JP2012196661A - Polymer flocculant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer flocculant that can greatly improve the dehydration efficiency of sludge by forming firm and coarse flocs in dehydration of hard-to-dehydrate organic sludge and the like.SOLUTION: The polymer flocculant includes (A) a water-soluble polymer containing a water-soluble unsaturated monomer (a) as a structural unit, and (B) an aromatic ring-containing carboxylic acid and/or its salt. Preferably, (A) is a water-soluble polymer obtained by radical polymerization of the water-soluble unsaturated monomer (a) in the presence of (B).

Description

  The present invention relates to a polymer flocculant. More specifically, the present invention relates to a polymer flocculant excellent in dewatering performance such as organic sludge.

Conventionally, among sewage or human waste (hereinafter abbreviated as sludge) or factory wastewater or inorganic sludge (hereinafter abbreviated as wastewater), poly (meth) acryloyloxyethyl has been used for dewatering sludge, particularly organic sludge. Amphoteric polymer flocculants such as trimethylammonium chloride, acrylamide-acryloyloxyethyltrimethylammonium chloride copolymer, polyamidine and other cationic polymer flocculants, and acrylamide-acrylic acid-acryloyloxyethyltrimethylammonium chloride copolymer are widely used.
For dehydration of waste water and the like, nonionic polymer flocculants such as polyacrylamide and anionic polymer flocculants such as acrylamide-sodium acrylate copolymer are widely used.
Known methods for producing these polymer flocculants include an aqueous solution polymerization method, a thin film polymerization method, a reverse phase suspension polymerization method, a precipitation polymerization method, and an emulsion polymerization method.

Among these polymer flocculants, in recent years, especially regarding the dewatering of organic sludge, there is an increasing need for an increase in the dewatering treatment speed from the viewpoint of increasing the amount of generated sludge and making sludge properties difficult to dewater. Therefore, a polymer flocculant that forms a stronger floc is desired.
In addition, the polymer flocculants that can reduce the moisture content of dehydrated cakes due to soaring incineration costs when dewatered cakes are incinerated, and the tightness of landfill sites when dehydrated cakes are landfilled as they are, It is desired.

  Recently, as a polymer flocculant for the purpose of improving the performance of these polymers, for example, an amphoteric high polymer having a partial cross-linking formed by reacting with a cross-linking agent chemically bonded to a carboxyl group in the polymer at the time of polymerization or after polymerization is reacted. A molecular flocculant (for example, see Patent Document 1), a product prepared by adding a polyalkylene oxide compound having an azo group or a polyalkylene oxide compound having a photocleavable group at the time of polymerization (for example, see Patent Document 2), at the time of polymerization Those manufactured by adding a nitroxy radical (for example, see Patent Document 3) are disclosed.

JP 2001-129511 A JP 2002-97236 A JP 2001-139606 A

However, currently used polymer flocculants have not yet reached a level that can sufficiently solve the above problems, and the disclosed polymer flocculants have a floc strength and a dehydrated cake moisture content. From the point of view, although it was improved somewhat, it was still insufficient.
An object of the present invention is to provide a polymer flocculant capable of forming a strong coarse floc in the dewatering treatment of hardly dewatering organic sludge and greatly improving the sludge dewatering efficiency.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems. That is, the present invention relates to a polymer flocculant comprising a water-soluble polymer (A) having a water-soluble unsaturated monomer (a) as a structural unit, and an aromatic ring-containing carboxylic acid and / or a salt thereof (B) ( P); and the above-mentioned polymer flocculant (P) is added to and mixed with sludge or wastewater to form flocs, and solid-liquid separation is performed.

The polymer flocculant of the present invention has the following effects.
(1) A strong coarse floc is formed in a dewatering process such as sludge.
(2) Since the formed floc is not easily broken or redispersed, the stability and processing speed of the aggregation treatment can be remarkably increased.
(3) The moisture content of the cake after the dehydration step is low, and the amount of waste and incineration costs can be reduced.

[Water-soluble polymer (A)]
The water-soluble polymer (A) in the present invention comprises a water-soluble unsaturated monomer (a) as an essential structural unit. (A) is a cationic monomer (a1) [(a11), (a12) represented by the following general formula (1) or (2), and (a13) described later, from the viewpoint of aggregation of the suspension. , (A14) etc.].
In (a), in addition to (a1), a nonionic monomer (a2) and / or an anionic monomer (a3) having one unsaturated group can be further contained as required.
In the following and below, a water-soluble unsaturated monomer or a water-soluble polymer means one having a solubility in water of 1 g or more / 100 g of water (20 ° C.). It means that the solubility is less than 1 g / 100 g of water (20 ° C.).

^{_{CH 2 = C (R 1)}} CO-Q-X-NR 2 R 3 (1)
^{_{CH 2 = C (R 1)}} CO-Q-X-N + R 2 R 3 R 4 · Z - (2)

In the general formulas (1) and (2), R ¹ is H or a methyl group, R ² and R ³ are carbon atoms (hereinafter abbreviated as C) 1 to 3 [aggregation performance (high From the viewpoint of floc strength, floc coarsening, low water content of dehydrated cake, etc., the same shall apply hereinafter), preferably represents an alkyl or alkoxyl group of 1-2], and R ² and R ³ are bonded to each other to form a ring. It may be formed.
R ⁴ represents H or a C1-7 alkyl, alkoxyl or benzyl group. R ^{1 to} R ⁴ may be the same as or different from each other.
Q represents O or NH, and X represents a C1-4 alkylene group or a C2-4 hydroxyalkylene group.
Z ⁻ represents an anion such as a halogen ion, a sulfate ion, a phosphate ion, or a nitrate ion.

Examples of (a1) to (a3) include the following.
(A1) 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. .
(A11) Nitrogen atom-containing (meth) acrylate [where (meth) acrylate represents acrylate or methacrylate. same as below. ]
C6-21, such as aminoalkyl (C2-3) (meth) acrylate, N, N-dialkyl (alkyl group is C1-2) aminoalkyl (C2-3) (meth) acrylate [N, N-dimethylamino Ethyl and -propyl (meth) acrylate, N, N-diethylaminoethyl and -propyl (meth) acrylate and the like], heterocycle-containing (meth) acrylate [N-morpholinoethyl (meth) acrylate and the like];
(A12) Nitrogen atom-containing (meth) acrylamide derivative C6-21, such as N, N-dialkyl (C1-2) aminoalkyl (C2-3) (meth) acrylamide [N, N-dimethylaminoethyl (meth) Acrylamide etc.];
(A13) Ethylenically unsaturated compound having an amino group C6-21, such as vinylamine, vinylaniline, (meth) allylamine, p-aminostyrene, etc.];
(A14) Compound having amine imide group C6-21, such as 1,1,1-trimethylamine (meth) acrylimide, 1,1-dimethyl-1-ethylamine (meth) acrylimide, 1,1-dimethyl-1 -(2'-Phenyl-2'-hydroxyethyl) amine (meth) acrylimide.

(A2) Nonionic monomer The following are mentioned, and these mixtures.
(A21) (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. Reference substance: Polystyrene] 5,000 or less, for example, hydroxyl group-containing (meth) acrylate [eg, hydroxyethyl-, diethylene glycol mono-, polyethylene glycol (degree of polymerization 3-50) mono- and (poly) glycerol (degree of polymerization 1 10) mono (meth) acrylate] and alkyl acrylate (alkyl group is C1-2) ester (C4-5, such as methyl acrylate, ethyl acrylate);
(A22) (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- Alkylol (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 ;
(A23) Nitrogen-containing ethylenically unsaturated compounds other than (a1) C3-30, such as acrylonitrile, N-vinylformamide, N-vinyl-2-pyrrolidone, N-vinylimidazole, N-vinylsuccinimide, N -AO2 to 10 mol adduct of vinylcarbazole and 2-cyanoethyl (meth) acrylate, hydroxyethylmaleimide.

(A3) 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.

