JP2997243B2 - Cement admixture - Google Patents

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. The technical innovation of cement admixtures, which have a great influence on the quality and performance of cement, has been actively carried out.

[0003] Each admixture maker has been energetically developing so-called high-performance AE water reducing agents capable of obtaining excellent fluidity. It is commercially available. As a polycarboxylic acid-based water reducing agent having an excellent feature that the highest water reduction rate can be obtained, various water-soluble vinyl copolymers have been proposed.

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 by the passage of water generated when water in the concrete comes to the surface, and the strength is reduced after hardening. This breathing
This is a kind of separation phenomenon caused by the difference in specific gravity between the concrete and the moisture in the concrete, and as a method of suppressing breathing, the viscosity is generally 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 the situation cannot be said to be 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. 53535/1994, and Japanese Patent Application Laid-Open No. 8-53522 disclose various terminal groups of the oxyalkylene group.
JP-A-8-29095, JP-A-9-2855, JP-A-9-241056, JP-A-9-241057 and the like propose various substituent groups.

[0006] Various high-performance AEs other than those proposed in these publications can be used by using various techniques other than those proposed in these publications.
As in the case of the water reducing agent, at present, the material separation cannot be sufficiently suppressed by the water reducing agent alone.

[0007]

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 fluidity, and a cement composition comprising the cement admixture. Is to do.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies on the chain length of the oxyalkylene group and the structure of the terminal group thereof.
A water-soluble vinyl copolymer having a specific graft structure having an alkyl terminal group having a specific number of carbon atoms having an appropriate hydrophobicity is excellent in material separation resistance, and is found to have good dispersibility. The present invention has been completed.

That is, the present invention relates to a cement admixture and a cement composition shown in the following (1) to (3).

(1) A copolymer obtained by copolymerizing a monomer (a) represented by the following general formula (1) and a monomer containing an unsaturated carboxylic acid monomer (b) as essential components: polymer (a) 及 beauty / or copolymer (a) further cement admixture as essential components a copolymer salt obtained by neutralizing with an alkaline substance (B).

General formula (1)

[0012]

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(Wherein, R ¹ is a hydrogen atom or a methyl group, R ² O is one of oxyalkylene groups having 2 to 4 carbon atoms)
Represents a species or a mixture of two or more species, and in the case of two or more species, may be added in a block form or in a random form; R ³ represents an alkyl group having 4 to 5 carbon atoms; the average addition mole number of oxyalkylene groups represent 5 0 or a positive number. (2) A cement composition comprising at least the cement admixture according to (1), cement and water.

(3) The cement according to the above (2), wherein the cement admixture is 0.01 to 1.0% by weight based on the cement and the weight ratio of water / cement is 0.15 to 0.7. Composition.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION First, a cement admixture according to the present invention comprises a copolymer (A) described below and / or a copolymer obtained by further neutralizing the copolymer (A) with an alkaline substance. Salt (B) is an essential component.

The copolymer (A) has the general formula (1)
Is obtained by polymerizing a monomer containing the monomer (a) represented by the formula (1) and the unsaturated carboxylic acid monomer (b) as essential components. Further, the copolymer salt (B) can be obtained by further neutralizing the 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 block form or in random form, R ³ represents an alkyl group having 4 to 5 carbon atoms, n is an average number of added moles of the oxyalkylene group, and 50 or more positive, preferably a positive number of 5 0-300.

