JP2015057276A - Polymer flocculant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer flocculant capable of forming floc reducing the water content of a dewatered cake.SOLUTION: A polymer flocculant including a water-soluble (co)polymer where a water-soluble unsaturated monomer containing a water-soluble cationic monomer represented by general formula (1): CH=C(CH)-CO-X-Q-NRRRZ(1) is a constitutional unit and a salt represented by general formula (2): X-NRRRY(2) and having a salt content based on the weight of the water-soluble (co)polymer of 1-20% and a treating method of sludge and waste water where the polymer flocculant is added and mixed in the sludge and the waste water, floc is formed and solid-liquid separation is performed are provided.

Description

  The present invention relates to a polymer flocculant. More specifically, the present invention relates to a polymer flocculant for sludge or wastewater treatment having excellent dewaterability.

  Conventionally, it is water-soluble as a treatment agent for sludge treatment such as sewage, wastewater treatment, mud treatment at civil engineering sites, and for promoting sedimentation and separation of muddy water at the time of reclamation, and also as a paper-making dehydrating agent and paper strength enhancer. Polymer flocculants made of polymers are widely used. Especially in recent years, the need to improve the speed of dewatering treatment has increased due to an increase in the amount of sludge generated, etc., and the cost of incineration of dewatered cake has increased due to the difficulty of dewatering the properties of organic sludge. From the tight situation of the landfill site when the landfill is disposed of as it is, there is a strong demand for a polymer flocculant capable of forming a stronger, coarser floc and greatly reducing the moisture content of the dehydrated cake. . In order to form stronger and coarser flocs, for example, cross-linked polymers (see, for example, Patent Documents 1 and 2) have been proposed.

JP 2004-255378 A JP 2001-129511 A

However, in the polymer flocculants described in Patent Documents 1 and 2, although the floc formed is somewhat strong, the moisture content of the cake is insufficient, and further reduction of the moisture content of the dehydrated cake is desired. It was.
An object of the present invention is to provide a polymer flocculant that forms flocs that reduce the water content of a dehydrated cake.

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 relates to a water-soluble (co) polymer (A) having a water-soluble unsaturated monomer (a) containing a water-soluble cationic monomer (a1) represented by the following general formula (1) as a structural unit: A polymer flocculant (P) comprising a salt (B) represented by the following general formula (2), wherein the content of (B) based on the weight of (A) is 1 to 20% ).

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

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

X ² −N ⁺ R ⁴ R ⁵ R ⁶ · Y ⁻ (2)

[Wherein X ² is a monovalent hydrocarbon group having 1 to 5 carbon atoms which may have a hetero atom, R ^{4 to} R ⁶ are H, and Y ⁻ is a residue other than H ⁺ of a protonic acid. Represent. ]

The polymer flocculant (P) of the present invention has the following effects.
(1) Form coarse and strong flocs (2) Good flocculation performance and increase in the amount of filtrate, thus improving the dehydration speed.
(3) Since the moisture content of the dehydrated cake is low, the amount of generated waste and incineration costs can be greatly reduced.

[Water-soluble (co) polymer (A)]
The water-soluble (co) polymer (A) in the present invention has a water-soluble unsaturated monomer (a) containing a water-soluble cationic monomer (a1) represented by the following general formula (1) as a structural unit. (Co) polymer.
Here, 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 1 -Q-N + R 1 R 2 R 3 · Z - (1)

In the general formula (1), R ^{1 to} R ³ are H, X ¹ is O or NH, and Q is an alkylene group having 1 to 4 carbon atoms (such as methylene, ethylene, and propylene groups). If the number of carbon atoms of the alkylene group (hereinafter sometimes abbreviated as C) exceeds 4, the solubility in water becomes poor.
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.) salt, etc.], and mixtures thereof.
(A11) Nitrogen atom-containing methacrylate As the nitrogen atom-containing methacrylate, those having C5-8, such as aminomethyl methacrylate, aminoethyl methacrylate, aminopropyl methacrylate, aminobutyl methacrylate;

(A12) Nitrogen atom-containing methacrylamide As nitrogen atom-containing methacrylamide, C5-8, for example, aminomethyl methacrylamide, aminoethyl methacrylamide, aminopropyl methacrylamide, aminobutyl methacrylamide.

  Of these salts (a11) and (a12), the salt of (a11) is preferred from the viewpoint of the aggregation performance and polymerizability of the polymer flocculant (P) described later, and more preferred is aminoethylmeta Acrylate and aminopropyl methacrylate salts, particularly preferred are aminoethyl methacrylate salts. Further, among these salts, preferred are hydrochloride, sulfate and methanesulfonate, 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 (degree of polymerization 3 to 50), mono and (poly) glycerol (degree of polymerization 1 to 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, manufactured by Tosoh Corporation Column: TSKgel 2 GMHXL + TSKgel
Multipore HXL-M, manufactured by Tosoh Corporation Solvent: Tetrahydrofuran (THF)
Detection device: Refractive index detector Reference material: Standard polystyrene (TSKstandard
POLYSTYRENE), manufactured by Tosoh Corporation

  Among the water-soluble unsaturated monomers (a2), from the viewpoint of copolymerization of the water-soluble (co) polymer (A), (a211), (a22), (a231), (a232), Preferred among (a211), (a222), (a223), (a231), and (a232) is a sulfo group-containing (meth) acrylate, a sulfo group-containing (meth) acrylamide, and most preferred is (a211) N, N-dimethylaminoethyl (meth) acrylate salt, (meth) acrylamide in (a222), acrylonitrile in (a223), N-vinylformamide, (meth) acrylic acid in (a231) 2- (meth) acryloyl of (a232), (anhydrous) maleic acid, (anhydrous) itaconic acid and alkali metal salts thereof Oxy ethanesulfonic acid, 2- and 3- (meth) acryloyloxy-propanesulfonic acid, 2- (meth) acryloyl-2,2-dimethyl-ethane sulfonic acid and alkali metal salts thereof. Moreover, these (a2) can be arbitrarily mixed and copolymerized.

