JP2004083668A - Manufacturing method for water-soluble polymer, polymeric coagulant, and dehydration method for sludge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a water-soluble polymer having a high cationic property and a high molecular weight, and a polymeric coagulant and sludge dehydration method that can exhibit excellent dehydration treatment capability for sludge that requires a high amount of cations. <P>SOLUTION: This water-soluble polymer is manufactured by polymerizing solely a cationic monomer having an acryloyl group, or a monomer mixture comprising not less than 90 mol% of a cationic monomer having an acryloyl group, in the presence of a poly(alkylene oxide) compound. A polymeric coagulant is composed of the water-soluble polymer obtained by the manufacturing method. According to the dehydration method, sludge is dehydrated by adding the polymeric coagulant to the sludge. <P>COPYRIGHT: (C)2004,JPO

Description

【００５１】
○実施例３（汚泥脱水処理）
処理対象汚泥として、都市下水混合生汚泥（ｐＨ＝６．０、ＳＳ＝２６０００ｍｇ／ｌ、ＶＳＳ＝２１０００ｍｇ／ｌ）を使用した。
混合生汚泥２００ｍｌを５００ｍｌのビーカーに採取し、高分子凝集剤として重合体Ｎｏ．Ａ−１の０．２％水溶液を添加後、攪拌機を用いて９０秒間攪拌して汚泥フロックを生成させ、フロックの粒径を測定した。
その後、８０メッシュの網をフィルターとして用いて、前記汚泥フロック分散液を重力濾過した。１０秒後の濾液容量を測定しこれを濾過速度として示した。得られたケーキをミニベルトプレス機にて圧搾脱水（面圧０．５ｋｇ／ｃｍ^２、３段）し含水量を測定した。
これら評価結果を表２に示す。
【００５２】
○比較例３（汚泥脱水処理）
重合体Ｎｏ．Ｂ−１において団子状とならなかった少量の乾燥粒子を用いた。
実施例３において、高分子凝集剤として重合体Ｎｏ．Ｂ−１の０．２％水溶液を使用した以外は同様の操作により、汚泥フロックを生成させ、フロックの粒径を測定した。
その後、実施例３と同様にして、濾過速度及び含水量を測定した。それら評価結果を表２に示す。
【００５３】
○比較例４（汚泥脱水処理）
重合体Ｎｏ．Ｂ−２において団子状とならなかった少量の乾燥粒子を用いた。
実施例３において、高分子凝集剤として重合体Ｎｏ．Ｂ−２の０．２％水溶液を使用した以外は同様の操作により、汚泥フロックを生成させ、フロックの粒径を測定した。
その後、実施例３と同様にして、濾過速度及び含水量を測定した。それら評価結果を表２に示す。
【００５４】
【表２】

【００５５】
【発明の効果】
本発明の製造方法によれば、高カチオン性でかつ高分子量の水溶性重合体を得ることができ、さらに得られた含水ゲル状の重合体は、容易に切断できるうえ、細断された重合体粒子は、乾燥工程において粒子同士が結合することなく、容易に乾燥することができる。
さらに得られた重合体は、高分子凝集剤、製紙工程における抄紙用薬剤、塗料用等の増粘剤及び膏体用基材等の種々の幅広い用途に応用することが可能であるばかりでなく、それらの用途において優れた特性をも発揮するものである。
特に高分子凝集剤として好ましく適用できるものであり、高カチオン要求量の汚泥に対しても、優れた脱水処理能力を発揮する。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a water-soluble polymer, a technical field for producing a water-soluble polymer, and a use related to a papermaking agent and a thickener, particularly a polymer flocculant using the water-soluble polymer. Technology.
[0002]
[Prior art]
BACKGROUND ART Conventionally, water-soluble polymers, particularly high-molecular-weight water-soluble polymers, have been used in various technical fields as polymer coagulants, retention aids, thickeners, and the like.
