JP2025041224A - Foaming agent for hydraulic compositions - Google Patents

Abstract

To provide a foaming agent for hydraulic compositions, a foam-containing hydraulic composition, and a method for producing the same, capable of lowering the specific gravity of the foam-containing hydraulic composition while maintaining the bubble diameter in the foam-containing hydraulic composition.SOLUTION: Provided is a foaming agent for hydraulic compositions, comprising the following components (A) and (B). Component (A): An anionic surfactant. Component (B): A fatty acid alkanolamide having a fatty acid moiety with a carbon number of 8 or more and 24 or less.SELECTED DRAWING: None

Description

The present invention relates to a foaming agent for hydraulic compositions, a bubble-containing hydraulic composition, and a method for producing the same.

Air bubbles are introduced into hydraulic compositions that use cement or gypsum as a hardening agent to reduce their weight. Typically, a lightweight air bubble-containing hydraulic composition is produced by foaming a liquid composition containing a foaming agent and water, and mixing the foam with the hydraulic composition, or with fine aggregate and various admixtures.

Patent Document 1 discloses a rheology modifier that contains (A) a sulfate ester or a salt thereof in which the carbon number of the hydrocarbon group is from 12 to 22 and the average number of moles of alkylene oxide added is from 0 to 25, and (B) a fatty acid alkanolamide in which the carbon number of the fatty acid moiety is from 10 to 22, thereby imparting thixotropy and viscosity to water.
Patent Document 2 discloses a foaming agent composition for hydraulic compositions, which contains the following component (A1), optionally the following component (A2), and the following component (B), and in which the mass ratio (A1)/[(A1)+(A2)] of the content of the component (A1) to the total content of the components (A1) and (A2) is 0.8 or more and 1 or less, and which can increase the bubble diameter in the hydraulic composition even if the hydraulic composition has the same specific gravity, thereby increasing the strength of the hardened body of the hydraulic composition.
Component (A1): one or more selected from alkyl or alkenyl sulfate esters having an alkyl or alkenyl group having from 8 to 10 carbon atoms, and salts thereof. Component (A2): one or more selected from surfactants other than component (A1). Component (B): a monohydric alcohol having from 6 to 10 carbon atoms. Patent Document 3 discloses a method for wetting a building material mixture of cement or gypsum and fibers bound thereto, which is characterized in that water is added to the building material mixture at least partially in the form of bubbles containing at least one surfactant and at least one bubble stabilizer, or the building material mixture is brought into contact with a surfactant and at least one bubble stabilizer to convert at least a portion of it into bubbles, and water is added to the building material mixture, and the amount of water in the building material mixture is such that the building material mixture is powdery and easily crumbles when wet, and it is disclosed that a fatty acid alkanolamide may be used as the bubble stabilizer.

JP 2018-83931 A JP 2023-070662 A Japanese Unexamined Patent Publication No. 1-306206

There is a demand for further weight reduction in hardened bodies of bubble-containing hydraulic compositions using cement or gypsum as a hardening agent, from the viewpoints of the cost and the effect of reducing the environmental impact (CO ₂ ) caused by the production, transportation, and procurement of raw materials.
The bubble-containing hydraulic composition can reduce the specific gravity of the hardened hydraulic composition by containing bubbles, and can reduce the weight. However, when the volume (ratio) of the bubbles is increased in order to further reduce the weight of the hardened hydraulic composition, the ratio of the hydraulic composition decreases, and the strength of the hardened hydraulic composition tends to decrease. On the other hand, as described in paragraph 0004 of JP-A-10-330174, the strength of the hardened hydraulic composition 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 hardened hydraulic composition of the bubble-containing hydraulic composition is accelerated, and there are merits such as reduction in fuel cost for drying and reduction in _CO2 emissions. In addition, when the bubble diameter in the bubble-containing hydraulic composition is increased, the distance between the bubbles increases, and the bubbles are less likely to communicate with each other, and the heat insulation and sound insulation can be improved.
Therefore, there is a demand for a technique for lowering the specific gravity of a bubble-containing hydraulic composition while maintaining the size of the bubble diameter in the bubble-containing hydraulic composition.

The present invention provides a foaming agent for a hydraulic composition, a bubble-containing hydraulic composition, and a method for producing the same, which can reduce the specific gravity of the bubble-containing hydraulic composition while maintaining the size of the bubble diameter in the bubble-containing hydraulic composition.

The present invention relates to a foaming agent for a hydraulic composition, comprising the following components (A) and (B):
Component (A): Anionic surfactant Component (B): Fatty acid alkanolamide having a fatty acid moiety with 8 to 24 carbon atoms

The present invention also relates to a bubble-containing hydraulic composition containing hydraulic powder, water, the above-mentioned component (A), and component (B).

