JP5422105B2 - Polycarboxylic acid copolymer and copolymer composition for concrete admixture - Google Patents

Description

The present invention relates to a polycarboxylic acid copolymer and a copolymer composition for concrete admixture. More specifically, the present invention relates to a polycarboxylic acid copolymer for concrete admixture that can be used as a water reducing agent such as a cement composition, and a copolymer composition containing the same.

Concrete admixtures are widely used in cement compositions such as cement paste, mortar and concrete, and are indispensable for constructing civil engineering and building structures from cement compositions. Such a concrete admixture is used as a water reducing agent, etc., and has the effect of improving the strength and durability of the cured product by reducing the water content of the cement composition by increasing the fluidity of the cement composition. . As a water reducing agent, a water reducing agent such as a naphthalene type has been conventionally used. However, a polycarboxylic acid type water reducing agent that exhibits higher water reducing performance than this has been proposed (for example, see Patent Document 1). As a high-performance AE water reducing agent, it has come to have many uses. However, with such a water reducing agent, although the fluidity of the cement composition is sufficient immediately after production, the fluidity is not sufficient over time, so that it can exhibit high fluidity even after a long time has passed. There is room for improvement to improve the workability by reducing the viscosity of the cement composition.

Therefore, in order to improve the fluidity of such a cement composition, fluidity retention with time, and viscosity, a technique using a polycarboxylic acid copolymer in which the molecular weight and molecular weight distribution are adjusted to a specific range ( For example, Patent Documents 2 and 3) and a method of using a mixture of a plurality of polycarboxylic acid copolymers having a specific structure (for example, see Patent Documents 4 and 5) have been proposed. By various methods, it is possible to improve each point that has been set as a problem. However, the problem point has not been improved at the same time, and further technical improvement is required.
JP 58-74552 A JP-A-9-86990 JP 2005-281022 A JP 2006-069859 A JP 2004-256320 A

The present invention has been made in view of the above situation, and can impart excellent fluidity to the cement composition and can exhibit high fluidity over a long period of time, and also handles the cement composition. To provide a polycarboxylic acid copolymer for a concrete admixture that can be made viscous so that it can be easily worked on site, and a copolymer composition for a concrete admixture comprising the copolymer. It is the purpose.

As a result of various studies on the copolymer for concrete admixture, the present inventors show that the polycarboxylic acid copolymer having a polyalkylene glycol in the side chain exhibits excellent water reduction performance with respect to a cement composition or the like. If the weight average molecular weight (Mw) of the copolymer is specified to be less than 10,000, the flowability of the cement composition over time (hereinafter also referred to as “retainability”) is noted. It has been found that the viscosity can be reduced and workability can be improved while being sufficient, and further, the range of the average number of repeats and molecular weight distribution (weight average molecular weight / number average molecular weight) of the alkylene glycol units of the polyalkylene glycol chain Is specified, it is possible to exhibit various performances such as fluidity, retention and workability of cement composition at the same time and with high performance. And, and conceived that can be admirably solved the above problems.

Here, the concrete admixture includes fluidity (= dispersibility, water-reducing property), retention (= fluidity retention over time), viscosity (ease of handling, cement in the cement composition). Various performances such as a sense of unity between the paste and the aggregate and the pumping ability are required. However, conventional polycarboxylic acid copolymers cannot exhibit these various performances at the same time. If we tried to improve the performance of the other, it was supposed to significantly impair the other performance. However, as described above, the present inventors can appropriately exhibit the configuration of the polycarboxylic acid copolymer as described above, so that all of these performances can be exhibited at the same time, and one or more performances are further enhanced. It has been found that it becomes possible.

In addition, a copolymer composition containing such a polycarboxylic acid copolymer for concrete admixture of the present invention and a copolymer different from this copolymer has sufficient fluidity, retentivity and required for a cement composition. It has been found that various performances such as workability can be exerted in a well-balanced manner, and in particular, when used in combination with a copolymer having a specified weight average molecular weight and An value, it has been found that the performance is particularly good, and the present invention has been achieved. is there.

That is, the present invention is a polycarboxylic acid copolymer for concrete admixture having a polyalkylene glycol chain, wherein the polycarboxylic acid copolymer has a weight average molecular weight (Mw) of less than 10,000, and The weight average molecular weight / number average molecular weight (Mw / Mn) exceeds 1.5, and the polyalkylene glycol chain has a polycarboxylic acid copolymer for concrete admixtures having an average number of repeating alkylene glycol units of 8 or more. It is a polymer.
The present invention is described in detail below.

The polycarboxylic acid copolymer for concrete admixture of the present invention (hereinafter also referred to as “copolymer (A)”) has a polyalkylene glycol in the side chain, and the alkylene glycol unit in the chain. The average number of repetitions is suitably 8 or more. As a result, the fluidity, retention and workability (good viscosity) of the cement composition can be all well balanced, but if it is less than 8, these various performances can be achieved simultaneously. In addition, there is a possibility that gel is generated during the polymerization reaction for obtaining the copolymer (A), and the productivity of the copolymer may not be sufficient. Preferably it is 9 or more, More preferably, it is 10 or more. On the other hand, if the average number of repetitions exceeds 300, problems in production may occur, and when used as a concrete admixture, the viscosity of the cement composition may increase, and workability may not be sufficient. Therefore, from the viewpoint of manufacturing, it is preferable that it is 300 or less. Preferably, it is 150 or less, more preferably 100 or less, and from the viewpoint of viscosity, it is further preferably 50 or less, still more preferably 25 or less, particularly preferably 15 or less, most preferably. 10 or less.
In such a region where the number of repetitions is relatively small, a slight change in the number greatly affects the performance of the copolymer (A) as a cement admixture. In this area, the difference of 1 in the number is a difference of 10% or more. Further, since the copolymer (A) has a small weight average molecular weight of less than 10,000 and a short main chain portion as will be described later, the side chain is a polyalkylene glycol chain as compared with the main chain portion of the copolymer. Has a significant impact on performance.

The copolymer (A) also suitably has a weight average molecular weight of less than 10,000. As a result, it becomes possible to improve the workability by reducing the viscosity while maintaining sufficient retention of the cement composition, but if it is 10,000 or more, there is a possibility that these performances cannot be sufficiently exhibited. is there. Preferably it is 9500 or less, More preferably, it is 9200 or less, More preferably, it is 9000 or less, Most preferably, it is 8800 or less. In addition, the copolymer (A) has a weight average molecular weight of preferably 2000 or more from the viewpoint that adsorbing power increases as the weight average molecular weight increases as the copolymer (A) adsorbs to cement particles to some extent. . More preferably, it is 3000 or more, More preferably, it is 4000 or more, Especially preferably, it is 4500 or more, Most preferably, it is 5000 or more.

The copolymer (A) preferably further has a weight average molecular weight / number average molecular weight (Mw / Mn) exceeding 1.5. Here, if the Mw / Mn of the copolymer (A) is too small or too large, it may affect various performances. This is because the cement particles have a certain particle size distribution. It is presumed that when / Mn also has a distribution suitable to some extent, it can be adsorbed on cement particles with a wide particle size and exhibit performance. Mw / Mn is preferably 1.52 or more, more preferably 1.54 or more, further preferably 1.56 or more, and particularly preferably 1.58 or more. Further, Mw / Mn is preferably 2 or less. More preferably, it is 1.9 or less, More preferably, it is 1.8 or less, Especially preferably, it is 1.7 or less, Most preferably, it is 1.65 or less.

Here, the molecular weight distribution (Mw / Mn) of the copolymer (A) is preferably regarded as uniform. Here, “uniform” does not mean “monodisperse”. This is because the (co) polymer usually has a molecular weight distribution. In order to obtain a monodisperse (co) polymer in a strict sense, it is necessary to use a method such as a living polymerization method or molecular weight fractionation. In the GPC (gel permeation chromatography) chromatogram of the copolymer (A), when the chromatogram curve on the higher molecular weight side than Mp (peak top molecular weight) is a gentle curve, it can be regarded as a uniform molecular weight distribution. . On the other hand, when there is a remarkable bent portion (shoulder) on the high molecular weight side or when there are a plurality of peak tops, the molecular weight distribution cannot be said to be uniform.
The copolymer (A) having a shoulder on the high molecular weight side or having a plurality of peak tops can be obtained, for example, by changing the monomer amount, the chain transfer agent amount, and other conditions during the polymerization process. it can. Since such a copolymer can be regarded as a mixture of a copolymer (A) satisfying the above-mentioned various conditions such as molecular weight and a copolymer (AA) having different molecular weights, the molecular weight is calculated separately. When the copolymer (AA) satisfies a predetermined condition, it can also be regarded as a copolymer (B) to be described later (hereinafter sometimes referred to as a copolymer (AB)).

The copolymer (A) containing the copolymers (AA) and (AB) having different molecular weights as described above is more preferable as described in the present invention than the copolymer (A) having a uniform molecular weight distribution. Performance may not be sufficient. Therefore, it is preferable that the content of the copolymer (A) is sufficiently high. In the RI (differential refractive index) area ratio of GPC, the area ratio of the copolymer (A) with respect to 100% of the total of the copolymer (A) and the copolymer (AA) or the copolymer (AB) is: It is preferably 70% or more, more preferably 80% or more, more preferably 90% or more, and more preferably 95% or more. In the calculation of the area ratio in this case, the copolymer (A) and the copolymer (AA) or copolymer (AB) shall be divided vertically at the intersection of the tangent lines of the RI chromatogram.
In the GPC chromatogram, the chromatogram curve on the lower molecular weight side than Mp (peak top molecular weight) often has peaks derived from dimers, trimers and the like. This is due to the separation conditions and should not be used to determine the uniformity of the molecular weight distribution.

