JP2015057272A - Polymer flocculant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer flocculant excellent in forming strong floc, reducing water content in a dewatered cake, reducing an addition amount, solubility in water and the like when treating sludge difficult to be dehydrated and waste water and to provide a treating method of the sludge and the waste water using the polymer flocculant.SOLUTION: A polymer flocculant includes a water-soluble (co)polymer obtained by the polymerization of a water-soluble unsaturated monomer containing a water-soluble cationic monomer represented by general formula (1): CH=C(CH)-CO-X-Q-NRRRZ(1) and a water-insoluble solvent having an SP (solubility parameter) value of 7.0-9.5 (cal/cm), and has a content of the water-insoluble solvent based on the weight of the water soluble (co)polymer of 0.5-2.0 wt.%.

Description

  The present invention relates to a polymer flocculant. More specifically, the present invention relates to a polymer flocculant having excellent dewaterability that can be used for sludge or wastewater treatment such as sewage or factory wastewater, and a method for treating sludge or wastewater using the polymer flocculant.

  Conventionally, as a treatment agent for sludge treatment of sewage, wastewater treatment, mud treatment at civil engineering sites, and for promoting sedimentation and separation of mud at the time of reclamation, especially for dehydration, poly (meth) acryloyloxyethyltrimethyl High water-soluble polymers such as ammonium chloride, acrylamide-acryloyloxyethyltrimethylammonium chloride copolymer, cationic polymer flocculants such as polyamidine, and amphoteric polymer flocculants such as acrylamide-acrylic acid-acryloyloxyethyltrimethylammonium chloride copolymer Molecular flocculants are widely used. In recent years, due to the increase in the amount of generated sludge, etc., there has been an increasing need for improving the speed of dewatering treatment, the increase in incineration disposal costs of dewatered cake due to the difficulty of dewatering the properties of organic sludge, and From the tight situation of the landfill site when it is disposed as it is, a polymer flocculant capable of forming a stronger and coarser floc and greatly reducing the moisture content of the dehydrated cake is strongly desired.

Recently, in order to improve the dewaterability of sludge, a method using an inorganic flocculant and an amphoteric polymer flocculant in combination (for example, see Patent Document 1) has been proposed and widely used. However, this method has a higher drug cost than the method using a cationic polymer flocculant, and has problems such as an increase in sludge cake generated by using an inorganic flocculant and an increase in ash after incineration. As a method not using an inorganic flocculant, an emulsion type flocculant characterized by containing a primary amine group (for example, see Patent Document 2) has been proposed for the purpose of excellent flocculant performance and reduction of the moisture content of the dehydrated cake. Yes. However, the method described in Patent Document 2 has poor stability over time in an emulsion state compared to a method using a powdered cationic polymer flocculant, and lacks practical utility. Since many additives are included, there is a problem that the amount of the active ingredient of the flocculant is small and the amount of the emulsion type flocculant required is large.
In order to form stronger and coarser flocs, cross-linked polymers (see, for example, Patent Documents 3 and 4) have been proposed. However, the polymer flocculant described in Patent Literature 3 has a problem that the floc strength is insufficient with respect to the pressure during cake dehydration because the reactivity of the crosslinking agent is low and the branched structure is large. Moreover, since the polymer flocculant described in Patent Document 4 has a non-uniform cross-linking reaction, there is a problem in that the high degree of cross-linking has a problem of poor solubility in water, and improvement has been desired.

Japanese Patent Laid-Open No. 2-180700 JP 2002-166104 A JP 2004-255378 A JP 2001-129511 A

Currently used polymer flocculants have not yet reached a level that can sufficiently solve the above-mentioned problems, and the disclosed polymer flocculants are from the viewpoint of floc strength and dehydrated cake moisture content. Although improved, it was still inadequate for the hardly dewatering sludge.
An object of the present invention is a polymer capable of reducing the water content of a dehydrated cake with a small amount of addition while maintaining solubility in water in a dehydration treatment of hardly dehydrated organic sludge and the like, with a small addition amount. It is to provide a flocculant.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have reached the present invention. That is, the present invention provides a water-soluble (co) polymer (A) obtained by polymerizing a water-soluble unsaturated monomer (a) containing a water-soluble cationic monomer (a1) represented by the following general formula (1). And a water-insoluble solvent (b) having an SP (solubility parameter) value of 7.0 to 9.5 (cal / cm ³ ) ^1/2 , based on the weight of the (A) It is a polymer flocculant (P) whose content of (b) is 0.5 to 2.0% by weight.

_{CH 2 = C (CH 3)} -CO-X-Q-N + R 1 R 2 R 3 · Z - (1)

[Wherein R ^{1 to} R ³ are H; X is O or NH; Q is an alkylene group having 1 to 4 carbon atoms; Z ⁻ represents a residue other than H ⁺ of a protonic acid. ]

The polymer flocculant of the present invention has the following effects in the dehydration treatment of hardly dewatering organic sludge.
(1) Since the solubility in water is excellent, the stability of the aggregation treatment can be enhanced.
(2) With a low addition amount, a strong floc can be formed, and since the formed floc is not easily broken or redispersed, the stability of the agglomeration treatment and the processing speed can be remarkably increased.
(3) Since the floc strength is strong and the moisture content of the dehydrated cake is low, the amount of waste generated and the incineration cost can be greatly reduced.

[Water-soluble cationic monomer (a1)]
The water-soluble cationic monomer (a1) in the present invention is represented by the following general formula (1). In the present invention, water-soluble means that the solubility in water is 1 g or more / 100 g of water (20 ° C.).

_{CH 2 = C (CH 3)} -CO-X-Q-N + R 1 R 2 R 3 · Z - (1)

In general formula (1), R ^{1 to} R ³ are H, X is O or NH, Q is an alkylene group having 1 to 4 carbon atoms (hereinafter sometimes abbreviated as C) (methylene, ethylene and propylene groups). Etc.). When C of an alkylene group exceeds 4, the solubility in water will worsen.
Z ⁻ represents a residue other than H ⁺ of the protonic acid. A proton acid is defined as an acid that gives a proton, and as the proton acid, an inorganic acid (hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc.) and an organic acid [sulfonic acid (paratoluenesulfonic acid, methanesulfonic acid) , Dodecylbenzenesulfonic acid, naphthalenesulfonic acid, etc.), carboxylic acids (oxalic acid, acetic acid, maleic acid, etc.), phosphonic acids (methylphosphonic acid, phenylphosphonic acid, etc.) and the like. Of these, sulfonic acid among inorganic acids and organic acids is preferable from the viewpoint of aggregating performance, hydrochloric acid, sulfuric acid and methanesulfonic acid are more preferable, and sulfuric acid and methanesulfonic acid are particularly preferable.

[Water-soluble unsaturated monomer (a)]
The water-soluble unsaturated monomer (a) includes the water-soluble cationic monomer (a1) represented by the general formula (1).

  Examples of (a1) include the following salts [inorganic acids (hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc.) salts, organic acids [sulfonic acids (paratoluenesulfonic acid, methanesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid, etc.) Carboxylic acid (oxalic acid, acetic acid, maleic acid, etc.), phosphonic acid (methylphosphonic acid, phenylphosphonic acid, etc.), etc., and mixtures thereof.

(A11) Nitrogen atom-containing methacrylate salt As the nitrogen atom-containing methacrylate, those having 5 to 8 carbon atoms such as aminomethyl methacrylate, aminoethyl methacrylate, aminopropyl methacrylate, aminobutyl methacrylate;

(A12) Salt of nitrogen atom-containing methacrylamide The nitrogen atom-containing methacrylamide is C5-8, such as aminomethyl methacrylamide, aminoethyl methacrylamide, aminopropyl methacrylamide, aminobutyl methacrylamide.

