JPWO2018088528A1 - Polycarboxylic acid copolymer, concrete admixture, and concrete composition - Google Patents

Abstract

Provided is a polycarboxylic acid-based copolymer capable of expressing both an excellent viscosity reducing effect, an excellent pipe passage property, and an excellent water-reducing property in a well-balanced manner with respect to the hydraulic powder-containing composition. Moreover, the concrete admixture containing such a polycarboxylic acid-type copolymer is provided. Also provided are concrete compositions comprising such concrete admixtures. The polycarboxylic acid copolymer of the present invention is a structural unit (I) derived from an unsaturated polyalkylene glycol monomer (a) represented by a specific general formula with respect to 100% by mass of all structural units: 35% by mass to 88.5% by mass, a carboxylic acid-based structural unit represented by a specific general formula (II): 8% by mass to 35% by mass, and a carboxylic acid represented by a specific general formula (III) Alkyl ester structural unit: It contains 3.5 mass%-30 mass%, and a weight average molecular weight is 30000 or less.

Description

  The present invention relates to a polycarboxylic acid copolymer, a concrete admixture, and a concrete composition.

  A hydraulic powder-containing composition (sometimes referred to as a concrete composition) such as cement paste, mortar, or concrete gives a cured product having excellent strength and durability. The hydraulic powder-containing composition is indispensable for constructing civil engineering and building structures. Here, the hydraulic powder means a powder that hardens in contact with water, for example, Portland cement, calcium silicate, calcium aluminate, calcium fluoroaluminate, calcium sulfoaluminate, calcium alumino. Examples thereof include ferrite, calcium phosphate, hemihydrate gypsum, anhydrous gypsum, and self-hardening quicklime powder.

  The hydraulic powder-containing composition is manufactured at a manufacturing plant, then transported to a construction site, pumped at a placement site, and filled into a mold. When pumping, the hydraulic powder-containing composition may become clogged due to material separation in the pipe, or it may take a long time to transport the viscous hydraulic powder-containing composition. The problem occurs. When filling the mold, if the mold has a complicated shape, the placed hydraulic powder-containing composition does not reach every corner of the mold, and a cured product with the desired shape is obtained. The problem that it is not possible, and the bubble remains on the formwork surface and the problem that the surface aesthetics are impaired.

  In order to solve the above problems, it is effective to lower the viscosity of the hydraulic powder-containing composition. Examples of a method for reducing the viscosity of the hydraulic powder-containing composition include a method for increasing the set flow value and a method for increasing the water / cement ratio. However, when the set flow value is increased, there is a problem that the hydraulic powder-containing composition is likely to be clogged in the pipe due to material separation during pumping. Moreover, when water / cement ratio is made high, the problem that the intensity | strength of the hardened | cured material of a hydraulic powder containing composition falls will generate | occur | produce.

  From the background as described above, there is a demand for a technique that is excellent in pipe passage at the time of pumping and reduces the viscosity of the hydraulic powder-containing composition itself.

  As a conventional technology that lowers the viscosity of the hydraulic powder-containing composition itself, a concrete blended with a polycarboxylic acid copolymer with a shortened side chain length in the structural unit derived from the unsaturated polyalkylene glycol monomer is proposed. (Patent Documents 1-3).

  Many polycarboxylic acid-based copolymers have been reported to be used by blending them in hydraulic powder-containing compositions, but polycarboxylic acid-based polymers that have solved the problem of reducing the viscosity of hydraulic powder-containing compositions themselves As a copolymer, only a polycarboxylic acid copolymer in which the side chain length in the structural unit derived from the unsaturated polyalkylene glycol monomer is shortened has been found. In addition, the use of a polycarboxylic acid copolymer in which the side chain length in the structural unit derived from the unsaturated polyalkylene glycol monomer is shortened makes the viscosity reduction excellent for a hydraulic powder-containing composition. The effect and excellent water reduction cannot be expressed in a balanced manner.

  On the other hand, various polycarboxylic acid-based copolymers have been reported as polycarboxylic acid-based copolymers used by blending with hydraulic powder-containing compositions.

  For example, there is a polycarboxylic acid copolymer having a structural unit derived from an unsaturated polyalkylene glycol ester monomer, a structural unit derived from a carboxylic acid monomer, and a structural unit derived from a carboxylic acid alkyl ester monomer. It has been reported (Patent Documents 4-7). These polycarboxylic acid copolymers are intended to improve the retainability of the hydraulic powder-containing composition, and have an excellent viscosity-reducing effect and an excellent water-reducing property with respect to the hydraulic powder-containing composition. Is not allowed to be expressed in a balanced manner.

  Further, a polycarboxylic acid copolymer having a structural unit derived from an unsaturated polyalkylene glycol ether monomer, a structural unit derived from a carboxylic acid monomer, and a structural unit derived from a carboxylic acid methyl ester monomer is provided. It has been reported (Patent Documents 8-10). In these polycarboxylic acid copolymers, the carboxylic acid methyl ester monomer specifically used is methyl acrylate. These polycarboxylic acid-based copolymers are also intended to improve the retention of the hydraulic powder-containing composition, and have an excellent viscosity-reducing effect and an excellent water-reducing property with respect to the hydraulic powder-containing composition. Is not allowed to be expressed in a balanced manner.

  Further, a structural unit derived from an unsaturated polyalkylene glycol ether monomer, a structural unit derived from a carboxylic acid monomer, and a structural unit derived from a carboxylic acid alkyl ester monomer (the alkyl group has 2 or more carbon atoms). A polycarboxylic acid-based copolymer having the following has been reported (Patent Documents 11 to 14). These polycarboxylic acid-based copolymers are also intended to improve the retention of the hydraulic powder-containing composition, and have an excellent viscosity-reducing effect and an excellent water-reducing property with respect to the hydraulic powder-containing composition. Is not allowed to be expressed in a balanced manner.

  Furthermore, a structural unit derived from an unsaturated polyalkylene glycol ether monomer, a structural unit derived from a carboxylic acid monomer, and a structural unit derived from a (meth) acrylic acid ester having 1 to 4 carbon atoms in the alkyl group. A polycarboxylic acid copolymer has been reported (Patent Document 15). This polycarboxylic acid-based copolymer is intended to reduce the viscosity of concrete, but it achieves a good balance between excellent viscosity-reducing effects and excellent pipe-passability for hydraulic powder-containing compositions. Expression is not allowed.

Japanese Patent No. 3578984 Japanese Patent No. 4290387 Japanese Patent No. 5513577 Japanese Patent Laid-Open No. 10-081549 JP 2000-044309 A JP 2008-543997 A JP 2009-096672 A JP 2010-100199 A JP 2010-120826 A JP 2013-040100 A JP 2012-171818 A JP 2014-024690 A JP 2014-205607 A International Publication No. 2014/010572 Pamphlet JP-T-2006-525938

  An object of the present invention is to provide a polycarboxylic acid copolymer capable of expressing both an excellent viscosity reducing effect, an excellent pipe passage property, and an excellent water reducing property in a balanced manner with respect to the hydraulic powder-containing composition. It is to provide a polymer. Moreover, it is providing the concrete admixture containing such a polycarboxylic acid type copolymer. Moreover, it is providing the concrete composition containing such a concrete admixture.

  The present inventor has studied to solve the above problems. As a result, the specific polyalkylene glycol-based monomer (a) -derived structural unit, the specific carboxylic acid-based structural unit, and the specific carboxylic acid alkyl ester-based structural unit each having a specific content ratio The present inventors have found that a carboxylic acid copolymer can solve the above problems, and have completed the present invention.

（一般式（１）中、Ｒ^１、Ｒ^２、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、ＡＯは、炭素原子数２〜１８のオキシアルキレン基を表し、ｍは、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、ｍは３０〜３００であり、ｘは０〜５の整数であり、ｙは０または１である。）

（一般式（ＩＩ）中、Ｒ^５、Ｒ^６、Ｒ^７は、同一または異なって、水素原子、メチル基、または−（ＣＨ_２）_ｎＣＯＯＭ^２基を表し、ｎは０〜２であり、Ｍ^１とＭ^２は、同一または異なって、水素原子、金属原子、アンモニウム基、または有機アミン基を表し、Ｒ^６とＲ^７は同時に−（ＣＨ_２）_ｎＣＯＯＭ^２基とはならず、Ｒ^７が−（ＣＨ_２）_ｎＣＯＯＭ^２基である場合には、Ｒ^５とＲ^６は、同一または異なって、水素原子またはメチル基である。）

（一般式（ＩＩＩ）中、Ｒ^８とＲ^９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^１０は炭素数２〜１８の炭化水素基または炭素数６〜１８の芳香族炭化水素基を表す。）The polycarboxylic acid copolymer of the present invention is
Structural unit (I) derived from unsaturated polyalkylene glycol monomer (a) represented by general formula (1): 35% by mass to 88.5% by mass with respect to 100% by mass of all structural units, Carboxylic acid structural unit represented by general formula (II): 8% by mass to 35% by mass, and carboxylic acid alkyl ester structural unit represented by general formula (III): 3.5% by mass to 30% by mass And including
The weight average molecular weight is 30000 or less.

(In General Formula (1), R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom or a methyl group, and R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. , AO represents an oxyalkylene group having 2 to 18 carbon atoms, m represents an average addition mole number of the oxyalkylene group represented by AO, m is 30 to 300, and x is 0 to 5 An integer, and y is 0 or 1.)

(In General Formula (II), R ⁵ , R ⁶ , and R ⁷ are the same or different and each represents a hydrogen atom, a methyl group, or — (CH ₂ ) _n COOM ² group, and n is 0 to 2, M ¹ and M ² are the same or different and each represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group, and R ⁶ and R ⁷ are not simultaneously a — (CH ₂ ) _n COOM ² group, ^{When 7} is a — (CH ₂ ) _n COOM ² group, R ⁵ and R ⁶ are the same or different and are a hydrogen atom or a methyl group.)

(In General Formula (III), R ⁸ and R ⁹ are the same or different and each represents a hydrogen atom or a methyl group, and R ¹⁰ represents a hydrocarbon group having 2 to 18 carbon atoms or an aromatic carbon atom having 6 to 18 carbon atoms. Represents a hydrogen group.)

（一般式（１ｅ）中、Ｒ^１、Ｒ^２、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、ＡＯは、炭素原子数２〜１８のオキシアルキレン基を表し、ｍは、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、ｍは３０〜３００であり、ｘは０〜５の整数である。）In one embodiment, the unsaturated polyalkylene glycol monomer (a) is an unsaturated polyalkylene glycol ether monomer (e) represented by the general formula (1e).

(In the general formula (1e), R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom or a methyl group, and R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. , AO represents an oxyalkylene group having 2 to 18 carbon atoms, m represents an average addition mole number of the oxyalkylene group represented by AO, m is 30 to 300, and x is 0 to 5 (It is an integer.)

In one embodiment, R ⁵ in the general formula (II) is a hydrogen atom, R ⁶ is a hydrogen atom, and R ⁷ is a hydrogen atom or a methyl group.

  As one embodiment, the content ratio of the carboxylic acid alkyl ester structural unit represented by the general formula (III) in the polycarboxylic acid copolymer is 4% by mass to 28% by mass.

In one embodiment, R ¹⁰ in the general formula (III) is an alkyl group having 2 to 10 carbon atoms.

  The concrete admixture of the present invention contains the polycarboxylic acid copolymer of the present invention.