[0003]
As the high molecular weight water-soluble polymer used in the above-mentioned applications, a polymer referred to as a so-called cationic polymer is often used. Specifically, a cationic monomer such as dimethylaminoethyl (meth) acrylate quaternary salt is used as a main component, and if necessary, a nonionic monomer such as (meth) acrylamide is polymerized as a copolymer component. Examples of the obtained polymer include a copolymer obtained by copolymerizing the polymer with an anionic monomer such as (meth) acrylic acid in addition to the cationic monomer and the nonionic monomer.
[0004]
[Problems to be solved by the invention]
By the way, in the dewatering treatment of sludge discharged from the sewage treatment, swine farm and dyeing process, since these sludges have a high cation demand, as the coagulant used in the dehydration treatment, among the water-soluble polymers, A so-called high cationic polymer having a large copolymerization ratio of a cationic monomer is used.
As the highly cationic polymer used in the flocculant, a polymer having a dimethylaminoethyl methacrylate quaternary salt of 90 mol% or more is used because production is relatively easy.
However, the coagulant has a problem that, although excellent in dewatering performance, growth of the obtained floc is insufficient.
In order to solve this problem, polymerization of the polymer has been studied. However, it is difficult to obtain a high molecular weight polymer of dimethylaminoethyl methacrylate quaternary salt because its polymerizability is insufficient. Was.
[0005]
On the other hand, since dimethylaminoethyl acrylate quaternary salt is excellent in polymerizability, it was expected that a high molecular weight polymer capable of solving the above problem could be produced.
However, when a monomer mixture having 90% by mole or more of dimethylaminoethyl acrylate quaternary salt is polymerized, the resulting hydrogel of the polymer has adhesiveness and is soft, so that the obtained polymer is cut. However, there is a problem that even if chopping is difficult, if the chopping is possible, the particles are bonded to each other in a drying step and drying is insufficient, so that a final product cannot be manufactured.
Therefore, in the conventional production method, the upper limit of the copolymerization ratio of dimethylaminoethyl acrylate quaternary salt is limited to 85 mol% in order to prevent the resulting polymer from sticking to the hydrogel.
However, when the flocculant composed of a polymer having the copolymerization ratio is used for dehydration of sludge having a high cation requirement amount as described above, since it is a high molecular weight substance, it has excellent floc forming ability, but has a cationic property. Due to the low water content, the dewatering performance becomes insufficient, and the water content of the obtained dewatered cake cannot be reduced.
[0006]
The present inventors have developed a production method capable of producing a water-soluble polymer having a high cationicity and a high molecular weight, and a polymer aggregation capable of exhibiting an excellent dehydration treatment ability even for sludge having a high cation requirement amount. In order to find a method for dehydrating the agent and sludge, they conducted intensive studies.
[0007]
[Means for Solving the Problems]
As a result of various studies, the present invention, in the presence of a polyalkylene oxide compound, if an acrylate-based cationic monomer having a high monomer ratio is polymerized, the resulting polymer does not become sticky, so that it can be easily chopped. Further, since the obtained polymer is highly cationic and has a high molecular weight, it has been found that the polymer has excellent dehydration performance when applied to sludge having a high cation requirement, and the present invention has been completed.
Hereinafter, the present invention will be described in detail.
In this specification, acrylate or methacrylate is represented as (meth) acrylate, acrylic acid or methacrylic acid is represented as (meth) acrylic acid, and acrylamide or methacrylamide is represented as (meth) acrylamide.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention relates to a water-soluble polymer which polymerizes only a cationic monomer having an acryloyl group or a monomer mixture having at least 90 mol% of a cationic monomer having an acryloyl group in the presence of a polyalkylene oxide compound. And a method for producing the same.
Hereinafter, each component will be described.
[0009]
1. Polyalkylene oxide compound Various compounds can be used as the polyalkylene oxide compound used in the production method of the present invention.
For example, polyethylene oxide, polypropylene oxide, polybutylene oxide and the like can be mentioned. Further, those having two or more kinds of polyalkylene oxide units in a block shape, for example, a polyethylene oxide / polypropylene oxide block copolymer can be mentioned. Among these, those having a polypropylene oxide unit are preferred.
