JP6640786B2 - Sulfonic acid group-containing polymer and method for producing the same - Google Patents

Description

The present invention relates to a sulfonic acid group-containing polymer and a method for producing the same. More specifically, the present invention relates to a sulfonic acid group-containing polymer useful as a raw material for detergent additives and the like, and a method for producing the same.

2. Description of the Related Art Conventionally, a detergent used for clothing has been blended with a detergent builder (detergent auxiliary) such as zeolite, carboxymethylcellulose, and polyethylene glycol for the purpose of improving the cleaning effect of the detergent.
Further, in addition to the above-mentioned various detergent builders, in recent years, polymers have been blended in detergent compositions as detergent builders.
For example, it is disclosed that a water-soluble copolymer obtained from an unsaturated monocarboxylic acid-based monomer and an unsaturated polyalkylene glycol-based monomer and / or a sulfonic acid group-containing monomer is used as a detergent builder or the like. (See Patent Documents 1 to 4).

Here, the performance required of the detergent builder is changing due to the increasing consumer awareness of environmental issues in recent years. In other words, consumers may use water remaining in the bath for washing to save water, and may prefer a less-used detergent (a compact detergent composition) to reduce the amount of detergent components to be drained. It has become.
The use of the remaining hot water causes a problem that washing must be performed under conditions with a large amount of dirt components and hardness components. A similar problem also occurs in areas where the hardness of water is high. In order to cope with the above problem, there is a demand for an agent having a higher ability to prevent re-contamination of a stain component on fibers and the like during washing under conditions of high hardness than ever before.

JP 2010-111792 A JP-A-2004-75977 JP-A-2002-138115 JP-A-2004-217891

As described above, although various polymers have been reported, the conventional polymers have room for improvement in the ability to prevent re-staining, particularly the ability to prevent re-staining of hydrophilic soil such as clay under high hardness conditions. was there. There is also a need for the development of detergent builders that are more adapted to the current consumer needs described above. In particular, in the polymer used for the detergent builder of Patent Document 1, further improvements such as the ability to prevent re-contamination and the hard water resistance were required.
Therefore, the present invention provides a polymer having a further improved anti-soil redeposition ability when used for detergents, particularly an anti-soil redeposition ability for hydrophilic stains under high hardness conditions, and a method for producing the same. The purpose is to do.

The present inventors have conducted various studies on polymers that can be suitably used as detergent additives and the like. As a result, the polymer has a specific ratio of structural units derived from a carboxyl group-containing monomer, and further has a (poly) oxyalkylene type. Structural units derived from the monomer, having a specific ratio of structural units derived from the sulfonic acid group-containing monomer, the ability to prevent re-contamination of the sulfonic acid group-containing polymer having a specific weight average molecular weight, In particular, it has been found that the ability to prevent re-contamination (hard water resistance) of hydrophilic stains under high hardness conditions is remarkably improved. is there.

That is, the first embodiment of the present invention is a sulfonic acid group-containing copolymer, wherein the sulfonic acid group-containing copolymer is a structural unit (a) derived from the sulfonic acid group-containing monomer (A). ) And the following general formula (1);

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(In the formula, Z represents the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ represents a hydrogen atom or an organic group having 1 to 30 carbon atoms. N represents 1 to 200. Is an integer.). A) a structural unit (b) derived from a (poly) oxyalkylene-based monomer (B) and a structural unit (c) derived from a carboxyl group-containing monomer (C). The sulfonic acid group-containing copolymer has the structural unit (c) in an amount of 20 to 100% by mass based on the total amount of the structural units derived from all the monomers forming the sulfonic acid group-containing copolymer. The weight ratio of the structural unit (b) to the structural unit (a), the weight average molecular weight Mw of the sulfonic acid group-containing copolymer, and n of the general formula (2). A sulfonic acid group-containing copolymer, wherein the product (P × Mw × n) is 950,000 to 800,000,000.

A second embodiment of the present invention is a sulfonic acid group-containing copolymer, wherein the sulfonic acid group-containing copolymer has a structural unit (a) derived from a sulfonic acid group-containing monomer (A), The following general formula (1);

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(In the formula, Z represents the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ represents a hydrogen atom or an organic group having 1 to 30 carbon atoms. N represents 1 to 200. Is an integer.). Having a structural unit (b) derived from the (poly) oxyalkylene-based monomer (B) and a structural unit (c) derived from the carboxyl group-containing monomer (C) The sulfonic acid group-containing copolymer has the structural unit (c) in an amount of 20 to 100% by mass based on the total amount of the structural units derived from all the monomers forming the sulfonic acid group-containing copolymer. 90 mass%, the mass ratio P of the structural unit (b) to the structural unit (a) is 1.2 to 20, the weight average molecular weight Mw is 20,000 to 200,000, This is a sulfonic acid group-containing copolymer in which the product of the mass ratio (P) of the structural unit (b) to the unit (a) and the (weight average molecular weight Mw) is 25,000 to 2,000,000.
Hereinafter, the present invention will be described in detail.
A combination of two or more individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

The sulfonic acid group-containing copolymer of the present invention has the first mode and the second mode as described above, but hereinafter, the “sulfonic acid group-containing copolymer” will be used unless otherwise specified. Is the content that applies to both the first mode and the second mode. The contents of only the sulfonic acid group-containing copolymer of the first embodiment and only the sulfonic acid group-containing copolymer of the second embodiment are described to that effect.

The copolymer of the present invention comprises a structural unit (a) derived from a sulfonic acid group-containing monomer (A), a structural unit (b) derived from a (poly) oxyalkylene-based monomer (B), and a carboxyl group. It is a copolymer having a structural unit (c) derived from the contained monomer (C).

[Sulfonic acid group-containing monomer (also referred to as sulfonic acid group-containing unsaturated monomer)]
The sulfonic acid group-containing monomer (A) of the present invention is a monomer having a sulfonic acid group and a carbon-carbon double bond. The sulfonic acid group includes sulfonic acid and a salt thereof. The salt of the sulfonic acid is not particularly limited, and examples thereof include a metal salt, an ammonium salt, and an organic amine salt of the sulfonic acid. The metal atom of the metal salt is preferably an alkali metal such as sodium or potassium; an alkaline earth metal such as magnesium, calcium, strontium or barium; aluminum or iron; and the organic amine group of the organic amine salt is Alkanolamine groups such as monoethanolamine group, diethanolamine group and triethanolamine group; alkylamine groups such as monoethylamine group, diethylamine group and triethylamine group; and polyamine groups such as ethylenediamine group and triethylenediamine group are preferable. The sulfonic acid salt is preferably potassium sulfonate, sodium sulfonate, ammonium sulfonate, or a quaternary amine of sulfonic acid. The sulfonic acid group-containing monomer (A) may have one sulfonic acid group or may have two or more sulfonic acid groups.
Examples of the sulfonic acid group-containing monomer (A) include 2-acrylamido-2-methylpropane sulfonic acid, styrene sulfonic acid, allyl sulfonic acid, vinyl sulfonic acid and salts thereof, and those represented by the following general formula (3). And the like.

(Wherein, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any one of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group.)

The sulfonic acid group-containing monomer (A) is preferably 2-acrylamido-2-methylpropanesulfonic acid or a compound represented by the general formula (3), and more preferably the general formula (3) It is a compound represented by these. When the copolymer of the present invention has a structure derived from the compound represented by the general formula (3), the ability to prevent re-contamination is improved. R ⁴ in the above general formula (3) is more preferably CH ₂ because the copolymer has a tendency to further improve the ability to prevent re-contamination. Further, it is preferable that one of X and Y in the general formula (3) is an SO ₃ M group, and the other is a hydroxyl group. More preferably, X is a hydroxyl group and Y is a SO ₃ M group. As the compound represented by the general formula (3), specifically, 3- (meth) allyloxy-2-hydroxypropanesulfonic acid (salt), 3- (meth) allyloxy-1-hydroxypropanesulfonic acid (salt) And particularly preferably 3- (meth) allyloxy-2-hydroxypropanesulfonic acid (salt). It is preferable that the sulfonic acid group-containing monomer (A) has a structure represented by the general formula (3) because the storage stability of the sulfonic acid group-containing copolymer becomes high.

The sulfonic acid group-containing copolymer has a structural unit (a) of 2 to 2 in terms of acid form, based on a total amount of 100% by mass of structural units derived from all monomers forming the sulfonic acid group-containing copolymer. It is preferred to have the content of 38% by mass. It is more preferably 2 to 30% by mass, further preferably 3 to 25% by mass, further preferably 4 to 20% by mass, particularly preferably 5 to 18% by mass, and most preferably 5 to 16% by mass. % By mass.
Further, in the sulfonic acid group-containing copolymer, the content ratio of the structural unit (a) derived from the sulfonic acid group-containing monomer (A) having two or more sulfonic acid groups is as follows. Is preferably 1% by mass or less based on 100% by mass of the total amount of the structural units derived from all the monomers forming the polymer.
In the present invention, “acid-type conversion” refers to the mass of the sulfonic acid group-containing monomer, the carboxyl group-containing monomer, and other acid group-containing monomers, relative to all monomer components. When calculating the ratio (composition ratio), it means that it is calculated as a corresponding acid type monomer. The same applies when calculating the mass ratio of the structure derived from the monomer to the structure derived from all the monomers of the copolymer. For example, when calculating the mass ratio of sodium acrylate to all monomer components, it means to calculate the mass as the corresponding acid acrylic acid, the structure derived from all monomer components of the structure derived from sodium acrylate When calculating the mass ratio with respect to, it means that the mass is calculated as a structure derived from acrylic acid which is a corresponding acid type structure. For example, similarly, when calculating the mass ratio of the amine base-containing monomer and the structural unit having the amine salt structure, the corresponding amine (amino group) -containing monomer and the structural unit having the amine structure (amino group structure) And calculate the mass.

The copolymer of the present invention preferably has a structural unit (a) derived from the sulfonic acid group-containing monomer (A) represented by the general formula (3). In the present invention, the structural unit (a) derived from the sulfonic acid group-containing monomer represented by the general formula (3) is defined as a radical polymerization of the sulfonic acid group-containing monomer represented by the general formula (3). And is represented by the following general formula (4).

(Wherein, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any one of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group.)

[(Poly) oxyalkylene monomer]
The (poly) oxyalkylene-based monomer (B) of the present invention is characterized by having a structure represented by the general formula (1).
In the structure represented by the general formula (1), preferably, R ¹ is a hydrogen atom, R ² is CH ₂ , or R ¹ is a methyl group, R ² is CH ₂ , or R ¹ is a methyl group and R ¹ is a methyl group. ² is CH ₂ CH ₂ . More preferably, R ¹ is a methyl group, R ² is CH ₂ , or R ¹ is a methyl group, and R ² is CH ₂ CH ₂ .
More preferably, R ¹ is a methyl group and R ² is CH ₂ CH ₂ .

In the general formula (2), Z represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms, R ⁰ represents a hydrogen atom or an organic group having 1 to 30 carbon atoms, and n represents a structure derived from the alkylene oxide. It is the number of repeating units and is an integer of 1 to 200.

Examples of the organic group for R ⁰ include an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, and an aryl group having 6 to 30 carbon atoms. These may further have a substituent. Further substituents include a heterocyclic group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfamoyl group, an acyl group, an acyloxy group, an amide group, a carbamoyl group, a ureido group, Examples include an alkylsulfonyl group, an arylsulfonyl group, an amino group, a halogen atom, a fluorinated hydrocarbon group, a cyano group, a nitro group, a hydroxy group, a mercapto group, and a silyl group. Specific examples of the organic group having 1 to 30 carbon atoms include a methyl group, an ethyl group, a butyl group, an octyl group, a lauryl group, a cyclohexyl group, a phenyl group, a naphthyl group, a pyridyl group, a pyrimidyl group, an imidazolidyl group, and a morpholyl. Butenyl, pentenyl, hexenyl, heptenyl, methylcarbonyl, ethylcarbonyl and the like.
Preferred R ⁰ is a hydrogen atom or a methyl group, more preferably a hydrogen atom.

In the above general formula (2), the “structure derived from alkylene oxide” refers to an oxyalkylene structure in which the alkylene oxide has been opened. For example, when the alkylene oxide is ethylene oxide (EO), the “structure derived from alkylene oxide” is an —OCH ₂ CH ₂ — group (oxyethylene group) that is an oxyalkylene structure in which ethylene oxide is opened.
As the structure derived from the alkylene oxide, the number of carbon atoms of the oxyalkylene group is 2 to 20, preferably 2 to 15, more preferably 2 to 10, and still more preferably 2 to 5, and particularly preferably 2 to 5. Preferably it is 2-3, most preferably 2.

Examples of the structure derived from the alkylene oxide include ethylene oxide (EO), propylene oxide (PO), isobutylene oxide, 1-butene oxide, 2-butene oxide, trimethylethylene oxide, tetramethylene oxide, tetramethylethylene oxide, and butadiene mono. Structures derived from compounds such as oxide, octylene oxide, styrene oxide, and 1,1-diphenylethylene oxide can be exemplified.
Above all, the structure (oxyalkylene group) derived from the alkylene oxide is preferably a group derived from EO or PO (that is, an oxyethylene group or an oxypropylene group), and more preferably an oxyethylene group. In addition, as an oxyalkylene group, only one kind may be present alone, or two or more kinds may be mixed.

The (poly) alkylene glycol chain (group formed by the oxyalkylene group) of the (poly) oxyalkylene-based monomer of the present invention is mainly composed of an oxyethylene group (—O—CH ₂ —CH ₂ —). Preferably, it is In this case, "mainly composed of oxyethylene groups" means that when two or more oxyalkylene groups are present in the monomer, oxyethylene groups occupy most of the total number of oxyalkylene groups. Means that Thereby, an excellent effect that the polymerization at the time of production proceeds smoothly and the water solubility and the ability to prevent re-contamination are improved can be obtained.

