JP2009161379A - Cement dispersant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cement dispersant which is high in water reducing property, less in setting retarding property, low in the viscosity of concrete, and satisfactory in the workability of construction. <P>SOLUTION: The cement dispersant excellent in water reducing property, setting retarding property and concrete viscosity and further the stability of these property with time is provided by using fumaric acid as a part of or a main raw material of a structural unit (II) in a polycarboxylic acid polymer formed by adding a structural unit (I) comprising a reactive alcohol alkylene oxide addition product, the structural unit (II) comprising a reactive dibasic acid and a structural unit (III) comprising an unsaturated carboxylic acid based compound and further preferably a structural unit (IV) containing a polyamide polyamine in the structural unit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cement dispersant excellent in water reduction and retention.

Conventionally, lignin sulfonate, naphthalene sulfonic acid formaldehyde condensate salt, and melamine sulfonic acid formaldehyde condensate salt have been used as cement dispersants for the purpose of ensuring the fluidity of cement compounds such as concrete. However, the above cement dispersant has a problem that the dispersibility is not sufficient and the slump loss is remarkably large.
In recent years, high-performance AE water reducing agents represented by polycarboxylic acid polymers and the like have been widely used as admixtures having both high water reducing performance and slump loss reduction effects. A high-performance AE water reducing agent is characterized by its superior water-reducing performance compared to conventional cement dispersants, but slump loss has little effect on concrete setting delay as long as it is within the appropriate usage range. These features that are not seen with other drugs are also important.

Various techniques have been disclosed as cement dispersants for improving the dispersion performance. For example, a cement dispersant using a copolymer containing a polyalkylene glycol alkenyl ether monomer and an unsaturated carboxylic acid monomer as essential components can include the following: polyethylene glycol monoallyl ether The main component is a copolymer derived by using a monomer (I) and a maleic acid monomer (II) and a monomer (III) copolymerizable with these monomers in a specific ratio. Cement dispersant (Patent Document 1), unsaturated polyalkylene glycol ether monomer (I), maleic acid monomer (II) and other monomers copolymerizable with these monomers ( III) a cement dispersant mainly comprising a copolymer obtained by copolymerization at a specific copolymerization ratio (Patent Document 2), a short-chain polyalkylene glycol alkenyl ether monomer and an unsaturated catalyst. Two types of copolymers: a copolymer (A) composed of a boronic acid monomer and a copolymer (B) composed of a long-chain polyalkylene glycol alkenyl ether monomer and an unsaturated carboxylic acid monomer Obtained by copolymerization of a cement dispersant (Patent Document 3), an unsaturated carboxylic acid monomer and / or an unsaturated acid anhydride monomer, and an unsaturated alcohol monomer, the essential component of which Amino group-containing polymer that can be used as a cement dispersant (Patent Document 4), which is partially introduced with amino groups, and a nitrogen atom-containing polymer that can be suitably used as a cement admixture for ultra-high-strength concrete. An unsaturated alcohol alkylene oxide adduct polymer comprising a saturated monomer, an unsaturated alcohol alkylene oxide, and an unsaturated carboxylic acid monomer (Patent Document 5).
As described above, although many copolymers have been studied and proposed as cement dispersants, it has been desired to develop a drug having further superior performance in water reduction, retention and concrete viscosity.

On the other hand, in the polycarboxylic acid-based cement dispersant described in each of the above-mentioned documents, as the unsaturated carboxylic acid-based monomer that can be used in the polycarboxylic acid-based polymer, (meth) acrylic acid, crotonic acid, (anhydrous ) Maleic acid, fumaric acid, itaconic acid, citraconic acid and the like. However, in the examples of these documents, test examples using (meth) acrylic acid as an unsaturated monocarboxylic acid monomer and (anhydrous) maleic acid as an unsaturated dicarboxylic acid monomer are described. However, there has been no experimental study to prepare a copolymer using other carboxylic acid, for example, fumaric acid, and actually use it as a cement dispersant.
Patent Document 6 describes Example 4 in which a water-soluble copolymer was obtained from an unsaturated alcohol component unit (3-methyl-3-buten-1-ol ethylene oxide / propylene oxide adduct) and fumaric acid. Although described, it is only used in tests to evaluate the dispersion performance of satin white (calcium sulfoaluminate hexahydrate) (Table 1). In addition, in this document, the use of the copolymer in a scale inhibitor, an inorganic pigment dispersant, and a detergent builder has been proposed, but there is no description of actual use as a cement dispersant, and a description suggesting it. Nor.
Japanese Patent Publication No. 58-38380 JP-A-10-236858 JP 2001-302306 A JP 2003-192722 A JP 2003-327644 A Japanese Patent Laid-Open No. 62-68806

  The present invention has been made in order to improve the performance of the cement dispersant under the background of such a conventional technique, and has a water-reducing property, a low setting retarding property, a low concrete viscosity, and the stability with time of these performances. It is an object to provide a cement dispersant that is considered excellent in terms of workability.

  As a result of intensive studies, the present inventors have found that in a polycarboxylic acid polymer comprising a reactive alcohol derivative having a polymerizable binding site, an unsaturated carboxylic acid compound, and an unsaturated carboxylic acid ester compound, fumaric acid and unsaturated It has been found that the basic performance as a cement dispersant, particularly the long-term slump retention performance and the viscosity reduction, is remarkably improved by using the carboxylic acid ester in combination. It has also been found that various properties as a concrete dispersant can be further improved by including a polyamide polyamine in the polycarboxylic acid polymer.

  That is, the present invention relates to a polycarboxylic acid polymer comprising a structural unit derived from a polyalkylene glycol alkenyl ether compound, a structural unit derived from an unsaturated carboxylic acid compound, and a structural unit derived from an unsaturated carboxylic ester compound. The content of the structural unit derived from fumaric acid is 50 to 100% by mass with respect to the total mass of the structural unit derived from the unsaturated carboxylic acid compound, and the unsaturated carboxylic acid compound Structural unit derived from: Structural unit derived from unsaturated carboxylic acid ester compound = 1 to 50% by mass: 99 to 50% by mass.

（式中、Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴はそれぞれ独立して水素原子又は炭素原子数１乃至２２の炭化水素基を表し、Ｘは―（ＣＨ₂）ｂＯ―を表し、ＡＯは炭素原子数２乃至４のアルキレ
ンオキサイド基を表す。ａはアルキレンオキサイドの平均付加モル数で１乃至２００の数
を表し、ｂは１乃至２０の整数を表す。）

（式中、Ｒ⁵乃至Ｒ⁸はそれぞれ独立して水素原子、炭素原子数１乃至２２の炭化水素基、−ＣＯＯＨ、−ＣＯＯＭを表し、但しＲ⁵乃至Ｒ⁸のうち少なくとも二つは−ＣＯＯＨ及び／又は−ＣＯＯＭを表し、またＲ⁵乃至Ｒ⁸のうち二つの基の一部は一緒になって酸無水物を形成することができる。Ｍはアルカリ金属、アルカリ土類金属、アンモニウム、アルカノールアミンを表す。）

（式中、Ｒ⁵及びＲ⁶は夫々独立して水素原子又は炭素原子数１乃至２２の炭化水素基を表し、Ｂは水素原子、アルカリ金属、アルカリ土類金属、アンモニウム、アルカノールアミンを表す。）