[0010]
In the polyalkylene oxide compound, the number of repeating units of the alkylene oxide is preferably 5 or more, more preferably 5 to 80. If the number is less than 5, the resulting gel polymer may have insufficient tackiness prevention. If it exceeds 80, the amount of unpolymerized material increases and the coagulant or dehydrating agent is used. Similarly, when used, sufficient dehydration performance may not be exhibited.
[0011]
Further, the structure of the terminal of the polyalkylene oxide compound is not necessarily limited, but those having an alkoxy group having 1 to 8 carbon atoms such as a methoxy group, an ethoxy group and a butoxy group, particularly Those having an alkoxy group are preferable because the resulting gel polymer has an excellent sticky prevention effect and can be produced stably without gelation during polymerization.
[0012]
In the present invention, it is preferable to use, as the polyalkylene oxide compound, a polyalkylene oxide oligomer having one end having an ethylenically unsaturated group represented by the following general formula (1), since a polymer can be easily produced.
Further, when other ethylenically unsaturated groups such as (meth) acryloyl groups are used, gelation is likely to occur during the production of the polymer. May not be water soluble.
[0013]
Embedded image
R ¹ CH = C (R ² ) -X- (1)
[0014]
[In the above formula, R ¹ and R ² are hydrogen or an alkyl group having 1 to 3 carbon atoms, X is —R ³ O—, —O—, or —R ⁴ NHCOO—, and R ³ and R ⁴ are alkylene group having 1 to 4 carbon atoms, or -Ph- or ^{-Ph-R 5} - and is, Ph is substituted is also phenylene group, ^{R 5} is from 1 to 4 carbon atoms It is an alkylene group. ]
[0015]
As the alkyl group having 1 to 3 carbon atoms for R ¹ and R ² , a methyl group is preferable.
X is ^-R 3 O -, - an O- or ^-R 4 NHCOO-, X is, if other than these, for example an ester bond, in the copolymer produced, easily cause gelation, gelling However, the resulting copolymer does not become water-soluble. The X, ^-R 3 O- or -O- is preferable.
[0016]
Wherein ^{R 3} and ^{R 4} is an alkylene group having 1 to 4 carbon atoms or -Ph- or ^{-Ph-R 5} - and is, Ph is a phenylene group which may have a substituent, ^{R 5} is And an alkylene group having 1 to 4 carbon atoms.
The alkylene group for R ³ and R ⁴ may be linear or branched, and the phenylene group which may have a substituent is specifically a p-phenylene group. , M-phenylene group, and a mixture thereof, and preferably a p-phenylene group. Examples of the substituent on the phenylene group include an alkyl group and an alkyl ester group.
The alkylene group for R ⁵ may be linear or branched.
As R ³ and R ⁴ , a methylene group or a phenylene group is particularly preferred.
[0017]
Specific examples of the ethylenically unsaturated group represented by the general formula (1) include allyloxy, methallyloxy, allylethoxy, allylpropoxy, allylbutoxy, propenyloxy, and vinylbenzyloxy groups. Among these, an allyloxy group, a methallyloxy group, and a propenyloxy group are preferable in terms of excellent reactivity and easy availability.
[0018]
Examples of the alkylene oxide constituting the main chain of the polyalkylene oxide oligomer include ethylene oxide, propylene oxide, and butylene oxide, and specifically, polyethylene oxide oligomer, polypropylene oxide oligomer, and polybutylene oxide oligomer.
Further, those having two or more kinds of polyalkylene oxide units in a block shape, for example, a polyethylene oxide / polypropylene oxide block oligomer can be mentioned.
Among these, those having a polypropylene oxide unit are preferred.
[0019]
In the polyalkylene oxide, the number of repeating units of the alkylene oxide is preferably 5 or more, more preferably 5 to 80, for the same reason as described above.
[0020]
The structure of the other terminal is not necessarily limited, but is preferably an alkoxy group having 1 to 8 carbon atoms such as a methoxy group, an ethoxy group and a butoxy group for the same reason as described above. .
[0021]
These polyalkylene oxide oligomers are prepared by esterification, etherification, urethanation reaction of a general polyalkylene oxide oligomer with an alcohol or an isocyanate compound, and some are commercially available. Can use those commercially available products.
