JP2018111621A - Cement dispersion improving agent and cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cement dispersion improving agent that can be blended in a cement composition to sufficiently improve the dispersibility of the cement composition even with the amount of use of water-reducing agent reduced, and provide a cement composition having sufficiently improved dispersibility even with the amount of use of water-reducing agent reduced.SOLUTION: A cement dispersion improving agent is blended in a cement composition to improve the dispersibility of the cement composition. The cement dispersion improving agent contains a polycarboxylic acid copolymer that has a structural unit (I) derived from an unsaturated polyalkylene glycol ether monomer (a) represented by a specific general formula and a structural unit (II) derived from an unsaturated carboxylic acid monomer (b) represented by a specific general formula. Relative to all the structural units of the polycarboxylic acid copolymer, a content of the structural unit (I) is 34 mol% or more.SELECTED DRAWING: None

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 may further contain a water reducing agent for the purpose of improving dispersibility (for example, Patent Document 1). ).

  In order to sufficiently increase the dispersibility of the cement composition, it is necessary to use a large amount of water reducing agent. However, there is a problem that using a large amount of water reducing agent is disadvantageous in terms of cost.

  Accordingly, there is a need for the development of a cement dispersibility improving aid that can sufficiently increase the dispersibility of the cement composition even if the amount of water reducing agent used is reduced.

JP2013-133241A

  An object of the present invention is to provide a cement dispersibility improving auxiliary agent that can sufficiently enhance the dispersibility of a cement composition even when the amount of a water reducing agent is reduced by being contained in the cement composition. is there. Another object of the present invention is to provide a cement composition having sufficiently high dispersibility even when the amount of water reducing agent used is reduced.

（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の数であり、ｘは０〜２の整数である。）

（一般式（２）中、Ｒ^４〜Ｒ^６は、同一または異なって、水素原子、メチル基、または−（ＣＨ_２）_ｚＣＯＯＭ基を表し、−（ＣＨ_２）_ｚＣＯＯＭ基は−ＣＯＯＸ基または他の−（ＣＨ_２）_ｚＣＯＯＭ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、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を表す。） The cement dispersibility improvement aid of the present invention is
A cement dispersibility improving aid for improving dispersibility of the cement composition by being contained in the cement composition,
Structural unit (I) derived from unsaturated polyalkylene glycol ether monomer (a) represented by general formula (1) and unsaturated carboxylic acid monomer (b) represented by general formula (2) A polycarboxylic acid copolymer having a structural unit (II) derived from,
The content ratio of the structural unit (I) to the total structural units constituting the polycarboxylic acid copolymer is 34 mol% or more.

(In 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; Represents an oxyalkylene group having 2 to 18 carbon atoms, n represents the average number of added moles of the oxyalkylene group represented by AO, n is a number from 1 to 500, and x is an integer from 0 to 2 .)

(In general formula (2), R ^{4 to} R ⁶ are the same or different and each represents a hydrogen atom, a methyl group, or — (CH ₂ ) _z COOM group, and — (CH ₂ ) _z COOM group represents a —COOX group. Or other — (CH ₂ ) _z COOM group may form an anhydride, z is an integer of 0 to 2, M is a hydrogen atom, alkali metal, alkaline earth metal, ammonium group, organic An ammonium group or an organic amine group is represented, and X represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, or an organic ammonium group.)

  In one embodiment, the cement dispersibility improving aid of the present invention contains an alkanolamine compound.

（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の数であり、ｘは０〜２の整数である。）

（一般式（２）中、Ｒ^４〜Ｒ^６は、同一または異なって、水素原子、メチル基、または−（ＣＨ_２）_ｚＣＯＯＭ基を表し、−（ＣＨ_２）_ｚＣＯＯＭ基は−ＣＯＯＸ基または他の−（ＣＨ_２）_ｚＣＯＯＭ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、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を表す。） The cement composition of the present invention comprises:
Structural unit (I) derived from unsaturated polyalkylene glycol ether monomer (a) represented by general formula (1) and unsaturated carboxylic acid monomer (b) represented by general formula (2) A cement composition comprising a polycarboxylic acid copolymer having a structural unit (II) derived from, and an alkanolamine compound,
The content ratio of the structural unit (I) to the total structural units constituting the polycarboxylic acid copolymer is 34 mol% or more.

(In 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; Represents an oxyalkylene group having 2 to 18 carbon atoms, n represents the average number of added moles of the oxyalkylene group represented by AO, n is a number from 1 to 500, and x is an integer from 0 to 2 .)

(In general formula (2), R ^{4 to} R ⁶ are the same or different and each represents a hydrogen atom, a methyl group, or — (CH ₂ ) _z COOM group, and — (CH ₂ ) _z COOM group represents a —COOX group. Or other — (CH ₂ ) _z COOM group may form an anhydride, z is an integer of 0 to 2, M is a hydrogen atom, alkali metal, alkaline earth metal, ammonium group, organic An ammonium group or an organic amine group is represented, and X represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, or an organic ammonium group.)

  According to the present invention, by including in the cement composition, it is possible to provide a cement dispersibility improving aid that can sufficiently enhance the dispersibility of the cement composition even if the amount of water reducing agent used is reduced. it can. Moreover, according to this invention, even if it reduces the usage-amount of a water reducing agent, the dispersibility sufficiently high cement composition 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.

≪Cement dispersibility improvement aid≫
The cement dispersibility improvement aid of the present invention is a cement dispersibility improvement aid that improves the dispersibility of the cement composition by being contained in the cement composition. More specifically, the cement dispersibility improving aid of the present invention can sufficiently enhance the dispersibility of the cement composition even when the amount of the water reducing agent is reduced by being contained in the cement composition. Cement dispersibility improving aid. As described above, any appropriate water reducing agent can be adopted as the water reducing agent that can be reduced by using the cement dispersibility improving aid of the present invention.

  Only one type of water reducing agent as described above may be used, or two or more types may be used.

  Examples of the water reducing agent as described above include a sulfonic acid-based dispersant having a sulfonic acid group in the molecule, a phosphoric acid-based dispersant having a phosphoric acid group, and a polymer having a polyoxyalkylene group and an anionic group ( However, a polycarboxylic acid-based copolymer contained in the cement dispersibility improving aid of the present invention is included, and preferably a polymer having a polyoxyalkylene group and an anionic group (however, the present invention Except for the polycarboxylic acid-based copolymer contained in the cement dispersibility improvement aid.

