JP2003073157A - Cement admixture and method of execution of cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cement admixture having high dispersibility, and imparting a hardened cement excellent strength and durability, capable of preventing degradation of fluidity at high temperatures, and to provide a method of execution of a cement composition using the admixture. SOLUTION: The cement admixture contains a copolymer (A) for the cement admixture and an oxicarboxylic acid compound (B) as essential ingredients in a ratio of 10/90-99.9/0.1 (in wt.%), the copolymer (A has a monomer unit (I) derived from an unsaturated polyalkylene glycol ether monomeric substance (a), represented by general formula (1): YO(R<1> O)nR<2> ...(1) and monomer unit (II) derived from an unsaturated carboxylic acid monomeric substance (b) as essential ingredients, and monomer units (I) and (II) occupy among total monomer units by >=1%, and the monomer unit (I) occupies in ratio of <=50 mol % of total monomer units.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cement admixture and a method for applying a cement composition using the same.

[0002]

2. Description of the Related Art Cement compositions give hardened cement products having excellent strength and durability, and
Widely used for building structures. Examples of such a cement composition include a cement paste obtained by adding water to cement, a mortar in which sand as a fine aggregate is mixed, and a concrete in which pebbles as a coarse aggregate are further mixed, and the like. Cement admixtures have been added to improve air entrainment and fluidity, but in recent years, their importance has been recognized and technological innovation has been actively carried out.

The task of the cement admixture is to achieve sufficient dispersibility even when the water content of the cement composition is reduced, to ensure its fluidity and workability, and to improve durability and strength by reducing water, and at the same time This is to obtain a good cement composition while maintaining stable dispersibility. In the recent concrete industry, there is a strong demand for concrete that achieves such performance, and in order to achieve this, it is an important issue to prevent reduction in fluidity as well as reduction of the unit water amount.

JP-A-62-68806 discloses a water-soluble copolymer which can be used as a cement admixture. Further, JP-A-10-236858 discloses that an unsaturated (poly) alkylene glycol ether-based monomer (I), a maleic acid-based monomer (II) and other monomers copolymerizable with these monomers are disclosed. Regarding a cement dispersant containing a copolymer (A) obtained by polymerizing a monomer (III) in a specific weight ratio, JP 2000-7403 A discloses a polyalkylene glycol 3-methyl-butenyl ether type. Monomer (I), maleic acid-based monomer (II),
And other monomers copolymerizable with these monomers (I
It is disclosed that the cement additive containing the copolymer (A) obtained by polymerizing II) may be used in combination with a retarder.

JP-A-8-283350 discloses that copolymers based on oxyalkylene glycol-alkenyl ethers and unsaturated dicarboxylic acid derivatives can be used as cement additives.

Japanese Unexamined Patent Publication No. 9-241055 relates to a cement dispersant containing a polyoxyalkylene compound as an essential component, and Japanese Unexamined Patent Publication No. 10-194808 discloses an alkenyl alcohol having a specific polyoxyalkylene chain and unsaturated. The present invention relates to a cement dispersant comprising a copolymer having a carboxylic acid compound as an essential constitutional unit, and JP-A No. 11-106247 discloses an adduct of ethylene oxide and propylene oxide of alkenyl alcohol or an alkyl ether compound thereof. It is disclosed that a cement dispersant comprising a copolymer as an essential constituent unit may be used in combination with a retarder.

However, in these techniques, there is room for devising a method for sufficiently preventing the fluidity of the cement composition from decreasing when the cement composition is used for construction. That is, during the construction of the cement composition, the cement admixture for improving the fluidity of the cement composition is formed as the cement hydrate is partially formed by the progress of the hydration reaction between the cement and water. Since it is taken into the cured product and cannot exert its effect, there is room for improvement to further improve workability in the construction of the cement composition. In particular, when the cement composition is constructed in a high temperature environment, the fluidity of the cement composition is prevented from decreasing and the workability is improved, the construction of the cement composition is efficiently conducted, and the cement composition is sufficiently hardened. It is desired to bring out the performance of objects.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and provides a cement hardened product having high dispersibility, excellent strength and durability, and having a flow property at high temperature. It is an object of the present invention to provide a cement admixture capable of preventing deterioration of the property and a method for constructing a cement composition using the same.

[0009]

Means for Solving the Problems As a result of intensive studies on the cement admixture, the present inventors have found that the copolymer (A) having a specific structural unit has a high dispersibility and is excellent in strength and durability. First of all, we focused on providing cement hardened products. When a cement composition is applied using a cement admixture containing such a copolymer (A), if a specific amount of the oxycarboxylic acid compound (B) is used in combination with the copolymer (A), The inventors have found that high dispersion performance and the like can be maintained and that deterioration of fluidity at high temperatures can be prevented, and that the above problems can be solved satisfactorily, and the present invention has been completed.

That is, according to the present invention, the copolymer (A) and the oxycarboxylic acid compound (B) are mixed in an amount of 10/90 to 99.9.
A cement admixture containing as an essential component at a ratio (weight%) of 0.1 / 0.1, wherein the copolymer (A) has the following general formula (1); YO (R ¹ O) nR ² (1) ( In the formula, Y represents an alkenyl group having 5 to 8 carbon atoms, and R ¹ O is the same or different and has 2 to 2 carbon atoms.
18 represents an oxyalkylene group. n is an average addition mole number of an oxyalkylene group, and represents a number of 1 to 500. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. ) Structural unit (I) derived from unsaturated (poly) alkylene glycol ether monomer (a) represented by
And an unsaturated carboxylic acid-based monomer (b) -derived structural unit (I
I) as an essential constitutional unit, and the constitutional unit (I) and the constitutional unit (II) each account for 1% by weight or more of all the constitutional units, and the proportion of the constitutional unit (I) is the whole. It is a cement admixture containing 50 mol% or less of the constituent unit.

The present invention is also a method of applying a cement composition, which comprises applying the cement admixture, cement and water as essential components at a temperature of 20 ° C. or higher. The present invention is described in detail below.

The cement admixture according to the present invention comprises the copolymer (A) and the oxycarboxylic acid compound (B) on 10/9.
It is contained as an essential component in a ratio (wt%) of 0 to 99.9 / 0.1. The above-mentioned copolymer (A) is a copolymer for a cement admixture, which exhibits a high dispersion performance in a cement composition and can give a hardened cement product having excellent strength and durability. Further, the oxycarboxylic acid compound (B) is used as a cement composition as the cement hydrate is partially formed when the hydration reaction between the cement and water progresses when the cement composition is used. The fluidity of the cement composition is reduced due to the fact that the copolymer (A) for improving the fluidity of the product is taken into the cement hardened product and the action thereof cannot be exhibited. In order to sufficiently prevent the above, it has the effect of delaying the hardening in the cement composition. By combining the copolymer (A) and the oxycarboxylic acid compound (B), it becomes possible to sufficiently exert the action and effect of the copolymer (A) in the construction of the cement composition. It is possible to prevent deterioration of fluidity at high temperature.