The present invention also relates to 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 foaming agent for hydraulic compositions of the present invention and water to obtain a foam.
<Step 2>
A step of mixing hydraulic powder, water, and the foam obtained in step 1.

The present invention provides a foaming agent for a hydraulic composition, a bubble-containing hydraulic composition, and a method for producing the same, which can reduce the specific gravity of the bubble-containing hydraulic composition while maintaining the size of the bubble diameter in the bubble-containing hydraulic composition.

The reason why the foaming agent for hydraulic compositions, the bubble-containing hydraulic composition, and the method for producing the same of the present invention can reduce the specific gravity of the bubble-containing hydraulic composition while maintaining the size of the bubble diameter in the bubble-containing hydraulic composition is not necessarily clear, but is presumed to be as follows.
The fatty acid alkanolamide, which is the component (B) of the present invention, has a high adsorption rate to the gas-liquid interface due to its high hydrophobicity, and gives high foaming properties, so by using it in combination with the anionic surfactant, which is the component (A) of the present invention, many bubbles can be introduced into the hydraulic composition, and the specific gravity of the bubble-containing hydraulic composition can be reduced. On the other hand, when many bubbles are introduced into the hydraulic composition, the bubble diameter becomes small, but the bubble film formed by the components (A) and (B) has a small hydrophilic group in the component (B) and does not excessively stabilize the bubble film, so that the bubbles are appropriately united when mixed with the hydraulic composition, and therefore the specific gravity of the bubble-containing hydraulic composition can be reduced while maintaining the size of the bubble diameter in the bubble-containing hydraulic composition.
However, the present invention is not limited to the above expression mechanism.

[Foaming agent for hydraulic composition]
<Component (A)>
The foaming agent for hydraulic compositions of the present invention contains an anionic surfactant as component (A).

Examples of the anionic surfactant of component (A) include sulfonic acid compounds, ether sulfate compounds, carboxylic acid compounds, phosphonic acid compounds, and phosphoric acid compounds having a hydrocarbon group having from 8 to 18 carbon atoms. Examples include one or more selected from alkyl or alkenyl sulfate esters having an alkyl group or an alkenyl group, alkyl or alkenyl sulfonic acids having an alkyl group or an alkenyl group, polyoxyalkylene alkyl or alkenyl ether sulfate esters having an alkyl group or an alkenyl group, polyoxyalkylene alkyl or alkenyl ether carboxylic acids having an alkyl group or an alkenyl group, and salts thereof.
Examples of the salts of these anionic surfactants include at least one selected from alkali metal salts such as sodium salts and potassium salts, ammonium salts, and organic ammonium salts.

From the viewpoint of foaming ability, particularly among foam performance in aqueous systems, the component (A) is preferably at least one selected from alkyl or alkenyl sulfate esters having an alkyl or alkenyl group having from 8 to 18 carbon atoms, alkyl or alkenyl sulfonic acids having an alkyl or alkenyl group having from 8 to 18 carbon atoms, polyoxyalkylene alkyl or alkenyl ether sulfate esters having an alkyl or alkenyl group having from 8 to 18 carbon atoms, and salts thereof.
Examples of the salts of these anionic surfactants include at least one selected from alkali metal salts such as sodium salts and potassium salts, ammonium salts, and organic ammonium salts.

From the viewpoint of foaming ability, particularly among foaming performance in aqueous systems, the (A) component is preferably one or more selected from (A1) an alkyl or alkenyl sulfate ester or a salt thereof having an alkyl or alkenyl group with 8 to 18 carbon atoms (hereinafter referred to as (A1) component), and (A2) a polyoxyalkylene alkyl or alkenyl ether sulfate ester or a salt thereof having an alkyl or alkenyl group with 8 to 18 carbon atoms (hereinafter referred to as (A2) component).

From the viewpoint of maintaining the bubble diameter in the hydraulic composition, the component (A1) preferably has an alkyl or alkenyl group, preferably an alkyl group, having 8 or more carbon atoms, more preferably 10 or more carbon atoms, and preferably 18 or less, more preferably 16 or less, even more preferably 14 or less, and still more preferably 12 or less.
Examples of the salt of the component (A1) include one or more salts selected from alkali metal salts such as sodium salts and potassium salts, ammonium salts, and organic ammonium salts.

Specific examples of the (A1) component include one or more compounds selected from octyl sulfate, decyl sulfate, dodecyl sulfate, tetradecyl sulfate, hexadecyl sulfate, octadecyl sulfate, 2-ethylhexyl sulfate, 2-propylheptyl sulfate, and salts thereof. From the viewpoint of maintaining the bubble size in the hydraulic composition, it is preferable to contain one or more compounds selected from decyl sulfate, dodecyl sulfate, tetradecyl sulfate, and salts thereof, and it is more preferable to contain one or more compounds selected from decyl sulfate, dodecyl sulfate, and salts thereof.