(A31) unsaturated carboxylic acids of C3-30, such as (meth) acrylic acid, (anhydrous) maleic acid, fumaric acid, (anhydrous) itaconic acid, vinylbenzoic acid, allylic acetic acid, maleic acid AO adduct monoester;
(A32) Unsaturated sulfonic acid C2-20 aliphatic unsaturated sulfonic acid (such as vinyl sulfonic acid), C6-20 aromatic unsaturated sulfonic acid (such as styrene sulfonic acid), sulfonic acid group-containing (meth) acrylate [ Sulfoalkyl (C2-20) (meth) acrylate [2- (meth) acryloyloxyethane, -propane and -butanesulfonic acid, 3- (meth) acryloyloxypropanesulfonic acid, 4- (meth) acryloyloxybutanesulfonic acid 2- (meth) acryloyloxy-2,2-dimethylethanesulfonic acid, p- (meth) acryloyloxymethylbenzenesulfonic acid, etc.], sulfonic acid group-containing (meth) acrylamide [2- (meth) acryloylaminoethanesulfone Acid, 2- and 3- (meth) acryloylaminoprop Sulfonic acid, 2- and 4- (meth) acryloylaminobutanesulfonic acid, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid, p- (meth) acryloylaminomethylbenzenesulfonic acid, etc.], alkyl ( C1-20) (meth) allylsulfosuccinic acid ester [methyl (meth) allylsulfosuccinic acid ester and the like] and the like;
(A33) (Meth) acryloyl polyoxyalkylene (alkylene group is C1-3) sulfate ester (meth) acryloyl polyoxyethylene (polymerization degree 2-50) sulfate ester and the like.

  Among (a), from the viewpoint of increasing the molecular weight of the water-soluble polymer (A), (a11), (a12), (a13) among the cationic monomers, (a21) among the nonionic monomers, (A22), (a31), (a32) of anionic monomers, more preferably (a11), (a12), (a13), (a21), (a22), (a31), and (a32) Of these, sulfonic acid group-containing (meth) acrylate, sulfonic acid group-containing (meth) acrylamide, particularly preferred are (a11), (a12), (a13), (a21), (a31), and (a32). Of these, sulfonic acid group-containing (meth) acrylate, sulfonic acid group-containing (meth) acrylamide, and most preferred is N, N-dimethylaminoethyl (meth) of (a11). ) Acrylates and their salts (as described above), (meth) acrylamide in (a22), acrylonitrile in (a23), N-vinylformamide, (meth) acrylic acid in (a31), (anhydrous) ) Maleic acid, (anhydrous) itaconic acid and alkali metal salts thereof, (a32) 2- (meth) acryloyloxyethanesulfonic acid, 2- and 3- (meth) acryloyloxypropanesulfonic acid, 2- ( (Meth) acryloylamino-2,2-dimethylethanesulfonic acid and alkali metal salts thereof. Moreover, these (a) can be arbitrarily mixed and copolymerized.

The GPC measurement of Mn and the weight average molecular weight described later in the present invention shall be in accordance with the following measurement conditions.
<GPC measurement conditions>
GPC model: HLC-8120GPC, column made by Tosoh Corporation: TSKgel 2 GMHXL + TSKgel
Multipore HXL-M, Tosoh Co., Ltd. detector: Refractive index detector reference material: Standard polystyrene (TSK standard POLYSTYRENE),
Made by Tosoh Corporation

  The content (mol%) of the cationic monomer (a1) in the water-soluble unsaturated monomer (a) is preferably 20 to 100 mol%, more preferably 30 to 100 mol% from the viewpoint of aggregation performance; The content (mol%) of (a2) is preferably 0 to 80 mol%, more preferably 0 to 50 mol%, from the viewpoint of high molecular weight and aggregation performance of (A); content of anionic monomer (a3) The amount (mol%) is preferably 0 to 30 mol%, more preferably 0 to 20 mol% from the viewpoint of increasing the molecular weight of (A) and neutralizing the charge on the sludge particle surface.

As a monomer constituting the water-soluble polymer (A), a water-insoluble monomer (x) and a cross-linkable monomer (y) are used in combination with the water-soluble unsaturated monomer (a) as necessary, as long as the effects of the present invention are not impaired. can do.
Examples of the water-insoluble monomer (x) include the following (x1) to (x5) and mixtures thereof.
(X1) (Meth) acrylate of C6-23 (meth) acrylate of aliphatic or alicyclic alcohol (C3-20) [propyl-, butyl-, lauryl-, octadecyl- and cyclohexyl (meth) acrylate etc.] and epoxy Group (C4-20) -containing (meth) acrylate [glycidyl (meth) acrylate and the like];

(X2) Unsaturated carboxylic acid of [monoalkoxy (C1-20)-, monocycloalkoxy (C3-12)-or monophenoxy] polypropylene glycol (polypropylene glycol is hereinafter abbreviated as PPG) (degree of polymerization 2-50) Monoester Monool (C1-20) or monohydric phenol (C6-20) propylene oxide (hereinafter abbreviated as PO) adduct (meth) acrylate ester [ω-methoxy PPG mono (meth) acrylate, ω-ethoxy PPG mono (meth) acrylate, ω-propoxy PPG mono (meth) acrylate, ω-butoxy PPG mono (meth) acrylate, ω-cyclohexyl PPG mono (meth) acrylate, ω-phenoxy PPG mono (meth) acrylate, etc.] and diol (C2-20) or Valence phenol (meth) acrylic acid ester [.omega.-hydroxyethyl (poly) oxypropylene mono (meth) acrylate] of the PO adduct of (C6-20) or the like;

(X3) C2-30 unsaturated hydrocarbon ethylene, nonene, styrene, 1-methylstyrene and the like;
(X4) Carboxylic acid (C2-30) ester (vinyl acetate, etc.) of unsaturated alcohol [C2-4, such as vinyl alcohol, (meth) allyl alcohol];
(X5) Halogen-containing monomer (C2-30, such as vinyl chloride).

  Further, as the crosslinkable monomer (y), the following (y1) to (y4) having two or more unsaturated groups, two or more reactive epoxy groups, or a reaction with an unsaturated group The following (y5), these salts having a total of 2 or more functional epoxy groups (for example, for basic monomers, inorganic acids (hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, sulfurous acid, Phosphoric acid, nitric acid, etc.) salt, methyl chloride salt, dimethyl sulfate salt and benzyl chloride salt, acidic monomer, alkali metal salt, alkaline earth metal salt, amine (C1-20, such as methylamine, ethylamine, cyclohexyl) Amine) salts], and mixtures thereof.

(Y1) Bispoly (2-4 or more) (meth) acrylamides C5-30, such as N, N′-methylenebis (meth) acrylamide;
(Y2) Poly (2-4 or more) (meth) acrylates of C8-30, such as ethylene glycol di (meth) acrylate, pentaerythritol poly (2-4) (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate;

(Y3) Vinyl group (2 to 20 or more) -containing monomer C4 or more and Mn 6,000 or less, for example, divinylamine, polyvalent (divalent to pentavalent or more) amine [C2 or more and Mn 3,000 or less, For example, poly (2-20) vinylamine, divinyl ether, polyhydric alcohol [C2 or more and Mn3,000 or less, such as alkylene (C2-6 or more) glycol of ethylenediamine, polyethyleneimine (C4 or more and Mn3,000 or less)] [Ethylene glycol (hereinafter abbreviated as EG), propylene glycol, 1,6-hexanediol, etc.], polyoxyalkylene [Mn 2,000 to 3,000, for example, polyethylene glycol (hereinafter abbreviated as PEG) (molecular weight of 106 or more and Mn 3,000 or less), PPG (molecular weight 1) 4 or more and Mn 3,000 or less), polyoxyethylene (molecular weight 106 or more and Mn 3,000 or less) / polyoxypropylene (molecular weight 134 or more and Mn 3,000 or less) block copolymer], trimethylolethane, trimethylolpropane, (poly ) (2-50) glycerin (glycerin is hereinafter abbreviated as GR), pentaerythritol, sorbitol, starch] poly (2-20) vinyl ether and the like;

(Y4) Allyl group (2 to 20 or more) -containing monomer C6 or more and Mn 3,000 or less, for example, di (meth) allylamine, N-alkyl (C1-20) di (meth) allylamine, polyvalent amine (above Poly (2-20) (meth) allylamine, di (meth) allyl ether, poly (2-20) (meth) allyl ether of polyhydric alcohol (above), poly (2-20) ( (Meth) allyloxyalkanes (C1-20) (tetraallyloxyethane and the like);
(Y5) having two or more reactive epoxy groups or a total of two or more unsaturated groups and reactive epoxy groups C8 or more and Mn 6,000 or less, such as EG diglycidyl ether, PEG diglycidyl Ether, GR triglycidyl ether, glycidyl (meth) acrylate, 3,4-epoxyhexahydrobenzyl (meth) acrylate.

  The content of each monomer based on the total number of moles of the monomer (a) constituting the water-soluble polymer (A) and (x) and (y) used in combination as necessary is (a) usually 50% or more, agglomeration From the viewpoint of performance, it is preferably 70 to 100%, more preferably 80 to 100%; (x) is usually 50% or less, preferably from the viewpoint of the aggregation performance expression and the solubility of the polymer flocculant in water. 1 to 20%, more preferably 0.5 to 10%; and (y) is usually 5% or less, and although depending on the polymerizability or reactivity of (y), expression of aggregation performance and polymer flocculant From the viewpoint of solubility in water, it is preferably 0.001 to 1%, more preferably 0.01 to 0.5%.

