JP6109240B2 - Cement admixture and cement composition - Google Patents

Description

The present invention relates to a cement admixture and a cement composition containing the same. More specifically, the present invention relates to a cement admixture that can be suitably used for cement compositions such as cement paste, mortar, and concrete, and a cement composition including the same.

Cement admixture is widely used as a water reducing agent for cement compositions such as cement paste, mortar, and concrete, and is indispensable for building civil engineering and building structures from cement compositions. It has become. Such a cement admixture has the effect of improving the strength, durability, and the like of the cured product by increasing the fluidity of the cement composition and reducing the water content of the cement composition. Among such water reducing agents, those containing a polycarboxylic acid polymer exhibit high water reducing performance as compared with conventional water reducing agents such as naphthalene, and thus have many achievements as high performance AE water reducing agents.

Furthermore, since mortar and concrete are hardened by the hydration reaction between cement and water over time, workability in the field of handling cement compositions generally decreases with the passage of time after the addition of water. It is. For this reason, cement admixture is required to have fluidity retention (slump retention) of the cement composition in addition to water reduction, and various cement admixtures are intended for such cement admixture. Has been developed.

For example, a cement admixture containing two kinds of polymers as an essential component and a blending ratio (mass%) of 1 to 99/99 to 1, in which one kind of polymer has a specific structure. The structural unit containing the structural unit (I) derived from an unsaturated (poly) alkylene glycol ether monomer and the structural unit (II) derived from an unsaturated monocarboxylic acid monomer as essential structural units The polymer in which (I) and the structural unit (II) each occupy 1% by mass or more of all the structural units, and the proportion of the structural unit (I) is 50 mol% or less in all the structural units, A cement admixture in which one polymer is a polymer having an oxyalkylene group or a polyoxyalkylene group and a carboxyl group is disclosed (for example, see Patent Document 1). Further, it is a cement admixture comprising at least two kinds of copolymers, and one of the copolymers is derived from a (poly) alkylene glycol monoalkenyl ether monomer having a specific structure. It is a copolymer that includes a structural unit and a structural unit derived from an unsaturated carboxylic acid monomer, and has an adsorption rate to cement particles of 40% or more. Another type of copolymer is a cement particle. Discloses a cement admixture that is a copolymer having an adsorption rate of less than 40% (see, for example, Patent Document 2).

JP-T-2004-519406 (page 1-2) JP 2008-133176 A (page 1-2)

As described above, various cement admixtures have been studied, but it is difficult to achieve both water reduction performance and slump retention performance, and it is further necessary to make them a cement admixture compatible at a high level. There was room for improvement. In addition, it is preferable from the viewpoint of economy that such excellent water reduction performance and slump retention performance can be achieved by adding a small amount of cement admixture.
The present invention has been made in view of the above situation, and in a cement composition containing fly ash, slag, etc., it has excellent water reduction performance and slump retention performance, and has a small amount of use and is economical. The object is to provide a high cement admixture.

The present inventor examined various cement admixtures, and firstly focused on the fact that the polycarboxylic acid-based polymer exhibits excellent water-reducing performance with respect to the cement composition and the like. By using a (poly) alkylene glycol ether copolymer, the cement admixture can be made highly economical, and the number of adsorbing groups having the ability to adsorb the copolymer to cement particles is five. A cement admixture having excellent water reduction performance and slump retention performance can be obtained by blending a polymer of less than 19 and a polymer of 19 or more and less than 70 in a specific ratio to obtain a cement admixture. I found out that I can do it. And since such cement admixture is excellent in performance, even if the amount used is suppressed, it is possible to exert a sufficient effect, and it is found that the amount used can be reduced, and the above problems can be solved brilliantly. Thus, the present invention has been achieved.

That is, the present invention is a cement admixture containing two types of polymers, polymer (A) and polymer (B), as essential components, and the polymer (A) and polymer (B) are: General formula (1);

(In the formula, Y represents an alkenyl group having 2 to 10 carbon atoms. R ^a O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. M is represented by R ^a O. The average added mole number of the oxyalkylene group, which represents a number of 1 to 500. R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.) Unsaturated (poly) alkylene glycol ether system Essential constitution of the structural unit (I) derived from the monomer (a) and the structural unit (II) derived from the unsaturated carboxylic acid monomer (b) having a carboxyl group and / or a salt thereof as an adsorbing group As a unit, the polymer (A) has 5 or more and less than 19 adsorbing groups per molecule of the polymer, and the polymer (B) has 19 adsorbing groups per molecule of the polymer. Is less than 70, and the weight of the cement admixture is The ratio (mass%) of a coalescence (A) and a polymer (B) is a cement admixture which is 40-99 / 60-1.
The present invention is described in detail below.

The cement admixture of the present invention contains two types of polymers, polymer (A) and polymer (B), as essential components, but each of polymer (A) and polymer (B) contains one type. You may use and 2 or more types may be used.
In addition, the cement admixture of the present invention includes a polymer (A) and a heavy polymer as long as it contains two types of polymers: a polymer corresponding to the polymer (A) and a polymer corresponding to the polymer (B). Other polymers that do not fall under the combination (B) and other components may be included. Even in such a case, since the polymer (A) and the polymer (B) are present in the cement admixture, the effect of the present invention is exhibited by two types of polymers having different numbers of adsorbing groups. Therefore, in this case, it is preferable that the polymer (A) and the polymer (B) are the main components in the cement admixture, and the polymer (A) and the polymer ( The total amount with B) is preferably 50% by mass or more. More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more. Particularly preferred is a form in which the cement admixture is substantially composed only of the polymer (A) and the polymer (B).

The polymer (A) and the polymer (B) are both derived from an unsaturated (poly) alkylene glycol ether monomer (a) (hereinafter also simply referred to as “monomer (a)”). A structural unit derived from the unit (I) and an unsaturated carboxylic acid monomer (b) having a carboxyl group and / or a salt thereof as an adsorbing group (hereinafter also simply referred to as “monomer (b)”) ( II) as an essential constituent unit. That is, the polymer (A) and the polymer (B) are both derived from a structural unit derived from an unsaturated (poly) alkylene glycol ether monomer (a) and from an unsaturated carboxylic acid monomer (b). These structural units are included. As will be described later, the monomer (a) and the polymer (A) and the polymer (B) having a structural unit derived from the monomer (a) and a structural unit derived from the monomer (b) It can be obtained by carrying out a copolymerization reaction using a monomer component containing the monomer (b).
The monomer (a) and the monomer (b) will be described in detail later.

In the polymer (A), the number of adsorbing groups capable of adsorbing to cement particles per molecule of the polymer (adsorbing group number) is 5 or more and less than 19, and the polymer (B) has 19 adsorbing groups. It is less than 70. Among the two types of polymers contained in the cement admixture, the number of adsorbing groups in one polymer is 5 or more and less than 19, and the number of adsorbing groups in the other polymer is 19 or more and less than 70, whereby the cement admixture A difference in the number of adsorbing groups of the polymers contained in the polymer, and the polymer (B) having a large number of adsorbing groups will improve the dispersibility of cement particles and the like, and therefore water reducing performance will be exhibited. The slump retention performance is exhibited by (A). As a result, these performances are exhibited in a well-balanced manner, and it is possible to obtain a cement admixture that achieves both water reduction performance and slump retention performance at a high level.
In the present invention, the number of adsorbing groups per molecule of polymer (the number of adsorbing groups) means the number of functional groups that can be adsorbed on cement particles contained in one molecule of polymer. Can be calculated.

The above mathematical formula (1) is for calculating the number of adsorbing groups per molecule of polymer when there are n types of constituent monomers from which the constituent units constituting the polymer are derived. Represents the number of adsorbing groups per molecule of polymer. Aj represents the number of adsorbing groups per molecule of the constituent monomer j. When the constituent monomer j is a monomer having no adsorption group, the calculation is performed with Aj = 0. Nj represents the number of constituent units derived from the constituent monomer j in one polymer molecule, and AjNj represents the number of adsorbing groups that the constituent units derived from the constituent monomer j have in one polymer molecule. Mwi represents the weight average molecular weight of the constituent monomer i. Xi represents the mole fraction of the constituent monomer i. Mwtital represents the weight average molecular weight of the polymer. Xj represents the mole fraction of the constituent monomer j.
Thus, the number of adsorbing groups possessed by the polymer is the ratio of the monomer having adsorbing groups to the entire constituent monomers that are the origin of the constituent units constituting the polymer, and the number of monomers having adsorbing groups. The number of adsorbing groups and the weight average molecular weight of the polymer will vary, and even if the proportion of the monomer having adsorbing groups in the entire constituent monomer is the same, the weight average molecular weight of the polymer will be The larger the number of adsorbing groups the polymer has, the more the weight average molecular weight of the polymer is the same. The number of adsorbing groups possessed by the coalescence increases.

In particular, the unsaturated carboxylic acid monomer (b) is an unsaturated monocarboxylic acid monomer (b′-1) described later, and is a constituent monomer from which the constituent units constituting the polymer are derived. As the monomer component containing n types of monomers, the monomer having an adsorbing group is only an unsaturated monocarboxylic acid monomer (b′-1), and the unsaturated monocarboxylic acid monomer When only one type of monomer is used as the monomer (b′-1), the number of adsorbing groups per molecule of the polymer can be calculated based on the following mathematical formula (2).

In the above mathematical formula (2), P represents the number of adsorbing groups per polymer molecule. N _b′-1 represents the number of constituent units derived from the unsaturated monocarboxylic acid monomer (b′-1) in one molecule of the polymer. Mwi represents the weight average molecular weight of the constituent monomer i. Xi represents the mole fraction of the constituent monomer i. X _b′-1 represents the molar fraction of the unsaturated monocarboxylic acid monomer (b′-1). Mwtital represents the weight average molecular weight of the polymer.

In addition, the unsaturated carboxylic acid monomer (b) is an unsaturated dicarboxylic acid monomer (b′-2) described later, and is a constituent monomer from which the constituent unit constituting the polymer is derived. Among the monomer components containing n types of monomers, the monomer having an adsorbing group is only the unsaturated dicarboxylic acid monomer (b′-2), and the unsaturated dicarboxylic acid monomer When only one type of monomer is used as (b′-2), the number of adsorbing groups per molecule of the polymer can be calculated based on the following mathematical formula (3).

In the above mathematical formula (3), P represents the number of adsorbing groups per polymer molecule. N _b′-2 represents the number of constituent units derived from the unsaturated dicarboxylic acid monomer (b′-2) in one molecule of the polymer. Mwi represents the weight average molecular weight of the constituent monomer i. Xi represents the mole fraction of the constituent monomer i. X _b′-2 represents the molar fraction of the unsaturated dicarboxylic acid monomer (b′-2). Mwtital represents the weight average molecular weight of the polymer.

The number of adsorbing groups per polymer molecule in the polymer (A) is not uniquely determined by the blending ratio of the polymer (A) and the polymer (B), but the polymer (A) When the blending ratio is large, the slump retention performance of the cement admixture improves as the number of adsorbing groups in the polymer (A) decreases, but the water-reducing performance tends to be difficult to occur. Preferably, it is 9 or more and less than 19, more preferably 10 or more and less than 19.
Further, the number of adsorbing groups per polymer molecule in the polymer (B) is not uniquely determined as in the case of the adsorbing group number in the polymer (A). It is preferable that it is 30 or more and less than 70.