  Of these (a11) and (a12), (a11) is preferable from the viewpoint of aggregation performance and copolymerizability, more preferable is a salt of aminoethyl methacrylate and aminopropyl methacrylate, and particularly preferable is aminoethyl. It is a salt of methacrylate. Further, among these salts, preferred are hydrochloride, sulfate, methanesulfonate and paratoluenesulfonate, more preferred are sulfate and methanesulfonate, and particularly preferred is sulfate.

  The water-soluble unsaturated monomer (a) can contain other water-soluble unsaturated monomer (a2) in addition to the water-soluble cationic monomer (a1).

  Examples of the other water-soluble unsaturated monomer (a2) include the following cationic monomer (a21), nonionic monomer (a22), anionic monomer (a23), and mixtures thereof.

(A21) Cationic monomer The following are included, and salts thereof [for example, inorganic acid (hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc.) salts, methyl chloride salts, dimethyl sulfate salts and benzyl chloride salts], and mixtures thereof. .

(A211) Nitrogen atom-containing (meth) acrylates other than (a1) C5-30, such as N, N-dialkyl (alkyl group is C1-2) aminoalkyl (C2-3) (meth) acrylate [N, N-dimethylamino-ethyl and -propyl (meth) acrylate, N, N-diethylamino-ethyl and -propyl (meth) acrylate and the like], heterocyclic-containing (meth) acrylate [N-morpholinoethyl (meth) acrylate and the like]; In the present invention, (meth) acrylate means methacrylate and acrylate.

(A212) ethylenically unsaturated compound having an amino group C2-21, such as vinylamine, vinylaniline, (meth) allylamine, p-aminostyrene;
(A213) Compound having an amine imide group C6-21, such as 1,1,1-trimethylamine (meth) acrylimide, 1,1-dimethyl-1-ethylamine (meth) acrylimide.

(A22) Nonionic monomer The following are mentioned, and these mixtures.

(A221) (Meth) acrylate C4 or more and number average molecular weight [hereinafter abbreviated as Mn. The measurement is based on a gel permeation chromatography (GPC) method under the measurement conditions described later. ] 5,000 or less, for example, hydroxyl group-containing (meth) acrylate [hydroxyethyl, diethylene glycol mono, polyethylene glycol (hereinafter abbreviated as PEG) (polymerization degree 3 to 50), mono and (poly) glycerol (polymerization degree 1 10) mono (meth) acrylate] and alkyl acrylate (alkyl group is C1-2) ester (C4-5, such as methyl acrylate, ethyl acrylate);

(A222) (meth) acrylamide and its derivatives C3-30, such as (meth) acrylamide, N-alkyl (C1-3) (meth) acrylamide [N-methyl and isopropyl (meth) acrylamide etc.], N-alkyl Roll (meth) acrylamide [N-methylol (meth) acrylamide etc.], N-alkylol (C1-2) (meth) acrylamide alkylene oxide (C2-3, hereinafter abbreviated as AO) 1-8 mol adduct;

(A223) Nitrogen-containing ethylenically unsaturated compounds other than the above (a1), (a21) and (a222) C3-30, such as acrylonitrile, N-vinylformamide, N-vinyl-2-pyrrolidone, N-vinyl AO2 to 10 mol adduct of imidazole, N-vinylsuccinimide, N-carbazole alkyl (C1-3) (meth) acrylate, 2-cyanoethyl (meth) acrylate, and hydroxyethylmaleimide.

(A23) Anionic monomer The following, these salts [alkali metal (lithium, sodium, potassium, etc., the same shall apply hereinafter) salt, alkaline earth metal (magnesium, calcium, etc., the same shall apply hereinafter) salt, ammonium salt and amine (C1-20) salts and the like], and mixtures thereof.

(A231) unsaturated carboxylic acids of C3-30, such as (meth) acrylic acid, (anhydrous) maleic acid, fumaric acid, (anhydrous) itaconic acid, vinylbenzoic acid, allyl acetic acid;

(A232) Unsaturated sulfonic acid Aliphatic unsaturated sulfonic acid (C2-20, for example, vinylsulfonic acid), aromatic unsaturated sulfonic acid (C6-20, for example, styrenesulfonic acid), sulfo group-containing (meth) acrylate [C2 To 24, such as sulfoalkyl (C2-20) (meth) acrylate [2- (meth) acryloyloxyethane, -propane and -butanesulfonic acid, 3- (meth) acryloyloxypropanesulfonic acid, 4- (meth) acryloyl Oxybutanesulfonic acid, 2- (meth) acryloyloxy-2,2-dimethylethanesulfonic acid, p- (meth) acryloyloxymethylbenzenesulfonic acid, etc.], sulfo group-containing (meth) acrylamide [2- (meth) acryloyl Aminoethanesulfonic acid, 2- and 3- (meth) acrylic Roylaminopropanesulfonic acid, 2- and 4- (meth) acryloylaminobutanesulfonic acid, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid, p- (meth) acryloylaminomethylbenzenesulfonic acid, etc.] Alkyl (C1-20) (meth) allylsulfosuccinate [methyl (meth) allylsulfosuccinate and the like] and the like;

(A233) (Meth) acryloyl polyoxyalkylene (alkylene group is C1-3) sulfate ester (meth) acryloyl polyoxyethylene [ethylene oxide (hereinafter abbreviated as EO) added mole number 2-50] sulfate ester and the like.

The GPC measurement of Mn and the weight average molecular weight (Mw) described later in the present invention shall conform to the following measurement conditions.
<GPC measurement conditions>
GPC model: HLC-8120GPC, column made by Tosoh Corporation: TSKgel 2 GMHXL + TSKgel
Multipore HXL-M, solvent manufactured by Tosoh Corporation: Tetrahydrofuran (THF)
Detection device: Refractive index detector reference material: Standard polystyrene (TSK standard)
POLYSTYRENE), manufactured by Tosoh Corporation

Among the water-soluble unsaturated monomers (a2), (a211), (a22), (a231), (a232) are preferable from the viewpoint of copolymerization of the water-soluble (co) polymer (A) described later. More preferably, among (a211), (a222), (a223), (a231), and (a232), sulfo group-containing (meth) acrylate, sulfo group-containing (meth) acrylamide, and most preferably (a211) ) Of N, N-dimethylaminoethyl (meth) acrylate, and (meth) acrylamide of (a222). Moreover, these (a2) can be arbitrarily mixed and copolymerized.
In addition, a known water-insoluble monomer (for example, 2-ethylhexyl methacrylate) other than the above (a1) and (a2), a known crosslinkable monomer (for example, ethylene glycol), as long as the effect of the present invention is not impaired. Dimethacrylate) may be used.

  The ratio of each monomer based on the total number of moles of monomers constituting the water-soluble (co) polymer (A) is preferably 60 to 100%, more preferably water-soluble cationic monomer (a1) from the viewpoint of aggregation performance. Is 80 to 100 mol%.

[Water-soluble (co) polymer (A)]
The water-soluble (co) polymer (A) is obtained by polymerizing the unsaturated monomer (a) containing the water-soluble cationic monomer (a1).
The (A) is a known aqueous solution polymerization (for example, adiabatic polymerization, thin film polymerization, spray polymerization, etc. described in JP-A No. 55-133413) or a known reverse phase suspension polymerization (for example, Japanese Patent Publication No. 54-30710). Various polymerization methods including those described in JP-A No. 56-26909 and JP-A No. 1-5808), photopolymerization (for example, those described in JP-B-6-804), precipitation polymerization ( For example, those described in JP-A No. 61-123610), reverse phase emulsion polymerization (for example, those described in JP-A No. 58-197398) and the like, and optionally using radical polymerization (d) described later. be able to.
Among the polymerization methods, the reverse phase suspension polymerization method is preferable from the viewpoint of aggregation performance.

