JP6715599B2 - Cement dispersibility improving aid and cement composition - Google Patents

Description

The present invention relates to a cement dispersibility improving aid and a cement composition.

Cement compositions such as mortar and concrete generally contain cement, aggregate and water, and a cement admixture is generally used to enhance the dispersibility of the cement (for example, Patent Document 1).

However, when attempting to improve the dispersibility of cement with a conventional cement admixture, there are cases in which sufficient dispersibility cannot be expressed, and a large amount of water reducing agent is required, which is disadvantageous in terms of cost. is there.

JP, 2013-133241, A

An object of the present invention is to provide a cement dispersibility improving aid which can sufficiently improve the dispersibility of cement in a cement composition and can reduce the amount of a water reducing agent. Another object is to provide a cement composition containing such a cement dispersibility improving aid.

（一般式（１）中、Ｒ^１およびＲ^２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^３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、ｎ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、ｎは１〜５００の整数であり、ｘは０〜２の整数である。） The cement dispersibility improving aid of the present invention,
Copolymer having structural unit (I) derived from unsaturated polyalkylene glycol ether monomer (a) represented by general formula (1) and structural unit (II) derived from hydroxyalkyl (meth)acrylate (b) Including coalescence.

(In the general formula (1), R ¹ and R ² are the same or different and each represents a hydrogen atom or a methyl group, R ³ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and AO represents Represents an oxyalkylene group having 2 to 18 carbon atoms, n represents the average number of moles of the oxyalkylene group represented by AO, n is an integer of 1 to 500, and x is an integer of 0 to 2. It is.)

In one embodiment, the hydroxyalkyl (meth)acrylate (b) is hydroxyethyl acrylate.

（一般式（３−１）中、Ｒ^４、Ｒ^５、およびＲ^６は、同一または異なって、水素原子またはメチル基を表し、Ｘは、水素原子、メチル基、エチル基、アルカリ金属、アルカリ土類金属、アンモニウム基、有機アンモニウム基、または有機アミン基を表す。）

（一般式（３−２）中、Ｒ^７、Ｒ^８、およびＲ^９は、同一または異なって、水素原子、メチル基、または−（ＣＨ_２）_ｚＣＯＯＭ^１基を表し、Ｒ^７、Ｒ^８、およびＲ^９の少なくとも１つが−（ＣＨ_２）_ｚＣＯＯＭ^１基であり、−（ＣＨ_２）_ｚＣＯＯＭ^１基は−ＣＯＯＸ基または他の−（ＣＨ_２）_ｚＣＯＯＭ^１基と無水物を形成していても良く、ｚは０〜２の整数であり、Ｍ^１は、水素原子、アルカリ金属、アルカリ土類金属、アンモニウム基、有機アンモニウム基、または有機アミン基を表し、Ｘは、水素原子、メチル基、エチル基、アルカリ金属、アルカリ土類金属、アンモニウム基、有機アンモニウム基、または有機アミン基を表す。） In one embodiment, the copolymer is a structural unit (III-1) derived from the unsaturated monocarboxylic acid monomer (c-1) represented by the general formula (3-1) and/or It has a structural unit (III-2) derived from the unsaturated polycarboxylic acid-based monomer (c-2) represented by the general formula (3-2).

(In the general formula (3-1), R ⁴ , R ⁵ , and R ⁶ are the same or different and represent a hydrogen atom or a methyl group, and X is a hydrogen atom, a methyl group, an ethyl group, an alkali metal, an alkali. Represents an earth metal, ammonium group, organic ammonium group, or organic amine group.)

(In the general formula (3-2), R ⁷ , R ⁸ and R ⁹ are the same or different and each represent a hydrogen atom, a methyl group or a —(CH ₂ ) _z COOM ¹ group, and R ⁷ , R ⁸ , And at least one of R ⁹ is a —(CH ₂ ) _z COOM ¹ group, and the —(CH ₂ ) _z COOM ¹ group forms an anhydride with a —COOX group or another —(CH ₂ ) _z COOM ¹ group. , Z is an integer of 0 to 2, M ¹ represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group, and X represents a hydrogen atom. , Represents a methyl group, an ethyl group, an alkali metal, an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group.)

The cement composition of the present invention contains the cement dispersibility improving aid of the present invention.

According to the present invention, it is possible to provide a cement dispersibility improving aid which can sufficiently improve the dispersibility of cement in a cement composition and can reduce the amount of a water reducing agent. Further, a cement composition containing such a cement dispersibility improving aid can be provided.

In the present specification, the expression "(meth)acrylic" means "acrylic and/or methacrylic", and the expression "(meth)acrylate" means "acrylate and/or methacrylate". And the expression "(meth)allyl" means "allyl and/or methallyl", and the expression "(meth)acrolein" means "acrolein and/or methacrolein". Means "rain". Further, in the present specification, the expression "acid (salt)" means "acid and/or salt thereof". Further, when the expression "mass" is used in the present specification, it may be read as "weight" which is conventionally commonly used as a unit of weight, and conversely, "weight" is used in the present specification. When there is the expression, it may be read as “mass” which is commonly used as an SI system unit showing weight.

<<Cement dispersibility improvement aid>>
The cement dispersibility improving aid of the present invention comprises a structural unit (I) derived from an unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) and a hydroxyalkyl (meth)acrylate (b). It includes a copolymer having the structural unit (II) derived from. The cement dispersibility improving aid of the present invention comprises a structural unit (I) derived from an unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) and a hydroxyalkyl (meth)acrylate (b). By including the copolymer having the derived structural unit (II), the dispersibility of cement in the cement composition can be sufficiently improved and the amount of the water reducing agent can be reduced.

The cement dispersibility improving aid of the present invention may contain any appropriate other component as long as the effect of the present invention is not impaired.

The content ratio of the copolymer in the cement dispersibility improving aid of the present invention is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and further preferably 90% by mass. % To 100% by mass, particularly preferably 95% to 100% by mass, most preferably substantially 100% by mass. The content of the copolymer in the cement dispersibility improving aid of the present invention is within the above range, the cement dispersibility improving aid of the present invention more sufficiently disperses the cement in the cement composition. In addition to being able to improve, the amount of the water reducing agent can be further reduced.

