KR102256143B1 - Water-soluble anion polymer dispersion having high molecular weight and the preparing method thereof - Google Patents

Abstract

The present invention relates to a water-dispersible anionic polymer dispersion of a high molecular weight more effective in water treatment, dredging, soil restoration and/or crude oil treatment, and a method for preparing the same, and more specifically, polymerization using a specific molecular weight modifier and/or structuring agent. A water-dispersible anion with high fluidity by controlling the balance between speed and salting-out speed and changing the molecular structure to ensure that the particle size is small, uniform, and high molecular weight, and the copolymerized anionic polymer particles are stably dispersed by electrostatic repulsion. It is possible to provide a polymer dispersion.

Description

High molecular weight water-dispersible anionic polymer dispersion and its manufacturing method {WATER-SOLUBLE ANION POLYMER DISPERSION HAVING HIGH MOLECULAR WEIGHT AND THE PREPARING METHOD THEREOF}

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

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

Among the water-soluble polymers, emulsion polymers containing oil are 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. It has also been used as an oil retention enhancer and as a genetic medicine.

Emulsion polymer dispersions or products in the form of powders containing oil have a high molecular weight, so it is confirmed that they exhibit excellent effects in terms of the ability to form flocs. However, in the case of emulsion polymer dispersions, not only must go through a aging step for a certain period of time after dissolution, but also phase separation and creaming due to oil content may cause a layer separation phenomenon during long-term storage, thereby deteriorating the storage stability of the product. In addition, due to the oil component contained within itself, it is inefficient in terms of economical efficiency and workability, since the secondary treatment must be performed to remove the phenomenon that impairs the quality of the final product and the oil component (impurity). In addition, it has a disadvantage of acting as a factor of increasing turbidity and COD in water due to the content of a large amount of surfactant.

In addition, the water-soluble polymer in the form of powder has a disadvantage that it takes a long time to dissolve, resulting in poor workability, an increase in additional equipment cost, and poor workability due to human body hazards due to dust. In addition, there is a problem in that not only economic loss due to undissolved but also undissolved products can cause severe side effects such as precipitation and adhesion in the oil-water separation process of crude oil.

On the other hand, water-soluble polymer dispersions that do not contain oil (hereinafter referred to as'water-dispersible polymer dispersions') are environmentally friendly and 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 pollution of various facilities (pipes, work places, 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 a dispersion polymerization method, but it has been difficult to prepare a water-soluble anionic polymer dispersion having a high molecular weight due to the limitation of the dispersion polymerization method.

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

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

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

In order to achieve the above technical problem, the present invention (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) an anionic polymer particle copolymerized in (h) a salt solution containing a polymerization initiator, and the anionic polymer particle has an average particle diameter (d50) of 1 to 30 µm and an anion degree of 3 to 90 mol %, effective concentration is 5-30% by weight, 0.5% salt viscosity is 250 It provides a water-dispersible anionic polymer dispersion of ~ 1,000 cps (at 25℃).

In one embodiment according to the present invention, the anionic polymer particles have an anionic dispersant adsorbed on a part or all of the surface, and the anionic dispersant is a naphthalene-based dispersant, a ligreen-based dispersant, a melamine-based dispersant, a sulfonic acid-based It may be one or more 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 ligreen, ligrinsulfonic 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 condensate, sodium dodecyldiphenyl ether disulfonate, sulfonate, alkylbenzene sulfonate, alkylbenzene sulfonate salt, lauryl ether sulfonic acid, lauryl ether sulfonate, polycar 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 lauryl ether sodium sulfate mixture, poly It may be at least one selected from the group consisting of a mixture of a carboxylate salt and a sodium sulfonate salt, a polycarboxylic acid copolymer having a side chain of polyoxyethylene, and a copolymer derived from a polycarbonate.

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 ( It may be one or more selected from the group consisting of methyl mercaptan, ethyl mercaptan, aryl mercaptan, and thioacetic acid having -SH).

For an 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, and dihydroxyethylene. It may be one or more 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 pH 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.

For example 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 example, the water-dispersible anionic polymer dispersion has a product viscosity (25°C) measured by a Brookfildo viscometer (DV2T type, measurement condition Spindle No. 62, 12 rpm) of 50 to 2,500 cps. I 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, by using at least one of a specific molecular weight modifier and a structuring agent to control the balance between the polymerization rate and the salting out rate, and to form a hard floc by changing the molecular structure, 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 and 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 on the copolymerized radical copolymer particles to have a negative charge on the surface, thereby making it possible to prepare an anionic polymer dispersion of high fluidity and uniformly dispersed by electrostatic repulsion. Compared to molecular weight products, it can 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 eco-friendly compared to the emulsion coagulant most commonly used as a liquid polymer coagulant, and can be used in place of the emulsion coagulant. .

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

The effects according to the present invention are 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 of preparing a high molecular weight water-dispersible anionic polymer dispersion according to an embodiment of the present invention.
2 is a process flow chart showing a method of manufacturing an anionic stabilizer according to an embodiment of the present invention.

