JPH11268939A - Cement admixture and cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cement admixture capable of decreasing slump loss at a high temperature, and increase of the adding amount at a low temperature, and having small temperature dependence of water-reducing properties by using a copolymer salt obtained by neutralizing a copolymer containing an oxyalkylene group with an alkaline material as an essential component. SOLUTION: This cement admixture comprises a salt of a copolymer obtained by neutralizing the copolymer having 1-98 wt.% structural unit of formula I, 1-98 wt.% structural unit of formula II [R<1> O and R<3> O are each a mixture of one or more kinds of 2-18C oxyalkylenes with the proviso that in a case of two or more kinds, the oxyalkylenes can be added to each other to form a block or random shape; (m) and (n) are each an average number of addition mols of oxyalkylene and >=10; R<2> and R<4> are each a 1-30C aliphatic or alicyclic hydrocarbon] and 1-45 wt.% structural unit of formula III R<5> to R<7> are each 11, methyl or (CH2 )p COOX [X is H, a monovalent metal, a divalent metal, ammonium or an organic amine; (p) is 0-2]; with the proviso that when two COOX groups are present, the COOX groups can foam anhydride} with an alkaline material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a cement admixture and a cement composition. More specifically, the present invention relates to a cement admixture and a cement composition which are excellent in fluidity retention at high temperature of cement paste, mortar or concrete and exhibit excellent fluidity even at low temperature.

[0002]

2. Description of the Related Art Since the early deterioration of concrete structures became a social problem in 1981, there has been a strong demand for reducing the amount of water in concrete to improve its workability and durability. 2. Description of the Related Art Technological innovations are being actively made on cement admixtures that greatly affect the quality and performance of products.

[0003] As a conventional method, an AE agent or AE
Flowability with added water reducing agent (hereinafter referred to as "slump")
A low-concentration ready-mixed concrete is manufactured in a plant, transported by a ready-mixed concrete truck to a casting site, and then fluidized by adding a fluidizing agent thereto to increase slump to a predetermined value. However, this method involves noise and environmental problems of exhaust gas generated when mixing and mixing a fluidizing agent to concrete in a ready-mixed concrete vehicle, responsibility for the quality of the obtained fluidized concrete, fluidized concrete. Remarkable decrease in slump over time (hereinafter "slump loss")
That. ), Etc.

[0004] Therefore, the development of a so-called high-performance AE water reducing agent that can be added in a raw plant is being vigorously carried out. However, under severe operating conditions such as transporting the obtained ready-mixed concrete to a remote place in summer, slump loss may not be sufficiently suppressed at present. On the other hand, in winter when the temperature decreases, the water-reducing performance decreases, and the amount of the water-reducing agent added to obtain a predetermined fluidity increases, which is problematic in terms of concrete quality control.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cement admixture and a cement composition which have a small slump loss at a high temperature and a small increase in the amount of addition at a low temperature and have a small temperature dependency of water reducing performance. Is to provide.

[0006]

Conventionally, a cement admixture containing a copolymer obtained by copolymerizing a polyalkylene glycol ester of (meth) acrylic acid and an unsaturated carboxylic acid has been disclosed in JP-A-8-268741, JP-A-8-05
No. 3522, JP-A-7-247150, JP-A-6-092703 and JP-A-6-144906. JP-A-9-040446 discloses a cement admixture containing two kinds of copolymers obtained by copolymerizing (meth) acrylic acid polyalkylene glycol-based ester and (meth) acrylic acid.

[0007] The cement admixtures disclosed in these publications are all aimed at reducing the amount of water and suppressing slump loss. However, it is not intended to reduce the temperature dependency of the water reducing performance, that is, to reduce the amount of addition in the water. The present inventor has conducted intensive studies in order to solve the above problems. Then, as a polyalkylene glycol-based ester of (meth) acrylic acid, the average addition mole number of the oxyalkylene group constituting the polyalkylene glycol chain is 10 or more, and an aliphatic or fatty acid having 1 to 30 carbon atoms at its terminal. For the first time, when a specific plurality of monomers having a cyclic hydrocarbon group is used and a monomer component having an unsaturated carboxylic acid content of 45% by weight or less is polymerized to obtain a copolymer, The present inventors have found that the above-mentioned objects can be achieved, and have completed the present invention.

That is, the cement admixture according to the present invention comprises a structural unit (I) represented by the following general formula (1) and a structural unit (II) represented by the following general formula (2) as essential components. A copolymer which is contained as a structural unit and may further contain a structural unit (III) represented by the following general formula (3), and the content of the structural unit (III) is 45% by weight or less based on the whole The essential component is (A) and / or a copolymer salt (B) obtained by further neutralizing the copolymer (A) with an alkaline substance.

[0009]

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[0010]

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(Wherein, R ¹ O and R ³ O represent one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms, and in the case of two or more, they are added in a block form.) M and n
Is the average number of moles of oxyalkylene group added, and 10
The above positive numbers are represented, and R ² and R ⁴ have 1 to 1 carbon atoms.
Represents 30 aliphatic or alicyclic hydrocarbon groups. )

[0012]

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(Wherein, R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom, a methyl group or (CH ₂ ) _p CO ₂ )
X represents an OX group, and X represents a hydrogen atom, a monovalent metal, a divalent metal,
Represents an ammonium group or an organic amine group;
Represents an integer of 2, and when two COOX groups are present,
An anhydride may be formed. Another cement admixture according to the present invention contains, as essential components, a monomer (a) represented by the following general formula (4) and a monomer (b) represented by the following general formula (5). , An unsaturated carboxylic acid monomer (c) may be further contained, and the content of the unsaturated carboxylic acid monomer (c) is not more than 45% by weight of The copolymer (C) obtained by polymerization and / or the copolymer salt (D) obtained by further neutralizing the copolymer (C) with an alkaline substance are used as essential components.

[0014]

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[0015]

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(Wherein, R ¹ O and R ³ O represent one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms, and in the case of two or more, they are added in a block form.) M and n
Is the average number of moles of oxyalkylene group added, and 10
The above positive numbers are represented, and R ² and R ⁴ have 1 to 1 carbon atoms.
Represents 30 aliphatic or alicyclic hydrocarbon groups. The cement composition according to the present invention contains cement, the above cement admixture, and water as essential components.

On the other hand, the copolymer disclosed in JP-A-8-268741 has a short polyalkylene glycol chain, and the copolymer disclosed in JP-A-8-053522 has a large amount of unsaturated carboxylic acid and a hydrophobic monomer. The copolymer of JP-A-6-144906 is an aromatic group at the end of the polyalkylene glycol chain, so that the copolymer can suppress slump loss at high temperatures. ,
It is not possible to simultaneously reduce the amount of addition at a low temperature. Also, JP-A-7-247150, JP-A-6-247150
The copolymers disclosed in JP-A-0927703 and JP-A-9-040446 each have a hydroxyl group at the terminal of the polyalkylene glycol chain, and therefore are easily gelled, and are difficult to produce industrially. Assuming that these copolymers could be produced in a laboratory, even when used as a cement admixture, it is necessary to add a large amount of a chain transfer agent for preventing gelation, and the water reducing performance is significantly reduced. On the other hand, in the present invention, no gelation occurs because the terminal of the polyalkylene glycol chain is an aliphatic or alicyclic hydrocarbon group.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a cement admixture and a cement composition according to the present invention will be described in detail. [Cement admixture] The cement admixture of the present invention essentially comprises a copolymer (A) and / or a copolymer salt (B) obtained by further neutralizing the copolymer (A) with an alkaline substance. Ingredients.

