JP2012232287A - Polymer flocculant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer flocculant capable of greatly improving dehydration treatment efficiency for sludge or waste water by forming dense and low water content flocks in the dehydration treatment of organic sludge difficult to dehydrate.SOLUTION: The polymer flocculant includes a water-soluble polymer satisfying the relational expression: -0.40≤ln[η]/lnV≤0.55 where [η] represents the intrinsic viscosity in aqueous solution of 1N-NaNOat 30°C; and Vs represents the 0.5 wt.% salt water solution viscosity in aqueous solution of 4 wt.% NaCl at 25°C. A method of treating sludge or waste water is also provided, the method including the steps of: adding the polymer flocculant to sludge or waste water; mixing them to form flocks; and subjecting the same to solid-liquid separation.

Description

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

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

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

  Recently, in order to improve the dewaterability of sludge, a method using an inorganic flocculant and an amphoteric polymer flocculant in combination (for example, see Patent Document 1) has been proposed and widely used. However, this method is expensive compared with the method using a cationic polymer flocculant, and there are problems such as an increase in sludge cake generated by using an inorganic flocculant and an increase in ash after incineration. Reduction of inorganic flocculants is required. However, if the amount of the inorganic flocculant is reduced, the strength of sludge flocculation floc (hereinafter abbreviated as “floc”) is lowered and becomes fragile, resulting in problems such as an increase in water content.

Japanese Patent Laid-Open No. 2-180700

Currently used polymer flocculants have not yet reached a level that can sufficiently solve the above-mentioned problems, and the disclosed polymer flocculants are from the viewpoint of floc strength and dehydrated cake moisture content. Although it was improved somewhat, it was still insufficient.
An object of the present invention is to provide a polymer flocculant capable of significantly improving sludge dewatering efficiency by forming dense and low moisture content floc in dewatering treatment of hardly dewatering organic sludge and the like. .

The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems. That is, the present invention relates to a polymer flocculant comprising a water-soluble polymer (A) satisfying the following relational expression [1]; and a floc obtained by adding and mixing the polymer flocculant to sludge or waste water. Is a method of treating sludge or wastewater that forms solids and liquids.

−0.40 ≦ ln [η] / ln V _s ≦ 0.55 [1]

[In the formula, [η] represents an intrinsic viscosity at 30 ° C. in a 1N—NaNO ₃ aqueous solution, and V _s represents a 0.5 wt% salt aqueous solution viscosity at 25 ° C. in a 4 wt% NaCl aqueous solution. ]

The polymer flocculant of the present invention has the following effects.
(1) Forming flocs with dense and low water content in the dewatering treatment of organic sludge.
(2) Since the formed floc is not easily broken or redispersed, the stability and processing speed of the aggregation treatment can be remarkably increased.
(3) The moisture content of the cake after the dehydration step is low, and the amount of waste and incineration costs can be reduced.

[Water-soluble polymer (A)]
The water-soluble polymer (A) in the present invention satisfies the following relational expression [1].

−0.40 ≦ ln [η] / lnV _s ≦ 0.55 [1]

In the above relational expression [1], [η] is an intrinsic viscosity at 30 ° C. in a 1N—NaNO ₃ aqueous solution (unit is dl / g), and V _s is 25 ° C. in a 4 wt% NaCl aqueous solution measured by the method described later. Represents 0.5 wt% salt aqueous solution viscosity (unit: mPa · s; hereinafter referred to as 0.5% salt aqueous solution viscosity), and ln [η] / lnV _s is the natural logarithm of [η] and V Represents the ratio of _{s to} the natural logarithm.
When the ratio is less than −0.40 or exceeds 0.55, the aggregation performance of the water-soluble polymer is deteriorated.
In the present invention, the water-soluble polymer or the water-soluble monomer described later means that the solubility in water is 2 g or more / 100 g of water (20 ° C.), and the aggregation performance in the present invention is the floc strength. It means the performance of the polymer flocculant evaluated by filtration rate, floc density, moisture content of dehydrated cake, and the like.

  In deriving the relational expression [1], the following hypothesis was made regarding the relationship between the water-soluble polymer spreading in water and the coagulation performance. That is, when the polymer chain is excessively shrunk, it is difficult to neutralize the charge on the sludge particle surface, a weak floc is formed, the water content is high, and the polymer chain is excessively spread Although the surface charge of the sludge particles is neutralized, flocs containing a lot of water are formed during aggregation, and the water content is estimated to increase. It is a hypothesis that it excels in performance.

In order to verify this hypothesis, many experiments were conducted, and based on the obtained results, the relationship between the spread of water-soluble polymers in water and the coagulation performance was considered.
Here, regarding the expansion of the water-soluble polymer in water, the following <Sakurada-Houwink formula> representing the relationship between the expansion of the polymer in the solution, the molecular weight, and the intrinsic viscosity was referred to. ("Molecular properties of polymers (bottom)" by Akio Nakajima and Masao Hosono, published by Kagaku Dojin, pages 314-319, "The World of Rheology" by Kunihiro Ozaki, published by Industrial Research Institute, page 86, etc. reference)

[Η] = KMα <Sakurada-Houwink formula>

In the formula, [η] is the intrinsic viscosity, M is the molecular weight of the polymer, and K and α are constants determined by the type of polymer, solvent, temperature, and the like.
Since α in the formula is a factor related to the shape of the polymer chain, from [Sakurada-Houwink formula], ln [η] / lnM represents a factor related to the shape of the polymer chain, that is, the spread of the polymer chain. It is derived that it corresponds to a factor.
In the case of a water-soluble polymer as a polymer flocculant, the molecular weight cannot be easily measured, so the 0.5% salt aqueous solution viscosity V _s , which is an alternative indicator, is replaced with M, and ln [η] / lnV _s is dissolved in water. It was set as a factor showing the spread of the water-soluble polymer in water.
Here, as described above, the 0.5% salt aqueous solution viscosity V _s is the viscosity of the water-soluble polymer in a salt solution having a high concentration (4% by weight NaCl), and is used as an alternative index representing the molecular weight of the water-soluble polymer. It is used. That is, the water-soluble polymer used in the polymer flocculant is in a state where the polymer chain is expanded in water by electrostatic repulsion or hydration due to ionic groups present in the polymer chain. On the other hand, in high-concentration salt aqueous solution, the electrostatic repulsion and hydration of polymer chains are suppressed by the electrolyte components, and the polymer chains are in a state of being shrunk to the limit. Therefore, an alternative index that represents the molecular weight of water-soluble polymers It is generally considered to be
As a result of the above experiments and discussions, the water-soluble polymer having an ln [η] / lnV _s ratio in the range of −0.40 to +0.55 representing the spread of the water-soluble polymer in water exhibits particularly excellent aggregation performance. Was found in the present invention.

The ln [η] / lnV _s ratio is preferably −0.30 to 0.48, more preferably −0.20 to 0.35. If the ratio is less than −0.40, the water-soluble polymer chain shrinks excessively, the charge on the sludge particle surface is difficult to neutralize with (A), the sludge cannot be sufficiently aggregated, and the floc is easily broken. The moisture content is increased. Also, When the ratio exceeds 0.55, the water-soluble polymer chain is excessively spread, flocs containing a large amount of water are formed, and the moisture content of the cake after dehydration is increased.

The water-soluble polymer (A) in the present invention has one unsaturated group and preferably has an octanol / water partition coefficient (logPow) of 1.0 to 6.0, more preferably 1.2 to 5.8. Particularly preferred is a water-soluble polymer comprising as constituent units a hydrophobic monomer (a) of 1.3 to 5.6 and a water-soluble monomer (b) having one unsaturated group.
When the octanol / water partition coefficient of (a) is 1.0 or more, re-dispersion of flocs formed when used as a polymer flocculant is less likely to occur, and the water content is more likely to decrease. Moreover, when the coefficient is 6.0 or less, the water-soluble polymer (A) is more preferable in water solubility, and the sludge is more sufficiently aggregated to form a stronger floc.
In the present invention, the hydrophobic monomer means a monomer having a solubility in water at 20 ° C. of less than 2 g / 100 g of water.

  The octanol / water partition coefficient (logPow) can be determined by a flask shaking method described in JIS Z7260-107 (2000). The coefficient is expressed as a common logarithm of the concentration of each target substance when the target substance is in an equilibrium state in a system where the octanol phase and the aqueous phase are in contact with each other. It will be. It shows that hydrophobicity is so large that this coefficient is large.

Examples of the hydrophobic monomer (a) include a (meth) acryloyl group-containing compound (a1) having a (meth) acryloyl group, a vinyl group-containing aromatic ring-containing compound (a2) having a vinyl group, and a vinyl group-containing vinyl group. Examples include aliphatic compounds (a3), vinylidene group-containing compounds having vinylidene groups (a4), vinylene group-containing compounds having vinylene groups (a5), and allyl group-containing compounds having allyl groups (a6). Two or more of them may be used in combination.
The (meth) acryloyl group means an acryloyl group and / or a methacryloyl group, and the same description method is used hereinafter.