[Other monomers other than the water-soluble unsaturated monomer (a)]
As a monomer constituting the water-soluble (co) polymer (A), in addition to the water-soluble unsaturated monomer (a), a water-insoluble unsaturated monomer (x) may be used in combination as long as the effects of the present invention are not impaired. can do.
Examples of the water-insoluble unsaturated monomer (x) include the following (x1) to (x5) and mixtures thereof.

(X1) C6-23 (meth) acrylate (meth) acrylate of aliphatic or cycloaliphatic 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) [monoalkoxy (C1-20), monocycloalkoxy (C3-12) and monophenoxy] polypropylene glycol (polypropylene glycol is hereinafter abbreviated as PPG) [propylene oxide (hereinafter abbreviated as PO) added mole number 2 50] Unsaturated carboxylic acid monoester monool (C1-20) or monohydric phenol (C6-20) PO adduct (meth) acrylic acid ester [ω-methoxy PPG, ω-ethoxy PPG, ω-propoxy , Ω-butoxy PPG, ω-cyclohexoxy PPG and ω-phenoxy PPG mono (meth) acrylate, etc.], and (meth) of PO adducts of dihydric alcohol (C2-20) or dihydric phenol (C6-20) Acrylic ester [ω-hydroxyethyl (poly) oxypropylene Mono (meth) acrylate, etc.] or the like;

(X3) C2-30 unsaturated hydrocarbon ethylene, nonene, styrene, α-methylstyrene and the like;
(X4) carboxylic acid (C2-30) ester of unsaturated alcohol [C2-4, for example, vinyl alcohol, (meth) allyl alcohol] (vinyl propionate, etc.);
(X5) A halogen-containing monomer (C2-30, such as vinyl chloride).

  The content of each monomer based on the total number of moles of monomers constituting the water-soluble (co) polymer (A) is preferably 90% or more, more preferably water-soluble cationic monomer (a1) from the viewpoint of aggregation performance. 95 mol% or more; the water-soluble unsaturated monomer (a2) is preferably 10 mol% or less, more preferably 5 mol% or less from the viewpoint of aggregation performance and high molecular weight; the water-insoluble unsaturated monomer (x) is The amount is usually 5 mol% or less, and preferably 1 mol% or less from the viewpoint of aggregation performance and solubility of the polymer flocculant in water.

The water-soluble (co) polymer (A) is prepared by using a radical polymerization initiator (d) and, if necessary, a chain transfer agent for radical polymerization (c), the above monomers to form a known aqueous solution (for example, JP-A-55). Adiabatic polymerization, thin film polymerization, spray polymerization and the like described in JP-A-133413) and known reversed-phase suspension polymerization (for example, JP-B-54-30710, JP-A-56-26909, JP-A-1-5808). Various polymerization methods (including those described in Japanese Patent Publication No. 6-804), precipitation polymerization (such as those described in JP-A-61-123610), reverse phase emulsification And the like (for example, those described in JP-A-58-197398 and JP-A-9-276605).
Among the polymerization methods, aqueous solution polymerization, reverse phase suspension polymerization, photopolymerization and reverse phase emulsion polymerization are preferable from an industrial viewpoint, and aqueous solution polymerization and reverse phase suspension polymerization are more preferable.

  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 (azobisdimethylvaleronitrile). , Azobisisobutyronitrile, azobiscyclohexanecarbonitrile, etc.]] and peroxides [water soluble [peracetic acid, t-butyl peroxide, hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, etc.] And oil-soluble ones [benzoyl peroxide, cumene hydroxy peroxide, etc.].

Examples of the salt in the azo compound include inorganic acid (hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc.) salts and alkali metal (lithium, sodium, potassium, etc.) salts.
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].
Further, the azo compound, peroxide and redox initiator may be used alone or in combination of two or more.

Of the radical polymerization initiator (d), an azo compound is preferable from the viewpoint of reducing the water-insoluble content of the water-soluble (co) polymer (A) to be obtained.
From the viewpoint of obtaining the optimum molecular weight of (A), the preferred lower limit is 0.001% by weight, more preferably 0, based on the total weight of the monomers constituting (A). 0.005% by weight, particularly preferably 0.01% by weight, and a preferred upper limit is 1% by weight, more preferably 0.5% by weight, particularly preferably 0.1% by weight, and most preferably 0.05% by weight.

The chain transfer agent (c) for radical polymerization is not particularly limited. For example, a compound having one or more hydroxyl groups in the molecule [molecular weight of 32 or more and Mn of 50,000 or less, such as methanol, ethanol, isopropyl alcohol, ethylene glycol , Propylene glycol, polyethylene glycol (molecular weight of 100 or more and Mn 50,000 or less) and polyethylene polypropylene glycol (molecular weight of 100 or more and Mn 50,000 or less)], ammonia, a compound having one or more amino groups in the molecule [ For example, amines (C1-30, such as methylamine, dimethylamine, triethylamine and propanolamine)], compounds having one or more thiol groups in the molecule (described later), and (hypo) phosphite compounds [suboxides Re Acid, hypophosphorous acid, and salts thereof [alkali metal (Na, K, etc.) salts, and derivatives, etc.] and the like.
Among these, a compound having one or two or more thiol groups in the molecule is preferable from the viewpoint of controlling the molecular weight of (A).

  The compounds having a thiol group in the molecule include the following (1), (2), mixtures thereof and salts thereof [alkali metal (for example, lithium, sodium and potassium) salts, alkaline earth metals (for example, magnesium and calcium) Salt), ammonium salt, amine (C1-20) salt and inorganic acid (eg hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid) salt].

