JP6386281B2 - Cement dispersant and cement composition - Google Patents

Description

  The present invention relates to a cement dispersant and a cement composition.

  Cement mortar, concrete, etc. have high fluidity and high fluidity that can be sufficiently maintained until they are placed after cement mortar, concrete, etc. are kneaded in order to improve the handleability during construction. Retention is required.

  In order to improve such fluidity and retention, various polycarboxylic acid polymers have been conventionally studied as cement dispersants (see, for example, Patent Documents 1 and 2). However, conventional cement dispersants still have room to improve performance.

  For this reason, a new cement dispersant that can exhibit high fluidity and high retainability is demanded.

JP 09-86990 A JP 2001-220417 A

  The subject of this invention is providing the cement dispersing agent which can express high fluidity | liquidity and high retainability. Moreover, it is providing the cement composition containing such a cement dispersing agent.

（一般式（１）中、Ｒ^１、Ｒ^２、およびＲ^３は、同一または異なって、水素原子またはメチル基を表し、Ｒ^４は、水素原子または炭素原子数１〜３０の炭化水素基を表し、Ｒ^ａＯは、炭素原子数２〜１８のオキシアルキレン基を表し、ｎは、Ｒ^ａＯで表されるオキシアルキレン基の平均付加モル数を表し、ｎは１〜５００の整数であり、ｘは０〜２の整数であり、ｙは０または１である。）

（一般式（２）中、Ｒ^５、Ｒ^６は、同一または異なって、水素原子またはメチル基を表し、Ｒ^７は水素原子を表し、Ｘは、水素原子、メチル基、エチル基、アルカリ金属、アルカリ土類金属、アンモニウム基、有機アンモニウム基、または有機アミン基を表す。）

（一般式（３）中、Ｒ^８は水素原子またはメチル基であり、Ｙは−ＮＨ−または−Ｏ−であり、Ｒ^９は炭素数１〜１０のアルキレン基であり、Ｍは、水素原子、金属原子、アンモニウム基（アンモニウム塩、すなわち、ＳＯ_３ＮＨ_４を構成）、または有機アミノ基（有機アミン塩を構成）である。） The cement dispersant of the present invention is
Structural unit (I) derived from unsaturated polyalkylene glycol alkenyl ether monomer (a) represented by general formula (1) and unsaturated carboxylic acid monomer (b) represented by general formula (2) A copolymer having the structural unit (III) derived from the structural unit (II) derived from the sulfonic acid (salt) group-containing monomer (c) represented by the general formula (3),
When the total of the structural unit (I), the structural unit (II) and the structural unit (III) is 100 parts by mass, the content ratio of the structural unit (II) exceeds 4 parts by mass and is less than 30 parts by mass. Is,
Cement dispersant.

(In General Formula (1), R ¹ , R ² , and R ³ are the same or different and represent a hydrogen atom or a methyl group, and R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. R ^a O represents an oxyalkylene group having 2 to 18 carbon atoms, n represents an average added mole number of the oxyalkylene group represented by R ^a O, and n is an integer of 1 to 500. , X is an integer from 0 to 2, and y is 0 or 1.)

(In General Formula (2), R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom or a methyl group, R ⁷ represents a hydrogen atom, and X represents a hydrogen atom, a methyl group, an ethyl group, or an alkali metal. Represents an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group.)

(In General Formula (3), R ⁸ is a hydrogen atom or a methyl group, Y is —NH— or —O—, R ⁹ is an alkylene group having 1 to 10 carbon atoms, and M is a hydrogen atom. , A metal atom, an ammonium group (which constitutes an ammonium salt, ie, SO ₃ NH ₄ ), or an organic amino group (which constitutes an organic amine salt).

  In preferable embodiment, y is 0 in the said General formula (1).

In preferable embodiment, R < ⁵ >, R < ⁶ > and R < ⁷ > are all hydrogen atoms in the said General formula (2).

（一般式（４）中、Ｍは、水素原子、金属原子、アンモニウム基（アンモニウム塩、すなわち、ＳＯ_３ＮＨ_４を構成）、または有機アミノ基（有機アミン塩を構成）である。） In a preferred embodiment, the sulfonic acid (salt) group-containing monomer (c) represented by the general formula (3) is 2-acrylamido-2-methylpropanesulfonic acid represented by the general formula (4). (Salt).

(In the general formula (4), M is a hydrogen atom, a metal atom, an ammonium group (ammonium salt, ie, SO ₃ NH ₄ is constituted), or an organic amino group (an organic amine salt is constituted).)

  The cement composition of the present invention contains the cement dispersant of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the cement dispersing agent which can express high fluidity | liquidity and high retainability can be provided. Moreover, the cement composition containing such a cement dispersing agent can be provided.

  In the present specification, the expression “(meth) acryl” means “acryl and / or methacryl”, and the expression “(meth) acrylate” means “acrylate and / or methacrylate”. Means “allyl and / or methallyl”, and “(meth) acrolein” means “acrolein and / or methacrole”. It means "rain". Further, in the present specification, the expression “acid (salt)” means “acid and / or salt thereof”.

≪Cement dispersant≫
The cement dispersant of the present invention comprises a structural unit (I) derived from an unsaturated polyalkylene glycol alkenyl ether monomer (a) represented by the general formula (1) and an unsaturated compound represented by the general formula (2). Copolymer having structural unit (II) derived from carboxylic acid monomer (b) and structural unit (III) derived from sulfonic acid (salt) group-containing monomer (c) represented by formula (3) Includes coalescence.

The structural unit (I) derived from the unsaturated polyalkylene glycol alkenyl ether monomer (a) represented by the general formula (1) is specifically represented by the following formula.

The structural unit (II) derived from the unsaturated carboxylic acid monomer (b) represented by the general formula (2) is specifically represented by the following formula.

The structural unit (III) derived from the sulfonic acid (salt) group-containing monomer (c) represented by the general formula (3) is specifically represented by the following formula.

In general formula (1) and structural unit (I), R ¹ , R ² , and R ³ are the same or different and represent a hydrogen atom or a methyl group.

In the general formula (1) and the structural unit (I), R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. Examples of the hydrocarbon group having 1 to 30 carbon atoms include an alkyl group having 1 to 30 carbon atoms (an aliphatic alkyl group and an alicyclic alkyl group), an alkenyl group having 1 to 30 carbon atoms, and the number of carbon atoms. Examples thereof include an alkynyl group having 1 to 30 carbon atoms and an aromatic group having 6 to 30 carbon atoms. R ⁴ is preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and more preferably a hydrogen atom or a carbon atom having 1 to 12 carbon atoms in that the effects of the present invention can be further exhibited. A hydrogen group, more preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, particularly preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, most preferably a hydrogen atom. It is.

In the general formula (1) and the structural unit (I), R ^a O represents an oxyalkylene group having 2 to 18 carbon atoms. R ^a O is preferably an oxyalkylene group having 2 to 8 carbon atoms, more preferably an oxyalkylene group having 2 to 4 carbon atoms, from the viewpoint that the effects of the present invention can be further exhibited. When R ^a O is any two or more selected from oxyethylene group, oxypropylene group, oxybutylene group, oxystyrene group, etc., the addition form of R ^a O is random addition or block addition. Any form such as alternate addition may be used. In order to secure a balance between hydrophilicity and hydrophobicity, it is preferable that the oxyalkylene group contains an oxyethylene group as an essential component, and more than 50 mol% of the entire oxyalkylene group is an oxyethylene group. Preferably, 90 mol% or more of the entire oxyalkylene group is more preferably an oxyethylene group, more preferably 95 mol% or more of the entire oxyalkylene group is an oxyethylene group, and 100 mol% of the entire oxyalkylene group. Is most preferably an oxyethylene group.