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

All terms (including technical and scientific terms) used in the present specification may be used with meanings that can be commonly understood by those of ordinary skill in the art, unless otherwise defined. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

In addition, throughout the present specification, when a certain 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, the term "above" or "on" means not only the case that is located above or below the target part, but also includes the case where there is another part in the middle, and must always refer to the direction of gravity. It does not mean that it is located above the standard.

<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, a salt solution; High molecular weight anionic polymer particles (or water-soluble polymer) dispersed in the salt solution; And an anionic dispersant adsorbed on 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 deteriorated.If the particle size is too small, the dispersibility and storage stability of the dispersion may decrease due to precipitation due to aggregation between coagulants. Therefore, it is desirable to optimize the size of the water-soluble polymer. However, when forming a water-soluble polymer 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 by using the difference in solubility of a monomer and a polymer in a salt solution, which is a dispersion medium. Specifically, a water-soluble monomer soluble in a salt solution is polymerized to precipitate polymer particles insoluble in a salt solution, This is a method of obtaining the final target product by imparting electrical stability and specific gravity stability considering the specific gravity of the dispersion medium to the generated polymer particles. 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 the salted-out particles. Accordingly, the polymerization reaction is stopped or the curing of the reactants occurs. In addition, if the polymerization rate of the reactant is too slow, the viscosity of the reactant does not increase, but the reaction time takes a long time because nucleation and salting out are also slow, and a product with unstable and irregular particles is produced as a final product with a low molecular weight is produced. .

Accordingly, 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, the molecular structure of the resulting polymer is changed. By forming a floc, improved effects can be exhibited in dehydration, sedimentation, and turbidity. In addition, the resulting water-soluble polymer can be formed uniformly while having a small particle size.

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

In one embodiment according to the present invention, the anionic polymer particles may 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) is produced by copolymerization in (h) a salt solution containing a radical polymerization initiator, and contains a specific component as the anionic dispersant, a molecular weight modifier, and a structuring agent in a predetermined amount. If necessary, at least one or more conventional additives known in the art may be further included.

Hereinafter, the composition of the water-dispersible anionic polymer dispersion will be described in detail.

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

The anionic monomer used in the present invention may be used without limitation, without limitation, a conventional material known in the art, for example, including 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, and p-carboxystyrene. ; And sulfone group-containing monomers such as 2-acrylamide-2-methyl1-propane sulfonic acid, vinyl sulfonic acid, vinylbenzene sulfonic acid, and styrene sulfonic acid. In addition, as the salt, an alkali metal salt, an alkaline earth metal salt, or an ammonium salt may be used, and specific examples thereof include sodium acrylate and sodium methacrylate.

In the present invention, the content of the anionic monomer 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 nonionic monomers that can be used include (meth)acrylamide, N,N-dimethylacrylamide, N-isopropylacrylamide, and N-butylacrylamide. (N-butyl acrylamide) N-methylolacrylamide, vinyl acetate, acrylonitrile, methyl acrylate, (meth)acrylate 2-hydroxyethyl, diacetoneacrylamide, N-vinyl-2-pyrrolidone , N-vinylformamide, N-vinylacetamide, vinylimidazole, N-vinylcarbazole, acryloylmorpholine, polyethylene glycol (meth)acrylate, polyglycerol (meth)acrylate, or a mixture thereof There is this.

In the present invention, the content of the nonionic monomer 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 fluidity by improving the dispersion stability of the resulting water-soluble anionic polymer particles.

If the anionic stabilizer plays the above-described role, it is not particularly limited in its components or usage, and known ones in the art may be used. As an example, polymerized polymers or copolymers may be used, and specifically, homopolymers of acrylic acid, sodium acrylate, methacrylic acid, sodium methacrylate, 2-acrylamide 2-methyl 1-propane sulfonic acid, and copolymers thereof You can use coalescence.

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 the viscosity is 2,000~ It can have 1,000 cps and pH 8-12.

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

At this time, the metal ion sequestering agent and the initiator are not particularly limited, and those known in the art may be used without limitation. Examples of the metal ion sequestering agent that can be used may be diethylenetriaminepentaacetic acid, and examples of the initiator include sodium hydrogen sulfite and azo-based (Vazo 56WSP). In addition, when preparing the anionic stabilizer, the amount of the metal ion sequestering agent may be 10 to 100 ppm, preferably 30 to 80 ppm, based on 100 parts by weight of the anionic and nonionic monomers. In addition, as an initiator, sodium hydrogen sulfite 200 to 2,000 ppm, and Vazo 56WSP 200 to 3,000 ppm may be used based on 100 parts by weight of anionic and nonionic monomers, preferably sodium hydrogen sulfite 500 to 1,000 ppm, Vazo 56WSP 500 to 1,500 ppm can 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 a polymer or copolymer particle (water-soluble polymer) produced by a polymerization reaction to have a predetermined charge, such as a negative (-) charge, so that a plurality of polymer particles It is uniformly dispersed by electrostatic repulsion to obtain a high-mobility polymer dispersion.

