JP7570840B2 - Dispersant for hydraulic compositions - Google Patents

Description

The present invention relates to a dispersant for hydraulic compositions.

Naphthalene-based, melamine-based, aminosulfonic acid-based, polycarboxylic acid-based and other admixtures 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, retaining fluidity (fluidity retention), and preventing hardening delay, and improvements have been proposed for polycarboxylic acid-based admixtures (dispersants) from this perspective.

For example, in consideration of flowability and flow retention, it has been proposed to use a combination of multiple polycarboxylic acid polymers.
Patent Document 1 describes a hydraulic powder dispersant containing a polycarboxylic acid copolymer, which contains a copolymer (I) containing, as constituent monomers, a monomer (1a) having an average number of moles of alkyleneoxy groups added of 15 or more and 80 or less, and an unsaturated carboxylic acid monomer (b), in a predetermined amount, and a copolymer (II) containing, as constituent monomers, a monomer (2a) having an average number of moles of alkyleneoxy groups added of 100 or more and 300 or less, and an unsaturated carboxylic acid monomer (b), in a predetermined amount, and in the polycarboxylic acid copolymer, the total proportion of the copolymer (I) and the copolymer (II) is 75 mass% or more, and the mol% (X 1b ) of the monomer (b) relative to the total of the monomer (1a) and the monomer (b) in the copolymer (I) and the mol% (X _2b ) of the monomer (b) relative to the total of the monomer (2a) and the monomer (b) in the copolymer (II ₎ are given. The absolute value of the difference between the coefficient of friction coefficient (I) and the coefficient of friction coefficient (II) is 15 or more and 50 or less, and the mass ratio of copolymer (I)/copolymer (II) is 50/50 or more and 95/5 or less.
Furthermore, Patent Document 2 discloses an effectiveness enhancer for cement dispersants, which comprises a copolymer obtained by copolymerizing a specific monomer (A) such as (meth)acrylic acid with a specific monomer (B) such as an ethylenically unsaturated carboxylic acid derivative having a polyoxyalkylene group so as to satisfy both a specific weight ratio and a specific molar ratio, and a cement dispersant composition containing the effectiveness enhancer for cement dispersants and a cement dispersant in a predetermined weight ratio.

Furthermore, in consideration of the influence of aggregates used in concrete and mortar, techniques for improving polycarboxylic acid-based dispersants have been proposed.
US Patent No. 5,399,633 discloses a method for improving clay activity and slump retention in a hydratable cementitious composition containing a clay-containing aggregate, comprising combining at least one cationic compound and at least one poly-hydroxyl or hydroxyl carboxylic acid or salt thereof together with the clay-containing aggregate which absorbs or otherwise acts to reduce the dosage efficiency of polycarboxylate dispersants.
Patent Document 4 discloses an admixture for hydraulic compositions, which contains a copolymer A (excluding copolymer B) obtained by polymerizing a specific monomer A1 represented by general formula (A1) with a monomer having a carboxylic acid group and/or a phosphoric acid group, and a copolymer B having a weight average molecular weight of 6,000 to 27,000 obtained by polymerizing a specific monomer B1 represented by general formula (B1) with 2-hydroxyethyl acrylate in an amount of 95% by weight or more of the constituent monomers.

JP 2017-1897 A Special Publication No. 2001-316151 JP 2011-136844 A JP 2013-133241 A

Polycarboxylic acid dispersants have a higher strength of the hardened hydraulic composition per added amount than naphthalene dispersants, but are easily affected by the clay component contained in the aggregate. In general, polycarboxylic acid dispersants are prone to fluctuations in the initial fluidity and fluidity retention of the hydraulic composition depending on the amount of clay in the aggregate.
The amount of clay in aggregates used in hydraulic compositions such as concrete and mortar varies depending on the place of collection, and concrete factories often use a combination of various types of aggregates obtained from different places, so the amount of clay in the aggregates varies. In hydraulic compositions such as concrete and mortar, the proportion of aggregate in a unit volume is relatively large, so polycarboxylic acid dispersants are also easily affected by the clay in the aggregate. As a result, the workability is not stable, and the amount of additive required to obtain the desired fluidity may vary.

The present invention provides a polycarboxylic acid-based dispersant for hydraulic compositions that can impart excellent fluidity to hydraulic compositions even when aggregates containing clay are used.

The present invention provides a dispersant for a clay-containing hydraulic composition, comprising the following component (A), the following component (B) and one or more components selected from the following component (C):
the ratio of the total content of the (B) component and the (C) component to the total content of the (A) component and the (B) component is 5% by mass or more and 20% by mass or less;
The present invention relates to a dispersant for a clay-containing hydraulic composition.
<Component (A)>
A copolymer (excluding components (B) and (C)) having a structural unit (A1) represented by the following formula (A1) and a structural unit (A2) represented by the following formula (A2), in which the proportion of the structural unit (A1) to the total of the structural units (A1) and (A2) is 5% by mass or more and less than 23% by mass.

[In the formula, R ^1a and R ^2a are the same or different and each represents a hydrogen atom or a methyl group, R ^3a represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ¹ represents a hydrogen atom or a counter ion that becomes a salt, X ¹ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and na represents the average number of moles of ethylene oxide added and is a number of 5 to 150.]
<Component (B)>
A copolymer having a structural unit (B1) represented by the following formula (B1) and a structural unit (B2) represented by the following formula (B2), wherein the proportion of the structural unit (B1) to the total of the structural units (B1) and (B2) is less than 5 mass%, and the copolymer has a weight average molecular weight of 50,000 or more and 100,000 or less.

[In the formula, R ^1b and R ^2b are the same or different and each represents a hydrogen atom or a methyl group, R ^3b represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ² represents a hydrogen atom or a counter ion that becomes a salt, X ² represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and nb represents the average number of moles of ethylene oxide added and is a number of 100 to 150.]
<Component (C)>
A copolymer having a structural unit (C1) represented by the following formula (C1) and a structural unit (C2) represented by the following formula (C2), wherein the proportion of the structural unit (C1) to the total of the structural units (C1) and (C2) is 23% by mass or more and 65% by mass or less, and the weight average molecular weight is 20,000 or more and 50,000 or less.

