JP6969955B2 - Hydration heat inhibitor for cement and cement hydration heat suppression method - Google Patents

Description

The present invention relates to a heat hydration inhibitor for cement and a method for suppressing heat hydration.

Concrete is known as an inexpensive and excellent material. Concrete forms hydrated crystals and hardens due to the hydration reaction between cement and water. By forming hydrated crystals over time, a high-density structure can be obtained and the strength of concrete can be improved.

Attempts have been made to increase the amount of powder used in the production of concrete for the purpose of improving workability and workability at work sites and for imparting strength. When a large amount of powder is added, the heat of hydration in the hydration reaction increases, which may cause a difference between the concrete external temperature and the concrete internal temperature. Therefore, self-shrinkage due to temperature stress may occur and cracks may occur.

As a method of preventing cracking when a large amount of powder is blended, there are a method of changing cement such as low heat cement and a method of blending an admixture such as fly ash. However, at production sites such as ready-mixed concrete factories, when these special materials are used, there is a cost disadvantage of preparing silos and it is necessary to newly adjust the composition. Therefore, there is a demand for a technique for simply suppressing heat of hydration without significantly changing the cement material.

Patent Document 1 proposes a low-heat cement composition that suppresses the calorific value of hydration hardening by using a specific cement material.
Further, in Patent Documents 2 and 3, by using a material having a retarding effect such as an organic acid as an admixture or a poorly water-soluble material such as dextrin as an admixture, water of cement such as Portland cement is used. It has been proposed to suppress the sum reaction.

Japanese Unexamined Patent Publication No. 11-1570906 Japanese Unexamined Patent Publication No. 2004-137091 Japanese Unexamined Patent Publication No. 2000-281409

The low-temperature cement composition of Patent Document 1 has a problem that the versatility of the obtained cement composition is low because the cement composition contains a specific material. In addition, when manufacturing a composition, it must be manufactured, stored, and shipped using a dedicated silo at a cement factory or the like. Therefore, there is a problem in workability and productivity.

When the admixture of Patent Document 2 is used, there is a problem that the concrete composition needs to be adjusted, which is complicated. In addition, since the amount of cement material is reduced, the strength may be reduced.

Further, it is known that the strength of concrete is generally determined by the ratio of water and cement, and that the smaller the ratio of water, the more dense hydrated crystals are formed and improved. Therefore, in recent years, the amount of water used for cement materials such as cement paste and mortar has been reduced.

When the amount of water used for the cement material is reduced, the cement particles tend to aggregate, and the fluidity may decrease, resulting in poor workability. Further, when reducing the amount of water used for the cement material, it is necessary to further suppress the amount of water evaporating due to the heat of hydration. Therefore, it is necessary to further improve the conventional technique for suppressing heat of hydration in Patent Document 3.

The subject of the present invention can be applied to ordinary concrete compounding, and even if the amount of water used for the cement material is reduced, fluidity is ensured, heat of hydration is sufficiently suppressed, and high-strength concrete is produced. It is to provide the heat of hydration inhibitor for cement to obtain.

（前記一般式（１）中、Ｒ^１は、炭素原子数２〜５のアルケニル基を表す。Ａ^１Ｏは、同一又は異なっていてもよい、炭素原子数２〜１８のオキシアルキレン基を表す。ｎ１は、オキシアルキレン基の平均付加モル数であり、１〜１００の整数を表す。Ｒ^２は、水素原子又は炭素原子数１〜３０の炭化水素基を表す。）

（前記一般式（２）中、Ｒ^３、Ｒ^４及びＲ^５は、それぞれ独立に、水素原子又は炭素原子数１〜３のアルキル基を表す。ｍは、０〜２の整数を表す。Ａ^２Ｏは、同一又は異なっていてもよい、炭素原子数２〜１８のオキシアルキレン基を表す。ｎ２は、オキシアルキレン基の平均付加モル数であり、１〜１００の整数を表す。Ｘは、水素原子又は炭素原子数１〜３０の炭化水素基を表す。）
〔６〕少なくともセメントと、水と、を含むセメント材料に、上記〔１〕〜〔５〕のいずれかに記載のセメント用水和熱抑制剤を添加する水和熱抑制方法。
〔７〕前記セメントと前記水の比率（水／セメント）が、６５％以下である上記〔６〕に記載の水和熱抑制方法。
〔８〕前記セメント用水和熱抑制剤の含有割合が、セメント全量に対して、０．０１〜５．００質量％である上記〔６〕又は〔７〕に記載の水和熱抑制方法。 As a result of diligent studies on the above problems, the present inventors have found that the above problems can be solved by containing a dispersant and a chelate compound, and have completed the present invention.
That is, the present inventors provide the following [1] to [8].
[1] A heat hydration inhibitor for cement containing a dispersant and a chelating agent.
[2] The heat hydration inhibitor for cement according to the above [1], wherein the chelating agent is a compound having an oxygen atom, a nitrogen atom or a phosphorus atom.
[3] The chelating agent is at least one selected from the group consisting of citric acid, ethylenediaminetetraacetic acid, hydroxyethanediphosphonic acid, nitrilotriacetic acid, and hydroxyethylethylenediaminetriacetic acid. 2] The heat hydration inhibitor for cement according to.
[4] The heat hydration inhibitor for cement according to any one of the above [1] to [3], wherein the dispersant is a polycarboxylic acid-based dispersant or an oxycarboxylic acid-based dispersant.
[5] The polycarboxylic acid-based dispersant is derived from a structural unit (I) derived from a monomer represented by the following general formula (1) and a monomer represented by the following general formula (2). Structural unit (II), structural unit (III) derived from unsaturated monocarboxylic acid-based monomer, and other monomers copolymerizable with the monomer (I) to the monomer (III). The hydration heat inhibitor for cement according to the above [4], which is a copolymer having at least two kinds of structural units selected from the group consisting of structural units (IV) derived from.

(In the general formula (1), R ¹ represents an alkenyl group having 2 to 5 carbon atoms, and A ¹ O represents an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. .N1 is the average number of moles of oxyalkylene group added and represents an integer of 1 to 100. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.