In the (poly) alkylene glycol chain of the (poly) oxyalkylene-based monomer of the present invention, "mainly containing oxyethylene groups" is represented by mol% of oxyethylene groups in 100 mol% of all oxyalkylene groups. At this time, the content is preferably 50 to 100 mol%. When the content of the oxyethylene group is 50 mol% or more, the hydrophilicity of the group formed from the oxyalkylene group can be further improved. It is more preferably at least 60 mol%, further preferably at least 70 mol%, particularly preferably at least 80 mol%, most preferably at least 90 mol%.

In the above general formula (2), n is the number of repeating structural units derived from the alkylene oxide, and is an integer of 1 to 200. It is preferably from 5 to 100, more preferably from 10 to 80, still more preferably from 25 to 75, and most preferably from 40 to 60. When the content is in the above-mentioned preferred range, the ability of the obtained sulfonic acid group-containing copolymer to prevent re-staining and the compatibility with a liquid detergent tend to be improved.

The sulfonic acid group-containing copolymer of the present invention contains the structural unit (b) in an amount of 9 to 76% by mass based on 100% by mass of the total amount of the structural units derived from all the monomers forming the sulfonic acid group-containing copolymer. %. It is more preferably from 10 to 70% by mass, further preferably from 12 to 65% by mass, further preferably from 15 to 60% by mass, particularly preferably from 18 to 50% by mass, still more preferably from 20 to 50% by mass. It is 49% by mass, most preferably 30 to 45% by mass. In the present invention, when calculating the total amount of structural units derived from all monomers, the sulfonic acid group-containing monomer, carboxyl group-containing monomer, and other acid groups contained in all monomer components are used. The weight of the contained monomer is calculated in terms of the weight of the corresponding acid type monomer.

The copolymer of the present invention has a structural unit (b) derived from the (poly) oxyalkylene-based monomer (B) represented by the general formula (1). The structural unit (b) derived from the oxyalkylene-based monomer is a structure in which the (poly) oxyalkylene-based monomer (B) is copolymerized by radical polymerization, and is represented by the following general formula (5). .

(In the formula, R ¹ represents a hydrogen atom or a methyl group. R ² represents a direct bond, CH ₂ or CH ₂ CH _2. X ⁰ represents a structure represented by the general formula (2). )

<Method for producing (poly) oxyalkylene monomer>
The method for producing the (poly) oxyalkylene-based monomer is not limited, but the preferred method for producing the (poly) oxyalkylene-based monomer (B) having the structure of the general formula (1) includes (i) A production method of adding an alkylene oxide to an alcohol having a carbon-carbon double bond such as allyl alcohol, methallyl alcohol, and isoprenol; A production method in which a (poly) alkylene glycol is added to a halide having a carbon double bond.

In the production method (i), the method of adding an alkylene oxide to an alcohol having a carbon-carbon double bond includes, for example, 1) a strong alkali such as an alkali metal hydroxide or an alkoxide, or an alkylamine. Polymerization as a base catalyst, 2) cationic polymerization using metal and metalloid halides, mineral acids, acetic acid and the like as catalysts, 3) alkoxides of metals such as aluminum, iron and zinc, alkaline earth compounds, Lewis acids A method of adding the above-described alkylene oxide to the hydroxyl group of the alcohol using a method such as coordination polymerization using a combination of the above-mentioned methods.

Since the (poly) oxyalkylene-based monomer (B) of the present invention has a structure represented by the general formula (1) and thus has good stability at the time of polymerization, recontamination of the obtained polymer is performed. The prevention ability is improved. Further, the (poly) oxyalkylene-based monomer (B) of the present invention has a structure represented by the above general formula (1), so that the obtained polymer is preferably stable with time. In addition, since it shows excellent stability when producing a product (composition) containing the polymer (sulfonic acid group-containing copolymer) of the present invention for application to various uses, the obtained product This is preferable because the performance is stable.

[Carboxyl group-containing monomer (also called carboxyl group-containing unsaturated monomer)]
The carboxyl group-containing monomer (C) of the present invention is a monomer having a carboxyl group and a carbon-carbon double bond. The carboxyl group includes a carboxylic acid and a salt thereof. The salt of the carboxylic acid is not particularly limited, and examples thereof include a metal salt, an ammonium salt, and an organic amine salt of the carboxylic acid. The metal atom of the metal salt is preferably an alkali metal such as sodium or potassium; an alkaline earth metal such as magnesium, calcium, strontium or barium; aluminum or iron; and the organic amine group of the organic amine salt is Alkanolamine groups such as monoethanolamine group, diethanolamine group and triethanolamine group; alkylamine groups such as monoethylamine group, diethylamine group and triethylamine group; and polyamine groups such as ethylenediamine group and triethylenediamine group are preferable. Examples of the carboxylic acid salt include a lithium salt, a potassium salt, a sodium salt, an ammonium salt, and a quaternary amine salt.

Examples of the carboxyl group-containing monomer (C) include (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, crotonic acid, 2-methyleneglutaric acid, and salts thereof. You. Among them, the carboxyl group-containing monomer is (meth) acrylic acid, maleic acid, maleic anhydride or a salt thereof from the viewpoint that the copolymer obtained with high polymerizability has a high ability to prevent re-contamination. Is more preferable, and acrylic acid, maleic acid, maleic anhydride or a salt thereof is further preferable, and acrylic acid or an acrylate is particularly preferable. In the case of a compound forming an acid anhydride such as maleic acid, these acid anhydrides may be used. One of these carboxyl group-containing monomers may be used alone, or two or more thereof may be used in combination.
In addition, structurally, the carboxyl group-containing monomer corresponding to the (poly) oxyalkylene-based monomer of the present invention should be calculated as a (poly) oxyalkylene-based monomer when calculating the mass ratio. And When the carboxyl group-containing monomer is an acid anhydride, the form in which the dicarboxylic acid is obtained by hydrolysis is calculated as the acid form.

The sulfonic acid group-containing copolymer of the present invention is obtained by converting the structural unit (c) in acid form conversion with respect to 100% by mass of the total amount of the structural units derived from all the monomers forming the sulfonic acid group-containing copolymer. 20 to 90% by mass, preferably 25 to 85% by mass, more preferably 30 to 80% by mass, further preferably 35 to 75% by mass, particularly preferably 40 to 73% by mass. %, Most preferably 40 to 55% by mass. When the proportion of the structural unit (c) is from 20 to 90% by mass, the ability of the sulfonic acid group-containing polymer of the present invention to prevent re-contamination, especially the ability to prevent re-contamination of hydrophilic stains under high hardness conditions, is improved. I do. Furthermore, from the viewpoint of improving the compatibility with the liquid detergent in addition to the ability to prevent re-contamination, the proportion of the structural unit (c) is most preferably 40 to 55% by mass. The mass ratio of the corresponding salt of the carboxyl group-containing monomer is calculated as the mass of the acid. When the carboxyl group-containing monomer is an acid anhydride, the form in which the dicarboxylic acid is obtained by hydrolysis is calculated as the acid form.
The sulfonic acid group-containing copolymer of the present invention is derived from a monocarboxylic acid such as (meth) acrylic acid with respect to a total amount of 100% by mass of the structural units (c) derived from the carboxyl group-containing monomer (C). It is preferable that it has a structural unit of 1 to 100% by mass in terms of acid form, more preferably 20 to 100% by mass, further preferably 50 to 100% by mass, and particularly preferably 80 to 100% by mass. %, And most preferably 100% by mass.

The copolymer of the present invention has a structural unit (c) derived from a carboxyl group-containing monomer (C), and the structural unit (c) is a copolymer of the carboxyl group-containing monomer (C) by radical polymerization. It is a polymerized structure. For example, when the carboxyl group-containing monomer is acrylic acid, it refers to a structure represented by —CH ₂ —CH (COOH) —.

[Other monomers]
The sulfonic acid group-containing copolymer of the present invention comprises a monomer other than the sulfonic acid group-containing monomer (A), the (poly) oxyalkylene monomer (B), and the carboxyl group-containing monomer (C). It may have a structural unit (e) derived from the monomer (E). The other monomer (E) is not particularly limited. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl Hydroxyl-containing alkyl (meth) acrylates such as (meth) acrylate, 4-hydroxybutyl (meth) acrylate, α-hydroxymethylethyl (meth) acrylate; methyl (meth) acrylate, ethyl (meth) acrylate, (meth) ) Alkyl (meth) acrylates obtained by esterification of (meth) acrylic acid such as butyl acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate and an alcohol having 1 to 18 carbon atoms; dimethylaminoethyl (Meth) acrylate or quaternary compound thereof Amino group-containing acrylates; Amide group-containing monomers such as (meth) acrylamide, dimethylacrylamide, isopropylacrylamide, etc .; Vinyl esters such as vinyl acetate; Alkenes such as ethylene and propylene; Maleimide derivatives such as maleimide, phenylmaleimide and cyclohexylmaleimide; vinyl monomers containing nitrile groups such as (meth) acrylonitrile;

Monomers having a phosphonic acid (salt) group such as vinylphosphonic acid, (meth) allylphosphonic acid and salts thereof; vinyl monomers containing an aldehyde group such as (meth) acrolein; methyl vinyl ether, ethyl vinyl ether And vinyl ethers such as butyl vinyl ether; vinyl chloride, vinylidene chloride, and allyl alcohol; and other functional group-containing monomers such as vinyl pyrrolidone. As for these other monomers, only one kind may be used alone, or two or more kinds may be used in combination.

In the copolymer of the present invention, the content ratio of the structural unit (e) derived from the other monomer (E) is 100% of the total amount of the structural units derived from all the monomers forming the sulfonic acid group-containing copolymer. It is preferably from 0 to 30% by mass relative to the mass%. The content is more preferably 0 to 20% by mass, further preferably 0 to 10% by mass, and most preferably 0% by mass.

In the present invention, the structural unit (e) derived from the other monomer (E) is a structure in which the other monomer (E) is copolymerized by radical polymerization, for example, the other monomer (E) Is methyl acrylate, it refers to a structure represented by —CH ₂ —CH (COOCH ₃ ) —.

It is more preferable that the copolymer of the present invention satisfies two or more of the preferable contents of the structural units (a), (b), (c) and (e) described above. That is, it is a preferred embodiment of the copolymer of the present invention to combine the above-mentioned preferable content ratios of the structural units (a), (b), (c) and (e). In addition, when the above preferable content ratios are combined, the sum of the respective content ratios is 100% by mass.

[Sulfonic acid group-containing copolymer]
The sulfonic acid group-containing copolymer according to the first embodiment of the present invention has a weight ratio P of the structural unit (b) to the structural unit (a), a weight average molecular weight Mw of the sulfonic acid group-containing copolymer, and a general formula: In (2), the product of n (P × Mw × n) is in the range of 950,000 to 800,000,000, and the value of (P × Mw × n) is 1,000,000. It is preferable that it is above. With such a value, the sulfonic acid group-containing polymer of the present invention further improves the adsorptivity to hydrophilic stains, and particularly the ability to prevent re-staining of hydrophilic stains under high hardness conditions. It is more preferably at least 1,500,000, and even more preferably at least 2,000,000. The value of (P × Mw × n) is preferably 500,000,000 or less, more preferably 100,000,000 or less.

The sulfonic acid group-containing copolymer according to the second embodiment of the present invention comprises a structural unit (a) derived from the sulfonic acid group-containing monomer (A) and a (poly) oxyalkylene monomer (B). And a structural unit (c) derived from the carboxyl group-containing monomer (C), and the mass ratio P of the structural unit (b) to the structural unit (a) is 1.2 to 20. The mass ratio P of the structural unit (b) to the structural unit (a) is preferably from 1.3 to 20, more preferably from 1.5 to 15, still more preferably from 2 to 10, and most preferably. 2.5-5.
When calculating the mass ratio P, the structural units (a) and (b) are calculated by converting them into the corresponding acid type structural units.
When the mass ratio P of the structural unit (b) to the structural unit (a) is 1.2 to 20, the ability of the sulfonic acid group-containing polymer of the present invention to prevent re-contamination, especially hydrophilicity under high hardness conditions. The ability to prevent re-contamination of dirt is improved. Furthermore, the mass ratio P of the structural unit (b) to the structural unit (a) is particularly preferably 3 to 10 from the viewpoint of improving the compatibility with the liquid detergent in addition to the ability to prevent re-contamination.

The weight average molecular weight Mw of the sulfonic acid group-containing copolymer of the second embodiment of the present invention is from 20,000 to 200,000. Preferably it is 22,000-150,000, More preferably, it is 25,000-100,000, More preferably, it is 30,000-80,000. When the weight average molecular weight Mw is 20,000 to 200,000, the ability of the sulfonic acid group-containing polymer of the present invention to prevent re-contamination, especially the ability to prevent re-contamination of hydrophilic soil under high hardness conditions, is improved. . Further, from the viewpoint of improving the compatibility with the liquid detergent in addition to the ability to prevent recontamination, the weight average molecular weight Mw is particularly preferably from 20,000 to 80,000, most preferably from 30,000 to 75,000. is there.
On the other hand, when the weight average molecular weight Mw is larger than 200,000, the viscosity becomes high and the handling may be complicated. On the other hand, if the weight average molecular weight Mw is less than 20,000, the ability to prevent re-contamination decreases, and sufficient performance as a detergent builder may not be exhibited. In addition, as the value of the weight average molecular weight Mw of the sulfonic acid group-containing copolymer of the present invention, a value measured by a method described in Examples described later is adopted.