In general formula (1) and structural unit (I), n represents the average added mole number of the oxyalkylene group represented by R ^a O, and is an integer of 1 to 500. From the viewpoint that the effects of the present invention can be further exhibited, n is preferably an integer of 2 to 500, more preferably an integer of 2 to 400, still more preferably an integer of 3 to 300, and particularly preferably. It is an integer of 5 to 200, and most preferably an integer of 10 to 100.

  In general formula (1) and structural unit (I), x is an integer of 0-2.

  In the general formula (1) and the structural unit (I), y is 0 or 1. Y is preferably 0 in that the effects of the present invention can be further exhibited.

  Examples of the unsaturated polyalkylene glycol monomer (a) represented by the general formula (1) include addition obtained by adding an alkylene oxide having 2 to 8 carbon atoms to an alkenyl alcohol having 1 to 20 carbon atoms. An esterified product of an alkoxypolyalkylene glycol obtained by adding an alkylene oxide having 2 to 8 carbon atoms to a saturated aliphatic alcohol having 1 to 20 carbon atoms and (meth) acrylic acid or crotonic acid; Esterified products of polyalkylene glycols obtained by polymerizing alkylene oxides having 2 to 18 carbon atoms on saturated aliphatic alcohols having 1 to 20 carbon atoms and (meth) acrylic acid or crotonic acid; (meth) allyl In unsaturated fatty alcohols having 3 to 20 carbon atoms such as alcohol, crotyl alcohol, oleyl alcohol, Esterified products of alkoxy polyalkylene glycols obtained by adding alkylene oxides having 2 to 8 prime atoms with (meth) acrylic acid or crotonic acid; carbon numbers such as (meth) allyl alcohol, crotyl alcohol, oleyl alcohol, etc. Esterified products of polyalkylene glycols obtained by polymerizing alkylene oxides having 2 to 18 carbon atoms with 3 to 20 unsaturated aliphatic alcohols and (meth) acrylic acid or crotonic acid; carbon such as cyclohexanol Esterified products of alkoxypolyalkylene glycols obtained by adding alkylene oxides having 2 to 8 carbon atoms to alicyclic alcohols having 3 to 20 carbon atoms and (meth) acrylic acid or crotonic acid; cyclohexanol, etc. C 3-20 alicyclic a Esterified products of polyalkylene glycols obtained by polymerizing C 2-18 alkylene oxides on coals and (meth) acrylic acid or crotonic acid; C 6-20 aromatic alcohols containing carbon Esterified products of alkoxypolyalkylene glycols obtained by adding alkylene oxides having 2 to 8 and (meth) acrylic acid or crotonic acid; aromatic alcohols having 6 to 20 carbons; And an esterified product of polyalkylene glycols obtained by polymerizing 18 alkylene oxides with (meth) acrylic acid or crotonic acid.

  The unsaturated polyalkylene glycol monomer (a) represented by the general formula (1) is preferably an alkoxy polyalkylene glycol of (meth) acrylic acid in that the effects of the present invention can be further exhibited. Esters of vinyl alcohol, (meth) allyl alcohol, 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol, 2- A compound obtained by adding 1 to 500 moles of alkylene oxide to any of methyl-2-buten-1-ol and 2-methyl-3-buten-1-ol; more preferably, alkylene to (meth) allyl alcohol A compound obtained by adding 1 to 500 moles of oxide, or a compound obtained by adding 1 to 500 moles of alkylene oxide to 3-methyl-3-buten-1-ol. More preferably 3-methyl-3-buten-1-compounds 1 to 500 mols of an alkylene oxide to all.

  The unsaturated polyalkylene glycol monomer (a) represented by the general formula (1) may be only one type or two or more types.

In general formula (2) and structural unit (II), R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom or a methyl group, and R ⁷ represents a hydrogen atom. R ⁵ , R ⁶ , and R ⁷ are preferably all hydrogen atoms from the viewpoint that the effects of the present invention can be further exhibited.

  In general formula (2) and structural unit (II), X represents a hydrogen atom, a methyl group, an ethyl group, an alkali metal, an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group.

  Examples of the unsaturated carboxylic acid monomer (b) represented by the general formula (2) include monocarboxylic acid monomers such as acrylic acid and crotonic acid, or salts thereof. Examples of the salt herein include alkali metal salts, alkaline earth metal salts, ammonium salts, organic ammonium salts, and organic amine salts. Examples of the alkali metal salt include lithium salt, sodium salt, potassium salt and the like. Examples of alkaline earth metal salts include calcium salts and magnesium salts. Examples of the organic ammonium salt include methyl ammonium salt, ethyl ammonium salt, dimethyl ammonium salt, diethyl ammonium salt, trimethyl ammonium salt, and triethyl ammonium salt. Examples of organic amine salts include alkanolamine salts such as ethanolamine salts, diethanolamine salts, and triethanolamine salts.

  The unsaturated carboxylic acid monomer (b) represented by the general formula (2) is preferably acrylic acid or a salt thereof in that the effects of the present invention can be further exhibited.

  The unsaturated carboxylic acid monomer (b) represented by the general formula (2) may be only one kind or two or more kinds.

  The sulfonic acid (salt) group-containing monomer (c) represented by the general formula (3) does not have an ether bond (an etheric —O— bond). The etheric —O— bond is different from the —O— bond in the ester bond (the —O— bond included in the COO bond).

In the present specification, the term “sulfonic acid (salt)” means sulfonic acid and / or a salt thereof. As the salt, M is a metal atom (metal salt), an ammonium group (ammonium salt, That is, it means a case of SO ₃ NH ₄ ) or an organic amino group (constituting an organic amine salt).

In the general formula (3) and the structural unit (III), R ⁸ is a hydrogen atom or a methyl group.

  In General Formula (3) and Structural Unit (III), Y is —NH— or —O—.

In the general formula (3) and the structural unit (III), R ⁹ is an alkylene group having 1 to 10 carbon atoms. R ⁹ is preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and still more preferably carbon in view of further manifesting the effects of the present invention. An alkylene group having 1 to 4 carbon atoms, particularly preferably an alkylene group having 2 to 4 carbon atoms (that is, —CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ —, —CH (CH ₃ ) CH ₂ — _{, -CH 2 CH 2 CH 2 CH} 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH 2 CH 2 CH (CH 3) -, - C _{(CH 3) (CH 3)} CH 2 -, - CH 2 C (CH 3) (CH 3) -, - CH (CH 2 CH 3) CH 2 -, - CH 2 CH (CH 2 CH 3) -, _{-CH (CH 3) CH (CH} 3) -, - C (CH 2 _{H 2 CH 3) -, -} C (CH (CH 3) (CH 3)) -) it is.