Examples of the (meth) acryloyl group-containing compound (a1) include the following and mixtures thereof.
(A11) (Meth) acrylic acid ester Carbon number (hereinafter abbreviated as C) 5 or more and number average molecular weight [hereinafter abbreviated as Mn, measurement is by gel permeation chromatography (GPC) method under the measurement conditions described later] . ] 500 or less, for example, (meth) acrylic acid alkyl ester, (meth) acrylic acid alkenyl ester, and (meth) acrylic acid polyoxypropylene ester: Specific examples include (meth) acrylic acid-methyl, -ethyl, -butyl , -Isobutyl and 2-ethylhexyl, polypropylene glycol (hereinafter abbreviated as PPG) (molecular weight 134 or more and Mn 400 or less) mono (meth) acrylic acid ester;

(A12) C4-24 N-substituted (meth) acrylamides N-alkyl substituted (meth) acrylamides, N-alkenyl substituted (meth) acrylamides, and N- (poly) oxypropyl substituted (meth) acrylamides; for example, N, N -Diethyl-, Nt-butyl-, N-2-ethylhexyl-, N-octyl-, N-dodecyl-, N-lauryl-, N-cetyl-, N-stearyl-, N-oleyl- and N, N-di (poly) oxypropyl [(poly) oxypropyl group is propylene oxide (hereinafter abbreviated as PO) 1-3 mol addition] (meth) acrylamide and the like.

Examples of the vinyl group-containing aromatic ring-containing compound (a2) include the following and mixtures thereof.
(A21) Monocyclic compound C8-13 monocyclic compound; for example, styrene, α- and β-methylstyrene, methylstyrene, dimethylstyrene, trimethylstyrene, hydroxystyrene, methoxystyrene;
(A22) Polycyclic compounds C12-15 polycyclic compounds such as vinylnaphthalene and vinylnaphthol.

  Examples of the vinyl group-containing aliphatic compound (a3) include linear or branched compounds having a vinyl group, and among them, a compound represented by the following general formula (1) from the viewpoint of having a preferred logPow value and these Is preferred.

CH ₂ = CHR ¹ (1)

(1) In the formula, R ¹ is a group represented by the following general formula (2) or (3).

-OC (= O) R ² (2)
-X ¹ (3)

(2) In the formula, R ² represents a C2-24 alkyl group, and examples of the alkyl group include an ethyl group and a propyl group.
(3) In the formula, X ¹ represents a C1-4 alkyl group, a halogen atom or a C1-4 halogenated alkyl group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group; halogen Examples of the atom include F, Cl, Br, and the like. Examples of the halogenated alkyl group include a methyl fluoride group and a methyl bromide group. )

  Specific examples of (a3) include, for example, unsaturated aliphatic compounds such as vinyl propionate; olefins such as propene, 1-butene, 1-pentene and 1-hexene; fluorinated ethylene, fluorinated propene and ethylene bromide. And halogenated vinyl compounds such as propene bromide.

  Examples of the vinylidene group-containing compound (a4) include linear or branched compounds having a vinylidene group, and among them, a compound represented by the following general formula (4) and a mixture thereof from the viewpoint of having a preferable logPow value Is preferred.

CH ₂ = CR ³ R ⁴ (4)

(4) In the formula, R ³ and R ⁴ are groups represented by the following general formula (5), (6), (7) or (8), and R ³ and R ⁴ may be the same or different from each other. Good.

_{- (CH 2) n -C (} = O) -O-R 5 (n = 0 or 1) (5)
—O—C (═O) R ⁶ (6)
—C (═O) NH—R ⁷ (7)
-X ² (8)

Wherein, R ^5, R ⁶ are alkyl groups (ethyl group, propyl group, etc.) C2~24; R ⁷ is an alkyl group (ethyl, propyl, etc.) of C1~15; X ² is a C1~4 Represents an alkyl group, a C6-15 aryl group, a halogen atom, or a C1-4 halogenated alkyl group, and examples thereof include the same groups as the alkyl group, halogen atom, and halogenated alkyl group represented by X ^1. Examples of the aryl group include a phenyl group, an alkylbenzenealkylphenyl group, a hydroxyphenyl group, an alkoxyphenyl group, and a naphthyl group.

  Specific examples of (a4) include itaconic acid dialkyl esters (diethyl itaconate, ethylpropyl itaconate, etc.), olefins (isobutene, 2,4,4, -trimethyl-1-pentene, etc.), vinylidene halide compounds (1 , 1-dichloroethylene, 1,1-dibromoethylene, etc.).

  Examples of the vinylene group-containing compound (a5) include linear or branched compounds having a vinylene group, and among these, a compound represented by the following general formula (9) and a mixture thereof from the viewpoint of having a preferable logPow value Is preferred.

^{R 8 -CH = CH-R 9} (9)

(9) In the formula, R ⁸ and R ⁹ are groups represented by the general formula (5), (6), (7) or (8), and R ⁸ and R ⁹ may be the same or different from each other. It may be bonded to each other to form a ring.
Specific examples of (a5) include maleic acid alkyl esters (diethyl maleate, ethylpropyl maleate, etc.), olefins (2-butene, 2-pentene, etc.), halogenated vinylene compounds (cis- and trans-dichloroethylene, etc.) Is mentioned.

  Examples of the allyl group-containing compound (a6) include straight-chain or branched compounds having an allyl group, and among them, a compound represented by the following general formula (10) and a mixture thereof from the viewpoint of having a preferable logPow value. Is preferred.

CH ₂ = CHCH ₂ R ¹⁰ (10)

In the formula (10), R ¹⁰ is a group represented by the general formula (5), (6) or (7) and a group represented by the following general formula (11).

-X ³ (11)

(11) wherein, X ³ is an alkyl group of C1 -4, (hydroxy) aryl group C6～15, a halogen atom or a halogenated alkyl group of C1 -4, for example, an alkyl group of the X ^1, halogen A group similar to an alkyl group; a halogen atom such as Br; and a C6-15 (hydroxy) aryl group include a phenyl group, an alkylbenzenealkylphenyl group, a hydroxyphenyl group, an alkoxyphenyl group, a naphthyl group, and the like. .
Specific examples of (a6) include allylbenzene, allylphenol, and allyl bromide.

  Of these (a1) to (a6), (a11) and (a21) are preferred from the viewpoints of hydrophobicity, copolymerizability with the water-soluble monomer (b) described below, and industrial viewpoint, and more preferably C4. ~ 15 (meth) acrylic acid-alkyl and -alkenyl esters, styrene, and alpha-methyl styrene, particularly preferred are methyl (meth) acrylate, -ethyl and -butyl, and styrene.

The GPC measurement of Mn and the weight average molecular weight described later in the present invention shall be in accordance with the following measurement conditions.
<GPC measurement conditions>
GPC model: HLC-8120GPC, manufactured by Tosoh Corporation Column: 2 TSKgel GMHXL + TSKgel Multipore
HXL-M, manufactured by Tosoh Corp .: Refractive index detector reference material: Standard polystyrene (TSK standard POLYSYRENE),
Tosoh Corporation solvent: Tetrahydrofuran (THF)

  In addition to the monomer (a), the unsaturated monomer constituting the water-soluble polymer (A) includes a water-soluble monomer having one unsaturated group [other than those corresponding to (a)] (b). included.

  The water-soluble monomer (b) having one unsaturated group includes the following cationic monomer (b1), nonionic monomer (b2), anionic monomer (b3), and mixtures thereof.

(B1) 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.
(B11) Nitrogen atom-containing (meth) acrylates of C5-30, such as aminoalkyl (C2-3) (meth) acrylate, N, N-dialkyl (alkyl group is C1-2) aminoalkyl (C2-3) ( Meth) acrylate [N, N-dimethylaminoethyl and -propyl (meth) acrylate, N, N-diethylaminoethyl and -propyl (meth) acrylate, etc.], heterocycle-containing (meth) acrylate [N-morpholinoethyl (meth) Acrylates and the like];
(B12) Ethylenically unsaturated compounds having an amino group C5-30, such as N, N-dialkyl (C1-2) aminoalkyl (C2-3) (meth) acrylamide [N, N-dimethylaminoethyl (meta ) Acrylamide, etc.], vinylamine, vinylaniline, (meth) allylamine, p-aminostyrene, diallyldialkyl (C1-12) ammonium, diallylalkyl (C1-12) benzylammonium, N, N-dibenzyldiallylammonium and the like;
(B13) 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;

  Among these (b1), from the viewpoint of increasing the molecular weight of the water-soluble polymer (A), (b11) and (b12) are preferable, (b11) is more preferable, and (b11) is particularly preferable. ) Salt of N, N-dimethylaminoethyl (meth) acrylate (such as methyl chloride salt).

(B2) Nonionic monomer The following thing and mixtures thereof are mentioned.
(B21) (Meth) acrylate C4 or more and Mn 5,000 or less, such as hydroxyl group-containing (meth) acrylate [for example, hydroxyethyl-, diethylene glycol mono-, polyethylene glycol (degree of polymerization 3-50) mono- and polyglycerol (polymerization) Degrees 1-10) mono (meth) acrylate] and methyl acrylate;
(B22) (meth) acrylamide and its derivatives C3-30, such as (meth) acrylamide, N-alkyl (C1-3) (meth) acrylamide [N-methyl- and N-isopropyl (meth) acrylamide etc.], N-alkylol (meth) acrylamide [N-methylol (meth) acrylamide etc.], alkylene oxide (C1-2, hereinafter abbreviated as AO) adduct of N-alkylol (meth) acrylamide;
(B23) Nitrogen-containing ethylenically unsaturated compounds other than the above (b1) and (b22) C3-30, such as acrylonitrile, N-vinylformamide, N-vinyl-2-pyrrolidone, N-vinylimidazole, N- AO2-10 mol adduct of vinylsuccinimide, N-vinylcarbazole and 2-cyanoethyl (meth) acrylate, hydroxymethyl- and hydroxyethylmaleimide.

