carbon atoms, and optionally an alkyl ether sulfate having 8 to 13 carbon atoms, for the purpose of reducing the weight of the gypsum wallboard while still allowing the gypsum wallboard to function as a building material. In the examples, a surfactant composition is disclosed that is composed of 75% alkyl sulfate having 10 carbon atoms and 25% alkyl sulfate having 12 carbon atoms.

[0004] In Patent Document 2, the objective of the present invention is to provide an inexpensive surfactant that can be easily produced from a commercially available product and has a strong foaming power, and the surfactant is combined with gypsum and water to produce a compound represented by the formula H(CH 2 ) n OSO 3 - M + A gypsum composition comprising a surfactant composition comprising an alkyl sulfate of the formula: wherein n is 6 to 16, and the average number of carbon atoms in the alkyl sulfate composition, n mis 10 to 11, and M is a monovalent cation. In the examples, it is disclosed that a surfactant containing 84.2% by weight of C10 alkyl sulfate and 15.8% by weight of C12 alkyl sulfate was used, and the surfactant composition was evaluated by measuring the amount of foam formed after mixing with water and stirring in a mixer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2018-527163 [Patent Document 2] Special Publication No. 2004-529050 Summary of the Invention [Problem to be solved by the invention]

[0006] The hardened foam of the air-containing hydraulic composition, which uses cement or gypsum as a hardening agent, has environmental (CO) 2 From the standpoint of weight reduction and cost, further weight reduction is required. The bubble-containing hydraulic composition can reduce the specific gravity of the set body of the hydraulic composition by containing bubbles, and thus can be made lighter. However, when the volume (ratio) of bubbles is increased in order to further reduce the weight of the set body of the hydraulic composition, the ratio of the hydraulic composition decreases, and the strength of the set body tends to decrease. On the other hand, as described in paragraph 0004 of JP-A-10-330174, the strength of the set body of the bubble-containing hydraulic composition can be increased by increasing the bubble diameter in the bubble-containing hydraulic composition in a bubble-containing hydraulic composition of the same specific gravity. In addition, when the bubble diameter in the bubble-containing hydraulic composition is increased, the drying time when obtaining the set body of the bubble-containing hydraulic composition is accelerated, which reduces the fuel cost for drying and CO2 emission. 2 In addition, when the bubble diameter in the bubble-containing hydraulic composition is increased, the distance between the bubbles increases, making it difficult for the bubbles to communicate with each other, and improving the heat insulation and sound insulation properties. Therefore, there is a demand for a technique for decreasing the specific gravity of the bubble-containing hydraulic composition and increasing the bubble diameter in the bubble-containing hydraulic composition.

[0007] The present invention provides a bubble-containing hydraulic composition having a low specific gravity and a large air bubble diameter in the bubble-containing hydraulic composition hardened body, a method for producing the same, and a foaming agent for hydraulic compositions that can reduce the specific gravity of the bubble-containing hydraulic composition hardened body and increase the air bubble diameter in the bubble-containing hydraulic composition hardened body. [Means for solving the problem]

[0008] The present invention relates to a bubble-containing hydraulic composition containing hydraulic powder, water, and (A) an alkyl or alkenyl sulfate or a salt thereof (hereinafter referred to as component (A)), the bubble-containing hydraulic composition containing, as component (A), (A1) an alkyl or alkenyl sulfate having an alkyl or alkenyl group with 10 carbon atoms or a salt thereof (hereinafter referred to as component (A1)), and (A2) an alkyl or alkenyl sulfate having an alkyl or alkenyl group with 12 carbon atoms or a salt thereof (hereinafter referred to as component (A2)), the total content of components (A1) and (A2) in component (A) being 99 mass% or more, and the mass ratio (A1) / (A2) of the content of component (A1) to the content of component (A2) being 0.2 or more and 2.4 or less.

[0009] The present invention also relates to a method for producing a bubble-containing hydraulic composition, comprising the following steps 1 and 2: <Process 1> A step of foaming a liquid composition containing the foaming agent for hydraulic compositions described below and water to obtain a foam. Foaming agent for hydraulic compositions: A foaming agent for hydraulic compositions containing component (A), which contains components (A1) and (A2) as component (A), the total content of components (A1) and (A2) in component (A) being 99 mass% or more, and the mass ratio (A1) / (A2) of the content of component (A1) to the content of component (A2) being 0.2 or more and 2.4 or less. <Process 2> A step of mixing hydraulic powder, water, and the foam obtained in step 1.

[0010] The present invention also relates to a foaming agent for hydraulic compositions containing component (A), the foaming agent for hydraulic compositions containing components (A1) and (A2) as component (A), the total content of components (A1) and (A2) in component (A) being 99 mass% or more, and the mass ratio (A1) / (A2) of the content of component (A1) to the content of component (A2) being 0.2 or more and 2.4 or less. Effect of the Invention

