JP2014218619A - Copolymer and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copolymer which can be suitably used for a dispersant, a cement admixture, a cement composition, and the like, which can exhibit a remarkably excellent property of maintaining fluidity for a long term and to provide a dispersant, a cement admixture, and a cement composition containing such a copolymer.SOLUTION: The copolymer comprises a structural unit (I) derived from an unsaturated polyalkylene glycol-based monomer (a) represented by a specific structural formula and a structural unit (II) derived from a hydrolyzable monomer (b) represented by a specific structural formula. Of total structural units constituting the copolymer, a content ratio of the structural unit (II) is 51 mol% or more.

Description

  The present invention relates to a copolymer. In detail, it is related with the copolymer which can be used suitably for a dispersing agent, a cement admixture, a cement composition, etc.

  Copolymers are used in various applications such as dispersants, cement admixtures, cement compositions, water treatment agents, scale inhibitors, and the like. Among these uses, as a main component of the cement admixture, it is indispensable for constructing civil engineering and building structures from cement compositions such as cement paste, mortar and concrete.

  A cement admixture containing such a copolymer is used as a water reducing agent, etc., and improves the strength and durability of the cured product by increasing the fluidity of the cement composition to reduce the water content of the cement composition. Have In addition, as a water reducing agent, a water reducing agent such as a naphthalene type has been conventionally used. However, a cement admixture mainly composed of a copolymer such as a polycarboxylic acid type copolymer has a high water reducing performance. Therefore, it has come to have many use results as a high performance AE water reducing agent.

  As such a cement admixture, recently, in addition to water reduction performance (dispersion performance) with respect to a cement composition, there is a demand for a cement admixture that can improve cure delay and develop strength early. For example, a concrete secondary product (precast concrete product) is made by pouring concrete into a formwork at a factory and then transported to the site where it is assembled. In order to save labor, it is required that the mold can be removed from the mold at an early stage. Also, in the field of ready-mixed concrete, if the concrete is hardened quickly after being placed, it is possible to quickly move to the next step. Therefore, development of a cement admixture that can develop strength at an early stage is desired. However, the conventional cement admixture has a high degree of curing delay, and does not exhibit sufficient strength at the initial stage of curing.

  Therefore, a cement dispersant essentially comprising a copolymer containing a structural unit derived from an unsaturated (poly) alkylene glycol ether monomer having an alkenyl group having 4 carbon atoms and a structural unit derived from an unsaturated monocarboxylic acid monomer. (See Patent Document 1), a cement admixture containing a structural unit derived from an unsaturated polyalkylene glycol ether monomer, a structural unit derived from an unsaturated carboxylic acid monomer, and a structural unit derived from an ester unsaturated monomer (patent Reference 2) and the like have been developed, and it is possible to improve the delay in hardening of the cement composition and to develop early strength as well as exhibiting dispersibility.

  However, in the conventional copolymer, it has not been possible to achieve remarkably excellent long-term fluidity retention.

JP 2002-121055 A JP 2011-84459 A

  The subject of this invention is providing the copolymer which can be used suitably for a dispersing agent, a cement admixture, a cement composition, etc. which can express the remarkably outstanding long-term fluidity retention property. Moreover, it is providing the dispersing agent, cement admixture, and cement composition containing such a copolymer.

（一般式（１）中、Ｙは炭素数２〜４のアルケニル基を表し、Ｒ^１Ｏは炭素数２〜１８のオキシアルキレン基の１種または２種以上を表し、Ｒ^２は水素原子または炭素数１〜１８のアルキル基を表し、ｍはオキシアルキレン基の平均付加モル数であって１〜５００である。）

（一般式（２）中、Ｒ^３、Ｒ^４、Ｒ^５は水素原子または炭素数１〜１８のアルキル基を表し、Ｒ^６Ｏは炭素数２〜１８のオキシアルキレン基の１種または２種以上を表し、Ｒ^７は水素原子または炭素数１〜１８のアルキル基を表し、ｎはオキシアルキレン基の平均付加モル数であって０〜５００である。ただし、ｎ＝０の場合は、Ｒ^７は炭素数１〜１８のアルキル基を表す。） The copolymer of the present invention is
Structural unit (I) derived from unsaturated polyalkylene glycol ether monomer (a) represented by general formula (1) and structural unit derived from hydrolyzable monomer (b) represented by general formula (2) A copolymer comprising (II),
The content rate of this structural unit (II) in all the structural units which comprise this copolymer is 51 mol% or more.

(In General Formula (1), Y represents an alkenyl group having 2 to 4 carbon atoms, R ¹ O represents one or more oxyalkylene groups having 2 to 18 carbon atoms, and R ² represents a hydrogen atom or Represents an alkyl group having 1 to 18 carbon atoms, and m is an average added mole number of an oxyalkylene group and is 1 to 500.)

(In General Formula (2), R ³ , R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and R ⁶ O is one or two kinds of oxyalkylene groups having 2 to 18 carbon atoms. R ⁷ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and n is an average added mole number of an oxyalkylene group, and is 0 to 500. However, when n = 0, R 7 ⁷ represents an alkyl group having 1 to 18 carbon atoms.)

  In a preferred embodiment, Y is an alkenyl group having 4 carbon atoms in the general formula (1).

  In preferable embodiment, Y is a methallyl group in the said General formula (1).

  In a preferred embodiment, the hydrolyzable monomer (b) represented by the general formula (2) is hydroxyethyl acrylate.

  In a preferred embodiment, the copolymer includes a structural unit (III) derived from an unsaturated carboxylic acid monomer (c).

  In a preferred embodiment, the unsaturated carboxylic acid monomer (c) is a (meth) acrylic acid monomer.

  The dispersant of the present invention contains the copolymer of the present invention.

  The cement admixture of the present invention contains the copolymer of the present invention.

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

  ADVANTAGE OF THE INVENTION According to this invention, the copolymer which can be used suitably for a dispersing agent, a cement admixture, a cement composition, etc. which can express the remarkably outstanding long-term fluidity retention property can be provided. Moreover, the dispersing agent, cement admixture, and cement composition containing such a copolymer can be provided.

（一般式（１）中、Ｙは炭素数２〜４のアルケニル基を表し、Ｒ^１Ｏは炭素数２〜１８のオキシアルキレン基の１種または２種以上を表し、Ｒ^２は水素原子または炭素数１〜１８のアルキル基を表し、ｍはオキシアルキレン基の平均付加モル数であって１〜５００である。）

（一般式（２）中、Ｒ^３、Ｒ^４、Ｒ^５は水素原子または炭素数１〜１８のアルキル基を表し、Ｒ^６Ｏは炭素数２〜１８のオキシアルキレン基の１種または２種以上を表し、Ｒ^７は水素原子または炭素数１〜１８のアルキル基を表し、ｎはオキシアルキレン基の平均付加モル数であって０〜５００である。ただし、ｎ＝０の場合は、Ｒ^７は炭素数１〜１８のアルキル基を表す。） ≪Copolymer≫
The copolymer of the present invention comprises a structural unit (I) derived from an unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) and a hydrolyzability represented by the general formula (2). And the structural unit (II) derived from the monomer (b).

(In General Formula (1), Y represents an alkenyl group having 2 to 4 carbon atoms, R ¹ O represents one or more oxyalkylene groups having 2 to 18 carbon atoms, and R ² represents a hydrogen atom or Represents an alkyl group having 1 to 18 carbon atoms, and m is an average added mole number of an oxyalkylene group and is 1 to 500.)

(In General Formula (2), R ³ , R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and R ⁶ O is one or two kinds of oxyalkylene groups having 2 to 18 carbon atoms. R ⁷ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and n is an average added mole number of an oxyalkylene group, and is 0 to 500. However, when n = 0, R 7 ⁷ represents an alkyl group having 1 to 18 carbon atoms.)

  The copolymer of the present invention may contain only one type of structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1). And 2 or more types may be contained.

The structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a) represented by the above general formula (1) in the copolymer of the present invention is specifically the above general formula. (1) A structural unit in which the polymerizable unsaturated double bond of the alkenyl group Y in (1) is cleaved by polymerization to form a single bond. For example, when the alkenyl group Y is represented by P = Q-, the structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) is represented by the general formula ( I).

  In the general formula (1), Y represents an alkenyl group having 2 to 4 carbon atoms. Y is preferably an alkenyl group having 3 to 4 carbon atoms, more preferably an alkenyl group having 4 carbon atoms, and still more preferably a methallyl group in that the effects of the present invention can be further expressed. Examples of Y include a vinyl group, allyl group, methallyl group, and 3-butenyl group. Among these, an allyl group and a methallyl group are particularly preferable, and a methallyl group is most preferable in that the effects of the present invention can be further exhibited.

In the general formula (1), R ¹ O represents one or more of oxyalkylene groups having 2 to 18 carbon atoms. R ¹ O is preferably one or more types of oxyalkylene groups having 2 to 8 carbon atoms, and more preferably one or more types of oxyalkylene groups having 2 to 4 carbon atoms. Examples of R ¹ O include an oxyethylene group, an oxypropylene group, an oxybutylene group, and an oxystyrene group. Examples of the addition format of R ¹ O include random addition, block addition, and alternate addition. In order to secure a balance between hydrophilicity and hydrophobicity, it is preferable that an oxyethylene group contains an oxyethylene group as an essential component. More specifically, with respect to 100 mol% of all oxyalkylene groups, 50 mol% or more is more preferably an oxyethylene group, 70 mol% or more is more preferably an oxyethylene group, and 90 mol% or more. Is particularly preferably an oxyethylene group, and most preferably 100 mol% is an oxyethylene group.

  In the above general formula (1), m is the average number of added moles of the oxyalkylene group, and m is 1 to 500. m is preferably 1 to 300, more preferably 20 to 250, still more preferably 50 to 200, particularly preferably 100 to 200, and most preferably 120 to 150. When m falls within the above range, the use of the copolymer of the present invention can effectively eliminate the setting delay of concrete. As m is smaller, there is a possibility that the problem of setting delay of concrete may occur, and the hydrophilicity of the resulting polymer is lowered, and the dispersibility may be lowered. If m is too large, the copolymerization reactivity may decrease.

In the general formula (1), R ² represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. Examples of the alkyl group having 1 to 18 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, cyclohexyl group, 2-ethylhexyl group, n- An octyl group, an isooctyl group, a lauryl group, a stearyl group, etc. are mentioned. In the general formula (1), R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a hydrogen atom or a methyl group. Is more preferable.

  Examples of the unsaturated polyalkylene glycol ether monomer (a) include unsaturated alcohols such as 3-buten-1-ol, 2-buten-1-ol, and 2-methyl-2-propen-1-ol. And a compound obtained by adding 1 to 500 moles of alkylene oxide.

  Specific examples of the unsaturated polyalkylene glycol ether monomer (a) include polyethylene glycol mono (3-butenyl) ether, polyethylene glycol mono (2-butenyl) ether, and polyethylene glycol mono (2-methyl). -2-propenyl) ether, polyethylene polypropylene glycol mono (2-methyl-2-propenyl) ether, methoxypolyethylene glycol mono (2-methyl-2-propenyl) ether, ethoxypolyethylene glycol mono (2-methyl-2-propenyl) Ether, 1-propoxypolyethylene glycol mono (2-methyl-2-propenyl) ether, cyclohexyloxypolyethylene glycol mono (2-methyl-2-propenyl) ether, 1-octyloxypo Ethylene glycol mono (2-methyl-2-propenyl) ether, nonylalkoxy polyethylene glycol mono (2-methyl-2-propenyl) ether, lauryl alkoxy polyethylene glycol mono (2-methyl-2-propenyl) ether, stearyl alkoxy polyethylene glycol Examples include mono (2-methyl-2-propenyl) ether, phenoxypolyethylene glycol mono (2-methyl-2-propenyl) ether, and naphthoxypolyethylene glycol mono (2-methyl-2-propenyl) ether.

  The copolymer of the present invention may contain only one type of structural unit (II) derived from the hydrolyzable monomer (b) represented by the general formula (2), or two or more types. It may be.

  The structural unit (II) derived from the hydrolyzable monomer (b) represented by the general formula (2) in the copolymer of the present invention is specifically the polymerization in the general formula (2). The structural unit in which the unsaturated double bond is cleaved by polymerization to form a single bond.

In said general formula (2), R < ³ >, R < ⁴ >, R < ⁵ > represents a hydrogen atom or a C1-C18 alkyl group. Examples of the alkyl group having 1 to 18 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, cyclohexyl group, 2-ethylhexyl group, n- An octyl group, an isooctyl group, a lauryl group, a stearyl group, etc. are mentioned. In the general formula (2), R ³ , R ⁴ and R ⁵ are preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Further, a hydrogen atom or a methyl group is more preferable. In the above general formula (2), particularly preferably, R ³ , R ⁴ and R ⁵ are all hydrogen atoms, or R ³ and R ⁴ are all hydrogen atoms and R ⁵ is a methyl group.

In the general formula (2), ^{R 6} O represents one kind or two or more kinds of oxyalkylene group having 2 to 18 carbon atoms. R ⁶ O is preferably one or more of oxyalkylene groups having 2 to 8 carbon atoms, more preferably one or more of oxyalkylene groups having 2 to 4 carbon atoms. Examples of R ⁶ O include an oxyethylene group, an oxypropylene group, an oxybutylene group, and an oxystyrene group. Examples of the addition format of R ⁶ O include random addition, block addition, and alternate addition. In order to secure a balance between hydrophilicity and hydrophobicity, it is preferable that an oxyethylene group contains an oxyethylene group as an essential component. More specifically, with respect to 100 mol% of all oxyalkylene groups, 50 mol% or more is more preferably an oxyethylene group, 70 mol% or more is more preferably an oxyethylene group, and 90 mol% or more. Is particularly preferably an oxyethylene group, and most preferably 100 mol% is an oxyethylene group.

In said general formula (2), n is the average addition mole number of an oxyalkylene group, and n is 0-500. n is preferably 0 to 300, more preferably 0 to 100, still more preferably 0 to 10, particularly preferably 0 to 3, and most preferably 0 to 1. When n is within the above range, it is possible to provide a copolymer that can be used for a dispersant, a cement admixture, a cement composition, and the like, which can express remarkably excellent long-term fluidity retention. When n = 0, R ⁷ represents an alkyl group having 1 to 18 carbon atoms, and the hydrolyzable monomer (b) represented by the general formula (2) is an unsaturated carboxylic acid alkyl ester. Even if it is such a form, the copolymer which can be used suitably for a dispersing agent, a cement admixture, a cement composition, etc. which can express the outstanding outstanding long-term fluidity | liquidity can be provided.

In the general formula (2), R ⁷ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. Examples of the alkyl group having 1 to 18 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, cyclohexyl group, 2-ethylhexyl group, n- An octyl group, an isooctyl group, a lauryl group, a stearyl group, etc. are mentioned. In the general formula (1), R ⁷ is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a hydrogen atom or a methyl group. An ethyl group is more preferable.

  Specifically, as the hydrolyzable monomer (b) represented by the general formula (2), for example, an unsaturated carboxylic acid alkyl such as alkyl (meth) acrylate which is an esterified product of alcohol and (meth) acrylic acid. Ester; (Poly) alkylene glycol mono (meth) acrylate, which is an esterified product of alkylene glycol (alkylene oxide) having 2 to 18 carbon atoms and (meth) acrylic acid; addition of alkylene glycol having 2 to 18 carbon atoms to alcohol And an alkoxy (poly) alkylene glycol (meth) acrylate, which is an esterified product of an alkoxy (poly) alkylene glycol and (meth) acrylic acid. Among these, as the hydrolyzable monomer (b) represented by the general formula (2), hydroxyethyl acrylate (particularly 2-hydroxyethyl acrylate) is preferable.

