JPH11106249A - Cement admixture and cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cement admixture excellent in material separation resistance and fluidity by including a copolymer prepared by copolymerizing monomers consisting essentially of plural specific monomers which are ester compounds of alkoxypolyalkylene glycols with (meth)acrylic acid and a specified amount of an unsaturated carboxylic acid-based monomer as an essential component. SOLUTION: This cement admixture consists essentially of a copolymer prepared by copolymerizing monomers consisting essentially of (A) two kinds of monomers represented by the formula and (B) an unsaturated carboxylic acid-based monomer in an amount of <=50 wt.% based on the total weight of the whole monomer component and/or a copolymer salt obtained by neutralizing the copolymer with an alkaline substance. In the formula, R<1> is H or CH3 ; R<2> Os are one or more 2-4C oxyalkylenes and the R<2> Os may be added in a block or a random form when the R<2> Os are two or more; (n) is >=1; R<3> is a 4-30C alkyl for the monomer A and H or an alkyl having a smaller number of carbon atoms than that of R<3> in the monomer A for the monomer B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a cement admixture and a cement composition. More specifically, the present invention relates to a cement admixture having excellent material separation resistance and excellent fluidity in a so-called cement mixture such as cement paste, mortar, and concrete, and a cement composition containing the cement admixture.

[0002]

BACKGROUND OF THE INVENTION Since the early deterioration of concrete structures became a social problem in 1981, there has been a strong demand for reducing the unit water content in concrete to improve its workability and durability. Technical innovations on cement dispersants, which greatly affect the quality and performance of cement, have been actively pursued.

[0003] As a conventional method, an AE agent or AE
Flowability with added water reducing agent (hereinafter referred to as "slump")
Low-grade ready-mixed concrete is manufactured in a plant, transported to a casting site by a ready-mixed concrete truck, then fluidized by adding a fluidizing agent to this, and a fluidization method of increasing slump to a predetermined value has been adopted. . 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. And other problems such as a remarkable decrease in the slump with time (hereinafter referred to as "slump loss").

[0004] Therefore, so-called high-performance AE water reducing agents which can be added in a raw conplant have been vigorously developed by admixture manufacturers, and currently naphthalene-based, aminosulfonic acid-based and polycarboxylic acid-based products are commercially available. . And
Various water-soluble vinyl copolymers have been proposed as a polycarboxylic acid-based water reducing agent having an excellent feature that the highest water reduction rate can be obtained.

However, these known water reducing agents are:
There is a problem in strength. That is, when the addition amount is increased in order to obtain high fluidity, there is a problem that a large amount of floating water (breathing) occurs after the concrete is constructed. When a large amount of breathing occurs, the uniformity and denseness of the concrete structure are impaired due to the passage of water generated when water in the concrete emerges on the surface, and the strength decreases after hardening. This breathing
It is a kind of separation phenomenon caused by the difference in specific gravity between the water in the concrete and the cement or aggregate.As a method of suppressing breathing, generally, the viscosity is increased by adding a fine powder or a thickener, Although a method of increasing the resistance to material separation has been adopted, there is a problem in economical efficiency and the like, and it cannot be said that this is a drastic measure.

Conventionally, it has been considered that in a water-soluble vinyl copolymer having an oxyalkylene group, the graft structure of the oxyalkylene chain causes steric hindrance, and excellent dispersibility is exhibited by suppressing the adhesion of particles. Have been. The number of moles of ethylene oxide and / or propylene oxide constituting the oxyalkylene group is described in JP-A-7-223852 and JP-A-7-223852.
-247149, JP-A-7-247150, JP-A-8-
12396, JP-A-8-225352, JP-A-9-40
For example, Japanese Patent Application Laid-Open No. 446906/1996, Japanese Patent Application Laid-Open No. 5-53522,
JP-A-8-29095, JP-A-9-2855, JP-A-9-241056, JP-A-9-241057 and the like propose various substituent groups.

[0007] Various techniques other than those proposed in these publications are used, and even when a polycarboxylic acid-based water reducing agent, which has been improved, is used, other high-performance AEs are used.
As in the case of the water reducing agent, there are cases where material separation and slump loss cannot be sufficiently suppressed.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cement admixture having good resistance to material separation and excellent slump retention, and a cement composition comprising the cement admixture. Is to do.

[0009]

The present inventors have conducted intensive studies on the chain length of the oxyalkylene group and the structure of its terminal group, and as a result, have found that a specific graft structure having two types of oxyalkylene groups having different terminal groups has been obtained. The present inventors have found that a water-soluble vinyl copolymer possesses excellent material separation resistance, good dispersibility, and excellent slump retention, and completed the present invention.

That is, the present invention relates to a cement admixture and a cement composition shown in the following (1) to (5).

(1) 2 represented by the following general formula (1)
Monomers containing the following types of monomers (a) and (b) and 50% by weight (% by weight based on the total of all monomer components) of unsaturated carboxylic acid-based monomers (c) as essential components: Copolymer (A) obtained by copolymerizing the copolymer and / or first copolymer (A) obtained by further neutralizing the copolymer (A) with an alkaline substance.
A cement admixture comprising the copolymer salt (B) as an essential component.

General formula (1)

[0013]

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(Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² O represents one or a mixture of two or more oxyalkylene groups having 2 to 4 carbon atoms. N may be an average number of moles of the oxyalkylene group added, and may be a positive number of 1 or more, and R ³ may be a monomer (a) represents an alkyl group having 4 to 30 carbon atoms, in the monomer (b) represents an alkyl group having a carbon number less than the number of carbon atoms in R ³ a hydrogen atom or a monomer (a).) (2) Monomer (a) represented by the following general formula (1)
And a second copolymer (A) obtained by copolymerizing a monomer containing an unsaturated carboxylic acid monomer (c) as an essential component.
1) and / or a second copolymer salt (B1) obtained by further neutralizing the copolymer (A1) with an alkaline substance, and a monomer represented by the following general formula (1) (B),
The third copolymer (A2) obtained by copolymerizing a monomer containing the unsaturated carboxylic acid monomer (c) as an essential component and / or the copolymer (A2) is further treated with an alkaline substance. A cement admixture containing a third copolymer salt (B2) obtained by neutralization as an essential component.

General formula (1)

[0016]

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(Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² O represents one or a mixture of two or more oxyalkylene groups having 2 to 4 carbon atoms. N may be an average number of moles of the oxyalkylene group added and represents a positive number of 1 or more, and R ³ represents a monomer (a) Represents an alkyl group having 4 to 30 carbon atoms, and in the monomer (b), represents a hydrogen atom or an alkyl group having a carbon number smaller than the carbon number of R ³ of the monomer (a).) The weight ratio of the copolymer (salt) (A1 and / or B1) to the copolymer (salt) (A2 and / or B2) is 1: 9.
The cement admixture according to the above (2), which is 9 to 99: 1.

