WO2021112416A1 - Water-dispersible anionic polymer dispersion of high molecular weight and method for producing same - Google Patents

Abstract

The present invention relates to a water-dispersible anionic polymer dispersion of a high molecular weight that is more effective in water treatment, dredging, soil remediation, and/or crude oil treatment, and a method for producing same. More specifically, the present invention may provide a water-dispersible anionic polymer dispersion not only having small, uniform particles and a high molecular weight by adjusting the balance between polymerization speed and salting out speed and changing the molecular structure using a specific molecular weight modifier and/or a structuring agent, but also having high fluidity by allowing copolymerized anionic polymer particles to be stably dispersed from one another by electrostatic repulsive force.

Description

High molecular weight, water-dispersible anionic polymer dispersion and method for preparing the same

The present invention relates to a high molecular weight eco-friendly water-dispersible anionic polymer dispersion and a method for preparing the same, which are more effective for water treatment, dredging, soil restoration and/or crude oil treatment.

Water-soluble polymers are convenient to use and easy to dissolve, and can be used immediately after dissolution without aging time. In addition, as it has excellent efficiency and does not contain other substances that may affect the final product, such as oil, it has been continuously studied from the beginning of development until now as it accommodates eco-friendly demands.

Among the water-soluble polymers, the emulsion polymer containing oil is used in industrial wastewater treatment, sewage treatment, water treatment, oil-water separation process, soil improvement and rapid separation of solids and liquids in various industries, and is used in the papermaking process It has also been used as a solvent retention enhancer and as an oil field drug.

It is confirmed that the emulsion polymer dispersion or powder-type product containing oil has a high molecular weight and exhibits an excellent effect in terms of floc-forming ability. However, in the case of an emulsion polymer dispersion, it has to undergo a certain period of aging after dissolution, and the storage stability of the product is lowered, such as layer separation during long-term storage due to phase separation and creaming caused by oil content. In addition, due to the oil component contained in itself, a phenomenon that impairs the quality of the final product and a secondary treatment for removing the oil component (impurity) is required, which is inefficient in terms of economic feasibility and workability. And due to the content of a large amount of surfactant, it has the disadvantage of acting as a factor for increasing turbidity and COD in water.

In addition, the water-soluble polymer in powder form takes a long time for dissolution operation, so workability is deteriorated, the cost of auxiliary equipment is increased, and workability is deteriorated due to the harmfulness to the human body due to dust. In addition, there is a problem that not only causes economic loss due to undissolved product, but also undissolved product may cause severe side effects such as precipitation and adhesion during oil-water separation process of crude oil.

On the other hand, oil-free water-soluble polymer dispersions (hereinafter referred to as 'water-dispersible polymer dispersions') are environmentally friendly, do not cause layer separation even when stored for a long period of time compared to emulsion polymers, and do not contain oil. Simplification and contamination of various facilities (piping, work area, etc.) are reduced. In addition, the cleanliness of the separated filtrate after use is excellent, and the recycling rate of the separated treated water can be increased. Such a water-soluble polymer dispersion is generally prepared by dispersion polymerization, but it is difficult to prepare a high molecular weight, water-soluble anionic polymer dispersion due to the limitations of the dispersion polymerization method.

Accordingly, there is a need for research on a method for preparing a water-dispersible polymer dispersion that is environmentally friendly and has a higher maximum molecular weight.

The present invention has been devised to solve the above problems, and it is a technical task to provide a high molecular weight, water-dispersible anionic polymer dispersion and a method for preparing the same even if a dispersion polymerization method is applied through discovery of new additives, establishment and optimization of appropriate reaction conditions do it with

Other objects and advantages of the present invention may be more clearly explained by the following detailed description and claims.

In order to achieve the above technical problem, the present invention is (a) an anionic monomer; (b) nonionic monomers; (c) anionic stabilizers; (d) anionic dispersants; (e) at least one of a molecular weight modifier and a structuring agent; (f) chelating agents; and (g) anionic polymer particles copolymerized in (h) a salt solution containing a polymerization initiator, wherein the anionic polymer particles have an average particle diameter (d50) of 1 to 30 μm, and an anion degree of 3 to 90 mol %, effective concentration of 5-30% by weight, and 0.5% salt viscosity of 250 ~ 1,000 cps (based on 25°C) to provide a water-dispersible anionic polymer dispersion.

In one embodiment according to the present invention, the anionic polymer particles have an anionic dispersant adsorbed on part or all of the surface, and the anionic dispersant is a naphthalene-based dispersant, a ligrin-based dispersant, a melamine-based dispersant, and a sulfonic acid-based dispersant. It may be at least one selected from the group consisting of a dispersant, and a polycarboxylic acid-based copolymer.

In one embodiment according to the present invention, the anionic dispersant is ligrin, ligrin sulfonic acid, lignin sulfonate, naphthalene sulfonic acid formalin condensate, melamine formaldehyde condensate, polyethylene glycol sulfonic acid ether, polyethylene glycol alkyl ether , naphthalenesulfonate, melaminesulfonic acid formalin condensate, sodium dodecyldiphenyletherdisulfonate, sulfonic acid salt, alkylbenzenesulfonate, alkylbenzenesulfonate salt, laurylethersulfonic acid, laurylethersulfonate, polycarryl Acid salt and polyethylene glycol mixture, methacrylic acid-methoxypolyethylene glycol monomethacrylate copolymer sodium salt, acrylamide copolymer and alcohol ethoxylate sulfite sodium salt mixture, acrylamide copolymer and sodium lauryl ether sulfate mixture, poly It may be at least one selected from the group consisting of a mixture of a carboxylate and sodium sulfonic acid salt, a polycarboxylic acid copolymer having a polyoxyethylene side chain, and a copolymer derived from a polycarboxylate.

In one embodiment according to the present invention, the anionic dispersant may be added in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer.

In one embodiment according to the present invention, the molecular weight modifier is glycolic acid, lactic acid, ethylene glycol, sodium hypophosphite monohydrate, thiol group ( -SH) may be at least one selected from the group consisting of methyl mercaptan, ethyl mercaptan, aryl mercaptan, and thioacetic acid.

In one embodiment according to the present invention, the molecular weight modifier may be added in an amount of 0.001 to 15 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer.

In one embodiment according to the present invention, the structuring agent is methylene-bis-acrylamide, arylthiourea, bis-acryloyl cystamine, dihydroxyethylene It may be at least one selected from the group consisting of bisacrylamide (dihydroxyethylene-bis-acylamide), ethylene diacrylate, and ethylene glycol dimethacrylate.

In one embodiment according to the present invention, the structuring agent may be added in an amount of 0.0001 to 2 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer.

In one embodiment according to the present invention, the anionic stabilizer is a homopolymer or a copolymer thereof produced in a solution containing (meth)acrylic acid, a hydroxyl group-containing compound, a metal ion sequestering agent and an initiator, and a viscosity of 2,000 to 10,000 It can have cps and a pH of 8-12.

In one embodiment according to the present invention, the anionic stabilizer may be added in an amount of 2 to 8 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer.

In one embodiment according to the present invention, the salt solution may be an aqueous solution containing 20 to 30% (w/v) of ammonium sulfonate.

In one embodiment according to the present invention, the pH before polymerization of the salt solution may be 4.7 to 5.2.

For an example according to the present invention, the water-dispersible anionic polymer dispersion has a product viscosity (25° C.) measured by a Brookpildo viscometer (DV2T type, measurement conditions Spindle No. 62, 12 rpm) of 50 to 2,500 cps. can

In one embodiment according to the present invention, the water-dispersible anionic polymer dispersion may have storage stability at a temperature of -10 °C or higher.

In one embodiment according to the present invention, the water-dispersible anionic polymer dispersion may be used for water treatment, dredging, soil restoration, or crude oil treatment.

According to an embodiment of the present invention, at least one of a specific molecular weight regulator and a structuring agent is used to control the balance between the polymerization rate and the salting-out rate, and by changing the molecular structure to form hard flocs, dehydration, sedimentation, It can provide a more improved effect in terms of turbidity. In addition, by providing a stable, water-dispersible, eco-friendly anionic polymer dispersion with small particle size, uniformity, and high fluidity, it can exhibit superior performance in water turbidity and COD compared to conventional emulsion products.

In addition, the specific anionic dispersant adopted in the present invention is adsorbed to the copolymerized radical copolymer particles to have a negative charge on the surface, thereby producing a high-flowing anionic polymer dispersion stably and uniformly dispersed by electrostatic repulsion. Compared to molecular weight products, it is possible to provide better performance in terms of sedimentation while reducing the amount of input.

In addition, since the high molecular weight, eco-friendly, water-dispersible anionic polymer dispersion according to the present invention is an oil-free product, it is more eco-friendly than the emulsion flocculant most commonly used as a conventional liquid polymer flocculant, and can be used instead of the emulsion flocculant. .