(B3) Anionic monomers The following, 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.

(B31) unsaturated carboxylic acids of C3-30, such as (meth) acrylic acid, (anhydrous) maleic acid, fumaric acid, (anhydrous) itaconic acid, vinylbenzoic acid, allylic acetic acid, maleic acid AO adduct monoester;
(B32) Unsaturated sulfonic acid C2-20 aliphatic unsaturated sulfonic acid (such as vinyl sulfonic acid), C6-20 aromatic unsaturated sulfonic acid (such as styrene sulfonic acid), sulfonic acid group-containing (meth) acrylate [ Sulfoalkyl (C2-20) (meth) acrylate [2- (meth) acryloyloxyethane, -propane and -butanesulfonic acid, 3- (meth) acryloyloxypropanesulfonic acid, 4- (meth) acryloyloxybutanesulfonic acid 2- (meth) acryloyloxy-2,2-dimethylethanesulfonic acid, p- (meth) acryloyloxymethylbenzenesulfonic acid, etc.], sulfonic acid group-containing (meth) acrylamide [2- (meth) acryloylaminoethanesulfone Acid, 2- and 3- (meth) acryloylaminoprop Sulfonic acid, 2- and 4- (meth) acryloylaminobutanesulfonic acid, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid, p- (meth) acryloylaminomethylbenzenesulfonic acid, etc.], alkyl ( C1-20) (meth) allylsulfosuccinic acid ester [methyl (meth) allylsulfosuccinic acid ester and the like] and the like;
(B33) (Meth) acryloyl polyoxyalkylene (alkylene group is C1 to 3) sulfate ester (meth) acryloyl polyoxyethylene (polymerization degree 2 to 50) sulfate ester and the like.

  Among these water-soluble monomers (b) having one unsaturated group, from the viewpoint of increasing the molecular weight of the water-soluble polymer (A), (b11) and (b12) of the cationic monomer (b1) are preferable. (B22) and (b23) of the nonionic monomer (b2), (b31) and (b32) of the anionic monomer (b3), and (b11), (b12) and (b22) are more preferable. , (B23), (b31), and (b32), sulfonic acid group-containing (meth) acrylate, sulfonic acid group-containing (meth) acrylamide, particularly preferably (b11), (b22), (b23), Of (b31) and (b32), sulfonic acid group-containing (meth) acrylate, sulfonic acid group-containing (meth) acrylamide, and most preferably , N-dimethylaminoethyl (meth) acrylate and salts thereof (the foregoing), (meth) acrylamide in (b22), acrylonitrile in (b23), N-vinylformamide, (b31) (Meth) acrylic acid, (anhydrous) maleic acid, (anhydrous) itaconic acid and alkali metal salts thereof, (b32) 2- (meth) acryloyloxyethanesulfonic acid, 2- and 3- (meth) acryloyl Oxypropanesulfonic acid, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid and alkali metal salts thereof. Moreover, these (b) can be arbitrarily mixed and copolymerized.

  The content (mol%) of the cationic monomer (b1) in the water-soluble monomer (b) having one unsaturated group is preferably 50 to 100%, more preferably 70 to 70% from the viewpoint of aggregation performance. 100%.

The content of the hydrophobic monomer (a) based on the total weight of unsaturated monomers constituting the water-soluble polymer (A) is to suppress the spread of the polymer chain of (A) in water and the solubility of (A) in water. In view of the above, preferably 3 to 60%, more preferably 4 to 45%, particularly preferably 5 to 30%; the content of the water-soluble monomer (b) is the solubility of (A) in water and (A) From the viewpoint of suppressing the spreading of the polymer chain in water, it is preferably 40 to 97%, more preferably 55 to 96%, and particularly preferably 70 to 95%.
The weight ratio of (a) and (b) is preferably 3/97 to 60/40, more preferably (A) from the viewpoint of suppression of polymer chain spreading and solubility of (A) in water. Is 4/96 to 45/55, particularly preferably 5/95 to 30/70.

As an unsaturated monomer which comprises water-soluble polymer (A), you may contain a crosslinkable monomer (x) as needed in the range which does not inhibit the effect of this invention other than (a) and (b). A crosslinkable monomer means a monomer having two or more (preferably 2 to 8) polymerizable unsaturated groups.
As the crosslinkable monomer (x), the following (x1) to (x4) having two or more unsaturated groups, two or more reactive epoxy groups, or an unsaturated group and reactive epoxy 2 or more in total (x5), 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. ) For acidic monomers such as salts, methyl chloride salts, dimethyl sulfate salts and benzyl chloride salts, alkali metal salts, alkaline earth metal salts, amine (C1-20, such as methylamine, ethylamine, cyclohexylamine, etc.) salts, etc.] , And mixtures thereof.

(X1) poly (2-4 or more) (meth) acrylamides of C5-30, such as N, N′-methylenebisacrylamide;
(X2) Poly (2-4 or more) (meth) acrylates of C8-30, such as ethylene glycol di (meth) acrylate, pentaerythritol [poly (2-4)] (meth) acrylate, polyethylene glycol di ( (Meth) acrylate, dipentaerythritol hexa (meth) acrylate;

(X3) Vinyl group (2 to 20 or more) -containing monomers C4 or more and Mn 6,000 or less, for example, divinylamine, polyvalent (divalent to pentavalent or more) amine [C2 or more and Mn 3,000 or less, For example, poly (2-20) vinylamine, divinyl ether, polyhydric alcohol [C2 or more and Mn3,000 or less, such as alkylene (C2-6 or more) glycol of ethylenediamine, polyethyleneimine (C4 or more and Mn3,000 or less)] [Ethylene glycol (hereinafter abbreviated as EG), propylene glycol, 1,6-hexanediol, etc.], polyoxyalkylene [C2 or more and Mn 3,000 or less, such as polyoxyethylene glycol (hereinafter abbreviated as PEG) (molecular weight 106 And Mn 3,000 or less), Polio Sipropylene glycol (molecular weight 134 or more and Mn 3,000 or less), polyoxyethylene (molecular weight 106 or more and Mn 3,000 or less) / polyoxypropylene (molecular weight 134 or more and Mn 3,000 or less) block copolymer, etc.], trimethylolethane, Poly (2-20) vinyl ether of trimethylolpropane, (poly) (2-50) glycerin (hereinafter abbreviated as GR), pentaerythritol, sorbitol, starch, etc.];

(X4) Allyl group (2 to 20 or more) -containing monomer C6 or more and Mn 3,000 or less, for example, di (meth) allylamine, N-alkyl (C1-20) di (meth) allylamine, polyvalent amine (above Poly (2-20) (meth) allylamine, di (meth) allyl ether, poly (2-20) (meth) allyl ether of polyhydric alcohol (above), poly (2-20) ( (Meth) allyloxyalkanes (C1-20) (tetraallyloxyethane and the like);
(X5) Two or more reactive epoxy groups, or a total of two or more unsaturated groups and reactive epoxy groups C8 or more and Mn 6,000 or less, for example, EG diglycidyl ether, PEG diglycidyl Ether, GR triglycidyl ether, glycidyl (meth) acrylate, 3,4-epoxyhexahydrobenzyl (meth) acrylate;

  The use amount of the crosslinkable monomer (x) is usually 1% or less based on the total weight of (a) and (b), preferably 0.0001 to from the viewpoint of aggregation performance and water solubility of the water-soluble polymer (A). 0.1%, more preferably 0.001 to 0.05%.

  The water-soluble polymer (A) is obtained by subjecting an unsaturated monomer containing (a), (b), and (x) as necessary, to a known aqueous solution polymerization (for example, heat insulation described in JP-A-55-133413). Polymerization, thin film polymerization, spray polymerization, etc.) and known reverse phase suspension polymerization (for example, those described in JP-B-54-30710, JP-A-56-26909, JP-A-1-5808). Various polymerization methods including [photopolymerization (for example, described in JP-B-6-804), precipitation polymerization (for example, described in JP-A-61-123610), reverse-phase emulsion polymerization (for example, JP-A-58-86) And the like) described in No. 1973398] and the like] using a radical polymerization initiator (d). Among the polymerization methods, the aqueous solution polymerization method is preferable from the industrial viewpoint that it is not necessary to use an organic solvent or the like.

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] and the like.
Further, the azo compound, peroxide and redox initiator may be used alone or in combination of two or more.
Among these, an azo compound is preferable from the viewpoint of reducing the water-insoluble content of the water-soluble polymer (A).
(D) is usually contained in the aqueous phase of the polymerization system, but depending on the polymerization method, it may be present in either the aqueous phase (or dispersed phase) and / or the oil phase (or continuous phase).

