KR20050058785A - Introduction and manufacturing method of bentonite involving dispersion polymer - Google Patents

Abstract

The present invention relates to water-soluble polymer dispersions containing bentonite for use in improving the papermaking process, in particular wet-end retention and drainage, and methods for their preparation.

The present invention provides 1 to 10% by weight of the compound of Formula 1, 0 to 20% by weight of the compound of Formula 2, 0.1 to 10% by weight of bentonite, and water such that the total composition is 100% by weight It provides a water-soluble polymer dispersion containing.

Description

Water-soluble polymer dispersion containing bentonite and its preparation method {INTRODUCTION AND MANUFACTURING METHOD OF BENTONITE INVOLVING DISPERSION POLYMER}

The present invention relates to water soluble polymer dispersions for the improvement of retention and drainage in papermaking processes. More specifically, the present invention relates to water soluble polymer dispersions which essentially contain bentonite in combination with certain cationic monomers and methods for their preparation.

In the manufacture of paper and cardboard, organic synthetic materials and inorganic minerals are used together with hydrophilic polymers in order to increase the efficiency of retention and drainage during the papermaking process, and the related art is as follows.

U.S. Patent No. 4,753,710 discloses improved retention, drainage, drying or coalescence when combined with organic polymer materials and inorganics in the stock. Especially when cationic polymers having a molecular weight of 500,000 or more are added at least 0.03% by weight relative to the dry pulp, and after one or more shearing steps, bentonite is generally added in a range of 0.03 to 0.5% by weight, preferably 0.08 to 0.25% by weight. It is disclosed that there is an excellent improvement effect.

U.S. Patent Nos. 4,388,150 and 4,710270 illustrate retention, drainage, and intelligence systems using colloidal silica in cationic starch and organic polymers.

U.S. Pat.Nos. 5,185,062 and 5,098,520 also disclose systems using high molecular weight cationic polymers and medium molecular weight anionic polymers, while US Pat. No. 6,238,521 discloses organic coagulants and diallyldimethylammonium chlorides. It is suggested that retention and drainage can be improved by adding microparticles selected from the group consisting of an organic material such as a copolymer of polyacrylic acid, an inorganic material such as bentonite, and a silica sol to a polymer containing.

U.S. Patent Nos. 4,929,655 and 5,587,415 exemplify the preparation of dispersion polymers polymerized in salt solutions and their application. In addition, Korean Patent No. 1998-034277 exemplifies a particulate water-soluble water dispersion containing colloidal silica and a method for preparing the same, and describes that the effect is superior to that of the prior art.

As such, in order to increase the efficiency of retention and drainage during the papermaking process, inorganic materials such as bentonite are widely used as retention enhancers, and are generally used in combination with cationic retention agents. However, bentonite can cause respiratory failure due to the large amount of dust when working in powder form, and the powder bentonite that has fallen around the workplace can slip on water and cause a safety accident.

On the other hand, Japanese Laid-Open Patent Publication No. 2003-96112 discloses a dispersion composed of anionic polymerized fine particles in the presence of inorganic particles such as bentonite and kaolin, and thus efforts to improve retention and drainage in the papermaking process are It is going on.

Applicants have found that a water soluble polymer dispersion essentially containing bentonite in combination with certain cationic monomers can improve the efficiency of retention and drainage in the papermaking process, and has completed the present invention.

This technical feature of the present invention is that, unlike the prior art, respectively, in which bentonite is used in parallel with a cationic retention agent, the two materials are integrated into one material. In addition, although bentonite is an anion, it has a property of not being gelled by combining with a cationic monomer.

Japanese Patent Laid-Open Publication No. 2003-96112 also discloses a water-soluble polymer in which inorganic substances such as bentonite and kaolin are added to anionic monomers such as acrylic acid or itaconic acid to be dispersed and polymerized, but the present invention is based on cationic monomers. I am doing it.

The water-soluble polymer dispersion containing bentonite of the present invention has the following distinctions from the prior art.

According to the present invention, it can be seen that the effects of the two drugs disclosed in U.S. Patent No. 4,753,710 are integrated in one drug. Thus, in the case of the water-soluble polymer according to the present invention in which the cationic monomer and the bentonite are integrated, It has a three-dimensional stabilization function in addition to the linear polymer function, it is strong in shear force and can exhibit an excellent effect on drainage.

The steric stabilization function refers to a function in which a polymer in bentonite aqueous solution injected into a stock forms its own bentonite and a kind of network structure so that the floc of the stock maintains a constant size and interval.