[In the formula, R ^1c and R ^2c are the same or different and each represents a hydrogen atom or a methyl group; R ^3c represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; M ³ represents a hydrogen atom or a counter ion that becomes a salt; X ³ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group; and nc represents the average number of moles of ethylene oxide added and is a number of 5 to 150.]

The present invention also relates to a clay-containing hydraulic composition comprising a hydraulic powder, an aggregate, clay, water, the component (A), and one or more components selected from the component (B) and the component (C),
The ratio of the clay content to the aggregate content is 1% by mass or more and 5% by mass or less,
the ratio of the total content of the (B) component and the (C) component to the total content of the (A) component and the (B) component is 5% by mass or more and 20% by mass or less;
The present invention relates to a clay-containing hydraulic composition.

The present invention also provides a method for producing a clay-containing hydraulic composition, comprising mixing a hydraulic powder, an aggregate containing clay, water, and one or more components selected from the group consisting of the component (A), the component (B), and the component (C),
The aggregate contains clay in an amount of 1% by mass or more and 5% by mass or less,
the ratio of the total amount of the mixed amount of the mixed amount of the (B) component and the mixed amount of the (C) component to the total amount of the mixed amount of the mixed amount of the (A) component and the mixed amount of the (B) component is 5% by mass or more and 20% by mass or less;
The present invention relates to a method for producing a clay-containing hydraulic composition.

According to the present invention, a polycarboxylic acid-based hydraulic composition dispersant is provided that can impart excellent fluidity to a hydraulic composition even when aggregate containing clay is used. In addition, according to the present invention, a hydraulic composition that exhibits excellent fluidity even when aggregate containing clay is used, and a method for producing the same are provided.

<Dispersant for clay-containing hydraulic composition>
The clay-containing hydraulic composition dispersant of the present invention contains component (A) and one or more components selected from component (B) and component (C) in a given ratio.

Component (A) is a copolymer (excluding components (B) and (C)) having a structural unit (A1) represented by the following formula (A1) and a structural unit (A2) represented by the following formula (A2), in which the proportion of structural unit (A1) to the total of structural units (A1) and (A2) is 5% by mass or more and less than 23% by mass.

[In the formula, R ^1a and R ^2a are the same or different and each represents a hydrogen atom or a methyl group, R ^3a represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ¹ represents a hydrogen atom or a counter ion that becomes a salt, X ¹ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and na represents the average number of moles of ethylene oxide added and is a number of 5 to 150.]

In formula (A1), R ^1a is preferably a hydrogen atom or a methyl group.
In formula (A1), M ¹ is preferably a hydrogen atom or sodium.

The structural unit (A1) can be obtained using a monomer selected from acrylic acid, methacrylic acid, and salts thereof. Examples of the salt include alkali metal salts, alkaline earth metal salts, ammonium salts, and mono-, di-, and trialkyl (e.g., having 2 to 8 carbon atoms) ammonium salts in which the hydroxyl group may be substituted.

In formula (A2), R ^2a is preferably a methyl group.
In formula (A2), R ^3a is preferably a hydrogen atom or a methyl group.
In formula (A2), X ¹ is preferably a direct bond or a carbonyl group.
In formula (A2), na is the average number of moles of ethyleneoxy groups added and is 5 or more, preferably 7 or more, and 150 or less, preferably 120 or less.

The structural unit (A2) can be obtained using a monomer selected from the corresponding monomer, for example, (1) a monoester of polyethylene glycol and acrylic acid or methacrylic acid, (2) an ester of polyethylene glycol, such as methoxypolyethylene glycol, capped at one end with an alkyl group, and acrylic acid or methacrylic acid, (3) a monoether of polyethylene glycol and vinyl alcohol, allyl alcohol, methallyl alcohol, or isoprenyl alcohol, (4) an ether of polyethylene glycol, such as methoxypolyethylene glycol, capped at one end with an alkyl group, and allyl alcohol or methallyl alcohol, and (5) an ethylene oxide adduct to acrylic acid, methacrylic acid, maleic acid, allyl alcohol, or methallyl alcohol.

From the viewpoint of ensuring initial fluidity, the copolymer of component (A) has a ratio of the structural unit (A1) to the total of the structural units (A1) and (A2) of 5% by mass or more, preferably 8% by mass or more, and less than 23% by mass, preferably 20% by mass or less, more preferably 19% by mass or less, and even more preferably 18% by mass or less. This ratio is calculated by [mass% of structural unit (A1)/[mass% of structural unit (A1)+mass% of structural unit (A2)]]×100.
From the viewpoint of ensuring initial fluidity, the proportion of the structural unit (A1) in the copolymer of component (A) to the total of the structural units (A1) and (A2) is, on a molar basis, preferably 40 mol% or more, more preferably 45 mol% or more, even more preferably 50 mol% or more, and preferably 95 mol% or less, more preferably 93 mol% or less, even more preferably 91 mol% or less. This proportion is calculated by [mol% of structural unit (A1)/[mol% of structural unit (A1)+mol% of structural unit (A2)]]×100.

The copolymer of component (A) may have a structural unit other than structural units (A1) and (A2) [hereinafter also referred to as structural unit (A3)]. Examples of structural unit (A3) include 2-(methacryloyloxy)ethyl phosphate (HEMA-P), 2-hydroxyethyl acrylate (HEA), methyl acrylate, methyl methacrylate, and 2-hydroxyethyl methacrylate (HEMA).

From the viewpoint of ensuring flowability, the proportion of the structural units (A1) and (A2) in all structural units of the copolymer of component (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and preferably 100% by mass or less.