[0011] According to the present invention, there are provided a bubble-containing hydraulic composition and a method for producing the same, which have a low specific gravity and a large bubble diameter in the bubble-containing hydraulic composition hardened body, as well as a foaming agent for hydraulic compositions that can reduce the specific gravity of the bubble-containing hydraulic composition hardened body and increase the bubble diameter in the bubble-containing hydraulic composition hardened body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The reason why the bubble-containing hydraulic composition and its manufacturing method of the present invention can reduce the specific gravity of the bubble-containing hydraulic composition cured body and increase the bubble diameter in the bubble-containing hydraulic composition cured body, and the foaming agent for hydraulic composition of the present invention can reduce the specific gravity of the bubble-containing hydraulic composition cured body and increase the bubble diameter in the bubble-containing hydraulic composition cured body is not necessarily clear, but it is presumed as follows. In the foaming agent for hydraulic composition, by blending a predetermined amount of component (A2) that forms a foam film in which bubbles are unlikely to break and coalesce with component (A1) that forms a foam film with high fluidity and easy coalescence of bubbles, it is possible to form a foam film that is both flexible and hard, and it is presumed that the disappearance of bubbles during the process of manufacturing the bubble-containing hydraulic composition can be suppressed, and at the same time, the coalescence of bubbles can be achieved to achieve both weight reduction and large bubble diameter in the bubble-containing hydraulic composition cured body. On the other hand, with regard to the content ratio of the (A1) component and the (A2) component, if the content of the (A1) component is too high, the air bubbles become more likely to break, and although it is possible to increase the diameter of the air bubbles in the air-containing hydraulic composition hardened body, it is presumed that it will be difficult to reduce the weight of the hardened body.

[0013] [Foaming agent for hydraulic composition] <Component (A)> The foaming agent for hydraulic compositions of the present invention contains, as component (A), an alkyl or alkenyl sulfate ester or a salt thereof. The foaming agent for hydraulic compositions of the present invention contains, as component (A), (A1) an alkyl or alkenyl sulfate ester having an alkyl or alkenyl group having 10 carbon atoms, or a salt thereof (hereinafter referred to as component (A1)), and (A2) an alkyl or alkenyl sulfate ester having an alkyl or alkenyl group having 12 carbon atoms, or a salt thereof (hereinafter referred to as component (A2)). The component (A1) is preferably an alkyl or alkenyl sulfate ester having a linear alkyl group or linear alkenyl group having 10 carbon atoms, or a salt thereof. Specific examples of the component (A1) include one or more members selected from decyl sulfate, 2-propylheptyl sulfate, and salts thereof, with decyl sulfate or a salt thereof being preferred. The component (A2) is preferably an alkyl or alkenyl sulfate ester having a linear alkyl group or linear alkenyl group having 12 carbon atoms, or a salt thereof. Specifically, the component (A2) is preferably lauryl sulfate or a salt thereof. Examples of the salts of the components (A), (A1), and (A2) include one or more salts selected from alkali metal salts such as sodium salts and potassium salts, ammonium salts, and organic ammonium salts.

[0014] <Composition, etc.> The foaming agent for hydraulic compositions of the present invention contains component (A) in an amount of preferably 2 mass % or more, more preferably 10 mass % or more, even more preferably 15 mass % or more, still more preferably 20 mass % or more, still more preferably 25 mass % or more, and preferably 40 mass % or less, more preferably 35 mass % or less, and even more preferably 30 mass % or less, in order to increase the bubble diameter in the bubble-containing hardened hydraulic composition and to decrease the specific gravity of the bubble-containing hardened hydraulic composition. In the present invention, the masses of the component (A), and the components (A1) and (A2) contained in the component (A) are defined as values ​​converted into sodium salts.

[0015] In the foaming agent for hydraulic compositions of the present invention, the total content of the (A1) and (A2) components in the (A) component is 99% by mass or more, preferably 99.5% by mass or more and 100% by mass or less, and preferably 100% by mass, from the viewpoints of increasing the bubble diameter in the bubble-containing hardened hydraulic composition and decreasing the specific gravity of the bubble-containing hardened hydraulic composition.

[0016] In the foaming agent for hydraulic compositions of the present invention, the content of the (A1) component in the (A) component is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and preferably 75% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 53% by mass or less, from the viewpoints of increasing the bubble diameter in the bubble-containing hydraulic composition hardened body and decreasing the specific gravity of the bubble-containing hydraulic composition hardened body, and the content of the (A2) component in the (A) component is preferably 25% by mass or more, more preferably 35% by mass or more, even more preferably 45% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 65% ​​by mass or less, and even more preferably 53% by mass or less, from the viewpoints of increasing the bubble diameter in the bubble-containing hydraulic composition hardened body and decreasing the specific gravity of the bubble-containing hydraulic composition hardened body.

[0017] In the foaming agent for hydraulic composition of the present invention, the mass ratio (A1) / (A2) of the content of the (A1) component to the content of the (A2) component is 0.2 or more, preferably 0.3 or more, more preferably 0.6 or more, even more preferably 0.9 or more, and 2.4 or less, preferably 2.3 or less, more preferably 2.0 or less, even more preferably 1.9 or less, even more preferably 1.3 or less, from the viewpoint of increasing the bubble diameter in the foaming agent for hydraulic composition of the present invention and decreasing the specific gravity of the foaming agent for hydraulic composition of the present invention. In addition, the mass ratio (A1) / (A2) of the content of the (A1) component to the content of the (A2) component is preferably 1.5 or less, more preferably 1.3 or less, from the viewpoint of reducing the concentration unevenness after freezing and thawing of the foaming agent for hydraulic composition used in the production of the foaming agent for hydraulic composition of the present invention.

