WO2006126674A1

WO2006126674A1 - Process for production of water-soluble polymers and use thereof

Info

Publication number: WO2006126674A1
Application number: PCT/JP2006/310554
Authority: WO
Inventors: Tetsuya Tsuzuki; Yoshio Mori; Ken Takeda; Koichi Adachi
Original assignee: Toagosei Co., Ltd.
Priority date: 2005-05-26
Filing date: 2006-05-26
Publication date: 2006-11-30
Also published as: JP4743205B2; JPWO2006126674A1

Abstract

[PROBLEMS] To provide a process for the production of water -soluble polymers which are excellent in water solubility even when used in the form of powder and which serve as polymer flocculant and exert excellent flocculation performance against various substances such as inorganic salt-rich sludge or in the paper making step under high shear. [MEANS FOR SOLVING PROBLEMS] A process for the production of water-soluble polymers which comprises subjecting a monomer mixture consisting of (A) a radical-polymerizable water-soluble monomer and (B) a compound having two or more ethylenically unsaturated groups and having a content of the component (B) ranging from 3 x 10-5 to 1 x 10-3 mmol per gram of the total of the components (A) and (B) to aqueous solution polymerization to obtain a water-swollen gel of a water-insoluble polymer and applying mechanical shearing force to the water-swollen gel to convert the water-insoluble polymer into a water-soluble one.

Description

Specification

Method for producing water-soluble polymer and use thereof

Technical field

The present invention relates to a method for producing a water-soluble polymer, and the polymer obtained by the present invention is useful as a polymer flocculant, a paper strength enhancer, and a thickener, and in particular, a sludge dehydrating agent. In addition, the polymer is useful as a polymer flocculant such as a yield improver, and belongs to the technical field of the polymer production method and the above-mentioned use.

Background art

Conventionally, water-soluble polymers, particularly high-molecular-weight water-soluble polymers, have been used in various applications such as polymer flocculants, yield improvers, paper strength enhancers, and thickeners. .

As such a water-soluble polymer, a cationic polymer is often used. Specifically, the main component is a cationic monomer such as dimethylaminoethyl (meth) acrylate quaternary salt, and a non-ionic monomer such as (meth) acrylamide is polymerized as necessary. In addition to the obtained polymer, a copolymer obtained by copolymerization with anionic monomer such as (meth) acrylic acid in addition to the cationic monomer and nonionic monomer.

[0003] However, when a conventional polymer flocculant composed of a water-soluble polymer is used as a sludge dehydrating agent, the adsorption reactivity to sludge particles and the like may be inferior. In some cases, sludge dewatering performance deteriorated with high drainage.

In addition, when the polymer flocculant is used as a yield improver, it is necessary for the yield improver to cause an agglomeration reaction under high shear in the paper making process. Was inferior.

Generally, in sludge dewatering, dewatering can be improved by increasing the amount of sludge dewatering agent added. However, the conventional sludge dewatering agent composed of a linear polymer has a problem that the sludge slurry thickens when a certain amount or more is added. This is because when the amount of sludge dehydrating agent increases, the amount of adsorption on the sludge increases and at the same time the concentration of non-adsorbing sludge dewatering agent increases in water, which causes problems such as poor stirring. In some cases, the amount added could not be increased substantially. Yield improvement Even when used as an agent, there were similar problems.

In order to improve this problem, a cross-linking agent in which a compound having two or more ethylenically unsaturated groups (hereinafter referred to as a polyfunctional compound) is added and a part of the polymer is cross-linked has been proposed. .

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 61-293510 (Claims)

Patent Document 2: Japanese Patent Application Laid-Open No. 64-85199 (Claims)

Patent Document 3: JP-A-2-219887 (Claims)

Patent Document 4: JP-A-4-226102 (Claims)

Disclosure of the invention

Problems to be solved by the invention

However, in the polymerization using the polyfunctional compound, the polyfunctional compound is used to prevent the resulting water-soluble polymer from being insoluble in water. There is an upper limit to the amount of addition, and in terms of performance, it was unsatisfactory to obtain a high molecular weight polymer having good solubility in water, especially in powder form.

[0006] On the other hand, if polymerization is performed by the reverse emulsion polymerization method, a polymer can be obtained even when a relatively large amount of the polyfunctional compound is used. However, the polymer obtained by the reverse emulsion polymerization method contains an organic solvent, has a problem of transportation cost, and a powdery coagulant is desired.