(1) Monovalent thiol Aliphatic thiol [C1-20, such as methanethiol, ethanethiol, propanethiol, n-octanethiol, n-dodecanethiol, hexadecanethiol, n-octadecanethiol, 2-mercaptoethanol, mercaptoacetic acid, 3-mercaptopropionic acid, 1-thioglycerol, thioglycolic acid monoethanolamine), 1-thioglycerol, thioglycolic acid monoethanolamine, thiomaleic acid, cysteine and 2-mercaptoethylamine], alicyclic thiols (C5-20) For example, cyclopentanethiol and cyclohexanethiol) and aromatic (aliphatic) thiols (C6-12, such as benzenethiol and benzyl mercaptan and thiosalicylic acid).

(2) polyvalent thiol dithiol [aliphatic (C2-40) dithiol (eg ethane dithiol, diethylene glycol dimercaptan, triethylene glycol dimercaptan, propanedithiol, 1,3- and 1,4-butanedithiol, 1,6- Hexanedithiol, neopentanedithiol, etc.), alicyclic (C5-20) dithiol (eg cyclopentanedithiol and cyclohexanedithiol) and aromatic (C6-16) dithiol (eg benzyl mercaptan, biphenyldithiol), trithiol (C3-20) For example, thioglycerin).

  The amount of the chain transfer agent for radical polymerization (c) used is usually 15% by weight or less based on the total weight of the polymerizable monomers constituting (A), the solubility of the polymer flocculant in water, the aggregation performance and From the viewpoint of obtaining an optimal molecular weight as (A), the preferred lower limit is 0.0001%, more preferably 0.0005%, particularly preferably 0.001%, most preferably 0.005%, and the preferred upper limit is 10%. %, More preferably 5%, particularly preferably 3%, most preferably 1%.

Among the production methods of the water-soluble (co) polymer (A), examples of the reverse phase suspension polymerization method include the following methods.
After the hydrophobic dispersion medium (e) and the dispersant (f) 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 tank The inside is sufficiently replaced with an inert gas (for example, nitrogen).
On the other hand, the water-soluble unsaturated monomer (a) containing the water-soluble cationic monomer (a1), the radical polymerization initiator (d), and optionally the radical transfer chain transfer agent (c), and the water-insoluble unsaturated monomer ( An aqueous monomer solution to which x) is added is prepared and sufficiently substituted with an inert gas, and then charged into a polymerization vessel 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 (c) and / or (x) added as necessary, or a separate aqueous solution, which is mixed immediately before dropping. Alternatively, they may be dropped simultaneously at the same time. 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.

The hydrophobic dispersion medium (e) means a dispersion medium having a solubility in water (20 ° C.) of less than 1 g / 100 g of water, and includes the following.
(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) and the like;
(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 (e) used is preferably 25%, more preferably 40%, particularly preferably 65% based on the total weight of the aqueous monomer solution from the viewpoint of the stability of the dispersion. From the viewpoint, the upper limit is preferably 1,000%, more preferably 400%, and particularly preferably 200%.

As the dispersant (f), from the viewpoint of controlling the dispersion stability of the reversed-phase suspended particles and the powder flowability of the resulting polymer flocculant, preferably HLB (Hydrophile-Lipophile Balance) is 1 to 8, More preferably, various oil-soluble substances of 2 to 7, particularly preferably 3 to 5, are mentioned. Here, HLB represents a balance between hydrophilicity and lipophilicity, and is determined from the following formula ("Surfactant Synthesis and Its Application", page 501, published by Tsuji Shoten in 1957; "Introduction to Surfactants", 212-213, 2007, published by Sanyo Kasei Kogyo, 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.

  In (f), weight average molecular weight [hereinafter abbreviated as Mw. The measurement is based on the GPC method under the above conditions. ] Is less than 5,000 (more preferably from 100 to 3,000, particularly preferably from 100 to 1,000), and a low molecular dispersant (f1), and Mw is 5,000 or more (more preferably from 7,000 to 1). , 1,000,000, particularly preferably 10,000 to 100,000) of the polymer dispersant (f2).

  (F1) includes fatty acid (C10-30) esters of polyhydric (2-8 or more) alcohols [sucrose fatty acid esters (C22-120, such as sucrose distearate, sucrose tristearate), sorbitan fatty acid esters (C16-120, eg sorbitan monostearate, sorbitan monooleate), (poly) glycerin fatty acid ester (C12-120, eg glycerin monostearate), PEG fatty acid ester [Mw 100-less than 5000, eg monostearate of PEG Rate] and the like, and alkyl (C1-30) allyl ether and the like.

  Of the above (f1), from the viewpoints of preventing polymer particle adhesion to the apparatus during production and the powder flowability of the polymer flocculant, fatty acid esters of polyhydric alcohols are preferred, and sucrose fatty acid esters are more preferred. Sorbitan fatty acid ester and PEG fatty acid ester.

  (F2) includes a copolymer of alkene and 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 ethers (for example, ethyl cellulose, ethyl hydroxyethyl cellulose), ethylene / vinyl acetate copolymers, and ethylene / vinyl acetate copolymers modified with maleic anhydride.

In using the dispersant (f), it is preferable to use (f1) and (f2) in combination from the viewpoints of dispersion stability of the reversed-phase suspended particles, powder flowability of the polymer flocculant, and particle size distribution. From the same viewpoint, the weight ratio [(f1) / (f2)] is preferably 70/30 to 1/99, more preferably 50/50 to 5/95.
When (f1) and (f2) are used in combination, a preferred 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, more preferably a PEG fatty acid. This is a combination of an ester and a maleic anhydride-modified ethylene / vinyl acetate copolymer.

  The amount of (f) used is usually 20% by weight or less based on the weight of the hydrophobic dispersion medium (e), the stability of the reversed phase suspension particles, the powder flowability of the polymer flocculant and the particle size control. From the viewpoint, it is preferably 0.01 to 10% by weight, more preferably 0.05 to 5% by weight.