[0018] From the viewpoint of enjoying the effects of the present invention, it is preferable that the foaming agent for hydraulic compositions of the present invention does not contain, as component (A), an alkyl or alkenyl sulfate ester having an alkyl or alkenyl group having 14 or more carbon atoms, or a salt thereof. Examples of the alkyl or alkenyl sulfate having an alkyl or alkenyl group having 14 or more carbon atoms, or a salt thereof, include one or more selected from myristyl sulfate, cetyl sulfate, stearyl sulfate, oleyl sulfate, and salts thereof.

[0019] The foaming agent for hydraulic compositions of the present invention may contain a polyoxyethylene alkyl or alkenyl ether sulfate or a salt thereof, but the content is limited from the viewpoint of obtaining the effects of the present invention. Examples of the polyoxyethylene alkyl or alkenyl ether sulfate or a salt thereof include one or more selected from polyoxyethylene octyl ether sulfate, polyoxyethylene decyl ether sulfate, polyoxyethylene lauryl ether sulfate, polyoxyethylene tridecyl ether sulfate, polyoxyethylene myristyl ether sulfate, polyoxyethylene cetyl ether sulfate, polyoxyethylene stearyl ether sulfate, and salts thereof.

[0020] In the foaming agent for hydraulic compositions of the present invention, the content of polyoxyethylene alkyl or alkenyl ether sulfate or its salt is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, from the viewpoint of increasing the bubble diameter in the bubble-containing hydraulic composition hardened body. In the present invention, the mass of polyoxyethylene alkyl or alkenyl ether sulfate or its salt is used as the value converted to sodium salt. In the viewpoint of increasing the bubble diameter in the bubble-containing hydraulic composition hardened body, it is preferable that the foaming agent for hydraulic compositions of the present invention does not contain polyoxyethylene alkyl or alkenyl ether sulfate or its salt.

[0021] The foaming agent for hydraulic compositions of the present invention may contain, as component (B), a monohydric alcohol having 6 to 10 carbon atoms, from the viewpoints of foaming speed and foam stability. The carbon number of the (B) component is 6 or more and 10 or less, and preferably 8, from the viewpoints of foaming speed and foam stability. From the viewpoints of rapid foaming and foam stability, component (B) is a monohydric alcohol having a linear or branched hydrocarbon group, preferably a linear or branched alkyl group, and more preferably a linear alkyl group.

[0022] Specific examples of the (B) component include one or more selected from hexanol, octanol, decanol, 2-ethylhexanol, and 2-propylheptanol. From the viewpoint of foamability, it is preferable that the (B) component contains one or more selected from octanol and decanol, and more preferably octanol.

[0023] The foaming agent for hydraulic compositions of the present invention may contain a nonionic surfactant as component (C) from the viewpoint of increasing the bubble diameter in the bubble-containing hardened hydraulic composition and decreasing the specific gravity of the bubble-containing hardened hydraulic composition. The nonionic surfactant may be one or more selected from alkyl monoglyceryl ether, polyoxyalkylene monoalkyl or alkenyl ether, alkyl glycoside or alkyl polyglycoside (glycoside-type nonionic surfactant), sorbitan-based nonionic surfactant, aliphatic alkanolamide, fatty acid monoglyceride, and sucrose fatty acid ester. Among these, it is preferable to contain a glycoside-type nonionic surfactant from the viewpoint of increasing the diameter of bubbles in the bubble-containing hydraulic composition hardened body.

[0024] The foaming agent for hydraulic compositions of the present invention may contain water. The foaming agent for hydraulic compositions of the present invention contains water in an amount of preferably 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less.

[0025] The foaming agent for hydraulic compositions of the present invention may optionally contain a thickener, a chelating agent, a heavy metal scavenger, a rust inhibitor, a preservative, a colorant, a fragrance, a defoamer, a solvent, a dispersant, a flocculant, a water-soluble polymer, etc. However, these do not fall under the category of component (A), component (A1), component (A2), component (B), and component (C).

[0026] The foaming agent for hydraulic compositions of the present invention can be obtained by mixing the components (A1), (A2), and optional components as the component (A). When mixing, heating may be performed appropriately to reduce the solution viscosity.

[0027] The foaming agent for hydraulic compositions of the present invention is intended for use in the following applications: hydraulic compositions containing air bubbles, such as gypsum slurry, lightweight milk (aerated milk, air milk), lightweight mortar (aerated mortar, air mortar), lightweight concrete (aerated concrete, air concrete), backfilling material, innerfilling material, architectural concrete block, ALC (lightweight aerated concrete), grout material, ceramic porous body, brick, refractory material, lightweight embankment, pump pressure mortar, etc. In these hydraulic compositions containing air bubbles, the addition of air bubbles is expected to provide functions such as weight reduction, strength improvement, fluidity improvement, heat insulation, heat resistance, viscosity, and fluidity control. Among these foam-containing hydraulic compositions, the foaming agent for hydraulic compositions of the present invention is suitable for use in gypsum slurries.