Further, since the copolymer (A) has a small Mw of less than 10,000, when the molecular weight is measured under GPC conditions described later, it is derived from the oligomer, residual monomer and monomer-derived compound in addition to the polymer peak in the chromatogram. A peak may appear. The monomer-derived compound refers to a compound that appears in almost the same elution capacity as that of the monomer and in which the double bond of the monomer is lost by a radical or the like.
In the molecular weight analysis of the copolymer (A), the residual monomer and the monomer-derived compound are excluded from the definition because they are not included in the polymer and have little influence on the performance. Oligomers such as dimer and trimer are included in the polymer. Further, when impurity peaks derived from monomers or raw materials are detected, they are excluded as much as possible.

In addition, the molecular weight in this specification is a measured value by gel permeation chromatography (GPC), and is preferably measured under the following conditions.
<GPC measurement conditions>
Column used: manufactured by Tosoh Corporation, TSK guard column SWXL + TSKgel G4000SWXL + G3000SWXL + G2000SWXL;
Eluent: Dissolve 115.6 g of sodium acetate trihydrate in a mixed solvent of 10999 g of water and 6001 g of acetonitrile, and use a solution further adjusted to pH 6.0 with acetic acid;
Sample injection amount: 100 μL;
Flow rate: 0.8 mL / min;
Column temperature: 40 ° C .;
Detector: Nippon Waters, 2414 differential refraction detector;
Analysis software: Nippon Waters, Empower Software + GPC option;
Standard material for creating calibration curve: polyethylene glycol [peak top molecular weight (Mp) 272500, 219300, 107000, 50000, 24000, 12600, 7100, 4250, 1470];
Calibration curve: Prepared by cubic equation based on Mp value and elution time of polyethylene glycol;
A sample is prepared by dissolving an aqueous polymer solution with the above eluent so that the polymer concentration is 0.5 mass%.
<Analysis of molecular weight>
In the obtained RI chromatogram, the portions that are flat and stable in the baseline immediately before and after elution of the polymer are connected by a straight line to detect and analyze the polymer. However, when monomer, monomer-derived impurities, etc. are partially overlapped with the polymer peak and measured, the polymer part and the monomer part are separated by vertically dividing them at the most concave part of the overlapping part of the polymer and only the polymer part. Measure molecular weight and molecular weight distribution. If the polymer part and the rest cannot be completely overlapped and separated, they are calculated together.

The copolymer (A) has a polyalkylene glycol in the side chain, and the average number of repeating alkylene glycol units, weight average molecular weight and molecular weight distribution (weight average molecular weight / number average molecular weight) are specified as described above. The structure is not particularly limited as long as it is a copolymer, for example, an unsaturated carboxylic acid-based monomer and an unsaturated polyalkylene glycol-based monomer are essential. It is preferable that the monomer composition is obtained by copolymerization. In addition, these monomer components can use 1 type (s) or 2 or more types, respectively.

Here, the carboxylic acid group possessed by the unsaturated carboxylic acid monomer imparts water-solubility and adsorption force to inorganic fine particles such as cement to the copolymer (A). When using the copolymer (A) as a concrete admixture, the content of the unsaturated carboxylic acid monomer is used to produce the copolymer (A) in order to express the required performance in a well-balanced manner. It is preferable that the content is 5% by mass or more with respect to 100% by mass of all the monomer components (unsaturated monomer composition) used in the above. More preferably, it is 10 mass% or more, More preferably, it is 15 mass% or more. Further, from the same viewpoint, it is preferably 40% by mass or less. More preferably, it is 35 mass% or less, More preferably, it is 30 mass% or less, Especially preferably, it is 25 mass% or less, Most preferably, it is 22.5 mass% or less.

In addition, the polyalkylene glycol chain of the unsaturated polyalkylene glycol-based monomer imparts water-solubility and dispersibility of inorganic fine particles such as cement to the copolymer (A). When the copolymer (A) is used as a concrete admixture, the content of the unsaturated polyalkylene glycol monomer is used to produce the copolymer (A) in order to express the required performance in a balanced manner. It is preferable that the amount be 60% by weight or more with respect to 100% by weight of all the monomer components (unsaturated monomer composition) used for the treatment. More preferably, it is 65 mass% or more, More preferably, it is 70 mass% or more, Especially preferably, it is 75 mass% or more, Most preferably, it is 77.5 mass% or more. From the same viewpoint, it is preferably 95% by mass or less. More preferably, it is 90 mass% or less, More preferably, it is 85 mass% or less, Especially preferably, it is 82.5 mass% or less, Most preferably, it is 80 mass% or less.

As a more preferable form as the copolymer (A), for example, the following general formula (1);

(In the formula, R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom, a methyl group or — (CH ₂ ) x COOM ^2. Note that — (CH ₂ ) x COOM ² represents —COOM ¹ or other _- (CH ²⁾ _xCOOM 2 and good .x also form an anhydride is .M ¹ and ^{M 2} is an integer of 0 to 2 are the same or different, a hydrogen atom, a monovalent metal atom Represents a divalent metal atom, a trivalent metal atom, a quaternary ammonium base or an organic amine base.) (Hereinafter referred to as “monomer (a1)”) And the following general formula (2);

(.AO ^wherein, R 4, ^{R 5} and ^{R 6} are the same or different, .R ⁷ represents a hydrogen atom or a methyl group, represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms are the same Or, differently, it represents one or more of oxyalkylene groups having 2 to 18 carbon atoms, and when there are two or more oxyalkylene groups represented by AO, these groups are introduced in a block form. And y is an integer of 0 to 2. z is 0 or 1. n1 represents the average number of added moles of the oxyalkylene group; An unsaturated monomer composition comprising an unsaturated polyalkylene glycol monomer (b1) (hereinafter also referred to as “monomer (b1)”) represented by the formula: Is a form obtained by copolymerization.

In the general formula (1), examples of the metal atom represented by M ¹ and M ² include monovalent metal atoms such as alkali metal atoms such as lithium, sodium and potassium; alkaline earth metals such as calcium and magnesium And divalent metal atoms such as atoms; trivalent metal atoms such as aluminum and iron. Examples of the organic amine base include alkanolamine groups such as ethanolamine group, diethanolamine group, triethanolamine group, and triethylamine group.

Specific examples of the monomer (a1) represented by the general formula (1) include, for example, monocarboxylic acid monomers such as acrylic acid, methacrylic acid, and crotonic acid; maleic acid, itaconic acid, fumaric acid, and the like. Dicarboxylic acid monomers of the above; anhydrides or salts of these carboxylic acids (for example, alkali metal salts, alkaline earth metal salts, trivalent metal salts, ammonium salts, organic amine salts) and the like. Among these, acrylic acid, methacrylic acid, maleic acid, maleic anhydride and salts thereof are preferable from the viewpoint of polymerizability, and acrylic acid, methacrylic acid and salts thereof are more preferable.

In the general formula (2), the hydrocarbon group having 1 to 20 carbon atoms represented by ^{R 7,} aliphatic alkyl group having 1 to 20 carbon atoms, alicyclic alkyl group having 3 to 20 carbon atoms, carbon A C2-C20 alkenyl group, a C2-C20 alkynyl group, a C6-C20 aryl group, etc. are mentioned. R ⁷ is preferably a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, still more preferably a hydrogen atom or a methyl group. is there.

In the general formula (2), the polyalkylene glycol chain represented by (AO) _n1 is preferably composed mainly of oxyethylene groups having 2 carbon atoms. As a result, the copolymer (A) becomes sufficiently hydrophilic, and sufficient water-solubility and cement particle dispersion performance are imparted to the copolymer (A).
Here, “mainly” means, for example, 50 to 100 mol% when oxyethylene groups in 100 mol% of all oxyalkylene groups (alkylene glycol units) constituting the polyalkylene glycol chain are expressed in mol%. It is preferable that If it is less than 50 mol%, the hydrophilicity of the oxyalkylene group may not be sufficient, and the dispersion performance of cement particles may not be sufficiently imparted. More preferably, it is 60 mol% or more, More preferably, it is 70 mol% or more, Especially preferably, it is 80 mol% or more, Most preferably, it is 90 mol% or more.

The polyalkylene glycol chain represented by the above (AO) _n1 may also include a part of the oxyalkylene group having 3 or more carbon atoms having higher hydrophobicity. When such a hydrophobic group is introduced, when used as a cement dispersant, the viscosity of the cement composition is adjusted due to the light hydrophobic interaction between polyalkylene glycol chains in an aqueous solution. This is because may be improved. When introducing an oxyalkylene group having 3 or more carbon atoms, the amount introduced is, for example, to maintain sufficient water solubility with respect to 100 mol% of all oxyalkylene groups (alkylene glycol units) constituting the polyalkylene glycol chain. Is preferably 50 mol% or less. More preferably, it is 25 mol% or less, More preferably, it is 10 mol% or less. Moreover, it is preferable that it is 1 mol% or more for workability | operativity improvement. More preferably, it is 2.5 mol% or more, More preferably, it is 5 mol% or more.
As the oxyalkylene group having 3 or more carbon atoms, a propylene oxide group and a butylene oxide group are preferable from the viewpoint of ease of production, and among them, a propylene oxide group is more preferable.