<Copolymer>
The copolymer contained in the cement dispersibility improving aid of the present invention comprises a structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) and a hydroxyalkyl ( It has a structural unit (II) derived from (meth)acrylate (b).

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

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

In formula (1) and structural unit (I), R ³ 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 alkyl groups having 1 to 30 carbon atoms (aliphatic alkyl groups and alicyclic alkyl groups), alkenyl groups having 1 to 30 carbon atoms, and carbon atoms. Examples thereof include an alkynyl group having 1 to 30 and an aromatic group having 6 to 30 carbon atoms. From the viewpoint that the effects of the present invention can be further expressed, R ³ 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. A hydrogen group is more preferable, a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms is more preferable, and a hydrogen atom or an alkyl group having 1 to 6 carbon atoms is particularly preferable.

In the general formula (1) and the structural unit (I), AO is an oxyalkylene group having 2 to 18 carbon atoms, preferably an oxyalkylene group having 2 to 8 carbon atoms, and more preferably the number of carbon atoms. 2 to 4 oxyalkylene groups. When AO is any two or more kinds selected from oxyethylene group, oxypropylene group, oxybutylene group, oxystyrene group, etc., the addition form of AO is random addition, block addition, alternate addition, etc. Either form may be used. In order to secure the balance between hydrophilicity and hydrophobicity, it is preferable that an oxyethylene group is contained as an essential component in the oxyalkylene group, and it is more preferable that 50 mol% or more of the entire oxyalkylene group is an oxyethylene group. It is more preferable that 90 mol% or more of all the oxyalkylene groups are oxyethylene groups, and it is particularly preferable that 100 mol% of all the oxyalkylene groups are oxyethylene groups.

In the general formula (1) and the structural unit (I), n represents the average number of added moles of the oxyalkylene group represented by AO, and is 1 to 500, preferably 2 to 500, and more preferably 5. ˜500, more preferably 10 to 500, particularly preferably 15 to 500, and most preferably 20 to 300.

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

Examples of the unsaturated polyalkylene glycol ether-based monomer (a) represented by the general formula (1) include vinyl alcohol, (meth)allyl alcohol, and 3-methyl-3-buten-1-ol (isoprenol). , 3-methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-2-buten-1-ol, 2-methyl-3-buten-1-ol The compound obtained by adding 1 to 500 mol of alkylene oxide to crab is more preferable, and the compound obtained by adding 1 to 500 mol of alkylene oxide to 3-methyl-3-buten-1-ol (isoprenol) is more preferable. The “alkylene oxide” in the above examples is preferably ethylene oxide, propylene oxide or butylene oxide, more preferably ethylene oxide or propylene oxide, and even more preferably ethylene oxide.

Specific examples of the unsaturated polyalkylene glycol ether-based monomer (a) represented by the general formula (1) 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, methoxy polyethylene glycol mono(3-methyl-3-butenyl) ether, ethoxy polyethylene glycol mono(3-methyl-3-butenyl) ether, 1-propoxy Polyethylene glycol mono(3-methyl-3-butenyl) ether, cyclohexyloxy polyethylene glycol mono(3-methyl-3-butenyl) ether, 1-octyloxy polyethylene glycol mono(3-methyl-3-butenyl) ether, nonylalkoxy Polyethylene glycol mono(3-methyl-3-butenyl) ether, lauryl alkoxy polyethylene glycol mono(3-methyl-3-butenyl) ether, stearyl alkoxy polyethylene glycol mono(3-methyl-3-butenyl) ether, phenoxy polyethylene glycol mono( Examples thereof include 3-methyl-3-butenyl) ether and naphthoxy polyethylene glycol mono(3-methyl-3-butenyl) ether.

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

The hydroxyalkyl (meth)acrylate (b) is preferably a hydroxyalkyl ester of (meth)acrylic acid having 2 to 5 carbon atoms, and specific examples thereof include hydroxyethyl (meth)acrylate and hydroxypropyl ( (Meth)acrylate, hydroxybutyl (meth)acrylate and hydroxypentyl (meth)acrylate are mentioned, preferably hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate, more preferably hydroxyethyl (meth)acrylate. And more preferably hydroxyethyl acrylate.

The hydroxyalkyl (meth)acrylate (b) may be only one kind or two or more kinds.

The structural unit (II) derived from hydroxyalkyl (meth)acrylate (b) is a structural unit formed by cleavage of the unsaturated double bond of hydroxyalkyl (meth)acrylate (b) by polymerization. In addition, the structural unit formed by cleavage of an unsaturated double bond by polymerization means a structure of "RpRqC=CRrRs" (Rp, Rq, Rr, and Rs are any suitable ones bonded to a carbon atom by a single bond). It is a structural unit of "-RpRqC-CRrRs-" formed by cleavage of the unsaturated double bond "C=C" of group) by polymerization.

The total content of the structural unit (I) and the structural unit (II) in the copolymer contained in the cement dispersibility improving aid of the present invention is preferably 50% by mass to 100% by mass, and It is preferably 70% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and particularly preferably 95% by mass to 100% by mass. When the total content of the structural unit (I) and the structural unit (II) in the copolymer contained in the cement dispersibility improving aid of the present invention is within the above range, the cement dispersibility of the present invention is improved. The auxiliary agent can more sufficiently improve the dispersibility of cement in the cement composition and can further reduce the amount of the water reducing agent.

The content ratio of the structural unit (I) and the structural unit (II) in the copolymer contained in the cement dispersibility improving aid of the present invention is a mass ratio of structural unit (I)/structural unit (II). , Preferably 99/1 wt% to 1/99 wt%, more preferably 98/2 wt% to 10/90 wt%, and still more preferably 95/5 wt% to 30/70 wt%. , More preferably 93/7% to 50/50% by weight, further preferably 92/8% to 60/40% by weight, particularly preferably 91/9% to 70/30% by weight. And most preferably 90/10 wt% to 80/20 wt%. When the content ratio of the structural unit (I) and the structural unit (II) in the copolymer contained in the cement dispersibility improving aid of the present invention is within the above range, the cement dispersibility improving aid of the present invention is The agent can more sufficiently improve the dispersibility of cement in the cement composition and can further reduce the amount of the water reducing agent.

