Use of additive in clay-containing hydraulic composition

Abstract

The present invention provides a use of a polycarboxylic acid-based additive for a hydraulic composition, the additive being capable of imparting excellent fluidity retention ability to a hydraulic composition even if the hydraulic composition contains clay. The present invention uses an additive for a clay-containing hydraulic composition, which contains a component (A) and a component (B) that are composed of specific copolymers different from each other, wherein the ratio of the content of the component (A) to the total of the content of the component (A) and the content of the component (B) is 1 mass% or more.

Description

Use of additives in clay-containing hydraulic compositions

[0001] The present invention relates to the use of an additive in a clay-containing hydraulic composition, and further to a clay-containing hydraulic composition containing the additive and a method for producing the same.

[0002] Naphthalene-based, melamine-based, aminosulfonic acid-based, polycarboxylic acid-based admixtures and the like are used to impart fluidity to hydraulic compositions such as concrete. Admixtures such as dispersants are required to have various performance properties, such as imparting fluidity to hydraulic compositions, maintaining fluidity (hereinafter also referred to as fluidity maintenance), and preventing setting delay, and improvements have also been proposed for polycarboxylic acid-based admixtures (dispersants) from these perspectives.

[0003] Polycarboxylic acid dispersants produce a hydraulic composition with higher strength per added amount than naphthalene dispersants and the like, but are easily affected by the clay components contained in the aggregate. Generally, polycarboxylic acid dispersants are prone to fluctuations in the initial fluidity and fluidity retention of hydraulic compositions depending on the amount of clay in the aggregate. The clay content of aggregates used in hydraulic compositions such as concrete and mortar varies depending on the source of collection. Furthermore, concrete factories often combine various types of aggregates obtained from different sources, resulting in variations in the amount of clay in the aggregate. Because the aggregate accounts for a relatively large proportion of the unit volume of hydraulic compositions such as concrete and mortar, polycarboxylic acid dispersants are also easily affected by the clay in the aggregate. As a result, workability is unstable, and the amount required to achieve the desired fluidity and fluidity retention may vary. In consideration of these issues, the use of a combination of multiple polycarboxylic acid polymers has been proposed.

[0004] JP 2014-205607 A discloses an additive for a hydraulic composition containing a polymer (A) that satisfies the following conditions: (i) of a vinyl monomer (a) having a polyoxyalkylene chain and a vinyl monomer (b) not having a polyoxyalkylene chain, the polymer (A) has only a structure derived from the monomer (a), or has a structure derived from both the monomer (a) and the monomer (b); (ii) the weight ratio of the monomer (a) to the monomer (b) is (a) / (b) = 50 / 50 to 100 / 0; and (iii) the monomer (a) contains a vinyl monomer having a polyoxyalkylene chain.

[0005] Furthermore, Japanese Patent Application Laid-Open No. 2022-18729 discloses a dispersant for a clay-containing hydraulic composition, which comprises components (A), (B), and (C), each of which is a copolymer of a different carboxylic acid monomer and a polyethylene glycol ester monomer of a carboxylic acid.

[0006] However, little research has been done on improving the fluidity retention of clay-containing hydraulic compositions using existing polycarboxylic acid-based dispersants, and there has been a demand for the development of a polycarboxylic acid-based additive for clay-containing hydraulic compositions that can impart excellent fluidity retention.

[0007] The present invention relates to the use of an additive containing the following component (A) and the following component (B) in a clay-containing hydraulic composition, wherein the ratio of the content of component (A) to the total content of components (A) and (B), expressed by [[content of component (A)] / [content of component (A)+content of component (B)]×100 (mass%), is 1 mass% or more in the clay-containing hydraulic composition. <Component (A)> A copolymer comprising a structural unit (A1) represented by general formula (A1) below, and a structural unit (A2) represented by general formula (A2) below, wherein the content of the structural unit (A1) relative to the total content of the structural unit (A1) and the structural unit (A2), expressed by the formula [content of structural unit (A1) / [content of structural unit (A1) + content of structural unit (A2)]] × 100 (mass%), is 0.1% by mass or more and 4.5% by mass or less, and the copolymer has a weight average molecular weight of 10,000 or more and 100,000 or less. [In the formula, R１ａ and R ２ａ are the same or different and each represents a hydrogen atom or a methyl group. ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents one or more selected from a hydrogen atom and a counter cation. １ represents an alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group. ２ CH ２ O-) and is a number of 5 or more and 99 or less.] <Component (B)> A copolymer comprising a structural unit (B1) represented by the following general formula (B1) and a structural unit (B2) represented by the following general formula (B2), wherein the content of the structural unit (B1) relative to the total content of the structural unit (B1) and the structural unit (B2), expressed by [content of structural unit (B1) / [content of structural unit (B1) + content of structural unit (B2)]] × 100 (mass%), is 5% by mass or more and less than 30% by mass. [In the formula, M １ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. １ｂ , R ２ｂ and R ３ｂ are the same or different and each represents a hydrogen atom, a methyl group, or a group represented by the general formula (1) -(CH ２ ) ｒ COOM ２ｂ (1) [wherein r represents 0, 1 or 2, and M ２ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. ２ ) ｒ COOM ２ｂ (1) is COOM in the same structural unit or in different structural units １ｂ and forms an acid anhydride structure -(CH ２ ) ｒC(=O)-O-C(=O)- may be formed, and -(CH ２ ) ｒ COOM ２ｂ and forms an acid anhydride structure -(CH ２ ) ｒ C(=O)-OC(=O)(CH ２ ) ｒ - may be formed, in which case M １ｂ , M ２ｂ does not exist.] [In the formula, R ４ｂ , R ５ｂ are the same or different and represent a hydrogen atom or a methyl group. AO represents an oxyalkylene group having 2 to 4 carbon atoms, q2 represents an integer of 0 to 6, p2 represents 0 or 1, and n2 is the average number of moles of AO added and represents a number of 5 to 150. R ６ｂ represents a hydrogen atom, a methyl group, a group represented by the general formula (2) -(CH ２ ) ｓ COOM ３ｂ (2) [wherein s represents 0, 1 or 2; M ３ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group.], or a group represented by the general formula (3) -(CH ２ ) ｑ２ (CO) ｐ２ O (AO) ｎ２ R ７ｂ (3) [wherein AO represents an oxyalkylene group having from 2 to 4 carbon atoms, q2 represents an integer of from 0 to 6, p2 represents 0 or 1, n2 represents the average number of moles of AO added and is a number of from 5 to 150, and R ７ｂrepresents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ] The present invention also relates to a clay-containing hydraulic composition containing hydraulic powder, aggregate, clay, water, the above component (A) and the above component (B), wherein the ratio of the clay content to the aggregate content, expressed by [[clay content] / [aggregate content]]×100 (mass%), is 5 mass% or less, and the ratio of the content of component (A) to the total content of component (A) and component (B), expressed by [[content of component (A)] / [content of component (A)+content of component (B)]]×100 (mass%), is 1 mass% or more. The present invention also relates to a method for producing a clay-containing hydraulic composition by mixing hydraulic powder, aggregate, clay, water, and the above-mentioned component (A) and component (B), wherein the ratio of the amount of clay to the amount of aggregate is 1% by mass or more and 5% by mass or less, and the ratio (parts by mass) of the content of component (A) to the total content (parts by mass) of component (A) and component (B) is 1% by mass or more.Furthermore, the present invention relates to the use of an additive containing the above-mentioned component (A) in a clay-containing hydraulic composition.

[0008] According to the present invention, there is provided the use of an additive for use in a polycarboxylic acid-based clay-containing hydraulic composition, which can impart excellent fluidity retention and excellent short-term strength to the clay-containing hydraulic composition. Also, according to the present invention, there are provided a clay-containing hydraulic composition containing an additive for use in a polycarboxylic acid-based clay-containing hydraulic composition, which exhibits excellent fluidity retention and short-term strength, and a method for producing the same. Note that excellent fluidity retention means that the decrease in the initial flow value in a flow test is small even over time. Modes for carrying out the invention

[0009] <Additive Containing Component (A) and Component (B)> The additive used in the clay-containing hydraulic composition of the present invention contains component (A) and component (B) in a predetermined ratio.

[0010] The component (A) is a copolymer having a structural unit (A1) represented by the following general formula (A1) and a structural unit (A2) represented by the following general formula (A2), in which the content of the structural unit (A1) relative to the total content of the structural unit (A1) and the structural unit (A2), expressed by [content of structural unit (A1) / [content of structural unit (A1) + content of structural unit (A2)]] × 100 (mass%), is 0.1% by mass or more and 4.5% by mass or less, and the copolymer has a weight average molecular weight of 10,000 or more and 100,000 or less.

[0011] [In the formula, R １ａ and R ２ａ are the same or different and each represents a hydrogen atom or a methyl group. ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents one or more selected from a hydrogen atom and a counter cation. １ represents an alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group. ２ CH ２ O-), and is a number of 5 or more and 99 or less.

[0012] First, the structural unit (A1) will be described. １ represents a hydrogen atom and one or more selected from alkali metals, alkaline earth metals (1 / 2 atoms), ammonium groups, alkylammonium groups, substituted alkylammonium groups, alkyl groups, hydroalkyl groups, and alkenyl groups. Examples of alkali metals include sodium and potassium; examples of alkaline earth metals include magnesium. Other examples include ammonium; mono-, di-, tri-, or tetra-(mono-, di-, or trialkyl)ammonium having from 2 to 8 carbon atoms, which may be substituted with a hydroxyl group; and the like. From the viewpoints of convenience and availability, alkali metals are preferred as the counter cation, and sodium is more preferred.