Examples of the oxycarboxylic acid compound (B) used in the present invention include gluconic acid, glucoheptonic acid, arabonic acid, malic acid and citric acid, and their sodium, potassium, calcium, magnesium, ammonium and tricarboxylic acids. Examples thereof include inorganic salts such as ethanolamine, organic salts, and the like. Among them, it is preferable to use gluconic acid. These may be used alone or in combination of two or more.

The ratio of the copolymer (A) to the oxycarboxylic acid compound (B), that is, the weight ratio (% by weight) in terms of solid content, is 10/90 to 99.9 / 0.1.
Is. When the proportion of the copolymer (A) is less than 10/90, the cement composition cannot be efficiently cured, and the copolymer (A) is more than 99.9 / 0.1.
When the ratio of is large, it becomes impossible to maintain the dispersibility of the cement composition during its construction. A preferable range of the above ratio is 30/70 to 99/1. More preferably, it is 60/40 to 97/3.

In the present invention, the cement admixture containing the cement admixture, cement and water as essential components is applied at a temperature of 20 ° C. or higher. As a result, the fluidity of the cement composition can be prevented from lowering when the cement admixture containing the copolymer (A) as an essential component is used, and the cement composition can be efficiently and easily applied. A method for applying such a cement composition is also 1 of the present invention.
Is one.

In the method for applying the above cement composition,
When the cement admixture that essentially requires the copolymer (A) is used, the cement composition has excellent fluidity, and therefore the work using the cement composition can be efficiently and easily performed. However, if the construction temperature is 20 ° C or higher,
The action and effect of the copolymer (A) will be reduced.
In the present invention, the combination of the copolymer (A) and the oxycarboxylic acid compound (B) results in a construction temperature of 20.
Even when the temperature is not lower than 0 ° C, it is possible to prevent the effect of the copolymer (A) from being lowered and to efficiently and easily carry out the work in the construction of the cement composition. A preferred embodiment of the present invention is that it is applied in construction such as in the summer, for example, when the construction temperature is 25 ° C. or higher. More preferably, it is 30 ° C. or higher.
The term "construction" as used in the present invention means a step in construction after preparing the cement composition until the cement composition is about to be hardened. For example, the cement composition is treated with an agitator car (fresh concrete mixer car). ), A pump or the like, or a process of filling a mold or the like. The construction temperature means the temperature of the cement composition when constructing the cement composition.

The copolymer (A) and the cement composition will be described below. The copolymer (A) includes the structural unit (I) derived from the unsaturated (poly) alkylene glycol ether monomer (a) represented by the general formula (1) and the unsaturated carboxylic acid monomer ( It is a polymer having the structural unit (II) derived from b) as an essential structural unit. The copolymer (A) is a structural unit (I) derived from the monomer (c) described below.
II) may be included. Each of these structural units may be of one type or of two or more types.

In the above copolymer (A), the structural unit (I) and the structural unit (II) each account for 1% by weight or more of the total structural units, and the structural unit (I) accounts for the total structural unit. It is 50 mol% or less. When the proportion of the structural unit (I) is less than 1% by weight, the proportion of the oxyalkylene group derived from the unsaturated (poly) alkylene glycol ether monomer (a) present in the copolymer (A) is too small. Further, when the proportion of the structural unit (II) is less than 1% by weight,
The proportion of the carboxyl groups derived from the unsaturated carboxylic acid monomer (b) present in the copolymer (A) is too small, and sufficient dispersibility cannot be exhibited. On the other hand, since the unsaturated (poly) alkylene glycol ether-based monomer (a) has a low polymerizability, the structural unit (I) occupies the copolymer (A) having a high dispersibility in a high yield. In order to obtain it, it is important that the content is 50 mol% or less in all the constituent units. The proportion of the structural unit (I) is preferably 5% by weight or more, more preferably 10% by weight or more,
20 wt% or more is more preferable, and 40 wt% or more is the most preferable. In addition, the total ratio (% by weight) of the structural unit (I) and the structural unit (II) in the copolymer (A) is preferably 50 to 100% by weight of the whole copolymer (A), and 70 to 100% by weight is more preferred.

In the copolymer (A), the number of milliequivalents (m) of carboxyl groups per 1 g of the copolymer (A) obtained by converting the carboxyl groups in the polymer (A) into an unneutralized type.
It is preferable to set the ratio of each structural unit so that eq / g) is 0.2 to 5.0. The number of milliequivalents (meq / g) of the carboxyl group is 0.3 to 4.5.
Is more preferable, 0.3 to 4.0 is further preferable, and 0.
4-3.5 is especially preferable, and 0.4-3.0 is the most preferable. When the number of milliequivalents of the carboxyl group becomes large, the slump retention tends to decrease, while when it becomes small, the initial dispersibility tends to decrease. The upper limit of the ratio of the structural unit (II) may be set such that the number of milliequivalents of the carboxyl group when the carboxyl group in the copolymer (A) is converted to the unneutralized type is in the above range. .

In addition to the structural unit (II) having a carboxyl group derived from the unsaturated carboxylic acid type monomer (b), the copolymer (A) has a structural unit having another carboxyl group. Since it is good, the copolymer (A)
The number of milliequivalents of the carboxyl group of the
It is not always due to the carboxyl group derived from I).

The above-mentioned "milliequivalent number of carboxyl groups (meq / g) per 1 g of the copolymer (A) obtained by converting the carboxyl groups in the copolymer (A) into a non-neutralized type" means co-weight The case where the combined (A) forms a salt is taken into consideration, and the calculation methods in the case of an acid and the case of forming a salt are listed below.
In the following calculation, only the carboxyl group derived from the structural unit (II) is exemplified, but when other structural units having a carboxyl group are included, this must also be included in the milliequivalent number of the carboxyl group. I won't.

(Calculation Example 1): Acrylic acid was used as the monomer (b), and monomer (a) / monomer (b) = 90/10
When a copolymer having a composition ratio of (% by weight) is obtained, the molecular weight of acrylic acid is 72, and thus 1 g of the polymer obtained by converting the carboxyl group derived from the monomer (b) into an unneutralized type. Number of equivalents of carboxyl group per unit (meq / g) =
(0.1 / 72) × 1000 = 1.39.

(Calculation Example 2): Sodium acrylate was used as the monomer (b), and the monomer (a) / monomer (b) =
When a copolymer having a composition ratio of 80/20 (% by weight) was obtained, the molecular weight of sodium acrylate was 94 and the molecular weight of acrylic acid was 72, so that the carboxyl group derived from the monomer (b) was The number of milliequivalents of carboxyl groups per 1 g of the polymer converted to the unneutralized type (meq / g) = (0.2
X 72/94) / (0.8 + 0.2 x 72/94) / 7
2 × 1000 = 2.23. It should be noted that, when acrylic acid is used during the polymerization and the carboxyl group derived from the acrylic acid is completely neutralized with sodium hydroxide after the polymerization, the same result as in this calculation example is obtained.