（式中、Ｒ⁹、Ｒ¹⁰はそれぞれ独立して水素原子又は炭素原子数１乃至２２の炭化水素基
を表し、Ｒ¹¹、Ｒ¹²はそれぞれ独立して水素原子、炭素原子数１乃至２２の炭化水素基、−ＣＯＯＨ、−ＣＯＯＭ、−ＣＯＯＹを表し、但し、Ｒ¹¹及びＲ¹²のうち少なくとも一方は−ＣＯＯＹを表す。Ｍはアルカリ金属、アルカリ土類金属、アンモニウム、アルカノールアミンを表し、Ｙは炭素原子数１乃至２２の炭化水素基又は（ＡＯ）ｃ−Ｒ¹³を表し、ＡＯは炭素原子数２乃至４のアルキレンオキサイド基を表し、ｃはアルキレンオキサイドの平均付加モル数で１乃至２００の数を表し、Ｒ¹³は水素原子又は炭素原子数１乃至２２の炭化水素基を表す。） In the present invention, the polycarboxylic acid polymer includes the following structural unit (I), structural unit (II), and structural unit (III), and is based on the total mass of the structural unit (II) below. The content ratio of the structural unit (IIa) derived from the following fumaric acid is 50 to 100% by mass, and the following structural unit (II): structural unit (III) is 1 to 50% by mass: 99 to 50%. The present invention relates to a cement dispersant, which is characterized by being a mass%.

(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, X represents — (CH ₂ ) bO—, and AO represents A C represents an alkylene oxide group having 2 to 4 carbon atoms, a represents an average added mole number of alkylene oxide and represents a number of 1 to 200, and b represents an integer of 1 to 20.

(Wherein R ^{5 to} R ⁸ each independently represents a hydrogen atom, a hydrocarbon group having 1 to 22 carbon atoms, —COOH, —COOM, provided that at least two of R ^{5 to} R ⁸ are —COOH. And / or —COOM, and two of R ^{5 to} R ⁸ may be combined to form an acid anhydride, where M is an alkali metal, alkaline earth metal, ammonium, alkanol. Represents amine.)

(In the formula, R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, and B represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an alkanolamine. )

(In the formula, R ⁹ and R ¹⁰ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, and R ¹¹ and R ¹² each independently represent a hydrogen atom and 1 to 22 carbon atoms. Represents a hydrocarbon group, —COOH, —COOM, —COOY, wherein at least one of R ¹¹ and R ¹² represents —COOY, M represents an alkali metal, an alkaline earth metal, ammonium, or an alkanolamine; Represents a hydrocarbon group having 1 to 22 carbon atoms or (AO) c-R ¹³ , AO represents an alkylene oxide group having 2 to 4 carbon atoms, and c is an average added mole number of alkylene oxide of 1 to 200. R ¹³ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms.)

（式中、Ｚは二塩基酸とポリアルキレンポリアミンを縮合させたポリアミドポリアミン及び／又は該ポリアミドポリアミンの活性イミノ基、アミノ基、アミド残基１当量に対して炭素原子数２乃至４のアルキレンオキサイドを０．１乃至１０モル付加させたポリアミドポリアミン変性物が、アミド結合を介して主鎖の炭素原子と結合する基を表す。） Furthermore, the present invention is such that the polycarboxylic acid-based polymer includes the following structural unit (IV) in addition to the structural unit (I), structural unit (II) and structural unit (III). The present invention relates to a cement dispersant.

(In the formula, Z is a polyamide polyamine obtained by condensing a dibasic acid and a polyalkylene polyamine and / or an alkylene oxide having 2 to 4 carbon atoms with respect to 1 equivalent of an active imino group, amino group or amide residue of the polyamide polyamine. Represents a group bonded to the carbon atom of the main chain through an amide bond.

  In addition to the polycarboxylic acid-based polymer, the present invention provides a polyamide polyamine obtained by condensing a dibasic acid and a polyalkylene polyamine and / or an active imino group, amino group, and amide residue of 1 equivalent of the polyamide polyamine. The present invention relates to a cement dispersant characterized by containing a polyamide polyamine modified product obtained by adding 0.1 to 10 moles of an alkylene oxide having 2 to 4 carbon atoms.

According to the present invention, it is possible to provide a cement dispersant that not only has excellent water reduction and slump retention performance, but also has good workability such as low concrete viscosity and low setting delay.
In addition, according to the present invention, the above-mentioned water reduction and slump retention performance can be stably maintained for a long time.

The present invention comprises a polycarboxylic acid polymer comprising a structural unit derived from a polyalkylene glycol alkenyl ether compound, a structural unit derived from an unsaturated carboxylic acid compound, and a structural unit derived from an unsaturated carboxylic acid ester compound. In the cement dispersant, the content ratio of the structural unit derived from fumaric acid is 50 to 100% by mass with respect to the total mass of the structural unit derived from the unsaturated carboxylic acid compound, and is derived from the unsaturated carboxylic acid compound. The structural unit is: a structural unit derived from the unsaturated carboxylic acid ester compound = 1 to 50% by mass: 99 to 50% by mass, and more particularly, the cement dispersant. The polycarboxylic acid polymer comprises the structural unit (I), structural unit (II) and structural unit (III) shown above. It is. Further, the polycarboxylic acid-based polymer includes the structural unit (IV) derived from a polyamide polyamine and / or a modified polyamide polyamine in addition to the structural units (I) to (III). The polycarboxylic acid polymer thus configured has a comb polymer structure in which a graft chain such as a polyalkylene oxide chain or a polyamide polyamine chain is bonded to the main chain skeleton.
The cement dispersant of the present invention can also contain a polyamide polyamine and / or a polyamide polyamine-modified product in addition to the polycarboxylic acid polymer.
The present invention is described in detail below.

（式中、Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴はそれぞれ独立して水素原子又は炭素原子数１乃至２２の炭化水素基を表し、Ｘは―（ＣＨ₂）ｂＯ―を表し、ＡＯは炭素原子数２乃至４のアルキレ
ンオキサイド基を表す。ａはアルキレンオキサイドの平均付加モル数で１乃至２００の数を表し、ｂは１乃至２０の整数を表す。） [Structural Unit (I) to Structural Unit (III)]
The structural unit (I) constituting the polycarboxylic acid polymer that is the cement dispersant of the present invention is represented by the following formula.

(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, X represents — (CH ₂ ) bO—, and AO represents A C represents an alkylene oxide group having 2 to 4 carbon atoms, a represents an average added mole number of alkylene oxide and represents a number of 1 to 200, and b represents an integer of 1 to 20.

In the above formula, AO is preferably composed of ethylene oxide having 2 carbon atoms, or two or more alkylene oxides. In this case, either block addition or random addition may be used.
When using 2 or more types of alkylene oxide, it is preferable that the alkylene oxide of 3 or 4 carbon atoms occupies less than 0.1-30 mol% in the alkylene oxide average addition mole number represented by a. In particular, among alkylene oxides having 3 or 4 carbon atoms, less than 0.1 to 20 mol% is the terminal side of the alkylene oxide chain (bonding position with R ⁴ ).
It is desirable to arrange in the point from the viewpoint of improving performance such as water reduction, retention, and concrete viscosity.

Further, in the above formula, R ⁴ is particularly preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, butyl group, phenyl group, etc.).

The structural unit (I) is, for example, a structural unit derived from the following compound; polyalkylene glycol monoallyl ether, polyalkylene glycol monoalkenyl ether, methoxypolyalkylene glycol monoallyl ether, methoxypolyalkylene glycol monoalkenyl ether, etc. Alkenyl ethers formed from the (alkoxy) polyalkylene glycol and alkenyl ether having 3 to 8 carbon atoms, unsaturated aliphatic ethers which are unsaturated aliphatic alcohol alkylene oxide adducts, and the like. Specific examples include an alkylene oxide adduct of 3-methyl-3-buten-1-ol, an alkylene oxide adduct of 2-propen-1-ol (allyl alcohol), an ether thereof, and the like. Among these, the specific example of the most preferable compound is an alkylene oxide adduct of 3-methyl-3-buten-1-ol.
The structural unit (I) may be a structural unit derived from one or a combination of these compounds.

