JP2016130199A - Copolymer for cement dispersant, cement dispersant composition, and cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copolymer for cement dispersant which can inhibit setting retardation when it is used for cement dispersant, a cement dispersant composition comprising such a copolymer for cement dispersant, and a cement composition comprising such a cement dispersant composition.SOLUTION: A copolymer for cement dispersant according to the present invention comprises a structural unit (I) derived from a specific unsaturated carboxylic acid monomer (a) and a structural unit (II) derived from a specific unsaturated polyalkylene glycol monomer (b).SELECTED DRAWING: None

Description

  The present invention relates to a copolymer for cement dispersant, a cement dispersant composition, and a cement composition.

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

  In order to improve such fluidity and retention, various polycarboxylic acid copolymers have been studied as copolymers for cement dispersants (see, for example, Patent Documents 1 and 2).

  However, when a conventional polycarboxylic acid copolymer is used as a cement dispersant, there is a problem that the setting delay of cement occurs.

JP 09-86990 A JP 2001-220417 A

  An object of the present invention is to provide a copolymer for a cement dispersant that can reduce the setting delay when used in a cement dispersant. Moreover, it is providing the cement dispersant composition containing such a copolymer for cement dispersants. Furthermore, it is providing the cement composition containing such a cement dispersant composition.

  In order to solve the above problems, the present inventor has intensively studied. First of all, it was thought that the reason for the delay in the setting of the cement was that the cement dispersant was present on the surface of the cement, so that the contact between the cement and water was hindered and the hydration reaction was slowed. And, if the cement dispersant is separated from the cement surface, we think that the setting delay of the cement can be alleviated, and about the structure of the copolymer for cement dispersant that can separate the cement dispersant from the cement surface Study was carried out. As a result, as a constituent unit of the copolymer for cement dispersant, a structural unit derived from an unsaturated polyalkylene glycol monomer that can be generally used in the copolymer for cement dispersant is used together with the cement dispersant from the surface of the cement. By adopting a structural unit derived from a specific unsaturated carboxylic acid monomer designed so as to have a releasing action, it was found that the above problems can be solved, and the present invention has been completed.

The copolymer for a cement dispersant of the present invention is
Derived from the structural unit (I) derived from the unsaturated carboxylic acid monomer (a) represented by the general formula (1) and the unsaturated polyalkylene glycol monomer (b) represented by the general formula (2) The structural unit (II)

（一般式（１）中、Ｒ^１、Ｒ^２、およびＲ^３は、同一または異なって、水素原子、メチル基、または−（ＣＨ_２）_ｍＣＯＯＭ基を表し、ｍは０〜２の整数であり、Ｍは、水素原子、金属原子、アンモニウム基、または有機アンモニウム基を表し、Ｘは、−ＣＨ_２−、−Ｏ−、−ＮＨ−、または−Ｓ−を表し、Ｙは直鎖状または分岐状の炭素原子数１〜５０のアルキレン基を表し、Ｒ^４およびＲ^５は、同一または異なって、−（ＣＨ_２）_ｎ−、−ＣＯ−、−ＣＨ（Ｒ^６ＯＨ）−、または−ＣＨ（Ｒ^７ＣＯＯＨ）−を表し、ｎは１〜１０の整数であり、Ｒ^６は炭素原子数１〜１０のアルキレン基または単結合を表し、Ｒ^７は炭素原子数１〜１０のアルキレン基または単結合を表し、ｘは０〜２０の整数であり、ｙは０または１であり、ｚは０〜５０の整数である。）

(In General Formula (1), R ¹ , R ² , and R ³ are the same or different and each represents a hydrogen atom, a methyl group, or — (CH ₂ ) _m COOM group, and m is an integer of 0-2. And M represents a hydrogen atom, a metal atom, an ammonium group, or an organic ammonium group, X represents —CH ₂ —, —O—, —NH—, or —S—, and Y represents a linear or Represents a branched alkylene group having 1 to 50 carbon atoms, and R ⁴ and R ⁵ are the same or different and represent — (CH ₂ ) _n —, —CO—, —CH (R ⁶ OH) —, or — CH (R ⁷ COOH) — represents an integer of 1 to 10, R ⁶ represents an alkylene group having 1 to 10 carbon atoms or a single bond, and R ⁷ represents an alkylene group having 1 to 10 carbon atoms. Or a single bond, x is an integer of 0 to 20, y is 0 or 1 Ri, z is an integer of 0 to 50.)