The monomer (a) represented by the general formula (1) used in the present invention includes 1 -butanol, 2-methyl-1-propanol, 2-butanol, and 2-methyl-2
-Propanol, 1-pentanol, 2-methyl-1-
Butanol, 3-methyl-1-butanol, 2-pentanol, 3-pentanol, 2-methyl-2-butano-
Aliphatic or alicyclic alcohols having an alkyl group having a carbon number of 4-5 such as Le, and alkoxy polyalkylene glycols obtained by adding alkylene oxide having 2 to 4 carbon atoms, (meth) acrylic acid And an ester compound. Specific examples include 1 -butoxy polyethylene glycol mono (meth) acrylate, 2-methyl-1-propoxy polyethylene glycol mono (meth) acrylate, 2-butoxy polyethylene glycol mono (meth) acrylate, and 2-methyl-2-propoxy polyethylene. Glycol mono (meth) acrylate, 1-pentoxy polyethylene glycol mono (meth) acrylate, 2-methyl-1-butoxy polyethylene glycol mono (meth) acrylate, 3-methyl-1-butoxy polyethylene glycol mono (meth) acrylate, 2 -Pentoxy polyethylene glycol mono (meth) acrylate, 3-pentoxy polyethylene glycol mono (meth) acrylate, 2-methyl-2
-Various alkoxy polyethylene glycol mono (meth) acrylates such as butoxy polyethylene glycol mono (meth) acrylate ; 1 -butoxy polypropylene glycol mono (meth) acrylate, 2-methyl-1
-Propoxy polypropylene glycol mono (meth) acrylate, 2-butoxy polypropylene glycol mono (meth) acrylate, 2-methyl-2-propoxy polypropylene glycol mono (meth) acrylate,
1-pentoxy polypropylene glycol mono (meth)
Acrylate, 2-methyl-1-butoxypolypropylene glycol mono (meth) acrylate, 3-methyl-
1-butoxy polypropylene glycol mono (meth) acrylate, 2-pentoxy polypropylene glycol mono (meth) acrylate, 3-pentoxy polypropylene glycol mono (meth) acrylate, 2-methyl-2-butoxy polypropylene glycol mono (meth)
Various alkoxy polypropylene glycol mono (meth) acrylates such as acrylates ; 1 -butoxypolybutylene glycol mono (meth) acrylate, 2-methyl-1-propoxypolybutylene glycol mono (meth) acrylate, 2-butoxypolybutylene glycol mono ( Various alkoxypolybutylene glycol mono (meth) acrylates such as (meth) acrylate and 2-methyl-2-propoxypolybutylene glycol mono (meth) acrylate; The average number of moles of the oxyalkylene groups of these monomers (a) are, if not 5 0 or a positive number in order to ensure the hydrophilicity since hydrophilicity decreases as reduction in the average addition molar number become not, but the other, in order to decrease the reactivity accordance increase in the average number of moles, and still more preferably a positive number of 5 0-300. or,
Any two or more alkylene oxide adducts selected from ethylene oxide, propylene oxide and butylene oxide can be used in any of random addition, block addition, and alternate addition. still,
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.
Further, two or more of these monomers (a) may be used,
When two or more monomers (a) are used,
It is preferable that the oxyalkylene group of the monomer (a) contains an oxyethylene group as an essential component.

The unsaturated carboxylic acid monomer (b) 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)

[0021]

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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. Specific examples of the unsaturated carboxylic acid monomer (b) 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. Incidentally, two or more of these monomers (b) may be used in combination.