From the viewpoint of foaming performance, particularly foaming ability, in aqueous systems, component (A) may contain, as component (A1), two types of alkyl or alkenyl sulfate esters or salts thereof, each having a different number of carbon atoms in the alkyl or alkenyl group.

From the viewpoint of maintaining the bubble diameter in the hydraulic composition, the component (A2) preferably has an alkyl or alkenyl group having 8 or more carbon atoms, more preferably 10 or more carbon atoms, and preferably 16 or less, more preferably 14 or less, and even more preferably 12 or less, and preferably an alkyl group.
The oxyalkylene group of the component (A2) is an oxyethylene group or an oxypropylene group, and is preferably an oxyethylene group. From the viewpoint of foaming performance, particularly foamability, in an aqueous system, the average number of moles of the oxyalkylene group added is preferably 1 or more, more preferably 2 or more, and from the viewpoint of foaming performance, particularly foamability, in an aqueous system, it is preferably 10 or less, more preferably 6 or less, and even more preferably 4 or less.
Examples of the salt of the component (A2) include one or more salts selected from alkali metal salts such as sodium salts and potassium salts, ammonium salts, and organic ammonium salts.

Specific examples of component (A2) include 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, polyoxypropylene octyl ether sulfate, polyoxypropylene decyl ether sulfate, polyoxypropylene lauryl ether sulfate, polyoxypropylene tridecyl ether sulfate, polyoxypropylene myristyl ether sulfate, polyoxypropylene cetyl ether sulfate, polyoxypropylene stearyl ether sulfate, polyoxyethylene polyoxypropylene octyl ether sulfate, polyoxyethylene polyoxypropylene decyl ether sulfate, and polyoxyethylene polyoxypropylene lauryl ether sulfate. ether, polyoxyethylene polyoxypropylene tridecyl ether sulfate, polyoxyethylene polyoxypropylene myristyl ether sulfate, polyoxyethylene polyoxypropylene cetyl ether sulfate, polyoxyethylene polyoxypropylene stearyl ether sulfate, and salts thereof. From the viewpoint of maintaining the bubble diameter in the hydraulic composition, preferred are polyoxyethylene decyl ether sulfate, polyoxyethylene lauryl ether sulfate, polyoxyethylene myristyl ether sulfate, polyoxypropylene decyl ether sulfate, polyoxypropylene lauryl ether sulfate, polyoxypropylene myristyl ether sulfate, polyoxyethylene polyoxypropylene decyl ether sulfate, polyoxyethylene polyoxypropylene lauryl ether sulfate, polyoxyethylene polyoxypropylene myristyl ether sulfate, and salts thereof.

<Component (B)>
The foaming agent for hydraulic compositions of the present invention contains, as component (B), a fatty acid alkanolamide in which the carbon number of the fatty acid moiety is from 8 to 24. The fatty acid moiety refers to an acyl group, and the carbon number of the fatty acid moiety refers to the carbon number of the acyl group.

The hydrocarbon group of the fatty acid portion is a hydrocarbon group containing a carbon atom of a carboxyl group in the raw material fatty acid of the fatty acid alkanolamide, and is preferably a linear or branched alkyl group or a linear or branched alkenyl group, more preferably a linear alkyl group or a linear alkenyl group, and even more preferably a linear alkyl group.

The number of carbon atoms in the fatty acid portion is the number of carbon atoms including the carbon atom of the carboxyl group in the raw fatty acid of the fatty acid alkanolamide, and from the viewpoint of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened hydraulic composition, it is 8 or more, preferably 10 or more, more preferably 12 or more, and 24 or less, preferably 18 or less, and even more preferably 16 or less.

Examples of fatty acid alkanolamides include one or more selected from fatty acid monoethanolamides, fatty acid methyl monoethanolamides, fatty acid ethyl monoethanolamides, fatty acid propyl monoethanolamides, fatty acid methanol ethanolamides, and fatty acid diethanolamides, and from the viewpoints of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened body of the hydraulic composition, one or more selected from fatty acid monoethanolamides, fatty acid methyl monoethanolamides, and fatty acid diethanolamides are preferred, and fatty acid diethanolamides are more preferred.

Component (B) may be, for example, one or more selected from oleic acid diethanolamide, stearic acid diethanolamide, palm kernel oil fatty acid diethanolamide, coconut oil fatty acid diethanolamide, myristic acid diethanolamide, and lauric acid diethanolamide. From the viewpoint of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened body of the hydraulic composition, component (B) is preferably one or more selected from palm kernel oil fatty acid diethanolamide, coconut oil fatty acid diethanolamide, and oleic acid diethanolamide, more preferably one or more selected from palm kernel oil fatty acid diethanolamide and oleic acid diethanolamide, and even more preferably palm kernel oil fatty acid diethanolamide.