  The concrete composition of the present invention contains the concrete admixture of the present invention.

  According to the present invention, a polycarboxylic acid-based copolymer that can exhibit both an excellent viscosity reducing effect, an excellent pipe passage property, and an excellent water reducing property in a balanced manner with respect to the hydraulic powder-containing composition. A polymer can be provided. Moreover, the concrete admixture containing such a polycarboxylic acid-type copolymer can be provided. Moreover, the concrete composition containing such a concrete admixture 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”. In addition, when there is an expression “mass” in the present specification, it may be read as “weight” conventionally used as a unit of weight in general, and conversely, “weight” in the present specification. May be read as “mass”, which is commonly used as an SI system unit indicating weight.

  In this specification, when calculating the content ratio of the structural unit, the content ratio of the monomer, etc., the unsaturated carboxylic acid monomer (b) is a monomer (sodium salt) completely neutralized with sodium. ). For example, when acrylic acid is used as the carboxylic acid monomer (b), the mass ratio (mass%) is calculated assuming that sodium acrylate is used as the carboxylic acid monomer (b).

≪Polycarboxylic acid copolymer≫
The polycarboxylic acid copolymer of the present invention is a structural unit (I) derived from an unsaturated polyalkylene glycol monomer (a) represented by the general formula (1) with respect to 100% by mass of all structural units. : 35% by mass to 88.5% by mass and the carboxylic acid-based structural unit represented by the general formula (II) (structural unit (II)): 8% by mass to 35% by mass and represented by the general formula (III) Carboxylic acid alkyl ester structural unit (structural unit (III)): 3.5% by mass to 30% by mass.

In this specification, “structural unit derived from monomer (x)” (x is any one of a, b, c, and d) means that monomer (x) is converted into a monomer unit by a polymerization reaction. Means the structure. For example, when the monomer (x) is represented by “R ^p R ^q C═CR ^r R ^s ” (R ^p , R ^q , R ^r , and R ^s are the same or different and represent a hydrogen atom or a hetero atom The structural unit derived from the monomer (x) is “—R ^p R ^q C—CR ^r R ^s —”.

  In the polycarboxylic acid copolymer, the structural unit (I) derived from the unsaturated polyalkylene glycol monomer (a) represented by the general formula (1) may be one type or two types. It may be the above.

  In the polycarboxylic acid copolymer, the carboxylic acid structural unit (structural unit (II)) represented by the general formula (II) may be one kind or two or more kinds.

  In the polycarboxylic acid copolymer, the carboxylic acid alkyl ester structural unit (structural unit (III)) represented by the general formula (III) may be one kind or two or more kinds. Good.

  The polycarboxylic acid copolymer may contain other structural units (IV). When the polycarboxylic acid copolymer includes other structural units (IV), the other structural units (IV) in the polycarboxylic acid copolymer may be one type or two or more types. There may be.

  In the polycarboxylic acid copolymer, the total of the structural unit (I), the structural unit (II), the structural unit (III), and the structural unit (IV) is 100% by mass. In the polycarboxylic acid copolymer, the total of the structural unit (I), the structural unit (II), and the structural unit (III) is preferably 100% by mass (that is, does not include the structural unit (IV)).

  The content ratio of the structural unit (I) in the polycarboxylic acid copolymer is 35% by mass to 88.5% by mass with respect to 100% by mass of all the structural units in the polycarboxylic acid copolymer. Preferably they are 37.5 mass%-88 mass%, More preferably, they are 40 mass%-87.5 mass%, More preferably, they are 44 mass%-86.5 mass%, Most preferably, they are 48 mass%. It is -85.5 mass%. When the content ratio of the structural unit (I) in the polycarboxylic acid copolymer is within the above range, the polycarboxylic acid copolymer can exhibit a sufficient steric repulsive force, and the dispersibility is improved. When the polycarboxylic acid copolymer is added to the hydraulic powder-containing composition, the fluidity of the hydraulic powder-containing composition can be further improved.

  The content ratio of the structural unit (II) in the polycarboxylic acid copolymer is 8% by mass to 35% by mass with respect to 100% by mass of all the structural units in the polycarboxylic acid copolymer, preferably It is 8.5 mass%-32 mass%, More preferably, it is 9 mass%-30 mass%, More preferably, it is 9.5 mass%-28 mass%. When the content ratio of the structural unit (II) in the polycarboxylic acid copolymer is within the above range, the polycarboxylic acid copolymer can exhibit sufficient adsorptive power and water solubility, and dispersibility. If the polycarboxylic acid copolymer is added to the hydraulic powder-containing composition, the fluidity of the hydraulic powder-containing composition can be further improved.

  The content ratio of the structural unit (III) in the polycarboxylic acid copolymer is 3.5% by mass to 30% by mass with respect to 100% by mass of all the structural units in the polycarboxylic acid copolymer, Preferably it is 4 mass%-28 mass%, More preferably, it is 4.5 mass%-26 mass%, More preferably, it is 5 mass%-24 mass%, Most preferably, it is 5.5 mass%-24 % By mass. When the content ratio of the structural unit (III) in the polycarboxylic acid copolymer is within the above range, when the polycarboxylic acid copolymer is added to the hydraulic powder-containing composition, the hydraulic powder It is possible to reduce the viscosity of the containing composition and to improve the passage of piping during pumping. Therefore, when the hydraulic powder-containing composition is pumped, it can be transported in a short time without clogging in the piping, and when the mold is filled, the mold has a complicated shape. Even if it has, it is possible to spread the cast hydraulic powder-containing composition to every corner of the mold, and there are few bubbles remaining on the mold surface, which is excellent in surface aesthetics A cured product can be obtained. Moreover, when the content ratio of the structural unit (III) in the polycarboxylic acid copolymer is within the above range, when the polycarboxylic acid copolymer is added to the hydraulic powder-containing composition, The water reducing property of the powder-containing composition can be improved. Therefore, when the content ratio of the structural unit (III) in the polycarboxylic acid copolymer is within the above range, when the polycarboxylic acid copolymer is added to the hydraulic powder-containing composition, An excellent viscosity reducing effect, an excellent pipe passage property, and an excellent water reducing property can be expressed in a well-balanced manner with respect to the powder-containing composition.

  The content ratio of the structural unit (IV) in the polycarboxylic acid copolymer is preferably 0% by mass to 53.5% by mass with respect to 100% by mass of all the structural units in the polycarboxylic acid copolymer. Yes, more preferably 0% by mass to 50% by mass, still more preferably 0% by mass to 40% by mass, and particularly preferably 0% by mass to 30% by mass.

  The content ratio of various structural units in the polycarboxylic acid copolymer can be known, for example, by various structural analyzes (for example, NMR) of the polycarboxylic acid copolymer. In addition, structural units derived from the various monomers calculated based on the amounts of the various monomers used when producing the polycarboxylic acid-based copolymer without performing the various structural analyzes as described above. It is good also as a content rate of various structural units in a polycarboxylic acid-type copolymer. Alternatively, the consumption rate of the monomer in the polymerization reaction may be analyzed by LC (liquid chromatography), and calculation may be made assuming that all of the consumed monomer is converted into a copolymer by the polymerization reaction.

  The weight average molecular weight of the polycarboxylic acid copolymer is 30000 or less, preferably 2000 to 30000, more preferably 4000 to 28000, still more preferably 6000 to 26000, and particularly preferably 8000 to 24000. is there. When the weight average molecular weight is below the above range, when the polycarboxylic acid copolymer is added to the hydraulic powder-containing composition, the water-reducing property of the hydraulic powder-containing composition is reduced, and the hydraulic powder-containing composition There is a risk that the fluidity of the liquid will decrease. If the weight average molecular weight exceeds the above range, the viscosity of the aqueous solution of the polycarboxylic acid copolymer may be increased and it may be difficult to handle. As a result, the polycarboxylic acid copolymer is added to the hydraulic powder-containing composition. Then, there exists a possibility that the viscosity reduction effect of a hydraulic powder containing composition and the outstanding pipe passage property cannot be expressed.

Unsaturated polyalkylene glycol monomer (a) represented by general formula (1), structural unit (I) derived from unsaturated polyalkylene glycol monomer (a) represented by general formula (1) Is specifically represented by the following formula.

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

In General Formula (1) and General Formula (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. It is a hydrogen group, more preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and particularly preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.

  In general formula (1) and general formula (I), AO is an oxyalkylene group having 2 to 18 carbon atoms, preferably an oxyalkylene group having 2 to 8 carbon atoms, more preferably the number of carbon atoms. 2 to 4 oxyalkylene groups. When AO is any two or more selected from oxyethylene group, oxypropylene group, oxybutylene group, oxystyrene group, etc., the addition form of AO is random addition, block addition, alternating addition, etc. Either form may be sufficient. 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 an oxyethylene group.

  In general formula (1) and general formula (I), m represents the average addition mole number of the oxyalkylene group represented by AO, and is 30-300, Preferably it is 32-250, More preferably, 35 It is -200, More preferably, it is 37-150, Especially preferably, it is 40-100, Most preferably, it is 45-70. When m is in the above range, the hydrophilicity of the resulting polycarboxylic acid copolymer can be improved, and the dispersion performance of the polycarboxylic acid copolymer can be improved. Further, when m is in the above range, the resulting polycarboxylic acid copolymer can be added to the hydraulic powder-containing composition, whereby the viscosity of the hydraulic powder-containing composition can be reduced and the pump Pipe passage at the time of pumping can be improved. Therefore, when the hydraulic powder-containing composition is pumped, it can be transported in a short time without clogging in the piping, and when the mold is filled, the mold has a complicated shape. Even if it has, it is possible to spread the cast hydraulic powder-containing composition to every corner of the mold, and there are few bubbles remaining on the mold surface, which is excellent in surface aesthetics A cured product can be obtained. Furthermore, when m is in the above range, when the resulting polycarboxylic acid-based copolymer is added to the hydraulic powder-containing composition, the water reduction of the hydraulic powder-containing composition can be improved. Therefore, when m is within the above range, when the resulting polycarboxylic acid-based copolymer is added to the hydraulic powder-containing composition, it has an excellent viscosity-reducing effect and superior to the hydraulic powder-containing composition. Therefore, it is possible to achieve both good pipe permeability and excellent water reduction in a balanced manner.

  In general formula (1) and general formula (I), x is an integer of 0-5.

  In general formula (1) and general formula (I), y is 0 or 1.

  As the unsaturated polyalkylene glycol monomer (a) represented by the general formula (1), for example, an alkylene oxide having 2 to 18 carbon atoms is polymerized on a saturated aliphatic alcohol having 1 to 20 carbon atoms. An esterified product of polyalkylene glycols obtained in the above and (meth) acrylic acid or crotonic acid; unsaturated fatty alcohols having 3 to 20 carbon atoms such as (meth) allyl alcohol, crotyl alcohol, oleyl alcohol, Esterified product of polyalkylene glycols obtained by polymerizing alkylene oxides having 2 to 18 carbon atoms and (meth) acrylic acid or crotonic acid; alicyclic alcohols having 3 to 20 carbon atoms such as cyclohexanol; Polyalkylene glycols obtained by polymerizing alkylene oxides having 2 to 18 carbon atoms and (meth) acrylic An esterified product with an acid or crotonic acid; a polyalkylene glycol obtained by polymerizing an alkylene oxide having 2 to 18 carbon atoms to an aromatic alcohol having 6 to 20 carbon atoms; and (meth) acrylic acid or crotonic acid; And the like.