The total content of the structural unit (I) and the structural unit (II) in the copolymer contained in the cement dispersibility improving aid of the present invention and the content ratio are, for example, various structural analyzes of the copolymer. (Eg, NMR, etc.). Further, it is calculated based on the amount of various monomers used in the production of the copolymer contained in the cement dispersibility improving aid of the present invention without performing various structural analyzes as described above. The total content of the structural unit (I) and the structural unit (II) in the copolymer contained in the cement dispersibility improving aid of the present invention, with the content ratio and the content ratio of the structural units derived from various monomers. It may be a ratio or a content ratio. That is, the unsaturated polyalkylene glycol ether-based monomer (a) and hydroxyalkyl (meth) in all the monomer components used when producing the copolymer contained in the cement dispersibility improving aid of the present invention. The content ratio of the total mass of the acrylate (b) and the total content ratio of the structural unit (I) and the structural unit (II) in the copolymer contained in the cement dispersibility improving aid of the present invention, It may be treated as a content ratio.

The copolymer contained in the cement dispersibility improving aid of the present invention has a structural unit (III-1) derived from the unsaturated monocarboxylic acid monomer (c-1) represented by the general formula (3-1). ) And/or the structural unit (III-2) derived from the unsaturated polycarboxylic acid-based monomer (c-2) represented by the general formula (3-2).

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

In formula (3-1) and structural unit (III-1), R ⁴ , R ⁵ , and R ⁶ are the same or different and each represents a hydrogen atom or a methyl group.

In the general formula (3-1) and the structural unit (III-1), X represents a hydrogen atom, a methyl group, an ethyl group, an alkali metal, an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group. ..

Examples of the unsaturated monocarboxylic acid-based monomer (c-1) represented by the general formula (3-1) include acrylic acid, methacrylic acid, crotonic acid, and salts thereof. Examples of the salt here include an alkali metal salt, an alkaline earth metal salt, an ammonium salt, an organic ammonium salt, an organic amine salt and the like. Examples of the alkali metal salt include lithium salt, sodium salt, potassium salt and the like. Examples of the alkaline earth metal salt include calcium salt, magnesium salt and the like. Examples of the organic ammonium salt include methylammonium salt, ethylammonium salt, dimethylammonium salt, diethylammonium salt, trimethylammonium salt, triethylammonium salt and the like. Examples of the organic amine salt include alkanolamine salts such as ethanolamine salt, diethanolamine salt and triethanolamine salt.

The unsaturated monocarboxylic acid-based monomer (c-1) represented by the general formula (3-1) is preferably acrylic acid, methacrylic acid, or, from the viewpoint that the effect of the present invention can be further exhibited. These are the salts.

The unsaturated monocarboxylic acid type monomer (c-1) represented by the general formula (3-1) may be only one kind, or may be two or more kinds.

The content ratio of the structural unit (III-1) in the copolymer contained in the cement dispersibility improving aid of the present invention is preferably 50 mol% or less, more preferably 0 mol% to 40 mol%. , More preferably 0 mol% to 30 mol%, further preferably 0 mol% to 20 mol%, particularly preferably 0 mol% to 10 mol%, and most preferably substantially 0 mol% ( That is, it does not include). When the content ratio of the structural unit (III-1) in the copolymer contained in the cement dispersibility improving aid of the present invention is within the above range, the cement dispersibility improving aid of the present invention is contained in the cement composition. The dispersibility of cement can be more sufficiently improved and the amount of the water reducing agent can be further reduced.

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

In general formula (3-2) and structural unit (III-2), R ⁷ , R ⁸ and R ⁹ are the same or different and each represent a hydrogen atom, a methyl group, or a —(CH ₂ ) _z COOM ¹ group. And at least one of R ⁷ , R ⁸ and R ⁹ is a —(CH ₂ ) _z COOM ¹ group. R ^{7, R 8,} and at least one of ^{R 9} _{- (CH} 2) For z COOM ¹ group, the _{- (CH} 2) z COOM ¹ group is -COOX groups or other _{- (CH} 2) z COOM ¹ It may form an anhydride with the group. z is an integer of 0-2. M ¹ represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group.

In general formula (3-2) and structural unit (III-2), X represents a hydrogen atom, a methyl group, an ethyl group, an alkali metal, an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group. ..

Examples of the unsaturated polycarboxylic acid-based monomer (c-2) represented by the general formula (3-2) include dicarboxylic acid-based monomers such as maleic acid, itaconic acid, and fumaric acid, or these. Examples thereof include salts; anhydrides of dicarboxylic acid type monomers such as maleic acid, itaconic acid and fumaric acid, or salts thereof; and the like. Examples of the salt here include an alkali metal salt, an alkaline earth metal salt, an ammonium salt, an organic ammonium salt, an organic amine salt and the like. Examples of the alkali metal salt include lithium salt, sodium salt, potassium salt and the like. Examples of the alkaline earth metal salt include calcium salt, magnesium salt and the like. Examples of the organic ammonium salt include methylammonium salt, ethylammonium salt, dimethylammonium salt, diethylammonium salt, trimethylammonium salt, triethylammonium salt and the like. Examples of the organic amine salt include alkanolamine salts such as ethanolamine salt, diethanolamine salt and triethanolamine salt.

The unsaturated polycarboxylic acid-based monomer (c-2) represented by the general formula (3-2) is preferably maleic acid or a salt thereof, from the viewpoint that the effects of the present invention can be further exhibited. It is maleic anhydride, and more preferably maleic acid or a salt thereof.

The unsaturated polycarboxylic acid-based monomer (c-2) represented by the general formula (3-2) may be only one type, or may be two or more types.

The content ratio of the structural unit (III-1) in the copolymer contained in the cement dispersibility improving aid of the present invention is preferably 50 mol% or less, more preferably 0 mol% to 40 mol%. , More preferably 0 mol% to 30 mol%, further preferably 0 mol% to 20 mol%, particularly preferably 0 mol% to 10 mol%, and most preferably substantially 0 mol% ( That is, it does not include). When the content ratio of the structural unit (III-2) in the copolymer contained in the cement dispersibility improving aid of the present invention is within the above range, the cement dispersibility improving aid of the present invention is contained in the cement composition. The dispersibility of cement can be more sufficiently improved and the amount of the water reducing agent can be further reduced.