Furthermore, by the method for producing a water-dispersible anionic polymer dispersion according to the present invention, a high-molecular-weight water-soluble polymer dispersion, which is a limitation of the dispersion polymerization method, can be prepared in high yield.

The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a process flow chart showing a method for preparing a high molecular weight, water-dispersible anionic polymer dispersion according to an embodiment of the present invention

Figure 2 is a process flow chart showing a method for producing an anionic stabilizer according to an embodiment of the present invention.

The present invention will be described in more detail with reference to the following examples. These examples are only for explaining the present invention in more detail, and it is for those of ordinary skill in the art to which the present invention pertains that the scope of the present invention is not limited by these examples according to the gist of the present invention. it will be self-evident

All terms (including technical and scientific terms) used in this specification may be used in the meaning commonly understood by those of ordinary skill in the art to which the present invention pertains, unless otherwise defined. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly specifically defined.

In addition, throughout the present specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, throughout the specification, "on" or "on" means that it includes not only the case where it is located above or below the target part, but also the case where there is another part in the middle, and the direction of gravity must be It does not mean that it is positioned above the reference.

< High molecular weight water dispersible anionic polymer dispersion >

The water-dispersible anionic polymer dispersion according to the present invention is a water-soluble polymer dispersion containing anionic polymer particles produced by dispersion polymerization in a solvent. More specifically, salt solutions; high molecular weight anionic polymer particles (or water-soluble polymer) dispersed in the salt solution; and an anionic dispersant adsorbed to a part or all of the surface of the polymer particle.

In general, if the particle size of the water-soluble polymer is too large, it is likely to precipitate in the dispersion and the storage stability of the dispersion may be reduced. If the particle size is too small, the dispersibility and storage stability of the dispersion may decrease due to precipitation due to agglomeration between coagulants. Therefore, it is desirable to optimize the size of the water-soluble polymer. However, when the water-soluble polymer is formed by dispersion polymerization, it is difficult to control the particle size of the water-soluble polymer.

In addition, the dispersion polymerization method is a method of polymerization using the difference in solubility between the monomer and the polymer in a salt solution as a dispersion medium. Specifically, a water-soluble monomer soluble in the salt solution is polymerized to precipitate as polymer particles that are not soluble in the salt solution, It is a method of obtaining a final target by giving the generated polymer particles specific gravity stability considering electrical safety and specific gravity of the dispersion medium. In such dispersion polymerization, it is very important to control the polymerization rate of the reactants. For example, if the polymerization rate of the reaction monomers is too fast, nucleation and salting out proceed together with an increase in the viscosity of the reactants, resulting in poor heat exchange of the reactants, resulting in poor molecular weight distribution, thereby reducing the stability of salted out particles, in some cases Accordingly, the polymerization reaction is stopped or the reactant is cured. In addition, if the polymerization rate of the reactant is too slow, the viscosity of the reactant does not increase, but nucleation and salting out also slow down, so the reaction time takes a long time, and the final product with a low molecular weight is produced, and a product with unstable and irregular particles is produced. .

Therefore, in the present invention, when preparing a water-soluble anionic polymer by dispersion polymerization, at least one of a specific molecular weight modifier and a structuring agent is used to control the balance between the polymerization rate and the salting-out rate, and at the same time to change the molecular structure of the generated polymer. By forming flocs, it is possible to exhibit improved effects in dehydration, sedimentation, turbidity, and the like. In addition, the resulting water-soluble polymer can be uniformly formed with a small particle size.

In addition, in the present invention, a specific anionic dispersant capable of imparting a negative charge to the surface of the water-soluble polymer particles copolymerized through adsorption is mixed with the molecular weight regulator and structuring agent described above. Accordingly, a plurality of water-soluble anionic polymers are uniformly dispersed with each other by electrostatic repulsion, thereby providing a stable water-soluble polymer dispersion with high fluidity.

For one embodiment according to the present invention, the anionic polymer particles include (a) an anionic monomer; (b) nonionic monomers; (c) anionic stabilizers; (d) anionic dispersants; (e) at least one of a molecular weight modifier and a structuring agent; (f) chelating agents; and (g) a radical polymerization initiator. It is produced by copolymerization in (h) a salt solution, and contains specific components as the anionic dispersant, molecular weight regulator and structuring agent in a predetermined amount. If necessary, it may further include at least one or more conventional additives known in the art.

Hereinafter, a detailed look at the composition of the water-dispersible anionic polymer dispersion is as follows.

The anionic polymer according to the present invention includes an anionic monomer and a nonionic monomer. Specifically, the polymer may be a homopolymer of an anionic monomer, a homopolymer of a nonionic monomer, or a copolymer of an anionic monomer and a nonionic monomer.

anionic monomer

As the anionic monomer used in the present invention, conventional materials known in the art may be used without limitation, and include, for example, a vinyl or allyl functional group, a carboxyl group, a sulfone group, a phosphonate or other anionized group, or It may be a compound containing an alkali metal, alkaline earth metal or ammonium salt thereof.

Non-limiting examples of usable anionic monomers include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, p-carboxystyrene, and the like. ; and sulfone group-containing monomers such as 2-acrylamide-2-methyl1-propanesulfonic acid, vinylsulfonic acid, vinylbenzenesulfonic acid, and styrenesulfonic acid. In addition, an alkali metal salt, an alkaline earth metal salt, or an ammonium salt may be used as the salt, and specific examples thereof include sodium acrylate and sodium methacrylate.

The content of the anionic monomer in the present invention is not particularly limited, and may be appropriately adjusted within the content range known in the art in consideration of commercial availability. For example, the anionic monomer may be added in an amount of 3 to 90 mol% based on the total mol% of the monomer, and specifically, it is preferably added in an amount of 5 to 85 mol%.

nonionic monomer

The nonionic monomer used in the present invention may be a conventional material known in the art without limitation, and may be, for example, a water-soluble allyl or vinyl monomer having no anionic or cationic charge.

Non-limiting examples of usable nonionic monomers include (meth)acrylamide, N,N-dimethylacrylamide (N,N-dimethylacrylamide), N-isopropylacrylamide (N-isopropylacrylamide), N-butylacrylamide (N-butyl acrylamide) N-methylolacrylamide, vinyl acetate, acrylonitrile, methyl acrylate, (meth)acrylate 2-hydroxyethyl, diacetone acrylamide, N-vinyl-2-pyrrolidone , N-vinylformamide, N-vinylacetamide, vinylimidazole, N-vinylcarbazole, acryloylmorpholine, polyethylene glycol (meth)acrylate, polyglycerol (meth)acrylate, or mixtures thereof, etc. There is this.

The content of the nonionic monomer in the present invention is not particularly limited, and may be appropriately adjusted within the content range known in the art in consideration of commercial availability. For example, the nonionic monomer may be added in an amount of 10 to 97 mol% based on the total mol% of the monomer, and specifically, it is preferably added in an amount of 15 to 95 mol%.

anionic stabilizer

The anionic stabilizer according to the present invention is used to improve the flowability by improving the dispersion stability of the resulting water-soluble anionic polymer particles.

The anionic stabilizer is not particularly limited, as long as it plays the above-mentioned role, and the component or amount thereof is not particularly limited, and those known in the art may be used. As an example, a polymerized polymer or copolymer may be used, and specifically, acrylic acid, sodium acrylic acid, methacrylic acid, sodium methacrylate, 2-acrylamide, 2-methyl 1-propane sulfonic acid, each homopolymer, and copolymers thereof synthesis can be used.

In one embodiment according to the present invention, the anionic stabilizer is a homopolymer or a copolymer thereof produced in a solution containing (meth)acrylic acid, a hydroxyl group-containing compound, a metal ion sequestering agent and an initiator, and has a viscosity of 2,000 ~ It can have 1,000 cps and a pH of 8-12.

For one specific example of the method for preparing the anionic stabilizer, it can be prepared by copolymerizing 15% polyacrylic acid using (meth)acrylic acid and a compound having a hydroxyl group (OH), and, if necessary, a metal ion sequestering agent and An initiator may be used.

At this time, the metal ion sequestrant and the initiator are not particularly limited, and those known in the art may be used without limitation. Examples of the sequestering agent that can be used may be diethylenetriaminepentaacetic acid, and examples of the initiator include sodium hydrogen sulfite and azo (Vazo 56WSP). In addition, when preparing the anionic stabilizer, the amount of the sequestering agent may be 10 to 100 ppm, preferably 30 to 80 ppm, based on 100 parts by weight of the anionic monomer and the nonionic monomer. In addition, 200 to 2,000 ppm of sodium bisulfite, and 200 to 3,000 ppm of Vazo 56WSP may be used as the initiator based on 100 parts by weight of the anionic monomer and the nonionic monomer, and preferably 500 to 1,000 ppm of sodium hydrogen sulfite, Vazo 56WSP 500 to 1,500 ppm may be used.