[0028] [Air-containing hydraulic composition and its manufacturing method] The method for producing a hydraulic composition containing bubbles is preferably a method in which the foaming agent for hydraulic compositions of the present invention is foamed and mixed with a hydraulic substance as foam to make the composition lighter, since this method entrains uniform bubbles. The foaming agent for hydraulic compositions of the present invention or a mixed liquid obtained by diluting it with water may be directly kneaded into paste, slurry, mortar, or concrete containing cement or gypsum as a hydraulic substance. There is no limitation on the method for adding the foaming agent for hydraulic compositions of the present invention to a hydraulic composition, and there is no limitation on the method for foaming the foaming agent for hydraulic compositions of the present invention or a mixed liquid obtained by diluting it with water.

[0029] The present invention provides a bubble-containing hydraulic composition that contains hydraulic powder, water, and component (A), in which component (A) contains components (A1) and (A2), the total content of components (A1) and (A2) in component (A) is 99 mass% or more, and the mass ratio (A1) / (A2) of the content of component (A1) to the content of component (A2) is 0.2 or more and 2.4 or less. The bubble-containing hydraulic composition of the present invention may further contain component (B). The bubble-containing hydraulic composition of the present invention may further contain component (C). The foaming agent for hydraulic compositions of the present invention can be appropriately applied to the foam-containing hydraulic composition of the present invention. The components (A), (A1), (A2), (B) and (C) are the same as those described in the foaming agent for hydraulic compositions of the present invention.

[0030] The hydraulic powder is a powder having the physical property of hardening through a hydration reaction, and examples of the powder include cement and gypsum, with gypsum being preferred. Examples of cement include ordinary Portland cement, belite cement, moderate heat cement, high-early strength cement, ultra-high-early strength cement, and sulfate-resistant cement, and may also include blast furnace slag cement, fly ash cement, and silica fume cement to which blast furnace slag, fly ash, silica fume, stone powder (calcium carbonate powder), etc. have been added. One or more of these may be used.

[0031] The bubble-containing hydraulic composition of the present invention has a water / hydraulic powder ratio of preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, still more preferably 50% by mass or more, and even more preferably 60% by mass or more from the viewpoint of hydraulic composition slurry fluidity, and from the viewpoint of the strength of the hardened body of the hydraulic composition, it is preferably 100% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less. Here, the water / hydraulic powder ratio is the mass percentage (mass%) of water and hydraulic powder in the hydraulic composition, and is calculated by water / hydraulic powder x 100. The water / hydraulic powder ratio is calculated based on the amount of powder having the physical property of being hardened by hydration reaction. When the powder having the physical property of being hardened by hydration reaction contains a high-strength admixture, the amount of the high-strength admixture is also included in the amount of hydraulic powder. The same applies to other quantitative relationships of the hydraulic composition regarding the hydraulic powder.

[0032] The bubble-containing hydraulic composition of the present invention contains, from the viewpoint of lowering the specific gravity of the hardened body of the hydraulic composition and increasing the bubble diameter, preferably 0.0005 parts by mass or more of component (A) per 100 parts by mass of hydraulic powder, more preferably 0.002 parts by mass or more, even more preferably 0.004 parts by mass or more, still more preferably 0.008 parts by mass or more, and preferably 0.1 parts by mass or less, more preferably 0.05 parts by mass or less, even more preferably 0.03 parts by mass or less, and still more preferably 0.01 parts by mass or less.

[0033] In the bubble-containing hydraulic composition of the present invention, the total content of the (A1) and (A2) components in the (A) component is 99 mass% or more, preferably 99.5 mass% or more, and 100 mass% or less, preferably 100 mass%, from the viewpoint of lowering the specific gravity of the hardened body of the hydraulic composition and increasing the bubble diameter.

[0034] In the bubble-containing hydraulic composition of the present invention, the content of the (A1) component in the (A) component is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 45% by mass or more, and preferably 75% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 53% by mass or less, from the viewpoints of increasing the bubble diameter in the hydraulic composition hardened body and decreasing the specific gravity of the hydraulic composition hardened body, and the content of the (A2) component in the (A) component is preferably 25% by mass or more, more preferably 35% by mass or more, even more preferably 45% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 65% ​​by mass or less, and even more preferably 53% by mass or less, from the viewpoints of increasing the bubble diameter in the hydraulic composition hardened body and decreasing the specific gravity of the hydraulic composition hardened body.

[0035] In the bubble-containing hydraulic composition of the present invention, the mass ratio (A1) / (A2) of the content of the (A1) component to the content of the (A2) component is 0.2 or more, preferably 0.3 or more, more preferably 0.6 or more, even more preferably 0.9 or more, and 2.4 or less, preferably 2.3 or less, more preferably 2.0 or less, even more preferably 1.9 or less, even more preferably 1.3 or less, from the viewpoint of reducing the specific gravity of the hardened hydraulic composition and increasing the bubble diameter. In addition, in the bubble-containing hydraulic composition of the present invention, the mass ratio (A1) / (A2) of the content of the (A1) component to the content of the (A2) component is preferably 1.5 or less, more preferably 1.3 or less, from the viewpoint of reducing the concentration unevenness after freezing and thawing of the foaming agent for hydraulic composition used in the production of the bubble-containing hydraulic composition of the present invention.

[0036] From the viewpoint of enjoying the effects of the present invention, it is preferable that the bubble-containing hydraulic composition of the present invention does not contain, as component (A), an alkyl or alkenyl sulfate ester having an alkyl or alkenyl group having 14 or more carbon atoms, or a salt thereof.