(4) A cement composition comprising at least the cement admixture according to any one of (1) to (3), cement and water.

(5) The cement according to the above (4), wherein the cement admixture is 0.01 to 2.0% by weight with respect to the cement and the weight ratio of water / cement is 0.15 to 0.7. Composition.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION First, a first cement admixture according to the present invention comprises a first copolymer (A) and / or the first copolymer (A) described later in an alkaline substance. The first copolymer salt (B) obtained by the addition is an essential component.

The first copolymer (A) is composed of two kinds of monomers (a) and (b) represented by the general formula (1) and 50% by weight (total monomer components). Weight% based on the sum of
It is obtained by copolymerizing a monomer containing the following unsaturated carboxylic acid monomer (c) as an essential component, and the monomers (a), (b) and (c) as essential components In addition, a monomer (d) copolymerizable with these monomers can be used as a copolymer component. Further, the first copolymer salt (B) is obtained by further neutralizing the first copolymer (A) with an alkaline substance.

In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² O represents one or a mixture of two or more oxyalkylene groups having 2 to 4 carbon atoms. May be added in the form of a block or may be added randomly, and n is the average number of moles of the oxyalkylene group added, and is a positive number of 1 or more, preferably a positive number of 2 to 500, and more preferably Represents a positive number of 2 to 300;
³ represents an alkyl group having 4 to 30 carbon atoms in the monomer (a), and represents a hydrogen atom in the monomer (b) or a carbon number smaller than the carbon number of R ^{3 in} the monomer (a). An alkyl group having at least 2 carbon atoms, preferably an alkyl group having at least 2 carbon atoms, more preferably an alkyl group having at least 3 carbon atoms.

The unsaturated carboxylic acid monomer (c) used in the present invention is an unsaturated monomer having a carboxyl group, and is represented by the following general formula (2) or an anhydride thereof. It is.

General formula (2)

[0025]

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(Wherein R ⁴ , R ⁵ and R ⁶ are hydrogen atoms,
X represents a methyl group or a (CH ₂ ) mCOOX group, X represents hydrogen, a monovalent metal, a divalent metal, an ammonium group or an organic amine group, and m represents an integer of 0 to 2. The second cement admixture according to the present invention comprises a second copolymer (A1) described later and / or the second copolymer (A1).
Is further neutralized with an alkaline substance to obtain a second copolymer salt (B1), a third copolymer (A2) described later, and / or the third copolymer (A2). The essential component is a mixture with the third copolymer salt (B2) obtained by neutralization with an alkaline substance.

The second copolymer (A1) comprises a monomer (a) represented by the above general formula (1) and an unsaturated carboxylic acid monomer (c) as essential components. Monomer (a) which is obtained by copolymerizing a monomer and is an essential component
In addition to (c) and (c), a monomer (d) copolymerizable with these monomers can be used as a copolymerization component. or,
The second copolymer salt (B1) is formed of the second copolymer (A
It is obtained by further neutralizing 1) with an alkaline substance.

The third copolymer (A2) comprises a monomer (b) represented by the above general formula (1) and an unsaturated carboxylic acid monomer (c) as essential components. Monomer (b) which is obtained by copolymerizing a monomer and is an essential component
In addition to (c) and (c), a monomer (d) copolymerizable with these monomers can be used as a copolymerization component. or,
The third copolymer salt (B2) is composed of the third copolymer (A
It is obtained by further neutralizing 2) with an alkaline substance.

The weight ratio of the second copolymer (A1) and / or copolymer salt (B1) to the third copolymer (A2) and / or copolymer salt (B2) is 1 : 99-99: 1,
Preferably 3:97 to 97: 3, more preferably 10:
90 to 90:10.

The monomer (a) represented by the general formula (1) used in the present invention is 1-butanol, 1-hexanol, cyclohexanol, octanol, 2-ethyl-
1-hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol and the like,
An alkyl group having 4 to 30 carbon atoms, preferably 4 to 2 carbon atoms
Ester compounds of alkoxy (poly) alkylene glycols obtained by adding alkylene oxides having 2 to 4 carbon atoms to aliphatic or alicyclic alcohols having 2 alkyl groups and (meth) acrylic acid It is. Specific examples include 1-butoxy (poly) ethylene glycol mono (meth) acrylate and 2-methyl-1
-Propoxy (poly) ethylene glycol mono (meth)
Acrylate, 2-butoxy (poly) ethylene glycol mono (meth) acrylate, 2-methyl-2-propoxy (poly) ethylene glycol mono (meth) acrylate, 1-pentoxy (poly) ethylene glycol mono (meth) acrylate, 2- Methyl-1-butoxy (poly) ethylene glycol mono (meth) acrylate, 3
-Methyl-1-butoxy (poly) ethylene glycol mono (meth) acrylate, 2-pentoxy (poly) ethylene glycol mono (meth) acrylate, 3-pentoxy (poly) ethylene glycol mono (meth) acrylate, 2-methyl-2 -Butoxy (poly) ethylene glycol mono (meth) acrylate, 1-hexoxy (poly) ethylene glycol mono (meth) acrylate, cyclohexoxy (poly) ethylene glycol mono (meth) acrylate, 1-octoxy (poly) ethylene glycol mono ( Meth) acrylate, 2-ethyl-1-
Hexoxy (poly) ethylene glycol mono (meth) acrylate, nonylalkoxy (poly) ethylene glycol mono (meth) acrylate, laurylalkoxy (poly) ethylene glycol mono (meth) acrylate, cetyl alkoxy (poly) ethylene glycol mono (meth) acrylate , Stearylalkoxy (poly)
Various alkoxy (poly) ethylene glycol mono (meth) acrylates such as ethylene glycol mono (meth) acrylate; 1-butoxy (poly) propylene glycol mono (meth) acrylate, 2-methyl-1-propoxy (poly) propylene glycol mono (Meth) acrylate, 2-butoxy (poly) propylene glycol mono (meth) acrylate, 2-methyl-2-propoxy (poly) propylene glycol mono (meth) acrylate, cyclohexoxy (poly) propylene glycol mono (meth) acrylate, 1-octoxy (poly) propylene glycol mono (meth) acrylate, 2-ethyl-1-hexoxy (poly) propylene glycol mono (meth) acrylate, nonylalkoxy (poly) propylene glycol Various alkoxy (poly) such as mono (meth) acrylate, lauryl alkoxy (poly) propylene glycol mono (meth) acrylate, cetyl alkoxy (poly) propylene glycol mono (meth) acrylate, stearyl alkoxy (poly) propylene glycol mono (meth) acrylate ) Propylene glycol mono (meth) acrylates; 1-butoxy (poly) butylene glycol mono (meth) acrylate, 2
-Methyl-1-propoxy (poly) butylene glycol mono (meth) acrylate, 2-butoxy (poly) butylene glycol mono (meth) acrylate, 2-methyl-2-propoxy (poly) butylene glycol mono (meth) acrylate, cyclohexyl Soxy (poly) butylene glycol mono (meth) acrylate, 1-octoxy (poly) butylene glycol mono (meth) acrylate, 2-ethyl-1-hexoxy (poly) butylene glycol mono (meth) acrylate, nonylalkoxy (poly) butylene Glycol mono (meth) acrylate, laurylalkoxy (poly) butylene glycol mono (meth) acrylate, cetylalkoxy (poly) butylene glycol mono (meth) acrylate, stearylalkoxy (poly) butyl Glycol mono (meth)
Various alkoxy (poly) butylene glycol mono (meth) acrylates such as acrylates;
The average number of moles of the oxyalkylene group of the monomer (a) is a positive number of 1 or more, and the hydrophilicity decreases as the average number of moles decreases, while the average number of moles increases. Since the reactivity decreases with an increase in the number, a positive number of 2 to 500 is preferable, and a positive number of 2 to 300 is more preferable. or,
Any two or more kinds of alkylene oxide adducts selected from ethylene oxide, propylene oxide and butylene oxide can be used in any of random addition, block addition, alternate addition and the like. or,
Two or more of these monomers (a) may be used.