(In the general formula (2), R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. M represents an integer of 0 to 2. A. ² O represents an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. N2 is the average number of added moles of the oxyalkylene group, and X represents an integer of 1 to 100. Represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.)
[6] A method for suppressing heat of hydration by adding the heat of hydration inhibitor for cement according to any one of the above [1] to [5] to a cement material containing at least cement and water.
[7] The method for suppressing heat of hydration according to the above [6], wherein the ratio of the cement to the water (water / cement) is 65% or less.
[8] The method for suppressing heat of hydration according to the above [6] or [7], wherein the content ratio of the heat of hydration inhibitor for cement is 0.01 to 5.00% by mass with respect to the total amount of cement.

According to the present invention, it can be applied to ordinary concrete compounding, and even if the amount of water used for cement material is reduced, fluidity is ensured, heat of hydration is sufficiently suppressed, and high-strength concrete is produced. It is possible to provide a heat hydration inhibitor for cement to be obtained.

FIG. 1 is a chart of calorific value measurement data of Comparative Example 1.

Hereinafter, the present invention will be described in detail according to the preferred embodiment thereof.
In the present specification, "cement material" is a general term for cement paste consisting of cement and water, and mortar containing cement, water and aggregate.

[1. Heat inhibitor for cement]
The heat hydration inhibitor for cement of the present invention contains a dispersant and a chelating agent.
By containing the dispersant, the heat hydration inhibitor for cement of the present invention can secure fluidity even if the amount of water used for the cement material is reduced. Further, the heat hydration inhibitor for cement of the present invention can be applied to ordinary concrete compounding by containing a chelating agent, and even if the amount of water used for the cement material is reduced, the heat of hydration is sufficiently suppressed. And can produce high-strength concrete.

[1-1. Dispersant]
The dispersant can ensure the fluidity of the cement material. As described above, in recent years, it has been desired to reduce the amount of water used for cement materials for the purpose of improving the strength of concrete. Generally, if the amount of water used for the cement material is reduced, the fluidity is lowered and the workability is deteriorated. By using the dispersant, even when the amount of water used for the cement material is small, it is possible to suppress the aggregation of cement particles and secure the fluidity.

As the dispersant, conventionally known ones may be used. Examples of the dispersant include polycarboxylic acid-based dispersants, lignin sulfonic acid-based dispersants, lignin derivatives, alkylallyl sulfonic acid-based dispersants, melamine sulfonic acid-based dispersants, and oxycarboxylic acid-based dispersants. Among them, the dispersant is preferably a polycarboxylic acid-based dispersant, a lignin sulfonic acid-based dispersant, a lignin derivative, or an oxycarboxylic acid-based dispersant, and preferably a polycarboxylic acid-based dispersant or an oxycarboxylic acid-based dispersant. ..

(Polycarboxylic acid-based dispersant)
The polycarboxylic acid-based dispersant includes a structural unit (I) derived from a monomer represented by the general formula (1), a structural unit (II) derived from a monomer represented by the general formula (2), and the like. Structural unit (III) derived from an unsaturated monocarboxylic acid-based monomer, and structural unit (IV) derived from other monomers copolymerizable with the monomers (I) to (III). It is preferable that the copolymer has at least two kinds of structural units selected from the group consisting of. The copolymer may be a salt.
Hereinafter, each monomer will be described.

The monomer (I) is a polyalkylene glycol monoalkenyl ether represented by the following general formula (1).

（一般式（１）中、Ｒ^１は、炭素原子数２〜５のアルケニル基を表す。Ａ^１Ｏは、同一又は異なっていてもよい、炭素原子数２〜１８のオキシアルキレン基を表す。ｎ１は、オキシアルキレン基の平均付加モル数であり、１〜１００の整数を表す。Ｒ^２は、水素原子又は炭素原子数１〜３０の炭化水素基を表す。）

(In the general formula (1), R ¹ represents an alkenyl group having 2 to 5 carbon atoms, and A ¹ O represents an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. n1 is the average number of moles of the oxyalkylene group added and represents an integer of 1 to 100. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.)

^{R 1} in the general formula (1) represents an alkenyl group having 2 to 5 carbon atoms. The number of carbon atoms of the alkenyl group is preferably 3 to 5. Examples of R ¹ include, but are not limited to, residues of an allyl group, a metharyl group, and 3-methyl-3-butene-1-ol.

^{A 1} O in the general formula (1) represents an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. Examples of the oxyalkylene group include an oxyethylene group (ethylene glycol unit), an oxypropylene group (propylene glycol unit), and an oxybutylene group (butylene glycol unit). Of these, an oxyethylene group (ethylene glycol unit) and an oxypropylene group (propylene glycol unit) are preferable.
“The same or may be different” means ^{that when a plurality of A 1} O are contained in the general formula (1) (when n1 is 2 or more), each A ¹ O is the same oxyalkylene group. It also means that it may be different (two or more kinds) oxyalkylene groups. The embodiment in the general formula (1) A ^{1 O} is contained more, selected from the group consisting of oxyethylene group (ethylene glycol units), oxypropylene group (propylene glycol units) and oxybutylene group (butylene glycol units) An embodiment in which two or more oxyalkylene groups are mixed can be mentioned. Among them, an embodiment in which an oxyethylene group (ethylene glycol unit) and an oxypropylene group (propylene glycol unit) are mixed, or an embodiment in which an oxyethylene group (ethylene glycol unit) and an oxybutylene group (butylene glycol unit) are mixed. It is preferable, and it is more preferable that the oxyethylene group (ethylene glycol unit) and the oxypropylene group (propylene glycol unit) are mixed.
In the embodiment in which different oxyalkylene groups are mixed, the addition of two or more kinds of oxyalkylene groups may be block-like addition or random addition.

In the general formula (1), n1 is the average number of moles of added oxyalkylene group and represents an integer of 1 to 100. n1 is preferably 1 or more, more preferably 5 or more, and even more preferably 8 or more. n1 is preferably 70 or less, more preferably 50 or less. n1 is usually 1 to 70, preferably 5 to 70, more preferably 8 to 70, and even more preferably 8 to 50.
The "average number of moles added" means the average value of the number of moles of the alkylene glycol unit added to 1 mole of the monomer.