  In the present specification, “(meth) acryl” means acryl and / or methacryl, and “(meth) acrylate” means acrylate and / or methacrylate. In the present specification, “(poly) alkylene” means alkylene and / or polyalkylene.

  Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol, C1-C30 aliphatic alcohols such as 3-hexanol, octanol, 2-ethyl-1-hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol; C3-C30 alicyclics such as cyclohexanol Alcohol; unsaturated alcohols having 1 to 30 carbon atoms such as (meth) allyl alcohol, 3-buten-1-ol, 3-methyl-3-buten-1-ol; and the like. These alcohols may be used alone or in combination of two or more. Among these alcohols, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol are preferable.

  As said C2-C18 alkylene glycol, Preferably it is C2-C8 alkylene glycol, More preferably, it is C2-C4 alkylene glycol. Examples of such alkylene glycol include ethylene glycol, propylene glycol, butylene glycol, isobutylene glycol, methyl ethylene glycol, octylene glycol, styrene glycol, and the like, and preferably ethylene glycol. Such alkylene glycol may be only one kind or two or more kinds. In the case of two or more kinds of alkylene glycols, the addition reaction may be in any form such as random addition, block addition, and alternate addition. The proportion of ethylene glycol in the total amount of alkylene glycol used is 100 mol%, preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, particularly preferably. Is 90 mol% or more, most preferably 100 mol%. Sufficient dispersibility can be exhibited when the proportion of ethylene glycol in the total amount of alkylene glycol used is 100 mol% within the above range.

  Examples of the unsaturated carboxylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, glycidyl (meth) acrylate, methyl crotonate, ethyl crotonate, and propyl crotonate. It is done. Among these, from the viewpoints of polymerizability and hydrolyzability, the unsaturated carboxylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester such as methyl acrylate, ethyl acrylate, or propyl acrylate.

  Examples of the (poly) alkylene glycol mono (meth) acrylate include hydroxyalkyl (meth) such as hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate. Acrylates; alkanediol mono (meth) acrylates such as 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate and 1,6-hexanediol mono (meth) acrylate; polyethylene glycol mono (Meth) acrylate, {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate Polyalkylene glycol mono (meth) acrylates such as {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} mono (meth) acrylate; and the like. Among these, hydroxyalkyl acrylates such as hydroxyethyl acrylate (particularly 2-hydroxyethyl acrylate) and hydroxypropyl acrylate (particularly 2-hydroxypropyl acrylate) are preferred from the viewpoints of polymerizability and hydrolyzability.

  Examples of the alkoxy (poly) alkylene glycol (meth) acrylate include methoxyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxy {polyethylene glycol (poly) propylene glycol} (meth) acrylate, and methoxy {polyethylene. Glycol (poly) butylene glycol} (meth) acrylate, methoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; ethoxyethylene glycol (meth) acrylate, ethoxy polyethylene glycol (meth) acrylate, ethoxy { Polyethylene glycol (poly) propylene glycol} (meth) acrylate, ethoxy {polyethylene glycol (Poly) butylene glycol} (meth) acrylate, ethoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; propoxyethylene glycol (meth) acrylate, propoxypolyethylene glycol (meth) acrylate, propoxy {Polyethylene glycol (poly) propylene glycol} (meth) acrylate, propoxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, propoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; butoxy Ethylene glycol (meth) acrylate, butoxypolyethylene glycol (meth) acrylate, butoxy {poly Tylene glycol (poly) propylene glycol} (meth) acrylate, butoxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, butoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; pentyloxy Ethylene glycol (meth) acrylate, pentyloxypolyethylene glycol (meth) acrylate, pentyloxy {polyethylene glycol (poly) propylene glycol} (meth) acrylate, pentyloxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, pentyloxy {Polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; Hexyloxyethylene glycol (meth) acrylate, hexyloxypolyethylene glycol (meth) acrylate, hexyloxy {polyethylene glycol (poly) propylene glycol} (meth) acrylate, hexyloxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, Hexyloxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; heptyloxyethylene glycol (meth) acrylate, heptyloxypolyethylene glycol (meth) acrylate, heptyloxy {polyethylene glycol (poly) propylene glycol} (Meth) acrylate, heptyloxy {polyethylene glycol (poly) butylene glycol } (Meth) acrylate, heptyloxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; octyloxyethylene glycol (meth) acrylate, octyloxypolyethylene glycol (meth) acrylate, octyloxy { Polyethylene glycol (poly) propylene glycol} (meth) acrylate, octyloxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, octyloxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; Nonyloxy polyethylene glycol (meth) acrylate, nonyloxy {polyethylene glycol (poly) propylene glycol Lumpur} (meth) acrylate, nonyloxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, nonyloxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; and the like.

  The copolymer of the present invention may contain only one type of structural unit (III) derived from the unsaturated carboxylic acid monomer (c), or may contain two or more types.

  The unsaturated carboxylic acid monomer (c) may be an unsaturated monocarboxylic acid monomer (c1) or an unsaturated dicarboxylic acid monomer (c2). The structural unit derived from the unsaturated carboxylic acid monomer (c) when the unsaturated carboxylic acid monomer (c) is the unsaturated monocarboxylic acid monomer (c1) is (III-1). The structural unit derived from the unsaturated carboxylic acid monomer (c) when the unsaturated carboxylic acid monomer (c) is the unsaturated dicarboxylic acid monomer (c2) is defined as (III-2). .

  The unsaturated carboxylic acid monomer (c) is preferably an unsaturated monocarboxylic acid monomer (c1), and more preferably a (meth) acrylic acid monomer. Examples of the (meth) acrylic acid-based monomer include (meth) acrylic acid and salts and derivatives thereof, preferably acrylic acid, acrylate, methacrylic acid, and methacrylate, more preferably , Acrylic acid, acrylate. The salt here is any of a metal atom, an ammonium group, and an organic amine group as described above.

The unsaturated monocarboxylic acid monomer (c1) is preferably represented by the general formula (3-1).

The structural unit (III-1) derived from the unsaturated monocarboxylic acid monomer (c1) represented by the general formula (3-1) is specifically represented by the general formula (III-1). Is done.

In general formula (3-1) and general formula (III-1), R < ⁸ >, R <^9> , R < ¹⁰ > is the same or different and represents a hydrogen atom or a methyl group.

In the general formula (3-1) and the general formula (III-1), R ⁸ and R ⁹ are preferably both hydrogen atoms, and R ¹⁰ is a hydrogen atom, in that the effects of the present invention can be further exhibited. Or it is preferably a methyl group.

In General Formula (3-1) and General Formula (III-1), M ¹ represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group.

  Any appropriate metal atom can be adopted as the metal atom. Examples of such metal atoms include monovalent metal atoms such as lithium, sodium and potassium; divalent metal atoms such as alkaline earth metal atoms such as calcium and magnesium; and the like.

  As the organic amine group, any appropriate organic amine group can be adopted as long as it is a protonated organic amine. Examples of the organic amine group include alkanolamine groups such as ethanolamine group, diethanolamine group and triethanolamine group, and triethylamine group.

  Any appropriate unsaturated monocarboxylic acid monomer can be adopted as the unsaturated monocarboxylic acid monomer (c1). The unsaturated monocarboxylic acid monomer (c1) is preferably a (meth) acrylic acid monomer. Specific examples include acrylic acid, methacrylic acid, crotonic acid, and monovalent metal salts, divalent metal salts, ammonium salts, and organic amine salts thereof. From the viewpoint of copolymerization, the unsaturated monocarboxylic acid monomer (c) is more preferably (meth) acrylic acid and / or a salt thereof (monovalent metal salt, divalent metal salt, ammonium salt). Organic amine salts and the like, and more preferably acrylic acid and / or salts thereof (monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts, etc.).

The unsaturated dicarboxylic acid monomer (c2) is preferably represented by the general formula (3-2).