[0013] There are no particular limitations on the method for introducing the structural unit (A1) into the component (A), but it is preferable to use a method represented by general formula (A1′): [In the formula, R １ａ and M １It is preferable to polymerize a monomer represented by the following formula (I):

[0014] M of the monomer (A1′) used to introduce the structural unit (A1) １ Counter cations can be introduced by copolymerizing the carboxyl groups using hydrogen atoms as raw materials, and then neutralizing the carboxyl groups with an alkali metal or alkaline earth metal hydroxide, ammonia, or a mono-, di-, or tri-(alkyl having from 2 to 8 carbon atoms, which may be substituted with a hydroxyl group)amine. Alternatively, neutralization can be achieved by exchanging the hydrogen atoms of the carboxyl groups for ammonium ions using a halide or hydroxide salt of (mono-, di-, tri-, or tetra-alkyl)ammonium (which may be substituted with a hydroxyl group) having from 2 to 8 carbon atoms. From the viewpoints of corrosion inhibition and safety, it is preferable that 20 to 95% of the hydrogen atoms of the carboxyl groups are neutralized.

[0015] Next, the structural unit (A2) will be described. From the viewpoint of good short-term strength and good fluidity retention due to the component (B), the structural unit (A2) R ２ａ is preferably a methyl group. １ is preferably a direct bond or a carbonyl group, more preferably a carbonyl group. In formula (A2), n a is preferably 5 or more, more preferably 7 or more, even more preferably 10 or more, and from the same viewpoint, is preferably 99 or less, more preferably 80 or less, even more preferably 70 or less.

[0016] There are no particular limitations on the method for introducing the structural unit (A2) into the component (A), but it is preferable to use a method for introducing the structural unit (A2) into a compound represented by general formula (A2') [In the formula, R ２ａ , R ３ａ , X １ and na are the same as above.] is preferably used as a raw material for polymerization.

[0017] More specifically, the following olefins can be used as the monomer (A2'): (1) X １ When X is an alkylene group: a reaction product of allyl alcohol, isoprenyl alcohol, or methallyl alcohol with ethylene oxide. (2) X １is a direct bond: a monoether of polyethylene glycol with vinyl alcohol, allyl alcohol, isoprenyl alcohol or methallyl alcohol, or an ether of alkoxypolyethylene glycol, one end of which is capped with an alkyl group, with allyl alcohol, isoprenyl alcohol or methallyl alcohol. (3) X １ is a carbonyl group: a monoester of polyethylene glycol with acrylic acid or methacrylic acid, an ester of alkoxypolyethylene glycol capped at one end with an alkyl group with acrylic acid or methacrylic acid, or a reaction product of acrylic acid, methacrylic acid, and ethylene oxide.

[0018] In the copolymer of component (A), from the viewpoint of achieving good short-term strength and good fluidity retention due to component (B), the proportion of the content of structural unit (A1) relative to the total content of structural unit (A1) and structural unit (A2) is 0.1% by mass or more, preferably 0.2% by mass or more, and from the same viewpoint, is 4.5% by mass or less, preferably 4% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. This proportion is calculated by [content of structural unit (A1) / [content of structural unit (A1) + content of structural unit (A2)]] × 100 (% by mass).

[0019] In the copolymer of component (A), from the viewpoint of good short-term strength and good fluidity retention due to component (B), the content of the structural unit (A2) relative to the total content of the structural unit (A1) and the structural unit (A2) is preferably 95.5% by mass or more, more preferably 96% by mass or more, even more preferably 97% by mass or more, and even more preferably 98% by mass or more. From the same viewpoint, it is preferably 99.9% by mass or less, more preferably 99.8% by mass or less. This proportion is calculated by [content of structural unit (A2) / [content of structural unit (A1) + content of structural unit (A2)]] × 100 (mass%). Note that the proportion of the structural units referred to here refers to the proportion of the raw material monomers derived from each structural unit in the copolymer, i.e., the ratio of the raw material monomers used to produce the copolymer may be equal to the proportion of the structural units contained in the copolymer. Furthermore, the proportion of each structural unit may be the average value of each structural unit contained in the entire copolymer.

[0020] The copolymer of component (A) may contain a structural unit other than the structural units (A1) and (A2) [hereafter referred to as structural unit (A3)]. Examples of the structural unit (A3) include structural units introduced by copolymerizing one or more acrylic acid monomers selected from 2-(methacryloyloxy)ethyl phosphate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, methyl acrylate, ethyl acrylate, acrylonitrile, methallylsulfonic acid, acrylamide, methacrylamide, styrene, styrenesulfonic acid, di-[2-(1-methylvinylcarbonyl)ethyl]phosphate, di-[2-(vinylcarbonyl)ethyl]phosphate, [2-(1-methylvinylcarbonyl)ethyl]phosphate, [2-(vinylcarbonyl)ethyl]acrylate, crotonic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid. These acrylic acid monomers may be in the form of alkali metal salts, alkaline earth metal salts, ammonium salts, or amine salts, or may be acid anhydrides such as maleic anhydride.

[0021] From the viewpoint of achieving good short-term strength and good fluidity retention due to component (B), the proportion of the total content of structural units (A1) and structural units (A2) relative to the content of component (A) is preferably at least 80% by mass, more preferably at least 90% by mass, and from the same viewpoint, is preferably at most 100% by mass. This proportion is calculated by [[content of component (A1) + content of component (A2)] / [content of component (A)]] × 100 (% by mass).

[0022] The copolymer of component (A) has a weight-average molecular weight of 10,000 or more, preferably 30,000 or more, from the viewpoint of good fluidity retention, and from the same viewpoint, 100,000 or less, preferably 80,000 or less. This weight-average molecular weight was measured using a high-performance GPC (HLC-8320GPC, manufactured by Tosoh Corporation) with an RI detector, G4000PWXL and G2500PWXL (anion) columns, a mobile phase of 0.2 M phosphate buffer / acetonitrile (9 / 1), a flow rate of 1.0 mL / min, a column temperature of 40°C, and a standard substance of polyethylene glycol.

[0023] The component (B) is a copolymer containing a structural unit (B1) represented by the following general formula (B1) and a structural unit (B2) represented by the following general formula (B2), in which the proportion of the content (parts by mass) of the structural unit (B1) relative to the total content (parts by mass) of the structural unit (B1) and the content (parts by mass) of the structural unit (B2) is 5% by mass or more and less than 30% by mass.

[0024] As described above, component (B) contains 5% by mass or more but less than 30% by mass of the structural unit (B1). The carboxyl groups of the structural unit (B1) adsorb to the surface of the hydraulic powder, and the steric repulsion effect of the alkyleneoxy chains of the structural unit (B2) inhibits aggregation between the hydraulic powder particles, thereby improving dispersibility. However, when clay is contained in the hydraulic composition, the alkyleneoxy chains of the structural unit (B2) adsorb to the clay, reducing the steric repulsion effect of component (B) and its adsorption efficiency to the hydraulic powder. This is thought to result in a decrease in dispersibility and fluidity retention. In the present invention, component (A), which is more easily adsorbed to clay than component (B), is also used in combination. It is presumed that the proportion of the structural unit (A1) in the component (A) is 0.1 mass % or more and 4.5 mass % or less, and the average number of moles of oxyethylene groups added in the structural unit (A2) is 5 or more and 99 or less, so that the component (A) can be appropriately adsorbed to both the clay and the hydraulic powder, and the adsorption of the component (B) to the clay is suppressed, thereby efficiently bringing about dispersibility of the hydraulic powder and exhibiting excellent fluidity retention of the hydraulic composition.

[0025] [In the formula, M １ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. １ｂ , R ２ｂ and R ３ｂ are the same or different and each represents a hydrogen atom, a methyl group, or a group represented by the general formula (1) -(CH ２ ) ｒ COOM ２ｂ (1) [wherein r represents 0, 1 or 2, and M ２ｂrepresents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. ２ ) ｒ COOM ２ｂ (1) is COOM in the same structural unit or in different structural units １ｂ and forms an acid anhydride structure -(CH ２ ) ｒ C(=O)-O-C(=O)- may be formed, and -(CH ２ ) ｒ COOM ２ｂ and forms an acid anhydride structure -(CH ２ ) ｒ C(=O)-OC(=O)(CH ２ ) ｒ - may be formed, in which case M １ｂ , M ２ｂ does not exist.]

[0026] [In the formula, R ４ｂ , R ５ｂ are the same or different and represent a hydrogen atom or a methyl group. AO represents an oxyalkylene group having 2 to 4 carbon atoms, q2 represents an integer of 0 to 6, p2 represents 0 or 1, and n2 is the average number of moles of AO added and represents a number of 5 to 150. R ６ｂ represents a hydrogen atom, a methyl group, a group represented by the general formula (2) -(CH ２ ) ｓ COOM ３ｂ (2) [wherein s represents 0, 1 or 2; M ３ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group.], or a group represented by the general formula (3) -(CH ２ ) ｑ２ (CO) ｐ２ O (AO) ｎ２ R ７ｂ(3) [wherein AO represents an oxyalkylene group having from 2 to 4 carbon atoms, q2 represents an integer of from 0 to 6, p2 represents 0 or 1, n2 represents the average number of moles of AO added and is a number of from 5 to 150, and R ７ｂ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0027] First, the structural unit (B1) will be described. １ｂ represents a hydrogen atom and one or more selected from alkali metals, alkaline earth metals (1 / 2 atoms), ammonium groups, alkylammonium groups, substituted alkylammonium groups, alkyl groups, hydroalkyl groups, and alkenyl groups. Examples of alkali metals include sodium and potassium; examples of alkaline earth metals include magnesium. Other examples include ammonium; mono-, di-, tri-, or tetra-(mono-, di-, or trialkyl)ammonium having from 2 to 8 carbon atoms, which may be substituted with a hydroxyl group; and the like. From the viewpoints of convenience and availability, alkali metals are preferred as the counter cation, and sodium is more preferred.

[0028] From the viewpoint of good short-term strength and good fluidity retention due to the component (B), R １ｂ and R ３ｂ is preferably a hydrogen atom. ２ｂ is preferably a methyl group.