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

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

  The cement dispersant composition of the present invention includes the copolymer for cement dispersant of the present invention.

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

  ADVANTAGE OF THE INVENTION According to this invention, when used for a cement dispersant, the copolymer for cement dispersants which can reduce a setting delay can be provided. Moreover, the cement dispersant composition containing such a copolymer for cement dispersants can be provided. Furthermore, a cement composition comprising such a cement dispersant 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”.

≪Copolymer for cement dispersant≫
The copolymer for a cement dispersant of the present invention comprises a structural unit (I) derived from an unsaturated carboxylic acid monomer (a) represented by the general formula (1) and a non-ionic compound represented by the general formula (2). It has a structural unit (II) derived from a saturated polyalkylene glycol monomer (b). The copolymer for cement dispersant of the present invention has such a constitution, that is, an unsaturated polyalkylene glycol monomer represented by the general formula (2) that can be generally used for the copolymer for cement dispersant ( b) derived from the unsaturated carboxylic acid monomer (a) represented by the specific general formula (1) designed to have a function of separating the cement dispersant from the cement surface together with the structural unit derived from By having the structural unit, the copolymer for cement dispersant of the present invention can alleviate the setting delay when used as a cement dispersant.

In the general formula (1) and the structural unit (I), R ¹ , R ² , and R ³ are the same or different and each represents a hydrogen atom, a methyl group, or a — (CH ₂ ) _m COOM group. m is an integer of 0 to 2, and M represents a hydrogen atom, a metal atom, an ammonium group, or an organic ammonium group.

In general formula (1) and structural unit (I), R ¹ is preferably a hydrogen atom. In the general formula (1) and the structural unit (I), R ² is preferably a hydrogen atom. In general formula (1) and structural unit (I), R ³ is preferably a methyl group.

In the general formula (1) and the structural unit (I), X represents —CH ₂ —, —O—, —NH—, or —S—.

  In general formula (1) and structural unit (I), X is preferably —NH—.

  In the general formula (1) and the structural unit (I), Y represents a linear or branched alkylene group having 1 to 50 carbon atoms.

In the general formula (1) and the structural unit (I), R ⁴ and R ⁵ are the same or different and represent — (CH ₂ ) _n —, —CO—, —CH (R ⁶ OH) —, or —CH ( R ⁷ COOH) —, n is an integer of 1 to 10, R ⁶ represents an alkylene group or a single bond having 1 to 10 carbon atoms, and R ⁷ represents an alkylene group or a single bond having 1 to 10 carbon atoms. Represents a bond.

In the general formula (1) and the structural unit (I), R ⁴ is preferably — (CH ₂ ) _n —, —CH (R ⁷ COOH) —, n is preferably 1, and R ⁷ Is a single bond.

In general formula (1) and structural unit (I), R ⁵ is preferably — (CH ₂ ) _n —, and n is preferably 1.

  In general formula (1) and structural unit (I), x is an integer of 0-20, y is 0 or 1, and z is an integer of 0-50.

  In general formula (1) and structural unit (I), x is preferably 0.

  In general formula (1) and structural unit (I), y is preferably 1.

  In general formula (1) and structural unit (I), z is preferably 0.

In general formula (1) and structural unit (I), more preferably, R ¹ is a hydrogen atom, R ² is a hydrogen atom, R ³ is a methyl group, X is —NH—, Y Is a linear or branched alkylene group having 1 to 50 carbon atoms, R ⁴ is —CH ₂ — or —CH (COOH) —, R ⁵ is —CH ₂ —, and x is 0. Y is 1 and z is 0.

  Specific examples of the unsaturated carboxylic acid monomer (a) represented by the general formula (1) include N-methacryloyl-β-alanine and N-methacryloyl-aspartic acid. In particular, when these compounds are used as the unsaturated carboxylic acid monomer (a), the cement dispersant can be effectively separated from the surface of the cement, and the setting delay of the cement can be effectively reduced.