（式中、Ｒ⁵乃至Ｒ⁸はそれぞれ独立して水素原子、炭素原子数１乃至２２の炭化水素基、−ＣＯＯＨ、−ＣＯＯＭを表し、但しＲ⁵乃至Ｒ⁸のうち少なくとも二つは−ＣＯＯＨ及び／又は−ＣＯＯＭを表し、またＲ⁵乃至Ｒ⁸のうち二つの基の一部は一緒になって酸無水物を形成することができる。Ｍはアルカリ金属、アルカリ土類金属、アンモニウム、アルカノールアミンを表す。） The structural unit (II) constituting the polycarboxylic acid polymer that is the cement dispersant of the present invention is represented by the following formula.

(Wherein R ^{5 to} R ⁸ each independently represents a hydrogen atom, a hydrocarbon group having 1 to 22 carbon atoms, —COOH, —COOM, provided that at least two of R ^{5 to} R ⁸ are —COOH. And / or —COOM, and two of R ^{5 to} R ⁸ may be combined to form an acid anhydride, where M is an alkali metal, alkaline earth metal, ammonium, alkanol. Represents amine.)

（式中、Ｒ⁵及びＲ⁶は夫々独立して水素原子又は炭素原子数１乃至２２の炭化水素基を表し、Ｂは水素原子、アルカリ金属、アルカリ土類金属、アンモニウム、アルカノールアミンを表す。）
上記構造単位（ＩＩ）において、フマル酸に由来する構造単位（ＩＩａ）として、酸（−ＣＯＯＨ）及び／又は酸塩（−ＣＯＯＭ）が含まれる場合、これらは酸の形態でも中和された形態でも良いが、部分中和又は完全中和された形態が製品形態として好ましい。 Specifically, the structural unit (II) is a structural unit derived from fumaric acid, maleic acid, maleic anhydride, etc., and at least a part thereof includes the structural unit (IIa) derived from fumaric acid.

(In the formula, R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, and B represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an alkanolamine. )
In the structural unit (II), when the acid (—COOH) and / or the acid salt (—COOM) is contained as the structural unit (IIa) derived from fumaric acid, these are also neutralized in the acid form. However, a partially neutralized or completely neutralized form is preferred as the product form.

  In the present invention, the content ratio of the structural unit (IIa) derived from fumaric acid is 50 to 100% by mass, preferably 60 to 100% by mass, more preferably 70 to 100% by mass with respect to the total mass of the structural unit (II). 100% by mass is preferable in terms of water reduction and slump retention.

（式中、Ｒ⁹、Ｒ¹⁰はそれぞれ独立して水素原子又は炭素原子数１乃至２２の炭化水素基
を表し、Ｒ¹¹、Ｒ¹²はそれぞれ独立して水素原子、炭素原子数１乃至２２の炭化水素基、−ＣＯＯＨ、−ＣＯＯＭ、−ＣＯＯＹを表し、但し、Ｒ¹¹及びＲ¹²のうち少なくとも一方は−ＣＯＯＹを表す。Ｍはアルカリ金属、アルカリ土類金属、アンモニウム、アルカノールアミンを表し、Ｙは炭素原子数１乃至２２の炭化水素基又は（ＡＯ）ｃ−Ｒ¹³を表し、ＡＯは炭素原子数２乃至４のアルキレンオキサイド基を表し、ｃはアルキレンオキサイドの平均付加モル数で１乃至２００の数を表し、Ｒ¹³は水素原子又は炭素原子数１乃至２２の炭化水素基を表す。） The structural unit (III) constituting the polycarboxylic acid polymer that is the cement dispersant of the present invention is represented by the following formula.

(In the formula, R ⁹ and R ¹⁰ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, and R ¹¹ and R ¹² each independently represent a hydrogen atom and 1 to 22 carbon atoms. Represents a hydrocarbon group, —COOH, —COOM, —COOY, wherein at least one of R ¹¹ and R ¹² represents —COOY, M represents an alkali metal, an alkaline earth metal, ammonium, or an alkanolamine; Represents a hydrocarbon group having 1 to 22 carbon atoms or (AO) c-R ¹³ , AO represents an alkylene oxide group having 2 to 4 carbon atoms, and c is an average added mole number of alkylene oxide of 1 to 200. R ¹³ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms.)

In the structural unit (III), when an acid (—COOH) and / or an acid salt (—COOM) is contained as R ¹¹ or R ¹² , these may be in an acid form or in a neutralized form. A summed or completely neutralized form is preferred as the product form.
In the structural unit (III), at least one of R ¹¹ and R ¹² is an ester (—COOY), specifically, Y is a partial ester or total ester having 1 to 22 carbon atoms, polyalkylene oxide Examples include partial esters or total esters of adducts, partial esters or total esters of alkoxypolyalkylene glycols, and the like. Alkylene oxides can be added individually or in a mixed manner. When two or more types of alkylene oxide are used, either block addition or random addition may be used.

The structural unit (III) specifically includes methoxypolyethylene glycol monofumarate, methoxypolypropylene glycol monofumarate, methoxypolyethylenepolypropyleneglycol monofumarate, methoxypolyethyleneglycol difumarate, methoxypolypropyleneglycol difumarate, methoxy Polyethylene polypropylene glycol difumarate, methoxypolyethylene glycol monomaleate, methoxypolypropylene glycol monomaleate, methoxypolyethylene polypropylene glycol monomaleate, methoxypolyethylene glycol dimaleate, methoxypolypropyleneglycol dimaleate, methoxypolyethylenepolypropyleneglycol dimaleate, methoxypolyethyleneglycolmonoa Relate, methoxy polypropylene glycol monoacrylate, methoxy polyethylene polypropylene glycol monoacrylate, methoxy polyethylene glycol monomethacrylate, methoxy polypropylene glycol monomethacrylate, a structural unit derived from such a methoxy polyethylene polypropylene glycol monomethacrylate.
Among the structural units (III), fumaric acid ester compounds, specifically, methoxypolyethylene glycol monofumarate, methoxypolypropylene glycol monofumarate, methoxypolyethylenepolypropyleneglycol monofumarate, methoxypolyethyleneglycol difumarate, methoxy Polypropylene glycol difumarate and methoxypolyethylene polypropylene glycol difumarate are preferably used in terms of water reduction and slump retention.

The structural unit (II) and the structural unit (III) are structural unit (II): structural unit (III) = 1 to 50% by mass: 99 to 50% by mass, preferably 1 to 40% by mass: It is desirable that it is 99-60 mass%, More preferably, it is 1-30 mass%: 99-70 mass%.
When the structural unit (III) derived from the unsaturated carboxylic acid ester is smaller than the above numerical range, slump and viscosity stability over time may not be obtained.

（式中、Ｚは二塩基酸とポリアルキレンポリアミンを縮合させたポリアミドポリアミン及び／又は該ポリアミドポリアミンの活性イミノ基、アミノ基、アミド残基１当量に対して炭素原子数２乃至４のアルキレンオキサイドを０．１乃至１０モル付加させたポリアミドポリアミン変性物が、アミド結合を介して主鎖の炭素原子と結合する基を表す。） [Structural unit (IV)]
In addition to the structural units (I) to (III), the polycarboxylic acid polymer as the cement dispersant of the present invention can also be configured to include a structural unit (IV) represented by the following formula.