As the anionic dispersant, at least one selected from the group consisting of a naphthalene-based dispersant, a ligreen-based dispersant, a melamine-based dispersant, a sulfonic acid-based dispersant, a polycarboxylic acid-based copolymer, and a salt thereof may be used. In addition, it is also within the scope of the present invention to use other anionic dispersants as long as they play the above-described role.

Specific examples of usable anionic dispersants include ligreen, ligrinsulfonic acid or a salt thereof, naphthalene sulfonic acid formalin condensate, melamine formaldehyde condensate, polyethylene glycol sulfonic acid ether, polyethylene glycol alkyl ether, naphthalene sulfonate, Melamine sulfonic acid formalin condensate, sodium dodecyldiphenyl ether disulfonate, sulphonic acid salt, alkylbenzene sulfonate and its salt, lauryl ether sulfonic acid and its salt, polycarboxylate and polyethylene glycol mixture, methacrylic acid-meth 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 one or more selected from the group consisting of a mixture of sodium sulfonate salts, a polycarboxylic acid having a side chain of polyoxyethylene, and a copolymer having 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 the 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 have a high molecular weight if the polymerized water-soluble polymer particles have a uniform and fine size by controlling the nucleation rate and the polymerization reaction rate to be balanced with each other during dispersion polymerization.

The molecular weight modifier may be 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 ) Having 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 the 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 1 to 4 parts by weight. Also in the case of lactic acid. It may be 0.1 to 5 parts by weight, specifically 0.1 to 2 parts by weight, and in the case of ethylene glycol, it may be 1 to 15 parts by weight, and may be specifically 4 to 10 parts by weight, and the sodium hypophosphite monohydrate In this case, 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 a polymer produced by dispersion polymerization to form a hard floc.

The structuring agent may be a conventional compound known in the art, and is not particularly limited. Non-limiting examples of structuring agents that can be used include, but are not limited to, 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 or arylthiourea.At this time, in the case of methylenebisacrylamide, a network-shaped molecular structure can be formed, and in the case of arylthiourea, a branched molecular structure Can be formed.

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 an anionic monomer and a nonionic monomer, and in the case of arylthiourea, it is preferable to use 0.05 to 2 parts by weight.

Chelating agent

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

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 amount of chelate (input amount) 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 50 to 1,000 ppm based on 100 parts by weight of the anionic monomer and the nonionic monomer.

Polymerization initiator

The polymerization initiator used in the present invention may be any radical polymerization initiator known in the art 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 a mixture thereof.

In addition, specific examples of the water-soluble azobis-based polymerization initiator include 2,2-azobis[2-(5-methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2-azo Bis(2-amidinopropane)dihydrochloride, 4,4-azobis(4-methoxy-2,4-dimethyl)valeronitrile, or mixtures 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 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 secondarily add an excess of polymerization initiator to treat the residual monomer. At this time, the secondly added polymerization initiator may be the same as or different from the firstly added polymerization initiator component, and preferably, potassium persulfate, which is a redox-based reducing initiator, is used. In addition, the amount of the secondly added polymerization initiator 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 conventional salts known in the art may be used. As an example, it may be one or more 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 monomer is polymerized as a polymerization reaction proceeds in a state in which a water-soluble salt and a monomer are dissolved in water, and particles are formed according to the difference in solubility thereof. At this time, when the concentration of salt is low, gelation proceeds due to an extreme viscosity increase, and when the concentration of salt is high, particles are formed quickly and agglomeration of formed polymer particles (islamic phenomenon) occurs, resulting in a low molecular weight. In addition, when the storage temperature is lowered, crystal precipitation occurs due to a decrease in solubility according to the temperature. In consideration of the above, the amount of salt 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 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, a 20 to 30 (w/v)% aqueous solution of an ammonium sulfate ionic salt is 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 can be appropriately adjusted within the content range known in the art.

Since the above-described high molecular weight water-dispersible anionic polymer dispersion of the present invention is an oil-free product, it not only has eco-friendly and excellent storage stability, but also has a small particle size and a high molecular weight radical copolymer 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 It may be 30% by weight.

For another embodiment, the anionic polymer may have a weight average molecular weight (Mw) of 8 million to 20 million g/mol, and specifically 9 million to 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 Brookfildo viscometer (DV2T type, measurement condition Spindle No. 62, 12 rpm) 250 ~ 1,000 cps (25 ℃ standard), it may be specifically 270 ~ 700 cps. In addition, the product viscosity (25°C) may be 50 to 2,500 cps, and specifically 50 to 1,000 cps.

For 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 storage stability of 10 days or more at -10°C, and specifically 30 to 90 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 and performed as necessary.