The use of an aqueous solution polymer containing bentonite having such steric stabilization function can smoothly achieve retention / drainage in high speed paper machine, high fine ash-containing recycled paper, and high ash (filler) paper. have.

In addition, the aqueous solution polymer containing bentonite according to the present invention is copolymerized with dimethylamine / epichlorohydrin / ethyleneamine terpolymer and polyethyleneimine to exhibit excellent effects on charge neutralization, removal of anion trash and drainage. . The reason is that dimethylamine / epichlorohydrin / ethyleneamine terpolymers have been widely used as charge neutralization, anion residue removal, and coating broth (Art Broke) pretreatment, and polyethyleneimine is a multi-layer paper machine. This is because the product was used for dehydration (particularly press parts). For this reason, particle stability, conversion neutralization, anion residue removal, and dehydration can be simultaneously achieved.

The present invention has to use a variety of processes and chemicals with conventional products and techniques, such as retention and drainage during the papermaking process, neutralization of charges and removal of anion trash, but the characteristics of the present invention is one process. To be intensive.

By using the aqueous solution containing bentonite according to the present invention, retention / drainage can be smoothly achieved in high speed paper machine, high fine powder-containing recycled paper, and high ash (filler) paper, which have been conventionally limited.

After all, the first object of the present invention is to provide a water-soluble polymer dispersion containing bentonite.

It is also a second object of the present invention to provide a method for producing a water-soluble polymer dispersion containing bentonite.

As a means for realizing the first object of the present invention, there is provided a water-soluble polymer dispersion containing a compound of formula (1), a compound of formula (2) and bentonite.

More specifically, the present invention provides 1 to 10% by weight of the compound of Formula 1, 0 to 20% by weight of the compound of Formula 2, 0.1 to 10% by weight of bentonite, and 100% by weight of the total composition. A water-soluble polymer dispersion is provided which contains water to

(In the meal,

R ₁ is hydrogen or an alkyl group having 1 to 3 carbon atoms;

R ₂ and R ₃ are each independently an alkyl group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms;

A ₁ is an oxygen or amine group, B ₁ is an alkylene or hydropropylene group having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, and X ₁ ⁻ is a counter anion)

(In the meal,

R ₄ is hydrogen or an alkyl group having 1 to 3 carbon atoms;

R ₅ and R ₆ are each independently an alkyl group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms;

R ₇ is hydrogen or an alkyl group having 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms;

A ₂ is oxygen or an amine group;

B ₂ is an alkylene group or a hydropropylene group having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, and X ₂ ⁻ is a counter anion.)

Hereinafter, the configuration of the present invention in more detail.

The present invention relates to a water soluble polymer dispersion which essentially contains certain cationic monomers and bentonite.

The water-soluble polymer dispersion according to the present invention contains a cationic monomer represented by the formula (1), a cationic monomer represented by the formula (2), bentonite, and may contain any other additives.

The water-soluble polymer dispersion according to the present invention contains 1 to 10% by weight of the cationic monomer represented by the formula (1). The cationic monomer represented by the formula (1) is dimethylaminoacrylate benzyl chloride quaternization.

The water-soluble polymer dispersion according to the present invention contains 0 to 20% by weight of the cationic monomer represented by the formula (2). Examples of the cationic monomer represented by the formula (2) include dimethylaminoethyl acrylate methacrylate quaternization.

The cationic monomer represented by Formula 1 may be contained alone in the water-soluble polymer dispersion according to the present invention, may be mixed with the cationic monomer represented by Formula 2, or may be used in the form of a copolymer of Formula 1 and Formula 2 have. At the time of mixing, the mixing ratio of the compounds of the formulas (1) and (2) is 0.2: 9.8 to 9.8: 0.2 and the ratio is adjusted according to the type of paper applied.

The water-soluble polymer dispersions according to the present invention contain bentonite from 0.1 to 10% by weight, preferably from 0.5 to 3.0% by weight. Although the kind of bentonite is not specifically limited, calcium modified bentonite, sodium modified bentonite, etc. are used preferably.

The water-soluble polymer dispersions according to the present invention essentially contain cationic monomers and bentonite, but in addition, 10 to 30% by weight of anionic salts, 1.0 to 10% by weight of dispersion stabilizers, 0.5 to 10% by weight of acrylamide, It may contain 0.2-3.0% by weight of dimethyl diallyl ammonium chloride.