[0029] There are no particular limitations on the method for introducing the structural unit (B1) into the component (B), but it is preferable to use a method represented by the general formula (B1') [In the formula, M １ｂ , R １ｂ , R ２ｂ and R ３ｂ It is preferable to polymerize a monomer represented by the following formula (I):

[0030] M of the olefin (B1′) used to introduce the structural unit (B1) １ｂCounter cations can be introduced by copolymerizing the carboxyl groups using hydrogen atoms as raw materials, and then neutralizing the carboxyl groups with an alkali metal or alkaline earth metal hydroxide, ammonia, or a mono-, di-, or tri-(alkyl having from 2 to 8 carbon atoms, which may be substituted with a hydroxyl group)amine. Alternatively, neutralization can be achieved by exchanging the hydrogen atoms of the carboxyl groups for ammonium ions using a halide or hydroxide salt of (mono-, di-, tri-, or tetra-alkyl)ammonium (which may be substituted with a hydroxyl group) having from 2 to 8 carbon atoms. From the viewpoints of corrosion inhibition and safety, it is preferable that 20 to 95% of the hydrogen atoms of the carboxyl groups are neutralized.

[0031] Next, the structural unit (B2) will be described. From the viewpoint of good short-term strength and good fluidity retention due to the component (B), the structural unit (B2) is preferably R ４ｂ and R ６ｂ is preferably a hydrogen atom, and R ５ｂ is preferably a methyl group.

[0032] Furthermore, from the standpoint of achieving good short-term strength and good fluidity retention due to component (B), a combination in which p2 and q2 in the structural unit (B2) are both 0, or q2 is 0 and p2 is 1, is preferred.

[0033] The n a of the structural unit (B2) is preferably 5 or greater, more preferably 10 or greater, even more preferably 20 or greater, and is preferably 150 or less, more preferably 140 or less, even more preferably 100 or less, and still more preferably 60 or less.

[0034] There are no particular limitations on the method for introducing the structural unit (B2) into the component (B), but it is preferable to use a method for introducing the structural unit (B2) into the component (B) represented by the general formula (B2') [In the formula, R ４ｂ , R ５ｂ , AO, q2, p2, R ６ｂ , n2 and R ７ｂ It is preferable to polymerize a monomer represented by the following formula (I):

[0035] The following olefins can be used as the monomer (B2'), for example. (1) When q2 is 1 or 2 and p2 is 0: a reaction product of allyl alcohol or methallyl alcohol with an alkylene oxide. (2) When q2 and p2 are both 0: a monoether of a polyalkylene glycol with vinyl alcohol, allyl alcohol, or methallyl alcohol, or an ether of an alkoxypolyalkylene glycol capped at one end with an alkyl group with allyl alcohol or methallyl alcohol. (3) When q2 is 0 and p2 is 1: a monoester of a polyalkylene glycol with acrylic acid or methacrylic acid, or an ester of an alkoxypolyalkylene glycol capped at one end with an alkyl group with acrylic acid or methacrylic acid, or a reaction product of acrylic acid, methacrylic acid, and an alkylene oxide.

[0036] From the viewpoint of achieving good short-term strength of the hydraulic composition and good fluidity retention due to component (B), the ratio of the content of structural unit (B1) to the total content of structural unit (B1) and structural unit (B2) is 5% by mass or more, preferably 7% by mass or more, and from the same viewpoint, 30% by mass or less, preferably 25% by mass or less. This ratio is calculated by [content of structural unit (B1) (parts by mass) / [content of structural unit (B1) (parts by mass) + content of structural unit (B2) (parts by mass)]] × 100 (% by mass). Note that the ratio of the structural units referred to here may be the ratio of the raw material monomers derived from each structural unit in the copolymer, i.e., the ratio of the raw material monomers used to produce the copolymer may be equal to the ratio of the structural units contained in the copolymer. Furthermore, the ratio of each structural unit may be the average value of each structural unit contained in the entire copolymer.

[0037] The copolymer of component (B) may also contain a structural unit other than the structural units (B1) and (B2) [hereinafter, also referred to as structural unit (B3)]. Examples of the structural unit (B3) include structural units introduced by copolymerizing one or more acrylic acid monomers selected from 2-(methacryloyloxy)ethyl phosphate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, methyl acrylate, ethyl acrylate, acrylonitrile, methallylsulfonic acid, acrylamide, methacrylamide, styrene, styrenesulfonic acid, di-[2-(1-methylvinylcarbonyl)ethyl]phosphate, di-[2-(vinylcarbonyl)ethyl]phosphate, [2-(1-methylvinylcarbonyl)ethyl]phosphate, [2-(vinylcarbonyl)ethyl]acrylate, crotonic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid. These acrylic acid monomers may be in the form of alkali metal salts, alkaline earth metal salts, ammonium salts, or amine salts, or may be acid anhydrides such as maleic anhydride.

[0038] From the viewpoint of achieving good short-term strength and good fluidity retention due to component (B), the proportion of the total content of structural units (B1) and structural units (B2) relative to the content of component (B) is preferably at least 80% by mass, more preferably at least 90% by mass, and from the same viewpoint, is preferably at most 100% by mass. This proportion is calculated by [[content of component (B1) + content of component (B2) / [content of component (B)]] × 100 (% by mass).

[0039] From the viewpoint of good fluidity retention, the copolymer of component (B) preferably has a weight-average molecular weight of 10,000 or more, more preferably 15,000 or more, and from the same viewpoint, preferably 100,000 or less, more preferably 90,000 or less. This weight-average molecular weight can be measured in the same manner as for component (A).

[0040] The ratio of the content of component (A) to the total content of component (A) and component (B) in the additive of the present invention is 1% by mass or more, preferably 2% by mass or more, from the viewpoint of good short-term strength and good fluidity retention due to component (B). From the same viewpoint, it is preferably 5% by mass or less, more preferably 4% by mass or less. Furthermore, from the viewpoint of good fluidity retention, the ratio of the content of component (A) to the total content of component (A) and component (B) in the additive is preferably 5% by mass or more. This ratio is calculated by [[content of component (A)] / [content of component (A) + content of component (B)] × 100 (% by mass).

[0041] The additive of the present invention may contain, as optional components, components such as retarders, hardening accelerators, air-enhancing agents, expansion agents, foaming agents, thickeners, fluidizing agents, foaming agents, waterproofing agents, and antifoaming agents (excluding those corresponding to components (A) and (B)).

[0042] The additive of the present invention can be blended with water. The additive for clay-containing hydraulic compositions of the present invention may be a liquid composition.

[0043] In the additive of the present invention, from the viewpoint of short-term strength and fluidity retention, the ratio of the total content of component (A) and component (B) to the additive excluding water is preferably 50% by mass or more, more preferably 70% by mass or more, and from the same viewpoint, is preferably 100% by mass or less, more preferably 90% by mass or less.

[0044] The clay-containing additive for hydraulic compositions of the present invention is used in hydraulic compositions containing clay. Examples of clay include bentonite, montmorillonite, kaolinite, smectite, etc., and also include mixtures of two or more of these. The clay is mixed into the hydraulic composition together with raw materials for producing the hydraulic composition, such as aggregate.

[0045] <Clay-containing hydraulic composition> The present invention provides a clay-containing hydraulic composition comprising a hydraulic powder, aggregate, clay, water, and the additive, wherein the ratio of the clay content to the aggregate content is 1% by mass or more and 5% by mass or less, and the ratio of the content of component (A) to the total content of component (A) and component (B) is 1% by mass or more.

[0046] The matters described in the additive for a clay-containing hydraulic composition of the present invention can be applied as appropriate to the clay-containing hydraulic composition of the present invention. For example, specific examples and preferred embodiments of the components (A) and (B) in the clay-containing hydraulic composition of the present invention are the same as those in the additive for a clay-containing hydraulic composition of the present invention. Furthermore, the preferred range of the ratio of the content of the component (A) to the total content of the components (A) and (B) in the clay-containing hydraulic composition of the present invention is also the same as that in the additive for a clay-containing hydraulic composition of the present invention.

[0047] In the clay-containing hydraulic composition of the present invention, from the viewpoint of achieving good short-term strength and good fluidity retention due to component (B), the ratio of the amount of component (A) to the total amount of component (A) and component (B) is preferably 1% by mass or more, more preferably 2% by mass or more, and from the same viewpoint, is preferably 5% by mass or less, more preferably 4% by mass or less. Furthermore, from the viewpoint of achieving good fluidity retention, the ratio of the content of component (A) to the total content of component (A) and component (B) in the additive is preferably 5% by mass or more. This ratio can be calculated by [[amount of component (A)] / [amount of component (A) + amount of component (B)] × 100 (% by mass).

[0048] Here, hydraulic powder refers to a powder that hardens upon hydration, such as cement or gypsum. Preferred examples 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 include pozzolanic and / or latent hydraulic powders, such as blast furnace slag, fly ash, and silica fume, or powders containing stone powder (calcium carbonate powder), such as blast furnace slag cement, fly ash cement, and silica fume cement. When the hydraulic powder includes powders that harden upon hydration, such as cement, as well as powders selected from pozzolanic powders, latent hydraulic powders, and stone powder (calcium carbonate powder), the amounts of these powders are also included in the amount of hydraulic powder in this invention. Furthermore, when the powder that hardens upon hydration contains a high-strength admixture, the amount of the high-strength admixture is also included in the amount of hydraulic powder. This also applies to parts by mass, mass ratios, etc., which are related to the mass of the hydraulic powder.

[0049] Examples of aggregates include those selected from fine aggregates and coarse aggregates. Examples of fine aggregates include those specified under number 2311 in JIS A0203-2014. Examples of fine aggregates include river sand, land sand, mountain sand, sea sand, lime sand, silica sand, and crushed sands thereof, blast furnace slag fine aggregate, ferronickel slag fine aggregate, lightweight fine aggregate (artificial and natural), and recycled fine aggregate. Examples of coarse aggregates include those specified under number 2312 in JIS A0203-2014. Examples of coarse aggregates include river gravel, land gravel, mountain gravel, sea gravel, lime gravel, crushed stones thereof, blast furnace slag coarse aggregate, ferronickel slag coarse aggregate, lightweight coarse aggregate (artificial and natural), and recycled coarse aggregate. Different types of fine aggregates and coarse aggregates may be mixed, or a single type may be used.

