JP2016186057A - Water-soluble polymer and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-soluble polymer that is high in molecular weight and has excellent coagulation performance.SOLUTION: A water-soluble polymer (A) 100 pts.wt. is crosslinked with an epoxy crosslinking agent (B) 1-10 pts.wt., where the water-soluble polymer has a specific structure obtained by subjecting a copolymer comprising acrylamide and acrylonitrile to Hofmann reaction, and thereafter, subjecting the reactant to neutralization and heating.SELECTED DRAWING: None

Description

  The present invention relates to a polyamidine-based water-soluble polymer having excellent aggregation performance and a method for producing the same.

  Amidine-type water-soluble polymers can be efficiently adsorbed to organic sludge by their high cation density, and can form strong flocs with excellent dewatering properties. It is known to be particularly effective as an agent.

  Conventionally, amidine-type water-soluble polymers have been produced by chemically modifying a formamide group into an amino group by acid treatment of a copolymer of vinylformamide and acrylonitrile, and then heat-treating the adjacent nitrile group and molecule. It was cyclized internally to form an amidine ring in the polymer chain. Since this method can efficiently form an amino group, it can be easily produced as a high amidine, and it can be said to be an excellent production method with few by-products (see, for example, Patent Document 1). However, since vinylformamide, which is one of the raw material monomers, is extremely expensive, it has been difficult to reduce its production cost.

  On the other hand, a method described in Patent Document 2 has been proposed as a method for producing a low-cost amidine-type water-soluble polymer. This method involves polymerizing a base polymer using inexpensive acrylamide and acrylonitrile as raw materials, and then modifying the amide group to an amino group by a Hofmann reaction using an oxidizing agent such as sodium hypochlorite and an alkali such as caustic soda. In the same manner as described above, an amidine ring is formed by acid treatment and heat treatment.

Japanese Patent No. 2624089 Japanese Patent No. 5057773

  However, in the method proposed in Patent Document 2, since the amide group is denatured from the amide group to the amino group by the Hofmann reaction using an oxidizing agent under severe basic conditions, molecular cleavage by the oxidizing agent occurs and is obtained. There have been problems such that the molecular weight of the water-soluble polymer is lowered, the aggregation performance tends to be lowered, and the aggregation performance of the water-soluble polymer is not always sufficient.

  As a result of intensive studies to solve the above problems, the present inventors have found that a specific polyamidine-based water-soluble polymer is excellent in aggregation performance, and have completed the present invention.

  That is, the present invention includes a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), a structural unit represented by the following formula (4), A structural unit represented by the following formula (5) and a structural unit represented by the following formula (6), and the structural unit represented by the following formula (1) is 3 mol% or more and 15 mol% or less; The present invention relates to a water-soluble polymer having a viscosity of 20 to 80 mPa · s in a 2% by weight aqueous solution and a method for producing the same.

（ここで、Ｒ_１は炭素数２〜４の炭化水素鎖を示し、ｎは１〜１０の数である。）

(Here, R ₁ represents a hydrocarbon chain having 2 to 4 carbon atoms, and n is a number of 1 to 10.)

（ここで、上記式中、Ｍ^＋は陽イオンを表し、Ｘ⁻は陰イオンを表す。）
以下、本発明を詳細に説明する。

(Here, in the above formula, M ⁺ represents a cation and X ⁻ represents an anion.)
Hereinafter, the present invention will be described in detail.

  The water-soluble polymer of the present invention is represented by the structural unit represented by the following formula (1), the structural unit represented by the following formula (2), the structural unit represented by the following formula (3), and the following formula (4). The structural unit includes a structural unit represented by the following formula (5) and a structural unit represented by the following formula (6), and the structural unit represented by the following formula (1) is 3 mol% or more and 15 mol% or less. The viscosity in a 0.2 wt% aqueous solution is 20 to 80 mPa · s.

（ここで、Ｒ_１は炭素数２〜４の炭化水素鎖を示し、ｎは１〜１０の数である。）

(Here, R ₁ represents a hydrocarbon chain having 2 to 4 carbon atoms, and n is a number of 1 to 10.)