  Examples of the sulfonic acid-based dispersant include polyalkylaryl sulfonate-based sulfonic acid-based dispersants such as naphthalene sulfonic acid formaldehyde condensate, methyl naphthalene sulfonic acid formaldehyde condensate and anthracene sulfonic acid formaldehyde condensate; melamine sulfonic acid Melamine formalin sulfonate-based sulfonic acid dispersants such as formaldehyde condensates; Aromatic amino sulfonate-based sulfonic acid dispersants such as aminoaryl sulfonic acid-phenol-formaldehyde condensates; lignin sulfonates, Lignin sulfonate sulfonic acid dispersants such as modified lignin sulfonate; polystyrene sulfonate sulfonic acid dispersants; alkenyl ether monomers obtained by adding ethylene oxide or the like to unsaturated alcohols and A copolymer or a salt thereof obtained from a monomer containing a sum sulfonic acid monomer and the like.

  Examples of the phosphoric acid dispersant include a copolymer obtained from an alkenyl ether monomer obtained by adding ethylene oxide or the like to an unsaturated alcohol and a monomer containing an unsaturated phosphoric acid monomer or a salt thereof; It is done.

  Examples of the polymer having a polyoxyalkylene group and an anionic group (excluding the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention) include (1) 3-methyl 3 A copolymer obtained from a monomer containing an alkenyl ether monomer obtained by adding ethylene oxide or the like to an unsaturated alcohol of -buten-1-ol and an unsaturated carboxylic acid monomer such as (meth) acrylic acid, or Its salts (excluding polycarboxylic acid copolymers contained in the cement dispersibility improvement aid of the present invention), (2) Addition of ethylene oxide or the like to unsaturated alcohol of 2-methyl-2-buten-1-ol Copolymer obtained from a monomer containing an alkenyl ether monomer and an unsaturated carboxylic acid monomer such as (meth) acrylic acid or a salt thereof (however, (3) alkenyl ether monomers obtained by adding ethylene oxide to vinyl ether and unsaturated carboxylic acids such as (meth) acrylic acid A copolymer obtained from a monomer-containing monomer or a salt thereof (excluding the polycarboxylic acid-based copolymer contained in the cement dispersibility improvement aid of the present invention), (4) hydroxybutyl vinyl ether A copolymer obtained from an alkenyl ether monomer added with ethylene oxide or the like and a monomer containing an unsaturated carboxylic acid monomer such as (meth) acrylic acid or a salt thereof (however, the cement dispersibility of the present invention (Except polycarboxylic acid-based copolymers contained in improvement aids), (5) (alkoxy) polyalkylene glycol mono (meth) acrylic acid esters Ether-based monomer and (meth) copolymers or salts thereof obtained from a monomer containing an unsaturated carboxylic acid monomer such as acrylic acid, and the like.

  The cement dispersibility improving aid of the present invention is represented by the structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) and the general formula (2). A polycarboxylic acid copolymer having a structural unit (II) derived from an unsaturated carboxylic acid monomer (b).

  The cement dispersibility improving aid of the present invention may contain any appropriate other component as long as the effects of the present invention are not impaired. The content ratio of the polycarboxylic acid copolymer in the cement dispersibility improvement aid of the present invention is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, Preferably it is 90 mass%-100 mass%, Especially preferably, it is 95 mass%-100 mass%, Most preferably, it is substantially 100 mass%. When the content ratio of the polycarboxylic acid 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 is contained in the cement composition. Even if the amount of the water reducing agent used is reduced, the dispersibility of the cement composition can be sufficiently improved.

  In the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, as will be described in detail later, the structural unit (I) with respect to all structural units constituting the polycarboxylic acid copolymer. The content ratio of is 34 mol% or more. Thus, in the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, the content ratio of the structural unit (I) to the total structural units constituting the polycarboxylic acid copolymer is By including the cement dispersibility improving aid of the present invention in the cement composition by being within the limited range, the dispersibility of the cement composition can be sufficiently increased even if the amount of water reducing agent is reduced. Can do.

<Polycarboxylic acid copolymer>
The polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention is a structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1). And a structural unit (II) derived from the unsaturated carboxylic acid monomer (b) represented by the general formula (2).

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

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

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

In the general formula (1) and the 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 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 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 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 6 carbon atoms, and particularly preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

  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, 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 more preferably an oxyethylene group, and 100 mol% or more of the entire oxyalkylene group is particularly preferably an oxyethylene group.

  In the general formula (1) and the structural unit (I), n represents the average added mole number of the oxyalkylene group represented by AO (sometimes referred to as “chain length”), and is a number of 1 to 500. The number is preferably 2 to 200, more preferably 5 to 200, still more preferably 8 to 100, particularly preferably 20 to 70, and most preferably 40 to 60. Is the number of When n is within the above range, the dispersibility of the cement composition is sufficiently improved even when the amount of the water reducing agent is reduced by including the cement dispersibility improving aid of the present invention in the cement composition. be able to.

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

  Examples of the unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) include vinyl alcohol, (meth) allyl alcohol, 3-methyl-3-buten-1-ol, 3- Alkylene in any of methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-2-buten-1-ol, 2-methyl-3-buten-1-ol A compound obtained by adding an average of 1 to 500 mol of an oxide; preferably, a compound obtained by adding an average of 1 to 500 mol of an alkylene oxide to 3-methyl-3-buten-1-ol, and an average of 1 of an alkylene oxide to a methallyl alcohol. It is a compound added with ˜500 mol.

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

In General Formula (2) and General Formula (II), R ^{4 to} R ⁶ are the same or different and each represents a hydrogen atom, a methyl group, or a — (CH ₂ ) _z COOM group. The — (CH ₂ ) _z COOM group may form an anhydride with the —COOX group or other — (CH ₂ ) _z COOM groups. z is an integer of 0-2.

  M represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, or an organic ammonium group.

  X represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, or an organic ammonium group.

  Examples of the unsaturated carboxylic acid monomer (b) represented by the general formula (2) include monocarboxylic acid monomers such as (meth) acrylic acid and crotonic acid or salts thereof; maleic acid, And dicarboxylic acid monomers such as itaconic acid and fumaric acid or salts thereof; anhydrides of dicarboxylic acid monomers such as maleic acid, itaconic acid and fumaric acid or salts thereof; and the like. Examples of the salt herein include alkali metal salts, alkaline earth metal salts, ammonium salts, and organic ammonium salts.

  Examples of the alkali metal salt include lithium salt, sodium salt, potassium salt and the like. Examples of alkaline earth metal salts include calcium salts and magnesium salts.