The structural unit (III-2) derived from the unsaturated dicarboxylic acid monomer (c2) represented by the general formula (3-2) is specifically represented by the general formula (III-2). The

In General Formula (3-2) and General Formula (III-2), R ¹¹ , R ¹² and R ¹³ are the same or different and each represents a hydrogen atom, a methyl group, or — (CH ₂ ) _n COOM ³ group. , R ¹¹ , R ¹² , R ¹³ is only a — (CH ₂ ) _n COOM ³ group. n is 0-2.

In General Formula (3-2) and General Formula (III-2), M ² and M ³ are the same or different and each represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group.

  Any appropriate metal atom can be adopted as the metal atom. Examples of such metal atoms include monovalent metal atoms such as lithium, sodium and potassium; divalent metal atoms such as alkaline earth metal atoms such as calcium and magnesium; and the like.

  As the organic amine group, any appropriate organic amine group can be adopted as long as it is a protonated organic amine. Examples of the organic amine group include alkanolamine groups such as ethanolamine group, diethanolamine group and triethanolamine group, and triethylamine group.

  Any appropriate unsaturated dicarboxylic acid monomer can be adopted as the unsaturated dicarboxylic acid monomer (c2). Specific examples of the unsaturated dicarboxylic acid monomer (c2) include maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, and monovalent metal salts, divalent metal salts thereof, Examples thereof include ammonium salts and organic amine salts. The unsaturated dicarboxylic acid monomer (c2) is preferably maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, and salts thereof (monovalent metal salt, divalent metal salt, ammonium salt) More preferably, maleic acid, fumaric acid, citraconic acid, itaconic acid, and salts thereof (monovalent metal salt, divalent metal salt, ammonium salt, organic amine salt, etc.), etc. And α, β-unsaturated dicarboxylic acid monomers.

  The total content of the structural unit (I) and the structural unit (II) in the copolymer of the present invention is preferably 50% by weight to 100% by weight, more preferably 70% by weight to 100%. % By weight, more preferably 80% by weight to 100% by weight, particularly preferably 90% by weight to 100% by weight, and most preferably 95% by weight to 100% by weight. If the total content ratio of the structural unit (I) and the structural unit (II) in the copolymer of the present invention is within the above range, it is possible to express remarkably excellent long-term fluidity retention. The copolymer which can be used suitably for an agent, a cement admixture, a cement composition, etc. can be provided.

  The total content of the structural unit (I) and the structural unit (II) in the copolymer of the present invention can be known, for example, by various structural analyzes (for example, NMR) of the copolymer. it can. In addition, the structural units derived from the various monomers calculated based on the amount of the various monomers used when producing the copolymer of the present invention without performing the various structural analyzes as described above. It is good also as a total content rate of the said structural unit (I) and the said structural unit (II) in the copolymer of this invention with a content rate.

  The total content of the structural unit (I), the structural unit (II), and the structural unit (III) in the copolymer of the present invention is preferably 50% by weight to 100% by weight, and more Preferably, it is 70 to 100% by weight, more preferably 80 to 100% by weight, particularly preferably 90 to 100% by weight, and most preferably 95 to 100% by weight. . If the total content of the structural unit (I), the structural unit (II) and the structural unit (III) in the copolymer of the present invention is within the above range, the outstanding long-term fluidity It is possible to provide a copolymer that can be used for a dispersant, a cement admixture, a cement composition, and the like that can exhibit retention.

  The total content of the structural unit (I), the structural unit (II) and the structural unit (III) in the copolymer of the present invention is, for example, various structural analyzes of the copolymer (for example, NMR etc.). In addition, the structural units derived from the various monomers calculated based on the amount of the various monomers used when producing the copolymer of the present invention without performing the various structural analyzes as described above. The content ratio may be the total content ratio of the structural unit (I), the structural unit (II), and the structural unit (III) in the copolymer of the present invention.

  The content ratio of the structural unit (II) in all the structural units constituting the copolymer of the present invention is 51 mol% or more, preferably 55 mol% to 99 mol%, more preferably 60 mol% to 90 mol%, More preferably, it is 65 mol%-85 mol%, Most preferably, it is 70 mol%-80 mol%, Most preferably, it is 70 mol%-75 mol%. When the content ratio of the structural unit (II) in all the structural units constituting the copolymer of the present invention falls within the above range, a remarkably excellent long-term fluidity retention can be expressed. The copolymer which can be used suitably for an agent, a cement composition, etc. can be provided.

  The polycarboxylic acid copolymer for cement admixture of the present invention may contain only one type of structural unit (IV) derived from other monomer (d), or two or more types. May be.

  Specific examples of the other monomer (d) include half esters and diesters of the unsaturated dicarboxylic acid monomer (c2) and an alcohol having 1 to 30 carbon atoms; Half amides and diamides of a dicarboxylic acid monomer (c2) and an amine having 1 to 30 carbon atoms; a half ester of an alkyl (poly) alkylene glycol and the unsaturated dicarboxylic acid monomer (c2); Diesters; half esters and diesters of the above unsaturated dicarboxylic acid monomer (c2) and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols; Alkoxy (poly) alkylene glycol obtained by adding 1 to 500 mol of alkylene oxide having 2 to 18 carbon atoms to ) Esters with unsaturated monocarboxylic acid monomers (c1) such as acrylic acid; (poly) ethylene glycol monomethacrylate, (poly) propylene glycol monomethacrylate, (poly) butylene glycol monomethacrylate, etc. ) 1-500 mol adducts of alkylene oxides having 2-18 carbon atoms to unsaturated monocarboxylic acid monomers (c1) such as acrylic acid; maleamic acid and glycols having 2-18 carbon atoms or these Half-amides of polyalkylene glycols with 2 to 500 moles of glycol added; Triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, (poly) Ethylene glycol (poly) propylene (Poly) alkylene glycol di (meth) acrylates such as recall di (meth) acrylate; bifunctional (meta) such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate ) Acrylates; (poly) alkylene glycol dimaleates such as triethylene glycol dimaleate and polyethylene glycol dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acrylate Roxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2 -Hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutyl sulfonate, (meth) acrylamidomethylsulfonic acid, (meth) acrylamidoethylsulfonic acid, 2-methylpropanesulfonic acid (meth) acrylamide, styrene sulfonic acid, etc. Saturated sulfonic acids, and their monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts; unsaturated monocarboxylic acid monomers (b1) such as methyl (meth) acrylamide and 1 to 1 carbon atoms Amides with 30 amines; Vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene; 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meta ) Acrylate, 1,6-hexanediol mono (meth) acrylate Alkanediol mono (meth) acrylates such as rate; dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene; (meth) acrylamide, (meth) acrylalkyl Unsaturated amides such as amide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; Unsaturated cyanates such as (meth) acrylonitrile, α-chloroacrylonitrile; Vinyl acetate, vinyl propionate, etc. Unsaturated esters; aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, vinyl Unsaturated amines such as pyridine; Divinyl aromatics such as zen; cyanurates such as triallyl cyanurate; allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; unsaturated amino compounds such as dimethylaminoethyl (meth) acrylate; methoxy Polyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxy polyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether, and other vinyl ethers or allyl ethers; polydimethylsiloxanepropylaminomaleamic acid, polydimethylsiloxaneamino Propyleneaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (di (Lopyleneaminomaleamic acid), polydimethylsiloxane- (1-propyl-3-acrylate), polydimethylsiloxane- (1-propyl-3-methacrylate), polydimethylsiloxane-bis- (1-propyl-3-acrylate) And siloxane derivatives such as polydimethylsiloxane-bis- (1-propyl-3-methacrylate);

  The copolymer of the present invention has a weight average molecular weight (Mw) in terms of polyethylene glycol by gel permeation chromatography (GPC), preferably 10,000 to 100,000, more preferably 20,000 to 80,000, and still more preferably 40000. ~ 60000. Provided is a copolymer that can be used suitably for a dispersant, a cement admixture, a cement composition, etc. that can exhibit a significantly excellent long-term fluidity retention because the weight average molecular weight (Mw) is within the above range. can do.