In the general formula (3) and the structural unit (III), M is a hydrogen atom, a metal atom, an ammonium group (constituting an ammonium salt, that is, COONH ₄ ), or an organic amino group (constituting an organic amine salt). Examples of the metal atom include alkali metals such as sodium atom and potassium atom, alkaline earth metals such as calcium atom, and transition metals such as iron atom. Examples of the organic amine salt include primary to quaternary amine salts such as methylamine salt, n-butylamine salt, monoethanolamine salt, dimethylamine salt, diethanolamine salt, morpholine salt, and trimethylamine salt.

The sulfonic acid (salt) group-containing monomer (c) represented by the general formula (3) is preferably 2-acrylamido-2-methylpropanesulfonic acid (salt) represented by the general formula (4), 2-sulfoethyl methacrylate (salt) represented by the general formula (5), more preferably 2-acrylamido-2-methylpropanesulfonic acid (salt) represented by the general formula (4). When the sulfonic acid (salt) group-containing monomer (c) represented by the general formula (3) is 2-acrylamido-2-methylpropanesulfonic acid (salt) represented by the general formula (4), The effects of the present invention can be further manifested.

In the general formula (4), M is a hydrogen atom, a metal atom, an ammonium group (constituting an ammonium salt, that is, SO ₃ NH ₄ ), or an organic amino group (constituting an organic amine salt).

In the general formula (5), M is a hydrogen atom, a metal atom, an ammonium group (composing an ammonium salt, that is, SO ₃ NH ₄ ), or an organic amino group (composing an organic amine salt).

  The total content of the structural unit (I), the structural unit (II), and the structural unit (III) in the copolymer contained in the cement dispersant of the present invention is preferably 50% by mass to 100% by mass. More preferably, it is 70 mass%-100 mass%, More preferably, it is 80 mass%-100 mass%, More preferably, it is 90 mass%-100 mass%, Most preferably, it is 95 mass%-100 mass% Most preferably, it is 98 mass%-100 mass%. If the total content of the structural unit (I), the structural unit (II), and the structural unit (III) in the copolymer contained in the cement dispersant of the present invention is within the above range, the cement dispersant of the present invention. Can express high fluidity and high retention

  The total content of the structural unit (I), the structural unit (II), and the structural unit (III) in the copolymer contained in the cement dispersant of the present invention is, for example, various structural analyzes of the copolymer ( For example, NMR). Further, the various single quantities calculated based on the use amounts of various monomers used for producing the copolymer contained in the cement dispersant of the present invention without performing the various structural analyzes as described above. Using the content ratio of the structural unit derived from the body, the total content ratio of the structural unit (I), the structural unit (II), and the structural unit (III) in the copolymer contained in the cement dispersant of the present invention is It may be calculated. That is, it is represented by the unsaturated polyalkylene glycol alkenyl ether monomer (a) and the general formula (2) in all monomer components used in producing the copolymer contained in the cement dispersant of the present invention. The content ratio of the total mass of the unsaturated carboxylic acid monomer (b) and the sulfonic acid (salt) group-containing monomer (c) represented by the general formula (3) is determined as the cement dispersion of the present invention. The total content of the structural unit (I), the structural unit (II), and the structural unit (III) in the copolymer contained in the agent may be handled.

  In the copolymer contained in the cement dispersant of the present invention, in addition to the structural unit (I), the structural unit (II), and the structural unit (III), the structural unit derived from the other monomer (d) (IV) ) May be included. The structural unit (IV) derived from the other monomer (d) may be only one kind or two or more kinds.

  The other monomer (d) is an unsaturated polyalkylene glycol alkenyl ether monomer (a), an unsaturated carboxylic acid monomer (b), or a sulfonic acid (salt) group-containing monomer monomer. It is a monomer copolymerizable with (c).

  Examples of the other monomer (d) include hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate; non-polymers such as methyl (meth) acrylate and glycidyl (meth) acrylate. Esters of saturated monocarboxylic acids and alcohols having 1 to 30 carbon atoms; (anhydrous) half esters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid and alcohols having 1 to 30 carbon atoms; (Anhydrous) Diesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid and alcohols having 1 to 30 carbon atoms; half amides of the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms A diamide of the above unsaturated dicarboxylic acid and an amine having 1 to 30 carbon atoms; Half esters of an alkyl (poly) alkylene glycol obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to coal or amine and the unsaturated dicarboxylic acid; 2 to 18 carbon atoms added to the alcohol or amine Diesters of alkyl (poly) alkylene glycols having 1 to 500 moles of alkylene oxide added thereto and the above unsaturated dicarboxylic acids; the above unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or the number of moles of these glycols added Half-esters with 2-500 polyalkylene glycols; diesters of unsaturated dicarboxylic acids with 2-18 carbon atoms or polyalkylene glycols with 2 to 500 addition moles of these glycols; 2-18 carbon atoms Chole or half amides of these glycols with polyalkylene glycols having an addition mole number of 2 to 500; (poly) alkylene glycols such as (poly) ethylene glycol di (meth) acrylate and (poly) propylene glycol di (meth) acrylate Di (meth) acrylates; polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate and trimethylolpropane tri (meth) acrylate; (poly) alkylene glycol dimaleates such as polyethylene glycol dimaleate; vinyl sulfonate Unsaturated sulfonic acids (salts) such as (meth) allyl sulfonate and styrene sulfonic acid; Amides of unsaturated monocarboxylic acids such as methyl (meth) acrylamide and amines having 1 to 30 carbon atoms; Styrene, α -Methyl Vinyl aromatics such as tylene and vinyltoluene; alkanediol mono (meth) acrylates such as 1,4-butanediol mono (meth) acrylate; dienes such as butadiene and isoprene; (meth) acrylic (alkyl) amide; Unsaturated amides such as N-methylol (meth) acrylamide and N, N-dimethyl (meth) acrylamide; unsaturated cyanates such as (meth) acrylonitrile; unsaturated esters such as vinyl acetate; amino (meth) acrylate Unsaturated amines such as ethyl, dimethylaminoethyl (meth) acrylate and vinylpyridine; divinyl aromatics such as divinylbenzene; allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; (methoxy) polyethylene Vinyl ether such as glycol monovinyl ether Kind; and the like.

  The content ratio of the structural unit (IV) in the copolymer contained in the cement dispersant of the present invention can be known, for example, by various structural analyzes (for example, NMR) of the copolymer. Further, the various single quantities calculated based on the use amounts of various monomers used for producing the copolymer contained in the cement dispersant of the present invention without performing the various structural analyzes as described above. You may calculate the content rate of structural unit (IV) in the copolymer contained in the cement dispersing agent of this invention using the content rate of the structural unit derived from a body. That is, the content ratio of the mass of the other monomer (d) in the total monomer components used when producing the copolymer contained in the cement dispersant of the present invention is determined in the cement dispersant of the present invention. You may handle as a content rate of structural unit (IV) in the copolymer contained.

  In the present invention, in the copolymer contained in the cement dispersant of the present invention, when the total of the structural unit (I), the structural unit (II) and the structural unit (III) is 100 parts by mass ( The content ratio of II) is more than 4 parts by mass and less than 30 parts by mass. When the content ratio of the structural unit (II) is within the above range, a cement dispersant that can exhibit high fluidity and high retention can be provided. When the content ratio of the structural unit (II) is 4 parts by mass or less or 30 parts by mass or more, the obtained cement dispersant may not exhibit high fluidity and high retention. The content ratio of the structural unit (II) is preferably 5 parts by mass to 29 parts by mass, more preferably 6 parts by mass to 28 parts by mass, and even more preferably, in that the effect of the present invention can be further manifested. Is 7 parts by mass to 27 parts by mass, particularly preferably 8 parts by mass to 26 parts by mass, and most preferably 8 parts by mass to 25 parts by mass.