  Examples of the organic ammonium salt include methyl ammonium salt, ethyl ammonium salt, dimethyl ammonium salt, diethyl ammonium salt, trimethyl ammonium salt, and triethyl ammonium salt.

  The unsaturated carboxylic acid monomer (b) represented by the general formula (2) is preferably (meth) acrylic acid, maleic acid, maleic anhydride in that the effects of the present invention can be further exhibited. More preferred are acrylic acid and methacrylic acid.

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

  In the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, the content ratio of the structural unit (I) with respect to all structural units constituting the polycarboxylic acid copolymer is 34 mol% or more. Preferably 34 mol% to 80 mol%, more preferably 34 mol% to 70 mol%, still more preferably 34 mol% to 60 mol%, and particularly preferably 34 mol% to 50 mol%. %. In the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, the content ratio of the structural unit (I) with respect to all structural units constituting the polycarboxylic acid copolymer is within the above range. If it exists, the dispersibility of a cement composition can fully be improved even if it reduces the usage-amount of a water reducing agent by containing the cement dispersibility improvement aid of this invention in a cement composition.

  The content ratio of the structural unit (II) to the total structural units constituting the polycarboxylic acid copolymer in the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention is preferably 66. Mol% or less, more preferably 20 mol% to 66 mol%, still more preferably 30 mol% to 66 mol%, particularly preferably 40 mol% to 66 mol%, most preferably 50 mol%. % To 66 mol%. In the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, the content ratio of the structural unit (II) to the total structural units constituting the polycarboxylic acid copolymer is within the above range. If it exists, the dispersibility of a cement composition can be fully improved even if it reduces the usage-amount of a water reducing agent by containing the cement dispersibility improvement aid of this invention in a cement composition.

  In the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, the structural unit (I) and the structural unit (II) with respect to all structural units constituting the polycarboxylic acid copolymer. The total content is preferably 50 mol% to 100 mol%, more preferably 70 mol% to 100 mol%, still more preferably 90 mol% to 100 mol%, and particularly preferably 95 mol%. -100 mol%, most preferably substantially 100 mol%. The total of structural unit (I) and structural unit (II) with respect to all structural units constituting the polycarboxylic acid copolymer in the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention If the content ratio is within the above range, the cement dispersibility improving aid of the present invention is contained in the cement composition, so that the dispersibility of the cement composition can be sufficiently improved even if the amount of water reducing agent is reduced. Can be increased.

  The content ratio of the structural unit (I) to the total structural units constituting the polycarboxylic acid copolymer in the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, the polycarboxylic acid The content ratio of the structural unit (II) with respect to all the structural units constituting the copolymer, the total of the structural unit (I) and the structural unit (II) with respect to all the structural units constituting the polycarboxylic acid copolymer. The content ratio can be known by, for example, various structural analyzes (for example, NMR) of the polycarboxylic acid copolymer. Further, the monomer (a) and the monomer used for producing the polycarboxylic acid-based copolymer contained in the cement dispersibility improving aid of the present invention without performing various structural analyzes as described above. Based on the content of the structural unit derived from the monomer (a) and the structural unit derived from the monomer (b) calculated based on the amount used and the polymerization rate of (b), the cement dispersion of the present invention The content ratio of the structural unit (I) to the total structural units constituting the polycarboxylic acid copolymer in the polycarboxylic acid copolymer contained in the property-improving aid, the polycarboxylic acid copolymer Calculate the content ratio of the structural unit (II) with respect to all the structural units constituting, and the total content ratio of the structural unit (I) and the structural unit (II) with respect to all the structural units constituting the polycarboxylic acid copolymer. May be.

  In the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, in addition to the structural unit (I) and the structural unit (II), structural units derived from other monomers (c) ( III) may be included.

  The monomer (c) is a monomer copolymerizable with the monomer (a) and the monomer (b). Only one type of monomer (c) may be used, or two or more types may be used.

  As the monomer (c), for example, hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate; unsaturated monomethyl such as methyl (meth) acrylate and glycidyl (meth) acrylate Esters of carboxylic acids and alcohols having 1 to 30 carbon atoms; various (alkoxy) (poly) alkylene glycol mono (meth) such as polyethylene glycol mono (meth) acrylate and methoxy (poly) ethylene glycol mono (meth) acrylate Acrylates; (anhydrous) half esters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid and alcohols having 1 to 30 carbon atoms; (anhydrous) unsaturated such as maleic acid, fumaric acid and itaconic acid Dicarboxylic acids and carbon atoms 1 Diesters with 0 alcohol; half amides of the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms; diamides of the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms; Half esters of an alkyl (poly) alkylene glycol obtained by adding an average of 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to an amine and the unsaturated dicarboxylic acid; the alcohol or amine having 2 to 18 carbon atoms Diesters of alkyl (poly) alkylene glycols having an average of 1 to 500 moles of alkylene oxide added thereto and the above unsaturated dicarboxylic acids; average addition moles of the above unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or these glycols Half-e with polyalkylene glycol of 2 to 500 Ters; diesters of the above unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or polyalkylene glycols having an average addition mole number of these glycols of 2 to 500; maleamic acid and glycols having 2 to 18 carbon atoms; Half-amides of these glycols with polyalkylene glycol having an average addition mole number of 2 to 500; (poly) alkylene glycol di (meth) acrylate such as (poly) ethylene glycol di (meth) acrylate and (poly) propylene glycol di (meth) acrylate (Meth) acrylates; polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate and trimethylolpropane tri (meth) acrylate; (poly) alkylene glycol dimaleates such as polyethylene glycol dimaleate; vinyl sulfo Nate, (meth) allylsulfonate, 2-methylpropanesulfonic acid (meth) acrylamide, unsaturated sulfonic acids (salts) such as styrenesulfonic acid; unsaturated monocarboxylic acids such as methyl (meth) acrylamide and 1 carbon atom Amides with -30 amines; vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene; alkanediol mono (meth) acrylates such as 1,4-butanediol mono (meth) acrylate; butadiene, isoprene Dienes such as; (meth) acrylic (alkyl) amides, unsaturated amides such as N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; unsaturated cyanides such as (meth) acrylonitrile; acetic acid Unsaturated esters such as vinyl; aminoethyl (meth) acrylate; Unsaturated amines such as dimethylaminoethyl acrylate and vinyl pyridine; divinyl aromatics such as divinylbenzene; allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; (methoxy) polyethylene glycol monovinyl ether Vinyl ethers such as (meth) allyl ethers such as (methoxy) polyethylene glycol mono (meth) allyl ether; and the like.