（ここで、上記式中、Ｍ^＋は陽イオンを表し、Ｘ⁻は陰イオンを表す。）
本発明の水溶性高分子中の上記式（１）で示される構造単位は、凝集性能と水溶性のバランスより、３モル％以上１５モル％以下の範囲であることが好ましく、３モル％以上１２モル％以下の範囲がさらに好ましい。上記式（１）で示される構造単位が３モル％未満では、架橋が不十分なため十分な凝集性能が得られず、１５モル％を上回ると水溶性が低下するといった問題がある。

(Here, in the above formula, M ⁺ represents a cation and X ⁻ represents an anion.)
The structural unit represented by the above formula (1) in the water-soluble polymer of the present invention is preferably in the range of 3 mol% or more and 15 mol% or less, preferably 3 mol% or more, from the balance of aggregation performance and water solubility. The range of 12 mol% or less is more preferable. When the structural unit represented by the above formula (1) is less than 3 mol%, there is a problem that sufficient aggregation performance cannot be obtained due to insufficient crosslinking, and when it exceeds 15 mol%, the water solubility decreases.

  The viscosity of the water-soluble polymer of the present invention in a 0.2% by weight aqueous solution is preferably in the range of 20 to 80 mPa · s, more preferably in the range of 30 to 70 mPa · s, from the balance of aggregation performance and handling. Further preferred. Here, the viscosity in a 0.2% by weight aqueous solution of a water-soluble polymer means the viscosity of a 0.2% by weight aqueous solution of the water-soluble polymer measured at 25 ° C. with a B-type viscometer. When the viscosity is less than 20 mPa · s, it is difficult to obtain sufficient agglomeration performance, and when it exceeds 80 mPa · s, the viscosity is too high and it is difficult to handle.

  The water-soluble polymer includes a structural unit represented by the above formula (2), a structural unit represented by the above formula (3), a structural unit represented by the above formula (4), and a structure represented by the above formula (5). Manufactured by crosslinking 1 to 10 parts by weight of the epoxy-based crosslinking agent (B) with respect to 100 parts by weight of the water-soluble polymer (A) containing the unit and the structural unit represented by the above formula (6). be able to.

  The epoxy-based crosslinking agent (B) used in the production of the water-soluble polymer of the present invention is preferably a glycidyl ether type epoxy compound because of its excellent reactivity and water solubility. The glycidyl ether type is not particularly limited, and examples thereof include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. Can do.

  The epoxy-based crosslinking agent (B) used in the production of the water-soluble polymer of the present invention is used in the range of 1 to 10 parts by weight with respect to 100 parts by weight of the water-soluble polymer (A). If the amount is less than 1 part by weight, a sufficient cross-linked structure cannot be obtained.

  The water-soluble polymer of the present invention is an epoxy-based crosslinking agent obtained by subjecting a copolymer comprising acrylamide and acrylonitrile to a water-soluble polymer (A) obtained by neutralizing the reaction product and subjecting it to heat treatment after the Hoffman reaction. It can also be produced by the method of crosslinking in (B).

  The water-soluble polymer (A) is produced, for example, by subjecting a copolymer containing 40 mol% or more and less than 60 mol% of acrylamide, and the balance being acrylonitrile, to acidification and heat treatment after Hoffman reaction. Can do.

  The copolymer used for the Hoffman reaction is a copolymer containing acrylamide in an amount of 40 mol% or more and less than 60 mol%, with the balance being acrylonitrile. When acrylamide is less than 40 mol%, the hydrophilicity of the copolymer is lowered, so that the Hoffman reaction and amidine cyclization in an aqueous medium do not proceed sufficiently, and a large amount of insoluble components are likely to be generated. On the other hand, when acrylamide is 60 mol% or more, the Hoffman reaction and amidine cyclization proceed without any trouble, and a water-soluble polymer having excellent solubility can be obtained. The number of groups and nitrile groups is not balanced, and as a result, the amount of amidine ring that can be formed is limited. Copolymerization of acrylamide and acrylonitrile can be performed by a conventionally known method such as solution polymerization, emulsion polymerization, suspension polymerization, or dispersion polymerization. In that case, although superposition | polymerization temperature is not specifically limited, For example, it can select from the range of 0-70 degreeC. The monomer concentration is not particularly limited, but can be selected from a range of 1 to 60% by weight, for example.

  As the radical polymerization initiator for carrying out the copolymerization reaction, both an oil-soluble initiator and a water-soluble initiator can be used. However, since the hydrophilicity of the monomer is relatively high, it is preferable to use a water-soluble initiator. More preferred. Examples of water-soluble initiators include 2,2′-azobis (2-amidinopropane) dichloride as an azo group, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane And dihydrochloride, 4,4′-azobis (4-cyanovaleric acid), and the like. Examples of peroxides include ammonium peroxodisulfate, potassium peroxodisulfate, and hydrogen peroxide. These can be used alone or in combination. For peroxide systems, it is also possible to apply a redox initiator system in combination with a reducing agent such as sodium sulfite or sodium bisulfite in order to proceed the polymerization at a lower temperature.