  The lower limit of the monomer concentration (% by weight) in the aqueous polymerizable monomer solution is usually 30%, preferably 40%, more preferably 45%, particularly preferably 50%, most preferably 55%, and the upper limit. Is usually 90%, preferably 85%, more preferably 80%, particularly preferably 75%, most preferably 70% from the viewpoint of polymerization temperature control.

The lower limit of the polymerization temperature is usually 10 ° C., 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. to prevent thermal degradation of the polymer. From the viewpoint, 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 calorific value of 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 pressure at the time of polymerization (unit: kPa, hereinafter referred to as absolute pressure) is not particularly limited, but in the case of reverse phase suspension polymerization, it is preferable that the dispersion is preferably performed at the polymerization temperature from the viewpoint of easy temperature control during the polymerization. A pressure at which the medium boils or a pressure at which the hydrophobic dispersion medium and water azeotrope is preferable. Specifically, the preferred lower limit is 5 kPa, more preferably 12 kPa, particularly preferably 25 kPa, and the preferred upper limit is 95 kPa, more preferably 80 kPa, and particularly preferably 65 kPa.

  The pH of the aqueous monomer solution at the time of polymerization is not particularly limited, but is preferably 0.5 to 7, more preferably 1 to 6, particularly preferably 1. from the viewpoint of the polymerization rate and the solubility of the resulting water-soluble polymer. 5-5.

  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.

  Viscosity of 0.5% by weight aqueous salt solution of (A) of 0.2% by weight aqueous solution of water-soluble (co) polymer (A) (unit: mPa · s, 25 ° C., hereinafter referred to as Vw) ( The ratio [Vw / Vs] to the unit: mPa · s, 25 ° C., hereinafter referred to as Vs) is preferably 6 to 35, more preferably 9 to 25, particularly from the viewpoint of reducing floc strength and cake moisture content described later. Preferably it is 12-20.

  The following hypothesis was made about the relationship between Vw / Vs and aggregation performance. That is, Vw / Vs indicates molecular shrinkage in salt water, and when the polymer chain is excessively shrunk, it is difficult to neutralize the charge on the sludge particle surface, and flocs with low strength are formed and the water content is low. When the polymer chain is excessively spread, the charge on the sludge particle surface is neutralized, but it is presumed that a floc containing a lot of water is formed at the time of agglomeration and the water content becomes high. Therefore, it is a hypothesis that the polymer chain has an appropriate spread when the polymer chain has an appropriate spread.

Vw 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.

The Vs of the water-soluble (co) polymer (A) in the present invention indicates the viscosity of a 0.5 wt% water-soluble (co) polymer (A) salt aqueous solution (the salt water is 4 wt% sodium chloride aqueous solution). Measured by method.
(1) Preparation of measurement sample (0.5 wt% salt aqueous solution) Preliminarily weigh 2.5 g of sample (converted to solid content), and take about 470 g of ion-exchanged water in a 500 ml glass beaker. Stir at the speed of 200 rpm with the same stirrer. A sample is added, and ion-exchange water is added so that the total weight (total weight of the sample and ion-exchange water) is 480 g, followed by stirring for 4 hours. When the mixture is stirred for 4 hours, 20 g of sodium chloride is added, and the mixture is further stirred for 30 minutes to prepare a 0.5 wt% salt aqueous solution.
The method for obtaining the solid content of the water-soluble (co) polymer (A) is the same as in the case of Vw.

(2) Measurement of viscosity Transfer a part of the aqueous solution prepared in (1) to a 200 ml tall beaker, adjust the temperature to 25 ° C. in a water bath, rotate the rotor at 60 rpm with a Brookfield viscometer with a rotor guard, The viscosity is measured 5 minutes after the start of rotation. The rotor number used is changed according to the measurable viscosity range of the instrument.

  The above Vs is controlled by the weight ratio of the chain transfer agent for radical polymerization (c) used at the time of polymerization to the weight of all monomers constituting (A), and Vs decreases as the weight ratio of (c) increases. Therefore, increasing Vw / Vs can be controlled by increasing (c), and conversely, decreasing Vw / Vs can be controlled by decreasing (c).

  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.

  Vs of the water-soluble (co) polymer (A) is preferably 1 to 100, more preferably 3 to 30, particularly preferably 5 to 5 from the viewpoints of aggregation performance and reactivity with suspended particles in sludge and the like. 14.

The salt water insoluble content of the water-soluble (co) polymer (A) is preferably 50 g or less, more preferably 30 g or less.
In the present invention, the salt water insoluble matter of (A) indicates the weight (g) of the solid content remaining on the wire mesh after filtering the 0.5 wt% salt aqueous solution with a wire mesh of 180 μm, and is measured by the following method. The
(1) Salt water insoluble matter (unit: g) [Evaluation of solubility in water]
The total amount of the liquid (about 500 g) prepared for the measurement of Vs was transferred onto a stainless steel sieve having an opening of 180 μm whose empty weight (W1) was measured in advance, and the residue on the sieve was washed with running water (5000 cm ^3). / Min), water droplets adhering to the sieve are wiped off, the weight (W2) of the whole (the sieve + solid content on the sieve) is measured, and the insoluble matter is calculated from the following formula.

Salt water insoluble matter (g) = (W2)-(W1)

[Salt (B)]
The salt (B) in the present invention is represented by the following general formula (2).

X ² −N ⁺ R ⁴ R ⁵ R ⁶ · Y ⁻ (2)

In the general formula (2), X ² is a C1-5 (preferably C2-3) monovalent hydrocarbon group which may have a hetero atom, R ^{4 to} R ⁶ are H, and Y ⁻ is a protonic acid. Represents a residue excluding H ⁺ of The X ² is less than C1, poor cake moisture content (dewatering), greater than C5 When hydrophilicity is lowered, aggregation ability is poor.