The (B) component is obtained by reacting a higher fatty acid with an alkanolamine, but by-products other than fatty acid alkanolamides are simultaneously produced. Examples of by-products include fatty acid alkanolamide fatty acid monoesters and fatty acid alkanolamide fatty acid diesters, which are obtained by dehydration condensation of fatty acid alkanolamides and fatty acids, as well as fatty acid alkanolamine monoesters and fatty acid alkanolamine diesters, which are obtained by dehydration condensation of alkanolamines and fatty acids. The (B) component of the present invention may contain trace amounts of the above-mentioned by-products as long as the effects of the present invention are not impaired. The content of the by-products in the (B) component is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the (B) component.

<Composition, etc.>
The foaming agent for hydraulic compositions of the present invention contains component (A) in an amount of preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, in terms of maintaining the bubble diameter in the hydraulic composition, reducing the specific gravity of the hardened hydraulic composition, and ease of handling the foaming agent.
In the present invention, the masses of the component (A), and the components (A1) and (A2) contained in the component (A) are expressed in terms of sodium salts.

The foaming agent for hydraulic compositions of the present invention contains component (B) in an amount of preferably 0.5% by mass or more, more preferably 1.0% by mass or more, even more preferably 1.5% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, in order to maintain the bubble diameter in the hydraulic composition and to reduce the specific gravity of the hardened hydraulic composition.

In the foaming agent for hydraulic compositions of the present invention, the mass ratio (A)/(B) of the content of the component (A) to the content of the component (B) is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 2 or more, even more preferably 5 or more, even more preferably 10 or more, even more preferably 15 or more, even more preferably 18 or more, and preferably 300 or less, more preferably 100 or less, even more preferably 50 or less, even more preferably 25 or less, even more preferably 22 or less, from the viewpoint of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened hydraulic composition.

The foaming agent for hydraulic compositions of the present invention can contain, as component (C), a monovalent nonionic alcohol having a LogP of 0 or more and 7.0 or less, from the viewpoint of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened hydraulic composition.

In the present invention, the logP value is a coefficient indicating the affinity of an organic compound to water and 1-octanol. The 1-octanol/water partition coefficient P is the distribution equilibrium when a trace amount of a compound is dissolved as a solute in a two-phase solvent of 1-octanol and water, and is the ratio of the equilibrium concentration of the compound in each solvent, and is generally expressed in the form of their logarithm logP to the base 10. The logP values of many compounds have been reported, and many values are listed in databases available from Daylight Chemical Information Systems, Inc. (Daylight CIS), etc., and can be referred to. If there is no measured logP value, it can be calculated using the program "ClogP" available from Daylight CIS, etc. This program outputs the value of "calculated logP (ClogP)" calculated by the fragment approach of Hansch and Leo, along with the measured logP value if there is one.
The fragment approach is based on the chemical structure of the compound, taking into account the number of atoms and the type of chemical bonds (cf. A. Leo, Comprehensive Medicinal Chemistry, Vol. 4, C. Hansch, PG Sammens, JB Tailor and CA Ramsden, Eds., p. 295, Pergamon Press, 1990). This ClogP value can be used instead of the measured logP value when selecting compounds. In the present invention, the measured logP value is used if available, and if not, the ClogP value calculated by the program CLOGP v4.01 is used.

As component (C), monohydric nonionic alcohols with a LogP of 0 to 3.0 include 1-propanol, 2-propanol (LogP: 0.05), 1-butanol (LogP: 0.88), 2-butanol (LogP: 0.61), 2-methyl-1-propanol (LogP: 0.76), 2-methyl-2-propanol (LogP: 0.35), 1-pentanol (LogP: 1.51), 2-pentanol (LogP: 1.19), 3-pentanol (LogP: 1.21), 2- Methyl-1-butanol (log P: 1.29), 2-methyl-2-butanol (Log P: 0.89), 3-methyl-2-butanol (Log P: 1.28), 3-methyl-1-butanol (Log P: 1.16), cyclopentanol (Log P: 0.71), benzyl alcohol (log P: 1.1), 2-hexanol (Log P: 1.76), 3-hexanol (Log P: 1.65), 2-methyl-1-pentanol (Log P: 1.75), 3-methyl-1-pentanol (Log P: P: 1.75), 4-methyl-1-pentanol (Log P: 1.75), 2-methyl-2-pentanol (Log P: 1.57), 3-methyl-2-pentanol (Log P: 1.57), 4-methyl-2-pentanol (Log P: 1.57), 2-methyl-3-pentanol (Log P: 1.57), 3-methyl-3-pentanol (Log P: 1.57), 2,2-dimethyl-1-butanol (Log P: 1.57), 2-ethyl-1-butanol (Log P: 1.75), cyclohexa Examples of the alcohol include one or more selected from the group consisting of 1-hexanol (log P: 1.23), 1-heptanol (log P: 2.62), 1-hexanol (log P: 2.03), 2-ethyl-1-hexanol (log P: 2.73), 6-methyl-1-heptanol (log P: 2.73), 1-octanol (log P: 3), 1-decanol (log P: 4.23), 1-dodecanol (log P: 5.13), 1-tetradecanol (log P: 5.5), and 1-hexadecanol (log P: 6.7).