The reverse phase suspension polymerization may be an ordinary method, and examples thereof include the following method.
That is, a water-insoluble solvent (b) and a dispersant (c), which will be described later, and a hydrophobic dispersion medium (f) as necessary are charged into a polymerization tank and heated to a predetermined polymerization temperature (usually 10 to 10) as necessary. After adjusting to 95 ° C., preferably 20 to 90 ° C., the inside of the tank is sufficiently replaced with an inert gas (for example, nitrogen).
On the other hand, an aqueous monomer solution containing the unsaturated monomer (a) containing the water-soluble cationic monomer (a1), the radical polymerization initiator (d), and, if necessary, the chain transfer agent (e) is prepared. After sufficient substitution, the mixture is placed in a polymerization tank under stirring and polymerized while being suspended.
The method for charging the monomer aqueous solution may be either batch charging or dropping. In this case, the monomer aqueous solution may be a uniform aqueous solution of (a), (d), or (e), may be a separate aqueous solution, may be mixed immediately before dropping, or may be simultaneously dropped simultaneously. May be. Examples of the method of replacing the monomer aqueous solution with an inert gas include a method of bubbling and supplying an inert gas to the monomer aqueous solution, a method of blending an inert gas with a static mixer or the like in a dropping line, and the like. From the viewpoint of properties, a method of blending an inert gas with a static mixer is preferred.

[Water-insoluble solvent (b)]
The water-insoluble solvent (b) in the present invention has an SP (solubility parameter) value of 7.0 to 9.5 (cal / cm ³ ) ^1/2 [below, only numerical values may be shown below. ] Is a solvent. When the SP value of (b) is less than 7, the water solubility of the polymer flocculant (P) is inferior, and when it exceeds 10, the flocculant performance of forming a strong floc of the polymer flocculant (P) is inferior. In addition, a non-aqueous solvent means the solvent whose solubility (20 degreeC) with respect to water is less than 1g / 100g of water.

Examples of (b) include hydrocarbons (b1) shown below and mixtures thereof.
(B1) Hydrocarbon Aliphatic hydrocarbon (C5-12, such as n-hexane, n-heptane, n-octane, n-nonane, n-decane), alicyclic hydrocarbon (C5-12, such as cyclopentane, Cyclohexane, cycloheptane, methylcyclohexane, cyclooctane, decalin) and aromatic ring-containing hydrocarbons (C6-12, such as benzene, toluene, xylene, ethylbenzene) and the like.

  Among these (b), from the viewpoint of water solubility and aggregation performance of (P), hydrocarbons having 6 to 10 carbon atoms are preferred, and n-hexane, n-heptane, n-octane, n are more preferred. -Nonane, n-decane, cyclohexane, particularly preferred are cyclohexane, n-decane.

Examples of the hydrophobic dispersion medium (f) that may be used in combination with (b) within a range not impairing the effects of the present invention include (f1) to (f3) other than (b) and mixtures thereof. .
Here, the hydrophobic dispersion medium means a dispersion medium having a solubility in water (20 ° C.) of less than 10 g / 100 g of water.

(F1) Ketone Aliphatic (C3-10, such as methyl-n-propyl ketone, diethyl ketone, methyl isobutyl ketone), alicyclic ring-containing (C5-10, such as cyclopentanone, cyclohexanone) and aromatic ring-containing ketone (C8- 13, for example, acetophenone, benzophenone) and the like];
(F2) Ether Aliphatic (C4-8, such as di-n-propyl ether, di-n-butyl ether, diethylene glycol dimethyl ether), cyclic (C4-18, such as tetrahydropyran) and aromatic ring-containing ether (C7-12, such as Anisole) etc.] etc .;
(F3) Esters Aliphatic (C3-10, eg n-butyl acetate, isobutyl acetate), alicyclic containing (C7-12, eg cyclohexyl acetate, methyl cyclohexanecarboxylate) and aromatic ring containing esters (C8-16, eg benzoic) Acid methyl, ethyl benzoate, n-butyl benzoate, benzyl acetate, dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate) and the like.

  Among these (f), from the viewpoints of handleability during production and temperature control during polymerization, aliphatic and alicyclic-containing esters are preferred, and n-butyl acetate, isobutyl acetate and cyclohexyl acetate are more preferred. .

  The amount of the non-aqueous solvent (b) used is preferably 25%, more preferably 40%, particularly preferably 65%, and the stability of the dispersion based on the total weight of the aqueous monomer solution from the viewpoint of the viscosity of the dispersion. From this viewpoint, the upper limit is preferably 1,000%, more preferably 400%, and particularly preferably 200%.

  The lower limit of the monomer concentration in the aqueous monomer solution is usually 30%, preferably 40% from the industrial viewpoint, more preferably 45%, particularly preferably 50%, most preferably 55%, the upper limit is usually 90%, and the temperature. From the viewpoint of control, it is preferably 85%, more preferably 80%, particularly preferably 78%, most preferably 75%.

Further, as the dispersant (c) used in the reverse phase suspension polymerization method, the dispersion stability of the reverse phase suspension particles and a polymer flocculant containing the (co) polymer (A) described later ( From the viewpoint of controlling the angle of repose of the dry particles P), that is, powder fluidity, HLB is preferably 1 to 8, more preferably 1.5 to 7.5, and particularly preferably 2 to 7, various oil solubility. Substances.
Here, HLB is an abbreviation of Hydrophile-Lipophile Balance, which represents a balance between hydrophilicity and lipophilicity, and is obtained from the following formula ["Synthesis of surfactants and their applications", page 501, 1957. Published by Sakai Shoten; “Introduction to Surfactant”, page 212, 2007, published by Sanyo Chemical Industries, Ltd., etc.].

HLB = 10 × (inorganic / organic)

In the above formula, the value in () represents the inorganic to organic ratio of the organic compound, and the ratio can be calculated from the values described in the above documents.

  The melting point of (c) is preferably 25 to 100 ° C., more preferably 30 to 80 ° C., particularly preferably 40 to 70 ° C., from the viewpoint of the angle of repose of the particles of the polymer flocculant (P). The melting point is measured using a melting point measuring apparatus according to JIS K0064-1992, 3.2 melting point test method.

  (C) is a weight average molecular weight [hereinafter abbreviated as Mw. The measurement is based on the GPC method. Low-molecular-weight dispersant (c1) having a reference material: polystyrene] of less than 5,000 (more preferably 100 to 3,000, particularly preferably 100 to 1,000), and Mw of 5,000 or more (more preferably 7 , 1,000 to 1,000,000, particularly preferably 10,000 to 100,000) of the polymer dispersant (c2).

(C1) includes fatty acid (C10-30) esters of polyhydric (2-8 or more) alcohols [sucrose fatty acid esters (of C22-120, such as sucrose distearate, sucrose tristearate), sorbitan Fatty acid esters (those of C16 to 120, such as sorbitan monostearate, sorbitan monooleate), (poly) glycerin fatty acid esters (those of C12 to 120, such as glycerin monostearate), PEG fatty acid esters [Mw 100 to less than 5,000 PEG mono and distearate, etc.], alkyl (C1-30) allyl ether, and the like.
Of the above (c1), the fatty acid ester of a polyhydric alcohol is preferred from the viewpoint of preventing the polymer particles from adhering to the polymerization apparatus during production and the angle of repose of the dried particles of the polymer flocculant after drying, more preferably Sucrose fatty acid ester, sorbitan fatty acid ester, and PEG fatty acid ester.

(C2) includes a copolymer of an alkene and an α, β-unsaturated polyvalent carboxylic acid (anhydride) or a derivative thereof [for example, 1-olefin (C11-100) / (anhydrous) maleic acid copolymer, And its amine reaction product], long-chain alkyl group (C12-50) -containing (meth) acrylate (co) polymer, modified (amino, carboxy, epoxy, hydroxy, mercapto, fatty acid ester, fatty acid amide modified, etc.) organopolysiloxane , Cellulose ether (for example, ethyl cellulose, ethyl hydroxyethyl cellulose), (maleic anhydride modified) ethylene / vinyl acetate copolymer, and the like.
Examples of the (maleic anhydride-modified) ethylene / vinyl acetate copolymer include a copolymer of ethylene and vinyl acetate, and an ethylene / vinyl acetate copolymer modified with maleic anhydride.
Examples of the ethylene / vinyl acetate copolymer modified with maleic anhydride include those obtained by adding maleic anhydride to the ethylene / vinyl acetate copolymer. The weight ratio is preferably 2/98 to 30/70, more preferably 5/95 to 20/80, from the viewpoint of dispersion stability of the reversed-phase suspended particles and adjustment of the molecular weight of the reaction product.

