JP5461158B2 - Polymer flocculant - Google Patents

Description

  The present invention relates to a polymer flocculant. More specifically, the present invention relates to a polymer flocculant useful for dewatering sewage sludge, for improving drainage yield or paper strength in the papermaking process, for coagulating and precipitating industrial wastewater, and for tertiary recovery of petroleum.

Conventionally, sewage or human waste (hereinafter abbreviated as sewage sludge) treatment, general industrial wastewater (hereinafter abbreviated as wastewater) treatment, or muddy water treatment at civil engineering sites, for promoting sedimentation and separation of mud at the time of reclamation, and for papermaking Poly (meth) acryloyloxyethyltrimethylammonium chloride, acrylamide-acryloyloxyethyl for dehydration of water-soluble polymers such as drainage yield improvers and paper strength enhancers, such as sludge and organic sludge such as wastewater Cationic polymer flocculants such as trimethylammonium chloride copolymer and polyvinylamidine (for example, see Patent Document 1), amphoteric polymer flocculants such as acrylamide-acrylic acid- (meth) acryloyloxyethyltrimethylammonium chloride copolymer are widely used. (For example, see Patent Document 2) .
Furthermore, anionic polymer flocculants characterized by increasing the agglomeration density by graft polymerizing water-soluble monomers to water-soluble polymers for the purpose of wastewater treatment or construction and civil engineering fields such as reclamation Are also known (see, for example, Patent Documents 3 and 4).

Conventionally, as a polymerization method of a polymer flocculant, an aqueous solution polymerization method, a thin film polymerization method, a reverse phase suspension polymerization method, a precipitation polymerization method, an emulsion polymerization method, and the like are known.
Among these, the reverse phase suspension polymerization method can be polymerized at a constant temperature because the polymerization heat can be easily removed by a hydrophobic dispersion medium, and a polymer flocculant having a high molecular weight and a relatively sharp molecular weight distribution can be obtained. It is excellent in that it can.
As a method for obtaining a polymer flocculant by the reverse phase suspension polymerization method, conventionally, a method using a water-soluble polyhydric alcohol as a chain transfer agent (for example, Patent Document 5), a method using an aliphatic saturated carboxylate, etc. (For example, patent document 6) etc. are known.

JP 63-274409 A Japanese Patent Laid-Open No. 3-189000 JP-A-6-254305 JP-A-6-254306 JP-A-56-53111 Japanese Patent Laid-Open No. 52-6787

However, the polymer flocculants described in Patent Documents 1 to 4 have a small floc particle size and poor drainage, a high moisture content of the solid-liquid separated cake, and a belt press dehydrator or filter press dehydrator. When used, it was difficult to obtain a sufficient dehydrating effect, such as poor peelability between the filter cloth and sludge.
In addition, the methods described in Patent Documents 5 and 6 have fatal disadvantages as a polymer flocculant because when the concentration of the monomer aqueous solution is increased in order to improve productivity, a large amount of water-insoluble matter is generated in the produced polymer. was there.

  The inventor of the present invention has arrived at the present invention as a result of intensive studies to solve these problems. That is, the present invention is obtained by subjecting a polymerizable monomer (a) comprising a water-soluble unsaturated monomer to reverse phase suspension polymerization in the presence of a chain transfer agent (f) having a chain transfer constant of 0.01 to 100. The ratio (Mw / Mn) of the weight average molecular weight (Mw) converted from the intrinsic viscosity to the number average molecular weight (Mn) measured by the membrane type osmotic pressure method is 1 to 40 dl / g. 50. A polymer flocculant comprising a (co) polymer (A) of 50 and having a water-insoluble content of 5% by weight or less.

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

(A) in the present invention is a water-soluble (co) polymer having a water-soluble unsaturated monomer (a) as a structural unit, and (a) includes the following nonionic monomer (a1), cationic monomer ( a2), anionic monomers (a3) and mixtures of two or more of these.
As the monomer constituting (A), in addition to (a), a water-insoluble unsaturated monomer (x) and a crosslinkable monomer (y) may be used in combination as necessary, as long as the effects of the present invention are not impaired.
Here, the water-soluble unsaturated monomer or water-soluble (co) polymer means an unsaturated monomer or (co) polymer having a solubility in water (20 ° C.) of 1 g / 100 g or more of water, and is water-insoluble unsaturated. Monomer means an unsaturated monomer having a solubility in water (20 ° C.) of less than 1 g / 100 g of water.

In the following, the number average molecular weight measured by gel permeation chromatography (GPC) method is abbreviated as GMn, and the weight average molecular weight is abbreviated as GMw. The GMn and GMw are obtained under the following GPC measurement conditions.
<GPC measurement conditions>
Apparatus: HLC-802A, manufactured by Tosoh Corporation Column: TSK gel GMH6 (2)
Measurement temperature: 40 ° C
Sample solution: 0.5 wt% tetrahydrofuran solution solution injection amount: 200 μl
Detector: Refractive index detector Standard: Polystyrene

(A1) Nonionic monomer The following are mentioned, and these mixtures.
(A11) (Meth) acrylate Carbon number (hereinafter abbreviated as C) 4 or more and number average molecular weight [measurement is by gel permeation chromatography (GPC) method. Hereinafter abbreviated as GMn. ] 5,000 or less, for example, hydroxyl group-containing (meth) acrylate [eg, hydroxyethyl-, diethylene glycol mono-, polyethylene glycol (polymerization degree 3-50) mono- and polyglycerol (polymerization degree 1-10) mono (meth) acrylate] And alkyl acrylate (alkyl group is C1-2) ester (C4-5, such as methyl acrylate, ethyl acrylate);
(A12) (Meth) acrylamide and derivatives thereof 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.];
(A13) Nitrogen-containing ethylenically unsaturated compounds other than the above C3-30, such as acrylonitrile, N-vinylformamide, N-vinyl-2-pyrrolidone, N-vinylimidazole, N-vinylsuccinimide, N-vinylcarbazole and 2 -Cyanoethyl (meth) acrylate.

(A2) Cationic monomer The following, these salts [for example, inorganic acid (hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc.) salts, methyl chloride salts, dimethyl sulfate salts, benzyl chloride salts, etc.], and mixtures thereof are mentioned. It is done.
(A21) Nitrogen atom-containing (meth) acrylate C5-30, such as aminoalkyl (C2-3) (meth) acrylate, N, N-dialkyl (C1-2) aminoalkyl (C2-3) (meth) acrylate [N N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, etc.], heterocycle-containing (Meth) acrylate [N-morpholinoethyl (meth) acrylate etc.];
(A22) Nitrogen atom-containing (meth) acrylamide derivative C5-30, such as N, N-dialkyl (C1-2) aminoalkyl (C2-3) (meth) acrylamide [N, N-dimethylaminoethyl (meth) acrylamide, etc. ];
(A23) Ethylenically unsaturated compound having amino group C5-30, such as vinylamine, vinylaniline, (meth) allylamine, p-aminostyrene, etc.];
(A24) Compound having amine imide group C5-30, 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 and the like;
(A25) Nitrogen atom-containing vinyl monomers other than the above C5-30, for example, 2-vinylpyridine, 3-vinylpiperidine, vinylpyrazine, vinylmorpholine.

(A3) Anionic monomer The following acids, salts thereof [alkali metal (lithium, sodium, potassium, etc., the same shall apply hereinafter) salts, alkaline earth metals (magnesium, calcium, etc., the same shall apply hereinafter) salts, ammonium salts and amines (C1-20) salts and the like], and mixtures thereof.
(A31) unsaturated carboxylic acid C3-30, such as (meth) acrylic acid, (anhydrous) maleic acid, fumaric acid, (anhydrous) itaconic acid, vinylbenzoic acid, allyl acetic acid;
(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) acryloyloxyethanesulfonic acid, 2- (meth) acryloyloxypropanesulfonic acid, 3- (meth) acryloyloxypropanesulfonic acid, 2- (meth) Acryloyloxybutanesulfonic 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) acryloyl Aminoethanesulfonic acid, 2- and 3- (meth) acryloylaminopropanesulfonic acid, 2- and 4- (meth) acryloylaminobutanesulfonic acid, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid, p- (meth) acryloylaminomethylbenzenesulfonic acid and the like], alkyl (C1-20) (meth) allylsulfosuccinate [methyl (meth) allylsulfosuccinate and the like] and the like;
(A33) (Meth) acryloyl polyoxyalkylene (C1-6) sulfate ester (meth) acryloyl polyoxyethylene (degree of polymerization 2 to 50) sulfate ester and the like.