(Calculation Example 3) Maleic acid was used as the monomer (b), and monomer (a) / monomer (b) = 90/10
When copolymerized at a composition ratio of (% by weight), the molecular weight of maleic acid is 116, and maleic acid is 2 in 1 molecule.
Since it is a divalent acid having one carboxyl group, the carboxyl group derived from the monomer (b) is converted to an unneutralized type, and the number of milliequivalents of the carboxyl group per 1 g of the polymer (m
eq / g) = 0.1 / (0.9 + 0.1) / (116 /
2) × 1000 = 1.72.

The number of milliequivalents of the above-mentioned carboxyl group (meq
/ G) is calculated by a calculation method based on the monomer as described above, and in consideration of the type of the counter ion of the carboxyl group of the copolymer (A), the copolymer (A) It can also be calculated by measuring the acid value of.

The above-mentioned copolymer (A) is, for example, an unsaturated (poly) alkylene glycol ether monomer (a) which gives the structural unit (I) and an unsaturated carboxylic acid type monomer which gives the structural unit (II). It can be produced by copolymerizing a monomer component containing the monomer (b) as an essential component, but is not limited thereto. For example, instead of the monomer (a), a monomer before addition of an alkylene oxide, that is, an unsaturated alcohol such as 3-methyl-3-buten-1-ol is used, and the presence of a polymerization initiator It can also be obtained by a method of copolymerizing the monomer (b) below and then adding 1 to 500 mol of alkylene oxide on average. When the monomer components are copolymerized, other monomers copolymerizable with the above monomers may be further copolymerized, if necessary.

In the general formula (1) representing the unsaturated (poly) alkylene glycol ether monomer (a),
The number of carbon atoms of the oxyalkylene group R ¹ O is 2 to
Although 18 is suitable, 2-8 are preferable and 2-4 are more preferable. Further, any two or more kinds of alkylene oxide adducts selected from ethylene oxide, propylene oxide, butylene oxide, styrene oxide and the like may be in any form such as random addition, block addition and alternate addition. In order to secure the balance between hydrophilicity and hydrophobicity, it is preferable to have an oxyethylene group as an essential component in the oxyalkylene group.
More preferably, mol% or more is an oxyethylene group, more preferably 90 mol% or more is an oxyethylene group, and most preferably 95 mol% or more is an oxyethylene group.

The average added mole number m of the oxyalkylene group in the above general formula (1) is suitably 1 to 500. Preferably 2-500, more preferably 5-
500, more preferably 10 to 500, particularly preferably 15 to 500, most preferably 20 to 300. The smaller the average number of added moles, the lower the hydrophilicity of the resulting polymer and the lower the dispersion performance.
If it exceeds, copolymerization reactivity tends to decrease. still,
The average addition mole number means the average value of the number of moles of the organic group added in 1 mole of the monomer.

R ² in the above general formula (1) may be a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms,
Examples of the hydrocarbon group having 1 to 30 carbon atoms include, for example,
Phenyl substituted with an alkyl group having 1 to 30 carbon atoms (aliphatic alkyl group or alicyclic alkyl group), phenyl group having 6 to 30 carbon atoms, alkylphenyl group, phenylalkyl group, (alkyl) phenyl group Group, an aromatic group having a benzene ring such as a naphthyl group, and the like. R ²
In the above, since the hydrophobicity increases as the number of carbon atoms of the hydrocarbon group increases and the dispersibility decreases, the number of carbon atoms when R ² is a hydrocarbon group is preferably 1 to 22, and 18 is more preferable, 1 to 12 is further preferable, 1 to 4 is particularly preferable, and the case where R ² is a hydrogen atom is the most preferable.

The number of carbon atoms of the alkenyl group represented by Y in the above general formula (1) is suitably 5 to 8, but an alkenyl group having 5 carbon atoms is preferable. Y in the general formula (1) is the following general formula (3);

[0031]

[Chemical 3]

(Where R is⁶, R⁷And R⁸Is the same young
Or differently, represents a hydrogen atom or a methyl group. However, R
⁶, R⁷And R⁸Are not all methyl groups
Yes. R⁹Is -O (R in the above general formula (1).¹O)
nR^TwoIs a point of attachment to₂-,-(CH₂)₂
-Or-C (CH₃)₂Represents-. R⁶, R⁷, R⁸as well as
R ⁹The total number of carbon atoms therein is 3. )
And are preferred. As such an alkenyl group, for example,
For example, 3-methyl-3-butenyl group, 3-methyl-2-but
Tenyl group, 2-methyl-3-butenyl group, 2-methyl-
2-butenyl group, 1,1-dimethyl-2-propenyl group
Etc., but a 3-methyl-3-butenyl group is preferred.
Good

Examples of the unsaturated (poly) alkylene glycol ether type monomer (a) represented by the above general formula (1) include 3-methyl-3-buten-1-ol,
3-methyl-2-buten-1-ol, 2-methyl-2
It can be produced by adding 1 to 500 mol of alkylene oxide to an unsaturated alcohol such as -buten-1-ol. Specifically, (poly) ethylene glycol 3-
Methyl-3-butenyl ether, (poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl ether, (poly) ethylene (poly) butylene glycol 3-methyl-3-butenyl ether and the like can be mentioned. In the present invention, as the monomer (a) that gives the structural unit (I), one of these can be used alone, or two or more can be used in combination.

The unsaturated carboxylic acid type monomer (b) used in the present invention is represented by the following general formula (2);

[0035]

[Chemical 4]

(In the formula, R ³ , R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom, a methyl group or-(CH ₂ ) p.
It represents a COOX group. X is the same or different and represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or an organic amine group. p represents an integer of 0 to 2. −
When two COOX groups are present, two -COOX
A -COOCO- group may be formed by the group. )
A monomer giving the structural unit (II) represented by That is, the structural unit (II) derived from the unsaturated carboxylic acid monomer (b) is preferably represented by the general formula (2). In the general formula (2), two -C
When the —COOCO— group is formed by the OOX group, the unsaturated carboxylic acid-based monomer (b) becomes an anhydride.

Specific examples of the unsaturated carboxylic acid type monomer (b) include unsaturated monocarboxylic acid type monomers.
Acrylic acid, methacrylic acid, crotonic acid and their metal salts, ammonium salts, amine salts and the like, and examples of unsaturated dicarboxylic acid type monomers include maleic acid, itaconic acid, citraconic acid, fumaric acid, or these. Examples thereof include metal salts, ammonium salts, amine salts, and the like, and examples of anhydrides thereof include maleic anhydride, itaconic anhydride, citraconic anhydride, and the like. Among them, as the unsaturated carboxylic acid-based monomer (b), one or more monomers selected from the group consisting of (meth) acrylic acid and salts thereof, maleic acid and salts thereof, and maleic anhydride. It is preferable that (meth) acrylic acid or a salt thereof is essential, and particularly acrylic acid or a salt thereof is particularly preferable, in order to reduce the curing retardation property. Incidentally, these monomers (b) may be used in combination of two or more kinds.