The water-soluble polymer (A) may be a known aqueous solution polymerization (for example, adiabatic polymerization, thin film polymerization, spray polymerization described in JP-A-55-133413) or a known reverse phase suspension polymerization (for example, JP-B-54- Various polymerization methods including those described in Japanese Patent No. 30710, Japanese Patent Application Laid-Open No. 56-26909, and Japanese Patent Application Laid-Open No. 1-5808 (photopolymerization (for example, those described in Japanese Patent Publication No. 6-804)), precipitation polymerization (For example, those described in JP-A-61-123610), reverse-phase emulsion polymerization (for example, those described in JP-A-58-197398), etc., using radical polymerization initiator (d) Can do. Among the polymerization methods, the aqueous solution polymerization method is preferable from an industrial viewpoint, for example, that it is not necessary to use an organic solvent.
The polymer flocculant (P) of the present invention can be produced by the following production methods (1) to (3) as described later, and the production of (A) in the case of (1) will be described later. In the presence of an aromatic ring-containing carboxylic acid and / or salt (B) thereof.
(1) A method for producing (A) in the presence of (B) (2) A method for producing (A) by impregnating (B) a hydrogel after production (3) (A) after production Method for producing powder by mixing (B)

Examples of the radical polymerization initiator (d) include various compounds such as azo compounds [water-soluble compounds [azobisamidinopropane (salt), azobiscyanovaleric acid (salt), 4,4′-azobis (4-cyano). Pentanoic acid) etc.] and oil-soluble [azobiscyanovaleronitrile, azobisisobutyronitrile, azobiscyclohexanecarbonitrile, etc.]] and peroxides [water-soluble [peracetic acid, t-butyl peroxide] , Hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate and the like] and oil-soluble ones (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.
Among these, an azo compound is preferable from the viewpoint of reducing the water-insoluble content of the water-soluble 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).

  The amount of (d) used is preferably 0.001 to 1.0%, more preferably 0.005 to 0.005% based on the total weight of the monomers constituting (A) from the viewpoint of obtaining an optimum molecular weight. 0.5%, particularly preferably 0.01-0.2%, most preferably 0.02-0.1%.

In the polymerization, a chain transfer agent (f) can be further used.
Examples of (f) include those having a chain transfer constant of 0.01 to 100, preferably 0.05 to 50, particularly preferably 0.1 to 10.
The definition of the chain transfer constant is as follows: “Handbook of Polymer Handbook (4th edition)” edited by J. Brandrup and EE Immag, published by J. Brandrup and EH Immergut, Polymer Handbook fourth edition, 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 (f), a compound having one or more amino groups in the molecule [C0-60, such as ammonia, 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, monoethanolamine thioglycolate, thiomaleic acid, mercaptosuccinic acid, cysteine, cysteamine), alicyclic thiol (C5-20, such as cyclopentanethiol, cyclohexanethiol) ), Aromatic thiols (C6-12, such as benzenethiol, thiosalicylic acid, thiocresol, thiolenol, thionaphthol) and araliphatic thiols (C7-20, such as α-to) Enethiol), and the like.

(2) Polyvalent thiol Dithiol [aliphatic dithiol (C2-40, such as ethanedithiol, diethylenedithiol, triethylenedithiol, n-, i- and sec-propanedithiol, 1,3- and 1,4-butane Dithiol, 1,6-hexanedithiol, neopentanedithiol, triethylene glycol dithiol, EG-di-2-mercaptoethyl ether), alicyclic dithiol (of C5-20, such as cyclopentanedithiol, cyclohexanedithiol), aroma Group dithiols (C6-16, such as benzenedithiol, biphenyldithiol) and araliphatic dithiols (C8-20, such as xylenedithiol).

Of the above (f), those having high water solubility are preferred from the viewpoint of reducing the water-insoluble content of the polymer flocculant, and the water / n-decane partition coefficient in (f) is preferably 10/90 to 100. / 0, more preferably 20/80 to 100/0, particularly preferably 50/50 to 100/0. The water / n-decane partition coefficient here is the same measurement method as the water / 1-octanol 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 (f) used is preferably 0.0001 to 1% based on the total weight of the monomers constituting (A), from the viewpoint of reducing the water-insoluble content of the polymer flocculant and increasing the molecular weight. Preferably it is 0.001-0.5%, Especially preferably, it is 0.01-0.3%, Most preferably, it is 0.05-0.1%.

Among the methods for producing the water-soluble polymer (A), examples of the reverse phase suspension polymerization method include the following methods.
That is, after the hydrophobic dispersion medium (b) and the dispersant (c) are charged into a polymerization tank and adjusted to a predetermined polymerization temperature (usually 20 to 100 ° C., preferably 30 to 80 ° C.) while heating as necessary. The inside of the tank is sufficiently replaced with an inert gas (for example, nitrogen).
On the other hand, a water-soluble unsaturated monomer (a), a radical polymerization initiator (d), and a chain transfer agent (f) as necessary, and a water-insoluble unsaturated monomer (x) and / or a crosslinkable monomer (y) were added. After preparing an aqueous monomer solution and sufficiently substituting with an inert gas, it is put into 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) and (x) and / or (y) to be added if necessary. It may be dropped simultaneously or separately. 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.

Among the production methods of the water-soluble polymer (A), the hydrophobic dispersion medium (b) used in the reverse phase suspension polymerization method or the reverse phase emulsion polymerization method includes the following hydrocarbons, ketones, ethers, esters and mixtures thereof. Is mentioned.
Here, the hydrophobic dispersion medium means a dispersion medium having a solubility in water (20 ° C.) of less than 1 g / 100 g of water.
(1) Hydrocarbon aliphatic (C5-12, such as n-hexane, n-heptane, n-octane, n-nonane, n-decane), alicyclic ring (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];
(2) Ketone Aliphatic (C3-10, such as methyl-n-propylketone, diethylketone, methylisobutylketone), alicyclic ring-containing (C5-10, such as cyclopentanone, cyclohexanone) and aromatic ring-containing ketone (C8- 13, for example, acetophenone, benzophenone) and the like];
(3) Ethers Aliphatic (C4-8, eg di-n-propyl ether, di-n-butyl ether, diethylene glycol dimethyl ether), cyclic (C4-18, eg tetrahydropyran) and aromatic ring-containing ethers (C7-12, eg Anisole) etc.] etc .;
(4) Esters Aliphatic (C3-10, eg n-butyl acetate, isobutyl acetate), alicyclic (C7-12, eg cyclohexyl acetate, methyl cyclohexanecarboxylate) and aromatic ring containing esters (C8-13, eg benzoic) Acid methyl, ethyl benzoate, n-butyl benzoate, benzyl acetate, dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate) and the like.

  Among these, from the viewpoints of handling during production and temperature control during polymerization, aliphatic and alicyclic hydrocarbons, aliphatic and alicyclic esters are preferable, and n-hexane, n-hexane are more preferable. Heptane, n-octane, n-nonane, n-decane, cyclohexane, methylcyclohexane, n-butyl acetate, isobutyl acetate and cyclohexyl acetate.

  The amount of the hydrophobic dispersion medium (b) used in reverse phase suspension polymerization is preferably 25%, more preferably 40%, particularly preferably, based on the total weight of the aqueous monomer solution from the viewpoint of the viscosity of the dispersion. 65%, and the upper limit is preferably 1,000% from the viewpoint of dispersion stability, more preferably 400%, particularly preferably 200%; in reverse emulsion polymerization, based on the total weight of the monomer aqueous solution from the viewpoint of emulsion viscosity. The preferable lower limit is 20%, more preferably 30%, particularly preferably 40%, and the preferable upper limit is 80%, more preferably 70%, particularly preferably 60% from the viewpoint of emulsion stability.

The dispersant (c) used in the reverse phase suspension polymerization method includes the reverse phase suspension or dispersion or emulsion stability of the emulsified particles, and the angle of repose of the dry particles of the water-soluble polymer (A) described below, that is, From the viewpoint of controlling the powder fluidity, various oil-soluble substances having an HLB of preferably 1 to 8, more preferably 1.5 to 7.5, and particularly preferably 2 to 7 may be mentioned.
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 New Surfactants”, pages 197-198, published by Sanyo Chemical Industries, Ltd. in 1992, 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 from the viewpoint of the angle of repose of the particles of the polymer flocculant containing the water-soluble polymer (A). ~ 70 ° C. 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 under the above conditions. 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 hydrophobic dispersion medium (b), the stability of the reversed phase suspended particles, the angle of repose of the dried particles of the polymer flocculant after drying, and the particles From the viewpoint of diameter control, it is preferably 0.01 to 10%, more preferably 0.05 to 5%.