The copolymer (A) contains the structural unit (I) represented by the general formula (1) and the structural unit (II) represented by the general formula (2) as essential structural units. It is a copolymer that may contain the structural unit (III) represented by the formula (3). The copolymer (A) preferably further contains a structural unit (III) represented by the general formula (3) as an essential structural unit, and a structural unit (IV) derived from a monomer (d) described below. May be included.

The ratio of each structural unit constituting the copolymer (A) is such that the structural unit (III) is 45% of the whole copolymer (A).
Wt% or less (preferably 40 wt% or less, more preferably 35 wt% or less, even more preferably 30 wt% or less,
Particularly preferably 25% by weight or less, most preferably 2% by weight.
0% by weight or less), there is no particular limitation, and the structural unit (I) / the structural unit (II) / the structural unit (III) / the structural unit (IV) = 1 to 98/1 to 98/1 to 45 / 0-7
The range of 0 (% by weight) is appropriate, but the structural unit (I) /
Structural unit (II) / Structural unit (III) / Structural unit (I
V) = 5 to 93/5 to 93/2 to 40/0 to 50 (% by weight) is preferable, and the structural unit (I) / the structural unit (I
I) / Structural unit (III) / Structural unit (IV) = 5-8
The range of 7/10 to 92/3 to 35/0 to 40 (% by weight) is more preferable, and the structural unit (I) / the structural unit (II) /
Structural unit (III) / Structural unit (IV) = 5 to 81/1
The range of 5 to 91/4 to 30/0 to 30 (% by weight) is more preferable, and the structural unit (I) / the structural unit (II) / the structural unit (III) / the structural unit (IV) = 10 to 76/20.
The range of from 86/4 to 25/0 to 30 (% by weight) is particularly preferable, and the structural unit (I) / the structural unit (II) / the structural unit (III) / the structural unit (IV) = 10 to 76/20.
The most preferred range is from 86/4 to 20/0 to 30 (% by weight). If the ratio is out of this range, the desired admixture with excellent performance will not be obtained. In particular, the structural unit (II
If I) exceeds 45% by weight, slump loss and curing retardation at high temperatures become remarkable, which is not preferable.

The copolymer (A) includes, for example, a monomer (for example, a monomer (a) described later) that provides the structural unit (I) and a monomer (for example, a monomer that provides the structural unit (II)). Monomer (b)) as an essential component, and copolymerizing a monomer component which may further contain a monomer (for example, a monomer (c) described below) to give the structural unit (III). Can be manufactured. The monomer component may further include a monomer that provides the structural unit (IV) (for example, a monomer (d) described below).

The copolymer (A) has at least one carboxyl group of a copolymer obtained by copolymerizing a monomer component containing acrylic acid and methacrylic acid as essential components.
It may be produced by directly esterifying an alkoxypolyalkylene glycol to a part. Another cement admixture of the present invention comprises a copolymer (C) and / or a copolymer salt (D) obtained by further neutralizing the copolymer (C) with an alkaline substance as an essential component. .

The copolymer (C) contains, as essential components, a monomer (a) represented by the aforementioned general formula (4) and a monomer (b) represented by the aforementioned general formula (5), It is a copolymer obtained by copolymerizing a monomer component which may further contain an unsaturated carboxylic acid monomer (c) described below. This monomer component can further include, as a copolymerization component, a monomer (d) copolymerizable with these monomers in addition to the monomers (a), (b), and (c). .

General formulas (1), (2), (4) and (5)
In the formula, R ¹ O and R ³ O represent one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms;
In the case of more than one kind, they may be added in a block shape or in a random shape. m and n are the average number of added moles of the oxyalkylene group, and represent a positive number of 10 or more;
R ² and R ⁴ represent an aliphatic or alicyclic hydrocarbon group having 1 to 30 carbon atoms.

R ² and R ⁴ are an aliphatic or alicyclic hydrocarbon group having 1 to 30 carbon atoms, but when a monomer which is a hydrogen atom is used in place of the hydrocarbon group, a It is not preferable because a structure is formed and gelation easily occurs, and a polymerization reaction becomes difficult. The monomer (a) represented by the general formula (4) used in the present invention includes methanol, ethanol,
2-propanol, 1-butanol, octanol, 2
-Carbon atoms such as saturated aliphatic alcohols having 1 to 30 carbon atoms such as ethyl-1-hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol and stearyl alcohol, allyl alcohol, methallyl alcohol, crotyl alcohol and oleyl alcohol Number 2-3
Alkoxy polyalkylene glycols obtained by adding alkylene oxides having 2 to 18 carbon atoms to any of alicyclic alcohols having 3 to 30 carbon atoms such as 0 unsaturated aliphatic alcohols and cyclohexanol And an ester compound of acrylic acid.

Specific examples of the monomer (a) include methoxy polyethylene glycol monoacrylate, ethoxy polyethylene glycol monoacrylate, 1-propoxy polyethylene glycol monoacrylate, 2-propoxy polyethylene glycol monoacrylate,
Butoxy polyethylene glycol monoacrylate, 2
-Butoxy polyethylene glycol monoacrylate,
2-methyl-1-propoxy polyethylene glycol monoacrylate, 2-methyl-2-propoxy polyethylene glycol monoacrylate, cyclohexoxy polyethylene glycol monoacrylate, 1-octoxy polyethylene glycol monoacrylate, 2-ethyl-1-hexanoxy polyethylene Glycol monoacrylate, nonylalkoxy polyethylene glycol monoacrylate, lauryl alkoxy polyethylene glycol monoacrylate, cetyl alkoxy polyethylene glycol monoacrylate, stearyl alkoxy polyethylene glycol monoacrylate, esterified product of allyl alcohol and acrylic acid with ethylene oxide added, and ethylene oxide added Methallyl alcohol and Various alkoxypolyethylene glycol monoacrylates such as esterified products with luic acid, and esterified products of crotyl alcohol and acrylic acid with ethylene oxide added; methoxy polypropylene glycol monoacrylate, ethoxy polypropylene glycol monoacrylate, 1-propoxy polypropylene glycol monoacrylate Acrylate, 2-propoxy polypropylene glycol monoacrylate, 1-butoxy polypropylene glycol monoacrylate, 2-butoxy polypropylene glycol monoacrylate, 2-methyl-1-propoxy polypropylene glycol monoacrylate, 2-methyl-2-propoxy polypropylene glycol monoacrylate, Cyclohexoxy polypropylene glycol monoacryle G, 1-octoxy polypropylene glycol monoacrylate, 2-ethyl-1-hexanoxy polypropylene glycol monoacrylate, nonylalkoxy polypropylene glycol monoacrylate, lauryl alkoxy polypropylene glycol monoacrylate, cetyl alkoxy polypropylene glycol monoacrylate, stearyl alkoxy polypropylene glycol Monoacrylate, esterified product of allyl alcohol and acrylic acid to which propylene oxide is added, esterified product of methallyl alcohol to which propylene oxide is added and acrylic acid, and crotyl alcohol and acrylic acid to which propylene oxide is added Various alkoxy polypropylene glycol monoacrylates such as esterified products; Cipolybutylene glycol monoacrylate, ethoxy polybutylene glycol monoacrylate, 1-propoxy polybutylene glycol monoacrylate, 2-
Propoxypolybutylene glycol monoacrylate,
1-butoxypolybutylene glycol monoacrylate, 2-butoxypolybutylene glycol monoacrylate, 2-methyl-1-propoxypolybutylene glycol monoacrylate, 2-methyl-2-propoxypolybutylene glycol monoacrylate, cyclohexoxypolybutylene glycol monoacrylate Acrylate, 1-octoxypolybutylene glycol monoacrylate, 2
-Ethyl-1-hexanoxypolybutylene glycol monoacrylate, nonylalkoxypolybutylene glycol monoacrylate, laurylalkoxypolybutylene glycol monoacrylate, cetylalkoxypolybutylene glycol monoacrylate, stearylalkoxypolybutylene glycol monoacrylate, butylene oxide Various alkoxy poly such as esterified products of allyl alcohol and acrylic acid, esterified products of methallyl alcohol with butylene oxide and acrylic acid, and esterified products of crotyl alcohol and acrylic acid with butylene oxide added Butylene glycol monoacrylates; methoxypolyethylene glycol polypropylene glycol monoacrylate, methoxypolyether Glycol polybutylene glycol monoacrylate, methoxy polyethylene glycol polystyrene glycol monoacrylate, 2 etc.
And various alkoxypolyalkylene glycol monoacrylates such as esterified products of alcohol and acrylic acid to which more than one type of alkylene oxide has been added. Further, two or more of these monomers (a) may be used in combination.