The monomer (b) represented by the general formula (1) used in the present invention is a compound represented by the general formula (1), wherein the terminal group of the oxyalkylene group represented by R ³ is a hydrogen atom,
Or, an alkyl group having a carbon number smaller than the number of carbon atoms of the terminal group of the oxyalkylene group of the monomer (a), preferably an alkyl group having a carbon number less than 2 or more, more preferably an alkyl group having a carbon number less than 3 or more Any group is acceptable. Therefore, the monomer (b) is obtained by adding an alkylene oxide adduct having 2 to 4 carbon atoms to (meth) acrylic acid, or methanol, ethanol, 1-propanol,
Any of aliphatic alcohols such as propanol, 1-butanol, 1-hexanol, octanol, 2-ethyl-1-hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol, and alicyclic alcohols such as cyclohexanol Alkoxy (poly) alkylene glycols obtained by adding an alkylene oxide having 2 to 4 carbon atoms to
It is an ester compound with (meth) acrylic acid. Specific examples include (poly) ethylene glycol mono (meth) acrylate; (poly) propylene glycol mono (meth) acrylate; (poly) butylene glycol mono (meth) acrylate; methoxy (poly) ethylene glycol mono (meth) acrylate, Ethoxy (poly) ethylene glycol mono (meth) acrylate, 1-propoxy (poly) ethylene glycol mono (meth) acrylate, 2-propoxy (poly) ethylene glycol mono (meth) acrylate, 1-butoxy (poly) ethylene glycol mono (Meth) acrylate, 2-methyl-1-propoxy (poly) ethylene glycol mono (meth) acrylate, 2-butoxy (poly) ethylene glycol mono (meth) acrylate, 2-methyl-2-propoxy (poly) Ethylene glycol mono (meth) acrylate, 1-pentoxy (poly) ethylene glycol mono (meth) acrylate, 1-hexoxy (poly) ethylene glycol mono (meth) acrylate, cyclohexoxy (poly) ethylene glycol mono (meth) acrylate, 1 -Octoxy (poly) ethylene glycol mono (meth) acrylate, 2-ethyl-1-hexoxy (poly) ethylene glycol mono (meth) acrylate, nonylalkoxy (poly) ethylene glycol mono (meth) acrylate, laurylalkoxy (poly) ethylene Glycol mono (meth) acrylate, cetylalkoxy (poly) ethylene glycol mono (meth) acrylate, stearylalkoxy (poly) ethylene glycol mono (meth) acrylate Various alkoxy (poly) ethylene glycol mono (meth) acrylates; methoxy (poly) propylene glycol mono (meth) acrylate, ethoxy (poly) propylene glycol mono (meth) acrylate, 1-propoxy (poly) propylene glycol mono (meth) ) Acrylate,
2-propoxy (poly) propylene glycol mono (meth) acrylate, 1-butoxy (poly) propylene glycol mono (meth) acrylate, 2-methyl-1-
Propoxy (poly) propylene glycol mono (meta)
Acrylate, 2-butoxy (poly) propylene glycol mono (meth) acrylate, 2-methyl-2-propoxy (poly) propylene glycol mono (meth) acrylate, cyclohexoxy (poly) propylene glycol mono (meth) acrylate, 1-octoxy (Poly) propylene glycol mono (meth) acrylate,
2-ethyl-1-hexoxy (poly) propylene glycol mono (meth) acrylate, nonylalkoxy (poly) propylene glycol mono (meth) acrylate,
Various alkoxy (poly) propylene glycol mono (meth) such as lauryl alkoxy (poly) propylene glycol mono (meth) acrylate, cetyl alkoxy (poly) propylene glycol mono (meth) acrylate, stearyl alkoxy (poly) propylene glycol mono (meth) acrylate ) Acrylates; methoxy (poly) butylene glycol mono (meth) acrylate, ethoxy (poly) butylene glycol mono (meth)
Acrylate, 1-propoxy (poly) butylene glycol mono (meth) acrylate, 2-propoxy (poly) butylene glycol mono (meth) acrylate, 1
-Butoxy (poly) butylene glycol mono (meth) acrylate, 2-methyl-1-propoxy (poly) butylene glycol mono (meth) acrylate, 2-butoxy (poly) butylene glycol mono (meth) acrylate, 2-methyl-2 -Propoxy (poly) butylene glycol mono (meth) acrylate, cyclohexoxy (poly) butylene glycol mono (meth) acrylate, 1-octoxy (poly) butylene glycol mono (meth) acrylate, 2-ethyl-1-hexoxy (poly) Butylene glycol mono (meth) acrylate, nonylalkoxy (poly) butylene glycol mono (meth) acrylate, laurylalkoxy (poly) butylene glycol mono (meth) acrylate, cetylalkoxy (poly) butylene Call mono (meth) acrylate, various alkoxy (poly) butylene glycol mono (meth) acrylates such as stearyl alkoxy (poly) butylene glycol mono (meth) acrylate; and the like. The average number of moles of the oxyalkylene group of the monomer (b) is a positive number of 1 or more, but the hydrophilicity decreases as the average number of moles decreases,
On the other hand, since the reactivity decreases as the average number of moles increases, a positive number of 2 to 500 is preferable, and a positive number of 2 to 300 is more preferable. In addition, any two selected from ethylene oxide, propylene oxide and butylene oxide.
As for the alkylene oxide adducts of more than one kind, any of random addition, block addition, alternate addition and the like can be used. Further, two or more of these monomers (b) may be used. In order to ensure the balance between hydrophilicity and hydrophobicity, it is preferable that an oxyethylene group is contained as an essential component in the oxyalkylene group of any one of the monomers (a) and (b).