  Among the above (c2), from the viewpoint of preventing the polymer particles from adhering to the polymerization apparatus during production and the angle of repose of the dried particles of the polymer flocculant after drying, the alkene and the α, β-unsaturated polyvalent carboxylic acid are preferable. A copolymer with an acid (anhydride) or a derivative thereof, a modified organopolysiloxane, and a (maleic anhydride modified) ethylene / vinyl acetate copolymer.

In using the dispersant (c), it is preferable to use (c1) and (c2) in combination from the viewpoints of dispersion stability of reversed-phase suspended particles, angle of repose of dry particles, and particle size distribution. The ratio [(c1) / (c2)] is preferably 70/30 to 1/99, more preferably 50/50 to 5/95, from the same viewpoint.
When (c1) and (c2) are used in combination, a preferable combination from the viewpoint of particle size distribution is a combination of a fatty acid ester of a polyhydric alcohol and a maleic anhydride-modified ethylene / vinyl acetate copolymer, and more preferably a PEG fatty acid ester. This is a combination of maleic anhydride-modified ethylene / vinyl acetate copolymer.

  The amount of (c) used is usually 20% or less based on the weight of the non-aqueous solvent (b), the stability of the reversed phase suspension particles, the angle of repose and the particle diameter of the dried particles of the polymer flocculant after drying. From the viewpoint of control, it is preferably 0.01 to 10%, more preferably 0.05 to 5%.

Examples of the radical polymerization initiator (d) include various compounds such as azo compounds [water-soluble compounds [azobisamidinopropane (salt), azobiscyanovaleric acid (salt), etc.]) and oil-soluble compounds [azobisdimethyl]. Valeronitrile, azobisisobutyronitrile, azobiscyclohexanecarbonitrile, etc.]] and peroxides [water-soluble [peracetic acid, t-butyl peroxide, hydrogen peroxide, ammonium persulfate, sodium persulfate, persulfate] Potassium etc.] and oil-soluble [benzoyl peroxide, cumene hydroxy peroxide, dicumyl peroxide, etc.]].
Examples of the salt in the azo compound include inorganic acid (hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc.) salts, alkali metal (lithium, sodium, potassium, etc.) salts, ammonium salts, and the like.

The above peroxide may be used as a redox initiator in combination with a reducing agent. Examples of the reducing agent include bisulfites (sodium bisulfite, potassium bisulfite, ammonium bisulfite, etc.), reducing metal salts [iron sulfate (II ), Etc.], amine complexes of transition metal salts [pentamethylenehexamine complexes of cobalt (III) chloride, diethylenetriamine complexes of copper (II) chloride, etc.], organic reducing agents [ascorbic acid, tertiary amine [dimethylaminobenzoic acid ( Salt), dimethylaminoethanol and the like] and the like.
Further, the azo compound, peroxide and redox initiator may be used alone or in combination of two or more.

Of these, azo compounds are preferred from the viewpoint of reducing the water-insoluble content of the water-soluble (co) polymer (A).
(D) is usually contained in the aqueous phase of the polymerization system, but depending on the polymerization method, it may be present in either the aqueous phase (or dispersed phase) and / or the oil phase (or continuous phase).

  From the viewpoint of obtaining an optimum molecular weight, the amount of (d) used is preferably 0.001 to 1.0%, more preferably 0.8%, based on the total weight of unsaturated monomers constituting (A). 005 to 0.5%, particularly preferably 0.01 to 0.2%, most preferably 0.02 to 0.1%.

In the polymerization, a chain transfer agent (e) can be further used. Examples of (e) include those having a chain transfer constant of 0.01 to 100, preferably 0.05 to 50, particularly preferably 0.1 to 10.
Chain transfer constants are defined by J. Brandrup and E. Etch Inmargut, “Polymer Handbook (4th edition)”, published by John Wiley and Sons (Polymer Handbook fourth edition, edited by J. Brandrup and EH Immergut). JOHN WILEY & SONS), pages 97-98.
The chain transfer constant in the present invention is measured using a general method described in “Experimental Methods for Polymer Synthesis” [Chemical Doujin Co., Ltd., published in 1993] and the like. It shall be a chain transfer constant.

  As (e), ammonia, a compound having one or more amino groups in the molecule [thing of C1-60, such as methylamine, dimethylamine, triethylamine, n- and i-propanolamine], molecule Compounds having one or more thiol groups (described later) and (hypo) phosphorous acid compounds [phosphorous acid, hypophosphorous acid, and salts thereof [alkali metal (Na, K, etc.) salts, etc.] And their derivatives] and the like. Among these, compounds having one or more thiol groups in the molecule and (hypo) phosphite compounds are preferable from the viewpoint of molecular weight control.

Examples of the compound having one or more thiol groups in the molecule include the following compounds, salts thereof [alkali metal salts, alkaline earth metal salts, ammonium salts, amines (C1-20, for example, methylamine). , Ethanolamine) salts, inorganic acid (hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc.) salts, and the like, and mixtures thereof.
(1) Monovalent thiol Aliphatic thiol (C1-20, such as methanethiol, ethanethiol, propanethiol, n-octanethiol, n-dodecanethiol, hexadecanethiol, n-octadecanethiol, 2-mercaptoethanol, mercapto Acetic acid, 3-mercaptopropionic acid, 1-thioglycerol, thiomaleic acid, mercaptosuccinic acid, cysteine, cysteamine), alicyclic thiol (C5-20, such as cyclopentanethiol, cyclohexanethiol), aromatic thiol (C6) -12, such as thiophenol, thiosalicylic acid, thiocresol, thioxylenol, thionaphthol) and araliphatic thiols (such as those of C7-20, such as α-toluene thiol).

(2) Polyvalent thiol dithiol [aliphatic dithiol (C2-40, such as ethanedithiol, 1,2- and 1,3-propanedithiol, 1,3- and 1,4-butanedithiol, 1,6- Hexanedithiol, neopentanedithiol), alicyclic dithiols (C5-20, such as cyclopentanedithiol, cyclohexanedithiol), aromatic dithiols (C6-16, such as benzenedithiol, biphenyldithiol) and araliphatic dithiols (C8-20, such as xylenedithiol).

  Of the above (e), those having high water solubility are preferable from the viewpoint of reducing the water-insoluble content of the powdery organic coagulant (P), and the water / n-decane partition coefficient of (e) is preferably 10 / 90 to 100/0, more preferably 20/80 to 100/0, and particularly preferably 50/50 to 100/0. The water / n-decane partition coefficient here is a measurement method according to 1-octanol / water partition coefficient (JIS Z7260-107) defined in Japanese Industrial Standard (JIS), and 1-octanol is converted to n-decane. It can measure by substituting.

  The amount of (e) used is preferably 0.0001 to from the viewpoint of reducing the water-insoluble content of the powdery organic coagulant (P) and controlling the molecular weight based on the total weight of the unsaturated monomers constituting (A). 5%, more preferably 0.001 to 3%, particularly preferably 0.01 to 2%, most preferably 0.05 to 1%.

  The polymerization temperature in the reverse phase suspension polymerization is usually 10 ° C. at the lower limit, preferably 20 ° C. from the viewpoint of the polymerization rate, more preferably 30 ° C., particularly preferably 40 ° C., most preferably 50 ° C., and the upper limit is usually 95 ° C. From the viewpoint of preventing thermal degradation of the polymer, it is preferably 90 ° C., more preferably 80 ° C., particularly preferably 70 ° C., and most preferably 60 ° C.