The average addition mole number m of the oxyalkylene group of the monomer (a) and the structural unit (I) is a positive number of 10 or more. , The dispersing performance is lowered, and the required addition amount is greatly increased, which is not preferable. On the other hand, as the average addition mole number increases, the reactivity decreases and the yield decreases.
Is more preferable, and a positive number of 15 to 300 is further preferable.

The carbon number of the oxyalkylene group R ¹ O in the monomer (a) and the structural unit (I) is suitably in the range of 2 to 18, preferably 2 to 8, and more preferably 2 to 8. 4
Is more preferable. As for any two or more kinds of alkylene oxide adducts selected from ethylene oxide, propylene oxide, butylene oxide, styrene oxide and the like, any of random addition, block addition, alternate addition and the like can be used.

When only one kind of the monomer (a) is used, it is preferable to include an oxyethylene group as an essential component in the oxyalkylene group in order to secure a balance between hydrophilicity and hydrophobicity. % Or more is preferably an oxyethylene group. The monomer (b) represented by the general formula (5) used in the present invention includes methanol, ethanol, 2-propanol, 1-butanol, octanol, 2-ethyl-1-hexanol, nonyl alcohol, lauryl alcohol, and cetyl. Alcohol, saturated aliphatic alcohols having 1 to 30 carbon atoms such as stearyl alcohol, allyl alcohol, methallyl alcohol,
Alkylene oxides having 2 to 18 carbon atoms to any of unsaturated aliphatic alcohols having 2 to 30 carbon atoms such as crotyl alcohol and oleyl alcohol, and alicyclic alcohols having 3 to 30 carbon atoms such as cyclohexanol; Is an ester compound of an alkoxypolyalkylene glycol obtained by adding methacrylic acid.

Specific examples of the monomer (b) include methoxy polyethylene glycol monomethacrylate, ethoxy polyethylene glycol monomethacrylate, 1-propoxy polyethylene glycol monomethacrylate,
-Propoxy polyethylene glycol monomethacrylate, 1-butoxy polyethylene glycol monomethacrylate, 2-butoxy polyethylene glycol monomethacrylate, 2-methyl-1-propoxy polyethylene glycol monomethacrylate, 2-methyl-2-propoxy polyethylene glycol monomethacrylate, cyclohexoxy polyethylene Glycol monomethacrylate, 1-octoxy polyethylene glycol monomethacrylate, 2-ethyl-1-hexanoxy polyethylene glycol monomethacrylate, nonylalkoxy polyethylene glycol monomethacrylate, lauryl alkoxy polyethylene glycol monomethacrylate,
Cetyl alkoxy polyethylene glycol monomethacrylate, stearyl alkoxy polyethylene glycol monomethacrylate, esterified product of allylic alcohol and methacrylic acid with ethylene oxide added, esterified product of methallyl alcohol with methacrylic acid added with ethylene oxide, and ethylene oxide added Various alkoxy polyethylene glycol monomethacrylates such as esterified product of crotyl alcohol and methacrylic acid; methoxy polypropylene glycol monomethacrylate, ethoxy polypropylene glycol monomethacrylate, 1-propoxy polypropylene glycol monomethacrylate, 2-propoxy polypropylene glycol monomethacrylate, 1- Butoxy polypropylene glycol Monomethacrylate, 2-butoxy polypropylene glycol monomethacrylate, 2-methyl-1-propoxy polypropylene glycol monomethacrylate, 2-methyl-2-propoxy polypropylene glycol monomethacrylate, cyclohexoxy polypropylene glycol monomethacrylate, 1-octoxy polypropylene glycol monomethacrylate , 2-ethyl-1-hexanoxy polypropylene glycol monomethacrylate, nonylalkoxy polypropylene glycol monomethacrylate, lauryl alkoxy polypropylene glycol monomethacrylate, cetyl alkoxy polypropylene glycol monomethacrylate, stearyl alkoxy polypropylene glycol monomethacrylate, propylene oxide Esters of allyl alcohol and methacrylate obtained by adding Sid,
Various alkoxypolypropylene glycol monomethacrylates such as esterified product of methallyl alcohol and methacrylic acid to which propylene oxide has been added, and esterified product of crotyl alcohol and methacrylic acid to which propylene oxide has been added; methoxy polybutylene glycol monomethacrylate; Ethoxypolybutylene glycol monomethacrylate, 1-propoxypolybutylene glycol monomethacrylate, 2-propoxypolybutylene glycol monomethacrylate, 1-butoxypolybutylene glycol monomethacrylate, 2-butoxypolybutylene glycol monomethacrylate, 2-methyl-1-propoxy Polybutylene glycol monomethacrylate, 2-methyl-2-propoxy polybutylene glycol monometh Relate, cyclohexoxypolybutylene glycol monomethacrylate, 1-octoxypolybutylene glycol monomethacrylate, 2-ethyl-1-hexanoxypolybutylene glycol monomethacrylate, nonylalkoxypolybutylene glycol monomethacrylate, laurylalkoxypolybutylene glycol monomethacrylate , Cetyl alkoxy polybutylene glycol monomethacrylate, stearyl alkoxy polybutylene glycol monomethacrylate,
Esterified product of allyl alcohol and methacrylic acid to which butylene oxide has been added, esterified product of methallyl alcohol to which butylene oxide has been added and methacrylic acid, esterified product of crotyl alcohol to which butylene oxide has been added and methacrylic acid, etc. Of various alkoxypolybutylene glycol monomethacrylates; alcohol and methacryl to which two or more kinds of alkylene oxides such as methoxypolyethylene glycol polypropylene glycol monomethacrylate, methoxypolyethylene glycol polybutylene glycol monomethacrylate, methoxypolyethylene glycol polystyrene glycol monomethacrylate, etc. are added Various alkoxy polyalkylene glycol monomethacrylates such as esterified products with an acid; It is. In addition, these monomers (b)
May be used in combination of two or more.

The average number of added moles n of the oxyalkylene group of the monomer (b) and the structural unit (II) is a positive number of 10 or more. , The dispersing performance is lowered, and the required addition amount is greatly increased, which is not preferable. On the other hand, as the average addition mole number increases, the reactivity decreases and the yield decreases.
A positive number of 0 is more preferable, and a positive number of 15 to 300 is further preferable.

The carbon number of the oxyalkylene group R ³ O of the monomer (b) and the structural unit (II) is suitably in the range of 2 to 18, preferably 2 to 8, and more preferably 2 to 8.
The range of 4 is more preferable. In addition, for any two or more alkylene oxide adducts selected from ethylene oxide, propylene oxide, butylene oxide, styrene oxide and the like, random addition, block addition,
Any of alternate addition and the like can be used.