≪Manufacture of copolymer≫
The copolymer of the present invention can be produced by any suitable method. The copolymer of the present invention preferably polymerizes a monomer component containing an unsaturated polyalkylene glycol ether monomer (a) and a hydrolyzable monomer (b) in the presence of a polymerization initiator. It can be manufactured by doing. The copolymer of the present invention uses, for example, an unsaturated alcohol before addition of alkylene oxide instead of the unsaturated polyalkylene glycol ether monomer (a) and a hydrolyzable monomer (b) ) In the presence of a polymerization initiator, followed by addition of alkylene oxide.

  Unsaturated polyalkylene glycol ether monomer (a), hydrolyzable monomer (b), and, if necessary, unsaturated carboxylic acid monomer (c) that can be used in the production of the copolymer of the present invention ) And other monomers (d) may be appropriately adjusted so as to be the proportion of structural units derived from each monomer in all the structural units constituting the copolymer of the present invention described above. Good. Preferably, assuming that the polymerization reaction proceeds quantitatively, each monomer is used in the same proportion as the proportion of structural units derived from each monomer in all the structural units constituting the copolymer of the present invention described above. It ’s fine.

  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 for 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, as a polymerization initiator, a water-soluble polymerization initiator, for example, persulfate such as ammonium persulfate, sodium persulfate, potassium persulfate; hydrogen peroxide; benzoyl peroxide, Peroxides such as lauroyl peroxide, sodium peroxide, t-butyl hydroperoxide, cumene hydroperoxide; azoamidine compounds such as 2,2′-azobis-2-methylpropionamidine hydrochloride; 2,2′-azobis- A cyclic azoamidine compound such as 2- (2-imidazolin-2-yl) propane hydrochloride; an azonitrile compound such as 2-carbamoylazoisobutyronitrile; an azo compound such as azobisisobutyronitrile; In producing the polycarboxylic acid copolymer for cement admixture of the present invention, it is particularly preferable to use a peroxide as the polymerization initiator. Examples of such peroxides include persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate; hydrogen peroxide; benzoyl peroxide, lauroyl peroxide, sodium peroxide, t-butyl hydroperoxide, And peroxides such as cumene hydroperoxide;

In producing the copolymer of the present invention, it is preferable to use the peroxide and a reducing agent in combination as a polymerization initiator. Any appropriate reducing agent can be adopted as such a reducing agent. For example, salts of metals in a low valence state such as iron (II), tin (II), titanium (III), chromium (II), V (II), Cu (II), etc. Amine compounds such as monoethanolamine, diethanolamine, triethanolamine, hydroxylamine, hydroxylamine hydrochloride, hydrazine and their salts; sodium dithionite, sodium formaldehyde sulfoxylate, sodium hydroxymethanesulfinate dihydrate; Organic compounds containing —SH group, —SO ₂ H group, —NHNH ₂ group, —COCH (OH) — group and salts thereof; alkali metal sulfites such as sodium sulfite, sodium bisulfite, metabisulfite; Phosphoric acid, sodium hypophosphite, sodium hydrosulfite, sodium hyponitrite Lower oxides such as D-fructose, D-glucose, etc .; thiourea compounds such as thiourea and thiourea dioxide; L-ascorbic acid (salt), L-ascorbic acid ester, erythorbic acid (salt), Erythorbic acid ester; and the like.

  The combination of the peroxide and the reducing agent is preferably a combination of a water-soluble peroxide and a reducing agent. For example, a combination of hydrogen peroxide and L-ascorbic acid (salt), hydrogen peroxide and A combination of erythorbic acid (salt), a combination of hydrogen peroxide and a molle salt, a combination of ammonium persulfate and sodium hydrogen sulfite, and a combination of ammonium persulfate and L-ascorbic acid (salt) can be mentioned. Particularly preferable combinations in that the effects of the present invention can be expressed more effectively are combinations of hydrogen peroxide and L-ascorbic acid (salt), and combinations of ammonium persulfate and L-ascorbic acid (salt). It is.

  The amount of the peroxide used is preferably 0.01 mol% to 30 mol%, more preferably 0.1 mol% to 20 mol%, based on the total amount of the monomer components, Preferably they are 0.5 mol%-10 mol%. There exists a possibility that an unreacted monomer may increase that the usage-amount of the said peroxide is less than 0.01 mol% with respect to the total amount of a monomer component. If the amount of the peroxide used exceeds 30 mol% with respect to the total amount of the monomer components, a copolymer having a large amount of oligomers may be obtained.

  The amount of the reducing agent to be used is preferably 0.1 mol% to 500 mol%, more preferably 1 mol% to 200 mol%, still more preferably 10 mol% to 100 mol%. When the amount of the reducing agent used is less than 0.1 mol% with respect to the peroxide, active radicals are not sufficiently generated, and the amount of unreacted monomers may increase. When the amount of the reducing agent used exceeds 500 mol% with respect to the peroxide, there is a risk that the reducing agent remaining without reacting with hydrogen peroxide will increase.

  In the polymerization of the monomer component, it is preferable that at least one of the peroxide and the reducing agent is always present in the reaction system. Specifically, it is preferable that the peroxide and the reducing agent are not added simultaneously. If peroxide and reducing agent are simultaneously added at once, the peroxide and reducing agent react rapidly, generating a large amount of reaction heat immediately after the addition, making reaction control difficult, and then radical concentration Therefore, a large amount of unreacted monomer components may remain. Furthermore, the radical concentration with respect to the monomer component is extremely different between the initial and second half of the reaction, so the molecular weight distribution becomes extremely large, and the performance when the resulting copolymer is used as a cement admixture may be reduced. There is. Therefore, for example, it is preferable to employ a method in which both the peroxide and the reducing agent are added over a long period of time, such as a method of continuously adding them by dropping or the like, or a method of adding them separately. The time from when one of the peroxide and the reducing agent is charged to when the other is started is preferably within 5 hours, more preferably within 3 hours.

  Any appropriate reaction temperature may be employed as the reaction temperature for the polymerization of the monomer components as long as the effects of the present invention are not impaired. Such a reaction temperature is preferably 30 ° C to 90 ° C, more preferably 35 ° C to 85 ° C, and further preferably 40 ° C to 80 ° C. If the polymerization reaction temperature is out of the above range, the polymerization rate may be lowered or the productivity may be lowered.

  Any appropriate polymerization time can be adopted as the polymerization time for the polymerization of the monomer component as long as the effects of the present invention are not impaired. The polymerization time is preferably 0.5 hours to 10 hours, more preferably 0.5 hours to 8 hours, and further preferably 1 hour to 6 hours. If the polymerization time is out of the above range, the polymerization rate may be lowered or the productivity may be lowered.

  Any appropriate method can be adopted as a method for 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. Specifically, for example, when an unsaturated polyalkylene glycol ether monomer (a), a hydrolyzable monomer (b), or an unsaturated carboxylic acid monomer (c) is used, the monomer (a) And a method in which the total amount of monomer (b) and the total amount of monomer (c) are continuously charged into the reaction vessel, a part of monomer (a) is initially charged into the reaction vessel, and the monomer ( A method in which the remainder of a), the total amount of monomer (b) and the total amount of monomer (c) are continuously charged into a reaction vessel, a part of monomer (a) and a part of monomer (b) are reacted A method of initially charging the container, and then charging the remainder of the monomer (a), the remainder of the monomer (b), and the total amount of the monomer (c) into the reaction container alternately in several times, etc. Can be mentioned. Furthermore, by changing the charging rate of each monomer into the reaction vessel during the reaction continuously or stepwise, the charging mass ratio per unit time of each monomer is changed continuously or stepwise, Two or more types of copolymers having different ratios of the structural unit (I), the structural unit (II), and the structural unit (III) may be synthesized simultaneously during the polymerization reaction. 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 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. Specific examples of such chain transfer agents include mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, and 3-mercaptopropion. Thiol chain transfer agents such as octyl acid, 2-mercaptoethanesulfonic acid, n-dodecyl mercaptan, octyl mercaptan, butylthioglycolate; halides such as carbon tetrachloride, methylene chloride, bromoform, bromotrichloroethane; Secondary alcohol; phosphorous acid, hypophosphorous acid, and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionic acid, metabisulfite, and salts thereof ( Sodium sulfite, potassium sulfite, Sodium hydrogen sulfate, potassium hydrogen sulfite, sodium dithionite, potassium dithionite, sodium metabisulfite, meta lower oxides of potassium metabisulfite and the like) and salts thereof; and the like.