  The content ratio of the structural unit (III) to the total structural units constituting the polycarboxylic acid copolymer in the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention is preferably 0. Mol% to 50 mol%, more preferably 0 mol% to 40 mol%, still more preferably 0 mol% to 30 mol%, particularly preferably 0 mol% to 20 mol%, most preferably Is 0 mol% to 10 mol%. In the polycarboxylic acid copolymer that can be included in the cement dispersibility improving aid of the present invention, the content ratio of the structural unit (III) to the total structural units constituting the polycarboxylic acid copolymer is within the above range. If it exists in this, even if it reduces the usage-amount of a water reducing agent by containing the cement dispersibility improvement aid of this invention in a cement composition, the dispersibility of a cement composition can be improved more fully.

  The content ratio of the structural unit (III) to the total structural units constituting the polycarboxylic acid copolymer in the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention is, for example, It can be known by various structural analyzes (for example, NMR) of the polycarboxylic acid copolymer. Further, the amount of the monomer (c) used in producing the polycarboxylic acid copolymer contained in the cement dispersibility improvement aid of the present invention without performing various structural analyzes as described above, and Based on the content ratio of the structural unit derived from the monomer (c) calculated based on the polymerization rate, the polycarboxylic acid copolymer in the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention You may calculate the content rate of structural unit (III) with respect to all the structural units which comprise a carboxylic acid type copolymer.

  When determining the content ratio of the structural unit in the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, when the structural unit has a carboxyl group salt, the acid moiety of the carboxyl group Are all converted to sodium salts.

  The weight average molecular weight (Mw) in terms of polyethylene glycol obtained by gel permeation chromatography of the polycarboxylic acid-based copolymer contained in the cement dispersibility improving aid of the present invention is preferably 10,000 to 120,000, more Preferably it is 15000-115000, More preferably, it is 20000-110000, Especially preferably, it is 25000-105000, Most preferably, it is 30000-100000. If the weight average molecular weight (Mw) in terms of polyethylene glycol obtained by gel permeation chromatography of the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention is within the above range, By including the cement dispersibility improving aid in the cement composition, the dispersibility of the cement composition can be sufficiently enhanced even if the amount of water reducing agent used is reduced.

  The polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention has a dispersity (Mw / Mn) of preferably 1.30 to 3.80, more preferably 1.40 to 3 .60, more preferably 1.50 to 3.40, particularly preferably 1.60 to 3.20, and most preferably 1.70 to 3.00. If the dispersity (Mw / Mn) is very low as described above, the cement dispersibility improving aid of the present invention is contained in the cement composition, so that the cement can be used even if the amount of water reducing agent is reduced. The dispersibility of the composition can be increased more sufficiently.

  The polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention can be produced by any appropriate method within a range not impairing the effects of the present invention. The polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention preferably comprises an unsaturated polyalkylene glycol monomer (a) and an unsaturated carboxylic acid monomer (b). The monomer component can be produced by polymerization in the presence of a polymerization initiator.

  An unsaturated polyalkylene glycol monomer (a), an unsaturated carboxylic acid monomer (b), which can be used in the production of the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention, and If necessary, the amount of the other monomer (c) used may be selected from each monomer in all structural units constituting the polycarboxylic acid copolymer contained in the cement dispersibility improving aid of the present invention. What is necessary is just to adjust suitably so that the ratio of the structural unit of origin may become what was mentioned above. Preferably, as the polymerization reaction proceeds quantitatively, the structural unit derived from each monomer in all the structural units constituting the polycarboxylic acid copolymer contained in the above-described cement dispersibility improving aid of the present invention. Each monomer may be used at the same ratio as the above ratio.

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

  When the monomer component is polymerized, a water-soluble polymerization initiator, for example, a persulfate such as ammonium persulfate, sodium persulfate, or potassium persulfate; hydrogen peroxide; 2,2′- Azoamidine compounds such as azobis-2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, 2-carbamoylazoisobutyronitrile, etc. Water-soluble azo initiators such as azonitrile compounds of These polymerization initiators include alkali metal sulfites such as sodium hydrogen sulfite, metabisulfites, sodium hypophosphite, Fe (II) salts such as molle salts, sodium hydroxymethanesulfinate dihydrate, hydroxylamine hydrochloride Accelerators such as salt, thiourea, L-ascorbic acid (salt), and erythorbic acid (salt) can also be used in combination. Among these combined forms, a combination of hydrogen peroxide and an accelerator 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 performing solution polymerization using a lower alcohol, aromatic hydrocarbon, aliphatic hydrocarbon, ester compound, or ketone compound as a solvent, or when performing bulk polymerization, benzoyl peroxide, lauroyl peroxide may be used as a polymerization initiator. Peroxides such as oxide and sodium peroxide; hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; azo compounds such as azobisisobutyronitrile; When such a polymerization initiator is used, an accelerator such as an amine compound can be used in combination. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various polymerization initiators or combinations of polymerization initiators and accelerators.

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

  Any appropriate method can be adopted as a method of charging the monomer component into the reaction vessel. As such a charging method, for example, a method in which the entire amount is initially charged into the reaction vessel, a method in which the entire amount is divided or continuously charged into the reaction vessel, a part is initially charged in the reaction vessel, and the rest is put in the reaction vessel. The method of dividing | segmenting or carrying out continuously etc. is mentioned. Specifically, a method in which the total amount of monomer (a) and the total amount of monomer (b) are continuously charged into the reaction vessel, a part of monomer (a) is initially charged into the reaction vessel, A method in which the remainder of the monomer (a) and the entire amount of the monomer (b) are continuously charged into the reaction vessel, a part of the monomer (a) and a part of the monomer (b) in the reaction vessel In the initial stage, and the remainder of the monomer (a) and the remainder of the monomer (b) are alternately fed into the reaction vessel in several divided portions. Furthermore, by changing the charging rate of each monomer into the reaction vessel during the reaction continuously or stepwise, the charging mass ratio per unit time of each monomer is changed continuously or stepwise, You may make it synthesize | combine simultaneously the 2 or more types of copolymer from which the ratio of structural unit (I) and structural unit (II) differs. The polymerization initiator may be charged into the reaction vessel from the beginning, may be dropped into the reaction vessel, or these may be combined according to the purpose.

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

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

  The produced polycarboxylic acid-based copolymer can be used as it is as a polycarboxylic acid-based copolymer contained in the cement dispersibility improving aid of the present invention. It is preferable to adjust the pH of the reaction solution after the production of the copolymer 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 using, for example, an alkaline substance such as inorganic salt such as monovalent metal or divalent metal hydroxide or carbonate; ammonia;

  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 after neutralization with a divalent metal hydroxide such as calcium or magnesium to obtain a polyvalent metal salt. You may use it by making it dry or carrying | supporting to inorganic powders, such as a silica type fine powder, and making it dry.