When the polyalkylene glycol chain is composed of an oxyethylene group having 2 carbon atoms and an oxyalkylene group having 3 or more carbon atoms, these sequences may be random or block, When the block arrangement is used, the hydrophilicity of the hydrophilic block is expressed more strongly than the random arrangement, and the hydrophobicity of the hydrophobic block seems to be expressed more strongly. This is preferable because workability is further improved. In particular, it is preferable to arrange them in an ABA block like (oxygen group having 2 carbon atoms) (oxyalkylene group having 3 or more carbon atoms) (oxyethylene group having 2 carbon atoms).

In the above general formula (2), n1 is a number of 8 to 300, but if it exceeds 300, problems in production occur, and the viscosity of the cement composition becomes high when used as a concrete admixture. May not be sufficient. As described above, from the viewpoint of production, n1 is preferably 300 or less, preferably 150 or less, more preferably 100 or less, and from the viewpoint of viscosity, more preferably 50 or less, More preferably, it is 25 or less, particularly preferably 15 or less, and most preferably 10 or less.
As described above, n1 is suitably 8 or more, preferably 9 or more, more preferably 10 or more, from the viewpoint of the balance of fluidity, retention and workability of the cement composition as described above. is there.

Specific examples of the monomer (b1) represented by the general formula (2) include an unsaturated alcohol polyalkylene glycol adduct and a polyalkylene glycol ester monomer.
The unsaturated alcohol polyalkylene glycol adduct may be a compound having a structure in which a polyalkylene glycol chain is added to an alcohol having an unsaturated group. The polyalkylene glycol ester-based monomer may be a monomer having a structure in which an unsaturated group and a polyalkylene glycol chain are bonded via an ester bond. Ester compounds are preferred, and (alkoxy) polyalkylene glycol mono (meth) acrylate is particularly preferred.

Examples of the unsaturated alcohol polyalkylene glycol adduct include vinyl alcohol alkylene oxide adduct, (meth) allyl alcohol alkylene oxide adduct, 3-buten-1-ol alkylene oxide adduct, isoprene alcohol (3-methyl- 3-buten-1-ol) alkylene oxide adduct, 3-methyl-2-buten-1-ol alkylene oxide adduct, 2-methyl-3-buten-2-ol alkylene oxide adduct, 2-methyl-2 -Butene-1-ol alkylene oxide adducts and 2-methyl-3-buten-1-ol alkylene oxide adducts are preferred.

Specific examples of the unsaturated alcohol polyalkylene glycol adduct include, for example, polyethylene glycol monovinyl ether, polyethylene glycol monoallyl ether, polyethylene glycol mono (2-methyl-2-propenyl) ether, polyethylene glycol mono (2-butenyl). ) Ether, polyethylene glycol mono (3-methyl-3-butenyl) ether, polyethylene glycol mono (3-methyl-2-butenyl) ether, polyethylene glycol mono (2-methyl-3-butenyl) ether, polyethylene glycol mono (2 -Methyl-2-butenyl) ether, polyethylene glycol mono (1,1-dimethyl-2-propenyl) ether, polyethylene polypropylene glycol mono (3-methyl-3- Tenenyl) ether, methoxypolyethyleneglycol mono (3-methyl-3-butenyl) ether, ethoxypolyethyleneglycolmono (3-methyl-3-butenyl) ether, 1-propoxypolyethyleneglycolmono (3-methyl-3-butenyl) ether , Cyclohexyloxypolyethylene glycol mono (3-methyl-3-butenyl) ether, phenoxypolyethyleneglycolmono (3-methyl-3-butenyl) ether, methoxypolyethyleneglycolmonoallylether, ethoxypolyethyleneglycolmonoallylether, phenoxypolyethyleneglycolmono Allyl ether, methoxy polyethylene glycol mono (2-methyl-2-propenyl) ether, ethoxy polyethylene glycol mono (2- Chill 2-propenyl) ether, phenoxy polyethylene glycol mono (2-methyl-2-propenyl) ether and the like.

Examples of the (alkoxy) polyalkylene glycol mono (meth) acrylate include, for example, alkoxy polyalkylene glycols obtained by adding 1 to 25 moles of an alkylene oxide group having 2 to 18 carbon atoms to alcohols, particularly alkoxy polyoxyethylene mainly composed of ethylene oxide. An esterified product of an alkylene glycol and (meth) acrylic acid is preferred.
Examples of the alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, and 2-hexanol. C1-C30 aliphatic alcohols such as 3-hexanol, octanol, 2-ethyl-1-hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol and stearyl alcohol; C3-C30 fats such as cyclohexanol Cyclic alcohols; unsaturated alcohols having 3 to 30 carbon atoms such as (meth) allyl alcohol, 3-buten-1-ol, 3-methyl-3-buten-1-ol, and the like.

Specifically, the following (alkoxy) polyethylene glycol (poly) (C2-C4 alkylene glycol) (meth) acrylic acid esters and the like are preferable as the esterified product.
Methoxy polyethylene glycol mono (meth) acrylate, methoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, methoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, methoxy {polyethylene glycol (poly) propylene glycol (Poly) butylene glycol} mono (meth) acrylate, ethoxypolyethyleneglycol mono (meth) acrylate, ethoxy {polyethyleneglycol (poly) propyleneglycol} mono (meth) acrylate, ethoxy {polyethyleneglycol (poly) butyleneglycol} mono (meta ) Acrylate, ethoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} mono (Meth) acrylate, propoxy polyethylene glycol mono (meth) acrylate, propoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, propoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, propoxy {polyethylene glycol ( Poly) propylene glycol (poly) butylene glycol} mono (meth) acrylate,

Butoxy polyethylene glycol mono (meth) acrylate, butoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, butoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, butoxy {polyethylene glycol (poly) propylene glycol (Poly) butylene glycol} mono (meth) acrylate, pentoxypolyethylene glycol mono (meth) acrylate, pentoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, pentoxy {polyethylene glycol (poly) butylene glycol} mono ( Meth) acrylate, pentoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol } Mono (meth) acrylate, hexoxypolyethylene glycol mono (meth) acrylate, hexoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, hexoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, hexoxy {Polyethylene glycol (poly) propylene glycol (poly) butylene glycol} mono (meth) acrylate,

Heptoxy polyethylene glycol mono (meth) acrylate, heptoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, heptoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, heptoxy {polyethylene glycol (poly) propylene Glycol (poly) butylene glycol} mono (meth) acrylate, octoxypolyethylene glycol mono (meth) acrylate, octoxy {polyethyleneglycol (poly) propyleneglycol} mono (meth) acrylate, octoxy {polyethyleneglycol (poly) butyleneglycol} mono (Meth) acrylate, octoxy {polyethylene glycol (poly) propylene glycol (poly) butylene Recall} mono (meth) acrylate, nonanoxy polyethylene glycol mono (meth) acrylate, nonanoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, nonanoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, Nonanoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} mono (meth) acrylate.

The unsaturated monomer composition used to obtain the copolymer (A) may also include other copolymerizable monomers other than the monomers (a1) and (b1) described above ( Hereinafter, it may also be referred to as “monomer (c)”.
The content of such a monomer (c) is based on 100% by mass of all monomer components (unsaturated monomer compositions) used to produce the copolymer (A). 30% by mass or less is preferable. More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less.

Specific examples of the monomer (c) include the following compounds, and one or more of these can be used.
Half esters and diesters of unsaturated dicarboxylic acid monomers such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid and the like and alcohols having 23 to 30 carbon atoms; Half amides and diamides of an alkyl group and an amine having 23 to 30 carbon atoms; an alkyl (poly) alkylene glycol obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to the alcohol or amine and the above unsaturated Half esters and diesters with dicarboxylic acid monomers; half of the above unsaturated dicarboxylic acid monomers and glycols having 5 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols Esters, diesters; maleamic acid and glycols having 5 to 18 carbon atoms, or Half amides of polyalkylene glycols of addition mole number 2 to 500 of glycol;

(Poly) alkylene glycols such as triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate, etc. Di (meth) acrylates; polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate; triethylene glycol dimaleate, polyethylene glycol (Poly) alkylene glycol dimaleates such as dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acrylate Xylpropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- ( Unsaturated sulfonic acids such as (meth) acryloxybutyl sulfonate, (meth) acrylamide methyl sulfonic acid, (meth) acrylamide ethyl sulfonic acid, 2-methylpropane sulfonic acid (meth) acrylamide, styrene sulfonic acid, and monovalents thereof Metal salts, divalent metal salts, ammonium salts and organic amine salts;

Amides of unsaturated monocarboxylic acids and amines having 1 to 30 carbon atoms such as methyl (meth) acrylamide; vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene; Alkanediol mono (meth) acrylates such as 4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate; butadiene, isoprene, 2- Dienes such as methyl-1,3-butadiene and 2-chloro-1,3-butadiene; (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) Unsaturated amides such as acrylamide; (meth) acrylonitrile, α-chloroa Unsaturated cyanides such as acrylonitrile; unsaturated esters such as vinyl acetate and vinyl propionate.

Next, the manufacturing method of the copolymer (A) in this invention is demonstrated below.
As said manufacturing method, it can carry out by methods, such as superposition | polymerization in a solvent, and block polymerization, using the said unsaturated monomer composition and a polymerization initiator, for example.
The solution polymerization can be performed batchwise, continuously, or a combination thereof. Examples of the solvent used in this case include water; alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; benzene, toluene, Aromatic or aliphatic hydrocarbons such as xylene, 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.