In the sulfonic acid group-containing copolymer according to the second embodiment of the present invention, the mass ratio P of the structural unit (b) to the structural unit (a) is set in the preferable range, and the weight average molecular weight Mw is set in the preferable range. And re-contamination due to the synergistic effect of combining the product of (weight ratio P of structural unit (b) to structural unit (a) with respect to structural unit (a)) and (weight average molecular weight Mw) within the above-mentioned preferred range. The ability to prevent contamination, particularly the ability to prevent re-contamination of hydrophilic stains under high hardness conditions, can be significantly improved. Further, from the viewpoint of improving the compatibility with the liquid detergent in addition to the ability to prevent re-contamination, the preferable range of the mass ratio P of the structural unit (b) to the structural unit (a) and the preferable range of the weight average molecular weight Mw are as follows. It is also preferable to combine the above-mentioned preferable range of the product of (weight ratio P of structural unit (b) to structural unit (a)) and (weight average molecular weight Mw), since a synergistic effect can be obtained.
Further, the number of repeating structural units derived from the alkylene oxide in the general formula (2) and the ratio of the structural unit (c) in the sulfonic acid group-containing copolymer also affect the ability to prevent re-contamination and compatibility with liquid detergents. To contribute, it is also preferable to combine these preferred ranges.
That is, the mass ratio P of the structural unit (b) to the structural unit (a) described above, the weight average molecular weight Mw, the (mass ratio P of the structural unit (b) to the structural unit (a)) and (weight average molecular weight Mw) The combination of the preferred ranges of the product, the ratio of the structural unit (c) in the sulfonic acid group-containing copolymer, and the number of repeating structural units derived from the alkylene oxide in the general formula (2) is also preferable. This is a simple embodiment.

Also in the sulfonic acid group-containing copolymer of the first embodiment of the present invention, the mass ratio P of the structural unit (b) to the structural unit (a) is preferably 1.2 to 20. It is more preferably from 1.3 to 20, still more preferably from 1.5 to 15, and particularly preferably from 2 to 10.
Further, also in the sulfonic acid group-containing copolymer of the first embodiment of the present invention, the sulfonic acid group-containing copolymer preferably has a weight average molecular weight Mw of 20,000 to 200,000. It is more preferably from 22,000 to 150,000, further preferably from 25,000 to 100,000, particularly preferably from 30,000 to 80,000.
In the sulfonic acid group-containing copolymer according to the first embodiment of the present invention, the weight ratio P and the weight average molecular weight Mw of the structural unit (b) to the structural unit (a) are preferably as described above. The ability to prevent recontamination of the contained polymer, particularly the ability to prevent recontamination of hydrophilic soil under high hardness conditions, is improved. When the weight average molecular weight Mw is the above-mentioned preferable value, the sulfonic acid group-containing polymer also has excellent compatibility with a liquid detergent.
Further, when both the mass ratio P of the structural unit (b) to the structural unit (a) and the weight average molecular weight Mw are as described above, the sulfonic acid group-containing copolymer of the first embodiment of the present invention also has: As described above, a synergistic effect of satisfying both of them can be exhibited.
That is, the fact that the sulfonic acid group-containing copolymer according to the first embodiment of the present invention also corresponds to the sulfonic acid group-containing copolymer according to the second embodiment of the present invention is that the sulfonic acid group-containing copolymer according to the first embodiment of the present invention. This is a preferred form of the acid group-containing copolymer.

The product of the above (mass ratio P of the structural unit (b) to the structural unit (a)) and the above (weight average molecular weight Mw) of the sulfonic acid group-containing copolymer of the present invention is 25,000 to 2,000,000. It is. Preferably it is 50,000-1,500,000, More preferably, it is 100,000-1,000,000. If the product of the (mass ratio P of the structural unit (b) to the structural unit (a) and the weight average molecular weight Mw) is 25,000 to 2,000,000, the sulfonic acid group-containing polymer of the present invention is used. Of a hydrophilic stain is improved, and in particular, the ability to prevent re-contamination of a hydrophilic stain under high hardness conditions is improved.
From the viewpoint of improving the compatibility with the liquid detergent in addition to the ability to prevent re-contamination, the product of the above (mass ratio P of structural unit (b) to structural unit (a)) and (weight average molecular weight Mw) is: It is preferably from 70,000 to 1,200,000, more preferably from 100,000 to 1,000,000, further preferably from 120,000 to 1,000,000, and most preferably from 130,000 to 800,000.

The sulfonic acid group-containing copolymer of the present invention preferably has a mass ratio of the structural units (a), (b), and (c) of from 2 to 38/9 to 76/20 to 90. More preferably, it is 2 to 30/10 to 70/25 to 85, still more preferably 3 to 25/12 to 65/30 to 80, and still more preferably 4 to 20/15 to 60/35 to 75. Yes, particularly preferably 5 to 18/18 to 50/40 to 73, still more preferably 5 to 16/20 to 49/43 to 70, and most preferably 5 to 16/30 to 45/40. 55.
However, the total mass ratio of the structural units (a), (b), and (c) is 100% by mass.

The method for producing the sulfonic acid group-containing copolymer of the present invention is not particularly limited, but the following [method for producing sulfonic acid group-containing copolymer] is preferred.

[Method for producing sulfonic acid group-containing copolymer]
The present invention is also a method for producing a sulfonic acid group-containing copolymer.
The method for producing the sulfonic acid group-containing copolymer of the present invention is not particularly limited, but a known polymerization method or a modified version of a known method can be used.
The production method described above comprises a sulfonic acid group-containing monomer (A) and the following general formula (1);

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(In the formula, Z represents the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ represents a hydrogen atom or an organic group having 1 to 30 carbon atoms. N represents 1 to 200. Is an integer.). A) copolymerizing a monomer component containing a (poly) oxyalkylene-based monomer (B) and a carboxyl group-containing monomer (C) represented by the following formula: The group-containing monomer (C) is contained in an amount of 20 to 90% by mass in terms of an acid type with respect to 100% by mass of all monomers, and the mass ratio P of the structural unit (b) to the structural unit (a) and the sulfone A production method characterized in that the product (P × Mw × n) of the weight average molecular weight Mw of the acid group-containing copolymer and n in the general formula (2) is 950,000 to 800,000,000. It is preferable that the method for producing such a sulfonic acid group-containing copolymer is also one aspect of the present invention.

Preferred monomers as the sulfonic acid group-containing monomer (A), (poly) oxyalkylene-based monomer (B) and carboxyl group-containing monomer (C) are the same as those described above. Can be

The proportion of the sulfonic acid group-containing monomer (A) with respect to 100% by mass of all the monomers is not particularly limited, but is preferably from 2 to 38 in terms of acid form from the viewpoint of sufficiently exerting the effects of the present invention. % By mass, more preferably 2 to 30% by mass, still more preferably 3 to 25% by mass, still more preferably 4 to 20% by mass, particularly preferably 5 to 18% by mass. Preferably it is 5 to 16% by mass.

The proportion of the (poly) oxyalkylene-based monomer (B) with respect to 100% by mass of all the monomers is not particularly limited, but is preferably 9 in terms of acid form from the viewpoint of sufficiently exerting the effects of the present invention. To 76% by mass, more preferably 10 to 70% by mass, still more preferably 12 to 65% by mass, further preferably 15 to 60% by mass, particularly preferably 18 to 50% by mass. , Even more preferably 20 to 49% by mass, and most preferably 30 to 45% by mass.

The ratio of the carboxyl group-containing monomer (C) to 100% by mass of the total monomer is preferably 20 to 90% by mass in terms of acid form from the viewpoint of sufficiently exerting the effects of the present invention. It is more preferably from 25 to 85% by mass, further preferably from 30 to 80% by mass, further preferably from 35 to 75% by mass, particularly preferably from 40 to 73% by mass, and still more preferably from 43 to 75% by mass. 70% by mass, most preferably 40 to 55% by mass.

Other monomers other than the sulfonic acid group-containing unsaturated monomer (A), the (poly) oxyalkylene-based monomer (B), and the carboxyl group-containing monomer (C), E) may be included, and the other monomer (E) is not particularly limited, and examples thereof include the same ones as described above. The content ratio of the other monomer (E) is preferably 0 to 30% by mass relative to 100% by mass of all the monomers. The content is more preferably 0 to 20% by mass, further preferably 0 to 10% by mass, and most preferably 0% by mass.

The monomer components include a sulfonic acid group-containing unsaturated monomer (A), a (poly) oxyalkylene-based monomer (B), a carboxyl group-containing monomer (C), and another monomer (E). ) Is more preferably contained at a preferable content ratio of each monomer described above. That is, each of the above-mentioned sulfonic acid group-containing unsaturated monomer (A), (poly) oxyalkylene-based monomer (B), carboxyl group-containing monomer (C) and other monomer (E) Combining a preferable content ratio in all monomers is also a preferred embodiment of the method for producing a sulfonic acid group-containing copolymer of the present invention.

In the step of copolymerizing the monomer components, the monomer components are preferably copolymerized using a polymerization initiator (hereinafter, also referred to as an initiator). As the initiator, known initiators can be used. For example, hydrogen peroxide; persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; dimethyl 2,2′-azobis (2-methylpropionate) ), 2,2'-azobis (2-amidinopropane) hydrochloride, 4,4'-azobis-4-cyanovaleric acid, azobisisobutyronitrile, 2,2'-azobis (4-methoxy-2, An azo compound such as 4-dimethylvaleronitrile); organic peroxides such as benzoyl peroxide, lauroyl peroxide, peracetic acid, di-t-butyl peroxide, cumene hydroperoxide, and the like are preferable. Of these polymerization initiators, hydrogen peroxide and persulfate are preferred, and persulfate is most preferred. These polymerization initiators may be used alone or in the form of a mixture of two or more.
The amount of the polymerization initiator used in the polymerization reaction may be appropriately adjusted according to the amount of the monomer component, and is not particularly limited. For example, based on 100 parts by mass of the monomer, preferably It is 0.001 part by mass or more and 20 parts by mass or less, more preferably 0.005 parts by mass or more and 15 parts by mass or less, further preferably 0.01 part by mass or more and 10 parts by mass or less.

In the method for producing a sulfonic acid group-containing copolymer of the present invention, it is preferable to use a chain transfer agent in addition to the polymerization initiator. The chain transfer agent that can be used at this time is not particularly limited as long as it is a compound that can control the molecular weight, and a known chain transfer agent can be used. Specifically, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2-mercaptoethanesulfonic acid, n A thiol chain transfer agent such as dodecyl mercaptan, octyl mercaptan, butyl thioglycolate; a halide such as carbon tetrachloride, methylene chloride, bromoform and bromotrichloroethane; a secondary alcohol such as isopropanol and glycerin; Acid, hypophosphorous acid, and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionous acid, metabisulfite, and salts thereof (sodium bisulfite, hydrogen sulfite) Potassium, sodium dithionite Um, potassium dithionite, sodium metabisulfite, metabisulfite potassium, etc.) and the like, and the like lower oxides and salts thereof. The above chain transfer agents may be used alone or in the form of a mixture of two or more.

The amount of the chain transfer agent used in the method for producing a sulfonic acid group-containing copolymer of the present invention is 0.5 to 10 g based on 1 mol of all monomer components, and it is preferable to use such a ratio. It becomes easy to produce a sulfonic acid group-containing copolymer having a molecular weight. The amount of the chain transfer agent to be used is preferably 1.0 to 7.0 g per 1 mol of all monomer components, and more preferably 2.0 to 5 g per 1 mol of all monomer components. 0.0 g.

In the method for producing a sulfonic acid group-containing copolymer of the present invention, a reaction accelerator may be added for the purpose of reducing the amount of an initiator or the like used. Examples of the reaction accelerator include heavy metal ions. In the present invention, the heavy metal ion means a metal having a specific gravity of 4 g / cm ³ or more. As the metal ion, for example, ions of iron, cobalt, manganese, chromium, molybdenum, tungsten, copper, silver, gold, lead, platinum, iridium, osmium, palladium, rhodium, ruthenium and the like are preferable. One or more of these heavy metals can be used. Among these, iron is more preferred. The valence of the heavy metal ion is not particularly limited. For example, when iron is used as the heavy metal, the iron ion in the initiator may be Fe ²⁺ or Fe ³⁺ , and these may be combined. It may be.

The heavy metal ion is not particularly limited as long as it is included as an ion form. However, it is preferable to use a method in which a solution obtained by dissolving a heavy metal compound is used because of excellent handleability. The heavy metal compound used at this time may be any compound containing a heavy metal ion desired to be contained in the initiator, and can be determined according to the initiator used. When iron is used as the heavy metal ion, Mohr salt (Fe (NH ₄ ) ₂ (SO ₄ ) ₂ .6H ₂ O), ferrous sulfate heptahydrate, ferrous chloride, ferric chloride, and the like can be used. It is preferable to use a heavy metal compound or the like. When manganese is used as the heavy metal ion, manganese chloride or the like can be preferably used. When these heavy metal compounds are used, since they are all water-soluble compounds, they can be used in the form of an aqueous solution, resulting in excellent handleability. The solvent of the solution obtained by dissolving the heavy metal compound is not limited to water, and does not hinder the polymerization reaction in the production of the hydrophobic group-containing copolymer of the present invention. Any substance can be used as long as it dissolves.

The content of the heavy metal ion is preferably 0.1 to 10 ppm with respect to the total mass of the polymerization reaction solution when the polymerization reaction is completed. When the content of the heavy metal ion is 0.1 ppm or more, the effect by the heavy metal ion can be more sufficiently exhibited. When the content of heavy metal ions is 10 ppm or less, the color tone of the obtained polymer can be further improved. Further, when the content of heavy metal ions is large, when the polymer as a product is used as a detergent builder, there is a possibility that the detergent builder may be stained. Such defects can be more sufficiently suppressed.
In addition, the completion of the polymerization reaction means the time when the polymerization reaction is substantially completed in the polymerization reaction liquid and the desired polymer is obtained. For example, when the polymer polymerized in the polymerization reaction solution is neutralized with an alkali component, the content of heavy metal ions is calculated based on the total mass of the neutralized polymerization reaction solution. When two or more heavy metal ions are included, the total amount of heavy metal ions may be within the above range.

As the combination of the initiator and the chain transfer agent, it is most preferable to use at least one of a persulfate and a sulfite. In this case, the mixing ratio of the persulfate and the sulfite is not particularly limited, but it is preferable to use 0.3 to 8 parts by mass of the sulfite with respect to 1 part by mass of the persulfate. More preferably, the lower limit of the sulfite is 0.5 part by mass, and most preferably 0.7 part by mass, relative to 1 part by mass of the persulfate. Further, the upper limit of the sulfite is more preferably 7 parts by mass, most preferably 6 parts by mass with respect to 1 part by mass of the persulfate. Here, if the sulfite is 0.3 parts by mass or more, the total amount of the initiator at the time of reducing the molecular weight can be suppressed lower, and if it is 8 parts by mass or less, the side reaction is more sufficiently suppressed. However, impurities due to this can be more sufficiently reduced.