Examples of the adsorbing group include a carboxyl group and / or a salt thereof of the monomer (b) and other copolymerizable monomers other than the monomer (a) and the monomer (b) described later. Although the sulfonic acid group and / or its salt which the unsaturated sulfonates and / or its salt contained in this corresponds, monomer (b) may have one adsorption group in 1 molecule. It is also possible to have a plurality. Further, when the monomer (b) has a plurality of adsorbing groups in one molecule, these adsorbing groups may all be the same or different.
Specific examples of the carboxyl group salt include metal salts such as sodium and potassium salts of carboxyl groups, ammonium salts, and organic ammonium salts. Among these, a carboxyl group and a metal salt of a carboxyl group are preferable as the adsorbing group.

In the cement admixture of the present invention, the blending ratio (% by mass) of the polymer (A) and the polymer (B) is the number of adsorbing groups per polymer molecule in the polymer (A) and the polymer (B). Although it is not uniquely determined by the number, it is 40 to 99/60 to 1. The mass ratio between the polymer (A) and the polymer (B) is also in this range, which is an important factor for exhibiting the effect of the present invention that combines excellent water reduction performance and slump retention performance. is there.
The blending ratio (% by mass) of the polymer (A) and the polymer (B) is preferably 45 to 99/55 to 1, more preferably 50 to 99/50 to 1, More preferably, it is 50-90 / 50-10. Most preferably, it is 55-85 / 45-15.
In addition, the said mass ratio is a value by solid content conversion.

The polymer (A) preferably has a weight average molecular weight of 1,000 to 500,000. More preferably, it is 5000-300000, More preferably, it is 10,000-150,000. Moreover, it is preferable that the weight average molecular weights of the said polymer (B) are 1000-500000. More preferably, it is 5000-300000, More preferably, it is 10,000-150,000.
In addition, the weight average molecular weight of the polymer was determined by gel permeation chromatography (GPC, equipment used: Waters, Waters Alliance (2695)) using polyethylene glycol as a standard substance, as in Examples described later. Column: manufactured by Tosoh Corporation, TSK guard column SWXL + TSKgel G4000SWXL + G3000SWXL + G2000SWXL).

The unsaturated (poly) alkylene glycol ether monomer (a) is represented by the following general formula (1);

(In the formula, Y represents an alkenyl group having 2 to 10 carbon atoms. R ^a O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. M is represented by R ^a O. It is an average addition mole number of an oxyalkylene group and represents a number of 1 to 500. R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

In the general formula (1), Y represents an alkenyl group having 2 to 10 carbon atoms, and the carbon number of Y is preferably 2 to 8, more preferably 3 to 5. Examples of the alkenyl group having 2 to 10 carbon atoms include vinyl group, allyl group, methallyl group, 3-butenyl group, 3-methyl-3-butenyl group, 3-methyl-2-butenyl group, 2-methyl- A 3-butenyl group, a 2-methyl-2-butenyl group, a 1,1-dimethyl-2-propenyl group and the like can be mentioned. Among these, an allyl group, a methallyl group, and a 3-methyl-3-butenyl group are preferable.

In the general formula (1), R ^a O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms, and represents one or more of oxyalkylene groups. When an oxyalkylene group is present, the addition form may be any addition form such as random addition, block addition, or alternate addition.
As carbon number of the oxyalkylene group represented by said R ^<a> O, 2-8 are preferable, More preferably, it is 2-4. Examples of the oxyalkylene group having 2 to 18 carbon atoms include structures formed of ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, and the like. Among these, an oxyethylene group and an oxypropylene group are preferable. Further, those mainly composed of oxyethylene groups are preferred.

The oxyalkylene group represented by R ^a O preferably has an oxyethylene group as a main component. Here, the oxyethylene group is predominant means that the number of moles of all alkylene oxides forming the oxyalkylene group when the oxyalkylene group represented by R ^a O is formed of two or more oxyalkylene groups. Means that ethylene oxide accounts for the majority. Since the oxyalkylene group represented by R ^a O is mainly composed of an oxyethylene group, the balance between hydrophilicity and hydrophobicity of the polymer (A) and the polymer (B) becomes good, and The effects exhibited by the combined body (A) and the polymer (B) will be more fully exhibited. The oxyalkylene group represented by R ^a O is more preferably 50 to 100 mol% of oxyethylene groups and 100 to 100 mol% of oxyethylene groups in 100 mol% of all oxyalkylene groups. Is more preferable. Even more preferably, it is 70-100 mol%, Most preferably, it is 80-100 mol%, Most preferably, it is 90-100 mol%.

M in the general formula (1) is the average number of moles of the oxyalkylene group represented by R a ^O, it is representative of the number of 1 to 500. When the average added mole number of the oxyalkylene group represented by R ^a O is in such a range, the polymerization reactivity of the monomer (a), and the polymer (A) and the polymer (B) The hydrophilicity is sufficient. As said m, it is preferable that it is 2-400, and 5-300 is more preferable. More preferably, it is 10-250, Most preferably, it is 15-200. Most preferably, it is 20-100.

In the general formula (1), R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. When R is in such a form, the hydrophilicity of the polymer (A) and the polymer (B) becomes sufficient. Preferably, they are a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, and an alicyclic alkyl group having 3 to 12 carbon atoms, more preferably a hydrogen atom, a straight chain having 1 to 4 carbon atoms. A chain or branched alkyl group, or an alicyclic alkyl group having 3 to 4 carbon atoms, more preferably a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a carbon number 3 An alicyclic alkyl group. Particularly preferred is a hydrogen atom.

As the unsaturated (poly) alkylene glycol ether monomer (a), the following general formula (3);

(Wherein R ³ and R ⁴ are the same or different and represent ^a hydrogen atom or a methyl group. R ^a O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. ^a is the average number of added moles of the oxyalkylene group represented by O, and represents a number of 1 to 500. R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, X is a carbon number of 1 to 6 It is preferable that it is an unsaturated alcohol (poly) alkylene glycol adduct represented by the following formula:

In the general formula (3), R ³ and R ⁴ are the same or different and represent a hydrogen atom or a methyl group. Among these, the form in which R ³ is a hydrogen atom and R ⁴ is a methyl group is one of the preferred embodiments of the present invention.
In the general formula ^(3), R a O, m and, R is, ^R a O in the general formula (1), respectively, m and are the same as R.

In the general formula (3), X represents a divalent alkylene group having 1 to 6 carbon atoms or a direct bond. When X represents a direct bond, the carbon atom bonded to X in the general formula (3) and the oxygen atom are directly bonded. Among these, X is preferably a divalent alkylene group having 1 to 4 carbon atoms, more preferably a methylene group, an ethylene group, a propylene group, or an isopropylene group, and particularly preferably methylene. Group, ethylene group.

Examples of the unsaturated (poly) alkylene glycol ether monomer (a) represented by the general formula (3) include (poly) ethylene glycol allyl ether, (poly) ethylene glycol methallyl ether, (poly) ethylene glycol 3 -Methyl-3-butenyl ether, (poly) ethylene (poly) propylene glycol allyl ether, (poly) ethylene (poly) propylene glycol methallyl ether, (poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl Ether, (poly) ethylene (poly) butylene glycol allyl ether, (poly) ethylene (poly) butylene glycol methallyl ether, (poly) ethylene (poly) butylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene Glycol Ryl ether, methoxy (poly) ethylene glycol methallyl ether, methoxy (poly) ethylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) propylene glycol allyl ether, methoxy (poly) ethylene (poly) propylene glycol Methallyl ether, methoxy (poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) butylene glycol allyl ether, methoxy (poly) ethylene (poly) butylene glycol methallyl ether, methoxy (Poly) ethylene (poly) butylene glycol 3-methyl-3-butenyl ether is preferred. In this invention, these 1 type (s) or 2 or more types can be used as a monomer (a) which gives structural unit (I).

The unsaturated (poly) alkylene glycol ether monomer (a) can be produced by various methods, and typical production methods are as follows.
1) In the case of the unsaturated (poly) alkylene glycol ether monomer (a) in which R in the general formula (1) is a hydrogen atom, allyl alcohol, methallyl alcohol, 3-methyl-3-butene-1 -Unsaturated alcohols having an alkenyl group having 2 to 10 carbon atoms such as 3-ol, 3-methyl-2-buten-1-ol, 2-methyl-2-buten-1-ol, potassium hydroxide, hydroxide A monomer (a) can be obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms in the presence of an alkali catalyst such as sodium or an acid catalyst such as boron trifluoride or tin tetrachloride. it can.

2) In the case of the unsaturated (poly) alkylene glycol ether monomer (a) in which R in the general formula (1) is an alkyl group having 1 to 18 carbon atoms, A compound obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to a saturated alcohol is further reacted with an alkyl halide having 1 to 18 carbon atoms such as methyl chloride in the presence of an alkali such as sodium hydroxide. A monomer can be obtained.
3) In the case of the unsaturated (poly) alkylene glycol ether monomer (a) in which R in the general formula (1) is an alkyl group having 1 to 18 carbon atoms, methanol is contrary to the above method 2). In addition, to a compound obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to an alcohol having 1 to 18 carbon atoms such as ethanol, allyl chloride, methallyl chloride in the presence of an alkali such as sodium hydroxide A monomer can be obtained by reacting an alkenyl halide having 2 to 10 carbon atoms such as.

The unsaturated carboxylic acid monomer (b) is not particularly limited as long as it is a monomer having a polymerizable unsaturated group and a carboxyl group which is an adsorbing group and / or a structure portion of a salt thereof. An unsaturated monocarboxylic acid monomer or an unsaturated dicarboxylic acid monomer is preferred. In this invention, these 1 type (s) or 2 or more types can be used as a monomer (b) which gives structural unit (II). Among these, the unsaturated carboxylic acid monomer (b) is represented by the following general formula (2);

(In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom or a methyl group. M ¹ represents a hydrogen atom, a metal atom, an ammonium group or an organic ammonium group. Z represents a hydrogen atom, or , -COOM ² , wherein M ² represents a hydrogen atom, a metal atom, an ammonium group, or an organic ammonium group.) And an unsaturated carboxylic acid monomer (b ′). The form is also one of the preferred embodiments of the present invention.

M ¹ and M ² in the general formula (2) each represent a hydrogen atom, a metal atom, an ammonium group, or an organic ammonium group. A divalent metal atom; a divalent metal atom such as an alkaline earth metal atom such as calcium or magnesium; a trivalent metal atom such as aluminum or iron;
Among these, as M ¹ and M ² , a hydrogen atom, sodium, and potassium are preferable.