[0050] Generally, when clay components are mixed into concrete or mortar, the amount of additives required is increased, which leads to problems such as increased costs, delayed setting, decreased strength, increased bleeding, and aggregate settling immediately after mixing. However, due to the recent deterioration of aggregate conditions, the use of aggregate with clay attached may be unavoidable. The clay-containing hydraulic composition of the present invention has a clay content ratio of, for example, 0.03% by mass or more, or 0.1% by mass or more, or even 0.5% by mass or more relative to the aggregate content. Even when using aggregates containing, for example, 5% by mass or less, 4% by mass or less, or even 3% by mass or less, the hydraulic composition can still be imparted with excellent fluidity. In the present invention, the amount of bentonite in the aggregate measured according to JIS Z 2451:2019 (spot method) can be used as the clay content in the aggregate. This ratio can be calculated by [clay content] / [aggregate content] × 100 (mass%).

[0051] In the clay-containing hydraulic composition of the present invention, from the viewpoint of achieving good short-term strength and fluidity retention due to component (B), the ratio of the amount of component (A) to the amount of clay is preferably 0.25% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.4% by mass or more, and from the same viewpoint, is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. This ratio can be calculated by [[amount of component (A)] / [clay content]]×100 (% by mass).

[0052] In the clay-containing hydraulic composition of the present invention, from the viewpoint of achieving good short-term strength and good fluidity retention due to component (B), the ratio of the amount of component (A) to the amount of hydraulic powder is preferably at least 0.01 part by mass, more preferably at least 0.015 part by mass, and even more preferably at least 0.02 part by mass, and from the same viewpoint, is preferably at most 0.25 part by mass, more preferably at most 0.2 part by mass, and even more preferably at most 0.15 part by mass. This ratio can be calculated by [[amount of component (A)] / [amount of hydraulic powder]]×100 (% by mass).

[0053] In the clay-containing hydraulic composition of the present invention, from the viewpoint of good fluidity retention, the ratio of the amount of component (B) to the amount of hydraulic powder is preferably 0.05% by mass or more, more preferably 0.075% by mass or more, and even more preferably 0.1% by mass or more, and from the same viewpoint, it is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, and even more preferably 0.3% by mass or less. This ratio can be calculated by [[amount of component (B)] / [amount of hydraulic powder]]×100 (% by mass).

[0054] Furthermore, in the clay-containing hydraulic composition of the present invention, from the viewpoint of achieving good short-term strength and good fluidity retention due to component (B), the ratio of the total amount of component (A) and component (B) to the amount of hydraulic powder is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, and even more preferably 0.2% by mass or more, and from the same viewpoint, is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, and even more preferably 0.35% by mass or less. This ratio can be calculated by [[amount of component (A) + amount of component (B)] / [amount of hydraulic powder]] × 100 (% by mass).

[0055] The clay-containing hydraulic composition of the present invention has a water / hydraulic powder ratio (mass percentage (mass %) of water to hydraulic powder in the slurry, usually abbreviated as W / P, but when the hydraulic powder is cement, abbreviated as W / C) of preferably 15% or more, more preferably 25% or more, from the viewpoints of strength development and workability, and from the same viewpoint, preferably 70% or less, more preferably 50% or less.

[0056] When the clay-containing hydraulic composition is concrete, the amount of coarse aggregate used is preferably 50% or more, more preferably 55% or more, and even more preferably 60% or more in terms of the strength of the hydraulic composition, reducing the amount of hydraulic powder such as cement used, and improving the fillability into forms, and from the same viewpoint, is preferably 100% or less, more preferably 90% or less, and even more preferably 80% or less. ３In addition, when the clay-containing hydraulic composition is concrete, the amount of fine aggregate used is preferably 500 kg / m from the viewpoint of improving the filling property into a formwork or the like. ３ More preferably, 600 kg / m ３ More preferably, 700 kg / m ３ From the same viewpoint, it is preferably 1,000 kg / m ３ or less, more preferably 900 kg / m ３ When the clay-containing hydraulic composition is a mortar, the amount of fine aggregate used is preferably 800 kg / m from the viewpoint of improving the filling property into a formwork or the like. ３ More preferably, 900 kg / m ３ More preferably, 1,000 kg / m ３ From the same viewpoint, it is preferably 2,000 kg / m ３ or less, more preferably 1,800 kg / m ３ More preferably, 1,700 kg / m or less ３ The following is the result.

[0057] The clay-containing hydraulic composition of the present invention may contain, as optional components, components such as retarders, hardening accelerators, air-enhancing agents, expanding agents, foaming agents, thickeners, fluidizing agents, foaming agents, waterproofing agents, and antifoaming agents (excluding those corresponding to components (A) and (B)).

[0058] The clay-containing hydraulic composition of the present invention can be hardened by a known method to obtain a hardened product. The hardening of the hydraulic composition can be carried out taking into consideration the use, shape, etc. of the hardened product.

[0059] <Method for producing clay-containing hydraulic composition> The present invention provides a method for producing a clay-containing hydraulic composition by mixing hydraulic powder, aggregate, clay, water, the component (A) and the component (B), wherein the ratio of the amount of clay mixed to the amount of aggregate mixed is 1% by mass or more and 5% by mass or less, and the ratio of the amount of component (A) mixed to the total amount of component (A) mixed and the amount of component (B) mixed is 1% by mass or more.

[0060] The matters described for the additive and clay-containing hydraulic composition of the present invention can be applied as appropriate to the method for producing the clay-containing hydraulic composition of the present invention. Specific examples and preferred embodiments of the hydraulic powder, aggregate, clay, component (A), component (B), and optional components used in the method for producing the clay-containing hydraulic composition of the present invention are the same as those for the additive for hydraulic compositions and the hydraulic composition of the present invention. Furthermore, the contents of each component in the additive for hydraulic compositions and the clay-containing hydraulic composition of the present invention can be expressed as the mixing amounts, and the preferred ranges can be applied to the method for producing the clay-containing hydraulic composition of the present invention.

[0061] In the method for producing a clay-containing hydraulic composition of the present invention, from the viewpoints of adsorption to clay and suppression of hetero-aggregation, the ratio of the amount of component (A) mixed to the total amount of component (A) mixed and component (B) mixed is preferably 1% by mass or more, more preferably 2% by mass or more, and from the same viewpoint, is preferably 5% by mass or less, more preferably 4% by mass or less. Furthermore, from the viewpoint of good fluidity retention, the ratio of the content of component (A) to the total content of component (A) and component (B) in the additive is preferably 5% by mass or more, more preferably 5% by mass or more. This ratio (mass%) is calculated by [[amount of component (A)] / [amount of component (A) mixed + amount of component (B)] x 100].

[0062] The method for producing the clay-containing hydraulic composition of the present invention is not limited to the order in which the components are mixed. However, a more convenient method for achieving a high effect is to mix the hydraulic powder with the clay-containing aggregate, and then mix the mixture containing the components (A) and (B) and water. For example, the hydraulic powder, coarse aggregate, and fine aggregate are mixed for a predetermined time, for example, from 5 to 60 seconds, and then the mixture is mixed with the mixture containing the components (A) and (B) and water. Mixing can be performed using a known mixer. The mixture may be an aqueous solution or an aqueous suspension.

[0063] In the method for producing a clay-containing hydraulic composition of the present invention, component (A) and component (B) can be mixed with the hydraulic powder so that their respective concentrations fall within the ranges described for the clay-containing hydraulic composition of the present invention. That is, in the method for producing a clay-containing hydraulic composition of the present invention, the ratio of the amount of component (A) mixed with the hydraulic powder to the amount of hydraulic powder is preferably 0.01% by mass or more, more preferably 0.015% by mass or more, even more preferably 0.02% by mass or more, and preferably 0.25% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.15% by mass or less. In addition, in the method for producing a clay-containing hydraulic composition of the present invention, the ratio of the amount of component (B) mixed with the hydraulic powder to the amount of hydraulic powder is preferably 0.05% by mass or more, more preferably 0.075% by mass or more, even more preferably 0.1% by mass or more, and preferably 0.5% by mass or less, more preferably 0.4% by mass or less, and even more preferably 0.3% by mass or less. Furthermore, in the method for producing a clay-containing hydraulic composition of the present invention, the total amount of the mixed amount of component (A) and the mixed amount of component (B) relative to the amount of hydraulic powder is preferably 0.1 mass% or more, more preferably 0.15 mass% or more, even more preferably 0.2 mass% or more, and is preferably 0.5 mass% or less, more preferably 0.4 mass% or less, even more preferably 0.3 mass% or less.

[0064] In the method for producing the clay-containing hydraulic composition of the present invention, optional components such as retarders, hardening accelerators, air-enhancing agents, expanding agents, foaming agents, thickeners, fluidizing agents, foaming agents, waterproofing agents, and antifoaming agents (excluding those corresponding to components (A) and (B)) can be mixed.

[0065] In the method for producing the clay-containing hydraulic composition of the present invention, from the viewpoint of workability, water and hydraulic powder may be mixed so that the water / hydraulic powder ratio (mass %) is preferably 15% or more, more preferably 25% or more, and from the same viewpoint, the water / hydraulic powder ratio may be mixed so that the water / hydraulic powder ratio is preferably 70% or less, more preferably 50% or less.

[0066] <Use of additive containing component (A) in clay-containing hydraulic composition> The present invention discloses the use of an additive containing component (A) (also referred to as additive 2) in a clay-containing hydraulic composition.