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

In general formula (2) and structural unit (II), R ¹ is preferably a hydrogen atom. In general formula (2) and structural unit (II), R ² is preferably a hydrogen atom. In general formula (2) and structural unit (II), R ³ is preferably a methyl group.

In the general formula (2) and the structural unit (II), R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.

In the general formula (2) and the structural unit (II), R ⁴ is preferably a hydrocarbon group having 1 to 30 carbon atoms, more preferably a hydrocarbon group having 1 to 10 carbon atoms, More preferred is a hydrocarbon group having 1 to 6 carbon atoms, and particularly preferred is a methyl group.

In the general formula (2) and the structural unit (II), R ^a O represents an oxyalkylene group having 2 to 18 carbon atoms.

In the general formula (2) and the structural unit (II), R ^a O is preferably an oxyalkylene group having 2 to 10 carbon atoms, and more preferably an oxyalkylene group having 2 to 8 carbon atoms. More preferably, it is an oxyalkylene group having 2 to 4 carbon atoms, particularly preferably an oxyalkylene group having 2 to 3 carbon atoms (oxyethylene group, oxypropylene group), most preferably a carbon atom. It is an oxyalkylene group of formula 2 (oxyethylene group). The addition form of R ^a O may be any form such as random addition, block addition, and alternate addition.

In general formula (2) and structural unit (II), n represents the average addition mole number of the oxyalkylene group represented by R ^a O, and n is an integer of 1 to 500.

  In general formula (2) and structural unit (II), n is preferably an integer of 1 to 400, more preferably an integer of 3 to 300, still more preferably an integer of 5 to 200, and particularly preferably. Is an integer from 10 to 100.

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

  In general formula (2) and structural unit (II), x is preferably 0.

  In general formula (2) and structural unit (II), y is 0 or 1.

  In general formula (2) and structural unit (II), y is preferably 1.

The unsaturated polyalkylene glycol monomer (b) represented by the general formula (2) is a monomer that can be generally used for a copolymer for a cement dispersant, and satisfies the general formula (2). Any suitable monomer can be employed as long as the effects of the present invention are not impaired. As such an unsaturated polyalkylene glycol monomer (b), specifically, for example, CH ₂ ═C (CH ₃ ) C (═O) (OC ₂ H ₄ ) _n OCH ₃ (n is And an integer of 10 to 100).

  The total content of the structural unit (I) and the structural unit (II) in the cement dispersant copolymer of the present invention is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, further preferably 90% by mass to 100% by mass, particularly preferably 95% by mass to 100% by mass, and most preferably 98% by mass. % To 100% by mass. By adjusting the total content ratio of the structural unit (I) and the structural unit (II) in the copolymer for cement dispersant of the present invention within the above range, the copolymer for cement dispersant of the present invention is When used in a cement dispersant, the setting delay can be further alleviated.

  The total content of the structural unit (I) and the structural unit (II) in the copolymer for cement dispersant of the present invention can be known by, for example, various structural analyzes (for example, NMR) of the copolymer. Can do. Moreover, it is derived from the various monomers calculated based on the amount of the various monomers used when producing the cement dispersant copolymer of the present invention without performing the various structural analyzes as described above. The total content ratio of the structural unit (I) and the structural unit (II) in the copolymer for a cement dispersant of the present invention may be calculated using the content ratio of the structural unit. That is, the unsaturated carboxylic acid monomer (a) represented by the general formula (1) and the general formula (1) in all the monomer components used when producing the copolymer for cement dispersant of the present invention ( 2) The content ratio of the total mass of the unsaturated polyalkylene glycol monomer (b) represented by the structural unit (I) and the structural unit (II) in the copolymer for cement dispersant of the present invention. ) As a total content.

  The content ratio of the structural unit (I) in the copolymer for cement dispersant of the present invention is preferably 1% by mass to 60% by mass, more preferably 5% by mass to 55% by mass, and still more preferably. Is 10% by mass to 50% by mass, more preferably 15% by mass to 45% by mass, and particularly preferably 20% by mass to 40% by mass. The copolymer for cement dispersant of the present invention was used as a cement dispersant by adjusting the total content ratio of the structural units (I) in the copolymer for cement dispersant of the present invention within the above range. In some cases, the setting delay can be more relaxed.