Among the above solution polymerizations, in aqueous solution polymerization, as a radical polymerization initiator, a water-soluble polymerization initiator, for example, a persulfate such as ammonium persulfate, sodium persulfate, or potassium persulfate; hydrogen peroxide; 2,2′- Azoamidine compounds such as azobis-2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, 2-carbamoylazoisobutyronitrile, etc. Water-soluble azo initiators such as azonitrile compounds are used. In this case, alkali metal sulfites such as sodium bisulfite, metabisulfites, sodium hypophosphite, Fe (II) salts such as molle salts, hydroxy Sodium methanesulfinate dihydrate, hydroxylamine hydrochloride, thiourea, L-ascorbic acid (salt), Accelerator such as Risorubin acid (salt) (reducing agent) can be used in combination. Among them, a combination of hydrogen peroxide and an organic reducing agent is preferable. As the organic reducing agent, L-ascorbic acid (salt), L-ascorbic acid ester, erythorbic acid (salt), erythorbic acid ester, and the like are preferable. Can be used. These radical polymerization initiators and accelerators (reducing agents) may be used alone or in combination of two or more.

In solution polymerization or bulk polymerization using a lower alcohol, aromatic or aliphatic hydrocarbon, ester compound, or ketone compound as a solvent, radical polymerization initiators such as benzoyl peroxide, lauroyl peroxide, sodium peroxide, etc. Peroxides; hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; azo compounds such as azobisisobutyronitrile can be used. In this case, an accelerator such as an amine compound is used in combination. It is also suitable.
Further, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various radical polymerization initiators or a combination of radical polymerization initiators and accelerators.

In the above copolymerization, the polymerization conditions such as the polymerization temperature are appropriately determined depending on the polymerization method used, the solvent, the polymerization initiator, and the chain transfer agent, but the polymerization temperature is preferably 0 ° C. or higher, It is preferable that it is 150 degrees C or less. More preferably, it is 30 degreeC or more, More preferably, it is 50 degreeC or more. More preferably, it is 120 degrees C or less, More preferably, it is 100 degrees C or less. In particular, in order to bring the copolymer (A) into a predetermined molecular weight or molecular weight distribution range, it is preferably 80 ° C. or lower, more preferably 70 ° C. or lower, and further preferably 60 ° C. or lower.

In the copolymerization, in order to obtain a copolymer having a predetermined molecular weight with good reproducibility, it is preferable to allow the polymerization reaction to proceed stably. Therefore, in the solution polymerization, the dissolved oxygen concentration at 25 ° C. of the solvent to be used is set to a range of 5 ppm or less (preferably 0.01 to 4 ppm, more preferably 0.01 to 2 ppm, still more preferably 0.01 to 1 ppm). It is preferable to do. In addition, when nitrogen substitution etc. are performed after adding an unsaturated monomer to a solvent, it is appropriate that the dissolved oxygen concentration of the system including the unsaturated monomer is within the above range.

The dissolved oxygen concentration of the solvent may be adjusted in a polymerization reaction tank, or a dissolved oxygen amount may be adjusted in advance. Examples of the method for driving off oxygen in the solvent include the following methods (1) to (5).
(1) After pressure-filling an inert gas such as nitrogen in a sealed container containing a solvent, the partial pressure of oxygen in the solvent is lowered by lowering the pressure in the sealed container. In that case, you may reduce the pressure in a sealed container under nitrogen stream.
(2) The liquid phase portion is vigorously stirred for a long time while the gas phase portion in the container containing the solvent is replaced with an inert gas such as nitrogen.
(3) An inert gas such as nitrogen is bubbled in the solvent in the container for a long time.
(4) The solvent is once boiled and then cooled in an inert gas atmosphere such as nitrogen.
(5) A static mixer (static mixer) is installed in the middle of the pipe, and an inert gas such as nitrogen is mixed in the pipe for transferring the solvent to the polymerization reaction tank.

The copolymer (A) obtained by the above copolymerization is adjusted to a pH range of slightly acidic or higher (more preferably pH 4 or higher, more preferably pH 5 or higher, particularly preferably pH 6 or higher) in an aqueous solution state. It can be easy to handle.
On the other hand, if the copolymerization reaction is carried out at a pH of 7 or more, the polymerization rate decreases, and at the same time, the copolymerizability is not sufficient, and the dispersion performance of the copolymer (A) may not be excellent. There is. Therefore, in the copolymerization reaction, it is preferable to perform the copolymerization reaction in a pH range from acidic to neutral (more preferably less than pH 6, more preferably less than pH 5.5, and still more preferably less than pH 5). Examples of preferable polymerization initiators that change the polymerization system from acidic to neutral include persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate, and azoamidine compounds such as azobis-2-methylpropionamidine hydrochloride. It is preferable to use a water-soluble azo initiator such as hydrogen peroxide, a combination of hydrogen peroxide and an organic reducing agent, or the like.

Therefore, after carrying out the copolymerization reaction at a low pH, it is preferable to adjust to a higher pH by adding an alkaline substance or the like. Specifically, a method of adjusting the pH to 6 or more by adding an alkaline substance after carrying out a copolymerization reaction at a pH of less than 6; a method of adjusting to a pH of 5 or more by adding an alkaline substance after carrying out a copolymerization reaction at a pH of less than 5 A method of adjusting the pH to 6 or more by adding an alkaline substance after carrying out the copolymerization reaction at a pH of less than 5;
The pH can be adjusted using, for example, an alkaline substance such as inorganic salt such as hydroxide or carbonate of monovalent metal or divalent metal; ammonia; organic amine; In addition, when pH is lowered, particularly when pH adjustment is required during polymerization, acidic substances such as phosphoric acid, sulfuric acid, nitric acid, alkylphosphoric acid, alkylsulfuric acid, alkylsulfonic acid, (alkyl) benzenesulfonic acid are used. Among these acidic substances, phosphoric acid and sulfuric acid capable of lowering the pH with addition of a small amount are preferable among these acidic substances. Further, after the reaction is completed, the concentration can be adjusted as necessary.

As a method for producing the copolymer (A), in order to produce the copolymer (A) having the “homogeneous molecular weight distribution” as described above, a factor affecting the molecular weight distribution is determined during production. It is preferable to keep within the range. In particular, since the influence of polymerization temperature, initiator, and chain transfer agent is large, it is preferable to keep them as constant as possible.
During the production process, the change in polymerization temperature is preferably ± 10 ° C, more preferably ± 5 ° C. However, immediately after the start of the polymerization reaction, the temperature is likely to change temporarily due to the addition of a monomer or an initiator, and thus is not limited thereto.
During the production process, the initiator is preferably added to the reaction system at a constant rate. When using a relatively high thermal stability initiator such as hydrogen peroxide in a redox system, a method in which the initiator and the reducing agent are added to the reaction system at a constant rate may be used. A method of charging all at once and adding the reducing agent at a constant rate may be used.
During the production process, it is preferred not to use a chain transfer agent or to add it to the reaction system at a constant rate.
As the production method, it is preferable that the semi-batch method and the stirred tank type continuous method are mainly used rather than the batch method and the tube-type continuous method from the viewpoint of suppressing the concentration change during the production.
The above conditions are not limited to this because the influence on the molecular weight distribution is small in the aging step after the polymerization reaction is almost completed.

The present invention is also a copolymer composition for a concrete admixture comprising the polycarboxylic acid copolymer (A) for a concrete admixture and a polycarboxylic acid copolymer (B) different therefrom. . In addition, the copolymer (A) and (B) which is a containing component can use 1 type (s) or 2 or more types, respectively.
As described above, the copolymer (A) and the copolymer (B) different from the copolymer (A) are used as a concrete admixture by including two or more kinds of polycarboxylic acid copolymers. In this case, since the various properties of the polycarboxylic acid-based copolymer blended with the concrete admixture are combined, various properties such as sufficient fluidity, retention and workability required for the cement composition are further balanced. It is possible to perform well.

The polycarboxylic acid copolymer (B) (hereinafter also referred to as “copolymer (B)”) includes the copolymer (A), acid value, molecular weight, structural unit structure, structural unit. The copolymer (A) may be any polycarboxylic acid-based copolymer that is different in terms of the composition, etc., and in particular, any one or more of the average number of repeating alkylene glycol units, the weight average molecular weight, and the molecular weight distribution. It is preferable that the numerical value range specified in (1) is not satisfied.
Such a copolymer (B) is obtained by copolymerizing an unsaturated monomer composition essentially comprising an unsaturated carboxylic acid monomer and an unsaturated polyalkylene glycol monomer. It is preferable. In addition, these monomer components can use 1 type (s) or 2 or more types, respectively.

Here, the carboxylic acid group possessed by the unsaturated carboxylic acid monomer imparts water-solubility and adsorption force to inorganic fine particles such as cement to the copolymer (B). When the copolymer (B) is used as a concrete admixture in combination with the copolymer (A), in order to sufficiently develop the adsorption force to the inorganic fine particles, it contains an unsaturated carboxylic acid monomer. The amount is preferably 2.5% by mass or more with respect to 100% by mass of all the monomer components (unsaturated monomer compositions) used to produce the copolymer (B). It is. More preferably, it is 5 mass% or more, More preferably, it is 10 mass% or more, Especially preferably, it is 15 mass% or more, Most preferably, it is 20 mass%. Further, from the same viewpoint, it is preferably 40% by mass or less. More preferably, it is 35 mass% or less, More preferably, it is 30 mass% or less, Especially preferably, it is 25 mass% or less, Most preferably, it is 22.5 mass% or less.