  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 30 to 300 moles of alkylene oxide to any of methyl-2-buten-1-ol and 2-methyl-3-buten-1-ol; more preferably 3-methyl-3-butene A compound obtained by adding 30 to 300 mol of alkylene oxide to at least one selected from -1-ol and methallyl alcohol.

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

The unsaturated polyalkylene glycol monomer (a) is preferably an unsaturated polyalkylene glycol ether monomer (e) represented by the general formula (1e).

In the general formula (1e), R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom or a methyl group.

In General Formula (1e), 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. It is a hydrogen group, more preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and particularly preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.

  In the general formula (1e), AO is an oxyalkylene group having 2 to 18 carbon atoms, preferably an oxyalkylene group having 2 to 8 carbon atoms, more preferably an oxyalkylene having 2 to 4 carbon atoms. It is a group. When AO is any two or more selected from oxyethylene group, oxypropylene group, oxybutylene group, oxystyrene group, etc., the addition form of AO is random addition, block addition, alternating addition, etc. Either form may be sufficient. 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 an oxyethylene group.

  In general formula (1e), m represents the average addition mole number of the oxyalkylene group represented by AO, and is 30-300, Preferably it is 32-250, More preferably, it is 35-200, Preferably it is 37-150, Most preferably, it is 40-100, Most preferably, it is 45-70. When m is in the above range, the hydrophilicity of the resulting polycarboxylic acid copolymer can be improved, and the dispersion performance of the polycarboxylic acid copolymer can be improved. Further, when m is in the above range, the resulting polycarboxylic acid copolymer can be added to the hydraulic powder-containing composition, whereby the viscosity of the hydraulic powder-containing composition can be reduced and the pump Pipe passage at the time of pumping can be improved. Therefore, when the hydraulic powder-containing composition is pumped, it can be transported in a short time without clogging in the piping, and when the mold is filled, the mold has a complicated shape. Even if it has, it is possible to spread the cast hydraulic powder-containing composition to every corner of the mold, and there are few bubbles remaining on the mold surface, which is excellent in surface aesthetics A cured product can be obtained. Furthermore, when m is in the above range, when the resulting polycarboxylic acid-based copolymer is added to the hydraulic powder-containing composition, the water reduction of the hydraulic powder-containing composition can be improved. Therefore, when m is within the above range, when the resulting polycarboxylic acid-based copolymer is added to the hydraulic powder-containing composition, it has an excellent viscosity-reducing effect and superior to the hydraulic powder-containing composition. Therefore, it is possible to achieve both good pipe permeability and excellent water reduction in a balanced manner.

  In general formula (1e), x is an integer of 0-5.

  Examples of the unsaturated polyalkylene glycol ether monomer (e) include 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 2-methyl-3-butene- Addition of 30 to 300 moles of alkylene oxide to unsaturated alcohols such as 2-ol, 2-methyl-2-buten-1-ol, 2-methyl-3-buten-1-ol, (meth) allyl alcohol, and vinyl alcohol And the like.

  Specific examples of the unsaturated polyalkylene glycol ether monomer (e) include polyethylene glycol mono (3-methyl-3-butenyl) ether and polyethylene glycol mono (3-methyl-2-butenyl) ether. Polyethylene glycol mono (2-methyl-3-butenyl) ether, polyethylene glycol mono (2-methyl-2-butenyl) ether, polyethylene glycol mono (1,1-dimethyl-2-propenyl) ether, polyethylene polypropylene glycol mono ( 3-methyl-3-butenyl) ether, methoxypolyethylene glycol mono (3-methyl-3-butenyl) ether, ethoxypolyethyleneglycol mono (3-methyl-3-butenyl) ether, 1-propoxypolyethyleneglycol Mono (3-methyl-3-butenyl) ether, cyclohexyloxypolyethyleneglycol mono (3-methyl-3-butenyl) ether, 1-octyloxypolyethyleneglycolmono (3-methyl-3-butenyl) ether, nonylalkoxypolyethyleneglycol Mono (3-methyl-3-butenyl) ether, laurylalkoxypolyethyleneglycolmono (3-methyl-3-butenyl) ether, stearylalkoxypolyethyleneglycolmono (3-methyl-3-butenyl) ether, phenoxypolyethyleneglycolmono (3- Methyl-3-butenyl) ether, naphthoxypolyethylene glycol mono (3-methyl-3-butenyl) ether, polyethylene glycol mono (meth) allyl ether, polyethylene group Glycol monomethyl ether, and vinyl propyl glycol and vinyl oxy butyl polyethylene glycol oxypropylene group and oxybutylene group vinyl oxygen and bond.

  The carboxylic acid structural unit is represented by the general formula (II).

In the general formula ^{(II), R 5, R} 6, R 7 are the same or different, a hydrogen atom, a methyl group or _- represents a _(CH ²⁾ n COOM 2 group. n is 0 to 2, and M ¹ and M ² are the same or different and each represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group. Examples of the metal atom include a monovalent metal atom (such as lithium, sodium and potassium) and a divalent metal atom (such as magnesium and calcium). Examples of the organic amine portion of the organic amine group include ethanolamine, diethanolamine, triethanolamine, and triethylamine. R ⁶ and R ⁷ are not simultaneously a — (CH ₂ ) _n COOM ² group, and when R ⁷ is a — (CH ₂ ) _n COOM ² group, R ⁵ and R ⁶ are the same or different. , A hydrogen atom or a methyl group.

  Examples of the carboxylic acid-based structural unit represented by the general formula (II) include a structural unit (unneutralized product) formed by polymerization of an unsaturated carboxylic acid-based monomer (b), or the structural unit. By a metal atom (for example, lithium, sodium, potassium, magnesium, calcium, etc.), an ammonium group, or an organic amine group (for example, ethanolamine, diethanolamine, triethanolamine, triethylamine, etc. as the organic amine moiety of the organic amine group) Substituted salts (neutralized products) can be mentioned.

In general formula (II), R ⁵ is preferably a hydrogen atom, R ⁶ is preferably a hydrogen atom, and R ⁷ is preferably a hydrogen atom or a methyl group.

  Examples of the unsaturated carboxylic acid monomer (b) include an unsaturated monocarboxylic acid monomer (b-1) and an unsaturated dicarboxylic acid monomer (b-2). The unsaturated carboxylic acid monomer (b) is preferably an unsaturated monocarboxylic acid monomer (b-1).

  Examples of the unsaturated monocarboxylic acid monomer (b-1) include (meth) acrylic acid, crotonic acid, and salts and derivatives thereof, preferably acrylic acid, acrylate, methacrylic acid. , Methacrylate, and more preferably acrylic acid and acrylate. Examples of the salt herein include metal salts, ammonium salts, and organic amine salts.

  Any appropriate metal salt can be adopted as the metal salt. Examples of such metal salts include monovalent metal atomic salts such as lithium salts, sodium salts, and potassium salts; divalent metal atomic salts such as magnesium salts and calcium salts;

  Any appropriate organic amine salt can be adopted as the organic amine salt as long as it is a salt of a protonated organic amine. Examples of the organic amine salt include alkanolamine salts such as ethanolamine salt, diethanolamine salt, and triethanolamine salt, and triethylamine salt.

  Examples of the unsaturated dicarboxylic acid monomer (b-2) include maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, and salts and derivatives thereof, preferably maleic acid, Fumaric acid, itaconic acid, citraconic acid, and salts thereof, and maleic acid and maleate are more preferable. Examples of the salt herein include metal salts, ammonium salts, and organic amine salts.

  Any appropriate metal salt can be adopted as the metal salt. Examples of such metal salts include monovalent metal atomic salts such as lithium salts, sodium salts, and potassium salts; divalent metal atomic salts such as magnesium salts and calcium salts;

  Any appropriate organic amine salt can be adopted as the organic amine salt as long as it is a salt of a protonated organic amine. Examples of the organic amine salt include alkanolamine salts such as ethanolamine salt, diethanolamine salt, and triethanolamine salt, and triethylamine salt.

  The carboxylic acid alkyl ester structural unit is represented by the general formula (III).

In general formula (III), R ⁸ and R ⁹ are the same or different and each represents a hydrogen atom or a methyl group. R ¹⁰ represents a hydrocarbon group having 2 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms.

In general formula (III), R ⁸ is preferably a hydrogen atom.

In general formula (III), R ¹⁰ is preferably an alkyl group having 2 to 10 carbon atoms, more preferably an alkyl group having 2 to 8 carbon atoms, from the viewpoint that the effects of the present invention can be further exhibited.

In general formula (III), as R ¹⁰ , specifically, for example, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, cyclohexyl group, 2-ethylhexyl group N-octyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, tridecyl group, lauryl group, myristyl group, stearyl group, isostearyl group, benzyl group, biphenyl group, naphthyl group, pyrenyl Group, anthryl group, phenanthryl group, dicyclopentenyl group, dicyclopentanyl group, isobornyl group and the like, preferably ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, Cyclohexyl group, 2-ethylhexyl group, n-octyl group, Sooctyl, nonyl, isononyl, decyl, isodecyl, naphthyl, pyrenyl, undecyl, lauryl, biphenyl, tridecyl, myristyl, anthryl, phenanthryl, palmityl, stearyl, isostearyl It is a group.

  Examples of the carboxylic acid alkyl ester structural unit represented by the general formula (III) include a structural unit formed by polymerization of an unsaturated carboxylic acid alkyl ester monomer (c).

  Specific examples of the unsaturated carboxylic acid alkyl ester monomer (c) include ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (Meth) acrylate etc. are mentioned, Preferably, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, ert-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl ( (Meth) acrylate, isodecyl (meth) acrylate, naphthyl (meth) acrylate, pyrenyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, biphenyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) Acrylate, anthryl (meth) acrylate, phenanthryl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, isostearyl Meth) acrylate.

  Examples of the other structural unit (IV) include a structural unit formed by polymerization of another monomer (d).

  As other monomer (d), unsaturated polyalkylene glycol ether monomer (a), unsaturated carboxylic acid monomer (b), unsaturated carboxylic acid alkyl ester monomer (c) Any suitable monomer can be employed as long as it is a monomer copolymerizable with the monomer.