In the above copolymer (A), other copolymerizable monomer (c) can be used in addition to the monomer component that provides the essential constituent unit. The structural unit (III) is formed by such a monomer (c). The monomer (c) that gives the structural unit (III) is a monomer copolymerizable with the monomer (a) and / or the monomer (b), and examples thereof include the followings. Named
These 1 type (s) or 2 or more types can be used.

Maleic acid, maleic anhydride, fumaric acid,
Half-esters of unsaturated dicarboxylic acids such as itaconic acid and citraconic acid with alcohols having 1 to 30 carbon atoms,
Diesters; Half amides of the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms; Diamides; Alkyl (polyamides obtained by adding 1 to 500 moles of alkylene oxide having 2 to 18 carbon atoms to the above alcohols and amines. )
Half-esters of alkylene glycol and the above unsaturated dicarboxylic acids, diesters; Half-esters of the above-mentioned unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or polyalkylene glycols having an addition mole number of these glycols of 2 to 500, Diesters; unsaturated monocarboxylic acids such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, glycidyl (meth) acrylate, methyl crotonate, ethyl crotonate and propyl crotonate, and 1 carbon atom Ester with an alcohol having 1 to 30 carbon atoms; an alkoxy (poly) alkylene glycol obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to an alcohol having 1 to 30 carbon atoms, and an (meth) acrylic acid or the like. Saturated monocarb Esters with acids; C2 to unsaturated monocarboxylic acids such as (meth) acrylic acid, such as (poly) ethylene glycol monomethacrylate, (poly) propylene glycol monomethacrylate, (poly) butylene glycol monomethacrylate, etc. ~ 18
1-500 mol adducts of alkylene oxides; and half amides of maleamic acid and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 added mols of these glycols.

(Poly) ethylene 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. ) Alkylene glycol di (meth) acrylates; polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate; triethylene glycol dimalate , (Poly) alkylene glycol dimaleates such as polyethylene glycol dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- ( A) acryloxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutyl sulfonate, (meth) acrylamidomethyl sulfonic acid,
Unsaturated sulfonic acids such as (meth) acrylamidoethylsulfonic acid, 2-methylpropanesulfonic acid (meth) acrylamide and styrenesulfonic acid, and monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts thereof; Amides of unsaturated monocarboxylic acids such as methyl (meth) acrylamide and amines having 1 to 30 carbon atoms; vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene and p-methylstyrene; 4-
Alkanediol mono (meth) acrylates such as butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate; butadiene, isoprene, 2-methyl- Dienes such as 1,3-butadiene and 2-chloro-1,3-butadiene.

Unsaturated amides such as (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; (meth) acrylonitrile, α-chloroacrylonitrile, etc. Unsaturated cyanides; unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate,
Dimethylaminopropyl (meth) acrylate, (meth)
Unsaturated amines such as dibutylaminoethyl acrylate and vinyl pyridine; Divinyl aromatics such as divinylbenzene; Cyanurates such as triallyl cyanurate; Allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; Vinyl ethers or allyl ethers such as methoxy polyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxy polyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether; polydimethylsiloxane propylaminomaleamic acid, polydimethylsiloxane Aminopropylene aminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane- Scan - (dipropylene amino maleamic acid), polydimethylsiloxane - (1-propyl-3-acrylate), poly dimethyl siloxane -
Siloxane derivatives such as (1-propyl-3-methacrylate), polydimethylsiloxane-bis- (1-propyl-3-acrylate), polydimethylsiloxane-bis- (1-propyl-3-methacrylate).

To obtain the copolymer (A) in the present invention, the above-mentioned monomer components may be copolymerized using a polymerization initiator. The copolymerization can be performed by a known method such as solution polymerization or bulk polymerization. The solution polymerization can be carried out batchwise or continuously, and the solvent used at that time is not particularly limited, and examples thereof include water; alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; benzene, toluene, xylene, Aromatic or aliphatic hydrocarbons such as cyclohexane and n-hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; cyclic ether compounds such as tetrahydrofuran and dioxane; From the solubility of the polymer obtained, it is preferable to use at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. Among them, water is used as the solvent, and the solvent removal step can be omitted. It is more preferable in terms.

When aqueous solution polymerization is carried out to produce the above-mentioned copolymer (A), as a radical polymerization initiator,
Water-soluble polymerization initiators, for example, persulfates such as ammonium persulfate, sodium persulfate and potassium persulfate; hydrogen peroxide; azoamidine compounds such as 2,2′-azobis-2-methylpropionamidine hydrochloride, 2, A cyclic azoamidine compound such as 2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, a water-soluble azo initiator such as an azonitrile compound such as 2-carbamoylazoisobutyronitrile, etc. are used, At this time, Fe (II) salts such as alkali metal sulfites such as sodium hydrogen sulfite, metadisulfite, sodium hypophosphite, Mohr salt, sodium hydroxymethanesulfinate dihydrate, hydroxylamine hydrochloride, thiourea , L-ascorbic acid (salt), erythorbic acid (salt) and the like can be used in combination. Among them, a combination of hydrogen peroxide and a promoter such as L-ascorbic acid (salt) is preferable. These radical polymerization initiators and accelerators may be used alone or in combination of two or more.

When solution polymerization is carried out using a lower alcohol, an aromatic or aliphatic hydrocarbon, an ester compound or a ketone compound as a solvent, a peroxide such as benzoyl peroxide, lauroyl peroxide or sodium peroxide; t -Hydroperoxides such as butyl hydroperoxide and cumene hydroperoxide; azo compounds such as azobisisobutyronitrile are used as radical polymerization initiators. At this time, an accelerator such as an amine compound may be used in combination. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected and used from the above various radical polymerization initiators or a combination of a radical polymerization initiator and an accelerator.

When bulk polymerization is further carried out, radical polymerization initiators such as benzoyl peroxide, lauroyl peroxide, sodium peroxide and the like; t-butyl hydroperoxide, cumene hydroperoxide and other hydroperoxides; Azo compounds such as azobisisobutyronitrile are used, and the amount is 50 to 200
It is carried out at a temperature of ° C.

In order to adjust the molecular weight of the above copolymer (A),
Chain transfer agents can be used. The chain transfer agent is not particularly limited, and examples thereof include mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolic acid, and octyl 3-mercaptopropionic acid. -A thiol chain transfer agent such as mercaptoethanesulfonic acid. These may be used alone or in combination of two or more. Furthermore, in order to adjust the molecular weight of the copolymer (A), it is effective to use a monomer having a high chain transfer property such as (meth) allylsulfonic acid (salt) as the monomer (c). .