[0067] The component (A) is a copolymer having a structural unit (A1) represented by the following general formula (A1) and a structural unit (A2) represented by the following general formula (A2), in which the content of the structural unit (A1) relative to the total content of the structural unit (A1) and the structural unit (A2), expressed by [content of structural unit (A1) / [content of structural unit (A1) + content of structural unit (A2)]] × 100 (mass%), is 0.1% by mass or more and 4.5% by mass or less, and the copolymer has a weight average molecular weight of 10,000 or more and 100,000 or less.

[0068] [In the formula, R １ａ and R ２ａ are the same or different and each represents a hydrogen atom or a methyl group. ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents one or more selected from a hydrogen atom and a counter cation. １ represents an alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group. ２ CH ２ O-), and is a number of 5 or more and 99 or less.

[0069] First, the structural unit (A1) will be described. １ represents a hydrogen atom and one or more selected from alkali metals, alkaline earth metals (1 / 2 atoms), ammonium groups, alkylammonium groups, substituted alkylammonium groups, alkyl groups, hydroalkyl groups, and alkenyl groups. Examples of alkali metals include sodium and potassium; examples of alkaline earth metals include magnesium. Other examples include ammonium; mono-, di-, tri-, or tetra-(mono-, di-, or trialkyl)ammonium having from 2 to 8 carbon atoms, which may be substituted with a hydroxyl group; and the like. From the viewpoints of convenience and availability, alkali metals are preferred, and sodium is more preferred.

[0070] There are no particular limitations on the method for introducing the structural unit (A1) into the component (A), but it is preferable to use a method represented by general formula (A1′): [In the formula, R １ａ and M １ It is preferable to polymerize a monomer represented by the following formula (I):

[0071] M of the monomer (A1′) used to introduce the structural unit (A1) １ Counter cations can be introduced by copolymerizing the carboxyl groups using hydrogen atoms as raw materials, and then neutralizing the carboxyl groups with an alkali metal or alkaline earth metal hydroxide, ammonia, or a mono-, di-, or tri-(alkyl having from 2 to 8 carbon atoms, which may be substituted with a hydroxyl group)amine. Alternatively, neutralization can be achieved by exchanging the hydrogen atoms of the carboxyl groups for ammonium ions using a halide or hydroxide salt of (mono-, di-, tri-, or tetra-alkyl)ammonium (which may be substituted with a hydroxyl group) having from 2 to 8 carbon atoms. From the viewpoints of corrosion inhibition and safety, it is preferable that 20 to 95% of the hydrogen atoms of the carboxyl groups are neutralized.

[0072] Next, the structural unit (A2) will be described. From the viewpoint of good fluidity retention, R ２ａ is preferably a methyl group. １ is preferably a direct bond or a carbonyl group, more preferably a carbonyl group. In formula (A2), n a is preferably 5 or more, more preferably 7 or more, even more preferably 10 or more, and from the same viewpoint, is preferably 99 or less, more preferably 80 or less, even more preferably 70 or less.

[0073] There are no particular limitations on the method for introducing the structural unit (A2) into the component (A), but it is preferable to use a method for introducing the structural unit (A2) into a compound represented by general formula (A2') [In the formula, R ２ａ , R ３ａ , X １ and na are the same as above.] is preferably used as a raw material for polymerization.

[0074] More specifically, the following olefins can be used as the monomer (A2'): (1) X １When X is an alkylene group: a reaction product of allyl alcohol, isoprenyl alcohol, or methallyl alcohol with ethylene oxide. (2) X １ is a direct bond: a monoether of polyethylene glycol with vinyl alcohol, allyl alcohol, isoprenyl alcohol or methallyl alcohol, or an ether of alkoxypolyethylene glycol, one end of which is capped with an alkyl group, with allyl alcohol, isoprenyl alcohol or methallyl alcohol. (3) X １ is a carbonyl group: a monoester of polyethylene glycol with acrylic acid or methacrylic acid, an ester of alkoxypolyethylene glycol capped at one end with an alkyl group with acrylic acid or methacrylic acid, or a reaction product of acrylic acid, methacrylic acid, and ethylene oxide.

[0075] In the copolymer of component (A), from the viewpoint of good fluidity retention, the ratio of the content of the structural unit (A1) to the total content of the structural unit (A1) and the structural unit (A2) is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and from the same viewpoint, it is preferably 4.5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less, and even more preferably 2% by mass or less. This ratio is calculated by [content of structural unit (A1) / [content of structural unit (A1) + content of structural unit (A2)]] × 100 (mass%). Note that the proportion of the structural units referred to here refers to the proportion of the raw material monomer derived from each structural unit in the copolymer, i.e., the ratio of the raw material monomer charge ratio when producing the copolymer may be equal to the structural unit contained in the copolymer. Furthermore, the proportion of each structural unit may be the average value of each structural unit contained in the entire copolymer.

[0076] In order to achieve good fluidity retention, the copolymer of component (A) preferably has a content of structural unit (A2) relative to the total content of structural unit (A1) and structural unit (A2) of 95.5% by mass or more, more preferably 96% by mass or more, even more preferably 97% by mass or more, and even more preferably 98% by mass or more, and from the same viewpoint, preferably 99.9% by mass or less, more preferably 99.8% by mass or less. This proportion is calculated by [content of structural unit (A2) / [content of structural unit (A1) + content of structural unit (A2)]] × 100 (% by mass).

[0077] The copolymer of component (A) may contain a structural unit other than the structural units (A1) and (A2) [hereafter referred to as structural unit (A3)]. Examples of the structural unit (A3) include structural units introduced by copolymerizing one or more acrylic acid monomers selected from 2-(methacryloyloxy)ethyl phosphate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, methyl acrylate, ethyl acrylate, acrylonitrile, methallylsulfonic acid, acrylamide, methacrylamide, styrene, styrenesulfonic acid, di-[2-(1-methylvinylcarbonyl)ethyl]phosphate, di-[2-(vinylcarbonyl)ethyl]phosphate, [2-(1-methylvinylcarbonyl)ethyl]phosphate, [2-(vinylcarbonyl)ethyl]acrylate, crotonic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid. These acrylic acid monomers may be in the form of alkali metal salts, alkaline earth metal salts, ammonium salts, or amine salts, or may be acid anhydrides such as maleic anhydride.

[0078] From the viewpoint of achieving good fluidity retention, the proportion of the total content of the structural units (A1) and (A2) relative to the content of the component (A) is preferably at least 80% by mass, more preferably at least 90% by mass, and from the same viewpoint, is preferably at most 100% by mass. This proportion is calculated by [[content of component (A1) + content of component (A2) / [content of component (A)]] × 100 (% by mass).

[0079] The copolymer of component (A) preferably has a weight-average molecular weight of 10,000 or more, more preferably 30,000 or more, from the viewpoint of good fluidity retention, and from the same viewpoint, preferably 100,000 or less, more preferably 80,000 or less. This weight-average molecular weight was measured using a high-performance GPC (HLC-8320GPC, manufactured by Tosoh Corporation) with an RI detector, G4000PWXL and G2500PWXL (anion) columns, a mobile phase of 0.2 M phosphate buffer / acetonitrile (9 / 1), a flow rate of 1.0 mL / min, a column temperature of 40°C, and polyethylene glycol as the standard.

[0080] Additive 2 may contain optional components such as retarders, hardening accelerators, air-enhancing agents, expansion agents, foaming agents, thickeners, fluidizing agents, foaming agents, waterproofing agents, and antifoaming agents (excluding those corresponding to component (A)).

[0081] Water can be blended with Additive 2. The additive for clay-containing hydraulic compositions of the present invention may be a liquid composition.

[0082] Additive 2 is used in hydraulic compositions containing clay. Examples of clay include bentonite, montmorillonite, kaolinite, smectite, etc., and also includes mixtures of two or more of these. Clay is mixed into the hydraulic composition together with raw materials for producing the hydraulic composition, such as aggregate.

[0083] Additive 2 can be used in a clay-containing hydraulic composition containing hydraulic powder, aggregate, clay, water, and the additive.

[0084] Here, hydraulic powder refers to a powder that hardens upon hydration, such as cement or gypsum. Preferred examples 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 include pozzolanic and / or latent hydraulic powders, such as blast furnace slag, fly ash, and silica fume, or powders containing stone powder (calcium carbonate powder), such as blast furnace slag cement, fly ash cement, and silica fume cement. When the hydraulic powder includes powders that harden upon hydration, such as cement, as well as powders selected from pozzolanic powders, latent hydraulic powders, and stone powder (calcium carbonate powder), the amounts of these powders are also included in the amount of hydraulic powder in this invention. Furthermore, when the powder that hardens upon hydration contains a high-strength admixture, the amount of the high-strength admixture is also included in the amount of hydraulic powder. This also applies to parts by mass, mass ratios, etc., which are related to the mass of the hydraulic powder.

[0085] Examples of aggregates include those selected from fine aggregates and coarse aggregates. Examples of fine aggregates include those specified under number 2311 in JIS A0203-2014. Examples of fine aggregates include river sand, land sand, mountain sand, sea sand, lime sand, silica sand, and crushed sands thereof, blast furnace slag fine aggregate, ferronickel slag fine aggregate, lightweight fine aggregate (artificial and natural), and recycled fine aggregate. Examples of coarse aggregates include those specified under number 2312 in JIS A0203-2014. Examples of coarse aggregates include river gravel, land gravel, mountain gravel, sea gravel, lime gravel, crushed stones thereof, blast furnace slag coarse aggregate, ferronickel slag coarse aggregate, lightweight coarse aggregate (artificial and natural), and recycled coarse aggregate. Different types of fine aggregates and coarse aggregates may be mixed, or a single type may be used.