The combination of the above chain transfer agent, initiator and reaction accelerator is not particularly limited, and can be appropriately selected from the above examples. For example, combinations of a chain transfer agent, an initiator, and a reaction accelerator include sodium bisulfite (SBS) / hydrogen peroxide (H ₂ O ₂ ), sodium bisulfite (SBS) / sodium persulfate (NaPS), and hydrogen sulfite. Sodium (SBS) / Fe, sodium bisulfite (SBS) / hydrogen peroxide (H ₂ O ₂ ) / Fe, sodium bisulfite (SBS) / sodium persulfate (NaPS) / Fe, sodium bisulfite (SBS) / Forms such as sodium sulfate (NaPS) / hydrogen peroxide (H ₂ O ₂ ) and sodium bisulfite (SBS) / oxygen / Fe are preferred. More preferred are sodium bisulfite (SBS) / sodium persulfate (NaPS), sodium bisulfite (SBS) / sodium persulfate (NaPS) / Fe, most preferably sodium bisulfite (SBS) / sodium persulfate ( NaPS) / Fe.

In the method for producing a sulfonic acid group-containing copolymer of the present invention, at the time of polymerization, in addition to the above-described polymerization initiator, a decomposition catalyst for the polymerization initiator or a reducing compound may be added to the reaction system. Examples of the decomposition catalyst for the polymerization initiator include metal halides such as lithium chloride and lithium bromide; metal oxides such as titanium oxide and silicon dioxide; hydrochloric acid, hydrobromic acid, perchloric acid, sulfuric acid, nitric acid and the like. Metal salts of inorganic acids; carboxylic acids such as formic acid, acetic acid, propionic acid, lacnic acid, isoleic acid, and benzoic acid; esters and metal salts thereof; and heterocyclic amines such as pyridine, indole, imidazole, and carbazole and derivatives thereof. No. One of these cracking catalysts may be used alone, or two or more thereof may be used in combination.

Examples of the reducing compound include organometallic compounds such as ferrocene; naphthenate metal salts such as iron naphthenate, copper naphthenate, nickel naphthenate, cobalt naphthenate and manganese naphthenate; iron, copper, nickel, cobalt, Inorganic compounds capable of generating metal ions such as manganese; inorganic compounds such as boron trifluoride ether adduct, potassium permanganate, perchloric acid; sulfur dioxide, sulfite, sulfate, bisulfite, thiosulfate, sulfoxy Acid-containing compounds, sulfur-containing compounds such as benzenesulfinic acid and substituted products thereof, and homologs of cyclic sulfinic acids such as paratoluenesulfinic acid; octylmercaptan, dodecylmercaptan, mercaptoethanol, α-mercaptopropionic acid, thioglycolic acid, and thiopropione Acid, sodium α-thiopropionate Mercapto compounds such as propyl ester and sodium sulfoethyl α-thiopropionate; nitrogen-containing compounds such as hydrazine, β-hydroxyethylhydrazine and hydroxylamine; formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, Aldehydes such as valerian aldehyde; ascorbic acid and the like. One of these reducing compounds may be used alone, or two or more thereof may be used in combination. A reducing compound such as a mercapto compound may be added as a chain transfer agent.

The total amount of the chain transfer agent, the initiator, and the reaction accelerator is based on the amount of the sulfonic acid group-containing monomer, the (poly) oxyalkylene monomer, the carboxyl group-containing monomer, and if necessary, other monomer. The amount is preferably 2 to 20 g with respect to 1 mol of all monomer components composed of monomers. When the content is in such a range, the sulfonic acid group-containing copolymer of the present invention can be efficiently produced, and the molecular weight distribution of the sulfonic acid group-containing copolymer can be made desired. More preferably, it is 2 to 15 g, and still more preferably, 3 to 10 g.

As a method for adding the polymerization initiator and the chain transfer agent to the reaction vessel, a continuous charging method such as dropping or divided charging can be applied. Further, the chain transfer agent may be independently introduced into the reaction vessel, or may be mixed in advance with each monomer, solvent and the like constituting the monomer component.

In the above-mentioned copolymerization method, as a method for adding the monomer components and the polymerization initiator to the reaction vessel, all of the monomer components are charged into the reaction vessel, and the polymerization initiator is added to the reaction vessel. A method of performing polymerization: charging a part of the monomer components into a reaction vessel, and adding the polymerization initiator and the remaining monomer components continuously or preferably in a stepwise manner (preferably continuously). A method in which a polymerization solvent is charged into a reaction vessel and the total amount of a monomer component and a polymerization initiator is added; one of monomers (for example, a (poly) oxyalkylene monomer) Is preferably charged into a reaction vessel, and copolymerization is performed by adding the polymerization initiator and the remaining monomer components (preferably continuously) to the reaction vessel. Among such methods, the molecular weight distribution of the obtained copolymer can be narrowed (sharpened), and the dispersibility when used as a detergent builder can be improved. It is preferable to carry out the copolymerization by a method of successively dropping a body component into a reaction vessel.

The above-mentioned copolymerization method can be carried out by a commonly used method such as solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization and the like, and is not particularly limited, but solution polymerization is preferred. As described above, the solvent that can be used at this time is preferably a mixed solvent in which 50% by mass of the total solvent is water or water. When only water is used, it is preferable in that the solvent removing step can be omitted.

The above-mentioned copolymerization method can be carried out either batchwise or continuously. In the copolymerization, known solvents can be used as necessary, and water can be used. Water; alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; glycerin; polyethylene glycol; benzene, toluene, and xylene And aromatic or aliphatic hydrocarbons such as cyclohexane and n-heptane; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; amides such as dimethylformamide; and ethers such as diethyl ether and dioxane. It is. These may be used alone or in combination of two or more. Among these, from the viewpoint of the solubility of the monomer component and the obtained copolymer, it is preferable to use one or more solvents selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. preferable.
In the method for producing a sulfonic acid group-containing copolymer of the present invention, an optional chain transfer agent, pH adjuster, buffer, and the like can be used as necessary.

The temperature at the time of polymerization is preferably 70 ° C. or higher, more preferably 75 to 110 ° C., and even more preferably 80 to 100 ° C. When the temperature at the time of polymerization is in the above range, the amount of residual monomer components decreases, and the ability to prevent recontamination of the polymer tends to be improved. Incidentally, the temperature at the time of polymerization, during the progress of the polymerization reaction, it is not necessary to always maintain a constant, for example, to start the polymerization from room temperature, to raise the temperature to a set temperature at an appropriate heating time or heating rate, Thereafter, the set temperature may be maintained, or the polymerization temperature may be changed (increased or decreased) over time during the progress of the polymerization reaction, depending on the method of dropping the monomer component or the initiator. Is also good.

The polymerization time is not particularly limited, but is preferably 30 to 420 minutes, more preferably 45 to 390 minutes, further preferably 60 to 360 minutes, and most preferably 90 to 240 minutes. In addition, in this invention, "polymerization time" represents the time which is adding a monomer.

The pressure in the reaction system may be any of normal pressure (atmospheric pressure), reduced pressure, and increased pressure. However, in terms of the molecular weight of the obtained polymer, the pressure in the reaction system is normal pressure or the inside of the reaction system is closed. However, it is preferable to carry out under pressure. Further, in terms of equipment such as a pressurizing device, a depressurizing device, a pressure-resistant reaction vessel and piping, it is preferable to perform the process under normal pressure (atmospheric pressure). The atmosphere in the reaction system may be an air atmosphere, but is preferably an inert atmosphere. For example, it is preferable to replace the inside of the system with an inert gas such as nitrogen before the start of polymerization.

The solid content concentration in the aqueous solution at the time when the polymerization reaction in the polymerization reaction system is completed (that is, the polymerization solid content concentration of the monomer) is preferably 35% by mass or more, and more preferably 40 to 70% by mass. . If the solid content concentration at the end of the polymerization reaction is as high as 35% by mass or more, the polymerization can be performed at a high concentration and in one step. For this reason, the sulfonic acid group-containing copolymer composition can be obtained efficiently, for example, the concentration step, which was necessary in some cases with the conventional production method, can be omitted. Therefore, the production efficiency can be significantly increased, and as a result, the productivity of the sulfonic acid group-containing copolymer composition can be significantly improved, and the increase in production cost can be suppressed. Becomes

After the completion of the above polymerization reaction, the degree of neutralization (final degree of neutralization) of the sulfonic acid group-containing copolymer obtained by appropriately adding an appropriate alkali component as a post-treatment is set to a predetermined range, if necessary. can do.

As the final degree of neutralization, for example, such as a weakly acidic detergent that is said to be gentle on the skin, such as when used as a detergent builder, it may be used without neutralizing while still acidic, Depending on the intended use, when used in neutral detergents or alkaline detergents, it may be neutralized with an alkali component as a post-treatment and neutralized to a degree of neutralization of 90 mol% or more. Since they are different, they are not particularly limited, and can be set in a very wide range of 1 to 100 mol%. In particular, when used as an acidic polymer composition, the final degree of neutralization is preferably from 1 to 75 mol%, more preferably from 5 to 70 mol%. When used as a neutral or alkaline polymer composition, the final degree of neutralization is preferably 70 to 99 mol%, more preferably 80 to 97 mol%. When the final degree of neutralization is 99 mol% or less when used as a neutral or alkaline polymer composition, coloring of the polymer aqueous solution can be further suppressed.

Examples of the alkali component include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, hydroxides of alkaline earth metals such as calcium hydroxide and magnesium hydroxide, ammonia, monoethanolamine, diethanolamine, and triethanolamine. Examples thereof include those represented by organic amines such as ethanolamine. As the alkali component, only one kind may be used, or a mixture of two or more kinds may be used.

[Sulfonic acid group-containing copolymer composition (polymer composition)]
The sulfonic acid group-containing copolymer of the present invention is essentially contained in the polymer composition of the present invention. In addition, unreacted sulfonic acid group-containing monomer, unreacted (poly) oxyalkylene-based monomer, unreacted carboxyl group-containing monomer, unreacted polymerization initiator, polymerization initiator decomposition product, Binary copolymer of a sulfonic acid group-containing monomer and a carboxyl group-containing monomer, a bisulfite addition compound (using a compound capable of generating the above-described bisulfite and / or bisulfite as a chain transfer agent, In addition, while the bisulfite is added to the carboxyl group-containing monomer, the carboxyl group-containing monomer is not polymerized, and the remaining impurities may be contained. Specific examples of the bisulfite addition compound include 3-sulfopropionic acid (salt). Since the polymer composition of the present invention is polymerized with the sulfonic acid group-containing monomer as an essential component according to the constitution of the present invention, the by-product of a homopolymer of the carboxyl group-containing monomer can be suppressed to a low level. For this reason, an effect is obtained in that the precipitation of the polymer can be significantly suppressed even in washing under high hardness. In addition, since a by-product of a homopolymer of a carboxyl group-containing monomer is suppressed, a secondary effect of improving temporal stability (suppression of layer separation) when blended in a liquid detergent or the like is also exerted.

The contents of the unreacted (poly) oxyalkylene-based monomer, the unreacted sulfonic acid group-containing unsaturated monomer and the 3-sulfopropionic acid (salt) present in the polymer composition are respectively determined by the polymer It is preferably less than 5% by mass relative to 100% by mass of the solid content of the composition. It is more preferably less than 3% by mass, and even more preferably less than 2% by mass. The content of the polymer comprising the acid group-containing unsaturated monomer present in the polymer composition is preferably less than 1% by mass based on 100% by mass of the solid content of the polymer composition. More preferably, it is less than 0.5% by mass. The content of the unreacted carboxyl group-containing monomer present in the polymer composition is preferably 5,000 mass ppm or less, more preferably 1,000 mass, based on 100% by mass of the solid content of the polymer composition. ppm or less, and most preferably 100 ppm by mass or less. The quantification of the unreacted (poly) oxyalkylene monomer, unreacted sulfonic acid group-containing unsaturated monomer, unreacted carboxyl group-containing monomer and 3-sulfopropionic acid (salt) is as follows. It can be performed using liquid chromatography under the conditions.
<Measurement conditions for unreacted (poly) oxyalkylene compound>
Measuring device: Tosoh Corporation 8020 series Detector: Tosoh Corporation RI detector Column: Shiseido Corporation CAPCELL PAK C1 UG120
Temperature: 40.0 ° C
Eluent: 10 mmol / L disodium hydrogen phosphate dodecahydrate aqueous solution (adjusted to pH 7 with phosphoric acid) / acetonitrile = 45/55 (volume ratio)
Flow rate: 1.0 ml / min
<Measurement conditions for unreacted sulfonic acid group-containing unsaturated monomer and unreacted carboxyl group-containing monomer>
Measuring device: Hitachi, Ltd. L-7000 series detector: Hitachi, Ltd. UV detector L-7400
Column: SHOdex RSpak DE-413 manufactured by Showa Denko KK
Temperature: 40.0 ° C
Eluent: 0.1% phosphoric acid aqueous solution flow rate: 1.0 ml / min
<Measurement conditions of 3-sulfopropionic acid (salt)>
Measuring device: Waters e2695
Detector: Waters RI detector 2414
Column: TSKgel ODS-100V manufactured by Tosoh Double temperature: 30.0 ° C
Eluent: 0.02M aqueous solution of potassium dihydrogen phosphate (pH 2.5)
Flow rate: 0.7ml / min

In addition, the polymer composition referred to in the present application is not particularly limited, but is preferably obtained without a purification step such as removal of impurities from the viewpoint of production efficiency. Further, after the polymerization step, the polymer obtained by diluting the obtained polymer composition with a small amount of water (about 1 to 400% by mass based on the obtained mixture) for convenience in handling is also a polymer referred to in the present application. Included in the composition.