From the viewpoints of maintaining the bubble diameter in the hydraulic composition, reducing the specific gravity of the hardened hydraulic composition, and handling of the foaming agent, the (C) component is preferably one or more selected from benzyl alcohol, 1-hexanol, 1-octanol, 1-decanol, and 1-dodecanol, more preferably one or more selected from benzyl alcohol, 1-hexanol, and 1-octanol, and even more preferably benzyl alcohol.

When the foaming agent for hydraulic compositions of the present invention contains component (C), the foaming agent contains component (C) in an amount of preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 3% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, from the viewpoints of maintaining the bubble diameter in the hydraulic composition, reducing the specific gravity of the hardened hydraulic composition, and ease of handling the foaming agent.

The foaming agent for hydraulic compositions of the present invention can contain an alkylglycoside type nonionic surfactant as component (D) from the viewpoint of lowering the specific gravity of the hardened hydraulic composition.

From the viewpoint of reducing the specific gravity of the hydraulic composition hardened body, the component (D) is preferably an alkylglycoside type nonionic surfactant represented by the following general formula (D1).
R ^1d - (OR ^2d ) _p G _q (D1)
[In the formula, R ^1d is an alkyl group having 6 to 18 carbon atoms, R ^2d is an alkylene group having 2 to 4 carbon atoms, G is a residue derived from a reducing sugar, p is a number of 0 to 10 indicating the average number of moles of oxyalkylene groups added, and p R ^2d may be the same or different. q is a number of 1 to 3 indicating the average degree of condensation of G.]

In formula (D1), the carbon number of R ^1d is preferably 8 or more, more preferably 10 or more, and preferably 14 or less, more preferably 12 or less, from the viewpoint of improving foamability.
R ^2d is preferably an ethylene group or a propylene group, more preferably an ethylene group.
p is preferably 5 or less, more preferably 2 or less, and may be 0.
q is preferably 2.5 or less, and more preferably 2 or less.
Examples of G include residues derived from monosaccharides such as glucose, galactose, xylose, mannose, lyxose, arabinose, fructose, or mixtures thereof, and examples of G include residues derived from disaccharides or higher such as maltose, xylobiose, isomaltose, cellobiose, gentiobiose, lactose, sucrose, nigerose, turanose, raffinose, gentianose, menzitose, or mixtures thereof. Among these, preferred raw materials are glucose and fructose for monosaccharides and maltose and sucrose for disaccharides or higher from the viewpoint of availability.

When the foaming agent for hydraulic compositions of the present invention contains component (D), the foaming agent contains component (D) in an amount of preferably 0.5% by mass or more, more preferably 1.0% by mass or more, even more preferably 1.5% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, from the viewpoints of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened hydraulic composition.

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 40% by mass or more, preferably 50% by mass or more, more preferably 60% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 85% by mass or less.

The foaming agent for hydraulic compositions of the present invention may optionally contain thickeners, chelating agents, heavy metal scavengers, rust inhibitors, preservatives, colorants, fragrances, defoamers, solvents, dispersants, flocculants, water-soluble polymers, etc. However, these do not fall under the category of components (A), (B), (C), and (D).

The foaming agent for hydraulic compositions of the present invention can be obtained by mixing component (A), component (B), and the optional components described above. When mixing, heating may be applied as appropriate to reduce the solution viscosity.

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, mortar for pumping, 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.

[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.

The present invention provides a bubble-containing hydraulic composition comprising a hydraulic powder, water, component (A), and component (B).
The bubble-containing hydraulic composition of the present invention may further contain component (C).
The bubble-containing hydraulic composition of the present invention may further contain component (D).
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), (B), (C) and (D) are the same as those described in the foaming agent for hydraulic compositions of the present invention.

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. These may also be supplemented with blast furnace slag cement, fly ash cement, or silica fume cement to produce these with the addition of blast furnace slag, fly ash, silica fume, or stone powder (calcium carbonate powder).

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, still more preferably 60% by mass or more, still more preferably 65% by mass or more from the viewpoint of slurry fluidity, and from the viewpoint of hardened body strength, it is preferably 100% by mass or less, more preferably 90% by mass or less, still more preferably 80% by mass or less, still more preferably 75% 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.