In one 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), first adding a salt, and then adding and mixing at least one of a molecular weight modifier 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 second polymerization reaction after adding a polymerization initiator to the resultant of the first reaction of step (iii) ('S40 step'); And (v) a second step of adding a salt to the resultant of the second reaction of step (iv) ('S50 step').

Meanwhile, referring to FIG. 1, the manufacturing method will be described by dividing each process step 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 will be omitted.

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

As an example of the method for preparing the anionic stabilizer with reference to FIG. 2 below, a monomer and pure water are mixed and stirred at a speed of 200 to 300 rpm, and then a compound having a hydroxyl group is maintained at 20 to 30°C. After the dropwise addition, the chelating agent is added, and the polymerization reaction may be carried out by adding an initiator in a nitrogen atmosphere. In this case, the polymerization reaction temperature condition is not particularly limited, and may be 40 to 80°C as an example. 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, followed by stirring and mixing at a speed of 200 to 300 rpm to obtain an aqueous solution in which the above-described components are uniformly mixed. Can be manufactured.

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

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

For a more specific example of the step S20, sodium hydroxide is added dropwise to the aqueous solution containing monomers uniformly mixed in step S10 while maintaining a temperature of 10 to 30°C, and a salt is first added to dissolve it. Subsequently, a molecular weight modifier, a structuring agent, and a chelating agent are respectively added and stirred, and then nitrogen is added and the temperature is raised to about 30 to 40°C.

On the other hand, in the case of using a monomer that does not consist of an anionic salt such as acrylic acid, _{it is used after replacing it with Na ions and NH 3} ions using sodium hydroxide or ammonia water having an OH group.At this time, the pH of the salt solution is different depending on the degree of substitution. You lose. Since this pH corresponds to 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 amount of the hydroxyl-containing compound (eg, sodium hydroxide) added.

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 reaction ('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 for 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 first 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. In the case of using a redox system or a water-soluble azobis system, it may be 25 to 50°C, preferably at 30 to 40°C for 4 to 6 hours.

(iv) Secondary polymerization reaction ('S40 step')

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

At this time, the polymerization initiator added secondarily may be the same as or different from the first polymerization initiator, and is not particularly limited. Preferably, potassium persulfate, which is a redox-based reducing initiator, is added to about 200 to 1,000 ppm.

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

(v) Salt 2nd input ('S50 step')

Subsequently, after cooling the resultant of the secondary polymerization reaction to room temperature, salt is secondarily added as needed, and post-treatment such as filtering is performed.

At this time, the secondary input of a salt (eg, ammonium sulfate) is added to ensure fluidity. As the amount of salt added increases, precipitation may occur due to a solubility problem according to temperature, so if the product viscosity is low, the secondary addition 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 27% or less.

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

The water-dispersible anionic polymer dispersion according to the present invention prepared as described above contains particles of a high-molecular-weight fine water-soluble polymer having excellent stability and dispersion effect at a high concentration. It can exhibit improved dehydration, sedimentation, and turbidity improvement effects. In addition, since the anionic polymer dispersion is an oil-free product, it is eco-friendly compared to the emulsion coagulant most commonly used as a liquid polymer coagulant in the related art, and can be used in place of the emulsion coagulant. In addition, in the present invention, a water-soluble anionic polymer dispersion having a high molecular weight, 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.

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 for solid-liquid separation processes in various industries, a polymer coagulant in wastewater treatment processes, and a papermaking process. It can be used as an enhancer, a dehydration accelerator, a strength enhancer, an oil-water separator in oilfield processes, and/or as a friction reducer in crude oil transfer.

For a more specific example, it can be used for coagulation treatment (floating tank, sedimentation tank, dehydrator) such as raw sludge, surplus sludge, digested sludge or mixtures thereof, dredging work, soil restoration, and sand collection of urban sewage or general industrial wastewater. , It can be used as an oil-water separator in the oil separation process to separate and treat oil from oil-containing industrial wastewater, and as a friction reducing agent to reduce the frictional heat in pipes when transporting crude oil over long distances, and also as a water-pollution 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 a 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.

In this case, throughout this specification, unless otherwise stated,% used to indicate the concentration of a specific substance is (weight/weight)% for solid/solid, (weight/volume)% for solid/liquid, and liquid /Liquid can be (vol/vol) %.

[Preparation example. Preparation of anion stabilizer]

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

The water-soluble anion stabilizer prepared as described above had an effective concentration of 15%, an anion 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 condition Spindle No 63, 12 rpm).

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

[Example 1]

In a 2L reactor, 50% acrylamide 343g, pure water 810g, acrylic acid 53g, 2-acrylamide 2 methyl 1-propane sulfonic acid 60g, 15% anion stabilizer 87g prepared in the preparation example, naphthalene-based anion dispersant (SNF OC-512) 10g The mixture was stirred, and 61 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30° C., and then 488 g of ammonium sulfate was added thereto to completely dissolve. 0.5 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction. After 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours.