  Of these, (a), (a1), (a21), (a22), (a31), (a32) are preferable, and (a12), (a13), (a21) are more preferable. , (A22), (a31), and (a32), sulfonic acid group-containing (meth) acrylate, sulfonic acid group-containing (meth) acrylamide, particularly preferably (a12), (a13), (a21), Of (a31) and (a32), sulfonic acid group-containing (meth) acrylate, sulfonic acid group-containing (meth) acrylamide, most preferably (meth) acrylamide of (a12), of (a13) Acrylonitrile, N-vinylformamide, N, N-dimethylaminoethyl (meth) acrylate of (a21) and salts thereof (above), (meth) acrylic acid, (anhydrous) maleic acid, (anhydrous) itaconic acid and alkali metal salts thereof in (a31), 2- (meth) acryloyloxyethanesulfonic acid in (a32), 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 use amount (mol%) of (a) is based on the total number of moles of the monomers constituting (A), and the aggregation performance (high floc strength, coarse floc, low moisture content of dehydrated cake, etc.) .) Is preferably 50 to 100%, and more preferably 80 to 100%.

Examples of the water-insoluble unsaturated monomer (x) that may be used in combination with (a) if necessary 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 monoester of [monoalkoxy (C1-20)-, monocycloalkoxy (C3-12)-or monophenoxy] polypropylene glycol (hereinafter abbreviated as PPG) (degree of polymerization 2-50) mono (Meth) acrylate ester [ω-methoxy PPG mono (meth) acrylate, ω-ethoxy PPG mono () of adducts of propylene oxide (hereinafter abbreviated as PO) of all (C1-20) or monohydric phenol (C6-20) 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 diols (C2- 20) or dihydric phenol (C6-20) Of PO adduct (meth) acrylic acid ester [.omega.-hydroxyethyl (poly) oxypropylene mono (meth) acrylate, etc.] or the like;

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

In addition, as the crosslinkable monomer (y), the following (y1) to (y5) and salts thereof [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, benzyl chloride salt, etc., for acidic monomers, alkali metal salts, alkaline earth metal salts, amines (C1-20, such as methylamine, ethylamine, Cyclohexylamine) salts], and mixtures thereof.
(Y1) Bispoly (2-4 or more) (meth) acrylamide C5-30, such as N, N′-methylenebisacrylamide;
(Y2) poly (2-4 or more) (meth) acrylates C8-30, such as ethylene glycol di (meth) acrylate, pentaerythritol [poly (2-4)] (meth) acrylate;

(Y3) Vinyl group (2 to 20 or more) -containing monomers C4 or more and GMn 6,000 or less, such as divinylamine, polyvalent (2 to 5 or more) amine [C2 or more and GMn 3,000 or less, such as ethylenediamine , Polyethyleneimine (C4 or more and GMn3,000 or less)] poly (2-20) vinylamine, divinyl ether, polyhydric alcohol [C2 or more and GMn3,000 or less, such as alkylene (C2-6 or more) glycol [ethylene Glycol, propylene glycol, 1,6-hexanediol (hereinafter abbreviated as EG, PG, HD, etc.)], polyoxyalkylene [GMn 2,000 to 3000, for example, polyethylene glycol (hereinafter abbreviated as PEG) (molecular weight 106 or more) And GMn 3,000 ), PPG (molecular weight 134 or more and GMn 3,000 or less), polyoxyethylene (molecular weight 106 or more and GMn 3,000 or less) / polyoxypropylene (molecular weight 134 or more and GMn 3,000 or less) block copolymer], trimethylolethane, Tri (methylolpropane), (poly) (2-50) glycerin, pentaerythritol, sorbitol (hereinafter abbreviated as TME, TMP, GR, PE, SO, respectively), starch] poly (2-20) vinyl ether, and the like;

(Y4) Allyl group (2 to 20 or more) -containing monomer C6 or more and GMn3,000 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) Epoxy group-containing monomer C8 or more and GMn6,000 or less, for example, EG diglycidyl ether, PEG diglycidyl ether, GR triglycidyl ether.

The use amount (mol%) of (x) is preferably 40 or less, based on the total number of moles of the monomer constituting (A), preferably from the viewpoint of aggregation performance and solubility of the polymer flocculant in water. It is 0.1-20, More preferably, it is 0.5-10.
The amount of (y) used (mol%) is usually 5 or less based on the total number of moles of the monomer constituting (A), although it depends on the polymerizability or reactivity of the crosslinkable monomer (y) used. From the viewpoint of aggregation performance expression and solubility of the polymer flocculant in water, it is preferably 0.001-1, and more preferably 0.01-0.5.

  (A) in the present invention has a specific (Mw / Mn) ratio of 1 to 50 as described later, and is produced by a reverse phase suspension polymerization method in order to control the ratio.

  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 monomer aqueous solution to which a water-soluble unsaturated monomer (a), a radical polymerization initiator (d), and, if necessary, a water-insoluble unsaturated monomer (x) and / or a crosslinkable monomer (y) is added is prepared and inactivated. After sufficiently substituting with gas, it is put into a polymerization tank under stirring and polymerized while being suspended. The method for charging the 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 for substituting the monomer aqueous solution with an inert gas include a method for bubbling and supplying an inert gas to the monomer aqueous solution, a method for blending with a static mixer or the like in a dropping line, and the like from the viewpoint of uniformity of polymerization. A method of blending with a static mixer is preferred.

The hydrophobic dispersion medium (b) in the present invention means a dispersion medium having a solubility in water (20 ° C.) of less than 1 g / 100 g of water.
As (b), hydrocarbon [aliphatic (C5-12, such as n-hexane, n-heptane, n-octane, n-nonane, n-decane), alicyclic group (C5-12, such as cyclopentane, Cyclohexane, cycloheptane, methylcyclohexane, cyclooctane, decalin) and aromatic rings (C6-12, such as benzene, toluene, xylene, ethylbenzene), etc.], ketones [aliphatic (C3-10, such as methyl-n-propyl ketone) , Diethyl ketone, methyl isobutyl ketone), alicyclic ring containing (C5-10, such as cyclopentanone, cyclohexanone) and aromatic ring containing (C8-13, such as acetophenone, benzophenone), etc.], ether [aliphatic (C4-8, For example, di-n-propyl ether, di-n-butyl ether, diethyl Glycol dimethyl ether), cyclic ether (C4-18, such as tetrahydropyrine) and aromatic ring-containing ether (C7-12, such as anisole), etc.], ester [aliphatic ester (C3-10, such as n-butyl acetate), alicyclic Containing ester (C7-12, eg, cyclohexyl acetate, methyl cyclohexanecarboxylate), aromatic ring containing ester (C8-13, eg, methyl benzoate, ethyl benzoate, n-butyl benzoate, benzyl acetate, dimethyl phthalate, diethyl phthalate, Di-n-butyl phthalate) and the like], and mixtures thereof.
Of these, from the viewpoint of handling during production and temperature control during polymerization, aliphatic and alicyclic hydrocarbons are preferred, and n-hexane, n-heptane, n-octane, and n-nonane are more preferred. N-decane, cyclohexane and methylcyclohexane.

As the dispersant (c) in the present invention, HLB (Hydrophile-Lipophile Balance) is preferably 1 to 8, more preferably from the viewpoint of dispersion stability and the angle of repose of dry particles described later, that is, powder flowability. Examples of various oil-soluble substances are 2 to 7, particularly preferably 3 to 5.
Here, HLB represents a balance between hydrophilicity and lipophilicity, and is obtained from the following formula (“Surfactant Synthesis and Its Application”, page 501, published by Tsuji Shoten in 1957; “New Surfactant” "Introduction", pp. 197-198, published by Sanyo Chemical Industries, 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.

  (C) includes a low molecular dispersant (c1) having a GMw of less than 5,000 (more preferably 100 to 3,000, particularly preferably 100 to 1,000), and a GMw of 5,000 or more (more preferably 7,000 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 (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 [GMw 100-5,000, eg PEG (GMw 100-4) , 700) monostearate] and the like], alkyl (C1-30) allyl ether and the like.

  Of the above (c1), from the viewpoint of preventing the polymer particles from adhering to the apparatus during production and the angle of repose of the dried particles of the polymer flocculant after drying, a fatty acid ester of a polyhydric alcohol is preferred, and a more preferred one is shochu. Sugar fatty acid ester and sorbitan 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.
The above (maleic anhydride modified) ethylene / vinyl acetate copolymer includes ethylene and / or maleic anhydride modified ethylene / vinyl acetate copolymer and ethylene / vinyl acetate copolymer modified with maleic anhydride. Etc. are included.
Examples of maleic anhydride-modified ethylene include those obtained by adding maleic anhydride to an ethylene / vinyl acetate copolymer. The weight ratio of maleic anhydride to ethylene / vinyl acetate copolymer is the dispersion stability and the molecular weight of the reaction product. From the viewpoint of adjustment, it is preferably 2/98 to 30/70, more preferably 5/95 to 20/80.
(Maleic anhydride modified) The copolymerization ratio (weight ratio) in the copolymer of ethylene and vinyl acetate is preferably 50/50 to 95 from the viewpoint of solubility in the dispersion medium (b) and dispersion stability. / 5, more preferably 70/30 to 90/10.