  From the viewpoint of obtaining an optimum molecular weight, the amount of (d) used is preferably 0.001 to 1.0%, more preferably 0.8%, based on the total weight of unsaturated monomers constituting (A). 005 to 0.5%, particularly preferably 0.01 to 0.2%, most preferably 0.02 to 0.15%.

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

  As (f), a compound having one or more amino groups in the molecule [C0-60, such as ammonia, methylamine, dimethylamine, triethylamine, n- and i-propanolamine], molecule Compounds having one or more thiol groups (described later) and (hypo) phosphorous acid compounds [phosphorous acid, hypophosphorous acid, and salts thereof [alkali metal (Na, K, etc.) salts, etc.] And their derivatives] and the like. Among these, compounds having one or more thiol groups in the molecule and (hypo) phosphite compounds are preferable from the viewpoint of molecular weight control.

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

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

  Among the chain transfer agents (f), those having high water solubility are preferable from the viewpoint of reducing the water-insoluble content of the polymer flocculant, and the water / n-decane distribution coefficient of (f) is preferably 10 / It is 90-100 / 0, More preferably, it is 20 / 80-100 / 0, Most preferably, it is 50 / 50-100 / 0. The water / n-decane partition coefficient here is the same measurement method as the water / 1-octanol partition coefficient (JIS Z7260-107) defined in Japanese Industrial Standard (JIS), and 1-octanol is converted to n-decane. It can measure by substituting.

  The amount of (f) used is preferably 0.0001 to 1% based on the total weight of unsaturated monomers constituting (A), from the viewpoint of reducing the water-insoluble content of the polymer flocculant and increasing the molecular weight. More preferably, it is 0.001 to 0.5%, particularly preferably 0.01 to 0.3%, and most preferably 0.05 to 0.1%.

Among the methods for producing the water-soluble polymer (A), examples of the reverse phase suspension polymerization method include the following methods.
That is, after the hydrophobic dispersion medium (e) 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 hydrophobic monomer (a) having one unsaturated group and a log Pow of 1.0 to 6.0, a water-soluble monomer (b) having one unsaturated group, a radical polymerization initiator (d ), Prepare a monomer aqueous solution to which the chain transfer agent (f) and, if necessary, the crosslinkable monomer (x) are added, and after sufficiently replacing with an inert gas, put them into the polymerization tank under stirring and suspend them. Polymerize while letting go.
The method for charging the monomer aqueous solution may be either batch charging or dropping. In this case, the aqueous monomer solution may be a uniform aqueous solution of (a), (b), (d), and (f) and / or (x) added as necessary, You may mix immediately before dripping and may drop simultaneously simultaneously. Examples of the method of replacing the monomer aqueous solution with an inert gas include a method of bubbling and supplying an inert gas to the monomer aqueous solution, a method of blending an inert gas with a static mixer or the like in a dropping line, and the like. From the viewpoint of properties, a method of blending an inert gas with a static mixer is preferred.

Among the production methods of the water-soluble polymer (A), the hydrophobic dispersion medium (e) used in the reverse phase suspension polymerization method and the reverse phase emulsion polymerization method includes the following hydrocarbons, ketones, ethers, esters and mixtures thereof. Is mentioned.
Here, the hydrophobic dispersion medium means a dispersion medium having a solubility in water (20 ° C.) of less than 1 g / 100 g of water.
(1) Hydrocarbon aliphatic (C5-12, such as n-hexane, n-heptane, n-octane, n-nonane, n-decane), alicyclic (C5-12, such as cyclopentane, Cyclohexane, cycloheptane, methylcyclohexane, cyclooctane, decalin) and aromatic ring-containing hydrocarbons (of C6-12, such as benzene, toluene, xylene, ethylbenzene, etc.), etc .;
(2) Ketone Aliphatic (C3-10, eg methyl-n-propylketone, diethylketone, methylisobutylketone), alicyclic (C5-10, eg cyclopentanone, cyclohexanone) and aromatic ring Ketones (of C8-13, such as acetophenone, benzophenone) and the like] and the like;
(3) Ether Aliphatic (C4-8, such as di-n-propyl ether, di-n-butyl ether, diethylene glycol dimethyl ether), cyclic (C4-18, such as tetrahydropyrine) and aromatic ring-containing ether (C7 ~ 12, such as anisole) and the like];
(4) Esters Aliphatic (C3-10, such as n-butyl acetate, isobutyl acetate), alicyclic (C7-12, such as cyclohexyl acetate, cyclohexanecarboxylate) and aromatic ring-containing esters (C8- 13 such as methyl benzoate, 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 in reverse phase suspension polymerization is preferably 25%, more preferably 40%, particularly preferably, based on the total weight of the aqueous monomer solution from the viewpoint of the viscosity of the dispersion. 65%, and the upper limit is preferably 1,000% from the viewpoint of dispersion stability, more preferably 400%, particularly preferably 200%; in reverse emulsion polymerization, based on the total weight of the monomer aqueous solution from the viewpoint of emulsion viscosity. The preferable lower limit is 20%, more preferably 30%, particularly preferably 40%, and the preferable upper limit is 80%, more preferably 70%, particularly preferably 60% from the viewpoint of emulsion stability.

The dispersant (c) used in the reverse phase suspension polymerization method includes the reverse phase suspension or dispersion or emulsion stability of the emulsified particles, and the angle of repose of the dry particles of the water-soluble polymer (A) described below, that is, From the viewpoint of controlling the powder fluidity, various oil-soluble substances having an HLB of preferably 1 to 8, more preferably 1.5 to 7.5, and particularly preferably 2 to 7 may be mentioned.
Here, HLB is an abbreviation of Hydrophile-Lipophile Balance, which represents a balance between hydrophilicity and lipophilicity, and is obtained from the following formula ["Synthesis of surfactants and their applications", page 501, 1957. Published by Sakai Shoten; “Introduction to New Surfactants”, pages 197-198, published by Sanyo Chemical Industries, Ltd. in 1992, etc.].

HLB = 10 × (inorganic / organic)

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

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

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

  (C1) includes fatty acid (C10-30) esters of polyhydric (2-8 or more) alcohols [sucrose fatty acid esters (of C22-120, such as sucrose distearate, sucrose tristearate), sorbitan Fatty acid esters (those of C16 to 120, such as sorbitan monostearate, sorbitan monooleate), (poly) glycerin fatty acid esters (those of C12 to 120, such as glycerin monostearate), PEG fatty acid esters [Mw 100 to less than 5,000 PEG mono and distearate, etc.], alkyl (C1-30) allyl ether, and the like.

  Of the above (c1), the fatty acid ester of a polyhydric alcohol is preferred from the viewpoint of preventing the polymer particles from adhering to the polymerization apparatus during production and the angle of repose of the dried particles of the polymer flocculant after drying, more preferably Sucrose fatty acid ester, sorbitan fatty acid ester, and PEG fatty acid ester.

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

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

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

  The amount of (c) used is usually 20% or less based on the weight of the hydrophobic dispersion medium (e), the stability of the reversed phase suspended particles, the angle of repose of the dried particles of the polymer flocculant after drying, and the particles From the viewpoint of diameter control, it is preferably 0.01 to 10%, more preferably 0.05 to 5%.

Parents who uniformly dissolve, emulsify or disperse (a) and (b) for the purpose of promoting the copolymerization of the hydrophobic monomer (a) and the water-soluble monomer (b) when producing the water-soluble polymer (A). A volatile compound (g) can be used.
Here, the amphiphilic compound (g) is a compound which dissolves in 1 g or more (/ water or 100 g of n-hexane) in both water and n-hexane, and (g) is an organic compound having the following C6 or less. Examples thereof include at least one selected from the group consisting of a solvent (g1), a modified silicone oil (g2), and a surfactant (g3).

(G1) C6 or lower organic solvent Alcohol (C1-6, such as methanol, ethanol, n- and i-propyl alcohol), ketone (C3-6, such as acetone, methyl ethyl ketone), ether [C2-6, such as tetrahydrofuran (THF) )], Amides [C3-5, such as dimethylformamide (DMF)], mixtures thereof and the like;

(G2) Modified silicone oils having Mn of 5,000 to 50,000, such as polyether-modified polysiloxane [polyoxyethylene-modified polysiloxane, poly (oxyethylene and / or oxypropylene) -modified polysiloxane, etc.], carboxy-modified polysiloxane Epoxy-modified polysiloxanes, amino-modified polysiloxanes, alkoxy-modified polysiloxanes, and mixtures thereof;

(G3) Surfactant (g31) Nonionic surfactant Higher fatty acid ester (sorbitan monostearate, sorbitan distearate, sorbitan monooleate, oleic acid sorbitan ester ethylene oxide adduct), polyoxyethylene long chain alkyl ether (lauryl) Alcohol polyoxyethylene ether, polyoxyethylene nonylphenyl ether, etc.) and long-chain alkyl alkanolamides (N, N-dihydroxyethyl lauryl amide, etc.);

(G32) Cationic surfactant, quaternary ammonium salt (dilauryldimethylammonium chloride, stearylbenzyldimethylammonium chloride, etc.) and the like;

(G33) Anionic surfactant Sulfate ester (poly) oxyethylene (average addition mole number 1-30) Sodium lauryl ether sulfate, sodium 2-hydroxydodecyloxysulfate, etc.] Ether carboxylate (poly) oxyethylene (average addition) Mole number 1-30) Sodium lauryl ether acetate, sodium 2-hydroxydodecyloxyacetate, etc.], sulfonate [sodium dodecylbenzenesulfonate, sodium α-olefin sulfonate, etc.], phosphate ester salt [sodium lauryl phosphate, (Poly) oxyethylene (average added mole number 1 to 100) sodium lauryl ether phosphate, etc.], fatty acid salts (sodium laurate, triethanolamine laurate, etc.) and the like.