When preparing the water-dispersible anionic polymer dispersion according to the present invention, the content of the anionic stabilizer is not particularly limited, and may be appropriately adjusted within the content range known in the art in consideration of commercial availability. For example, the anionic stabilizer may be added in an amount of 2 to 8 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer.

anionic dispersant

The anionic dispersant used in the present invention is adsorbed on the surface of the polymer or copolymer particles (water-soluble polymer) produced by the polymerization reaction to have a predetermined charge, such as a negative (-) charge, so that a plurality of polymer particles are mutually attached to each other. It is uniformly dispersed by electrostatic repulsion and serves to obtain a high-flowing polymer dispersion.

As the anionic dispersant, at least one selected from the group consisting of naphthalene-based dispersants, ligrin-based dispersants, melamine-based dispersants, sulfonic acid-based dispersants, polycarboxylic acid-based copolymers, and salts thereof may be used. In addition, it is also within the scope of the present invention to use other anionic dispersants if they serve the above-mentioned roles.

Specific examples of usable anionic dispersants include ligrin, ligrinsulfonic acid or a salt thereof, naphthalenesulfonic acid formalin condensate, melamine formaldehyde condensate, polyethylene glycol sulfonic acid ether, polyethylene glycol alkyl ether, naphthalene sulfonic acid salt, Melamine sulfonic acid formalin condensate, sodium dodecyl diphenyl ether disulfonate, sulfonic acid salt, alkylbenzene sulfonate and its salt, lauryl ether sulfonic acid and its salt, polycarboxylate and polyethylene glycol mixture, methacrylic acid-methyl Sodium oxypolyethylene glycol monomethacrylate copolymer, acrylamide copolymer and (C ₁₀ ~ C ₁₆ ) alcohol ethoxylate sulfite sodium salt mixture, acrylamide copolymer and sodium lauryl ether sulfate mixture, polycarboxylate and It may be at least one selected from the group consisting of a mixture of sodium sulfonic acid salts, polycarboxylic acids having polyoxyethylene side chains, and a salt thereof as a main component.

In the water-dispersible anionic polymer dispersion according to the present invention, the content of the anionic dispersant is not particularly limited, and may be appropriately adjusted within a content range known in the art in consideration of commercial availability. For example, the anionic dispersant may be added in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer.

molecular weight modifier

The molecular weight modifier used in the present invention serves to control the nucleation rate and the polymerization reaction rate to be balanced with each other during dispersion polymerization so that the polymerized water-soluble polymer particles have a uniform and fine size, so that they have a high molecular weight.

The molecular weight modifier may use a conventional compound known in the art, and is not particularly limited. Non-limiting examples of usable molecular weight modifiers include glycolic acid, lactic acid, ethylene glycol, sodium hypophosphite monohydrate, thiol group (-SH) ), methyl mercaptan, ethyl mercaptan, aryl mercaptan, thioacetic acid, or mixtures thereof. Specifically, it is preferable to use glycolic acid, lactic acid, ethylene glycol, sodium hypophosphite monohydrate.

In the water-dispersible anionic polymer dispersion according to the present invention, the content of the molecular weight modifier is not particularly limited, and may be appropriately adjusted within a content range known in the art in consideration of commercial availability. For example, the molecular weight modifier may be added in an amount of 0.001 to 15 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer, and the content range may be partially different depending on the material used. For example, in the case of glycolic acid, 0.1 to 6 parts by weight may be used based on 100 parts by weight of the anionic monomer and the nonionic monomer, and specifically may be 1 to 4 parts by weight. In addition, in the case of lactic acid, it may be 0.1 to 5 parts by weight, specifically, it may be 0.1 to 2 parts by weight, and in the case of ethylene glycol, it may be 1 to 15 parts by weight, and specifically 4 to 10 parts by weight, and sodium hypo In the case of phosphite monohydrate, it may be 0.001 to 0.02 parts by weight, and specifically 0.001 to 0.01 parts by weight.

structuring agent

The structuring agent used in the present invention serves as a functional monomer that changes the molecular structure of the polymer produced by dispersion polymerization to form hard flocs.

The structuring agent may use a conventional compound known in the art, and is not particularly limited. Non-limiting examples of usable structuring agents include methylene-bis-acrylamide, bis-acryloyl cystamine, dihydroxyethylene-bis-acylamide ), ethylene diacrylate, ethylene glycol dimethacrylate, arylthiourea, or a mixture thereof. In particular, when mixed with the aforementioned molecular weight modifier, a more stable polymer dispersion can be prepared. Specifically, it is preferable to use methylenebisacrylamide and arylthiourea. In this case, in the case of methylenebisacrylamide, a molecular structure in the form of a network can be formed, and in the case of arylthiourea, a branched molecular structure can form.

In the water-dispersible anionic polymer dispersion according to the present invention, the content (input amount) of the structuring agent is not particularly limited, and may be appropriately adjusted within a range known in the art in consideration of commercial availability. For example, the structuring agent may be added in an amount of 0.0001 to 2 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer. More specifically, in the case of methylenebisacrylamide, 0.0001 to 0.2 parts by weight may be used based on 100 parts by weight of the anionic monomer and the nonionic monomer, and in the case of arylthiourea, 0.05 to 2 parts by weight is preferably used.

chelating agent

The chelating agent used in the present invention may be any chelating agent known in the art without limitation.

Non-limiting examples of chelating agents that can be used include nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, or mixtures thereof.

In the water-dispersible anionic polymer dispersion according to the present invention, the content (input amount) of the chelate is not particularly limited, and may be appropriately adjusted within a range known in the art in consideration of commercial availability. For example, the chelate may be used in an amount of 50 to 1,000 ppm based on 100 parts by weight of the anionic monomer and the nonionic monomer.

polymerization initiator

As the polymerization initiator used in the present invention, any radical polymerization initiator known in the art may be used without limitation. For example, a water-soluble azobis-based radical initiator, a redox-based radical polymerization initiator, or a mixture thereof may be used.

Specific examples of the redox-based radical polymerization initiator include potassium persulfate, ammonium persulfate, benzoyl peroxide, sodium hydrogen sulfite, sodium sulfite, sodium thiosulfate, hydrogen peroxide, triethanolamine, anhydrous sodium sulfate, or mixtures thereof.

Further, specific examples of the water-soluble azobis-based polymerization initiator include 2,2-azobis[2-(5-methyl-2-imidazorin-2-yl)propane]dihydrochloride, 2,2-azo bis(2-amidinopropane)dihydrochloride, 4,4-azobis(4-methoxy-2,4-dimethyl)valeronitrile, or a mixture thereof.

In the water-dispersible anionic polymer dispersion according to the present invention, the content (input amount) of the polymerization initiator is not particularly limited, and may be appropriately adjusted within a range known in the art in consideration of commercial availability. For example, the polymerization initiator may be used in an amount of 100 to 300 ppm based on 100 parts by weight of the anionic monomer and the nonionic monomer.

In addition, after the polymerization reaction is terminated, it is preferable to treat the residual monomer by adding an excess of a polymerization initiator secondarily. In this case, the polymerization initiator added secondarily may be the same as or different from the polymerization initiator component added primarily, and preferably, potassium persulfate, which is a redox-based reducing initiator, is used. In addition, the amount of the polymerization initiator added secondarily may be added in an excess of about 200 to 1,000 ppm under the same standard.

salt

The salt used in the present invention is not particularly limited, and a conventional salt known in the art may be used. For example, it may be at least one selected from the group consisting of ammonium sulfate, sodium sulfate, sodium bisulfite, ammonium chloride and sodium chloride, preferably ammonium sulfate.

Dispersion polymerization is a mechanism in which a water-soluble salt and a monomer are dissolved in water, and as the polymerization reaction proceeds, the monomer is polymerized and the monomer is formed into particles according to the difference in solubility. At this time, when the salt concentration is low, gelation proceeds due to an extreme viscosity increase phenomenon, and when the salt concentration is high, particles are formed quickly, and agglomeration of the formed polymer particles (music phenomenon) occurs, indicating a low molecular weight. In addition, when the storage temperature is lowered, crystal precipitation is caused due to a decrease in solubility according to the temperature. In consideration of the above, the amount of salt added should be appropriately adjusted.

In the water-dispersible anionic polymer dispersion according to the present invention, the content (input amount) of the salt is not particularly limited, and may be appropriately adjusted within a range known in the art in consideration of commercial availability. For example, the salt is preferably 20 to 30% (or parts by weight) based on 100 parts by weight of the total water-dispersible polymer dispersion.