  Among the above (c2), from the viewpoint of preventing the polymer particles from adhering to the apparatus during production and the angle of repose of the dried particles of the polymer flocculant after drying, alkene and α, β-unsaturated polyvalent carboxylic acid are preferable. Copolymers with (anhydrides) or derivatives thereof, modified organopolysiloxanes, and (maleic anhydride modified) ethylene / vinyl acetate copolymers.

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 dispersed particles of (A), the angle of repose of the dried particles of the polymer flocculant after drying, and From the viewpoint of particle diameter control, it is preferably 0.01 to 10%, more preferably 0.05 to 5%.

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

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 (azobiscyano). Valeronitrile, azobisisobutyronitrile, azobiscyclohexanecarbonitrile, etc.]] and peroxides [water-soluble [peracetic acid, t-butyl peroxide, hydrogen peroxide, ammonium persulfate, sodium persulfate, persulfate] Potassium etc.] and oil-soluble [benzoyl peroxide, cumene hydroxy peroxide, 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].
Further, the azo compound, peroxide and redox initiator may be used alone or in combination of two or more.
(D) is usually present in the dispersed phase (aqueous solution), but may be present in either the dispersed phase (aqueous solution) and / or the continuous phase (hydrophobic dispersion medium).

  From the viewpoint of obtaining an optimum molecular weight, the amount of (d) used is preferably 0.001%, more preferably 0.005%, particularly preferably based on the total weight of the monomers constituting (A). Is 0.01%, most preferably 0.02%, and the upper limit is preferably 1%, more preferably 0.5%, particularly preferably 0.1%, and most preferably 0.05%.

  The total concentration of monomers in the dispersed phase in the present invention (hereinafter sometimes referred to as the dispersed phase concentration) is preferably 20% or more, more preferably 25% or more, from the viewpoint of productivity, based on the weight of the dispersed phase. In particular, it is preferably 30% or more, preferably 90% or less, more preferably 85% or less, and particularly preferably 80% or less from the viewpoint of preventing adhesion of polymer particles to the apparatus.

The chain transfer agent (f) in the present invention has a chain transfer constant (Cf) of 0.01 to 100, preferably 0.05 to 50, particularly preferably 0.1 to 10. If the chain transfer constant is less than 0.01, the insoluble content increases, and if it exceeds 100, a polymer having a desired molecular weight cannot be obtained.
Chain transfer constants are defined by J. Brandrup and E. Etch Inmargut, “Polymer Handbook (4th edition)”, published by John Wiley and Sons (Polymer Handbook fourth edition, edited by J. Brandrup and EH Immergut). JOHN WILEY & SONS), pages 97-98.
The chain transfer constant in the present invention is measured using a general method described in “Experimental Methods for Polymer Synthesis” [Chemical Doujin Co., Ltd., published in 1993] and the like. It shall be a chain transfer constant.

  As (f), a compound having one or more amino groups in the molecule [C0-60, such as ammonia, methylamine, dimethylamine, triethylamine, n- and i-propanolamine], 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 derivatives thereof, etc.]. 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, such as methylamine, ethanol Amine) 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, mercaptoacetic acid, 3-mercaptopropionic acid, 1-thioglycerol, thioglycolic acid monoethanolamine, thiomaleic acid, mercaptosuccinic acid, cysteine, cysteamine), alicyclic-containing thiol (C5-20, such as cyclopentanethiol, cyclohexanethiol), aromatic ring Containing thiols (C6-12, such as benzenethiol, thiosalicylic acid, thiocresol, thiolenol, thionaphthol) and araliphatic thiols (C7-20, such as α-toluenethiol). It is.

(2) Polyvalent thiol dithiol [aliphatic dithiol (C2-40, such as ethanedithiol, diethylenedithiol, triethylenedithiol, n-, i- and sec-propanedithiol, 1,3- and 1,4-butanedithiol, 1,6-hexanedithiol, neopentanedithiol, triethyleneglycoldithiol), alicyclic dithiol (C5-20, such as cyclopentanedithiol, cyclohexanedithiol), aromatic dithiol (C6-16, such as benzenedithiol, biphenyldithiol) And araliphatic dithiols (C8-20, such as xylene dithiols).

  Of the above (f), those having high water solubility are preferable from the viewpoint of reducing the water-insoluble content, and the water / n-decane partition coefficient is preferably 25/75 to 100/0, more preferably 50/50. -100/0, particularly preferably 80 / 20-100 / 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.

  From the viewpoint of obtaining the optimum molecular weight of the polymer flocculant of the present invention, the amount used of (f) is the sum of (a) or (x) and (y) used together with (a) as necessary. Based on weight, the preferred lower limit is 0.0001%, more preferably 0.001%, particularly preferably 0.01%, most preferably 0.05%, and the preferred upper limit is 10%, more preferably 5%, especially Preferably it is 3%, most preferably 1%.

  The chain transfer agent (f) preferably remains in the polymer flocculant of the present invention from the viewpoint of reducing the water-insoluble matter described later. The residual amount (Wf) of (f) based on the weight of the polymer flocculant is preferably 0.0001 to 10%, more preferably 0.001 to 1%, from the viewpoint of reducing the water-insoluble content and adjusting the molecular weight. .

The chain transfer agent (f) in the present invention is usually used by mixing with a monomer, but most of the chain transfer agent in the monomer is consumed during the polymerization. As a method for bringing the residual amount (Wf) into the above range, (1) a method of additionally charging during or at the end of polymerization, and (2) an amphiphilic chain transfer agent that is soluble in both the aqueous phase and the oil phase. The method of using is mentioned.
Examples of the additional method (1) include a method of adding an aqueous solution of a chain transfer agent in a lump and a method of dropping the aqueous solution.
The amphiphilic chain transfer agent (2) preferably has a water / n-decane distribution coefficient in the range of 10/90 to 80/20.

From the viewpoint of reducing the water-insoluble content, the chain transfer constant (Cf) of (f) and the residual amount (Wf) (wt%) of the chain transfer agent in the polymer flocculant are expressed by the following formula (1): Is preferably satisfied.

0.0001 ≦ (Cf) × (Wf) ≦ 1,000 (1)

The residual amount of chain transfer agent [(Wf) wt%] is determined by the polymer flocculant, the organic solvent or water / organic solvent mixture in which the chain transfer agent is dissolved [for example, water / acetone mixed solvent (volume ratio = 20/80) ] Can be determined by measuring by column chromatography (gas chromatography, high performance liquid chromatography, GPC, etc.). Examples of specific measurement conditions in gas chromatography are shown below.
<Examples of measurement conditions for residual amount of chain transfer agent>
Equipment: Shimadzu GCMS-QP2010Plus
Column: ZB-5
Column temperature: 80 ° C
Vaporization chamber temperature: 280 ° C
Sample solution: 3 g of sample was extracted with 30 g of water / acetone mixed solvent (volume ratio = 20/80).
Solution solution injection volume: 20 μl
Detection device: MS detector (SIM mode)

The pH of the aqueous monomer solution in the present invention is not particularly limited, but from the viewpoint of increasing the molecular weight, the preferable lower limit is 2, more preferably 2.5, particularly preferably 3, and the preferable upper limit is 8 from the viewpoint of preventing hydrolysis. It is preferably 7, particularly preferably 6.5. The pH adjuster used for pH adjustment is not particularly limited, and when the monomer aqueous solution is alkaline, inorganic acid (sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, etc.), inorganic solid acidic substance (acidic sodium phosphate, acidic bladder) Glass, ammonium chloride, ammonium sulfate, ammonium sulfate, sulfamic acid, etc.) and organic acids (C2-20, such as oxalic acid, succinic acid, malic acid). When the aqueous monomer solution is acidic, an inorganic alkaline substance (sodium hydroxide) , Potassium hydroxide, ammonia and the like) and organic alkaline substances (guanidine and the like).
In addition, pH here is a value measured at room temperature (20 degreeC) using the stock solution of monomer aqueous solution using a pH meter [For example, brand name "LAB pH meter M-12", Horiba Ltd. make].