The amount of the amphiphilic compound (g) used is that when the polymer as a polymer flocculant is formed without inhibiting the uniform compatibility, emulsification or dispersion of (a) and (b) and the radical polymerization reaction of the monomer. In view of the above, it is preferably 0.1 to 30%, more preferably 1 to 28%, particularly preferably 5 to 25% based on the total weight of (a) and (b).

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

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

  When (A) obtained by polymerization by an aqueous solution polymerization method or the like is a hydrous gel [consisting of (A) and water], it is shredded as necessary, and further dehydrated and dried to form a powder. The polymer flocculant (P) of the present invention containing (A) can be obtained.

0.5% salt aqueous solution viscosity V _s (mPa · s, 25 ° C.) of a water-soluble polymer (A) contained in the polymer flocculant (P) of the present invention in a 4 wt% NaCl aqueous solution at 25 ° C. Is preferably 1 to 150, more preferably 2 to 130, particularly preferably 3 to 120. When the 0.5% salt aqueous solution viscosity is 1 or more, the coagulation performance is good, and when it is 150 or less, the reactivity with suspended particles in sludge and the like is good. In addition, 0.5% salt aqueous solution viscosity can be measured by the below-mentioned method.

  The molecular weight of the water-soluble polymer (A) is represented by intrinsic viscosity [η] (dl / g, 30 ° C.), and the intrinsic viscosity is preferably 1 to 30, and more preferably 4 to 4 for cationic and amphoteric polymers. 20, more preferably 10 to 25 for nonionic and anionic polymers. When the intrinsic viscosity is 1 or more, the cohesiveness is good, and when it is 30 or less, the reactivity with suspended particles in sludge and the like is good.

The water-soluble polymer (A) in the present invention satisfies the following relational expression [1] with respect to the intrinsic viscosity [η] and the 0.5% salt aqueous solution viscosity V _s as described above.

−0.40 ≦ ln [η] / ln V _s ≦ 0.55 [1]

The water-soluble polymer (A) in the present invention can satisfy the above-mentioned relational expression [1] by setting both the intrinsic viscosity [η] and the 0.5% salt aqueous solution viscosity V _s within the above preferred ranges. From the viewpoint of exhibiting better agglomeration performance when the ratio is in the further preferred range, the unsaturated monomer containing the hydrophobic monomer (a) and the water-soluble monomer (b) is polymerized to obtain (A). In the production, it is more preferable to polymerize in the presence of the heterocyclic compound (h) containing one secondary nitrogen atom in the ring structure.

  Examples of (h) include the following (h1) to (h3), and these may be used in combination of two or more.

(H1) heterocyclic compounds having only one secondary nitrogen atom in the ring structure and no other heteroatoms, such as those of C2-20, such as saturated heterocyclic compounds (ethyleneimine, azacyclobutane, Pyrrolidine, piperidine, hexamethyleneimine, etc.), unsaturated heterocyclic compounds (pyrrole, azatropyridene, indole, isoindole, carbazole, etc.), and derivatives thereof;

(H2) Heterocyclic compounds having one secondary nitrogen atom in the ring structure and one or more nitrogen atoms in addition to that of C3-20, such as saturated heterocyclic compounds (2-alkylpyrazo Lysine, 3-alkylimidazolidine, 4-alkylpiperazine, etc.), unsaturated heterocyclic compounds (imidazole, pyrazole, imidazoline, benzimidazole, purine, porphyrin, chlorin, choline, etc.), and derivatives thereof;

(H3) Heterocyclic compounds having one secondary nitrogen atom and one or more heteroatoms other than nitrogen in the ring structure, such as those of C3-20, for example, other than secondary nitrogen atoms in the ring structure Those having a sulfur atom (thiazine, phenothiazine, isothiazolidine, thiomorpholine, etc.), those having an oxygen atom in addition to a secondary nitrogen atom in the ring structure (morpholine, isoxazolidine, etc.), secondary in the ring structure Having a selenium atom in addition to the nitrogen atom (selenomorpholine and the like), a ring structure having a tellurium atom in addition to the secondary nitrogen atom (tellulomorpholine and the like), and derivatives thereof.

Among the above (h1) to (h3), from the viewpoint of setting the ln [η] / lnV _s ratio of the water-soluble polymer (A) to a preferable range, the unsaturated complex of (h1) and (h2) is preferable. A heterocyclic compound having a sulfur atom in addition to the secondary nitrogen atom in the ring structure of the cyclic compound (h3), a heterocyclic compound having an oxygen atom in addition to the secondary nitrogen atom in the ring structure More preferred are pyrrole, azatropylidene, isoindole, carbazole in (h1), imidazole, pyrazole, benzimidazole in (h2), thiazine and phenothiazine in (h3). In addition, the above-mentioned preferable thing includes those derivatives.

  The use amount of (h) based on the total weight of unsaturated monomers constituting (A) is preferable from the viewpoint of the aggregation performance of the polymer flocculant (P) and the radical polymerizability of the unsaturated monomers constituting (A). Is 0.0005 to 0.01%, more preferably 0.0008 to 0.0075%, and particularly preferably 0.001 to 0.005%.

  The water-soluble polymer (A) has a 0.2 wt% aqueous solution viscosity (hereinafter sometimes referred to as 0.2% aqueous solution viscosity) (mPa · s, 25 ° C.), preferably 50 to 1,000, more preferably 100 to 800, particularly preferably 200 to 600. When the 0.2% aqueous solution viscosity is 50 or more, the cohesiveness is good, and when it is 1,000 or less, the reactivity with the suspended particles is good. The 0.2% aqueous solution viscosity can be measured by the method described later.

  As a simple measuring method capable of expressing the molecular weight distribution of the water-soluble polymer (A), there is a string length L (mm) of a 0.4 wt% aqueous solution. The thread length (mm) is preferably 20 to 200, more preferably 40 to 150, and more preferably cationic and amphoteric polymer aggregation from the viewpoint of industrial and aggregation performance in the nonionic and anionic polymer flocculants described later. In the agent, from the same viewpoint, it is preferably 5 to 100, more preferably 6 to 80.

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

  The ratio (L / [η]) between the yarn length L (mm) and the intrinsic viscosity [η] (dl / g) of (A) is preferably 1 to 8, more preferably from the viewpoint of industrial and aggregation performance. 1.5 to 7, particularly preferably 2 to 5.

[Polymer flocculant (P)]
The polymer flocculant (P) of the present invention comprises a water-soluble polymer (A) that satisfies the relational expression [1].
As the polymer flocculant of the present invention, a suitable ionic one is used depending on the application.
Generally, in sewage sludge, the size of suspended particles is relatively large, and the surface of suspended particles in water has a negative charge, so that the polymer flocculant for dehydration is cationic or amphoteric. Polymer flocculants and mixtures thereof are preferred.
In wastewater, in order to treat soluble organic matter and the like, an inorganic flocculant is often added first, and in that case, the suspended particle surface is covered with the inorganic flocculant and has a positive charge. As the polymer flocculant for the coagulation sedimentation treatment, anionic or nonionic and mixtures thereof are preferable.
For the tertiary recovery of petroleum, those having a relatively large molecular weight are used, and anionic or nonionic and mixtures thereof are preferred.
Cationic or amphoteric polymer flocculants and mixtures thereof are preferred for improving drainage yield or enhancing paper strength in the papermaking process.
The above ionicity is derived from the ionicity of the water-soluble polymer (A) in the polymer flocculant of the present invention.