  The content ratio of the structural unit (II) in the copolymer for cement dispersant of the present invention is preferably 40% by mass to 99% by mass, more preferably 45% by mass to 95% by mass, and still more preferably. Is 50% by mass to 90% by mass, more preferably 55% by mass to 85% by mass, and particularly preferably 60% by mass to 80% by mass. The copolymer for a cement dispersant of the present invention was used as a cement dispersant by adjusting the total content of the structural units (II) in the copolymer for a cement dispersant of the present invention within the above range. In some cases, the setting delay can be more relaxed.

  The content ratio of the structural unit (I) or the structural unit (II) in the copolymer for a cement dispersant of the present invention can be known, for example, by various structural analyzes (for example, NMR) of the copolymer. . Moreover, it is derived from the various monomers calculated based on the amount of the various monomers used when producing the cement dispersant copolymer of the present invention without performing the various structural analyzes as described above. The content ratio of the structural unit (I) or the structural unit (II) in the copolymer for a cement dispersant of the present invention may be calculated using the content ratio of the structural unit. That is, the content of the unsaturated carboxylic acid monomer (a) represented by the general formula (1) in all monomer components used in producing the copolymer for cement dispersant of the present invention. The ratio may be treated as the content ratio of the structural unit (I) in the copolymer for cement dispersant of the present invention, and the unsaturated polyalkylene glycol monomer represented by the general formula (2) ( You may treat the content rate of the mass of b) as a content rate of structural unit (II) in the copolymer for cement dispersants of this invention.

  The copolymer for a cement dispersant of the present invention may contain a structural unit (III) derived from another monomer (c) in addition to the structural unit (I) and the structural unit (II). The structural unit (III) derived from the other monomer (c) may be only one kind or two or more kinds.

  The other monomer (c) includes an unsaturated carboxylic acid monomer (a) represented by the general formula (1) and an unsaturated polyalkylene glycol monomer represented by the general formula (2) ( a monomer copolymerizable with b).

  Examples of the other monomer (c) include monocarboxylic acid monomers such as acrylic acid, methacrylic acid, and crotonic acid or salts thereof; dicarboxylic acid monomers such as maleic acid, itaconic acid, and fumaric acid. Bodies or salts thereof; anhydrides of dicarboxylic acid monomers such as maleic acid, itaconic acid, and fumaric acid or salts thereof; hydroxyalkyl (meth) such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate Acrylates; esters of unsaturated monocarboxylic acids such as methyl (meth) acrylate and glycidyl (meth) acrylate and alcohols having 1 to 30 carbon atoms; (anhydrous) unsaturated such as maleic acid, fumaric acid and itaconic acid Half esters of dicarboxylic acids and alcohols having 1 to 30 carbon atoms; (anhydrous) maleic acid Diesters of unsaturated dicarboxylic acids such as fumaric acid and itaconic acid and alcohols having 1 to 30 carbon atoms; half amides of the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms; and the above unsaturated dicarboxylic acids And an alkyl (poly) alkylene glycol obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to the alcohol or amine, and the unsaturated dicarboxylic acid. Half esters; diesters of alkyl (poly) alkylene glycols obtained by adding 1 to 500 moles of alkylene oxides having 2 to 18 carbon atoms to the alcohols or amines; and unsaturated dicarboxylic acids; unsaturated dicarboxylic acids and carbon Glycols of 2 to 18 atoms or addition moles of these glycols Half-esters with 2-500 polyalkylene glycols; diesters of unsaturated dicarboxylic acids with 2-18 carbon atoms or polyalkylene glycols with 2 to 500 addition moles of these glycols; Half amides of glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols; (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate (Poly) alkylene glycol di (meth) acrylates such as: polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate and trimethylolpropane tri (meth) acrylate; (poly) alls such as polyethylene glycol dimaleate Xylene glycol dimaleates; unsaturated sulfonic acids (salts) such as vinyl sulfonate, (meth) allyl sulfonate and styrene sulfonic acid; unsaturated monocarboxylic acids such as methyl (meth) acrylamide and amines having 1 to 30 carbon atoms Amides with styrene; Vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene; Alkanediol mono (meth) acrylates such as 1,4-butanediol mono (meth) acrylate; Dienes such as butadiene and isoprene Unsaturated amides such as (meth) acrylic (alkyl) amide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; unsaturated cyanides such as (meth) acrylonitrile; Saturated esters; aminoethyl (meth) acrylate, (meth) acrylate Unsaturated amines such as dimethylaminoethyl silylate and vinylpyridine; divinyl aromatics such as divinylbenzene; allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; (methoxy) polyethylene glycol monovinyl ether and the like Vinyl ethers; and the like. Examples of the salt herein include alkali metal salts, alkaline earth metal salts, ammonium salts, organic ammonium salts, and organic amine salts. Examples of the alkali metal salt include lithium salt, sodium salt, potassium salt and the like. Examples of alkaline earth metal salts include calcium salts and magnesium salts. Examples of the organic ammonium salt include methyl ammonium salt, ethyl ammonium salt, dimethyl ammonium salt, diethyl ammonium salt, trimethyl ammonium salt, and triethyl ammonium salt. Examples of organic amine salts include alkanolamine salts such as ethanolamine salts, diethanolamine salts, and triethanolamine salts.