[0086] Generally, when clay components are mixed into concrete or mortar, a large amount of additive 2 must be added. However, increasing the amount of additive increases costs, delays setting, reduces strength, increases bleeding, and causes aggregate settling immediately after mixing. However, due to the recent deterioration of aggregate conditions, the use of aggregate with clay attached is sometimes unavoidable. Clay-containing hydraulic compositions have a clay content of, for example, 0.03% by mass or more, 0.1% by mass or more, or even 0.5% by mass or more relative to the aggregate content. Even when aggregate is used at a clay content of, for example, 5% by mass or less, 4% by mass or less, or even 3% by mass or less, excellent fluidity can be imparted to the hydraulic composition. In the present invention, the amount of bentonite in the aggregate measured according to JIS Z 2451:2019 (spot method) can be used as the clay content in the aggregate. This ratio can be calculated by [clay content] / [aggregate content] × 100 (mass%).

[0087] In the clay-containing hydraulic composition, from the viewpoint of good fluidity retention, the ratio of the content of component (A) to the content of clay is preferably 0.25% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.4% by mass or more, and from the same viewpoint, it is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. This ratio can be calculated by [[content of component (A)] / [content of clay]]×100 (% by mass).

[0088] In order to provide a clay-containing hydraulic composition with good fluidity retention, the ratio of the amount of component (A) to the amount of hydraulic powder is preferably at least 0.01 part by mass, more preferably at least 0.015 part by mass, and even more preferably at least 0.02 part by mass, and from the same viewpoint, is preferably at most 0.25 part by mass, more preferably at most 0.2 part by mass, and even more preferably at most 0.15 part by mass. This ratio can be calculated by [[amount of component (A)] / [amount of hydraulic powder]]×100 (% by mass).

[0089] The clay-containing hydraulic composition has a water / hydraulic powder ratio (mass percentage (mass%) of water to hydraulic powder in the slurry, usually abbreviated as W / P, but when the hydraulic powder is cement, abbreviated as W / C) of preferably 15% or more, more preferably 25% or more, from the viewpoints of strength development and workability, and from the same viewpoint, preferably 70% or less, more preferably 50% or less.

[0090] When the clay-containing hydraulic composition is concrete, the amount of coarse aggregate used is preferably 50% or more, more preferably 55% or more, and even more preferably 60% or more in terms of the strength of the hydraulic composition, reducing the amount of hydraulic powder such as cement used, and improving the fillability into forms, and from the same viewpoint, is preferably 100% or less, more preferably 90% or less, and even more preferably 80% or less. ３ In addition, when the clay-containing hydraulic composition is concrete, the amount of fine aggregate used is preferably 500 kg / m from the viewpoint of improving the filling property into a formwork or the like. ３ More preferably, 600 kg / m ３ More preferably, 700 kg / m ３ From the same viewpoint, it is preferably 1,000 kg / m ３ or less, more preferably 900 kg / m ３ When the clay-containing hydraulic composition is a mortar, the amount of fine aggregate used is preferably 800 kg / m from the viewpoint of improving the filling property into a formwork or the like. ３ More preferably, 900 kg / m ３ More preferably, 1,000 kg / m ３ From the same viewpoint, it is preferably 2,000 kg / m ３ or less, more preferably 1,800 kg / m ３ More preferably, 1,700 kg / m or less ３ It may be the following:

[0091] In order to ensure good fluidity retention, the clay-containing hydraulic composition preferably contains 0.1% by mass or more of component (A) relative to the amount of hydraulic powder, more preferably 0.15% by mass or more, and even more preferably 0.2% by mass or more, and from the same viewpoint, preferably 0.5% by mass or less, more preferably 0.4% by mass or less, and even more preferably 0.35% by mass or less. This ratio can be calculated by [[amount of component (A)] / [amount of hydraulic powder]]×100 (% by mass).

[0092] The clay-containing hydraulic composition has a water / hydraulic powder ratio (mass percentage (mass%) of water to hydraulic powder in the slurry, usually abbreviated as W / P, but when the hydraulic powder is cement, abbreviated as W / C) of preferably 15% or more, more preferably 25% or more, from the viewpoints of strength development and workability, and from the same viewpoint, preferably 70% or less, more preferably 50% or less.

[0093] The clay-containing hydraulic composition may contain, as optional components, components such as retarders, hardening accelerators, air-enhancing agents, expanding agents, foaming agents, thickeners, fluidizing agents, foaming agents, waterproofing agents, and antifoaming agents (excluding those corresponding to component (A)).

[0094] A clay-containing hydraulic composition can be hardened by a known method to obtain a hardened product. The hardening of the hydraulic composition can be carried out taking into consideration the use, shape, etc. of the hardened product.

[0095] The matters described for Additive 2 and the clay-containing hydraulic composition can be applied as appropriate to the method for producing the clay-containing hydraulic composition. Specific examples and preferred embodiments of the hydraulic powder, aggregate, clay, component (A), and optional components used in the method for producing the clay-containing hydraulic composition of the present invention are the same as those for the additive for clay-containing hydraulic compositions and the clay-containing hydraulic composition of the present invention. Furthermore, the contents of each component in the additive for clay-containing hydraulic compositions and the clay-containing hydraulic composition of the present invention can be converted into the mixing amounts, and the preferred ranges can be applied to the method for producing the clay-containing hydraulic composition of the present invention.

[0096] The method for producing a clay-containing hydraulic composition is not limited to the order in which the components are mixed. However, a method for more easily achieving a high effect includes, for example, mixing a hydraulic powder with a clay-containing aggregate, followed by mixing with a kneading liquid containing component (A) and water. For example, a method includes mixing a hydraulic powder with a coarse aggregate and a fine aggregate for a predetermined time, for example, from 5 to 60 seconds, and then mixing with a kneading liquid containing component (A) and water. Mixing can be performed using a known mixer. The kneading liquid may be an aqueous solution or an aqueous suspension.

[0097] In the method for producing the clay-containing hydraulic composition of the present invention, component (A) can be mixed with the hydraulic powder so that the respective amounts fall within the ranges described for the clay-containing hydraulic composition of the present invention. That is, in the method for producing the clay-containing hydraulic composition, the ratio of the amount of component (A) mixed with respect to the amount of hydraulic powder is preferably 0.01% by mass or more, more preferably 0.015% by mass or more, even more preferably 0.02% by mass or more, and is preferably 0.25% by mass or less, more preferably 0.2% by mass or less, even more preferably 0.15% by mass or less.

[0098] In the method for producing a clay-containing hydraulic composition, optional components such as retarders, hardening accelerators, air-enhancing agents, expanding agents, foaming agents, thickeners, fluidizing agents, foaming agents, waterproofing agents, and antifoaming agents (excluding those corresponding to component (A)) can be mixed.

[0099] In the method for producing the clay-containing hydraulic composition, from the viewpoint of workability, the water and hydraulic powder may be mixed so that the water / hydraulic powder ratio (mass %) is preferably 15% or more, more preferably 25% or more, and from the same viewpoint, is preferably 70% or less, more preferably 50% or less.

[0100] The following monomers were used as raw materials for producing the copolymers of components (A) and (B): Components (A1) and (B1): methacrylic acid Component (A2): Methacrylic acid MEPEG (na) ester: an ester of methacrylic acid and polyethylene glycol monomethyl ether having an average number of moles of oxyethylene groups added of na (na = 9 or 23) Component (B2): Methacrylic acid MEPEG (nb) ester: an ester of methacrylic acid and polyethylene glycol monomethyl ether having an average number of moles of oxyethylene groups added of nb (nb = 23 or 120) Component (A3): methyl acrylate

[0101] Copolymer A-1 was produced as follows. 340.8 g of water was placed in a glass reaction vessel equipped with a stirrer, and the mixture was purged with nitrogen while stirring and heated to 80°C in a nitrogen atmosphere. A mixture of 618.4 g of an aqueous solution containing MEPEG (23) methacrylate and methacrylic acid (MEPEG (23) methacrylate content: 371.1 g, methacrylic acid content: 3.2 g, neutralized salt of the acid catalyst used in esterification: 25.8 g, water: 218.3 g) and 1.06 g of 3-mercaptopropionic acid, and a solution of 1.27 g of ammonium persulfate in 25 g of water were each added dropwise to the vessel over 1.5 hours. Next, a solution of 0.42 g of ammonium persulfate in 10.00 g of water was added dropwise over 30 minutes, and the mixture was then aged at the same temperature (80°C) for 1 hour. After the aging was completed, the mixture was neutralized with 1.24 g of a 48% aqueous solution of sodium hydroxide to obtain a reaction product containing water and copolymer A-1 having a weight average molecular weight of 47,000.

[0102] In the same manner as in the above-mentioned Production Example A-1, the following components (A) and (B) were produced by changing the types and amounts of the monomers used.

[0103] <Component (A)> A-1: ​​A copolymer of methacrylic acid / methacrylic acid MEPEG (23) ester=1 / 99 (mass%) (weight average molecular weight 47,000) in which a portion of the carboxy groups has been neutralized with sodium hydroxide to form the Na salt. A-2: A copolymer of methacrylic acid / methacrylic acid MEPEG (9) ester=1 / 99 (mass%) (weight average molecular weight 45,000) in which a portion of the carboxy groups has been neutralized with sodium hydroxide to form the Na salt. A-3: A copolymer of methacrylic acid / methacrylic acid MEPEG (23) ester / methyl acrylate=1 / 94 / 5 (mass%) (weight average molecular weight 37,000) in which a portion of the carboxy groups has been neutralized with sodium hydroxide to form the Na salt. A-4: A copolymer (weight average molecular weight 22,000) of methacrylic acid / methacrylic acid MEPEG (9) ester / methyl acrylate = 1 / 89 / 10 (mass%), in which some of the carboxyl groups were neutralized with sodium hydroxide to form the Na salt.

[0104] <Component (B)> B-1: A copolymer (weight average molecular weight 45,000) of methacrylic acid / methacrylic acid MEPEG (23) ester=17 / 83 (mass %), in which some of the carboxy groups have been neutralized with sodium hydroxide to form a Na salt.