  Examples of the other monomer (d) include hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate; an unsaturated dicarboxylic acid monomer (b-2) and Half esters and diesters with alcohols having 1 to 30 carbon atoms; Half amides and diamides of unsaturated dicarboxylic acid monomers (b-2) and amines with 1 to 30 carbon atoms; alkyl (poly) alkylene glycols Ester and unsaturated dicarboxylic acid monomer (b-2) half ester and diester; unsaturated dicarboxylic acid monomer (b-2) and glycol having 2 to 18 carbon atoms or addition moles of these glycols Half esters and diesters with polyalkylene glycols having 2 to 500 carbon atoms; Esters of alkoxy (poly) alkylene glycols to which 1 to 500 moles of alkylene oxide of -18 are added and unsaturated monocarboxylic acid monomers (b-1) such as (meth) acrylic acid; (poly) ethylene glycol 2-18 carbon atoms into unsaturated monocarboxylic acid monomer (b-1) such as (meth) acrylic acid, such as monomethacrylate, (poly) propylene glycol monomethacrylate, (poly) butylene glycol monomethacrylate 1-500 mole adduct of alkylene oxide; half amide of maleamic acid and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols; triethylene glycol di (meth) acrylate , (Poly) ethylene glycol di (meth) acrylate (Poly) alkylene glycol di (meth) acrylates such as polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate; hexanediol di (meth) acrylate, trimethylolpropane tri ( Bifunctional (meth) acrylates such as (meth) acrylate and trimethylolpropane di (meth) acrylate; (poly) alkylene glycol dimaleates such as triethylene glycol dimaleate and polyethylene glycol dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth ) Acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutylsulfonate, (meth) acrylamidomethylsulfonic acid, (meth) acrylamidoethylsulfone Acids, unsaturated sulfonic acids such as 2-methylpropanesulfonic acid (meth) acrylamide and styrenesulfonic acid, and monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts thereof; methyl (meth) acrylamide and the like Amides of unsaturated monocarboxylic acid monomers (b-1) and amines having 1 to 30 carbon atoms; vinyl aromatic compounds such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene; 1 , 4-Butanediol mono (meth) acrylate Alkanediol mono (meth) acrylates such as 1,5-pentanediol mono (meth) acrylate and 1,6-hexanediol mono (meth) acrylate; butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chloro Dienes such as 1,3-butadiene; unsaturated amides such as (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; (meth) acrylonitrile, unsaturated cyanide compounds such as α-chloroacrylonitrile; unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, ( (Meth) acrylic acid dimethylaminopropy , Unsaturated amines such as dibutylaminoethyl (meth) acrylate and vinylpyridine; divinyl aromatic compounds such as divinylbenzene; cyanurates such as triallyl cyanurate; allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether Compounds; unsaturated amino compounds such as dimethylaminoethyl (meth) acrylate; and the like.

  The polycarboxylic acid-based copolymer of the present invention can be produced by any appropriate method as long as the effects of the present invention are not impaired. The polycarboxylic acid copolymer of the present invention is preferably an unsaturated polyalkylene glycol monomer (a), an unsaturated carboxylic acid monomer (b), and an unsaturated carboxylic acid alkyl ester monomer. It can be produced by polymerizing a monomer component containing (c) and, if necessary, other monomer (d) in the presence of a polymerization initiator.

  Unsaturated polyalkylene glycol monomer (a), unsaturated carboxylic acid monomer (b), and unsaturated carboxylic acid alkyl ester monomer that can be used in the production of the polycarboxylic acid copolymer of the present invention The amount of (c) and, if necessary, the other monomer (d) used is such that the proportion of structural units derived from each monomer in all structural units constituting the polycarboxylic acid copolymer of the present invention is as follows. What is necessary is just to adjust suitably so that it may become what was mentioned above. Preferably, assuming that the polymerization reaction proceeds quantitatively, each unit has the same ratio as the ratio of structural units derived from each monomer in all the structural units constituting the polycarboxylic acid copolymer of the present invention described above. A mer may be used.

  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. These solvents may be used alone or in combination of two or more.

  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 the polymerization initiators, persulfate and hydrogen peroxide are preferable. Among the accelerators, Fe (II) salts such as molle salt and L-ascorbic acid (salt) are preferable. These polymerization initiators and accelerators may be used alone or in combination of two or more.

  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.

As the dissolved oxygen concentration during the polymerization of the monomer component, in order to obtain a polymer with a predetermined molecular weight with good reproducibility, it is necessary to proceed the polymerization reaction stably. The dissolved oxygen concentration at 25 ° C. of the solvent to be used is preferably 5 ppm or less. The dissolved oxygen concentration is more preferably 0.01 ppm to 4 ppm, further preferably 0.01 ppm to 2 ppm, and particularly preferably 0.01 ppm to 1 ppm. In addition, when nitrogen substitution etc. are performed after adding a monomer to a solvent, it is preferable to make the dissolved oxygen concentration of the system | strain containing a monomer into the said range. The dissolved oxygen concentration of the solvent may be adjusted in a polymerization reaction tank, or a dissolved oxygen amount may be adjusted in advance. Examples of the method for driving off oxygen in the solvent include the following methods (1) to (5).
(1) After pressure-filling an inert gas such as nitrogen 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.

  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. Further, the charging rate of each monomer into the reaction vessel may be changed continuously or stepwise during the reaction, and the charging mass ratio per unit time of each monomer may be changed 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. The chain transfer agent may be one type or two or more types.

  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 polycarboxylic acid-based copolymer can be used as it is as the polycarboxylic acid-based copolymer of the present invention, but from the viewpoint of handleability, the reaction solution after the production of the polycarboxylic acid-based copolymer is used. It is preferable to adjust the pH to 5 or more. However, in order to improve the polymerization rate, it is preferable to perform the polymerization at a pH of less than 5 and adjust the pH to 5 or more 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 polycarboxylic acid-based copolymer can be subjected to concentration adjustment, if necessary, with respect to the solution obtained by the production.

  The produced polycarboxylic acid copolymer may be used as it is in the form of a solution, or may be used after powdered.

≪Concrete admixture≫
The concrete admixture of the present invention contains the polycarboxylic acid copolymer of the present invention.

  The concrete admixture of the present invention may contain any appropriate other component in addition to the polycarboxylic acid copolymer of the present invention.

  In the concrete admixture of the present invention, the following (1) to (6) may be mentioned as particularly preferred embodiments for other components.

  (1) <1> A combination comprising essentially two components of the polycarboxylic acid copolymer of the present invention and <2> an oxyalkylene antifoaming agent. As the oxyalkylene-based antifoaming agent, polyoxyalkylenes, polyoxyalkylene acetylene ethers, polyoxyalkylene alkylamines and the like can be used, and polyoxyalkylenes are particularly preferable. In addition, as a compounding mass ratio of <2> oxyalkylene type | system | group antifoamer, the range of 0.01 mass%-20 mass% is preferable with respect to the polycarboxylic acid type copolymer of <1> this invention.

  (2) A combination comprising essentially three components of <1> the polycarboxylic acid copolymer of the present invention, <2> an oxyalkylene antifoaming agent, and <3> an AE agent. As the oxyalkylene-based antifoaming agent, polyoxyalkylenes, polyoxyalkylene acetylene ethers, polyoxyalkylene alkylamines and the like can be used, and polyoxyalkylenes are particularly preferable. As the AE agent, resin soaps, saturated or unsaturated fatty acids, modified rosin acids, alkylaryl sulfonates, polyoxyalkylene alkyl ether sulfates, etc. can be used. Modified rosin acids, alkylaryl sulfonates Is particularly preferred. In addition, as a compounding mass ratio of <2> oxyalkylene type | system | group antifoamer, the range of 0.01 mass%-20 mass% is preferable with respect to the polycarboxylic acid type copolymer of <1> this invention. Moreover, as a compounding mass ratio of <3> AE agent, the range of 0.001 mass%-2 mass% with respect to a cement is preferable.

(3) <1> A combination of the polycarboxylic acid copolymer of the present invention and <2> a known cement dispersant. Known cement dispersants include:
(I) Polyalkylaryl sulfonate-based dispersants such as naphthalene sulfonic acid formaldehyde condensates; Melamine formalin resin sulfonate-based dispersants such as melamine sulfonic acid formaldehyde condensates; aminoaryl sulfonic acid-phenol-formaldehyde condensates Aromatic aminosulfonate-based dispersants; lignin sulfonate-based dispersants such as lignin sulfonates and modified lignin sulfonates; polystyrene sulfonate-based dispersants; Sulfonic acid-based dispersants,
(Ii) Polyalkylene glycol mono (meth) acrylic acid ester monomers, (meth) acrylic acid monomers, and these as described in JP-B-59-18338 and JP-A-7-223852 Copolymers obtained from monomers copolymerizable with these monomers: JP-A-10-236858, JP-A-2001-220417, JP-A-2002-121055, JP-A-2002-121056 A copolymer obtained from an unsaturated (poly) alkylene glycol ether monomer, a maleic acid monomer or a (meth) acrylic acid monomer; Various polycarboxylic acid-based dispersants having an alkylene group and a carboxyl group;
(Iii) A copolymer obtained from (alkoxy) polyalkylene glycol mono (meth) acrylate, a phosphoric acid monoester monomer, and a phosphoric acid diester monomer as described in JP-A-2006-52381 And various phosphoric acid dispersants having a (poly) oxyalkylene group and a phosphoric acid group in the molecule. In addition, as a compounding ratio of <1> the polycarboxylic acid copolymer of the present invention and <2> a known cement dispersant, a mass ratio of 1/99 to 99/1 is preferable, and 5/95 to The range of 95/5 is more preferable, and the range of 10/90 to 90/10 is more preferable.

  (4) <1> A combination comprising two components of the polycarboxylic acid copolymer of the present invention and <2> retarder. 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), etc. can be used. Particularly preferred are oxycarboxylic acids. In addition, as a compounding ratio of <1> the polycarboxylic acid copolymer of the present invention and <2> retarder, a mass ratio of 50/50 to 99.9 / 0.1 is preferable, and 70 / A range of 30 to 99/1 is more preferable.

  (5) <1> A combination comprising essentially two components of the polycarboxylic acid copolymer of the present invention and <2> 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. In addition, as a compounding ratio of <1> the polycarboxylic acid copolymer of the present invention and the accelerator of <2>, a mass ratio of 10/90 to 99.9 / 0.1 is preferable, and 20 The range of / 80 to 99/1 is more preferable.

  (6) <1> A combination comprising essentially two components of the polycarboxylic acid copolymer of the present invention and <2> a material separation reducing agent. Various thickeners such as nonionic cellulose ethers can be used as the material separation reducing agent. The mixing ratio of <1> the polycarboxylic acid copolymer of the present invention to <2> the material separation reducing agent is preferably 10/90 to 99.99 / 0.01 in terms of mass ratio. 50-99.9 / 0.1 is more preferable. A concrete composition of this combination is suitable as a high fluidity concrete, a self-filling concrete, and a self-leveling material.

≪Concrete composition≫
One embodiment of the concrete composition of the present invention (sometimes referred to as a hydraulic powder-containing composition) includes the concrete admixture of the present invention. Another embodiment of the concrete composition of the present invention includes the polycarboxylic acid-based copolymer of the present invention. That is, when the concrete composition of the present invention is produced, the polycarboxylic acid copolymer of the present invention is blended, and the form of blending is blended with the polycarboxylic acid copolymer of the present invention itself. The form which mixes the concrete admixture of this invention containing the polycarboxylic acid-type copolymer of this invention may be sufficient.

  A concrete composition is a composition which essentially contains hydraulic powder. The hydraulic powder means a powder that is cured by contact with water. Examples of hydraulic powder include Portland cement, calcium silicate, calcium aluminate, calcium fluoroaluminate, calcium sulfoaluminate, calcium aluminoferrite, calcium phosphate, hemihydrate gypsum, anhydrous gypsum, and self-hardening lime powder. Examples include the body.

  The concrete composition may contain a non-hydraulic powder. Non-hydraulic powder means powder that does not harden when contacted with water by itself, and its components are eluted in an alkaline or acidic atmosphere or high-pressure steam atmosphere and other previously eluted substances. It is meant to include powders that react with components to form products. Examples of the non-hydraulic powder include calcium hydroxide powder, dihydrate gypsum powder, calcium carbonate powder, silica stone powder, clay powder, blast furnace granulated slag, fly ash, and silica fume.

  The content ratio of the hydraulic powder with respect to the total amount of the hydraulic powder and the non-hydraulic powder is preferably 50% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, Preferably it is 90 mass%-100 mass%, Most preferably, it is 95 mass%-100 mass%, Most preferably, it is 100 mass%.