  The cement dispersibility improving aid of the present invention may contain an alkanolamine compound. When the cement dispersibility improving aid of the present invention contains an alkanolamine compound, it is possible to suppress the by-product of sodium sulfate in the cement dispersibility improving aid of the present invention.

  1 type may be sufficient as an alkanolamine compound, and 2 or more types may be sufficient as it.

  The content ratio of the alkanolamine compound in the cement dispersibility improving aid of the present invention is preferably 5% by mass to 500% by mass, more preferably 10% by mass to 100% by mass, and further preferably 20% by mass. It is -80 mass%, Most preferably, it is 30 mass%-60 mass%. By adjusting the content ratio of the alkanolamine compound in the cement dispersibility improving aid of the present invention within the above range, it is possible to further suppress the byproduct of sodium sulfate in the cement dispersibility improving aid of the present invention.

  Any appropriate alkanolamine compound can be adopted as the alkanolamine compound as long as the effects of the present invention are not impaired. Examples of such alkanolamine compounds include low molecular alkanolamine compounds and high molecular alkanolamine compounds.

  Examples of the low molecular alkanolamine compound include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, methylethanolamine, methylisopropanolamine, methyldiethanolamine, methyldiisopropanolamine, Diethanolisopropanolamine, diisopropanolethanolamine, tetrahydroxyethylethylenediamine, N, N-bis (2-hydroxyethyl) 2-propanolamine, N, N-bis (2-hydroxypropyl) -N- (hydroxyethyl) amine, N, N-bis (2-hydroxyethyl) -N- (2-hydroxypropyl) amine, N, N, N ′, N′-tetrakis (2- Mud hydroxypropyl) ethylenediamine, tris (2-hydroxybutyl) amine, and the like. Among these, the low molecular alkanolamine compound is preferably triisopropanolamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, or diisopropanolethanolamine. Other low molecular alkanolamine compounds include, for example, monomers having a triisopropanolamine skeleton.

  Examples of the polymer type alkanolamine compound include alkanolamines having a structure in which a part of alkanolamine is bonded to a polymer. Examples of such a high molecular alkanolamine compound include a polymer having a triisopropanolamine skeleton.

≪Cement composition≫
The cement composition of the present invention contains the above polycarboxylic acid copolymer (polycarboxylic acid copolymer contained in the cement dispersibility improvement aid of the present invention) and an alkanolamine compound.

  For the description of the polycarboxylic acid-based copolymer contained in the cement composition of the present invention, the description in the above-mentioned <Polycarboxylic acid-based copolymer> can be cited.

  The cement composition of the present invention preferably includes cement, water, and aggregate, and more preferably includes cement, water, aggregate, and a cement admixture.

  The content of the polycarboxylic acid copolymer in the cement composition of the present invention is preferably 0.001% by mass to 1% by mass, more preferably 0.005% by mass, based on the solid content of the cement. % To 0.9% by mass, more preferably 0.01% to 0.8% by mass, particularly preferably 0.01% to 0.7% by mass, and most preferably 0.01% to 0.9% by mass. It is mass%-0.5 mass%. If the content of the polycarboxylic acid copolymer in the cement composition of the present invention is within the above range with respect to the cement, the dispersibility of the cement composition is sufficiently improved even if the amount of water reducing agent is reduced. be able to.

  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.

  The cement admixture preferably contains a polymer for cement admixture in that the effects of the present invention can be expressed more effectively.

  The cement admixture may contain any appropriate other component in addition to the cement admixture polymer as long as the effects of the present invention are not impaired.

  Examples of other components include a water reducing agent. When a water reducing agent is used, the blending ratio of the cement admixture polymer and the water reducing agent (cement admixture polymer / water reducing agent) is arbitrary depending on the type of water reducing agent used, blending conditions, test conditions, etc. An appropriate blending ratio can be set. Only one type of water reducing agent may be used, or two or more types may be used.

  As the water reducing agent, for example, a sulfonic acid-based dispersant having a sulfonic acid group in the molecule, a phosphoric acid-based dispersant having a phosphoric acid group, a polymer having a polyoxyalkylene group and an anionic group (however, the present invention) And the like, preferably a polymer having a polyoxyalkylene group and an anionic group (however, the cement dispersibility of the present invention is excluded). Excluding polycarboxylic acid copolymers contained in the improvement aid.

  Examples of the sulfonic acid-based dispersant include polyalkylaryl sulfonate-based sulfonic acid-based dispersants such as naphthalene sulfonic acid formaldehyde condensate, methyl naphthalene sulfonic acid formaldehyde condensate and anthracene sulfonic acid formaldehyde condensate; melamine sulfonic acid Melamine formalin sulfonate-based sulfonic acid dispersants such as formaldehyde condensates; Aromatic amino sulfonate-based sulfonic acid dispersants such as aminoaryl sulfonic acid-phenol-formaldehyde condensates; lignin sulfonates, Lignin sulfonate sulfonic acid dispersants such as modified lignin sulfonate; polystyrene sulfonate sulfonic acid dispersants; alkenyl ether monomers obtained by adding ethylene oxide or the like to unsaturated alcohols and A copolymer or a salt thereof obtained from a monomer containing a sum sulfonic acid monomer and the like.

  Examples of the phosphoric acid dispersant include a copolymer obtained from an alkenyl ether monomer obtained by adding ethylene oxide or the like to an unsaturated alcohol and a monomer containing an unsaturated phosphoric acid monomer or a salt thereof; It is done.

  When a water reducing agent is contained in the cement composition of the present invention, the content of the water reducing agent in the cement composition of the present invention is solid content with respect to the cement, preferably 1% by mass or less, more preferably Is 0.8% by mass or less, more preferably 0.6% by mass or less, particularly preferably 0.4% by mass or less, and most preferably 0.2% by mass or less. By containing the polycarboxylic acid copolymer in the cement composition, the content of the water reducing agent in the cement composition of the present invention can be reduced as described above. The lower limit of the content of the water reducing agent in the cement composition of the present invention is better as it is smaller in terms of cost. Actually, the lower limit value of the content of the water reducing agent in the cement composition of the present invention is preferably 0.001% by mass or more, more preferably 0.005% by mass in terms of solid content with respect to the cement. % Or more, and more preferably 0.01% by mass or more.