The unsaturated monocarboxylic acid-based monomer may be any monomer that has one unsaturated group and one carboxyl group which is an adsorbing group and / or a structure portion of a salt thereof in the molecule, preferably , The following general formula (4);

(In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom or a methyl group. M ¹ represents a hydrogen atom, a metal atom, an ammonium group, or an organic ammonium group.) It is a monocarboxylic acid monomer (b′-1). The unsaturated monocarboxylic acid monomer (b′-1) corresponds to a form in which Z represents a hydrogen atom in the general formula (2). Thus, the form in which the unsaturated carboxylic acid monomer (b) is the unsaturated monocarboxylic acid monomer (b′-1) represented by the above general formula (4) is also the present invention. This is one of the preferred embodiments.

In the general formula ^(4), R 1, ^{R 2,} and, ^{M 1} is, ^R 1, ^{R 2} in the general formula (2), respectively, and are the same as ^{M 1.}
Specific examples of the unsaturated monocarboxylic acid monomer (b′-1) include acrylic acid, methacrylic acid, crotonic acid, and their monovalent metal salts, divalent metal salts, and ammonium. Examples thereof include salts and organic ammonium salts. Among these, acrylic acid, methacrylic acid, or their monovalent metal salt, divalent metal salt, ammonium salt, and organic ammonium salt are preferable from the viewpoint of cement water reduction performance, and more preferably acrylic acid, methacrylic acid, An acid, or a monovalent metal salt thereof or a divalent metal salt, and more preferably acrylic acid or a monovalent metal salt thereof.

The unsaturated dicarboxylic acid-based monomer may be any monomer having one unsaturated group in the molecule and two structural parts of a carboxyl group and / or a salt thereof as an adsorbing group, For example, maleic acid, itaconic acid, citraconic acid, fumaric acid, etc., and various monovalent metal salts, divalent metal salts, ammonium salts, organic ammonium salts, or anhydrides thereof The structure of this is mentioned. Preferably, the following general formula (5);

(In the formula, R ¹ and R ² are the same or different and represent a hydrogen atom or a methyl group. M ¹ and M ² are the same or different and represent a hydrogen atom, a metal atom, an ammonium group, or an organic ammonium group. .) Is an unsaturated dicarboxylic acid monomer (b′-2). The unsaturated dicarboxylic acid monomer (b′-2) corresponds to a form in which Z represents a group represented by —COOM ² in the general formula (2). Thus, the form in which the unsaturated carboxylic acid monomer (b) is the unsaturated dicarboxylic acid monomer (b′-2) represented by the general formula (5) is also suitable for the present invention. It is one of the embodiments.

In the general formula ^{(5), R 1, R} 2, M 1, and, ^{M 2} is, ^R 1 in the general formula (2), ^{respectively,} R 2, ^{M 1,} and are the same as ^{M 2.}
Specific examples of the unsaturated dicarboxylic acid monomer (b′-2) include maleic acid, citraconic acid, or a monovalent metal salt, a divalent metal salt, an ammonium salt, and an organic ammonium. Examples thereof include salts or anhydrides thereof. Among these, maleic acid, citraconic acid, or a monovalent metal salt thereof, a divalent metal salt, or an anhydride thereof is preferable, and maleic acid or a monovalent metal salt thereof is more preferable. It is a divalent metal salt or an anhydride thereof.

Other examples of the unsaturated dicarboxylic acid monomer include a half ester of an unsaturated dicarboxylic acid monomer and an alcohol having 1 to 30 carbon atoms, an unsaturated dicarboxylic acid monomer and an amine having 1 to 30 carbon atoms. And a half amide of an unsaturated dicarboxylic acid monomer and a glycol having 2 to 4 carbon atoms, a half amide of maleamic acid and a glycol having 2 to 4 carbon atoms, and the like can also be used.
However, when these half esters or half amides are used as unsaturated dicarboxylic acid monomers, when calculating the number of adsorbing groups per molecule of the above-mentioned polymer, these unsaturated dicarboxylic acid monomers The number of adsorbing groups per molecule is calculated as one.

The polymer (A) and the polymer (B) are other copolymerizable monomers other than the structural unit derived from the monomer (a) and the structural unit derived from the monomer (b). You may have the structural unit which originates.
Examples of the other copolymerizable monomers include diesters of unsaturated dicarboxylic acid monomers such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, and alcohols having 1 to 30 carbon atoms. Diamides of the above unsaturated dicarboxylic acid monomers and amines having 1 to 30 carbon atoms; alkyls obtained by adding 1 to 500 moles of alkylene oxides having 2 to 18 carbon atoms to the above alcohols and amines (poly ) Diesters of alkylene glycol and unsaturated dicarboxylic acid monomer; unsaturated dicarboxylic acid monomer and glycol having 2 to 18 carbon atoms, or polyalkylene having 2 to 500 addition moles of these glycols Diesters with glycols; maleamic acid and glycols having 2 to 18 carbon atoms or the number of moles of these glycols added Half-amides with ~ 500 polyalkylene glycols; triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol (Poly) alkylene glycol di (meth) acrylates such as di (meth) acrylate; polyfunctional (meta) such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate ) Acrylates; (poly) alkylene glycol dimaleates such as triethylene glycol dimaleate and polyethylene glycol dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- ( T) Acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) Acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutylsulfonate, (meth) acrylamide methylsulfonic acid, (meth) acrylamide ethylsulfonic acid, 2-methylpropanesulfonic acid (meth) acrylamide, styrenesulfonic acid Unsaturated carboxylic acids such as monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts thereof; unsaturated monocarboxylic acids such as methyl (meth) acrylamide and amines having 1 to 30 carbon atoms; Amides; vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene; 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1 Alkanediol mono (meth) acrylates such as 1,6-hexanediol mono (meth) acrylate; dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene; Unsaturated amides such as (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; Unsaturated cyanides such as (meth) acrylonitrile and α-chloroacrylonitrile Unsaturated esters such as vinyl acetate and vinyl propionate; Unsaturated amines such as aminoethyl methacrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, and vinylpyridine Divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate; polydimethylsiloxanepropylaminomaleamic acid, polydimethylsiloxaneaminopropylaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamide) Acid), polydimethylsiloxane-bis- (dipropyleneaminomaleamic acid), polydimethylsiloxane- (1-propyl-3-acrylate), polydimethylsiloxane- (1-propyl-3-methacrylate) Rate), polydimethylsiloxane - bis - (1-propyl-3-acrylate), poly dimethyl siloxane - bis - (such as 1-propyl-3-methacrylate) siloxane derivatives and the like. As other copolymerizable monomers, one or more of these can be used.

As described above, the polymer (A) and the polymer (B) may have a structural unit derived from the other copolymerizable monomer, but may be derived from the monomer (a). The structural unit and the structural unit derived from the monomer (b) are preferably the main components. In 100% by mass of the polymer, the structural unit derived from the monomer (a) and the monomer (b) It is preferable that the total of the derived structural units is 50 to 100% by mass. More preferably, it is 70-100 mass%, More preferably, it is 80-100 mass%, Most preferably, it is 90-100 mass%. And the form which is a polymer which consists only of the structural unit derived from the monomer (a) and the structural unit derived from the monomer (b) is the most preferable for both the polymer (A) and the polymer (B). Each of these structural units may be one kind or two or more kinds.

The larger the proportion of the structural unit (II) derived from the unsaturated carboxylic acid monomer (b) in the structural units constituting the polymer (A) and the polymer (B), As the weight average molecular weight increases, the number of adsorbing groups of the polymer increases. Therefore, the type of unsaturated carboxylic acid monomer (b) to be used, the weight average molecular weight of the required polymer, and the required Depending on the number of adsorbing groups of the polymer, the structural unit (I) derived from the unsaturated (poly) alkylene glycol ether monomer (a) and the unsaturated carboxylic acid monomer (b) in the polymer The ratio with the structural unit (II) can be appropriately set.

As a ratio of the structural unit (I) and the structural unit (II) in the polymer (A), since the polymer (A) has 5 or less and less than 19 adsorbing groups per polymer molecule, Within the range satisfying the number of adsorbing groups, the structural unit (I) / structural unit (II) (mass ratio) is preferably 60/40 to 99.5 / 0.5. By such a ratio, the slump retention performance of the polymer (A) becomes better. More preferably, it is 70 / 30-99 / 1 as a structural unit (I) / structural unit (II) (mass ratio) in a polymer (A), More preferably, it is 80 / 20-98.5 / 1. 5.

Moreover, as a ratio of the structural unit (I) and the structural unit (II) in the polymer (B), the polymer (B) has 19 or more and less than 70 adsorbing groups per polymer molecule. Therefore, it is preferable that the structural unit (I) / structural unit (II) (mass ratio) is 1/99 to 99/1 within a range satisfying the number of adsorbing groups. By being such a ratio, the water reduction performance of the polymer (B) becomes better. More preferably, it is 10 / 90-98 / 2 as a structural unit (I) / structural unit (II) (mass ratio) in a polymer (B), More preferably, it is 20 / 80-95 / 5.
The ratio (mass ratio) between the structural unit (I) and the structural unit (I) is obtained by multiplying the amount of each monomer used for the synthesis of the polymer by the reaction rate of each monomer. Assuming that they are combined structural units, the amount of each structural unit is calculated, and the mass ratio can be determined from those values.

The polymer (A) and the polymer (B) are an unsaturated (poly) alkylene glycol ether monomer (a) that gives the structural unit (I), and an unsaturated carboxylic acid that gives the structural unit (II). The monomer component containing the monomer (b) as an essential component can be copolymerized and produced, but the production method is not limited thereto. For example, instead of the monomer (a), a monomer before addition of the alkylene oxide, that is, an unsaturated alcohol such as methallyl alcohol is used, and this is added to the monomer (b) in the presence of a polymerization initiator. (If necessary, other monomers copolymerizable with these monomers may be further copolymerized), and then obtained by an average addition of 1 to 500 moles of alkylene oxide. be able to.
The copolymerization reaction can be performed using a polymerization initiator, and can be performed by a method such as polymerization in a solvent or bulk polymerization.
The amount of each monomer used in the copolymerization reaction is such that the proportion of each structural unit in the polymer is in the above-described range, taking into account the reaction rate during the copolymerization reaction of each monomer, It is preferable to set appropriately.

The polymerization in the solvent can be carried out batchwise or continuously. The solvent used in this case is water; lower alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, cyclohexane, Aromatic or aliphatic hydrocarbons such as n-hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone are preferred. These may be used alone or in combination of two or more. From the solubility of the raw material monomer and the resulting polymers (A) and (B) and the convenience during use of the polymer, at least selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms One type is preferably used. In that case, methyl alcohol, ethyl alcohol, isopropyl alcohol and the like are particularly effective among the lower alcohols having 1 to 4 carbon atoms.

In the case of carrying out the aqueous solution polymerization, as a radical polymerization initiator, a water-soluble polymerization initiator, for example, a persulfate such as ammonium persulfate, sodium persulfate, potassium persulfate; hydrogen peroxide; 2,2'-azobis- Azoamidine compounds such as 2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, and azonitriles such as 2-carbamoylazoisobutyronitrile Water-soluble azo initiators such as compounds are used. In this case, alkali metal sulfites such as sodium hydrogen sulfite, metabisulphite, sodium hypophosphite, Fe (II) salts such as Mole salt, hydroxymethanesulfine Acid sodium dihydrate, hydroxylamine hydrochloride, thiourea, L-ascorbic acid (salt), erysol It can also be used in combination accelerator such as phosphate (salt). When hydrogen peroxide is used as the water-soluble polymerization initiator, it is preferably used in combination with an accelerator such as L-ascorbic acid (salt).