  The concrete composition of the present invention may contain water. The concrete composition of the present invention may contain aggregate. The concrete composition of the present invention may contain other components. Moreover, when using sand as an aggregate, the concrete composition of this invention may be called a mortar composition. The concrete composition of the present invention may be an uncured product before curing, a partially cured semi-cured product, or a cured product.

  Any appropriate aggregate such as fine aggregate (sand, etc.) or coarse aggregate (crushed stone, etc.) can be adopted as the aggregate. 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 concrete compositions and mortar compositions, the unit water amount per 1 m ³ , the amount of hydraulic powder-containing powder composition (= non-hydraulic powder + hydraulic powder), and water / hydraulic powder Any appropriate value can be set as the body-containing powder composition ratio. Such values, preferably, unit water is ^{50kg / m 3 ~200kg / m 3} , the amount of the hydraulic powder-containing powder composition is ^{200kg / m 3 ~800kg / m 3} , Water / hydraulic powder-containing powder composition ratio (mass ratio) = 0.1 to 0.7, more preferably unit water amount is 100 kg / m ^{3 to} 185 kg / m ³ , and hydraulic powder the amount of containing powder composition is ^{250kg / m 3 ~600kg / m 3} , water / hydraulic powder-containing powder composition ratio (mass ratio) is a = 0.15 to 0.6.

  As a content ratio of the polycarboxylic acid copolymer of the present invention in the concrete composition of the present invention, any appropriate content ratio can be adopted depending on the purpose. The content ratio is preferably 0.01 parts by mass to 10 parts by mass as the content ratio of the polycarboxylic acid copolymer of the present invention with respect to 100 parts by mass of the hydraulic powder-containing powder composition. More preferably, it is 0.02 mass part-5 mass parts, More preferably, it is 0.05 mass part-3 mass parts. 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 concrete admixture of the present invention in the concrete 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 concrete admixture of this invention with respect to 100 mass parts of hydraulic powder containing powder compositions, Preferably it is 0.01 mass part-10 mass parts, More preferably, it is 0. 0.05 parts by mass to 8 parts by mass, and more preferably 0.1 parts by mass to 5 parts by mass. 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 content ratio of the hydraulic powder-containing powder composition in the concrete composition of the present invention is preferably 2.5% by mass or more, more preferably 5% by mass to 90% by mass, and still more preferably. It is 7.5 mass%-70 mass%, More preferably, it is 10 mass%-50 mass%, Most preferably, it is 12.5 mass%-40 mass%, Most preferably, it is 15 mass%-30 mass% It is.

  The concrete composition and the mortar composition 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.

≪Method for reducing viscosity of concrete composition≫
The method for reducing the viscosity of a concrete composition according to the present invention is a method for reducing the viscosity of a concrete composition essentially including hydraulic powder and water, and comprises the polycarboxylic acid copolymer of the present invention, hydraulic powder and water. Is added.

  Specifically, the method for reducing the viscosity of a concrete composition according to the present invention includes the preparation of a concrete composition essentially containing hydraulic powder and water, and the polycarboxylic acid copolymer of the present invention and hydraulic powder. Blend body and water. Thereby, the viscosity of the concrete composition prepared is reduced.

  The form of blending the polycarboxylic acid copolymer of the present invention may be the form of blending the polycarboxylic acid copolymer of the present invention itself, or the polycarboxylic acid copolymer of the present invention. The form which mix | blends the concrete admixture of this invention containing may be sufficient.

  In the case where the polycarboxylic acid copolymer of the present invention is blended, the blending ratio of the polycarboxylic acid copolymer of the present invention is preferably set to be 100% by weight of the hydraulic powder. The blending ratio of the carboxylic acid copolymer is preferably 0.01 to 10 parts by mass, more preferably 0.02 to 5 parts by mass, and even more preferably 0.05 to 3 parts by mass. Part by mass. By setting it as such a mixture ratio, the viscosity of a concrete composition is reduced more.

  In the case of blending the concrete admixture of the present invention containing the polycarboxylic acid copolymer of the present invention, the blending ratio of the concrete admixture of the present invention is preferably the present invention with respect to 100 parts by mass of the hydraulic powder. The mixing ratio of the concrete admixture is preferably 0.01 parts by weight to 10 parts by weight, more preferably 0.05 parts by weight to 8 parts by weight, and further preferably 0.1 parts by weight to 5 parts by weight. It is. By setting it as such a mixture ratio, the viscosity of a concrete composition is reduced more.

  The concrete description of the concrete composition, hydraulic powder, water, the polycarboxylic acid copolymer of the present invention, and the concrete admixture of the present invention is the above-mentioned << polycarboxylic acid copolymer >>, << concrete The description in each item of admixture >> and << concrete composition >> can be used.

≪Use of polycarboxylic acid copolymer to reduce viscosity of concrete composition≫
The polycarboxylic acid copolymer of the present invention can be used for reducing the viscosity of a concrete composition.

  Specifically, the use of the polycarboxylic acid-based copolymer for reducing the viscosity of the concrete composition is specifically the use of the polycarboxylic acid-based copolymer of the present invention in preparing a concrete composition containing hydraulic powder and water. The polycarboxylic acid copolymer of the present invention is used so that the polymer, the hydraulic powder, and water are blended. Thereby, the viscosity of the concrete composition prepared is reduced.

  The form using the polycarboxylic acid copolymer of the present invention may be the form using the polycarboxylic acid copolymer itself of the present invention, or the polycarboxylic acid copolymer of the present invention. The form using the concrete admixture of the present invention containing may be sufficient.

  In the case of using the polycarboxylic acid copolymer of the present invention itself, the use ratio of the polycarboxylic acid copolymer of the present invention is preferably as follows. The blending ratio of the carboxylic acid copolymer is preferably 0.01 to 10 parts by mass, more preferably 0.02 to 5 parts by mass, and even more preferably 0.05 to 3 parts by mass. Part by mass. By setting it as such a use rate, the viscosity of a concrete composition is reduced more.

  In the case of using the concrete admixture of the present invention containing the polycarboxylic acid copolymer of the present invention, the use ratio of the concrete admixture of the present invention is preferably the present invention with respect to 100 parts by mass of the hydraulic powder. The mixing ratio of the concrete admixture is preferably 0.01 parts by weight to 10 parts by weight, more preferably 0.05 parts by weight to 8 parts by weight, and further preferably 0.1 parts by weight to 5 parts by weight. It is. By setting it as such a use rate, the viscosity of a concrete composition is reduced more.

  The concrete description of the concrete composition, hydraulic powder, water, the polycarboxylic acid copolymer of the present invention, and the concrete admixture of the present invention is the above-mentioned << polycarboxylic acid copolymer >>, << concrete The description in each item of admixture >> and << concrete composition >> can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all. Unless otherwise specified, parts and% in the examples are based on mass.

In Tables 1 and 2 below, “monomer composition (preparation composition)” and “monomer composition (composition of monomer-derived structural units in the copolymer)” mean the following: is there.
“Monomer composition (charge composition)”: a composition calculated from the amount of monomer charged in a reaction vessel to produce a copolymer.
"Monomer composition (composition of monomer-derived structural units in the copolymer)": by LC (liquid chromatography), the monomer charged into the reaction vessel to produce the copolymer, A composition calculated by analyzing the consumption rate in a polymerization reaction and converting all consumed monomers into a copolymer by the polymerization reaction. The LC (liquid chromatography) analysis conditions are as follows.

<LC analysis conditions>
Model: Waters Alliance (2695)
Analysis software: Waters, Empor2 Professional column: Waters, Atlantis dC18 guard column + Atlantis dC18, 4.6 x 250 mm, 2
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996)
Eluent: A solution obtained by dissolving 3.75 g of sodium acetate trihydrate and 52.2 g of acetic acid in a mixed solvent of 9000 g of water and 6000 g of acetonitrile.
Flow rate: 1 mL / min Column temperature: 40 ° C

<LC analysis method>
A calibration curve for each monomer was prepared, and the consumption was determined from the residual amount of each monomer in the polymer solution after polymerization.

<GPC analysis method>
The weight average molecular weight was measured under the following measurement conditions.
Device: Waters Alliance (2695)
Analysis software: Waters, Empor2 Professional + GPC option Column: Tosoh Corporation, TSKguardcolumns SWXL + TSKgel G4000SWXL + G3000SWXL + G2000SWXL
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996)
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.
Standard substance for preparing calibration curve: 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 standard.
Flow rate: 1 mL / min Column temperature: 40 ° C
Measurement time: 45 minutes Standard substance sample solution injection amount: 100 μL (eluent solution with polymer concentration of 0.1% by mass)
Polymer sample solution injection amount: 100 μL (eluent solution having a polymer concentration of 0.5% by mass)

<GPC analysis conditions (analysis of polymer)>
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 with a straight line, and the polymer was detected and analyzed. However, when the peak of the monomer or monomer-derived impurity is measured partially overlapping the polymer peak, the polymer part and the monomer are divided vertically at the most concave part of the overlapping part of the polymer and the polymer peak. The molecular weight and molecular weight distribution of only the polymer part were calculated. When there was no recessed part, it calculated collectively.
The pure polymer content was calculated as follows from the ratio of the peak areas measured by the RI detector.
Polymer pure content = (polymer peak area) / (polymer peak area + monomer or impurity peak area)

<Mortar test>
(Contains mortar)
The mortar formulation was C / S / W = 550/1350/220 (g).
C: Ordinary Portland cement (manufactured by Taiheiyo Cement)
S: JIS standard sand W: ion-exchanged water (including copolymer and antifoaming agent)

(Mortar preparation procedure)
The experimental environment was 20 ° C. plus / minus 1 ° C., humidity 60% plus / minus 10%. A predetermined amount of an aqueous solution of a polycarboxylic acid copolymer is weighed, and 15% by mass of Adecanol LG-299 (manufactured by Adeka) as an antifoaming agent is added to the solid content of the polycarboxylic acid copolymer. Further, ion exchange water was added to make 220 g, which was sufficiently uniformly dissolved.
For mortar kneading, a stainless steel beater (stirring blade) attached to a N-50 mixer manufactured by HOBART was used. First, a predetermined amount of C and S was charged into a kneading container, kneaded at a first speed for 1 minute, then charged with W and then kneaded at a first speed for 3 minutes. Thereafter, the kneading was stopped, and the mortar attached to the container wall was scraped off for 15 seconds and allowed to stand for 2 minutes and 45 seconds. Further, the mixture was kneaded at a first speed for 2 minutes to complete the kneading, and the mortar was transferred from the kneading container to a polyethylene 1 L container.

(Mortar fluidity measurement procedure)
A mortar slump test instrument according to JIS-A-1171 was used for measurement of mortar fluidity. After stirring the kneaded mortar 20 times with a spatula, half of the mortar is packed in a slump cone (top inner diameter 50 mm, lower end inner diameter 100 mm, height 150 mm) placed on a horizontally installed steel plate. The surface was uniformly filled by poking 15 times with a stick, and the remaining half was filled in the same procedure, and the surface was evenly conditioned. Subsequently, the slump cone was pulled up vertically, and after the flow of the mortar stopped, the diameter of the spread mortar was measured at two points in length and width, and the average value was taken as the flow value. Next, the drop of the top of the mortar was measured and used as the slump value.
Finally, the mortar workability value calculated by the following formula was used as an index of mortar fluidity.
Mortar workability (mm) = flow value (mm) + slump value (mm)-100 (mm)
The addition amount of the polycarboxylic acid copolymer was adjusted so that the mortar workability was 200 ± 10 mm.