  The content ratio of the structural unit (III) in the copolymer for cement dispersant of the present invention can be known, for example, by various structural analyzes (for example, NMR) of the copolymer. Moreover, it is derived from the various monomers calculated based on the amount of the various monomers used when producing the cement dispersant copolymer of the present invention without performing the various structural analyzes as described above. The content ratio of the structural unit (III) in the copolymer for a cement dispersant of the present invention may be calculated using the content ratio of the structural unit. That is, the content ratio of the mass of the other monomer (c) in the total monomer component used when producing the cement dispersant copolymer of the present invention is defined as the copolymer weight of the cement dispersant of the present invention. You may handle as a content rate of structural unit (III) in coalescence.

  The mass average molecular weight (Mw) of the copolymer for cement dispersant of the present invention is preferably 3000 to 100,000, more preferably as the mass average molecular weight (Mw) in terms of polyethylene glycol by gel permeation chromatography (GPC). Is from 5,000 to 100,000, more preferably from 5,000 to 70,000, particularly preferably from 10,000 to 70,000, and most preferably from 10,000 to 50,000. By adjusting the mass average molecular weight (Mw) of the copolymer for cement dispersant of the present invention within the above range, the copolymer for cement dispersant of the present invention exhibits a setting delay when used as a cement dispersant. Can be more relaxed.

  The molecular weight distribution (Mw / Mn) of the copolymer for cement dispersant of the present invention is preferably 1.0 to 6.0, more preferably 1.0 to 5.0, still more preferably 1. It is 0-4.0, Most preferably, it is 1.0-3.5, Most preferably, it is 1.0-3.0. By adjusting the molecular weight distribution (Mw / Mn) of the copolymer for a cement dispersant of the present invention within the above range, the copolymer for a cement dispersant of the present invention can be delayed in setting when used as a cement dispersant. Can be more relaxed.

  The copolymer for cement dispersants of the present invention can be produced by any appropriate method as long as the effects of the present invention are not impaired. The copolymer for a cement dispersant of the present invention preferably starts polymerization of a monomer component containing an unsaturated carboxylic acid monomer (a) and an unsaturated polyalkylene glycol monomer (b). It can be carried out in the presence of an agent.

  Unsaturated carboxylic acid monomer (a), unsaturated polyalkylene glycol monomer (b) that can be used for the production of the copolymer for cement dispersant of the present invention, and other units as required. The amount of the monomer (c) used is appropriately adjusted so that the proportion of the structural units derived from the respective monomers in the total structural units constituting the cement dispersant copolymer of the present invention is as described above. That's fine. Preferably, assuming that the polymerization reaction proceeds quantitatively, each unit has the same ratio as the ratio of structural units derived from each monomer in all the structural units constituting the copolymer for cement dispersant of the present invention described above. A mer may be used.