^{R 2} in the general formula (1) represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. If the number of carbon atoms is large, the cement dispersibility of the cement admixture may not be sufficiently exhibited. Therefore, R ² is preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and even more preferably a hydrogen atom or a methyl group.

Examples of the method for producing the monomer (I) include a method of adding 1 to 80 mol of alkylene oxide to an unsaturated alcohol such as allyl alcohol, methallyl alcohol, and 3-methyl-3-butene-1-ol. ..

Examples of the monomer (I) include (poly) ethylene glycol allyl ether, (poly) ethylene glycol metallic ether, (poly) ethylene glycol 3-methyl-3-butenyl ether, and (poly) ethylene (poly) propylene. Glycolallyl ether, (poly) ethylene (poly) propylene glycol metallic ether, (poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl ether, (poly) ethylene (poly) butylene glycol allyl ether, (poly) Ethylene (poly) butylene glycol metallic ether, (poly) ethylene (poly) butylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene glycol allyl ether, methoxy (poly) ethylene glycol metallic ether, methoxy (poly) Ethylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) propylene glycol allyl ether, methoxy (poly) ethylene (poly) propylene glycol metallic ether, methoxy (poly) ethylene (poly) propylene glycol 3- Methyl-3-butenyl ether, methoxy (poly) ethylene (poly) butylene glycol allyl ether, methoxy (poly) ethylene (poly) butylene glycol metalyl ether, methoxy (poly) ethylene (poly) butylene glycol 3-methyl-3- Butenyl ether can be mentioned.

Among the above, it is preferable to use (poly) ethylene glycol allyl ether or (poly) ethylene glycol metallyl ether from the viewpoint of the balance between hydrophilicity and hydrophobicity. The average number of moles of the oxyalkylene group (polyalkylene glycol) added to the monomer (I) is usually 1 to 70, preferably 5 to 70, more preferably 8 to 70, and even more preferably 8 to 50.
As used herein, "(poly)" means that one or more of the structural units or raw materials described immediately after that are bonded together.
The monomer (I) may be of one type or a combination of two or more types.

The monomer (II) is represented by the following general formula (2).

（一般式（２）中、Ｒ^３、Ｒ^４及びＲ^５は、それぞれ独立に、水素原子又は炭素原子数１〜３のアルキル基を表す。ｍは、０〜２の整数を表す。Ａ^２Ｏは、同一又は異なっていてもよい、炭素原子数２〜１８のオキシアルキレン基を表す。ｎ２は、オキシアルキレン基の平均付加モル数であり、１〜１００の整数を表す。Ｘは、水素原子又は炭素原子数１〜３０の炭化水素基を表す。）

(In the general formula (2), R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ^{M represents an integer of 0 to 2. A 2} O represents an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. N2 is the average number of added moles of the oxyalkylene group, and X represents an integer of 1 to 100. Hydrogen. Represents an atom or a hydrocarbon group having 1 to 30 carbon atoms.)

^{R 3} , R ⁴ and R ⁵ in the general formula (2) independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. m represents an integer of 0 to 2, and 0 is preferable.

^{A 2} O in the general formula (2) represents an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. Examples of the oxyalkylene group include an oxyethylene group (ethylene glycol unit), an oxypropylene group (propylene glycol unit), and an oxybutylene group (butylene glycol unit). Of these, an oxyethylene group (ethylene glycol unit) and an oxypropylene group (propylene glycol unit) are preferable.
“The same or may be different” means ^{that when a plurality of A 2} O are contained in the general formula (2) (when n2 is 2 or more), each A ² O is the same oxyalkylene group. It also means that it may be different (two or more kinds) oxyalkylene groups. ^{The embodiment in which a plurality of A 2} O are contained in the general formula (2) is selected from the group consisting of an oxyethylene group (ethylene glycol unit), an oxypropylene group (propylene glycol unit) and an oxybutylene group (butylene glycol unit). An embodiment in which two or more oxyalkylene groups are mixed can be mentioned. Of these, a mode in which an oxyethylene group (ethylene glycol unit) and an oxypropylene group (propylene glycol unit) are mixed, and a mode in which an oxyethylene group (ethylene glycol unit) and an oxybutylene group (butylene glycol unit) are mixed are preferable. A mode in which an oxyethylene group (ethylene glycol unit) and an oxypropylene group (propylene glycol unit) are mixed is more preferable.
In the embodiment in which different oxyalkylene groups are mixed, the addition of two or more kinds of oxyalkylene groups may be block-like addition or random addition.

N2 in the general formula (2) is the average number of moles of substance added of the oxyalkylene group, and represents an integer of 1 to 100. n2 is preferably 1 to 50, more preferably 5 to 50, and even more preferably 8 to 50.
The monomer (II) may be one kind of monomer represented by the general formula (2) or a combination of two or more kinds. The monomer (II) preferably contains a combination of two types of monomers (IIa) and (IIb) having different average addition moles of oxyalkylene groups, and the combination is preferable. The monomer (II) preferably contains a monomer (IIa) having n2 of 1 to 5 and a monomer (IIb) having n2 of 6 to 100. The weight ratio (IIa) / (IIb) of the monomer (IIa) to the monomer (IIb) is preferably 1/99 to 99/1.

X in the general formula (2) represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. If the number of carbon atoms is large, the cement dispersibility of the cement admixture may not be sufficiently exhibited. Therefore, X is preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and even more preferably a hydrogen atom or a methyl group.

Examples of the monomer (II) include unsaturated monocarboxylic acids such as (meth) acrylate (hereinafter, “(meth) acrylate” means “at least one of acrylate and methacrylate”) and (. Poly) ethylene glycol, (poly) ethylene (poly) propylene glycol, (poly) ethylene (poly) butylene glycol, methoxy (poly) ethylene glycol, methoxy (poly) ethylene (poly) propylene glycol, methoxy (poly) ethylene (poly) ) An esterified product of (poly) alkylene glycol such as butylene glycol can be mentioned. Specifically, for example, (poly) ethylene glycol (meth) acrylate, (poly) ethylene (poly) propylene glycol (meth) acrylate, (poly) ethylene (poly) butylene glycol (meth) acrylate, methoxy (poly) ethylene glycol. Examples thereof include (poly) alkylene glycol (meth) acrylates such as (meth) acrylates, methoxy (poly) ethylene (poly) propylene glycol (meth) acrylates, and methoxy (poly) ethylene (poly) butylene glycol (meth) acrylates.