[0105] Furthermore, as comparative substances for component (A), copolymer A'-1 in which component (A2) had an NA of 120 and polymer A'-2 not containing component (A1) were also obtained in the same manner as in the Production Examples. A'-1: A copolymer of methacrylic acid / methacrylic acid MEPEG (120) ester = 3 / 97 (mass%) (weight average molecular weight 70,000) in which some of the carboxy groups were neutralized with sodium hydroxide to form the Na salt. A'-2: A polymer of methacrylic acid MEPEG (23) ester (weight average molecular weight 39,000).

[0106] <Preparation of Clay-Containing Hydraulic Composition Additive> Components (A) and (B) were mixed so that the amounts added to the clay-containing hydraulic composition were as shown in Table 1 to prepare additives for clay-containing hydraulic compositions. Components (A) and (B) were each used as 40% by mass aqueous solutions. The amounts of components (A) and (B) added were such that the initial flow value of the composition immediately after kneading was 200 mm, as measured by the JIS R 5201 test method (flow test) using a 100 mm diameter conical container. For each additive, 5 g of a 1% by mass aqueous solution was added to 100 parts by mass of antifoaming agent No. 21 (manufactured by Kao Corporation) additive for hydraulic compositions.

[0107] <Mortar Preparation> Using a mortar mixer (Nishi Nippon Shikenki Co., Ltd., Universal Mixer Agitator, Model: C-210, Small Mortar Mixer), cement (C) and fine aggregate (S) were charged and dry-mixed for 10 seconds at a low rotation speed (63 rpm). The prepared clay-containing hydraulic composition additive was then added to the mixing water (W). The mixture was then fully mixed for 120 seconds at a low rotation speed (63 rpm) to prepare mortar. The mortar formulation conditions for all mortar temperatures were 400 g of cement (C), 680 g of fine aggregate (S), and 20 g of Kasaoka clay, with a water-to-cement ratio (W / C) of 35% by mass. The clay-containing hydraulic composition additive was added to the mixing water so that the contents of components (A) and (B) per 100 parts by mass of cement were as shown in Table 1. In this example, it is assumed that the fine aggregate contains 2.9% by mass of clay (Kasaoka clay).

[0108] The components used in preparing the mortar were as follows: Water (W): tap water Cement (C): ordinary Portland cement (two-type mixture: Taiheiyo Cement Co., Ltd. / Sumitomo Osaka Cement Co., Ltd. = 1 / 1 (mass ratio)) Density: 3.16 g / cm ３ ・Fine aggregate (S): Mountain sand from Joyo, density 2.55g / cm ３ Kasaoka clay (clay mainly composed of bentonite, manufactured by Kasanen Kogyo) Density 2.70 g / cm ３

[0109] <Evaluation of Mortar Fluidity> The kneaded compositions were placed in a conical container with a diameter of 100 mm. After 20 minutes, the fluidity of each composition was evaluated according to the test method (flow test) of JIS R 5201, and the value was shown as the flow value after 20 minutes. The retention rate was calculated and shown using the following formula: Retention rate = [Flow value after 20 minutes] ÷ [Flow value (200 mm) immediately after kneading] × 100 (%). The higher the retention rate value, the better the fluidity immediately after kneading was maintained. The fluidity retention rate was calculated as a retention ratio using the flow value after 20 minutes of 136 mm for a composition (Comparative Example 1-1) containing only component (B) without component (A) as the standard (Comparative Example 1-1). Retention ratio = [(flow value after 20 minutes for each Example or Comparative Example) - 100] ÷ [(flow value after 20 minutes for Comparative Example 1-1) - 100] x 100 (%) The higher the retention ratio, the higher the fluidity that is retained.

[0110] In addition, the compressive strength after 16 hours was measured in accordance with the test method of JIS A 1108. The test specimen size was Φ5 cm and height 10 cm. Unbonded capping was used. The compressive strength ratio was calculated using the compressive strength of Comparative Example 1-1 after 16 hours, 10.6 MPa, as the standard, using the following formula: Strength ratio = (compressive strength of each Example or Comparative Example after 16 hours) ÷ (compressive strength of Comparative Example 1-1 after 16 hours) × 100 (%)

[0111] Table 1 shows the retention rates, retention ratios and compressive strength ratios for various examples and comparative examples.

[0112]

[0113] In Comparative Example 1-1, which did not contain component (A), 0.301 mass% of additive was required to achieve an initial flow value of 200 mm. Furthermore, the retention rate, which is the ratio of the flow value after 20 minutes to the initial flow value, was 68%, indicating a decrease in fluidity. When the content of component (A) was set to 10 mass% relative to the total content of component (A) and component (B), and components A-1 to A-4 were used as the (A) component and B-1 was used as the (B) component, an initial flow value of 200 mm was achieved with 0.242 to 0.265 mass% of additive, which was lower than in Comparative Example 1-1. Furthermore, the retention rate was 75 to 80%, indicating that fluidity was maintained even after 20 minutes compared to Comparative Example 1-1. Furthermore, a high retention rate of 136 to 164% was observed. The compressive strength ratio was also high, at 109 to 119%. On the other hand, in Comparative Examples 1-2 and 1-3, which used copolymer A'-1 in which the na of the (A2) component was 120 and polymer A'-2 which did not contain the (A1) component, the amount of additive required to achieve an initial flow value of 200 mm, the retention rate, the retention ratio, and the compressive strength ratio were all lower than those of Examples 1-1 to 1-4, and the retention ratio was particularly poor.

[0114] The content of the (A) component was set to 30% by mass relative to the total content of the (A) component and the (B) component, and A-1 to A-4 were used as the (A) component and B-1 as the (B) component. Compared to Comparative Example 1-1, the amount of additive required to achieve an initial flow value of 200 mm was low at 0.236 to 0.256% by mass, the retention rate was high at 78 to 81%, and the retention ratio was also high at 153 to 172%. The compressive strength ratio was also high at 113 to 118%. On the other hand, in Comparative Examples 2-1 and 2-2, which used copolymer A'-1 having an (A2) component na of 120 and polymer A'-2 not containing the (A1) component, the amount of additive required to achieve an initial flow value of 200 mm was high at 0.261 to 0.263% by mass, and the retention rate was low at 69 to 71%. In addition, both the retention ratio and the compressive strength ratio were lower than those of Examples 2-1 to 2-4, and the retention ratio was particularly poor.

[0115] The content of the (A) component was set to 50% by mass relative to the total content of the (A) component and the (B) component, and an investigation was conducted using A-1 as the (A) component and B-1 as the (B) component. Compared to Comparative Example 1-1, the amount of additive required to achieve an initial flow value of 200 mm was low at 0.276% by mass, the retention rate was high at 76%, and the retention ratio was also high at 144%. The compressive strength ratio was also high at 117%. On the other hand, in Comparative Examples 3-1 and 3-2, which used copolymer A'-1 having an (A2) component na of 120 and polymer A'-2 not containing the (A1) component, the amount of additive required to achieve an initial flow value of 200 mm was high at 0.280 to 0.294% by mass, and the retention rate was low at 67 to 70%. Furthermore, both the retention rate and compressive strength ratio were lower than those of Example 3-1, and the retention ratio was particularly poor.

Claims

1. Use of an additive containing the following component (A) and the following component (B) in a clay-containing hydraulic composition, in which the ratio of the content of component (A) to the total content of components (A) and (B), expressed as [content of component (A)] / [content of component (A)+content of component (B)]×100 (mass%), is 1 mass% or more. <Component (A)> A copolymer comprising a structural unit (A1) represented by general formula (A1) below, and a structural unit (A2) represented by general formula (A2) below, wherein the content of structural unit (A1) relative to the total content of structural unit (A1) and structural unit (A2), represented by the formula [content of structural unit (A1) / [content of structural unit (A1)+content of structural unit (A2)]]×100 (mass%), is 0.1% by mass or more and 4.5% by mass or less, and the copolymer has a weight average molecular weight of 10,000 or more and 100,000 or less. [In the formula, R １ａ and R ２ａ are the same or different and each represents a hydrogen atom or a methyl group. ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents one or more selected from a hydrogen atom and a counter cation. １ represents an alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group. ２ CH ２ It represents the average number of moles added of structural unit (B1), and is a number of 5 or more and 99 or less.] <Component (B)> A copolymer comprising a structural unit (B1) represented by the following general formula (B1) and a structural unit (B2) represented by the following general formula (B2), in which the content of structural unit (B1) relative to the total content of structural unit (B1) and structural unit (B2), represented by the formula [content of structural unit (B1) / [content of structural unit (B1)+content of structural unit (B2)]×100 (mass%), is 5 mass% or more and less than 30 mass%. [In the formula, M １ｂ R represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. １ｂ , R ２ｂ and R ３ｂ are the same or different and each represents a hydrogen atom, a methyl group, or a group represented by the general formula (1): -(CH ２ ) ｒ COOM ２ｂ (1) wherein r is 0, 1 or 2; M ２ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. ２ ) ｒ COOM ２ｂ (1) is COOM in the same or different structural units １ｂ and forms an acid anhydride structure -(CH ２ ) ｒ C(=O)-O-C(=O)- may be formed, and -(CH ２ ) ｒ COOM ２ｂ and forms an acid anhydride structure -(CH ２ ) ｒ C(=O)-OC(=O)(CH ２ ) ｒ -, in which case M １ｂ , M. ２ｂ does not exist. [In the formula, R ４ｂ , R ５ｂ are the same or different and each represents a hydrogen atom or a methyl group. AO represents an oxyalkylene group having 2 to 4 carbon atoms, q2 represents an integer of 0 to 6, p2 represents 0 or 1, and n2 represents the average number of moles of AO added and is a number of 5 to 150. ６ｂ is a hydrogen atom, a methyl group, or a group represented by the general formula (2) -(CH ２ ) ｓ COOM ３ｂ (2) [wherein s is 0, 1 or 2; M ３ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group.], or a group represented by the general formula (3) -(CH ２ ) ｑ２ (CO) ｐ２ O (AO) ｎ２ R ７ｂ (3) [In the formula, AO represents an oxyalkylene group having 2 to 4 carbon atoms, q2 represents an integer of 0 to 6, p2 represents 0 or 1, n2 represents the average number of moles of AO added and is a number of 5 to 150, and R ７ｂ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

2. X １ 2. Use of the additive according to claim 1, wherein is a carbonyl group, q2 is 0 and p2 is 1 in a clay-containing hydraulic composition.