(In the formula, Z is a polyamide polyamine obtained by condensing a dibasic acid and a polyalkylene polyamine and / or an alkylene oxide having 2 to 4 carbon atoms with respect to 1 equivalent of an active imino group, amino group or amide residue of the polyamide polyamine. Represents a group bonded to the carbon atom of the main chain through an amide bond.

  In the structural unit (IV), the dibasic acid constituting Z is an aliphatic saturated dibasic acid having 2 to 10 carbon atoms, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, Examples include pimelic acid, suberic acid, azelaic acid, sebacic acid, and the like. The polyalkylene polyamines constituting Z are ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, Or the mixture of the high molecular polyethylene polyamine which is a mixture containing many ethylene units and nitrogen atoms can be mentioned.

The structural unit (IV) is a polyamide polyamine which is a condensate of these dibasic acid and polyalkylene polyamine and / or the number of carbon atoms with respect to 1 equivalent of the active imino group, amino group and amide residue of the polyamide polyamine. This is a structural unit formed by modifying a polyamide polyamine modified with 0.1 to 10 moles of 2 to 4 alkylene oxide added via maleic anhydride, maleic acid, fumaric acid and an amide bond.
Since some of these polyamide polyamines or polyalkylene oxide-modified polyamide polyamines have a property of being basic in an aqueous solution, they may act as a neutralizing agent for the polycarboxylic acid polymer.

[Composition ratio of each structural unit]
In the polycarboxylic acid polymer composed of the structural unit (I) to the structural unit (III), the constituent ratio is as follows: structural unit (I): structural unit (II): structural unit (III) = 90 to 50 mass %: 1 to 10% by mass: 1 to 40% by mass, more preferably, structural unit (I): structural unit (II): structural unit (III) = 85 to 50% by mass: 2 to 8% by mass: 1
It is desirable to be in the range of 0 to 40% by mass.
In the polycarboxylic acid polymer comprising the structural unit (I) to the structural unit (IV), the structural unit (I): the structural unit (II): the structural unit (III): the structural unit (IV) = 90 to 50% by mass: 1 to 10% by mass: 1 to 40% by mass: 1 to 10% by mass, more preferably structural unit (I): structural unit (II): structural unit (III): structural unit (IV) = 85 It is desirable to be in the range of 50 to 50% by mass: 2 to 8% by mass: 10 to 40% by mass: 2 to 7% by mass. (However, the total of the structural unit (I) to the structural unit (III) or the structural unit (I) to the structural unit (IV) is 100% by mass.)
It should be noted that, in any of the above constituent ratios, it is desirable for the preferred implementation of the present invention that the structural unit (II): structural unit (III) = 1 to 60 mol%: 99 to 40 mol% is satisfied. .

[Other structural units (V) that can be contained]
In the above-mentioned polycarboxylic acid polymer, the structural unit (V) can be contained in addition to the structural units (I) to (IV).
Examples of the compound from which the other structural unit (V) that can be contained include (meth) acrylic acid (salt), (meth) allylsulfonic acid (salt), styrenesulfonic acid (salt), and alkyl (meth) acrylate. , Styrene, (meth) acrylamide and the like, and compounds exemplified as monomers for conventional polycarboxylic acid-based cement dispersants and compounds capable of forming a polymer with the structural units (I) to (IV). The type is not particularly limited. In particular, incorporation of a structural unit derived from an alkali hydrolyzable compound so as to impart slump retention to the polycarboxylic acid polymer is one of the means that can be easily conceived in combination with Japanese Patent No. 3780465. It is.
The structural ratio of the structural unit (V) is a range of the polycarboxylic acid polymer or the like (structural units (I) to (IV)): structural unit (V) = 100 to 70% by mass: 0 to 30% by mass. However, it is preferably in the range of 100% by mass.

[Polyamide polyamine and / or modified polyamide polyamine]
The cement dispersant of the present invention is a polyamide polyamine obtained by condensing a dibasic acid and a polyalkylene polyamine and / or an active imino group, amino group, and 1 equivalent of an amide residue in addition to the above polycarboxylic acid polymer. In view of improving the concrete viscosity, it is preferable to contain a modified polyamide polyamine obtained by adding 0.1 to 10 moles of an alkylene oxide having 2 to 4 carbon atoms.
The content ratio of these polyamide polyamine and / or polyamide polyamine modified product may be in the range of the above polycarboxylic acid polymer: polyamide polyamine and / or polyamide polyamine modified product = 98 to 90 mass%: 2 to 10 mass%. preferable.

The polyalkylene polyamines constituting the polyamide polyamine include ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, hexaethylene heptamine, or a high molecular polyethylene which is a mixture containing a large amount of ethylene units and nitrogen atoms. A mixture of polyamines, polymers of cyclic imines such as polyethyleneimine, polypropyleneimine, poly-3-methylpropylimine, poly-2-ethylpropylimine, polymers of unsaturated amines such as polyvinylamine and polyallylamine, etc. Can be mentioned. Furthermore, polyalkylene polyamines are cyclic imines such as ethyleneimine, propyleneimine, 3-methylpropylimine, 2-ethylpropylimine, unsaturated amides such as N-vinylacetamide, N-vinylformamide, N-vinylphthalimide, and unsaturated. It may be a copolymer of an imide and an unsaturated compound copolymerizable therewith. Examples of unsaturated compounds copolymerizable with cyclic imines, unsaturated amides, unsaturated imides, etc. include dimethylacrylamide, styrene, methyl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, styrene sulfonic acid and their salts, Cyclic sulfide compounds such as ethylene sulfide and propylene sulfide, cyclic ethers such as oxetane, mono- or bisalkyloxetane, mono- or bisalkylchloromethyloxetane, tetrahydrofuran, mono- or bisalkyltetrafluorofuran, 1,2-dioxofuran, trioxy Examples thereof include cyclic formals such as sofuran and N-substituted alkylimines such as N-methylethyleneimine.

Examples of the dibasic acid constituting the polyamide polyamine include fatty acids having 2 to 10 carbon atoms in total such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid. Group saturated dibasic acids.
Derivatives thereof can also be used as dibasic acids, for example, dibasic acid anhydrides (eg, anhydrides of the above dibasic acids), dibasic acid esters (eg, monomethyl esters, monoethyl esters, monobutyl esters of the above dibasic acids) , Monopropyl ester, dimethyl ester, diethyl ester, dibutyl ester, dipropyl ester, etc.), or dibasic acid dihalides (dichloride, dibromide, diiodide, etc. of the dibasic acid).

  The modified polyamide polyamine is a compound obtained by adding 0.1 to 10 moles of alkylene oxide having 2 to 4 carbon atoms to 1 equivalent of the active imino group, amino group, and amide residue of the polyamide polyamine. That is, examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and the like. These can be used alone or in combination. When two or more alkylene oxides are used, they are polymerized in a block shape. Alternatively, it may be polymerized randomly.

[Method for producing each structural unit and polycarboxylic acid polymer]
In obtaining the polycarboxylic acid polymer that is the cement dispersant of the present invention, the method for producing the polyalkylene glycol alkenyl ether compound from which the structural unit (I) is derived, and the polymerization method for obtaining the polycarboxylic acid polymer are: There is no particular limitation.
However, in the alkylene oxide addition reaction during the production of the polyalkylene glycol alkenyl ether compound, the polymerization active group (unsaturated group) does not lose its polymerization activity, does not transfer the position of the polymerization active group, and is a by-product. It needs to be manufactured with attention paid to reducing the diol content. In addition, the polyalkylene oxide adduct of alcohol having a polymerization active group can be used as a raw material for polymerization regardless of the presence or absence of a purification process after production.
In the method for producing a polycarboxylic acid polymer, the same polymer can be obtained by any of solvent polymerization, aqueous solution polymerization, continuous method, and batch method, but the solubility of the compound used for copolymerization In general, it is often carried out by aqueous solution polymerization.