[0022]
2. Cationic monomer having an acryloyl group Various compounds are used as the cationic monomer having an acryloyl group (hereinafter referred to as an acrylic cationic monomer) used in the production method of the present invention. be able to.
Specific examples of the acrylic cationic monomer include tertiary salts such as hydrochloride and sulfate of dialkylaminoalkyl acrylates such as dimethylaminoethyl acrylate, diethylaminoethyl acrylate and diethylamino-2-hydroxypropyl acrylate; dimethylaminopropyl acrylamide Tertiary salts such as dialkylaminoalkyl (meth) acrylamide hydrochloride and sulfate; halogenated alkyl adducts such as methyl chloride adduct of dialkylaminoalkyl acrylates and aryl halide adducts such as benzyl chloride adducts; And quaternary salts such as halogenated alkyl adducts such as methyl chloride adduct of dialkylaminoalkylacrylamide and aryl halide adducts such as benzyl chloride adduct.
[0023]
3. Other monomers The production method of the present invention requires the above-mentioned acrylic cation monomer, but if necessary, a monomer copolymerizable with the acrylic cation monomer (Hereinafter, referred to as other monomers). In this case, the proportion of other monomers in the monomer mixture needs to be less than 10 mol%.
Other monomers include cationic monomers other than acrylic cationic monomers, anionic monomers and nonionic monomers.
[0024]
Examples of the cationic monomer other than the acrylic cationic monomer include a compound in which the acrylate compound exemplified as a specific example of the acrylic cationic monomer is replaced with methacrylate.
[0025]
The use of the anionic monomer is not limited as long as it has radical polymerizability, and specific examples thereof include unsaturated carboxylic acids and salts thereof. More specifically, (meth) acrylic acid , Crotonic acid, itaconic acid and maleic acid, and the preferred monomer in the present invention is (meth) acrylic acid.
[0026]
Examples of the salt of the unsaturated carboxylic acid include ammonium salts and alkali metal salts such as sodium and potassium.
[0027]
Nonionic monomers include acrylamide, methacrylamide, dimethylacrylamide, diethylacrylamide, methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, ethyl carbitol acrylate, acrylonitrile and vinyl acetate, etc. Can be mentioned.
[0028]
These cationic monomers, anionic monomers and nonionic monomers can be used alone or in combination of two or more.
Among these, it is preferable to use (meth) acrylamide in combination, since the copolymerizability of the cationic monomer and the oligomer can be improved and the properties of the obtained copolymer can be adjusted.
The ratio of (meth) acrylamide is preferably less than 10 mol% of the whole monomer.
[0029]
4. Method for producing water-soluble polymer The production method of the present invention is directed to a method for producing a monomer having an acrylic cation monomer alone or an acrylic cation monomer in an amount of 90 mol% or more in the presence of a polyalkylene oxide compound. This is a method for producing a water-soluble polymer by polymerizing a mixture.
[0030]
In this case, the ratio of the polyalkylene oxide compound is preferably 0.05 to 10 mol% based on all monomers used.
If this ratio is less than 0.05 mol%, a high molecular weight cationic polymer can be obtained, but it may be sticky and may not be chopped. If it exceeds 10 mol%, many unpolymerized monomers are present. Or the resulting polymer may be insoluble in water.
[0031]
As a polymerization method, in the presence of a polyalkylene oxide compound, an acrylic cation monomer, and further, if necessary, a mixture with other monomers, a mixture with other monomers, as a method for obtaining a water-soluble polymer, What is necessary is just to carry out the polymerization by a specific polymerization method, and among these, the method of polymerizing in an aqueous medium is preferable.
[0032]
As a specific example of the polymerization method in such an aqueous medium, an example of aqueous solution polymerization will be described. That is, an aqueous monomer solution having a monomer concentration of 10 to 80% by mass, preferably 25 to 60% by mass, in the absence of oxygen, using a polymerization initiator and a polymerization initiation temperature of 0 to 35 ° C and a polymerization temperature of This is a method of polymerizing at 100 ° C. or lower for 0.1 to 10 hours to obtain a polymer.