  In the present invention, in the copolymer contained in the cement dispersant of the present invention, when the total of the structural unit (I), the structural unit (II) and the structural unit (III) is 100 parts by mass ( The content ratio of I) is preferably 30 parts by mass to 99 parts by mass, more preferably 50 parts by mass to 99 parts by mass, still more preferably 50 parts by mass to 97 parts by mass, and particularly preferably 70 parts by mass. Part to 97 parts by weight, most preferably 70 parts to 95 parts by weight. When the content ratio of the structural unit (I) is within the above range, it is possible to provide a cement dispersant that can exhibit higher fluidity and higher retainability. When the content ratio of the structural unit (I) is less than 30 parts by mass or exceeds 99 parts by mass, the obtained cement dispersant may not exhibit high fluidity and high retainability.

  In the present invention, in the copolymer contained in the cement dispersant of the present invention, when the total of the structural unit (I), the structural unit (II) and the structural unit (III) is 100 parts by mass ( The content ratio of III) is preferably 1 part by mass to 30 parts by mass, more preferably 1 part by mass to 25 parts by mass, further preferably 3 parts by mass to 25 parts by mass, and particularly preferably 3 parts by mass. Part to 20 parts by weight, and most preferably 3 parts to 15 parts by weight. When the content ratio of the structural unit (III) is within the above range, it is possible to provide a cement dispersant that can exhibit higher fluidity and higher retainability. When the content ratio of the structural unit (III) is less than 1 part by mass or exceeds 30 parts by mass, the obtained cement dispersant may not exhibit high fluidity and high retainability.

  The mass average molecular weight (Mw) of the copolymer contained in the cement dispersant of the present invention is preferably 3000 to 100,000 as the mass average molecular weight (Mw) in terms of polyethylene glycol by gel permeation chromatography (GPC). More preferably, it is 5000-100000, More preferably, it is 5000-70000, Especially preferably, it is 10,000-70000, Most preferably, it is 10,000-50000. Since the weight average molecular weight (Mw) of the copolymer contained in the cement dispersant of the present invention falls within the above range, the cement dispersant of the present invention can exhibit higher fluidity and higher retainability.

  The molecular weight distribution (Mw / Mn) of the copolymer contained in the cement dispersant of the present invention is preferably 1.0 to 6.0, more preferably 1.0 to 5.0, and still more preferably. It is 1.0-4.0, Most preferably, it is 1.0-3.5, Most preferably, it is 1.0-3.0. Since the molecular weight distribution (Mw / Mn) of the copolymer contained in the cement dispersant of the present invention falls within the above range, the cement dispersant of the present invention can exhibit higher fluidity and higher retainability.

  The copolymer contained in the cement dispersant of the present invention can be produced by any appropriate method. The copolymer contained in the cement dispersant of the present invention is preferably an unsaturated polyalkylene glycol alkenyl ether monomer (a), an unsaturated carboxylic acid monomer (b), and a sulfonic acid (salt) group. The monomer component containing the monomer (c) can be polymerized in the presence of a polymerization initiator.

  Unsaturated polyalkylene glycol alkenyl ether monomer (a), unsaturated carboxylic acid monomer (b), sulfonic acid (salt) group which can be used for the production of the copolymer contained in the cement dispersant of the present invention The amount of the monomer (c) contained and, if necessary, the other monomer (d) is such that each single unit in all the structural units constituting the copolymer contained in the cement dispersant of the present invention. What is necessary is just to adjust suitably so that the ratio of the structural unit derived from a monomer may become what was mentioned above. Preferably, as the polymerization reaction proceeds quantitatively, in the same proportion as the proportion of structural units derived from each monomer in all the structural units constituting the copolymer contained in the cement dispersant of the present invention described above, Each monomer may be used.

  The unsaturated polyalkylene glycol alkenyl ether monomer (a) can be synthesized by any appropriate method. For example, it can be synthesized by adding an alkylene oxide to an unsaturated alcohol such as allyl alcohol, methallyl alcohol, 3-methyl-3-buten-1-ol (isoprenol), hydroxyethyl vinyl ether, hydroxybutyl vinyl ether or the like.

  The polymerization of the monomer component can be performed by any appropriate method. Examples thereof include solution polymerization and bulk polymerization. Examples of the solution polymerization method include a batch method and a continuous method. Solvents that can be used in the solution polymerization include water; alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane, and n-hexane; esters such as ethyl acetate. Compounds; ketone compounds such as acetone and methyl ethyl ketone; cyclic ether compounds such as tetrahydrofuran and dioxane; and the like.

  When the monomer component is polymerized, a water-soluble polymerization initiator, for example, a persulfate such as ammonium persulfate, sodium persulfate, or potassium persulfate; hydrogen peroxide; 2,2′- Azoamidine compounds such as azobis-2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, 2-carbamoylazoisobutyronitrile, etc. Water-soluble azo initiators such as azonitrile compounds of These polymerization initiators include alkali metal sulfites such as sodium hydrogen sulfite, metabisulfites, sodium hypophosphite, Fe (II) salts such as molle salts, sodium hydroxymethanesulfinate dihydrate, hydroxylamine hydrochloride Accelerators such as salt, thiourea, L-ascorbic acid (salt), and erythorbic acid (salt) can also be used in combination. Among these combined forms, a combination of an ammonium persulfate and an accelerator such as L-ascorbic acid (salt) is preferable. Each of these polymerization initiators and accelerators may be only one kind or two or more kinds.

  When performing solution polymerization using a lower alcohol, aromatic hydrocarbon, aliphatic hydrocarbon, ester compound, or ketone compound as a solvent, or when performing bulk polymerization, benzoyl peroxide, lauroyl peroxide may be used as a polymerization initiator. Peroxides such as oxide and sodium peroxide; hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; azo compounds such as azobisisobutyronitrile; When such a polymerization initiator is used, an accelerator such as an amine compound can be used in combination. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various polymerization initiators or combinations of polymerization initiators and accelerators.

  The reaction temperature for the polymerization of the monomer component is appropriately determined depending on the polymerization method, solvent, polymerization initiator, and chain transfer agent used. The reaction temperature is preferably 0 ° C. or higher, more preferably 30 ° C. or higher, further preferably 50 ° C. or higher, preferably 150 ° C. or lower, more preferably 120 ° C. or lower. More preferably, it is 100 ° C. or lower.

  Any appropriate method can be adopted as a method of charging the monomer component into the reaction vessel. As such a charging method, for example, a method in which the entire amount is initially charged into the reaction vessel, a method in which the entire amount is divided or continuously charged into the reaction vessel, a part is initially charged in the reaction vessel, and the rest is put in the reaction vessel. The method of dividing | segmenting or carrying out continuously etc. is mentioned. In addition, the charging rate of each monomer into the reaction vessel may be changed continuously or stepwise during the reaction to change the charging mass ratio of each monomer per unit time continuously or stepwise. . The polymerization initiator may be charged into the reaction vessel from the beginning, may be dropped into the reaction vessel, or these may be combined according to the purpose.