From the viewpoint of ensuring dispersibility, the copolymer of component (A) preferably has a weight average molecular weight of 10,000 or more, more preferably 30,000 or more, and preferably 100,000 or less, more preferably 80,000 or less. This weight average molecular weight was measured using a high-speed GPC (HLC-8320GPC) Tosoh Corporation, detector: RI, column: G4000PWXL + G2500PWXL (anion), mobile phase: 0.2 M phosphate buffer/acetonitrile = 9/1, flow rate: 1.0 ml/min., column temperature: 40°C, standard substance: polyethylene glycol).

Component (B) is a copolymer having a structural unit (B1) represented by the following formula (B1) and a structural unit (B2) represented by the following formula (B2), in which the proportion of structural unit (B1) to the total of structural units (B1) and (B2) is less than 5 mass%, and the weight average molecular weight is 50,000 or more and 100,000 or less.

[In the formula, R ^1b and R ^2b are the same or different and each represents a hydrogen atom or a methyl group, R ^3b represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ² represents a hydrogen atom or a counter ion that becomes a salt, X ² represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and nb represents the average number of moles of ethylene oxide added and is a number of 100 to 150.]

In formula (B1), R ^1b is preferably a hydrogen atom or a methyl group.
In formula (B1), M ² is preferably a hydrogen atom or sodium.

The structural unit (B1) can be obtained using a monomer selected from acrylic acid, methacrylic acid, and salts thereof. Examples of the salt include alkali metal salts, alkaline earth metal salts, ammonium salts, and mono-, di-, and trialkyl (e.g., having 2 to 8 carbon atoms) ammonium salts in which the hydroxyl group may be substituted.

In formula (B2), R ^2b is preferably a hydrogen atom or a methyl group.
In formula (B2), R ^3b is preferably a hydrogen atom or a methyl group.
In formula (B2), X ² is preferably a direct bond or a carbonyl group.
In formula (B2), nb is the average number of moles of ethyleneoxy groups added and is 100 or more, preferably 110 or more, and 150 or less, preferably 130 or less.

The structural unit (B2) can be obtained using a monomer selected from the corresponding monomer, for example, (1) a monoester of polyethylene glycol and acrylic acid or methacrylic acid, (2) an ester of polyethylene glycol, such as methoxypolyethylene glycol, capped at one end with an alkyl group, and acrylic acid or methacrylic acid, (3) a monoether of polyethylene glycol and vinyl alcohol, allyl alcohol, methallyl alcohol, or isoprenyl alcohol, (4) an ether of polyethylene glycol, such as methoxypolyethylene glycol, capped at one end with an alkyl group, and allyl alcohol or methallyl alcohol, and (5) an ethylene oxide adduct to acrylic acid, methacrylic acid, maleic acid, allyl alcohol, or methallyl alcohol.

From the viewpoint of adsorption to clay, the copolymer of component (B) has a ratio of the structural unit (B1) to the total of the structural units (B1) and (B2) of less than 5% by mass, preferably 4% by mass or less, more preferably 3% by mass or less, and preferably 0.1% by mass or more, based on the mass. This ratio is calculated by [mass% of structural unit (B1)/[mass% of structural unit (B1)+mass% of structural unit (B2)]]×100.
In addition, in terms of the adsorption to clay, the copolymer of component (B) has a molar ratio of the structural unit (B1) to the total of the structural units (B1) and (B2) of preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less. This ratio is calculated by [mol% of structural unit (B1)/[mol% of structural unit (B1)+mol% of structural unit (B2)]]×100.

The copolymer of component (B) may have a structural unit other than structural units (B1) and (B2) [hereinafter also referred to as structural unit (B3)]. Examples of structural unit (B3) include 2-(methacryloyloxy)ethyl phosphate (HEMA-P), 2-hydroxyethyl acrylate (HEA), methyl acrylate, methyl methacrylate, and 2-hydroxyethyl methacrylate (HEMA).

From the viewpoint of adsorption to clay, the copolymer of component (B) preferably has a ratio of structural units (B1) and structural units (B2) of all structural units of 80% by mass or more, more preferably 90% by mass or more, and preferably 100% by mass or less.

From the viewpoint of adsorption to clay, the copolymer of component (B) has a weight average molecular weight of 50,000 or more, preferably 60,000 or more, and 100,000 or less, more preferably 90,000 or less. This weight average molecular weight is measured in the same manner as component (A).

Component (C) is a copolymer having a structural unit (C1) represented by the following formula (C1) and a structural unit (C2) represented by the following formula (C2), in which the proportion of structural unit (C1) to the total of structural units (C1) and (C2) is 23% by mass or more and 65% by mass or less, and the weight average molecular weight is 20,000 or more and 50,000 or less.

[In the formula, R ^1c and R ^2c are the same or different and each represents a hydrogen atom or a methyl group; R ^3c represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; M ³ represents a hydrogen atom or a counter ion that becomes a salt; X ³ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group; and nc represents the average number of moles of ethylene oxide added and is a number of 5 to 150.]

In formula (C1), R ^1c is preferably a hydrogen atom or a methyl group.
In formula (C1), ^M3 is preferably a hydrogen atom or sodium.
The structural unit (C1) can be obtained using a monomer selected from acrylic acid, methacrylic acid, and salts thereof. Examples of the salt include alkali metal salts, alkaline earth metal salts, ammonium salts, and mono-, di-, or trialkyl (e.g., having 2 to 8 carbon atoms) ammonium salts that may be substituted with a hydroxyl group.

In formula (C2), R ^2c is preferably a hydrogen atom or a methyl group.
In formula (C2), R ^3c is preferably a hydrogen atom or sodium.
In formula (C2), X ³ is preferably a direct bond or a carbonyl group.
In formula (C2), nc is the average number of moles of ethyleneoxy groups added and is 5 or more, preferably 8 or more, and 150 or less, preferably 130 or less.