For example, the salt solution according to the present invention may contain 20 to 30% of ammonium sulfonate, and more specifically, 20 to 30 (w/v)% aqueous solution of ammonium sulfate ionic salt is mixed with 100 to 300 mesh. It may be a salt solution purified by a filter of

If necessary, the water-dispersible anionic polymer dispersion according to the present invention may use at least one additive known in the art without limitation within a range that does not impair the effects of the present invention. In addition, the content of these additives is not particularly limited, and may be appropriately adjusted within the content range known in the art.

Since the above-mentioned high molecular weight, water-dispersible anionic polymer dispersion of the present invention is an oil-free product, it is eco-friendly and has excellent storage stability, and has a small particle size and is uniform and unique in that a high molecular weight radical copolymer is stably dispersed. It may be a homogeneous dispersion.

For example, the anionic polymer (radical copolymer) contained in the water-dispersible anionic polymer dispersion has an average particle diameter (d50) of 1 to 30 μm, an anion degree of 3 to 90 mol%, and an effective concentration of 5 to 30% by weight.

For another example, the anionic polymer may have a weight average molecular weight (Mw) of 8 million to 20 million g/mol, specifically, 9,17 million g/mol.

In another embodiment, the water-dispersible anionic polymer dispersion containing the anionic polymer has a 0.5% salt viscosity (4% NaCl) measured by a Brookfield viscometer (DV2T type, measurement conditions Spindle No. 62, 12 rpm) 250 ~ 1,000 cps (based on 25 ℃), specifically, may be 270 ~ 700 cps. In addition, the product viscosity (25 ℃) may be 50 ~ 2,500 cps, specifically 50 ~ 1,000 cps.

In another embodiment, the water-dispersible anionic polymer dispersion contains 20 to 30% of ammonium sulfate, and the pH before polymerization may be in the range of 4.7 to 5.2.

In another embodiment, the water-dispersible anionic polymer dispersion may have excellent storage stability at a temperature of -10°C or higher, for example, may have a storage stability of 10 days or more at -10°C, specifically 30 to 90 days. It could be about a day.

Hereinafter, a method for preparing a water-dispersible anionic polymer dispersion according to an embodiment of the present invention will be described. However, it is not limited only by the following manufacturing method, and the steps of each process may be modified or selectively mixed as needed.

For an embodiment of the preparation method, (i) preparing a mixture comprising an anionic monomer, a nonionic monomer, an anionic stabilizer, and an anionic dispersant ('S10 step'); (ii) adding a hydroxyl group-containing compound to the mixture of step (i) and first adding a salt, then adding and mixing at least one of a molecular weight regulator and a structuring agent and a chelating agent ('S20 step'); (iii) performing a first polymerization reaction after first adding a polymerization initiator to the mixture of step (ii) ('S30 step'); (iv) performing a secondary polymerization reaction after the secondary addition of a polymerization initiator to the primary reaction product of step (iii) ('S40 step'); and (v) a second step of adding a salt to the second reaction product of step (iv) ('S50 step'); may be configured to include.

Meanwhile, with reference to FIG. 1 , the manufacturing method is divided into each process step and described as follows.

(i) mixture preparation step ('S10 step')

In this step, an aqueous solution in which an anionic monomer, a nonionic monomer, an anionic stabilizer, and an anionic dispersant are uniformly mixed is prepared.

Since the anionic monomer, the nonionic monomer, and the anionic dispersant are the same as those described above, a separate description thereof will be omitted.

In addition, the anionic stabilizer may use the above-mentioned polymer or copolymer, and specifically, 15% polyacrylic acid copolymerized using a compound having (meth)acrylic acid and a hydroxyl group (OH) may be used. In this case, if necessary, a sequestering agent and an initiator may be used.

For one specific example of the method for preparing the anionic stabilizer with reference to FIG. 2, a monomer and pure water are mixed and stirred at a speed of 200 to 300 rpm, and then the compound having a hydroxyl group is maintained at 20 to 30° C. After the dropwise addition, a chelating agent may be added, and an initiator may be added under a nitrogen atmosphere to carry out the polymerization reaction. At this time, the polymerization reaction temperature condition is not particularly limited, and may be, for example, 40 to 80°C. When the polymerization reaction is completed, it is cooled to room temperature to obtain an anionic stabilizer.

For a specific example of the step S10, an anionic monomer, a nonionic monomer, pure water, an anionic stabilizer and an anionic dispersant are added and stirred and mixed at a speed of 200 to 300 rpm to obtain an aqueous solution in which the above-mentioned components are uniformly mixed can be manufactured.

(ii) Molecular weight modifier / structuring agent input step ('S20 step')

In this step, after adding a molecular weight regulator, a structuring agent, and a chelating agent to the mixture of the previous step S10, nitrogen gas is added and the temperature is raised to a predetermined range.

As a more specific example of the step S20, sodium hydroxide is added dropwise to the monomer-containing aqueous solution uniformly mixed in step S10 while maintaining the temperature of 10 to 30° C., and the salt is first added and dissolved. Then, a molecular weight regulator, a structuring agent, and a chelating agent are added and stirred, then nitrogen is added and the temperature is raised to about 30 to 40°C.

On the other hand, when using a monomer that does not consist of an anionic salt such as acrylic acid, it is used after replacing it _{with Na ion or NH 3 ion using sodium hydroxide or ammonia water having an OH group.} will lose Since this pH is a factor that greatly affects the reaction rate, in the present invention, the pH of the salt solution before polymerization is adjusted to a predetermined range by adjusting the input amount of the hydroxyl group-containing compound (eg, sodium hydroxide).

For example, the pH before polymerization of the salt solution may be 4.5 to 5.5, and a preferred pH range for obtaining a high molecular weight, water-dispersible anionic polymer dispersant may be 4.7 to 5.2.

(iii) primary polymerization ('S30 step')

In this step, a polymerization initiator is first added to the mixture of the previous step S20, and then the first polymerization reaction is performed within a predetermined range.

The conditions of the first polymerization reaction are not particularly limited, and may be appropriately adjusted within polymerization conditions known in the art.

Specifically, the temperature of the primary polymerization reaction is related not only to the type of polymerization initiator to be added, but also to the composition of the monomer to be polymerized. When a redox system is used or a water-soluble azobis system is used, the temperature may be 25 to 50 °C, and preferably, the temperature is 30 to 40 °C for 4 to 6 hours.

(iv) secondary polymerization ('S40 step')

In this step, an excess of a polymerization initiator is secondarily added to the result of the first polymerization reaction in the previous step S30, and then a second polymerization reaction is performed within a predetermined range to treat the residual monomer.

In this case, the secondary polymerization initiator may be the same as or different from the primary polymerization initiator, and is not particularly limited. Preferably, about 200 to 1,000 ppm of potassium persulfate, which is a redox-based reducing initiator, is added.

In addition, the conditions of the secondary polymerization are not particularly limited, and for example, may be carried out at 40 to 45° C. for 10 to 18 hours, specifically for about 12 to 16 hours.

(v) salt secondary input ('S50 step')

Then, after the secondary polymerization reaction product is cooled to room temperature, a secondary salt is added as necessary and post-treatment such as filtering is performed.

In this case, the secondary input of salt (eg, ammonium sulfate) is input to secure fluidity. As the amount of salt added increases, precipitation may occur due to solubility problems depending on temperature. Therefore, if the product viscosity is low, the secondary input of salt may not be performed.

The secondary input amount of the salt is not particularly limited, and may be adjusted to 28% or less (based on -10°C) in consideration of the storage stability of the water-dispersible anionic polymer dispersion, and preferably may be 27% or less.

Meanwhile, in the present invention, it has been described that steps S10 and S20 are sequentially performed, but it is not particularly limited thereto, and it is also within the scope of the present invention to carry out steps S10 and S20 as a single process without distinguishing them as separate processes. .

Since the water-dispersible anionic polymer dispersion according to the present invention prepared as described above contains high-molecular-weight, fine water-soluble polymer particles having excellent stability and dispersion effect in a high concentration, it forms fast and hard flocs with high reactivity. It may exhibit improved dehydration, sedimentation, and turbidity improvement effects. In addition, since the anionic polymer dispersion is an oil-free product, it is more environmentally friendly than the emulsion coagulant which is most commonly used as a conventional liquid polymer coagulant, and can be used as a substitute for the emulsion coagulant. In addition, in the present invention, a high molecular weight, water-soluble anionic polymer dispersion, which is a limitation of the dispersion polymerization method, can be prepared in high yield. Accordingly, it can be usefully used for water treatment, dredging, soil restoration and/or crude oil treatment applications.

Therefore, the water-dispersible anionic polymer dispersion can be usefully used for water treatment, dredging, soil restoration and/or crude oil treatment, and specifically, a separation aid in the solid-liquid separation process of various industries, a polymer coagulant in the wastewater treatment process, retention of the papermaking process It can be used as an improver, dehydration accelerator, strength enhancer, oil-water separator in oilfield processing and/or friction reducer in crude oil transfer.