The content ratio of the structural units (I), (II), (III-1) and (III-2) in the copolymer contained in the cement dispersibility improving aid of the present invention is, for example, the copolymer. Can be known by various structural analyzes (for example, NMR). Further, it is calculated based on the amount of various monomers used in the production of the copolymer contained in the cement dispersibility improving aid of the present invention without performing various structural analyzes as described above. The structural units (I), (II), (III-1) and (III-2) in the copolymer contained in the cement dispersibility improving aid of the present invention have a content ratio of structural units derived from various monomers. ) May be included. That is, the unsaturated polyalkylene glycol ether-based monomer (a) or hydroxyalkyl (meth) in all the monomer components used in producing the copolymer contained in the cement dispersibility improving aid of the present invention. The content ratio of the mass of the acrylate (b), the unsaturated monocarboxylic acid-based monomer (c-1) and the unsaturated polycarboxylic acid-based monomer (c-2) is set to the cement dispersibility improving aid of the present invention. It may be treated as the content ratio of the structural units (I), (II), (III-1) and (III-2) in the copolymer contained in the agent.

In the copolymer contained in the cement dispersibility improving aid of the present invention, other than the structural unit (I), the structural unit (II), the structural unit (III-1) and the structural unit (III-2), The structural unit (IV) derived from the monomer (d) may be included. The structural unit (IV) derived from the other monomer (d) may be only one type or two or more types.

The other monomer (d) is the same as the unsaturated polyalkylene glycol ether-based monomer (a), the hydroxyalkyl (meth)acrylate (b), and the unsaturated monocarboxylic acid-based monomer (c-1). It is a monomer copolymerizable with the saturated polycarboxylic acid-based monomer (c-2).

Examples of the other monomer (d) include esters of unsaturated monocarboxylic acids such as methyl (meth)acrylate and glycidyl (meth)acrylate with alcohols having 1 to 30 carbon atoms; polyethylene glycol mono (meth). ) Acrylate, various (alkoxy)(poly)alkylene glycol mono(meth)acrylates such as methoxy(poly)ethylene glycol mono(meth)acrylate; (anhydrous) unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid Half-esters with alcohols having 1 to 30 carbon atoms; (anhydrous) diesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and alcohols having 1 to 30 carbon atoms; And amides having 1 to 30 carbon atoms; diamides of the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms; 1 alkylene oxide having 2 to 18 carbon atoms in the alcohol or amine ~ 500 moles of alkyl (poly) alkylene glycol and the above unsaturated dicarboxylic acids half-esters; alkyl (poly) obtained by adding 1 to 500 moles of alkylene oxide having 2 to 18 carbon atoms to the above alcohol or amine Diesters of alkylene glycol and the above unsaturated dicarboxylic acids; Half esters of the above unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or polyalkylene glycols having an addition mole number of these glycols of 2 to 500; Diesters of saturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or addition glycols of these glycols with polyalkylene glycols having 2 to 500 carbon atoms; maleamic acid and glycols having 2 to 18 carbon atoms or addition moles of these glycols Half amides with polyalkylene glycol having a number of 2 to 500; (poly)alkylene glycol di(meth)acrylates such as (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate; hexane Polyfunctional (meth)acrylates such as diol di(meth)acrylate and trimethylolpropane tri(meth)acrylate; (poly)alkylene glycol dimaleates such as polyethylene glycol dimaleate; vinyl sulfonate, (meth)allyl sulfonate, styrene Unsaturated sulfonic acids (salts) such as sulfonic acid; vinyl such as styrene, α-methylstyrene and vinyltoluene Aromatic compounds; Alkanediol mono(meth)acrylates such as 1,4-butanediol mono(meth)acrylate; Diene compounds such as butadiene and isoprene; Unsaturated cyan compounds such as (meth)acrylonitrile; Vinyl acetate compounds Saturated esters; aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, unsaturated amines such as vinylpyridine; divinylaromatics such as divinylbenzene; (meth)allyl alcohol, glycidyl (meth)allyl Allyls such as ethers; vinyl ethers such as (methoxy) polyethylene glycol monovinyl ether; (meth) allyl ethers such as (methoxy) polyethylene glycol mono(meth) allyl ether; glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, etc. A compound in which ammonia, monoethanolamine, monoisopropanolamine, monoethanolmonoisopropanolamine, diisopropanolamine, etc. are added to the glycidyl group-containing monomer of (for example, a compound in which diisopropanolamine is added to glycidyl methacrylate); Can be mentioned. The “alkylene oxide” in the above examples is preferably ethylene oxide, propylene oxide or butylene oxide, more preferably ethylene oxide or propylene oxide, and even more preferably ethylene oxide.

The content ratio of the structural unit (IV) in the copolymer contained in the cement dispersibility improving aid of the present invention can be known, for example, by various structural analyzes (for example, NMR) of the copolymer. Further, it is calculated based on the amount of various monomers used in the production of the copolymer contained in the cement dispersibility improving aid of the present invention without performing various structural analyzes as described above. The content ratio of the structural unit (IV) in the copolymer contained in the cement dispersibility improving aid of the present invention may be calculated using the content ratio of the structural units derived from various monomers. That is, the content ratio of the mass of the other monomer (d) to the total amount of the monomer components used in producing the copolymer contained in the cement dispersibility improving aid of the present invention is the cement of the present invention. It may be treated as the content ratio of the structural unit (IV) in the copolymer contained in the dispersibility improving aid.

When obtaining the content ratio of the structural unit in the copolymer contained in the cement dispersibility improving aid of the present invention, when the structural unit has a carboxyl group, it is calculated as being completely neutralized I do.

The mass average molecular weight (Mw) of the copolymer contained in the cement dispersibility improving aid of the present invention is preferably 40,000 to 1,000,000, more preferably 45,000 to 800,000, further preferably 50,000 to 600,000, It is particularly preferably 60,000 to 400,000, and most preferably 70,000 to 200,000. When the mass average molecular weight (Mw) of the copolymer contained in the cement dispersibility improving aid of the present invention is within the above range, the cement dispersibility improving aid of the present invention has a dispersibility of cement in the cement composition. And the amount of the water reducing agent can be further reduced.