As the monomer (II), the above-mentioned one type or a combination of two or more types can be used. Of these, methoxy (poly) alkylene glycol (meth) acrylate or (poly) alkylene glycol (meth) acrylate is preferable, and (poly) ethylene glycol (meth) acrylate and methoxy (poly) ethylene glycol (meth) acrylate are more preferable. preferable.

Examples of the unsaturated monocarboxylic acid-based monomer (III) include carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and salts thereof (for example, monovalent metal salt, divalent metal salt, ammonium salt, and organic salt). Amine salt). As the unsaturated monocarboxylic acid-based monomer (III), one or more of the above can be used. Of these, acrylic acid or a salt thereof, methacrylic acid or a salt thereof is preferable.

The monomer (IV) is not particularly limited as long as it is a monomer copolymerizable with one or more monomers selected from the group consisting of the monomers (I), (II) and (III). .. The monomer (IV) does not contain the monomers corresponding to the monomers (I) to the monomers (III).

As the monomer (IV), diallyl bisphenols represented by the following general formula (4-1), monoallyl bisphenols represented by the following general formula (4-2), and represented by the following general formula (4-3). Allylphenol and other compounds can be exemplified. As the monomer (IV), one kind or two or more kinds of these compounds can be used.

Examples of the diallyl bisphenols represented by the general formula (4-1) include the 3 and 3'positions of 4,4'-dihydroxydiphenylpropane, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylsulfone and the like. Examples include allyl substitutions.

Examples of the monoallyl bisphenols represented by the general formula (4-2) include 3-position allyl substitutions such as 4,4'-dihydroxydiphenylpropane, 4,4'-dihydroxydiphenylmethane, and 4,4'-dihydroxydiphenylsulfone. Things can be mentioned.

Examples of other compounds include the following compounds.
Half-esters and diesters of unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, and citraconic acid with alcohols having 1 to 30 carbon atoms;
Halfamides and diamides of the unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms;
Half esters and diesters of alkyl (poly) alkylene glycols obtained by adding 1 to 500 mol of an alkylene oxide having 2 to 18 carbon atoms to the alcohol or amine and the unsaturated dicarboxylic acids.
Half-esters and diesters of the unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 moles of these glycols;
Half-amides of maleamide acid and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 moles of these glycols;
Esters of an alkoxy (poly) alkylene glycol obtained by adding 1 to 500 mol of an alkylene oxide having 2 to 18 carbon atoms to an alcohol having 1 to 30 carbon atoms and unsaturated monocarboxylic acids such as (meth) acrylic acid;
An alkylene oxide having 2 to 18 carbon atoms to unsaturated monocarboxylic acids such as (meth) acrylic acid such as (poly) ethylene glycol monomethacrylate, (poly) propylene glycol monomethacrylate, and (poly) butylene glycol monomethacrylate. 1-500 mol adducts;

(Poly) alkylene glycols such as triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate Di (meth) acrylates;
Polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and trimethylolpropane di (meth) acrylate;
(Poly) alkylene glycol dimalates such as triethylene glycol dimalate and polyethylene glycol dimalate;
Vinyl Sulfonate, (Meta) Allyl Sulfonate, 2- (Meta) Acryloxyethyl Sulfonate, 3- (Meta) Acryloxypropyl Sulfonate, 3- (Meta) Acryloxy-2-Hydroxypropyl Sulfonate, 3- (Meta) Acryloxy-2 -Hydroxypropyl sulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyl oxysulfobenzoate, 4- (meth) acryloxibutyl sulfonate, (meth) acrylamide methyl sulfonic acid, (meth) acrylamide ethyl sulfonic acid, 2- Saturated sulfonic acids such as methylpropane sulfonic acid (meth) acrylamide, styrene sulfonic acid, and their monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts;
Amides of unsaturated monocarboxylic acids such as methyl (meth) acrylamide and amines with 1 to 30 carbon atoms;
Vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene;
Alkanediol mono (meth) acrylates such as 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, and 1,6-hexanediol mono (meth) acrylate;
Dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chlor-1,3-butadiene;

Unsaturated amides such as (meth) acrylamide, (meth) acrylic alkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide;
(Meta) Unsaturated cyanides such as acrylonitrile and α-chloroacrylonitrile;
Unsaturated esters such as vinyl acetate and vinyl propionate;
Unsaturation of (meth) aminoethyl acrylate, (meth) methylaminoethyl acrylate, (meth) dimethylaminoethyl acrylate, (meth) dimethylaminopropyl acrylate, (meth) dibutylaminoethyl acrylate, vinyl pyridine, etc. Amine;
Divinyl aromatics such as divinylbenzene;
Cyanurates such as triallyl cyanurate;
Allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether;
Vinyl ethers or allyl ethers such as methoxypolyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether;
Polydimethylsiloxane propylaminomale amidoic acid, polydimethylsiloxane aminopropylene aminomale amidoic acid, polydimethylsiloxane-bis- (propylaminomale amidoic acid), polydimethylsiloxane-bis- (dipropyleneaminomale amidoic acid), polydimethyl Siloxane- (1-propyl-3-acrylate), Polydimethylsiloxane- (1-propyl-3-methacrylate), Polydimethylsiloxane-bis- (1-propyl-3-acrylate), Polydimethylsiloxane-bis- (1) -Siloxane derivatives such as propyl-3-methacrylate).

In obtaining the copolymer or a salt thereof, if necessary, a monomer other than the monomer (I), the monomer (II), the monomer (III) and the monomer (IV) is used. May be good.

The copolymer or a salt thereof can be prepared by copolymerizing each predetermined monomer by a known method. Examples of the method include polymerization methods such as polymerization in a solvent and bulk polymerization.