For a more specific example, raw sludge, surplus sludge, digested sludge, or mixtures thereof, dredging works, soil restoration, sand collection, etc. of raw sludge of municipal sewage or general industrial wastewater (floating tank, settling tank, dehydrator) can be used. , can be used as an oil-water separator in the oil separation process for separating oil from oil-containing industrial wastewater, as a friction reducing agent to reduce frictional heat in pipes when crude oil is transported long distances, and as a water freeness improver used in the papermaking process, dehydration It is also useful as an additive for formulation, such as an accelerator, a retention agent used in the papermaking process, or a recovery agent for valuables in white water during the papermaking process.

Hereinafter, the present invention will be described in detail through examples. However, the following examples are merely illustrative of the present invention, and the present invention is not limited by the following examples.

At this time, throughout the present specification, % used to indicate the concentration of a specific substance is (weight/weight) %, solid/liquid (weight/volume) %, and liquid, unless otherwise specified. /liquid can be (volume/volume) %.

[Preparation example. manufacture of anion stabilizer]

After taking 312 g of acrylic acid and 531 g of pure water in a 2L reactor, while stirring, 343 g of sodium hydroxide was slowly added dropwise while maintaining 10 to 30° C. to replace it with sodium acrylate, then 1,505 g of pure water and 0.34 g of diethylenetriamine pentaacetic acid were added. Nitrogen was added for 20 minutes while stirring, and the temperature of the reactant was adjusted to 55°C. As a polymerization initiator, 2.3 g of 5% sodium bisulfite and 4.5 g of 5% V-50 (Vazo 56WSP) were added, and the polymerization reaction was carried out for 4 hours.

The water-soluble anion stabilizer prepared as described above had an effective concentration of 15%, an anion level of 100 mol%, and a product viscosity of 2,000 to 10,000 cps. In addition, the viscosity was measured with a Brookfield viscometer (DV2T type, measurement conditions Spindle No 63, 12 rpm).

[Examples 1 to 18. Water-dispersible anionic polymer dispersion]

[Example 1]

In a 2L reactor, 343 g of 50% acrylamide, 810 g of pure water, 53 g of acrylic acid, 60 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 10 g of naphthalene-based anion dispersant (SNF OC-512) was added and stirred, and after slowly adding 61 g of 50% sodium hydroxide dropwise while maintaining 10 to 30 °C, 488 g of ammonium sulfate was added to completely dissolve. 0.5 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate a polymerization reaction, and after 6 hours, 0.06 g of potassium persulfate was added, followed by polymerization for 15 hours.

[Example 2]

In a 2L reactor, 345 g of 50% acrylamide, 870 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, naphthalene-based anion dispersant (FLOWMIX Super-1, Dongnam Corporation) ) was added and stirred, and after slowly adding 61 g of 50% sodium hydroxide dropwise while maintaining 10 to 30°C, 491 g of ammonium sulfate was added to dissolve completely. 0.5 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate a polymerization reaction, and after 6 hours, 0.06 g of potassium persulfate was added and polymerization was carried out for 15 hours.

[Example 3]

In a 2L reactor, 50% acrylamide 345 g, pure 870 g, acrylic acid 54 g, 2-acrylamide 2-methyl 1-propane sulfonic acid 61 g, 15% anion stabilizer prepared in Preparation Example 87 g, lignin-based anion dispersant (Daedong Chemtech ligrin) 0.2 g was added and stirred, and after slowly adding 61 g of 50% sodium hydroxide dropwise while maintaining 10 to 30 °C, 491 g of ammonium sulfate was added to completely dissolve. 0.5 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 37°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate a polymerization reaction, and after 2 hours, 4.5 g of 1% VA-044 (Vazo 44WSP), and 2 hours later, 1% VA-044 (Vazo 44WSP) was added. ) 4.5 g, 0.06 g of potassium persulfate was added after 6 hours, and polymerization was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 4]

In a 2L reactor, 343 g of 50% acrylamide, 815 g of pure water, 53 g of acrylic acid, 60 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, polycarboxylic acid-based anion dispersant (No. ENT, JNT-07) was added and stirred, and after slowly adding 61 g of 50% sodium hydroxide dropwise while maintaining 10 to 30°C, 522 g of ammonium sulfate was added thereto to completely dissolve. 0.5 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate a polymerization reaction, and after 6 hours, 0.06 g of potassium persulfate was added and polymerization was carried out for 15 hours. When the polymerization reaction was completed, 12 g of ammonium sulfate was added.

[Example 5]

In a 2L reactor, 345 g of 50% acrylamide, 842 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, polycarboxylic acid-based anion dispersant (Dongnam Company FLOWMIX Super-4) 10g) was added and stirred, and 61g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 502g of ammonium sulfate was added and completely dissolved. 0.5 g of lactic acid was added, and diethylenetriamine pen 0.25 g of acetic acid was added, nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 35 °C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 6]

In a 2L reactor, 345 g of 50% acrylamide, 842 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, polycarboxylic acid-based anion dispersant (SAN) 10 g of NOPCO L-400S) was added and stirred, and after slowly adding 61 g of 50% sodium hydroxide dropwise while maintaining 10 to 30° C., 502 g of ammonium sulfate was added to completely dissolve. 0.2 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 7]

In a 2L reactor, 345 g of 50% acrylamide, 842 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, polycarboxylic acid-based anion dispersant (Daedong) Chemtech NEOPERSE D-400N) 10g) was added and stirred, and after slowly adding 61 g of 50% sodium hydroxide dropwise while maintaining 10 to 30°C, 502 g of ammonium sulfate was added and completely dissolved. 0.2 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 8]

In a 2L reactor, 345 g of 50% acrylamide, 842 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, polycarboxylic acid-based anion dispersant (Daedong) 10 g of Chemtech NEOFLOW RS-7015) was added and stirred, and after slowly adding 61 g of 50% sodium hydroxide dropwise while maintaining 10 to 30°C, 502 g of ammonium sulfate was added and completely dissolved. 0.2 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 9]

In a 2L reactor, 345 g of 50% acrylamide, 835 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, polycarboxylic acid-based anion dispersant (silk) 10 g of load PEMA-SP1000) was added and stirred, and 66 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30° C., and then 500 g of ammonium sulfate was added and completely dissolved. 0.2 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 10]

In a 2L reactor, 345 g of 50% acrylamide, 830 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, polycarboxylic acid-based anion dispersant (silk) Load PEMA-SR3000) 25g) was added and stirred, and 66 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30°C, and then 498 g of ammonium sulfate was added to completely dissolve. 0.6 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 11]

In a 2L reactor, 345 g of 50% acrylamide, 842 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1) ) was added and stirred, and 62 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30°C, and then 502 g of ammonium sulfate was added to completely dissolve. 0.6 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 12]

In a 2L reactor, 345 g of 50% acrylamide, 842 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, sulfonic acid-based anion dispersant (PILOT CALIMULSE L) -50) was added and stirred, and 62 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30°C, and then 502 g of ammonium sulfate was added to completely dissolve. 0.6 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 13]

In a 2L reactor, 233 g of 50% acrylamide, 980 g of pure water, 33 g of acrylic acid, 38 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 19 g of glycerin, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1) ) was added and stirred, and 36 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30 °C, and then 540 g of ammonium sulfate was added to completely dissolve. 3 g of glycolic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 26 g of ammonium sulfate was added.

[Example 14]

In a 2L reactor, 348 g of 50% acrylamide, 844 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1) ) was added and stirred, and 58 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30 °C, and then 504 g of ammonium sulfate was added to completely dissolve. 10 g of ethylene glycol was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 15]

In a 2L reactor, 348 g of 50% acrylamide, 844 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1) ) was added and stirred, and 58 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30 °C, and then 504 g of ammonium sulfate was added to completely dissolve. 0.3 g of lactic acid and 0.3 g of arylthiourea were added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 16]

In a 2L reactor, 348 g of 50% acrylamide, 844 g of pure water, 54 g of acrylic acid, 61 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1) ) was added and stirred, and 58 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30 °C, and then 504 g of ammonium sulfate was added to completely dissolve. 0.3g of lactic acid and 10g of 0.1% methylenebisacrylamide were added, 0.25g of diethylenetriaminepentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 17]

In a 2L reactor, 520 g of 50% acrylamide, 775 g of pure water, 10.8 g of acrylic acid, 12.24 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 87 g of 15% anion stabilizer prepared in Preparation Example, 19 g of glycerin, sulfonic acid-based anion dispersant (DOW) 10 g of DOWFAX 2A1) was added and stirred, and 12 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30° C., and then 500 g of ammonium sulfate was added and completely dissolved. 0.2 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 18]

In a 2L reactor, 182 g of 50% acrylamide, 840 g of pure water, 90 g of acrylic acid, 100 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 90 g of 15% anion stabilizer prepared in Preparation Example, 20 g of glycerin, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1) ) was added and stirred, and 96 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30°C, and then 495 g of ammonium sulfate was added to completely dissolve. 0.2 g of lactic acid was added, 0.25 g of diethylenetriamine pentaacetic acid was added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 35°C.