  The obtained copolymer undergoes Hoffman reaction with hypohalite and alkali to modify the amide group into an amino group. At this time, as the hypohalite used, for example, hypochlorite is preferable, and specific examples include sodium hypochlorite and potassium hypochlorite. Moreover, as an alkali to coexist, sodium hydroxide, potassium hydroxide, etc. are mentioned as a suitable thing, for example. The amino group produced by modification can be cyclized with an adjacent nitrile group by heat treatment under acidic conditions to form an amidine ring.

  The method for crosslinking the water-soluble polymer (A) with the epoxy-based crosslinking agent (B) can be any method and is not particularly limited. For example, the water-soluble polymer (A) Add the epoxy-based crosslinking agent (B) to the produced aqueous solution and heat to crosslink, or dissolve the isolated water-soluble polymer (A) in the solvent and add the epoxy-based crosslinking agent (B). And a method of crosslinking by heating.

  The temperature at which the water-soluble polymer (A) is crosslinked using the epoxy-based crosslinking agent (B) is not particularly limited, but is preferably 25 to 100 ° C. from the viewpoint of reaction rate and economy. 40-80 degreeC is especially preferable.

  The solvent for crosslinking the water-soluble polymer (A) with the epoxy-based crosslinking agent (B) can be any as long as it is generally used as a solvent, and is not particularly limited. However, water is preferable from the viewpoint of solubility and economy.

  When the water-soluble polymer (A) is crosslinked using the epoxy-based crosslinking agent (B), a catalyst may be used as necessary. Any catalyst can be used as long as it is a catalyst generally used for the ring-opening reaction of epoxy, and is not particularly limited, but examples thereof include acid catalysts such as sulfuric acid and hydrochloric acid, and basic catalysts such as metal alkoxides. be able to.

  The present invention will be described in more detail below based on examples, but these are examples for helping understanding of the present invention, and the present invention is not limited to these examples. Commercially available products were used unless otherwise specified.

<Epoxy-based crosslinking agent (B)>
Epoxy crosslinking agent (B-1): ethylene glycol diglycidyl ether (general reagent) manufactured by Wako Pure Chemical Industries, Ltd.

  Epoxy crosslinking agent (B-2): Propylene glycol diglycidyl ether (general reagent) manufactured by Wako Pure Chemical Industries, Ltd.

Epoxy crosslinking agent (B-3): Polyethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Epolite 400E)
<Structural unit ratio>
The content of the structural unit ratio in the sample was calculated from the ratio of the peak area of each corresponding structural unit from the ¹³ C-NMR spectrum.

<Aqueous solution viscosity>
0.4 g of a sample was precisely weighed, and ion exchange water was added to prepare 200 g of a 0.2 wt% aqueous solution. The viscosity of the aqueous solution at 25 ° C. and B type viscometer at 50 rpm was measured.

<Cation degree>
In a 200 ml beaker, 90 ml of ion-exchanged water was added, 500 ppm of an aqueous sample solution was added, the pH was adjusted to 4.0 with an aqueous hydrochloric acid solution, and the mixture was stirred for about 1 minute. 3-5 drops of toluidine blue indicator was added to the measurement sample thus prepared, and titration was performed with N / 400 polyvinyl potassium sulfate reagent (N / 400 PVSK) to calculate the cation degree.

<Aggregation test>
100 g of industrial sludge treated with activated sludge (solid content 0.20%, pH 7.8) was weighed into a 200 ml beaker, and 5.0 g of a 0.2 wt% aqueous water-soluble polymer solution was added. A rotor having a length of 3 cm was placed, stirred for 10 seconds at 1000 rpm with a magnetic stirrer, allowed to stand for 30 seconds, and then filtered through a 300-mesh filter cloth having a diameter of 7 cm. The aggregation state of the aggregate collected on the filter cloth was visually evaluated and used as an index of aggregation.

(Criteria)
○: Several large aggregates are dispersed on the filter cloth.

      X: Suspended particles pass through the filter cloth, and almost no aggregated particles can be observed on the filter cloth.