The copolymer contained in the cement dispersibility improving aid of the present invention can be produced by any appropriate method. The copolymer contained in the cement dispersibility improving aid of the present invention preferably contains essentially an unsaturated polyalkylene glycol ether monomer (a) and a hydroxyalkyl (meth)acrylate (b), Polymerization of a monomer component that may contain a saturated monocarboxylic acid-based monomer (c-1), an unsaturated polycarboxylic acid-based monomer (c-2), and another monomer (d), It can be produced by carrying out in the presence of a polymerization initiator.

Unsaturated polyalkylene glycol ether type monomer (a), hydroxyalkyl (meth)acrylate (b), unsaturated monocarboxylic acid type which can be used for producing the copolymer contained in the cement dispersibility improving aid of the present invention The amounts of the monomer (c-1), the unsaturated polycarboxylic acid-based monomer (c-2), and the other monomer (d) used are included in the cement dispersibility improving aid of the present invention. It may be appropriately adjusted so that the ratio of the structural unit derived from each monomer in all the structural units constituting the copolymer becomes the above-mentioned ratio. Preferably, as the polymerization reaction proceeds quantitatively, the same as the proportion of the structural units derived from each monomer in all the structural units constituting the copolymer contained in the cement dispersibility improving aid of the present invention described above. Each monomer may be used in a ratio.

The unsaturated polyalkylene glycol ether-based monomer (a) can be synthesized by any appropriate method. For example, it can be synthesized by adding alkylene oxide to 3-methyl-3-buten-1-ol (isoprenol).

Polymerization of the monomer component can be performed by any suitable 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 solution polymerization include water; alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane and n-hexane; esters such as ethyl acetate. Compounds; ketone compounds such as acetone and methyl ethyl ketone; cyclic ether compounds such as tetrahydrofuran and dioxane; and the like.

When the monomer component is polymerized, a water-soluble polymerization initiator, for example, a persulfate such as ammonium persulfate, sodium persulfate, potassium persulfate or the like; a hydrogen peroxide; 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. A water-soluble azo initiator such as the azonitrile compound of. These polymerization initiators include alkali metal sulfites such as sodium bisulfite, metadisulfite, sodium hypophosphite, Fe(II) salts such as Mohr salt, sodium hydroxymethanesulfinate dihydrate, and hydroxylamine hydrochloride. An accelerator such as salt, thiourea, L-ascorbic acid (salt) or erythorbic acid (salt) may be used in combination. Among these combined modes, a combination of ammonium persulfate and a promoter such as L-ascorbic acid (salt) is preferable. These polymerization initiators and accelerators may be used alone or in combination of two or more.

When carrying out solution polymerization using a lower alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester compound, or a ketone compound as a solvent, or when carrying out bulk polymerization, benzoyl peroxide, lauroyl peroxide are used as a polymerization initiator. Oxides, peroxides such as sodium peroxide; hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; azo compounds such as azobisisobutyronitrile; and the like can be used. When such a polymerization initiator is used, an accelerator such as an amine compound can also be used together. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected and used from the above-mentioned various polymerization initiators or a combination of a polymerization initiator and an accelerator.

The reaction temperature at the time of polymerizing the monomer component is appropriately determined depending on the polymerization method, solvent, polymerization initiator and chain transfer agent used. Such 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. And more preferably 100° C. or lower.

Any appropriate method can be adopted as a method for charging the monomer component into the reaction vessel. As such a charging method, for example, a method of initially charging the entire amount into the reaction container at once, a method of dividing or continuously charging the entire amount into the reaction container, a part of which is initially charged into the reaction container, and the rest into the reaction container. Examples include a method of dividing or continuously charging. Further, the rate of charging each monomer into the reaction vessel may be continuously or stepwise changed during the reaction, and the mass ratio of each monomer charged per unit time may be continuously or stepwise changed. .. The polymerization initiator may be charged into the reaction vessel from the beginning or may be added dropwise to the reaction vessel, or these may be combined depending on the purpose.

A chain transfer agent may be preferably used in the polymerization of the monomer components. Use of a chain transfer agent facilitates the adjustment of the molecular weight of the resulting copolymer. The chain transfer agent may be only one type, or may be 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, dithionous acid, metabisulfite, And lower salts of its salts (sodium sulfite, potassium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, sodium dithionite, potassium dithionite, sodium metabisulfite, potassium metabisulfite, etc.) and salts thereof; Are listed.

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

The concentration of the produced copolymer can be adjusted in the solution obtained by the production, if necessary.

The produced copolymer may be used as it is in the form of a solution, or may be neutralized with a hydroxide of a divalent metal such as calcium or magnesium to give a polyvalent metal salt, and then dried. The powder may be used by supporting it on an inorganic powder such as silica-based fine powder and drying the powder.

The cement dispersibility improving aid of the present invention may contain any appropriate other component in addition to the copolymer as described above, as long as the effects of the present invention are not impaired.

<<Cement composition>>
The cement composition of the present invention contains the cement dispersibility improving aid of the present invention.

In addition to the cement dispersibility improving aid of the present invention, the cement composition of the present invention preferably contains cement, water and an aggregate, and more preferably contains cement, water, an aggregate and a cement admixture.

The content of the cement dispersibility-improving aid of the present invention in the cement composition of the present invention is preferably 0.001% by mass to 1% by mass, more preferably 0. 003% by mass to 0.5% by mass, more preferably 0.005% by mass to 0.3% by mass, particularly preferably 0.007% by mass to 0.2% by mass, and most preferably 0. It is 0.01% by mass to 0.1% by mass. If the content of the cement dispersibility improving aid of the present invention in the cement composition of the present invention is within the above range relative to the cement, the dispersibility of the cement in the cement composition can be more sufficiently improved. The amount of water reducing agent can be further reduced.