For polymerization using a lower alcohol, aromatic hydrocarbon, aliphatic hydrocarbon, ester compound or ketone compound as a solvent, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; azo An azo compound such as bisisobutyronitrile is used as a polymerization initiator. In this case, an accelerator such as an amine compound can be used in combination. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various polymerization initiators or combinations of polymerization initiators and accelerators. The polymerization temperature is appropriately determined depending on the solvent to be used and the polymerization initiator, but is usually 0 to 120 ° C.

The bulk polymerization uses a peroxide such as benzoyl peroxide or lauroyl peroxide as a polymerization initiator; a hydroperoxide such as cumene hydroperoxide; an azo compound such as azobisisobutyronitrile, and the like, at a temperature of 50 to 200 ° C. Done in

The method of charging each monomer into the reaction vessel is not particularly limited. The method of initially charging the entire amount into the reaction vessel at once, the method of dividing or continuously charging the entire amount into the reaction vessel, and the initial charging into the reaction vessel. Any method may be used in which the remainder is divided or continuously charged into the reaction vessel. Specific examples of a suitable charging method include the following methods (1) to (4).
(1) A method of continuously charging all of the monomers into the reaction vessel.
(2) A method in which all of the monomer (a) is initially charged into the reaction vessel and all other monomers are continuously charged into the reaction vessel.
(3) A method in which a part of the monomer (a) is initially charged into the reaction vessel, and the remainder of the monomer (a) and all other monomers are continuously charged into the reaction vessel.
(4) A part of the monomer (a) and a part of the other monomer are initially charged into the reaction vessel, and the remainder of the monomer (a) and the rest of the other monomer are respectively added to the reaction vessel. A method of splitting into several times alternately.
Furthermore, by changing the charging rate of each monomer into the reaction vessel during the reaction continuously or stepwise, the charging mass ratio of each monomer per unit time can be changed continuously or stepwise. You may make it synthesize | combine the mixture of the copolymer from which the ratio of each structural unit in a polymer differs in a polymerization reaction. The radical polymerization initiator may be charged into the reaction vessel from the beginning, may be dropped into the reaction vessel, or may be combined according to the purpose.

Moreover, a chain transfer agent can also be used together for molecular weight adjustment of the obtained polymers (A) and (B). Chain transfer agents include mercaptoethanol, thioglycerol, thioglycolic acid, 3-mercaptopropionic acid, thiomalic acid, 2-mercaptoethanesulfonic acid and other thiol chain transfer agents; isopropyl alcohol and other secondary alcohols; phosphorous acid Hypophosphorous acid and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionic acid, metabisulfite and salts thereof (sodium sulfite, sodium hydrogen sulfite, dithione) Known hydrophilic chain transfer agents such as sodium oxide, sodium metabisulfite and the like lower oxides and salts thereof can be used. Furthermore, the use of a hydrophobic chain transfer agent is effective in improving the viscosity of the cement composition. Hydrophobic chain transfer agents include 3 or more carbon atoms such as butanethiol, octanethiol, decanethiol, dodecanethiol, hexadecanethiol, octadecanethiol, cyclohexyl mercaptan, thiophenol, octyl thioglycolate, octyl 3-mercaptopropionate, etc. It is preferable to use a thiol chain transfer agent having the following hydrocarbon group. Two or more types of chain transfer agents can be used in combination, and a hydrophilic chain transfer agent and a hydrophobic chain transfer agent may be used in combination. Furthermore, in order to adjust the molecular weight of the polymer, it is also effective to use a monomer having high chain mobility such as (meth) allylsulfonic acid (salt) as the other copolymerizable monomer. is there.

In the above polymerization, in order to obtain the polymers (A) and (B) having a predetermined molecular weight with good reproducibility, it is necessary to allow the polymerization reaction to proceed stably. The dissolved oxygen concentration at 25 ° C. is preferably 5 ppm or less. More preferably, it is 0.01-4 ppm, More preferably, it is 0.01-2 ppm, Most preferably, it is 0.01-1 ppm. In addition, when nitrogen substitution etc. are performed after adding a monomer to a solvent, it is preferable to make the dissolved oxygen concentration of the system | strain containing a monomer into the said range.

Adjustment of the dissolved oxygen concentration of the solvent may be performed in a polymerization reaction tank, or a solution in which the amount of dissolved oxygen is adjusted in advance may be used. As a method for driving out oxygen in the solvent, the following (1) to ( The method 5) is preferred.
(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. You may reduce the pressure in an airtight 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.

Each polymer obtained as described above can be used as it is by blending it with a cement admixture, but if necessary, it may be further neutralized with an alkaline substance. As the alkaline substance, inorganic salts such as hydroxides or carbonates of monovalent metals or divalent metals; ammonia; organic amines are suitable. Further, after the reaction is completed, the concentration can be adjusted if necessary. The pH is adjusted after the copolymerization reaction is carried out using the corresponding unsaturated carboxylic acid ester monomer without using the unsaturated carboxylic acid monomer (b) as a monomer component. By partially hydrolyzing the ester bond portion of the structural unit derived from the unsaturated carboxylic acid ester monomer, the structural unit (II) derived from the unsaturated carboxylic acid monomer (b) is overlapped. It can also be introduced into coalescence.

The cement admixture of the present invention may contain non-polymerizable (poly) alkylene glycol (P) having no alkenyl group in addition to the polymer (A) or polymer (B) which is an essential component. .

In the present invention, in addition to the monomer (a) which is the main product in the production of the unsaturated (poly) alkylene glycol ether monomer (a) described above, (poly) alkylene glycol which is a by-product The following polymerization reaction can be carried out using a composition that also contains (P) as a raw material. As a result, in addition to the essential component polymer (A) or polymer (B), non-polymerizable that does not have an alkenyl group It becomes a cement admixture which also contains (poly) alkylene glycol (P). In addition, in the monomer composition containing the monomer (a) and the (poly) alkylene glycol (P) used for the polymerization reaction, the (poly) alkylene glycol (P) with respect to the monomer (a) The proportion is suitably 0.5% by mass or more. In order to reduce the proportion of (poly) alkylene glycol (P) produced as a by-product, in various raw materials used in the addition reaction of alkylene oxides such as unsaturated alcohols, or on the wall surface or gas phase of the reactor It takes a long time for the dehydration process for removing impurities having active hydrogen such as water from the reaction system, or for removing (poly) alkylene glycol (P) after completion of the addition reaction of alkylene oxide. Since a purification process is required and the productivity of the monomer (a) is lowered, it is not preferable. On the other hand, when the ratio of (poly) alkylene glycol (P) to monomer (a) exceeds 100% by mass, the monomer concentration during the polymerization reaction decreases, and polymer (A) or This is not preferable because the molecular weight of the union (B) decreases. Therefore, the lower limit of the ratio is preferably 1% by mass or more, more preferably 1.5% by mass or more, further preferably 2% by mass or more, and particularly preferably 2.5% by mass or more. On the other hand, the upper limit of the ratio is preferably 80% by mass or less, more preferably 50% by mass or less, still more preferably 30% by mass or less, and particularly preferably 20% by mass or less.

Further, the polymer (A) depends on the proportion of the unsaturated (poly) alkylene glycol ether monomer (a) used in the monomer component used in the polymerization reaction and the polymerization rate (reaction rate) of each monomer. ) Or the ratio of (poly) alkylene glycol (P) to polymer (B) varies, but the lower limit of the ratio is preferably 1% by mass or more, more preferably 1.5% by mass or more, and 2% by mass. The above is more preferable and 2.5% by mass or more is particularly preferable. On the other hand, the upper limit of the ratio is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and particularly preferably 20% by mass or less.
In addition, after completion | finish of the manufacturing process of unsaturated (poly) alkylene glycol ether monomer (a), the polymer by the fall of the monomer density | concentration at the time of a polymerization reaction is used for (poly) alkylene glycol (P) synthesize | combined separately. (A) or the polymer (B) may be blended so as to be within the above-mentioned ratio range that does not cause a decrease in the molecular weight. Further, (poly) alkylene glycol (P) synthesized separately after the completion of the polymerization reaction You may mix | blend. The (poly) alkylene glycol (P) to be blended may have the same structure as or different from the (poly) alkylene glycol (P) contained as a by-product. Therefore, the cement admixture of the present invention may contain two or more kinds of (poly) alkylene glycol (P).

The number of carbon atoms of the oxyalkylene group of the (poly) alkylene glycol (P) is a by-product when the (poly) alkylene glycol (P) is produced in the production of the unsaturated (poly) alkylene glycol ether monomer (a). When it is a product, it corresponds to the alkylene oxide used for the production of the monomer (a). On the other hand, when (poly) alkylene glycol (P) synthesized separately is blended, 2 to 18 is suitable, but 2 to 8 is preferred, and 2 to 4 is more preferred. Further, any two or more alkylene oxide adducts selected from ethylene oxide, propylene oxide, butylene oxide, styrene oxide and the like can be used in any of random addition, block addition, alternating addition, and the like. In order to secure a balance between hydrophilicity and hydrophobicity, it is preferable to include an oxyethylene group as an essential component in the oxyalkylene group, more preferably 50 mol% or more is an oxyethylene group, and 90 mol% or more. More preferably, it is an oxyethylene group.

The terminal group of the (poly) alkylene glycol (P) is when the (poly) alkylene glycol (P) is a by-product in the production of the unsaturated (poly) alkylene glycol ether monomer (a) Depending on the production method of the monomer (a), it is usually a hydrogen atom or an alkyl group having 1 to 18 carbon atoms in accordance with R in the general formula (1). Specific examples thereof are the same as R in the general formula (1), but usually one or both ends are hydrogen atoms. On the other hand, when the separately synthesized (poly) alkylene glycol (P) is blended, it does not depend on the production method of the monomer (a), but is similar to R in the above general formula (1) as a hydrogen atom or carbon. It is preferably an alkyl group having 1 to 18 atoms. In addition, as (poly) alkylene glycol (P) having both ends as hydrogen atoms starting from water, specifically, (poly) ethylene glycol, (poly) propylene glycol, (poly) ethylene (poly) Propylene glycol, (poly) ethylene (poly) butylene glycol, and the like can be mentioned, but since it is preferably water-soluble, (poly) ethylene glycol or (poly) ethylene (poly) propylene glycol is more preferred, and (poly) More preferred is ethylene glycol.

As the weight average molecular weight of the (poly) alkylene glycol (P) (in terms of polyethylene glycol by GPC), when the (poly) alkylene glycol (P) is a by-product in the production of the monomer (a) Although depending on the production conditions of the monomer (a), particularly the average number of moles m added of the oxyalkylene group, it is usually in the range of 50 to 50,000. Moreover, when mix | blending (poly) alkylene glycol (P) synthesize | combined separately, the range of 100-200000 is preferable, The range of 500-100000 is more preferable, The range of 1000-50000 is still more preferable.