The structural unit (C2) can be obtained using a monomer selected from the corresponding monomers, for example, (1) monoesters of polyethylene glycol and acrylic acid or methacrylic acid, (2) esters of polyethylene glycols with one alkyl end blocked at one end, such as methoxypolyethylene glycol, with acrylic acid or methacrylic acid, (3) monoethers of polyethylene glycols with vinyl alcohol, allyl alcohol, methallyl alcohol, or isoprenyl alcohol, (4) ethers of polyethylene glycols with one alkyl end blocked at one end, such as methoxypolyethylene glycol, with allyl alcohol or methallyl alcohol, and (5) ethylene oxide adducts to acrylic acid, methacrylic acid, maleic acid, allyl alcohol, or methallyl alcohol.

From the viewpoint of adsorption to cement, the copolymer of component (C) has a ratio of the structural unit (C1) to the total of the structural units (C1) and (C2) of 23 mass% or more, preferably 25 mass% or more, more preferably 30 mass% or more, and 65 mass% or less, preferably 60 mass% or less, more preferably 50 mass% or less. This ratio is calculated by [mass% of structural unit (C1)/[mass% of structural unit (C1)+mass% of structural unit (C2)]]×100.
From the viewpoint of adsorption to cement, the copolymer of component (C) preferably has a molar ratio of the structural unit (C1) to the total of the structural units (C1) and (C2) of 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, and preferably 99 mol% or less, more preferably 98 mol% or less, even more preferably 97 mol% or less. This ratio is calculated by [mol% of structural unit (C1)/[mol% of structural unit (C1)+mol% of structural unit (C2)]×100.

The copolymer of component (C) may have a structural unit other than structural units (C1) and (C2) [hereinafter also referred to as structural unit (C3)]. Examples of structural unit (C3) include 2-(methacryloyloxy)ethyl phosphate (HEMA-P), 2-hydroxyethyl acrylate (HEA), methyl acrylate, methyl methacrylate, and 2-hydroxyethyl methacrylate (HEMA).

From the viewpoint of adsorption to clay, the copolymer of component (C) preferably has a ratio of structural units (C1) and structural units (C2) out of all structural units of 80% by mass or more, more preferably 90% by mass or more, and preferably 100% by mass or less.

From the viewpoint of ensuring dispersibility, the copolymer of component (C) preferably has a weight average molecular weight of 20,000 or more, more preferably 25,000 or more, and from the viewpoint of suppressing adsorption to clay, preferably 50,000 or less, more preferably 40,000 or less. This weight average molecular weight is measured in the same manner as component (A).

The clay-containing hydraulic composition dispersant of the present invention has a ratio of the total content of the (B) component and the (C) component to the total content of the (A) component and the (B) component, and the total content of the (C) component, of 5% by mass or more and 20% by mass or less. The clay-containing hydraulic composition dispersant of the present invention contains the (A) component, and also contains the (B) component and/or the (C) component.

In terms of adsorption to clay and suppression of hetero-aggregation of clay and cement, the dispersant for clay-containing hydraulic compositions of the present invention has a ratio of the total content of the (B) component and the (C) component to the total content of the (A) component and the (B) component in the dispersant of 5% by mass or more, preferably 7% by mass or more, and 20% by mass or less, preferably 15% by mass or less. This ratio (% by mass) is calculated by [[content of (B) component + content of (C) component] / [content of (A) component + content of (B) component + content of (C) component]] x 100.

When the clay-containing hydraulic composition dispersant of the present invention contains both the (B) component and the (C) component, the total of the two components may satisfy the above ratio. When the clay-containing hydraulic composition dispersant of the present invention contains both the (B) component and the (C) component, the ratio of at least one of the content of the (B) component and the content of the (C) component to the total of the content of the (A) component and the content of the (B) component may be 1% by mass or more, and further 3% by mass or more.

The clay-containing hydraulic composition dispersant of the present invention can contain optional components such as retarders, hardening accelerators, AE agents, expanding agents, foaming agents, thickeners, fluidizing agents, foaming agents, waterproofing agents, and defoamers (excluding those corresponding to components (A) to (C)).

The clay-containing hydraulic composition dispersant of the present invention may contain water. The clay-containing hydraulic composition dispersant of the present invention may be a liquid composition.

The clay-containing hydraulic composition dispersant of the present invention is used in a hydraulic composition containing clay. Examples of clay include bentonite, montmorillonite, and kaolinite. The clay is mixed into the hydraulic composition together with the manufacturing raw materials of the hydraulic composition, such as aggregate.

<Clay-containing hydraulic composition>
The present invention relates to a concrete composition comprising a hydraulic powder, an aggregate, clay, water, the component (A), and one or more components selected from the component (B) and the component (C). A clay-containing hydraulic composition comprising:
The ratio of the clay content to the aggregate content is 1% by mass or more and 5% by mass or less,
The ratio of the total content of the (A) component and the (B) component to the total content of the (C) component is 5 mass % or less. % or more and 20% by mass or less,
A clay-containing hydraulic composition is provided.

The matters described in the dispersant for the clay-containing hydraulic composition of the present invention can be appropriately applied to the clay-containing hydraulic composition of the present invention. For example, specific examples and preferred aspects of the (A), (B) and (C) components in the clay-containing hydraulic composition of the present invention are the same as those in the dispersant for the clay-containing hydraulic composition of the present invention. In addition, the preferred range of the ratio of the total content of the (B) component and the (C) component to the total content of the (A) component and the (B) component in the clay-containing hydraulic composition of the present invention is also the same as that in the dispersant for the clay-containing hydraulic composition of the present invention.

In the clay-containing hydraulic composition of the present invention, from the viewpoint of clay adsorption and hetero-aggregation suppression to ensure dispersibility, the ratio of the total content of the (B) component and the (C) component to the total content of the (A) component and the (B) component in the composition is 5% by mass or more, preferably 7% by mass or more, and 20% by mass or less, preferably 15% by mass or less.