  The monomer concentration in the aqueous monomer solution in the radical polymerization method is usually 1% based on the total weight of the aqueous monomer solution in aqueous solution polymerization, preferably 5% from an industrial viewpoint, more preferably 10%, and particularly preferably 15%. %, Most preferably 20%, upper limit is usually 80%, preferably 75%, more preferably 70%, particularly preferably 65%, most preferably 60% from the viewpoint of temperature control during polymerization; The lower limit is usually 30%, preferably 40% from the same viewpoint as described above, more preferably 45%, particularly preferably 50%, most preferably 55%, and the upper limit is usually 90%, preferably from the same viewpoint as described above. Is 85%, more preferably 80%, particularly preferably 78%, most preferably 75%; in reverse phase emulsion polymerization, the lower limit is usually 10%, From the same viewpoint as described above, preferably 20%, more preferably 30%, particularly preferably 40%, most preferably 55%, the upper limit is usually 90%, and from the same viewpoint as described above, preferably 80%, more preferably 75%. %, Particularly preferably 70%, most preferably 65%.

  The water-soluble polymer (A) in the present invention may be further modified. As the polymer modification method, for example, when (meth) acrylamide having a hydrolyzable functional group in the molecule is used as the water-soluble unsaturated monomer (a), a caustic alkali (sodium hydroxide, hydroxide) is used during or after the polymerization. Potassium etc.) or alkali carbonate (sodium carbonate, potassium carbonate, etc.) is added, and the amide group of (a) is partially hydrolyzed to introduce a carboxyl group (see JP-A-56-16505 etc.) ); Formaldehyde, dialkylamine (C1-12) and halogenated (chlorine, bromine, iodine, etc.) alkylated (C1-12) (methyl chloride, ethyl chloride, etc.) are added, and a cationic group is partially introduced by the Mannich reaction. Obtained by hydrolysis of nitrile groups such as acrylonitrile and vinylformamide A method of forming an amidine ring in a molecule by a ring-closing reaction with an amino group (see JP-A-5-192513, etc.); and a method of adding a crosslinkable monomer (y) after polymerization to cause a crosslinking reaction (patent) No. 3305688) and the like.

[Aromatic ring-containing carboxylic acid and / or salt thereof (B)]
The polymer flocculant (P) of the present invention contains an aromatic ring-containing carboxylic acid and / or a salt thereof (B) together with the water-soluble polymer (A). The number of carboxyl groups and / or bases in (B) is preferably 2 to 8, more preferably 2 to 6, from the viewpoint of the aggregation performance and water solubility of (P). In the present invention, polycarboxylic acid is used in the sense of containing an anhydride.
When the polymer flocculant (P) contains (B), the floc diameter is large, and the floc diameter change due to stirring is small (the floc strength is large).
Examples of (B) include the following (B1) to (B3), salts thereof [metal salts [alkali metal (K, Na, etc.) salts, alkaline earth metal (Ca, Mg, etc.) salts, etc.], etc.]. The same applies to the following metal salts. And mixtures thereof. The aromatic ring (B) includes an aromatic ring (benzene ring, naphthalene ring, etc.) in which only carbon forms a ring, an aromatic ring (pyridine ring, etc.) in which carbon and nitrogen form a ring, and the like.

(B1) (Poly) carboxylic acid having a single aromatic ring C7-30, for example, having one carboxyl group: one having a carboxyl group directly linked to the aromatic ring [benzoic acid, methylbenzoic acid, dimethylbenzoic acid (Xylyl acid, hemelic acid, mesitylene acid, etc.), trimethylbenzoic acid (planicylic acid, isodiuric acid, jurylic acid, mesitonic acid), salicylic acid, methoxybenzoic acid, isopropylbenzoic acid, hydroxymethylbenzoic acid, dihydroxybenzoic acid, hydroxymethoxy Benzoic acid, dimethoxybenzoic acid, dihydroxymethylbenzoic acid, trihydroxybenzoic acid (gallic acid), hydroxydimethoxybenzoic acid, trimethoxybenzoic acid, 4-pyridinecarboxylic acid, 4-methylpyridine-3-carboxylic acid, etc.], carboxyl group Is not directly connected to the aromatic ring Phenylacetic acid, hydroxyphenylacetic acid, (4-methoxyphenyl) acetic acid, dihydroxyphenylacetic acid, phenoxyacetic acid, 2-phenylpropanoic acid, 3-phenylpropanoic acid and the like];

Those having two carboxyl groups: those having two carboxyl groups directly linked to an aromatic ring [benzenedicarboxylic acid (phthalic acid, isophthalic acid, terephthalic acid, etc.), methylisophthalic acid, dimethoxyphthalic acid, 3,5-pyridinedicarboxylic acid Acid etc.] One carboxyl group directly linked to an aromatic ring [Carboxymethylbenzoic acid (homophthalic acid, homoisophthalic acid, homoterephthalic acid etc.), Carboxycarbonylbenzoic acid (phthalonic acid, isophthalonic acid, terephthalonic acid etc.) And so on;

Those having three carboxyl groups: those having three carboxyl groups directly linked to an aromatic ring [benzenetricarboxylic acid (hemimellitic acid, trimellitic acid, trimesic acid, etc.), etc.], etc .;
Those having 4 carboxyl groups: those having 4 carboxyl groups directly linked to an aromatic ring [benzenetetracarboxylic acid (merophane acid, pyromellitic acid, etc.), etc.];
And acid anhydrides thereof.

(B2) (Poly) carboxylic acid having two aromatic rings C11-30, for example, having one carboxyl group: one having a carboxyl group directly linked to an aromatic ring [naphthalenecarboxylic acid, hydroxynaphthalenecarboxylic acid, dihydroxy Naphthalenecarboxylic acid, phenylbenzoic acid, methoxynaphthalenecarboxylic acid, aminonaphthalenecarboxylic acid, chlorohydroxynaphthalenecarboxylic acid, bromonaphthalenecarboxylic acid, trimethoxydihydronaphthalenecarboxylic acid, etc.], wherein the carboxyl group is not directly linked to the aromatic ring [2- Naphthylacetic acid, acetoxynaphthylacetic acid, etc.];

Those having two carboxyl groups: those having two carboxyl groups directly linked to an aromatic ring [1,4-, 1,6-, 1,8-, 2,3- and 2,6-naphthalenedicarboxylic acid, hydroxy Naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,2′-bipyridine-5,5′-dicarboxylic acid, etc.];

Those having three carboxyl groups: those having three carboxyl groups directly linked to an aromatic ring [naphthalene tricarboxylic acid, biphenyl tricarboxylic acid, etc.] and the like;
Those having 4 carboxyl groups: those having 4 carboxyl groups directly linked to the aromatic ring [naphthalene tetracarboxylic acid, biphenyl tetracarboxylic acid, etc.] and the like;
And acid anhydrides thereof.

(B3) (Poly) carboxylic acids having 3 or more aromatic rings C15-40, for example those having 1 to 8 carboxyl groups: those having a carboxyl group directly linked to the aromatic ring [phenanthrene and anthracene mono- and Poly (2 to 8) carboxylic acid, octacarboxyphthalocyanine and the like], and their acid anhydrides.

Of the above (B1) to (B3), from the viewpoint of floc diameter at the time of treatment such as sludge with the polymer flocculant (P) used in combination with the water-soluble polymer (A), floc diameter change (floc strength) by stirring, Preferred are polycarboxylic acids having 2 to 6 carboxyl groups, more preferred are those polycarboxylic acids in (B1), more preferred are those in which at least two carboxyl groups are directly linked to an aromatic ring, particularly preferred. Are benzenedi-, tri- and tetracarboxylic acids, most preferred are hemimellitic acid, trimellitic acid, trimesic acid, merophanic acid and pyromellitic acid. In addition, said preferable thing includes a corresponding acid anhydride and a metal salt.
(B) is preferably non-polymerizable having no ethylenically unsaturated group from the viewpoint of water solubility of (P).

[Polymer flocculant (P)]
The polymer flocculant (P) of the present invention comprises the above (A) and (B).
The content of (B) is preferably 0.1 to 10%, more preferably 0.2 to 5 based on the total weight of the monomers constituting (A) from the viewpoint of aggregation performance and water-insoluble content. %, Particularly preferably 0.5 to 4%, most preferably 1 to 3%.