[0037] The bubble-containing hydraulic composition of the present invention may contain a polyoxyethylene alkyl or alkenyl ether sulfate or a salt thereof, but the content is limited from the viewpoint of obtaining the effects of the present invention. In the bubble-containing hydraulic composition of the present invention, the content of the polyoxyethylene alkyl or alkenyl ether sulfate or its salt is preferably 0.001 part by mass or less, more preferably 0.0008 part by mass or less, even more preferably 0.0006 part by mass or less, and even more preferably 0.0001 part by mass or less, per 100 parts by mass of hydraulic powder, from the viewpoint of increasing the bubble diameter of the hardened body of the hydraulic composition. From the viewpoint of increasing the diameter of bubbles in the hardened product of the bubble-containing hydraulic composition of the present invention, it is preferred that the bubble-containing hydraulic composition does not contain polyoxyethylene alkyl or alkenyl ether sulfate or a salt thereof.

[0038] The bubble-containing hydraulic composition of the present invention may contain fine aggregate and / or coarse aggregate, and may contain admixtures or additives known in the art.

[0039] The bubble-containing hydraulic composition of the present invention can be dried and cured to give a hardened product. The specific gravity of the hardened body of the bubble-containing hydraulic composition of the present invention is, from the viewpoint of strength, preferably 0.3 or more, more preferably 0.4 or more, and even more preferably 0.5 or more, and from the viewpoint of handleability, is preferably 0.9 or less, more preferably 0.8 or less, and even more preferably 0.7 or less.

[0040] The bubble-containing hydraulic composition of the present invention contains bubbles. The average bubble diameter of the hardened product of the bubble-containing hydraulic composition of the present invention is preferably 230 μm or more, more preferably 250 μm or more, and even more preferably 300 μm or more from the viewpoint of improving the strength of the hardened product, and is preferably 800 μm or less, more preferably 700 μm or less, even more preferably 600 μm or less, still more preferably 500 μm or less, and even more preferably 400 μm or less from the viewpoint of cross-sectional appearance. The average bubble diameter is calculated by preparing a hardened product of a bubble-containing hydraulic composition, arbitrarily cutting the hardened product to prepare a cross section, observing the cross section with a digital microscope, measuring the diameter of 100 randomly selected bubble cross sections, and averaging these values ​​(arithmetic mean). The diameter of the bubble cross section is measured when the bubble cross section is circular, the major axis when the bubble cross section is elliptical, and the longest part when the bubble cross section is irregular.

[0041] The present invention provides a method for producing a bubble-containing hydraulic composition, comprising the following steps 1 and 2. The foaming agent for hydraulic compositions described below is the same as the foaming agent for hydraulic compositions of the present invention, and the embodiments described for the foaming agent for hydraulic compositions of the present invention can be appropriately applied. <Process 1> A step of foaming a liquid composition containing the foaming agent for hydraulic compositions described below and water to obtain a foam. Foaming agent for hydraulic compositions: A foaming agent for hydraulic compositions containing component (A), which contains components (A1) and (A2) as component (A), the total content of components (A1) and (A2) in component (A) being 99 mass% or more, and the mass ratio (A1) / (A2) of the content of component (A1) to the content of component (A2) being 0.2 or more and 2.4 or less. <Process 2> A step of mixing hydraulic powder, water, and the foam obtained in step 1. In step 2, a hydraulic composition containing hydraulic powder and water may be prepared, and the hydraulic composition and the foam obtained in step 1 may be mixed.

[0042] The bubble-containing hydraulic composition of the present invention can be prepared by this manufacturing method. The foaming agent for hydraulic compositions of the present invention and the aspects described for the foaming agent for hydraulic compositions of the present invention and the foaming composition of the present invention can be appropriately applied to the method for producing the bubble-containing hydraulic composition of the present invention. In the manufacturing method of the bubble-containing hydraulic composition of the present invention, the contents of the components and their mass ratios described in the bubble-containing hydraulic composition of the present invention can be appropriately applied by replacing the contents of the components with the mixed amounts.

[0043] In step 1, the expansion ratio of the liquid composition varies depending on the application of the hydraulic composition, but from the viewpoint of economy, it is preferably 5 times or more, more preferably 7 times or more, and even more preferably 10 times or more, and from the viewpoint of kneadability, it is preferably 30 times or less, more preferably 25 times or less, and even more preferably 20 times or less.

[0044] In step 2, depending on the use of the hydraulic composition, the foam is mixed with the hydraulic composition in an amount of preferably 50% by volume or more, more preferably 100% by volume or more, and even more preferably 150% by volume or more from the viewpoint of weight reduction of the bubble-containing hydraulic composition hardened body, and preferably 400% by volume or less, more preferably 300% by volume or less, and even more preferably 200% by volume or less from the viewpoint of strength of the bubble-containing hydraulic composition hardened body. In this manufacturing method, admixtures and admixtures known in the art can be mixed in step 1 and / or step 2.

[0045] [Gas-containing gypsum slurry and its manufacturing method] In the bubble-containing hydraulic composition of the present invention, the hydraulic powder is preferably gypsum. In the present invention, the bubble-containing hydraulic composition in which the hydraulic powder is gypsum is also called a bubble-containing gypsum slurry. That is, the present invention provides a bubble-containing gypsum slurry containing gypsum, water, and component (A), the component (A) containing components (A1) and (A2), the total content of components (A1) and (A2) in component (A) being 99 mass% or more, and the mass ratio (A1) / (A2) of the content of component (A1) to the content of component (A2) being 0.2 or more and 2.4 or less. The bubble-containing gypsum slurry of the present invention is suitable for use in gypsum boards.