The salt (B) is not particularly limited, but from the viewpoint of the aggregation performance of the polymer flocculant (P) described later, a primary composed of a primary amine (b1) having X ² and a protonic acid (b2). Amine protonic acid salts are preferred.

Examples of the primary amine (b1) having X ² include the following (b11) to (b14).

(B11) alkylamines such as methylamine, ethylamine;
(B12) hydroxyalkylamines such as monoethanolamine, monopropanolamine, monoisopropanolamine;
(B13) alkoxyalkylamines such as methoxyethylamine;
(B14) Alkylthioether alkylamine For example, methylthioethylamine.

  Of the above (b1), from the viewpoint of the aggregation performance of (P), (b11) and (b12) are preferable, (b12) is more preferable, and monoethanolamine is particularly preferable.

Y ⁻ in the general formula (2) is a residue obtained by removing H ⁺ of the protonic acid from the protonic acid (b2). Examples of the protonic acid (b2) include the following (b21) to (b26). It is done.

(B21) inorganic acids such as hydrogen halides (eg HF, HCl, HBr and HI), sulfuric acid, nitric acid and phosphoric acid;
(B22) sulfate ester, for example, C1-3 alkyl or alkenyl sulfate esters (eg, methyl sulfate, ethyl sulfate, propyl sulfate);
(B23) Sulfonic acid, for example, C1-3 alkyl or alkenyl sulfonic acids (for example, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid);

(B24) Phosphate ester For example, C1-3 alkyl or alkenyl phosphate ester (eg, methyl phosphate ester, ethyl phosphate ester, propyl phosphate ester);
(B25) Phosphonic acid, for example C1-3 alkyl or alkenyl phosphonic acids (for example methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid);
(B26) Carboxylic acid For example, C1-3 alkyl or alkenyl carboxylic acid (for example, acetic acid, propionic acid).

  Of the above (b2), from the viewpoint of the aggregation performance of (P), (b21) and (b23) are preferable, sulfuric acid and sulfonic acid are more preferable, and methanesulfonic acid is particularly preferable.

  Among the salts (B), from the viewpoint of the aggregation performance of (P), ethylamine sulfate, ethylamine methanesulfonate, monoethanolamine sulfate, monopropanolamine sulfate, monoethanolamine methanesulfonate, Monopropanolamine methanesulfonate, more preferably monoethanolamine methanesulfonate.

[Polymer flocculant (P)]
The polymer flocculant (P) of the present invention comprises the water-soluble (co) polymer (A) and the salt (B). The content of the salt (B) based on the weight of the (A) is 1 to 20%, preferably 3 to 15%, more preferably 5 to 9%. If it is less than 1%, the moisture content of the dehydrated cake is inferior, and if it exceeds 20%, the agglomeration performance by the water-soluble (co) polymer (A) is inferior, and the flocs are liable to collapse.
Although it is a hypothesis that the polymer flocculant (P) exhibits remarkable flocculation performance, it is considered that the specific amount of salt (B) interacts with sludge or waste water suspended particles. .
Further, by polymerizing the water-soluble unsaturated monomer (a) in the presence of a specific amount of the salt (B), the molecular weight distribution of the water-soluble (co) polymer (A) in the polymer flocculant (P), It is presumed that the polymer chain spread is more suitable.

  The salt (B) may be contained either during production of the water-soluble (co) polymer (A) (for example, an aqueous monomer solution) or after production of (A). From the industrial viewpoint and the viewpoint of the cohesive performance of (P), the method of incorporating (A) is preferable.

The content (α) of the salt (B) based on the weight of (A) can be determined, for example, by the following method.
[1] In a 500 mL glass container, 250 g of methyl ethyl ketone is added to 5.0 g of the polymer flocculant (P), and a magnetic stirrer [Mighty Stirrer Power Type HE-16GB, manufactured by Koike Seimitsu Seisakusho] is used at room temperature for 30. Stir for 5 minutes at 500 rpm.
[2] The entire content is pressure filtered to obtain a filter cake (β) and a filtrate (γ).
[3] Transfer the entire amount of the filter cake (β) to a stainless steel container. Next, (A) is isolated by drying at 100 ° C. for 5 hours with a circulating drier, and the weight (Wβ) of (A) in (P) is precisely weighed.
[4] Transfer the entire amount of the filtrate (γ) to a stainless steel container. Next, the salt (B) is isolated by drying at 100 ° C. for 5 hours with a circulating dryer, and the weight (Wγ) of the salt (B) in (P) is precisely weighed.
[5] The content (α) of the salt (B) based on the weight of (A) is calculated according to the following formula (unit: wt%).

(Α) = (Wγ) × 100 / (Wβ)

  In addition to (A) and (B), the anti-foaming agent, chelating agent, and pH adjuster that are usually used for the polymer flocculant as long as the effects of the present invention are not impaired as necessary. An additive selected from the group consisting of a surfactant, an anti-blocking 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 in which (A) and (B) and these additives are stirred and mixed at room 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 a specific agglomeration effect that has not existed in the past, it is a polymer for dewatering treatment of sludge such as sewage, organic sludge generated by treatment of factory wastewater, and inorganic sludge. 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 exerted, a cationic water-soluble (co) polymer is more preferable.
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 form of the polymer flocculant (P) of the present invention is in the form of powder (for example, crushed, true spherical and kitchen), film, aqueous solution, water-in-oil (w / o) emulsion and suspension. Or any other known form.

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, a predetermined amount of powdered (P) is added while stirring a pre-weighed water using a stirring device such as a jar tester, and several hours. 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 Vw and Vs of the water-soluble (co) polymer (A) and the solid content of the polymer flocculant (P) were 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 floc particle diameter, filtrate amount, filter cloth peelability, and cake moisture content in this example were evaluated according to the following methods.