The production method of the polymer flocculant (P) of the present invention includes the following production methods (1), (2) and (3), and the production method (1) is preferred from the viewpoint of aggregation performance.
(1) The water-soluble unsaturated monomer (a) and, if necessary, (x) and (y) are polymerized in the presence of (B) to contain (B) and the water-soluble polymer (A) (P ). The addition of (B) to the monomer to be polymerized may be before polymerization and / or during polymerization, but is preferably before polymerization from the viewpoint of increasing the molecular weight.
(2) After producing an aqueous gel of the water-soluble polymer (A) by polymerizing an aqueous solution of the water-soluble unsaturated monomer (a) and, if necessary, monomers added with (x) and (y), (B) (A) The method of making it osmose | permeate the hydrous gel. In the permeation method, the solution or dispersion of (B) in which (B) is dissolved or dispersed in water or an organic solvent in an aqueous solution or a mixture of water and an organic solvent containing the hydrous gel of (A) And stirring, and (B) is allowed to permeate the hydrogel of (A). Among the methods (2), from the viewpoint of the permeability of (B) to (A), a method using a solution in which (B) is dissolved is preferable.
(3) A method of mixing powdery (B) with powdery (A) dried after polymerization (dry blending method).

  Water-containing gel obtained by the polymerization [in the production method (1), the water-soluble polymer (A), (B) and water, or in the production method (2), (A), (B), water and / or organic solvent Is composed of, if necessary, dehydrated and dried to obtain a powdery water-soluble polymer.

0.5% by weight salt aqueous solution viscosity (hereinafter 0.5% salt) of the polymer flocculant (P) of the present invention containing the water-soluble polymer (A) and the aromatic ring-containing carboxylic acid and / or salt thereof (B) (It may be called aqueous solution viscosity) (mPa * s, 25 degreeC) becomes like this. Preferably it is 1-200, More preferably, it is 2-180, Most preferably, it is 3-150. When the 0.5% salt aqueous solution viscosity is 1 or more, the cohesiveness in the treatment of sludge and the like is good, and when it is 200 or less, the reactivity with the suspended particles is good. In addition, 0.5% salt aqueous solution viscosity can be measured by the below-mentioned method.
Further, the 0.2% by weight aqueous solution viscosity of the water-soluble polymer (A) (hereinafter sometimes referred to as 0.2% aqueous solution viscosity) (mPa · s, 25 ° C.) is preferably 50 to 1,000, more preferably 100 to 900, particularly preferably 200 to 800. When the 0.2% aqueous solution viscosity is 50 or more, the cohesiveness in the treatment of sludge is good, and when it is 1,000 or less, the reactivity with the suspended particles is good. The 0.2% aqueous solution viscosity can be measured by the method described later.

As a simple measuring method capable of expressing the molecular weight distribution of the polymer flocculant, there is a string length of a 0.4 wt% aqueous solution. The smaller the string length, the narrower the molecular weight distribution, and the larger the string length. It can be shown that the molecular weight distribution is broad.
In the nonionic and anionic polymer flocculants described later, the thread length (mm) of the 0.4% by weight aqueous solution of the polymer flocculant (P) is preferably 20 to 200 from the viewpoint of industrial and aggregation performance. More preferably, it is 40 to 150, and the cationic and amphoteric polymer flocculants are preferably 5 to 100, more preferably 6 to 80 from the same viewpoint.

Here, the string length L (mm) can be measured by the following procedure using a stringiness measuring instrument [manufactured by Kyowa Interface Science Co., Ltd.].
Take 0.80 g of polymer (polymer flocculant) particles (in terms of solid content) in a 300 ml glass beaker, and quickly add ion exchange water so that the total weight of the particles and ion exchange water is 200.0 g. Stir using a stick or the like until the polymer swells and disperses uniformly (about 1 minute). At this time, care is taken so that the polymer does not remain. Then, after covering with a transparent resin film and allowing to stand at room temperature (about 20 ° C.) for about 20 hours, stirring with a plate-like PVC stirring blade (diameter 5 cm, height 2 cm, thickness 0.2 cm) A jar tester equipped with a stick is set and stirred at 120 rpm for 1 hour to prepare a 0.4 wt% aqueous solution of the measurement sample. After adjusting the temperature of the measurement sample to 25 ± 2 ° C., a glass spheroid (hereinafter referred to as a glass sphere) (short diameter 7 mm, long diameter 11 mm, long diameter) attached to the lower end of the hanging thread of the spinnability measuring instrument. Is suspended so that the upper end of the major axis of the glass sphere is located immediately below the liquid surface of the measurement sample, and held for 15 seconds, then the glass sphere is pulled up at a speed of 16 mm / second, and the yarn of the polymer aqueous solution is cut. Measure the distance from the liquid level to the lower end of the glass bulb. The immersion position of the glass sphere in the measurement sample is changed, the measurement is repeated 10 times, the average value is calculated, and the value is taken as the value of the string length L (mm).

The intrinsic viscosity η of the polymer flocculant (P) (measured value in a 1N-NaNO ₃ aqueous solution at 30 ° C., the unit is dl / g. The same applies hereinafter) is agglomeration and reactivity with suspended particles (aggregation rate). From this viewpoint, it is preferably 2 to 30, more preferably 10 to 20.

As described above, the yarn length generally correlates with the molecular weight or the molecular weight distribution, and becomes larger as the molecular weight is larger or the molecular weight distribution is wider. Also, when comparing different water-soluble polymers, if the water-insoluble amount is small and the molecular weight is the same (difference in intrinsic viscosity is within ± 5%), the shorter thread length is better. It can be determined that the molecular weight distribution is sharp and the aggregation performance is excellent. From the relationship between the yarn length, molecular weight (intrinsic viscosity) and agglomeration performance, in the present invention, the ratio of the yarn length to the intrinsic viscosity (L / η) is further set to a specific range, thereby further aggregating. It has been found that performance can be demonstrated.
That is, the ratio (L / η) of the yarn length L (mm) and the intrinsic viscosity η (dl / g) of (P) is preferably 1 to 8, more preferably 1. 5 to 7, particularly preferably 2 to 5.

As the polymer flocculant (P) of the present invention, a suitable ionic one is used depending on the application.
In general, in sludge, the size of suspended particles is relatively large, and the surface of suspended particles in water is negatively charged. Molecular flocculants and mixtures thereof are preferred.
In wastewater, in order to treat soluble organic matter and the like, an inorganic flocculant is often added first, and in that case, the suspended particle surface is covered with the inorganic flocculant and has a positive charge. As the polymer flocculant for the coagulation sedimentation treatment, anionic or nonionic and mixtures thereof are preferable.
For the tertiary recovery of petroleum, those having a relatively large molecular weight are used, and anionic or nonionic and mixtures thereof are preferred.
Cationic or amphoteric polymer flocculants and mixtures thereof are preferred for improving drainage yield or enhancing paper strength in the papermaking process.
The above ionicity is derived from the ionicity of the water-soluble polymer (A) in the polymer flocculant of the present invention.

  Here, the cationic polymer flocculant is a polymer flocculant having a cationic group in the molecule, that is, a polymer flocculant exhibiting a cationic property when dissolved in water, and an amphoteric polymer flocculant and Is a polymer flocculant having a cationic group and an anionic group in the molecule, that is, a polymer flocculant exhibiting cationic and anionic properties when dissolved in water. About the cationic or anionic evaluation method of these polymer flocculants in water, it can obtain | require as a colloid equivalent value (meq / g). That is, the cationic group equivalent value in the cationic flocculant can be determined as the cation colloid equivalent value, and the cationic group equivalent value and the anionic group equivalent value in the amphoteric flocculant are the cationic colloid equivalent value and the anionic colloid respectively. It can be determined as an equivalent value.

When the polymer flocculant of the present invention is a cationic polymer flocculant, the preferable lower limit of the cation colloid equivalent value (meq / g) in the flocculant is 0.1, more preferably 0.8. 5, more preferably 1.0, particularly preferably 1.5, most preferably 2.0, and from the viewpoint of agglomeration performance, a preferable upper limit is 7.0, more preferably 6.0, still more preferably 5.5, especially Preferably it is 5.2, most preferably 5.0.
When the polymer flocculant of the present invention is an amphoteric polymer flocculant, the lower limit of the cation colloid equivalent value (meq / g) in the flocculant is preferably 0.1, more preferably 0.8. 5, more preferably 1.0, particularly preferably 1.5, most preferably 2.0, and from the viewpoint of agglomeration performance, a preferable upper limit is 7.0, more preferably 6.0, still more preferably 5.5, especially Preferably, it is 5.2, and most preferably 5.0; the anion colloid equivalent value (meq / g) is preferably -13.0, more preferably -10.0, more preferably from the viewpoint of aggregation performance. −8.0, particularly preferably −5.0, most preferably −3.0, and the upper limit is preferably −0.05, more preferably −0.1, still more preferably −0.3, from the viewpoint of aggregation performance. Especially preferred -0.5, and most preferably -1.0.