Example 1
A 300 ml four-necked flask equipped with a stirrer and a condenser tube was charged with 29.63 g (416.8 mmol) of acrylamide, 15.37 g (289.67 mmol) of acrylonitrile, and 180.0 g of ion-exchanged water. The mixture was stirred for 4 hours, and 4.5 g of a 2% by weight aqueous solution of 2,2′-azobis (2-amidinopropane) dichloride was poured into the flask and polymerized at 40 ° C. for 24 hours. Thereafter, the temperature was raised to 55 ° C., and the polymerization was further continued for 6 hours to obtain a polymer suspension. The obtained polymer suspension had a solid content concentration of 19.0% by weight and a conversion rate of 95%.

  15.0 g of the obtained polymer suspension (solid content 2.85 g, acrylamide content 59 mol%) was weighed into a beaker and diluted with 22.0 g of ion-exchanged water. To this polymer suspension, 21.1 g (23.8 mmol) of an 8.4 wt% sodium hypochlorite aqueous solution and 7.7 g (92.4 mmol) of 48 wt% sodium hydroxide were added at 30 ° C., and the Hoffman reaction was performed. Went. After 15 minutes, the reaction solution was acidified by adding 56.2 g (110.9 mmol) of 7.2% by weight hydrochloric acid and heated at 85 ° C. for 4 hours. Thereafter, 3 parts by weight (0.087 g) of the epoxy-based crosslinking agent (B-1) was added to the solid content in the polymer suspension and reacted at 40 ° C. for 4 hours. After completion of the reaction, acetone was added to the reaction solution to precipitate the polymer, followed by vacuum drying to obtain an ocher polymer (3.0 g).

As a result of calculating the ratio of each repeating unit of the obtained polymer using ¹³ C-NMR, the structural unit represented by the above formula (1) was 4 mol%, and the structural unit represented by the above formula (2) was 48 mol. %, 2 mol% of the structural unit represented by the formula (3), 13 mol% of the structural unit represented by the formula (4), 22 mol% of the structural unit represented by the formula (5), The structural unit represented by 6) was analyzed as 11 mol%. Table 1 shows the evaluation results of the aqueous solution viscosity, the cation degree, and the aggregation test. The resulting polymer had a high aqueous solution viscosity and exhibited excellent agglomeration performance.

実施例２
エポキシ系架橋剤（Ｂ−１）の配合量をポリマー懸濁液中の固形分に対して８重量部（０．２３ｇ）とした以外は実施例１と同様の方法でポリマーを得た。

Example 2
A polymer was obtained in the same manner as in Example 1 except that the amount of the epoxy crosslinking agent (B-1) was 8 parts by weight (0.23 g) based on the solid content in the polymer suspension.

As a result of calculating the ratio of each repeating unit using ¹³ C-NMR for the obtained polymer, the structural unit represented by the above formula (1) was 12 mol%, and the structural unit represented by the above formula (2) was 47 mol. %, The structural unit represented by the above formula (3) is 2 mol%, the structural unit represented by the above formula (4) is 15 mol%, the structural unit represented by the above formula (5) is 16 mol%, the above formula ( The structural unit represented by 6) was analyzed as 8 mol%. Table 1 shows the evaluation results of the aqueous solution viscosity, the cation degree, and the aggregation test. The resulting polymer had a high aqueous solution viscosity and exhibited excellent agglomeration performance.

Example 3
A 300 ml four-necked flask equipped with a stirrer and a condenser is charged with 25.77 g (362.5 mmol) of acrylamide, 19.23 g (362.4 mmol) of acrylonitrile and 180 g of ion-exchanged water and stirred for 1 hour under a nitrogen stream. Then, 4.5 g of a 2 wt% aqueous solution of 2,2′-azobis (2-amidinopropane) dichloride was poured into the flask and polymerized at 40 ° C. for 24 hours. Thereafter, the temperature was raised to 55 ° C., and the polymerization was further continued for 6 hours to obtain a polymer suspension. The obtained polymer suspension had a solid content concentration of 19.3% by weight and a conversion rate of 97%.

  15.0 g of the obtained polymer suspension (solid content 2.90 g, acrylamide content 50 mol%) was weighed into a beaker and diluted with 26.0 g of ion-exchanged water. To this polymer suspension, 18.6 g (21.0 mmol) of an 8.4 wt% sodium hypochlorite aqueous solution and 6.8 g (81.6 mmol) of 48 wt% sodium hydroxide were added at 30 ° C., and the Hoffman reaction was performed. Went. After 15 minutes, 49.6 g (98.0 mmol) of 7.2 wt% hydrochloric acid was added to the reaction solution for acidification, and the mixture was heated at 85 ° C. for 4 hours. Thereafter, 5 parts by weight (0.145 g) of the epoxy-based crosslinking agent (B-2) was added to the solid content in the polymer suspension and reacted at 60 ° C. for 4 hours. After completion of the reaction, acetone was added to the reaction solution to precipitate the polymer, followed by vacuum drying to obtain an ocher polymer (3.1 g).