  In the polymerization of the monomer component, a chain transfer agent can be preferably used. When a chain transfer agent is used, the molecular weight of the resulting copolymer can be easily adjusted. Only one type of chain transfer agent may be used, or two or more types may be used.

  Any appropriate chain transfer agent can be adopted as the chain transfer agent. Examples of such chain transfer agents include thiol chain transfer agents such as mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, and 2-mercaptoethanesulfonic acid; Secondary alcohols such as isopropanol; phosphorous acid, hypophosphorous acid, and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionite, metabisulfite, And lower salts of salts thereof (sodium sulfite, potassium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, sodium dithionite, potassium dithionite, sodium metabisulfite, potassium metabisulfite, etc.) and salts thereof, etc. Is mentioned.

  The produced copolymer can be used as it is as a copolymer contained in the cement dispersant of the present invention, but from the viewpoint of handleability, the pH of the reaction solution after the production of the copolymer is 5 or more. It is preferable to adjust. In this case, in order to improve the polymerization rate, it is preferable to perform polymerization at a pH lower than 5 and adjust the pH to 5 or higher after the polymerization. The pH can be adjusted, for example, using an alkaline substance such as an inorganic salt such as monovalent metal or divalent metal hydroxide or carbonate; ammonia; organic amine;

  The produced copolymer can be subjected to concentration adjustment, if necessary, with respect to the solution obtained by the production.

  The produced copolymer may be used as it is in the form of a solution, or neutralized with a divalent metal hydroxide such as calcium or magnesium to obtain a polyvalent metal salt and then dried, You may use it by making it powder by carrying | supporting to inorganic powders, such as a silica type fine powder, and making it dry.

  The cement dispersant of the present invention may contain any appropriate other component within the range not impairing the effects of the present invention, in addition to the copolymer as described above.

  Examples of other components include other cement dispersants. When other cement dispersant is used, the blending ratio of the copolymer contained in the cement dispersant of the present invention and the other cement dispersant (copolymer / other cement dispersant) may be used. Any appropriate blending ratio can be set depending on the type, blending conditions, test conditions, and the like. Such a blending ratio is preferably 50 to 100/50 to 0, more preferably 60 to 100/40 to 0, and still more preferably 70 to 50% as a mass ratio (mass%) in terms of solid content. 100 / 30-0. Only one type of other cement dispersant may be used, or two or more types may be used.

  Examples of other cement dispersants include, for example, a sulfonic acid-based dispersant having a sulfonic acid group in the molecule, and a polycarboxylic acid-based dispersant other than the polycarboxylic acid-based copolymer contained in the cement dispersant composition of the present invention. Etc.

  Examples of the sulfonic acid-based dispersant include polyalkylaryl sulfonate-based sulfonic acid-based dispersants such as naphthalene sulfonic acid formaldehyde condensate, methyl naphthalene sulfonic acid formaldehyde condensate and anthracene sulfonic acid formaldehyde condensate; melamine sulfonic acid Melamine formalin sulfonate-based sulfonic acid dispersants such as formaldehyde condensates; Aromatic amino sulfonate-based sulfonic acid dispersants such as aminoaryl sulfonic acid-phenol-formaldehyde condensates; lignin sulfonates, Examples thereof include lignin sulfonate sulfonic acid dispersants such as modified lignin sulfonate; polystyrene sulfonate sulfonic acid dispersants;

  The cement dispersant of the present invention can contain any appropriate other cement additive (material) as long as the effects of the present invention are not impaired. Examples of such other cement additives (materials) include other cement additives (materials) exemplified in the following (1) to (12). The blending ratio of the copolymer contained in the cement dispersant of the present invention and such other cement additives (materials) is arbitrarily appropriate depending on the type and purpose of the other cement additives (materials) used. Various mixing ratios can be employed.

(1) Water-soluble polymer substances: nonionic cellulose ethers such as methylcellulose, ethylcellulose, carboxymethylcellulose; polysaccharides produced by microbial fermentation such as yeast glucan, xanthan gum, β-1.3 glucans; polyethylene glycol, etc. Polyoxyalkylene glycols; polyacrylamide and the like.

(2) Polymer emulsion: Copolymers of various vinyl monomers such as alkyl (meth) acrylate.

(3) Curing retarder: oxycarboxylic acid or salt thereof such as gluconic acid, glucoheptonic acid, alabonic acid, malic acid, citric acid; sugar and sugar alcohol; polyhydric alcohol such as glycerin; aminotri (methylenephosphonic acid) Phosphonic acid and its derivatives.

(4) Early strengthening agents / accelerators: soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide and calcium iodide; chlorides such as iron chloride and magnesium chloride; sulfates; potassium hydroxide; Sodium hydroxide; carbonate; thiosulfate; formate such as formic acid and calcium formate; alkanolamine; alumina cement; calcium aluminate silicate.

(5) Oxyalkylene-based antifoaming agent: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; polyoxyalkylene alkyl ethers such as diethylene glycol heptyl ether; polyoxyalkylene acetylene ethers; ) Oxyalkylene fatty acid esters; polyoxyalkylene sorbitan fatty acid esters; polyoxyalkylene alkyl (aryl) ether sulfate salts; polyoxyalkylene alkyl phosphate esters; polyoxypropylene polyoxyethylene laurylamine (propylene oxide 1-20) Mole additions, ethylene oxide 1-20 mol adducts, etc.), fatty acid-derived amines obtained from cured beef tallow added with alkylene oxide (propylene oxide 1-20 mol) Additionally, polyoxyalkylene alkyl amines ethylene oxide 20 mol adduct) or the like; polyoxyalkylene amide.

(6) Antifoaming agents other than oxyalkylene type: Mineral oil type, fat type, fatty acid type, fatty acid ester type, alcohol type, amide type, phosphate ester type, metal soap type, silicone type and the like.

(7) AE agent: resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, ABS (alkylbenzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl) ether, polyoxyethylene alkyl (phenyl) ether Sulfate ester or a salt thereof, polyoxyethylene alkyl (phenyl) ether phosphate ester or a salt thereof, protein material, alkenyl sulfosuccinic acid, α-olefin sulfonate and the like.

(8) Other surfactants: various anionic surfactants; various cationic surfactants such as alkyltrimethylammonium chloride; various nonionic surfactants; various amphoteric surfactants.

(9) Waterproofing agent: fatty acid (salt), fatty acid ester, fats and oils, silicon, paraffin, asphalt, wax and the like.

(10) Rust inhibitor: nitrite, phosphate, zinc oxide and the like.

(11) Crack reducing agent: polyoxyalkyl ether and the like.

(12) Expansion material: Ettlingite, coal, etc.

  Other known cement additives (materials) include cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancers, self-leveling agents, rust preventives, colorants, and antifungal agents. An agent etc. can be mentioned. These known cement additives (materials) may be one kind or two or more kinds.

≪Cement composition≫
The cement composition of the present invention contains the cement dispersant of the present invention. The cement composition of the present invention preferably contains the cement dispersant of the present invention, cement and water.