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

When the polymer flocculant (P) of the present invention is a cationic polymer flocculant, the lower limit of the cation colloid equivalent value of the water-soluble polymer (A) in the flocculant is preferably 1.5 from the viewpoint of aggregation performance. More preferably 1.8, still more preferably 2.0, particularly preferably 2.3, most preferably 2.5, and the upper limit preferable from the viewpoint of aggregation performance is 8.0, more preferably 7.0, still more preferably 6.5, particularly preferably 6.2, and most preferably 6.0.
When the polymer flocculant of the present invention is an amphoteric polymer flocculant, the lower limit of the cation colloid equivalent value of the water-soluble polymer (A) in the flocculant is preferably 1.5, more preferably from the viewpoint of aggregation performance. 1.8, more preferably 2.0, particularly preferably 2.3, most preferably 2.5, and from the viewpoint of aggregation performance, the upper limit is preferably 8.0, more preferably 7.0, and even more preferably 6.5. The anionic colloid equivalent value is preferably -13.0, more preferably -10.0, and still more preferably -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, particularly preferably from the viewpoint of aggregation performance. -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) 0.2 g of sample (converted to solid content) is precisely weighed and taken in a 200 ml Erlenmeyer flask, and the total weight (total weight of sample and ion-exchanged water) is 100 g. After adding ion-exchanged water, the mixture was stirred for 3 hours with a magnetic stirrer (a cylindrical magnet having a length of 40 mm and a diameter of 5 mm, a rotation speed of 1,000 rpm), and completely dissolved. An aqueous solution of the water-soluble polymer (A) is prepared. Take 10 ml of the prepared aqueous solution in a 500 ml beaker, add ion-exchanged water so that the total weight (total weight of aqueous solution 10 ml and ion-exchanged water) becomes 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 water-soluble polymer (A) was determined by weighing about 1.0 g of a powdered sample into a petri dish (diameter: 100 mm, depth: 10 mm) (W1). 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) 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 titration amount (unit: ml) is determined with the time point when the measurement sample changes from blue to reddish purple and the reddish purple 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 determine the titer (unit: ml) in the same manner as (2) above.
(4) Blank test The same operation as (2) or (3) is performed except that 100 g of ion-exchanged water is used instead of the measurement sample, and a titer (unit: ml) is obtained.
(5) Calculation method

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

  In addition to the water-soluble polymer (A), the polymer flocculant (P) of the present invention may further contain a water-soluble polymer (B) as necessary from the viewpoint of increasing the floc diameter. The water-soluble polymer (B) is a polymer which does not contain the hydrophobic monomer (a) and contains only the water-soluble monomer (b) having one unsaturated group as a structural unit.

Intrinsic viscosity [η] (dl / g) of (B) is preferably 1 to 30 from the viewpoint of agglomeration performance and industrial, more preferably 4 to 20 for cationic and amphoteric polymers, nonionic and anionic polymers Then, it is more preferably 10-25.
The 0.5% salt aqueous solution viscosity (mPa · s) of (B) is preferably from 3 to 100, more preferably from 5 to 80, from the viewpoint of aggregation performance and industry.
The 0.2% aqueous solution viscosity (mPa · s) of (B) is preferably 50 to 1,000, more preferably 100 to 800, from the viewpoint of aggregation performance and industrial viewpoint.
The thread length L (mm) of (B) is preferably 20 to 200, more preferably 40 to 150, and more preferably cationic and amphoteric polymer flocculants for nonionic and anionic polymers from the viewpoint of industrial and aggregation performance. Then, from the same viewpoint, it is preferably 5 to 100, more preferably 6 to 80.
The ratio L / [η] of the yarn length and the intrinsic viscosity of (B) is preferably 1 to 8, more preferably 1.5 to 7, particularly preferably 2 to 5 from the viewpoint of industrial and aggregation performance. .

  The content of (B) is usually 70% or less based on the weight of (P), preferably from 10 to 50%, more preferably from 20 to 30% from the viewpoint of increasing the floc diameter and agglomeration performance.

  In addition to the water-soluble polymer (A), (B), the polymer flocculant (P) of the present invention is usually used for the polymer flocculant as long as it does not inhibit the effects of the present invention. An additive (C) selected from the group consisting of an antifoaming agent, a chelating agent, a pH adjusting agent, a surfactant, an antiblocking agent, an antioxidant, an ultraviolet absorber and a preservative can be contained.

Among these additives (C), additives other than the anti-blocking agent are preliminarily contained in the aqueous monomer solution before the production of the water-soluble polymer (A) or (B) as long as the effects of the present invention are not impaired. May be.
The total amount of the additive (C) used is preferably 50% or less based on the total weight of (A) and (B), preferably from the viewpoint of the additive effect of (C) and agglomeration performance (particularly floc strength). 1 to 40%, more preferably 2 to 30%.
About the usage-amount of each additive, based on the same weight as the above, normally, an antifoamer is 5% or less, a chelating agent is 30% or less, a pH adjuster is 10% or less, surfactant and blocking prevention Each of the agents is 5% or less, each of the antioxidant, the ultraviolet absorber and the preservative is 5% or less; preferably from the same viewpoint as described above, the antifoaming agent is 1 to 3%, the chelating agent is 2 to 10%, The pH adjuster is 1 to 5%, the surfactant and the antiblocking agent are 1 to 3%, respectively, and the antioxidant, the ultraviolet absorber and the preservative are 0.1 to 2%.

In addition, the polymer flocculant (P) of the present invention is prepared from other polymer flocculants (Q) described in, for example, the specification of Japanese Patent Application No. 2011-48186, from the viewpoint of improving the flocculation performance (floc strength, filtration rate, etc.). You may use together. The (Q) is a water-soluble polymer obtained by radical polymerization of a water-soluble unsaturated monomer (b) in the presence of an aromatic ring-containing carboxylic acid having 1 to 8 carboxyl groups and / or a salt (q) thereof. It is a polymer flocculant formed.
The polymer flocculant (P) of the present invention may be used in combination with another polymer flocculant (Q) other than (P) from the viewpoint of improving the agglomeration performance (floc strength, filtration rate, etc.). . The (Q) includes a polymer flocculant described in Japanese Patent Application No. 2011-48186 [referred to herein as (Q1)], and a polymer flocculant described in Japanese Patent Application No. 2011-55783 [this specification] Will be referred to as (Q2)]. The (Q1) is a polymer flocculant comprising a water-soluble polymer having a water-soluble unsaturated monomer as a structural unit, and an aromatic ring-containing carboxylic acid having 1 to 8 carboxyl groups and / or a salt thereof. And (Q2) is an unsaturated monomer containing a water-soluble unsaturated monomer having a water-soluble unsaturated monomer having a tertiary amine base or a quaternary ammonium base having a halogen ion as a counter ion as an essential monomer, A polymer flocculant containing a water-soluble polymer that is radically polymerized in the presence of a saturated aliphatic polycarboxylic acid having 10 carboxyl groups and / or a salt thereof.

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

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

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

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

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

When the polymer flocculant (P) of the present invention is applied to sludge or wastewater, if the sludge or wastewater is organic sludge or anaerobic bacteria-treated sludge, a coagulant ( D) (inorganic and / or organic coagulant) is preferably used in combination.
Inorganic coagulant (D1) includes sulfuric acid band, polyaluminum chloride, ferric chloride, ferric sulfate, polyiron sulfate, slaked lime, etc .; organic coagulant (D2) includes 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, And (meth) allylamine or di (meth) allylamine-itaconic acid, (meth) allylamine or di (meth) allylamine-fumaric acid copolymer.

  When (D) is used in combination, sludge or wastewater is treated with a mixture obtained by adding (D) in advance to the polymer flocculant (P) of the present invention, or (D) is added to sludge or wastewater in advance to perform primary treatment. After agglomeration, either (P) may be added for treatment.

  The amount used when (D) is used in combination varies depending on the type of sludge or wastewater, the size of suspended particles, the type of coagulant used, etc., but is not particularly limited, based on the TS in the sludge or wastewater, For inorganic coagulants, it is usually 20% or less, and the preferable lower limit from the viewpoint of setting performance is 0.5%, more preferably 1%, particularly preferably 1.5%, and the preferable upper limit from the viewpoint of reducing the amount of sludge after dewatered cake incineration. 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. From the viewpoint of 0.05% and floc strength, the upper limit is preferably 0.5%, more preferably 0.2%, and particularly preferably 0.15%.

When adding the polymer flocculant (P) of the present invention, the pH of sludge or waste water may be adjusted in advance. The pH adjustment range is usually 3 to 8, and the lower limit is preferably 3.5 from the viewpoint of preventing hydrolysis of (P), more preferably 4, particularly preferably 4.5, and the upper limit preferable from the viewpoint of solubility of (P). Is 7, more preferably 6, particularly preferably 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 and / or organic coagulant to sludge or wastewater in advance.

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

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, the part in an Example represents a weight part and% represents weight%.

The composition, symbols, etc. of the raw materials used in the examples and comparative examples are as follows.
(1) a hydrophobic monomer having one unsaturated group and having an octanol / water partition coefficient (logPow) of 1.0 to 6.0 (a)
(A1-1): Methyl methacrylate (logPow1.4)
(A1-2): 2-ethylhexyl methacrylate (logPow 4.5)
(A1-3): Nt-butylacrylamide (logPow 1.0)
(A1-4): Butyl methacrylate (logPow 2.9)
(A1-5): Decyl acrylate (logPow 5.5)
(A1-6): N-laurylacrylamide (logPow 5.8)
(A2-1): Styrene (logPow 3.0)
(A3-1): 1-butene (logPow 2.4)
(A4-1): Isobutene (logPow 2.4)
(A5-1): cyclohexene (logPow 2.9)
(2) Hydrophobic monomer having one unsaturated group and logPow exceeding 6 (a ′)
(A′-1): Dodecyl methacrylate (logPow 6.7)
(3) Water-soluble monomer having one unsaturated group (b)
(B1-1): 78.3% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl methacrylate (b1-2): 70% aqueous solution of methyl chloride salt of N, N-dimethylaminoethyl acrylate (b1-3 ): 65% aqueous solution of diallyldimethylammonium chloride [Wako Pure Chemical Industries, Ltd.]
(B1-4): 2-hydroxyethyl methacrylate (b2-1): methyl acrylate (logPow 0.8)
(B2-2): 50% aqueous solution of acrylamide (b3-1): 80% aqueous solution of acrylic acid (5) Crosslinkable monomer (x)
(X2-1) PEG (Mw600) diacrylate [trade name “Light acrylate 14EG-A”], 1% aqueous solution (6) chain transfer agent (f) manufactured by Kyoeisha Chemical Co., Ltd.
(F-1): 1% aqueous solution of 1-thioglycerol (f-2): 1% aqueous solution of ethylene glycol-di-2-mercaptoethyl ether