As the aggregate, any suitable aggregate such as fine aggregate (sand or the like) or coarse aggregate (crushed stone or the like) can be adopted. Examples of such aggregates include gravel, crushed stone, granulated slag, and recycled aggregate. Further, examples of such aggregates include fire-resistant aggregates such as silica, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromag and magnesia.

The cement admixture preferably contains a polymer for a cement admixture from the viewpoint that the effects of the present invention can be more effectively exhibited.

The cement admixture may contain, in addition to the polymer for the cement admixture, any other appropriate component as long as the effect of the present invention is not impaired.

Examples of other components include cement dispersants. When a cement dispersant is used, the mixing ratio of the polymer for cement admixture and the cement dispersant (polymer for cement admixture/cement dispersant) is different in the type of cement dispersant used, compounding conditions, test conditions, etc. Any appropriate blending ratio can be set. The cement dispersant may be only one type, or may be two or more types.

Examples of the cement dispersant include a sulfonic acid-based dispersant having a sulfonic acid group in the molecule, a copolymer other than the copolymer contained in the cement dispersibility improving aid of the present invention, and the like.

Examples of the sulfonic acid type dispersant include polyalkylaryl sulfonate type sulfonic acid type dispersants such as naphthalene sulfonic acid formaldehyde condensate, methylnaphthalene sulfonic acid formaldehyde condensate and anthracene sulfonic acid formaldehyde condensate; melamine sulfonic acid. Melamine formalin resin sulfonate dispersant such as formaldehyde condensate; Aromatic amino sulfonate dispersant such as aminoaryl sulfonic acid-phenol-formaldehyde condensate; lignin sulfonate; Examples include lignin sulfonate-based sulfonic acid dispersants such as modified lignin sulfonate; polystyrene sulfonate-based sulfonic acid dispersants; and the like.

The cement admixture can contain any appropriate other cement additive (material) within a range that does not impair the effects of the present invention. Examples of such other cement additives (materials) include other cement additives (materials) exemplified in the following (1) to (12). The compounding ratio of the polymer for cement admixture that can be contained in the cement admixture and such other cement additive (material) is arbitrary and appropriate depending on the type and purpose of the other cement additive (material) to be used. Various mixing ratios can be adopted.

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

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

(3) Curing retarder: oxycarboxylic acids such as gluconic acid, glucoheptonic acid, arabonic acid, malic acid, citric acid or salts thereof; sugars and sugar alcohols; polyhydric alcohols such as glycerin; aminotri(methylenephosphonic acid), etc. Phosphonic acid and its derivatives.

The ratio of the curing retarder to the compound (A) is preferably 1% by mass to 10000% by mass, more preferably 5% by mass to 1000% by mass, and further preferably 10% by mass to 500% by mass. And particularly preferably 30% by mass to 300% by mass, and most preferably 50% by mass to 200% by mass.

(4) Early strengthening agents/accelerators: soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide and calcium iodide; chlorides such as iron chloride and magnesium chloride; sulfates; potassium hydroxide; Sodium hydroxide; carbonates; thiosulfates; formates such as formic acid and calcium formate; alkanolamines; alumina cements; calcium aluminate silicates.

(5) Oxyalkylene-based defoaming agent: polyoxyalkylenes such as (poly)oxyethylene (poly)oxypropylene adducts; polyoxyalkylene alkyl ethers such as diethylene glycol heptyl ether; polyoxyalkylene acetylene ethers; (poly ) Oxyalkylene fatty acid ester; polyoxyalkylene sorbitan fatty acid ester; polyoxyalkylene alkyl (aryl) ether sulfate ester salt; polyoxyalkylene alkyl phosphate ester; polyoxypropylene polyoxyethylene lauryl amine (propylene oxide 1 to 20) Mol addition, ethylene oxide 1 to 20 mol adduct, etc.), polyoxy such as amine derived from fatty acid obtained from hardened beef tallow to which alkylene oxide is added (propylene oxide 1 to 20 mol addition, ethylene oxide 1 to 20 mol adduct, etc.) Alkylene alkylamines; polyoxyalkylene amides and the like.

(6) Defoaming agents other than oxyalkylene-based defoaming agents: mineral oil-based, oil/fat-based, fatty acid-based, fatty acid ester-based, alcohol-based, amide-based, phosphate ester-based, metal soap-based, silicone-based defoaming agents, and the like.

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

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

(9) Waterproofing agent: fatty acid (salt), fatty acid ester, oil and fat, silicone, paraffin, asphalt, wax and the like.

(10) Antirust agent: nitrite, phosphate, zinc oxide and the like.

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

(12) Expansive material; ettringite type, coal type, etc.

Other known cement additives (materials) include a cement wetting agent, a thickener, a separation reducing agent, a coagulant, a drying shrinkage reducing agent, a strength enhancer, a self-leveling agent, a rust preventive, a coloring agent, and a fungicide. Examples thereof include agents. These known cement additives (materials) may be used alone or in combination of two or more.

Any appropriate cement can be adopted as the cement contained in the cement composition of the present invention. Examples of such cement include, for example, Portland cement (normal, early strength, super early strength, moderate heat, sulfate resistant and low alkali type of each), various mixed cements (blast furnace cement, silica cement, fly ash cement), White Portland cement, Alumina cement, Super rapid hardening cement (1 clinker quick hardening cement, 2 clinker quick hardening cement, magnesium phosphate cement), grout cement, oil well cement, low heat generation cement (low heat generation type blast furnace cement, fly ash mixture low) Exothermic blast furnace cement, high belite content cement), ultra-high strength cement, cement-based solidifying material, eco-cement (cement manufactured from at least one of municipal waste incineration ash and sewage sludge incineration ash) and the like. Furthermore, fine powder such as blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica powder, and limestone powder or gypsum may be added to the cement composition of the present invention. The cement contained in the cement composition of the present invention may be only one kind or two or more kinds.

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

When the cement composition of the present invention contains a cement admixture polymer, the content of the cement admixture polymer in the cement composition of the present invention, depending on the purpose, adopts any appropriate content ratio. obtain. As such a content ratio, when used for mortar or concrete using hydraulic cement, the content ratio of the polymer for cement admixture is preferably 0.01 parts by mass to 10 parts by mass with respect to 100 parts by mass of cement. And more preferably 0.02 to 5 parts by mass, and further preferably 0.05 to 3 parts by mass. With such a content ratio, various desirable effects such as a reduction in the amount of unit water, an increase in 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, and when the content ratio exceeds 10 parts by mass, the effect that can be exhibited is substantially flattened and also from the economical aspect. May be disadvantageous.