  Arbitrary appropriate cement can be employ | adopted as a cement contained in the cement composition of this invention. Examples of such cements include Portland cement (ordinary, early strength, ultra-early strength, moderate heat, sulfate resistance and low alkali types thereof), various mixed cements (blast furnace cement, silica cement, fly ash cement), White Portland Cement, Alumina Cement, Super Fast Cement (1 Clinker Fast Cement, 2 Clinker Fast Cement, Magnesium Phosphate Cement), Grout Cement, Oil Well Cement, Low Exothermic Cement (Low Exothermic Blast Furnace Cement, Low Fly Ash Mixing) Exothermic blast furnace cement, belite high-content cement), ultra-high strength cement, cement-based solidified material, eco-cement (cement produced from one or more of municipal waste incineration ash and sewage sludge incineration ash). Furthermore, fine powders and gypsum such as blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica powder, and limestone powder may be added to the cement composition of the present invention. The cement contained in the cement composition of the present invention may be only one type or two or more types.

  The cement composition of the present invention may contain any appropriate aggregate such as fine aggregate (sand or the like) or coarse aggregate (crushed stone or the like).

  Examples of such aggregates include gravel, crushed stone, granulated slag, and recycled aggregate. Examples of such aggregates include refractory aggregates such as siliceous, clay, zircon, high alumina, silicon carbide, graphite, chromic, chromic, and magnesia.

In the cement composition of the present invention, any appropriate value can be set as the unit water amount per 1 m ³ , the amount of cement used, and the water / cement ratio. Such values, preferably, unit water is ^{100kg / m 3 ~185kg / m 3} , the amount of cement used is ^{250kg / m 3 ~800kg / m 3} , water / cement ratio (mass ratio) = is 0.1 to 0.7, more preferably, a unit water amount is ^{120kg / m 3 ~175kg / m 3} , the amount of cement used is ^{270kg / m 3 ~800kg / m 3} , water / cement ratio ( (Mass ratio) = 0.12 to 0.65. As described above, the cement composition of the present invention can be widely used from poor blending to rich blending, and can be used for both high-strength concrete with a large amount of unit cement and poor blended concrete with a unit cement amount of 300 kg / m ³ or less. It is valid.

  As a content ratio of the copolymer contained in the cement dispersant of the present invention in the cement composition of the present invention, any appropriate content ratio can be adopted depending on the purpose. As such a content ratio, when used for mortar or concrete using hydraulic cement, the content ratio of the copolymer contained in the cement dispersant of the present invention is preferably 0 with respect to 100 parts by mass of cement. 0.01 parts by mass to 10 parts by mass, more preferably 0.02 parts by mass to 5 parts by mass, and still more preferably 0.05 parts by mass to 3 parts by mass. By setting it as such a content rate, various favorable effects, such as reduction of unit water amount, an increase in intensity | strength, and an improvement in durability, are brought about. When the content ratio is less than 0.01 parts by mass, sufficient performance may not be exhibited. When the content ratio exceeds 10 parts by mass, the effect that can be achieved substantially reaches its peak and also from the economical aspect. May be disadvantageous.

  As a content ratio of the cement dispersant of the present invention in the cement composition of the present invention, any appropriate content ratio can be adopted depending on the purpose. As such a content rate, as a content rate of the cement dispersant composition of this invention with respect to 100 mass parts of cement, Preferably it is 0.01 mass part-10 mass parts, More preferably, it is 0.05 mass part-8 mass parts. It is a mass part, More preferably, it is 0.1 mass part-5 mass parts. When the content ratio is less than 0.01 parts by mass, sufficient performance may not be exhibited. When the content ratio exceeds 10 parts by mass, the effect that can be achieved substantially reaches its peak and also from the economical aspect. May be disadvantageous.

  The cement composition of the present invention can be effective for ready-mixed concrete, concrete for concrete secondary products, concrete for centrifugal molding, concrete for vibration compaction, steam-cured concrete, shotcrete, and the like. The cement composition of the present invention includes medium-fluidity concrete (concrete with a slump value of 22 to 25 cm), high-fluidity concrete (concrete with a slump value of 25 cm or more and a slump flow value of 50 to 70 cm), self-filling concrete, self It can also be effective for mortar and concrete that require high fluidity, such as leveling materials.

  The cement composition of the present invention may be prepared by blending the constituent components by any appropriate method. For example, the method etc. which knead | mix a structural component in a mixer are mentioned.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples. Unless otherwise specified, the term “part” means mass part, and the term “%” means mass%.

<GPC measurement conditions>
Column used: Tosoh Corporation, TSK guard column SWXL + TSKgel G4000SWXL + G3000SWXL + G2000SWXL
Eluent: A solution prepared by dissolving 115.6 g of sodium acetate trihydrate in a mixed solvent of 10999 g of water and 6001 g of acetonitrile, and adjusting the pH to 6.0 with acetic acid was used.
Sample injection amount: 100 μL
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detector: Nippon Waters Co., 2414 Differential Refraction Detector Analysis Software: Nippon Waters Co., Empower Software + GPC Option Calibration Curve Preparation Standard Material: Polyethylene Glycol [Peak Top Molecular Weight (Mp) 272500, 219300, 107000, 50000, 24000, 12600, 7100, 4250, 1470]
Calibration curve: Prepared by a cubic equation based on the Mp value and elution time of the polyethylene glycol.
Sample preparation: A sample was prepared by dissolving an aqueous solution of a polymer to be measured with the above eluent so that the polymer concentration was 0.5% by mass.

<Analysis of mass average molecular weight>
In the obtained RI chromatogram, the portions that were flat and stable in the baseline immediately before and after elution of the polymer were connected by straight lines, and the polymer was detected and analyzed. However, when monomer, monomer-derived impurities, etc. are partially overlapped with the polymer peak and measured, the polymer part and monomer part are separated by vertically dividing at the most concave part of the overlapping part between them and the polymer, and only the polymer part The molecular weight and molecular weight distribution of were measured. When the polymer portion and other portions could not be completely overlapped and separated, the calculation was made collectively.

<Mortar test>
The mortar test was performed in an environment where the temperature was 20 ° C. ± 1 ° C. and the relative humidity was 60% ± 10%.
The mortar formulation was C / S / W = 587/1350/264 (g). Here, C, S, and W are as follows.
C: Ordinary Portland cement (manufactured by Taiheiyo Cement)
S: Standard sand for cement strength test (Cement Association)
W: Ion exchange aqueous solution of polymer (copolymer) and antifoaming agent As W, the amount of the polymer aqueous solution shown in Table 1 was weighed and MA-404 (manufactured by Pozoris) was used as the antifoaming agent. And 10% by mass with respect to the solid content of the polymer, and further ion-exchanged water was added to obtain a predetermined amount, which was sufficiently uniformly dissolved. In Table 1, the addition amount of the polymer is represented by mass% of the polymer solid content with respect to the cement mass.
A stainless beater (stirring blade) was attached to a Hobart mortar mixer (model number N-50, manufactured by Hobart), C and W were added, and kneaded at a first speed for 30 seconds. Furthermore, S was added over 30 seconds while kneading at a first speed. After the completion of S addition, after kneading for 30 seconds in duplicate, the mixer was stopped, the mortar was scraped off for 15 seconds, and then allowed to stand for 75 seconds. The mixture was allowed to stand for 75 seconds and then kneaded at a second speed for 60 seconds to prepare a mortar.
The mortar was transferred from the kneading container to a 1 L polyethylene container, stirred with a spatula 20 times, and then immediately packed in a half of the flow cone (described in JIS R5201-1997) placed on a flow table (described in JIS R5201-1997). I struck with a stick with a turn, and stuffed the mortar to the full extent of the flow cone, struck with a stick with a turn of 15 times, and finally made up the shortage to smooth the surface of the flow cone. Thereafter, 5 minutes, 30 minutes and 60 minutes after the preparation of the mortar, the flow cone was immediately pulled up vertically, and the diameter of the expanded mortar (the diameter of the longest part (major axis) and the part forming 90 degrees with respect to the major axis) ) Was measured at two locations, and the average value was taken as the flow value. Further, a value of (flow value after 60 minutes / 5 flow values after 5 minutes) × 100 was calculated as a flow retention rate (%).