Examples of the solvent include water; lower alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as cyclohexane and n-hexane; esters such as ethyl acetate. Kind: Ketones such as acetone and methyl ethyl ketone.
Above all, from the viewpoint of solubility of the monomer as a raw material and the obtained copolymer, it is preferable to use at least one of water and a lower alcohol, and it is more preferable to use water.

When copolymerizing in a solvent, each monomer and the polymerization initiator may be continuously dropped into the reaction vessel, or a mixture of the monomers and the polymerization initiator may be continuously dropped into the reaction vessel, respectively. .. Further, a solvent may be charged into the reaction vessel, and a mixture of the monomer and the solvent and a polymerization initiator solution may be continuously added dropwise to the reaction vessel, and a part or all of the monomer may be charged into the reaction vessel to initiate polymerization. The agent may be continuously dropped.

When the polymerization is carried out in an aqueous solvent, examples of the polymerization initiator that can be used for the polymerization include persulfates such as ammonium persulfate, sodium persulfate and potassium persulfate; and water solubility such as t-butyl hydroperoxide. Examples include organic peroxides. At this time, an accelerator such as sodium bisulfite or moor salt may be used in combination.
When copolymerization is carried out in a solvent such as a lower alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester or a ketone, examples of the polymerization initiator that can be used for the copolymerization include benzoyl peroxide and lauryl. Examples thereof include peroxides such as peroxide; hydrocarbonides such as cumene peroxide; and aromatic azo compounds such as azobisisobutyronitrile. At this time, an accelerator such as an amine compound may be used in combination.
Further, when the copolymerization is carried out in a mixed solvent of water and a lower alcohol, it can be appropriately selected and used from the above-mentioned polymerization initiator or combination of the polymerization initiator and the accelerator. The polymerization temperature varies depending on the polymerization conditions such as the solvent used and the type of the polymerization initiator, but is usually carried out in the range of 50 to 120 ° C.

Further, in the copolymerization, the molecular weight can be adjusted by using a chain transfer agent as needed. Examples of the chain transfer agent include L-ascorbic acid, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thioapple acid, octyl thioglycolate, 2-mercaptoethanesulfonic acid and the like. Known thiol compounds: sodium bisulfite, hypophosphite, salts thereof (sodium bisulfite, potassium hypophosphite, etc.), sulfite, hydrogen sulfite, dithionic acid, metabisulfite, among them. Examples thereof include lower oxides such as salts (sodium bisulfite, potassium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, sodium bisulfite, potassium bisulfite, sodium metabisulfite, potassium metabisulfite, etc.). These may be used alone or in combination of two or more.
Further, it is also effective to use a monomer (V) having high chain transferability for adjusting the molecular weight of the copolymer or a salt thereof. Examples of the monomer (V) having high chain transferability include (meth) allylsulfonic acid (salt) -based monomers. The blending ratio of the monomer (V) is usually 20% by weight or less, preferably 10% by weight or less in the copolymer or a salt thereof. The compounding ratio is the total of the monomers (I) to (IV) of the copolymer or a salt thereof (the compounding ratio of the monomer (I) + the compounding ratio of the monomer (II) + the monomer. The compounding ratio when the compounding ratio of (III) + the compounding ratio of the monomer (IV) is 100% by weight.

When copolymerizing in an aqueous solvent when obtaining a copolymer, the pH at the time of polymerization is usually strongly acidic due to the influence of a monomer having an unsaturated bond. Therefore, the pH may be adjusted to an appropriate level. In particular, when an ester-based monomer is used, it is preferable to carry out the polymerization at pH 2 to 7 in order to eliminate the instability of the ester bond. When acidifying as the adjustment of the pH at the time of polymerization, an acidic substance such as phosphoric acid, sulfuric acid, nitric acid, alkyl phosphoric acid, alkyl sulfate, alkyl sulfonic acid, and (alkyl) benzene sulfonic acid can be used. Among these acidic substances, it is preferable to use phosphoric acid because it has a pH buffering effect. When the pH is adjusted to be alkaline during polymerization, an alkaline substance such as NaOH or Ca (OH) ₂ can be used as the alkaline substance that can be used to adjust the pH.
The pH adjustment may be performed on the monomer before the polymerization or on the copolymer solution after the polymerization. Further, the pH of the copolymer may be further adjusted after the polymerization is carried out by adding a part of the alkaline substance before the polymerization.

The copolymer or a salt thereof is preferably obtained by neutralizing the product obtained by the copolymerization with an alkaline substance. Neutralization means adjusting the solution containing the product obtained by the copolymerization to pH 2.0 to pH 7.20.

The weight average molecular weight of the copolymer or a salt thereof is preferably 10,000 to 60,000, more preferably 10,000 to 50,000. When the weight average molecular weight is less than 10,000, the cement dispersibility of the heat hydration inhibitor for cement is not sufficiently exhibited, the fluidity or workability is not improved, and the effect of the purpose of use of the dispersant is not sufficiently exhibited. In some cases. On the other hand, if the weight average molecular weight exceeds 60,000, the workability may be deteriorated due to the agglutination effect.

The molecular weight distribution (Mw / Mn) of the copolymer or a salt thereof is preferably in the range of 1.2 to 3.0.

In the hydration heat inhibitor for cement of the present invention, the content form of the copolymer or its salt is not limited, and the copolymer or its salt may be contained as it is, or the copolymer or its salt may be dissolved in a solvent. It may be included as a dispersed solution, a dispersed dispersion, or a suspended suspension.

(Oxycarboxylic acid-based dispersant)
The oxycarboxylic acid-based dispersant is usually an oxycarboxylic acid-based compound or a composition containing the same. Examples of the oxycarboxylic acid-based compound include gluconic acid, glucoheptonic acid, arabonic acid, malic acid, citric acid, inorganic salts thereof (sodium salt, potassium salt, calcium salt, magnesium salt, ammonium salt, etc.), and organic salt. (Triethanolamine salt, etc.) can be mentioned.