The bubble-containing hydraulic composition of the present invention contains component (A) in an amount of preferably 0.001 part by mass or more, more preferably 0.003 part by mass or more, even more preferably 0.005 part by mass or more, and preferably 0.1 part by mass or less, more preferably 0.08 part by mass or less, even more preferably 0.07 part by mass or less, per 100 parts by mass of hydraulic powder, from the viewpoints of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened body of the hydraulic composition.

The bubble-containing hydraulic composition of the present invention contains component (B) in an amount of preferably 0.00015 parts by mass or more, more preferably 0.0002 parts by mass or more, even more preferably 0.0003 parts by mass or more, and preferably 0.03 parts by mass or less, more preferably 0.01 parts by mass or less, even more preferably 0.005 parts by mass or less, and even more preferably 0.001 parts by mass or less, per 100 parts by mass of hydraulic powder, from the viewpoints of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened body of the hydraulic composition.

In the bubble-containing hydraulic composition of the present invention, the mass ratio (A)/(B) of the content of the component (A) to the content of the component (B) is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 2 or more, even more preferably 5 or more, even more preferably 10 or more, even more preferably 15 or more, even more preferably 18 or more, and preferably 300 or less, more preferably 100 or less, even more preferably 50 or less, even more preferably 25 or less, even more preferably 22 or less, from the viewpoint of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened hydraulic composition.

When the bubble-containing hydraulic composition of the present invention contains component (C), the bubble-containing hydraulic composition of the present invention contains component (C) in an amount of preferably 0.0001 parts by mass or more, more preferably 0.00015 parts by mass or more, even more preferably 0.0002 parts by mass or more, and preferably 0.05 parts by mass or less, more preferably 0.03 parts by mass or less, even more preferably 0.02 parts by mass or less, per 100 parts by mass of hydraulic powder, from the viewpoints of maintaining the bubble diameter in the hydraulic composition and reducing the specific gravity of the hardened body of the hydraulic composition.

When the bubble-containing hydraulic composition of the present invention contains component (D), the amount of component (D) is preferably 0.00015 parts by mass or more, more preferably 0.0002 parts by mass or more, even more preferably 0.0003 parts by mass or more, and preferably 0.03 parts by mass or less, more preferably 0.01 parts by mass or less, even more preferably 0.005 parts by mass or less, per 100 parts by mass of hydraulic powder, from the viewpoint of reducing the specific gravity of the hardened hydraulic composition.

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

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.

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, 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 the 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 200 to 400 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, when the bubble cross section is elliptical, and when the bubble cross section is irregular, the diameter is the longest part. The bubble diameter of the hardened product of the bubble-containing hydraulic composition is the same as the bubble diameter of the bubble-containing hydraulic composition before hardening.

The bubble-containing hydraulic composition of the present invention can be produced by using the foaming agent for hydraulic compositions of the present invention.
That is, the present invention provides 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 foaming agent for hydraulic compositions of the present invention and water to obtain a foam.
<Step 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 may be mixed with the foam obtained in step 1.

The bubble-containing hydraulic composition of the present invention can be prepared by this manufacturing method.
The method for producing the bubble-containing hydraulic composition of the present invention can appropriately employ the embodiments described for the foaming agent composition for hydraulic compositions of the present invention and 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.

In step 1, the expansion ratio of the liquid composition depends 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.

In step 2, depending on the use of the hydraulic composition, from the viewpoint of reducing the specific gravity of the hardened body, 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, and from the viewpoint of the strength of the hardened body, preferably 400% by volume or less, more preferably 300% by volume or less, and even more preferably 200% by volume or less. In this manufacturing method, admixtures and additives known in the industry can be mixed in step 1 and/or step 2.

After step 2, the following step 3 is further carried out to produce a hardened product of the bubble-containing hydraulic composition.
Step 3: A step of forming the bubble-containing hydraulic composition slurry obtained in step 2 and hardening it.

The specific gravity of the cured product of the bubble-containing hydraulic composition obtained by the method for producing a 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.
The average bubble diameter of the hardened product of the bubble-containing hydraulic composition obtained by the method for producing a bubble-containing hydraulic composition of the present invention is preferably 230 μm or more, more preferably 250 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.

[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 an air bubble-containing gypsum slurry containing gypsum, water, component (A), and component (B). The air bubble-containing gypsum slurry of the present invention is suitable for use in gypsum boards.

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 bubble-containing gypsum slurry of the present invention may further contain component (C).
The bubble-containing gypsum slurry of the present invention may further contain component (D).
The components (A), (B), (C) and (D) 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.

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 hydrous silicate minerals (hereinafter referred to as clay minerals) having a layered structure, and examples of 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).