  In order to obtain a copolymer having a predetermined molecular weight with good reproducibility, it is important to allow the copolymerization reaction to proceed stably. For this reason, when performing solution polymerization, the dissolved oxygen concentration of the solvent used at 25 ° C. is preferably 5 ppm or less, more preferably 0.01 ppm to 4 ppm, and further preferably 0.01 ppm to 2 ppm. Yes, particularly preferably from 0.01 ppm to 1 ppm.

The dissolved oxygen concentration of the solvent may be adjusted in the reaction vessel, or a solvent whose dissolved oxygen amount is adjusted in advance may be used. Examples of the method for driving off oxygen in the solvent include the following methods (1) to (5).
(1) After an inert gas such as nitrogen is pressure-filled in a sealed container containing a solvent, the partial pressure of oxygen in the solvent is lowered by lowering the pressure in the sealed container. You may reduce the pressure in an airtight container under nitrogen stream.
(2) The liquid phase portion is vigorously stirred for a long time while the gas phase portion in the container containing the solvent is replaced with an inert gas such as nitrogen.
(3) An inert gas such as nitrogen is bubbled in the solvent in the container for a long time.
(4) The solvent is once boiled and then cooled in an inert gas atmosphere such as nitrogen.
(5) A static mixer (static mixer) is installed in the middle of the pipe, and an inert gas such as nitrogen is mixed in the pipe for transferring the solvent to the polymerization reaction tank.

  The copolymer obtained by the production method as described above can be used as it is as the polycarboxylic acid copolymer for cement admixture of the present invention, but from the viewpoint of handleability, It is preferable to adjust the pH to 5 or more. In this case, the polymerization may be carried out at a pH of 5 or more, but in this case, the polymerization rate may decrease and at the same time the copolymerizability may deteriorate, so the polymerization is carried out at a pH of less than 5 and the pH is raised to 5 or more after the polymerization. It is preferable to adjust. The pH can be adjusted using, for example, an alkaline substance such as inorganic salt such as hydroxide or carbonate of monovalent metal or divalent metal; ammonia; organic amine;

  The concentration of the copolymer of the present invention can be adjusted as necessary with respect to the solution obtained by the production.

  The copolymer of the present invention may be used as it is in the form of a solution, or may be 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.

≪Use of copolymer≫
The copolymers of the present invention can be used for any suitable application. The copolymer of the present invention can exhibit good performance as a water-insoluble inorganic or organic dispersant, for example. The copolymer of the present invention exhibits good performance as, for example, a dispersant for inorganic pigments such as heavy or light calcium carbonate and clay used in paper coating; a dispersant for water slurries such as cement and coal; obtain. The copolymer of the present invention also has a water treatment agent for preventing scale in a cooling water system, boiler water system, seawater desalination unit, pulp digester, black liquor concentration tank, etc .; scale inhibitor; It can also be suitably used for fiber treatment agents such as prevention aids, adhesives, sealing agents, components for imparting flexibility to various polymers, detergent builders, and the like. The copolymer of the present invention can also be widely applied to body detergents such as shampoos, rinses and body soaps; uses in the fields of fiber processing, building material processing, paints, ceramics, and the like.

  The copolymer of the present invention is preferably used for cement admixture among various uses. In this case, the early strength and fluidity retention can be remarkably expressed with good balance at the same time. It is also useful as a cement admixture for secondary concrete products (precast concrete products).

≪Cement admixture≫
The copolymer of the present invention can be used as a cement admixture of the present invention in combination with any appropriate component as required.

  Examples of the component that can be used as the cement admixture of the present invention in combination with the copolymer of the present invention include a cement dispersant. When a cement dispersant is used, the blending ratio of the copolymer of the present invention to the cement dispersant (copolymer / cement dispersant of the present invention) is determined depending on the type of cement dispersant used, blending conditions, test conditions, etc. Although it is not uniquely determined by the difference, it is preferably 1 to 99/99 to 1, more preferably 5 to 95/95 to 5, more preferably as a weight ratio (% by weight) in terms of solid content. Preferably it is 10-90 / 90-10. Only one cement dispersant may be used, or two or more cement dispersants may be used.

  Examples of the cement dispersant include a sulfonic acid-based dispersant having a sulfonic acid group in the molecule, and a polycarboxylic acid-based dispersant having a polyoxyalkylene chain and a carboxyl group in the molecule.

  The cement admixture 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, for example, water-soluble polymer substances, polymer emulsions, retarders, early strengthening agents / accelerators, mineral oil-based antifoaming agents, fat-based antifoaming agents, and fatty acid-based ones. Antifoam, fatty acid ester antifoam, oxyalkylene antifoam, alcohol antifoam, amide antifoam, phosphate ester antifoam, metal soap antifoam, silicone antifoam , AE agent, surfactant, waterproofing agent, rust preventive agent, crack reducing agent, expansion material, cement wetting agent, thickener, separation reducing agent, flocculant, drying shrinkage reducing agent, strength enhancer, self-leveling agent, Examples thereof include a rust inhibitor, a colorant, and an antifungal agent. The blending ratio of the polycarboxylic acid copolymer for cement admixture of the present invention and such other cement additives (materials) is arbitrary depending on the type and purpose of the other cement additives (materials) used. An appropriate blending ratio can be adopted.

  Examples of particularly preferred embodiments of the cement admixture of the present invention include the following 1) to 7).

1) (1) The copolymer of the present invention, and (2) a combination comprising essentially two components of an oxyalkylene antifoaming agent. The blending weight ratio of the oxyalkylene antifoaming agent (2) is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the copolymer of the present invention (1).

2) (1) Copolymer of the present invention, (2) Polyalkylene glycol mono (meth) acrylate ester having a polyoxyalkylene chain obtained by adding 2 to 300 average addition moles of an alkylene oxide having 2 to 18 carbon atoms Copolymers comprising a monomer based on (meth) acrylic acid monomer and a monomer copolymerizable with these monomers (Japanese Patent Publication No. 59-18338, Japanese Patent Laid-Open No. 7-223852) JP, 9-2441056 A, etc.), (3) Combination which makes the three components of an oxyalkylene type antifoamer essential. The blending weight ratio of the copolymer of the present invention (1) to the copolymer (2) is preferably 5:95 to 95: 5, more preferably 10:90 to 90:10. It is. The blending weight ratio of the oxyalkylene antifoaming agent (3) is preferably 100 parts by weight based on the total amount of the copolymer of the present invention (1) and the copolymer (2). 0.01 parts by weight to 10 parts by weight.

3) (1) The copolymer of the present invention, (2) A combination comprising essentially two components of a sulfonic acid-based dispersant having a sulfonic acid group in the molecule. Examples of the sulfonic acid dispersant include lignin sulfonate, naphthalene sulfonic acid formalin condensate, melamine sulfonic acid formalin condensate, polystyrene sulfonate, aminoaryl sulfonic acid-phenol-formaldehyde condensate and the like. An agent or the like can be used. The blending weight ratio of the copolymer of the present invention (1) to the sulfonic acid dispersant (2) is preferably 5:95 to 95: 5, more preferably 10:90 to 90. : 10.

4) (1) The copolymer of the present invention, (2) A combination comprising two components of lignin sulfonate as essential. The blending weight ratio of the copolymer of the present invention (1) and the lignin sulfonate salt of (2) is preferably 5:95 to 95: 5, more preferably 10:90 to 90: 10.