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, and acrylic acid monomers. Amine salts and the like.
Further, as the unsaturated dicarboxylic acid monomer, maleic anhydride, maleic acid, itaconic anhydride, itaconic acid, citraconic anhydride, citraconic acid, fumaric acid, or a metal salt, an ammonium salt, an amine salt thereof and the like. No.
Incidentally, two or more of these monomers (c) may be used in combination.

The monomer (d) is a monomer copolymerizable with the monomers (a), (b) and (c). Examples of the monomer (d) include unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid, and having 1 to 30 carbon atoms.
Half-esters and diesters with alcohols; half-amides and diamides of the unsaturated dicarboxylic acids with amines having 1 to 30 carbon atoms; 1 to 500 moles of alkylene oxides having 2 to 4 carbon atoms added to the alcohols and amines A half ester or diester of an alkyl (poly) alkylene glycol with the unsaturated dicarboxylic acid; a half of the unsaturated dicarboxylic acid with a glycol having 2 to 4 carbon atoms or a polyalkylene glycol having an addition mole number of 2 to 500 of these glycols. Esters, diesters; half amides of maleamic acid with glycols having 2 to 4 carbon atoms or polyalkylene glycols having 2 to 500 moles of these glycols added; triethylene glycol di (meth) acrylate, (poly) ethylene glycol di ( Meta) a (Poly) alkylene glycol di (meth) acrylates such as acrylate, polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate; hexanediol di (meth) acrylate, trimethylolpropane Bifunctional (meth) acrylates such as tri (meth) acrylate and trimethylolpropane di (meth) acrylate; (poly) alkylene glycol dimaleates such as triethylene glycol dimaleate and polyethylene glycol dimaleate; vinyl sulfonate; ) Allyl sulfonate, 2-
(Meth) acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth)
Acryloxy-2-hydroxypropyl sulfonate,
3- (meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2
-Hydroxypropyloxysulfobenzoate, 4-
Unsaturated sulfonic acids such as (meth) acryloxybutylsulfonate, (meth) acrylamidomethylsulfonic acid, (meth) acrylamidoethylsulfonic acid, 2-methylpropanesulfonic acid (meth) acrylamide, styrenesulfonic acid, and monovalent thereof Metal salts, divalent metal salts, ammonium salts and organic amine salts; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2- (meth) acrylate Esters of (meth) acrylic acid such as ethylhexyl, methyl crotonate, glycidyl (meth) acrylate and alcohols having 1 to 30 carbon atoms;
Amides of unsaturated monocarboxylic acids and amines having 1 to 30 carbon atoms such as methyl (meth) acrylamide; vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene; Alkanediol mono (meth) acrylates such as 4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate; butadiene, isoprene, 2- Methyl-1,3-butadiene, 2-chloro-
Dienes such as 1,3-butadiene; unsaturated amides such as (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; and (meth) acrylonitrile , Unsaturated cyanides such as α-chloroacrylonitrile; unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate;
Unsaturated amines such as methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, and vinylpyridine; divinyl such as divinylbenzene Aromatics; cyanurates such as triallyl cyanurate; allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; unsaturated amino compounds such as dimethylaminoethyl (meth) acrylate; methoxypolyethylene glycol monovinyl ether Vinyl ethers or allyl ethers such as polyethylene glycol monovinyl ether, methoxy polyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether; Dimethylsiloxane propylaminomaleamic acid, polydimethylsiloxaneaminopropyleneaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (dipropyleneaminomaleamic acid), polydimethylsiloxane -(1-propyl-3-acrylate), polydimethylsiloxane-
Siloxane derivatives such as (1-propyl-3-methacrylate), polydimethylsiloxane-bis- (1-propyl-3-acrylate), polydimethylsiloxane-bis- (1-propyl-3-methacrylate);
Unsaturated phosphates such as acryloyloxyethyl phosphate and 2-methacryloyloxyethyl phosphate; and one or more of these can be used.

The first copolymer (A) of the present invention comprises a monomer (a), a monomer (b) and a monomer having a content of not more than 50% by weight (% by weight based on the total of all monomer components). Monomer (c) or monomer (a), monomer (b), monomer (c) and monomer (d) of 50% by weight or less (% by weight based on the total of all monomer components) ) Are copolymerized. The reaction ratio of these monomers is as follows: monomer (a) / monomer (b) / monomer (c) / monomer (d) = 1 to 98/1 to 98/1 to 50/0 ~ 50
(% By weight), and preferably, monomer (a) / monomer (b) / monomer (c) / monomer (d) =
The range is from 5 to 94/5 to 94/1 to 40/0 to 50 (% by weight), and more preferably, monomer (a) / monomer (b) / monomer (c) / monomer Monomer (d) = 10-85 / 1
The range is from 0 to 85/5 to 40/0 to 40 (% by weight). 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 5
If the content exceeds 0% by weight, the slump retention is remarkably reduced, which is not preferable.

In order to obtain the copolymer (A), 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 a 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 (A) and the convenience at the time of using the copolymer (A), it was selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. It is preferable to use at least one kind. 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.

In order to control the molecular weight of the copolymer (A) obtained, a thiol chain transfer agent may be used in combination. Thiol chain transfer agents used in this case, the general formula HS-R ¹⁰ -Eg (provided that wherein R ¹⁰ is C 1 -C
Represents an alkyl group of ~ 2, E is -OH, -COOM,
Represents a —COOR ¹¹ or —SO ₃ M group, M represents hydrogen, 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, and g represents 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 (A) thus obtained
Is used as a main component of the cement admixture as it is, but if necessary, a copolymer salt (B) obtained by further neutralizing with an alkaline substance may be used as a main component of the cement admixture. Preferred examples of the alkaline substance include inorganic substances such as hydroxides, chlorides and carbon salts of monovalent and divalent metals; ammonia; and organic amines.