(1) Flock particle size (unit: mm)
Jar tester [Miyamoto Riken Kogyo Co., Ltd., Model JMD-6HS-A] with two plate-shaped PVC stirring blades (diameter 5 cm, height 2 cm, thickness 0.2 cm) up and down to form a cross It was continuously attached to a stirring rod, 200 g of sewage sludge and the like were taken in a 500 ml beaker and set in a jar tester. While rotating the jar tester at 120 rpm and slowly stirring sewage sludge, etc., a predetermined amount of 0.2% polymer flocculant aqueous solution was added at once, stirred for 30 seconds, and then the stirring was stopped and the size of the aggregates Was measured visually.
Subsequently, the number of revolutions was set to 300 rpm, and after stirring for 30 seconds, stirring was stopped and the size of the aggregate was visually measured again.

(2) Filtrate (unit: mL)
T-1189 nylon filter cloth [Shikishima Kanbusu Co., Ltd., circular shape, diameter 9 cm], Nutsche funnel, graduated cylinder that can measure 300 ml, set sludge after the above floc particle size test and filter at once Then, using a stopwatch, the amount of filtrate after 60 seconds from immediately after the addition was measured to evaluate the treatment speed.

(3) Filter cloth peelability A part of the filtered material on the filter cloth of (2) is taken out with a spatula and subjected to a dehydration test (load 2 kg / cm ² , 60 seconds) using a press filter tester. The peelability of the dehydrated cake from the filter cloth when the dewatered cake attached to the filter cloth was peeled off with a spatula was evaluated according to the following criteria.
A: Very easy to peel off (almost no filter cloth deposits)
○: Easy to peel off (Slightly attached filter cloth)
Δ: Slightly difficult to peel off (there is a filter cloth deposit, slightly sticking to the inside of the filter cloth)
×: Hard to peel off (attaches to the inside of the filter cloth)

(4) Moisture content of cake (unit:%)
About 3.0 g of the dehydrated cake after the filter cloth peelability test was weighed (W3) in a petri dish (inner diameter: 105 cm, depth: 20 cm) until the water completely evaporated in the circulating dryer (105 ± 5 ° C. 8 hours), the moisture content of the cake was calculated from the following equation, assuming that the weight of the dry cake remaining in the petri dish was (W4).

Cake moisture content (%) = [(W3) − (W4)] × 100 / (W3)

(5) Flock strength The floc particle diameters at 120 rpm and 300 rpm in the above (1) were compared, and the floc strength was evaluated from the change in the floc particle size according to the following criteria.
<Evaluation criteria>
◎ Very strong (no change in particle size)
○ Strong (partially subdivided)
△ Slightly weak (partially subdivided)
× Weak (Overall segmentation)

  In the following, the examples of <Manufacturing polymer coagulant> or comparative examples and the examples or comparative examples of <aggregation performance evaluation> will be denoted by the same numbers for convenience.

<Production of salt (B)>
Production Example 1
After charging 1,000 parts of a 70% aqueous solution of methanesulfonic acid in a glass reaction vessel with a stirring blade, 445 parts of monoethanolamine was added dropwise over 60 minutes while stirring. After dripping, the inside of a tank was pressure-reduced and water was distilled off. 1,145 parts of monoethanolamine methanesulfonate (B-1) (white solid, moisture 0.1%) were obtained from the reaction vessel.

Production Example 2
Monopropanolamine in the same manner as in Production Example 1 except that 1,000 parts of sulfuric acid and 750 parts of monopropanolamine were used instead of 1,000 parts of 70% aqueous methanesulfonic acid and 445 parts of monoethanolamine in Production Example 1. 1,710 parts of sulfate (B-2) was obtained.

Production Example 3
In Production Example 1, 1,010 parts of ethylamine methanesulfonate (B-3) was obtained in the same manner as in Production Example 1 except that 445 parts of ethylamine was used instead of 445 parts of monoethanolamine.

Comparative production example 1
860 parts of sodium methanesulfonate (B′-1) was obtained in the same manner as in Production Example 1, except that 445 parts of monoethanolamine was replaced with 608 parts of a 48% aqueous solution of sodium hydroxide in Production Example 1.

<Manufacture of polymer flocculant>
Example 1
750 parts of an 80% aqueous solution of aminoethyl methacrylate sulfate (a1-1), 12 parts of salt (B-1) produced in Production Example 1, 237 parts of ion-exchanged water, 1-thioglycerol (c A mixture of 0.36 parts of a 10% aqueous solution of -1) 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 applies hereinafter) (dissolved oxygen concentration of 100 ppb or less), and then 0.60 part of a 10% aqueous solution of azobisamidinopropane hydrochloride was added. A homogeneous solution was prepared to prepare an aqueous monomer solution.
Separately, 1,000 parts of n-decane 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 maleic anhydride-modified ethylene as a dispersant. Add 7.0 parts of vinyl acetate copolymer [trade name “Orevac 930S”, manufactured by Arkema Co., Ltd.] and stir the stirring blade at a rotation speed of 500 rpm. Then, 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, the slurry after polymerization was added to 1,000 parts of isopropyl alcohol while stirring with a magnetic stirrer, and the mixture was stirred for 10 minutes. After stirring, the supernatant was removed by decantation, and the precipitate was filtered under reduced pressure. A polymer flocculant (P-1) containing a water-soluble (co) polymer (A-1), which is spread in a stainless steel container and dried for 10 hours in a circulating dryer at 50 ° C. 648 parts were obtained (solid content 92.6%).

Example 2
In Example 1, instead of 12 parts of (B-1), a water-soluble (co) polymer (A-2) was obtained in the same manner as in Example 1 except that a mixed solution of 42 parts of (B-1) was used. 647 parts of a polymer flocculant (P-2) containing (solid content 92.8%) were obtained.

Example 3
In Example 1, instead of 12 parts of (B-1), a water-soluble (co) polymer (A-3) was obtained in the same manner as in Example 1 except that 114 parts of (B-1) was used. 695 parts of a polymer flocculant (P-3) containing (solid content 93.8%) was obtained.