[Example 2]

In a 2L reactor, 50% acrylamide 345g, pure water 870g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g prepared in the preparation example, naphthalene-based anion dispersant (Dongnam company FLOWMIX Super-1 ) 10g was added and stirred, and 61g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 491g of ammonium sulfate was added to completely dissolve. 0.5 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was carried out for 15 hours.

[Example 3]

In a 2L reactor, 50% acrylamide 345g, pure water 870g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g prepared in the preparation example, lignin-based anion dispersant (Daedong Chemtech Ligreen) 0.2 g was added and stirred, and 61 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30° C., and then 491 g of ammonium sulfate was added thereto to completely dissolve. 0.5 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 the polymerization reaction, and 4.5 g of 1% VA-044 (Vazo 44WSP) after 2 hours, and 1% VA-044 (Vazo 44WSP) after 2 hours. ) 4.5g, after 6 hours, 0.06g 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 4]

In a 2L reactor, 50% acrylamide 343g, pure water 815g, acrylic acid 53g, 2-acrylamide 2 methyl 1-propane sulfonic acid 60g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 20g, polycarboxylic acid-based anionic dispersant (agent ENT, JNT-07) 10g was added and stirred, and 61g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 522g of ammonium sulfate was added thereto to completely dissolve. 0.5 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction. After 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 12 g of ammonium sulfate was added.

[Example 5]

In a 2L reactor, 50% acrylamide 345g, pure water 842g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 20g, polycarboxylic acid-based anion dispersant (Southeast 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 to completely dissolve. 0.5 g of lactic acid was added, and diethylenetriaminephene After adding 0.25 g of taacetic acid, nitrogen was added thereto 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 6]

In a 2L reactor, 50% acrylamide 345g, pure water 842g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g, glycerin 20g, polycarboxylic acid anionic dispersant (SAN NOPCO L-400S) 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. 0.2 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 7]

In a 2L reactor, 50% acrylamide 345g, pure water 842g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g, glycerin 20g, polycarboxylic acid anionic dispersant (Daedong Chemtech NEOPERSE D-400N) 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 to completely dissolve. 0.2 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 8]

In a 2L reactor, 50% acrylamide 345g, pure water 842g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 20g, polycarboxylic acid-based anion dispersant (Daedong Chemtech NEOFLOW RS-7015) 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 to completely dissolve. 0.2 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 9]

In a 2L reactor, 50% acrylamide 345g, pure water 835g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g, glycerin 20g, polycarboxylic acid anionic dispersant (silk Load PEMA-SP1000) 10g was added and stirred, and 66g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and 500g of ammonium sulfate was added thereto to completely dissolve. 0.2 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 10]

In a 2L reactor, 50% acrylamide 345g, pure water 830g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g, glycerin 20g, polycarboxylic acid anionic dispersant (silk Load PEMA-SR3000) 25g was added and stirred, and 66g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 498g of ammonium sulfate was added thereto to completely dissolve. 0.6 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 11]

In a 2L reactor, 50% acrylamide 345g, pure water 842g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 20g, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1 ) 10 g 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 diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 12]

In a 2L reactor, 50% acrylamide 345g, pure water 842g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 20g, sulfonic acid-based anion dispersant (PILOT CALIMULSE L -50) 10g was added and stirred, and 62g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 502g of ammonium sulfate was added thereto to completely dissolve. 0.6 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 13]

In a 2L reactor, 50% acrylamide 233g, pure water 980g, acrylic acid 33g, 2-acrylamide 2 methyl 1-propane sulfonic acid 38g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 19g, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1 ) 10g was added and stirred, and 36g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 540g of ammonium sulfate was added to completely dissolve. 3 g of glycolic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 26 g of ammonium sulfate was added.

[Example 14]

In a 2L reactor, 50% acrylamide 348g, pure water 844g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 20g, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1 ) 10g was added and stirred, and 58g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 504g of ammonium sulfate was added and completely dissolved. 10 g of ethylene glycol was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 15]

In a 2L reactor, 50% acrylamide 348g, pure water 844g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 20g, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1 ) 10g was added and stirred, and 58g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 504g of ammonium sulfate was added and completely dissolved. 0.3 g of lactic acid and 0.3 g of arylthiourea were added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 16]

In a 2L reactor, 50% acrylamide 348g, pure water 844g, acrylic acid 54g, 2-acrylamide 2 methyl 1-propane sulfonic acid 61g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 20g, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1 ) 10g was added and stirred, and 58g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 504g of ammonium sulfate was added to completely dissolve. 0.3 g of lactic acid and 10 g of 0.1% methylenebisacrylamide were added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 17]

In a 2L reactor, 50% acrylamide 520g, pure water 775g, acrylic acid 10.8g, 2-acrylamide 2 methyl 1-propane sulfonic acid 12.24g, 15% anion stabilizer 87g prepared in the preparation example, glycerin 19g, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1) 10g was added and stirred, and 12g of 50% sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and 500g of ammonium sulfate was added thereto to completely dissolve. 0.2 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 24 g of ammonium sulfate was added.