The second copolymer (A1) of the present invention is obtained by copolymerizing the monomers (a) and (c) or the monomers (a), (c) and (d). is there. The reaction ratio of these monomers is such that monomer (a) / monomer (c) / monomer (d) = 1
The range of -99/1 to 99/0 to 50 (% by weight) is appropriate, and preferably, monomer (a) / monomer (c) / monomer (d) = 5 to 99/1. To 95/0 to 50 (% by weight), and more preferably, monomer (a) / monomer (c) / monomer (d) = 10 to 95/5 to 90/0. 4
0 (% by weight). If the ratio is out of this range, a desired cement admixture with excellent performance cannot be obtained.

The third copolymer (A2) of the present invention is obtained by copolymerizing the monomers (b) and (c) or the monomers (b), (c) and (d). is there. The reaction ratio of these monomers is such that monomer (b) / monomer (c) / monomer (d) = 1
The range of -99/1 to 99/0 to 50 (% by weight) is appropriate, and preferably, monomer (b) / monomer (c) / monomer (d) = 5 to 99/1. To 95/5 to 50 (% by weight), and more preferably, monomer (b) / monomer (c) / monomer (d) = 10 to 95/5 to 90/0. 4
0 (% by weight). If the ratio is out of this range, a desired cement admixture with excellent performance cannot be obtained.

The second and third copolymers (A1) and (A2), and the second and third copolymer salts (B1) and (B2) are also the first copolymer (A )) And the first copolymer salt (B).

The weight ratio of the second copolymer (A1) and / or copolymer salt (B1) to the third copolymer (A2) and / or copolymer salt (B2) is 1 : 99-99: 1,
Preferably 3:97 to 97: 3, more preferably 10:
90 to 90:10. In addition, the second copolymer (A1)
And the ratio (% by weight) of the monomer (c) introduced into the third copolymer (A2) and the ratio (% by weight) of the monomer (c) introduced into the third copolymer (A2) Is preferably 1 to 50% by weight, more preferably 1 to 40% by weight, and still more preferably 5 to 40% by weight. If the proportion of the monomer (c) exceeds 50% by weight, the slump retention is remarkably reduced, which is not preferable.

The weight average molecular weight of (A), (A1), (A2) and / or the copolymer salts (B), (B1) and (B2) used as the cement admixture of the present invention is as follows. 500-500,000, especially 5,000-30
It is preferable to be in the range of 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, a molecular weight exceeding 500,000 is not preferable because the water reducing performance and the slump holding performance of the cement admixture are reduced.

The cement admixture of the present invention can be used for hydraulic cements such as Portland cement, cement containing a high content of belite, alumina cement, various types of mixed cement, and hydraulic materials other than cement such as gypsum.

When the cement admixture of the present invention is used for mortar or concrete using hydraulic cement,
0.01 to 2.0% of cement weight, preferably 0.0
What is necessary is just to add the amount of the ratio which becomes 2-1.0% at the time of kneading. This addition achieves a high water reduction rate, improves material separation resistance, improves slump retention performance, reduces unit water volume,
Various favorable effects such as an increase in strength and an improvement in durability are provided. If the added amount 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 and the economical disadvantage is disadvantageous.

In the cement composition of the present invention, the amount of cement used per m ^{3 of the} cement composition and the unit water amount are not particularly limited, but the unit water amount is 120 to 185 kg / m 2.
^3, the water / cement weight ratio = 0.15 to 0.7, preferably in unit water amount 120～175Kg / m ^3, water / cement weight ratio = 0.2 to 0.5 is recommended.

The cement admixture of the present invention can be used in combination with a known cement dispersant. Known cement dispersants used in combination include, for example, lignin sulfonic acid salt; polyol derivative; naphthalene sulfonic acid formalin condensate; melamine sulfonic acid formalin condensate; polystyrene sulfonic acid salt; Aminosulfonic acids such as phenol-formaldehyde condensates;
267705, a copolymer of a polyalkylene glycol mono (meth) acrylate compound and a (meth) acrylic compound and / or a salt thereof as the component (a), and a polyalkylene glycol mono (meth) as the component (b) A) a copolymer of an allyl ether compound and maleic anhydride and / or a hydrolyzate and / or a salt thereof;
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. Polycarboxylic acids (salts) such as (meth) acrylic acid esters and, if necessary, copolymers comprising monomers copolymerizable therewith, or salts thereof; Multiple combinations of agents are also possible.

Further, the cement admixture of the present invention can be used in combination with other known cement additives (materials) as exemplified below.

(1) Water-soluble polymer substance: Polymerization of unsaturated carboxylic acid such as polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), and sodium salt of acrylic acid / maleic acid copolymer Stuff;
Polyoxyethylene or polyoxypropylene polymers such as polyethylene glycol and polypropylene glycol or copolymers thereof; methylcellulose,
Nonionic cellulose ethers such as ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, carboxyethylcellulose and hydroxypropylcellulose; yeast glucan, xanthan gum, β-1.3 glucan (linear, branched chain) Polysaccharides produced by microbial fermentation such as curdlan, baramiron, bakiman, scleroglucan, laminaran, etc .; polyacrylamide; polyvinyl alcohol; starch; starch phosphate; alginic acid Sodium; gelatin; copolymers of acrylic acid having an amino group in the molecule and quaternary compounds thereof.

(2) Polymer emulsion: copolymers of various vinyl monomers such as alkyl (meth) acrylate and the like.

(3) Delaying agents: gluconic acid, glucoheptonic acid, arabonic acid, malic acid or citric acid, and inorganic or organic salts thereof such as sodium, potassium, calcium, magnesium, ammonium, triethanolamine, etc. Oxycarboxylic acid; monosaccharides such as glucose, fructose, galactose, saccharose, xylose, abitose, repose, and isomerized sugar; oligosaccharides such as disaccharide, trisaccharide; and oligosaccharides such as dextrin;
Or polysaccharides such as dextran; saccharides such as molasses containing them; sugar alcohols such as sorbitol; magnesium silicofluoride; phosphoric acid and salts or borates thereof; aminocarboxylic acids and salts thereof; Humic acid; tannic acid; phenol; polyhydric alcohols such as glycerin.

(4) Early strength agent / promoter: calcium chloride,
Calcium nitrite, calcium nitrate, calcium bromide,
Soluble calcium salts such as 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;

(5) Mineral oil-based antifoaming agents: kerosene, liquid paraffin, etc.