The colloid equivalent value can be determined by the colloid titration method shown below. The subsequent measurement is performed at room temperature (about 20 ° C.).
(1) Preparation of measurement sample (50 ppm aqueous solution of polymer flocculant) Weigh accurately 0.2 g of sample (in terms of solid content), put it in a 200 ml Erlenmeyer flask, and total weight (total of sample and ion-exchanged water) After adding ion-exchanged water so that the weight becomes 100 g, the mixture is stirred for 3 hours with a magnetic stirrer (a cylindrical magnet having a length of 40 mm and a diameter of 5 mm, a rotational speed of 1,000 rpm) to completely dissolve it. Prepare a 2% by weight polymer flocculant solution. Take 10 ml of the prepared solution in a 500 ml beaker, add ion exchange water so that the total weight (total weight of solution 10 ml and ion exchange water) is 400 g, and again magnetic stirrer (1,000 to 1,200 rpm). Then, stir for 30 minutes to obtain a uniform measurement sample.
The solid content of the polymer flocculant was weighed (W1) in a petri dish (diameter: 100 mm, depth: 10 mm) and dried at 105 ± 5 ° C. for 90 minutes in a circulating drier. This is a value calculated from the following equation, assuming that the remaining weight after (W2).

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

(2) Measurement of cation colloid equivalent value 100 g of a measurement sample is placed in a 200 ml conical beaker, and a 0.5 wt% aqueous sulfuric acid solution is gradually added while stirring with a magnetic stirrer (500 rpm) to adjust to pH 3. Next, add 2-3 drops of toluidine blue indicator (TB indicator) and titrate with N / 400 potassium potassium sulfate (N / 400 PVSK) reagent. The titration rate is 2 ml / min, and the end point is the time when the measurement sample changes color from blue to reddish purple and the reddish purple color is maintained for 30 seconds.
(3) Measurement of anion colloid equivalent value 100 g of a measurement sample was placed in a 200 ml conical beaker, 0.5 ml of an N / 10 sodium hydroxide aqueous solution was added while stirring with a magnetic stirrer (500 rpm), and further N / 200 methyl glycol chitosan. After adding 5 ml of an aqueous solution, the mixture is stirred for 5 minutes (pH about 10.5 at that time). Add 2-3 drops of TB indicator and titrate in the same manner as in (2) above.
(4) Blank test The same operation as (2) and (3) is performed except that 100 g of ion-exchanged water is used instead of the measurement sample.
(5) Calculation method

Colloid equivalent value (meq / g) = (1/2) × (sample titration-blank test titration)
× (N / 400 PVSK titer)

In addition to the above (A) and (B), the polymer flocculant (P) of the present invention is an antifoaming agent that is usually used for the polymer flocculant as long as it does not inhibit the effects of the present invention. An additive selected from the group consisting of a chelating agent, a pH adjusting agent, a surfactant, an antiblocking agent, an antioxidant, an ultraviolet absorber and a preservative can be contained.
From the viewpoint of flock strength, the total content of the additives is preferably 30% or less, more preferably 10% or less, based on the total weight of (A) and (B).

The method for adding the polymer flocculant (P) of the present invention to sludge or wastewater is not particularly limited, and examples thereof include the methods described in Japanese Patent No. 13111340 or Japanese Patent No. 2038341.
The amount of the polymer flocculant (P) of the present invention varies depending on the type of sludge or waste water, the content of suspended particles, the molecular weight of the polymer flocculant, etc., but there is no particular limitation, and evaporation in the sludge or waste water Based on the weight of the residue (hereinafter abbreviated as TS), usually 0.01 to 10%. From the viewpoint of agglomeration performance, the lower limit is preferably 0.1%, more preferably 0.5%, particularly preferably 1%. From the viewpoint of cost, the preferable upper limit is 5%, more preferably 3%, and particularly preferably 2%.

As a method of using the polymer flocculant (P) of the present invention, it is preferable to make it into an aqueous solution from the viewpoint of sufficient flocculation performance and then add it to sludge or wastewater. However, (P) is directly added to sludge or wastewater in a solid state. It can also be added. The concentration when (P) is used as an aqueous solution is preferably 0.05 to 1% by weight from the viewpoint of handling and dissolution rate.
The method for dissolving (P) is not particularly limited. For example, a predetermined amount of (P) is gradually added while stirring water previously weighed using a stirring device such as a jar tester, and several hours. A method of dissolving over about 2 to 4 hours can be employed. When powdered (P) is dissolved in water, the method of adding a predetermined amount of (P) at a stretch is undesirably resulting in undesired dissolution and difficulty in completely dissolving in water.

  When the polymer flocculant (P) of the present invention is used for tertiary recovery of petroleum, it is usually used as an aqueous solution. The concentration (% by weight) of (P) is usually from 0.001 to 3%, preferably from 0.005 to 1%, more preferably from 0.01 to 0. 5%.

  The polymer flocculant (P) of the present invention may be used in combination with another polymer flocculant (Q) other than (P) from the viewpoint of improving the agglomeration performance (floc strength, filtration rate, etc.). . The (Q) includes a polymer flocculant described in Japanese Patent Application No. 2011-55783. The (Q) is an unsaturated monomer containing a water-soluble unsaturated monomer whose essential monomer is a water-soluble unsaturated monomer having a tertiary amine base or a quaternary ammonium base with a halogen ion as a counter ion. It is a polymer flocculant containing a water-soluble polymer obtained by radical polymerization in the presence of a saturated aliphatic polycarboxylic acid having one carboxyl group and / or a salt thereof.

As a method of using (P) and (Q) in combination, each of the prepared powdery (P) and (Q) is mixed in advance, dissolved in water and added to sludge or waste water, and (P) After preparing each aqueous solution of (Q), these are added to sludge or wastewater (P), (Q) almost simultaneously, (P) is added and after the primary treatment, (Q) is added 2 Examples include a sequential addition method in which the next treatment is performed, or (Q) is added and the first treatment is performed, and then (P) is added and the second treatment is performed.
Among these methods, from the viewpoint of improving the agglomeration performance (floc strength, filtration speed, etc.), powdery (P) and (Q) are preferably mixed in advance, dissolved in water, and added to sludge or wastewater. Is the method.

  When (P) and (Q) are used in combination, the amount of (Q) used is usually 90% or less based on the total weight of (P) and (Q). From this viewpoint, it is preferably 5-70%, more preferably 10-30%.

When the polymer flocculant (P) of the present invention is applied to sludge or wastewater, when the sludge or wastewater is organic sludge or anaerobic bacteria-treated sludge, inorganic and / or from the viewpoint of charge neutralization of sludge particles. Or it is preferable to use an organic coagulant together.
Inorganic coagulants include sulfuric acid band, polyaluminum chloride, ferric chloride, ferric sulfate, polyiron sulfate, slaked lime, etc .; organic coagulants include aniline-formaldehyde polycondensate hydrochloride, polyvinylbenzyltrimethylammonium chloride , Dimethyldi (meth) allyl ammonium chloride, (meth) allylamine or di (meth) allylamine-maleic acid copolymer, (meth) allylamine or di (meth) allylamine-citraconic acid copolymer, (meth) allylamine or di ( Examples include (meth) allylamine-itaconic acid, (meth) allylamine, di (meth) allylamine-fumaric acid copolymer, and the like.
When an inorganic and / or organic coagulant is used in combination, the sludge or wastewater is treated with a mixture obtained by adding these to the polymer flocculant (P) of the present invention in advance, or the inorganic coagulant and / or the sludge or wastewater is previously treated. After the organic aggregating agent is added for primary agglomeration, the polymer aggregating agent (P) of the present invention may be added for treatment, but the latter method is preferable from the viewpoint of floc strength.

  The amount used in combination with an inorganic coagulant and / or organic coagulant varies depending on the type of sludge or wastewater, the size of suspended particles, the type of coagulant used, etc., but there is no particular limitation. Sludge or wastewater Based on TS, the inorganic coagulant is usually 20% or less, preferably 0.5% from the viewpoint of setting performance, more preferably 1%, particularly preferably 1.5%, and the upper limit preferable from the viewpoint of setting performance. 10%, more preferably 5%, and particularly preferably 3%. In the case of an organic coagulant, it is usually 1% or less, and a preferable lower limit from the viewpoint of setting performance is 0.01%, more preferably 0.025%, particularly preferably. The upper limit is preferably 0.5%, more preferably 0.2%, and particularly preferably 0.15% from the viewpoint of setting performance of 0.05%.