[0033]
Specific examples of the polymerization initiator in this case include persulfates such as sodium persulfate and potassium persulfate, organic peroxides such as benzoyl peroxide, 2,2′-azobis- (amidinopropane) hydrochloride, Azo compounds such as azobiscyanovaleric acid, 2,2′-azobisisobutyronitrile and 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) -propionamide], and peroxidation Redox catalysts comprising a combination of hydrogen, sodium persulfate, sodium bisulfite, ferrous sulfate, and the like are included.
Further, the polymerization can be carried out by irradiation with ultraviolet rays. For example, the polymerization can be carried out using a photopolymerization initiator such as a ketal type or an acetophenone type.
[0034]
The amount of the polymerization initiator to be used may be determined according to the degree of polymerization and viscosity of the target copolymer, and is usually 100,000 to 20,000 based on the total amount of all the monomers and the polymerization initiator. It is preferable to use ppm.
The molecular weight of the copolymer can be adjusted by changing the type and ratio of the copolymer and the polymerization initiator in addition to the type and ratio of the monomer and the polymerization initiator used.
Examples of the chain transfer agent in this case include thiol compounds such as mercaptoethanol and mercaptopropionic acid, and reducing inorganic salts such as sodium sulfite, sodium bisulfite, and sodium hypophosphite.
[0035]
In addition, when producing a high molecular weight copolymer to be used as a flocculant, the amount is preferably 10 to 2000 ppm, and when producing a copolymer to be used as a papermaking agent, 100 to 2,000 ppm. 20,000 ppm is preferred.
[0036]
The gel polymer obtained by the present invention is thereafter cut and shredded by a known method. According to the production method of the present invention, the obtained high molecular weight polymer can be easily cut. In this case, as a cutting method to be adopted, for example, a method such as a meat chopper is used.
The shredded polymer is dried at a temperature of about 60 to 150 ° C. using a dryer such as a band dryer, a rotary dryer, a far-infrared dryer and a vibrating fluid dryer, and a roll grinder. When used as a polymer flocculant or the like, a powdery copolymer is formed by pulverization with a pulverizer or the like, and an additive or the like is then added as needed when used as a polymer flocculant or the like.
[0037]
5. Use The polymer obtained by the production method of the present invention can be applied to various uses. For example, a polymer flocculant, a papermaking agent such as a retention aid in a papermaking process, a thickener such as for a paint, and a base material for a plaster, and the like, which are particularly suitable as a polymer flocculant and a papermaking agent It is something.
[0038]
When used as a polymer flocculant, a polymer having an average molecular weight of several millions to 1,000s millions is preferable, and particularly, a 0.5% salt viscosity measured by the following measurement method is 5 to 200 mPa.s. s is preferred. Further, it is preferable that the amount of the 0.1% insoluble matter in the polymer after washing is 5 ml or less.
[0039]
0.1% insoluble content:
The polymer is dissolved in pure water to prepare 400 ml of a 0.1% by mass (solid content) solution. The whole amount of the solution is filtered through a sieve having a diameter of 20 cm and 83 mesh, and the insoluble matter remaining on the sieve is collected and its capacity is measured.
[0040]
0.5% salt viscosity:
The polymer is dissolved in a 4% by mass aqueous sodium chloride solution to prepare a 0.5% by mass copolymer solution. The viscosity of the polymer solution after 25 minutes at a temperature of 25 ° C. and 60 rpm is measured using a B-type viscometer.
[0041]
When the polymer flocculant of the present invention is used, it may be used by mixing with known additives such as sodium hydrogen sulfate, sodium sulfate and sulfamic acid as long as the dehydration treatment is not adversely affected.
[0042]
The polymer flocculant of the present invention is added to various kinds of sludge to form a floc having an excellent balance of floc strength, filtration rate and moisture content. There is no special method, and the method currently used can be applied without any problem.The applicable sludge is not particularly limited, and specific examples include sludge for domestic wastewater treatment, sludge for food industry wastewater treatment, and chemical wastewater treatment. Industrial wastewater treatment sludge, swine farm wastewater treatment sludge, pulp or papermaking industrial sludge, and the like.