The polymer and polymer composition of the present invention can be used as a water treatment agent, a fiber treatment agent, a dispersant, a detergent builder (or a detergent composition), and the like. As a detergent builder, it can be used by being added to detergents for various uses such as clothing, tableware, housing, hair, body, toothpaste, and automobile.

<Water treatment agent>
The polymer composition of the present invention can be used for a water treatment agent. In the water treatment agent, if necessary, a polymerized phosphate, a phosphonate, an anticorrosive, a slime control agent, or a chelating agent may be used as another compounding agent.
The water treatment agent is useful for preventing scale in a cooling water circulation system, a boiler water circulation system, a seawater desalination apparatus, a pulp digester, a black liquor concentrator, and the like. Further, any appropriate water-soluble polymer may be contained within a range that does not affect the performance and the effect.

<Fiber treatment agent>
The polymer composition of the present invention can be used for a fiber treatment agent. The fiber treating agent contains at least one selected from the group consisting of a dye, a peroxide and a surfactant, and the polymer composition of the present invention.
The content of the polymer composition of the present invention in the fiber treatment agent is preferably 1 to 100% by weight, more preferably 5 to 100% by weight, based on the whole fiber treatment agent. Further, any appropriate water-soluble polymer may be contained as long as the performance and the effect are not affected.
Below, the example of compounding of a fiber treatment agent which is closer to the embodiment is shown. This fiber treatment agent can be used in the steps of refining, dyeing, bleaching, and soaping in fiber treatment. Dyes, peroxides and surfactants include those commonly used in fiber treatment agents.

The compounding ratio of the polymer composition of the present invention and at least one selected from the group consisting of a dye, a peroxide, and a surfactant is, for example, whiteness of fiber, color unevenness, and improvement in dyeing degree. In order to achieve this, at least one selected from the group consisting of a dye, a peroxide and a surfactant is used in an amount of 0.1 to 1 part by weight of the polymer composition of the present invention in terms of a pure amount of the fiber treatment agent. It is preferable to use a composition blended at a ratio of 100 parts by weight as a fiber treatment agent.
Any appropriate fiber can be adopted as the fiber in which the fiber treatment agent can be used. Examples thereof include cellulosic fibers such as cotton and hemp; chemical fibers such as nylon and polyester; animal fibers such as wool and silk; semi-synthetic fibers such as human silk; and woven and blended products thereof.
When the above-mentioned fiber treating agent is applied to the refining step, it is preferable to blend the polymer composition of the present invention, an alkali agent and a surfactant. When applied to the bleaching step, it is preferable to blend the polymer composition of the present invention, a peroxide, and a silicate-based agent such as sodium silicate as a decomposition inhibitor of an alkaline bleaching agent.

<Inorganic pigment dispersant>
The polymer composition of the present invention can be used as an inorganic pigment dispersant. If necessary, condensed phosphoric acid and its salts, phosphonic acid and its salts, and polyvinyl alcohol may be used as other compounding agents in the inorganic pigment dispersant.
The content of the polymer composition of the present invention in the inorganic pigment dispersant is preferably 5 to 100% by weight based on the entire inorganic pigment dispersant. Further, any appropriate water-soluble polymer may be contained as long as the performance and the effect are not affected.
The inorganic pigment dispersant can exhibit good performance as an inorganic pigment dispersant for heavy or light calcium carbonate and clay used in paper coating. For example, by adding a small amount of an inorganic pigment dispersant to an inorganic pigment and dispersing the same in water, a high-concentration calcium carbonate having a low viscosity and high fluidity, and having good aging stability of their performance, Highly concentrated inorganic pigment slurries such as slurries can be produced.
When the inorganic pigment dispersant is used as a dispersant for an inorganic pigment, the amount of the inorganic pigment dispersant used is preferably 0.05 to 2.0 parts by weight based on 100 parts by weight of the inorganic pigment. When the amount of the inorganic pigment dispersant is within the above range, a sufficient dispersing effect can be obtained, and an effect commensurate with the added amount can be obtained, which can be economically advantageous.

<Detergent composition>
The polymer composition of the present invention may be added to a detergent composition.
Although the polymer composition of the present invention contains the above-mentioned sulfonic acid group-containing copolymer, the content of the sulfonic acid group-containing copolymer in the detergent composition is not particularly limited. However, from the viewpoint that excellent builder performance can be exhibited, the content of the sulfonic acid group-containing copolymer is preferably 0.1 to 15% by mass, and more preferably the total amount of the detergent composition. Is from 0.3 to 10% by mass, more preferably from 0.5 to 5% by mass.

Detergent compositions used for detergent applications usually contain surfactants and additives used in detergents. The specific forms of these surfactants and additives are not particularly limited, and conventionally known knowledge in the detergent field can be appropriately referred to. The detergent composition may be a powder detergent composition or a liquid detergent composition.

The surfactant is one or more selected from the group consisting of an anionic surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant. When two or more kinds are used in combination, the total amount of the anionic surfactant and the nonionic surfactant is preferably 50% by mass or more, more preferably 60% by mass, based on the total amount of the surfactant. Or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more.

Examples of the anionic surfactant include alkyl benzene sulfonate, alkyl ether sulfate, alkenyl ether sulfate, alkyl sulfate, alkenyl sulfate, α-olefin sulfonate, α-sulfo fatty acid or ester salt, and alkane sulfonate. , A saturated fatty acid salt, an unsaturated fatty acid salt, an alkyl ether carboxylate, an alkenyl ether carboxylate, an amino acid surfactant, an N-acyl amino acid surfactant, an alkyl phosphate or a salt thereof, an alkenyl phosphate or Salts and the like are preferred. The alkyl group or alkenyl group in these anionic surfactants may have an alkyl group such as a methyl group branched.

Nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyethylene alkyl phenyl ethers, higher fatty acid alkanolamides or alkylene oxide adducts thereof, sucrose fatty acid esters, alkyl glycooxides, fatty acid glycerin monoesters. Esters, alkylamine oxides and the like are preferred. The alkyl group and the alkenyl group in these nonionic surfactants may have an alkyl group such as a methyl group branched.

As the cationic surfactant, a quaternary ammonium salt or the like is suitable. As the amphoteric surfactant, a carboxyl-type amphoteric surfactant, a sulfobetaine-type amphoteric surfactant and the like are preferable. The alkyl group and alkenyl group in these cationic surfactants and amphoteric surfactants may have branched alkyl groups such as methyl groups.

The mixing ratio of the surfactant is usually 10 to 60% by mass, preferably 15 to 50% by mass, more preferably 20 to 45% by mass, and particularly preferably, to the total amount of the detergent composition. Is 25 to 40% by mass. If the blending ratio of the surfactant is too small, sufficient detergency may not be exhibited, and if the blending ratio of the surfactant is too large, the economic efficiency may decrease.

Additives include alkali builders, chelate builders, anti-redeposition agents to prevent redeposition of contaminants such as sodium carboxymethylcellulose, stain inhibitors such as benzotriazole and ethylene-thiourea, soil release agents, and color transfer. Inhibitors, softeners, alkaline substances for pH adjustment, fragrances, solubilizers, fluorescent agents, colorants, foaming agents, foam stabilizers, polishes, bactericides, bleaching agents, bleaching aids, enzymes, dyes , Solvents and the like are preferred. In the case of a powder detergent composition, zeolite is preferably blended.

The detergent composition may contain other detergent builders in addition to the polymer composition of the present invention. Examples of other detergent builders include, but are not particularly limited to, alkali builders such as carbonates, bicarbonates, and silicates, and tripolyphosphates, pyrophosphates, borate, nitrilotriacetate, ethylenediaminetetraacetate, and citric acid. Acid salts, (meth) acrylic acid copolymer salts, acrylic acid-maleic acid copolymers, fumarate salts, chelate builders such as zeolites, and carboxyl derivatives of polysaccharides such as carboxymethyl cellulose. Examples of the counter salt used in the builder include alkali metals such as sodium and potassium, ammonium, and amine.

Usually, the total mixing ratio of the above additive and other detergent builders is preferably 0.1 to 50% by mass relative to 100% by mass of the detergent composition. It is more preferably 0.2 to 40% by mass, further preferably 0.3 to 35% by mass, particularly preferably 0.4 to 30% by mass, and most preferably 0.5 to 20% by mass. is there. If the mixing ratio of the additive / other detergent builder is less than 0.1% by mass, sufficient detergent performance may not be exhibited, and if it exceeds 50% by mass, the economic efficiency may be reduced.

In addition, the concept of the above-mentioned detergent composition includes synthetic detergents for household detergents, textile and other industrial detergents, hard surface detergents, and other specific uses such as bleach detergents that enhance the function of one of the components. Detergents used only are also included.

When the detergent composition is a liquid detergent composition, the amount of water contained in the liquid detergent composition is usually preferably from 0.1 to 75% by mass relative to the total amount of the liquid detergent composition, more preferably. Is 0.2 to 70% by mass, more preferably 0.5 to 65% by mass, still more preferably 0.7 to 60% by mass, particularly preferably 1 to 55% by mass, Preferably it is 1.5 to 50% by mass.

When the detergent composition is a liquid detergent composition, the detergent composition preferably has a kaolin turbidity of 200 mg / L or less, more preferably 150 mg / L or less, and still more preferably 120 mg / L or less. And particularly preferably 100 mg / L or less, and most preferably 50 mg / L or less.

Further, the change (difference) in kaolin turbidity between the case where the polymer composition of the present invention is added to the liquid detergent composition as a detergent builder and the case where it is not added is preferably 500 mg / L or less, more preferably It is 400 mg / L or less, more preferably 300 mg / L or less, particularly preferably 200 mg / L or less, and most preferably 100 mg / L or less. As the value of kaolin turbidity, a value measured by the following method is adopted.

<Method of measuring kaolin turbidity>
A sample (liquid detergent), which was uniformly stirred, was placed in a 50 mm square cell having a thickness of 10 mm, and air bubbles were removed. (Kaolin turbidity: mg / L) is measured.

As the enzyme which can be blended in the above-mentioned detergent composition, protease, lipase, cellulase and the like are suitable. Among them, protease, alkaline lipase and alkaline cellulase having high activity in an alkaline washing solution are preferred.

The amount of the enzyme added is preferably 5% by mass or less based on 100% by mass of the detergent composition. If it exceeds 5% by mass, no improvement in detergency can be seen, and the economy may be reduced.

Even when used in hard water (for example, 100 mg / L or more) where the concentration of calcium ions or magnesium ions is high, the detergent composition has less salt precipitation and has an excellent cleaning effect. This effect is particularly noticeable when the detergent composition contains an anionic surfactant such as LAS.

The sulfonic acid group-containing polymer of the present invention has the above-mentioned constitution, and is excellent in the ability to prevent re-contamination, especially the ability to prevent re-contamination of hydrophilic stains under high hardness conditions, and thus is suitable as a raw material for detergent additives and the like. Can be used.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to only these Examples. Unless otherwise specified, “parts” means “parts by weight” and “%” means “% by mass”.
The weight average molecular weight Mw, the number average molecular weight, and the solid content of the aqueous polymer solution of the polymer of the present invention were measured according to the following methods.

<Measurement conditions of weight average molecular weight Mw (GPC)>
Apparatus: Tosoh Corporation HLC-8320GPC
Detector: RI
Column: SHOdex Asahipak GF-310-HQ, GF-710-HQ, GF-1G 7B manufactured by Showa Denko KK
Column temperature: 40 ° C
Flow rate: 0.5 mL / min
Calibration curve: POLYACRYLIC ACID STANDARD manufactured by Souwa Kagaku Co., Ltd.
Eluent: 0.1N sodium acetate / acetonitrile = 3/1 (mass ratio)
<Method for measuring solid content of polymer aqueous solution>
In a nitrogen atmosphere, the polymer composition (1.0 g of the polymer composition + 1.0 g of water) was left for 1 hour in an oven heated to 130 ° C. to perform a drying treatment. From the weight change before and after drying, the solid content (%) and the volatile component (%) were calculated.

<Evaluation of recontamination prevention ability>
In the present invention, in order to evaluate the ability to prevent re-contamination under high-hardness conditions, evaluation was performed using a clay shown in the following (4) instead of carbon black as a soil component.
(1) A cotton cloth obtained from Test fabric was cut into 5 cm × 5 cm to prepare a white cloth. The whiteness of the white cloth was measured in advance by using a colorimetric colorimeter SE6000 manufactured by Nippon Denshoku Industries Co., Ltd. in terms of reflectance.
(2) Pure water was added to 5.0 g of calcium chloride dihydrate to make 17 kg, and hard water was prepared.
(3) Pure water was added to 4.0 g of polyoxyethylene (8) lauryl ether to make 100.0 g to prepare a surfactant aqueous solution. The pH was adjusted to 8.5 with sodium hydroxide.
(4) Set the turgot meter at 25 ° C., put 1 L of hard water, 5 g of an aqueous surfactant solution, 1 g of a 2% polymer aqueous solution in terms of solid content, and 1 g of 11 kinds of JIS Z 8901 test powder 1 clay 1 g in a pot. And stirred at 100 rpm for 1 minute. Thereafter, five white cloths were put and stirred at 100 rpm for 10 minutes.
(5) The white cloth was drained by hand, 1 L of hard water at 25 ° C. was put into a pot, and the mixture was stirred at 100 rpm for 2 minutes.
(6) A white cloth was put on the cloth, and dried while stretching wrinkles with an iron. Then, the whiteness of the white cloth was measured again by the reflectance using the above colorimeter.
(7) From the above measurement results, the ability to prevent re-contamination was determined by the following equation.
(8) Recontamination prevention ability (%) = [(whiteness after washing) / (whiteness of original white cloth)] × 100.