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

(8) Hydrophobic dispersion medium (e)
(E-1): n-decane (9) Dispersant (c)
(C1-1): Distearic acid ester of PEG (Mn300) [trade name “IONET
DS-300 ", manufactured by Sanyo Chemical Industries, HLB7.3, Mn800
Low molecular weight dispersant]
(C2-1): Polymer dispersant (HLB2.1, obtained in Production Example 1 described later)
Mw 15,000)
(10) Amphiphilic compound (g)
(G1-1): Methanol (g3-1): Sodium alkyldiphenyl ether disulfonate [trade name “ELE”
Minol MON-7 ", Sanyo Chemical Industries, HLB21.4]

(11) A heterocyclic compound containing one secondary nitrogen atom in the ring structure (h)
(H1-1) pyrrole (h2-1) benzimidazole (h3-1) thiazine (h3-2) phenothiazine (12) organic coagulant (D2)
(D2-1) Polydiallyldimethylammonium chloride [trade name “Swivel Rock
SR-2000 ", manufactured by Suirei Co., Ltd.]
(13) Aromatic ring-containing carboxylic acid and / or salt thereof [Japanese Patent Application No. 2011-48186, “Aromatic ring-containing carboxylic acid having 1 to 8 carboxyl groups and / or salt thereof (B) Applicable to In this application, the symbol (q) is attached. ]
(Q-1): 10% aqueous solution of trimellitic acid sodium salt

<Evaluation method>
The solid content of the polymer flocculant composed of the water-soluble polymer (A) was evaluated by the above method, and the other items were evaluated by the following methods.
Evaporation residue weight (TS), suspended solids (SS), and organic content (loss on ignition) in sewage sludge, etc. are in accordance with the analysis method described in “Sewage Test Method” (Japan Sewerage Association, 1984 version). I went.

(1) 0.2% aqueous solution viscosity (mPa · s, 25 ° C.)
Jar tester [model “JMD-6HS-A”, manufactured by Miyamoto Riken Kogyo Co., Ltd., and so on. ] Using a stirrer in which two plate-like stirrer blades (diameter: 5 cm, height: 2 cm, thickness: 0.2 cm) are attached to a stir bar continuously up and down so as to form a cross. 499 g of exchange water was added, and a sample having a solid content of 1.0 g was gradually added with stirring at 300 rpm at a water temperature of 20 to 25 ° C., and completely dissolved over 3 hours. Thereafter, a part of the obtained aqueous solution was transferred to a 200 mL tall beaker and left to stand in a thermostatic bath at 25 ° C. for 20 minutes to adjust the temperature. Then, a B-type viscometer [model “TV-10M”, Toki Sangyo Co., Ltd. ) Made the same below. ], The value after 300 seconds from the start of measurement at an M2 rotor and 30 rpm was defined as a 0.2% aqueous solution viscosity.

(2) 0.5% salt aqueous solution viscosity (mPa · s, 25 ° C.)
Using the same stirrer as described above, 477.5 g of ion-exchanged water is put into a 500 mL beaker, and a sample with a solid content of 2.5 g is gradually added while stirring at 200 rpm at a water temperature of 20 to 25 ° C., and complete over 4 hours. Dissolved in. Thereafter, 20 g of sodium chloride was added, and the mixture was further stirred for 30 minutes to be dissolved. Thereafter, a part of the obtained salt aqueous solution (sodium chloride concentration is 4%) was transferred to a 200 mL tall beaker, left in a thermostatic bath at 25 ° C. for 20 minutes to adjust the temperature, and then M1 rotor with a B-type viscometer. The value 300 seconds after the start of measurement at 60 rpm was taken as the 0.5% salt aqueous solution viscosity.

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

Water-insoluble amount (g) = (W4)-(W3)

Based on the water-insoluble amount determined from the above formula, water solubility was evaluated according to the following criteria.
<Evaluation criteria>
◎ Very good water solubility (water insoluble content ≦ 5)
○ Good (5 <water-insoluble matter ≦ 15)
△ Slightly bad (15 <water insoluble content ≦ 30)
× Poor (30 <water insoluble matter)

(4) Flock particle size (mm)
200 ml of sludge was put into a 300 ml beaker and set in the same stirring apparatus as the above (1). The rotation speed of the jar tester was set to 300 rpm, and while the sludge was gradually stirred, an aqueous solution of a polymer flocculant having a predetermined concentration was added by a predetermined method and stirred for 30 seconds. The diameter (mm) was observed visually. Subsequently, the number of revolutions was changed to 650 rpm, and the mixture was further stirred for 30 seconds. Then, the stirring was stopped and the particle size (mm) of the formed floc was again visually observed.

(5) Flock strength The floc particle sizes at the rotation speeds of 300 rpm and 650 rpm in the above (4) were compared, and the floc strength was evaluated from the change of 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)

(6) Liquid volume after 10 seconds, liquid volume behind 60 seconds (ml)
A filtration device was set using a T-1189 nylon filter cloth (Shikishima Canvas Co., Ltd., circular shape, diameter 9 cm), a Nutsche funnel, and a measuring cylinder capable of measuring 300 ml. The sludge after the floc particle size test of (4) above is filtered all at once on the Nutsche filtration surface, and the amount of filtrate that has passed from 10 seconds to 60 seconds after measurement is measured using a stopwatch. did.

(7) Flock density (%)
About 10 g of flocs after measuring the amount of the filtrate in (6) above is placed on a sieve dish of 750 μm, and is thinly stretched with a spatula and then allowed to stand at 25 ° C. for 5 minutes. Thereafter, about 3 g of floc was weighed in a petri dish (W5), dried in a circulating air dryer at 105 ± 5 ° C. for 8 hours, and the weight of the dried cake remaining on the petri dish was set as (W6). The solid fraction of the floc after filtration was calculated from the formula. Since the smaller the solid ratio, the higher the density of the floc, the higher the solid ratio (%) was evaluated as an index of the floc density.

Density of floc after filtration (%) = [(W5) − (W6)] × 100 / (W5)

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

(9) Dehydrated cake moisture content (%)
About 3 g of the dehydrated cake after the filter cloth peelability test in (8) above was weighed (W7) in a petri dish, dried in a circulating air dryer at 105 ± 5 ° C. for 8 hours, and then left on the petri dish. The moisture content of the cake was calculated from the following equation with the weight of the dry cake as (W8).

Dehydrated cake moisture content (%) = [(W7) − (W8)] × 100 / (W7)

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

In the following, examples of production of polymer flocculants and performance evaluation of the obtained polymer flocculants and comparative examples are the same NO. It will be expressed as.
Example 1 [Production of polymer flocculant (P-1)] (aqueous solution polymerization)
In accordance with Table 1, a hydrophobic monomer (a1-1), a water-soluble monomer (b1-1), a buffering agent, a heterocyclic compound (h3-2), and ion-exchanged water are mixed in a reaction vessel equipped with a stirrer. The monomer aqueous solution [aqueous phase (1)] was mixed and stirred until the system became a homogeneous solution. Under stirring, the pH of the aqueous monomer solution (20 ° C.) was adjusted to 3.0 using sulfuric acid while monitoring with a pH meter.
Next, the solution temperature was adjusted to 5 ° C. in a constant temperature water bath at 0 ° C., and the system was sufficiently substituted with nitrogen (purity 99.999% or more) (gas phase oxygen concentration of about 5 ppm). Thereafter, an aqueous initiator solution in which radical polymerization initiators (d-2), (d-3), (d-4), (d-5), and ion-exchanged water were blended based on Table 1 [aqueous phase (2 )] Is added, the polymerization is started at a solution temperature of 5 ° C., the temperature of the solution rises due to the heat generated by the polymerization, and when the solution temperature reaches 70 ° C., the reaction is performed in a 90 ° C. constant temperature bath. The vessel was placed and kept warm for 10 hours to complete the polymerization. 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. After drying with hot air for 2 hours, the mixture was pulverized with a juicer mixer to obtain 920 parts of a powdery polymer flocculant (P-1) containing the water-soluble polymer (A-1) (yield 92%, Solid content 95%). The composition and the like are shown in Table 1.

Examples 2 to 7, Comparative Examples 1 to 7 [Production of polymer flocculants (P-2) to (P-7), (RP-1) to (RP-7)]
Each polymer flocculant was obtained in the same manner as in Example 1 except that the monomer aqueous solution was replaced with the monomer aqueous solution blended based on Tables 1 and 4 in Example 1. When using a chain transfer agent, it mix | blended in initiator aqueous solution [aqueous phase (2)]. Tables 1 and 4 show the composition of each polymer flocculant.