[0046] The foaming agent for hydraulic composition of the present invention, the bubble-containing hydraulic composition of the present invention, and the method for producing the bubble-containing hydraulic composition of the present invention can be appropriately applied to the bubble-containing gypsum slurry of the present invention. The air-bubble gypsum slurry of the present invention may further contain component (B). The air-bubble gypsum slurry of the present invention may further contain component (C). The components (A), (A1), (A2), (B) and (C) are the same as those described in the foaming agent for hydraulic compositions of the present invention. In the bubble-containing gypsum slurry of the present invention, the contents of the components and their mass ratios described in the bubble-containing hydraulic composition of the present invention can be appropriately applied by substituting hydraulic powder for gypsum. In the hardened product of the gas bubble-containing gypsum slurry of the present invention, the specific gravity and the average gas bubble diameter are in the same ranges as those described for the gas bubble-containing hydraulic composition of the present invention.

[0047] Any type of gypsum can be used, including high-quality neutralized gypsum, phosphogypsum which is a by-product of phosphoric acid, flue gas desulfurization gypsum generated in thermal power generation, natural gypsum containing various impurities and clay, and mixtures of these. The clay contained in gypsum is mainly composed of hydrated silicate minerals (hereinafter referred to as clay minerals) with a layered structure, and the clay minerals contained as fine particles in this clay include kaolin minerals (kaolinite, dickite, and nacrite), serpentine (lizardite, antigorite, and chrysotile), mica clay minerals (illite, sericite, glauconite, and celadonite), chlorite, vermiculite, and smectite (montmorillonite, beidellite, nontronite, saponite, and hectorite).

[0048] Gypsum includes anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum, etc. As the raw gypsum, natural gypsum, neutralized gypsum, by-product gypsum, or other chemical gypsum can be used alone or in combination of two or more of them. Examples of main chemical gypsum include phosphate gypsum, hydrofluoric gypsum, titanic gypsum, and flue gas desulfurization gypsum. The raw gypsum may also include recycled gypsum. The recycled gypsum may be any recycled gypsum recovered from waste gypsum boards generated by gypsum board manufacturers, waste gypsum boards generated during new construction and demolition, etc. The present invention can be suitably used with any one or more of these raw gypsums, and excellent effects can be obtained with blends of various ratios.

[0049] The bubble-containing gypsum slurry of the present invention can contain additives used for gypsum boards, etc. Such additives include general-purpose water-reducing agents, defoamers, foam stabilizers, hardening regulators, water repellents, adhesives, retarders, etc. Furthermore, glass fibers, carbon fibers, waste paper, virgin pulp, etc. can be added as reinforcing fibers, or gypsum boards can be produced together with lightweight aggregates such as perlite and foamed steel.

[0050] The present invention provides a method for producing an air-containing gypsum slurry, which includes the following steps 1 and 2. The foaming agent for hydraulic compositions described below is the same as the foaming agent for hydraulic compositions of the present invention, and the embodiments described for the foaming agent for hydraulic compositions of the present invention can be appropriately applied. <Process 1> A step of foaming a liquid composition containing the foaming agent for hydraulic compositions described below and water to obtain a foam. Foaming agent for hydraulic compositions: A foaming agent for hydraulic compositions containing component (A), which contains components (A1) and (A2) as component (A), the total content of components (A1) and (A2) in component (A) being 99 mass% or more, and the mass ratio (A1) / (A2) of the content of component (A1) to the content of component (A2) being 0.2 or more and 2.4 or less. <Process 2> A step of mixing gypsum, water, and the foam obtained in step 1. In step 2, a gypsum slurry containing gypsum and water may be prepared, and the gypsum slurry may be mixed with the foam obtained in step 1.

[0051] This manufacturing method allows the preparation of the air-filled gypsum slurry of the present invention. The method for producing the bubble-containing gypsum slurry of the present invention can be appropriately applied to the aspects described for the foaming agent for hydraulic composition of the present invention, the bubble-containing hydraulic composition and its production method of the present invention, and the bubble-containing gypsum slurry of the present invention. In the manufacturing method of the bubble-containing hydraulic composition of the present invention, the contents of the components and their mass ratios described in the bubble-containing hydraulic composition of the present invention can be appropriately applied by replacing the hydraulic powder with gypsum and further replacing the contents of the components with the mixing amounts. The temperatures of the foam and gypsum slurry used for mixing are preferably 15°C or higher and 40°C or lower, respectively. Steps 1 and 2 can be carried out in accordance with the method for producing the bubble-containing hydraulic composition of the present invention. EXAMPLES

[0052] The components used in the examples and comparative examples are shown below. Component (A) C10AS: Sodium decyl sulfate, component (A1) C12AS: Sodium lauryl sulfate, component (A2) ·C14AS: Sodium myristyl sulfate

[0053] (1) Preparation of foaming agent for hydraulic composition The foaming agents for hydraulic compositions shown in Tables 1 and 2 were prepared by the following method. Each raw material was added to a 50 mL screw tube in the specified ratio so that the total amount was 30 g, and the mixture was stirred for 3 hours at 1000 rpm using a stirrer. If the solution viscosity was high and the stirring efficiency was poor, the mixture was heated to 40°C as needed.