(Amount of mortar air)
About 200 mL of mortar was packed in a 500 mL Pyrex (registered trademark) graduated cylinder, and rough bubbles were removed by poking with a round bar having a diameter of 8 mm. Furthermore, about 200 mL of mortar was added and air bubbles were similarly removed, and then the mass was measured. The amount of air was calculated from the volume, mass, and density of each material.

(Mortar condition evaluation)
As the mortar state evaluation, when the mortar was stirred with a spatula, it was judged that the mortar had a low viscosity or a small amount of mortar adhered to the spatula. Specifically, it is as follows.
(Double-circle): The viscosity of a mortar is low at the time of stirring, and there is almost no adhesion of the mortar to a spatula.
○: Although the viscosity of the mortar is low at the time of stirring, adhesion of the mortar to the spatula is observed.
(Triangle | delta): The viscosity of a mortar is high at the time of stirring, and adhesion of the mortar to a spatula is also seen.
X: The viscosity of the mortar is high during stirring, and the adhesion of the mortar to the spatula is large.

(Pipe passage)
A mortar funnel flow test was conducted as an evaluation of the passage of piping during pumping. It was judged that pipes having good mortar flowability did not clog in the middle and flowed in a short time. The specific method of the funnel flow test is as follows.
A rubber stopper was attached to the lower end of a J14 funnel (upper end inner diameter 70 mm, lower end inner diameter 14 mm, height 392 mm) defined in the Japan Society of Civil Engineers standard JSCE-F541, and supported vertically on a table. Next, an electronic balance for measuring the amount of mortar that flowed out was installed below the lower end of the J14 funnel.
The obtained mortar was poured to the upper surface of the J14 funnel to smooth the upper surface. Next, the rubber plug was removed to allow the mortar to flow out, and the time from the start of mortar outflow until 1200 g flowed down was measured with a stopwatch, and this was taken as the funnel flow-down time.
In addition, when the funnel flow time can be shortened by 10% or more, it can be said that it is particularly excellent in pipe passage.
Further, from the viewpoint of excellent piping passage, the absolute value of the funnel flow time is preferably 45 seconds or less, more preferably 43 seconds or less, further preferably 40 seconds or less, particularly preferably 37 seconds or less, and 35 seconds or less. Most preferred.

[Example 1]
An aqueous solution (1a) in which 0.1 part of L-ascorbic acid and 3.8 parts of 3-mercaptopropionic acid were dissolved in 28.4 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser. 72.8 parts of water and 3-methyl-3-buten-1-ol added with an average of 50 moles of ethylene oxide 291.0 parts of an alkylene glycol ether monomer (IPN-50), 1.8 parts of a 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 2 .9 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.2 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above-mentioned mixed solution (1a) was constant over 4.5 hours, and 41.8 parts of acrylic acid (AA) and 18.2 parts of 2-ethylhexyl acrylate (2EHA) were constant over 2.5 hours. Weighed dropwise at a speed. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (1a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (1) was obtained. The weight average molecular weight Mw of the obtained copolymer (1) was 16100. The results are shown in Table 1.
Various tests were conducted using the obtained copolymer (1) as a concrete admixture. The results are shown in Table 3.

[Example 2]
An aqueous solution (2a) in which 0.2 part of L-ascorbic acid and 2.7 parts of 3-mercaptopropionic acid were dissolved in 37.5 parts of water was prepared.
Unsaturated poly with 90.9 parts of water and an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol in a reaction vessel equipped with a thermometer, stirrer, dropping device, nitrogen inlet tube and reflux condenser 363.8 parts of alkylene glycol ether monomer (IPN-50), 2.2 parts of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 3 Then, the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere, and then 1.5 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (2a) was added over 4.5 hours, and 52.3 parts of acrylic acid (AA) and 22.7 parts of 2-ethylhexyl acrylate (2EHA) were added over 2.5 hours. Weighed dropwise at a speed. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (2a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.5 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (2) was obtained. The weight average molecular weight Mw of the obtained copolymer (2) was 26500. The results are shown in Table 1.
Various tests were performed using the obtained copolymer (2) as a concrete admixture. The results are shown in Table 3.

Example 3
An aqueous solution (3a) in which 0.2 part of L-ascorbic acid and 3.7 parts of 3-mercaptopropionic acid were dissolved in 26.3 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser, 49.5 parts of water, and unsaturated polyoxyethylene having an average of 50 mol of ethylene oxide added to 3-methyl-3-buten-1-ol. 198.2 parts of alkylene glycol ether monomer (IPN-50), 1.4 parts of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 2 Then, 0.0 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.3 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (3a) was added for 4.5 hours, and 32.5 parts of acrylic acid (AA) and 42.5 parts of butyl acrylate (BA) were added for 2.5 hours at a constant rate. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (3a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (3) was obtained. The weight average molecular weight Mw of the obtained copolymer (3) was 15500. The results are shown in Table 1.
Various tests were performed using the obtained copolymer (3) as a concrete admixture. The results are shown in Table 3.

Example 4
An aqueous solution (4a) in which 0.1 part of L-ascorbic acid and 2.9 parts of 3-mercaptopropionic acid were dissolved in 27.0 parts of water was prepared.
38.7 parts of water and an unsaturated polysiloxane having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol in a reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube, and a reflux condenser 154.8 parts of alkylene glycol ether monomer (IPN-50), 1.2 parts of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 1 Then, 5 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.2 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (4a) was added at a constant rate over 4.5 hours, and 27.4 parts of acrylic acid (AA) and 47.6 parts of butyl acrylate (BA) were added over 2.5 hours. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (4a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (4) was obtained. The weight average molecular weight Mw of the obtained copolymer (4) was 15800. The results are shown in Table 1.
Various tests were conducted using the obtained copolymer (4) as a concrete admixture. The results are shown in Table 3.

Example 5
An aqueous solution (5a) in which 0.2 part of L-ascorbic acid and 4.9 parts of 3-mercaptopropionic acid were dissolved in 36.7 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser. 98.0 parts of water and 3-methyl-3-buten-1-ol added with an average of 50 moles of ethylene oxide 392.1 parts of alkylene glycol ether monomer (IPN-50), 2.3 parts of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 3 .9 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.5 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (5a) was fixed over 4.5 hours, 55.6 parts of acrylic acid (AA) and 19.4 parts of 2-ethylhexyl acrylate (2EHA) over 2.5 hours, respectively. Weighed dropwise at a speed. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (5a), 60 ° C. was continuously maintained for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (5) was obtained. The weight average molecular weight Mw of the obtained copolymer (5) was 16,800. The results are shown in Table 1.
Various tests were conducted using the obtained copolymer (5) as a concrete admixture. The results are shown in Table 3.

Example 6
An aqueous solution (6a) in which 0.1 part of L-ascorbic acid and 2.9 parts of 3-mercaptopropionic acid were dissolved in 27.5 parts of water was prepared.
Unsaturated poly in which 63.5 parts of water is added to a reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen introduction tube, and a reflux condenser, and 50 mol of ethylene oxide is added to 3-methyl-3-buten-1-ol on average. 254.0 parts of an alkylene glycol ether monomer (IPN-50), 1.6 parts of a 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 2 Then, 5 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.1 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (6a) was added at a constant rate over 4.5 hours, 24.6 parts of acrylic acid (AA) and 35.4 parts of butyl acrylate (BA) over 2.5 hours, respectively. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (6a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (6) was obtained. The weight average molecular weight Mw of the obtained copolymer (6) was 16,200. The results are shown in Table 1.
Various tests were conducted using the obtained copolymer (6) as a concrete admixture. The results are shown in Table 3.

Example 7
An aqueous solution (7a) in which 0.2 part of L-ascorbic acid and 3.7 parts of 3-mercaptopropionic acid were dissolved in 30.6 parts of water was prepared.
61.7 parts of water and an unsaturated polysiloxane having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol in a reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube and a reflux condenser. 246.7 parts of alkylene glycol ether monomer (IPN-50), 1.6 parts of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 2 Then, 4 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.4 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (7a) was added at a constant rate over 4.5 hours, 38.3 parts of acrylic acid (AA) and 36.4 parts of butyl acrylate (BA) over 2.5 hours, respectively. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (7a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (7) was obtained. The weight average molecular weight Mw of the obtained copolymer (7) was 17000. The results are shown in Table 1.
Various tests were performed using the obtained copolymer (7) as a concrete admixture. The results are shown in Table 3.

Example 8
An aqueous solution (8a) in which 0.2 part of L-ascorbic acid and 3.5 parts of 3-mercaptopropionic acid were dissolved in 26.4 parts of water was prepared.
39.8 parts of water and 3-methyl-3-buten-1-ol with an average of 50 moles of ethylene oxide added to a reaction vessel equipped with a thermometer, stirrer, dripping device, nitrogen inlet tube, and reflux condenser 159.2 parts of alkylene glycol ether monomer (IPN-50), 1.2 parts of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 1 Then, the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere, and then 1.5 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (8a) was added at a constant rate over 4.5 hours, 47.6 parts of acrylic acid (AA) and 27.4 parts of butyl acrylate (BA) over 2.5 hours, respectively. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (8a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.5 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (8) was obtained. The weight average molecular weight Mw of the obtained copolymer (8) was 18500. The results are shown in Table 1.
Various tests were performed using the obtained copolymer (8) as a concrete admixture. The results are shown in Table 3.

Example 9
An aqueous solution (9a) in which 0.1 part of L-ascorbic acid and 5.9 parts of 3-mercaptopropionic acid were dissolved in 21.6 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen introduction tube, and a reflux condenser, 49.3 parts of water, and unsaturated polyoxyethylene having an average of 50 mol of ethylene oxide added to 3-methyl-3-buten-1-ol. 197.4 parts of an alkylene glycol ether monomer (IPN-50), 1.3 parts of a 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 1 .9 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.1 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (9a) was added over 4.5 hours, 30.7 parts of acrylic acid (AA) and 29.3 parts of butyl acrylate (BA) over 2.5 hours, respectively, at a constant rate. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (9a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (9) was obtained. The weight average molecular weight Mw of the obtained copolymer (9) was 10400. The results are shown in Table 1.
Various tests were conducted using the obtained copolymer (9) as a concrete admixture. The results are shown in Table 3.

Example 10
An aqueous solution (10a) in which 0.2 parts of L-ascorbic acid and 2.1 parts of 3-mercaptopropionic acid were dissolved in 32.3 parts of water was prepared.
61.7 parts of water and an unsaturated polysiloxane having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol in a reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube and a reflux condenser. 246.7 parts of alkylene glycol ether monomer (IPN-50), 1.6 parts of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of iron (II) sulfate hexahydrate 2 Then, 4 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.4 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (10a) was added at a constant rate over 4.5 hours, and 38.3 parts of acrylic acid (AA) and 36.7 parts of butyl acrylate (BA) were added over 2.5 hours. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (10a), 60 ° C. was continuously maintained for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (10) was obtained. The weight average molecular weight Mw of the obtained copolymer (10) was 27500. The results are shown in Table 1.
Various tests were conducted using the obtained copolymer (10) as a concrete admixture. The results are shown in Table 3.