[1-2. Chelating agent]
The chelating agent can be applied to ordinary concrete formulations, and even if the amount of water used for the cement material is reduced, the heat of hydration can be sufficiently suppressed to produce high-strength concrete. As described above, in recent years, it has been desired to reduce the amount of water used for cement materials for the purpose of improving the strength of concrete. When the amount of water used for the cement material is reduced, it is necessary to further suppress the amount of water that evaporates due to the heat of hydration. By using the chelating agent, even when the amount of water is small, the heat of hydration can be sufficiently suppressed and high-strength concrete can be produced.
In addition, in this specification, a "chelating agent" means a compound which captures a calcium ion and forms a complex.
Examples of the chelating agent include oxyphenols such as catechol and pyrogallol; amino alcohols such as diethanolamine and triethanolamine; oxy acids such as glycolic acid, lactic acid, hydroxyacrylic acid and citric acid and their methyls and ethyls. Esters such as hydroxyethyl; Oxyaldehydes such as glycolaldehyde; Amino acids such as glycine and alanine; β-diketones such as acetylacetone, benzoylacetone, stearoylacetone, stearoylbenzoylmethane, dibenzoylmethane; acetoacetic acid, propionylacetic acid , Β-ketone acids such as benzoylacetic acid and esters thereof such as methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl; ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), Hydroxyethyliminodiacetic acid (HIDA), hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminetetraacetic acid (DTPA), triethylenetetraminehexacetic acid (TTHA), 1,3-propanediaminetetraacetic acid (PDTA), dihydroxyethylethylenediaminediamine Examples thereof include acetic acid (DHEDDA), hydroxyethanediphosphonic acid (HEDP), and metal (sodium, potassium, etc.) salts thereof. The chelating agent is preferably a compound having an oxygen atom, a nitrogen atom or a phosphorus atom, and is at least selected from the group consisting of citric acid, ethylenediaminetetraacetic acid, hydroxyethanediphosphonic acid, nitrilotriacetic acid, and hydroxyethylethylenediaminetriacetic acid. One is more preferred.
The chelating agent can be used at room temperature regardless of whether it is a solid, a powder or a liquid.

The amount of the chelating agent used with respect to the total mass of the dispersant is preferably 1 to 400% by mass, more preferably 1 to 350% by mass, still more preferably 1 to 300% by mass. When the amount of the chelating agent used is 1% by mass or more, the effect of suppressing heat of hydration can be produced. Further, when the amount of the chelating agent used is 400% by mass or less, it is possible to suppress the concrete from becoming uncured.

[1-3. Any additive]
The heat hydration inhibitor for cement of the present invention may contain a conventionally known additive for cement as long as it does not have the effects of improving dispersibility and suppressing heat of hydration. Examples of additives for cement include water-soluble polymers, polymer emulsions, cement wetting agents, swelling agents, waterproofing agents, retarders, thickeners, flocculants, drying shrinkage reducing agents, strength enhancers, and curing accelerators. , Defoaming agent, AE agent, surfactant, water reducing agent, high performance water reducing agent, AE water reducing agent, high performance AE water reducing agent, fluidizing agent, pumping aid, low thixotropy aid.

Examples of the water-soluble polymer include polyalkylene glycol. More specifically, polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, polyethylene polybutylene glycol and the like can be mentioned.
Examples of the retarder include sugars such as glucose; sugar alcohols such as sorbitol.
Examples of the curing accelerator include soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate; chlorides such as iron chloride and magnesium chloride; thiosulfate; formic acid and formates such as calcium formate.
Examples of the thickener include hydroxypropylmethyl cellulose, carboxymethyl cellulose, known cellulose nanofibers, and known cellulose nanocrystals.
As the defoaming agent, a commercially available product may be used. For example, "Floric DF-753" manufactured by Floric Co., Ltd. can be mentioned.
As the high-performance AE water reducing agent, a commercially available product may be used. For example, "Floric SF500S" and "Floric SF500R" manufactured by Floric can be mentioned.
Examples of the low thixotropic aid include "Floric FBL-200" manufactured by Floric.

[2. Hydration heat suppression method]
The method for suppressing heat of hydration of the present invention applies to a cement material containing at least cement and water [1. It is a method of adding the hydration heat inhibitor for cement described in [Cement hydration heat inhibitor]. Since the heat of hydration inhibitor of the present invention uses the above-mentioned heat of hydration inhibitor for cement, it can be applied to ordinary concrete compounding, and even if the amount of water used for the cement material is reduced, the fluidity is ensured. This is a method that can sufficiently suppress the heat of hydration and produce high-strength concrete.

[2-1. Cement material]
The cement material contains at least cement, water, and may include aggregate.
The cement is not particularly limited. For example, Portoland cement (normal, early-strength, ultra-fast-strength, moderate heat, sulfate-resistant and each low-alkali form), various mixed cements (blast furnace cement, silica cement, fly ash cement), white Portorand cement, alumina cement, Ultra-fast-hardening cement (1 clinker fast-hardening cement, 2 clinker fast-hardening cement, magnesium phosphate cement), grout cement, oil well cement, low heat-generating cement (low-heat-generating blast furnace cement, fly ash mixed low-heat-generating blast furnace cement, belite High-content cement), ultra-high-strength cement, cement-based solidifying material, eco-cement (cement manufactured from one or more of municipal waste incineration ash and sewage sludge incineration ash) and the like. Fine powder such as blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, limestone powder, gypsum and the like may be added to the cement.

The water that can be used for the cement composition is not particularly limited, and examples thereof include tap water, water other than tap water (river water, lake water, well water, etc.), and recovered water.

The aggregates include, for example, sand, gravel, crushed stone; granulated slag; recycled aggregate, etc .; silica stone, clayey, zirconite, high alumina, silicon carbide, graphite, chromium, chromog, magnesia. Fire-resistant aggregates such as.

The method for suppressing heat of hydration of the present invention is effective even if the ratio of water to cement (water / cement) is an arbitrary value. However, considering the effect of the heat hydration inhibitor chelating calcium ions, it is considered that the larger the unit amount of cement that elutes calcium ions, the more the effect of suppressing heat hydration is reflected. Therefore, the ratio of water to cement (water / cement) is preferably 65% or less, more preferably 60% or less, still more preferably 55% or less.