Hydraulic powder refers to powder that has the property of hardening by hydration reaction, and examples thereof include cement, gypsum, etc. Preferred are ordinary portland cement, belite cement, moderate heat cement, high-early strength cement, ultra-high-early strength cement, sulfate-resistant cement, etc., and may also be blast furnace slag, fly ash, silica fume, etc., powders with pozzolanic action and/or latent hydraulic properties, or blast furnace slag cement, fly ash cement, silica fume cement, etc., to which stone powder (calcium carbonate powder) has been added. Here, when the hydraulic powder includes powders selected from powders with pozzolanic action, powders with latent hydraulic properties, and stone powder (calcium carbonate powder) in addition to powders with the property of hardening by hydration reaction such as cement, in the present invention, the amount of these powders is also included in the amount of hydraulic powder. In addition, when the powders with the property of hardening by hydration reaction contain high-strength admixtures, the amount of the high-strength admixtures is also included in the amount of hydraulic powder. This also applies to parts by mass and mass ratios that involve the mass of the hydraulic powder.

The aggregate may be selected from fine aggregate and coarse aggregate. Examples of fine aggregate include those specified by number 2311 in JIS A0203-2014. Examples of fine aggregate 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 aggregate include those specified by number 2312 in JIS A0203-2014. For example, examples of coarse aggregate 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. Fine aggregate and coarse aggregate of different types may be mixed and used, or a single type may be used.

By using the (A) component of the present invention in combination with the (B) component and/or the (C) component under predetermined conditions, stable fluidity can be imparted to the hydraulic composition even if aggregate containing clay is used or the clay content in the aggregate varies. Therefore, aggregate containing clay can be used as the aggregate. The clay content of the aggregate containing clay is, for example, preferably 0.03 mass% or more, more preferably 0.1 mass% or more, and preferably 10 mass% or less, more preferably 5 mass% or less. In the present invention, the amount of fine particles in the aggregate measured according to JIS A 1103 can be regarded as the clay content in the aggregate.

From the viewpoint of ensuring flowability, the clay-containing hydraulic composition of the present invention contains, per 100 parts by mass of hydraulic powder, preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, even more preferably 0.05 parts by mass or more, and preferably 1.0 part by mass or less, more preferably 0.8 part by mass or less, and even more preferably 0.5 part by mass or less of component (A).

From the viewpoint of sacrificial adsorption ability to clay, the clay-containing hydraulic composition of the present invention contains, per 100 parts by mass of hydraulic powder, preferably 0.001 parts by mass or more of component (B), more preferably 0.003 parts by mass or more, even more preferably 0.005 parts by mass or more, and preferably 0.1 parts by mass or less, more preferably 0.08 parts by mass or less, and even more preferably 0.05 parts by mass or less.

From the viewpoint of suppressing hetero-aggregation, the clay-containing hydraulic composition of the present invention contains, per 100 parts by mass of hydraulic powder, preferably 0.001 parts by mass or more of component (C), more preferably 0.003 parts by mass or more, even more preferably 0.005 parts by mass or more, and preferably 0.1 parts by mass or less, more preferably 0.08 parts by mass or less, and even more preferably 0.05 parts by mass or less.

The clay-containing hydraulic composition of the present invention has a water/hydraulic powder ratio (mass percentage (mass%) of water and 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, and preferably 70% or less, more preferably 50% or less, from the viewpoints of strength expression and workability.

When the clay-containing hydraulic composition is concrete, the amount of coarse aggregate used is preferably 50% or more, more preferably 55% or more, even more preferably 60% or more, and preferably 100% or less, more preferably 90% or less, even more preferably 80% or less, in terms of the expression of strength of the hydraulic composition, reducing the amount of hydraulic powder such as cement used, and improving the filling property into formwork, etc. Bulk volume is the ratio of the volume (including voids) of coarse aggregate in 1 ^m3 of concrete.
When the clay-containing hydraulic composition is concrete, the amount of fine aggregate used is preferably 500 kg/m3 or ^more , more preferably 600 kg/m3 or ^more , even more preferably 700 kg/ ^m3 or more, from the viewpoint of improving the filling property into a formwork, and is preferably 1,000 kg/m3 ^or less, more preferably 900 kg/m3 or ^less .
When the clay-containing hydraulic composition is a mortar, the amount of fine aggregate used is preferably 800 kg/ ^m3 or more, more preferably 900 kg/m3 or ^more , even more preferably 1,000 kg/m3 or more, and preferably 2,000 kg/m3 ^{or less} , more preferably 1,800 kg/m3 ^or less, even more preferably 1,700 kg/m3 or ^less .

The clay-containing hydraulic composition of the present invention may contain, as optional components, retarders, hardening accelerators, AE agents, expanding agents, foaming agents, thickeners, fluidizing agents, foaming agents, waterproofing agents, and defoamers (excluding those corresponding to components (A) to (C)).

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 application, shape, etc. of the hardened product.

<Method for producing clay-containing hydraulic composition>
The present invention relates to a method for producing a concrete concrete composition comprising a hydraulic powder, an aggregate containing clay, water, and one or more components selected from the group consisting of the component (A), the component (B), and the component (C). A method for producing a clay-containing hydraulic composition, comprising:
The aggregate contains clay in an amount of 1% by mass or more and 5% by mass or less,
The ratio of the total amount of the mixed components (B) and (C) to the total amount of the mixed components (A) and (B) is 5% by mass or less. % or more and 20% by mass or less,
A method for producing a clay-containing hydraulic composition is provided.

The matters described in the clay-containing hydraulic composition dispersant and clay-containing hydraulic composition of the present invention can be appropriately applied to the method for producing the clay-containing hydraulic composition of the present invention. Specific examples and preferred aspects of the hydraulic powder, aggregate, component (A), component (B), component (C), and optional components used in the method for producing the clay-containing hydraulic composition of the present invention are the same as those of the hydraulic composition additive and hydraulic composition of the present invention. In addition, the content of each component in the clay-containing hydraulic composition dispersant and clay-containing hydraulic composition of the present invention can be replaced with the mixed amount, and the preferred range can be applied to the method for producing the clay-containing hydraulic composition of the present invention.