The above-mentioned copolymer (A) can be used as it is as a main component of the cement admixture, but if necessary, it may be further neutralized with an alkaline substance before use. Such an alkaline substance is not particularly limited, and for example, it is preferable to use one or more inorganic salts such as monovalent metal or divalent metal hydroxides and carbonates; ammonia; organic amines and the like. . Further, after the completion of the reaction, the concentration can be adjusted if necessary.

The weight average molecular weight of the above copolymer (A) is preferably 1,000 to 500,000 in terms of polyethylene glycol by gel permeation chromatography (hereinafter also referred to as "GPC"), but it is 5,000.
To 300000 are preferable, and 10000 to 150,000
Is more preferable. By selecting such a weight average molecular weight range, a cement admixture exhibiting higher dispersion performance can be obtained.

The cement admixture of the present invention contains the copolymer (A) and the oxycarboxylic acid compound (B) as essential components, but it can be used as it is as a main component of the cement admixture in the form of an aqueous solution. Alternatively, it may be dried and powdered before use. When the cement admixture is added to the cement composition, a cement admixture in which the copolymer (A) and the oxycarboxylic acid compound (B) are mixed in advance may be added, or the copolymer (A ) And the oxycarboxylic acid compound (B) may be added separately.

The cement admixture of the present invention can be used for various hydraulic materials, that is, cement compositions such as cement and gypsum, and other hydraulic materials. Specific examples of hydraulic compositions containing such a hydraulic material, water and the cement admixture of the present invention, and further containing fine aggregate (sand etc.) and coarse aggregate (crushed stone etc.) as required Is a cement paste,
Mortar, concrete, plaster, etc. are mentioned.

Among the above hydraulic compositions, a cement composition using cement as a hydraulic material is the most general, and the cement composition is the cement admixture of the present invention,
Containing cement and water as essential components. Such a cement composition is one of the preferred embodiments of the present invention.

The cement used in the above cement composition is not particularly limited. For example, Portland cement (normal, early strength, super early strength, moderate heat, sulfate resistant and low alkali type of each), various mixed cements (blast furnace cement, silica cement, fly ash cement), white Portland cement, alumina cement,
Super quick hardening cement (1 clinker quick hardening cement, 2 clinker quick hardening cement, magnesium phosphate cement), grout cement, oil well cement, low heat generation cement (low heat generation blast furnace cement, fly ash mixed low heat generation blast furnace cement, belite High-content cement), ultra-high-strength cement, cement-based solidifying material, eco-cement (cement produced from one or more of municipal waste incineration ash and sewage sludge incineration ash), and blast furnace slag,
Fine powder such as fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, limestone powder, or gypsum may be added. Further, as aggregates, in addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., siliceous, clay-like, zircon-like, high-alumina-like, silicon carbide-like, graphite-like, chrome-like, chromagous, magnesia-like Fire-resistant aggregates such as can be used.

In the above cement composition, 1 m
There is no particular limitation on the unit water amount per ³ units, the amount of cement used, and the water / cement ratio, and the unit water amount is 100 to 185 kg /
m ³ , amount of cement used 250-800 kg / m ³ , water /
Cement ratio (weight ratio) = 0.1 to 0.7, preferably unit water amount 120 to 175 kg / m ³ , cement amount used 27
0-800 kg / m ³ , water / cement ratio (weight ratio) =
0.2 to 0.65 is recommended, it can be widely used from poor mix to rich mix, and is effective for both high strength concrete with a large amount of unit cement and poor mix concrete with a unit cement amount of 300 kg / m ³ or less. Is.

The blending ratio of the cement admixture of the present invention in the above cement composition is not particularly limited,
When used for mortar and concrete using hydraulic cement, the cement weight is 0.01 to
The amount may be 5.0%, preferably 0.02 to 2.0%, and more preferably 0.05 to 1.0%. Such an added amount brings about various desirable effects such as reduction of the unit water amount, increase of strength, and improvement of durability. If the blending ratio is less than 0.01%, the performance may not be sufficient, and conversely, even if a large amount of more than 5.0% is used, the effect is substantially leveled off and also from the economical aspect. It will be a disadvantage.

The above cement composition is also excellent in pumpability, significantly improves workability during construction, and has high fluidity, so that it is used for ready-mixed concrete and secondary concrete products (precast concrete). , Concrete for centrifugal molding, concrete for vibration compaction, steam curing concrete, sprayed concrete, etc., and moreover, medium flow concrete (concrete with slump value in the range of 22 to 25 cm), high flow concrete (slump). It is also effective for mortar and concrete that require high fluidity, such as concrete with a value of 25 cm or more and a slump flow value in the range of 50 to 70 cm), self-filling concrete, and self-leveling material.

The above cement composition can contain a cement dispersant as described below, for example.
Lignin sulfonate; polyol derivative; naphthalene sulfonic acid formalin condensate; melamine sulfonic acid formalin condensate; polystyrene sulfonate;
Aminosulphonic acid-based compounds such as aminoaryl sulfonic acid-phenol-formaldehyde condensates as described in JP-A-113419; polyalkylene glycol mono (meth) acrylic acid as component (a) as described in JP-A-7-267705. A copolymer of an ester compound and a (meth) acrylic acid compound and / or a salt thereof, and (b)
As a component, a copolymer of a polyalkylene glycol mono (meth) allyl ether compound and maleic anhydride and / or a hydrolyzate thereof, and / or a salt thereof, and as a component (c), a polyalkylene glycol mono ( Cement dispersant containing a copolymer of a (meth) allyl ether compound and a maleic acid ester of a polyalkylene glycol compound and / or a salt thereof; Patent No. 250
As described in No. 8113, as the A component, (meth)
A copolymer of a polyalkylene glycol ester of acrylic acid and (meth) acrylic acid (salt), a concrete admixture comprising a specific polyethylene glycol polypropylene glycol-based compound as the B component, and a specific surfactant as the C component; As described in JP-A-62-216950, polyethylene (propylene) glycol ester of (meth) acrylic acid or polyethylene (propylene) glycol mono (meth) allyl ether, (meth) allyl sulfonic acid (salt), and ( A copolymer composed of (meth) acrylic acid (salt).