[Example 18]

In a 2L reactor, 50% acrylamide 182g, pure water 840g, acrylic acid 90g, 2-acrylamide 2 methyl 1-propane sulfonic acid 100g, 15% anion stabilizer 90g prepared in the preparation example, glycerin 20g, sulfonic acid-based anion dispersant (DOW DOWFAX 2A1 ) 10 g was added and stirred, and 96 g of 50% sodium hydroxide was slowly added dropwise while maintaining 10 to 30° C., and 495 g of ammonium sulfate was added thereto to completely dissolve. 0.2 g of lactic acid was added, 0.25 g of diethylenetriaminepentaacetic 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 reaction, and after 6 hours, 0.06 g of potassium persulfate was added and the polymerization reaction was performed 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 354g, pure water 851g, ammonium sulfate 475g, acrylic acid 55g, 2-acrylamide 2 methyl 1-propane sulfonic acid 62g, 15% anion stabilizer 90g prepared in the preparation example, and glycerin 20g were added to a 2L reactor and stirred, After slowly adding 72 g of sodium hydroxide 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 reaction to 30~45℃. I got it.

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 reaction. After 6 hours, the same amount of initiator was added again, and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 59 g of ammonium sulfate was added.

[Comparative Example 2]

50% acrylamide 354g, pure water 851g, ammonium sulfate 475g, acrylic acid 55g, 2-acrylamide 2 methyl 1-propane sulfonic acid 62g, 15% anion stabilizer 90g prepared in the preparation example, and glycerin 20g were added to a 2L reactor and stirred, 73g of sodium hydroxide was slowly added dropwise while maintaining 10~30℃, then 1.55g of 1% sodium hypophosphite monohydrate and 0.25g of diethylenetriaminepentaacetic acid were added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was reduced to 30 It was set to -45℃.

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

[Comparative Example 3]

50% acrylamide 354g, pure water 851g, ammonium sulfate 511g, acrylic acid 55g, 2-acrylamide 2 methyl 1-propane sulfonic acid 62g, 15% anion stabilizer 90g prepared in the preparation example, and glycerin 20g were added to a 2L reactor and stirred, 68 g of sodium hydroxide was slowly added dropwise while maintaining 10 to 30°C, 18 g of ethylene glycol and 0.25 g of diethylenetriaminepentaacetic acid were added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product 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 reaction. After 6 hours, the same amount of initiator was added again, and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 48 g of ammonium sulfate was added.

[Comparative Example 4]

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

As a polymerization initiator, 6 g of 1% VA-044 (Vazo 44WSP) was added to initiate the polymerization reaction. After 6 hours, the same amount of initiator was added again, and the polymerization reaction was performed for 15 hours. When the polymerization reaction was completed, 47 g of ammonium sulfate was added.

[Comparative Example 5]

In a 2L reactor, 50% acrylamide 542g, pure water 490g, ammonium sulfate 399g, acrylic acid 92g, 2-acrylamide 2 methyl 1-propane sulfonic acid 96g, 15% anion stabilizer 90g prepared in Preparation Example, and glycerin 20g were added and stirred, After slowly adding 104 g of sodium hydroxide dropwise while maintaining 10~30℃, add 28.3g of ethylene glycol and 0.25g of diethylenetriaminepentaacetic acid, add nitrogen for 30 minutes while stirring, and adjust the temperature of the reactant to 30~45℃. I got it.

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

[Comparative Example 6]

50% acrylamide 471 g, pure water 700 g, ammonium sulfate 452 g, acrylic acid 78 g, 2-acrylamide 2 methyl 1-propane sulfonic acid 83 g, 15% anion stabilizer 90 g prepared in the preparation example, and glycerin 20 g were added and stirred, 91g of sodium hydroxide is slowly added dropwise while maintaining 10~30℃, 0.7g of arylthiourea and 0.25g of diethylenetriaminepentaacetic acid are added, and nitrogen is added for 30 minutes while stirring, and the temperature of the reactant is adjusted to 30~45℃. I got it.

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

[Comparative Example 7]

50% acrylamide 394g, pure water 770g, ammonium sulfate 583g, acrylic acid 92g, 15% anion stabilizer 100g, glycerin 14g prepared in the 2L reactor were added and stirred, and 65g of sodium hydroxide was slowly added dropwise while maintaining 10~30℃ After that, 0.5 g of arylthiourea and 0.25 g of diethylenetriaminepentaacetic acid were added, and nitrogen was added for 30 minutes while stirring, and the temperature of the reaction product was adjusted to 30 to 45°C.