(6) Oil-based antifoaming agents: animal and vegetable oils, sesame oil,
Castor oil, their alkylene oxide adducts 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-based antifoaming agents: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adduct; diethylene glycol heptyl ether, polyoxyethylene oleyl ether;
(Poly) oxyalkyl ethers such as polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene 2-ethylhexyl ether, and oxyethylene oxypropylene adducts to higher alcohols having 12 to 14 carbon atoms; polyoxypropylene phenyl ether, polyoxy (Poly) oxyalkylene (alkyl) aryl ethers such as ethylene nonylphenyl ether; 2,4,7,9-tetramethyl-5-decyne-
4,7-diol, 2,5-dimethyl-3-hexyne-
Acetylene ethers obtained by addition-polymerizing an alkylene oxide to acetylene alcohol such as 2,5-diol, 3-methyl-1-butyn-3-ol; diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate, etc. (Poly) oxyalkylene fatty acid esters;
(Poly) oxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan trioleate; (poly) oxy such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecyl phenol ether sulfate Alkylene alkyl (aryl) ether sulfates; (poly)
(Poly) such as oxyethylene stearyl phosphate
Oxyalkylenealkyl phosphates; (poly) oxyalkylenealkylamines such as polyoxyethylene laurylamine; polyoxyalkyleneamides;

(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 antifoaming agents: tributyl phosphate, sodium octyl phosphate and the like.

(13) Metal soap antifoaming agents: aluminum stearate, calcium oleate, etc.

(14) Silicone-based antifoaming agents: 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 (alkyl benzene sulfonic acid), LAS (linear alkyl benzene 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 sulfonates and the like.

(16) Other surfactants: 6 to 3 per molecule such as octadecyl alcohol and stearyl alcohol.
Aliphatic monohydric alcohol having 0 carbon atoms, alicyclic monohydric alcohol having 6 to 30 carbon atoms in a molecule such as abiethyl alcohol, 6 to 30 carbon atoms in a molecule such as dodecyl mercaptan, etc. Monovalent mercaptans having atoms, nonylphenols and the like, alkylphenols having 6 to 30 carbon atoms in the molecule, dodecylamines and the like having 6 to 30 carbon atoms in the molecule, molecules such as lauric acid and stearic acid Polyalkylene oxide derivatives in which an alkylene oxide such as ethylene oxide or propylene oxide is added in an amount of 10 mol or more to a carboxylic acid having 6 to 30 carbon atoms therein; and may have an alkyl group or an alkoxy group as a substituent. Alkyl diphenyl ether in which two phenyl groups having a sulfone group are ether-bonded Sulfonates; various anionic surfactants; alkylamine acetates, various cationic surfactants such as alkyl trimethyl ammonium chloride; and various nonionic surfactants; various amphoteric surfactants.

(17) Waterproofing agent: fatty acid (salt), fatty acid ester, oil and fat, silicone, 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. A plurality of these known cement additives (materials) can be used in combination.

[0072]

The present invention will be described more specifically with reference to the following examples. The first copolymer (A) and the second copolymer (A
Production examples of 2) and the third copolymer (A3) are shown below. In the examples, unless otherwise specified,% means% by weight,
Parts are parts by weight.

Production Example 1 Production of Cement Admixture (1) 700 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 stirred. The atmosphere was replaced with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Next, 150 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 120), 90 parts of methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 40), 60 parts of methacrylic acid, 200 parts of water
And a monomer aqueous solution mixed with 5.0 parts of 3-mercaptopropionic acid as a chain transfer agent and 200 parts of a 1.5% ammonium persulfate aqueous solution are added dropwise over 2 hours. 10
0 parts were added dropwise in 1 hour. After that, it is 8 for one hour
While maintaining the temperature at 0 ° C., the polymerization reaction was completed to obtain a cement admixture (1) corresponding to the first copolymer, which was composed of an aqueous solution of a copolymer having a weight average molecular weight of 35,000.

Production Example 2 Production of Cement Admixture (2) 700 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 stirred. The atmosphere was replaced with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Next, 150 parts of cyclohexoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 70), 90 parts of methoxypolyethylene glycol monomethacrylate (average number of moles of added ethylene oxide: 100), 60 parts of methacrylic acid, 2 parts of water
And a monomer aqueous solution obtained by mixing 6.5 parts of 3-mercaptopropionic acid as a chain transfer agent and 1.5%
200 parts of ammonium persulfate aqueous solution was dropped in 2 hours,
After completion of the dropwise addition, 100 parts of a 1.5% 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 a cement admixture (2) corresponding to the first copolymer, comprising an aqueous solution of a copolymer having a weight average molecular weight of 30,000, was obtained. .

Production Example 3 Production of Cement Admixture (3) 700 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 stirred. The atmosphere was replaced with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Next, 120 parts of 1-octoxypolyethylene glycol monomethacrylate (135 average addition moles of ethylene oxide), 120 parts of ethoxy polyethylene glycol monomethacrylate (35 average addition moles of ethylene oxide), 60 parts of methacrylic acid, 2 parts of water
And an aqueous monomer solution containing 5.0 parts of 3-mercaptopropionic acid as a chain transfer agent and 1.5%
200 parts of ammonium persulfate aqueous solution was dropped in 2 hours,
After completion of the dropwise addition, 100 parts of a 1.5% 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 a cement admixture (3) corresponding to the first copolymer, comprising an aqueous solution of a copolymer having a weight average molecular weight of 33,000, was obtained. .

Production Example 4 Production of Cement Admixture (4) 700 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 stirred. The atmosphere was replaced with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Next, 105 parts of 1-octoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide 135), 90 parts of ethoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 35), 30 parts of ethyl methacrylate 30
Parts, 75 parts of methacrylic acid, 200 parts of water, and a monomer aqueous solution obtained by mixing 5.1 parts of 3-mercaptopropionic acid as a chain transfer agent and 200 parts of a 1.5% aqueous solution of ammonium persulfate were added dropwise over 2 hours. And 1.
100 parts of a 5% aqueous solution of ammonium persulfate was added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and a cement admixture (4) corresponding to the first copolymer, comprising an aqueous solution of a copolymer having a weight average molecular weight of 34,000, was obtained. .

Production Example 5 Production of Cement Admixture (5) 700 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 stirred. The atmosphere was replaced with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Next, 60 parts of lauryl alkoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 220), 180 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 40), 60 parts of methacrylic acid 60
, 200 parts of water and 5.1 parts of 3-mercaptopropionic acid as a chain transfer agent, and 200 parts of a 1.5% ammonium persulfate aqueous solution were added dropwise over 2 hours. 100 parts of a 10% aqueous solution of ammonium persulfate were added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and a cement admixture (5) corresponding to the first copolymer, comprising an aqueous solution of a copolymer having a weight average molecular weight of 37000, was obtained. .