Example 4
In Example 1, 750 parts of an 80% aqueous solution of (a1-1), 12 parts of (B-1), 249 parts of ion-exchanged water, 0.36 part of a 10% aqueous solution of (c-1), azobisamidinopropane hydrochloride Instead of 0.60 part of 10% aqueous solution of salt, 895 parts of 80% aqueous solution of methanesulfonate (a1-2) of aminoethyl methacrylate, 50 parts of (B-1), 300 parts of ion-exchanged water, (c Water-soluble (co) polymer (A) in the same manner as in Example 1, except that 0.54 part of 10% aqueous solution of -1) and 0.72 part of 10% aqueous solution of azobisamidinopropane hydrochloride were used. -4) was obtained, and 680 parts of polymer flocculants (P-4) were obtained (solid content 93.5%).

Example 5
In a glass adiabatic reaction vessel, 783 parts of 80% aqueous solution of (a1-2), 12.5 parts of (B-1), 0.47 part of 10% aqueous solution of (c-1), the total concentration of monomers in the system is 246 parts of ion-exchanged water was added so that it might become 60%, and it stirred until the inside of a system became uniform aqueous solution. While further stirring, the pH (20 ° C.) of the monomer aqueous solution was adjusted to 2.0 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, 19 parts of a 10% aqueous solution of azobisamidinopropane hydrochloride, 0.3 part of a 1% aqueous solution of iron (II) sulfate, and 0.3 part of a 1% aqueous solution of hydrogen peroxide as initiators were added all at once with stirring. . After the content temperature reached 50 ° C., the content temperature was adjusted to 80 ° C. by heating from the outside. 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 by a meat chopper machine [model number “12VR-400K”, manufactured by ROYAL Co., Ltd., mesh opening 6 mm], and further minced into 80 ° C. 650 parts of a polymer flocculant (P-5) containing a water-soluble (co) polymer (A-5) in powder form after being dried with hot air for 2 hours and then pulverized with a juicer mixer (solid content 92. 9%).

Example 6
In Example 5, 783 parts of an 80% aqueous solution of (a1-2), 12.5 parts of (B-1), 0.47 part of a 10% aqueous solution of (c-1), 246 parts of ion-exchanged water, azobisamidino Instead of 19 parts of 10% aqueous solution of propane hydrochloride, 928 parts of 80% aqueous solution of (a1-2), 52 parts of (B-1), 0.56 parts of 10% aqueous solution of (c-1), ion-exchanged water A polymer flocculant (P) containing a water-soluble (co) polymer (A-6) in the same manner as in Example 5 except that 290 parts and 23 parts of a 10% aqueous solution of azobisamidinopropane hydrochloride were used. -6) 720 parts were obtained (solid content 92.7%).

Example 7
In Example 5, 783 parts of an 80% aqueous solution of (a1-2), 12.5 parts of (B-1), 0.47 part of a 10% aqueous solution of (c-1), 246 parts of ion-exchanged water, azobisamidino Instead of 19 parts of 10% aqueous solution of propane hydrochloride, 839 parts of 80% aqueous solution of (a1-2), 31.8 parts of 50% aqueous solution of acrylamide (a2-1), 131 parts of (B-1), (c -1) water-soluble (co) polymer in the same manner as in Example 5 except that 0.52 parts of 10% aqueous solution, 270 parts of ion-exchanged water, and 21 parts of 10% aqueous solution of azobisamidinopropane hydrochloride were used. 795 parts of a polymer flocculant (P-7) containing A-7) was obtained (solid content 92.7%).

Example 8
In Example 6, instead of (a1-2) 928 parts, (B-1) 52 parts, and ion-exchanged water 290 parts, (a1-2) 689 parts, (a2-1) 50% aqueous solution 61 parts, (B-1) Polymer flocculant (P-8) containing a water-soluble (co) polymer (A-8) in the same manner as in Example 6 except that 41 parts and 210 parts of ion-exchanged water were used. 687 parts were obtained (solid content 93.5%).

Example 9
In Example 6, in place of 0.56 parts of the 10% aqueous solution of (c-1), 0.074 parts of the 10% aqueous solution of (c-1) was used, and the water-soluble ( 666 parts of a polymer flocculant (P-9) containing the (co) polymer (A-9) was obtained (solid content 93.5%).

Example 10
In Example 2, a polymer containing the water-soluble (co) polymer (A-10) in the same manner as in Example 2 except that (B-2) was used instead of (B-1). 634 parts of flocculant (P-10) were obtained (solid content 91.0%).

Example 11
In Example 4, a polymer comprising the water-soluble (co) polymer (A-11) in the same manner as in Example 4 except that (B-3) was used instead of (B-1). 684 parts of flocculant (P-11) were obtained (solid content 94.0%).

Example 12
In Example 5, 783 parts of an 80% aqueous solution of (a1-2), 12.5 parts of (B-1), 0.47 part of a 10% aqueous solution of (c-1), 246 parts of ion-exchanged water, azobisamidino Instead of 19 parts of 10% aqueous solution of propane hydrochloride, 928 parts of 80% aqueous solution of (a1-2), 0 part of (B-2), 0.56 part of 10% aqueous solution of (c-1), ion-exchanged water Example 5 except that 290 parts, 23 parts of 10% aqueous solution of azobisamidinopropane hydrochloride, and 52 parts of (B-2) were further added to the obtained hydrous gel and mixed and kneaded by a meat chopper machine. Similarly, 659 parts of a polymer flocculant (P-12) containing the water-soluble (co) polymer (A-12) was obtained (solid content: 93.3%).