The polymerization temperature (° C.) of the reverse phase suspension polymerization is preferably less than the boiling point of the hydrophobic dispersion medium from the viewpoint of preventing change in the monomer concentration during the polymerization. When the boiling point of the dispersion medium is exceeded, the dispersion medium concentration changes, and it becomes difficult to obtain a uniform particle size. Further, when water azeotropes, the monomer concentration in the system changes and (Mw / Mn) in the present invention increases, which is not preferable.
As the polymerization temperature, the preferable lower limit is 10, more preferably 30, particularly preferably 40, most preferably 50, from the viewpoint of the polymerization rate, and the preferable upper limit is 95, more preferably 80, from the viewpoint of molecular weight and dispersed particle stability. Particularly preferred is 70, most preferred 60. Further, during polymerization, it is preferable to adjust by appropriately heating and cooling so that the predetermined polymerization temperature is kept constant (for example, the predetermined polymerization temperature ± 5 ° C.).
In order to keep the polymerization temperature constant, the monomer may be added dropwise to the dispersion medium that has been previously adjusted to a predetermined polymerization temperature under stirring. The dropping time at that time varies depending on the monomer concentration and the amount of heat generated by the polymerization reaction, but is usually 0.5 to 20 hours, preferably 1 to 10 hours.

The end of the polymerization reaction can be confirmed by the point that the heat generation due to the polymerization is eliminated, but the polymerization time is 1 to 24 hours from the time when the polymerization start is confirmed by the normal heat generation, and the viewpoint that the polymerization is completed and the residual monomer is reduced. Therefore, the preferable lower limit is 2 hours, more preferably 3 hours, and the preferable upper limit from an industrial viewpoint is 12 hours, more preferably 10 hours. When the monomer is added dropwise 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, polymerization method, initiator type, and the like.

Pressure during polymerization [kPa (absolute pressure), only numerical values are shown below. ] Is not particularly limited, but is usually performed under atmospheric pressure. From the viewpoint that the monomer concentration during polymerization does not change, a pressure at which the hydrophobic dispersion medium (b) does not boil at the polymerization temperature and a pressure at which (b) does not azeotrope with water are preferred, particularly when a low-boiling solvent is used. For this, it is preferable to increase the pressure to less than the boiling point.
The preferable lower limit of the pressure is 50, more preferably 70, particularly preferably 90, and the preferable upper limit is 1,000, more preferably 500, and particularly preferably 300.

  Further, the (co) polymer (A) in the present invention may be further subjected to a modification reaction. As the polymer modification method, for example, when acrylamide having a hydrolyzable functional group in the molecule is used as the water-soluble unsaturated monomer (a), a caustic alkali (sodium hydroxide, potassium hydroxide, etc.) during or after polymerization Alternatively, a method of adding an alkali carbonate (sodium carbonate, potassium carbonate, etc.) and partially hydrolyzing the amide group of (a) to introduce a carboxyl group (JP 56-16505 A, etc.); formaldehyde, A method in which a dialkylamine (C1-12) and a halogenated (chlorine, bromine, iodine, etc.) alkyl (C1-12) (methyl chloride, ethyl chloride, etc.) are added, and a cationic group is partially introduced by Mannich reaction; acrylonitrile Amino acids obtained by hydrolysis of nitrile groups such as vinylformamide A method of forming an amidine ring in a molecule by a ring-closing reaction with (a Japanese Patent Laid-Open No. 5-192513), and a method of adding a crosslinkable monomer (y) after polymerization to cause a cross-linking reaction (Japanese Patent No. 3305688) ) And the like.

In the present invention, (A) intrinsic viscosity [η] (measured value in a 1N-NaNO ₃ aqueous solution at 30 ° C., unit is dl / g, the same shall apply hereinafter) is 1 to 40, preferably 4 to 30, more preferably. It is 6 to 25, particularly preferably 8 to 20, and most preferably 9.5 to 18. When the intrinsic viscosity is less than 1, the aggregation performance is deteriorated, and when it exceeds 40, the aggregation rate is lowered.

The weight average molecular weight (Mw) of (A) in the present invention is determined by conversion from the intrinsic viscosity. The viscosity formula of the polyacrylamide polymer: [η] = 3.73 × 10 ⁻⁴ × (Mw) (Mw) can be obtained from x 0.66 [Radical Polymerization Handbook, published by NTS, page 558 (1999)]. According to the formula, (Mw) can be obtained not only for polyacrylamide (A) but also for cationic, anionic and amphoteric polymers.

The number average molecular weight (Mn) of (A) is determined by a membrane osmotic pressure measurement method. In the case of an ideal solution, the Phantohof equation: πV = wRT / M (π: osmotic pressure, V: volume, w : Mass, R: gas constant, T: absolute temperature, M: number average molecular weight), if C _m (volume molar concentration) = w / (MV) is substituted, π = C _m RT. Here, when measuring a high molecular weight material as in the present invention, it is necessary to correct, and from the correction equation π = C _m RT + αC _m ² , π / C _m = RT + αC _m . (Α: constant independent of concentration)
Here, when the concentration C is expressed in g per capacity, C _m = C / M may be substituted, so the above equation becomes π / C = RT / M + (α / M ² ) C.
By measuring the osmotic pressure by changing the concentration, if C and π / C are plotted on the graph as the X axis and Y axis, respectively, and the point where the extension line crosses the Y axis (π / C) is obtained, Since the height corresponds to RT / M, M of (A) in the infinitely diluted solution, that is, Mn in the present invention can be obtained therefrom. Usually, the measurement temperature is 37 ° C., and the gas constant R is 8.31 Pa · m ³ / mol · K.

  (Mw / Mn) representing the molecular weight distribution of (A) in the present invention is 1 to 50, preferably 5 to 45, more preferably 10 to 40, and particularly preferably 12 to 35. If (Mw / Mn) is less than 1, it cannot be theoretically, and if it exceeds 50, the aggregation performance is deteriorated.

  (Mw / Mn) in the present invention is a polymerization temperature and drying temperature control, the monomer concentration during polymerization is kept constant at an appropriate concentration, specifically, the hydrophobicity below the boiling point by adjusting the polymerization temperature and pressure. This can be reduced by reversed-phase suspension polymerization in the presence of a dispersion medium, whereby (Mw / Mn) in the above range can be obtained.

The polymer flocculant of the present invention is obtained in the form of hydrous gel particles immediately after production, but it can be obtained by further dehydrating and drying.
The dehydration method is not particularly limited, but after polymerization, a method of dehydration by a drying method such as hot air drying, infrared drying, indirect heating drying (vacuum drying, stirring type dryer, drum dryer), etc., in a hydrophobic dispersion medium A method of azeotropic boiling and dehydration under reduced pressure is conceivable. Moreover, these methods can be used together arbitrarily. From the viewpoint of preventing crosslinking by local heating, vacuum drying and azeotropic distillation in a hydrophobic dispersion medium and dehydration under reduced pressure are preferred. The drying temperature (° C.) is usually 20 to 200, the lower limit is preferably 30 from the viewpoint of the drying speed, more preferably 40, and the upper limit is preferably 150, more preferably 120 from the viewpoint of preventing crosslinking.

The polymer flocculant particles of the present invention preferably have an angle of repose of 25 to 40 (more preferably 30 to 38) degrees from the viewpoint of moderate powder fluidity.
As described above, the polymer flocculant particles of the present invention may have an angle of repose within a preferable range of 25 to 40 degrees by performing reverse phase suspension polymerization using the dispersant (c) having a specific HLB. it can.
Here, the angle of repose is a value obtained by the cylindrical rotation method, and is expressed by an inclination angle when the cylindrical container containing the powder is slowly rotated and the powder forms a stable inclined surface, It can be measured using a three-wheel repose angle measuring machine [manufactured by Tsutsui Riken Kikai Co., Ltd.].

The weight average particle diameter (μm) of the polymer flocculant particles of the present invention is preferably 150, more preferably 200, particularly preferably 250, most preferably 300, to water, from the viewpoint of preventing dust generation during use. From the viewpoint of solubility, the upper limit is preferably 2,000, more preferably 1,700, particularly preferably 1,400, most preferably 1,000.
The weight average particle size (μm) is determined by using a low-tap test sieve shaker and a standard sieve defined in JIS Z8801-2000, Perry's Chemical Engineers Handbook, 6th edition (MacGlow Hill Book Company) Publication, 1984, p. 21).
That is, the above standard sieve having an appropriate opening, for example, opening of 2, 1.7, 1.4, 1.18, 11.0 mm, 850, 710, 500, 425, 355, 300, 250, 180 and 150 μm Take 50.0 g of the polymer flocculant particles on each standard sieve, shake for 1 minute with a low-tap test sieve shaker [eg, Iida Seisakusho Co., Ltd.], and weigh the sample remaining on each sieve To do. The results are plotted on logarithmic probability paper, and the particle diameter (median diameter) when the weight is 50% is defined as the weight average particle diameter.