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

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

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

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

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

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

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

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

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

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

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

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

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

  Other known cement additives (materials) include cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancers, self-leveling agents, colorants, fungicides, and the like. be able to. These known cement additives (materials) may be only one kind or two or more kinds.

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

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

  When the cement composition of the present invention contains a polymer for cement admixture, any appropriate content ratio may be adopted as the content of the polymer for cement admixture in the cement composition of the present invention depending on the purpose. obtain. As such a content ratio, when used for mortar or concrete using hydraulic cement, the content ratio of the polymer for 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, 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 cement admixture in the cement composition of the present invention, any appropriate content ratio can be adopted 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 mass part-5 mass parts. When the content ratio is less than 0.01 parts by mass, sufficient performance may not be exhibited. When the content ratio exceeds 10 parts by mass, the effect that can be achieved substantially reaches its peak and also from the economical aspect. May be disadvantageous.

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

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

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

<Conditions for weight average molecular weight analysis>
The weight average molecular weight was measured under the following conditions.
Device: Waters Alliance (2695)
Analysis software: Waters, Empor professional + GPC option column: Tosoh, TSKguardcolumns SWXL + TSKgel G4000SWXL + G3000SWXL + G2000SWXL
Detector: differential refractometer (RI) detector (Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters 2996)
Eluent: A solution obtained 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 polyethylene glycol.
Flow rate: 1 mL / min Column temperature: 40 ° C
Measurement time: 45 minutes Sample solution injection amount: 100 μL

[Production Example 1]: Production of water reducing agent (1) Ion exchange in a glass reactor equipped with a Dimroth condenser, a Teflon (registered trademark) stirrer and a stirrer with a stir seal, a nitrogen inlet tube, and a temperature sensor Water: 80.0 parts was charged and heated to 70 ° C. while stirring at 250 rpm and introducing nitrogen at 200 mL / min. Next, methoxypolyethylene glycol monomethacrylic acid ester (average number of added moles of ethylene oxide: 93.4): 133.4 parts, methacrylic acid: 26.6 parts, mercaptopropionic acid: 1.53 parts, and ion-exchanged water: 106. 7 parts of the mixed solution was dropped over 4 hours, and simultaneously, a mixed solution of ammonium persulfate: 1.19 parts and ion-exchanged water: 50.6 parts was dropped over 5 hours. After completion of the dropwise addition, the polymerization reaction was completed by maintaining at 70 ° C. for 1 hour. And it neutralized with sodium hydroxide aqueous solution, and obtained the aqueous solution of the water reducing agent (1) whose weight average molecular weight = 20000.

[Production Example 2]: Production of water reducing agent (2) Dimroth condenser, Teflon (registered trademark) stirrer blade and stirrer with stirring seal, nitrogen inlet tube, glass reaction vessel equipped with temperature sensor, 3 -Methyl-3-buten-1-ol (isoprenol) added with ethylene oxide (average number of moles of ethylene oxide added 50) (hereinafter referred to as IPN-50) (80% aqueous solution) 198.2 parts, Charge 0.32 parts of acrylic acid, 12.47 parts of hydrogen peroxide (2% aqueous solution), 44.75 parts of ion-exchanged water, and warm to 58 ° C while introducing nitrogen at 200 mL / min while stirring at 250 rpm. did. Next, a mixed solution composed of 27.12 parts of acrylic acid and 108.5 parts of ion-exchanged water was dropped over 3 hours, and at the same time 0.74 parts of L-ascorbic acid, 1.61 parts of 3-mercaptopropionic acid, ions A mixed solution consisting of 86.31 parts of exchange water was added dropwise over 3 hours and 30 minutes. After completion of the dropping, the polymerization reaction was completed by maintaining at 58 ° C. for 1 hour. And it neutralized with sodium hydroxide aqueous solution, and obtained the aqueous solution of the water reducing agent (2) of mass mean molecular weight = 35000.

[Production Example 3]: Production of water reducing agent (3) In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 76.8 g of ion-exchanged water and ethylene oxide were added to methallyl alcohol. 132.1 g of unsaturated polyalkylene glycol ether (MLA-50) added with an average of 50 mol of (EO) was charged, and the reaction apparatus was purged with nitrogen under stirring, and the temperature was raised to 80 ° C. Next, an aqueous solution obtained by diluting 17.86 g of acrylic acid with 20.61 g of ion-exchanged water was dropped over 5 hours. At the same time, an aqueous solution prepared by dissolving 0.7 g of ammonium persulfate in 16.76 g of ion-exchanged water and 0.65 g of 3-mercaptopropionic acid in 34.42 g of ion-exchanged water was added dropwise over 5 hours. After completion of the dropping, stirring was continued at 80 ° C. for 1 hour to complete the polymerization reaction, and an aqueous solution of a polycarboxylic acid copolymer having a mass average molecular weight (Mn) of 32000 was obtained. A sodium hydroxide aqueous solution was added to the obtained polycarboxylic acid copolymer aqueous solution to neutralize to pH 7. In this way, an aqueous solution of the water reducing agent (3) was obtained. The results are shown in Table 1.

[Production Example 4]: Production of water reducing agent (4) Except that the water reducing agent was changed as shown in Table 1, the same procedure as in Production Example 3 was carried out to obtain an aqueous solution of the water reducing agent (4). The results are shown in Table 1.

[Production Example 5]: Production of water reducing agent (5) Except that the water reducing agent was changed as shown in Table 1, the same procedure as in Production Example 3 was carried out to obtain an aqueous solution of the water reducing agent (5). The results are shown in Table 1.

[Production Example 6]: Production of water reducing agent (6) Except that the water reducing agent was changed as shown in Table 1, the same procedure as in Production Example 3 was performed to obtain an aqueous solution of the water reducing agent (6). The results are shown in Table 1.

[Production Example 7]: Production of water reducing agent (7) Water reducing agent (2) and Mighty 150 (manufactured by Kao Corporation) were blended at a mass ratio of 3: 1 to obtain water reducing agent (7).

[Production Example 8]: Production of water reducing agent (8) Water reducing agent (2) and Master Pozzolith No. 8 (made by BASF Japan) was mix | blended by 3: 1 by mass ratio, and the water reducing agent (8) was obtained.