Moreover, the polyalkylene glycol chain which the said unsaturated polyalkylene glycol-type monomer has will provide the dispersion power of inorganic fine particles, such as water solubility and cement, with respect to a copolymer (B). When the copolymer (B) is used in combination with the copolymer (A) as a concrete admixture, the content of the unsaturated polyalkylene glycol monomer should be It is preferable that the content be 60% by weight or more with respect to 100% by mass of all monomer components (unsaturated monomer compositions) used to produce the polymer (B). More preferably, it is 70 mass% or more, More preferably, it is 75 mass% or more, Especially preferably, it is 80 mass% or more, Most preferably, it is 85 mass% or more. On the other hand, if the amount of the unsaturated polyalkylene glycol monomer is too large, the amount of the unsaturated carboxylic acid monomer having an adsorptive power to cement particles becomes relatively small. The following is preferable. More preferably, it is 95 mass% or less, More preferably, it is 92.5 mass% or less, Especially preferably, it is 90 mass% or less, Most preferably, it is 87.5 mass% or less.

As a more preferable form as the copolymer (B), for example, the following general formula (3);

^(Wherein, R 8, ^{R 9} and ^{R 10} are the same or different, a hydrogen atom, a methyl group or _- represents a (CH 2) pCOOM ⁴ _{Note, -. (CH 2) pCOOM} 4 is -COOM ³ or It may form an anhydride with other — (CH ₂ ) pCOOM ^4. p is an integer of 0 to 2. M ³ and M ⁴ are the same or different and are a hydrogen atom or a monovalent metal atom. , Represents a divalent metal atom, a trivalent metal atom, a quaternary ammonium base or an organic amine base.) (Hereinafter referred to as “monomer (a2)”) And general formula (4) below;

(.AO ^wherein, R ^{11, R 12} and ^{R 13} are the same or different, ^{.R 14} represents a hydrogen atom or a methyl group, represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms are the same Or, differently, it represents one or more of oxyalkylene groups having 2 to 18 carbon atoms, and when there are two or more oxyalkylene groups represented by AO, these groups are introduced in a block form. May be introduced randomly, q is an integer of 0 to 2. r is 0 or 1. n2 represents the average number of added moles of the oxyalkylene group; The unsaturated polyalkylene glycol monomer (b2) (hereinafter also referred to as “monomer (b2)”) represented by the following formula: Is a form obtained by copolymerization.

In the above general formula (3), the metal atom represented by M ³ and M ⁴ is the same as M ¹ and M ² in the above general formula (1), and the single atom represented by the above general formula (3). Specific examples of the monomer (a2) are also the same as those of the monomer (a1) represented by the general formula (1).

In the general formula (4), the group represented by R ¹⁴ and the polyalkylene glycol chain represented by (AO) _n2 are also represented by the group represented by R ⁷ and (AO) n1 in the general formula (2). The specific example of the monomer (b2) represented by the general formula (4) is also the same as the polyalkylene glycol chain represented by the general formula (4). ).

N2 in the above general formula (4) is a number from 1 to 300, but if it exceeds 300, problems in production occur or the viscosity of the cement composition becomes high when used as a concrete admixture, May not be sufficient. From the viewpoint of production, n2 is suitably 300 or less, preferably 200 or less, more preferably 150 or less, still more preferably 100 or less, particularly preferably 75 or less, and most preferably 50. It is as follows. Further, n2 is preferably 4 or more from the viewpoint of strongly dispersing cement particles. More preferably, it is 6 or more, More preferably, it is 10 or more, Most preferably, it is 25 or more.

The unsaturated monomer composition used to obtain the copolymer (B) may also include other copolymerizable monomers other than the monomers (a2) and (b3) described above ( Hereinafter, it may be also referred to as “monomer (c2)”), and specific examples thereof are the same as those of the monomer (c1) in the copolymer (A).
As content of such a monomer (c2), 100 mass% of all monomer components (unsaturated monomer compositions) used to produce the copolymer (B). 30% by mass or less is preferable. More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less.

The copolymer (B) preferably has a weight average molecular weight (Mw) of 150,000 or less. If the Mw exceeds 150,000, the retainability and viscosity of the cement composition may not be improved. Preferably it is 100,000 or less, more preferably 70,000 or less, still more preferably 60,000 or less, even more preferably 50,000 or less, particularly preferably 40,000 or less, most preferably 30,000. It is as follows. Moreover, it is preferable that Mw is 10,000 or more from the viewpoint that the copolymer (B) is more likely to exhibit performance when adsorbed to cement particles to some extent, and that the adsorbing force increases as Mw increases. More preferably, it is 15000 or more, More preferably, it is 18000 or more, Most preferably, it is 20,000 or more.

In the copolymer (B), if the weight average molecular weight / number average molecular weight (Mw / Mn) of the copolymer (B) is too large, the dispersion performance may be affected. It is preferable that it is 4 or less. More preferably, it is 3.5 or less, More preferably, it is 3 or less, Especially preferably, it is 2.5 or less, Most preferably, it is 2.2 or less.

The copolymer (B) further has the following formula:
An value = A value × 100 × n
(In the formula, the value A is the total mass of all monomer components when the carboxylic acid groups in the charged monomer are all sodium salts during the production of the polycarboxylic acid copolymer (B). This represents the mass ratio (mass%) of the sodium carboxylate-containing monomer with respect to 100 mass%, where n is the average number of alkylene glycol unit repeats of the polyalkylene glycol chain of the polycarboxylic acid copolymer (B). In addition, it is preferable that the An value represented by the An value is rounded to an integer by rounding off the decimal point.
An example of such a polymer that satisfies the An value is a copolymer of 363.5 parts by weight of methoxypolyethylene glycol methacrylate (n = 10) and 96.5 parts by weight of methacrylic acid (Mw 86.09). In this case, assuming that methacrylic acid is a sodium salt, sodium methacrylate (Mw 108.07) corresponds to 121.1 parts by weight, and the A value is 121.1 / (363.5 + 121). .1) = 25%. Therefore, An value = 25% × 100 × 10 = 250.

The An value of the copolymer (B) indicates the balance between the amount of carboxylic acid groups that are adsorbing groups on the cement particles and the length of the polyalkylene glycol chain in which cement and particles are dispersed. When the An value of the copolymer (B) is too small, sufficient performance may not be exhibited when used as a concrete admixture with the copolymer (A). Is preferably 230 or more. More preferably, it is 250 or more, More preferably, it is 300 or more, Most preferably, it is 400 or more. On the other hand, when the An value of the copolymer (B) is too large, sufficient performance may not be exhibited when used as a concrete admixture with the copolymer (A). is there. More preferably, it is 1500 or less, More preferably, it is 1000 or less, Especially preferably, it is 750 or less, Most preferably, it is 500 or less.

In the present invention, it is particularly preferable that the copolymer (B) has a weight average molecular weight (Mw) of 10,000 or more and an An value of 230 or more. By using such a copolymer (B) together with the copolymer (A), it becomes possible to impart sufficient fluidity, retention and viscosity to the cement composition.
In addition, as a manufacturing method of the said copolymer (B), it can carry out similarly to the said copolymer (A). Further, as described above with respect to the copolymer (A), also in the production method of the copolymer (B), a mixture of two or more kinds of copolymers can be obtained by changing the conditions of the polymerization reaction. The above copolymer can be mixed to make a blend mixture. Even in such a case, the weight average molecular weight of the copolymer mixture can be measured, or the alkylene glycol in the polyalkylene glycol chain can be measured. Even if the number of repeating units is measured or calculated, it can be evaluated that it falls under the copolymer (B) of the present invention even when specified as described above.

In the copolymer composition, the mass ratio (A / B) between the copolymer (A) and the copolymer (B) is preferably 5/95 to 95/5, more preferably. Is 20/80 to 80/20. More preferably, the proportion of the copolymer (A) is 30% by mass or more with respect to 100% by mass of the total amount of the copolymer composition for concrete admixture. In addition, the function and effect of the present invention can be more sufficiently exhibited at the same time with high workability. More preferably, it is 40 mass% or more, and is 30-70 mass% as a suitable range.

Although it does not specifically limit as a manufacturing method of the copolymer composition containing the said copolymer (A) and a copolymer (B), For example, a copolymer (A) and a copolymer (B) are obtained, respectively. It is preferable to employ a method of mixing them after a while. In addition, before adding to cement composition etc., these copolymers may be mixed (blended), and may become a mixture, or by adding separately to cement composition etc., cement composition It may be a mixture in the medium.

The copolymer (A) and the copolymer composition in the present invention are each suitable as a main component of a concrete admixture, and thus the polycarboxylic acid copolymer for the concrete admixture, or The concrete admixture comprising the copolymer composition for concrete admixture is also one aspect of the present invention.
Such a concrete admixture can be used in addition to a cement composition such as cement paste, mortar, concrete and the like, and preferably includes cement, water, fine aggregate, coarse aggregate, etc. It is. That is, a cement composition containing a concrete admixture containing the copolymer (A) or copolymer composition, cement, and water is also one preferred embodiment of the present invention.

In the above cement composition, as the cement, Portland cement (ordinary, early strength, ultra-early strength, moderate heat, sulfate resistance, and low alkali type of each); various mixed cements (blast furnace cement, silica cement, fly ash cement) ); White Portland cement; alumina cement; super fast cement (1 clinker fast cement, 2 clinker fast cement, magnesium phosphate cement); grout cement; oil well cement; low heat cement (low heat blast furnace cement, fly ash) Mixed low heat generation type blast furnace cement, cement with high content of belite); ultra-high strength cement; cement-based solidified material; eco-cement (cement manufactured from one or more of municipal waste incineration ash and sewage sludge incineration ash) Others, blast furnace slag, fly ash, shi Dar ash, clinker ash, husk ash, silica fume, silica powder, and a film obtained by adding a fine powder and gypsum limestone powder. In addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., the aggregates are siliceous, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromic, magnesia. Refractory aggregates, and the like.