In the method for producing a clay-containing hydraulic composition of the present invention, from the viewpoint of adsorption to clay and suppression of hetero-aggregation, the ratio of the sum of the mixed amounts of the (B) component and the (C) component to the sum of the mixed amounts of the (A) component and the (B) component is 5% by mass or more, preferably 7% by mass or more, and 20% by mass or less, preferably 15% by mass or less.

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, but an example of a method for more easily obtaining a high effect is to mix the hydraulic powder with aggregate containing clay, and then mix the kneading liquid containing the (A), (B) and/or (C) components, 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 kneading liquid containing the (A), (B) and/or (C) components, and water is mixed. Mixing can be performed with a known mixer. The kneading liquid may be an aqueous solution or an aqueous suspension.

In the method for producing the hydraulic composition of the present invention, the components (A), (B), and (C) can be mixed with the hydraulic powder so that they fall within the ranges described for the clay-containing hydraulic composition of the present invention.
That is, in the method for producing the hydraulic composition of the present invention, the (A) component is mixed in an amount of preferably 0.01 part by mass or more, more preferably 0.03 part by mass or more, even more preferably 0.05 part by mass or more, and preferably 1.0 part by mass or less, more preferably 0.8 part by mass or less, and even more preferably 0.5 part by mass or less, relative to 100 parts by mass of the hydraulic powder.
In the method for producing the hydraulic composition of the present invention, the (B) component is mixed in an amount of preferably 0.001 part by mass or more, more preferably 0.003 part by mass or more, even more preferably 0.005 part by mass or more, and preferably 0.1 part by mass or less, more preferably 0.08 part by mass or less, and even more preferably 0.05 part by mass or less, relative to 100 parts by mass of the hydraulic powder.
In the method for producing the hydraulic composition of the present invention, the (C) component is mixed in an amount of preferably 0.001 part by mass or more, more preferably 0.003 part by mass or more, even more preferably 0.005 part by mass or more, and preferably 0.1 part by mass or less, more preferably 0.08 part by mass or less, and even more preferably 0.05 part by mass or less, relative to 100 parts by mass of the hydraulic powder.

In the method for producing the hydraulic composition of the present invention, components such as retarders, hardening accelerators, AE agents, expanding agents, foaming agents, thickeners, fluidizing agents, foaming agents, waterproofing agents, and defoamers (excluding those corresponding to components (A) to (C)) can be mixed as optional components.

In addition, in the method for producing the hydraulic composition of the present invention, from the viewpoint of workability, water and hydraulic powder are mixed so that the water/hydraulic powder ratio (mass%) is preferably 15% or more, more preferably 25% or more, and preferably 70% or less, more preferably 50% or less.

The following were used as components (A), (B), (C), and (D). Component (D) is a copolymer other than components (A), (B), and (C).

<Component (A)>
A-1: acrylic acid/methallyl ether (55)=82/18 (mol%)=12.0/88.0 (mass%) copolymer, sodium salt, weight average molecular weight 40,000
A-2: Methacrylic acid/MEPEG(120) ester=80/20 (mol%)=6.0/94.0 (mass%) copolymer, sodium salt, weight average molecular weight 53,000
A-3: acrylic acid/MEPEG(55) ester=82/18 (mol%)=12.0/88.0 (mass%) copolymer, sodium salt, weight average molecular weight 50,000
A-4: Methacrylic acid/MEPEG(120) ester=90/10 (mol%)=12.5/87.5 (mass%) copolymer, sodium salt, weight average molecular weight 39,000
A-5: Methacrylic acid/MEPEG(9) ester = 47/53 (mol%) = 13.3/86.7 (mass%) copolymer, sodium salt, weight average molecular weight 70,000

<Component (B)>
B-1: Methacrylic acid/MEPEG(120) ester = 65/35 (mol%) = 2.9/97.1 (mass%) copolymer, sodium salt, weight average molecular weight 60,000

<Component (C)>
C-1: Methacrylic acid/MEPEG(9) ester=90/10 (mol%)=60.9/39.1 (mass%) copolymer, sodium salt, weight average molecular weight 36,000
C-2: Methacrylic acid/MEPEG(9) ester=80/20 (mol%)=41.0/59.0 (mass%) copolymer, sodium salt, weight average molecular weight 37,000
C-3: Methacrylic acid/MEPEG(9) ester = 75/25 (mol%) = 34.2/65.8 (mass%) copolymer, sodium salt, weight average molecular weight 35,000
C-4: Methacrylic acid/MEPEG(9) ester=70/30 (mol%)=28.8/71.2 (mass%) copolymer, sodium salt, weight average molecular weight 34,000
C-5: Methacrylic acid/MEPEG(23) ester=90/10 (mol%)=41.1/58.9 (mass%) copolymer, sodium salt, weight average molecular weight 31,000
C-6: Methacrylic acid/MEPEG(120) ester=95/5 (mol%)=23.2/76.8 (mass%) copolymer, sodium salt, weight average molecular weight 33,000
C-7: Methacrylic acid/MEPEG(120) ester=95/5 (mol%)=23.2/76.8 (mass%) copolymer, sodium salt, weight average molecular weight 25,000

<Component (D)>
D-1: Methacrylic acid/MEPEG(23) ester = 40/60 (mol%) = 4.9/95.1 (mass%) copolymer, sodium salt, weight average molecular weight 45,000
D-2: Methacrylic acid/MEPEG(120) ester=95/5 (mol%)=23.2/76.8 (mass%) copolymer, sodium salt, weight average molecular weight 64,000

The monomers of the above copolymers are as follows.
Methallyl ether (55): ethylene oxide adduct of methallyl alcohol (average number of moles added: 55)
MEPEG (9) ester: methoxypolyethylene glycol (9) monomethacrylate (the number in parentheses is the average number of moles of ethylene oxide added; the same applies below)
MEPEG (23) ester: methoxypolyethylene glycol (23) monomethacrylate MEPEG (55) ester: methoxypolyethylene glycol (23) monomethacrylate MEPEG (120) ester: methoxypolyethylene glycol (120) monomethacrylate