3. Use of the additive according to claim 1 or 2 in a clay-containing hydraulic composition, in which the ratio of the content of the (A) component, expressed by [[content of the structural unit (A1) + content of the structural unit (A2)] / [content of the (A) component]] x 100 (mass%), to the total content of the structural unit (A1) and the structural unit (A2), is 80 mass% or more and 100 mass% or less.

4. Use of the additive according to claim 1 or 2 in a clay-containing hydraulic composition, in which the ratio of the content of the (A) component to the total content of the (A) component and the (B) component, expressed by [content of the (A) component] / [content of the (A) component + content of the (B) component] x 100 (mass%), is 5 mass% or less.

5. Use of the additive according to claim 1 or 2 in a clay-containing hydraulic composition, in which the ratio of the content of the structural unit (A2) to the total content of the structural unit (A1) and the structural unit (A2), expressed by [content of structural unit (A2) / [content of structural unit (A1) + content of structural unit (A2)]] x 100 (mass%), is 95.5 mass% or more and 99.9 mass% or less.

6. A clay-containing hydraulic composition comprising hydraulic powder, aggregate, clay, water, component (A) and component (B) as shown below, wherein the ratio of the clay content to the aggregate content, expressed by [[clay content] / [aggregate content]] x 100 (mass%), is 5 mass% or less, and the ratio of the content of component (A) to the total content of component (A) and component (B), expressed by [[content of component (A)] / [content of component (A) + content of component (B)]] x 100 (mass%), is 1 mass% or more. <Component (A)> A copolymer comprising a structural unit (A1) represented by general formula (A1) below, and a structural unit (A2) represented by general formula (A2) below, wherein the content of structural unit (A1) relative to the total content of structural unit (A1) and structural unit (A2), represented by the formula [content of structural unit (A1) / [content of structural unit (A1)+content of structural unit (A2)]]×100 (mass%), is 0.1% by mass or more and 4.5% by mass or less, and the copolymer has a weight average molecular weight of 10,000 or more and 100,000 or less. [In the formula, R １ａ and R ２ａ are the same or different and each represents a hydrogen atom or a methyl group. ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents one or more selected from a hydrogen atom and a counter cation. １ represents an alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group. ２ CH ２ It represents the average number of moles of structural unit (B1) added, and is a number of 5 or more and 99 or less.] <Component (B)> A copolymer comprising a structural unit (B1) represented by general formula (B1) below, and a structural unit (B2) represented by general formula (B2) below, wherein the proportion of the content of structural unit (B1) to the total content (parts by mass) of structural unit (B1) and the content (parts by mass) of structural unit (B2) is 5% by mass or more and less than 30% by mass. [In the formula, M １ｂ R represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. １ｂ , R ２ｂ and R ３ｂ are the same or different and each represents a hydrogen atom, a methyl group, or a group represented by the general formula (1): -(CH ２ ) ｒ COOM ２ｂ (1) wherein r is 0, 1 or 2; M ２ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. １ｂ and forms an acid anhydride structure -(CH ２ ) ｒ C(=O)-O-C(=O)- may be formed, and -(CH ２ ) ｒ COOM ２ｂ and forms an acid anhydride structure -(CH ２ ) ｒ C(=O)-OC(=O)(CH ２ ) ｒ -, in which case M １ｂ , M. ２ｂ does not exist. [In the formula, R ４ｂ , R ５ｂ are the same or different and each represents a hydrogen atom or a methyl group. AO represents an oxyalkylene group having 2 to 4 carbon atoms, q2 represents an integer of 0 to 6, p2 represents 0 or 1, and n2 represents the average number of moles of AO added and is a number of 5 to 150. ６ｂ is a hydrogen atom, a methyl group, or a group represented by the general formula (2) -(CH ２ ) ｓ COOM ３ｂ (2) [wherein s is 0, 1 or 2; M ３ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group.], or a group represented by the general formula (3) -(CH ２ ) ｑ２ (CO) ｐ２ O (AO) ｎ２ R ７ｂ (3) [In the formula, AO represents an oxyalkylene group having 2 to 4 carbon atoms, q2 represents an integer of 0 to 6, p2 represents 0 or 1, n2 represents the average number of moles of AO added and is a number of 5 to 150, and R ７ｂ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

7. X １ The clay-containing hydraulic composition according to claim 6, wherein: is a carbonyl group; q2 is 0 and p2 is 1.

8. A clay-containing hydraulic composition as described in claim 6 or 7, in which the ratio of the clay content to the aggregate content, expressed as [clay content] / [aggregate content] x 100 (mass%), is 0.03 mass% or more and 5 mass% or less.

9. A clay-containing hydraulic composition according to any one of claims 6 to 8, in which the ratio of the content of component (A) to the content of clay, expressed as [content of component (A) / content of clay] x 100 (mass%), is 0.25 mass% or more and 5 mass% or less.

10. A clay-containing hydraulic composition according to any one of claims 6 to 9, containing 0.01 to 0.25 parts by mass of component (A) per 100 parts by mass of hydraulic powder.

11. A clay-containing hydraulic composition according to any one of claims 6 to 9, in which the total content of components (A) and (B) is 0.1 parts by mass or more and 0.5 parts by mass or less per 100 parts by mass of hydraulic powder.

12. A method for producing a clay-containing hydraulic composition by mixing hydraulic powder, aggregate, clay, water, and the following component (A) and component (B), wherein the ratio of the amount of clay mixed to the amount of aggregate mixed is 1% by mass or more and 5% by mass or less, and the ratio (parts by mass) of the content of component (A) to the total content (parts by mass) of component (A) and component (B) is 1% by mass or more. <Component (A)> A copolymer containing a structural unit (A1) represented by the following general formula (A1) and a structural unit (A2) represented by the following general formula (A2), wherein the ratio of the content (parts by mass) of structural unit (A1) to the total content (parts by mass) of structural unit (A1) and component (A2) is 0.1% by mass or more and 4.5% by mass or less, and the copolymer has a weight average molecular weight of 10,000 or more and 100,000 or less. [In the formula, R １ａ and R ２ａ are the same or different and each represents a hydrogen atom or a methyl group. ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents one or more selected from a hydrogen atom and a counter cation. １ represents an alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group. ２ CH ２ It represents the average number of moles of structural unit (B1) added, and is a number of 5 or more and 99 or less.] <Component (B)> A copolymer comprising a structural unit (B1) represented by general formula (B1) below, and a structural unit (B2) represented by general formula (B2) below, wherein the proportion of the content of structural unit (B1) to the total content (parts by mass) of structural unit (B1) and the content (parts by mass) of structural unit (B2) is 5% by mass or more and less than 30% by mass. [In the formula, M １ｂ R represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. １ｂ , R ２ｂ and R ３ｂ are the same or different and each represents a hydrogen atom, a methyl group, or a group represented by the general formula (1): -(CH ２ ) ｒ COOM ２ｂ (1) wherein r is 0, 1 or 2; M ２ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group. １ｂ and forms an acid anhydride structure -(CH ２ ) ｒ C(=O)-O-C(=O)- may be formed, and -(CH ２ ) ｒ COOM ２ｂ and forms an acid anhydride structure -(CH ２ ) ｒ C(=O)-OC(=O)(CH ２ ) ｒ - may be formed, in which case M １ｂ , M. ２ｂ does not exist. [In the formula, R ４ｂ , R ５ｂ are the same or different and each represents a hydrogen atom or a methyl group. AO represents an oxyalkylene group having 2 to 4 carbon atoms, q2 represents an integer of 0 to 6, p2 represents 0 or 1, and n2 represents the average number of moles of AO added and is a number of 5 to 150. ６ｂ is a hydrogen atom, a methyl group, or a group represented by the general formula (2) -(CH ２ ) ｓ COOM ３ｂ (2) [wherein s is 0, 1 or 2; M ３ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group, or an alkenyl group.], or a group represented by the general formula (3) -(CH ２ ) ｑ２ (CO) ｐ２ O (AO) ｎ２ R ７ｂ (3) [In the formula, AO represents an oxyalkylene group having 2 to 4 carbon atoms, q2 represents an integer of 0 to 6, p2 represents 0 or 1, n2 represents the average number of moles of AO added and is a number of 5 to 150, and R ７ｂ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

13. X １ The method for producing a clay-containing hydraulic composition according to claim 12, wherein is a carbonyl group, q2 is 0 and p2 is 1.

14. The method according to claim 12 or 13, wherein the clay is mixed into the hydraulic composition together with the aggregate.

15. The method according to any one of claims 12 to 14, wherein the hydraulic powder is mixed with aggregate containing clay, and then a kneading liquid containing components (A) and (B) and water is mixed therewith.

16. Use of an additive containing the following component (A) in a clay-containing hydraulic composition. <Component (A)> A copolymer containing a structural unit (A1) represented by the following general formula (A1) and a structural unit (A2) represented by the following general formula (A2), in which the content of structural unit (A1) relative to the total content of structural unit (A1) and structural unit (A2), expressed by [content of structural unit (A1) / [content of structural unit (A1)+content of structural unit (A2)]]×100 (mass%), is 0.1 mass% or more and 4.5 mass% or less, and the weight average molecular weight is 10,000 or more and 100,000 or less. [In the formula, R １ａ and R ２ａ are the same or different and each represents a hydrogen atom or a methyl group. ３ａ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents one or more selected from a hydrogen atom and a counter cation. １ represents an alkylene group having 1 to 6 carbon atoms, a direct bond, or a carbonyl group. ２ CH ２ O-) and is a number of 5 to 99.

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