Gypsum includes anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum, etc. As 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. Major examples of chemical gypsum include phosphate gypsum, hydrofluoric gypsum, titanic gypsum, and flue gas desulfurization gypsum. Raw gypsum may also include recycled gypsum. 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 of these raw gypsum, and excellent effects can be obtained with blends of various ratios.

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 fiber, carbon fiber, waste paper, virgin pulp, etc. can be added as reinforcing fibers, or gypsum boards can be made with lightweight aggregates such as perlite and foamed steel.

The foam-containing gypsum slurry of the present invention can be produced using the foaming agent for hydraulic compositions of the present invention.
That is, the present invention provides a method for producing an air-bubble gypsum slurry, comprising the following steps 1 and 2.
<Step 1>
A step of foaming a liquid composition containing the foaming agent for hydraulic compositions of the present invention and water to obtain a foam.
<Step 2>
Mixing gypsum, water, and the foam obtained in step 1.
Note that 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.

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 embodiments 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 the 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.

After step 2, the following step 3 is further carried out to manufacture a gypsum board.
Step 3: A step of forming and hardening the bubble-containing gypsum slurry obtained in step 2.
The molding and hardening can be carried out by known methods. For example, a gypsum board can be prepared by referring to "Gypsum Board Manufacturing" described on pages 322-324 of "Gypsum Lime Handbook" (edited by the Gypsum Lime Society).

The specific gravity of the hardened body of the bubble-containing hydraulic composition obtained by the method for producing a bubble-containing gypsum slurry 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.
The average bubble diameter of the hardened product of the air bubble-containing hydraulic composition obtained by the method for producing an air bubble-containing gypsum slurry of the present invention is, from the viewpoint of improving the strength of the hardened product, preferably 230 μm or more, more preferably 250 μm or more, and from the viewpoint of cross-sectional appearance, 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 still more preferably 400 μm or less.

The components used in the examples and comparative examples are shown below.
Component (A): C10AS: sodium decyl sulfate, C12AS: sodium dodecyl sulfate, AES: sodium polyoxyethylene alkyl ether sulfate (mass ratio of carbon numbers of alkyl groups: C12/C14=75/25 (mass%) (based on raw material alcohol), average number of moles of oxyethylene groups added: 2)

(B) Components B-1: coconut oil fatty acid N-methylethanolamide (a compound in which the fatty acid moiety has an alkyl group with 8 to 18 carbon atoms), Aminone C-11S, manufactured by Kao Corporation B-2: lauric acid diethanolamide, Aminone L-02, manufactured by Kao Corporation B-3: coconut oil fatty acid monoethanolamide (a compound in which the fatty acid moiety has an alkyl group with 8 to 18 carbon atoms), Amizol CME, manufactured by Kawaken Fine Chemical Co., Ltd. B-4: oleic acid diethanolamide, Amizol ODE, manufactured by Kawaken Fine Chemical Co., Ltd. B-5: palm kernel oil fatty acid diethanolamide (a compound in which the fatty acid moiety has an alkyl group with 8 to 18 carbon atoms), Aminone PK-02S, manufactured by Kao Corporation

(C) Component BzA: benzyl alcohol, Log P: 1.1
ROH: aliphatic alcohol (mass ratio of the carbon numbers of aliphatic alcohols: C8/C10/C12/C14/C16 = 33.3/33.3/22.7/8.7/2 (mass%), LogP of the carbon numbers of aliphatic alcohols: C8/C10/C12/C14/C16 = 3/4.23/5.13/5.5/6.7)

(1) Preparation of Foaming Agent for Hydraulic Composition The foaming agents for hydraulic compositions shown in Table 1 were prepared by the following method.
Each raw material was added to a 50 mL screw tube in a predetermined ratio so that the total amount was 30 g, and the mixture was stirred with a stirrer at 1000 rpm for 30 minutes to prepare a foaming agent for hydraulic compositions having uniform and transparent properties.

(2) Preparation of gypsum slurry The foaming agent for hydraulic compositions prepared in Table 1 and water were mixed in a mass ratio of 0.25:99.75 to prepare an aqueous solution with a concentration (as is) of the foaming agent for hydraulic compositions of 0.25 mass%. 19 g of the prepared aqueous solution was added to a 1 L disposable cup, and the mixture was stirred by rotating the container by hand using a flat 6-blade paddle blade (FP-50, manufactured by AS ONE Corporation) at 2000 rpm (EUROSTAR 200 control, manufactured by IKA Japan Co., Ltd.) for 15 seconds, and the container was placed and stirred for an additional 45 seconds to obtain a foam.
In a 500 mL disposable cup, 200 g of calcined gypsum (Sakura brand gypsum grade A, manufactured by Yoshino Gypsum Co., Ltd.), 4 g of dihydrate gypsum (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.), 127 g of tap water in which 1.5 g of potassium sulfate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) has been dissolved, and 0.36 g of a water reducing agent (Mighty 150, manufactured by Kao Corporation) were added, and the mixture was stirred for 5 seconds at memory 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 blade in the 1 L disposable cup to obtain a gypsum slurry containing air bubbles. The temperature of the foam and gypsum slurry used for kneading was both 20 ° C.