[0054] (2) Preparation of gypsum slurry The foaming agents for hydraulic compositions prepared in Tables 1 and 2 were mixed with water in a mass ratio of 0.3 to 99.7 to prepare an aqueous solution with a concentration (as is) of 0.3 mass% for the foaming agent for hydraulic compositions. 19 g of the prepared aqueous solution was added to a 1-L disposable cup, and the mixture was stirred by hand for 15 seconds at 2000 rpm (EUROSTAR200control, IKA Japan) using a flat 6-blade paddle blade (FP-50, AS ONE Co., Ltd.), while rotating the container by hand. The container was then placed down and stirred for an additional 45 seconds to obtain a foam. 200 g of calcined gypsum, 4 g of dihydrate gypsum, 127 g of tap water in which 1.5 g of potassium sulfate was dissolved, and 0.36 g of a water reducing agent (Mighty 150, manufactured by Kao Corporation) were added to a 500 mL disposable cup, and the mixture was stirred for 5 seconds at a setting of 3 using a hand mixer (MK-H4, manufactured by Panasonic Corporation) to prepare a gypsum slurry before adding foam. The entire amount of the prepared gypsum slurry was added to 19 g of foam prepared in a 1 L disposable cup, and the mixture was kneaded for 10 seconds at 1150 rpm using the flat 6-blade paddle in the 1 L disposable cup to obtain a gypsum slurry containing air bubbles. The temperatures of the foam and gypsum slurry used in the kneading were both 20°C.

[0055] (3) Measurement of specific gravity of gypsum specimen The resulting gypsum slurry containing bubbles was poured into a cylindrical specimen mold (Plamold, manufactured by Nifco Corporation) with a diameter of 5 cm and a height of 10 cm, and left to stand at room temperature for at least 1 hour. The hardened gypsum slurry was removed from the cylindrical specimen mold and left to stand in a thermostatic chamber at 80°C for 17 hours to dry, after which the weight of the resulting specimen was measured. The specific gravity of the gypsum specimen was calculated by dividing the weight of the resulting specimen by the volume of the mold. The results are shown in Tables 1 and 2.

[0056] (4) Measurement of the average bubble diameter in gypsum specimens A cut was made in the 5 cm high section of the gypsum specimen obtained in (3) to create a cross section of the gypsum specimen. The cross section was observed with a digital microscope (42x magnification), and the diameters of 100 bubbles were measured, starting from the smallest visible bubbles, and the average bubble diameter was calculated from the arithmetic mean of these values. When the bubble cross section was circular, the diameter was taken as the diameter; when the bubble cross section was elliptical, the major axis was taken as the diameter; and when the bubble cross section was irregular, the longest part was taken as the diameter. The results are shown in Tables 1 and 2.

[0057] (5) Penetration resistance test The penetration resistance value was measured when a needle with a diameter of 12.5 mm was pressed 6 cm into the side of the gypsum specimen obtained in (3). The measurement was performed three times at points 2.5 cm, 5 cm, and 7.5 cm from the bottom of the side of the gypsum specimen, and the average value was taken as the penetration resistance value of the gypsum specimen. Example 1-1 and Comparative Examples 1-2 and 1-3 were evaluated. The results are shown in Table 2. The higher the penetration resistance value, the higher the strength of the gypsum specimen.

[0058] [Table 1]

[0059] [Table 2]

[0060] In Table 1, the foaming agents for hydraulic compositions of Examples 1-1 to 1-6 can reduce the specific gravity while making the average bubble diameter of the gypsum specimen 250 μm or more, compared to the foaming agents for hydraulic compositions of Comparative Examples 1-1, 1-4, and 1-5. Note that the specific gravity of Comparative Examples 1-4 and 1-5 is larger than that of Examples 1-1 to 1-6, and the average bubble diameter was not measured because the gypsum specimen did not contain an amount of bubbles that could be accurately measured. In addition, in Table 2, the foaming agent for hydraulic compositions of Example 1-1 can increase the average bubble diameter in the gypsum, compared to the foaming agents for hydraulic compositions of Comparative Examples 1-2 and 1-3, although the specific gravity of the gypsum specimen is the same. As a result, as shown in Table 2, the strength of the gypsum specimen can be increased.

[0061] (6) Performance evaluation after freezing and thawing 85 mL of the foaming agent for hydraulic compositions of Example 1-3 was placed in Maruemu screw tube No. 8 (height 12 cm, capacity 110 mL), stored at 0 ° C for 3 days, and frozen. The solidified or precipitated sample was left to stand at 20 ° C for 2 hours, melted, and 2 mL of the foaming agent for hydraulic compositions was collected from a liquid surface height of 1 cm, which was used as the upper layer. Meanwhile, 2 mL of the foaming agent for hydraulic compositions was collected from a height of 0.5 cm from the bottom of the Maruemu screw tube, which was used as the lower layer. Using these collected foaming agents for hydraulic compositions, a gypsum slurry was prepared in the same manner as in (2) above, and the average bubble diameter in the gypsum specimen was determined in the same manner as in (4) above. The results are shown in Table 3.