[Example 1]
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser was charged with 112.0 parts of ion-exchanged water, heated to 58 ° C., and then charged with 72.6 parts of water with 3-methyl-3-butene. 137-21 parts of unsaturated alcohol obtained by adding 10 moles of ethylene oxide to -1-ol, 19.25 parts of acrylic acid, 13.67 parts of 2-acrylamido-2-methylpropanesulfonic acid, 0.32 of 3-mercaptopropionic acid An aqueous solution in which parts were dissolved, an aqueous solution in which 2.17 parts of ammonium persulfate were dissolved in 14.51 parts of water, and an aqueous solution in which 0.42 parts of L-ascorbic acid were dissolved in 27.87 parts of water were added dropwise over 5 hours. did. Thereafter, the temperature is maintained at 58 ° C. for 60 minutes to complete the polymerization reaction, the temperature is lowered to 50 ° C. or lower, neutralized to a pH of 6 to 7 using a 30% aqueous solution of sodium hydroxide, Mass average molecular weight having a structural unit derived from saturated alcohol (78% by mass), a structural unit derived from sodium acrylate (14% by mass), and a structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid (8% by mass) Of 31000 and Mw / Mn of 2.69 were obtained.
Various evaluation results are shown in Tables 1 and 2.

[Example 2]
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser was charged with 112.0 parts of ion-exchanged water, heated to 58 ° C., and then charged with 73.75 parts of water with 3-methyl-3-butene. 147-79 parts of unsaturated alcohol obtained by adding 10 moles of ethylene oxide to -1-ol, 10.82 parts of acrylic acid, 14.09 parts of 2-acrylamido-2-methylpropanesulfonic acid, 0.26 of 3-mercaptopropionic acid An aqueous solution in which parts were dissolved, an aqueous solution in which 1.82 parts of ammonium persulfate was dissolved in 12.19 parts of water, and an aqueous solution in which 0.35 parts of L-ascorbic acid was dissolved in 26.93 parts of water were dropped over 5 hours. did. Thereafter, the temperature is maintained at 58 ° C. for 60 minutes to complete the polymerization reaction, the temperature is lowered to 50 ° C. or lower, neutralized to a pH of 6 to 7 using a 30% aqueous solution of sodium hydroxide, Mass average molecular weight having a structural unit derived from saturated alcohol (84% by mass), a structural unit derived from sodium acrylate (8% by mass), and a structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid (8% by mass) Of 14000 and an Mw / Mn of 1.75 was obtained as an aqueous solution of a cement dispersant.
Various evaluation results are shown in Tables 1 and 2.

Example 3
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser was charged with 112.0 parts of ion-exchanged water, heated to 58 ° C., and then charged with 71.54 parts of water with 3-methyl-3-butene. 126.65 parts of unsaturated alcohol obtained by adding 10 mol of ethylene oxide to -1-ol, 26.97 parts of acrylic acid, 14.14 parts of 2-acrylamido-2-methylpropanesulfonic acid, 0.36 of 3-mercaptopropionic acid An aqueous solution in which 2.49 parts of ammonium persulfate was dissolved in 16.69 parts of water, and an aqueous solution in which 0.48 parts of L-ascorbic acid were dissolved in 28.66 parts of water were added dropwise over 5 hours. did. Thereafter, the temperature is maintained at 58 ° C. for 60 minutes to complete the polymerization reaction, the temperature is lowered to 50 ° C. or lower, neutralized to a pH of 6 to 7 using a 30% aqueous solution of sodium hydroxide, Mass average molecular weight having a structural unit derived from saturated alcohol (72% by mass), a structural unit derived from sodium acrylate (20% by mass), and a structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid (8% by mass) Of 49000 and Mw / Mn of 3.60 was obtained as an aqueous solution of a cement dispersant.
Various evaluation results are shown in Tables 1 and 2.

[Comparative Example 1]
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser was charged with 112.0 parts of ion-exchanged water, heated to 58 ° C., and then charged with 72.93 parts of water with 3-methyl-3-butene. -13-08 parts of unsaturated alcohol obtained by adding 10 mol of ethylene oxide to -1-ol, 20.13 parts of methacrylic acid, 13.65 parts of 2-acrylamido-2-methylpropanesulfonic acid, 0.30 of 3-mercaptopropionic acid An aqueous solution in which 2.04 parts of ammonium persulfate was dissolved in 13.68 parts of water, and an aqueous solution in which 0.39 parts of L-ascorbic acid was dissolved in 27.79 parts of water were dropped over 5 hours. did. Thereafter, the temperature is maintained at 58 ° C. for 60 minutes to complete the polymerization reaction, the temperature is lowered to 50 ° C. or lower, neutralized to a pH of 6 to 7 using a 30% aqueous solution of sodium hydroxide, Mass average molecular weight having a structural unit derived from saturated alcohol (78% by mass), a structural unit derived from sodium methacrylate (14% by mass), and a structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid (8% by mass) Was obtained and an aqueous solution of a cement dispersant having an Mw / Mn of 1.67 was obtained.
Various evaluation results are shown in Tables 1 and 2.

[Comparative Example 2]
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser was charged with 112.0 parts of ion-exchanged water, heated to 58 ° C., and then charged with 72.62 parts of water with 3-methyl-3-butene. An aqueous solution in which 150.88 parts of unsaturated alcohol obtained by adding 10 moles of ethylene oxide to -1-ol, 19.25 parts of acrylic acid, and 0.29 part of 3-mercaptopropionic acid are dissolved, and ammonium persulfate is added to 16.35 parts of water. An aqueous solution in which 2.02 parts were dissolved and an aqueous solution in which 0.39 parts of L-ascorbic acid was dissolved in 26.19 parts of water were added dropwise over 5 hours. Thereafter, the temperature is maintained at 58 ° C. for 60 minutes to complete the polymerization reaction, the temperature is lowered to 50 ° C. or lower, neutralized to a pH of 6 to 7 using a 30% aqueous solution of sodium hydroxide, An aqueous solution of a cement dispersant having a structural unit derived from a saturated alcohol (86% by mass) and a structural unit derived from sodium acrylate (14% by mass) and having a mass average molecular weight of 26000 and Mw / Mn of 2.20 was obtained.
Various evaluation results are shown in Tables 1 and 2.