As a result of calculating the ratio of each repeating unit using ¹³ C-NMR for the obtained polymer, the structural unit represented by the above formula (1) was 6 mol%, and the structural unit represented by the above formula (2) was 39 mol. %, The structural unit represented by the above formula (3) is 4 mol%, the structural unit represented by the above formula (4) is 20 mol%, the structural unit represented by the above formula (5) is 15 mol%, and the above formula ( The structural unit represented by 6) was analyzed as 16 mol%. Table 1 shows the evaluation results of the aqueous solution viscosity, the cation degree, and the aggregation test. The resulting polymer had a high aqueous solution viscosity and exhibited excellent agglomeration performance.

Example 4
A 300 ml four-necked flask equipped with a stirrer and a condenser was charged with 21.23 g (298.7 mmol) of acrylamide, 23.77 g (447.9 mmol) of acrylonitrile and 180 g of ion-exchanged water, and stirred for 1 hour under a nitrogen stream. Then, 4.5 g of a 2 wt% aqueous solution of 2,2′-azobis (2-amidinopropane) dichloride was poured into the flask and polymerized at 40 ° C. for 24 hours. Thereafter, the temperature was raised to 55 ° C., and the polymerization was further continued for 6 hours to obtain a polymer suspension. The resulting polymer suspension had a solid content concentration of 18.8% by weight and a conversion rate of 94%.

  15.0 g of the obtained polymer suspension (solid content 2.82 g, acrylamide content 40 mol%) was weighed into a beaker and diluted with 30.0 g of ion-exchanged water. To this polymer suspension, 14.93 g (16.8 mmol) of an 8.4 wt% sodium hypochlorite aqueous solution and 5.5 g (65.5 mmol) of 48 wt% sodium hydroxide were added at 30 ° C., and the Hoffman reaction was performed. Went. After 15 minutes, the reaction solution was acidified by adding 39.81 g (78.6 mmol) of 7.2 wt% hydrochloric acid and heated at 85 ° C. for 4 hours. Thereafter, 10 parts by weight (0.28 g) of the epoxy-based cross-linking agent (B-3) was added to the solid content in the polymer suspension and reacted at 80 ° C. for 8 hours. After completion of the reaction, acetone was added to the reaction solution to precipitate the polymer, followed by vacuum drying to obtain an ocher polymer (3.0 g).

As a result of calculating the ratio of each repeating unit using ¹³ C-NMR for the obtained polymer, the structural unit represented by the above formula (1) was 3 mol%, and the structural unit represented by the above formula (2) was 32 mol. %, 1 mol% of the structural unit represented by the above formula (3), 23 mol% of the structural unit represented by the above formula (4), 35 mol% of the structural unit represented by the above formula (5), The structural unit represented by 6) was analyzed as 6 mol%. Table 1 shows the evaluation results of the aqueous solution viscosity, the cation degree, and the aggregation test. The resulting polymer had a high aqueous solution viscosity and exhibited excellent agglomeration performance.

Comparative Example 1
15.0 g (solid content 2.85 g, acrylamide content 59 mol%) obtained in Example 1 was weighed into a beaker and diluted with 22.0 g of ion-exchanged water. To this polymer suspension, 21.1 g (23.8 mmol) of an 8.4 wt% sodium hypochlorite aqueous solution and 7.7 g (92.4 mmol) of 48 wt% sodium hydroxide were added at 30 ° C., and the Hoffman reaction was performed. Went. After 15 minutes, the reaction solution was acidified by adding 56.2 g (110.9 mmol) of 7.2% by weight hydrochloric acid and heated at 85 ° C. for 4 hours. After completion of the reaction, acetone was added to the reaction solution to precipitate the polymer, followed by vacuum drying to obtain an ocher polymer (2.3 g).

As a result of calculating the ratio of each repeating unit using ¹³ C-NMR for the obtained polymer, the structural unit represented by the above formula (1) was 0 mol%, and the structural unit represented by the above formula (2) was 47 mol. %, 2 mol% of the structural unit represented by the formula (3), 14 mol% of the structural unit represented by the formula (4), 24 mol% of the structural unit represented by the formula (5), The structural unit represented by 6) was analyzed as 13 mol%. Table 1 shows the evaluation results of the aqueous solution viscosity, the cation degree, and the aggregation test. The resulting polymer had a low aqueous solution viscosity, resulting in poor agglomeration performance.