As described in JP-A-1-226757, polyethylene (propylene) glycol ester of (meth) acrylic acid, (meth) allylsulfonic acid (salt),
And a copolymer consisting of (meth) acrylic acid (salt); as described in JP-B-5-36377, polyethylene (propylene) glycol ester of (meth) acrylic acid, (meth) allylsulfonic acid (salt) or p- (meth) allyloxybenzenesulfonic acid (salt), and
Copolymer composed of (meth) acrylic acid (salt);
As described in JP-A-149056, a copolymer of polyethylene glycol mono (meth) allyl ether and maleic acid (salt); polyethylene glycol ester of (meth) acrylic acid, as described in JP-A-5-170501. (Meth) allylsulfonic acid (salt), (meth) acrylic acid (salt), alkanediol mono (meth) acrylate, polyalkylene glycol mono (meth) acrylate, and α, β-unsaturation having an amide group in the molecule Copolymer composed of monomers; polyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) acrylate, (meth) acrylic acid alkyl ester, (meth) acrylic acid as described in JP-A-6-191918. (Salt), and (meth) allyl sulfonic acid (salt) or Copolymer comprising p- (meth) allyloxybenzenesulfonic acid (salt); JP-A-5-432
As described in JP-A-88, a copolymer of an alkoxypolyalkylene glycol monoallyl ether and maleic anhydride, or a hydrolyzate thereof, or a salt thereof; a polyethylene glycol monopolyester as described in JP-B-58-38380. A copolymer of allyl ether, maleic acid, and a monomer copolymerizable with these monomers, or a salt thereof, or an ester thereof.

As described in JP-B-59-18338, polyalkylene glycol mono (meth) acrylic acid ester-based monomer, (meth) acrylic acid-based monomer, and
Copolymers of monomers copolymerizable with these monomers; (meth) acrylic acid ester having a sulfonic acid group as described in JP-A-62-119147 and optionally copolymerizable therewith A copolymer composed of various monomers, or a salt thereof; a copolymer of an alkoxypolyalkylene glycol monoallyl ether and maleic anhydride as described in JP-A-6-271347, and an alkenyl group at the end. Esterification reaction product with polyoxyalkylene derivative; copolymer of alkoxypolyalkylene glycol monoallyl ether and maleic anhydride as described in JP-A-6-298555, and polyoxyalkylene derivative having hydroxyl group at terminal. Esterification reaction product of. These cement dispersants may be used alone or in combination of two or more.

When the above cement dispersant is used, the ratio of the above copolymer (A) to the above cement dispersant, that is, the weight ratio (% by weight) in terms of solid content, is the above copolymer (A). ) And the above-mentioned cement dispersant, the optimum ratio varies depending on the performance balance, but 1/99 to 99/1 is preferable, 5/95 to 95/5 is more preferable, and 10 /
90 to 90/10 is the most preferable. Further, the cement composition can contain other known cement additives (materials) as exemplified in the following (1) to (20).

(1) Water-soluble polymeric substance: unsaturated carboxylic acid polymerization such as polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), sodium salt of acrylic acid / maleic acid copolymer object;
Polymers of polyoxyethylene or polyoxypropylene such as polyethylene glycol and polypropylene glycol or copolymers thereof; methyl cellulose,
Non-ionic cellulose ethers such as ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose and hydroxypropyl cellulose; alkylated or hydroxyalkylated derivatives of polysaccharides such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose and hydroxypropyl cellulose Part or all of the hydrogen atoms of the hydroxyl group are substituted with a hydrophobic substituent having a hydrocarbon chain of 8 to 40 carbon atoms as a partial structure and an ionic hydrophilic substituent having a sulfonic acid group or a salt thereof as a partial structure. Polysaccharide derivative thus obtained; yeast glucan, xanthan gum, β-1.3 glucan (both linear and branched, examples include curdlan, paramylon, pakiman, Polysaccharides produced by microbial fermentation such as cleroglucan, laminaran, etc .; polyacrylamide; polyvinyl alcohol; starch; starch phosphate esters; sodium alginate; gelatin; copolymers of acrylic acid having an amino group in the molecule and its quaternary Compounds, etc.

(2) Polymer emulsion: a copolymer of various vinyl monomers such as alkyl (meth) acrylate. (3) Curing retarders other than the oxycarboxylic acid compound (B): monosaccharides such as glucose, fructose, galactose, saccharose, xylose, apiose, ribose and isomerized sugar, and oligosaccharides such as disaccharides and trisaccharides, Or oligosaccharides such as dextrin, polysaccharides such as dextran, sugars such as molasses containing these; sugar alcohols such as sorbitol; magnesium silicofluoride; phosphoric acid and its salts or borate esters; aminocarboxylic acids and their Salt; Alkali-soluble protein; Humic acid; Tannic acid; Phenol; Polyhydric alcohol such as glycerin; Aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriamine Penta (methylenephosphonic acid) and these Alkali metal salts, and phosphonic acids and derivatives thereof such as alkaline earth metal salts.

(4) Early strengthening agent / accelerator: 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; carbonates; thiosulfates; formates such as formic acid and calcium formate; alkanolamines; alumina cements; calcium aluminate silicates. (5) Mineral oil type antifoaming agent: kerosene, liquid paraffin, etc. (6) Oil-and-fat defoaming agents: animal and vegetable oils, sesame oils, castor oils, alkylene oxide adducts thereof, and the like. (7) Fatty acid type defoaming agent: oleic acid, stearic acid, alkylene oxide adducts thereof, and the like. (8) Fatty acid ester-based antifoaming agent: glycerin monoricinoleate, alkenylsuccinic acid derivative, sorbitol monolaurate, sorbitol trioleate, natural wax and the like.

(9) Oxyalkylene antifoaming agent: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether,
(Poly) oxyalkyl ethers such as polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene 2-ethylhexyl ether, and oxyethyleneoxypropylene adducts of higher alcohols having 12 to 14 carbon atoms; polyoxypropylene phenyl ether, poly (Poly) oxyalkylene (alkyl) aryl ethers such as oxyethylene nonylphenyl ether; 2,4,7,9-tetramethyl-5-decyne-
4,7-diol, 2,5-dimethyl-3-hexyne-
Acetylene ethers obtained by addition-polymerizing alkylene oxides to acetylene alcohols such as 2,5-diol and 3-methyl-1-butyn-3-ol; diethylene glycol oleate, diethylene glycol lauryl ester, 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 dodecylphenol ether sulfate Alkylene alkyl (aryl) ether sulfate salts; (poly)
(Poly) such as oxyethylene stearyl phosphate
Oxyalkylenealkyl phosphates; (poly) oxyalkylenealkylamines such as polyoxyethylenelaurylamine; polyoxyalkyleneamides and the like.

(10) Alcohol type antifoaming agent: octyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like. (11) Amide-based defoaming agent: acrylate polyamine and the like. (12) Phosphate defoamer: tributyl phosphate,
Sodium octyl phosphate and the like. (13) Metal soap-based defoaming agent: aluminum stearate, calcium oleate and the like. (14) Silicone antifoaming agent: dimethyl silicone oil,
Silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), fluorosilicone oil, etc.

(15) AE agent: resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, ABS (alkylbenzenesulfonic acid), LAS (linear alkylbenzenesulfonic 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, alkenylsulfosuccinic acid, α- Olefin sulfonate, etc.