(3) Measurement of specific gravity of gypsum hardened body The obtained gypsum slurry containing bubbles was poured into a cylindrical specimen mold (Plamold, manufactured by Nifco Co., Ltd.) having a diameter of 5 cm and a height of 10 cm, and left to stand at room temperature for more than 1 hour. The hardened gypsum slurry was removed from the cylindrical specimen mold, left to stand in a thermostatic bath at 80 ° C. for 17 hours, and then dried, and the weight of the obtained hardened body was measured. The specific gravity of the gypsum hardened body was calculated by dividing the weight of the obtained hardened body by the volume of the mold. The results are shown in Table 1.

(4) Measurement of average bubble diameter in gypsum A cut was made in the 5 cm high part of the obtained gypsum hardened body to create a cross section of the hardened body. The cross section was photographed with a digital microscope (DSX1000, manufactured by OLYMPUS Corporation, 42x), and 200 to 400 bubbles were randomly extracted from the obtained image using software to measure the diameter of the bubble cross section, and the average bubble diameter was calculated from the arithmetic mean of these values. Note that the measurement of the diameter of the bubble cross section is the diameter when the bubble cross section is circular, and the longest part when the bubble cross section is elliptical or irregular. The results are shown in Table 1.

From Table 1, it can be seen that the foaming agents for hydraulic compositions of Comparative Examples 1 to 2, which contain component (A) but not component (B), have specific gravities of the resulting gypsum hardened body of 0.80 and 0.82, respectively, whereas the foaming agents for hydraulic compositions of Examples 1 to 12, which contain components (A) and (B), have a specific gravities of the resulting gypsum hardened body reduced to 0.72 to 0.65. It can also be seen that the foaming agents for hydraulic compositions of Examples 1 to 12 and Comparative Examples 1 and 2 maintain the bubble diameter of the resulting gypsum hardened body in the range of 230 to 280 μm.

Claims (12)

A foaming agent for a hydraulic composition, comprising the following components (A) and (B):
Component (A): Anionic surfactant Component (B): Fatty acid alkanolamide having a fatty acid moiety with 8 to 24 carbon atoms The foaming agent for hydraulic compositions according to claim 1, wherein component (A) is at least one selected from alkyl or alkenyl sulfate esters having an alkyl or alkenyl group with 8 to 18 carbon atoms, alkyl or alkenyl sulfonic acids having an alkyl or alkenyl group with 8 to 18 carbon atoms, polyoxyalkylene alkyl or alkenyl ether sulfate esters having an alkyl or alkenyl group with 8 to 18 carbon atoms, and salts thereof. The foaming agent for hydraulic compositions according to claim 1 or 2, wherein component (B) is one or more selected from fatty acid monoethanolamides, fatty acid methyl monoethanolamides, and fatty acid diethanolamides. The foaming agent for hydraulic compositions according to any one of claims 1 to 3, wherein the mass ratio (A)/(B) of the content of the (A) component to the content of the (B) component is 0.1 or more and 300 or less. The foaming agent for hydraulic compositions according to any one of claims 1 to 4, further comprising, as component (C), a monohydric nonionic alcohol having a LogP of 0 to 7.0. The foaming agent for hydraulic compositions according to any one of claims 1 to 5, which is for use in gypsum slurries. A bubble-containing hydraulic composition comprising a hydraulic powder, water, and the following components (A) and (B):
Component (A): Anionic surfactant Component (B): Fatty acid alkanolamide having a fatty acid moiety with 8 to 24 carbon atoms The bubble-containing hydraulic composition according to claim 7, wherein the mass ratio (A)/(B) of the content of the (A) component to the content of the (B) component is 0.1 or more and 300 or less. The bubble-containing hydraulic composition according to claim 8, wherein the hydraulic powder is gypsum. A method for producing a bubble-containing hydraulic composition, comprising the following steps 1 and 2.
<Step 1>
A process for foaming a liquid composition containing the foaming agent for hydraulic compositions according to any one of claims 1 to 6 and water to obtain a foam.
<Step 2>
A step of mixing hydraulic powder, water, and the foam obtained in step 1. The method for producing a bubble-containing hydraulic composition according to claim 10, wherein the hydraulic powder is gypsum. A method for producing a hardened product of a bubble-containing hydraulic composition, comprising the steps 1 and 2 of the method for producing a bubble-containing hydraulic composition according to claim 10 or 11, and further comprising the following step 3:
<Step 3>
A step of forming the bubble-containing hydraulic composition slurry obtained in step 2 and hardening it.