5) (1) The copolymer of the present invention, (2) A combination which essentially comprises two components of a material separation reducing agent. As a material separation reducing agent, various thickeners such as nonionic cellulose ethers, a hydrophobic substituent composed of a hydrocarbon chain having 4 to 30 carbon atoms as a partial structure, and an alkylene oxide having 2 to 18 carbon atoms are added on average. A compound having a polyoxyalkylene chain having 2 to 300 moles added can be used. The blending weight ratio of the copolymer of the present invention (1) to the material separation reducing agent (2) is preferably 10:90 to 99.99: 0.01, more preferably 50: 50-99.9: 0.1. A cement admixture comprising this combination is suitable for highly fluid concrete, self-filling concrete, self-leveling material and the like.

6) (1) The copolymer of the present invention, (2) A combination comprising two components of the retarder as essential. As the retarder, oxycarboxylic acids such as gluconic acid (salt) and citric acid (salt), sugars such as glucose, sugar alcohols such as sorbitol, phosphonic acids such as aminotri (methylenephosphonic acid), and the like can be used. . In addition, the blending weight ratio of the copolymer of the present invention (1) and the retarder (2) is preferably 50:50 to 99.9: 0.1, more preferably 70:30 to 99: 1.

7) (1) The copolymer of the present invention, (2) A combination comprising two components of an accelerator. As the accelerator, soluble calcium salts such as calcium chloride, calcium nitrite and calcium nitrate, chlorides such as iron chloride and magnesium chloride, formates such as thiosulfate, formic acid and calcium formate, and the like can be used. The blending weight ratio of the copolymer of the present invention (1) and the accelerator (2) is preferably 10:90 to 99.9: 0.1, more preferably 20:80 to 99: 1.

≪Cement composition≫
The cement composition of the present invention comprises the copolymer of the present invention, cement and water.

  The cement composition of the present invention preferably comprises the cement admixture 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, Fly Ash Mix Low 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.

  Any appropriate antifoaming agent may be included in the cement composition of the present invention. Examples of such an antifoaming agent include the various antifoaming agents described above.

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 (weight 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 ( (Weight ratio) = 0.15 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. Further, the cement composition of the present invention has a relatively high water reduction rate, that is, a water / cement ratio (weight ratio) = 0.15 to 0.5 (preferably 0.15 to 0.4). It can be used satisfactorily even in a region with a low cement ratio.

  As a content ratio of the copolymer 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 of the present invention with respect to 100 parts by weight of cement is preferably 0.01 part by weight to 10 parts by weight. Parts, more preferably 0.02 parts by weight to 5 parts by weight, still more preferably 0.05 parts by weight to 3 parts by weight. 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. If the content is less than 0.01 parts by weight, sufficient performance may not be exhibited. If the content is more than 10 parts by weight, the effect that can be achieved substantially reaches its peak and is also economical. May be disadvantageous.

  As the content ratio of the cement admixture 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 admixture of this invention with respect to 100 weight part of cement, Preferably it is 0.01 weight part-10 weight part, More preferably, it is 0.05 weight part-8 weight part. More preferably, it is 0.1 to 5 parts by weight. If the content is less than 0.01 parts by weight, sufficient performance may not be exhibited. If the content is more than 10 parts by weight, the effect that can be achieved substantially reaches its peak and is also economical. May be disadvantageous.

  The cement composition of the present invention may be effective for concrete secondary product concrete, centrifugal molding concrete, vibration compaction concrete, steam-cured concrete, shotcrete, and the like. The cement composition of the present invention may be effective for mortar and concrete that require high fluidity, such as high fluidity concrete, self-filling concrete, and self-leveling material.

  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 “part by weight”, and “%” means “% by weight”. Further, “weight” in this specification may be read as “mass”.

The measurement conditions of the weight average molecular weight (GPC measurement conditions) are as follows.
<GPC measurement conditions>
The GPC measurement conditions are as follows.
Used column: TSK guard column SWXL, manufactured by Tosoh Corporation
TSKgel G4000SWXL
TSKgel G3000SWXL
TSKgel G2000SWXL connected in this order.
Eluent: A solution prepared by dissolving 115.6 g of sodium acetate trihydrate in a solution of 6001 g of acetonitrile and 10999 g of water and adjusting the pH to 6.0 with acetic acid was used.
Sample: A sample was prepared by dissolving an aqueous polymer solution in the eluent so that the polymer concentration was 0.5% by weight.
Sample injection amount: 100 μL
Flow rate: 1.0 mL / min Column temperature: 40 ° C
Detector: Empower Software manufactured by Japan Waters
Standard material for preparing a calibration curve: polyethylene glycol [peak top molecular weight (Mp) 272500, 219300, 107000, 50000, 24000, 11840, 6450, 4250, 1470]
Calibration curve: Prepared by a cubic equation based on the Mp value and elution time of the polyethylene glycol.

[Example 1]: Polymer (1)
In a glass reactor equipped with a thermometer, a stirrer, a dripping device, a nitrogen introduction tube, and a reflux cooling device, 73.7 g of ion-exchanged water, unsaturated polyalkylene glycol having an average of 25 mol of ethylene oxide added to methallyl alcohol 80.9 g of ether and 0.146 g of acrylic acid were charged, the inside of the reactor was purged with nitrogen under stirring, and the mixture was heated to 58 ° C. in a nitrogen atmosphere. While maintaining the inside of the reaction vessel at 58 ° C., 48.83 g of a 2% aqueous hydrogen peroxide solution was added. An aqueous solution prepared by dissolving 7.30 g of acrylic acid and 46.7 g of 2-hydroxyethyl acrylate in 21.5 g of ion-exchanged water was added dropwise over 3 hours while maintaining the inside of the reaction vessel at 58 ° C. An aqueous solution in which 2.53 g of L-ascorbic acid and 1.83 g of 3-mercaptopropionic acid were dissolved in 16.6 g of exchange water was dropped over 3.5 hours. Then, after maintaining the temperature at 58 ° C. for 1 hour, the polymerization reaction was terminated. Thereafter, the acidic reaction solution was neutralized to pH 6 using an aqueous sodium hydroxide solution at a temperature lower than the reaction temperature to obtain an aqueous solution of a weight average molecular weight 26000 polymer (polymer (1)).

[Example 2]: Polymer (2)
In place of the unsaturated polyalkylene glycol ether obtained by adding an average of 25 mol of ethylene oxide to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether obtained by adding an average of 50 mol of ethylene oxide to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were carried out according to Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 35,000 (polymer (2)).

[Example 3]: Polymer (3)
In place of the unsaturated polyalkylene glycol ether having an average of 25 mol of ethylene oxide added to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether having an average of 100 mol of ethylene oxide added to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were performed according to Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 45,000 (polymer (3)).

[Example 4]: Polymer (4)
In place of the unsaturated polyalkylene glycol ether obtained by adding an average of 25 mol of ethylene oxide to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether obtained by adding an average of 150 mol of ethylene oxide to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were performed according to Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 52,000 (polymer (4)).

[Example 5]: Polymer (5)
Instead of the unsaturated polyalkylene glycol ether obtained by adding an average of 25 mol of ethylene oxide to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether obtained by adding an average of 200 mol of ethylene oxide to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were carried out in accordance with Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 56000 (polymer (5)).

[Example 6]: Polymer (6)
Except having changed into the monomer composition of Table 1, it superposed | polymerized and neutralized according to Example 1, and obtained the aqueous solution of the polymer (polymer (6)) of the weight average molecular weight 27000.

[Example 7]: Polymer (7)
In place of the unsaturated polyalkylene glycol ether obtained by adding an average of 25 mol of ethylene oxide to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether obtained by adding an average of 50 mol of ethylene oxide to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were performed according to Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 35,000 (polymer (7)).

[Example 8]: Polymer (8)
In place of the unsaturated polyalkylene glycol ether having an average of 25 mol of ethylene oxide added to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether having an average of 100 mol of ethylene oxide added to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were performed according to Example 1 to obtain an aqueous solution (polymer 8) of a polymer having a weight average molecular weight of 44,000 (polymer (8)). It was.