When only one kind of the monomer (b) is used, it is preferable to include an oxyethylene group as an essential component in the oxyalkylene group in order to secure a balance between hydrophilicity and hydrophobicity, and furthermore, 50 moles. % Or more is preferably an oxyethylene group. Average addition mole number m of oxyalkylene group of monomer (a) and structural unit (I)
There is no particular limitation on the relationship between the oxyalkylene group of the monomer (b) and the structural unit (II) and the average number of moles n added. Therefore, if one of these is 10
It is not necessary that the oxyalkylene chain has a short oxyalkylene chain having a short chain length of 30 mol and the other has an oxyalkylene chain having a long chain length of 110 to 300 mol. 30 to 10
It is preferable to have an oxyalkylene chain having a medium chain length of 0 mol, a oxyalkylene chain having a long chain length of 100 to 300 mol, and the like.
The case where the chain length of 0 to 100 moles has a medium or short oxyalkylene chain, the case where the chain length of 30 to 300 moles has a medium or long oxyalkylene chain, and the like are also preferable.

The unsaturated carboxylic acid monomer (c) used in the present invention is an unsaturated monomer having a carboxyl group, and is a monomer represented by the following general formula (6).

[0035]

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(Wherein, R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom, a methyl group or (CH ₂ ) _p CO ₂ )
X represents an OX group, and X represents a hydrogen atom, a monovalent metal, a divalent metal,
Represents an ammonium group or an organic amine group;
Represents an integer of 2, and when two COOX groups are present,
An anhydride may be formed. Specific examples of the unsaturated carboxylic acid monomer (c) used in the present invention include acrylic acid, methacrylic acid, crotonic acid and their metal salts, ammonium salts, amine salts as acrylic acid monomers. And the like. Examples of unsaturated dicarboxylic acid monomers include maleic acid, itaconic acid, citraconic acid, fumaric acid, and metal salts, ammonium salts, and amine salts thereof, and further, as anhydrides thereof, maleic anhydride. , Itaconic anhydride, citraconic anhydride and the like. Among them, acrylic acid monomers are preferred. In addition, two or more of these monomers (c) may be used in combination. The monomer (d) is composed of the monomers (a) and (b)
And a monomer copolymerizable with (c).

Specific examples of the monomer (d) include half esters and diesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid with alcohols having 1 to 30 carbon atoms; Half amides and diamides of dicarboxylic acids and amines having 1 to 30 carbon atoms;
Alkyl (poly) obtained by adding 1 to 500 mol of an alkylene oxide having 2 to 18 carbon atoms to the alcohol or amine.
A half ester or diester of an alkylene glycol with the unsaturated dicarboxylic acid; a half ester or diester of the unsaturated dicarboxylic acid with a glycol having 2 to 18 carbon atoms or a polyalkylene glycol having an addition mole number of 2 to 500 of these glycols; (Poly) ethylene glycol mono (meth) acrylate, (poly) propylene glycol mono (meth) acrylate, (poly)
Such as butylene glycol mono (meth) acrylate,
Dehydrogenation (oxidation) of acrylic acid, methacrylic acid or fatty acid
1 to 2 alkylene oxide having 2 to 18 carbon atoms
500 mol adduct; maleamic acid and glycol having 2 to 18 carbon atoms or addition mole number of these glycols of 2 to 2
Half amide with 500 polyalkylene glycols;
(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; bifunctional (meth) acrylates such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and trimethylolpropane di (meth) acrylate; triethylene glycol dimaleate, polyethylene glycol (Poly) alkylene glycol dimaleates such as dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) Acryloxypropylsulfonate, 3- (meth) acryloxy-2-hydroxypropylsulfonate, 3- (meth) acryloxy-2-hydroxypropylsulfophenylether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (Meth) acryloxybutylsulfonate, (meth) acrylamidomethylsulfonic acid,
Unsaturated sulfonic acids such as (meth) acrylamidoethylsulfonic acid, 2-methylpropanesulfonic acid (meth) acrylamide and styrenesulfonic acid, and their monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts; Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate,
(Meth) acrylic acid such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, methyl crotonate, glycidyl (meth) acrylate, and 1 to 30 carbon atoms
With an alcohol; unsaturated monocarboxylic acids such as methyl (meth) acrylamide and 1 to 3 carbon atoms
Amides with 0 amines; vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, and p-methylstyrene; 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono ( Alkanediol mono (meth) acrylates such as meth) acrylate and 1,6-hexanediol mono (meth) acrylate; butadiene, isoprene, 2-methyl-1,3
-Dienes such as butadiene and 2-chloro-1,3-butadiene; unsaturated such as (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide and N, N-dimethyl (meth) acrylamide Amides; unsaturated cyanates such as (meth) acrylonitrile and α-chloroacrylonitrile; vinyl acetate;
Unsaturated esters such as vinyl propionate; (meth)
Unsaturated amines such as aminoethyl acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, and vinylpyridine; Divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate; (meth) allyl alcohol, glycidyl (meth)
Allyls such as allyl ether; unsaturated amino compounds such as dimethylaminoethyl (meth) acrylate; methoxypolyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl Vinyl ether or allyl ether such as ether; polydimethylsiloxane propylaminomaleamic acid, polydimethylsiloxane aminopropyleneaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- ( Dipropyleneaminomaleamic acid), polydimethylsiloxane- (1-propyl-3-acrylate), polydimethylsiloxane Hexane - (1-propyl-3
Methacrylate), polydimethylsiloxane-bis-
Siloxane derivatives such as (1-propyl-3-acrylate) and polydimethylsiloxane-bis- (1-propyl-3-methacrylate); and one or more of these can be used. .

The copolymer (C) is a copolymer of the monomers (a) and (b); a copolymer of the monomers (a), (b) and (c); (A), (b),
Any of those obtained by copolymerizing (c) and (d) may be used. The reaction ratio of these monomers is such that the monomer (c) is 45% by weight or less (preferably 40% by weight) of the total monomer components.
Below, more preferably 35% by weight or less, further preferably 30% by weight or less, particularly preferably 25% by weight or less, and most preferably 20% by weight or less. Monomer (b) / monomer (c)
/ Monomer (d) = 1-98 / 1-98 / 1-45 / 0
The range of 70 (% by weight) is appropriate, but the monomer (a) /
Monomer (b) / monomer (c) / monomer (d) = 5-93
/ 5 to 93/2 to 40/0 to 50 (% by weight) are preferable, and the monomer (a) / monomer (b) / monomer (c) /
Monomer (d) = 5-87 / 10-92 / 3-35 / 0-
A range of 40 (% by weight) is more preferable, and the monomer (a) /
Monomer (b) / monomer (c) / monomer (d) = 5-81
/ 15 to 91/4 to 30/0 to 30 (% by weight) is more preferable, and monomer (a) / monomer (b) / monomer (c) / monomer (d) = 10-76 / 20-86 / 4-
A range of 25/0 to 30 (% by weight) is particularly preferred,
Monomer (a) / monomer (b) / monomer (c) / monomer (d) = 10-76 / 20-86 / 4-20 / 0-30
(% By weight) is most preferable. If the ratio is out of this range, a desired cement admixture with excellent performance cannot be obtained. In particular, when the monomer (c) is used in a large amount exceeding 45% by weight, slump loss and curing retardation at high temperatures become remarkable, which is not preferable.

In order to obtain the copolymer (C), the above monomer components may be copolymerized using a polymerization initiator. The copolymerization can be performed by a method such as polymerization in a solvent or bulk polymerization. The polymerization in the solvent can be carried out batchwise or continuously, with the solvent used being water;
Lower alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane and n-hexane; ester compounds such as ethyl acetate;
Ketone compounds such as acetone and methyl ethyl ketone; and the like. From the solubility of the raw material monomer and the obtained copolymer (C) and the convenience at the time of using this copolymer (C),
It is preferable to use at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. In that case, among lower alcohols having 1 to 4 carbon atoms, methyl alcohol, ethyl alcohol, isopropyl alcohol and the like are particularly effective.