<Production Example 1: Production of Copolymer A-1>
Copolymer A-1 was prepared as follows.
215.9 g of methallyl ether (55) and 136.7 g of water were charged into a glass reaction vessel equipped with a stirrer, and the mixture was replaced with nitrogen while stirring, and the temperature was raised to 80°C in a nitrogen atmosphere. Then, 0.92 g of hydrogen peroxide (35%) was added. A mixture of 34.57 g of acrylic acid and 34.6 g of water and a mixture of 1.63 g of 3-mercaptopropionic acid and 18.0 g of water were dropped into the vessel over 3.0 hours, respectively, and a solution of 0.42 g of L-ascorbic acid dissolved in 41.28 g of water was dropped into the vessel over 3.5 hours. Then, the mixture was aged at the same temperature (80°C) for 1 hour. After the aging, the mixture was neutralized with 15.98 g of a 48% aqueous sodium hydroxide solution to obtain a reaction product containing a copolymer A-1 having a weight average molecular weight of 40,000 and water.

<Production Example 2: Production of Copolymer C-7>
Copolymer C-7 was prepared as follows.
410.1 g of water was charged into a glass reaction vessel equipped with a stirrer, and the mixture was replaced with nitrogen while stirring, and the temperature was raised to 80 ° C. in a nitrogen atmosphere. 432.86 g of an aqueous solution containing MEPEG (120) ester and methacrylic acid (effective content 60.85 mass%, water content 39.15 mass%, MEPEG (120) ester content 222.37 g, methacrylic acid content 12.84 g), 54.38 g of methacrylic acid and 9.16 g of 3-mercaptopropionic acid mixed and dissolved, and 4.69 g of ammonium persulfate dissolved in 18.75 g of water were each dropped into the vessel over 1.5 hours. Next, 3.75 g of ammonium persulfate dissolved in 15.00 g of water was dropped over 30 minutes, and then aged at the same temperature (80 ° C.) for 1 hour. After the aging was completed, the mixture was neutralized with 48.56 g of a 48% aqueous sodium hydroxide solution to obtain a reaction product containing water and a copolymer C-7 having a weight average molecular weight of 25,000.

The other copolymers in the table were produced in the same manner as above, except that the type and amount of monomer used were changed. Table 1 shows the monomer composition and weight average molecular weight of components (A) to (D).

(1-1) Preparation of clay-containing hydraulic composition dispersant The components (A) to (C) and other components were mixed so that the additives to cement were as shown in Tables 2 and 3, to prepare a clay-containing hydraulic composition dispersant. At that time, the components (A), (B), and (D) were each used as an aqueous solution with a concentration of 40% by mass. The component (C) was used as an aqueous solution with a concentration of 35% by mass. The other component, PEG13000, is a polyethylene glycol with a number average molecular weight of 13,000.

(2-1) Preparation of mortar Using a mortar mixer (Dalton Co., Ltd., universal mixer, model: 5DM-03-γ), cement (C) and fine aggregate (S) were added and dry mixed for 10 seconds at a low rotation speed (63 rpm) of the mortar mixer, and mixing water (W) containing the prepared clay-containing hydraulic composition dispersant was added. Then, the mixture was mixed for 120 seconds at a low rotation speed (63 rpm) of the mortar mixer to prepare mortar. The mixing conditions of the mortar were 400 g of cement, 672 g of fine aggregate, and 28 g of Sumiclair, and the water/cement ratio (W/C) was 35 mass% for all mortar temperatures. The clay-containing hydraulic composition dispersant was added to the mixing water so that the contents of the components (A) to (D) were as shown in Tables 2 and 3 per 100 parts by mass of cement. In this example, it is assumed that the fine aggregate contains 4% by weight of clay (sumi clay).

The ingredients used in preparing the mortar were as follows:
Water (W): Tap water was used.
Cement (C): Ordinary Portland cement (two-type mixture: Taiheiyo Cement/Sumitomo Osaka Cement = 1/1, mass ratio) Density 3.16 g/ ^cm3
・Fine aggregate (S): Joyo mountain sand density 2.55g/cm ³
・Sumiclay (Sumitomo Osaka Cement) Density 2.70 g/ ^cm3

(2-2) Evaluation of Mortar Fluidity Fluidity was evaluated 2 minutes after the start of mixing according to the test method (flow test) of JIS R 5201. The start of mixing is the time when mixing water (W) is added to the mortar mixer and the cement and mixing water first come into contact with each other.

Claims (6)

A dispersant for a clay-containing hydraulic composition, comprising the following component (A), the following component (B), and optionally the following component (C):
the ratio of the total content of the (B) component and the (C) component to the total content of the (A) component and the (B) component is 5% by mass or more and 20% by mass or less;
Dispersant for clay-containing hydraulic compositions.
<Component (A)>
A copolymer (excluding components (B) and (C)) having a structural unit (A1) represented by the following formula (A1) and a structural unit (A2) represented by the following formula (A2), wherein the proportion of the structural unit (A1) relative to the total of the structural units (A1) and (A2) is 5% by mass or more and less than 23% by mass, 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, R ^3a represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ¹ represents a hydrogen atom or a counter ion that becomes a salt, X ¹ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and na represents the average number of moles of ethylene oxide added and is a number of 5 to 150.]
<Component (B)>
A copolymer having a structural unit (B1) represented by the following formula (B1) and a structural unit (B2) represented by the following formula (B2), wherein the proportion of the structural unit (B1) to the total of the structural units (B1) and (B2) is less than 5 mass%, and the copolymer has a weight average molecular weight of 50,000 or more and 100,000 or less.

[In the formula, R ^1b and R ^2b are the same or different and each represents a hydrogen atom or a methyl group, R ^3b represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ² represents a hydrogen atom or a counter ion that becomes a salt, X ² represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and nb represents the average number of moles of ethylene oxide added and is a number of 100 to 150.]
<Component (C)>
A copolymer having a structural unit (C1) represented by the following formula (C1) and a structural unit (C2) represented by the following formula (C2), wherein the proportion of the structural unit (C1) to the total of the structural units (C1) and (C2) is 23% by mass or more and 65% by mass or less, and the weight average molecular weight is 20,000 or more and 50,000 or less.