[Example 9]: Polymer (9)
In place of the unsaturated polyalkylene glycol ether obtained by adding an average of 25 mol of ethylene oxide to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether obtained by adding an average of 150 mol of ethylene oxide to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were carried out in accordance with Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 51,000 (polymer (9)).

[Example 10]: Polymer (10)
Instead of the unsaturated polyalkylene glycol ether obtained by adding an average of 25 mol of ethylene oxide to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether obtained by adding an average of 200 mol of ethylene oxide to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were performed according to Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 54,000 (polymer (10)).

[Comparative Example 1]: Comparative polymer (1)
In place of the unsaturated polyalkylene glycol ether in which an average of 75 moles of ethylene oxide was added to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether in which an average of 100 moles of ethylene oxide was added to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were carried out in accordance with Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 44,000 (comparative polymer (1)).

[Comparative Example 2]: Comparative polymer (2)
In place of the unsaturated polyalkylene glycol ether obtained by adding an average of 75 mol of ethylene oxide to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether obtained by adding an average of 200 mol of ethylene oxide to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were carried out according to Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 54,000 (comparative polymer (2)).

[Comparative Example 3]: Comparative polymer (3)
In place of the unsaturated polyalkylene glycol ether in which an average of 75 moles of ethylene oxide was added to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether in which an average of 150 moles of ethylene oxide was added to methallyl alcohol was used. Except for changing to the monomer composition described in 1., polymerization and neutralization were performed according to Example 1 to obtain an aqueous solution of a polymer having a weight average molecular weight of 53,000 (comparative polymer (3)).

  Table 1 shows the types and composition ratios of the raw material monomers of the polymers in each Example and Comparative Example.

Each abbreviation in Table 1 is as follows.
MAL25: Unsaturated polyalkylene glycol ether obtained by adding an average of 25 mol of ethylene oxide to methallyl alcohol MAL50: Unsaturated polyalkylene glycol ether obtained by adding an average of 50 mol of ethylene oxide to methallyl alcohol MAL100: An average of 100 mol of methallyl alcohol Unsaturated polyalkylene glycol ether MAL150 with ethylene oxide added: Unsaturated polyalkylene glycol ether MAL200 with an average of 150 moles of ethylene oxide added to methallyl alcohol MAL200: Unsaturated polyalkylene glycol ether with an average of 200 moles of ethylene oxide added to methallyl alcohol HEA: 2-hydroxyethyl acrylate AA: acrylic acid

[Mortar test]
Mortar was prepared using the polymers (1) to (10) obtained in Examples 1 to 10 and the comparative polymers (1) to (3) obtained in Comparative Examples 1 to 3, and slump flow was performed by the following method. Value, slump flow value change with time, and air volume. In addition, the material used for the test, the forced kneading mixer, and the measuring instruments are conditioned in this test temperature atmosphere so that the temperature of the mortar becomes 20 ° C. The kneading and each measurement are performed in this test temperature atmosphere. I went there. The results are shown in Table 2. In Table 2, “polymer use amount (% / cement)” means the ratio (% by weight) of the weight of the copolymer in terms of solid content to the total amount of cement of 100% by weight.

(Preparation of aqueous cement admixture)
Weigh out a predetermined amount of polymer aqueous solution, add antifoaming agent “MA404” (manufactured by Pozzolith Products Co., Ltd.) 10% by weight with respect to the polymer content, and further add ion-exchanged water to 210 g, sufficiently uniform Dissolved.

(Contains mortar)
The mortar formulation was C / S / W / = 600/1350/210 (g).
C: Ordinary Portland cement (manufactured by Taiheiyo Cement)
S: ISO standard sand (made by Cement Association)
W: Cement admixture aqueous solution

(Mortar test environment)
The mortar test environment was a temperature of 20 ° C. ± 1 ° C. and a relative humidity of 60% ± 10%.

(Measurement of flow value (15 stroke flow value))
After 600 g of the cement and 210 g of the cement admixture aqueous solution were kneaded at a low speed for 30 seconds with a Hobart type mortar mixer (model No. N-50, manufactured by Hobart), 1350 g of the ISO standard sand was charged over 30 seconds. Next, after kneading at high speed for 30 seconds, the kneading was stopped and the mortar on the wall of the kettle was scraped off over 15 seconds. The mixture was further left for 75 seconds and then kneaded at a high speed for 60 seconds to adjust the mortar.
Half amount of the prepared mortar is packed in a flow cone (JIS R5201: 1997) having a hollow cone with an upper base inner diameter of 70 mm, a lower base inner diameter of 100 mm, and a height of 60 mm placed on a horizontal flow table (JIS R5201: 1997). I struck it 15 times with a stick. In addition, the mortar was filled to the full extent of the flow cone and pierced 15 times with a stick. The flow cone filled with mortar was then gently lifted vertically. Thereafter, the handle is rotated 15 times at a rate of once per second to give an up-and-down motion, the major axis (mm) and minor axis (mm) of the mortar spread on the table are measured, and the average value is obtained as the flow value (15 Stroke flow value). Furthermore, the time when this measurement was performed was set to 0 minute, and thereafter, the entire amount of the mortar was allowed to stand in a sealed container, and after 30 minutes, 65 minutes, and 100 minutes, the same operation was repeated, and the flow value changed with time. It was measured. The amount of the polymer used was adjusted so that the maximum value of the flow value changing with time was within the range of 200 mm to 220 mm.

(Measurement of mortar air volume)
About 200 mL of mortar was packed in a 500 mL glass graduated cylinder and pierced with a round bar having a diameter of 8 mm, and then the container was vibrated to remove coarse bubbles. Further, about 200 mL of mortar was added and air bubbles were similarly removed. Then, the volume and weight were measured, and the amount of air was calculated from the weight and the density of each material.

  As shown in Table 2, in Examples 1 to 10, a 15-stroke flow value of 180 mm or more is exhibited even after 100 minutes, and the fluidity can be maintained for a long time. That is, in this invention, the concrete which is excellent in workability over a long time can be provided.

  The copolymer of this invention is used suitably for various uses, such as a dispersing agent, a cement admixture, and a cement composition.

Claims (9)

Structural unit (I) derived from unsaturated polyalkylene glycol ether monomer (a) represented by general formula (1) and structural unit derived from hydrolyzable monomer (b) represented by general formula (2) A copolymer comprising (II),
The content ratio of the structural unit (II) in all the structural units constituting the copolymer is 51 mol% or more,
Copolymer.

(In General Formula (1), Y represents an alkenyl group having 2 to 4 carbon atoms, R ¹ O represents one or more oxyalkylene groups having 2 to 18 carbon atoms, and R ² represents a hydrogen atom or Represents an alkyl group having 1 to 18 carbon atoms, and m is an average added mole number of an oxyalkylene group and is 1 to 500.)

(In General Formula (2), R ³ , R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and R ⁶ O is one or two kinds of oxyalkylene groups having 2 to 18 carbon atoms. R ⁷ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, and n is an average added mole number of an oxyalkylene group, and is 0 to 500. However, when n = 0, R 7 ⁷ represents an alkyl group having 1 to 18 carbon atoms.)   The copolymer according to claim 1, wherein Y in the general formula (1) is an alkenyl group having 4 carbon atoms.   The copolymer according to claim 2, wherein Y in the general formula (1) is a methallyl group.   The copolymer according to any one of claims 1 to 3, wherein the hydrolyzable monomer (b) represented by the general formula (2) is hydroxyethyl acrylate.   The copolymer according to any one of claims 1 to 4, wherein the copolymer comprises a structural unit (III) derived from an unsaturated carboxylic acid monomer (c).   The copolymer according to claim 5, wherein the unsaturated carboxylic acid monomer (c) is a (meth) acrylic acid monomer.   The dispersing agent containing the copolymer in any one of Claim 1-6.   A cement admixture comprising the copolymer according to any one of claims 1 to 6. A cement composition comprising the copolymer according to any one of claims 1 to 6, cement and water.