[Example 1]
Dimroth condenser, Teflon (registered trademark) stirring blade and stirrer with stirring seal, nitrogen introduction tube, ion reaction water: 55.81 parts, 3-methyl-3- What added ethylene oxide to the hydroxyl group of buten-1-ol (isoprenol) (hereinafter referred to as IPN-50) (80% aqueous solution): 192.25 parts were charged at 250 rpm While stirring, nitrogen was introduced at 200 mL / min and warmed to 58 ° C. Next, a mixed solution consisting of 6.2 parts of acrylic acid and 24.81 parts of ion exchange water was added dropwise over 4 hours. Moreover, the mixed solution which consists of L-ascorbic acid: 0.07 part and ion-exchange water: 102.49 part, and the mixed solution which consists of ammonium persulfate: 0.37 part and ion-exchange water: 18 parts over 5 hours, respectively It was dripped. After completion of the dropping, the polymerization reaction was completed by maintaining at 58 ° C. for 1 hour. And it neutralized with sodium hydroxide aqueous solution to pH 7.0, and obtained the aqueous solution of the cement dispersibility improvement adjuvant (1) which is a copolymer of weight average molecular weight = 83000.
The results are shown in Table 2.

[Example 2]
Dimroth condenser, Teflon (registered trademark) stirring blade and stirrer with stirring seal, nitrogen introduction tube, ion reaction water: 55.81 parts, 3-methyl-3- What added ethylene oxide to the hydroxyl group of buten-1-ol (isoprenol) (hereinafter referred to as IPN-50) (80% aqueous solution): 192.25 parts were charged at 250 rpm While stirring, nitrogen was introduced at 200 mL / min to warm to 50 ° C. Next, a mixed solution consisting of 6.2 parts of acrylic acid and 24.81 parts of ion exchange water was added dropwise over 4 hours. Moreover, the mixed solution which consists of L-ascorbic acid: 0.07 part and ion-exchange water: 102.49 part, and the mixed solution which consists of ammonium persulfate: 0.37 part and ion-exchange water: 18 parts over 5 hours, respectively It was dripped. After completion of the dropwise addition, the polymerization reaction was completed by maintaining at 50 ° C. for 1 hour. And it neutralized with sodium hydroxide aqueous solution to pH 7.0, and obtained the aqueous solution of the cement dispersibility improvement adjuvant (2) which is a copolymer of weight average molecular weight = 105000.
The results are shown in Table 2.

Example 3
Dimroth condenser, Teflon (registered trademark) stirrer and stirrer with stirring seal, nitrogen inlet tube, glass reaction vessel equipped with temperature sensor: ion exchange water: 56.27 parts, 3-methyl-3- What added ethylene oxide to the hydroxyl group of buten-1-ol (isoprenol) (hereinafter referred to as IPN-50) (80% aqueous solution): charged with 193.81 parts at 250 rpm While stirring, nitrogen was introduced at 200 mL / min and warmed to 58 ° C. Next, a mixed solution consisting of 4.95 parts of acrylic acid and 19.8 parts of ion exchange water was added dropwise over 4 hours. Further, a mixed solution composed of 0.06 part of L-ascorbic acid and 108.76 parts of ion exchange water, and a mixed solution composed of 0.33 part of ammonium persulfate and 16.02 parts of ion exchange water for 5 hours, respectively. It was dripped over. After completion of the dropping, the polymerization reaction was completed by maintaining at 58 ° C. for 1 hour. And it neutralized with sodium hydroxide aqueous solution to pH 7.0, and obtained the aqueous solution of the cement dispersibility improvement adjuvant (3) which is a copolymer of weight average molecular weight = 72000.
The results are shown in Table 2.

Example 4
Dimroth condenser, Teflon (registered trademark) stirrer and stirrer with stir seal, nitrogen introduction tube, ion reaction water: 27.68 parts, 3-methyl-3- What added ethylene oxide to the hydroxyl group of buten-1-ol (isoprenol) (hereinafter referred to as IPN-50) (80% aqueous solution): charged with 95.34 parts at 250 rpm While stirring, nitrogen was introduced at 200 mL / min and warmed to 58 ° C. Next, a mixed solution composed of 3.73 parts of acrylic acid and 14.92 parts of ion exchange water was dropped over 4 hours. Also, a mixed solution comprising L-ascorbic acid: 0.04 part, 3-mercaptopropionic acid: 0.08 part: 0.09 part and ion-exchanged water: 248.1 parts, ammonium persulfate: 0.20 part Ion-exchanged water: A mixed solution consisting of 9.99 parts was added dropwise over 5 hours. After completion of the dropping, the polymerization reaction was completed by maintaining at 58 ° C. for 1 hour. And it neutralized to pH 7.0 with sodium hydroxide aqueous solution, and obtained the aqueous solution of the cement dispersibility improvement adjuvant (4) which is a copolymer of weight average molecular weight = 40000.
The results are shown in Table 2.

Example 5
Dimroth condenser, Teflon (registered trademark) stirrer and stirrer with stirring seal, nitrogen inlet tube, ion reaction water: 57.62 parts, 3-methyl-3- What added ethylene oxide to the hydroxyl group of buten-1-ol (isoprenol) (hereinafter referred to as IPN-50) (80% aqueous solution): 198.46 parts were charged at 250 rpm. While stirring, nitrogen was introduced at 200 mL / min and warmed to 58 ° C. Next, a mixed solution consisting of 1.23 parts of acrylic acid and 4.92 parts of ion exchange water was added dropwise over 4 hours. Moreover, the mixed solution which consists of L-ascorbic acid: 0.04 part and ion-exchange water: 127.38 part, and the mixed solution which consists of ammonium persulfate: 0.21 part and ion-exchange water: 10.15 part for 5 hours, respectively It was dripped over. After completion of the dropping, the polymerization reaction was completed by maintaining at 58 ° C. for 1 hour. And it neutralized to pH 7.0 with sodium hydroxide aqueous solution, and obtained the aqueous solution of the cement dispersibility improvement aid (5) which is a copolymer of weight average molecular weight = 30000.
The results are shown in Table 2.

Example 6
100 parts of an aqueous solution of the cement dispersibility improving aid (1) obtained in Example 1 and 20 parts of triisopropanolamine (manufactured by Wako Pure Chemical Industries, Ltd.) are mixed, and the cement dispersibility improving aid (6) is mixed. An aqueous solution was obtained.