[In the formula, R ^1c and R ^2c are the same or different and each represents a hydrogen atom or a methyl group; R ^3c represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; M ³ represents a hydrogen atom or a counter ion that becomes a salt; X ³ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group; and nc represents the average number of moles of ethylene oxide added and is a number of 5 to 150.] The dispersant for a clay-containing hydraulic composition according to claim 1, which contains the components (B) and (C), and in which the ratio of the content of at least one of the components (B) and (C) to the total content of the components (A) and (B) is 1 mass% or more. A clay-containing hydraulic composition comprising a hydraulic powder, an aggregate, clay, water, and one or more components selected from the group consisting of component (A) shown below, component (B) shown below, and component (C) shown below,
The ratio of the clay content to the aggregate content is 1% by mass or more and 5% by mass or less,
the ratio of the total content of the (B) component and the (C) component to the total content of the (A) component and the (B) component is 5% by mass or more and 20% by mass or less;
Clay-containing hydraulic composition.
<Component (A)>
A copolymer (excluding components (B) and (C)) having a structural unit (A1) represented by the following formula (A1) and a structural unit (A2) represented by the following formula (A2), wherein the proportion of the structural unit (A1) relative to the total of the structural units (A1) and (A2) is 5% by mass or more and less than 23% by mass, 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, R ^3a represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ¹ represents a hydrogen atom or a counter ion that becomes a salt, X ¹ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and na represents the average number of moles of ethylene oxide added and is a number of 5 to 150.]
<Component (B)>
A copolymer having a structural unit (B1) represented by the following formula (B1) and a structural unit (B2) represented by the following formula (B2), wherein the proportion of the structural unit (B1) to the total of the structural units (B1) and (B2) is less than 5 mass%, and the copolymer has a weight average molecular weight of 50,000 or more and 100,000 or less.

[In the formula, R ^1b and R ^2b are the same or different and each represents a hydrogen atom or a methyl group, R ^3b represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ² represents a hydrogen atom or a counter ion that becomes a salt, X ² represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and nb represents the average number of moles of ethylene oxide added and is a number of 100 to 150.]
<Component (C)>
A copolymer having a structural unit (C1) represented by the following formula (C1) and a structural unit (C2) represented by the following formula (C2), wherein the proportion of the structural unit (C1) to the total of the structural units (C1) and (C2) is 23% by mass or more and 65% by mass or less, and the weight average molecular weight is 20,000 or more and 50,000 or less.

[In the formula, R ^1c and R ^2c are the same or different and each represents a hydrogen atom or a methyl group; R ^3c represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; M ³ represents a hydrogen atom or a counter ion that becomes a salt; X ³ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group; and nc represents the average number of moles of ethylene oxide added and is a number of 5 to 150.] The clay-containing hydraulic composition according to claim 3, which contains the components (B) and (C), and in which the ratio of at least one of the contents of the components (B) and (C) to the total of the contents of the components (A) and (B) is 1 mass% or more. A method for producing a clay-containing hydraulic composition, comprising mixing a hydraulic powder, an aggregate containing clay, water, and one or more components selected from the group consisting of component (A) shown below, component (B) shown below, and component (C) shown below,
The aggregate contains clay in an amount of 1% by mass or more and 5% by mass or less,
the ratio of the total amount of the mixed amount of the mixed amount of the (B) component and the mixed amount of the (C) component to the total amount of the mixed amount of the mixed amount of the (A) component and the mixed amount of the (B) component is 5% by mass or more and 20% by mass or less;
A method for producing a clay-containing hydraulic composition.
<Component (A)>
A copolymer (excluding components (B) and (C)) having a structural unit (A1) represented by the following formula (A1) and a structural unit (A2) represented by the following formula (A2), wherein the proportion of the structural unit (A1) relative to the total of the structural units (A1) and (A2) is 5% by mass or more and less than 23% by mass, 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, R ^3a represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ¹ represents a hydrogen atom or a counter ion that becomes a salt, X ¹ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and na represents the average number of moles of ethylene oxide added and is a number of 5 to 150.]
<Component (B)>
A copolymer having a structural unit (B1) represented by the following formula (B1) and a structural unit (B2) represented by the following formula (B2), wherein the proportion of the structural unit (B1) to the total of the structural units (B1) and (B2) is less than 5 mass%, and the copolymer has a weight average molecular weight of 50,000 or more and 100,000 or less.

[In the formula, R ^1b and R ^2b are the same or different and each represents a hydrogen atom or a methyl group, R ^3b represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, M ² represents a hydrogen atom or a counter ion that becomes a salt, X ² represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group, and nb represents the average number of moles of ethylene oxide added and is a number of 100 to 150.]
<Component (C)>
A copolymer having a structural unit (C1) represented by the following formula (C1) and a structural unit (C2) represented by the following formula (C2), wherein the proportion of the structural unit (C1) to the total of the structural units (C1) and (C2) is 23% by mass or more and 65% by mass or less, and the weight average molecular weight is 20,000 or more and 50,000 or less.

[In the formula, R ^1c and R ^2c are the same or different and each represents a hydrogen atom or a methyl group; R ^3c represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; M ³ represents a hydrogen atom or a counter ion that becomes a salt; X ³ represents a divalent alkylene group having 1 to 6 carbon atoms, a direct bond or a carbonyl group; and nc represents the average number of moles of ethylene oxide added and is a number of 5 to 150.] The method for producing a clay-containing hydraulic composition according to claim 5, wherein the (B) component and the (C) component are mixed, and the ratio of the amount of the (B) component mixed and the amount of the (C) component mixed to the total amount of the (A) component mixed and the amount of the (B) component mixed and the amount of the (C) component mixed is 1 mass% or more.