[Comparative Example 3]
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser was charged with 112.0 parts of ion-exchanged water, heated to 58 ° C., and then charged with 72.22 parts of water with 3-methyl-3-butene -13-53 parts of unsaturated alcohol obtained by adding 10 mol of ethylene oxide to -1-ol, 18.20 parts of maleic acid, 13.38 parts of 2-acrylamido-2-methylpropanesulfonic acid, 0.26 of 3-mercaptopropionic acid An aqueous solution in which parts are dissolved, an aqueous solution in which 1.76 parts of ammonium persulfate are dissolved in 14.25 parts of water, and an aqueous solution in which 0.34 parts of L-ascorbic acid are dissolved in 30.07 parts of water are dropped over 5 hours. did. Thereafter, the temperature is maintained at 58 ° C. for 60 minutes to complete the polymerization reaction, the temperature is lowered to 50 ° C. or lower, neutralized to a pH of 6 to 7 using a 30% aqueous solution of sodium hydroxide, Mass average molecular weight having a structural unit derived from saturated alcohol (78% by mass), a structural unit derived from sodium maleate (14% by mass), and a structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid (8% by mass) Was obtained and an aqueous solution of a cement dispersant having an Mw / Mn of 1.62 was obtained.
Various evaluation results are shown in Tables 1 and 2.

[Comparative Example 4]
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser was charged with 112.0 parts of ion-exchanged water, heated to 58 ° C., and then charged with 74.50 parts of water with 3-methyl-3-butene. -15-91 parts of unsaturated alcohol obtained by adding 10 moles of ethylene oxide to -1-ol, 5.35 parts of acrylic acid, 14.11 parts of 2-acrylamido-2-methylpropanesulfonic acid, 0.23 of 3-mercaptopropionic acid An aqueous solution in which 1.59 parts of ammonium persulfate was dissolved in 10.66 parts of water, and an aqueous solution in which 0.31 part of L-ascorbic acid was dissolved in 26.34 parts of water were dropped over 5 hours. did. Thereafter, the temperature is maintained at 58 ° C. for 60 minutes to complete the polymerization reaction, the temperature is lowered to 50 ° C. or lower, neutralized to a pH of 6 to 7 using a 30% aqueous solution of sodium hydroxide, Mass average molecular weight having a structural unit derived from saturated alcohol (88% by mass), a structural unit derived from sodium acrylate (4% by mass), and a structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid (8% by mass) Was obtained and an aqueous solution of a cement dispersant having an Mw / Mn of 1.52 was obtained.
Various evaluation results are shown in Tables 1 and 2.

[Comparative Example 5]
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser was charged with 112.0 parts of ion-exchanged water, heated to 58 ° C, and then charged with 69.70 parts of water with 3-methyl-3-butene. 109.15 parts of unsaturated alcohol obtained by adding 10 mol of ethylene oxide to -1-ol, 40.44 parts of acrylic acid, 14.07 parts of 2-acrylamido-2-methylpropanesulfonic acid, 0.44 of 3-mercaptopropionic acid An aqueous solution in which 3.05 parts of ammonium persulfate was dissolved in 20.44 parts of water, and an aqueous solution in which 0.59 parts of L-ascorbic acid was dissolved in 30.12 parts of water were added dropwise over 5 hours. did. Thereafter, the temperature is maintained at 58 ° C. for 60 minutes to complete the polymerization reaction, the temperature is lowered to 50 ° C. or lower, neutralized to a pH of 6 to 7 using a 30% aqueous solution of sodium hydroxide, Mass average molecular weight having a structural unit derived from saturated alcohol (62% by mass), a structural unit derived from sodium acrylate (30% by mass), and a structural unit derived from 2-acrylamido-2-methylpropanesulfonic acid (8% by mass) Of 75,000 and Mw / Mn of 4.86 was obtained as an aqueous solution of a cement dispersant.
Various evaluation results are shown in Tables 1 and 2.

  In Tables 1 and 2, IPN-10 is an unsaturated alcohol obtained by adding 10 mol of ethylene oxide to 3-methyl-3-buten-1-ol, SAA is sodium acrylate, SMAA is sodium methacrylate, and SMA is maleic acid Sodium and AMPS mean 2-acrylamido-2-methylpropanesulfonic acid.

  From Table 1, for example, the following can be seen. That is, comparing Comparative Example 1 with Example 1, it can be seen that when methacrylic acid is used instead of acrylic acid, fluidity cannot be obtained even if the amount of cement dispersant added is increased. Further, when Comparative Example 2 is compared with Example 1, when the sulfonic acid (salt) group-containing monomer is not used, the flow retention rate is higher than that of Example 1 even if the amount of cement dispersant added is increased. It turns out that it has fallen. Furthermore, when Comparative Example 3 is compared with Example 1, when maleic acid is used instead of acrylic acid, the flow retention is greatly reduced compared to Example 1 even if the amount of cement dispersant added is increased. You can see that

  From Table 2, for example, the following can be seen. That is, when Comparative Example 4 and Comparative Example 5 are compared with Examples 1 to 3, if the acrylic acid content exceeds 4 parts by mass and falls outside the range of less than 30 parts by mass, fluidity may not be obtained. I understand.

  The cement dispersant of the present invention is suitably used for cement compositions such as cement paste, mortar and concrete.

Claims (4)

Structural unit (I) derived from unsaturated polyalkylene glycol alkenyl ether monomer (a) represented by general formula (1) and unsaturated carboxylic acid monomer (b) represented by general formula (2) A copolymer having the structural unit (III) derived from the structural unit (II) derived from the sulfonic acid (salt) group-containing monomer (c) represented by the general formula (3),
The total content of the structural unit (I), the structural unit (II), and the structural unit (III) in the copolymer is 50% by mass to 100% by mass,
When the total of the structural unit (I), the structural unit (II) and the structural unit (III) is 100 parts by mass, the content ratio of the structural unit (II) is 8 parts by mass or more and less than 30 parts by mass. ,
Cement dispersant.

(In General Formula (1), R ¹ , R ² , and R ³ are the same or different and represent a hydrogen atom or a methyl group, and R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. R ^a O represents an oxyalkylene group having 2 to 18 carbon atoms, n represents an average added mole number of the oxyalkylene group represented by R ^a O, and n is an integer of 1 to 500. , X is an integer from 0 to 2, and y is 0. )

(In General Formula (2), R ⁵ and R ⁶ are the same or different and each represents a hydrogen atom or a methyl group, R ⁷ represents a hydrogen atom, and X represents a hydrogen atom, a methyl group, an ethyl group, or an alkali metal. Represents an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group.)

(In General Formula (3), R ⁸ is a hydrogen atom or a methyl group, Y is —NH— or —O—, R ⁹ is an alkylene group having 1 to 10 carbon atoms, and M is a hydrogen atom. , A metal atom, an ammonium group (which constitutes an ammonium salt, ie, SO ₃ NH ₄ ), or an organic amino group (which constitutes an organic amine salt). The cement dispersant according to claim 1 , wherein in the general formula (2), R ⁵ , R ⁶ , and R ⁷ are all hydrogen atoms. The sulfonic acid (salt) group-containing monomer (c) represented by the general formula (3) is 2-acrylamido-2-methylpropanesulfonic acid (salt) represented by the general formula (4). The cement dispersant according to claim 1 or 2 .

(In the general formula (4), M is a hydrogen atom, a metal atom, an ammonium group (ammonium salt, ie, SO ₃ NH ₄ is constituted), or an organic amino group (an organic amine salt is constituted).) A cement composition comprising the cement dispersant according to any one of claims 1 to 3 .