Comparative Example 2
15.0 g (solid content 2.85 g, acrylamide content 59 mol%) obtained in Example 1 was weighed into a beaker and diluted with 22.0 g of ion-exchanged water. To this polymer suspension, 21.1 g (23.8 mmol) of an 8.4 wt% sodium hypochlorite aqueous solution and 7.7 g (92.4 mmol) of 48 wt% sodium hydroxide were added at 30 ° C., and the Hoffman reaction was performed. Went. After 15 minutes, the reaction solution was acidified by adding 56.2 g (110.9 mmol) of 7.2% by weight hydrochloric acid and heated at 85 ° C. for 4 hours. Thereafter, 20 parts by weight (0.58 g) of the epoxy-based crosslinking agent (B-1) was added to the solid content in the polymer suspension and reacted at 40 ° C.

As a result, the entire reaction solution was gelled and a water-soluble polymer could not be obtained, and ¹³ C-NMR measurement, aqueous solution viscosity, cation degree and aggregation performance could not be evaluated.

Comparative Example 3
15.0 g of the polymer suspension obtained in Example 4 (solid content 2.82 g, acrylamide content 40 mol%) was weighed into a beaker and diluted with 30.0 g of ion-exchanged water. To this polymer suspension, 14.93 g (16.8 mmol) of an 8.4 wt% sodium hypochlorite aqueous solution and 5.5 g (65.5 mmol) of 48 wt% sodium hydroxide were added at 30 ° C., and the Hoffman reaction was performed. Went. After 15 minutes, the reaction solution was acidified by adding 39.81 g (78.6 mmol) of 7.2 wt% hydrochloric acid and heated at 85 ° C. for 4 hours. Thereafter, 15 parts by weight (0.42 g) of the epoxy-based cross-linking agent (B-2) was added to the solid content in the polymer suspension and reacted at 80 ° C. for 8 hours. After completion of the reaction, acetone was added to the reaction solution to precipitate the polymer, followed by vacuum drying to obtain an ocher polymer (3.0 g).

As a result of calculating the ratio of each repeating unit of the obtained polymer using ¹³ C-NMR, the structural unit represented by the above formula (1) was 20 mol%, and the structural unit represented by the above formula (2) was 39 mol. %, The structural unit represented by the above formula (3) is 4 mol%, the structural unit represented by the above formula (4) is 19 mol%, the structural unit represented by the above formula (5) is 17 mol%, the above formula ( The structural unit represented by 6) was analyzed as 1 mol%. Table 1 shows the evaluation results of the aqueous solution viscosity, the cation degree, and the aggregation test. The obtained polymer had a high aqueous solution viscosity, resulting in clogging of the filter cloth, and the aggregation performance could not be evaluated.

  The water-soluble polymer of the present invention is suitable as a polymer flocculant because it has a high aqueous solution viscosity, a high cationic degree, and has a rigid amidine skeleton in the main chain and excellent aggregation performance. In particular, it is useful as a polymer flocculant used in various industrial wastewater, sludge treatment and sewage sludge treatment.

Claims (2)

In the structural unit represented by the following formula (1), the structural unit represented by the following formula (2), the structural unit represented by the following formula (3), the structural unit represented by the following formula (4), and the following formula (5) And a structural unit represented by the following formula (1), the structural unit represented by the following formula (1) is 3 mol% or more and 15 mol% or less, and the viscosity in a 0.2 wt% aqueous solution: Is 20 to 80 mPa · s, a water-soluble polymer.

(Here, R ₁ represents a hydrocarbon chain having 2 to 4 carbon atoms, and n is a number of 1 to 10.)

(Here, in the above formula, M ⁺ represents a cation and X ⁻ represents an anion.) A structural unit represented by the following formula (2), a structural unit represented by the following formula (3), a structural unit represented by the following formula (4), a structural unit represented by the following formula (5), and the following formula (6) The water-soluble polymer according to claim 1, wherein 1 to 10 parts by weight of the epoxy-based crosslinking agent (B) is crosslinked with respect to 100 parts by weight of the water-soluble polymer (A) containing the structural unit represented by formula (1). For producing a conductive polymer.

(Here, in the above formula, M ⁺ represents a cation and X ⁻ represents an anion.)