The cement admixture of the present invention may contain an unsaturated (poly) alkylene glycol ether monomer (a) in addition to the polymer (A) and the polymer (B) which are essential components.

Since the unsaturated (poly) alkylene glycol ether monomer (a) is not homopolymerizable, it tends to remain after the polymerization reaction, and in order to reduce the content below the detection limit, It is necessary to increase or add an initiator later in the polymerization, or to increase the polymerization reaction time. However, it is difficult to suppress the molecular weight or the productivity is lowered. It is preferable to stop the polymerization reaction at the time when is remaining. On the other hand, a hot water bath in which the ratio of the monomer (a) to the polymer (A) or the polymer (B) exceeds 100% by mass is not preferable because the dispersibility with respect to cement is lowered. Accordingly, the lower limit of the ratio of the monomer (a) to the polymer (A) or the polymer (B) is suitably 0.5% by mass or more, preferably 1% by mass or more, and 2% by mass or more. Is more preferably 3% by mass or more, and particularly preferably 4% by mass or more. On the other hand, the upper limit of the ratio is suitably 100% by mass or less, preferably 90% by mass or less, more preferably 80% by mass or less, still more preferably 70% by mass or less, and particularly preferably 60% by mass or less. In addition, even if it complete | finishes the superposition | polymerization process of a polymer (A) or a polymer (B), even if it mix | blends a monomer (a) so that it may become in the range of the said ratio which does not cause the fall of the dispersibility with respect to a cement. The monomer (a) to be blended may be the same as or different from the monomer (a) remaining as an unreacted monomer.

A preferred method for producing the polymer (A) and the polymer (B) of the present invention includes an alkenyl group in addition to the monomer component containing the unsaturated (poly) alkylene glycol ether monomer (a) as an essential component. This is a method in which a polymerization reaction is performed using as a raw material a composition that also contains a non-polymerizable (poly) alkylene glycol (P), and the polymerization reaction is stopped when the monomer (a) remains. . By this method, it is possible to easily obtain the cement admixture of the present invention including the monomer (a) and the (poly) alkylene glycol (P) in addition to the polymer (A) and the polymer (B). it can. The composition containing the unsaturated (poly) alkylene glycol ether monomer (a) and the non-polymerizable (poly) alkylene glycol (P) not having an alkenyl group is the above-mentioned unsaturated (poly) alkylene glycol. It can be obtained by a method for producing the ether monomer (a).

The cement admixture of the present invention contains two types of polymers, polymer (A) and polymer (B), as essential components, but each polymer is directly used as a main component of the cement admixture in the form of an aqueous solution. May be used, or neutralized with a hydroxide of a divalent metal such as calcium or magnesium to form a polyvalent metal salt and then dried, or supported on an inorganic powder such as silica-based fine powder You may use it by pulverizing by making it dry.

The cement admixture of the present invention can be used for various hydraulic materials, that is, hydraulic materials other than cement, such as cement and gypsum. As a hydraulic composition containing 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 necessary, cement paste Mortar, concrete and plaster are preferred.

Among the hydraulic compositions, a cement composition using cement as a hydraulic material is the most common, and such cement composition includes the cement admixture of the present invention, cement, and water as essential components. It will be. Such a cement composition is also one aspect of the present invention.

Examples of the cement used in the cement composition of the present invention include Portland cement (ordinary, early strength, ultra-early strength, moderate heat, sulfate-resistant and their respective low alkali types), 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 exothermic cement (low exothermic blast furnace cement) , Fly ash mixed low heat generation type blast furnace cement, belite high content cement), 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) In addition, blast furnace slag, fly Mesh, cinder ash, clinker ash, husk ash, silica fume, silica powder, a fine powder and gypsum limestone powder they may be added. 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 aggregate such as can be used.

In the cement composition of the present invention, the unit water amount per 1 m ³ , the total use amount of cement, fly ash and slag (hereinafter also referred to as “B”), and the water / B ratio are as follows: Preferably, the unit water amount is 100 to 185 kg / m ³ , the used B amount is 250 to 800 kg / m ³ , and the water / B ratio (mass ratio) is 0.1 to 0.7, and more preferably, the unit water amount is 120 to 175 kg. / M ³ , used B amount 270 to 800 kg / m ³ , water / B ratio (mass ratio) = 0.2 to 0.65, can be used widely from poor blending to rich blending, and has a large unit B amount It is effective for both high-strength concrete and poor blended concrete having a unit B amount of 300 kg / m ³ or less.

The blending ratio of the cement admixture of the present invention in the cement composition of the present invention is, for example, 0 for the total mass of cement, fly ash and slag when used for mortar or concrete using hydraulic cement. It is preferable to set it as 0.01 to 5.0%. By this addition, various preferable effects such as reduction in unit water amount, increase in strength, and improvement in durability are brought about. If the above blending ratio is less than 0.01%, the performance may be insufficient. On the other hand, even if a large amount exceeding 5.0% is used, the effect is practically peaked and disadvantageous in terms of economy. There is a risk of becoming. More preferably 0.02% or more, and 2.0% or less, still more preferably 0.05% or more, and 1.0% or less. do it. Moreover, as a suitable range of a mixture ratio, More preferably, it is 0.02-2.0%, More preferably, it is 0.05-1.0%.

The cement admixture of the present invention can be used in combination with those conventionally used as cement dispersants, and can also be used in combination with a plurality of conventionally used cement dispersants. When a conventional cement dispersant is used, the blending mass ratio between the cement admixture of the present invention and the cement dispersant is unambiguous due to differences in the type, blending, and test conditions of the cement dispersant. Although it is not decided, 1-99 / 99-1 are preferable, 5-95 / 95-5 are more preferable, and 10-90 / 90-10 are still more preferable.

The cement composition of the present invention is also effective for ready-mixed concrete, concrete for concrete secondary products (precast concrete), centrifugal molded concrete, vibration compacted concrete, steam-cured concrete, shotcrete, etc. High fluidity is required for fluidized 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, etc. It is also effective for mortar and concrete.

Furthermore, the cement composition of this invention can contain what was conventionally used as a cement additive (material) like the following (1)-(20).
(1) Water-soluble polymer material: polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), unsaturated carboxylic acid polymer such as sodium salt of acrylic acid / maleic acid copolymer; methylcellulose Nonionic cellulose ethers such as ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, hydroxypropyl cellulose; alkylated or hydroxyalkylated derivatives of polysaccharides such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, etc. Hydrophobic substituents in which some or all of the hydroxyl atoms have a hydrocarbon chain having 8 to 40 carbon atoms as a partial structure, sulfonic acid groups or Polysaccharide derivatives substituted with an ionic hydrophilic substituent containing such a salt as a partial structure; yeast glucan, xanthan gum, β-1.3 glucans (both linear and branched) For example, polysaccharides produced by microbial fermentation such as curdlan, paramylon, pachyman, scleroglucan, laminaran, etc.); polyacrylamide; polyvinyl alcohol; starch; starch phosphate ester; sodium alginate; gelatin; Copolymers of acrylic acid having groups and quaternary compounds thereof.

(2) Polymer emulsion: Copolymers of various vinyl monomers such as alkyl (meth) acrylate.
(3) retarder: oxycarboxylic such as gluconic acid, glucoheptonic acid, arabonic acid, malic acid or citric acid, and inorganic salts or organic salts thereof such as sodium, potassium, calcium, magnesium, ammonium, triethanolamine, etc. Acids: monosaccharides such as glucose, fructose, galactose, saccharose, xylose, apiose, ribose, isomerized sugar, oligosaccharides such as disaccharide and trisaccharide, oligosaccharides such as dextrin, polysaccharides such as dextran, etc. Sugars such as molasses; sugar alcohols such as sorbitol; magnesium silicofluoride; phosphoric acid and its salts or borate esters; aminocarboxylic acids and salts thereof; alkali-soluble proteins; humic acid; tannic acid; Polyhydric alcohols such as glycerin; aminotri (methylenephos Acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) and their alkali metal salts, alkaline earth metal salts and other phosphonic acids and their derivatives etc.

(4) Early strengthening agents / accelerators: soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide and calcium iodide; chlorides such as iron chloride and magnesium chloride; sulfates; potassium hydroxide; Sodium hydroxide; carbonate; thiosulfate; formate such as formic acid and calcium formate; alkanolamine; alumina cement; calcium aluminate silicate.
(5) Mineral oil-based antifoaming 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 oxyethyleneoxypropylene adducts to higher alcohols having 12 to 14 carbon atoms; (poly) oxyalkylenes such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether (Alkyl) aryl ethers; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1- Spotted Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohol such as -3-ol; (poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate; polyoxyethylene sorbitan (Poly) oxyalkylene sorbitan fatty acid esters such as monolaurate and polyoxyethylene sorbitan trioleate; (poly) oxyalkylene alkyl (aryl) such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecylphenol ether sulfate ) Ether sulfate esters; (Poly) oxy such as (poly) oxyethylene stearyl phosphate Ruki alkylene alkyl phosphate 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 or alkoxy 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 nonionics Surfactant; 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 ether and the like.
(20) Expansion material: Ettlingite, coal, etc.

Other conventionally used cement additives (materials) include cement wetting agents, thickeners, separation reducers, flocculants, drying shrinkage reducers, strength enhancers, self-leveling agents, rust inhibitors, and coloring. Agents, fungicides and the like. The above-described conventional cement additives (materials) can be used in combination.

In the cement composition of the present invention, the following 1) to 4) are particularly preferable embodiments for components other than cement and water.
1) (1) A combination comprising two components of the cement admixture of the present invention and (2) an oxyalkylene-based antifoaming agent. The blending mass ratio of the oxyalkylene antifoaming agent (2) is preferably 0.01 to 10% by mass with respect to the cement admixture (1).

2) A combination that essentially comprises two components, (1) the cement admixture of the present invention and (2) a material separation reducing agent. As a material separation reducing agent, various thickeners such as nonionic cellulose ethers, a hydrophobic substituent composed 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 having a polyoxyalkylene chain having 2 to 300 moles added can be used. The blending mass ratio of the cement admixture (1) and the material separation reducing agent (2) is preferably 10/90 to 99.99 / 0.01, and 50/50 to 99.9 / 0.0. 1 is more preferable. A cement composition comprising this combination is suitable as high fluidity concrete, self-filling concrete, and self-leveling material.

3) (1) The cement admixture of the present invention, and (2) a combination comprising two retarders as essential components. As the retarder, oxycarboxylic acids such as gluconic acid (salt) and citric acid (salt), sugars such as glucose, sugar alcohols such as sorbitol, phosphonic acids such as aminotri (methylenephosphonic acid), and the like can be used. . The blending mass ratio of the cement admixture (1) and the retarder (2) is preferably 50/50 to 99.9 / 0.1, more preferably 70/30 to 99/1.