The content ratio of the heat hydration inhibitor for cement is usually 0.01 to 5.0% by mass, preferably 0.01 to 4.0% by mass, and more preferably 0, based on the total amount of cement. It is 0.01 to 3.0% by mass. With this addition amount, the obtained hydraulic composition has various preferable effects such as reduction of unit water amount, increase of strength, and improvement of durability. When the above ratio is 0.01% by mass or more, the above-mentioned effects of the obtained hydraulic composition can be expected. On the other hand, when the ratio is 5.0% by mass or less, the effect is sufficiently exhibited, which is preferable from the viewpoint of economy.
In addition, in this specification, "the total amount of cement" refers only to the mass of cement (including a binder), and does not include the mass other than a binder such as water and aggregate.

There are no particular restrictions on the method of manufacturing, transporting, placing, curing, managing, etc. of the cement material, and ordinary methods can be adopted.

Hereinafter, the present invention will be described in detail with reference to Examples. The following examples are for the purpose of suitably explaining the present invention, and do not limit the present invention. The "part" is based on mass.

[Weight average molecular weight (Mw), number average molecular weight (Mn)]
It was measured by a known method for polyethylene glycol conversion by gel permeation chromatography (GPC). The measurement conditions of GPC are described below.
Measuring device: Tosoh Co., Ltd. Column used: Shodex Volume OH-pak SB-806HQ, SB-804HQ, SB-802.5HQ
Eluent: 0.05 mM sodium nitrate / acetonitrile 8/2 (v / v)
Standard substance: Polyethylene glycol (manufactured by Tosoh, GL Science)
Detector: Differential refractometer (manufactured by Tosoh Corporation)
Calibration curve: Polyethylene glycol standard

<Production Examples 1 to 4: Preparation of Dispersant>
[Manufacturing Example 1]
874 parts of water was charged in a glass reaction vessel equipped with a thermometer, a stirrer, a reflux device, a nitrogen introduction tube and a dropping device, and the reaction vessel was replaced with nitrogen under stirring to raise the temperature to 100 ° C. Then, a monomer aqueous solution containing 425 parts (36 mol%) of methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added, block addition), 75 parts (64 mol%) of methacrylic acid, and 125 parts of water was added. A mixed solution of 14 parts of ammonium sulfate and 287 parts of water was continuously added dropwise to a reaction vessel kept at 100 ° C. for 2 hours each. Further, the reaction was carried out for 1 hour while the temperature was maintained at 100 ° C. to obtain an aqueous solution of the copolymer (A). This aqueous solution was adjusted to pH 7 with sodium hydroxide to obtain an aqueous solution of a copolymer salt (A-1) having a weight average molecular weight of 16000 and Mw / Mn1.5.

[Manufacturing Example 2]
501 parts of water, an ethylene adduct adduct of 3-methyl-3-buten-1-ol (average adduct of ethylene oxide) in a glass reaction vessel equipped with a thermometer, agitator, recirculation device, nitrogen introduction tube and dropping device. 25 parts) 500 parts (35 mol%) and 2 parts (0.006 mol%) of the compound in which the 3 and 3'positions of 4,4'-dihydroxydiphenyl sulfone were allyl-substituted, and the reaction vessel was stirred under stirring. It was replaced with nitrogen and the temperature was raised to 100 ° C. Then, a monomer aqueous solution in which 135 parts (65 mol%) of acrylic acid, 501 parts of water, and 1 part of a 30% NaOH aqueous solution were mixed, and a mixed solution of 12 parts of ammonium persulfate and 188 parts of water were mixed at 100 ° C. for 1 hour each. It was continuously dropped into the reaction vessel held in. Further, the reaction was carried out for 1 hour while the temperature was maintained at 100 ° C. to obtain an aqueous solution of the copolymer (B). This aqueous solution was adjusted to pH 7 with a 30% NaOH aqueous solution to obtain an aqueous solution of a copolymer salt (B-1) having a weight average molecular weight of 20000 and Mw / Mn 1.7.

[Manufacturing Example 3]
400 parts of water, 771 parts of polyethylene glycol monoallyl ether (average number of added moles of ethylene oxide: 12), and 4,4 in a glass reaction vessel equipped with a thermometer, agitator, recirculation device, nitrogen introduction tube and dropping device. Three parts of the compound in which the 3 and 3'positions of ′ -dihydroxydiphenyl sulfone were allyl-substituted were charged, the reaction vessel was substituted with nitrogen under stirring, and the temperature was raised to 100 ° C. Then, an aqueous monomer solution in which 200 parts of acrylic acid and 600 parts of water were mixed and a mixed solution of 12 parts of ammonium persulfate and 88 parts of water were continuously added dropwise to a reaction vessel kept at 100 ° C. for 1 hour each. Further, the reaction was carried out for 1 hour while the temperature was maintained at 100 ° C. to obtain an aqueous solution of the copolymer (C). This aqueous solution was adjusted to pH 7 with a 30% NaOH aqueous solution to obtain an aqueous solution of a polycarboxylic acid-based copolymer salt (C-1) having a weight average molecular weight of 13,000 and Mw / Mn1.5.

[Manufacturing Example 4]
In a glass reaction vessel equipped with a thermometer, agitator, a reflux device, a nitrogen introduction tube and a dropping device, 148 parts of water and polyethylene glycol polypropylene glycol monoallyl ether (average number of moles of ethylene oxide added: 10, propylene oxide). An average number of added moles of 5 and 94 parts of ethylene oxide and propylene oxide (random addition) were charged, the inside of the reaction vessel was replaced with nitrogen under stirring, and the temperature was raised to 80 ° C. After that, 35 parts of methacrylic acid, 5 parts of acrylic acid, 63 parts of methoxypolyethylene glycol methacrylate (average number of added moles of ethylene oxide 25), 60 parts of 2-hydroxypropyl acrylate, 8 parts of 3-mercaptopropionic acid, 165 parts of water. A mixed solution of 3 parts of ammonium persulfate and 47 parts of water was continuously added dropwise to a reaction vessel kept at 80 ° C. for 2 hours each. Further, the reaction was carried out for 1 hour while the temperature was maintained at 100 ° C. to obtain an aqueous solution of the copolymer (D). This aqueous solution was adjusted to pH 7 with a 30% NaOH aqueous solution to obtain an aqueous solution of a salt (D-1) of a polycarboxylic acid-based copolymer having a weight average molecular weight of 15,000 and Mw / Mn 1.7.