Examples of the unit water amount per 1 m ³ of the cement composition, the cement use amount, and the water / cement ratio (mass ratio) include, for example, a unit water amount of 100 to 185 kg / m ³ , a use cement amount of 200 to 800 kg / m ³ , and a water / cement ratio. The cement ratio (mass ratio) is preferably 0.1 to 0.7, and more preferably, the unit water amount is 120 to 175 kg / m ³ , the cement amount used is 250 to 800 kg / m ³ , and the water / cement ratio ( (Mass ratio) = 0.2 to 0.65. Thus, the concrete admixture containing the copolymer (A) or copolymer composition of the present invention can be used in a wide range from poor blending to rich blending, and has a high water reduction rate range, that is, It can be used even in a region where the water / cement ratio is low, such as water / cement ratio (mass ratio) = 0.15 to 0.5 (preferably 0.15 to 0.4). It is effective for both high-strength concrete with a small cement ratio and poor blended concrete with a unit cement amount of 300 kg / m ³ or less.

As a concrete admixture containing the copolymer (A) or the copolymer composition, the fluidity, retention and workability can be exhibited in a balanced and high performance even in a high water reduction rate region, and the workability is excellent. Therefore, it can be effectively used for ready-mixed concrete, concrete for concrete secondary products (precast concrete), concrete for centrifugal molding, concrete for vibration compaction, steam-cured concrete, shotcrete, etc. Furthermore, medium-fluidity concrete (concrete with a slump value of 22 to 25 cm), high fluidity concrete (concrete with a slump value of 25 cm or more and a slump flow value of 50 to 70 cm), self-filling concrete, self-leveling material Mortar and concrete that require high fluidity such as REIT also be effective.

When the concrete admixture containing the copolymer (A) or the copolymer composition is used in a cement composition, the blending ratio is such that the copolymer (A) as an essential component of the present invention is a solid content. In terms of conversion, it is preferably set to be 0.01 to 10% by mass with respect to 100% by mass of the total cement mass. If it is less than 0.01% by mass, the performance may not be sufficient. On the other hand, if it exceeds 10% by mass, the effect will substantially reach its peak, which may be disadvantageous in terms of economy. More preferably, it is 0.02-8 mass%, More preferably, it is 0.05-6 mass%.

The concrete admixture containing the copolymer (A) or copolymer composition can also be used in combination with other cement additives. As another cement additive, 1 type (s) or 2 or more types, such as a cement additive (material) as shown below, can be used, for example. Among these, it is particularly preferable to use an oxyalkylene antifoaming agent or an AE agent in combination.
In addition, it is suitable for the addition ratio of a cement additive to be 0.0001-10 weight part with respect to 100 weight part of solid content of the said copolymer (A).

(1) Water-soluble polymer substances: polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), unsaturated carboxylic acid polymer such as sodium salt of acrylic acid / maleic acid copolymer; polyethylene Polyoxyethylene or polyoxypropylene polymers such as glycol and polypropylene glycol or copolymers thereof; Nonionic cellulose ethers such as methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, carboxyethylcellulose, hydroxypropylcellulose; yeast glucan Or xanthan gum, β-1,3 glucans (both linear and branched), and examples include curdlan, paramylon, pachyman, Polysaccharides produced by microbial fermentation such as cleroglucan, laminaran, etc .; polyacrylamide; polyvinyl alcohol; starch; starch phosphate ester; sodium alginate; gelatin; copolymer of acrylic acid having an amino group in its molecule and its quaternary Compounds and the like.

(2) Polymer emulsion (3) Retardant: Gluconic acid, malic acid or citric acid, and oxycarboxylic such as inorganic salt or organic salt such as sodium, potassium, calcium, magnesium, ammonium, triethanolamine, etc. Acids and salts thereof; glucose, fructose, galactose, saccharose; sugar alcohols such as sorbitol; magnesium fluorosilicate; phosphoric acid and salts thereof or boric acid esters; aminocarboxylic acids and salts thereof; alkali-soluble proteins; Tannic acid; Phenol; Polyhydric alcohol such as glycerin; Aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), and this Alkali metal salts, and phosphonic acids and derivatives thereof such as alkaline earth metal salts.

(4) Early strengthening agent / accelerator: soluble calcium salt such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide, calcium iodide; alkanolamine; alumina cement; calcium aluminate silicate.
(5) Mineral oil-based antifoaming agent: cocoon oil, liquid paraffin, etc.
(6) Fat and oil-based antifoaming agents: animal and vegetable oils, sesame oil, castor oil, alkylene oxide adducts thereof and the like.
(7) Fatty acid-based antifoaming agent: oleic acid, stearic acid, and these alkylene oxide adducts.
(8) Fatty acid ester antifoaming agent: glycerin monoricinoleate, alkenyl succinic acid derivative, sorbitol monolaurate, sorbitol trioleate, natural wax and the like.

(9) Oxyalkylene antifoaming agents: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene (Poly) oxyalkyl ethers such as 2-ethylhexyl ether and higher alcohols having 12 to 14 carbon atoms such as oxyethyleneoxypropylene adducts; (poly) oxy such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether Alkylene (alkyl) aryl ethers; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1 -Bu Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohol such as n-3-ol; (poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate; polyoxyethylene (Poly) oxyalkylene sorbitan fatty acid esters such as sorbitan monolaurate and polyoxyethylene sorbitan trioleate; (poly) oxyalkylene alkyl such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecylphenol ether sulfate ( Aryl) ether sulfate esters; (poly) oxyethylene stearyl phosphates, etc. Polyoxyalkylene alkyl phosphoric acid esters; polyoxyethylene such as polyoxyethylene lauryl amine (poly) oxyalkylene alkyl amines; polyoxyalkylene amide.

(10) Alcohol-based antifoaming agent: octyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like.
(11) Amide antifoaming agent: acrylate polyamine and the like.
(12) Phosphate ester antifoaming agent: tributyl phosphate, sodium octyl phosphate, etc.
(13) Metal soap type antifoaming agent: aluminum stearate, calcium oleate, etc.
(14) Silicone antifoaming agent: dimethyl silicone oil, silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), fluorosilicone oil and the like.
(15) AE agent: resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, ABS (alkyl benzene sulfonic acid), LAS (linear alkyl benzene 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, protein material, alkenyl sulfosuccinic acid, α-olefin sulfonate, and the like.

(16) Other surfactants: aliphatic monohydric alcohols having 6 to 30 carbon atoms in the molecule such as octadecyl alcohol and stearyl alcohol, and those having 6 to 30 carbon atoms in the molecule such as abiethyl alcohol Intramolecular such as alicyclic monohydric alcohol, dodecyl mercaptan, etc. Intramolecular such as monovalent mercaptan having 6-30 carbon atoms in the molecule, such as nonylphenol, alkylphenol having 6-30 carbon atoms in the molecule, dodecylamine, etc. 10 mol or more of an alkylene oxide such as ethylene oxide or propylene oxide was added to a carboxylic acid having 6 to 30 carbon atoms in the molecule such as an amine having 6 to 30 carbon atoms, lauric acid or stearic acid. Polyalkylene oxide derivatives; having an alkyl group or alkoxyl group as a substituent Alkyl diphenyl ether sulfonates in which two phenyl groups having a sulfone group are ether-bonded; various anionic surfactants; various cationic surfactants such as alkylamine acetate and alkyltrimethylammonium chloride; various nonions 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 preventive: nitrite, phosphate, zinc oxide and the like.
(19) Crack reducing agent: polyoxyalkyl ethers; alkanediols such as 2-methyl-2,4-pentanediol.
(20) Expansion material: Ettlingite, coal, etc.

Other cement additives (materials) include, for example, cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancing agents, self-leveling agents, rust preventives, colorants, antifungal agents , Blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, gypsum and the like.

Since the polycarboxylic acid copolymer and copolymer composition for concrete admixture of the present invention are configured as described above, they can impart excellent fluidity to the cement composition and have high fluidity. Can be exhibited over a long period of time, and can be made to have a viscosity that makes it easy to work in the field where the cement composition is handled, so that it is very useful as a concrete admixture.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.
The weight average molecular weight (Mw), number average molecular weight (Mn), and peak top molecular weight (Mp) of the polymers obtained in the following production examples were measured under the above-described measurement conditions, and the An value was also as described above. Was calculated as follows.

Production Example 1
Into a reaction vessel equipped with a thermometer, a stirrer, a reflux device, and a dropping device, 204.8 parts by weight of water was charged, heated to 70 ° C., and purged with nitrogen at 200 ml / min for 1 hour. Thereafter, a mixed solution of 373.6 parts by weight of methoxypolyethyleneglycol methacrylate (average added mole number 10), 86.4 parts by weight of methacrylic acid, 123.5 parts by weight of water, and 15.3 parts by weight of 2-mercaptopropionic acid ( 1) for 4 hours, a mixed solution (3) of 3.8 parts by weight of 30% aqueous hydrogen peroxide and 71.2 parts by weight of water, a mixed solution of 1.5 parts by weight of L-ascorbic acid and 73.5 g of water ( 3) was continuously added dropwise to a reaction vessel maintained at 70 ° C. for 5 hours. Furthermore, the temperature was maintained at 70 ° C. for 1 hour to obtain a copolymer solution. When the solution temperature was 30 ° C., a 30% NaOH aqueous solution was added dropwise to adjust the solution pH to 7. The weight average molecular weight of the obtained copolymer was 5500, and Mw / Mn was 1.55. This copolymer is referred to as “copolymer (A1)”.