Example 8 [Production of polymer flocculant (P-8)] (reverse phase suspension polymerization)
[First Step] According to Table 1, a monomer aqueous solution [aqueous phase (1)] containing a hydrophobic monomer (a1-1), a water-soluble monomer (b1-1), a buffering agent, and ion-exchanged water was added at room temperature (20 ˜25 ° C.). Further, the pH (20 ° C.) of the aqueous phase (1) was adjusted to 3.0 using sulfamic acid while monitoring with a pH meter. In another container, a radical polymerization initiator (d-1) and ion-exchanged water were blended according to Table 1 to prepare an aqueous initiator solution [aqueous phase (2)]. The aqueous phases (1) and (2) were separately purged with nitrogen (purity 99.999% or more; the same shall apply hereinafter) and thoroughly substituted with nitrogen (dissolved oxygen concentration of 20 ppb or less).
Apart from these, in a reaction vessel equipped with a stirring blade (Max Blend blade), 1,770 parts of a hydrophobic dispersion medium (e-1), 21.3 parts of a dispersant (c1-1) and (c2-1) An oil phase was prepared by charging 5.3 parts. While stirring the stirring blade at a rotation speed of 340 rpm, the inside of the reaction vessel was replaced with nitrogen (gas phase oxygen concentration: 10 ppm or less), then heated to 80 ° C. and held for 30 minutes, and then to the polymerization temperature of 50 ° C. Cooled down. After reaching the polymerization temperature, the water phase (1) and (2) are each fed at 25 ° C. with a dropping pump under a pressure condition of 0.1 kPa, and continuously mixed with a static mixer. (Monomer aqueous solution) was dropped into the reaction vessel over 2 hours. Thereafter, stirring was continued at 50 ° C. for 2 hours to carry out reverse phase suspension polymerization.

[Second Step] Thereafter, 9 parts of the aqueous phase (2) prepared at the same mixing ratio was further added, and after 1 hour, 14 parts of sodium bisulfite and 0.19 parts of mercaptoacetic acid were added to 10 parts of ion-exchanged water. The dissolved aqueous solution was further added, and from the time of the addition, stirring was continued at 55 ° C. for 30 minutes to complete the polymerization.
The temperature of the reaction system was 55 ° C., and azeotropic dehydration was performed under reduced pressure (3 to 20 kPa) to obtain a slurry. The slurry is supplied to a vacuum filter and subjected to solid-liquid separation, and then the solid content is dried in a vacuum dryer (1.3 kPa, 40 ° C. × 2 hours) to dry the water-soluble polymer (A-8). The polymer flocculant (P-8) which is particle | grains was obtained. Table 1 shows the composition of (P-8).

Examples 9 to 20 [Production of polymer flocculants (P-9) to (P-20)]
Each polymer flocculant was obtained in the same manner as in Example 1 except that the monomer aqueous solution was replaced with the monomer aqueous solution blended based on Tables 2 and 3 in Example 1. When using a chain transfer agent, it mix | blended in initiator aqueous solution [aqueous phase (2)]. Tables 2 and 3 show the composition of each polymer flocculant.

Example 21 [Production of polymer flocculant (P-21)]
20 parts of the water-soluble polymer (RA-2) obtained in Comparative Example 2 is blended with 20 parts of the powdered resin particles of the water-soluble polymer (A-2) obtained in Example 2, and 25 ° C. Was stirred and mixed for 1 hour to obtain a polymer flocculant (P-21) comprising a mixture of the water-soluble polymer (A-2) and the water-soluble polymer (RA-2). Table 3 shows the composition of (P-21).

Example 22 [Production of polymer flocculant (P-22)]
10 parts of the water-soluble polymer (RA-3) obtained in Comparative Example 2 are blended with 30 parts of the powdered resin particles of the water-soluble polymer (A-2) obtained in Example 2, and 25 ° C. Was stirred and mixed for 1 hour to obtain a polymer flocculant (P-22) comprising a mixture of the water-soluble polymer (A-2) and the water-soluble polymer (RA-3). Table 3 shows the composition of (P-22).

Example 23 [Production of polymer flocculant (PD-1)]
To 36 parts of the powdered resin particles of the water-soluble polymer (A-2) obtained in Example 2, 4 parts of an organic coagulant (D2-1) was blended and stirred and mixed at 25 ° C. for 1 hour. A polymer flocculant (PD-1) comprising a mixture of the water-soluble polymer (A-2) and the organic coagulant (D2-1) was obtained. Table 3 shows the composition of (PD-1).

Example 24 [Production of polymer flocculant (PQ-1)]
[Production of polymer flocculant (Q-1)]
In Example 1, a polymer flocculant (Q-1) was obtained in the same manner as in Example 1, except that the monomer aqueous solution and the initiator aqueous solution were replaced with the monomer aqueous solution and the initiator aqueous solution prepared as follows. . The 0.5% salt aqueous solution viscosity of (Q-1) was 150 mPa · s, and the 0.2% aqueous solution viscosity was 500 mPa · s.
<Preparation of aqueous monomer solution>
1,21 parts of water-soluble unsaturated monomer (b1-3), 156 parts of (b2-2), 92.6 parts of 10% aqueous solution of sodium salt of trimellitic acid (q-1), 13.6 parts of buffer, And 131 parts of ion-exchanged water were blended.
<Preparation of aqueous initiator solution>
Radical polymerization initiator (d-1) 13.8 parts, (d-3) 0.23 parts, (d-4) 0.58 parts, (d-5) 0.55 parts, chain transfer agent (f- 1) 0.55 part and 131 parts of ion-exchanged water were blended.
<Production of polymer flocculant (PQ-1)>
8 parts of the polymer flocculant (Q-1) is blended with 32 parts of the powdered resin particles of the water-soluble polymer (A-2) obtained in Example 2, and the mixture is stirred and mixed at 25 ° C. for 1 hour. Thus, a polymer flocculant (PQ-1) comprising a mixture of the polymer flocculant (P-2) and polymer flocculant (Q-1) containing (A-2) was obtained. The evaluation results of (PQ-1) are shown in Table 3.

Comparative Example [Production of Polymer Flocculants (RP-8) to (RP-9)]
In Example 1, each polymer flocculant was obtained in the same manner as in Example 1 except that the monomer aqueous solution was replaced with the monomer aqueous solution blended based on Table 4. When using a chain transfer agent, it mix | blended in initiator aqueous solution [aqueous phase (2)]. Table 4 shows the composition of each polymer flocculant.

Examples 1 to 24, Comparative Examples 1 to 9 [Performance evaluation of polymer flocculant]
The obtained polymer flocculants were each dissolved in ion exchange water to obtain an aqueous solution having a solid content of 0.2%. 200 parts of digested sludge [pH 7.4, TS 2.9%, SS 2.7%, organic content 65%, alkalinity 4,543 mg-CaCO ₃ / L] collected from the treated city A treatment plant in a 500 mL beaker Then, 20 parts of each aqueous solution of the polymer flocculant was added (the amount of solid content added was 0.7% / TS at this time), and the performance was evaluated. The results are shown in Tables 5 and 6.

  From Tables 5 and 6, in Examples 1 to 24, compared to Comparative Examples 1 to 9, flocs once formed under low agitation (300 rpm) are less likely to break even under high agitation (650 rpm) (high flock strength). In addition, since the amount of liquid after 10 seconds is large, the initial filtration rate is fast, the flocs are dense (low moisture content), the filter cloth peelability is excellent, and the dewatering property (dehydrated cake moisture content). It turns out that the outstanding effect is shown.

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

Claims (8)

A polymer flocculant (P) comprising a water-soluble polymer (A) satisfying the following relational expression [1].

−0.40 ≦ ln [η] / ln V _s ≦ 0.55 [1]

[In the formula, [η] represents an intrinsic viscosity at 30 ° C. in a 1N—NaNO ₃ aqueous solution, and V _s represents a 0.5 wt% salt aqueous solution viscosity at 25 ° C. in a 4 wt% NaCl aqueous solution. ] (A) a hydrophobic monomer (a) having one unsaturated group and an octanol / water partition coefficient (logPow) of 1.0 to 6.0 and a water-soluble monomer having one unsaturated group The polymer flocculant according to claim 1, which is a water-soluble polymer containing (b) as a structural unit. The polymer flocculant according to claim 2 or 3, wherein the content of (a) based on the total weight of unsaturated monomers constituting (A) is 3 to 60%. The polymer flocculant according to claim 2 or 3, wherein the weight ratio of (a) and (b) is from 3/97 to 60/40. The polymer flocculant according to any one of claims 1 to 4, further comprising a water-soluble polymer (B) obtained by polymerizing only a water-soluble monomer (b) having one unsaturated group. The polymer flocculant according to claim 5, wherein the content of (B) based on the weight of (P) is 70% or less. A hydrophobic monomer (a) having one unsaturated group and an octanol / water partition coefficient (logPow) of 1.0 to 6.0, and a water-soluble monomer (b) having one unsaturated group Containing a water-soluble polymer (A) characterized in that the unsaturated monomer contained is polymerized in the presence of a heterocyclic compound (h) containing one secondary nitrogen atom in the ring structure The manufacturing method of the polymer flocculent (P) which becomes. A method for treating sludge or wastewater, wherein the polymer flocculant according to any one of claims 1 to 6 is added to and mixed with sludge or wastewater to form a floc and solid-liquid separation.