The anion salt which may be contained in the water-soluble polymer dispersion according to the present invention is not particularly limited, but preferably ammonium sulfate, ammonium hydrogen sulfate, sodium sulfate, sodium hydrogen sulfate, magnesium sulfate, magnesium hydrogen sulfate, aluminum sulfate, hydrogen sulfate It is selected from the group consisting of aluminum, sodium chloride, ammonium chloride, ammonium phosphate, sodium phosphate, sodium citrate, mainly divalent salts are used, depending on the characteristics of the product can also be used by adding a small amount of monovalent salts.

The dispersant stabilizer that may be contained in the water-soluble polymer dispersion according to the present invention is not particularly limited, but preferably dimethylamine / epichlorohydrin / ethyleneamine terpolymer, dimethyl diallyl ammonium chloride polymer, polyethyleneimine, and the like can be used. have.

Means for realizing a second object of the present invention, comprising: a first step of heating and mixing a part of bentonite with a compound of formula 1, optionally a compound of formula 2 and other additives; A second step of polymerization by adding a polymerization initiator; A third step of further polymerizing by further adding the remaining bentonite and the secondary polymerization initiator; And a fourth step of adding a anion salt to obtain a polymer.

In the first step, other additives include, but are not limited to, anionic salts, dispersant stabilizers, acrylamide and dimethyl diallyl ammonium chloride.

The heating temperature in the first step is 20 to 70 ℃, preferably 25 to 55 ℃, the stirring speed is 20 to 400 rpm, preferably 150 to 300 rpm.

Although it does not specifically limit as a polymerization initiator used for manufacture of the water-soluble polymer dispersion which concerns on this invention, but AIBN- (nitrogen type) -2,2- azobis 2- (2-imidazolin-2-yl) propanedihydro Chloride is preferably used.

In preparing the water-soluble polymer dispersion according to the present invention, bentonite may be added at one time at the beginning of the reaction, but it is preferable to add it separately in the initial and middle stages of the reaction, since it may reduce mechanical overload during the production process. . When bentonite is added separately, it is preferable to add 0.1 to 10% of the total amount to be added in the first step and the remaining amount in the third step.

The split dose of bentonite in the third step is preferably performed 10 minutes to 60 minutes before the secondary initiator input, preferably 20 minutes to 40 minutes, most preferably about 30 minutes before.

The water-soluble polymer dispersion according to the present invention is characterized in that it contains hydrophilic cellulose and bentonite used in the papermaking process mainly containing mineral fillers such as talc, clay, CaCO ₃ , TiO ₂ , and at least 2 mol% of cationic monomers. A water soluble monomer mixture containing the above is prepared in a solution of anionic salts.

The water-soluble polymer dispersions according to the present invention, unlike conventional products, are not affected by polymerization and final pH. Korean Patent No. 1998-0082096 describes adjusting the pH of the final product to 4.0 or less. In order to lower the pH, it is troublesome to add a strong acid solution such as glacial acetic acid, hydrochloric acid, sulfuric acid, etc. There is a problem. However, according to the present invention, there is almost no change in pH from the start of the reaction to the final product, and the pH of the final product is in the range of 4.5 to 6.0 depending on the amount of bentonite added.

In addition, one of the characteristics of the present invention was to increase the reaction temperature 10 to 15 ℃ before the end of the reaction 2 hours to 6 hours to ensure the stability of the product by minimizing the remaining monomers by adding a reaction terminator and residual monomer remover .

EXAMPLE

Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example.

The water-soluble polymer prepared in the following example was reacted to an amount of about 1 kg.

Example 1

16.8% by weight of ammonium sulfate, 25.9% by weight of acrylamide, 2.56% by weight of dimethylaminoethylacrylatebenzylchloride salt, 2.4% of dimethylamine epichlorohydrinethyleneamine terpolymer in a flask that can be heated and cooled, dimethylaminoethylacrylatemethyl 0.75% by weight of chloride polymer, 3.43% by weight of diaryldimethylammonium chloride polymer, 0.45% by weight of glycerin, and 36.778% by weight of deionized water were added thereto while stirring and 4.5% by weight of bentonite. At this time, the flask is heated and stirred while continuously blowing nitrogen gas, the stirring speed is 150 to 300 rpm. When the temperature reaches 33 ° C., 0.0015% by weight of azobis-based polymerization catalyst is added. After reacting for about 6 hours, 1.429% by weight of bentonite was added, followed by additional addition of 0.0015% by weight of 2.2-azobis2- (2-imidazolin-2-yl) propanedihydrochloride after about 30 minutes. After about 10 to 14 hours, the reaction temperature was increased to 10 to 15 ° C., and then, for about 1 to 2 minutes after adding 0.03% to 0.06% of ammonium persulfate, 0.15% to 0.3% of the total amount of sodium bisulfite was added. After further addition, 6.5 wt% of sodium sulfate was added, and the reaction product obtained was passed through a filter to obtain a water-soluble polymer containing bentonite.