<Compatibility test for liquid detergent>
Various detergents were prepared using the novel copolymer obtained in the examples and the following components. The components were sufficiently stirred so as to be uniform, and the turbidity at 25 ° C. was visually evaluated.
The evaluation results were based on the following three levels.
A: No separation, precipitation or cloudiness was observed visually.
：: Slightly cloudy visually.
Δ: Cloudy visually.
Detergent formulation:
SFT-70H (sophthanol 70H, Nippon Shokubai Co., Ltd., polyoxyethylene alkyl ether); 11 g
Neoperex F-65 (manufactured by Kao Corporation, sodium dodecylbenzenesulfonate); 32 g
Diethanolamine; 10 g
Ethanol; 5g
Novel copolymer and comparative polymer obtained in Examples; 1.0 g as solid content
Pure water; total over balance: 100g

<Example 1>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 49.7 g of pure water and 0.010 g of Mohr's salt, heated to 85 ° C. with stirring, and then heated to 80% acrylic acid (hereinafter referred to as 80% acrylic acid). % AA) 112.5 g, 40% aqueous solution of sodium 3-allyloxy-2-hydroxypropanesulfonate (hereinafter abbreviated as 40% HAPS) 54.9 g (92 mmol), 10 mol of isoprenol ethylene oxide adduct 90.0 g of an 80% aqueous solution (hereinafter abbreviated as 80% IPN10), 30.2 g of 15% sodium persulfate (hereinafter abbreviated as 15% NaPS), and 35% sodium bisulfite (hereinafter abbreviated as 35% SBS). ) 12.9 g and pure water 50.9 g were respectively dropped from different dropping ports. The respective dropping times were 180 minutes for 80% AA, 150 minutes for 40% HAPS, 90 minutes for 80% IPN10, 190 minutes for 15% NaPS, and 175 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 89.1 g of 48% sodium hydroxide (hereinafter abbreviated as 48% NaOH). Thus, an aqueous copolymer solution (1) having a solid content of 44% and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as polymer (1)). The result of the compatibility test for the polymer (1) was ◎.

<Example 2>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 74.1 g of pure water and 0.010 g of Mohr's salt, heated to 85 ° C. with stirring, and then 121.5 g of 80% AA. 65.9 g (111 mmol) of 40% HAPS, 102.0 g of a 60% aqueous solution (hereinafter abbreviated as 60% IPN25) of 25 mol of ethylene oxide adduct of isoprenol, 20.6 g of 15% NaPS, and 11.2 g of 35% SBS. 0 g were dropped from different dropping ports. The respective dropping times were 180 minutes for 80% AA, 150 minutes for 40% HAPS, 150 minutes for 60% IPN25, 190 minutes for 15% NaPS, and 175 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 95.7 g of 48% NaOH. Thus, an aqueous copolymer solution (2) having a solid content of 44% and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as polymer (2)). The result of the compatibility test for the polymer (2) was ○.

<Example 3>
83.1 g of pure water and 0.013 g of Mohr's salt were charged into a 500 ml glass separable flask equipped with a reflux condenser and a stirrer, and heated to 85 ° C. with stirring, and then 198.0 g of 80% AA was added. 25.9 g (44 mmol) of 40% HAPS, 31.1 g of a 60% aqueous solution (hereinafter abbreviated as 60% IPN50) of 50 mol of ethylene oxide adduct of isoprenol, 30.1 g of 15% NaPS, and 10.1 g of 35% SBS. 3 g were dropped from different dropping ports. The respective dropping times were 180 minutes for 80% AA, 150 minutes for 40% HAPS, 150 minutes for 60% IPN50, 190 minutes for 15% NaPS, and 175 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 56.3 g of pure water and 162.6 g of 48% NaOH. Thus, an aqueous copolymer solution (3) having a solid content of 40% and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as polymer (3)).

<Example 4>
118.0 g of pure water and 0.012 g of Mohr's salt were charged into a 500 ml glass separable flask equipped with a reflux condenser and a stirrer, heated to 85 ° C. with stirring, and then 157.5 g of 80% AA was added. 54.9 g (92 mmol) of 40% HAPS, 60.0 g of a 60% aqueous solution (hereinafter abbreviated as 60% IPN50) of 50 mol of isoprenol ethylene oxide adduct, 37.3 g of 15% NaPS, and 12.3 g of 35% SBS. 5 g were dropped from different dropping ports. The respective dropping times were 180 minutes for 80% AA, 150 minutes for 40% HAPS, 150 minutes for 60% IPN50, 190 minutes for 15% NaPS, and 175 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After the completion of the polymerization, the reaction solution was allowed to cool and neutralized by adding 126.6 g of 48% NaOH. Thus, a copolymer aqueous solution (4) having a solid content of 40% and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as polymer (4)).

<Example 5>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 75.0 g of pure water and 0.011 g of Mohr salt, heated to 85 ° C. with stirring, and then 103.5 g of 80% AA. 85.7 g (144 mmol) of 40% HAPS, 131.6 g of 60% IPN50, 22.4 g of 15% NaPS, 9.2 g of 35% SBS, and 5.0 g of pure water were dropped from different dropping ports. . The respective dropping times were 180 minutes for 80% AA, 60 minutes for 40% HAPS, 100 minutes for 60% IPN50, 210 minutes for 15% NaPS, and 200 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 59.4 g of pure water and 56.6 g of 48% NaOH. Thus, an aqueous copolymer solution (5) having a solid content of 40% and a final degree of neutralization of 70 mol% was obtained (the copolymer is referred to as a polymer (5)). The result of the compatibility test for the polymer (5) was ◎.

<Example 6>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 116.5 g of pure water and 0.012 g of Mohr's salt, and heated to 85 ° C. with stirring. 65.9 g (111 mmol) of 40% HAPS, 84.0 g of 60% IPN50, 32.7 g of 15% NaPS, and 11.7 g of 35% SBS were dropped from different dropping ports. The respective dropping times were 180 minutes for 80% AA, 150 minutes for 40% HAPS, 150 minutes for 60% IPN50, 190 minutes for 15% NaPS, and 175 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 107.0 g of 48% NaOH. Thus, a copolymer aqueous solution (6) having a solid content of 40% and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as polymer (6)).

<Example 7>
88.9 g of pure water and 0.014 g of Mohr's salt were charged into a 500 ml glass separable flask equipped with a reflux condenser and a stirrer, and heated to 85 ° C. with stirring, and then 135.0 g of 80% AA was added. 75.1 g (126 mmol) of 40% HAPS, 150.0 g of 60% IPN50, 23.5 g of 15% NaPS, 15.3 g of 35% SBS, and 10.0 g of pure water were dropped from different dropping ports. . The respective dropping times were 180 minutes for 80% AA, 60 minutes for 40% HAPS, 100 minutes for 60% IPN50, 210 minutes for 15% NaPS, and 200 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out aging to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 62.4 g of pure water and 106.2 g of 48% NaOH. Thus, a copolymer aqueous solution (7) having a solid content of 40% and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (7)). The result of the compatibility test for the polymer (7) was ◎.

<Example 8>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 75.0 g of pure water and 0.011 g of Mohr's salt, heated to 85 ° C. with stirring, and then 112.5 g of 80% AA. 50.1 g (84 mmol) of 40% HAPS, 120.0 g of 60% IPN50, 22.8 g of 15% NaPS, 7.7 g of 35% SBS, and 5.0 g of pure water were dropped from different dropping ports. . The respective dropping times were 180 minutes for 80% AA, 60 minutes for 40% HAPS, 100 minutes for 60% IPN50, 210 minutes for 15% NaPS, and 200 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 56.5 g of pure water and 67.3 g of 48% NaOH. Thus, an aqueous copolymer solution (8) having a solid content of 40% and a final degree of neutralization of 70 mol% was obtained (the copolymer is referred to as polymer (8)). The result of the compatibility test for the polymer (8) was ◎.

<Example 9>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 45.0 g of pure water, 60.0 g of 60% IPN50 and 0.014 g of Mohr salt, and heated to 85 ° C. with stirring. 72.0 g of 80% AA, 96.1 g (162 mmol) of 40% HAPS, 266.4 g of 60% IPN50, 70.8 g of 15% NaPS, 10.3 g of 35% SBS, 10.0 g of pure water, Each was dropped from another dropping port. The respective dropping times were 180 minutes for 80% AA, 30 minutes for 40% HAPS, 90 minutes for 60% IPN50, 210 minutes for 15% NaPS, and 200 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 48% NaOH (51.2 g). Thus, a copolymer aqueous solution (9) having a solid content of 47% and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (9)). The result of the compatibility test for the polymer (9) was ◎.

<Example 10>
69.0 g of pure water and 0.011 g of Mohr's salt were charged into a 500 ml glass separable flask equipped with a reflux condenser and a stirrer, and heated to 85 ° C. with stirring. 25.0 g (42 mmol) of 40% HAPS, 147.0 g of 60% IPN50, 20.5 g of 15% NaPS, 7.0 g of 35% SBS, and 4.6 g of pure water were dropped from different dropping ports. . The respective dropping times were 180 minutes for 80% AA, 90 minutes for 40% HAPS, 100 minutes for 60% IPN50, 210 minutes for 15% NaPS, and 200 minutes for 35% SBS and pure water. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 70.5 g of pure water and 64.3 g of 48% NaOH. Thus, an aqueous copolymer solution (10) having a solid content of 40% and a final degree of neutralization of 70 mol% was obtained (the copolymer is referred to as polymer (10)). The result of the compatibility test for the polymer (10) was ◎.

<Example 11>
69.6 g of pure water and 0.010 g of Mohr's salt were charged into a 500 ml glass separable flask equipped with a reflux condenser and a stirrer, and the mixture was heated to 85 ° C. with stirring, and 90.0 g of 80% AA was added. 4.2 g of 48% NaOH, 74.1 g (136 mmol) of a 40% aqueous solution of a 2-acrylamido-2-methylpropanesulfonic acid aqueous solution (hereinafter abbreviated as 40% AMPS), 114.4 g of 60% IPN50, 15% 31.9 g of NaPS and 15.7 g of 35% SBS were dropped from different dropping ports. The respective drop times were 80% AA and 48% NaOH for 180 minutes, 40% AMPS and 60% IPN50 for 100 minutes, 15% NaPS for 200 minutes, and 35% SBS for 210 minutes. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 49.3 g of 48% NaOH and 42.8 g of pure water. Thus, a copolymer aqueous solution (11) having a solid content of 40% and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (11)). The result of the compatibility test for the polymer (11) was ○.

<Example 12>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 2. A copolymer aqueous solution (12) having a concentration of 0.2 / 7.7 / 90.1, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (12)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 3.7, the weight average molecular weight Mw was 42,000, and the mass ratio of the structural unit (b) to the structural unit (a) was: P) and the product of (weight average molecular weight Mw) (hereinafter referred to as P × Mw) is 154,000, and the (mass ratio P of the structural unit (b) to the structural unit (a) P) and (weight The product of the average molecular weight (Mw) and the value of n in the general formula (2) (hereinafter referred to as P × Mw × n) was 7,700,000.

<Example 13>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 20. / 29/51, a solid content concentration of 40%, and a final neutralization degree of 90 mol% (13) were obtained as a copolymer aqueous solution (the copolymer is referred to as a polymer (13)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 1.5, the weight average molecular weight Mw was 23,000, (P × Mw) was 33,400, and (P × Mw × n) was 1,670,000.

<Example 14>
Polymerization and post-treatment were carried out in the same manner as in Example 1 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 11. A copolymer aqueous solution (14) having a ratio of / 34/55, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as polymer (14)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 3.1, the weight average molecular weight Mw was 36,000, (P × Mw) was 111,000, and (P × Mw × n) was 1,110,000.

<Example 15>
Polymerization and post-treatment were carried out in the same manner as in Example 2 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 11. A copolymer aqueous solution (15) having a ratio of / 34/55, a solid content of 44%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as polymer (15)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 3.1, the weight average molecular weight Mw was 44,000, (P × Mw) was 136,000, and (P × Mw × n) was 3,400,000.

<Example 16>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 38. / 21/41, a solid content concentration of 39%, and a final neutralization degree of 90 mol% (16) were obtained as a copolymer aqueous solution (the copolymer is referred to as a polymer (16)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 0.55, the weight average molecular weight Mw was 50,000, (P × Mw) was 27,600, and (P × Mw × n) was 1,380,000.

<Example 17>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 26. A copolymer aqueous solution (17) having a ratio of / 20/54, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as polymer (17)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 0.77, the weight average molecular weight Mw was 29,000, (P × Mw) was 22,300, and (P × Mw × n) was 1,110,000.

<Example 18>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 11. A copolymer aqueous solution (18) having a concentration of / 12/12/77, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (18)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 1.1, the weight average molecular weight Mw was 57,000, (P × Mw) was 62,200, and (P × Mw × n) was 3,110,000.

<Example 19>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 27. A copolymer aqueous solution (19) having a ratio of / 35/38, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (19)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 1.3, the weight average molecular weight Mw was 15,000, (P × Mw) was 19,400, and (P × Mw × n) was 972,000. The result of the compatibility test for the polymer (19) was ◎.

<Example 20>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 16. A copolymer aqueous solution (20) having a ratio of / 34/50, a solid concentration of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (20)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 2.1, the weight average molecular weight Mw was 12,000, (P × Mw) was 25,500, and (P × Mw × n) was 1,280,000. The result of the compatibility test for the polymer (20) was ◎.

<Example 21>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 18. A copolymer aqueous solution (21) having a ratio of / 40/42, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (21)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 2.2, the weight average molecular weight Mw was 31,000, (P × Mw) was 68,900, and (P × Mw × n) was 3,440,000.

<Example 22>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 11. A copolymer aqueous solution (22) having a ratio of / 34/55, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as polymer (22)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 3.1, the weight average molecular weight Mw was 28,000, (P × Mw) was 86,500, and (P × Mw × n) was 4,330,000. The result of the compatibility test for the polymer (22) was ○.

<Example 23>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 11. A copolymer aqueous solution (23) having a ratio of / 34/55, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (23)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 3.1, the weight average molecular weight Mw was 57,000, (P × Mw) was 176,000, and (P × Mw × n) was 8,810,000.

<Example 24>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 12. A copolymer aqueous solution (24) having a ratio of / 40/48, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the copolymer is referred to as a polymer (24)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 3.3, the weight average molecular weight Mw was 25,000, (P × Mw) was 83,300, and (P × Mw × n) was 4,170,000. The result of the compatibility test for the polymer (24) was ◎.