Production Example 2
A reaction vessel equipped with a thermometer, a stirrer, a reflux device and a dropping device was charged with 213.3 parts by weight of water, heated to 70 ° C., and purged with nitrogen at 200 ml / min for 1 hour. Thereafter, a mixed solution of 363.5 parts by weight of methoxypolyethyleneglycol methacrylate (average added mole number 10), 96.5 parts by weight of methacrylic acid, 123.5 parts by weight of water, and 7.6 parts by weight of 2-mercaptopropionic acid ( 1) for 4 hours, a mixed solution (2) of 4.1 parts by weight of 30% aqueous hydrogen peroxide and 70.9 parts by weight of water, a mixed solution of 1.6 parts by weight of L-ascorbic acid and 73.4 parts of water ( 3) was continuously added dropwise to a reaction vessel maintained at 70 ° C. for 5 hours. Furthermore, the temperature was maintained at 70 ° C. for 1 hour to obtain a copolymer solution. When the solution temperature was 30 ° C., a 30% NaOH aqueous solution was added dropwise to adjust the solution pH to 7. The weight average molecular weight of the obtained copolymer was 8200, and Mw / Mn was 1.67. This copolymer is referred to as “copolymer (A2)”.

Production Example 3
A reaction vessel equipped with a thermometer, a stirrer, a reflux device and a dropping device was charged with 350.0 parts by weight of water, heated to 70 ° C., and purged with nitrogen at 200 ml / min for 1 hour. Then, 373.6 parts by weight of methacrylic acid ester of (H- (OC ₂ H ₄ ) _3- (OC ₃ H ₆ )-(OC ₂ H ₄ ) ₆ -OCH ₃ , 74.4 parts by weight of methacrylic acid, water 112 .1 part by weight and a mixed solution (1) of 2-mercaptopropionic acid 9.09 parts by weight over 4 hours, a mixed solution of 3.5 parts by weight of 30% aqueous hydrogen peroxide and 31.5 parts by weight of water ( 2) A mixed solution (3) of 1.3 parts by weight of L-ascorbic acid and 29.0 of water was continuously dropped into a reaction vessel kept at 70 ° C. for 5 hours, and the temperature was 1 at 70 ° C. The solution was maintained for a time to obtain a copolymer solution, and when the solution temperature was 30 ° C., a 30% NaOH aqueous solution was added dropwise to adjust the solution pH to 7. The weight average molecular weight of the obtained copolymer was 7500, Mw. / Mn was 1.65. A copolymer (A3) ".

Production Example 4
In a reaction vessel equipped with a thermometer, a stirrer, a reflux device and a dropping device, 293.7 parts by weight of water was charged, the temperature was raised to 70 ° C., and the atmosphere was replaced with nitrogen at 200 ml / min for 1 hour. Thereafter, a mixed solution of 363.5 parts by weight of methoxypolyethyleneglycol methacrylate (average added mole number 10), 96.5 parts by weight of methacrylic acid, 123.5 parts by weight of water, and 6.8 parts by weight of 2-mercaptopropionic acid ( 1) was added dropwise over 4 hours, and a mixed solution (2) of 4.6 parts by weight of ammonium persulfate and 70.4 parts by weight of water was continuously added dropwise to a reaction vessel maintained at 100 ° C. for 5 hours. Furthermore, the temperature was maintained at 70 ° C. for 1 hour to obtain a copolymer solution. When the solution temperature was 30 ° C., a 30% NaOH aqueous solution was added dropwise to adjust the solution pH to 7. The weight average molecular weight of the obtained copolymer was 18000, and Mw / Mn was 2.05. This copolymer is referred to as “copolymer (B1)”.

Production Example 5
In a reaction vessel equipped with a thermometer, a stirrer, a reflux apparatus and a dropping apparatus, 2373 parts by weight of water and an unsaturated polyalkylene glycol monomer as an ethylene oxide adduct (average addition) of 3-methyl-3-buten-1-ol Mole number 50) 4800 parts by weight and 8.7 parts by weight of acrylic acid were charged, heated to 58 ° C., and purged with nitrogen at 200 ml / min for 1 hour. Thereafter, a mixed solution (1) of 21.5 parts by weight of 30% hydrogen peroxide and 460 parts by weight of water was added to the reaction vessel, 640.4 parts by weight of acrylic acid was added dropwise over 3 hours, and L-ascorbic acid 9. A mixed solution (2) of 8 parts by weight, 25.3 parts by weight of 2-mercaptopropionic acid and 1310 parts by weight of water was continuously added dropwise to a reaction vessel maintained at 58 ° C. for 3.5 hours. Furthermore, the temperature was maintained at 58 ° C. for 1 hour to obtain a copolymer solution. When the solution temperature was 30 ° C., a 30% aqueous NaOH solution was added dropwise to adjust the solution pH to 6.5. The weight average molecular weight of the obtained copolymer was 35000, and Mw / Mn was 2.04. This copolymer is referred to as “copolymer (B2)”.

Comparative production example 1
A reaction vessel equipped with a thermometer, a stirrer, a reflux device and a dropping device was charged with 283.4 parts by weight of water and heated to 100 ° C. Thereafter, a mixed solution of 373.6 parts by weight of methoxypolyethyleneglycol methacrylate (average added mole number 10), 86.4 parts by weight of methacrylic acid, 126.9 parts by weight of water, and 15.3 parts by weight of 2-mercaptopropionic acid ( A mixed solution (2) of 5.6 parts by weight of ammonium persulfate and 69.4 parts by weight of water was continuously added dropwise to the reaction vessel maintained at 100 ° C. for 5 hours. Furthermore, the temperature was maintained at 100 ° C. for 1 hour to obtain a copolymer solution. When the solution temperature was 30 ° C., a 30% NaOH aqueous solution was added dropwise to adjust the solution pH to 7. The weight average molecular weight of the obtained copolymer was 5800, and Mw / Mn was 1.42. This copolymer is referred to as “copolymer (CA1)”.

Comparative production example 2
A reaction vessel equipped with a thermometer, a stirrer, a reflux device and a dropping device was charged with 201.8 parts by weight of water, heated to 70 ° C., and purged with nitrogen at 200 ml / min for 1 hour. Thereafter, a mixed solution of 363.5 parts by weight of methoxypolyethylene glycol methacrylate (average addition mole number 6), 96.5 parts by weight of methacrylic acid, 123.5 parts by weight of water, and 6.7 parts by weight of 2-mercaptopropionic acid ( 1) for 4 hours, a mixed solution (2) of 4.8 parts by weight of a 30% aqueous hydrogen peroxide solution and 70.2 parts by weight of water, a mixed solution of 1.9 parts by weight of L-ascorbic acid and 73.1 parts of water ( 3) was continuously added dropwise to a reaction vessel maintained at 70 ° C. for 5 hours. Furthermore, the temperature was maintained at 70 ° C. for 1 hour to obtain a copolymer solution. When the solution temperature was 30 ° C., a 30% NaOH aqueous solution was added dropwise to adjust the solution pH to 7. The weight average molecular weight of the obtained copolymer was 8500, and Mw / Mn was 1.67. This copolymer is referred to as “copolymer (CA2)”.

Comparative production example 3
A reaction vessel equipped with a thermometer, a stirrer, a reflux device and a dropping device was charged with 212.6 parts by weight of water, heated to 70 ° C., and purged with nitrogen at 200 ml / min for 1 hour. Thereafter, a mixed solution of 373.6 parts by weight of methoxypolyethyleneglycol methacrylate (average added mole number 10), 86.4 parts by weight of methacrylic acid, 126.9 parts by weight of water, and 7.2 parts by weight of 2-mercaptopropionic acid ( 1) for 4 hours, a mixed solution (2) of 3.8 parts by weight of 30% aqueous hydrogen peroxide and 71.2 parts by weight of water, a mixed solution of 1.5 parts by weight of L-ascorbic acid and 73.5 parts of water ( 3) was continuously added dropwise to a reaction vessel maintained at 70 ° C. for 5 hours. Furthermore, the temperature was maintained at 70 ° C. for 1 hour to obtain a copolymer solution. When the solution temperature was 30 ° C., a 30% NaOH aqueous solution was added dropwise to adjust the solution pH to 7. The weight average molecular weight of the obtained copolymer was 12000, and Mw / Mn was 1.80. This copolymer is referred to as “copolymer (CA3)”.

Table 1 shows specific compositions of the copolymers obtained in the production examples and comparative production examples. However, the composition represents the weight ratio when all the carboxylic acid groups in the charged monomer are converted into sodium salts. For example, in Production Example 2, the feeds were 363.5 parts by weight of methoxypolyethylene glycol methacrylate (n = 10) and 96.5 parts by weight of methacrylic acid (Mw 86.09). In this case, methacrylic acid was converted to a sodium salt. Then, it corresponds to 121.1 parts by weight as sodium methacrylate (Mw 108.17). Therefore, PGM10E / SMAA = 363.5 / 121.1 = 75/25.
The symbols in the table are as follows.
PGM10E: Methoxypolyethylene glycol methacrylate (average added mole number 10)
PGM6E: Methoxypolyethylene glycol methacrylate (average added mole number 6)
_{EPE613E: (H- (OC 2 H} 4) 3 - (OC 3 H 6) - (OC 2 H 4) 6 -OCH 3 methacrylic acid ester IPN50: 3- methyl-3-buten-1-ol ethylene oxide addition Body (average number of moles added 50)
SMAA: sodium methacrylate SAA: sodium acrylate

Examples 1-4, Comparative Examples 1-5, Reference Examples 1-2
The copolymers obtained in the production examples and comparative production examples were mixed in the following composition, and as concrete admixtures, the slump flow values immediately after kneading and the elapsed time, and the concrete state were evaluated. The results are shown in Table 2. The concrete test conditions and methods are as follows.