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

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

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

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

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

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

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

  The produced copolymer can be used as it is as the copolymer for a cement dispersant of the present invention, but from the viewpoint of handling, the pH of the reaction solution after the production of the copolymer is adjusted to 5 or more. It is preferable to keep it.

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

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

≪Cement dispersant composition≫
The cement dispersant composition of the present invention includes the copolymer for cement dispersant of the present invention. In this case, preferably, the copolymer for cement dispersant of the present invention is used as a cement dispersant.

  The cement dispersant composition of the present invention may contain any appropriate other component as long as the effects of the present invention are not impaired, in addition to the cement dispersant copolymer of the present invention.

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

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

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

  The cement dispersant composition of the present invention can contain any appropriate other cement additive (material) as long as the effects of the present invention are not impaired. Examples of such other cement additives (materials) include other cement additives (materials) exemplified in the following (1) to (12). The compounding ratio of the copolymer for cement dispersant of the present invention contained in the cement dispersant composition of the present invention and such other cement additive (material) is the kind of other cement additive (material) to be used. Any appropriate compounding ratio can be adopted depending on the purpose.

(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: Ettringite, lime, etc.

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

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

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

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

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

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

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

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

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

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

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

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

<Condensation test method>
The setting test was performed in an environment where the temperature was 20 ° C. ± 1 ° C. and the relative humidity was 60% ± 10%.
The mortar formulation was C / S / W = 600/1350/210 (g). Here, C, S, and W are as follows.
C: Ordinary Portland cement (manufactured by Taiheiyo Cement)
S: Standard sand for cement strength test (Cement Association)
W: ion exchange aqueous solution of polymer (copolymer) and antifoaming agent As W, the polymer aqueous solution was weighed so that the polymer was 0.12% by mass with respect to C, and MA-404 ( 10% by mass with respect to the solid content of the polymer was added in solid form, and ion-exchanged water was added to obtain a predetermined amount, which was sufficiently uniformly dissolved.
A stainless beater (stirring blade) was attached to a Hobart mortar mixer (model number N-50, manufactured by Hobart), C and W were added, and kneaded at a first speed for 30 seconds. Furthermore, S was added over 30 seconds while kneading at a first speed. After the completion of S addition, after kneading for 30 seconds at the second speed, the mixer was stopped, the mortar was scraped off for 15 seconds, and then allowed to stand for 75 seconds. The mixture was allowed to stand for 75 seconds and then kneaded at a second speed for 60 seconds to prepare a mortar.
The mortar was transferred from the kneading container to a 600 cc container made of polypropylene. Cover and let stand for 4 hours. After standing, pierce once per hour using a penetration resistance tester. If the resistance value exceeds 10 MPa, perform a penetration test once every 30 minutes thereafter. The time when the resistance value exceeded 28 MPa was defined as the curing time. Before performing the penetration test, bleeding water was removed, and a penetration needle with a diameter of 4 mm was allowed to penetrate 25 mm over 10 seconds, and the resistance value was measured.

[Production Example 1]: Production of N-methacryloyl-β-alanine Into a glass reaction vessel equipped with a thermometer, a stirrer, and a dropping funnel, 20 g of sodium hydroxide: 40 g was added, and β-alanine: 8. 9g was added little by little with stirring and dissolved. After adding an ice bath and cooling to 5 ° C., 10.5 g of methacrylic acid chloride was added dropwise over 2 hours, and stirring was further performed for 2 hours after the completion of the addition. After completion of the reaction, 14.7 g of 37 mass% hydrochloric acid was added, extraction was performed with ethyl acetate, and ethyl acetate was distilled off to obtain 13.6 g of N-methacryloyl-β-alanine as a white solid.

[Production Example 2]: Production of N-methacryloyl-aspartic acid Into a glass reaction vessel equipped with a thermometer, a stirrer, and a dropping funnel, 20 g of sodium hydroxide: 120 g was charged, and 26.6 g of aspartic acid: It was added little by little with stirring and dissolved. After adding an ice bath and cooling to 5 ° C., 20.9 g of methacrylic acid chloride was added dropwise over 2 hours, and the mixture was further stirred for 2 hours after completion of the addition. 40.6g of 37 mass% hydrochloric acid was added after completion | finish of reaction, it extracted with ethyl acetate, and N-methacryloyl-aspartic acid: 25.7g was obtained as white solid by distilling off ethyl acetate.