  The structural unit (IV) is produced by condensing a dibasic acid and a polyamide polyamine in accordance with a usual amidation method, and further forming an amide group with maleic acid, fumaric acid, and maleic anhydride. If necessary, alkylene oxide A method of adding a polybasic acid, a polycondensate of a dibasic acid and a polyamide polyamine, or a method of forming an alkylene oxide-modified polyamide polyamine added with an alkylene oxide and grafting it to a polycarboxylic acid polymer, after forming a polyamide polyamine Examples thereof include a method of adding alkylene oxide to an aqueous polymer solution grafted to a polymer.

The finally obtained polycarboxylic acid polymer which is the cement dispersant of the present invention has a weight average molecular weight (gel permeation chromatography method (hereinafter referred to as “GPC method”), in terms of polyethylene glycol) of 10,000 to The range of 500,000 is appropriate, and if it is out of this range, the water reduction is remarkably reduced or the desired slump loss reduction effect cannot be obtained. More preferably, it is desirable that the weight average molecular weight is in the range of 10,000 to 100,000 to further exhibit water reduction. In addition, the molecular weight can be controlled by adjusting the type and / or amount of radical polymerization initiator used in aqueous solution polymerization, but the molecular weight distribution can also be controlled by using a chain transfer agent together. It is.
In the present invention, the “polymer” may be only the polymer itself, or includes the unreacted components generated in each polymerization step, alkylene oxide addition step, and other components including side reaction products. Alternatively, a polymer may be used.

[Cement admixture and additives that can be used in combination]
The cement dispersant of the present invention can be combined into a cement admixture by employing a suitable publicly known admixture according to various concrete production conditions. Specifically, cement dispersants other than the cement dispersant of the present invention, air entraining agents, setting retarders, accelerators, separation reducing agents, thickeners, antifoaming agents, shrinkage reducing agents, and the like.
In addition, the cement dispersant comprising the polycarboxylic acid polymer of the present invention is a form in which a publicly known admixture is blended in addition to the polycarboxylic acid polymer described above to form a cement admixture, or the above-mentioned at the time of concrete production. The polycarboxylic acid polymer and the publicly known admixture are added separately and finally mixed in concrete. The publicly known admixtures are exemplified below.

Generally, cement dispersants are appropriately combined and used according to concrete production conditions and performance requirements. The same applies to the cement dispersant of the present invention, which is used as a cement dispersant alone or as a main agent, but as a modification aid for a cement dispersant having a large slump loss, or has an initial water reduction. It can be used in combination as a high cement dispersant.
As well-known cement dispersants other than the present invention, in addition to the above-mentioned Patent Document 1, Japanese Patent Publication No. 59-18338, Japanese Patent No. 2628486, Japanese Patent No. 2774445, Japanese Patent No. 323002, and Japanese Patent No. 3336456. No. 3,780,456, and the like, and salts of polycarboxylic acid copolymers, naphthalene sulfonic acid formalin condensate, melamine sulfonic acid formalin condensate salt, lignin sulfonate, gluconate soda, sugar Also includes alcohol. The blending ratio of the cement dispersant of the present invention and the cement dispersant other than the present invention is 1:99 to 99: 1 mass%.

  Specific examples of the air entraining agent include <1> anionic air entraining agent, <2> nonionic air entraining agent, and <3> amphoteric air entraining agent. <1> As anionic air entraining agents, sulfuric acid ester salts of higher alcohols (or alkylene oxide adducts thereof), resin soap salts such as alkylbenzene sulfonates and rosin soaps, phosphoric acid of higher alcohols (or alkylene oxide adducts thereof) <2> Nonionic air entraining agents such as ester salts include alkylene glycol, alkylene oxide adducts of higher alcohols, esters of fatty acids and alkylene glycols, alkylene glycol adducts of sugar alcohols, etc. <3> anions and cations Examples of the amphoteric air entraining agent comprising alkylbetaine type, alkylamide betaine type, and amino acid type amphoteric activator type. The preferred amount of addition of the air entraining agent is 0.001 to 0.03% by mass with respect to the cement dispersant.

Examples of setting retarders include: <1> inorganic setting retarders: phosphates, silicofluorides, zinc oxide, zinc carbonate, zinc chloride, zinc monoxide, copper hydroxide, magnesia salts, borax, boron oxide <2> Organic coagulation retarders: phosphonic derivatives, saccharides and derivatives thereof, oxycarboxylates, lignin sulfonates, and more specific examples include phosphonic derivatives: aminotri (methylenephosphonic acid), aminotri (methylenephosphonic acid) ) Pentasodium salt, 1-hydroxyethylidene-1,1-diphosphonic acid, diethylenetriaminepenta (methylenephosphonic acid) and alkali metal salts, phosphonic acids of alkaline earth metal salts and derivatives thereof, saccharides: saccharose, maltose, raffinose, lactose Glucose, fructose, mannose, arabinose, key Loin, Abitosu, Repose, oxy carboxylic acid salt:
Examples thereof include gluconic acid, citric acid, glucoheptonic acid, malic acid, tartaric acid, alkali metal salts and alkaline earth metal salts thereof. A preferable addition amount of the setting retarder is 0.01 to 1.5% by mass with respect to a binding material such as cement.

  Examples of the accelerator include inorganic accelerators represented by calcium chloride, calcium nitrite and the like, and organic accelerators represented by alkanolamine and the like. A preferable addition amount of the accelerator is 0.5 to 5% by mass with respect to a binding material such as cement.

  Examples of thickeners / separation reducing agents include: <1> Cellulose-based water-soluble polymer: cellulose ether (MC, etc.), <2> Polyacrylamide-based water-soluble polymer: Polyacrylamide, <3> Biopolymer: Curdlan , Welan gum, <4> nonionic thickener: polyalkylene glycol fatty acid diester, polyalkylene glycol urethane condensate, and the like. A preferable blending ratio of the thickening / separation reducing agent is 0.01 to 0.5% by mass with respect to the concrete composition.

  Examples of antifoaming agents include nonionic defoaming agents such as aliphatic alcohol alkylene oxide adducts, fatty acid alkylene oxide adducts, alkylene oxide difatty acid esters, polyhydric alcohol alkylene oxide adducts, polyalkylene polyamine alkylene oxide adducts, etc. And silicone-based antifoaming agents using silicone oil as an emulsion, higher alcohols using higher alcohol as an emulsion, and mixtures containing these as main components. The preferred amount of addition of the antifoaming agent is 0.01 to 1% by mass with respect to the cement dispersant.

  Examples of shrinkage reducing agents include polyalkylene glycols, lower alcohol alkylene oxide adducts, and emulsions when these are oily. The preferred addition amount is 0.1 to 5% by mass with respect to the binding material such as cement. is there.