<Concrete test>
1. Concrete mixing water: 172 kg / m ³
Cement (ordinary Portland cement manufactured by Taiheiyo Cement): 573.3 kg / m ³
Coarse aggregate (Ome fossil): 861.5kg / m ³
Fine aggregate (mixture of Oigawa river sand and Chiba Kimitsu sand, Oigawa: Kimitsu = 80/20): 739.4 kg / m ³
Microair MA404 (manufactured by Pozzolith Products Co., Ltd.) as an antifoaming agent is 0.02% with respect to the cement mass, and microair MA202 (manufactured by Pozzolith Products) as an AE agent is 0.003% with respect to cement. Blended. In addition, the compounding quantity of the concrete admixture with respect to the cement mass was calculated by the solid content of the admixture, and indicated by “% (mass%)” in the table.

2. Concrete production method In the above blending, cement and fine aggregate are put into a 50L biaxial forced kneading mixer and kneaded for 10 seconds, then water containing concrete admixture, antifoaming agent and AE agent is added. After kneading for 90 seconds, coarse aggregate was added and the mixture was further kneaded for 90 seconds to prepare concrete.

3. Evaluation method (1) Slump flow value The measurement of the slump flow value (unit: cm) of the obtained concrete was performed according to Japanese Industrial Standards (JIS A 1101, 1128, 6204 (2005)). “0-60” in Table 2 is a difference obtained by subtracting the slump flow value immediately after kneading (0 minutes) from the slump flow value 60 minutes after kneading.
(2) Concrete condition The condition of concrete was evaluated as follows.
When concrete is rubbed with a scoop, the viscosity of the concrete is high, and a large amount of mortar adheres to the scoop. The condition of the concrete is poor, the lower the viscosity of the concrete, the less mortar adheres to the scoop. The better, the better the concrete. Specifically, it is as follows.
(Double-circle): The viscosity of concrete is low at the time of kneading, and there is almost no adhesion of the mortar part to a scoop.
○: The viscosity of the concrete is low at the time of re-mixing, but adhesion of mortar to the scoop is observed.
(Triangle | delta): The viscosity of concrete is high at the time of mixing, and adhesion of the mortar part to a scoop is also seen.
X: The viscosity of the concrete is high at the time of kneading, and there is much adhesion of mortar to the scoop.

From the results in Table 2, the following can be understood.
That is, in Examples 1 to 3 in which the copolymer (A) of the present invention and the copolymer (B) in a particularly preferred form are used in combination, fluidity, retention and workability (good viscosity) ), It was shown that suitable results were obtained, but instead of the copolymer (A1 to 3) of the present invention, a copolymer (CA1) having Mw / Mn = 1.42 In Comparative Example 1 using No. 1, the amount added was almost the same as in Examples 1 to 3, but the results were inferior to those in Examples 1 to 3 in terms of retention and viscosity. Further, in Comparative Example 2 using the copolymer (CA2) in which the average number of repeating alkylene glycol units in the polyalkylene glycol chain is 6 instead of the copolymer (A1 to 3) of the present invention, the retention property is In addition, although the results are good in terms of viscosity, the amount added is much larger than in Examples 1 to 3, indicating that the water-reducing property is inferior. And in the comparative example 3 which made the addition amount substantially the same amount as Examples 1-3, it is shown that the fluidity | liquidity immediately after kneading | mixing fell remarkably. Moreover, in the comparative example 4 which uses the copolymer (CA3) whose weight average molecular weight = 12000 instead of the copolymer (A1-3) of this invention, it has become a result in which a retainability is remarkably inferior, Further, it can be seen that good results were not obtained in terms of state.
Moreover, it replaced with the copolymer (A1) in Example 4 implemented using the copolymer (B2) in which a structure differs from the copolymer (B1) used in Examples 1-3. In comparison with Comparative Example 5 carried out using the copolymer (CA1) with Mw / Mn = 1.42, Comparative Example 5 gave good results in both retention and viscosity. You can see that there wasn't.

Claims (5)

A polycarboxylic acid copolymer for a concrete admixture having a polyalkylene glycol chain,
The polycarboxylic acid-based copolymer has a weight average molecular weight (Mw) of less than 10,000 and a weight average molecular weight / number average molecular weight (Mw / Mn) of more than 1.5 and 2 or less ,
The polyalkylene glycol chain has an average number of repeating alkylene glycol units of 8 or more, and is represented by the following general formula (1);

(In the formula, R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom, a methyl group or — (CH ₂ ) x COOM ^2. Note that — (CH ₂ ) x COOM ² represents —COOM ¹ or other _- (CH ²⁾ _xCOOM 2 and good .x also form an anhydride is .M ¹ and ^{M 2} is an integer of 0 to 2 are the same or different, a hydrogen atom, a monovalent metal atom Represents a divalent metal atom, a trivalent metal atom, a quaternary ammonium base or an organic amine base.) And an unsaturated carboxylic acid monomer (a1) represented by the following general formula (2);

(.AO ^wherein, R 4, ^{R 5} and ^{R 6} are the same or different, .R ⁷ represents a hydrogen atom or a methyl group, represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms are the same Or, differently, it represents one or more of oxyalkylene groups having 2 to 18 carbon atoms, and when there are two or more oxyalkylene groups represented by AO, these groups are introduced in a block form. Or y may be introduced randomly, y is 0. z is 1. n1 represents the average number of added moles of the oxyalkylene group, and is a number from 8 to 300. And a polycarboxylic acid for concrete admixture, which is obtained by copolymerizing an unsaturated monomer composition comprising an unsaturated polyalkylene glycol monomer (b1) represented by Acid copolymer. Concrete admixture for polycarboxylic acid-based copolymer polymer (A), there at different polycarboxylic acid type copolymer (B) and concrete admixtures for copolymer composition characterized by containing from this And
The above-mentioned polycarboxylic acid copolymer for concrete admixture (A) is a polycarboxylic acid copolymer for concrete admixture having a polyalkylene glycol chain, and has a weight average molecular weight (Mw) of less than 10,000, And the weight average molecular weight / number average molecular weight (Mw / Mn) exceeds 1.5,
The polyalkylene glycol chain has an average number of repeating alkylene glycol units of 8 or more, and is represented by the following general formula (1);

(In the formula, R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom, a methyl group or — (CH ₂ ) x COOM ^2. Note that — (CH ₂ ) x COOM ² represents —COOM ¹ or other _- (CH ²⁾ _xCOOM 2 and good .x also form an anhydride is .M ¹ and ^{M 2} is an integer of 0 to 2 are the same or different, a hydrogen atom, a monovalent metal atom Represents a divalent metal atom, a trivalent metal atom, a quaternary ammonium base or an organic amine base.) And an unsaturated carboxylic acid monomer (a1) represented by the following general formula (2);

(.AO ^wherein, R 4, ^{R 5} and ^{R 6} are the same or different, .R ⁷ represents a hydrogen atom or a methyl group, represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms are the same Or, differently, it represents one or more of oxyalkylene groups having 2 to 18 carbon atoms, and when there are two or more oxyalkylene groups represented by AO, these groups are introduced in a block form. Or y may be introduced randomly, y is 0. z is 1. n1 represents the average number of added moles of the oxyalkylene group, and is a number from 8 to 300. ), And an unsaturated monomer composition essentially comprising an unsaturated polyalkylene glycol monomer (b1) represented by
The polycarboxylic acid copolymer (B) has the following general formula (3);

^(Wherein, R 8, ^{R 9} and ^{R 10} are the same or different, a hydrogen atom, a methyl group or _- represents a (CH 2) pCOOM ⁴ _{Note, -. (CH 2) pCOOM} 4 is -COOM ³ or It may form an anhydride with other — (CH ₂ ) pCOOM ^4. p is an integer of 0 to 2. M ³ and M ⁴ are the same or different and are a hydrogen atom or a monovalent metal atom. Represents a divalent metal atom, a trivalent metal atom, a quaternary ammonium base or an organic amine base.) And an unsaturated carboxylic acid monomer (a2) represented by the following general formula (4);

(.AO ^wherein, R ^{11, R 12} and ^{R 13} are the same or different, ^{.R 14} represents a hydrogen atom or a methyl group, represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms are the same Or, differently, it represents one or more of oxyalkylene groups having 2 to 18 carbon atoms, and when there are two or more oxyalkylene groups represented by AO, these groups are introduced in a block form. May be introduced randomly, q is an integer of 0 to 2. r is 0 or 1. n2 represents the average number of added moles of the oxyalkylene group; It is obtained by copolymerizing an unsaturated monomer composition essentially comprising an unsaturated polyalkylene glycol monomer (b2) represented by:
The polycarboxylic acid copolymer (B) has a weight average molecular weight (Mw) of 10,000 or more, and is a copolymer composition for a concrete admixture. The polycarboxylic acid copolymer (B) has the following formula:
An value = A value × 100 × n
(In the formula, the value A is the total mass of all monomer components when the carboxylic acid groups in the charged monomer are all sodium salts during the production of the polycarboxylic acid copolymer (B). This represents the mass ratio (mass%) of the sodium carboxylate-containing monomer with respect to 100 mass%, where n is the average number of alkylene glycol unit repeats of the polyalkylene glycol chain of the polycarboxylic acid copolymer (B). represented. in addition, an value is rounded off to the decimal point shall be rounded to an integer. an value represented by) of claim 2, characterized in that as a 230 to 2,000 Copolymer composition for concrete admixture. A concrete admixture comprising the polycarboxylic acid copolymer for concrete admixture according to claim 1 . A concrete admixture comprising the copolymer composition for concrete admixture according to claim 2.