Example 2

15.2% by weight of ammonium sulfate, 13.894% by weight of acrylamide, 12.676% by weight of dimethylaminoethylacrylatebenzylchloride quaternary salt, 3.64% by weight of dimethylaminoethylacrylatemethylchloride, and dimethylamine epichlorohydrinethylene in a flask that can be heated and cooled 0.675% of amine terpolymer, 1.5% by weight of dimethylaminoethylacrylatemethylchloride polymer, 0.553% by weight of diaryldimethylammonium chloride polymer, 0.4% by weight of glycerin, 39.0% by weight of deionized water, 4.5% by weight of bentonite Input At this time, the flask is heated and stirred while continuously blowing nitrogen gas, the stirring speed is 150 ~ 300 rpm. When the temperature reaches 33 ° C., 0.002% of 2.2-azobis2- (2-imidazolin-2-yl) propanedihydrochloride is added as an azobis polymerization catalyst. After reacting for about 6 hours, additional bentonite 0.358% was added, and after about 30 minutes, additional 2.2-azobis2- (2-imidazolin-2-yl) propanedihydrochloride was added 0.002%. After about 10 to 14 hours, the reaction temperature was raised to 10 to 15 ° C, and then 0.02% to 0.06% of ammonium persulfate was added in about 1 to 2 minutes, and then 0.15% to 0.3% of sodium bisulfite was added. After the addition, 7.60% of ammonium sulfate was added and the reaction product obtained was passed through a filter to obtain a water-soluble polymer containing bentonite.

Example 3

15.3% by weight of ammonium sulfate, 13.89% by weight of acrylamide, 12.67% by weight of dimethylaminoethylacrylatebenzylchloride quaternary salt, 3.64% by weight of dimethylaminoethylacrylatemethylchloride, and dimethylaminoethylacrylatemethylchloride in a flask capable of heating and cooling 5.00% by weight of bentonite is added while stirring by adding 5.00% by weight of polymer, 0.6% by weight of dimethylamine epichlorohydrin ethyleneamine terpolymer, 0.2% by weight of polyethyleneimine, 0.6% by weight of glycerin, and 32.643% of deionized water. At this time, the flask is heated and stirred while continuously blowing nitrogen gas, the stirring speed is 150 ~ 300 rpm. When the temperature reaches 45 ° C., 0.002% by weight of azobis-based polymerization catalyst is added. After reacting for about 4 hours, add 2.859% by weight of bentonite, and then add 0.0015% by weight of azobis-based polymerization catalyst after about 30 minutes, and then increase the reaction temperature by 10 to 15 ° C after about 10 hours. After 1 to 2 minutes of adding 0.03% to 0.06% of ammonium persulfate, 0.15% to 0.3% of sodium bisulfite is added, and 7.595% by weight of ammonium sulfate is added, and then the reaction product is filtered. Passing through gave a water soluble polymer containing bentonite.

Example 4

16.88% by weight of ammonium sulfate, 23.94% by weight of acrylamide, 0.054% by weight of dimethylaminoethylacrylatebenzylchloride quaternary salt, 0.976% by weight of diaryldimethylammonium chloride, dimethylaminoethylacrylatemethylchloride polymer in a flask capable of heating and cooling 0.75 Wt%, dimethylamine epichlorohydrin ethyleneamine terpolymer, 1.35 wt%, glycerin 0.375 wt%, deionized water, 42.3165 wt% were added to a flask with a jacket capable of heating and cooling to add 2.429 wt% of bentonite while stirring. do. At this time, the flask is heated and stirred while continuously blowing nitrogen gas, the stirring speed is 150 ~ 300 rpm. When the temperature reaches 33 ° C., 0.00175% by weight of 2.2-azobis2- (2-imidazolin-2-yl) propanedihydrochloride is added as an azobis-based polymerization catalyst. After reacting for about 6 hours, an additional 1.429% of bentonite was added, and an additional 0.00175% by weight of 2.2-azobis2- (2-imidazolin-2-yl) propanedihydrochloride was added after about 30 minutes. After about 10 to 14 hours, the reaction temperature was raised to 10 to 15 ° C, and then 0.02% to 0.06% of ammonium persulfate was added. After 1 to 2 minutes, sodium bisulfite was added to 0.15% to 0.3% of the total amount. After the addition, 6.497% by weight of sodium sulfate was added, and the obtained reaction product was passed through a filter to obtain a water-soluble polymer containing bentonite.