  Further, during polymerization, it is preferable to adjust by appropriately heating and cooling so that the predetermined polymerization temperature is kept constant (for example, predetermined polymerization temperature ± 5 ° C.). In order to keep the polymerization temperature constant, the monomer may be added dropwise to the dispersion medium that has been previously adjusted to a predetermined polymerization temperature under stirring. The dropping time at that time varies depending on the monomer concentration and the amount of heat generated by the polymerization reaction, but is usually 0.5 to 20 hours, and preferably 1 to 10 hours from the viewpoint of productivity and temperature control.

The polymerization time can be confirmed to end when the exotherm is eliminated by polymerization, but from the viewpoint of completing the polymerization from 1 to 24 hours from the point of confirming the start of polymerization by normal exotherm, and reducing the residual monomer. , Preferably 2 to 12 hours. As in the case of reverse phase suspension polymerization, when the monomer is dropped at any time, it is preferable to carry out the polymerization for the above time after completion of the dropping.
The monomer concentration, polymerization temperature, and polymerization time can be appropriately adjusted depending on the monomer composition, the initiator type, and the like.

  The pH of the aqueous monomer solution at the time of polymerization is not particularly limited, but is preferably 1 to 8, more preferably 1.5 to 7, particularly preferably 1. from the viewpoint of polymerization rate and solubility of the resulting water-soluble polymer. 8 to 6.5.

  In addition, (A) may be prepared by the above-described method, followed by polymer modification reaction. As the polymer modification reaction, for example, when a water-soluble unsaturated monomer having a hydrolyzable functional group in the molecule such as acrylamide is used, caustic alkali (sodium hydroxide, potassium hydroxide, etc.) or carbonic acid is used during or after the polymerization. Alkali (sodium carbonate, potassium carbonate, etc.) is added, and the amide group of the monomer is partially hydrolyzed (the hydrolysis rate is about 1 to 60 mol% based on the total number of moles of all monomers) to form a carboxyl group. Methods of introduction (for example, JP-A-56-16505), formaldehyde, dialkyl (C1-12) amine and halogenated (for example, chloride, bromide and iodide) alkyl (C1-12) (for example, methyl chloride and ethyl) Chloride) and partially introducing a cationic group by the Mannich reaction, and And nitrile group such as acrylonitrile, and a method of forming an amidine ring in a molecule by ring closure reaction of an amino group obtained by the hydrolysis of vinyl formamide (for example, Japanese Unexamined 5-192513 JP) is.

  Moreover, when using 2 or more types of water-soluble (co) polymers as (A), you may mix after manufacturing each beforehand, and it manufactures one beforehand and adds to the monomer at the time of the other manufacture. May be manufactured.

  The lower limit of the volume average particle diameter of (A) is usually 50 μm, preferably 150 μm, more preferably 200 μm, more preferably 200 μm, and the upper limit is usually 2.0 mm, preferably 1 from the viewpoint of dissolution rate. 0.5 mm, more preferably 1.0 mm.

The viscosity (unit: mPa · s, 25 ° C., hereinafter referred to as Vw) Vw of a 0.2 wt% aqueous solution of the water-soluble (co) polymer (A) in the present invention is measured by the following method. The measurement is performed at room temperature (about 25 ° C.).
(1) Preparation of measurement sample (0.2% by weight aqueous solution) In advance, 0.4 g (sample converted to solid content) of sample was precisely weighed, and about 199 g of ion-exchanged water was separately taken in a 500 ml glass beaker. [Model “JMD-6HS-A” manufactured by Miyamoto Riken Kogyo Co., Ltd., and so on. ] Using a stirring device in which two plate-like stirring blades made of PVC (diameter: 5 cm, height: 2 cm, thickness: 0.2 cm) are attached to the stirring rod in a vertical manner in a cross shape at a speed of 200 rpm. Stir. Add sample, add ion exchange water so that the total weight (total weight of sample and ion exchange water) is 200 g, then stir for 3 hours to completely dissolve, 0.2 wt% water-soluble ( A (co) polymer (A) solution is prepared.
The solid content of the water-soluble (co) polymer (A) was determined by weighing about 1.0 g of a sample into a petri dish (inner diameter 105 mm, depth 20 mm) (W1) and circulating in a circulating dryer at 105 ± 5 ° C. This is a value calculated from the following equation, where (W2) is the residual weight after drying for 90 minutes.

Solid content (% by weight) = (W2) × 100 / (W1)

(2) Viscosity measurement The entire amount of the aqueous solution prepared in (1) was transferred to a 200 ml tall beaker, the temperature was adjusted to 25 ° C. in a water bath, and a Brookfield viscometer with a rotor guard [model “TV-10M”, Toki The same applies to Sangyo Co., Ltd. ], Rotate the rotor at 30 rpm, and measure the viscosity 5 minutes after the start of rotation. The rotor number used is changed according to the measurable viscosity range of the instrument.

  Viscosity of 0.5 wt% salt aqueous solution of water-soluble (co) polymer (A) in the present invention (unit: mPa · s, 25 ° C., hereinafter referred to as Vs) Vs is 0.5 wt% water-soluble (co) The viscosity of polymer (A) salt aqueous solution (salt water is 4 weight% sodium chloride aqueous solution) is shown, and is measured by the method described later.

The Vw of the water-soluble (co) polymer (A) is preferably 50 to 2,500, more preferably 100 to 2,000, particularly from the viewpoint of agglomeration performance and reaction rate with suspended particles in sludge and the like. Preferably it is 150-1,500.
The Vs of the water-soluble (co) polymer (A) is preferably 5 to 50, more preferably 15 to 30, particularly preferably 20 to 20 from the viewpoint of agglomeration performance and reactivity with suspended particles in sludge and the like. 25.

[Polymer flocculant (P)]
The polymer flocculant (P) of the present invention comprises the water-soluble (co) polymer (A) and the water-insoluble solvent (b).
Based on the weight of the water-soluble (co) polymer (A), the content of the non-aqueous solvent (b) is 0.5 to 2.0% by weight, preferably 0.5 to 1.5, Preferably it is 0.5 to 1.0% by weight. When the content of (b) is less than 0.5% by weight, the water solubility of (P) is poor, and when it exceeds 2.0% by weight, the aggregation performance of (P) is poor.

When the non-aqueous solvent (b) satisfies the above content, the presence of (b) in the powder (particles) of (P) creates gaps in the powder (particles), and water in the water As a result of the promotion of penetration, (P) is presumed to have excellent water solubility and excellent aggregation performance.
On the other hand, when (b) is less than the above range, it is estimated that (P) is inferior in water solubility as a result of not promoting the penetration of water.
When (b) exceeds the above range, (b) is excessively present on the surface of the powder (particles) of (P), and the powders (particles) of (P) are easily bonded together. Further, it is presumed that the aggregation performance of (P) is inferior because the spread of the water-soluble (co) polymer (A) in water is inhibited by (b).

The content (α) of (b) based on the weight of (A) can be measured by the following method.
[1] Add 1 g of (A) and 50 g of acetone to a 100 mL lidded container, and use a magnetic stirrer [Mighty Stirrer Power Type HE-16GB, manufactured by Koike Seimitsu Seisakusho] at room temperature for 30 minutes at 500 rpm. After stirring, let stand for 10 minutes.
[2] The content (b) content (% by weight) of the supernatant of the contents of the supernatant is quantified by gas chromatography.
<Gas chromatographic conditions>
Device: Shimadzu GC2010
Column: Silicon SE 30 20% Chromosorb W
80-100μm AW-DMCS 3mmφ × 2m
Column temperature: 200 ° C
Sample introduction part temperature: 220 ° C
Carrier gas: Nitrogen 40ml / min Detector: FID
Sample injection volume: 2 μl
[3] Obtain (α) by the following formula (unit: wt%).

(Α) = [(b) content (% by weight) in the supernatant] × 50/1

In the examples, (α) followed the method.