Production Example 6 Production of Cement Admixture (6) 700 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 stirred. The atmosphere was replaced with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Next, 60 parts of stearylalkoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 280) 60 parts, 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 120) 165 parts, methacrylic acid 7
A monomer aqueous solution obtained by mixing 5 parts, 200 parts of water, and 7.7 parts of 3-mercaptopropionic acid as a chain transfer agent and 200 parts of a 1.5% aqueous solution of ammonium persulfate were added dropwise over 2 hours. 100 parts of a 5% aqueous solution of ammonium persulfate was added dropwise over 1 hour. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and a cement admixture (6) corresponding to the first copolymer, comprising an aqueous solution of a copolymer having a weight average molecular weight of 43,000, was obtained. .

Production Example 7 Production of Cement Admixture (7) 222.5 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.
The atmosphere in the reaction vessel was replaced with nitrogen under stirring, and the pressure was reduced to 80 in a nitrogen atmosphere.
Heated to ° C. Next, 187.6 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 25), 62.6 parts of methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 23), methacrylic acid 49.
An aqueous monomer solution obtained by mixing 8 parts, 75.0 parts of water, and 2.6 parts of 3-mercaptopropionic acid as a chain transfer agent was dropped into the reaction vessel over 4 hours. At the same time, an initiator aqueous solution consisting of 3.4 parts of ammonium persulfate and 63.2 parts of water was dropped into the reaction vessel over 5 hours. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and a cement admixture (7) corresponding to the first copolymer, comprising an aqueous solution of a copolymer having a weight average molecular weight of 21,800, was obtained. .

Production Example 8 Production of Cement Admixture (8) 222.5 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.
The atmosphere in the reaction vessel was replaced with nitrogen under stirring, and the pressure was reduced to 80 in a nitrogen atmosphere.
Heated to ° C. Next, 125.1 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 25), 125.1 parts of methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 23), methacrylic acid 4
A monomer aqueous solution obtained by mixing 9.8 parts, 75.0 parts of water, and 2.5 parts of 3-mercaptopropionic acid as a chain transfer agent was dropped into the reaction vessel over 4 hours. At the same time, an initiator aqueous solution consisting of 3.4 parts of ammonium persulfate and 63.2 parts of water was dropped into the reaction vessel over 5 hours.
Thereafter, the temperature was maintained at 80 ° C. for 1 hour to complete the polymerization reaction, and a cement admixture (8) corresponding to the first copolymer, which was composed of an aqueous solution of a copolymer having a weight average molecular weight of 20,800, was obtained. .

Production Example 9 Production of Cement Admixture (9) 847.3 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.
The atmosphere in the reaction vessel was replaced with nitrogen under stirring, and the pressure was reduced to 80 in a nitrogen atmosphere.
Heated to ° C. Next, 183.8 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 75), 91.8 parts of methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide 75), methacrylic acid 24.
A monomer aqueous solution obtained by mixing 4 parts, 200.0 parts of water, and 2.7 parts of 3-mercaptopropionic acid as a chain transfer agent was dropped into the reaction vessel over 4 hours. At the same time,
An aqueous initiator solution consisting of 3.4 parts of ammonium persulfate and 146.6 parts of water was dropped into the reaction vessel over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour to complete the polymerization reaction, and a cement admixture (9) corresponding to the first copolymer, which was composed of an aqueous solution of a copolymer having a weight average molecular weight of 32,800, was obtained. .

Production Example 10 Production of Cement Admixture (10) 847.3 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.
The atmosphere in the reaction vessel was replaced with nitrogen under stirring, and the pressure was reduced to 80 in a nitrogen atmosphere.
Heated to ° C. Next, 137.8 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 75), 137.8 parts of methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 75), methacrylic acid 2
4.4 parts, 200.0 parts of water, and 3- as a chain transfer agent
An aqueous monomer solution mixed with 2.7 parts of mercaptopropionic acid was dropped into the reaction vessel over 4 hours. At the same time, an initiator aqueous solution consisting of 3.4 parts of ammonium persulfate and 146.6 parts of water was dropped into the reaction vessel over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for one hour,
The polymerization reaction was completed to obtain a cement admixture (10) corresponding to the first copolymer, which was composed of an aqueous solution of a copolymer having a weight average molecular weight of 34,300.

Production Example 11 Production of Cement Admixture (11) 500 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 stirred. The atmosphere was replaced with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Next, 225 parts of lauryl alkoxy polyethylene glycol monomethacrylate (average number of moles of added ethylene oxide: 220), 75 parts of methacrylic acid,
A monomer aqueous solution obtained by mixing 400 parts of water and 9.5 parts of 3-mercaptopropionic acid as a chain transfer agent;
200 parts of a 5% ammonium persulfate aqueous solution was added dropwise over 2 hours, and after completion of the addition, 100 parts of a 1.5% 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 a cement admixture (11) corresponding to the second copolymer, comprising an aqueous solution of a copolymer having a weight average molecular weight of 35,000, was obtained. .

Production Example 12 Production of Cement Admixture (12) 700 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 stirred. The atmosphere was replaced with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Next, 270 parts of methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 100), methacrylic acid 30 parts, water 200
, And a monomer aqueous solution obtained by mixing 6.1 parts of 3-mercaptopropionic acid as a chain transfer agent and 200 parts of a 1.5% ammonium persulfate aqueous solution are dropped over 2 hours. 10
0 parts were added dropwise in 1 hour. After that, it is 8 for one hour
While maintaining the temperature at 0 ° C., the polymerization reaction was completed, and a cement admixture (12) corresponding to a third copolymer, comprising an aqueous solution of a copolymer having a weight average molecular weight of 34,000, was obtained.

Production Example 13 Production of Cement Admixture (13) 597.3 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.
The atmosphere in the reaction vessel was replaced with nitrogen under stirring, and the pressure was reduced to 80 in a nitrogen atmosphere.
Heated to ° C. Next, 275.6 parts of lauryl alkoxy polyethylene glycol monomethacrylate (average number of moles of added ethylene oxide: 75), methacrylic acid 2
An aqueous monomer solution obtained by mixing 4.4 parts, 450 parts of water, and 2.7 parts of 3-mercaptopropionic acid as a chain transfer agent was dropped into the reaction vessel over 4 hours. At the same time,
An aqueous initiator solution consisting of 3.4 parts of ammonium persulfate and 146.6 parts of water was dropped into the reaction vessel over 5 hours. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and a cement admixture (13) corresponding to the second copolymer, comprising an aqueous solution of a copolymer having a weight average molecular weight of 38,100, was obtained. .