As a polymerization initiator, 4.5 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 25 g of ammonium sulfate was added.

[Comparative Examples 1 to 8. Water dispersible anionic polymer dispersion]

[Comparative Example 1]

50% acrylamide 354 g, pure water 851 g, ammonium sulfate 475 g, acrylic acid 55 g, 2-acrylamide 2-methyl 1-propane sulfonic acid 62 g, 15% anion stabilizer prepared in Preparation Example 90 g, glycerin 20 g were put in a 2L reactor and stirred, After slowly adding 72 g of sodium hydroxide dropwise while maintaining 10~30℃, add 9g of 70% glycolic acid and 0.25g of diethylenetriaminepentaacetic acid, and add nitrogen for 30 minutes while stirring, and adjust the temperature of the reactant to 30~45℃ It was.

As a polymerization initiator, 2.5 g of 1% potassium persulfate and 1.9 g of 1% VA-044 (Vazo 44WSP) were added to initiate the polymerization reaction, and after 6 hours, the same amount of initiator was added again, and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 59 g of ammonium sulfate was added.

[Comparative Example 2]

50% acrylamide 354 g, pure water 851 g, ammonium sulfate 475 g, acrylic acid 55 g, 2-acrylamide 2-methyl 1-propane sulfonic acid 62 g, 15% anion stabilizer prepared in Preparation Example 90 g, glycerin 20 g were put in a 2L reactor and stirred, After slowly adding 73 g of sodium hydroxide dropwise while maintaining 10 to 30 ° C, 1.55 g of 1% sodium hypophosphite monohydrate and 0.25 g of diethylenetriamine pentaacetic acid were added, nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 30 It was adjusted to ~45°C.

As a polymerization initiator, 4.6 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, the same amount of the initiator was added again, and the polymerization reaction was carried out for 15 hours. Upon completion of the polymerization reaction, 47 g of ammonium sulfate was added.

[Comparative Example 3]

In a 2L reactor, 354 g of 50% acrylamide, 851 g of pure water, 511 g of ammonium sulfate, 55 g of acrylic acid, 62 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 90 g of 15% anion stabilizer prepared in Preparation Example, and 20 g of glycerin were put and stirred, After slowly adding 68 g of sodium hydroxide dropwise while maintaining 10 to 30 ° C, 18 g of ethylene glycol and 0.25 g of diethylene triamine pentaacetic acid were added, nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 30 to 45 ° C.

As a polymerization initiator, 4.6 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization, and after 6 hours, the same amount of the initiator was added again, and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 48 g of ammonium sulfate was added.

[Comparative Example 4]

In a 2L reactor, 354 g of 50% acrylamide, 845 g of pure water, 484 g of ammonium sulfate, 55 g of acrylic acid, 62 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 90 g of 15% anion stabilizer prepared in Preparation Example, and 20 g of glycerin were added and stirred, After slowly adding 67 g of sodium hydroxide dropwise while maintaining 10 to 30 ° C, 1.2 g of lactic acid and 0.25 g of diethylenetriamine pentaacetic acid were added, nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 30 to 45 ° C. .

As a polymerization initiator, 6 g of 1% VA-044 (Vazo 44WSP) was added to start the polymerization, and after 6 hours, the same amount of the initiator was added again, and the polymerization reaction was carried out for 15 hours. Upon completion of the polymerization reaction, 47 g of ammonium sulfate was added.

[Comparative Example 5]

In a 2L reactor, 542 g of 50% acrylamide, 490 g of pure water, 399 g of ammonium sulfate, 92 g of acrylic acid, 96 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 90 g of 15% anion stabilizer prepared in Preparation Example, and 20 g of glycerin were added and stirred, After slowly adding 104 g of sodium hydroxide dropwise while maintaining 10 to 30 ° C, 28.3 g of ethylene glycol and 0.25 g of diethylene triamine pentaacetic acid are added, nitrogen is added for 30 minutes while stirring, and the temperature of the reactant is adjusted to 30 to 45 ° C. It was.

As a polymerization initiator, 7 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization reaction, and after 6 hours, the same amount of the initiator was added again, and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 38.5 g of ammonium sulfate was added.

[Comparative Example 6]

In a 2L reactor, 471 g of 50% acrylamide, 700 g of pure water, 452 g of ammonium sulfate, 78 g of acrylic acid, 83 g of 2-acrylamide 2-methyl 1-propane sulfonic acid, 90 g of 15% anion stabilizer prepared in Preparation Example, and 20 g of glycerin were added and stirred, After slowly adding 91 g of sodium hydroxide dropwise while maintaining 10 to 30 ° C, 0.7 g of arylthiourea and 0.25 g of diethylenetriamine pentaacetic acid were added, nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 30 to 45 ° C. It was.

As a polymerization initiator, 5 g of 1% VA-044 (Vazo 44WSP) was added to start the polymerization reaction, and after 6 hours, the same amount of the initiator was added again, and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 44 g of ammonium sulfate was added.

[Comparative Example 7]

In a 2L reactor, 394 g of 50% acrylamide, 770 g of pure water, 583 g of ammonium sulfate, 92 g of acrylic acid, 100 g of the 15% anion stabilizer prepared in Preparation Example, and 14 g of glycerin were added and stirred, and 65 g of sodium hydroxide was slowly added dropwise while maintaining 10 to 30 ° C. Then, 0.5 g of arylthiourea and 0.25 g of diethylenetriamine pentaacetic acid were added, nitrogen was added for 30 minutes while stirring, and the temperature of the reactant was adjusted to 30-45°C.

As a polymerization initiator, 6 g of 1% VA-044 (Vazo 44WSP) was added to start the polymerization, and after 6 hours, the same amount of the initiator was added again, and the polymerization reaction was carried out for 15 hours.

[Comparative Example 8]

50% acrylamide 354 g, pure water 851 g, ammonium sulfate 475 g, acrylic acid 55 g, 2-acrylamide 2-methyl 1-propane sulfonic acid 62 g, 15% anion stabilizer prepared in Preparation Example 90 g, glycerin 20 g were put in a 2L reactor and stirred, After slowly adding 72 g of sodium hydroxide dropwise while maintaining 10 to 30 ° C, 9 g of 70% glycolic acid, 10 g of 0.1% methylenebisacrylamide, 0.25 g of diethylenetriamine pentaacetic acid were added, nitrogen was added for 30 minutes while stirring, and the reaction mixture was stirred. The temperature was adjusted to 30-45°C.

As the polymerization initiator, 2.5 g of 1% potassium persulfate and 1.9 g of 1% VA-044 (Vazo 44WSP) were added to initiate the polymerization, and after 6 hours, the same amount of the initiator was added and the polymerization reaction was carried out for 15 hours. When the polymerization reaction was completed, 59 g of ammonium sulfate was added.

[Experimental Example 1. Evaluation of physical properties of water-dispersible anionic polymer dispersion (1)]

Examples 1 to 18; And the water-dispersible anionic polymer dispersions prepared in Comparative Examples 1 to 8 were evaluated for physical properties as follows, and the results thereof are described in Tables 1 and 2, respectively.

As the equipment and reagents for the evaluation of the physical properties of Experimental Example 1, a high-speed stirrer (IKA EUROSTAR60), a stirring bar, a scale (4th decimal place), a 5ml syringe, a stopwatch, a 300ml beaker, a Brookfield viscometer (DV2T type), a thermometer , a thermostat, a microscope (Olympus, product name: CX23), a disposable pipette, 4% sodium chloride (NaCl), pure water, and the like were used.

(1) Product viscosity

After the sample was adjusted to 25° C., it was measured with a Brookfield viscometer (Spindle No. 62, 12 rpm).

(2) 0.5% solution viscosity

After taking 193.333 g of pure water in a 300 ml beaker, a stirring rod was attached to a high-speed stirrer, and 6.667 g of the sample was taken into a disposable syringe while stirring at a speed of 1,000 rpm, and then dissolved for 10 minutes. After adjusting the sample to 25 ℃ was measured with a Brookfield viscometer (Spindle No. 62, 12rpm). At this time, when the effective concentration of the sample is 10%, 190 g of pure water and 10 g of the sample; 193.333 g of pure water and 6.667 g of sample at 15%; 195 g of pure water and 5 g of sample when the effective concentration is 20%; When the effective concentration was 25%, a composition of 196 g of pure water and 4.0 g of the sample was used.