[Example 1]
A glass container equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube, and a reflux condenser was charged with 82.5 parts of ion exchange water, and the temperature was raised to 80 ° C. while performing nitrogen flow. _{Then, M-230G (CH 2 =} C (CH 3) C (= O) (OC 2 H 4) n OCH 3, n = 23, manufactured by Shin-Nakamura Chemical Co., Ltd.): 22.00 parts Production Example 1 A mixed solution of N-methacryloyl-β-alanine: 8.00 parts, mercaptopropionic acid: 0.23 parts and water: 155.02 parts obtained in 1 above was added dropwise over 4 hours, and at the same time, ammonium persulfate: 0.0. A mixed solution of 32 parts and 31.9 parts of water was added dropwise over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, followed by cooling to room temperature to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 7 using sodium hydroxide to obtain an aqueous solution of the copolymer for cement dispersant (1) having a weight average molecular weight of 13100.
The results are shown in Table 1.

[Example 2]
A glass container equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube, and a reflux condenser was charged with 82.5 parts of ion exchange water, and the temperature was raised to 80 ° C. while performing nitrogen flow. _{Thereafter, M-230G (CH 2 =} C (CH 3) C (= O) (OC 2 H 4) n OCH 3, n = 23, manufactured by Shin-Nakamura Chemical Co., Ltd.): 20.47 parts Preparation Example 2 A mixed solution of N-methacryloyl-aspartic acid: 9.53 parts, mercaptopropionic acid: 0.22 parts, water: 157.28 parts obtained in 1 above was added dropwise over 4 hours, and at the same time ammonium persulfate: 0.30 Part and water: 29.7 parts of a mixed solution was added dropwise over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, followed by cooling to room temperature to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 7 using sodium hydroxide to obtain an aqueous solution of the copolymer for cement dispersant (2) having a weight average molecular weight of 13500.
The results are shown in Table 1.

[Comparative Example 1]
A glass container equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube, and a reflux condenser was charged with 82.5 parts of ion exchange water, and the temperature was raised to 80 ° C. while performing nitrogen flow. _{Thereafter, M-230G (CH 2 =} C (CH 3) C (= O) (OC 2 H 4) n OCH 3, n = 23, manufactured by Shin-Nakamura Chemical Co., Ltd.): 25.02 parts of methacrylic acid: A mixed solution of 4.98 parts, mercaptopropionic acid: 0.26 parts and water: 150.57 parts was added dropwise over 4 hours, and at the same time, a mixed solution of ammonium persulfate: 0.37 parts and water: 36.3 parts. Was added dropwise over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, followed by cooling to room temperature to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 7 using sodium hydroxide to obtain an aqueous solution of a copolymer for cement dispersant (C1) having a weight average molecular weight of 15900.
The results are shown in Table 1.

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

Claims (3)

Derived from the structural unit (I) derived from the unsaturated carboxylic acid monomer (a) represented by the general formula (1) and the unsaturated polyalkylene glycol monomer (b) represented by the general formula (2) A copolymer for a cement dispersant having the structural unit (II):

(In General Formula (1), R ¹ , R ² , and R ³ are the same or different and each represents a hydrogen atom, a methyl group, or — (CH ₂ ) _m COOM group, and m is an integer of 0-2. And M represents a hydrogen atom, a metal atom, an ammonium group, or an organic ammonium group, X represents —CH ₂ —, —O—, —NH—, or —S—, and Y represents a linear or Represents a branched alkylene group having 1 to 50 carbon atoms, and R ⁴ and R ⁵ are the same or different and represent — (CH ₂ ) _n —, —CO—, —CH (R ⁶ OH) —, or — CH (R ⁷ COOH) — represents an integer of 1 to 10, R ⁶ represents an alkylene group having 1 to 10 carbon atoms or a single bond, and R ⁷ represents an alkylene group having 1 to 10 carbon atoms. Or a single bond, x is an integer of 0 to 20, y is 0 or 1 Ri, z is an integer of 0 to 50.)

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