  Although the addition amount of the cement dispersant of the present invention varies depending on the blending conditions including the concrete material, it is generally added in an amount of about 0.05 to 5.0% by mass in terms of solid content with respect to the cement mass. In order to obtain water-reducing properties and slump flow retention, it is better that the amount added is larger. However, if the amount is too large, a setting delay is caused, and in some cases, a curing failure is caused. The method of use is the same as in the case of ordinary cement dispersants, and is added to the stock solution during concrete kneading or diluted in kneading water in advance. Alternatively, concrete or mortar may be added after kneading and kneaded uniformly again. Here, the components other than the cement dispersant are conventional concrete components, such as cement (for example, ordinary Portland cement, early strong Portland cement, low heat / moderate heat Portland cement or blast furnace cement), aggregate (that is, fine aggregate). And coarse aggregates), admixtures (for example, silica fume, calcium carbonate powder, blast furnace slag powder), expansion material and water. Further, as an admixture that can be added separately at the time of preparation with an admixture other than the cement dispersant of the present invention, the above-mentioned publicly known air entraining agent, setting retarder, accelerator, separation reducing agent, thickener, antifoaming agent, There are shrinkage reducing agents and the like, and these can be appropriately blended. The blending ratio of each of these components can be appropriately determined according to the type of the selected component and the purpose of use.

As described above, a polycarboxylic acid copolymer comprising a monomer mixture containing a polyalkylene glycol alkenyl ether monomer and an unsaturated carboxylic acid monomer has been conventionally used as a cement dispersant. Yes. In order to achieve a balance between the dispersibility immediately after blending and the long-term slump retention, it is proposed to use an acid and / or acid salt and an acid ester compound in the unsaturated carboxylic acid monomer. ing.
However, when using acrylic acid as the type of acid, when using methacrylic acid, when using maleic acid, etc., in each case, an acid compound suitable for balancing the initial dispersibility of cement and slump retention The mixing ratio of the acid ester compound is different. Conventionally, in the case where fumaric acid is used, such a blending ratio has not been studied in detail.
As a result of repeated studies on many polymers, the present inventors have found that a polycarboxylic acid composed of a specific reactive alcohol polyalkylene glycol, fumaric acid, and unsaturated carboxylic acid ester compounds such as fumaric acid ester and acrylic acid ester. In a cement dispersant comprising an acid polymer and a polycarboxylic acid polymer containing the polycarboxylic acid polymer and a polyamide polyamine and / or a polyalkylene oxide-modified polyamide polyamine as a structural unit, an unsaturated carboxylic acid ester compound More preferably, the use rate of fumaric acid is increased more than the use rate of fumaric acid, preferably 1 to 40% by weight of fumaric acid, and 99 to 60% by weight of unsaturated carboxylic acid ester compound. 1-30% by mass of fumaric acid, unsaturated carboxylic By the ester compound and 99 to 70 wt%, the conventional analogous compounds superior water reducing property (initial water reducing property), and have found that it has a slump retention performance (water reduction over time).
Considering the actual construction situation in particular, if the difference between the initial fluidity of the cement and the fluidity over time is large, the material separation problem that the cement liquefies and the aggregate separates, and the fluidity is lost. This causes a problem that the filling property is lowered. In other words, it will cause a serious quality problem for the concrete after hardening, so the small difference between the initial water reduction and the water reduction over time in the cement dispersant is a very important point in actual use. It has become.
Furthermore, it has been found that the cement dispersant of the present invention has an effect that the viscosity of concrete is low and the setting delay is also eliminated.

It has not yet been elucidated how the above-mentioned excellent effects can be obtained. As one of the assumptions, a combination of the above structural units, particularly maleic acid and / or derivatives thereof, which has been widely used as unsaturated carboxylic acid compounds in the past, is changed to a structure using structural units derived from fumaric acid. Fumaric acid itself functions as an acid group with a high water-reducing effect due to the change in the arrangement of acid groups when incorporated into the polymer and the strength of acidity, and this contributes to the improvement of cement dispersion performance. I think that it is.
Also, from the viewpoint of the monomer that forms the polymer, the fumaric acid and the fumaric acid ester can be used together to improve the fumaric acid dissolution state in the polymerization system, and thus the polymerization rate of the polycarboxylic acid polymer is increased. The unreacted monomer can be decreased as compared with the case where maleic acid is used, which is considered to lead to an improvement in water reduction. In addition, the ability to control molecular weight due to moderate polymerizability works, and this also suppresses the formation of unnecessary high molecular weight polymers, and thus the molecular weight distribution of the polymer is narrowed. It is considered that the water-reducing property can be expressed by the addition amount, and that the difference in water-reducing property with time is small, so that it contributes to the effect that stable fluidity can be obtained.
In addition, the rate of hydrolysis under alkali in the cement and the ability to adsorb the exposed acid groups to the cement are also considered to be related to the effects of the present invention. By examining the blending ratio, it is considered that the synergistic effect of these was derived and the cement dispersion performance was improved.
In addition, although it has been found that a suitable amount of air can be stably introduced into fresh concrete by blending polyamide polyamine, the relationship between the presence or absence of blending of polyamide polyamine and the stability of air volume has not been elucidated. . However, it seems that the effect of stably introducing an appropriate amount of air contributes to the effect of reducing the viscosity of concrete.

Next, based on an Example, this invention is demonstrated in detail. In addition, this invention is obtained by the said manufacturing method, and is not limited to this Example.
In addition, unless otherwise indicated,% shown below represents mass%.

[Production Example A1 (Production of EO-added polyamide polyamine)]
Into a reaction vessel equipped with a stirrer equipped with a nitrogen introduction tube, a thermometer, and a test tube with a condenser, 199 g of polyalkylene polyamine (product name: Polyate) and 68 g of adipic acid were charged, stirred while introducing nitrogen, and then the temperature was changed to 160 The temperature was raised to 0 ° C. The reaction was continued for 8 hours, and the reaction was terminated when the acid value reached 10. The amount of reaction dehydration was 17 g. Next, after adding 339 g of water and cooling to 60 ° C. as an aqueous solution, 89 g of ethylene oxide was added over 4 hours at the same temperature, followed by aging for 1 hour, and 678 g of an aqueous solution of EO-added polyamide polyamine A1 (solid content concentration: 50%) )

[Production Example A2 (Production of polyamide polyamine)]
Into a reaction vessel equipped with a stirrer equipped with a nitrogen introduction tube, a thermometer, and a water sample tube with a condenser, 199 g of polyalkylene polyamine (product name: Polyate) and 68 g of adipic acid were charged and stirred while introducing nitrogen. The temperature was raised to 0 ° C. The reaction was continued for 8 hours, and the reaction was terminated when the acid value reached 10. The amount of reaction dehydration was 17 g. Next, 250 g of water was added and cooled to 60 ° C. as an aqueous solution to obtain 500 g of an aqueous solution of polyamide polyamine A2 (solid content concentration: 50%).