(3) 0.5% salt viscosity (4% NaCl)

After taking 193.333 g of 4% sodium chloride in a 300 ml beaker, a stirring rod was attached to a high-speed stirrer, and while stirring at a speed of 1,000 rpm, 6.667 g of the sample was taken into a disposable syringe and dissolved for 10 minutes. After adjusting the sample to 25 ℃ was measured with a Brookfield viscometer (Spindle No. 62, 12rpm). At this time, when the effective concentration of the sample is 15%, 4% sodium chloride 193.333g and the sample material 6.667g, when the effective concentration is 20%, 4% sodium chloride 195g and the sample 5g, when the effective concentration is 25%, 4% sodium chloride 196g and 4.0 g of the sample.

(4) Molecular weight measurement

① Put 200 ml of pure water in a 500 ml beaker, and then a stirring rod was attached to the stirrer and stirred at 1000 rpm.

② Wet the inside of the 2.5cc disposable syringe with the sample.

③ The weight of the syringe was measured up to the unit of mg (0.0001 g), and the measured sample amount was accurately taken up to the error range of ㅁ0.003 g and put into the VORTEX (Term ⓛ) in the beaker.

※ Sample collection amount (g) = 40 ㆇ (% Polymer effective concentration)

④ After stirring the above solution for 15 minutes, it was visually confirmed whether the solution was completely dissolved, and then _{200 ml of 2.0M NaNO 3} solution was added.

⑤ Continue stirring at 1000 rpm for 30 minutes.

⑥ Using a WATER-BATH, the sample was stirred with a thermometer and adjusted to 25ㅁ0.5℃.

⑦ Using a 20 cc disposable syringe to the prepared ULA chamber (CHAMBER) equipped viscometer, 20 ml of the sample was put into the chamber.

⑧ After designating the type of SPINDLE (SP00) and adjusting the speed to 60 rpm, the Viscometer was switched on (n: reading value).

⑨ After 15 seconds, the displayed viscosity value was read and calculated according to the following equation to calculate the molecular weight.

[Equation] MW(g) = 2.6 × (n-1.0) × 10 ⁶ (n = BROOKFIELD READING (cps))

(5) particle size

A sample was collected using a disposable pipette on a slide glass, and then the light source was turned on. After placing the slide glass in the center of the light source, the condenser was moved to the highest position. After adjusting the coarse motion adjusting screw to put the objective lens and the sample at the closest position, the objective lens was moved to the opposite side of the sample using the fine motion adjusting screw to focus, and then the slide glass was moved to the part to be viewed. After focusing, the iris and voltage of the light source and the position and diaphragm of the capacitor were adjusted to obtain a clean and clear image. Then, by moving the slide glass, the best phase was found and the particle size of the anionic polymer was measured.

	molecular weight regulator	functional monomer	anionic dispersant	effective concentration	Ionic (mol%)	Product viscosity (cps)	0.5% solution viscosity (cps)	0.5% salt viscosity (cps)	Molecular Weight (millions)	Average particle size (㎛)
Example 1	lactic acid	-	naphthalene	15%	34	240	650	300	10.5	5
Example 2	lactic acid	-		15%	34	255	823	370	13.0	4
Example 3	lactic acid	-	lignin	15%	34	200	630	278	9.3	6
Example 4	lactic acid	-	polycarboxylic acid	15%	34	540	752	315	11.0	5
Example 5	lactic acid	-		15%	34	522	640	295	10.0	5
Example 6	lactic acid	-		15%	34	445	720	345	12.2	4
Example 7	lactic acid	-		15%	34	285	665	290	9.8	5
Example 8	lactic acid	-		15%	34	462	648	270	9.0	6
Example 9	lactic acid	-		15%	34	240	793	358	12.7	4
Example 10	lactic acid	-		15%	34	202	645	270	9.0	6
Example 11	lactic acid	-	sulfonic acid	15%	34	160	863	420	14.8	3
Example 12	lactic acid	-		15%	34	185	650	283	9.4	5
Example 13	glycolic acid	-	sulfonic acid	10%	34	120	950	470	16.5	4
Example 14	ethylene glycol	-	sulfonic acid	15%	34	165	800	365	12.8	4
Example 15	lactic acid	Arylthiourea	sulfonic acid	15%	34	250	760	320	11.2	5
Example 16	lactic acid	Methylenebisacrylamide	sulfonic acid	15%	34	280	880	310	10.8	6
Example 17	lactic acid	-	sulfonic acid	15%	10	120	580	300	10.0	3
Example 18	lactic acid	-	sulfonic acid	15%	60	350	1000	323	11.3	8

	molecular weight regulator	functional monomer	anionic dispersant	effective concentration	Ionic (mol%)	Product viscosity (cps)	0.5% solution viscosity (cps)	0.5% salt viscosity (cps)	Molecular Weight (millions)	Average particle size (㎛)
Comparative Example 1	glycolic acid			15%	34	170	420	170	6.0	5
Comparative Example 2	Sodium hypophosphite monohydrate	-	-	15%	34	440	615	247	8.7	6
Comparative Example 3	ethylene glycol	-	-	15%	34	460	430	180	6.2	5
Comparative Example 4	lactic acid	-	-	15%	34	355	590	247	8.7	5
Comparative Example 5	ethylene glycol	-	-	25%	34	400	650	175	6.1	9
Comparative Example 6	Arylthiourea	-	-	20%	34	215	670	180	6.2	8
Comparative Example 7	Arylthiourea	-	-	15%	34	360	480	165	5.8	7
Comparative Example 8	glycolic acid	Methylenebisacrylamide	-	15%	34	280	620	150	5.2	8

As shown in Tables 1 and 2 above, in the case of the water-dispersible anionic polymer dispersions of Examples 1 to 18 containing at least one of a molecular weight regulator and a structuring agent and an anionic dispersant, a comparison without an anionic dispersant Compared to Examples 1 to 8, it was possible to prepare a polymer dispersion having a high 0.5% salt viscosity and a high molecular weight of about 270 to 470 cps.

Specifically, as a result of examining 12 types for each series among the anionic dispersants currently in circulation in the market, Example 11 using a sulfonic acid-based anionic dispersant (eg, DOWFAX 2A1); Example 2 using a naphthalene-based anionic polymer (eg, Dongnam Corporation FLOWMIX Super-1); and polycarboxylic acid-based anionic polymers (eg, Silk Road PEMA-SP1000, SAN NOPCO L-400S). It was confirmed that the anionic polymer dispersions of Examples 6 and 9 exhibited better dispersant performance.

On the other hand, in the case of Comparative Examples 1 to 8, which did not include an anionic dispersant, by using a molecular weight regulator and a structuring agent without using a surfactant, the balance between the nucleation rate and the polymerization reaction rate was controlled, and the particle size was small It was possible to prepare a uniform, high-flowing, stable, water-dispersible anionic polymer dispersion. However, it only showed a relatively low salt viscosity of about 150 to 247 cps and a low molecular weight of less than 9 million.

[Experimental Example 2. Evaluation of physical properties of water-dispersible anionic polymer dispersion (2)]

Examples 1 to 12; And the water-dispersible anionic polymer dispersions prepared in Comparative Examples 1 to 8 were evaluated for physical properties as follows, and the results are described in Tables 3 to 4, respectively.

As the equipment and reagents for the evaluation of the physical properties of Experimental Example 2, a high-speed stirrer (IKA EUROSTAR60), a stirring bar, a scale (4th decimal place), 5ml syringe, 25ml syringe, stopwatch, 300ml beaker, Jar-Test machine, filter cloth (80 mesh), 500ml measuring cylinder, colorimetric tube, turbidimeter (HACH, 2100Q), COD meter (HUMAS HS-1000Plus), etc. were used.

1) Performance evaluation method

After taking 300 ml of soil restoration washing water sample in the colorimetric tube, adding the water-dispersible anionic polymer dispersion dissolved at 0.2% (based on effective concentration), shaking it up and down 5 times, and checking the sedimentation rate from 300 ml to 100 ml, 5 It was allowed to stand for a minute, and the supernatant was taken and the turbidity was measured.