<Example 25>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 13. / 52/35, a solid content concentration of 40%, and a final degree of neutralization of 70 mol% (25) were obtained (the copolymer is referred to as polymer (25)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 4.0, the weight average molecular weight Mw was 36,000, (P × Mw) was 144,000, and (P × Mw × n) was 7,200,000.

<Example 26>
Polymerization and post-treatment were carried out in the same manner as in Example 10 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 11. A copolymer aqueous solution (26) having a ratio of / 50/39, a solid content of 40%, and a final degree of neutralization of 70 mol% was obtained (the copolymer is referred to as a polymer (26)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 4.5, the weight average molecular weight Mw was 65,000, (P × Mw) was 295,000, and (P × Mw × n) was 14,800,000.

<Comparative Example 1>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 46.2 g of pure water and 0.011 g of Mohr's salt, heated to 85 ° C. with stirring, and then 135.0 g of 80% AA. 135.0 g (227 mmol) of 40% HAPS, 54.0 g of IPN10, 36.6 g of 15% NaPS, and 26.1 g of 35% SBS were dropped from different dropping ports. The time of each drop was 180 minutes for 80% AA, 90 minutes for 40% HAPS, 120 minutes for IPN10, 190 minutes for 15% NaPS, and 175 minutes for 35% SBS. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 106.3 g of 48% NaOH. In this way, a comparative copolymer aqueous solution (1) having a solid content of 48% by weight and a final degree of neutralization of 94 mol% was obtained (the copolymer is referred to as Comparative polymer (1)). The result of the compatibility test for Comparative Polymer (1) was Δ.

<Comparative Example 2>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 80.0 g of pure water and 0.013 g of Mohr salt, heated to 85 ° C. with stirring, and then 126.0 g of 80% AA. 224.2 g (377 mmol) of 40% HAPS, 20.2 g of a 5 mol adduct of isoprenol ethylene oxide (hereinafter abbreviated as IPN5), 61.4 g of 15% NaPS, 8.4 g of 35% SBS, and pure water 10 0.0g was dropped from another dropping port, respectively. The respective drop times were 80% AA for 180 minutes, 40% HAPS for 40 minutes, IPN5 for 90 minutes, 15% NaPS for 190 minutes, and 35% SBS and pure water for 120 minutes. The dropping was started at the same time except for 35% SBS and pure water, and the dropping of 35% SBS and pure water was started 60 minutes after the start of the 80% AA dropping. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool and neutralized by adding 84.4 g of 48% NaOH. Thus, a comparative copolymer aqueous solution (2) having a solid content of 40% by weight and a final degree of neutralization of 90 mol% was obtained (the comparative copolymer is referred to as Comparative polymer (2)). The result of the compatibility test for Comparative Polymer (2) was Δ.

<Comparative Example 3>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 12.9 g of pure water and 0.012 g of Mohr's salt, and heated to 85 ° C. with stirring. 138.5 g (233 mmol) of 40% HAPS, 36.9 g of 60% IPN50, 30.2 g of 15% NaPS, and 32.2 g of 35% SBS were dropped from different dropping ports. The respective drop times were 80% AA for 180 minutes, 40% HAPS for 150 minutes, 60% IPN50 for 150 minutes, 15% NaPS for 190 minutes, and 35% SBS for 175 minutes. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 141.7 g of 48% NaOH. In this way, a comparative copolymer aqueous solution (3) having a solid content of 48% by weight and a final degree of neutralization of 92 mol% was obtained (the comparative copolymer is referred to as Comparative polymer (3)). The result of the compatibility test for Comparative Polymer (3) was Δ.

<Comparative Example 4>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 80.3 g of pure water and 0.011 g of Mohr's salt, and heated to 85 ° C. with stirring. 175.8 g (295 mmol) of 40% HAPS, 120.0 g of 60% IPN50, 34.2 g of 15% NaPS, and 14.7 g of 35% SBS were dropped from different dropping ports. The respective drop times were 80% AA for 180 minutes, 40% HAPS for 150 minutes, 60% IPN50 for 150 minutes, 15% NaPS for 190 minutes, and 35% SBS for 175 minutes. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 37.7 g of 48% NaOH. Thus, a comparative copolymer aqueous solution (4) having a solid content of 40% and a final degree of neutralization of 90 mol% was obtained (the comparative copolymer is referred to as comparative polymer (4)). The result of the compatibility test for Comparative Polymer (4) was ◎.

<Comparative Example 5>
Polymerization and post-treatment were performed in the same manner as in Comparative Example 2 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based monomer The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 32 / 19/48, a solid content concentration of 40%, and a final neutralization degree of 90 mol% (5) were obtained as a comparative copolymer aqueous solution (the comparative copolymer is referred to as a comparative polymer (5)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 0.59, the weight average molecular weight Mw was 7,000, (P × Mw) was 4,160, and (P × Mw × n) was 20,800.

<Comparative Example 6>
Polymerization and post-treatment were performed in the same manner as in Comparative Example 2 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based monomer The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 10 / 20/70, a solid content concentration of 40%, and a final degree of neutralization of 90 mol% were obtained as a comparative copolymer aqueous solution (6) (the comparative copolymer is referred to as a comparative polymer (6)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 2.0, the weight average molecular weight Mw was 12,000, (P × Mw) was 24,000, and (P × Mw × n) was 120,000. The result of the compatibility test for Comparative Polymer (6) was Δ.

<Comparative Example 7>
A 500 ml glass separable flask equipped with a reflux condenser and a stirrer was charged with 85.3 g of pure water and 0.011 g of Mohr salt, heated to 85 ° C. with stirring, and then 141.8 g of 80% AA was added. 60.4 g (102 mmol) of 40% HAPS, 58.5 g of 80% IPN10, 35.8 g of 15% NaPS, and 10.7 g of 35% SBS were dropped from different dropping ports. The time of each drop was 180 minutes for 80% AA, 150 minutes for 40% HAPS, 150 minutes for 80% IPN10, 190 minutes for 15% NaPS, and 175 minutes for 35% SBS. The start of the dropping was all the same. The temperature was maintained at 85 ° C. until the completion of the 80% AA dropping. Further, the same temperature was maintained for 30 minutes after the completion of the 80% AA dropping to carry out ripening to complete the polymerization. After completion of the polymerization, the reaction solution was allowed to cool, and then neutralized by adding 113.0 g of 48% NaOH. Thus, the structural unit (a) derived from the sulfonic acid group-containing monomer (A), the structural unit (b) derived from the (poly) oxyalkylene-based monomer (B), and the carboxyl group-containing monomer Comparison of the mass ratio of the structural unit (c) derived from the monomer (C) (a) / (b) / (c) = 11/26/63, the solid content concentration of 44%, and the final degree of neutralization of 90 mol% An aqueous copolymer solution (7) was obtained (the comparative copolymer is referred to as comparative polymer (7)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 2.4, the weight average molecular weight Mw was 39,000, (P × Mw) was 92,200, and (P × Mw × n) was 922,000. The result of the compatibility test for Comparative Polymer (7) was ○.

<Comparative Example 8>
Polymerization and post-treatment were carried out in the same manner as in Comparative Example 7 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 32. / 19/49, a solid content concentration of 43%, and a final degree of neutralization of 90 mol% were obtained as a comparative copolymer aqueous solution (8) (the comparative copolymer is referred to as a comparative polymer (8)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 0.59, the weight average molecular weight Mw was 18,000, (P × Mw) was 10,700, and (P × Mw × n) was 107,000.

<Comparative Example 9>
Polymerization and post-treatment were carried out in the same manner as in Comparative Example 7 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 21. / 20/59, a solid content concentration of 44%, and a final neutralization degree of 90 mol% were obtained as a comparative copolymer aqueous solution (9) (the comparative copolymer is referred to as a comparative polymer (9)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 1.0, the weight average molecular weight Mw was 33,000, (P × Mw) was 31,400, and (P × Mw × n) was 314,000.

<Comparative Example 10>
Polymerization and post-treatment were carried out in the same manner as in Comparative Example 7 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 34. A comparative copolymer aqueous solution (10) having a ratio of / 34/32, a solid content of 44%, and a final degree of neutralization of 90 mol% was obtained (the comparative copolymer is referred to as comparative polymer (10)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 1.0, the weight average molecular weight Mw was 33,000, (P × Mw) was 33,000, and (P × Mw × n) was 330,000.

<Comparative Example 11>
Polymerization and post-treatment were carried out in the same manner as in Comparative Example 7 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 19. / 20/61, a solid content concentration of 44%, and a final neutralization degree of 90 mol% were obtained as a comparative copolymer aqueous solution (11) (the comparative copolymer is referred to as a comparative polymer (11)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 1.1, the weight average molecular weight Mw was 24,000, (P × Mw) was 25,300, and (P × Mw × n) was 253,000.

<Comparative Example 12>
Polymerization and post-treatment were carried out in the same manner as in Comparative Example 7 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 17. / 24/59, a solid content concentration of 43%, and a final neutralization degree of 90 mol% were obtained as a comparative copolymer aqueous solution (12) (the comparative copolymer is referred to as a comparative polymer (12)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 1.4, the weight average molecular weight Mw was 13,000, (P × Mw) was 18,400, and (P × Mw × n) was 184,000.

<Comparative Example 13>
Polymerization and post-treatment were carried out in the same manner as in Comparative Example 7 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 10 A comparative copolymer aqueous solution (13) having a ratio of / 40/50, a solid content of 44%, and a final neutralization degree of 90 mol% was obtained (the comparative copolymer is referred to as a comparative polymer (13)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 4.0, the weight average molecular weight Mw was 15,000, (P × Mw) was 60,000, and (P × Mw × n) was 600,000.

<Comparative Example 14>
Polymerization and post-treatment were carried out in the same manner as in Example 2 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 32 / 19/49, a solid content concentration of 40%, and a final degree of neutralization of 90 mol% (14) were obtained as a comparative copolymer aqueous solution (the comparative copolymer is referred to as a comparative polymer (14)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer was 0.59, the weight average molecular weight Mw was 11,000, (P × Mw) was 6,530, and (P × Mw × n) was 163,000.

<Comparative Example 15>
Polymerization and post-treatment were carried out in the same manner as in Example 2 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 26. / 26/48, a solid content concentration of 40%, and a final degree of neutralization of 90 mol% were obtained as a comparative copolymer aqueous solution (15) (the comparative copolymer is referred to as a comparative polymer (15)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 1.0, the weight average molecular weight Mw was 9,000, (P × Mw) was 9,000, and (P × Mw × n) was 225,000.

<Comparative Example 16>
Polymerization and post-treatment were carried out in the same manner as in Example 2 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 32 / 32/36, a solid content concentration of 40%, and a final degree of neutralization of 90 mol% were obtained as a comparative copolymer aqueous solution (16) (the comparative copolymer is referred to as a comparative polymer (16)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer is 1.0, the weight average molecular weight Mw is 22,000, (P × Mw) is 22,000, and (P × Mw × n) was 550,000.

<Comparative Example 17>
Polymerization and post-treatment were carried out in the same manner as in Example 2 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) and the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 18. / 20/62, a solid content concentration of 44%, and a final degree of neutralization of 90 mol% were obtained as a comparative copolymer aqueous solution (17) (the comparative copolymer is referred to as a comparative polymer (17)). The mass ratio P of the structural unit (b) to the structural unit (a) of this polymer is 1.1, the weight average molecular weight Mw is 23,000, (P × Mw) is 25,600, and (P × Mw × n) was 639,000.

<Comparative Example 18>
Polymerization and post-treatment were carried out in the same manner as in Example 2 except that the proportion of the monomer was changed, and the structural unit (a) derived from the sulfonic acid group-containing monomer (A) and the (poly) oxyalkylene-based The mass ratio of the structural unit (b) derived from the monomer (B) to the structural unit (c) derived from the carboxyl group-containing monomer (C) is (a) / (b) / (c) = 10 A comparative copolymer aqueous solution (18) having a ratio of / 20/70, a solid content of 40%, and a final degree of neutralization of 90 mol% was obtained (the comparative copolymer is referred to as comparative polymer (18)). The mass ratio P of the structural unit (b) to the structural unit (a) of the polymer was 2.0, the weight average molecular weight Mw was 9,000, (P × Mw) was 18,000, and (P × Mw × n) was 450,000.

For the polymers obtained in Examples and Comparative Examples, the monomer components, the ratio of the structural units (a) to (c), the ratio of the structural unit (b) to the structural unit (a), and the weight average molecular weight (Mw) , (Product of weight ratio P of structural unit (b) to structural unit (a)) and (weight average molecular weight Mw), (weight ratio P of structural unit (b) to structural unit (a)) and (weight average molecular weight) Table 1 shows the product of Mw) and n in the general formula (2), the results of the evaluation of the ability to prevent re-contamination, and the compatibility test with liquid detergents.

In the evaluation of the ability to prevent re-contamination according to the present invention, the evaluation is performed using a detergent formulation that assumes a liquid detergent containing no zeolite. Since zeolite is a water softener that reduces the hardness of water by capturing metal ions such as calcium and magnesium contained in water, it must be tested under higher hardness conditions than when using a detergent containing zeolite. Becomes In addition, a test is performed using mud (11 types of clay of JIS Z 8901 test powder 1) as a soil component of typical hydrophilic particles. Therefore, the evaluation of the ability to prevent re-soiling showed that the polymer of the present invention was excellent in the ability to prevent re-staining of hydrophilic particles under high hardness conditions.