When the polymerization is carried out in an aqueous medium, a water-soluble polymerization initiator such as ammonium or alkali metal persulfate or hydrogen peroxide is used as the polymerization initiator. At this time, an accelerator such as sodium bisulfite and Mohr's salt can be used in combination. For polymerization using lower alcohols, aromatic hydrocarbons, aliphatic hydrocarbons, ester compounds or ketone compounds as solvents, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; An aromatic azo compound such as bisisobutyronitrile is used as a polymerization initiator. In this case, an accelerator such as an amine compound may be used in combination. Further, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various polymerization initiators or a combination of the polymerization initiator and the accelerator. The polymerization temperature is appropriately determined depending on the solvent and the polymerization initiator to be used.
It is performed within the range of ° C.

The bulk polymerization is carried out using a polymerization initiator such as a peroxide such as benzoyl peroxide or lauroyl peroxide; a hydroperoxide such as cumene hydroperoxide; an aliphatic azo compound such as azobisisobutyronitrile; It is performed within a temperature range of 200 ° C. Further, a thiol-based chain transfer agent can be used in combination for controlling the molecular weight of the obtained copolymer (C). The thiol-based chain transfer agent used at this time has the general formula HS
-R ¹⁰ -Eg (provided that wherein R ¹⁰ represents an alkyl group having a carbon number of 1 to 2, E is -OH, -COOM, -CO
OR ¹¹ or SO ₃ M represents a group, M represents a hydrogen atom, a monovalent metal, a divalent metal, an ammonium group or an organic amine group; R ¹¹ represents an alkyl group having 1 to 10 carbon atoms;
g represents an integer of 1 to 2. And, for example, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, and octyl 3-mercaptopropionate. One or more of these can be used.

The copolymer (C) or copolymer (A) thus obtained can be used as a main component of the cement admixture as it is, but if necessary, further neutralized with an alkaline substance. The copolymer salt (D) or the copolymer salt (B) obtained by the above method may be used as a main component of the cement admixture. Examples of such alkaline substances include inorganic substances such as hydroxides, chlorides and carbon salts of monovalent metals and divalent metals;
Ammonia; organic amines and the like are preferred.

The weight average of the copolymer (A) and / or the copolymer salt (B), the copolymer (C) and / or the copolymer salt (D) used as the cement admixture of the present invention. The molecular weight is 500-500,000, especially 5,000.
It is preferably in the range of ~ 300,000. If the weight average molecular weight is less than 500, the water reducing performance of the cement admixture is undesirably reduced. On the other hand, 500,000
If the molecular weight exceeds 3, the water reducing performance and the slump loss preventing ability of the cement admixture are undesirably reduced. (Cement composition) Cement composition according to the present invention,
A composition containing cement, the cement admixture and water as essential components, and is used as, for example, cement paste, mortar, and concrete.

As the cement, a hydraulic cement such as Portland cement, a high belite cement, an alumina cement, various mixed cements, or a hydraulic material such as gypsum can be used. The mixing ratio of the cement admixture in the cement composition of the present invention is not particularly limited, but when used in mortar or concrete using hydraulic cement, the cement weight is 0.01 to 2.0%.
%, Preferably 0.02 to 1.0%, more preferably 0.05 to 0.5%. By adding the above amount at the time of kneading, various preferable effects such as achievement of high water reduction rate, improvement of slump loss prevention performance, reduction of unit water amount, increase of strength, improvement of durability and the like are brought about. . If the mixing ratio is less than 0.01%, the performance is insufficient,
Conversely, even if a large amount exceeding 2.0% is used, the effect is substantially flattened, which is disadvantageous in terms of economy.

In the cement composition of the present invention, (1)
m and cement usage per ^3, but are not limited to the unit water amount, the unit water amount 100～185Kg / m ^3, water / cement weight ratio from 0.10 to 0.7, preferably in unit water amount 120～175Kg / m ³ , Water / cement weight ratio = 0.
2-0.65 is recommended. Aggregates such as sand and gravel are further blended into the cement composition as necessary.

The cement composition of the present invention may contain a known cement dispersant. Examples of such known cement dispersants include lignin sulfonate; polyol derivative; naphthalenesulfonic acid formalin condensate; melaminesulfonic acid formalin condensate; polystyrene sulfonate; and aminoaryl sulfone as disclosed in JP-A-1-113419. Aminosulfonic acids such as acid-phenol-formaldehyde condensates; JP-A-7-2677
05, a copolymer of a polyalkylene glycol mono (meth) acrylate compound and a (meth) acrylic compound and / or a salt thereof as the component (a),
(B) a copolymer of a polyalkylene glycol mono (meth) allyl ether compound and maleic anhydride and / or a hydrolyzate and / or a salt thereof as a component,
As a component (c), a dispersant for cement comprising a copolymer of a polyalkylene glycol mono (meth) allyl ether compound and a maleic acid ester of a polyalkylene glycol compound and / or a salt thereof, Patent Publication No. 250
No. 8113, copolymer of polyalkylene glycol ester of (meth) acrylic acid and (meth) acrylic acid (salt) as component A, specific polyethylene glycol polypropylene glycol compound as component B, specific interface as component C Concrete admixture consisting of activator,
JP-A-62-216950, polyethylene (propylene) glycol ester of (meth) acrylic acid or polyethylene (propylene) glycol mono (meth) allyl ether, (meth) allylsulfonic acid (salt), (meth) acrylic acid (salt) ), A copolymer comprising:
Copolymer of polyethylene (propylene) glycol ester of (meth) acrylic acid, (meth) allyl sulfonic acid (salt), (meth) acrylic acid (salt) as in 26757, and (meth) as in JP-B 5-36377 Polyethylene (propylene) glycol ester of acrylic acid,
Copolymers of (meth) allylsulfonic acid (salt) or p- (meth) allyloxybenzenesulfonic acid (salt) and (meth) acrylic acid (salt), JP-A-4-14956
Copolymers of polyethylene glycol mono (meth) allyl ether and maleic acid (salt) as described in JP-A-5-17
Polyethylene glycol ester of (meth) acrylic acid such as 0501, (meth) allylsulfonic acid (salt),
(Meth) acrylic acid (salt), alkanediol mono (meth) acrylate, polyalkylene glycol mono (meth) acrylate, α, β- having an amide group in the molecule
Copolymers comprising unsaturated monomers, JP-A-6-19191
8, polyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) acrylate, alkyl (meth) acrylate, (meth)
Copolymers of acrylic acid (salt), (meth) allylsulfonic acid (salt) or p- (meth) allyloxybenzenesulfonic acid (salt), and alkoxypolyalkylene glycol monoallyl ether as disclosed in JP-A-5-43288. A copolymer with maleic anhydride, or a hydrolyzate or a salt thereof, such as polyethylene glycol monoallyl ether, maleic acid as described in JP-B-58-38380, and a monomer copolymerizable with these monomers Copolymers or salts or esters thereof, JP-B-59-1
Polyalkylene glycol mono (meth) such as 8338
Acrylic ester-based monomers, (meth) acrylic acid-based monomers, and copolymers composed of monomers copolymerizable with these monomers, and sulfonic acid groups as disclosed in JP-A-62-119147. A copolymer comprising a (meth) acrylic acid ester and, if necessary, a monomer copolymerizable therewith, or a salt thereof, or a copolymer of an alkoxypolyalkylene glycol monoallyl ether and maleic anhydride as disclosed in JP-A-6-271347. Esterification reaction product of polymer and polyoxyalkylene derivative having alkenyl group at terminal
Esterification reaction product of a copolymer of an alkoxypolyalkylene glycol monoallyl ether and maleic anhydride with a polyoxyalkylene derivative having a hydroxyl group at a terminal, such as JP-298555;
Alkenyl ether-based monomers, unsaturated carboxylic acid-based monomers obtained by adding ethylene oxide or the like to specific unsaturated alcohols such as -methyl-3-buten-1-ol, and copolymerizable with these monomers And polycarboxylic acids (salts) such as copolymers of monomers or salts thereof; and a plurality of these known cement dispersants can be used in combination.