The copolymer (A) of the present invention comprises, in addition to the monomers (a) and (b), which are essential components, a monomer (a) copolymerizable with the monomers (a) and (b). c) can be used as a copolymerization component. Examples of the monomer (c) 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 with amines of formulas 1 to 30; half esters and diesters of alkyl polyalkylene glycols obtained by adding 1 to 500 moles of alkylene oxides having 2 to 4 carbon atoms to the alcohol or amine and the unsaturated dicarboxylic acids A half ester or diester of the unsaturated dicarboxylic acid and a glycol having 2 to 4 carbon atoms or a polyalkylene glycol having an addition mole number of 2 to 500; maleamic acid and a glycol having 2 to 4 carbon atoms or a glycol thereof. Having 2 to 500 moles of addition Half amide with coal; 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, etc. (Poly) alkylene glycol di (meth) acrylates; bifunctional (meth) acrylates such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and trimethylolpropane di (meth) acrylate; triethylene (Poly) alkylene glycol dimaleates such as glycol dimaleate and polyethylene glycol dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl Sulfonates, 3- (meth) acryloxy propyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfophenyl ether, 3
-(Meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutylsulfonate, (meth) acrylamidomethylsulfonic acid, (meth) acrylamidoethylsulfonic acid, 2-
Unsaturated sulfonic acids such as methylpropanesulfonic acid (meth) acrylamide and styrenesulfonic acid, and their monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts; methyl (meth) acrylate, (meth) acrylic acid Ethyl acid, propyl (meth) acrylate, (meth)
Butyl acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, methyl crotonate, (meth) acrylic acid (Meth) acrylic acid such as glycidyl and carbon number 1
Esters with up to 30 alcohols; amides of unsaturated monocarboxylic acids such as methyl (meth) acrylamide with amines having 1 to 30 carbon atoms; styrene, α-methylstyrene, vinyltoluene, p-methylstyrene Vinyl aromatics such as 1,4-butanediol mono (meth) acrylate, alkanediol mono (meth) acrylate such as 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate
Acrylates; Dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene; (meth) acrylamide, (meth)
Unsaturated amides such as acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; (meth) acrylonitrile, α
-Unsaturated cyanides such as chloroacrylonitrile; unsaturated esters such as vinyl acetate and vinyl propionate;
Unsaturation such as aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, and vinylpyridine Amines; divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate; allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; unsaturated aminos such as dimethylaminoethyl (meth) acrylate Compounds: vinyl alcohols such as methoxypolyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, and polyethylene glycol mono (meth) allyl ether Ter or allyl ethers: polydimethylsiloxane propylaminomaleamic acid, polydimethylsiloxane aminopropyleneaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (dipropyleneaminomaleic acid) Amic acid), polydimethylsiloxane- (1-propyl-3-
Acrylate), polydimethylsiloxane- (1-propyl-3-methacrylate), polydimethylsiloxane-bis- (1-propyl-3-acrylate), polydimethylsiloxane-bis- (1-propyl-3-methacrylate) and the like. Siloxane derivatives; unsaturated phosphates such as 2-acryloyloxyethyl phosphate and 2-methacryloyloxyethyl phosphate; and the like, and one or more of these can be used.

The copolymer (A) of the present invention comprises a monomer (a)
And (b), or copolymerized monomers (a), (b) and (c). The reaction ratio of these monomers is as follows: monomer (a) / monomer (b) / monomer (c) = 1 to 99 /
The range of 1 to 99/0 to 70 (% by weight) is appropriate, and preferably, monomer (a) / monomer (b) / monomer (c)
= 5 to 97/3 to 60/0 to 50 (% by weight), more preferably monomer (a) / monomer (b) / monomer (c) = 10 to 95 / It is in the range of 5 to 50/0 to 40 (% by weight), and more preferably the monomer (a) /
Monomer (b) / monomer (c) = 20-95 / 5-5 /
It is in the range of 0 to 40 (% by weight). If the ratio is out of this range, a desired cement admixture with excellent performance cannot be obtained.

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 can 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 obtained copolymer (A), 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 weight average molecular weight of the copolymer (A) and / or the copolymer salt (B) used as the cement admixture of the present invention is preferably in the range of 500 to 500,000, particularly preferably 5,500. It is preferably in the range of 000 to 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, a molecular weight exceeding 500,000 is not preferable because the water reducing performance and the slump loss preventing ability of the cement admixture decrease.

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

When the cement admixture of the present invention is used for mortar or concrete using hydraulic cement,
0.01-1.0% of cement weight, preferably 0.0
What is necessary is just to add the amount of the ratio which becomes 2-0.8% at the time of kneading. By this addition, various favorable effects such as achievement of a high water reduction rate, improvement of material separation resistance, reduction of unit water amount, increase of strength and improvement of durability are brought about. If the addition amount is less than 0.01%, the performance is insufficient.
Even if a large amount exceeding% is used, the effect is substantially flattened, and it is disadvantageous from the viewpoint of economy.

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. If necessary, aggregates such as sand and gravel are added to the cement composition.