<Chelating agent>
Chelating agent I: Ethylenediaminetetraacetic acid (EDTA) (manufactured by Wako Pure Chemical Industries, Ltd.)
Chelating agent II: Nitrilotriacetic acid (NTA) (manufactured by Dojin Chemical Co., Ltd.)
Chelating agent III: Hydroxyethanediphosphonic acid (HEDP) (manufactured by Chelest)
Chelating agent IV: Citric acid (manufactured by Wako Pure Chemical Industries, Ltd.)

<Examples 1 to 13, Comparative Examples 1 to 6: Preparation of cement composition>
At the environmental temperature (20 ° C.), cement (binding material), water, and aggregate are mixed so as to be in each formulation shown in Table 1, and further, the dispersants of each Example and each Comparative Example shown in Table 2 and chelate. An agent and a heat hydration inhibitor for cement containing the agent were added. Then, the cement composition was obtained by mechanically kneading with a mortar mixer for 60 seconds at low speed and 90 seconds at high speed. In Table 2, the addition amounts of the dispersant and the chelating agent are both the amounts used in terms of solids, and the content ratio of the chelating agent is a value with respect to the total amount of cement.

The abbreviations in Table 1 are shown below.
OPC: Ordinary Portland cement Taiheiyo Cement (d = 3.16 g / cm ³ )
MPC: Moderate heat cement Taiheiyo Cement Co., Ltd. (d = 3.21 g / cm ³ )
LPC: Low heat cement Taiheiyo Cement (d = 3.22g / cm ³ )
FA: Fly Ash Type II Nippon Paper Industries "CfFA (d = 2.12g / cm ³ )"
BFS: Blast furnace slag fine powder 4000 (d = 2.91 g / cm ³ )
Aggregate: S land sand (d = 2.58 g / cm ³ )
G crushed stone 2005 (d = 2.65 g / cm ³ )

Using the cement compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 6, the following slump test, calorific value measurement, and compressive strength measurement were performed. The results are shown in Table 3.

[Slump test]
The slump values immediately after kneading and 45 minutes after kneading were measured according to JIS A 1101.

[Measurement of calorific value]
A plastic mold having a diameter of 100 mm × 200 mm was filled with the cement composition immediately after kneading so as to be uniform. After that, I put the whole formwork in the curing box so that it would not lose its shape. The curing box was covered with styrofoam beads so that it could be sufficiently insulated.
Immediately after that, a sensor was placed in the center of the cement composition, the lid of the curing box was closed, and the calorific value of the concrete was continuously measured with the data logger TDS303 (measurement interval: 0.5 minutes). , The heat generation start time, the maximum temperature arrival time, the temperature immediately after kneading, and the maximum temperature were measured. FIG. 1 shows the calorific value measurement data of Comparative Example 1.
It is known that the heat generated immediately after water injection has a small calorific value and is practically meaningless. Therefore, the heat generation start time of the secondary peak including the maximum temperature was defined as the heat generation start time.

[Temperature rise value]
From the following formula (A), the temperature rise value (° C./Kg) per cement unit weight was calculated.
Equation (A):
Temperature rise value (° C / Kg) = (maximum temperature (° C) -temperature immediately after kneading (° C)) / binder weight (kg)

<Compressive strength>
A compressive strength test (MPa) was carried out after 7 days and 28 days according to JIS A 1108.

As can be seen from Table 3, the heat hydration inhibitor for cement of the present invention can secure fluidity and hydrate even when applied to a conventional cement material produced by reducing the amount of water. It can suppress heat and produce high-strength concrete.

1: 1st-order peak, 2: 2nd-order peak start point, 3: 2nd-order peak

Claims (6)

With polycarboxylic acid dispersants,
A chelate that captures calcium ions to form a complex, including at least one selected from the group consisting of citrate, ethylenediaminetetraacetic acid, hydroxyethandiphosphonic acid, and nitrilotriacetic acid, hydroxyethylethylenediaminetriacetic acid. Agent and
Contains ,
The ratio of the content of the chelating agent to the content of the polycarboxylic acid-based dispersant is 33.3 to 240%.
Heat inhibitor for cement. The heat hydration inhibitor for cement according to claim 1, wherein the chelating agent is a compound having an oxygen atom, a nitrogen atom or a phosphorus atom. The polycarboxylic acid-based dispersant
Structural unit (I) derived from the monomer represented by the following general formula (1), structural unit (II) derived from the monomer represented by the following general formula (2), unsaturated monocarboxylic acid system. From the group consisting of a structural unit (III) derived from a monomer and a structural unit (IV) derived from another monomer copolymerizable with the monomer (I) to the monomer (III). The heat hydration inhibitor for cement according to claim 1 or 2 , which is a selected copolymer having at least two kinds of structural units.

(In the general formula (1), R ¹ represents an alkenyl group having 2 to 5 carbon atoms, and A ¹ O represents an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. .N1 is the average number of moles of oxyalkylene group added and represents an integer of 1 to 100. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.

(In the general formula (2), R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. M represents an integer of 0 to 2. A. ² O represents an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. N2 is the average number of added moles of the oxyalkylene group, and X represents an integer of 1 to 100. Represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.) For cement materials, including at least cement and water,
The method for suppressing heat of hydration by adding the heat of hydration inhibitor for cement according to any one of claims 1 to 3. The method for suppressing heat of hydration according to claim 4 , wherein the ratio of the cement to the water (water / cement) is 65% or less. The method for suppressing heat of hydration according to claim 4 or 5 , wherein the content ratio of the heat of hydration inhibitor for cement is 0.01 to 5.00% by mass with respect to the total amount of cement.

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