In this case, Comparative Sample 1 used Comparative Example 4 (molecular weight 8.7 million) not using an anionic dispersant, and Comparative Sample 2 used our product, HA-520 (molecular weight 14 million) emulsion product, respectively.

division	Molecular Weight (millions)	0.5% salt viscosity (cps)	Dosage (ppm)	Settling speed (sec)
Comparative Sample 1 (Comparative Example 4)	8.7	247	1.5	35
			2.0	20
			2.5	16
Comparative sample 2	14.0	-	2	31
Example 1	10.5	300	1.5	31
Example 2	13.0	370	1.5	20
Example 3	9.3	278	1.5	33
Example 4	11.0	315	1.5	30
Example 5	10.0	295	1.5	30
Example 6	12.2	345	1.5	28
Example 7	9.8	290	1.5	31
Example 8	9.0	270	1.5	33
Example 9	12.7	358	1.5	21
Example 10	9.0	270	1.5	32
Example 11	14.8	420	1.5	19
Example 12	9.4	283	1.5	32
Example 13	16.5	470	1.5	18
Example 14	12.8	365	1.5	21
Example 15	11.2	320	1.5	25
Example 16	10.8	310	1.5	29
Example 17	10.0	300	1.5	30
Example 18	11.3	323	1.5	32
Note: Sludge Solids: 3.5%

division	Molecular Weight (millions)	0.5% salt viscosity (cps)	Dosage (ppm)	Settling speed (sec)	Turbidity (NTU)	COD(Mn)
Comparative sample 2	14.0	-	2	31	1950	23
Comparative Example 1	6.0	170	2	27	1,370	12
Comparative Example 2	8.7	247	2	20	1,620	15
Comparative Example 3	6.2	180	2	25	1,420	14
Comparative Example 4	8.7	247	2	20	1,520	14
Comparative Example 5	6.1	175	2	24	1,290	11
Comparative Example 6	6.2	180	2	22	685	7
Comparative Example 7	5.8	165	2	25	1,380	13
Comparative Example 8	5.2	150	2	28	1,640	18

As shown in Table 3, in the case of the water-dispersible anionic polymer dispersions of Examples 1 to 18 containing at least one of a molecular weight modifier and a structuring agent and an anionic dispersant, 0.5% compared to Comparative Sample 1 (Comparative Example 4) It was confirmed that the salt viscosity and molecular weight were higher. In addition, in terms of sedimentation rate according to the input amount, it was confirmed that the water-dispersible anionic polymer dispersions of Examples 1 to 18 had a faster sedimentation rate than Comparative Sample 1 (Comparative Example 4). In addition, when comparing the water-dispersible anionic polymer dispersion of Examples 1 and 7 and Comparative Sample 2 having the same sedimentation rate, Examples 1 and 7 of the present invention have the same effect even if the amount of the water-dispersible anionic polymer dispersion is reduced than that of Comparative Example 2 was found to be able to perform.

On the other hand, in the case of Comparative Examples 1 to 8 containing at least one of a molecular weight regulator and a structuring agent, compared with the coagulant of Comparative Sample 2, which is an emulsion product containing oil and a surfactant, it is more improved in terms of sedimentation rate, supernatant turbidity and COD was confirmed (see Table 4 above).

[Experimental Example 3. Evaluation of storage stability according to the amount of salt added]

Under the same conditions as in Example 18, the storage temperature and storage stability were evaluated by changing the secondary dose of ammonium sulfate (salt).

In the evaluation criteria of Table 5 below, ○ means a good state without increase in viscosity or salt precipitation, △ indicates a state in which viscosity increases and salt precipitation occurs over time, and X is a salt with increased viscosity. Each of the states in which precipitation occurs is shown.

Total input of salt (%)	Storage temperature (℃)
	0℃	-5℃	-10℃	-15℃
25%	○	○	○	○
27%	○	○	○	○
29%	○	○	△	X
31%	○	X	X	X
33%	X	X	X	X

As shown in Table 5 above, when the storage temperature standard is set to -10°C on the basis of the winter season, when atmospheric temperature changes and salt dissolution according to seasons are the lowest, the appropriate amount of ammonium sulfate is 28% or less based on 100% of the total. was found to be the most appropriate.

[Experimental Example 4. Evaluation of polymerization reactivity according to reaction pH]

The reaction was carried out under the same conditions as in Example 18, but by adjusting the input amount of sodium hydroxide used when substituting Na for acrylic acid, the tendency according to the primary reaction pH was evaluated, and an appropriate pH condition was confirmed.

In the evaluation criteria of Table 6 below, ○ means a good increase in viscosity, △ indicates a state in which a severe increase in viscosity or agglomeration occurs, and X indicates a state in which an extreme increase in viscosity occurs, respectively.

pH before reaction	50% NaOH input (g)	Viscosity after polymerization (cps)	Molecular weight [salt viscosity (4% NaCl)]	result
4.6	49g	1,600	230	△
4.8	55g	225	450	○
5.0	62g	160	420	○
5.2	69g	2,200	320	△
5.4	75g	8,500	180	X

As shown in Table 6, when the pH is high, the initial reactivity is fast and the viscosity increase during the reaction is increased, and when the stirring force is weak, the possibility of gelation is increased. In addition, when the pH is low, polymerization tends to be difficult due to the occurrence of agglomeration due to polymer precipitation. Accordingly, it was confirmed that the pH before the reaction of the salt solution according to the present invention was more appropriate in the range of 4.7 to 5.2.

Claims (14)

1. (a) anionic monomers; (b) nonionic monomers; (c) anionic stabilizers; (d) anionic dispersants; (e) at least one of a molecular weight modifier and a structuring agent; (f) chelating agents; and (g) anionic polymer particles copolymerized in (h) a salt solution containing a polymerization initiator,

   The anionic polymer particles have an average particle diameter (d50) of 1 to 30 μm, an anion degree of 3 to 90 mol%, an effective concentration of 5 to 30% by weight, and a 0.5% salt viscosity of 250 to 1,000 cps (25° C.) standard), a water dispersible anionic polymer dispersion
2. According to claim 1,

   The anionic polymer particles have an anionic dispersant adsorbed on some or all of the surface,

   The anionic dispersant is at least one selected from the group consisting of a naphthalene-based dispersant, a ligrin-based dispersant, a melamine-based dispersant, a sulfonic acid-based dispersant, and a polycarboxylic acid-based copolymer, a water-dispersible anionic polymer dispersion.
3. According to claim 1,

   The anionic dispersant is ligrin, ligrin sulfonic acid, lignin sulfonate, naphthalene sulfonic acid formalin condensate, melamine formaldehyde condensate, polyethylene glycol sulfonic acid ether, polyethylene glycol alkyl ether, naphthalene sulfonate, melamine sulfonic acid formalin condensation Water, sodium dodecyl diphenyl ether disulfonate, sulfonate, alkylbenzene sulfonate, alkylbenzene sulfonate salt, lauryl ether sulfonic acid, lauryl ether sulfonate, polycarboxylate and polyethylene glycol mixture, methacrylic acid- Methoxy polyethylene glycol monomethacrylate copolymer sodium salt, acrylamide copolymer and alcohol ethoxylate sulfite sodium salt mixture, acrylamide copolymer and sodium lauryl ether sulfate mixture, polycarboxylate and sodium sulfonic acid salt mixture, A water-dispersible anionic polymer dispersion of at least one selected from the group consisting of a polycarboxylic acid copolymer having a polyoxyethylene side chain, and a copolymer derived from a polycarbonate.
4. According to claim 1,

   The anionic dispersant is added in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer, a water-dispersible anionic polymer dispersion.
5. According to claim 1,

   The molecular weight modifier is selected from the group consisting of glycolic acid, lactic acid, ethylene glycol, sodium hypophosphite monohydrate, methyl mercaptan having a thiol group (-SH), ethyl mercaptan, aryl mercaptan, and thioacetic acid At least one water-dispersible anionic polymer dispersion
6. According to claim 1,

   The molecular weight modifier is added in an amount of 0.001 to 15 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer, a water-dispersible anionic polymer dispersion.
7. According to claim 1,

   The structuring agent is at least one selected from the group consisting of methylenebisacrylamide, arylthiourea, bisacryloylcystamine, dihydroxyethylenebisacrylamide, ethylenediacrylate, and ethyleneglycoldimethacrylate, Water-dispersible anionic polymer dispersion.
8. According to claim 1,

   The structuring agent is a water-dispersible anionic polymer dispersion which is added in an amount of 0.0001 to 2 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer.
9. According to claim 1,

   The anionic stabilizer is a homopolymer or copolymer produced in a solution containing (meth)acrylic acid, a hydroxyl group-containing compound, a sequestering agent and an initiator, and has a viscosity of 2,000 to 10,000 cps and a pH of 8 to 12, a water-dispersible anion polymer dispersion.
10. According to claim 1,

    The anionic stabilizer is a water-dispersible anionic polymer dispersion which is added in an amount of 2 to 8 parts by weight based on 100 parts by weight of the anionic monomer and the nonionic monomer.
11. According to claim 1,

    The salt solution contains 20 to 30% of ammonium sulfonate, a water-dispersible anionic polymer dispersion.
12. According to claim 1,

    The pH of the salt solution before polymerization is 4.7 to 5.2, a water-dispersible anionic polymer dispersion.
13. According to claim 1,

    A water-dispersible anionic polymer dispersion having a product viscosity (25°C) of 50 to 2,500 cps measured by a Brookfildo viscometer (DV2T type, measurement conditions Spindle No. 62, 12 rpm).
14. According to claim 1,

    A water-dispersible anionic polymer dispersion having storage stability at a temperature of -10°C or higher.

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