Moreover, D10 / D50 of the polymer fine particles in the present invention is preferably 1 to 3, more preferably 1 to 2.5, and particularly preferably 1 to 2.
Here, D10 / D50 is an index representing the particle size distribution. The index is obtained by the above-described method using the low-tap test sieve shaker, and D10 represents the particle size when the integrated weight is 10% when plotted in the descending order of the openings of the standard sieve, and D50 Represents the particle diameter (referred to as the weight average particle diameter) when the cumulative weight is 50% when plotted in the same manner. The closer the value of D10 / D50 is to 1, the smaller the coarse particles and the sharper the particle size distribution.

  The water-insoluble content (% by weight) in the polymer flocculant of the present invention is 5% or less, preferably 0 to 3%, more preferably 0 to 1%. If the water-insoluble content exceeds 5%, the agglomeration performance per input amount deteriorates, and equipment problems such as the clogging agent aqueous solution pump being easily clogged arise. The water-insoluble content (% by weight) is measured by the method described later.

In sewage sludge, the size of suspended particles is relatively large, and the surface of suspended particles in water has a negative charge. Therefore, as a polymer flocculant for dehydration, a cationic or amphoteric polymer flocculant is used. And mixtures thereof.
In wastewater, an inorganic flocculant is often added to treat soluble organic matter, and in that case, since the suspended particle surface is covered with the inorganic flocculant, it 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.

  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

Cation or anion colloid equivalent value (meq / g) = (1/2) ×
(Titration of sample-titration of blank test) x (N / 400 PVSK titer)

  The polymer flocculant of the present invention is an antifoaming agent (B1), a chelating agent (B2), a pH adjusting agent (B3), a surfactant (B4), as long as it does not inhibit the effects of the present invention. An additive (B) selected from the group consisting of an antiblocking agent (B5), an antioxidant (B6), an ultraviolet absorber (B7) and a preservative (B8) can be used in combination.

  Examples of the antifoaming agent (B1) include silicone compounds [GMn100 to 100,000, such as dimethylpolysiloxane], mineral oil (spindle oil, kerosene, etc.), metal soap (C12-22, such as calcium stearate), etc .; As the agent (B2), aminocarboxylic acid (C6-24, for example, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid and triethylenetetraminehexaacetic acid), polyvalent carboxylic acid [C4 or more and GMn10, 000 or less, such as maleic acid, polyacrylic acid (GMn 1,000 to 10,000) and isoamylene / maleic acid copolymer (GMn 1,000 to 10,000)], hydroxycarboxylic acid (C3 to 10 such as , Gluconic acid, lactic acid and malic acid), condensed phosphoric acid (tripolyphosphoric acid, trimetaphosphoric acid, etc.) and their salts [alkali metal salts, alkaline earth metal salts, ammonium salts, alkylamines (C1-20, such as methylamine, Ethylamine, octylamine etc.) salts and alkanolamine (C2-12, eg mono-, di- and triethanolamine etc.) salts] etc .;

  Examples of the pH adjuster (B3) include caustic alkali (caustic soda, caustic potash, etc.), amine (C1-20, such as methylamine, ethylamine, mono-, di- and triethanolamine), inorganic acid (salt) [inorganic acid ( Hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, sulfamic acid, carbonic acid, etc.) and their metals [alkali metals, alkaline earth metals, etc.] salts (sodium carbonate, potassium carbonate, sodium sulfate, sodium hydrogen sulfate, monosodium phosphate, etc.) ) And ammonium salts (such as ammonium carbonate and ammonium sulfate)], organic acids (salts) [organic acids [carboxylic acids (C2-15, such as acetic acid, citric acid), sulfonic acids (C1-15, such as methanesulfonic acid, Ethanesulfonic acid, p-toluenesulfonic acid) and phenol], and their metal (same as above) salts (sodium acetate And lactic acid soda) and ammonium salts (ammonium acetate, ammonium lactate, etc.), etc.] and the like;

  Surfactants (B4) include surfactants described in US Pat. No. 4,331,447, such as polyoxyethylene nonylphenyl ether and dioctylsulfosuccinate soda; antiblocking agents (B5) include polyether-modified silicone oil ( GMn 100-3,000), for example polyoxyethylene modified silicone and polyoxyethylene / polyoxypropylene modified silicone];

  Antioxidants (B6) include phenol compounds [hydroquinone, methoxyhydroquinone, catechol, 2,6-di-t-butyl-p-cresol (BHT) and 2,2′-methylenebis (4-methyl-6-t). -Butylphenol), etc.], sulfur-containing compounds [thiourea, tetramethylthiuram disulfide, dimethyldithiocarbamic acid and its salts [for example, metal (same as above) salts and ammonium salts, etc.], sodium sulfite, sodium thiosulfate, 2-mercapto Benzothiazole and salts thereof (same as above), dilauryl 3,3′-thiodipropionate (DLTDP) and distearyl 3,3′-thiodipropionate (DSTDP), etc.], phosphorus-containing compounds [triphenyl phosphite , Triethyl phosphite, sodium phosphite , Sodium hypophosphite, triphenyl phosphite (TPP) and triisodecyl phosphite (TDP) and the like] and nitrogen-containing compounds [amines (octylated diphenylamine, Nn-butyl-p-aminophenol and N, N-diisopropyl-p-phenylenediamine etc.), urea, guanidine and guanidine inorganic acid (same as above) salts] and the like;

Examples of the ultraviolet absorber (B7) include benzophenone compounds (2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, etc.), salicylate compounds (phenyl salicylate, 2,4-di-t-butylphenyl-3,5-di). -T-butyl-4-hydroxybenzoate, etc.), benzotriazole compounds [(2′-hydroxyphenyl) benzotriazole, (2′-hydroxy-5′-methylphenyl) benzotriazole, etc.] and acrylates [ethyl-2-cyano −3,3-diphenyl acrylate, methyl-2-carbomethoxy-3- (paramethoxybenzyl) acrylate, etc.] and the like;
Examples of the preservative (B8) include benzoic acid, paraoxybenzoic acid ester, and sorbic acid.

The above (B) may be added in advance to the monomer aqueous solution before polymerization or may be added to the polymer after production. (B) The total amount used is usually 30% or less based on the monomer or polymer weight, and preferably 0 to 10% from the viewpoint of aggregation performance.
The amount of each additive of (B1) to (B8) used is usually 5% or less, preferably 1 to 3%, and (B2) is usually 20% or less, based on the same weight as above. Preferably 2 to 10%, (B3) is usually 10% or less, preferably 1 to 5%, (B4) and (B5) are each usually 5% or less, preferably 1 to 3%, (B6), (B7 ) And (B8) are each usually 5% or less, preferably 0.1 to 2%.

The method for adding the polymer flocculant of the present invention to sewage sludge, waste water or the like (hereinafter abbreviated as sewage sludge or the like) is not particularly limited, and is described in, for example, Japanese Patent No. 1311340 or Japanese Patent No. 2038341. A method is mentioned.
The amount of the polymer flocculant used in the present invention varies depending on the type of sewage sludge, the content of suspended particles, the molecular weight of the polymer flocculant, etc., but is not particularly limited, and the weight of evaporation residue in sewage sludge etc. (Hereinafter abbreviated as TS), usually from 0.01 to 10%, preferably from the viewpoint of agglomeration performance, the lower limit is 0.1%, more preferably 0.5%, particularly preferably 1%, from the viewpoint of processing costs Therefore, the preferable upper limit is 5%, more preferably 3%, and particularly preferably 2%.

As a method of using the polymer flocculant of the present invention, it is preferable to add it to sewage sludge after making it into an aqueous solution from the viewpoint of sufficient flocculation performance, but the polymer flocculant is added directly to sewage sludge etc. in a solid state. You can also The concentration when the polymer flocculant 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 the polymer flocculant is not particularly limited. For example, a predetermined amount of the polymer flocculant is gradually added while stirring the water weighed in advance using a stirring device such as a jar tester, A method of dissolving for several hours (about 2 to 4 hours) can be employed. When the powdery polymer flocculant is dissolved in water, a method of adding a predetermined amount of the polymer flocculant at a stretch is undesirably caused by the fact that it becomes difficult to completely dissolve in water.

  When the polymer flocculant of the present invention is used for the third recovery of petroleum, it is usually used as an aqueous solution. The concentration (% by weight) of the aqueous polymer solution is usually 0.001 to 3%, preferably from 0.005 to 1%, more preferably from 0.01 to 0.5 from the viewpoint of the thickening effect and the viscosity capable of feeding. %.

When the polymer flocculant of the present invention is applied to sewage sludge, etc., if the sewage sludge is organic sludge or anaerobic bacteria-treated sludge, inorganic and / or organic coagulation is performed from the viewpoint of charge neutralization of the sludge particles. It is preferable to use an agent in combination.
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, sewage sludge is treated with a mixture obtained by adding these to the polymer flocculant of the present invention in advance, or an inorganic coagulant and / or an organic coagulant is preliminarily applied to the sewage sludge. After the primary agglomeration is added, the polymer flocculant of the present invention may be added and treated, but the latter method is preferred from the viewpoint of floc strength.