When adding the polymer flocculant (P) of the present invention, the pH of sludge or waste water may be adjusted in advance. The pH adjustment range is usually from 3 to 8, the lower limit preferable from the viewpoint of hydrolysis prevention is 3.5, more preferably 4, particularly preferably 4.5, and the upper limit preferable from the viewpoint of solubility is 7, more preferably 6. Particularly preferred is 5.5.
The pH adjustment method is not particularly limited, and an acidic substance such as inorganic acid (sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, etc.) or an alkaline substance such as caustic alkali (sodium hydroxide, potassium hydroxide, etc.) is used. The method to use is mentioned. Moreover, it can also adjust to the said pH by previously adding the said inorganic or organic coagulant to sludge or wastewater.

  In addition, as a dehydration method (solid-liquid separation method) of floc formed by adding the polymer flocculant (P) of the present invention to sludge or wastewater, centrifugal dehydration, filter press dehydration, belt press dehydration, screw press dehydration Various dehydration methods such as capillary dehydration can be applied. Among these, screw press dewatering and belt press dewatering are preferable from the viewpoint of high floc strength, which is a specific aggregating performance of the polymer flocculant (P) of the present invention.

  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 composition, symbols, etc. of the raw materials used in the examples and comparative examples are as follows.
(1) Water-soluble unsaturated monomer (a)
(A-1): Methyl chloride salt of N, N-dimethylaminoethyl methacrylate
80% aqueous solution of (a-2): methyl chloride salt of N, N-dimethylaminoethyl acrylate
(A-3): 50% aqueous solution of acrylamide (a-4): Acrylic acid (2) Aromatic ring-containing carboxylic acid and / or salt thereof (B)
(B1-1): sodium salt of trimellitic acid (B1-2): phthalic acid (B1-3): sodium salt of pyromellitic acid (B1-4): 4-hydroxybenzoic acid (B3-1): 2 , 3-Anthracene dicarboxylic acid sodium salt (B3-2): Octacarboxyphthalocyanine sodium salt (3) Chain transfer agent (f)
(F-1): 1% aqueous solution of 1-thioglycerol (f-2): 1% aqueous solution of ethylene glycol-di-2-mercaptoethyl ether (f-3): 1% aqueous solution of sodium hypophosphite f-4) 2-Aminobenzenethiol

(4) Radical polymerization initiator (d)
(D-1): Azobisamidinopropane hydrochloride [manufactured by Wako Pure Chemical Industries, Ltd., “V-
50 ”, 10 hour half-life temperature: 56 ° C.] (d-2): 4,4′-azobis (4-cyanopentanoic acid) [manufactured by Wako Pure Chemical Industries, Ltd.,
10% aqueous solution (water) of “V-501”, 10 hour half-life temperature: 69 ° C.
Adjusted to pH 7.0 with aqueous sodium oxide solution. )
(D-3): 1% aqueous solution of hydrogen peroxide (d-4): 1% aqueous solution of ascorbic acid (d-5): 1% aqueous solution of iron (II) sulfate (d-6): Dicumylper Oxide

(5) Hydrophobic dispersion medium (b)
(B-1): n-decane (6) Dispersant (c)
(C1-1): Distearic acid ester of PEG (Mn300) [trade name “IONET DS-300”, manufactured by Sanyo Chemical Industries, HLB6.6, Mw700]
(C2-1): Dispersant (HLB2.1, Mw15,000) obtained in Production Example 1 described later

The string length and the solid content were evaluated by the above methods, and the other items were evaluated by the following methods.
In addition, the evaporation residue weight (TS), suspended solids (SS), organic content (loss on ignition), and alkalinity in sludge or wastewater are analyzed according to “Sewage Test Method” (Japan Sewerage Association, 1984 version). It carried out according to the method.

(1) 0.2% aqueous solution viscosity (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. 499 g of exchange water is added, and a polymer flocculant sample having a solid content of 1.0 g is gradually added with stirring at 300 rpm at a water temperature of 20 to 25 ° C., and completely dissolved over 3 hours. Thereafter, a part of the obtained aqueous solution 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. Then, a B-type viscometer [model “TV-10M”, Toki Sangyo Co., Ltd. ) Made the same below. ], The value 300 seconds after the start of measurement at 30 rpm with an M2 rotor is defined as the 0.2% aqueous solution viscosity.

(2) 0.5% salt aqueous solution viscosity (mPa · s, 25 ° C.)
Using the same stirrer as described above, 477.5 g of ion-exchanged water was put into a 500 mL beaker, and a polymer flocculant sample having a solid content of 2.5 g was gradually added while stirring at 200 rpm at a water temperature of 20 to 25 ° C. Dissolve completely over time. 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.

(3) Water solubility The total amount of the aqueous solution (W5) prepared when the above 0.5% salt aqueous solution viscosity was measured was transferred to a sieve (mesh size 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, the moisture adhering to the sieve frame was wiped off with a cloth, the weight (W4) was measured, and the amount of water insoluble was calculated from the following formula.

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

Based on the water-insoluble amount determined from the above formula, water solubility was 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 ≦ 6%)
× Bad (6% <water insoluble matter)

(4) 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 rotational speed is changed to 650 rpm, and the mixture is further stirred for 30 seconds, and then the stirring is stopped and the particle diameter (mm) of the formed floc is again visually observed.

(5) Flock strength The floc particle sizes at the rotation speeds of 300 rpm and 650 rpm in the above (3) are 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)

(6) Liquid volume after 10 seconds, liquid volume behind 60 seconds (ml)
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 filtered at once on the Nutsche filtration surface, and the amount of filtrate that has passed from 10 seconds to 60 seconds after the addition is measured using a stopwatch. To do.

(7) Filter cloth peelability A part of the filtered sludge is removed with a spatula and subjected to a dehydration test (1 kg / cm ² , 60 seconds) using a press filter tester, and the dehydrated cake adhered to the filter cloth after the test is obtained. The peelability of the dehydrated cake when peeled with a spatula is evaluated according to the following criteria.
<Evaluation criteria>
A: Very easy to peel off (no deposit on the filter cloth)
○: Easy to peel off (Slight deposits on filter cloth)
△: Slightly difficult to peel off (There are deposits on the filter cloth, and there are deposits slightly inside the filter cloth.)
×: Hard to peel off (There are many deposits even inside the filter cloth)

(8) Moisture content of dehydrated cake (%)
About 3 g of the dehydrated cake after the filter cloth peelability test of (7) above was weighed (W6) in a petri dish, dried in a circulating air dryer at 105 ± 5 ° C. for 8 hours, and then left on the petri dish. Using the weight of the dry cake as (W7), the moisture content of the cake is calculated from the following equation.

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

Production Example 1 [Production of Dispersant (c2-1)]
In a stainless steel autoclave, ethylene / vinyl acetate copolymer [trade name “AC-POLY-400”, manufactured by Honeywell, vinyl acetate unit content 14%] 171 parts, maleic anhydride 17.1 parts, xylene 117. 7 parts were charged and heated to 100 ° C. to obtain a uniform solution to prepare a polymer solution. In another container, 11.8 parts of a polymerization initiator (d-6), 11.8 parts of xylene, and 0.092 parts of n-dodecanethiol were charged and uniformly mixed to obtain an initiator solution.
The above initiator solution is added to the polymer solution heated to 150 ° C. at a dropping rate of 0.4 part / minute (where “part” is replaced with “g” to indicate g / minute) over 1 hour. Then, after reacting at the same temperature for 3 hours, xylene was stripped at 140 to 160 ° C. for 2 hours under a reduced pressure of 3 to 20 kPa to obtain a dispersant (c2-1) (maleic anhydride-modified ethylene. Vinyl acetate copolymer) was obtained.

Example 1 [Production of polymer flocculant (P-1)] (aqueous solution polymerization)
According to Table 1, a reaction vessel equipped with a stirrer was charged with (a), (B), a buffering agent and ion-exchanged water and mixed and stirred as an aqueous phase (1) until uniform. Under stirring, the pH (20 ° C.) of the aqueous phase (1) was adjusted to 3.0 using sulfuric acid while monitoring with a pH meter.
Next, the solution temperature was adjusted to 5 ° C. in a constant temperature water bath at 0 ° C., and the system was sufficiently substituted with nitrogen (purity 99.999% or more) (gas phase oxygen concentration of about 5 ppm). Then, based on Table 1, radical polymerization initiators (d-1), (d-3), (d-4), (d-5) and a chain transfer agent (f-1) were used as the aqueous phase (2). About the added monomer aqueous solution formulation, polymerization is started at a solution temperature of 5 ° C., the temperature of the solution rises due to heat generated by the polymerization, and when the solution temperature reaches 70 ° C., the reaction vessel is placed in a 90 ° C. constant temperature bath. The mixture was kept warm for 10 hours to complete the polymerization. During the polymerization, the contents became highly viscous and stirring was difficult, so stirring was stopped midway.
Thereafter, the obtained hydrogel was taken out, mixed and kneaded by a meat chopper machine [model number “12VR-400K”, manufactured by ROYAL Co., Ltd., mesh opening 6 mm], and further minced into 80 ° C. Powdery polymer flocculant comprising water-soluble polymer (A-1) and aromatic ring-containing carboxylate [sodium salt of trimellitic acid (B1-1)] after drying with hot air for 2 hours and pulverizing with a juicer mixer 920 parts of (P-1) were obtained (yield 92%, solid content 95%). The evaluation results are shown in Table 1.