(16) Other surfactants: 6 to 3 in the molecule of octadecyl alcohol, stearyl alcohol, etc.
Aliphatic monohydric alcohol having 0 carbon atoms, abiethyl alcohol and the like, alicyclic monohydric alcohol having 6 to 30 carbon atoms in the molecule, dodecyl mercaptan and the like, 6 to 30 carbons in the molecule Atoms having 1 to 30 carbon atoms in the molecule such as monovalent mercaptan, nonylphenol and the like, amines having 6 to 30 carbon atoms in the molecule such as dodecylamine, molecules such as lauric acid and stearic acid Polyalkylene oxide derivatives obtained by adding 10 moles or more of alkylene oxides such as ethylene oxide and propylene oxide to a carboxylic acid having 6 to 30 carbon atoms therein; alkyl group or alkoxy group may be substituted. , An alkyldiphenyl 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, etc. (18) Anticorrosion agent: nitrite, phosphate, zinc oxide and the like. (19) Crack reducing agent: polyoxyalkyl ether and the like. (20) Expansive material: ettringite type, coal type and the like.

Other known cement additives (materials) include cement wetting agents, thickening agents, separation reducing agents, flocculants,
Examples thereof include a dry shrinkage reducing agent, a strength enhancer, a self-leveling agent, a rust preventive, a coloring agent and a fungicide. These known cement additives (materials) may be used alone,
You may use 2 or more types together.

In the above cement composition, the following (1) to (4) are mentioned as particularly preferred embodiments for components other than cement and water. (1) A combination in which the cement admixture of the present invention and an oxyalkylene antifoaming agent are essential. still,
As the compounding weight ratio of the oxyalkylene antifoaming agent,
The range of 0.001 to 10% by weight is preferable with respect to the cement admixture.

(2) The cement admixture of the present invention, and
A combination that requires two components, a material separation reducing agent. As the material separation-reducing agent, various thickening agents such as nonionic cellulose ethers, a hydrophobic substituent consisting of a hydrocarbon chain having 4 to 30 carbon atoms as a partial structure and an alkylene oxide having 2 to 18 carbon atoms are added on average. A compound or the like having a polyoxyalkylene chain added with 2 to 300 in terms of the number of moles can be used. The mixing weight ratio of the cement admixture with the material separation reducing agent is 10/90 to 99.99 /
0.01 is preferable and 50 / 50-99.9 / 0.1 is more preferable. The cement composition of this combination is suitable as high-fluidity concrete, self-compacting concrete, and self-leveling material.

(3) The cement admixture of the present invention, and
A combination that requires two components of a sulfonic acid-based dispersant having a sulfonic acid group in the molecule. As the sulfonic acid-based dispersant, an aminosulfonic acid-based dispersion such as a ligninsulfonic acid salt, a naphthalenesulfonic acid formalin condensate, a melaminesulfonic acid formalin condensate, a polystyrenesulfonic acid salt, or an aminoarylsulfonic acid-phenol-formaldehyde condensate. Agents and the like can be used. The blending weight ratio of the cement admixture with the sulfonic acid-based dispersant having a sulfonic acid group in the molecule is 5/95 to 9
5/5 is preferable and 10/90 to 90/10 is more preferable.

(4) The cement admixture of the present invention, and
A combination that requires two components of lignin sulfonate. The blending weight ratio of the cement admixture with the lignin sulfonate is preferably 5/95 to 95/5, more preferably 10/90 to 90/10.

[0073]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Unless otherwise specified, "%" means% by weight,
“Parts” means parts by weight.

<Weight average molecular weight measurement conditions> Model: Waters LCM1 Detector: Differential refractometer (RI) detector (Waters 41)
0) Eluent: Type 0.05M sodium acetate, acetonitrile / ion exchange aqueous solution = 40/60 (vol%), adjusted to pH 6.0 with acetic acid Flow rate 0.6 ml / min Column: Type Tosoh Corp., TSK- GEL G4
000SWXL + G3000SWXL + G2000SW
XL + GUARD COLUMN 7.8 × 300 mm, 6.0 × 40 mm Temperature 40 ° C. Calibration curve: polyethylene glycol standard

Production Example 1 Ion-exchanged water 1291 was placed in a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube and a reflux condenser.
Parts, 1812 parts of an unsaturated polyalkylene glycol ether obtained by adding 50 mol of ethylene oxide to 3-methyl-3-buten-1-ol on average, and 188 parts of maleic acid were charged, and the atmosphere in the reaction vessel was replaced with nitrogen under stirring to obtain a nitrogen atmosphere. The temperature was raised to 60 ° C. below. NC-32W (manufactured by Nihonbo Chemical Co., Ltd.
50 parts of 15% aqueous solution of 2,2′-azobis-2methylpropionamidine hydrochloride (87% product) was added, and the mixture was treated for 60 hours for 7 hours
The temperature was maintained at 0 ° C, the temperature was further raised to 80 ° C, and the mixture was stirred for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 7 with an aqueous sodium hydroxide solution at a temperature not higher than the polymerization reaction temperature, and a copolymer corresponding to the copolymer (A) of the present invention, which is an aqueous polymer solution having a weight average molecular weight of 27,000. (A-1) was obtained. In addition, the residual amount of unsaturated polyalkylene glycol ether obtained by adding 50 mol of ethylene oxide to 3-methyl-3-buten-1-ol and maleic acid was measured by liquid chromatography (LC) to determine the polymerization rate. The polymerization rate of the unsaturated polyalkylene glycol ether was 90.0%, and the polymerization rate of maleic acid was 90.1%. Therefore, the copolymerization composition ratio is unsaturated polyalkylene glycol ether / maleic acid = 87.5 / 12.5 (wt%) = 32.7 / 67.
3 (mol%), amount of carboxylic acid equivalent to unneutralized copolymer =
It was 1.62 (meq / g).

Production Example 2 In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube and a reflux condenser, ion-exchanged water 72.2 was placed.
6 parts, 127.74 parts of unsaturated polyalkylene glycol ether in which 50 mol of ethylene oxide was added to 3-methyl-3-buten-1-ol were charged, and the temperature was raised to 65 ° C., and 30% hydrogen peroxide was added thereto. 0.38 parts of an aqueous solution was added. Next, 19.83 parts of a 40% aqueous solution of acrylic acid was dropped into the reaction vessel over 3 hours, and at the same time, 3
-Mercaptopropionic acid 0.35 part was dropped into the reaction vessel over 3 hours, and L-ascorbic acid 2.1% aqueous solution 6.99 parts over 3.5 hours. Then, the temperature was maintained at 65 ° C. for 60 minutes to complete the polymerization reaction, and the temperature was lowered to 50 ° C. or lower to obtain a sodium hydroxide 5.0% aqueous solution 7
It was neutralized to pH 7 with 9.12 parts to obtain a copolymer (A-2) corresponding to the copolymer (A) of the present invention, which is an aqueous polymer solution having a weight average molecular weight of 27,000. Also, 3
The residual amount of unsaturated polyalkylene glycol ether obtained by adding 50 mol of ethylene oxide to -methyl-3-buten-1-ol and acrylic acid was measured by liquid chromatography (LC) to determine the polymerization rate. The polymerization rate of saturated polyalkylene glycol ether is 7
The polymerization rate of 8.4% and acrylic acid was 98.4%.
Therefore, the copolymerization composition ratio is unsaturated polyalkylene glycol ether / acrylic acid = 90.8 / 9.2 (% by weight)
= 28.8 / 71.2 (mol%), and the amount of carboxylic acid in terms of unneutralized copolymer was 1.00 (meq / g).