The content of the cement admixture in the cement composition of the present invention may be any appropriate content depending on the purpose. As such a content ratio, the content ratio of the cement admixture with respect to 100 parts by mass of cement is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.05 parts by mass to 8 parts by mass, More preferably, it is 0.1 to 5 parts by mass. When the content ratio is less than 0.01 parts by mass, sufficient performance may not be exhibited, and when the content ratio exceeds 10 parts by mass, the effect that can be exhibited is substantially flattened and also from the economical aspect. May be disadvantageous.

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

The cement composition of the present invention may be prepared by blending the constituent components by any suitable method. For example, a method of kneading the constituent components in a mixer may be used.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, “parts” means “parts by mass” and “%” means “% by mass”.

<Conditions for mass average molecular weight analysis>
The mass average molecular weight was measured under the following conditions.
Device: Waters Alliance (2695)
Analysis software: Waters, Empower Professional + GPC option column: Tosoh, TSKguardcolumnsSWXL+TSKgel G4000SWXL+G3000SWXL+G2000SWXL
Detector: Differential Refractometer (RI) Detector (Waters 2414), Multiwavelength 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 further adjusting the pH to 6.0 with acetic acid.
Calibration curve preparation standard substance: polyethylene glycol (peak top molecular weight (Mp) 272500, 219300, 107,000, 50000, 24000, 12600, 7100, 4250, 1470)
Calibration curve: A cubic curve was prepared based on the Mp value of polyethylene glycol and the elution time.
Flow rate: 1 mL/min Column temperature: 40°C
Measurement time: 45 minutes Sample solution injection amount: 100 μL

[Manufacturing Example 1]: Manufacture of water reducing agent Ion-exchanged water: 80 in a glass reaction container equipped with a Dimroth condenser, a Teflon (registered trademark) stirring blade and a stirrer with a stirring seal, a nitrogen introducing tube, and a temperature sensor. 0.0 part was charged, and the mixture was heated to 70° C. while introducing nitrogen at 200 mL/min while stirring at 250 rpm. Next, methoxy polyethylene glycol monomethacrylic acid ester (average number of moles of ethylene oxide added: 9): 133.4 parts, methacrylic acid: 26.6 parts, mercaptopropionic acid: 1.53 parts, and deionized water: 106. A mixed solution of 7 parts was added dropwise over 4 hours, and at the same time, a mixed solution of ammonium persulfate: 1.19 parts and ion-exchanged water: 50.6 parts was added dropwise over 5 hours. After completion of the dropping, the polymerization reaction was completed by maintaining the temperature at 70° C. for 1 hour. Then, it was neutralized with an aqueous solution of sodium hydroxide to obtain an aqueous solution of the water reducing agent (1) having a mass average molecular weight of 20,000.

[Example 1]
Dimroth condenser, a Teflon (registered trademark) stirring blade and a stirrer with a stirring seal, a nitrogen introducing tube, and a glass reaction vessel equipped with a temperature sensor were charged with 103.7 parts of ion-exchanged water and stirred at 250 rpm. , While introducing nitrogen at 200 mL/min, the temperature was raised to 70°C. Next, ethylene oxide was added to the hydroxyl group of 3-methyl-3-buten-1-ol (isoprenol) (average number of moles of ethylene oxide added was 50) (hereinafter referred to as IPN-50) (80% aqueous solution): A mixed solution of 180 parts, hydroxyethyl acrylate: 16.0 parts, and ion-exchanged water: 44.0 parts was added dropwise over 4 hours, and at the same time, 3-mercaptopropionic acid: 0.06 part and ion-exchanged water: A mixed solution of 40.2 parts and a mixed solution of ammonium persulfate: 1.98 parts and ion-exchanged water: 64.05 parts were added dropwise over 5 hours. After completion of the dropping, the polymerization reaction was completed by maintaining the temperature at 70° C. for 1 hour. Then, it was neutralized with an aqueous solution of sodium hydroxide to obtain an aqueous solution of a copolymer (1) as a cement additive having a mass average molecular weight of 81,000.

[Example 2]
Dimroth condenser, Teflon (registered trademark) stirring blade and stirrer with stirring seal, nitrogen inlet tube, glass reactor equipped with temperature sensor, charged with ion exchanged water: 143.97 parts, and stirred at 250 rpm , Nitrogen was introduced at 200 mL/min, and the temperature was raised to 70°C. Then, a mixed solution of IPN-50 (80% aqueous solution): 180 parts, hydroxyethyl acrylate: 16.0 parts, ion-exchanged water: 44.0 parts was added dropwise over 4 hours, and at the same time, ammonium persulfate: A mixed solution of 1.98 parts and ion-exchanged water: 64.05 parts was added dropwise over 5 hours. After completion of the dropping, the polymerization reaction was completed by maintaining the temperature at 70° C. for 1 hour. Then, it was neutralized with an aqueous solution of sodium hydroxide to obtain an aqueous solution of a copolymer (2) as a cement additive having a mass average molecular weight of 118000.

[Example 3]
Dimroth condenser, a Teflon (registered trademark) stirring blade and a stirrer with a stirring seal, a nitrogen introducing tube, and a glass reaction vessel equipped with a temperature sensor were charged with 103.7 parts of ion-exchanged water and stirred at 250 rpm. , While introducing nitrogen at 200 mL/min, the temperature was raised to 70°C. Next, ethylene oxide was added to the hydroxyl group of 3-methyl-3-buten-1-ol (isoprenol) (average number of moles of ethylene oxide added was 50) (hereinafter referred to as IPN-50) (80% aqueous solution): 170 parts, hydroxyethyl acrylate: 24.0 parts, ion-exchanged water: 32.67 parts was added dropwise over 4 hours, and at the same time, 3-mercaptopropionic acid: 0.17 parts and ion-exchanged water: A mixed solution of 48.21 parts and a mixed solution of ammonium persulfate: 0.64 part and ion-exchanged water: 20.62 parts were added dropwise over 5 hours. After completion of the dropping, the polymerization reaction was completed by maintaining the temperature at 70° C. for 1 hour. Then, it was neutralized with an aqueous solution of sodium hydroxide to obtain an aqueous solution of a copolymer (3), which is a cement additive having a mass average molecular weight of 85,000.