[Production Example B1 (Production of polycarboxylic acid polymer)]
374 g of 3-methyl-3-buten-1-ol 50EO2PO adduct (block adduct, MBO50EO2PO), 260 g of ion-exchanged water, 12.3 g of fumaric acid, maleic anhydride in a stainless steel autoclave equipped with a nitrogen introduction tube, a stirrer and a thermometer 5.2 g and 91 g of methoxypolyethylene glycol difumarate (compound D1, molecular weight of about 400) were charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 22.5 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Subsequently, 27.1 g of polyamide polyamine A1 aqueous solution and 201 g of ion-exchanged water were added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C., neutralized with 6.5 g of 48% sodium hydroxide aqueous solution, and 1000 g of an aqueous solution of polycarboxylic acid polymer B1 (solid content concentration: 50.1%, weight average molecular weight: 24,000). )

[Production Example B2 (Production of polycarboxylic acid polymer)]
374 g of 3-methyl-3-buten-1-ol 50EO2PO adduct (block adduct), 260 g of ion-exchanged water, 12.3 g of fumaric acid, maleic anhydride 5. 2 g and 90 g of methoxypolyethylene glycol dimaleate (compound D4, molecular weight of about 400) were charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 22.5 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Subsequently, 27.1 g of polyamide polyamine A1 aqueous solution and 201 g of ion-exchanged water were added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C., neutralized with 6.5 g of 48% sodium hydroxide aqueous solution, and 999 g of an aqueous solution of polycarboxylic acid polymer B2 (solid content concentration: 50.1%, weight average molecular weight: 25,000). )

[Production Example B3 (Production of polycarboxylic acid polymer)]
In a stainless steel autoclave with a nitrogen introduction tube, a stirrer, and a thermometer, 334 g of 3-methyl-3-buten-1-ol 50EO adduct (MBO50EO), 232 g of ion-exchanged water, 23.1 g of fumaric acid, 4.9 g of maleic anhydride and 119 g of methoxypolyethylene glycol dimaleate (Compound D5, molecular weight of about 900) was charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 22.4 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Next, 27.1 g of an aqueous polyamide polyamine A1 solution and 228 g of ion-exchanged water were added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C., neutralized with 10.4 g of 48% aqueous sodium hydroxide solution, and 1001 g of an aqueous solution of polycarboxylic acid polymer B3 (solid content concentration: 5
0.0%, weight average molecular weight: 26,000).

[Production Example B4 (Production of polycarboxylic acid polymer)]
368 g of 3-methyl-3-buten-1-ol 50EO adduct, 256 g of ion-exchanged water, 12.7 g of fumaric acid, 5.4 g of maleic anhydride and methoxypolyethylene glycol in a stainless steel autoclave with a nitrogen inlet tube, a stirrer and a thermometer 94 g of dimaleate (Compound D4, molecular weight of about 400) was charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 22.4 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Subsequently, 27.1 g of polyamide polyamine A1 aqueous solution and 208 g of ion-exchanged water were added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C., neutralized with 6.8 g of 48% sodium hydroxide aqueous solution, and 1000 g of an aqueous solution of polycarboxylic acid polymer B4 (solid content concentration: 49.8%, weight average molecular weight: 30,000). )

[Production Example B5 (Production of polycarboxylic acid polymer)]
362 g of 3-methyl-3-buten-1-ol 50EO adduct, 252 g of ion-exchanged water, 24.9 g of fumaric acid and methoxypolypropylene glycol difumarate (compound D3, A molecular weight of about 600) 92 g was charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 22.4 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Subsequently, 27.1 g of polyamidepolyamine A2 aqueous solution and 210 g of ion-exchanged water were added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C., neutralized with 9.4 g of 48% sodium hydroxide aqueous solution, and 1000 g of an aqueous solution of polycarboxylic acid polymer B5 (solid content concentration: 49.8%, weight average molecular weight: 24,000). )

[Production Example B6 (Production of polycarboxylic acid polymer)]
375 g of 3-methyl-3-buten-1-ol 50EO adduct, 260 g of ion-exchanged water, 12.9 g of fumaric acid, 5.5 g of maleic anhydride, and methoxypolyethylene in a stainless steel autoclave with a nitrogen inlet tube, a stirrer, and a thermometer 85 g of glycol monoacrylate (compound D6, molecular weight of about 250) was charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 22.3 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Subsequently, 27.1 g of polyamide polyamine A2 aqueous solution and 205 g of ion-exchanged water were added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C., neutralized with 6.9 g of 48% sodium hydroxide aqueous solution, and 1000 g of an aqueous solution of polycarboxylic acid polymer B6 (solid content concentration: 49.7%, weight average molecular weight: 30,000). )

[Production Example B7 (Production of polycarboxylic acid polymer)]
A stainless steel autoclave with a nitrogen introduction tube, a stirrer, and a thermometer, 330 g of polyoxyalkylene monoallyl monomethyl ether (methyl ether of allyl alcohol 30EO adduct: Allyl30EO-OMe), 339 g of ion-exchanged water, 22.5 g of fumaric acid, and methoxypolyethylene 153 g of glycol monofumarate (compound D2, molecular weight of about 1100) was charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 23.6 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Next, 132 g of ion-exchanged water was added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C. to obtain 1000 g of an aqueous solution of polycarboxylic acid polymer B7 (solid content concentration: 50.9%, weight average molecular weight: 18,000).

[Production Example B8 (Production of polycarboxylic acid polymer)]
A stainless steel autoclave with a nitrogen inlet tube, a stirrer, and a thermometer, 351 g of polyoxyalkylene monoallyl ether (allyl alcohol 28EO2PO adduct: Allyl28EO2PO), 244 g of ion-exchanged water, 26.3 g of fumaric acid, and methoxypolyethyleneglycol difumarate (compound 129 g of D1, molecular weight of about 400) was charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 23.6 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Next, 226 g of ion-exchanged water was added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C. to obtain 1000 g of an aqueous solution of polycarboxylic acid polymer B8 (solid content concentration: 51.0%, weight average molecular weight: 17,000).

[Production Example C1]
In a stainless steel autoclave equipped with a nitrogen introduction tube, a stirrer, and a thermometer, 402 g of 3-methyl-3-buten-1-ol 50EO2PO adduct (block adduct), 286 g of ion-exchanged water, 6.62 g of maleic anhydride, 59.fumaric acid 59. 6 g was charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 22.2 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Next, 26.7 g of polyamide polyamine A1 aqueous solution and 170 g of ion-exchanged water were added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C., neutralized with 25.0 g of 48% aqueous sodium hydroxide solution, and 998 g of an aqueous solution of polycarboxylic acid polymer C1 of Comparative Example (solid content concentration: 49.6%, weight average molecular weight: 26,000).

[Production Example C2]
A stainless steel autoclave equipped with a nitrogen inlet tube, a stirrer, and a thermometer was charged with 413 g of 3-methyl-3-buten-1-ol 50EO adduct, 324 g of ion-exchanged water, and 85.3 g of maleic anhydride. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 11.4 g of a 2,2′-azobis-2-methylpropionamidine hydrochloride 15% aqueous solution was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C. and aging was performed for 1 hour. Add 166 g of ion-exchanged water and cool to 50 ° C. to obtain 1,000 g of an aqueous solution of the polycarboxylic acid polymer C2 of Comparative Example (solid content concentration: 50.0%, weight average molecular weight: 40,000). It was.

[Production Example C3]
A four-necked flask equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube, and a reflux condenser was charged with 395 g of water, and the inside of the flask was purged with nitrogen while stirring and heated to 80 ° C. in a nitrogen atmosphere. Next, a mixture of 250 g of methoxypolyethylene glycol methacrylate (ethylene oxide average addition mole number 5 mol, MPG5), 62.5 g of methacrylic acid, 9.4 g of 10% aqueous solution of thioglycolic acid, and 9.4 g of sodium persulfate 10% solution is taken over 120 minutes. Then, the mixture was stirred at the same temperature for 4 hours to complete the polymerization reaction. After cooling the reaction solution to 50 ° C., neutralization was performed using 48% caustic soda to pH 7, and 837 g of an aqueous solution of the polycarboxylic acid polymer C2 of Comparative Example (solid content concentration: 40.3%, weight average) Molecular weight: 26,000).