When the cement composition of the present invention contains these known cement dispersants, the compounding ratio is not uniquely determined by the kind of the cement dispersant, the compounding and the test conditions. The compounding weight ratio of the cement admixture to the known cement dispersant is in the range of 5 to 95:95 to 5, preferably 10 to 90:90 to 10. Further, the cement composition of the present invention may contain other known cement additives (materials) as exemplified in the following (1) to (20). (1) Water-soluble polymer: unsaturated carboxylic acid polymer such as polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), sodium salt of acrylic acid / maleic acid copolymer; polyethylene Polyoxyethylene or polyoxypropylene polymers such as glycol and polypropylene glycol or copolymers thereof; nonionics such as methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, carboxyethylcellulose and hydroxypropylcellulose Cellulose ethers; yeast glucan, xanthan gum, β-1.3 glucans (either linear or branched, and for example, curdlan, baramiron, bakiman, Cleroglucan, laminaran, etc.)
Polyacrylamide; polyvinyl alcohol; starch; starch phosphate; sodium alginate; gelatin; a copolymer of acrylic acid having an amino group in the molecule and a quaternary compound thereof. (2) Polymer emulsion: a copolymer of various vinyl monomers such as alkyl (meth) acrylate. (3) retarders: gluconic acid, glucoheptonic acid, arabonic acid, malic acid or citric acid, and oxycarboxylic acids such as inorganic salts or organic salts such as sodium, potassium, calcium, magnesium, ammonium, and triethanolamine; Acids; monosaccharides such as glucose, fructose, galactose, saccharose, xylose, apiose, ribose, isomerized sugars, oligosaccharides such as disaccharides, trisaccharides, or oligosaccharides such as dextrin, or polysaccharides such as dextran; Saccharides such as molasses containing; sugar alcohols such as sorbitol; magnesium silicofluoride; phosphoric acid and salts or borate esters thereof; aminocarboxylic acids and salts thereof; alkali-soluble proteins; humic acid; tannic acid; Polyhydric alcohols such as glycerin;
Aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) and phosphonic acids such as alkali metal salts and alkaline earth metal salts thereof And its derivatives. (4) Fasteners / promoters: Soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide, calcium iodide; chlorides such as iron chloride and magnesium chloride; sulfates; potassium hydroxide; Sodium hydroxide; carbonate; thiosulfate; formate such as formic acid and calcium formate; alkanolamine; alumina cement; calcium aluminate silicate; (5) Mineral oil-based antifoaming agents: kerosene, liquid paraffin and the like. (6) Oil-based antifoaming agents: animal and vegetable oils, sesame oil, castor oil, alkylene oxide adducts thereof and the like. (7) Fatty acid antifoaming agents: oleic acid, stearic acid, alkylene oxide adducts thereof and the like. (8) Fatty acid ester antifoaming agents: glycerin monoricinoleate, alkenyl succinic acid derivatives, sorbitol monolaurate, sorbitol trioleate, natural wax and the like. (9) oxyalkylene antifoaming agents: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adduct; diethylene glycol heptyl ether;
Polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene 2-ethylhexyl ether, having 12 to 12 carbon atoms
(Poly) oxyalkyl ethers such as oxyethylene oxypropylene adduct to 14 higher alcohols; (poly) oxyalkylene (alkyl) aryl ethers such as polyoxypropylene phenyl ether and polyoxyethylene nonyl phenyl ether; 4,7,9
-Tetramethyl-5-decyne-4,7-diol, 2,
5-dimethyl-3-hexyne-2,5-diol, 3-
Acetylene ethers obtained by addition-polymerizing an alkylene oxide to an acetylene alcohol such as methyl-1-butyn-3-ol; (poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, and ethylene glycol distearate (Poly) oxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan trioleate; (poly) such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecyl phenol ether sulfate Oxyalkylene alkyl (aryl) ether sulfates; (poly) oxyethylene stearyl phosphate, etc. (Poly) oxyalkylene alkyl phosphoric acid esters; polyoxyethylene such as polyoxyethylene lauryl amine (poly) oxyalkylene alkyl amines; polyoxyalkylene amide. (10) Alcohol antifoaming agents: octyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like. (11) Amide-based antifoaming agent: acrylate polyamine and the like. (12) Phosphate ester antifoam: tributyl phosphate,
Sodium octyl phosphate and the like. (13) Metal soap-based antifoaming agents: aluminum stearate, calcium oleate and the like. (14) silicone antifoaming agent: dimethyl silicone oil,
Silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), fluorosilicone oil and the like. (15) AE agent: resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, ABS (alkylbenzene sulfonic acid), L
AS (linear alkylbenzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl)
Ether, polyoxyethylene alkyl (phenyl) ether sulfate or salt thereof, polyoxyethylene alkyl (phenyl) ether phosphate or salt thereof, protein material, alkenyl sulfosuccinic acid, α-olefin sulfonate and the like. (16) Other surfactants: aliphatic monohydric alcohols having 6 to 30 carbon atoms in a molecule such as octadecyl alcohol and stearyl alcohol, and 6 to 30 carbon atoms in a molecule such as abiethyl alcohol Alicyclic 1
6 to 6 in the molecule of polyhydric alcohol, dodecyl mercaptan, etc.
Monovalent mercaptans having 30 carbon atoms, nonylphenols, etc., alkylphenols having 6 to 30 carbon atoms, dodecylamines, etc. having 6 to 3 carbon atoms in the molecule.
Polyalkylene oxide obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide by 10 mol or more to a carboxylic acid having 6 to 30 carbon atoms in a molecule such as an amine having 0 carbon atoms, lauric acid or stearic acid. Derivatives; alkyl diphenyl ether sulfonates which may have an alkyl group or an alkoxy group as a substituent, and two phenyl groups having a sulfone group are ether-bonded; various anionic surfactants; alkyl amine acetate; alkyl Various cationic surfactants such as trimethylammonium chloride; various nonionic surfactants; various amphoteric surfactants and the like. (17) Waterproofing agents: fatty acids (salts), fatty acid esters, oils and fats, silicon, paraffin, asphalt, wax and the like. (18) Rust inhibitors: nitrites, phosphates, zinc oxide and the like. (19) Crack reducing agent: polyoxyalkyl ether and the like. (20) Expansive materials: ettringite, coal, etc.

Other known cement additives (materials) include cement wetting agents, thickening agents, separation reducing agents, flocculants,
Drying shrinkage reducing agent, strength enhancer, self-leveling agent, rust inhibitor, coloring agent, fungicide, blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, etc. The cement composition can also contain a plurality of these known cement additives (materials).

Regarding the components other than the cement and water contained in the cement composition of the present invention, particularly preferred embodiments include the following 1) to 4). 1) A combination comprising two components of the cement admixture of the present invention and lignin sulfonate as essential components. The compounding weight ratio of the cement admixture of the present invention to the lignin sulfonate is preferably in the range of 5 to 95:95 to 5,
The range of 90:90 to 10 is more preferable.