Examples of the method for adjusting the non-aqueous solvent (b) based on the weight of the water-soluble (co) polymer (A) include the following methods.
(I) In the case where (A), a gel-like reactant containing water or the like (for example, aqueous solution polymerization, photopolymerization) is obtained, a predetermined amount of (b) is added in an arbitrary step of obtaining the gel-like reactant. Then, the drying conditions are adjusted to obtain the polymer flocculant (P).
(Ii) In the case of the obtained gel-like reaction product containing water or the like (for example, aqueous solution polymerization, photopolymerization), an excess (b) is added, preferably uniformly (for example, mixed), and then (b ) To obtain a polymer flocculant (P) by adjusting the drying conditions so as to be a predetermined amount.
(Iii) In the case of a suspension reaction product (for example, reverse phase suspension polymerization), a slurry is obtained by azeotropic dehydration of the non-aqueous solvent (b) under normal pressure or reduced pressure conditions. Furthermore, after performing solid-liquid separation such as supplying the slurry to a vacuum filter or the like, the polymer flocculant (P) is obtained by adjusting the drying conditions so that (b) becomes a predetermined amount.
Of the methods (i) to (iii), (ii) and (iii) are preferable from the industrial viewpoint, and (iii) is more preferable from the viewpoint of aggregation performance.

  The polymer flocculant (P) of the present invention includes, in addition to the above (A), an antifoaming agent and a chelating agent that are usually used for the polymer flocculant as long as the effects of the present invention are not impaired, if necessary. An additive selected from the group consisting of a pH adjuster, a surfactant, an antiblocking agent, an antioxidant, an ultraviolet absorber and a preservative can be contained. The method for containing the additive is not particularly limited, and examples thereof include a method of stirring and mixing (A) and these additives at normal temperature or under heating.

The amount of the additive used is usually 5% or less, preferably 1 to 3%, and the chelating agent is usually 30% or less, preferably 2 to 10%, based on the weight of (A). The regulator is usually 10% or less, preferably 1 to 5%, the surfactant and the anti-blocking agent are each usually 5% or less, preferably 1 to 3%, and the antioxidant, the ultraviolet absorber and the preservative are each usually 5%. % Or less, preferably 0.1 to 2%.
The content of (A) in (P) is preferably 50% by weight or more, and more preferably 80% by weight or more.

Since the polymer flocculant (P) of the present invention exhibits an unprecedented specific flocculation effect, the polymer for dehydration treatment of organic sludge or inorganic sludge generated by the treatment of sludge such as sewage or factory wastewater. It can be used as a flocculant and is particularly preferably used for dewatering treatment of organic sludge.
In the case of organic sludge, the aqueous particles used in the polymer flocculant (P) of the present invention are from the viewpoint that the size of the suspended particles is relatively large and the surface of the suspended particles is negatively charged in water. The hydrophilic (co) polymer (A) is preferably composed of a cationic water-soluble (co) polymer and / or an amphoteric water-soluble (co) polymer. From the viewpoint that it can be further exhibited, it is more preferable to use a cationic water-soluble (co) polymer.

  Here, the cationic water-soluble (co) polymer is a water-soluble (co) polymer having a cationic group in the molecule, that is, a water-soluble (co) polymer that exhibits cationic properties when dissolved in water. The amphoteric water-soluble (co) polymer is a water-soluble (co) polymer having a cationic group and an anionic group in the molecule, or a water-soluble (co) polymer having a cationic group in the molecule and a molecule. It is a mixture of water-soluble (co) polymers having an anionic group therein, that is, a water-soluble (co) polymer that exhibits cationic and anionic properties when dissolved in water.

  The cationicity or anionicity of these water-soluble (co) polymers in water can be evaluated using the colloid equivalent value (meq / g) as a guide. That is, the cationic group equivalent value in the cationic water-soluble (co) polymer can be determined as the cationic colloid equivalent value, and the cationic group equivalent value and the anionic group equivalent value in the amphoteric water-soluble (co) polymer. Can be determined as a cation colloid equivalent value and an anion colloid equivalent value, respectively.

  The method for treating sludge or wastewater of the present invention is particularly limited as long as the polymer flocculant (P) of the present invention is added to and mixed with sludge or wastewater to form a floc and perform solid-liquid separation. There is nothing.

  Among the above treatment methods, the polymer flocculant is preferably added to sludge or wastewater from the viewpoint of the effects of the present invention (flocculation performance, that is, high floc strength, coarse floc, low water content of dehydrated cake). , Mixing to form flocs and performing solid-liquid separation. In addition, when adding a polymer flocculent to sludge or wastewater, it is preferable to make these into the form of aqueous solution previously from a uniform mixing viewpoint.

Further, when the polymer flocculant (P) is applied to sludge or wastewater, one or more known inorganic coagulants and organic coagulants may be used in combination as long as the effects of the present invention are not impaired. . When using these together,
(I) a method of previously adding to (P),
(Ii) a method of adding simultaneously with the addition of (P) to sludge or wastewater,
(Iii) Either an inorganic coagulant and / or an organic coagulant may be added to sludge or wastewater in any order before and / or after addition of (P).
Among these, the method of adding an inorganic coagulant and / or an organic coagulant to sludge or waste water is preferable from the viewpoint of coagulation performance before adding (P) of (iii).

Examples of the inorganic coagulant include sulfate band, polyaluminum chloride, ferric chloride, ferric sulfate, polyiron sulfate and slaked lime.
Examples of organic coagulants include polycondensates of epihalohydrin and amine (or its hydrochloride, hereinafter abbreviated as hydrochloride), polycondensates of epihalohydrin and alkylenediamine (hydrochloride), polyethyleneimine (hydrochloride), alkyl, and the like. Range halide-alkylene polyamine polycondensate (hydrochloride), aniline-formaldehyde polycondensate (hydrochloride), polyvinylbenzyltrimethylammonium chloride, polyvinylpyridine (hydrochloride), (di) methyldi (meth) allylammonium chloride and polyvinylimidazoline (Hydrochloride). These inorganic coagulants and organic coagulants may be used singly or in combination, or both may be used in combination.

  When the coagulant is added to (P) in advance, the amount used is usually 100% or less based on the weight of (P), preferably from 5 to 50 from the viewpoint of coagulation performance and coagulation performance. %, More preferably 10 to 30%, and the organic coagulant is usually 20% or less, preferably 1 to 10%, more preferably 2 to 5% from the same viewpoint.

  When the inorganic coagulant and / or organic coagulant is added to sludge or waste water separately from (P), the amount of the inorganic coagulant and / or organic coagulant used in [Method (iii) above] is the sludge or waste water. Depending on the type, the size of suspended particles, and the solid content in sludge or wastewater (hereinafter abbreviated as TS), etc. Therefore, the preferred lower limit is 0.5% by weight, more preferably 1% by weight, particularly preferably 2% by weight, and from the viewpoint of sludge reduction after dewatered cake incineration, the preferred upper limit is 10% by weight, more preferably 8% by weight, Particularly preferred is 5% by weight. In the case of an organic coagulant, the preferred lower limit is 0.01% by weight, more preferably 0.05% by weight, particularly preferably from the viewpoint of floc strength. 0.1 wt%, from the viewpoint of floc particle size, the preferred upper limit is 5% by weight, more preferably 3 wt%, particularly preferably 1% by weight.

Further, the method for adding the polymer flocculant (P) to the sludge or wastewater in the above method is not particularly limited, and (P) may be added to the sludge or wastewater as it is, but is preferable from the viewpoint of uniform mixing. No. is a method of adding (P) to sludge or waste water after making it into an aqueous solution.
When (P) is used as an aqueous solution, the concentration (% by weight) is preferably 0.05 to 3%, more preferably 0.1 to 1%. The dissolution method and the dilution method after dissolution are not particularly limited. For example, while stirring a pre-weighed water using a stirring device such as a jar tester, a predetermined amount of powdered (X) is added and several hours are added. A method of stirring and dissolving (about 1 to 4 hours) can be employed.