Example 11
An aqueous solution (11a) was prepared by dissolving 0.1 part of L-ascorbic acid and 3.9 parts of 3-mercaptopropionic acid in 28.2 parts of water.
49.5 parts of water and an unsaturated polysiloxane having an average of 150 moles of ethylene oxide added to 2-methyl-2-propen-1-ol in a reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube and a reflux condenser 198.2 parts of alkylene glycol ether monomer (MLA-150), 1.4 parts of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 2 Then, 0.0 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.2 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (11a) was added at a constant rate over 4.5 hours and 32.5 parts of acrylic acid (AA) and 42.5 parts of butyl acrylate (BA) were added over 2.5 hours. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (11a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (11) was obtained. The weight average molecular weight Mw of the obtained copolymer (11) was 27300. The results are shown in Table 1.
Various tests were performed using the obtained copolymer (11) as a concrete admixture. The results are shown in Table 3.

Example 12
An aqueous solution (12a) in which 0.06 parts of L-ascorbic acid and 1.4 parts of 3-mercaptopropionic acid were dissolved in 15.3 parts of water was prepared.
19.8 parts of water and 3-methyl-3-buten-1-ol with an average of 50 moles of ethylene oxide added to a reaction vessel equipped with a thermometer, stirrer, dropping device, nitrogen inlet tube, and reflux condenser 79.3 parts of alkylene glycol ether monomer (IPN-50), 0.5 part of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 0 Then, 8 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 0.5 part of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above-mentioned mixed solution (12a) was added over 4.5 hours, 13.0 parts of acrylic acid (AA) and 17.0 parts of propyl acrylate (PA) were added over 2.5 hours at a constant rate. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (12a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (12) was obtained. The weight average molecular weight Mw of the obtained copolymer (12) was 18300. The results are shown in Table 1.
Various tests were performed using the obtained copolymer (12) as a concrete admixture. The results are shown in Table 3.

Example 13
Methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added 45) (MPG-45) 178.4 parts, methacrylic acid (MAA) 28.8 parts, butyl acrylate (BA) 26.5 parts, 3-mercaptopropionic acid An aqueous solution (13a) in which 2.7 parts were dissolved in 47.4 parts of water and an aqueous solution (13b) in which 2.9 parts of ammonium persulfate were dissolved in 13.0 parts of water were prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube, and a reflux condenser was charged with 32.0 parts of water, and the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 80 ° C. under a nitrogen atmosphere The temperature rose.
The above mixed solution (13a) was metered dropwise at a constant rate over 4 hours and the mixed solution (13b) over 5 hours. The temperature during this period was constant at 80 ° C.
After completion of the dropwise addition of the mixed solution (13b), the temperature was maintained at 80 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (13) was obtained. The weight average molecular weight Mw of the obtained copolymer (13) was 15800. The results are shown in Table 1.
Various tests were performed using the obtained copolymer (13) as a concrete admixture. The results are shown in Table 3.

Example 14
An aqueous solution (14a) in which 0.1 part of L-ascorbic acid and 11.8 parts of 3-mercaptopropionic acid were dissolved in 15.7 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen introduction tube, and a reflux condenser, 49.3 parts of water, and unsaturated polyoxyethylene having an average of 50 mol of ethylene oxide added to 3-methyl-3-buten-1-ol. 197.4 parts of an alkylene glycol ether monomer (IPN-50), 1.3 parts of a 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 1 .9 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.1 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (14a) was added at a constant rate over 4.5 hours, 30.7 parts of acrylic acid (AA) and 29.3 parts of butyl acrylate (BA) over 2.5 hours, respectively. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (14a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (14) was obtained. The weight average molecular weight Mw of the obtained copolymer (14) was 7200. The results are shown in Table 1.
Various tests were performed using the obtained copolymer (14) as a concrete admixture. The results are shown in Table 3.

Example 15
A solution (15a) in which 4.0 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in 46.2 parts of isopropyl alcohol was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser averaged ethylene oxide in 34.3 parts of water, 19.3 parts of isopropyl alcohol, and 3-methyl-3-buten-1-ol. First, 136.9 parts of an unsaturated polyalkylene glycol ether monomer (IPN-50) added with 50 moles and 0.2 part of acrylic acid (AA) were charged, and then the reaction vessel was purged with nitrogen under stirring. The temperature was raised to 60 ° C. in an atmosphere.
After 30 minutes, the above mixed solution (15a) was charged with 3.5 hours of acrylic acid (AA) 20.7 parts, stearyl acrylate (STA) 18.3 parts, 3-mercaptopropionic acid 0.4 parts and A mixed solution of 9.9 parts of isopropyl alcohol was metered dropwise at a constant rate over 3 hours. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (15a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. In this way, a polymer solution containing the copolymer (15) was obtained. The weight average molecular weight Mw of the obtained copolymer (15) was 14600. The results are shown in Table 1.
Various tests were conducted using the obtained copolymer (15) as a concrete admixture. The results are shown in Table 3.

Example 16
An aqueous solution (16a) in which 0.6 parts of L-ascorbic acid was dissolved in 32.0 parts of water and an aqueous solution (16b) in which 3.0 parts of 3-mercaptopropionic acid were dissolved in 32.0 parts of water were prepared. did.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser. 63.3 parts of water and 3-methyl-3-buten-1-ol added with an average of 50 moles of ethylene oxide 199.7 parts of alkylene glycol ether monomer (IPN-50), 2.0 parts of 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate, 70% aqueous solution 1 of paratoluenesulfonic acid monohydrate 1 .3 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 1.3 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (16a) was taken for 4.5 hours, the above mixed solution (16b) was taken for 3.5 hours, 20.4 parts of acrylic acid (AA), 2-hydroxylethyl acrylate A mixed solution of 13.3 parts of (HEA), 26.6 parts of butyl acrylate (BA) and 6.7 parts of water was metered dropwise at a constant rate over 2.5 hours. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (16a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (16) was obtained. The weight average molecular weight Mw of the obtained copolymer (16) was 21000. The results are shown in Table 1.
Various tests were performed using the obtained copolymer (16) as a concrete admixture. The results are shown in Table 3.

[Comparative Example 1]
An aqueous solution (C1a) in which 0.4 part of L-ascorbic acid and 0.8 part of 3-mercaptopropionic acid were dissolved in 50.0 parts of water was prepared.
90.4 parts of water and 3-methyl-3-buten-1-ol with an average of 50 moles of ethylene oxide added to a reaction vessel equipped with a thermometer, stirrer, dropping device, nitrogen inlet tube and reflux condenser First, 191.0 parts of an alkylene glycol ether monomer (IPN-50) and 0.3 parts of acrylic acid (AA) were charged. Subsequently, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. After warming, 0.9 part of a 35% hydrogen peroxide aqueous solution was added.
After 30 minutes, the above-mentioned mixed solution (C1a) was metered dropwise at a constant rate over 3.5 hours and 25.5 parts of acrylic acid (AA) over 3.0 hours. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C1a), 60 ° C. was continuously maintained for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (C1) was obtained. The weight average molecular weight Mw of the obtained copolymer (C1) was 32000. The results are shown in Table 2.
Various tests were conducted using the obtained copolymer (C1) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 2]
An aqueous solution (C2a) in which 0.7 parts of L-ascorbic acid and 1.5 parts of 3-mercaptopropionic acid were dissolved in 78.6 parts of water was prepared.
A reactor equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser, 77.2 parts of water, and an unsaturated polysiloxane having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol Charge 308.7 parts of an alkylene glycol ether monomer (IPN-50) and 0.6 part of acrylic acid (AA). Then, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. After warming, 1.6 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (C2a) was fixed over 3.5 hours, and 42.7 parts of acrylic acid (AA) and 11.3 parts of 2-ethylhexyl acrylate (2EHA) were added over 3.0 hours. Weighed dropwise at a speed. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C2a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (C2) was obtained. The obtained copolymer (C2) had a weight average molecular weight Mw of 27800. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C2) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 3]
An aqueous solution (C3a) in which 0.7 parts of L-ascorbic acid and 1.5 parts of 3-mercaptopropionic acid were dissolved in 108.6 parts of water was prepared.
A reactor equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser, 47.2 parts of water, and an unsaturated polysiloxane having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol. Charge 188.2 parts of an alkylene glycol ether monomer (IPN-50) and 0.6 part of acrylic acid (AA). Then, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. After warming, 1.6 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (C3a) was fixed over 3.5 hours, 42.7 parts of acrylic acid (AA) and 131.7 parts of 2-ethylhexyl acrylate (2EHA) over 3.0 hours, respectively. Although an attempt was made to meter-drop at a speed, the polymerization reaction was stopped because a large amount of white precipitate was formed in the reaction vessel during the dropping, making stirring difficult.