2) Combination essentially comprising two components of the cement admixture of the present invention and an oxyalkylene-based antifoaming agent.
The weight ratio of the oxyalkylene-based antifoaming agent is 0.01 to 0.01 with respect to the cement admixture of the present invention.
A range of 10% by weight is preferred. 3) The cement admixture of the present invention, JP-B-59-183.
Polyoxyalkylene glycol mono (meth) acrylate-based monomers, (meth) acrylic acid-based monomers, copolymers composed of monomers copolymerizable with these monomers, oxyalkylenes such as 38 Combination that requires three components of a system defoamer. The compounding weight ratio of the oxyalkylene antifoaming agent is 0.01 to 10% by weight based on the total amount of the copolymer with the cement admixture of the present invention.
Is preferable.

4) The cement admixture of the present invention, as disclosed in JP-A-62-68806, 3-methyl-3-butene-1-
Alkenyl ether-based monomers obtained by adding ethylene oxide or the like to a specific unsaturated alcohol such as an all, unsaturated carboxylic acid-based monomers, and copolymers composed of monomers copolymerizable with these monomers, Combination in which three components of an oxyalkylene antifoaming agent are essential. The weight ratio of the oxyalkylene-based antifoaming agent is 0.01% based on the total amount of the copolymer with the cement admixture of the present invention.
A range of from 10 to 10% by weight is preferred.

[0052]

The present invention will now be described more specifically with reference to examples. Unless otherwise specified in the examples, "%"
Represents "% by weight", "parts" represents "parts by weight", and the weight average molecular weight represents a weight average molecular weight in terms of polyethylene glycol by gel permeation chromatography (GPC). Example 1 Production of Cement Admixture (1) 150 parts of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was replaced with nitrogen under stirring. And heated to 80 ° C. under a nitrogen atmosphere. Next, 91 parts of methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 23) and methoxy polyethylene glycol monoacrylate (average number of moles of added ethylene oxide: 25)
89 parts, acrylic acid 20 parts, water 50 parts, and a monomer aqueous solution obtained by mixing 1.8 parts of 3-mercaptopropionic acid as a chain transfer agent and 35 parts of a 5.2% ammonium persulfate aqueous solution were dropped in 4 hours, After completion of the dropwise addition, 9 parts of a 5.2% ammonium persulfate aqueous solution was further added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and the cement admixture (1) of the present invention comprising a copolymer aqueous solution having a weight average molecular weight of 20,800
I got Example 2 Production of Cement Admixture (2) 150 parts of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was replaced with nitrogen under stirring. And heated to 80 ° C. under a nitrogen atmosphere. Next, 45 parts of methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 23) and methoxypolyethylene glycol monoacrylate (average number of moles of added ethylene oxide: 25)
35 parts of a monomer aqueous solution obtained by mixing 135 parts, 20 parts of acrylic acid, 50 parts of water, and 1.8 parts of 3-mercaptopropionic acid as a chain transfer agent, and 35 parts of a 5.2% aqueous solution of ammonium persulfate were added dropwise over 4 hours. After completion of the dropwise addition, 9 parts of a 5.2% ammonium persulfate aqueous solution was further added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and the cement admixture (2) of the present invention comprising a copolymer aqueous solution having a weight average molecular weight of 24,000
I got Example 3 Production of Cement Admixture (3) 150 parts of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was replaced with nitrogen under stirring. And heated to 80 ° C. under a nitrogen atmosphere. Next, 135 parts of methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 23) and methoxy polyethylene glycol monoacrylate (average number of moles of added ethylene oxide: 2)
5 parts) 45 parts of acrylic acid, 20 parts of acrylic acid, 50 parts of water, and 1.7 parts of 3-mercaptopropionic acid as a chain transfer agent in a monomer aqueous solution mixed with 35 parts of a 5.2% ammonium persulfate aqueous solution were dropped in 4 hours. After the addition, 9 parts of a 5.2% aqueous ammonium persulfate solution was further added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. for 1 hour to complete the polymerization reaction, and the cement admixture (3) of the present invention comprising a copolymer aqueous solution having a weight average molecular weight of 22,000.
I got Example 4 Production of Cement Admixture (4) 278 parts of water was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reaction vessel was replaced with nitrogen under stirring. And heated to 80 ° C. under a nitrogen atmosphere. Next, 48 parts of butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 130) and 48 parts of butoxy polyethylene glycol monoacrylate (average number of moles of ethylene oxide 1)
30 parts) 45 parts, methacrylic acid 2 parts, acrylic acid 5 parts,
4. a monomer aqueous solution obtained by mixing 100 parts of water and 1.1 parts of 3-mercaptopropionic acid as a chain transfer agent;
18 parts of a 2% aqueous solution of ammonium persulfate were added dropwise over 4 hours, and after completion of the addition, 4 parts of a 5.2% aqueous solution of ammonium persulfate were added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, and the polymerization reaction was completed.
Neutralized with aqueous sodium hydroxide solution to obtain a weight average molecular weight of 4
Thus, a cement admixture (4) of the present invention comprising a 7,500 aqueous copolymer solution was obtained. Example 5 Production of Cement Admixture (5) 278 parts of water was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reaction vessel was replaced with nitrogen under stirring. And heated to 80 ° C. under a nitrogen atmosphere. Next, butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 130) 47 parts, butoxy polyethylene glycol monoacrylate (average number of moles of ethylene oxide 1 1)
30 parts) A monomer aqueous solution obtained by mixing 48 parts, acrylic acid 6 parts, water 100 parts, and 1.0 part of 3-mercaptopropionic acid as a chain transfer agent and 18 parts of a 5.2% ammonium persulfate aqueous solution were dropped in 4 hours. After the addition, 4 parts of a 5.2% aqueous ammonium persulfate solution was further added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and the mixture was neutralized with a 30% aqueous sodium hydroxide solution to obtain a cement admixture of the present invention comprising a copolymer aqueous solution having a weight average molecular weight of 50,500 ( 5) was obtained. Comparative Example 1 Production of Comparative Cement Admixture (1) 150 parts of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was replaced with nitrogen under stirring. Then, it was heated to 80 ° C. under a nitrogen atmosphere. Next, a monomer aqueous solution obtained by mixing 180 parts of methoxypolyethylene glycol monomethacrylate (average number of added moles of ethylene oxide: 23), 20 parts of acrylic acid, 50 parts of water, and 1.5 parts of 3-mercaptopropionic acid as a chain transfer agent; 35 parts of a 5.2% aqueous ammonium persulfate solution was added dropwise over 4 hours, and after completion of the addition, 9 parts of a 5.2% aqueous ammonium persulfate solution was further added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and the weight average molecular weight was 22,500.
A comparative cement admixture (1) consisting of an aqueous solution of the copolymer was obtained. Comparative Example 2 Production of Comparative Cement Admixture (2) 150 parts of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was replaced with nitrogen under stirring. Then, it was heated to 80 ° C. under a nitrogen atmosphere. Next, methoxypolyethylene glycol monoacrylate (average number of moles of ethylene oxide added: 2)
5 parts) 180 parts of acrylic acid, 20 parts of acrylic acid, 50 parts of water, and 1.9 parts of 3-mercaptopropionic acid as a chain transfer agent in a monomer aqueous solution mixed with 35 parts of a 5.2% ammonium persulfate aqueous solution were dropped in 4 hours. After the addition, 9 parts of a 5.2% aqueous ammonium persulfate solution was further added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, thereby obtaining a comparative cement admixture (2) comprising a copolymer aqueous solution having a weight average molecular weight of 23,000. Comparative Example 3 Production of Comparative Cement Admixture (3) 150 parts of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was replaced with nitrogen under stirring. Then, it was heated to 80 ° C. under a nitrogen atmosphere. Next, 100 parts of methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 23), 100 parts of methacrylic acid, 50 parts of water,
And 3-mercaptopropionic acid as a chain transfer agent;
9 parts of a mixed monomer aqueous solution and 35 parts of a 5.2% ammonium persulfate aqueous solution were added dropwise over 4 hours. After the addition was completed, 9 parts of a 5.2% ammonium persulfate aqueous solution was further added to 1 part.
Dropped in time. Thereafter, the temperature was maintained at 80 ° C. for 1 hour to complete the polymerization reaction, and the weight average molecular weight was 24.
A comparative cement admixture (3) consisting of a 000 aqueous copolymer solution was obtained. Comparative Example 4 Production of Comparative Cement Admixture (4) 150 parts of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was replaced with nitrogen under stirring. Then, it was heated to 80 ° C. under a nitrogen atmosphere. Then, 62 parts of methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 4) and methoxypolyethylene glycol monoacrylate (average number of moles of added ethylene oxide: 25)
Aqueous solution of 118 parts, 118 parts of acrylic acid, 20 parts of acrylic acid, 50 parts of water, and 2.2 parts of 3-mercaptopropionic acid as a chain transfer agent, and 35 parts of a 5.2% ammonium persulfate aqueous solution were dropped in 4 hours, After completion of the dropwise addition, 9 parts of a 5.2% ammonium persulfate aqueous solution was further added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. for 1 hour to complete the polymerization reaction, neutralized with a 30% aqueous sodium hydroxide solution, and a comparative cement admixture consisting of an aqueous solution of a copolymer having a weight average molecular weight of 19,900 (4) I got Comparative Example 5 Production of Comparative Cement Admixture (5) 278 parts of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was replaced with nitrogen under stirring. Then, it was heated to 80 ° C. under a nitrogen atmosphere. Next, 96 parts of butoxy polyethylene glycol monomethacrylate (average number of added moles of ethylene oxide: 130), 4 parts of methacrylic acid, 100 parts of water, and 0.9 of 3-mercaptopropionic acid as a chain transfer agent.
Of a mixed monomer solution and 18 parts of a 5.2% aqueous ammonium persulfate solution were added dropwise over 4 hours.
Further, 4 parts of a 5.2% ammonium persulfate aqueous solution was added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, neutralized with a 30% aqueous sodium hydroxide solution, and prepared as a comparative cement admixture comprising a copolymer aqueous solution having a weight average molecular weight of 52,800 (5). I got Comparative Example 6 Production of Comparative Cement Admixture (6) 278 parts of water was charged into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was replaced with nitrogen under stirring. Then, it was heated to 80 ° C. under a nitrogen atmosphere. Next, butoxy polyethylene glycol monoacrylate (the average number of moles of ethylene oxide added was 1)
30 parts) 95 parts of acrylic acid, 6 parts of acrylic acid, 100 parts of water and 1.0 part of 3-mercaptopropionic acid as a chain transfer agent, and 18 parts of a 5.2% aqueous solution of ammonium persulfate were added dropwise over 4 hours. After the addition, 4 parts of a 5.2% aqueous ammonium persulfate solution was further added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, neutralized with a 30% aqueous sodium hydroxide solution, and prepared as a comparative cement admixture comprising a copolymer aqueous solution having a weight average molecular weight of 51,000 (6). I got [Mortar test] Cement admixture (1) of the present invention
(5) and a mortar (cement composition) to which comparative cement admixtures (1) to (6) were respectively added for comparison, and flow values were measured.