[Production Example C4]
366 g of 3-methyl-3-buten-1-ol 50EO2PO adduct (block adduct), 312 g of ion-exchanged water, 18.1 g of maleic anhydride and methoxypolyethylene glycol in a stainless steel autoclave equipped with a nitrogen introduction tube, a stirrer and a thermometer Dimalate (Compound D4, molecular weight about 400) was charged with stirring. After sufficiently purging with nitrogen and raising the temperature to 60 ° C., 22.4 g of a 14% aqueous solution of sodium persulfate was charged and reacted for 6 hours while maintaining the same temperature. After completion of the reaction, the temperature was raised to 80 ° C., and stirring was continued for 1 hour. Subsequently, 26.7 g of polyamide polyamine A1 aqueous solution and 150 g of ion-exchanged water were added, and the mixture was further stirred for 1 hour. The polymerization solution was cooled to 50 ° C., neutralized with 6.8 g of 48% sodium hydroxide aqueous solution, and 1,000 g of aqueous solution of polycarboxylic acid polymer C4 of comparative example (solid content concentration: 50.0%, weight average) Molecular weight: 32,000) was obtained.

[Examples 1 to 8, Comparative Examples 1 to 5: Fresh concrete test 1]
Using the polycarboxylic acid polymers B1 to B8 and the polycarboxylic acid polymers C1 to C4 obtained in the above production examples, a fresh concrete test was performed with the concrete composition shown in Table 3 below.
For mixing concrete, a 55 liter forced biaxial mixer was used, and each polycarboxylic acid polymer (B1 to B8, C1 to C3) was added in advance to coarse aggregate, cement, and fine aggregate, and prepared water was added. In addition, it was mixed for 90 seconds. Then, immediately after the concrete is discharged, the fresh concrete test (slump test JIS A 1101 (measures the spread of fresh concrete as a flow value), the air amount JIS A 1128, and the setting test (until the penetration resistance reaches 3.5 N / mm ²⁾ (Corresponding to the initial setting time) and concrete viscosity evaluation). The concrete viscosity evaluation was judged by sensory evaluation (lightness of kneading feeling) because a unified evaluation method was not established in the industry.

[Fresh concrete test results]
Table 4 shows the concrete composition, and Tables 5 and 6 show the results of the fresh concrete test.

  As shown in Table 5 and Table 6 above, Examples 1 to 8 have excellent stability over time with no significant fluctuations in slump, flow value, and air amount even when 1 hour has passed immediately after kneading. As a result, it was confirmed that the viscosity was kept good and the concrete was kept in good condition for a long time.

On the other hand, in Comparative Example 1 using the polymer C1 which contains only the structural unit derived from the fumaric acid compound as the unsaturated carboxylic acid and does not contain the structural unit derived from the unsaturated carboxylic acid ester compound, it is good immediately after kneading. Although the water-reducing property and viscosity were exhibited, the result that the performance as a dispersant could not be maintained after 30 minutes was obtained. Further, in Comparative Example 2 in which the addition amount was increased, the dispersibility became too high, resulting in material separation.
Furthermore, Comparative Example 3 using the polymer C2 which does not contain any structural unit derived from a fumaric acid compound or an unsaturated carboxylic acid ester compound, and Comparative Example 4 using the polymer C3 are excellent in initial water reduction. However, the performance deteriorates with the passage of time.
As a result, the performance as a dispersant could not be maintained after 0 minutes.
Moreover, although the structural unit derived from the unsaturated carboxylic acid ester compound is included, in the comparative example using the polymer C4 which does not include the structural unit derived from the fumaric acid compound, the result that the water reducing property decreases with the passage of time. Obtained.

  In the concrete viscosity evaluation in the present example, “freshness” representing the state of concrete represents a state in which the surface water does not float and is appropriately wet. If it gets too wet, the surface water will float and aggregates and breathing are likely to occur. “Gasatsu” indicates a state of insufficient wettability. This is due to insufficient fluidity when subjected to vibration, or due to insufficient filling (junction (a void formed by mainly coarse aggregate concentrated on the concrete surface or inside). This shows that many non-uniform portions are likely to occur. “Handling is light” means a feeling that is lighter than the measured air volume, light kneadability, low resistance when pumping, a sense of unity of the material, and high material separation resistance It means that there is.

  As described above, the cement dispersant of the present invention is a fresh concrete that exhibits excellent water reduction when applied to concrete, maintains a low viscosity, has a light feeling of kneading, and is excellent in fluidity. It is also possible to improve the performance that is important at the time of concrete construction, such as excellent stability over time that such excellent performance can be maintained well even after 1 hour from just after kneading. Results were obtained.

Claims (4)

Cement dispersant comprising a polycarboxylic acid polymer comprising a structural unit derived from a polyalkylene glycol alkenyl ether compound, a structural unit derived from an unsaturated carboxylic acid compound, and a structural unit derived from an unsaturated carboxylic ester compound In
The content ratio of the structural unit derived from fumaric acid is 50 to 100% by mass with respect to the total mass of the structural unit derived from the unsaturated carboxylic acid compound, and
A structural unit derived from the unsaturated carboxylic acid compound: a structural unit derived from the unsaturated carboxylic acid ester compound = 1 to 50% by mass: 99 to 50% by mass. The polycarboxylic acid polymer comprises the following structural unit (I), structural unit (II) and structural unit (III),
The content ratio of the structural unit (IIa) derived from the following fumaric acid is 50 to 100% by mass with respect to the total mass of the structural unit (II) below, and
The cement dispersant according to claim 1, wherein the following structural unit (II): structural unit (III) is 1 to 50% by mass: 99 to 50% by mass.

(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, X represents — (CH ₂ ) bO—, and AO represents A C represents an alkylene oxide group having 2 to 4 carbon atoms, a represents an average added mole number of alkylene oxide and represents a number of 1 to 200, and b represents an integer of 1 to 20.

(Wherein R ^{5 to} R ⁸ each independently represents a hydrogen atom, a hydrocarbon group having 1 to 22 carbon atoms, —COOH, —COOM, provided that at least two of R ^{5 to} R ⁸ are —COOH. And / or —COOM, and two of R ^{5 to} R ⁸ may be combined to form an acid anhydride, where M is an alkali metal, alkaline earth metal, ammonium, alkanol. Represents amine.)

(In the formula, R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, and B represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or an alkanolamine. )

(In the formula, R ⁹ and R ¹⁰ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, and R ¹¹ and R ¹² each independently represent a hydrogen atom and 1 to 22 carbon atoms. Represents a hydrocarbon group, —COOH, —COOM, —COOY, wherein at least one of R ¹¹ and R ¹² represents —COOY, M represents an alkali metal, an alkaline earth metal, ammonium, or an alkanolamine; Represents a hydrocarbon group having 1 to 22 carbon atoms or (AO) c-R ¹³ , AO represents an alkylene oxide group having 2 to 4 carbon atoms, and c is an average added mole number of alkylene oxide of 1 to 200. R ¹³ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms.) In addition to the structural unit (I), the structural unit (II), and the structural unit (III), the polycarboxylic acid polymer further includes the following structural unit (IV), The cement dispersant according to claim 2.

(In the formula, Z is a polyamide polyamine obtained by condensing a dibasic acid and a polyalkylene polyamine and / or an alkylene oxide having 2 to 4 carbon atoms with respect to 1 equivalent of an active imino group, amino group or amide residue of the polyamide polyamine. Represents a group bonded to the carbon atom of the main chain through an amide bond. In addition to the polycarboxylic acid polymer according to any one of claims 1 to 3, a polyamide polyamine obtained by condensing a dibasic acid and a polyalkylene polyamine and / or an active imino group, an amino group of the polyamide polyamine, A cement dispersant comprising a modified polyamide polyamine obtained by adding 0.1 to 10 moles of an alkylene oxide having 2 to 4 carbon atoms to 1 equivalent of an amide residue.