Production Example 14 Production of Cement Admixture (14) 848.3 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.
The atmosphere in the reaction vessel was replaced with nitrogen under stirring, and the pressure was reduced to 80 in a nitrogen atmosphere.
Heated to ° C. Next, 275.6 parts of methoxypolyethylene glycol monomethacrylate (average number of added moles of ethylene oxide: 75), 24.4 parts of methacrylic acid,
A monomer aqueous solution obtained by mixing 200 parts of water and 1.7 parts of 3-mercaptopropionic acid as a chain transfer agent was dropped into the reaction vessel over 4 hours. At the same time, an initiator aqueous solution consisting of 3.4 parts of ammonium persulfate and 146.6 parts of water was dropped into the reaction vessel over 5 hours. Thereafter, the temperature was maintained at 80 ° C. continuously for 1 hour to complete the polymerization reaction, and a cement admixture (14) corresponding to the third copolymer, comprising a copolymer aqueous solution having a weight average molecular weight of 56,000,
I got

Production Example 15 (Comparative) Production of Cement Admixture (15) 222.5 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.
The atmosphere in the reaction vessel was replaced with nitrogen under stirring, and the pressure was reduced to 80 in a nitrogen atmosphere.
Heated to ° C. Next, 45.0 parts of 1-butoxy polyethylene glycol monomethacrylate (average addition mole number of ethylene oxide: 25), 90.0 parts of methoxy polyethylene glycol monomethacrylate (average addition mole number of ethylene oxide: 23), 165.
A monomer aqueous solution obtained by mixing 0 parts, 75.0 parts of water, and 5.2 parts of 3-mercaptopropionic acid as a chain transfer agent was dropped into the reaction vessel over 4 hours. At the same time, an initiator aqueous solution consisting of 3.4 parts of ammonium persulfate and 63.2 parts of water was dropped into the reaction vessel over 5 hours. Thereafter, the temperature was maintained at 80 ° C. for 1 hour, and the polymerization reaction was completed to obtain a cement admixture (15) composed of an aqueous solution of a copolymer having a weight average molecular weight of 25,800.

Mortar test The mortars obtained in the above production examples to which the cement admixture of the present invention and the comparative cement admixture were added were prepared, and the flow value and the amount of separated water were measured.

The materials and mortar composition used in the test were as follows:
400 g of Chichibu Onoda ordinary Portland cement, 800 g of Toyoura standard sand, and 240 g of water containing the inventive or comparative cement admixture. Table 1 shows the amount of each cement admixture (% by weight of the solid content relative to the cement).

The mortar is prepared by mechanical kneading using a Hobart mortar mixer (Model N-50, manufactured by Tesco Corp.) for 3 minutes, and the 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 remaining mortar, except for the mortar required for the measurement of the amount of separated water shown below, was allowed to stand in a closed container for a predetermined time, and the same operation as above was repeated to measure the change over time in the flow value. On the other hand, the prepared mortar was placed in a 500 ml glass measuring cylinder for 50 minutes.
0 ml, leave to stand, 15 minutes, 30 minutes, 45 minutes, 60 minutes
The amount of water separated above the mortar after one minute was measured and defined as the amount of separated water. Table 1 shows the results.

[0091]

[Table 1]

From Table 1, it can be seen that the mortar to which the comparative admixture was added provided the necessary fluidity, but had a large amount of separated water, or the fluidity could not be obtained even if a large amount was added. The mortar to which the cement admixture of the present invention is added has excellent fluidity, and the amount of water to be separated is small, so that the material separation resistance is low or the value of the value is either remarkably reduced with time. Is good.

[0093]

As described above, the cement admixture according to the present invention has good material separation resistance and excellent slump retention, and the cement composition containing the cement admixture has a high material separation resistance. And excellent slump retention. Therefore, the cement admixture of the present invention is effective for highly fluid concrete.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C08L 33/02 C08L 33/02 33/14 33/14 55/00 55/00 // C04B 103: 32 (72) Inventor Niwa Hirokazu 5-8 Nishiburi-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd. (72) Inventor Hirokatsu Kawakami 5-8 Nishi-Motomachi, Suita-shi, Osaka Nippon Shokubai

Claims (5)

[Claims] 1. Two kinds of monomers (a) and (b) represented by the following general formula (1) and an unsaturated content of not more than 50% by weight (% by weight based on the sum of all monomer components). A first copolymer (A) obtained by copolymerizing a monomer containing a carboxylic acid monomer (c) as an essential component and / or the copolymer (A) is further neutralized with an alkaline substance A cement admixture comprising the first copolymer salt (B) obtained as an essential component. General formula (1) (Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² O represents one or a mixture of two or more oxyalkylene groups having 2 to 4 carbon atoms. N may be an average number of moles of the oxyalkylene group added and represents a positive number of 1 or more, and R ³ represents a carbon number in the monomer (a). 4 ~
30 represents an alkyl group, and in the monomer (b), represents a hydrogen atom or an alkyl group having a carbon number smaller than the carbon number of R ³ of the monomer (a). ) 2. A copolymer obtained by copolymerizing a monomer (a) represented by the following general formula (1) and a monomer containing an unsaturated carboxylic acid monomer (c) as an essential component. 2) a copolymer (A1) and / or a second copolymer salt (B1) obtained by further neutralizing the copolymer (A1) with an alkaline substance;
And a third copolymer obtained by copolymerizing a monomer (b) represented by the following general formula (1) and a monomer containing an unsaturated carboxylic acid monomer (c) as an essential component. Polymer (A2) and / or
Alternatively, a cement admixture containing a third copolymer salt (B2) obtained by further neutralizing the copolymer (A2) with an alkaline substance as an essential component. General formula (1) (Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² O represents one or a mixture of two or more oxyalkylene groups having 2 to 4 carbon atoms. N may be an average number of moles added to the oxyalkylene group, and may be a positive number of 1 or more, and R ³ may be a carbon number in the monomer (a). 4 ~
30 represents an alkyl group, and in the monomer (b), represents a hydrogen atom or an alkyl group having a carbon number smaller than the carbon number of R ³ of the monomer (a). ) 3. The copolymer (salt) (A1 and / or B)
The cement admixture according to claim 2, wherein the weight ratio of 1) to the copolymer (salt) (A2 and / or B2) is 1:99 to 99: 1. 4. A cement composition comprising at least the cement admixture according to claim 1, a cement and water. 5. The cement composition according to claim 4, wherein the cement admixture is 0.01 to 2.0% by weight with respect to the cement, and the weight ratio of water / cement is 0.15 to 0.7. .