<Curing Retarder> The following compounds were used as the oxycarboxylic acid compound (B) and the curing retarder (C). (B-1) Sodium gluconate (B-2) Malic acid (C-1) Dipotassium hydrogen phosphate

<Concrete Test> (Preparation of Concrete Composition) Ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) as cement, Oigawa water system land sand as fine aggregate, crushed stone from Aomi as coarse aggregate, and tap water as kneading water. A concrete composition was prepared with the following composition. In addition, the materials used in the test, the forced kneading mixer, and the measuring instruments are adjusted in the above test temperature atmosphere so that the temperature of the concrete composition reaches the test temperature of 30 ° C. or 15 ° C., and the kneading and each measurement are performed. Was carried out under the above test temperature atmosphere. Further, in order to avoid the influence of bubbles in the concrete composition on the fluidity of the concrete composition,
If necessary, use a commercially available oxyalkylene-based defoaming agent,
The amount of air was adjusted to be 1.0 ± 0.3%. (Compound) Cement: 320 kg / m ³ , water: 176 kg
/ M ³ , fine aggregate: 822 kg / m ³ , coarse aggregate: 892k
g / m ³ , fine aggregate ratio (fine aggregate / fine aggregate + coarse aggregate) (volume ratio): 48%, water / cement ratio (weight ratio) = 0.55

Under the above conditions, concrete was produced using a forced kneading mixer for a mixing time of 2 minutes, and the slump value, setting time (setting time) and air content were measured. The slump value, the setting time (setting time) and the amount of air were measured according to JIS-A-1101, JIS-A-6204 Annex I and JIS-A-1128, respectively. still,
The addition amount of the copolymer (A) and / or the oxycarboxylic acid compound (B) or the setting retarder (C) in the table represents the weight% of the solid content relative to the cement, and the initial slump value is 20.
The amount of addition was adjusted so that it was ± 1 cm, and comparison was made. The test results are shown in Table 1.

[0080]

[Table 1]

As shown in Table 1, when the copolymer (A-1) or (A-2) was used alone at a test temperature of 30 ° C., an inorganic curing agent other than the oxycarboxylic acid compound was used. In any case where the retarder was used, the fluidity was largely decreased with time, while when the oxycarboxylic acid compound (B-1) or (B-2) was used alone, the fluidity was sufficient. Was not obtained. On the other hand, when the cement admixture of the present invention in which the copolymer (A-1) or (A-2) and the oxycarboxylic acid compound (B-1) or (B-2) are used in combination, the test temperature is At 15 ° C, the decrease in fluidity with time was small but the curing was slow, whereas at a test temperature of 30 ° C, the decrease in fluidity with time was small and the curing was fast.

[0082]

EFFECTS OF THE INVENTION By adding the cement admixture of the present invention to a cement composition, it becomes possible to prevent deterioration of fluidity for a long time even at high temperatures such as in summer, and the cement composition can be transferred by a pump or the like. Workability in the process of filling a frame or the like is improved.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08F 216/16 C08F 216/16 220/04 220/04 222/00 222/00 290/06 290/06 / / C04B 103: 40 C04B 103: 40 (72) Inventor Ken Hirata 5-8 Nishimitabicho, Suita City, Osaka Prefecture Nihon Shokubai F-Term Co., Ltd. (reference) 4G012 PA04 PB17 PB31 PC03 PC05 PC12 PC14 4J027 AC01 AC02 AC03 AC07 BA04 BA06 CC02 CD00 4J100 AE01P AE18P AE26P AJ01Q AJ02Q AJ08Q AJ09Q AK01Q AK04Q AK18Q AK29Q AK31Q BA02P BA03P BA04P BA32Q CA04 JA67

Claims (4)

[Claims] 1. A cement admixture comprising a copolymer (A) and an oxycarboxylic acid compound (B) as essential components in a ratio (wt%) of 10/90 to 99.9 / 0.1. The copolymer (A) has the following general formula (1); YO (R ¹ O) nR ² (1) (In the formula, Y represents an alkenyl group having 5 to 8 carbon atoms. R ¹ O Are the same or different and have 2 to 2 carbon atoms.
18 represents an oxyalkylene group. n is an average addition mole number of an oxyalkylene group, and represents a number of 1 to 500. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. ) Structural unit (I) derived from unsaturated (poly) alkylene glycol ether monomer (a) represented by
And an unsaturated carboxylic acid-based monomer (b) -derived structural unit (I
I) as an essential constitutional unit, and the constitutional unit (I) and the constitutional unit (II) each account for 1% by weight or more of all the constitutional units, and the proportion of the constitutional unit (I) is the whole. A cement admixture characterized by being 50 mol% or less in the constitutional unit. 2. The structural unit (II) derived from the unsaturated carboxylic acid monomer (b) has the following general formula (2); (In the formula, R ³ , R ⁴ and R ⁵ are the same or different and represent a hydrogen atom, a methyl group or a-(CH ₂ ) pCOOX group. X is the same or different and is a hydrogen atom or a monovalent metal atom. Represents a divalent metal atom, an ammonium group or an organic amine group, p represents an integer of 0 to 2. When two COOX groups are present, two -COOX groups are used to form -C.
An OOCO- group may be formed. The cement admixture according to claim 1, which is represented by the formula (1). 3. Y in the general formula (1) is one of the following:
General formula (3); [Chemical 2] (In the formula, R⁶, R⁷And R⁸Are the same or different
Represents a hydrogen atom or a methyl group. However, R⁶, R⁷Over
And R⁸Are not all methyl groups. R⁹Is
In the general formula (1), -O (R¹O) nR^TwoConnection with
The point is -CH₂-,-(CH₂)₂-Or-C
(CH₃)₂Represents-. R⁶, R⁷, R⁸And R ⁹Inside
The total number of carbon atoms is 3. ) Is represented by
The cement admixture according to claim 1 or 2. 4. A method for applying a cement composition, which comprises applying the cement admixture according to claim 1, 2 or 3 and a cement composition containing cement and water as essential components at a temperature of 20 ° C. or higher.