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

[Comparative Example 8]

50% acrylamide 354g, pure water 851g, ammonium sulfate 475g, acrylic acid 55g, 2-acrylamide 2 methyl 1-propane sulfonic acid 62g, 15% anion stabilizer 90g prepared in the preparation example, and glycerin 20g were added to a 2L reactor and stirred, 72g of sodium hydroxide was slowly added dropwise while maintaining 10~30℃, and then 70% glycolic acid 9g, 0.1% methylenebisacrylamide 10g, diethylenetriaminepentaacetic acid 0.25g were added, and nitrogen was added for 30 minutes while stirring. The temperature was set to 30~45℃.

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 reaction. After 6 hours, the same amount of initiator was added again, and the polymerization reaction was performed 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 are shown in Tables 1 to 2, respectively.

Equipment and reagents for the evaluation of the physical properties of Experimental Example 1 include a high-speed stirrer (IKA EUROSTAR60), a stirring rod, a scale (4th decimal place), a 5ml syringe, a stopwatch, a 300ml beaker, a Brookfield viscometer (DV2T type), and a thermometer. , A constant temperature bath, 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, 6.667 g of a sample was taken into a disposable syringe and dissolved for 10 minutes while stirring at a speed of 1,000 rpm by attaching a stirring rod to a high-speed stirrer. After setting 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%, 190g of pure water and 10g of sample; 193.333 g of pure water and 6.667 g of sample at 15%; 195g of pure water and 5g of sample when the effective concentration is 20%; When the effective concentration was 25%, the composition was 196g of pure water and 4.0g of sample.

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

After taking 193.333 g of 4% sodium chloride in a 300 ml beaker, 6.667 g of a sample was put into a disposable syringe while stirring at a speed of 1,000 rpm by attaching a stirring rod to a high-speed stirrer, and dissolved for 10 minutes. After setting 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 sample material 6.667g, when the effective concentration is 20%, 4% sodium chloride 195g and sample 5g, when the effective concentration is 25%, 4% sodium chloride 196g And 4.0 g of samples.

(4) molecular weight measurement

① 200 ml of pure water was put in a 500 ml beaker, and a stirring rod was attached to the stirrer, followed by stirring at 1000 rpm.

② The inside of the 2.5㏄ disposable syringe was wetted with a sample.

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

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

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

⑤ Subsequently, the mixture was stirred at 1000 rpm for 30 minutes.

⑥ Using WATER-BATH, set the sample to 25ㅁ0.5℃ while stirring the sample with a thermometer.

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

⑧ After designating the type of SPINDLE (SP00) and adjusting the SPEED to 60 rpm, the Viscometer Switch was turned 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

After collecting a sample using a disposable pipette on the slide glass, the power of 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 adjustment screw to place 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 adjustment screw to focus, and the slide glass was moved to the part to be viewed. When the focus is achieved, the aperture and voltage of the light source, and the position and aperture of the capacitor were adjusted to obtain a clear and clear image. Then, the slide glass was moved to find the best phase and the particle size of the anionic polymer was measured.

Molecular Weight
Modulator Functional
Monomer Anionic
Dispersant available
density Ionic
(mol%) product
Viscosity
(cps) 0.5%
solution
Viscosity
(cps) 0.5% salt
Viscosity
(cps) Molecular Weight
(million) 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 - Regreen system 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
Modulator Functional
Monomer Anionic
Dispersant available
density Ionic
(mol%) product
Viscosity
(cps) 0.5% solution
Viscosity
(cps) 0.5% salt
Viscosity
(cps) Molecular Weight
(million) 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 to 2, in the case of the water-dispersible anionic polymer dispersion of Examples 1 to 18 containing at least one of a molecular weight modifier and a structuring agent and an anionic dispersant, a comparison containing no anionic dispersant Compared to Examples 1 to 8, a polymer dispersion having a high 0.5% salt viscosity and a high molecular weight of about 270 to 470 cps could be prepared. Specifically, as a result of examining 12 types of anionic dispersants currently distributed in the market for each series, Example 11 using a sulfonic acid-based anionic dispersant (eg, DOWFAX 2A1); Example 2 using a naphthalene-based anionic polymer (eg, Southeast Corporation FLOWMIX Super-1); And it was found that the anionic polymer dispersions of Examples 6 and 9 using polycarboxylic acid-based anionic polymers (eg, Silkroad PEMA-SP1000, SAN NOPCO L-400S) exhibited superior dispersant performance.

On the other hand, in the case of Comparative Examples 1 to 8 containing no anionic dispersant, by using a molecular weight modifier and a structuring agent without using a surfactant, the balance between the nucleation rate and the polymerization reaction rate was adjusted, so that the particle size was small. It was possible to prepare a uniform, high fluidity, and stable water-dispersible anionic polymer dispersion. However, it only exhibited a relatively low salt viscosity of 150-247 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 shown in Tables 3 to 4, respectively.