Claims (11)

A sulfonic acid group-containing copolymer,
The sulfonic acid group-containing copolymer comprises a structural unit (a) derived from a sulfonic acid group-containing monomer (A) and the following general formula (1):

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(Wherein, Z is the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkenyl group having 2 to 12 carbon atoms. Or an aryl group having 6 to 12 carbon atoms, and n is an integer of 1 to 200.) Having a structural unit (b) derived from the (poly) oxyalkylene-based monomer (B) and a structural unit (c) derived from the carboxyl group-containing monomer (C),
The sulfonic acid group-containing monomer (A) includes 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, allylsulfonic acid, vinylsulfonic acid and salts thereof, and the following general formula (3);

(In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group.) At least one selected from the group consisting of
The sulfonic acid group-containing copolymer contains 34 to 76% by mass of the structural unit (b) based on 100% by mass of the total amount of the structural units derived from all the monomers forming the sulfonic acid group-containing copolymer. And a monocarboxylic acid-derived structural unit at a ratio of 20 to 60% by mass in terms of an acid type with respect to 100% by mass of the total amount of the structural units derived from all the monomers. A), the content of the structural unit (e) derived from the monomer (E) other than the monomer (B) and the monomer (C) is 100% by mass of the total structural units derived from all the monomers. % To 0 to 30% by mass,
The other monomer (E) includes a hydroxyl group-containing alkyl (meth) acrylate, an alkyl (meth) acrylate obtained by esterification of (meth) acrylic acid with an alcohol having 1 to 18 carbon atoms, and an amino group-containing alkyl (meth) acrylate. Acrylates, amide group-containing monomers, vinyl esters, alkenes, aromatic vinyl monomers, maleimide derivatives, nitrile group-containing vinyl monomers, monomers having a phosphonic acid (salt) group , An aldehyde group-containing vinyl monomer, alkyl vinyl ethers, vinyl chloride, vinylidene chloride, allyl alcohol and at least one compound selected from the group consisting of vinylpyrrolidone,
The product (P × Mw × n) of the mass ratio P of the structural unit (b) to the structural unit (a), the weight average molecular weight Mw of the sulfonic acid group-containing copolymer and n in the general formula (2) is obtained. A sulfonic acid group-containing copolymer having a molecular weight of 950,000 to 800,000,000. A sulfonic acid group-containing copolymer,
The sulfonic acid group-containing copolymer comprises a structural unit (a) derived from a sulfonic acid group-containing monomer (A) and the following general formula (1):

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(Wherein, Z is the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. Or an aryl group having 6 to 12 carbon atoms, and n is an integer of 25 to 200.) Having a structural unit (b) derived from the (poly) oxyalkylene-based monomer (B) and a structural unit (c) derived from the carboxyl group-containing monomer (C),
The sulfonic acid group-containing monomer (A) includes 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, allylsulfonic acid, vinylsulfonic acid and salts thereof, and the following general formula (3);

(In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group.) At least one selected from the group consisting of
The sulfonic acid group-containing copolymer is obtained by converting a structural unit derived from a monocarboxylic acid into an acid type with respect to a total amount of 100% by mass of structural units derived from all monomers forming the sulfonic acid group-containing copolymer. At a ratio of 20 to 90% by mass of the structural unit (e) derived from the monomer (E) other than the monomer (A), the monomer (B), and the monomer (C). The content ratio is 0 to 30% by mass relative to 100% by mass of the total amount of the structural units derived from all the monomers,
The other monomer (E) includes a hydroxyl group-containing alkyl (meth) acrylate, an alkyl (meth) acrylate obtained by esterification of (meth) acrylic acid with an alcohol having 1 to 18 carbon atoms, and an amino group-containing alkyl (meth) acrylate. Acrylates, amide group-containing monomers, vinyl esters, alkenes, aromatic vinyl monomers, maleimide derivatives, nitrile group-containing vinyl monomers, monomers having a phosphonic acid (salt) group , An aldehyde group-containing vinyl monomer, alkyl vinyl ethers, vinyl chloride, vinylidene chloride, allyl alcohol and at least one compound selected from the group consisting of vinylpyrrolidone,
The product (P × Mw × n) of the mass ratio P of the structural unit (b) to the structural unit (a), the weight average molecular weight Mw of the sulfonic acid group-containing copolymer and n in the general formula (2) is obtained. A sulfonic acid group-containing copolymer having a molecular weight of 950,000 to 800,000,000. A sulfonic acid group-containing copolymer,
The sulfonic acid group-containing copolymer comprises a structural unit (a) derived from a sulfonic acid group-containing monomer (A) and the following general formula (1):

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(Wherein, Z is the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkenyl group having 2 to 12 carbon atoms. Or an aryl group having 6 to 12 carbon atoms, and n is an integer of 1 to 200.) Having a structural unit (b) derived from the (poly) oxyalkylene-based monomer (B) and a structural unit (c) derived from the carboxyl group-containing monomer (C),
The sulfonic acid group-containing monomer (A) has the following general formula (3):

(In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group) and / or 2-acrylamido-2-methylpropanesulfonic acid,
The sulfonic acid group-containing copolymer contains 34 to 76% by mass of the structural unit (b) based on 100% by mass of the total amount of the structural units derived from all the monomers forming the sulfonic acid group-containing copolymer. And the structural unit (c) has a ratio of 20 to 55% by mass in terms of an acid type with respect to 100% by mass of the total amount of the structural units derived from all the monomers. Having a structural unit derived from a monocarboxylic acid in a ratio of 1 to 100% by mass in terms of an acid type, with respect to 100% by mass of the total amount of
The product (P × Mw × n) of the mass ratio P of the structural unit (b) to the structural unit (a), the weight average molecular weight Mw of the sulfonic acid group-containing copolymer and n in the general formula (2) is obtained. A sulfonic acid group-containing copolymer having a molecular weight of 950,000 to 800,000,000. A sulfonic acid group-containing copolymer,
The sulfonic acid group-containing copolymer comprises a structural unit (a) derived from a sulfonic acid group-containing monomer (A) and the following general formula (1):

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(Wherein, Z is the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. Or an aryl group having 6 to 12 carbon atoms, and n is an integer of 25 to 200.) Having a structural unit (b) derived from the (poly) oxyalkylene-based monomer (B) and a structural unit (c) derived from the carboxyl group-containing monomer (C),
The sulfonic acid group-containing monomer (A) has the following general formula (3):

(In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group) and / or 2-acrylamido-2-methylpropanesulfonic acid,
The sulfonic acid group-containing copolymer is obtained by converting the structural unit (c) into an acid type in an amount of 20% by mass relative to the total amount of 100% by mass of the structural units derived from all the monomers forming the sulfonic acid group-containing copolymer. Having a ratio of from 1 to 100% by mass, and having a structural unit derived from a monocarboxylic acid in a ratio of from 1 to 100% by mass in terms of an acid type, based on 100% by mass of the total amount of the structural units (c);
The product (P × Mw × n) of the mass ratio P of the structural unit (b) to the structural unit (a), the weight average molecular weight Mw of the sulfonic acid group-containing copolymer and n in the general formula (2) is obtained. A sulfonic acid group-containing copolymer having a molecular weight of 950,000 to 800,000,000. The sulfonic acid group-containing monomer (A) has the following general formula (3);

(In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group) and / or The sulfonic acid group-containing copolymer according to claim 1 or 2 , which is 2-acrylamido-2-methylpropanesulfonic acid. The sulfonic acid group-containing copolymer according to any one of claims 1 to 5 , wherein the sulfonic acid group-containing copolymer has a weight average molecular weight Mw of 20,000 to 200,000. The sulfone according to any one of claims 1 to 6 , wherein the sulfonic acid group-containing copolymer has a mass ratio P of the structural unit (b) to the structural unit (a) of 1.2 to 20. Acid group-containing copolymer. A method for producing a sulfonic acid group-containing copolymer,
The production method includes a sulfonic acid group-containing monomer (A) and the following general formula (1):

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(Wherein, Z is the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkenyl group having 2 to 12 carbon atoms. Or an aryl group having 6 to 12 carbon atoms, and n is an integer of 1 to 200.) A) copolymerizing a monomer component containing a (poly) oxyalkylene monomer (B) and a carboxyl group-containing monomer (C) represented by
The sulfonic acid group-containing monomer (A) includes 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, allylsulfonic acid, vinylsulfonic acid and salts thereof, and the following general formula (3);

(In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group.) At least one selected from the group consisting of
The monomer component contains 34 to 76% by mass of the (poly) oxyalkylene-based monomer (B) with respect to 100% by mass of all monomers, and contains The carboxylic acid is contained in an amount of 20 to 60% by mass in terms of an acid form, and the content of the monomer (E) other than the monomer (A), the monomer (B), and the monomer (C) is all 0 to 30% by mass relative to 100% by mass of the monomer;
The other monomer (E) includes a hydroxyl group-containing alkyl (meth) acrylate, an alkyl (meth) acrylate obtained by esterification of (meth) acrylic acid with an alcohol having 1 to 18 carbon atoms, and an amino group-containing alkyl (meth) acrylate. Acrylates, amide group-containing monomers, vinyl esters, alkenes, aromatic vinyl monomers, maleimide derivatives, nitrile group-containing vinyl monomers, monomers having a phosphonic acid (salt) group , An aldehyde group-containing vinyl monomer, alkyl vinyl ethers, vinyl chloride, vinylidene chloride, allyl alcohol and at least one compound selected from the group consisting of vinylpyrrolidone,
The product (P × Mw × n) of the mass ratio P of the structural unit (b) to the structural unit (a), the weight average molecular weight Mw of the sulfonic acid group-containing copolymer and n in the general formula (2) is obtained. A method for producing a sulfonic acid group-containing copolymer, which is from 950,000 to 800,000,000. A method for producing a sulfonic acid group-containing copolymer,
The production method includes a sulfonic acid group-containing monomer (A) and the following general formula (1):

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(Wherein, Z is the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. Or an aryl group having 6 to 12 carbon atoms, and n is an integer of 25 to 200.) A) copolymerizing a monomer component containing a (poly) oxyalkylene monomer (B) and a carboxyl group-containing monomer (C) represented by
The sulfonic acid group-containing monomer (A) includes 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, allylsulfonic acid, vinylsulfonic acid and salts thereof, and the following general formula (3);

(In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group.) At least one selected from the group consisting of
The monomer component contains a monocarboxylic acid in an amount of 20 to 90% by mass in terms of an acid type with respect to 100% by mass of all monomers, and contains a monomer (A), a monomer (B), and a monomer ( The content ratio of other monomers (E) other than C) is 0 to 30% by mass relative to 100% by mass of all monomers,
The other monomer (E) includes a hydroxyl group-containing alkyl (meth) acrylate, an alkyl (meth) acrylate obtained by esterification of (meth) acrylic acid with an alcohol having 1 to 18 carbon atoms, and an amino group-containing alkyl (meth) acrylate. Acrylates, amide group-containing monomers, vinyl esters, alkenes, aromatic vinyl monomers, maleimide derivatives, nitrile group-containing vinyl monomers, monomers having a phosphonic acid (salt) group , An aldehyde group-containing vinyl monomer, alkyl vinyl ethers, vinyl chloride, vinylidene chloride, allyl alcohol and at least one compound selected from the group consisting of vinylpyrrolidone,
The product (P × Mw × n) of the mass ratio P of the structural unit (b) to the structural unit (a), the weight average molecular weight Mw of the sulfonic acid group-containing copolymer and n in the general formula (2) is obtained. A method for producing a sulfonic acid group-containing copolymer, which is from 950,000 to 800,000,000. A method for producing a sulfonic acid group-containing copolymer,
The production method includes a sulfonic acid group-containing monomer (A) and the following general formula (1):

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(Wherein, Z is the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkenyl group having 2 to 12 carbon atoms. Or an aryl group having 6 to 12 carbon atoms, and n is an integer of 1 to 200.) A) copolymerizing a monomer component containing a (poly) oxyalkylene monomer (B) and a carboxyl group-containing monomer (C) represented by
The sulfonic acid group-containing monomer (A) has the following general formula (3):

(In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group) and / or 2-acrylamido-2-methylpropanesulfonic acid,
The monomer component contains 34 to 76% by mass of the (poly) oxyalkylene monomer (B) and 100% by mass of the carboxyl group-containing monomer (C) based on 100% by mass of the total monomer. 20 to 55% by mass in terms of an acid form with respect to 100% by mass of a monomer, and 1 to 100% by mass of a monocarboxylic acid in terms of an acid form with respect to 100% by mass of the total amount of the carboxyl group-containing monomer (C). Including
The product (P × Mw × n) of the mass ratio P of the structural unit (b) to the structural unit (a), the weight average molecular weight Mw of the sulfonic acid group-containing copolymer and n in the general formula (2) is obtained. A method for producing a sulfonic acid group-containing copolymer, which is from 950,000 to 800,000,000. A method for producing a sulfonic acid group-containing copolymer,
The production method includes a sulfonic acid group-containing monomer (A) and the following general formula (1):

(Wherein, R ¹ represents a hydrogen atom or a methyl group; R ² represents a direct bond, CH ₂ or CH ₂ CH ₂ ; X ⁰ represents the following general formula (2);

(Wherein, Z is the same or different and represents a structure derived from an alkylene oxide having 2 to 20 carbon atoms. R ⁰ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. Or an aryl group having 6 to 12 carbon atoms, and n is an integer of 25 to 200.) A) copolymerizing a monomer component containing a (poly) oxyalkylene monomer (B) and a carboxyl group-containing monomer (C) represented by
The sulfonic acid group-containing monomer (A) has the following general formula (3):

(In the formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a direct bond, any of CH ₂ and CH ₂ CH _2. X and Y represent a hydroxyl group or a SO ₃ M group. In the SO ₃ M group, M represents a hydrogen atom, Li, Na, or K, provided that at least one of X and Y represents an SO ₃ M group) and / or 2-acrylamido-2-methylpropanesulfonic acid,
The monomer component contains the carboxyl group-containing monomer (C) in an amount of 20 to 90% by mass in terms of an acid type with respect to 100% by mass of the total monomer, and the total amount of the carboxyl group-containing monomer (C) is 100%. Based on the mass%, the monocarboxylic acid contains 1 to 100 mass% in acid form conversion,
The product (P × Mw × n) of the mass ratio P of the structural unit (b) to the structural unit (a), the weight average molecular weight Mw of the sulfonic acid group-containing copolymer and n in the general formula (2) is obtained. A method for producing a sulfonic acid group-containing copolymer, which is from 950,000 to 800,000,000.