The materials and mortar composition used for the test were as follows:
It is 600 g of Chichibu Onoda ordinary Portland cement, 600 g of Toyoura standard sand, and 200 g of water containing the present or comparative cement admixture. Table 1 shows the amount of each cement admixture (% by weight of the solid content relative to the cement). (1) Mortar test at normal temperature (25 ° C.) The mortar is a Hobart type mortar mixer (N-50 type,
The mixture is prepared by mechanical kneading for 3 minutes using Hobart Co., Ltd., and mortar is packed in a hollow cylinder having a diameter of 55 mm and a height of 55 mm. Next, after lifting the cylinder vertically, the diameter of the mortar spread on the table was measured in two directions, and the average was taken as the flow value. Thereafter, the entire amount of the mortar was allowed to stand in a closed container for a predetermined period of time, and then the same operation as above was repeated to measure the change over time in the flow value. Table 1 shows the results. (2) Mortar test at low temperature (5 ° C.) The materials, mortar mixer, and measuring instruments used for the test were cooled in a 5 ° C. atmosphere, mortar was prepared in the same procedure as at normal temperature, and the flow value was measured. . In addition, the addition amount of each cement admixture was adjusted so that a value almost equal to the flow value at room temperature was obtained. Table 1 shows the results.

[0054]

[Table 1]

From Table 1, it can be seen that the mortar to which the comparative admixture is added has a remarkable slump loss at normal temperature, a large increase in the required addition amount at low temperature, or an extremely large addition amount at normal temperature and low temperature. On the other hand, the mortar to which the cement admixture of the present invention is added has a significantly reduced flow value even after 90 minutes at room temperature, and exhibits an excellent effect of reducing slump loss. Also, it can be seen that the rate of increase in the required addition amount is small at low temperatures.

[0056]

As described above, the cement admixture of the present invention has a low slump loss at high temperatures and exhibits sufficient dispersing performance even at low temperatures, and has a small increase in the amount of water added. It has low dispersibility, has excellent dispersion performance, and is effective for mortar and concrete that require high fluidity such as high fluidity concrete.

Since the cement composition of the present invention contains the above-mentioned cement admixture, it shows a high flow value and has excellent fluidity.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C08F290 / 06 C08F290 / 06 C04B 103: 32 (72) Inventor Hirokazu Niwa 5-8 Nishimitabicho, Suita-shi, Osaka Nippon Shokubai Co., Ltd.

Claims (3)

[Claims] 1. A composition comprising a structural unit (I) represented by the following general formula (1) and a structural unit (II) represented by the following general formula (2) as essential structural units; The copolymer (A) may further contain the structural unit (III) represented by (3), and the content of the structural unit (III) is 45% by weight or less of the whole, and / or A cement admixture comprising, as an essential component, a copolymer salt (B) obtained by further neutralizing the copolymer (A) with an alkaline substance. Embedded image Embedded image (In the formula, R ¹ O and R ³ O represent one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms. In the case of two or more, R ¹ O and R ³ O are random even if added in a block form. M and n are the average number of moles of the oxyalkylene group and represent a positive number of 10 or more, and R ² and R ⁴ are aliphatic or aliphatic having 1 to 30 carbon atoms. Represents a cyclic hydrocarbon group.) (Wherein, R ⁵ , R ⁶ , and R ⁷ each independently represent a hydrogen atom, a methyl group, or a (CH ₂ ) _p COOX group, and X represents a hydrogen atom, a monovalent metal, a divalent metal, or an ammonium group. Or p represents an organic amine group, p represents an integer of 0 to 2, and when two COOX groups are present, they may form an anhydride.) 2. An unsaturated carboxylic acid monomer comprising a monomer (a) represented by the following general formula (4) and a monomer (b) represented by the following general formula (5) as essential components: Copolymer containing at least 45% by weight of the unsaturated carboxylic acid-based monomer (c) in some cases. A cement admixture comprising, as an essential component, a copolymer (C) and / or a copolymer salt (D) obtained by further neutralizing the copolymer (C) with an alkaline substance. Embedded image Embedded image (In the formula, R ¹ O and R ³ O represent one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms. In the case of two or more, R ¹ O and R ³ O are random even if added in a block form. M and n are the average number of moles of the oxyalkylene group and represent a positive number of 10 or more, and R ² and R ⁴ are aliphatic or aliphatic having 1 to 30 carbon atoms. Represents a cyclic hydrocarbon group.) 3. A cement composition comprising a cement, the cement admixture according to claim 1 and water as essential components.