[0043]
The polymer coagulant of the present invention can be used alone, but can also be used in combination with an inorganic coagulant or an organic cationic compound. Examples of the inorganic coagulant include aluminum sulfate, polyaluminum chloride, ferric chloride and poly (organic coagulant). Examples of the organic cationic compound include polymer polyamines, polyamidines, and cationic surfactants.
[0044]
In particular, when the polymer flocculant of the present invention is amphoteric, the method of adding the polymer flocculant to the sludge to which the inorganic flocculant has been added is more efficient as a dehydration method. After the addition of the flocculant, the pH is preferably adjusted to 4 to 8, more preferably 5 to 7.
[0045]
The amount of the polymer flocculant of the present invention added to sludge is usually 0.1 to 3% / dry solid content of sludge, preferably 0.2 to 2% / dry solid content of sludge. If it is less than 3%, the sludge suspension recovery rate is not sufficient, and even if it exceeds 3%, the effect is not improved.
[0046]
The formed floc can be dewatered using a dehydrator such as a screw press dehydrator, a belt press dehydrator, a filter press dehydrator, a screw decanter, etc., to obtain a dewatered cake.
[0047]
The coagulant of the present invention is also applicable to a dehydration method using a granulating and concentrating tank having a filtration unit. Specifically, an inorganic coagulant is added to sludge, and a polymer coagulant is further added. , Or together with the polymer flocculant, the sludge is introduced into a granulation and concentration tank having a filtration unit, the filtrate is taken out from the filtration unit and granulated, and the granulated product is dehydrated with a dehydrator. Examples of the method include a processing method.
[0048]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
In the following, "%" means% by mass.
○ Example 1
In a stainless steel reaction vessel, dimethylaminoethyl acrylate methyl chloride quaternary salt aqueous solution (hereinafter, referred to as DAC), acrylamide aqueous solution (hereinafter, referred to as AM) and allyloxy poly (ethylene glycol / propylene glycol) monobutyl ether [Nippon Yushi ( Co., Ltd. product name PKA-5015. Ethylene glycol / propylene glycol is a block copolymer with a molar ratio of 75:25. The number of repeating ethylene oxide = 24 on average, the number of repeating propylene oxide = 8 on average. Number average molecular weight = 1600. Hereinafter, it is referred to as PKA-5015. And distilled water was added so that the total monomer concentration was 55% and the total weight was 1.0 kg at a molar ratio of 95, 5.0 and 0.3, respectively.
Subsequently, the temperature of the solution was adjusted to 10 ° C. while blowing nitrogen gas into the solution for 60 minutes, to obtain an aqueous solution of the monomer mixture.
Furthermore, azobisamidinopropane hydrochloride (hereinafter, referred to as V-50) and sodium bisulfite were added at 1000 ppm and 20 ppm, respectively, based on the total monomer weight, and added from above the reaction vessel. Polymerization was performed by irradiating with a 100 W black light at an irradiation intensity of 6.0 mW / cm ² for 60 minutes to obtain a water-containing gel-like water-soluble copolymer.
The water-soluble gel-like water-soluble copolymer was taken out of the container and cut using a small meat chopper. This was dried at a temperature of 80 ° C. for 5 hours and then pulverized to obtain a powdery water-soluble copolymer. In this case, the state at the time of cutting and drying of the gel (hereinafter referred to as a hydrogel treatment state) was evaluated in the following three stages.
：: At the time of cutting, adhesion of particles was small, and dried particles were also separated from each other.
Δ: Adhesion between particles is remarkable at the time of cutting. The dried particles were combined into small clusters and the interior was undried.
×: Adhesion between particles is remarkable during cutting. The dried particles combined to form a large dumpling and the interior was undried.
This water-soluble copolymer was measured for 0.1% insoluble content and 0.5% salt viscosity. Table 1 shows the results.
[0049]
○ Example 2, Comparative Examples 1 and 2
A powdery water-soluble copolymer was obtained in the same manner as in Example 1, except that the monomer, the polymerization initiator, and the like were changed to the contents shown in Table 1. At this time, the state of the hydrogel treatment was evaluated in the same manner as in Example 1.