  The amount used when using an inorganic coagulant and / or an organic coagulant varies depending on the type of sewage sludge, the size of suspended particles, the type of coagulant used, etc., but there is no particular limitation. 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 the polymer flocculant of the present invention is added, the pH of sewage sludge and the like 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. In addition, the pH can be adjusted by adding the inorganic or organic coagulant to sewage sludge or the like in advance.

  Further, as a dehydration method (solid-liquid separation method) for floc formed by adding the polymer flocculant of the present invention to sewage sludge, various methods such as centrifugal dehydration, belt press dehydration, filter press dehydration, and capillary dehydration are available. Dehydration method can be applied. Among these, centrifugal dehydration, belt press dehydration, and filter press dehydration are preferable from the viewpoint of high floc strength, which is the specific aggregation performance of the polymer flocculant 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 intrinsic viscosity [η], solid content, Mw, π / C, Mn, Mw / Mn, weight average particle diameter and angle of repose of the polymer flocculant were measured by the above methods, and other evaluation items were as follows: It is as follows.
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).

<Water-insoluble matter (% by weight)>
In a 1 L beaker, 500 g of a 0.1 wt% sodium chloride aqueous solution was added, 2.5 g of a polymer flocculant sample was added to the aqueous solution, and a motor equipped with a stirring blade having a length of 50 mm and a width of 20 mm was used. Stir for hours to dissolve. The lysate is filtered through a 100 μm mesh weighed in advance. The residue is placed on an aluminum dish together with the mesh and dried for 2 hours in a circulating air dryer at 120 ° C. Let the value calculated | required with the following formula be a water-insoluble amount (weight%).

Water insoluble matter = 100 × [residue weight after drying (g)] / [sample weight at dissolution (g)]

<Adhesion rate (% by weight)>
This is a value obtained by dividing the polymer solid content adhering to the inner wall of the reaction vessel or the stirring blade after polymerization by the theoretical yield.

<Flock particle size>
Jar tester [Miyamoto Riken Kogyo Co., Ltd., model JMD-6HS-A, and so on. ] Two plate-shaped stirring blades made of polyvinyl chloride (diameter 5 cm, height 2 cm, thickness 0.2 cm) were attached to the stirring bar continuously in a vertical shape so as to form a cross, and 200 ml of sludge was taken in a 300 ml beaker, Set it on the jar tester. The rotation speed of the jar tester was set to 120 rpm, and while stirring the sludge gradually, an aqueous solution of a polymer flocculant having a predetermined concentration was added by a predetermined method, and after stirring for 30 seconds, the stirring was stopped and the size of the floc was visually observed. [The floc particle size (unit: mm) at 120 rpm is shown in Table 2].
Subsequently, the number of revolutions was set to 300 rpm, and after stirring for 30 seconds, the stirring was stopped and the size of the floc was again visually observed. [Table 2 shows the floc particle size (unit: mm) at the number of revolution of 300 rpm] .

<Amount of filtrate>
Set T-1189 nylon filter cloth [Shikishima Kanbusu Co., Ltd., circular shape, diameter 9 cm], Nutsche funnel, 300 ml measuring graduated cylinder. Using a stopwatch, measure the amount of filtrate 60 seconds after the start.
<Filter cloth peelability>
Part of the filtered sludge is removed with a spatula and subjected to a dehydration test (2 kg / cm ² , 60 seconds) using a press filter tester, and the peelability of the dewatered cake from the filter cloth after the test is evaluated according to the following criteria: To do.

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)

<Moisture content of cake>
About 3 g of dehydrated cake after the filter cloth peelability test was weighed (W3) in a petri dish and dried in a circulating dryer until the water was completely evaporated (for example, at 105 ± 5 ° C. for 8 hours). Using the weight of the dry cake remaining on the petri dish as (W4), the moisture content of the cake is calculated from the following equation.

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

Production Example 1 [Production Method of Dispersant (C-1)]
A reaction vessel equipped with a reflux dehydration tube, a dropping funnel and a stirring blade was charged with 500 parts of xylene, 50 parts of maleic anhydride, and 500 parts of ethylene vinyl acetate resin [trade name “A-C400”, manufactured by Honeywell Co., Ltd.] The inside of the reaction vessel was heated to 150 ° C. under nitrogen flow and stirred to obtain a uniform solution. Separately, a solution consisting of 50 parts of xylene and 50 parts of dicumyl peroxide [trade name “Park Mill D”, manufactured by NOF Corporation] was prepared and charged into a dropping funnel and dropped into the reaction vessel over 1 hour. The mixture is then stirred at 150 ° C. for 3 hours to complete the reaction, xylene is distilled off under reduced pressure, the product is taken out, cooled and pulverized to disperse the ethylene vinyl acetate resin grafted with maleic anhydride (C- 1) 540 parts were obtained. (C-1) was Mn 18,000, Mw was 40,000, melting point 45 ° C., and HLB2.1.

Example 1
839 parts of 70% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl acrylate, 108 parts of 50% aqueous solution of acrylamide, 333 parts of ion-exchanged water, chain transfer constant 0.8, water / n-decane partition coefficient = 99/1) 0.064 parts of a mixture was prepared at room temperature (20-25 ° C.). Furthermore, the pH (20 ° C.) of the aqueous monomer solution was adjusted to 3.0 using sulfuric 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 100 ppb or less), and then 1.94 parts of a 10% aqueous solution of azobisamidinopropane hydrochloride was added. A homogeneous solution was prepared to prepare an aqueous monomer solution.
Separately, 1,282 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 alkene (C30 or higher) and anhydrous as a dispersant. Copolymer of maleic acid [trade name “Diacarna 30”, manufactured by Mitsubishi Chemical Corporation, HLB2.1, melting point 65 ° C., GMw 10,000, and so on. 12.8 parts were added, and the inside of the reaction vessel was purged with nitrogen (gas phase oxygen concentration: 10 ppm or less) while stirring the stirring blade at a rotation speed of 340 rpm, and then the temperature was raised to 57 ° C. After reaching 57 ° C., the above-mentioned monomer aqueous solution previously charged in the dropping funnel was charged into the reaction tank over 60 minutes under normal pressure conditions (103 kPa), and stirring was continued at 57 ° C. for 180 minutes after completion of the charging. Reverse phase suspension polymerization was then carried out. Further, 0.19 part of mercaptoacetic acid was dissolved in 10 parts of ion-exchanged water, which was additionally charged into the reaction vessel, and stirring was continued at 57 ° C. for 180 minutes to complete the polymerization.
After the polymerization, the polymer was azeotropically dehydrated at 50 ° C. under reduced pressure (3 kPa), then the slurry was supplied to a vacuum filter and subjected to solid-liquid separation, and then in a vacuum dryer (1.3 kPa, 40 ° C. × 2 Time) to obtain 688 parts of a polymer flocculant (A1) made of a copolymer (solid content 93.2%).

Example 2
In Example 1, instead of 839 parts of a 70% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl acrylate, 344 parts of a 64% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl methacrylate, and a 50% aqueous solution of acrylamide 603 parts instead of 108 parts, 357 parts instead of 333 parts of ion-exchanged water, hypophosphorous acid instead of 0.064 parts of mercaptoacetic acid (chain transfer constant 2, water / n-decane partition coefficient = 99. 9 / 0.1) 0.026 parts, and a high copolymer consisting of a copolymer in the same manner as in Example 1 except that 0.052 parts of hypophosphorous acid was used instead of 0.19 parts of mercaptoacetic acid added additionally. 556 parts of molecular flocculant (A2) (solid content 93.8%) were obtained.

Example 3
In Example 1, instead of 839 parts of a 70% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl acrylate, 108 parts of a 50% aqueous solution of acrylamide, and 333 parts of ion-exchanged water, N, N-dimethylaminoethyl acrylate 152 parts of 70% aqueous solution of methyl chloride, 469 parts of 50% aqueous solution of acrylamide, 268 parts of 64% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl methacrylate, 59.4 parts of acrylic acid, 469.7 ion-exchanged water In addition to 0.064 parts of mercaptoacetic acid, 0.029 parts of thioglycerol (chain transfer constant 0.6, water / n-decane partition coefficient = 99.99 / 0.01), 0 additional mercaptoacetic acid Instead of 19 parts, 0.029 parts of thioglycerol is used and azobisamidinop is used. In the same manner as in Example 1, except that 1.94 parts of a 10% aqueous solution of pan hydrochloride was used instead of 1.94 parts, and 11.4 parts of monosodium phosphate was used, 633 parts of a molecular flocculant (A3) (solid content 92.1%) were obtained.