4) (1) The cement admixture of the present invention, and (2) a combination which essentially comprises two components of accelerator. As the accelerator, soluble calcium salts such as calcium chloride, calcium nitrite and calcium nitrate, chlorides such as iron chloride and magnesium chloride, formates such as thiosulfate, formic acid and calcium formate, and the like can be used. The blending mass ratio of the cement admixture (1) and the accelerator (2) is preferably 10/90 to 99.9 / 0.1, and more preferably 20/80 to 99/1.

The cement admixture of the present invention has the above-described configuration, and has a combination of excellent water reduction performance and slump retention performance even in a cement composition containing fly ash, slag, etc. Cement 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%”.

In the following examples and comparative examples, measurement and evaluation were performed as follows.
<Method for measuring solid content (nonvolatile content) of polymer>
About 0.5 g of a sample was weighed on an aluminum dish, diluted with about 1 g of water, and spread evenly. The sample was dried at 130 ° C. for 1 hour in a nitrogen atmosphere, allowed to cool in a desiccator, and then weighed after drying. The solid content (nonvolatile content) concentration was calculated from the difference in mass before and after drying.

<Weight average molecular weight (Mw) measurement conditions>
The weight average molecular weight of the polymer was measured under the following measurement conditions by gel permeation chromatography (GPC) in terms of polyethylene glycol.
Measurement condition apparatus: Waters Alliance (2695), manufactured by Waters
Analysis software: Waters, Empor professional + GPC option column: Tosoh, TSK guard column SWXL + TSKgel G4000SWXL + G3000SWXL + G2000SWXL
Detector: differential refractometer (RI) detector (Waters 2414, manufactured by Waters)
Eluent: 115.6 g of sodium acetate trihydrate dissolved in a mixed solvent of 10,999 g of water and 6,001 g of acetonitrile, and further adjusted to pH 6.0 with acetic acid. Standard substance for preparing a calibration curve: polyethylene glycol [peak Top molecular weight (Mp) 300000, 200000, 107000, 50000, 27700, 11840, 6450, 1470]
Calibration curve: Created by cubic equation based on Mp value and elution time of polyethylene glycol Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Measurement time: 45 minutes Sample solution injection amount: 100 μL (eluent preparation solution with sample concentration of 0.5 wt%)

<Measurement of reaction rate of raw material monomer>
Quantification of the unsaturated (poly) alkylene glycol ether monomer (a) was performed by high performance liquid chromatography under the following conditions.
Measurement condition apparatus: Waters Alliance (2695), manufactured by Waters
Analysis software: Waters, Empor professional use Column: Waters, Atlantis dC18 5 μm Guard Column 2PK (4.6 mm × 20 mm) + Waters, Atlantis dC18 5 μm (4.6 mm × 250 mm)
Detector: differential refractometer (RI) detector (Waters, Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters, Waters 2996)
Eluent: 4.5 g of sodium acetate trihydrate in a mixed solvent of 10800 g of water and 7200 g of acetonitrile, and a solution flow rate adjusted to pH 4.0-4.5 in which 63 g of acetic acid was dissolved: 1.0 mL / min
Column temperature: 40 ° C
Measurement time: 30 minutes Sample solution injection amount: 100 μL (eluent preparation solution with sample concentration of 1.0 wt%)

The unsaturated carboxylic acid monomer (b) was quantified by high performance liquid chromatography under the following conditions.
Measurement condition apparatus: Waters Alliance (2695), manufactured by Waters
Analysis software: manufactured by Waters, Emper professional use column: manufactured by Shiseido Co., Ltd., CAPCELL PAK AQ C18 3 μm (4.6 mm × 100 mm)
Detector: differential refractometer (RI) detector (Waters, Waters 2414), multi-wavelength visible ultraviolet (PDA) detector (Waters, Waters 2996)
Eluent: Solution flow rate adjusted to pH 4.0-4.5 in which 51 g of sodium acetate trihydrate and 90 g of acetic acid were dissolved in a mixed solvent of 18480 g of water and 380 g of acetonitrile: 1.0 mL / min
Column temperature: 40 ° C
Measurement time: 60 minutes Sample solution injection amount: 100 μL (eluent preparation solution with sample concentration of 1.0 wt%)

[Preparation of polymer (A) and polymer (B)]
<Production Example 1>
Unsaturated polyalkylene glycol ether in which an average of 50 mol of ethylene oxide (EO) is added to 308.1 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. (IPN-50) 252.1 g was charged and the temperature was raised to 60 ° C., and then 10.3 g of a 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 11.8 g of acrylic acid with 2.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 756.2 g of IPN-50 in 324.1 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 0.5 g of L-ascorbic acid and 3.5 g of 3-mercaptopropionic acid were dissolved in 330.6 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-1) having a weight average molecular weight (Mw) of 12000 was obtained. An aqueous solution was obtained. The nonvolatile content was 45.2%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

Here, the above-mentioned active ingredient concentration is solid in an active ingredient ratio calculated by using the respective reaction rates of the unsaturated carboxylic acid monomer and the unsaturated polyalkylene glycol ether monomer that are polymerizable monomers. It is a value multiplied by a minute and is defined by the following formula.
Active ingredient concentration = [(a + b) / (A + B)] × NV
Abbreviations in the above formula are as follows.
A: Amount of unsaturated carboxylic acid monomer used B: Amount of unsaturated polyalkylene glycol ether monomer used a: Amount of unsaturated carboxylic acid monomer used x reaction rate b: Unsaturated polyalkylene Amount of glycol ether monomer used x reaction rate NV: solid content

For example, in Production Example 1, the unsaturated carboxylic acid monomer corresponds to the sodium salt of acrylic acid, and the unsaturated polyalkylene glycol ether monomer corresponds to IPN-50.
The weight composition ratio of acrylic acid sodium salt / IPN-50 as the raw material monomer is 1.5 / 98.5, the reaction rate of sodium salt of acrylic acid is 99.9%, the reaction rate of IPN-50 Is 32.5%, so 1.5% × 0.999 + 98.5% × 0.325 = 33.5% is the active ingredient ratio with respect to the total amount of raw material monomers. Therefore, the active ingredient concentration is non-volatile content 45.2% × 0.335 = 15.1%.
In Production Examples 1 to 4 , 6 to 8 , 10 to 21 , 23 , 24 , and 26 to 29, acrylic acid or maleic acid was used as the unsaturated carboxylic acid monomer, but a copolymer was produced. Thereafter, since neutralization with sodium hydroxide, for convenience, the weight composition ratio, reaction rate, and copolymer composition ratio of the raw material monomer are converted into a sodium salt of acrylic acid or a sodium salt of maleic acid. It shows in Table 2.