[Comparative Example 4]
An aqueous solution (C4a) in which 1.1 parts of L-ascorbic acid and 2.6 parts of 3-mercaptopropionic acid were dissolved in 38.1 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser, 59.7 parts of water, and an unsaturated polysiloxane having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol Charge 238.9 parts of an alkylene glycol ether monomer (IPN-50) and 0.4 part of acrylic acid (AA). Then, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. After warming, 2.4 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (C4a) was weighed at a constant rate over 3.5 hours, and 38.8 parts of acrylic acid (AA) and 51.2 parts of methyl acrylate (AM) were taken over 3 hours. It was dripped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C4a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (C4) was obtained. The weight average molecular weight Mw of the obtained copolymer (C4) was 17000. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C4) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 5]
An aqueous solution (C5a) in which 1.1 parts of L-ascorbic acid and 2.6 parts of 3-mercaptopropionic acid were dissolved in 38.1 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube, and a reflux condenser, 54.0 parts of water, and unsaturated polyoxyethylene having an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol Charge 244.7 parts of an alkylene glycol ether monomer (IPN-50) and 0.4 part of acrylic acid (AA). Then, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. After warming, 2.4 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (C5a) was weighed at a constant rate over 3.5 hours and 42.9 parts of acrylic acid (AA) and 75.3 parts of methyl acrylate (AM) over 3 hours. It was dripped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C5a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. In this way, an aqueous polymer solution containing the copolymer (C5) was obtained. The weight average molecular weight Mw of the obtained copolymer (C5) was 15300. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C5) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 6]
An aqueous solution (C6a) in which 0.6 parts of L-ascorbic acid and 1.1 parts of 3-mercaptopropionic acid were dissolved in 31.7 parts of water was prepared.
Unsaturated poly with 66.3 parts of water and an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol in a reaction vessel equipped with a thermometer, stirrer, dropping device, nitrogen inlet tube, and reflux condenser Charge 265.1 parts of an alkylene glycol ether monomer (IPN-50) and 0.5 part of acrylic acid (AA). Then, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. After warming, 1.3 parts of a 35% aqueous solution of hydrogen peroxide was added.
After 30 minutes, the above mixed solution (C6a) was measured at a constant rate over 3.5 hours, 18.2 parts of acrylic acid (AA) and 35.8 parts of butyl acrylate (BA) over 3 hours, respectively. It was dripped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C6a), 60 ° C. was continuously maintained for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (C6) was obtained. The obtained copolymer (C6) had a weight average molecular weight Mw of 16,400. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C6) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 7]
An aqueous solution (C7a) in which 0.8 part of L-ascorbic acid and 1.2 parts of 3-mercaptopropionic acid were dissolved in 39.1 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser. Unsaturated poly having 423.2 parts of water and an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol. Charge 238.3 parts of an alkylene glycol ether monomer (IPN-50) and 0.4 part of acrylic acid (AA). Then, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. After warming, 1.7 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (C7a) was weighed at a constant rate over 3.5 hours and 36.6 parts of acrylic acid (AA) and 35.4 parts of butyl acrylate (BA) over 3 hours. It was dripped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C7a), 60 ° C. was continuously maintained for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (C7) was obtained. The weight average molecular weight Mw of the obtained copolymer (C7) was 37700. The results are shown in Table 2.
Various tests were conducted using the obtained copolymer (C7) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 8]
An aqueous solution (C8a) in which 0.6 part of L-ascorbic acid and 4.4 parts of 3-mercaptopropionic acid were dissolved in 9.1 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen inlet tube, and a reflux condenser. 338.4 parts of water and 3-methyl-3-buten-1-ol added with an average of 50 moles of ethylene oxide First, 190.5 parts of an alkylene glycol ether monomer (IPN-50) and 0.3 part of acrylic acid (AA) were charged. Subsequently, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. After warming, 1.3 parts of a 35% aqueous solution of hydrogen peroxide was added.
After 30 minutes, the above mixed solution (C8a) was added at a constant rate over 3.5 hours, 37.6 parts of acrylic acid (AA) and 7.4 parts of butyl acrylate (BA) were added over 3.0 hours. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C8a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (C8) was obtained. The weight average molecular weight Mw of the obtained copolymer (C8) was 11700. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C8) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 9]
An aqueous solution (C9a) in which 0.7 parts of L-ascorbic acid and 3.0 parts of 3-mercaptopropionic acid were dissolved in 23.4 parts of water was prepared.
Unsaturated poly with 68.6 parts of water and an average of 50 moles of ethylene oxide added to 3-methyl-3-buten-1-ol in a reaction vessel equipped with a thermometer, stirrer, dropping device, nitrogen inlet tube and reflux condenser. 274.5 parts of an alkylene glycol ether monomer (IPN-50), 1.6 parts of a 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 2 Then, 7 parts were charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After the temperature was raised to 60 ° C. in a nitrogen atmosphere, 3.1 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (C9a) was weighed at a constant rate over 4.5 hours, and 38.9 parts of acrylic acid (AA) and 13.6 parts of styrene (ST) over 2.5 hours. It was dripped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C9a), the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (C9) was obtained. The obtained copolymer (C9) had a weight average molecular weight Mw of 15,300. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C9) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 10]
An aqueous solution (C10a) in which 0.5 part of L-ascorbic acid and 0.8 part of 3-mercaptopropionic acid were dissolved in 18.0 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dripping device, a nitrogen introduction tube, and a reflux condenser. 404.8 parts of water and 3-methyl-3-buten-1-ol added with an average of 50 moles of ethylene oxide Charge 238.0 parts of an alkylene glycol ether monomer (IPN-50) and 0.4 part of acrylic acid (AA), then purge the reaction vessel with nitrogen under stirring and raise the temperature to 60 ° C. under a nitrogen atmosphere. After warming, 1.1 parts of a 35% aqueous solution of hydrogen peroxide was added.
After 30 minutes, the above mixed solution (C10a) was added at a constant rate over 3.5 hours, 16.2 parts of acrylic acid (AA) and 28.9 parts of butyl acrylate (BA) were added over 3.0 hours. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C10a), 60 ° C. was continuously maintained for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (C10) was obtained. The weight average molecular weight Mw of the obtained copolymer (C10) was 34500. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C10) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 11]
An aqueous solution (C11a) in which 0.5 part of L-ascorbic acid and 0.9 part of 3-mercaptopropionic acid were dissolved in 24.4 parts of water was prepared.
264.5 parts of water and 3-methyl-3-buten-1-ol with an average of 50 moles of ethylene oxide added to a reaction vessel equipped with a thermometer, stirrer, dropping device, nitrogen inlet tube and reflux condenser Charge 148.9 parts of an alkylene glycol ether monomer (IPN-50) and 0.3 part of acrylic acid (AA). Then, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. After warming, 1.1 parts of a 35% aqueous solution of hydrogen peroxide was added.
After 30 minutes, the above mixed solution (C11a) was added at a constant rate over 3.5 hours, 22.9 parts of acrylic acid (AA) and 22.1 parts of butyl acrylate (BA) were added over 3.0 hours. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C11a), 60 ° C. was continuously maintained for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (C11) was obtained. The weight average molecular weight Mw of the obtained copolymer (C11) was 32600. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C11) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 12]
An aqueous solution (C12a) in which 0.2 part of L-ascorbic acid and 1.7 parts of 3-mercaptopropionic acid were dissolved in 27.9 parts of water was prepared.
39.7 parts of water and an unsaturated polysiloxane having an average of 10 moles of ethylene oxide added to 3-methyl-3-buten-1-ol in a reaction vessel equipped with a thermometer, stirrer, dropping device, nitrogen inlet tube, and reflux condenser 159.2 parts of alkylene glycol ether monomer (IPN-10), 1.2 parts of 70% aqueous solution of paratoluenesulfonic acid monohydrate, 0.1% aqueous solution of ammonium iron (II) sulfate hexahydrate 1 Then, the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. in a nitrogen atmosphere. Then, 1.7 parts of a 35% aqueous hydrogen peroxide solution was added.
After 30 minutes, the above mixed solution (C12a) was added at a constant rate over 4.5 hours, 47.6 parts of acrylic acid (AA) and 27.4 parts of butyl acrylate (BA) over 2.5 hours, respectively. Weighed and dropped. The temperature during this period was constant at 60 ° C.
After completion of the dropwise addition of the mixed solution (C12a), 60 ° C. was continuously maintained for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (C12) was obtained. The weight average molecular weight Mw of the obtained copolymer (C12) was 27100. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C12) as a concrete admixture. The results are shown in Table 4.

[Comparative Example 13]
486.7 parts of an unsaturated polyalkylene glycol ether monomer (IPN-25) obtained by adding an average of 25 moles of ethylene oxide to 3-methyl-3-buten-1-ol, 29.5 parts of acrylic acid (AA), 3 -An aqueous solution (C13a) in which 2.2 parts of mercaptopropionic acid was dissolved in 212.4 parts of water, an aqueous solution (C13b) in which 1.1 parts of L-ascorbic acid was dissolved in 244.0 parts of water, and hydrogen peroxide An aqueous solution (C13c) in which 2.6 parts of 35% aqueous solution was dissolved in 34.7 parts of water was prepared.
A reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube, and a reflux condenser was charged with 105.0 parts of water. Subsequently, the reaction vessel was purged with nitrogen and stirred at 70 ° C. under a nitrogen atmosphere. The temperature rose.
The above mixed solution (C13a) and 45.0 parts of butyl acrylate (BA) were metered dropwise at a constant rate over 5 hours and the mixed solution (C13b) and mixed solution (C13c) over 6 hours. The temperature during this period was constant at 70 ° C.
After completion of the dropwise addition of the mixed solutions (C13b) and (C13c), the temperature was maintained at 70 ° C. for 1 hour to complete the polymerization reaction. Thereafter, the pH of the reaction solution was neutralized to pH = 6.3 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature. Thus, the polymer aqueous solution containing a copolymer (C13) was obtained. The weight average molecular weight Mw of the obtained copolymer (C13) was 16300. The results are shown in Table 2.
Various tests were performed using the obtained copolymer (C13) as a concrete admixture. The results are shown in Table 4.

  From Tables 3 and 4, Examples 1 to 16 each containing specific structural units (I), (II), and (III) at specific content ratios are excellent in both the mortar state and pipe permeability. Recognize.

  For example, Comparative Examples 1 to 3, and 8 are those in which the content ratio of the structural unit (III) is out of the range defined in the present invention, and the mortar state and the pipe permeability are inferior compared to the examples. It can be seen that a white precipitate is formed during the polymerization, and the polymerized product cannot be obtained well.

  In Comparative Examples 4, 5, and 9, the structure of the structural unit (III) is outside the range defined in the present invention, and in Comparative Examples 6 and 10, the content ratio of the structural unit (II) is defined in the present invention. Comparative examples 1, 7, 10 and 11 are out of the range defined in the present invention, and Comparative Examples 12 and 13 are structural units (I). Although the average added mole number of the oxyalkylene group is out of the range defined in the present invention, it can be seen that these are inferior in the mortar state and pipe permeability as compared with the Examples.

The polycarboxylic acid copolymer of the present invention can be suitably used as a material for a concrete composition such as cement paste, mortar, or concrete.

Claims (7)

Structural unit (I) derived from unsaturated polyalkylene glycol monomer (a) represented by general formula (1): 35% by mass to 88.5% by mass with respect to 100% by mass of all structural units, Carboxylic acid structural unit represented by general formula (II): 8% by mass to 35% by mass, and carboxylic acid alkyl ester structural unit represented by general formula (III): 3.5% by mass to 30% by mass Including
The weight average molecular weight is 30000 or less,
Polycarboxylic acid copolymer.

(In General Formula (1), R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom or a methyl group, and R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. , AO represents an oxyalkylene group having 2 to 18 carbon atoms, m represents an average addition mole number of the oxyalkylene group represented by AO, m is 30 to 300, and x is 0 to 5 An integer, and y is 0 or 1.)

(In General Formula (II), R ⁵ , R ⁶ , and R ⁷ are the same or different and each represents a hydrogen atom, a methyl group, or — (CH ₂ ) _n COOM ² group, and n is 0 to 2, M ¹ and M ² are the same or different and each represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group, and R ⁶ and R ⁷ are not simultaneously a — (CH ₂ ) _n COOM ² group, ^{When 7} is a — (CH ₂ ) _n COOM ² group, R ⁵ and R ⁶ are the same or different and are a hydrogen atom or a methyl group.)

(In General Formula (III), R ⁸ and R ⁹ are the same or different and each represents a hydrogen atom or a methyl group, and R ¹⁰ represents a hydrocarbon group having 2 to 18 carbon atoms or an aromatic carbon atom having 6 to 18 carbon atoms. Represents a hydrogen group.) The polycarboxylic acid type according to claim 1, wherein the unsaturated polyalkylene glycol monomer (a) is an unsaturated polyalkylene glycol ether monomer (e) represented by the general formula (1e). Copolymer.

(In the general formula (1e), R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom or a methyl group, and R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. , AO represents an oxyalkylene group having 2 to 18 carbon atoms, m represents an average addition mole number of the oxyalkylene group represented by AO, m is 30 to 300, and x is 0 to 5 (It is an integer.) The polycarboxylic acid copolymer according to claim 1 or 2, wherein R ⁵ in the general formula (II) is a hydrogen atom, R ⁶ is a hydrogen atom, and R ⁷ is a hydrogen atom or a methyl group.   The content ratio of the carboxylic acid alkyl ester structural unit represented by the general formula (III) in the polycarboxylic acid copolymer is 4% by mass to 28% by mass, or any one of claims 1 to 3. The polycarboxylic acid copolymer described in 1. The polycarboxylic acid copolymer according to any one of claims 1 to 4, wherein R ¹⁰ in the general formula (III) is an alkyl group having 2 to 10 carbon atoms.   A concrete admixture comprising the polycarboxylic acid copolymer according to any one of claims 1 to 5. A concrete composition comprising the concrete admixture according to claim 6.