Example 4
In Example 1, instead of 839 parts of a 70% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl acrylate, 108 parts of a 50% aqueous solution of acrylamide, and 333 parts of ion-exchanged water, N, N-dimethylaminoethyl acrylate 363 parts of a 70% aqueous solution of methyl chloride, 262 parts of a 50% aqueous solution of acrylamide, 85.3 parts of a 64% aqueous solution of methyl chloride of N, N-dimethylaminoethyl methacrylate, 132 parts of acrylic acid, 586.9 In place of 12.8 parts of a copolymer of alkene (C30 or higher) and maleic anhydride, a maleic anhydride-modified ethylene / vinyl acetate copolymer [trade name “Orevac 9318”, manufactured by Arkema Co., Ltd., HLB1 .2, melting point 50 ° C., GMw 11,000] 6.4 parts and PEG Fatty acid ester [trade name "Ionet DS-300", manufactured by Sanyo Chemical Industries, Ltd., HLB7.3, melting point 35 ℃, GMw850, following the same. 0.64 parts, 0.017 parts of triethylene glycol dithiol (chain transfer constant 1, water / n-decane partition coefficient = 80/20) instead of 0.064 parts of mercaptoacetic acid, and phosphoric acid A polymer flocculant (A4) 622 parts (solid) made of a copolymer was used in the same manner as in Example 1 except that 11.4 parts of monosodium was used but 0.19 part of mercaptoacetic acid was not added. A content of 93.7%).

Example 5
In Example 1, instead of 839 parts of a 70% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl acrylate, 590 parts of the same, 456 parts of the same instead of 108 parts of a 50% aqueous solution of acrylamide, and 333 parts of ion-exchanged water. Instead, 236 parts of the same, instead of 0.064 parts of mercaptoacetic acid, 0.0064 parts of 2-mercaptoethanol (chain transfer constant 10, water / n-decane partition coefficient = 99/1), 10 of azobisamidinopropane hydrochloride Polymer flocculant made of a copolymer in the same manner as in Example 1 except that 1.7 parts of the same was used instead of 1.94 parts of an aqueous solution and 0.19 part of mercaptoacetic acid was not added. (A5) 686 parts (solid content 93.5%) were obtained.

Example 6
In Example 1, instead of 839 parts of 70% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl acrylate, 215 parts of the same, 808 parts of the same instead of 108 parts of 50% aqueous solution of acrylamide, and 333 parts of ion-exchanged water Instead of 237 parts of the same, 0.0083 parts of thioglycerol instead of 0.064 parts of mercaptoacetic acid, 0.55 parts of the same instead of 1.94 parts of 10% aqueous solution of azobisamidinopropane hydrochloride, the alkene (C30 And 6.3 parts of dispersant (C-1) and 14.7 parts of PEG fatty acid ester instead of 12.8 parts of copolymer of maleic anhydride and 0.19 parts of mercaptoacetic acid. 542 parts (solid content 93.0%) of a polymer flocculant (A6) comprising a copolymer were obtained in the same manner as in Example 1 except that there was not.

Example 7
In Example 2, except that 12.8 parts of dispersant (C-1) and 3.8 parts of PEG fatty acid ester were used instead of 12.8 parts of copolymer of alkene (C30 or higher) and maleic anhydride. In the same manner as in Example 2, 557 parts (solid content 93.7%) of a polymer flocculant (A7) made of a copolymer was obtained.

Comparative Example 1
839 parts of 70% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl acrylate, 108 parts of 50% aqueous solution of acrylamide, mercaptoacetic acid (chain transfer constant 0.8, water / n-decane partition coefficient = 99/1) 064 parts and 333 parts of ion exchange water were blended to prepare an aqueous monomer solution at room temperature (20 to 25 ° C.). Furthermore, the pH (20 ° C.) of the aqueous monomer solution was adjusted to 3.0 using sulfuric acid while monitoring with a pH meter. After this monomer aqueous solution was adjusted to 10 ° C., it was charged into an adiabatic reaction vessel, and the inside of the polymerization tank was sufficiently substituted with nitrogen (gas phase oxygen concentration of 10 ppm or less). After nitrogen substitution, 11.3 parts of a 5% aqueous solution of azobisamidinopropane hydrochloride, 0.9 part of a 0.1% aqueous solution of hydrogen peroxide, and 0.8 part of a 0.1% aqueous solution of ascorbic acid were added. After about 10 minutes, the liquid temperature began to rise, and the reaction system gradually thickened to obtain a gel-like polymer. When heat generation is no longer observed, the temperature is maintained, and after 7 hours, the gel is chopped (1 mm square), dried with hot air at 100 ° C. for 5 hours, pulverized with a mixer, As a result, 691 parts of a polymer flocculant (solid content 92.8%) composed of a coalescence (ratio A1) was obtained.

Comparative Example 2
In Comparative Example 1, the same monomer solution as in Example 2 containing 0.026 part of hypophosphorous acid (chain transfer constant 2, water / n-decane partition coefficient = 99.9 / 0.1) was used. Except that, a polymer flocculant (ratio A2) made of a copolymer was obtained in the same manner as in Comparative Example 1.

Comparative Example 3
In Example 3, 0.57 parts of triethylene glycol (chain transfer constant 0.006, water / n-decane partition coefficient = 98/2) was used instead of 0.029 parts of thioglycerol, and an additional charge of thioglycerol 0 A polymer flocculant (ratio A3) made of a copolymer was obtained in the same manner as in Example 3 except that 0.029 part was not added.

Comparative Example 4
In Example 4, instead of 6.4 parts of maleic anhydride-modified ethylene / vinyl acetate copolymer and 0.64 part of PEG fatty acid ester, 12.8 parts of a copolymer of alkene (C30 or more) and maleic anhydride, In the same manner as in Example 4 except that 1.7 parts of sodium acetate (chain transfer constant 0.001, water / n-decane partition coefficient = 100/0) was used instead of 0.017 parts of ethylene glycol dithiol. A polymer flocculant (ratio A4) made of a polymer was obtained.

Comparative Example 5
Example 5 Example 5 except that 0.57 parts of malonic acid (chain transfer constant 0.002, water / n-decane partition coefficient = 98/2) was used instead of 0.0064 parts of 2-mercaptoethanol. In the same manner as in Example 5, a polymer flocculant (ratio A5) made of a copolymer was obtained.

Comparative Example 6
In Example 6, Example 6 was used except that 0.86 part of dimethylaminoethanol (chain transfer constant 0.002, water / n-decane partition coefficient = 99/1) was used instead of 0.0083 part of thioglycerol. In the same manner as above, a polymer flocculant (ratio A6) made of a copolymer was obtained.

  About Examples 1-7 and Comparative Examples 1-6, intrinsic viscosity of the obtained polymer flocculant, Mw, π / C, Mn, Mw / Mn, water insoluble matter, chain of chain transfer agent used for polymerization Table 1 shows the results of the transfer constant (Cf), the remaining amount of chain transfer agent (Wf) in the polymer flocculant, the adhesion rate, and the angle of repose.

表１から、実施例１〜７では比較例１〜６に比べて（Ｍｗ／Ｍｎ）比が小さく、水不溶解分が少なく、高分子凝集剤中に連鎖移動剤がすべて残存し、安息角が適度な値であることがわかる。

From Table 1, in Examples 1-7, the (Mw / Mn) ratio is small compared to Comparative Examples 1-6, the water-insoluble content is small, all the chain transfer agents remain in the polymer flocculant, and the angle of repose It can be seen that is a moderate value.

Example 8 and Comparative Example 7
(A1) and (Ratio A1) were each dissolved in ion-exchanged water to obtain an aqueous solution having a solid content of 0.2%. 200 parts of surplus sludge [pH 5.3, TS 3.3%, organic content 78.3%] collected from the T treatment plant was placed in a 300 mL beaker, and 32 parts, 35 and 38 of an aqueous solution of (A1) and (ratio A1). Parts are added to each sludge (the amount of solid added at this time is 1.0, 1.1, 1.2% / TS, respectively) and thoroughly stirred and mixed with a hand mixer. The particle size, filtrate amount, filter cloth peelability and cake moisture content were measured. The results are shown in Table 2.

表２から、実施例８では、比較例７に比べて、大粒径のフロックが形成され、高撹拌下（３００ｒｐｍ）でも一旦形成されたフロックが壊れにくい（フロック強度が大）こと、ろ布剥離性および脱水性（ケーキ含水率）において優れた効果を示すこと、および凝集性能の添加量への依存性が小さいことがわかる。

From Table 2, in Example 8, compared to Comparative Example 7, flocs having a large particle diameter were formed, and the flocs once formed were not easily broken even under high agitation (300 rpm) (the floc strength was high). It can be seen that an excellent effect in peelability and dewaterability (cake water content) is exhibited, and that the agglomeration performance is less dependent on the added amount.