[Example 4]
Dimroth condenser, a Teflon (registered trademark) stirring blade and a stirrer with a stirring seal, a nitrogen introducing tube, and a glass reaction vessel equipped with a temperature sensor were charged with 103.7 parts of ion-exchanged water and stirred at 250 rpm. , Nitrogen was introduced at 200 mL/min, and the temperature was raised to 70°C. Next, ethylene oxide was added to the hydroxyl group of 3-methyl-3-buten-1-ol (isoprenol) (average number of moles of ethylene oxide added was 50) (hereinafter referred to as IPN-50) (80% aqueous solution): 170 parts, hydroxyethyl acrylate: 24 parts, ion-exchanged water: 32.67 parts was added dropwise over 4 hours, and at the same time, 3-mercaptopropionic acid: 0.08 part and ion-exchanged water: 48. A mixed solution of 29 parts and a mixed solution of ammonium persulfate (0.64 parts) and ion-exchanged water (20.62 parts) were added dropwise over 5 hours. After completion of the dropping, the polymerization reaction was completed by maintaining the temperature at 70° C. for 1 hour. Then, it was neutralized with an aqueous solution of sodium hydroxide to obtain an aqueous solution of a copolymer (4) which is a cement additive having a mass average molecular weight of 140,000.

[Examples 5-14, Comparative Examples 1-2]
≪Concrete test≫
A concrete test was conducted using the cement dispersibility improving aids obtained in Examples 1 to 4.
Specifically, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) is used as cement, Oigawa water system land sand is used as fine aggregate, Aomi crushed stone is used as coarse aggregate, and tap water is used as kneading water. Cement: 382 kg/m ³ , water: 172kg / ^{m 3,} fine aggregate: 796 kg / ^{m 3,} coarse aggregate: 930 kg / ^{m 3,} fine aggregate ratio (fine aggregate / Hosoara aggregate + coarse aggregate) (volume ratio): 47% A concrete composition was prepared with a water/cement ratio (weight ratio)=0.45. The materials used in the test, the forced kneading mixer, and the measuring instruments were adjusted in the above test temperature atmosphere so that the temperature of the concrete composition reached the test temperature of 20° C. The test was conducted under an atmosphere of test temperature. In order to avoid the influence of air bubbles in the concrete composition on the fluidity of the concrete composition, an oxyalkylene-based defoaming agent is used, if necessary, so that the air content is 1.0±0.5%. Adjusted to.
Under the above conditions, concrete was produced using a forced kneading mixer for a mixing time of 90 seconds, and the slump value, the flow value and the air amount were measured. The slump value, the flow value, and the amount of air were measured according to Japanese Industrial Standards (JIS-A-1101, 1128). The amount of the cement water reducing agent added was such that the flow value was 37.5 to 42.5 cm. At the same flow value, the smaller the added amount, the better the cement water reducing agent.
The results are shown in Tables 1 and 2.

As shown in Tables 1 and 2, when the cement dispersibility improving aid of the present invention is used, the amount of the water reducing agent can be significantly reduced. In addition, the 28-day compressive strength was improved by adding the cement dispersibility improving aid.

The cement dispersibility improving aid of the present invention is suitably used for cement compositions such as mortar and concrete.

Claims (4)

Copolymer having structural unit (I) derived from unsaturated polyalkylene glycol ether monomer (a) represented by general formula (1) and structural unit (II) derived from hydroxyalkyl (meth)acrylate (b) A cement dispersibility improving aid including coalescence,
The content of the copolymer in the cement dispersibility improving aid is 90% by mass to 100% by mass,
The total content of the structural unit (I) and the structural unit (II) in the copolymer is 95 % by mass to 100% by mass,
The content ratio of the structural unit (I) and the structural unit (II) is 93/7% by weight to 1/99% by weight in terms of a structural unit (I)/structural unit (II) mass ratio.
Cement dispersibility improving aid.

(In the general formula (1), R ¹ and R ² are the same or different and each represents a hydrogen atom or a methyl group, R ³ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and AO represents Represents an oxyalkylene group having 2 to 18 carbon atoms, n represents the average number of moles of the oxyalkylene group represented by AO, n is an integer of 1 to 500, and x is an integer of 0 to 2. It is.) The cement dispersibility improving aid according to claim 1, wherein the hydroxyalkyl (meth)acrylate (b) is hydroxyethyl acrylate. The copolymer is a structural unit (III-1) derived from an unsaturated monocarboxylic acid monomer (c-1) represented by general formula (3-1) and/or general formula (3-2). The cement dispersibility improving aid according to claim 1 or 2, which has a structural unit (III-2) derived from the unsaturated polycarboxylic acid-based monomer (c-2) represented by.

(In the general formula (3-1), R ⁴ , R ⁵ , and R ⁶ are the same or different and represent a hydrogen atom or a methyl group, and X is a hydrogen atom, a methyl group, an ethyl group, an alkali metal, an alkali. Represents an earth metal, ammonium group, organic ammonium group, or organic amine group.)

(In the general formula (3-2), R ⁷ , R ⁸ and R ⁹ are the same or different and each represent a hydrogen atom, a methyl group or a —(CH ₂ ) _z COOM ¹ group, and R ⁷ , R ⁸ , And at least one of R ⁹ is a —(CH ₂ ) _z COOM ¹ group, and the —(CH ₂ ) _z COOM ¹ group forms an anhydride with a —COOX group or another —(CH ₂ ) _z COOM ¹ group. , Z is an integer of 0 to 2, M ¹ represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group, and X represents a hydrogen atom. , Represents a methyl group, an ethyl group, an alkali metal, an alkaline earth metal, an ammonium group, an organic ammonium group, or an organic amine group.) A cement composition comprising the cement dispersibility improving aid according to any one of claims 1 to 3.