About the obtained water-soluble copolymer, 0.1% insoluble content and 0.5% salt viscosity were measured. Table 1 shows the results.
[0050]
[Table 1]

[0051]
○ Example 3 (sludge dewatering treatment)
Municipal sewage mixed raw sludge (pH = 6.0, SS = 26000 mg / l, VSS = 21000 mg / l) was used as the sludge to be treated.
200 ml of mixed raw sludge was collected in a 500 ml beaker, and polymer No. 1 was used as a polymer flocculant. After adding a 0.2% aqueous solution of A-1, the mixture was stirred for 90 seconds using a stirrer to generate sludge flocs, and the particle size of the flocs was measured.
Thereafter, the sludge floc dispersion was subjected to gravity filtration using an 80-mesh net as a filter. The filtrate volume after 10 seconds was measured and indicated as the filtration rate. The obtained cake was squeezed and dewatered (surface pressure: 0.5 kg / cm ² , three stages) with a mini-belt press to measure the water content.
Table 2 shows the evaluation results.
[0052]
○ Comparative Example 3 (Sludge dewatering treatment)
Polymer No. A small amount of dry particles that did not form a ball in B-1 was used.
In Example 3, polymer No. 1 was used as the polymer flocculant. Sludge floc was generated by the same operation except that a 0.2% aqueous solution of B-1 was used, and the particle size of the floc was measured.
Thereafter, the filtration rate and the water content were measured in the same manner as in Example 3. Table 2 shows the evaluation results.
[0053]
○ Comparative Example 4 (Sludge dewatering treatment)
Polymer No. A small amount of dry particles that did not form a dump in B-2 was used.
In Example 3, polymer No. 1 was used as the polymer flocculant. Sludge floc was generated by the same operation except that a 0.2% aqueous solution of B-2 was used, and the particle size of the floc was measured.
Thereafter, the filtration rate and the water content were measured in the same manner as in Example 3. Table 2 shows the evaluation results.
[0054]
[Table 2]

[0055]
【The invention's effect】
According to the production method of the present invention, a water-soluble polymer having a high cationicity and a high molecular weight can be obtained, and the obtained hydrogel polymer can be easily cut and cut into finely divided weights. The coalesced particles can be easily dried without bonding the particles in the drying step.
Furthermore, the obtained polymer can be applied not only to a polymer flocculant, a papermaking agent in a papermaking process, a thickening agent for paint and the like, and a wide variety of uses such as a base material for plaster, And also exhibit excellent characteristics in those applications.
Particularly, it can be preferably used as a polymer flocculant, and exhibits excellent dehydration treatment ability even for sludge having a high cation requirement.

Claims (6)

A water-soluble polymer comprising polymerizing only a cationic monomer having an acryloyl group or a monomer mixture having at least 90 mol% of a cationic monomer having an acryloyl group in the presence of a polyalkylene oxide compound. Manufacturing method of coalescence. The method for producing a water-soluble polymer according to claim 1, wherein the polyalkylene oxide compound is a polyalkylene oxide oligomer having one end having an ethylenically unsaturated group represented by the following general formula (1).

[In the above formula, R ¹ and R ² are hydrogen or an alkyl group having 1 to 3 carbon atoms, X is —R ³ O—, —O—, or —R ⁴ NHCOO—, and R ³ and R ⁴ are alkylene group having 1 to 4 carbon atoms, or -Ph- or ^{-Ph-R 5} - and is, Ph is substituted is also phenylene group, ^{R 5} is from 1 to 4 carbon atoms It is an alkylene group. ] The method for producing a water-soluble polymer according to claim 2, wherein the polyalkylene oxide oligomer has 5 or more repeating units of an alkylene oxide unit. The method for producing a water-soluble polymer according to claim 2 or 3, wherein the other end of the polyalkylene oxide oligomer is an alkoxyl group having 1 to 8 carbon atoms. A polymer flocculant comprising a water-soluble polymer obtained by the production method according to claim 1. A method for dewatering sludge, comprising adding the polymer flocculant according to claim 5 to sludge for dehydration treatment.