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: unsaturated carboxylic acid polymerization such as polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), and sodium salt of acrylic acid / maleic acid copolymer object;
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 emulsions: 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 defoamer: 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 oxyethyleneoxypropylene 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
Oxyalkylene alkyl phosphates; (poly) oxyalkylene alkylamines such as polyoxyethylene laurylamine; 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 antifoaming agents: tributyl phosphate, sodium octyl phosphate and the like.

(13) Metallic soap-based antifoaming agents: aluminum stearate, calcium oleate and the like.

(14) Silicone 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 (alkylbenzene sulfonic acid), LAS (linear alkylbenzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl ( Phenyl) ether, polyoxyethylene alkyl (phenyl) ether sulfate or a salt thereof, polyoxyethylene alkyl (phenyl) ether phosphate or a salt thereof, a 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; various cationic surfactants such as alkylamine acetate and alkyltrimethylammonium chloride; various nonionic surfactants; various amphoteric surfactants.

(17) Waterproofing agent: fatty acid (salt), fatty acid ester, oil and fat, silicon, paraffin, asphalt,
Wax and the like.

(18) Rust inhibitor: nitrite, phosphate, zinc oxide, etc.

(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.

[0058]

The present invention will be described more specifically with reference to the following examples. In the examples,% is% by weight unless otherwise specified.
And parts represent parts by weight.

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, 250 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 120), 50 parts of methacrylic acid, and 20 parts of water
0 parts and a monomer aqueous solution mixed with 8.0 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. Aqueous solution 1
00 parts were added dropwise in one hour. Thereafter, the temperature was maintained at 80 ° C. for 1 hour to complete the polymerization reaction, thereby obtaining the cement admixture (1) of the present invention comprising an aqueous solution of a copolymer having a weight average molecular weight of 31,000.

Example 2 Production of Cement Admixture (2) 847.7 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, 275.6 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of added ethylene oxide: 75), 24.4 parts of methacrylic acid,
, 200.0 parts of water and 2.3 parts of 3-mercaptopropionic acid as a chain transfer agent, were 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. After the completion of the dropwise addition of the initiator aqueous solution, the temperature was maintained at 80 ° C. for an additional hour to complete the polymerization reaction. Then, the mixture is neutralized to pH 7 with a 30% aqueous sodium hydroxide solution to give a weight average molecular weight of 37.
A cement admixture (2) of the present invention consisting of 300 copolymer aqueous solutions was obtained.

Example 3 Production of Cement Admixture (3) 747.4 parts was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser. At 80 ° C under nitrogen atmosphere
Until heated. Next, 275.6 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 130), methacrylic acid 24.4 parts
, 300.0 parts of water and 2.7 parts of 3-mercaptopropionic acid as a chain transfer agent were 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. After the completion of the dropwise addition of the initiator aqueous solution, the temperature was maintained at 80 ° C. for an additional hour to complete the polymerization reaction. Then, the mixture was neutralized to pH 7 with a 30% aqueous sodium hydroxide solution to give a weight average molecular weight of 42.
Cement admixture (3) of the present invention consisting of 600 copolymer aqueous solutions was obtained.

Comparative Example 1 Production of Comparative Cement Admixture (1) 847.7 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 under nitrogen atmosphere.
Heated to ° C. Next, 275.6 parts of 1-butoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 25), methacrylic acid 24.4 parts
, 200.0 parts of water, and 5.8 parts of 3-mercaptopropionic acid as a chain transfer agent were 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. After the completion of the dropwise addition of the initiator aqueous solution, the temperature was maintained at 80 ° C. for an additional hour to complete the polymerization reaction. Then, the mixture is neutralized to pH 7 with a 30% aqueous sodium hydroxide solution to give a weight average molecular weight of 20.
A comparative cement admixture (1) consisting of 200 copolymer aqueous solutions was obtained.