[Comparative Example 1]
Dimroth condenser, Teflon (registered trademark) stirrer and stirrer with stirring seal, nitrogen inlet tube, glass reaction vessel equipped with temperature sensor: ion-exchanged water: 54.67 parts, 3-methyl-3- What added ethylene oxide to the hydroxyl group of buten-1-ol (isoprenol) (hereinafter referred to as IPN-50) (80% aqueous solution): 188.30 parts were charged at 250 rpm. While stirring, nitrogen was introduced at 200 mL / min and warmed to 58 ° C. Next, a mixed solution consisting of 9.36 parts of acrylic acid and 37.44 parts of ion exchange water was added dropwise over 4 hours. Moreover, the mixed solution which consists of L-ascorbic acid: 0.09 part and ion-exchange water: 86.7 parts, and the mixed solution which consists of ammonium persulfate: 0.47 part and ion-exchange water: 22.98 parts are each 5 hours. It was dripped over. After completion of the dropping, the polymerization reaction was completed by maintaining at 58 ° C. for 1 hour. And it neutralized with sodium hydroxide aqueous solution to pH 7.0, and obtained the aqueous solution of the cement dispersibility improvement adjuvant (C1) which is a copolymer of weight average molecular weight = 112000.
The results are shown in Table 2.

[Comparative Example 2]
100 parts of the aqueous solution of the cement dispersibility improvement aid (C1) obtained in Comparative Example 1 and 20 parts of hydroxyethyl diisopropanolamine (Aldrich) were mixed to prepare an aqueous solution of the cement dispersibility improvement aid (C2). Obtained.

[Examples 7 to 16, Comparative Examples 3 to 5]
Concrete tests were conducted using the cement dispersibility improvement aid obtained in Examples 1 to 5 and Comparative Example 1 and the water reducing agent (1) obtained in Production Example 1 (Examples 7 to 16 and Comparative Example 3). ~ 4). Moreover, the concrete test was done using the water reducing agent (1) obtained in Production Example 1 without using the cement dispersibility improvement aid (Comparative Example 5).
The results are shown in Table 3.

[Examples 17 to 25, Comparative Examples 6 to 14]
Concrete tests and mirabilite tests were carried out using the cement dispersibility improvement aids obtained in Examples 1 to 6 and Comparative Examples 1 and 2 and the water reducing agent obtained in Production Examples 1 to 8 (Examples 17 to 25). Comparative Examples 6-14).
The results are shown in Table 4.

<Concrete test>
Specifically, ordinary Portland cement (manufactured by Taiheiyo Cement) is used as cement, Oikawa water-based land sand as fine aggregate, Qinghai crushed stone as coarse aggregate, tap water as kneaded water, and cement as shown in Table 2 improving dispersibility aids, using water-reducing agent, a cement: 382kg / ^{m 3,} water: 172kg / ^{m 3,} fine aggregate: 796 kg / ^{m 3,} coarse aggregate: 930 kg / ^{m 3,} fine aggregate ratio (fine Concrete / fine coarse aggregate + coarse aggregate (volume ratio): 47%, water / cement ratio (weight ratio) = 0.45. In addition, the temperature of the material used for the test, the forced kneading mixer, and the measuring instruments are adjusted in the above test temperature atmosphere so that the temperature of the concrete composition becomes 20 ° C. The kneading and each measurement are performed as described above. The test was performed 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 antifoaming agent is used as necessary so that the air amount becomes 1.0 ± 0.5%. Adjusted.
Concrete was produced in a kneading time of 90 seconds using a forced kneading mixer under the above conditions, and the slump value, flow value, and air amount were measured. In addition, the measurement of the slump value, the flow value, and the air amount was performed according to Japanese Industrial Standards (JIS-A-1101, 1128).
The cement dispersibility improving aid and the water reducing agent were added in such an amount that the flow value was 37.5 to 42.5 cm. That is, when the same flow value is obtained, the smaller the total amount of the cement dispersibility improving aid and the water reducing agent is, the better.

<Frost glass test>
The cement dispersibility improvement aids obtained in the examples and comparative examples were made into aqueous solutions adjusted so that the solid content concentration contained in the cement dispersibility was 40% by mass, and the amount of by-product of bow nitrate was 2 ° C. Was observed. In accordance with the following criteria, the amount of by-product of bow glass was evaluated.
A: By-product of bow glass was not observed.
◯: Only a slight amount of bow glass was observed.
Δ: Byproduct of bow glass was observed.
×: Many by-products of bow glass were observed.

  As shown in Tables 3 and 4, it can be seen that when the cement dispersibility improving aid of the present invention is used, the amount of water reducing agent can be reduced. Moreover, the 28-day compressive strength improved by adding the cement dispersibility improvement aid of this invention.

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

Claims (3)

A cement dispersibility improving aid for improving dispersibility of the cement composition by being contained in the cement composition,
Structural unit (I) derived from unsaturated polyalkylene glycol ether monomer (a) represented by general formula (1) and unsaturated carboxylic acid monomer (b) represented by general formula (2) A polycarboxylic acid copolymer having a structural unit (II) derived from,
The content ratio of the structural unit (I) to the total structural units constituting the polycarboxylic acid copolymer is 34 mol% or more.
Cement dispersibility improvement aid.

(In 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; Represents an oxyalkylene group having 2 to 18 carbon atoms, n represents the average number of added moles of the oxyalkylene group represented by AO, n is a number from 1 to 500, and x is an integer from 0 to 2 .)

(In general formula (2), R ^{4 to} R ⁶ are the same or different and each represents a hydrogen atom, a methyl group, or — (CH ₂ ) _z COOM group, and — (CH ₂ ) _z COOM group represents a —COOX group. Or other — (CH ₂ ) _z COOM group may form an anhydride, z is an integer of 0 to 2, M is a hydrogen atom, alkali metal, alkaline earth metal, ammonium group, organic An ammonium group or an organic amine group is represented, and X represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, or an organic ammonium group.)   The cement dispersibility improvement adjuvant of Claim 1 containing an alkanolamine compound. Structural unit (I) derived from unsaturated polyalkylene glycol ether monomer (a) represented by general formula (1) and unsaturated carboxylic acid monomer (b) represented by general formula (2) A cement composition comprising a polycarboxylic acid copolymer having a structural unit (II) derived from, and an alkanolamine compound,
The content ratio of the structural unit (I) to the total structural units constituting the polycarboxylic acid copolymer is 34 mol% or more.
Cement composition.

(In 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; Represents an oxyalkylene group having 2 to 18 carbon atoms, n represents the average number of added moles of the oxyalkylene group represented by AO, n is a number from 1 to 500, and x is an integer from 0 to 2 .)

(In general formula (2), R ^{4 to} R ⁶ are the same or different and each represents a hydrogen atom, a methyl group, or — (CH ₂ ) _z COOM group, and — (CH ₂ ) _z COOM group represents a —COOX group. Or other — (CH ₂ ) _z COOM group may form an anhydride, z is an integer of 0 to 2, M is a hydrogen atom, alkali metal, alkaline earth metal, ammonium group, organic An ammonium group or an organic amine group is represented, and X represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, or an organic ammonium group.)