Example 13
Example 5 is the same as Example 5 except that (B-1) 12.5 parts and (c-1) 0.062 parts instead of 0.47 parts of (c-1) 10% aqueous solution were used. Similarly, a powdery water-soluble (co) polymer (A-13) is obtained, and then 12.5 parts of (B-2) is added and mixed with a mixer to obtain a water-soluble (co) polymer ( 657 parts of a polymer flocculant (P-13) containing A-13) was obtained (solid content 94.0%).

Comparative Example 1
In Example 1, a water-soluble (co) polymer (ratio A-1) was contained in the same manner as in Example 1 except that instead of 12 parts of (B-1), it was 150 parts of (B-1). Thus, 652 parts of a polymer flocculant (ratio P-1) was obtained. (Solid content 93.6%).

Comparative Example 2
In Example 1, a water-soluble (co) polymer (ratio A-2) was used in the same manner as in Example 1 except that instead of 12 parts of (B-1), 2.4 parts of (B-1) were used. There were obtained 662 parts of a polymer flocculant (ratio P-2). (Solid content 93.0%).

Comparative Example 3
In Example 6, a water-soluble (co) polymer (ratio) was obtained in the same manner as in Example 6 except that 52 parts of (B-1) was replaced with 52 parts of sodium methanesulfonate (B′-1). 650 parts of a polymer flocculant (ratio P-3) containing A-3) was obtained (solid content 93.4%).

Comparative Example 4
In Example 2, instead of 750 parts of an 80% aqueous solution of (a1-1) and 0.36 part of a 10% aqueous solution of (c-1), a methylclad quaternary ammonium salt of N, N-dimethylaminoethyl methacrylate A water-soluble (co) polymer (ratio A-4) in the same manner as in Example 2 except that 750 parts of an 80% aqueous solution of (a2-2) and 0.042 part of a 10% aqueous solution of (c-1) were used. 625 parts of a polymer flocculant (ratio P-4) was obtained (solid content 93.6%).

The polymer flocculants obtained above are shown in Table 1. The contents of the symbols in Table 1 are as follows.
AEMS (a1-1): Sulfate of aminoethyl methacrylate AEMCS (a1-2): Methanesulfonate of aminoethyl methacrylate AAm (a2-1): Acrylamide DAMQ (a2-2): N, N-dimethyl Of aminoethyl methacrylate
Methyl Clyde Quaternary Ammonium Salt Salt (B-1): Monoethanolamine / Methanesulfonate Salt (B-2): Monopropanolamine / Sulfate Salt (B-3): Ethylamine / Methanesulfonate Salt (B '-1): Methanesulfonic acid sodium salt

<Aggregation performance evaluation>
Examples 1-13, Comparative Examples 1-4
The polymer flocculants (P-1) to (P-13) and (ratio P-1) to (ratio P-4) were each dissolved in ion-exchanged water to obtain an aqueous solution having a solid content of 0.2%. .
J Excess sludge collected from the sewage treatment plant [pH 6.2, TS 0.8%, organic content 83%] was put in 17 separate 500 mL beakers of 200 parts each, and (P-1) to (P -13), 8 parts of each of the above aqueous solutions (ratio P-1) to (ratio P-4) were added to each beaker, and each beaker was mixed according to the evaluation method (1) [(P- The solid content of 1) to (P-13) and (ratio P-1) to (ratio P-4) is 0.4% / TS]. These treated products were evaluated for floc particle size, filtrate amount, filter cloth peelability, cake moisture content and floc strength according to the evaluation methods (1) to (5). The results are shown in Table 2.

  From the results in Table 2, the polymer flocculant (P) of the present invention forms a coarse floc having a large particle size compared to the comparative one, and the floc once formed is not easily broken even under high agitation (300 rpm). It can be seen that the film has excellent effects in any of (floc is strong), filter cloth peelability, and dewaterability (cake moisture content).

  Since the polymer flocculant of the present invention exhibits a higher dewatering rate (that is, lower cake water content) than conventional ones, it is used for dehydration treatment of organic or inorganic sludge such as sewage or factory wastewater or wastewater. It can be used as a polymer flocculant and is particularly preferably used for dehydration treatment of organic sludge. Other uses include, for example, agglomerating agents for drilling and muddy water treatment, papermaking chemicals (for example, paper industry formation aids, drainage yield improvers, drainage improvers, and paper strength enhancers), and increased crude oil production. Additives (crude oil secondary and tertiary recovery additives), dispersants, scale inhibitors, coagulants, decolorizers, thickeners, antistatic agents, and textile treatment agents. It is suitably used as a flocculant for muddy water treatment, a papermaking chemical and an additive for increasing crude oil production.

Claims (4)

A water-soluble (co) polymer (A) having a water-soluble unsaturated monomer (a) containing a water-soluble cationic monomer (a1) represented by the following general formula (1) as a structural unit, and the following general formula (2) And (B) based on the weight of (A), and the content of (B) based on the weight of (A) is 1 to 20%.

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

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

X ² −N ⁺ R ⁴ R ⁵ R ⁶ · Y ⁻ (2)

[Wherein X ² is a monovalent hydrocarbon group having 1 to 5 carbon atoms which may have a hetero atom, R ^{4 to} R ⁶ are H, and Y ⁻ is a residue other than H ⁺ of a protonic acid. Represent. ]   The polymer flocculant according to claim 1, wherein the content of (a1) based on the total number of moles of monomers constituting the water-soluble (co) polymer (A) is 90% or more. The polymer flocculant according to claim 1 or 2, wherein the water-soluble (co) polymer (A) satisfies the following relational expression.

6 ≦ Vw / Vs ≦ 35

[In formula, Vw represents the viscosity (mPa * s, 25 degreeC) of 0.2 weight% aqueous solution, and Vs represents the viscosity (mPa * s, 25 degreeC) of 0.5 weight% salt aqueous solution. ]   A method for treating sludge or wastewater, wherein the polymer flocculant according to any one of claims 1 to 3 is added to and mixed with sludge or wastewater to form a floc for solid-liquid separation.