  In the above treatment method, the amount of (P) used when added to sludge or wastewater varies depending on the type of sludge or wastewater, the content of suspended particles, the molecular weight of the polymer flocculant, etc. However, based on the TS in the sludge or wastewater, from the viewpoint of floc strength, the preferred lower limit is 0.01% by weight, more preferably 0.1% by weight, particularly preferably 1% by weight, most preferably 1.5%. From the viewpoint of reducing the moisture content of the dehydrated cake, the upper limit is preferably 10% by weight, more preferably 8% by weight, particularly preferably 5% by weight, and most preferably 3% by weight.

  In addition, as a dehydration method (solid-liquid separation method) of floc sludge formed by the above processing method, for example, gravity sedimentation, membrane filtration, column filtration, pressurized flotation, a concentration device (for example, thickener), a dewatering device (for example, Examples include a method using a centrifugal dehydrator, a belt press dehydrator, a filter press dehydrator, and a capillary dehydrator. Among these, preferred from the viewpoint of high floc strength, which is the specific aggregation performance of the polymer flocculant of the present invention, is a method using a dehydrator, particularly a centrifugal dehydrator, a belt press dehydrator, or a filter press dehydrator. .

  Other uses of the polymer flocculant of the present invention other than sludge or wastewater treatment include, for example, a flocculant for excavation and muddy water treatment, a papermaking agent (formation aid for paper industry, drainage yield improver, Drainage improver, paper strength enhancer, etc.), crude oil production additive (crude oil secondary and tertiary recovery additive), dispersant, scale inhibitor, coagulant, decolorizer, thickener, antistatic agent and Examples thereof include a treating agent for fibers.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, the part in an Example represents a weight part and% represents weight%.
The solid content of the polymer flocculant (P) containing the water-soluble (co) polymer (A) was measured by the method described above.
TS in sewage sludge and the like, suspended solids (SS), and organic content (loss on ignition) were performed according to the analysis method described in “Sewage test method” (Japan Sewerage Association, 1984 version).
Moreover, the 0.5% salt aqueous solution viscosity, water solubility, floc particle size, floc strength, and cake moisture content in this example were evaluated according to the following methods.

(1) 0.5% salt aqueous solution viscosity (Vs) (mPa · s, 25 ° C.)
Jar tester [model “JMD-6HS-A”, manufactured by Miyamoto Riken Kogyo Co., Ltd., and so on. ] Using a stirrer in which two plate-like stirrer blades (diameter: 5 cm, height: 2 cm, thickness: 0.2 cm) are attached to a stir bar continuously up and down so as to form a cross. 477.5 g of exchange water is added, and a polymer flocculant sample having a solid content of 2.5 g is gradually added with stirring at 200 rpm at a water temperature of 20 to 25 ° C., and completely dissolved over 4 hours. Thereafter, 20 g of sodium chloride is added, and the mixture is further stirred for 30 minutes to dissolve. Thereafter, a portion of the obtained aqueous salt solution (sodium chloride concentration is 4% by weight) was transferred to a 200 mL tall beaker and left to stand in a thermostatic bath at 25 ° C. for 20 minutes to adjust the temperature. Machine Industry Co., Ltd., model TV-10M, and so on. The value after 300 seconds from the start of measurement at the M1 rotor and 60 rpm is taken as the 0.5% salt aqueous solution viscosity.

(2) Water solubility The whole amount of the aqueous solution (W5) prepared when the above-mentioned 0.5% salt aqueous solution viscosity was measured was transferred to a sieve (aperture 180 μm) whose weight (W3) was measured in advance and filtered. After filtration, the residue on the sieve was washed for 3 minutes with running tap water (flow rate: about 10 L / min). After washing, wipe off the moisture adhering to the sieve frame with a cloth, measure the weight (W4), and calculate the amount of water-insoluble matter from the following formula.

Water insoluble content (%) = [(W4) − (W3)] × 100 / (W5)

Based on the water-insoluble amount determined from the above formula, water solubility is evaluated according to the following criteria.
<Evaluation criteria>
◎ Very good water solubility (water insoluble content ≤ 1%)
○ Good (1% <water-insoluble content ≦ 3%)
△ Slightly bad (3% <water insoluble content ≦ 6%)
× Poor (6% <water insoluble amount)

(3) Flock particle size (mm)
Put 200 ml of sludge in a 300 ml beaker and set in the same stirring device as in (1) above. The rotation speed of the jar tester was set to 300 rpm, and while the sludge was gradually stirred, an aqueous solution of a polymer flocculant having a predetermined concentration was added by a predetermined method and stirred for 30 seconds. The diameter (mm) is visually observed. Subsequently, the number of revolutions is changed to 1,000 rpm, and after stirring for 30 seconds, stirring is stopped and the particle diameter (mm) of the formed floc is visually observed again.

(4) Flock strength The floc particle size at the rotation speeds of 300 rpm and 1,000 rpm in the above (3) is compared, and the floc strength is evaluated according to the following criteria from the change in the floc particle size.
<Evaluation criteria>
◎ Very strong (no change in particle size)
○ Strong (partially subdivided)
△ Slightly weak (partially subdivided)
× Weak (Overall segmentation)

(5) Dehydrated cake moisture content (%)
T-1189 nylon filter cloth (Shikishima Canvas Co., Ltd., circular shape, diameter 9 cm), Nutsche funnel, and measuring cylinder are set using a measuring cylinder capable of measuring 300 ml. All the sludge after the floc particle size test of (3) above is put into the Nutsche filtration surface all at once and filtered. A part of the filtered sludge is taken out with a spatula and subjected to a dehydration test (1 kgf / cm ² , 60 seconds) using a press filter tester. About 3 g of dehydrated cake was weighed into a petri dish (W6), dried in a circulating air dryer at 105 ± 5 ° C. for 8 hours, and the weight of the dry cake remaining on the petri dish was taken as (W7), Calculate the moisture content of the cake.

Dehydrated cake moisture content (%) = [(W6) − (W7)] × 100 / (W6)

Example 1
[Polymer flocculant (P-1)]
750 parts of a 70% aqueous solution (a1-1) of para-toluenesulfonate of aminoethyl methacrylate, 249 parts of ion-exchanged water, 0.12 part of a 10% aqueous solution of 1-thioglycerol (e-1) as a chain transfer agent The mixture was prepared at room temperature (20-25 ° C.). Further, the pH (20 ° C.) of the aqueous monomer solution was adjusted to 3.0 using sulfamic acid while monitoring with a pH meter. The obtained mixed solution was sufficiently substituted with nitrogen (purity 99.999% or more, the same shall apply hereinafter) (dissolved oxygen concentration 100 ppb or less), and then a 10% aqueous solution (d-1) of azobisamidinopropane hydrochloride was obtained. An aqueous monomer solution was prepared by adding 55 parts to obtain a homogeneous solution.
Separately, 1,000 parts of n-decane (b-1) was charged into a reaction vessel equipped with a reflux dehydration pipe, a dropping funnel, a nitrogen introduction pipe and a stirring blade (Max Blend blade), and then, as a dispersant, anhydrous maleic acid. 7.0 parts of acid-modified ethylene / vinyl acetate copolymer [trade name “Orevac 930S”, manufactured by Arkema Co., Ltd.] was added, and the inside of the reaction vessel was stirred while stirring the stirring blade at 500 rpm. After substitution (gas phase oxygen concentration of 10 ppm or less), the temperature was raised to 50 ° C. After reaching 50 ° C., the above-mentioned monomer aqueous solution previously charged in the dropping funnel was charged into the reaction vessel over 60 minutes under normal pressure (103 kPa), and stirring was continued at 50 ° C. for 180 minutes after completion of the charging. Reverse phase suspension polymerization was then carried out.
After polymerization, after removing the supernatant by decantation, without filtering, the slurry containing (b-1) was spread in a stainless steel container and dried for 10 hours in a circulating air dryer at 50 ° C. 680 parts of polymer flocculants (P-1) containing a water-soluble (co) polymer (A-1) were obtained.