Examples 2 to 12, Comparative Examples 1 to 3 [Production of polymer flocculants (P-2) to (P-12), (RP-1) to (RP-3)]
In Example 1, each polymer flocculant was obtained in the same manner as in Example 1 except that the monomer aqueous solution formulation was replaced with the monomer aqueous solution formulation formulated according to Tables 1 and 2. The evaluation results of each polymer flocculant are shown in Tables 1-2.

Example 13 [Production of Polymer Flocculant (P-13)] (Reverse Phase Suspension Polymerization)
[First Step] According to Table 2, (a), (B) and a buffering agent were charged into a container, and an aqueous phase (1) was prepared at room temperature (20 to 25 ° C.). Further, the pH (20 ° C.) of the aqueous phase (1) was adjusted to 3.0 using sulfamic acid while monitoring with a pH meter. In a separate container, a polymerization initiator (d-1), a chain transfer agent (f-1) and ion-exchanged water were blended according to Table 1 to prepare an aqueous phase (2). The aqueous phases (1) and (2) were separately purged with nitrogen (purity 99.999% or more; the same shall apply hereinafter) and thoroughly substituted with nitrogen (dissolved oxygen concentration of 20 ppb or less).
Apart from these, in a reaction vessel equipped with a stirring blade (Max Blend blade), 1,770 parts of a hydrophobic dispersion medium (b-1), 21.3 parts of a dispersant (c1-1) and (c2-1) An oil phase was prepared by charging 5.3 parts. While stirring the stirring blade at a rotation speed of 340 rpm, the inside of the reaction vessel was replaced with nitrogen (gas phase oxygen concentration: 10 ppm or less), then heated to 80 ° C. and held for 30 minutes, and then to the polymerization temperature of 50 ° C. Cooled down. After reaching the polymerization temperature, the aqueous phases (1) and (2) are each fed at room temperature (20 to 25 ° C.) with a dropping pump under a pressure condition of 0.1 kPa and continuously mixed with a static mixer. The entire amount of the mixed solution (monomer aqueous solution) was dropped into the reaction vessel over 2 hours. Thereafter, stirring was continued at 50 ° C. for 2 hours to carry out reverse phase suspension polymerization.

[Second Step] Thereafter, 9 parts of the aqueous phase (2) prepared at the same mixing ratio was further added, and after 1 hour, 14 parts of sodium bisulfite and 0.19 parts of mercaptoacetic acid were dissolved in 10 parts of ion-exchanged water. The added aqueous solution was added, and the temperature of the reaction system was changed to 55 ° C. from the time of the addition, and stirring was continued for 30 minutes to complete the polymerization.
A slurry was obtained by azeotropic dehydration under reduced pressure (3 to 20 kPa). The slurry was supplied to a vacuum filter and subjected to solid-liquid separation, and then the solid content was dried in a vacuum dryer (1.3 kPa, 40 ° C. × 2 hours) to obtain a water-soluble polymer (A-13) and an aromatic ring. 960 parts of a polymer flocculant (P-13) which is a dry particle containing the containing carboxylate [sodium trimellitic acid salt (B1-1)] (yield 96%, solid content 95) %). The evaluation results of (P-13) are shown in Table 2.

Example 14 [Production of polymer flocculant (P-14)] [Production method (2) in which (B) is infiltrated into the water-containing gel of (A)]
In the production of the water-soluble polymer (A-1) of Example 1, mince-like chopping comprising a water-containing polymer (A-14) -containing gel in the same manner as in Example 1 except that (B) was not used. I got a thing. Thereafter, (M-14) sodium trimellitic acid salt (B1-1) and ion-exchanged water are blended based on Table 2 with respect to the total amount of the minced shredded product comprising the hydrous gel, and this is stirred. Then, it was dissolved uniformly to obtain a hydrous gel. Thereafter, the obtained hydrogel was dried in hot air at 80 ° C. for 2 hours in the same manner as in Example 1 and then pulverized with a juicer mixer to form a powder consisting of water-soluble polymers (A-14) and (B1-1). 890 parts of a polymer flocculant (P-14) was obtained (yield 88%, solid content 95%). The evaluation results of (P-14) are shown in Table 2.

Example 15 [Production of polymer flocculant (P-15)] [Production method (3) in which powder (B) is mixed with powder (A)]
In the production of the water-soluble polymer (A-1) of Example 1, a powdery water-soluble polymer (A-15) was obtained in the same manner as in Example 1 except that (B) was not used. Then, the powder of sodium salt of trimellitic acid (B1-1) is blended based on Table 2 with respect to the total amount of the powder (A-15), and mixed by the dry blend method to obtain (A-15) And 920 parts of a powdery polymer flocculant (P-15) composed of (B1-1) (yield 91%, solid content 95%). The evaluation results of (P-15) are shown in Table 2.

実施例１６〜３０、比較例４〜６［高分子凝集剤の性能評価］
得られた高分子凝集剤をそれぞれイオン交換水に溶解させて固形分含量０．２％の水溶液とした。Ａ市処理場から採取した消化処理した消化汚泥［ｐＨ７．４、ＴＳ２．９％、ＳＳ２．７％、有機分６５％、アルカリ度４，５４３ｍｇ−ＣａＣＯ₃／Ｌ］２００ｇを５００ｍＬのビーカーに採り、上記高分子凝集剤の各水溶液２０ｇ添加（この時の固形分添加量０．７％／ＴＳ）し、性能を評価した。結果を表３に示す。

Examples 16 to 30, Comparative Examples 4 to 6 [Performance evaluation of polymer flocculant]
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 digested digested sludge [pH 7.4, TS 2.9%, SS 2.7%, organic content 65%, alkalinity 4,543 mg-CaCO ₃ / L] collected from A city treatment plant is taken in a 500 mL beaker. Then, 20 g of each aqueous solution of the polymer flocculant was added (the amount of solid content added was 0.7% / TS at this time), and the performance was evaluated. The results are shown in Table 3.

  From Table 3, in Examples 16-30, compared to Comparative Examples 4-6, flocs having a large particle size were formed, and flocs once formed under low agitation (300 rpm) were broken even under high agitation (650 rpm). The polymer flocculant of the present invention is difficult (high flock strength), has a high initial filtration rate due to a large amount of liquid after 10 seconds, and exhibits an excellent effect in dewaterability (water content of dehydrated cake). It can be seen that (P) is extremely excellent in aggregation performance.

  Since the polymer flocculant of the present invention exhibits unprecedented specific flocculation performance, the polymer flocculant for dewatering sludge or wastewater, the polymer for improving the drainage yield in the papermaking process, or the paper strength enhancing polymer In addition to the flocculant, it is widely and suitably used as a polymer flocculant for flocculation and precipitation treatment of industrial wastewater, tertiary recovery of petroleum, etc. and is extremely useful.

Claims (8)

A polymer flocculant (P) comprising a water-soluble polymer (A) having a water-soluble unsaturated monomer (a) as a structural unit, and an aromatic ring-containing carboxylic acid and / or a salt thereof (B). The polymer flocculant according to claim 1, wherein (A) is a water-soluble polymer obtained by radical polymerization of the water-soluble unsaturated monomer (a) in the presence of (B). The polymer flocculant according to claim 1 or 2, wherein the number of carboxyl groups and / or bases in (B) is 2-6. The polymer flocculant according to any one of claims 1 to 3, wherein the content of (B) based on the total weight of the monomers constituting (A) is 0.1 to 10%. The polymer flocculant according to any one of claims 2 to 4, wherein (A) is a water-soluble polymer obtained by radical polymerization of (a) in the presence of a chain transfer agent (f). The polymer flocculant according to claim 5, wherein the amount of (f) used based on the total weight of the monomers constituting (A) is 0.0001 to 1%. (A) and (A), wherein the water-soluble unsaturated monomer (a) is radically polymerized into a water-soluble polymer (A) in the presence of an aromatic ring-containing carboxylic acid and / or a salt thereof (B). A method for producing a polymer flocculant (P) containing B). A method for treating sludge or wastewater, wherein the polymer flocculant (P) according to any one of claims 1 to 6 is added to and mixed with sludge or wastewater to form a floc, and solid-liquid separation is performed.