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

1) Performance evaluation method

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

At this time, Comparative Sample 1 used Comparative Example 4 (molecular weight 8.7 million) without using an anionic dispersant, and Comparative Sample 2 used our product, HA-520 (molecular weight 14 million) emulsion products, respectively.

division Molecular Weight
(million) 0.5% salt viscosity
(cps) input
(ppm) Sedimentation 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 solid content: 3.5%

division Molecular Weight
(million) 0.5% salt
Viscosity (cps) input
(ppm) Sedimentation speed
(sec) Turbidity
(NTU) COD
(Mn) Comparative sample 2 14.0 - 2 31 1,950 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 dispersion 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, 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 terms of sedimentation rate depending on the amount of input. 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 when the amount of water-dispersible anionic polymer dispersion is reduced compared to Comparative Example 2. Was able to demonstrate.

On the other hand, in the case of Comparative Examples 1 to 8 containing at least one of a molecular weight modifier and a structuring agent, compared to the coagulant of Comparative Sample 2, an emulsion product containing oil and surfactant, it was found that the sedimentation rate, supernatant turbidity, and COD were improved. It could be confirmed (see Table 4 above).

[Experimental Example 3. Storage stability evaluation according to salt input amount]

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

In the evaluation criteria of Table 5 below, ○ means a state in which there is no increase in viscosity or salt precipitation, △ is a state in which the viscosity increases, and salt precipitation occurs over time, and X is the salt precipitation accompanied by an increase in viscosity. Each represents the state in which it occurs.

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

As shown in Table 5, when the storage temperature standard is set to -10°C based on the winter season in which the air temperature change according to the season and salt dissolution are the lowest, the appropriate amount of ammonium sulfate is 28% or less based on 100% of the total. Is 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 the tendency according to the primary reaction pH was evaluated by adjusting the amount of sodium hydroxide used when substituting Na for acrylic acid, and the appropriate pH condition was confirmed.

In the evaluation criteria of Table 6 below, ○ means a good viscosity increase occurs, △ is 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 amount (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 increases during the reaction, and when the stirring force is weak, the possibility of gelation increases. In addition, when the pH is low, polymerization tends to become difficult due to the occurrence of coagulation due to precipitation of polymers. Accordingly, it was confirmed that the pH before the reaction of the salt solution according to the present invention is more appropriate in the range of 4.7 to 5.2.

Claims (14)

(a) anionic monomers;
(b) nonionic monomers;
(c) anionic stabilizers;
(d) anionic dispersants;
(e) molecular weight modifiers, or molecular weight modifiers and structuring agents;
(f) chelating agents;
(g) polymerization initiator; And
It includes anionic polymer particles copolymerized in (h) a salt solution containing a hydroxyl group-containing compound,
The molecular weight modifier is at least one selected from the group consisting of glycolic acid, lactic acid, and ethylene glycol,
The pH before polymerization of the salt solution is 4.7 to 5.2,
The average particle diameter (d50) of the anionic polymer particles is 1 ~ 30 ㎛, anion degree is 3 ~ 90 mol%, effective concentration is 5 ~ 30% by weight, 0.5% salt viscosity is 250 ~ 1,000 cps (25 ℃ Standard) phosphorus, water-dispersible anionic polymer dispersion. The method of claim 1,
The anionic polymer particles have an anionic dispersant adsorbed on a part or all of the surface,
The anionic dispersant is at least one selected from the group consisting of a naphthalene-based dispersant, a ligreen-based dispersant, a melamine-based dispersant, a sulfonic acid-based dispersant, and a polycarboxylic acid-based copolymer. The method of claim 1,
The anionic dispersant is ligreen, ligrinsulfonic 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 dodecyldiphenyl 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 lauryl ether sodium sulfate mixture, polycarboxylate and sodium sulfonate salt mixture, A water-dispersible anionic polymer dispersion, which is at least one selected from the group consisting of a polycarboxylic acid copolymer having a side chain of polyoxyethylene and a polycarboxylic acid-derived copolymer. The method of 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. delete The method of 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. The method of claim 1,
The structuring agent is at least one selected from the group consisting of methylenebisacrylamide, arylthiourea, bisacryloylcystamine, dihydroxyethylenebisacrylamide, ethylenediacrylate, and ethylene glycol dimethacrylate, Water dispersible anionic polymer dispersion. The method of claim 1,
The structuring agent is a water-dispersible anionic polymer dispersion that 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. The method of 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 having a viscosity of 2,000 to 10,000 cps and a pH of 8 to 12, a water-dispersible anion Polymer dispersion. The method of claim 1,
The anionic stabilizer is a water-dispersible anionic polymer dispersion that 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. The method of claim 1,
The salt solution contains 20 to 30% of ammonium sulfonate, a water-dispersible anionic polymer dispersion. delete The method of claim 1,
A water-dispersible anionic polymer dispersion with a product viscosity (25℃) of 50 ~ 2,500 cps measured by a Brookfield viscometer (DV2T type, measurement condition, Spindle No. 62, 12 rpm). The method of claim 1,
A water-dispersible anionic polymer dispersion that has storage stability at temperatures of -10°C or higher.

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