Comparative Example 2 Production of Comparative Cement Admixture (2) 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 under 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 200.0 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. After dropping the initiator aqueous solution, the temperature was maintained at 80 ° C. for another hour,
The polymerization reaction was completed. Then, the mixture was neutralized to pH 7 with a 30% aqueous sodium hydroxide solution to give a weight average molecular weight of 5600.
Comparative cement admixture consisting of an aqueous solution of a copolymer (2)
I got

Comparative Example 3 Production of Comparative Cement Admixture (3) 597.3 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 under 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
4.4 parts, 450.0 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. After the completion of the dropwise addition of the initiator aqueous solution, the temperature was maintained at 80 ° C. for an additional hour to complete the polymerization reaction. Then, the mixture was neutralized to pH 7 with a 30% aqueous sodium hydroxide solution to obtain a comparative cement admixture (3) comprising a copolymer aqueous solution having a weight average molecular weight of 38,100.

Comparative Example 4 Production of Comparative Cement Admixture (4) 746.6 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, 275.6 parts of methoxypolyethylene glycol monomethacrylate (150 average addition moles of ethylene oxide), 24.4 parts of methacrylic acid.
, 300.0 parts of water and 3.5 parts of 3-mercaptopropionic acid as a chain transfer agent were 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. After the completion of the dropwise addition of the initiator aqueous solution, the temperature was maintained at 80 ° C. for an additional hour to complete the polymerization reaction. Then, the mixture is neutralized to pH 7 with a 30% aqueous sodium hydroxide solution to give a weight average molecular weight of 45.
A comparative cement admixture (4) consisting of 500 aqueous copolymer solutions was obtained.

Mortar test A mortar to which the cement admixtures (1) to (3) of the present invention and the comparative cement admixtures (1) to (4) were added for comparison was prepared, and the flow value and the amount of separated water were measured. It was 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 with a Hobart mortar mixer (Model N-50, manufactured by Tesco Corporation) 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. In addition, 500 ml of the prepared mortar was placed in a 500 ml glass measuring cylinder.
After filling and standing, the amount of water separated on the upper part of the mortar after 15 minutes, 30 minutes, 45 minutes, and 60 minutes was measured and defined as the amount of separated water. Table 1 shows the results.

[0069]

[Table 1]

From Table 1, it can be seen that the mortar to which the comparative admixture is added can obtain the required fluidity but has a large amount of separated water, or does not provide sufficient fluidity even if added in a large amount. On the other hand, the mortar to which the cement admixture of the present invention is added has excellent fluidity and a small amount of separated water, indicating that the material separation resistance is good.

[0071]

As described above, the cement admixture according to the present invention has good material separation resistance and can impart excellent fluidity, and the cement composition containing the cement admixture is High material separation resistance and excellent fluidity. Therefore, the cement admixture of the present invention is effective for highly fluid concrete.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI // C04B 103: 32 (72) Inventor Hirokazu Niwa 5-8 Nishiburi-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd. (72 ) Inventor Hirokatsu Kawakami 5-8, Nishiobari-cho, Suita-shi, Osaka Inside of Nippon Shokubai Co., Ltd. (56) References JP-A-8-12397 (JP, A) JP-A-59-203745 (JP, A) JP-A-3-75252 (JP, A) JP-A-6-321596 (JP, A) JP-A-6-298557 (JP, A) (58) Fields studied (Int. Cl. ⁷ , DB name) C04B 24/26 C08F 290/06 C04B 103: 32

Claims (3)

(57) [Claims] 1. A copolymer obtained by copolymerizing a monomer containing a monomer (a) represented by the following general formula (1) and an unsaturated carboxylic acid monomer (b) as essential components: Coalescing (A )
及 beauty / or copolymer (A) further cement admixture as essential components a copolymer salt obtained by neutralizing with an alkaline substance (B). 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. may also have added to the random form have been, R ³ represents an alkyl group having 4-5 carbon atoms, n represents a 5 0 or a positive number of the average number of moles of the oxyalkylene group.) 2. A cement composition comprising at least the cement admixture according to claim 1, cement and water. 3. The cement composition according to claim 2, wherein the cement admixture is 0.01 to 1.0% by weight with respect to the cement, and the weight ratio of water / cement is 0.15 to 0.7. .