Example 5

16.268 weight percent ammonium sulfate, 21.460 weight percent acrylamide, 4.525 weight percent dimethylaminoethyl acrylate benzyl chloride quaternary salt, 0.812 weight percent dimethylaminoethyl acrylate methyl chloride, dimethylaminoethyl acrylate methyl chloride in a flask capable of heating and cooling 0.75 wt% polymer, 1.286 wt% diaryldimethylammonium chloride polymer, 0.9 wt% dimethylamine epichlorohydrin ethyleneamine terpolymer, 0.15 wt% polyethyleneimine, 0.45 wt% glycerin, 38.715 wt% deionized water 7.15 wt% of bentonite is added while stirring. At this time, the flask is heated and stirred while continuously blowing nitrogen gas, the stirring speed is 150 ~ 300 rpm. When the temperature reaches 33 ° C., 0.0015% by weight of 2.2-azobis2- (2-imidazolin-2-yl) propanedihydrochloride is added as an azobis polymerization catalyst. After reacting for about 6 hours, 0.0015% by weight of 2.2-azobis2- (2-imidazolin-2-yl) propanedihydrochloride was further added, and the reaction temperature was 10 to 15 after about 10 to 14 hours. After raising the temperature to about 1 minute to 2 minutes after adding 0.03% to 0.06% of ammonium persulfate, and adding 0.15% to 0.3% of sodium bisulfite, and then adding 7.531% by weight of sodium sulfate The product was passed through a filter to obtain a water soluble polymer containing bentonite.

Example 6

15.949% by weight of ammonium sulfate, 6.496% by weight of acrylamide, 15.409% by weight of dimethylaminoethylacrylatebenzylchloride quaternary salt, 5.531% by weight of dimethylaminoethylacrylatemethylchloride, and dimethylaminoethylacrylatemethylchloride in a flask that can be heated and cooled 3.00% by weight of polymer, 0.20% by weight of glycerin, 46.364% by weight of deionized water are added, and 1.50% by weight of bentonite is added while stirring. At this time, the flask is heated and stirred while continuously blowing nitrogen gas, the stirring speed is 150 ~ 300 rpm. When the temperature reaches 33 to 0.0015% of 2.2-azobis2- (2-imidazolin-2-yl) propanedihydrochloride is added as an azobis-based polymerization catalyst. After reacting for about 6 hours, an additional 1.50 wt% of bentonite was added, and an additional 0.0015 wt% of 2.2-azobis2- (2-imidazolin-2-yl) propanedihydrochloride was added after about 30 minutes. After about 10 to 14 hours, the reaction temperature was increased to 10 to 15 ° C., and then 0.02% to 0.06% of ammonium persulfate was added in about 1 to 2 minutes. Sodium bisulfite was 0.15% to 0.3% of the total amount. After further addition, 4.051% by weight of ammonium chloride was added, and the obtained reaction product was passed through a filter to obtain a water-soluble polymer containing bentonite.

Paper Application Experiment 1: Application Examples 1 to 5

Paper grade: boxed (cardboard) 180 g / m ²

pH: 6.8

Stock concentration: 0.63%

Composition of materials: 100% domestic box (KOCC)

Laboratory equipment: Brittjar

TABLE 1

Application contents (input amount based on 1 ton of paper) Percent transient holdoff (%) of fines Turbidity (NTU) Application example 1  No reserve 18.26 784 Application example 2 Conventional Cationic Retention Agent 300ppm + Bentonite 2500ppm 63.47 485 Application example 3 Conventional Cationic Starch 700ppm + Colloidal Silica 800ppm 65.85 402 Application example 4 Conventional Cationic Retention Agent 300ppm + Colloidal Silica 2000ppm 48.31 531 Application example 5 300 ppm of the polymer of Example 1 of the present invention 80.62 327