<Production Example 2>
Unsaturated polyalkylene glycol ether with an average of 50 moles of ethylene oxide (EO) added to 304.5 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. (IPN-50) 249.1 g was charged and the temperature was raised to 60 ° C., and then 26.0 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 23.6 g of acrylic acid with 5.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 747.3 g of IPN-50 in 320.3 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 1.3 g of L-ascorbic acid and 3.2 g of 3-mercaptopropionic acid were dissolved in 318.8 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-2) having a weight average molecular weight (Mw) of 17500 is An aqueous solution was obtained. The nonvolatile content was 45.3%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 3>
Unsaturated polyalkylene glycol ether in which 302.0 g of ion-exchanged water and isoprenol were added with an average of 50 moles of ethylene oxide (EO) to a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. (IPN-50) 247.1 g was charged and heated to 60 ° C., and then 29.6 g of 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 31.6 g of acrylic acid with 7.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 741.3 g of IPN-50 in 317.7 g of ion-exchanged water were dropped over 4 hours. At the same time, an aqueous solution in which 1.5 g of L-ascorbic acid and 3.3 g of 3-mercaptopropionic acid were dissolved in 317.9 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-3) having a weight average molecular weight (Mw) of 22500 is obtained. An aqueous solution was obtained. The nonvolatile content was 45.9%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 4>
Unsaturated polyalkylene glycol ether with an average of 50 moles of ethylene oxide (EO) added to 297.1 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. (IPN-50) 243.1 g was charged and heated to 60 ° C., and then 36.9 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 47.6 g of acrylic acid with 11.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 729.3 g of IPN-50 in 312.6 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 1.9 g of L-ascorbic acid and 4.2 g of 3-mercaptopropionic acid were dissolved in 315.4 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-4) having a weight average molecular weight (Mw) of 21000 is obtained. An aqueous solution was obtained. The nonvolatile content was 45.6%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 6>
Unsaturated polyalkylene obtained by adding an average of 25 moles of ethylene oxide (EO) to 300.1 g of ion-exchanged water and methallyl alcohol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. After charging 245.5 g of glycol ether (MLA-25) and heating to 60 ° C., 46.0 g of 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 37.9 g of acrylic acid with 9.5 g of ion-exchanged water and an aqueous solution obtained by dissolving 736.5 g of MLA-25 in 315.7 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 2.4 g of L-ascorbic acid and 7.9 g of 3-mercaptopropionic acid were dissolved in 298.5 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-6) having a weight average molecular weight (Mw) of 13000 was obtained. An aqueous solution was obtained. The nonvolatile content was 45.7%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 7>
Unsaturated polyalkylene glycol ether with an average of 25 moles of ethylene oxide (EO) added to 299.6 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. (IPN-25) 245.1 g was charged and heated to 60 ° C., and then 46.7 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 39.5 g of acrylic acid with 9.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 735.3 g of IPN-25 in 315.1 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 2.4 g of L-ascorbic acid and 6.6 g of 3-mercaptopropionic acid were dissolved in 299.7 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-7) having a weight average molecular weight (Mw) of 20000. An aqueous solution was obtained. The nonvolatile content was 45.6%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 8>
Unsaturated polyalkylene obtained by adding an average of 25 moles of ethylene oxide (EO) to 304.0 g of ion-exchanged water and methallyl alcohol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. After charging 248.7 g of glycol ether (MLA-25) and heating to 60 ° C., 40.4 g of 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 25.2 g of acrylic acid with 6.3 g of ion-exchanged water and an aqueous solution prepared by dissolving 746.1 g of MLA-25 in 319.8 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 2.1 g of L-ascorbic acid and 2.9 g of 3-mercaptopropionic acid were dissolved in 304.6 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-8) having a weight average molecular weight (Mw) of 34000 was obtained. An aqueous solution was obtained. The nonvolatile content was 45.5%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 10>
Unsaturated polyalkylene glycol ether with an average of 75 moles of ethylene oxide (EO) added to 305.7 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. (IPN-75) 250.1 g was charged and the temperature was raised to 60 ° C., and then 9.3 g of a 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 19.7 g of acrylic acid with 4.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 750.3 g of IPN-75 in 321.5 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 0.5 g of L-ascorbic acid and 1.6 g of 3-mercaptopropionic acid were dissolved in 336.5 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature not higher than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-10) having a weight average molecular weight (Mw) of 19,500 was obtained. An aqueous solution was obtained. The nonvolatile content was 45.8%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 11>
Unsaturated polyalkylene glycol ether in which an average of 75 moles of ethylene oxide (EO) is added to 302.5 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. (IPN-75) 247.5 g was charged and the temperature was raised to 60 ° C., and then 14.1 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution in which 30.0 g of acrylic acid was diluted with 7.5 g of ion-exchanged water and an aqueous solution in which 742.5 g of IPN-75 were dissolved in 318.2 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 0.7 g of L-ascorbic acid and 2.2 g of 3-mercaptopropionic acid were dissolved in 334.7 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature not higher than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-11) having a weight average molecular weight (Mw) of 23,500 was obtained. An aqueous solution was obtained. The nonvolatile content was 45.2%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 12>
Unsaturated polyalkylene in which an average of 75 moles of ethylene oxide (EO) is added to 299.6 g of ion-exchanged water and methallyl alcohol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. After charging 245.1 g of glycol ether (MLA-75) and raising the temperature to 60 ° C., 18.7 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 39.5 g of acrylic acid with 9.9 g of ion-exchanged water and an aqueous solution prepared by dissolving 735.3 g of MLA-75 in 315.1 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 1.0 g of L-ascorbic acid and 3.0 g of 3-mercaptopropionic acid were dissolved in 332.8 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-12) having a weight average molecular weight (Mw) of 23500 is obtained. An aqueous solution was obtained. The nonvolatile content was 45.7%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 13>
Unsaturated polyalkylene glycol ether with an average of 50 mol of ethylene oxide (EO) added to 309.3 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. (IPN-50) 253.0 g was charged and the temperature was raised to 60 ° C., and then 18.7 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 7.8 g of acrylic acid with 2.0 g of ion-exchanged water and an aqueous solution obtained by dissolving 759.1 g of IPN-50 in 325.3 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 1.0 g of L-ascorbic acid and 3.9 g of 3-mercaptopropionic acid was dissolved in 319.8 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-13) having a weight average molecular weight (Mw) of 11000 is obtained. An aqueous solution was obtained. The nonvolatile content was 45.4%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 14>
Unsaturated polyalkylene glycol ether with an average of 50 moles of ethylene oxide (EO) added to 304.5 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. (IPN-50) 249.1 g was charged and the temperature was raised to 60 ° C., and then 26.0 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 23.6 g of acrylic acid with 5.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 747.3 g of IPN-50 in 320.3 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 1.3 g of L-ascorbic acid and 5.8 g of 3-mercaptopropionic acid were dissolved in 316.3 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-14) having a weight average molecular weight (Mw) of 7500 An aqueous solution was obtained. The nonvolatile content was 45.6%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 15>
Unsaturated polyalkylene glycol ether in which an average of 50 moles of ethylene oxide (EO) is added to 302.5 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. (IPN-50) 247.5 g was charged and the temperature was raised to 60 ° C., and then 23.5 g of a 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 29.9 g of maleic acid with 50.0 g of ion-exchanged water and an aqueous solution obtained by dissolving 742.6 g of IPN-50 in 318.2 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 1.2 g of L-ascorbic acid and 4.0 g of 3-mercaptopropionic acid were dissolved in 283.5 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (A-15) having a weight average molecular weight (Mw) of 15000 is obtained. An aqueous solution was obtained. The nonvolatile content was 45.2%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 16>
Unsaturated polyalkylene glycol ether with an average of 50 mol of ethylene oxide (EO) added to 294.7 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. (IPN-50) 241.1 g was charged and the temperature was raised to 60 ° C., and then 20.3 g of a 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 55.6 g of acrylic acid with 13.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 723.3 g of IPN-50 in 310.0 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 3.3 g of 3-mercaptopropionic acid was dissolved in 167.3 g of ion-exchanged water was added dropwise over 4.5 hours. At the same time, 62.0 g of an aqueous solution dissolved in 1.1 g of L-ascorbic acid in 169.5 g of ion-exchanged water was added dropwise over a total of 4.5 hours in the first half hour and 68.5 g in the second half hour. . After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and ion-exchanged water for adjusting the concentration is added to obtain a polycarboxylic acid having a weight average molecular weight (Mw) of 22,000. An aqueous solution of the acid copolymer (B-1) was obtained. The nonvolatile content was 45.7%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 17>
Unsaturated polyalkylene glycol ether with an average of 50 moles of ethylene oxide (EO) added to 293.4 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. (IPN-50) 240.1 g was charged and the temperature was raised to 60 ° C., and then 21.2 g of a 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 59.7 g of acrylic acid with 14.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 720.3 g of IPN-50 in 308.7 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 2.4 g of 3-mercaptopropionic acid was dissolved in 168.5 g of ion-exchanged water was added dropwise over 4.5 hours. At the same time, 83.7 g of an aqueous solution dissolved in 1.1 g of L-ascorbic acid in 169.8 g of ion-exchanged water was added dropwise over a total of 4.5 hours in the first 2 hours and 87.2 g in the second 3.5 hours. . After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and ion-exchanged water for adjusting the concentration is added to obtain a polycarboxylic acid having a weight average molecular weight (Mw) of 30000. An aqueous solution of the acid copolymer (B-2) was obtained. The nonvolatile content was 45.6%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 18>
Unsaturated polyalkylene glycol ether in which 282.1 g of ion-exchanged water and isoprenol were added with an average of 50 moles of ethylene oxide (EO) to a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. After charging 230.9 g of (IPN-50) and raising the temperature to 60 ° C., 59.3 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 96.5 g of acrylic acid with 24.1 g of ion-exchanged water and an aqueous solution obtained by dissolving 692.6 g of IPN-50 in 296.8 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 3.5 g of 3-mercaptopropionic acid was dissolved in 155.7 g of ion-exchanged water was added dropwise over 4.5 hours. At the same time, 19.2 g of an aqueous solution dissolved in 3.1 g of L-ascorbic acid in 155.3 g of ion-exchanged water was added dropwise over a total of 4.5 hours in the first 30 minutes and 139.6 g in the latter 4 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and ion-exchanged water for adjusting the concentration is added to obtain a polycarboxylic acid having a weight average molecular weight (Mw) of 34500. An aqueous solution of the acid copolymer (B-3) was obtained. The nonvolatile content was 45.2%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 19>
Unsaturated polyalkylene glycol ether in which an average of 50 moles of ethylene oxide (EO) is added to 274.5 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. (IPN-50) 224.6 g was charged and heated to 60 ° C., and then 70.7 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 121.5 g of acrylic acid with 30.4 g of ion-exchanged water and an aqueous solution prepared by dissolving 673.9 g of IPN-50 in 288.8 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 3.7 g of L-ascorbic acid and 3.5 g of 3-mercaptopropionic acid were dissolved in 308.4 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (B-4) having a weight average molecular weight (Mw) of 40000. An aqueous solution was obtained. The nonvolatile content was 45.3%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 20>
Unsaturated polyalkylene obtained by adding an average of 25 moles of ethylene oxide (EO) to 294.7 g of ion-exchanged water and methallyl alcohol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. After charging 241.1 g of glycol ether (MLA-25) and raising the temperature to 60 ° C., 20.3 g of 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 55.6 g of acrylic acid with 13.9 g of ion-exchanged water and an aqueous solution prepared by dissolving 723.3 g of MLA-25 in 310.0 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 3.3 g of 3-mercaptopropionic acid was dissolved in 167.3 g of ion-exchanged water was added dropwise over 4.5 hours. At the same time, 62.0 g of an aqueous solution dissolved in 1.1 g of L-ascorbic acid in 169.5 g of ion-exchanged water was added dropwise over a total of 4.5 hours in the first half hour and 68.5 g in the second half hour. . After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, ion-exchanged water for adjusting the concentration is added, and a polycarboxylic acid having a weight average molecular weight (Mw) of 25000 is obtained. An aqueous solution of the acid copolymer (B-5) was obtained. The nonvolatile content was 45.8%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 21>
Unsaturated polyalkylene glycol ether with an average of 25 mol of ethylene oxide (EO) added to 287.2 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introduction tube and a reflux condenser. (IPN-25) 235.0 g was charged and heated to 60 ° C., and then 64.7 g of 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 80.0 g of acrylic acid with 20.0 g of ion-exchanged water and an aqueous solution obtained by dissolving 705.0 g of IPN-25 in 302.1 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 3.4 g of L-ascorbic acid and 5.9 g of 3-mercaptopropionic acid were dissolved in 296.7 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and a polycarboxylic acid copolymer (B-6) having a weight average molecular weight (Mw) of 25000 was obtained. An aqueous solution was obtained. The nonvolatile content was 45.1%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 23>
Unsaturated polyalkylene glycol ether in which 258.4 g of ion-exchanged water and isoprenol were added with an average of 25 moles of ethylene oxide (EO) in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. (IPN-25) 227.8 g was charged and the temperature was raised to 60 ° C., and then 77.5 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 109.0 g of acrylic acid with 27.2 g of ion-exchanged water and an aqueous solution obtained by dissolving 683.3 g of IPN-25 in 292.8 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 4.0 g of L-ascorbic acid and 3.9 g of 3-mercaptopropionic acid were dissolved in 296.1 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and a polycarboxylic acid copolymer (B-8) having a weight average molecular weight (Mw) of 45000 An aqueous solution was obtained. The nonvolatile content was 45.7%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 24>
Unsaturated polyalkylene obtained by adding an average of 75 moles of ethylene oxide (EO) to 291.0 g of ion-exchanged water and methallyl alcohol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. After charging 238.1 g of glycol ether (MLA-75) and raising the temperature to 60 ° C., 32.0 g of 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 67.8 g of acrylic acid with 16.9 g of ion-exchanged water and an aqueous solution prepared by dissolving 714.2 g of MLA-75 in 306.1 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 1.7 g of L-ascorbic acid and 3.3 g of 3-mercaptopropionic acid were dissolved in 329.1 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (B-9) having a weight average molecular weight (Mw) of 19,500 was obtained. An aqueous solution was obtained. The nonvolatile content was 45.8. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 26>
Unsaturated polyalkylene glycol ether in which an average of 75 moles of ethylene oxide (EO) was added to 291.0 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. (IPN-75) 238.1 g was charged and the temperature was raised to 60 ° C., and then 32.0 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 67.8 g of acrylic acid with 16.9 g of ion-exchanged water and an aqueous solution obtained by dissolving 714.2 g of IPN-75 in 306.1 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 1.7 g of L-ascorbic acid and 2.3 g of 3-mercaptopropionic acid were dissolved in 330.1 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and a polycarboxylic acid copolymer (B-11) having a weight average molecular weight (Mw) of 35000 was obtained. An aqueous solution was obtained. The nonvolatile content was 45.8%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 27>
Unsaturated polyalkylene in which an average of 75 moles of ethylene oxide (EO) is added to 275.8 g of ion-exchanged water and methallyl alcohol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. After charging 225.7 g of glycol ether (MLA-75) and raising the temperature to 60 ° C., 55.4 g of 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution in which 117.3 g of acrylic acid was diluted with 29.3 g of ion-exchanged water and an aqueous solution in which 677.0 g of MLA-75 was dissolved in 290.2 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 2.9 g of L-ascorbic acid and 3.4 g of 3-mercaptopropionic acid were dissolved in 323.1 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution is neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (B-12) having a weight average molecular weight (Mw) of 41500 is obtained. An aqueous solution was obtained. The nonvolatile content was 45.6%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 28>
Unsaturated polyalkylene glycol ether in which an average of 50 moles of ethylene oxide (EO) is added to 274.5 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. (IPN-50) 224.6 g was charged and heated to 60 ° C., and then 70.7 g of a 4% hydrogen peroxide aqueous solution was added thereto. Next, an aqueous solution obtained by diluting 121.5 g of acrylic acid with 30.4 g of ion-exchanged water and an aqueous solution prepared by dissolving 673.9 g of IPN-50 in 288.8 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 3.7 g of L-ascorbic acid and 2.4 g of 3-mercaptopropionic acid were dissolved in 309.5 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (B-13) having a weight average molecular weight (Mw) of 60000 An aqueous solution was obtained. The nonvolatile content was 45.5%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