Examples 9, 10 and Comparative Example 8
(A2), (A7) and (Ratio A2) were each dissolved in ion-exchanged water to obtain an aqueous solution having a solid content of 0.2%. 200 parts of mixed raw sludge [pH 5.3, TS 2.3%, organic content 80.2%] collected from the N treatment plant was taken in a 300 mL beaker, and each of (A2), (A7) and (Ratio A2) Add 12, 14 and 16 parts of aqueous solution to each sludge, and add and stir well with a hand mixer (the amount of solids added is 0.5, 0.6 and 0.7% / TS, respectively). The floc particle size, filtrate amount, filter cloth peelability and cake moisture content were measured by the above-described methods. The results are shown in Table 3.

表３から、実施例９、実施例１０では、比較例８に比べて、大粒径のフロックが形成され、高撹拌下（３００ｒｐｍ）でも一旦形成されたフロックが壊れにくい（フロック強度が大）こと、ろ布剥離性および脱水性（ケーキ含水率）において優れた効果を示すこと、および凝集性能の添加量への依存性が小さいことがわかる。

From Table 3, in Example 9 and Example 10, a floc having a large particle diameter is formed as compared with Comparative Example 8, and the floc once formed is not easily broken even under high agitation (300 rpm) (the floc strength is large). In addition, it can be seen that the filter cloth peelability and dewaterability (cake water content) are excellent, and that the cohesive performance is less dependent on the added amount.

Example 11 and Comparative Example 9
(A4) and (Ratio A4) were each dissolved in ion-exchanged water to obtain an aqueous solution having a solid content of 0.2%. 200 parts of mixed sludge collected from T treatment plant [excess sludge / digested sludge = 1/1 (weight ratio), pH 5.9, TS 2.7%, organic content 72.2%] were taken in a 300 mL beaker, respectively, [Nippon Mining Co., Ltd., the same applies hereinafter] After adding 0.27 parts and stirring and mixing with a hand mixer for 30 seconds, 20 parts, 23 parts and 26 parts of each of the aqueous solutions (A4) and (ratio A4) were added ( At this time, the solid content was 0.7, 0.8, and 0.9% / TS, respectively, and sufficiently stirred and mixed with a hand mixer, and the floc particle size, filtrate amount, The filter cloth peelability and cake moisture content were measured. The results are shown in Table 4.

表４から、実施例１１では、比較例９に比べて、大粒径のフロックが形成され、高撹拌下（３００ｒｐｍ）でも一旦形成されたフロックが壊れにくい（フロック強度が大）こと、ろ布剥離性および脱水性（ケーキ含水率）において優れた効果を示すこと、および凝集性能の添加量への依存性が小さいことがわかる。

From Table 4, in Example 11, compared to Comparative Example 9, flocs having a large particle diameter were formed, and the flocs once formed were not easily broken even under high agitation (300 rpm) (floc strength was high). It can be seen that an excellent effect in peelability and dewaterability (cake water content) is exhibited, and that the agglomeration performance is less dependent on the added amount.

Example 12 and Comparative Example 10
(A5) and (Ratio A5) were each dissolved in ion-exchanged water to obtain an aqueous solution having a solid content of 0.2%. 200 parts of excess sludge [pH 5.5, TS 3.2%, organic content 81.1%] collected from the M treatment plant was put in a 300 mL beaker, and 19 parts, 22 and 26 of an aqueous solution of (A5) and (ratio A5). Parts are added to each sludge (the solids added at this time are 0.6, 0.7 and 0.8% / TS, respectively) and thoroughly stirred and mixed with a hand mixer. The particle size, filtrate amount, filter cloth peelability and cake moisture content were measured. The results are shown in Table 5.

表５から、実施例１２では、比較例１０に比べて、大粒径のフロックが形成され、高撹拌下（３００ｒｐｍ）でも一旦形成されたフロックが壊れにくい（フロック強度が大）こと、ろ布剥離性および脱水性（ケーキ含水率）において優れた効果を示すこと、および凝集性能の添加量への依存性が小さいことがわかる。

From Table 5, in Example 12, compared to Comparative Example 10, flocs having a large particle diameter were formed, and the flocs once formed were not easily broken even under high agitation (300 rpm) (the floc strength was high). It can be seen that an excellent effect in peelability and dewaterability (cake water content) is exhibited, and that the agglomeration performance is less dependent on the added amount.

Example 13 and Comparative Example 11
(A6) and (Ratio A6) were each dissolved in ion-exchanged water to obtain an aqueous solution having a solid content of 0.2%. 200 parts of mixed raw sludge [pH 5.2, TS 2.2%, organic content 79.8%] collected from the K treatment plant was placed in a 300 mL beaker, and 11 parts, 13 and 13 of an aqueous solution of (A6) and (ratio A6) 15 parts are added to each sludge (the amount of solids added at this time is 0.5, 0.6, 0.7% / TS, respectively) and thoroughly stirred and mixed with a hand mixer. Flock particle size, filtrate amount, filter cloth peelability and cake moisture content were measured. The results are shown in Table 6.

表６から、実施例１３では、比較例１１に比べて、大粒径のフロックが形成され、高撹拌下（３００ｒｐｍ）でも一旦形成されたフロックが壊れにくい（フロック強度が大）こと、ろ布剥離性および脱水性（ケーキ含水率）において優れた効果を示すこと、および凝集性能の添加量への依存性が小さいことがわかる。

From Table 6, in Example 13, compared to Comparative Example 11, flocs having a large particle diameter were formed, and the flocs once formed were not easily broken even under high agitation (300 rpm) (the floc strength was high). It can be seen that an excellent effect in peelability and dewaterability (cake water content) is exhibited, and that the agglomeration performance is less dependent on the added amount.

Example 14 and Comparative Example 12
(A3) and (Ratio A3) were each dissolved in ion-exchanged water to obtain an aqueous solution having a solid content of 0.2%. 800 parts of a 3% strength core fiber slurry (30 ° C., pH 4.5), 72 parts of each aqueous solution of (A3) and (ratio A3) (solid content added 0.6% / TS) and sulfuric acid band 0.96 part was added and paper was made to produce a paper having the basis weight shown in Table 7. Moreover, the same operation was performed as a blank, without adding a polymer flocculant. Table 7 shows the results of breaking length and drainage amount. The breaking length and the amount of drainage were measured according to JISP-8113 and JIS P-8121.

表７から、実施例１４では、比較例１２に比べて、裂断長およびろ水量が高く、製紙工程用薬剤として優れた効果を示すことがわかる。

From Table 7, it can be seen that, in Example 14, the tearing length and the amount of drainage are higher than those of Comparative Example 12, and show excellent effects as a chemical for papermaking process.

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

Claims (5)

A polymerizable monomer (a) comprising a water-soluble unsaturated monomer is converted from a compound having one or more thiol groups in a molecule having a chain transfer constant of 0.05 to 50 and a (hypo) phosphite compound. Reverse phase suspension polymerization in the presence of at least one chain transfer agent (f) selected from the group consisting of: (f) adding (f) during the polymerization or at the end of the polymerization, or (f) As a water / n-decane partition coefficient of 10/90 to 80/20, having an intrinsic viscosity of 6 to 25 dl / g, and a weight average molecular weight (Mw) converted from the intrinsic viscosity and membrane It is composed of a (co) polymer (A) having a ratio (Mw / Mn) to a number average molecular weight (Mn) of 12 to 35 by a formula osmometry, and has a water insoluble content of 5% by weight or less, (f) The remaining amount of is 0.001-1% by weight Polymer flocculant to be. The polymer flocculant according to claim 1, wherein the amount of (f) used based on the weight of (a) is 0.001 to 10%. The polymer flocculant according to claim 1 or 2, which is used for dewatering sewage sludge. The polymer flocculant according to claim 1 or 2, which is used for improving drainage yield or enhancing paper strength in a papermaking process. A polymerizable monomer (a) comprising a water-soluble unsaturated monomer comprises a compound having one or more thiol groups in a molecule having a chain transfer constant of 0.05 to 50 and a (hypo) phosphite compound. Reverse-phase suspension polymerization is carried out in the presence of at least one chain transfer agent (f) selected from the group, and (f) is additionally charged during or at the end of the polymerization, or Weight average molecular weight (Mw) having an intrinsic viscosity of 6 to 25 dl / g and converted from the intrinsic viscosity, characterized by using an / n-decane partition coefficient of 10/90 to 80/20 It consists of a (co) polymer (A) having a ratio (Mw / Mn) to a number average molecular weight (Mn) of 12 to 35 as measured by a membrane osmotic pressure measurement method, and has a water insoluble content of 5% by weight or less (f ) Residual amount of 0.001 to 1% by weight Manufacturing method of the flocculant.