Paper Application Experiment 2: Application Examples 6 to 10

Paper grade: neutral paper 80g / m ²

pH: 7.21

Concentration of stock: 0.51% Composition of stock: Bleached pulp 80% + Filler (ash) 20% (CaCO ₃ )

Laboratory equipment: Brittjar

TABLE 2

Application contents (dosing amount is based on 1 ton of paper) Hot-holding rate (OPR) of batch (%) Turbidity (NTU) Application example 6 No reserve 12.31 324 Application example 7 Conventional Cationic Retention Agent 400ppm + Bentonite 2000ppm 52.47 209 Application example 8 Conventional Cationic Starch 8000ppm + Colloidal Silica 6000ppm 49.75 238 Application example 9 Example 1 polymer 400ppm of the present invention 57.11 164 Application Example 10 400 ppm of Example 2 polymer of the present invention 65.30 125

Paper Application Experiment 3: Application Examples 6 to 10

Paper grade: 46g / m ² newspaper

pH: 6.94

Stock concentration: 0.43%

Constituents: Domestic newspaper notice 50% + Foreign newspaper notice 35% + Magazine notice 15%

Laboratory equipment: Brittjar

TABLE 3

Application contents (dosing amount is based on 1 ton of paper) Transient retention rate of fines (OPR) (%) Turbidity (NTU) No reserve 20.41 512 Conventional Cationic Retention Agent 200ppm + Bentonite 2000ppm 54.37 351 Conventional Cationic Retention Agent 200ppm + Colloidal Silica 2000ppm 47.68 384 Example 3 Polymer of the Invention 200 ppm 61.26 246 Example 4 Polymer 200ppm of the Invention 68.95

As can be seen from the results of Tables 1 to 3, in the case of the water-soluble polymer according to the present invention in which the cationic monomer and the bentonite are integrated, the cationic retention agent (or cationic starch) and bentonite (or colloidal silica) are respectively It can be seen that the fine powder and ash transient retention ratio (OPR) is higher than the conventional techniques added, which means that the yield is improved, thereby reducing the cost and minimizing the amount of raw materials flowing into the wastewater plant. The processing efficiency can be increased. In addition, it can be seen that turbidity is also improved in the case of the polymer according to the present invention.

When the water-soluble polymer dispersion containing the specific cationic monomer and bentonite produced by the present invention is used in the papermaking process, the efficiency of retention and drainage can be further improved.

Claims (7)

1 to 10% by weight of the compound of formula 1, 0 to 20% by weight of the compound of formula 2, 0.1 to 10% by weight of bentonite, and water such that the total weight of the total composition is 100% by weight Water-soluble polymer dispersion containing: [Formula 1] (In the meal, R ₁ is hydrogen or an alkyl group having 1 to 3 carbon atoms; R ₂ and R ₃ are each independently an alkyl group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms; A ₁ is an oxygen or amine group, B ₁ is an alkylene group having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, and X ₁ ⁻ is a counter anion) [Formula 2] (In the meal, R ₄ is hydrogen or an alkyl group having 1 to 3 carbon atoms; R ₅ and R ₆ are each independently an alkyl group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms; R ₇ is hydrogen or an alkyl group having 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms; A ₂ is oxygen or an amine group; B ₂ is 2 to 8 carbon atoms, preferably 2 to 4 alkylene groups, and X ₂ ⁻ is a counter anion) The water-soluble polymer dispersion according to claim 1, which further contains 1 to 10% by weight of anionic salts. The water-soluble polymer dispersion according to claim 1, which further contains 0.1 to 10% by weight of a dispersion stabilizer. 4. The water-soluble polymer dispersion according to claim 3, wherein said dispersion stabilizer is selected from the group consisting of dimethylamine / epichlorohydrin / ethyleneamine terpolymer, dimethyl diallyl ammonium chloride polymer and polyethyleneimine. The water-soluble polymer dispersion according to claim 1, which further contains 0.5 to 10% by weight of acrylamide. A process for preparing a water-soluble polymer dispersion containing bentonite according to any one of claims 1 to 5, comprising: a first step of heating and mixing a part of bentonite with a compound of Formula 1, an optional compound of Formula 2, and other additives ; A second step of polymerization by adding a polymerization initiator; A third step of further polymerizing by further adding the remaining bentonite and the secondary polymerization initiator; And a fourth step of adding an anionic salt to obtain a polymer. The method according to claim 6, wherein the reaction terminator and the remaining monomer remover are added after raising the reaction temperature 10 to 15 DEG C 2 to 6 hours before the end of the reaction.