[0062] [Table 3]

[0063] In Table 3, it can be seen that the foaming agent for hydraulic compositions in Examples 1-3 has a small difference in average bubble diameter in the gypsum specimens prepared using the upper and lower layers after freezing and thawing, and the foaming agent for hydraulic compositions has a small concentration unevenness after solidifying and redissolving.

Claims

1. A bubble-containing hydraulic composition comprising a hydraulic powder, water, and (A) an alkyl or alkenyl sulfate ester or a salt thereof (hereinafter referred to as component (A)), wherein component (A) contains (A1) an alkyl or alkenyl sulfate ester having a C10 alkyl or alkenyl group or a salt thereof (hereinafter referred to as component (A1)), and (A2) an alkyl or alkenyl sulfate ester having a C12 alkyl or alkenyl group or a salt thereof (hereinafter referred to as component (A2)), the total content of component (A1) and component (A2) in component (A) is 99% by mass or more, and the mass ratio (A1) / (A2) of the content of component (A1) to the content of component (A2) is 0.2 or more and 2.4 or less.

2. The bubble-containing hydraulic composition according to claim 1, wherein the average bubble diameter of the hardened body of the bubble-containing hydraulic composition is 220 μm or more and 800 μm or less.

3. A bubble-containing hydraulic composition according to claim 1 or 2, which does not contain an alkyl or alkenyl sulfate ester having an alkyl or alkenyl group having 14 or more carbon atoms, or a salt thereof.

4. The bubble-containing hydraulic composition according to claim 1 or 2, wherein component (A) is contained in an amount of 0.0005 parts by mass or more and 0.01 parts by mass or less per 100 parts by mass of hydraulic powder.

5. The bubble-containing hydraulic composition according to claim 1 or 2, wherein the content of polyoxyethylene alkyl or alkenyl ether sulfate ester, or a salt thereof, is 0.001 parts by mass or less per 100 parts by mass of hydraulic powder.

6. The bubble-containing hydraulic composition according to claim 1 or 2, wherein the hydraulic powder is gypsum.

7. The bubble-containing hydraulic composition according to claim 1 or 2, wherein component (A1) is an alkyl or alkenyl sulfate ester having a linear alkyl group or linear alkenyl group having 10 carbon atoms, or a salt thereof, and component (A2) is an alkyl or alkenyl sulfate ester having a linear alkyl group or linear alkenyl group having 12 carbon atoms, or a salt thereof.

8. The bubble-containing hydraulic composition according to claim 1 or 2, wherein the content of component (A1) in component (A) is 20% by mass or more and 75% by mass or less, and the content of component (A2) in component (A) is 25% by mass or more and 80% by mass or less.

9. A method for producing a bubble-containing hydraulic composition, comprising the following steps 1 and 2. <Step 1> A step of foaming a liquid composition containing the following foaming agent for hydraulic compositions and water to obtain foam. Foaming agent for hydraulic compositions: A foaming agent for hydraulic compositions containing (A) an alkyl or alkenyl sulfate ester or a salt thereof (hereinafter referred to as (A) component), wherein (A) component contains (A1) an alkyl or alkenyl sulfate ester having a C10 alkyl or alkenyl group or a salt thereof (hereinafter referred to as (A1) component), and (A2) an alkyl or alkenyl sulfate ester having a C12 alkyl or alkenyl group or a salt thereof (hereinafter referred to as (A2) component), the total content of (A1) component and (A2) component in (A) component is 99% by mass or more, and the mass ratio of the content of (A1) component to the content of (A2) component (A1) / (A2) is 0.2 or more and 2.4 or less. <Step 2> A step of mixing hydraulic powder, water, and the foam obtained in step 1.

10. A method for producing a bubble-containing hydraulic composition according to claim 9, wherein the average bubble diameter of the hardened body of the bubble-containing hydraulic composition is 220 μm or more and 800 μm or less.

11. A method for producing a bubble-containing hydraulic composition according to claim 9 or 10, wherein the hydraulic powder is gypsum.

12. A foaming agent for hydraulic compositions, comprising (A) an alkyl or alkenyl sulfate ester or a salt thereof (hereinafter referred to as component (A)), wherein component (A) contains (A1) an alkyl or alkenyl sulfate ester having a C10 alkyl or alkenyl group or a salt thereof (hereinafter referred to as component (A1)), and (A2) an alkyl or alkenyl sulfate ester having a C12 alkyl or alkenyl group or a salt thereof (hereinafter referred to as component (A2)), the total content of component (A1) and component (A2) in component (A) is 99% by mass or more, and the mass ratio (A1) / (A2) of the content of component (A1) to the content of component (A2) is 0.2 or more and 2.4 or less.

13. A foaming agent for hydraulic compositions according to claim 12, which does not contain an alkyl or alkenyl sulfate ester having an alkyl or alkenyl group having 14 or more carbon atoms, or a salt thereof.

14. (A) A foaming agent for hydraulic compositions according to claim 12 or 13, comprising 2% by mass or more and 40% by mass or less of component (A).

15. The foaming agent for hydraulic compositions according to claim 12 or 13, wherein the content of polyoxyethylene alkyl or alkenyl ether sulfate ester, or a salt thereof, is 10% by mass or less.

16. A foaming agent for hydraulic compositions according to claim 12 or 13, which is for use with gypsum slurry.