Examples 2-10, Comparative Examples 1-4
[Polymer flocculants (P-2) to (P-10), (RP-1) to (RP-4)]
In Example 1, the polymer flocculants (P-2) to (P-10) and (RP-) were changed in the same manner as in Example 1 except that the composition was changed based on the monomer liquid composition (parts) shown in Table 1. 1) to (RP-4) were obtained. The results are shown in Table 1.

Example 11
[Polymer flocculant (P-11)]
Add 750 parts of a 70% aqueous solution of methanesulfonate of aminoethyl methacrylate (a1-2), 0.45 part of (e-1) and 243 parts of ion-exchanged water to a reaction vessel with agitation to make an aqueous solution with a uniform system inside. Stir until. While further stirring, the pH of the monomer aqueous solution (20 ° C.) was adjusted to 4.0 using sulfuric acid while monitoring with a pH meter. Next, the temperature of the aqueous solution was adjusted to 25 ° C., and the inside of the system was sufficiently replaced with nitrogen (purity 99.999% or more) (gas phase oxygen concentration 10 ppm or less). Next, 6 parts of 10% aqueous solution (d-1) of azobisamidinopropane hydrochloride as an initiator, 0.3 part of 1% aqueous solution (d-3) of iron (II) sulfate, 1% aqueous solution of hydrogen peroxide (d -2) 0.3 part was added at a time with stirring. After the content temperature reached 50 ° C., 10 parts of (b-1) was added and heated from the outside to adjust the content temperature to 80 ° C. Thereafter, the same temperature was maintained for 2 hours to complete the polymerization reaction. During the polymerization, the content became highly viscous and stirring became difficult, so stirring was stopped halfway. Thereafter, the obtained hydrogel was taken out, mixed and kneaded with a meat chopper machine [model number “12VR-400K”, manufactured by ROYAL Co., Ltd., mesh opening 6 mm], and further minced into 70 ° C. After drying with hot air for 2 hours, the mixture was pulverized with a juicer mixer to obtain 500 parts of a polymer flocculant (P-11) containing a powdery water-soluble (co) polymer (A-11).

Example 12
[Polymer flocculant (P-12)]
In a glass container, 250 parts of (a1-2) and 750 parts of ion-exchanged water were charged and stirred until the inside of the system became a uniform aqueous solution. While further stirring, the pH of the monomer aqueous solution (20 ° C.) was adjusted to 4.0 using sulfuric acid while monitoring with a pH meter.
This monomer aqueous solution was charged into a glass reaction vessel having a height of 50 mm, and then the temperature of the aqueous solution was adjusted to 15 ° C., and the system was sufficiently substituted with nitrogen (purity 99.999% or more) (gas phase oxygen concentration 10 ppm). Less than). Subsequently, 3 parts of 10% aqueous solution (d-1) of azobisamidinopropane hydrochloride as an initiator, 0.8 part of 1% aqueous solution of ammonium persulfate (d-4), 0% aqueous solution of sodium bisulfite (d-5) 0 .8 parts were added all at once with stirring.
From above the glass reaction vessel, the polymerization reaction was completed by irradiation with 100 watt black light at an irradiation intensity of 5.5 mW / cm ² for 1 hour. Thereafter, the obtained hydrous gel was taken out, and 3.5 parts of (b-1) was continuously added by a meat chopper machine [model number “12VR-400K”, manufactured by ROYAL Co., Ltd .; While mixing, kneading, further chopping into minced shapes, drying with hot air at 70 ° C. for 2 hours and pulverizing with a juicer mixer, the powdered water-soluble (co) polymer (A-12) is contained. 170 parts of polymer flocculants (P-12) were obtained.

  The results of the polymer flocculant obtained above are shown in Table 1. The contents of the symbols in Table 1 are as follows.

(1) Water-soluble cationic monomer (a1)
(A1-1): para-toluenesulfonic acid salt of aminoethyl methacrylate
(A1-2): 70% aqueous solution of methanesulfonate of aminoethyl methacrylate (a1-3): 70% aqueous solution of sulfate of aminoethyl methacrylate (2) Water-soluble unsaturated monomer (a2)
(A2-1): 50% aqueous solution of acrylamide (a2-2): N, N-dimethylaminoethyl methacrylate
80% aqueous solution of methyl chloride salt (3) Water-insoluble solvent (b)
(B-1): n-decane (SP value 7.6)
(B-2): Cyclohexane (SP value 8.2)
(B′-3): Cyclohexanone (SP value 9.9)

(4) Chain transfer agent (e)
(E-1): 10% aqueous solution of 1-thioglycerol (5) radical polymerization initiator (d)
(D-1): Azobisamidinopropane hydrochloride [manufactured by Wako Pure Chemical Industries, Ltd.
10% aqueous solution of “V-50”, 10-hour half-life temperature: 56 ° C.] (d-2): 1% aqueous solution of hydrogen peroxide (d-3): 1% aqueous solution of iron (II) sulfate (d- 4): 1% aqueous solution of ammonium persulfate (d-5): 1% aqueous solution of sodium hydrogen sulfite

Examples 13-24, Comparative Examples 5-8
[Performance evaluation of polymer flocculants]
The obtained polymer flocculants were each dissolved in ion exchange water to obtain an aqueous solution having a solid content of 0.2%. 200 g of mixed raw sludge [pH 4.7, TS 3.0%, SS 2.4%, organic content 55%, alkalinity 600 mg-CaCO ₃ / L] collected from the H city treatment plant is taken in a 500 mL beaker, and the above polymer 20 g of each aqueous solution of a flocculant was added (the solid content addition amount at this time was 0.5% / TS), and the performance was evaluated. The results are shown in Table 2.

  From Table 2, the polymer flocculant (P) of the present invention was superior in water solubility compared to the comparative one, formed a floc with a large particle size, and once formed under low agitation (300 rpm). The polymer flocculant (P) of the present invention is resistant to breakage (high flock strength) even under high agitation (1,000 rpm) and has an excellent effect on dewaterability (water content of dehydrated cake). It can be seen that the aggregation performance is extremely excellent.

  Since the polymer flocculant of the present invention exhibits unprecedented agglomeration performance, it is used for dewatering polymer flocculants such as sewage sludge, as well as dye fixing agents, papermaking chemicals (for example, paper industry It is extremely useful because it can be used for a wide range of applications such as a forming aid, a drainage yield improver, a drainage improver and a paper strength enhancer.

Claims (5)

A water-soluble (co) polymer (A) obtained by polymerizing a water-soluble unsaturated monomer (a) containing a water-soluble cationic monomer (a1) represented by the following general formula (1), and SP (solubility parameter) And a water-insoluble solvent (b) having a value of 7.0 to 9.5 (cal / cm ³ ) ^1/2 , and the content of (b) based on the weight of (A) Is a polymer flocculant (P) having a content of 0.5 to 2.0% by weight.

_{CH 2 = C (CH 3)} -CO-X-Q-N + R 1 R 2 R 3 · Z - (1)

[Wherein R ^{1 to} R ³ are H; X is O or NH; Q is an alkylene group having 1 to 4 carbon atoms; Z ⁻ represents a residue other than H ⁺ of a protonic acid. ]   The polymer flocculant according to claim 1, wherein the ratio of (a1) based on the total number of moles of monomers constituting the water-soluble (co) polymer (A) is 80 to 100 mol%.   The polymer flocculant according to claim 1 or 2, wherein (b) is a hydrocarbon having 6 to 10 carbon atoms.   The polymer flocculent according to any one of claims 1 to 3, wherein (A) has a viscosity (25 ° C) of a 0.5 wt% salt aqueous solution of 15 to 30 mPa · s.   A method for treating sludge or wastewater, comprising adding and mixing the polymer flocculant according to any one of claims 1 to 4 to sludge or wastewater to form a floc for solid-liquid separation.