<Production Example 29>
Unsaturated polyalkylene glycol ether in which an average of 50 mol of ethylene oxide (EO) is added to 265.5 g of ion-exchanged water and isoprenol in a glass reaction vessel equipped with a thermometer, a sales expansion machine, a dropping funnel, a nitrogen introducing tube and a reflux condenser. (IPN-50) 217.2 g was charged and the temperature was raised to 60 ° C., and then 84.2 g of a 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution in which 151.1 g of acrylic acid was diluted with 37.8 g of ion-exchanged water and an aqueous solution in which 651.7 g of IPN-50 was dissolved in 279.3 g of ion-exchanged water were added dropwise over 4 hours. At the same time, an aqueous solution in which 4.4 g of L-ascorbic acid and 4.7 g of 3-mercaptopropionic acid were dissolved in 304.1 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Thereafter, the reaction solution was neutralized to pH 6 using a 30% aqueous solution of sodium hydroxide at a temperature equal to or lower than the polymerization reaction temperature, and the polycarboxylic acid copolymer (B-14) having a weight average molecular weight (Mw) of 41500 was obtained. An aqueous solution was obtained. The nonvolatile content was 45.4%. The obtained aqueous solution was adjusted by adding diluted water so that the active ingredient concentration was 10.0%.

[List of production examples of polymer (A) and polymer (B)]
Table 1 shows the polycarboxylic acid copolymer A, Table 2 shows the weight composition ratio of each raw material monomer used to prepare the polycarboxylic acid copolymer B, the reaction rate of each raw material monomer, and the copolymer. The composition ratio, the weight average molecular weight (Mw) and the number of adsorbing groups were shown.
In Tables 1 and 2, the monomer (a) represents an unsaturated (poly) alkylene glycol ether monomer, and the monomer (b) represents an unsaturated carboxylic acid monomer.
In addition, the monomer (b) described in Table 1 and Table 2 is a sodium salt of acrylic acid or a sodium salt of maleic acid. For convenience, in Production Examples 1 to 4 , 6 to 8 , 10 to 21 , 23 , 24 , and 26 to 29, acrylic acid or maleic acid is used.

[Calculation example of the number of adsorbed groups]
Tables 1 and 2 show copolymer composition ratios (% by mass) of the respective copolymers A and B. In Production Examples 1 to 4, 6 to 8 , 10 to 21 , 23 , 24 , and 26 to 29, the monomer having an adsorbing group is one kind of unsaturated carboxylic acid monomer (b). The number of adsorption groups of the copolymers produced in Examples 1 to 4, 6 to 8 , 10 to 21, 23, 24, and 26 to 29 is calculated using the above formula (2) or (3).
Specifically, for example, the composition ratio of copolymer A-1 in Production Example 1 is as follows: monomer (b) (Mw: 94.042, sodium salt of acrylic acid) / monomer (a) (Mw : 2288.783, IPN-50) = 4.47 / 95.53 (mass%).
The molar fraction of monomer (b) was (4.47 / 94.04) / {(4.47 / 94.04) + (95.53 / 2288.78)} = 0.532, The mole fraction of the monomer (a) is 1-0.532 = 0.468.
Since Mw of the copolymer A-1 is 12000, the number N of adsorbing groups is 12000 / (94.04 + 2288.78 × 0.468 / 0.532) = 5.7.
Hereinafter, copolymers A-2 to 4, A-6 to 8, A-10 to 15, and B-1 to 6 of Production Examples 2 to 4, 6 to 8, 10 to 21, 23, 24, and 26 to 29 , B-8, B-9, and B-11 to 14 are similarly calculated and obtained.

[Concrete test]
<Examples 1 , 3-8, 11-28 , Comparative Examples 1-8 , Reference Examples 1-3 >
(Adjustment of concrete composition)
The adjustment of the concrete composition is carried out by adjusting the materials used in the test, the forced kneading mixer, and the measuring instruments under a test temperature atmosphere of 20 ° C. so that the test temperature is 20 ° C., and kneading and each measurement are performed at 20 ° C. Was carried out in a temperature atmosphere. In order to avoid the influence of air bubbles in the concrete composition on the fluidity of the concrete composition, a commercially available AE agent (trade name “MA202”, manufactured by Pozoris Co., Ltd.) was used, and the air amount was 4 ± 0.5%. It adjusted so that it might become.
As a cement admixture, using the one obtained by blending the copolymer obtained in the above production example with the blending ratio shown in Table 3 and Table 4, blending with the concrete blending shown below, the time when water was added The mixture was kneaded for 3 minutes using a forced kneading mixer at 0 minutes to produce concrete, and the additive amount of the admixture active ingredient for obtaining a predetermined flow value and the flow values after 5 minutes and 60 minutes were evaluated. The flow value, the change over time of the flow value, and the measurement of the air amount were performed according to Japanese Industrial Standards (JIS-A-1101, 1128). The test results, blending samples and blending ratios of the examples are shown in Table 3. Table 4 shows the test results, blended samples, and blending ratios of the comparative examples.

(Concrete mix)
Amount ^{unit, W: 147kg / m 3,} C: 151kg / m 3, FA: 146kg / m 3, SL: 71kg / m 3, G: 1028kg / m 3, S: was 737kg / ^{m 3.}
The abbreviations are as follows.
W: Cement admixture, AE agent (air entraining agent), water (tap water)
C: Ordinary Portland cement manufactured by Taiheiyo Cement FA: Chubu Electric Power Company, fly ash SL: manufactured by Nippon Steel Cement Co., Ltd., Spirits 4000 (slag)
G: Coarse aggregate, Ome hard sandstone (specific gravity 2.65)
S: Fine aggregate, river sand from Kakegawa (Oigawa water system, specific gravity 2.59)

(Concrete test performance evaluation)
Water loss was evaluated based on the following evaluation criteria, using as an index the amount of addition determined by the amount of active ingredient added / B (mass%) necessary to achieve an initial flow of 500 ± 50 mm. It means that it is excellent in water reduction, so that there is little active ingredient addition amount / B. In addition, an active ingredient addition amount shows the sum total of the active ingredient amount of compounding copolymer (X) and (Y), B shows the total amount of C + FA + SL.
Evaluation criteria for water-reducing properties ◎: Evaluation of addition amount less than 0.110% ○: Evaluation of addition amount of 0.110% or more and less than 0.135% ○ to Δ: Addition amount of 0.135% or more and less than 0.160% Evaluation Δ: Addition amount is 0.160% or more and less than 0.185% Evaluation ×: Addition amount is 0.185% or more

In addition, the retention was evaluated based on the following evaluation criteria using the retention defined as a value obtained by dividing the flow value after 60 minutes by the flow value at the initial 5 minutes. Higher retention means better retention.
Evaluation criteria evaluation of retention ◎: Retention rate is 100% or more Evaluation ○: Retention rate is less than 100% 75% or more Evaluation Δ: Retention rate is less than 75% 50% or more Evaluation ×: Retention rate is less than 50%

The following was found from the results of the above Examples and Comparative Examples.
The structural unit (I) derived from the unsaturated (poly) alkylene glycol ether monomer (a) and the structural unit (II) derived from the unsaturated carboxylic acid monomer (b) are included as essential structural units. A polymer (A) having 5 or more and less than 19 adsorbing groups per molecule of the polymer, and a structural unit (I) derived from an unsaturated (poly) alkylene glycol ether monomer (a), A polymer (B) comprising a structural unit (II) derived from an unsaturated carboxylic acid monomer (b) as an essential structural unit, and the number of adsorbing groups per polymer molecule being 19 or more and less than 70 It was found that a cement admixture excellent in water-reducing property and slump retention property can be obtained by including 40 to 99/60 to 1 (polymer (A) / polymer (B)). .
In addition, in the said Example, what has a specific structural unit in a specific ratio is used as a polymer (A) and a polymer (B), but the number of adsorption groups of a polymer (A) is 5 or more and less than 19 In the cement admixture compounded at a compounding ratio of 40 to 99/60 to 1 (polymer (A) / polymer (B)), the number of adsorbing groups of the polymer (B) is 19 or more and less than 70, All the mechanisms with excellent slump retention are the same.
Therefore, it can be said from the results of the above-described embodiments that the present invention can be applied in the entire technical scope of the present invention and in various forms disclosed in this specification, and can exhibit advantageous effects.

Claims (4)

A cement admixture comprising two types of polymers, polymer (A) and polymer (B), as essential components,
The polymer (A) and the polymer (B) are represented by the following general formula (1);

(In the formula, Y represents an alkenyl group having 2 to 10 carbon atoms. R ^a O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. M is represented by R ^a O. The average added mole number of the oxyalkylene group, which represents a number of 1 to 500. R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.) Unsaturated (poly) alkylene glycol ether system Essential constitution of the structural unit (I) derived from the monomer (a) and the structural unit (II) derived from the unsaturated carboxylic acid monomer (b) having a carboxyl group and / or a salt thereof as an adsorbing group Including as a unit,
In the polymer (A), the number of adsorbing groups per polymer molecule is 5 or more and less than 19,
The polymer (B) has 19 or more and less than 70 adsorbing groups per polymer molecule,
The polymer in the cement admixture (A) and the polymer (B) ratio of the (mass%) of cement admixture which is a 40-85 / 60-15. The unsaturated carboxylic acid monomer (b) has the following general formula (2):

(In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom or a methyl group. M ¹ represents a hydrogen atom, a metal atom, an ammonium group, or an organic ammonium group. Z represents a hydrogen atom, or , -COOM ² , wherein M ² represents a hydrogen atom, a metal atom, an ammonium group, or an organic ammonium group.) And an unsaturated carboxylic acid monomer (b ′). The cement admixture according to claim 1. The unsaturated (poly) alkylene glycol ether monomer (a) is represented by the following general formula (3);

(Wherein R ³ and R ⁴ are the same or different and represent ^a hydrogen atom or a methyl group. R ^a O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. ^a is the average number of added moles of the oxyalkylene group represented by O, and represents a number of 1 to 500. R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, X is a carbon number of 1 to 6 3. The cement admixture according to claim 1, wherein the admixture is an unsaturated alcohol (poly) alkylene glycol adduct represented by the following formula: A cement composition comprising the cement admixture according to any one of claims 1 to 3, cement, and water as essential components.