[0007] The present inventors have excellent water solubility even when used as a powder, and when used as a polymer flocculant, the present inventors have various kinds of sludge containing a high concentration of inorganic salt and papermaking processes under high shear. In order to find a method for producing a water-soluble polymer having excellent agglomeration performance, intensive studies were conducted.

Means for solving the problem

[0008] As a result of various studies, the present invention has been studied based on the idea that a water-soluble polymer having a sufficient branched structure is effective in solving the above problems. As a result, a relatively large amount of polyfunctional compound is added to the water-soluble monomer to form a structure having one or more branch points in every polymer molecule. A water-insoluble polymer gel is converted into a water-soluble polymer by applying mechanical shear (shearing force) to the polymer gel. As a result, the present invention has been completed.

The present invention will be described in detail below.

In the present specification, attalylate or metatalylate is represented as (meth) acrylate, acrylic acid or methacrylic acid is represented as (meth) acrylic acid, and acrylamide or methacrylamide is represented as (meth) acrylamide.

[0009] 1. Method of making water-soluble polymer

The present invention comprises (A) a radically polymerizable water-soluble monomer and (B) a compound having two or more ethylenically unsaturated groups, wherein the proportion of (B) component is (A) component and (B) component respect of the total amount is ^{^{3 X 10- 5 ~1 X 10- 3}} mmolZg after the monomer mixture was aqueous solution polymerization, in water swollen gel of the resulting water-soluble polymer, mechanical shearing The present invention relates to a method for producing a water-soluble polymer by adding force to form a water-soluble polymer.

That is, the present invention provides an insoluble polymer by aqueous solution polymerization of a monomer mixture containing the component (B) as a crosslinking agent sufficiently with respect to the total amount of the components (A) and (B). Then, a mechanical shearing force is applied to the water-swelling gel of the polymer to produce a powder-type water-soluble polymer. The resulting polymer has a branched shape and is low in viscosity. Even if the amount of addition is high, even if the deviation is excellent, the performance is excellent! The amount of additive slag is wide, and the sludge and paper are thickly absorbed by sludge and paper efficiently. It exhibits excellent agglomeration performance that can reduce the water content efficiently. Hereinafter, the components used and the production method will be described.

[0010] 1) (A) Radical polymerizable water-soluble monomer

As the component (A), various compounds can be used as long as they have radical polymerizability and water solubility.

Component (A) includes a radical polymerizable cationic monomer (hereinafter simply referred to as cationic monomer V) and a radical polymerizable anionic monomer (hereinafter simply referred to as anionic monomer! /) ) And radically polymerizable nonionic monomers (hereinafter simply referred to as “nonionic monomers”).

[0011] As the cationic monomer, various compounds can be used as long as they have radical polymerizability, and specifically, dimethylaminoethyl (meth) acrylate, jetyl aminoethyl (meth) acrylate. RATES AND JETILLAMINO 2-HYDROXYPROPYL (METH) ATALYLATE, etc. Tertiary salts of dialkylaminoalkyl (meth) atalylates such as hydrochlorides and sulfates; Alkyl halide adducts such as methyl chloride-containing adducts of dialkylaminoalkyl (meth) atalylates and benzyl chloride addition Quaternary salts such as adducts such as halogenated aryls, etc .; N, N —dialkyl (meth) acrylamides such as dimethyl (meth) acrylamide and tertiary salts such as sulfates and sulfates; dialkyl (meth) acrylamides Halogenated compounds such as methyl chloride adducts and quaternary salts such as alkyl adducts and halogenated adducts such as benzyl chloride adducts.

Of these, dialkylaminoalkyl (meth) acrylate quaternary salts are preferred, and dialkylaminoalkyl (meth) acrylate haloalkyl adducts are more preferred.

[0012] Various compounds can be used as the teron monomer as long as it has radical polymerizability. Specifically, (meth) acrylic acid and its salt; crotonic acid, itaconic acid and maleic acid are used. Examples thereof include unsaturated carboxylic acids such as inic acid and salts thereof; acrylamide alkylalkanesulfonic acids such as acrylamide-2-methylpropanesulfonic acid and salts thereof; and bulesulfonic acid and salts thereof. Examples of the salt include an ammonium salt and alkali metal salts such as sodium and cadmium.

Among these, (meth) acrylic acid is preferable.

[0013] As the nonionic monomer, various compounds can be used as long as they have radical polymerizability. Specifically, (meth) acrylamide; dimethyl (meth) acrylamide and jet (meth) Dialkyl (meth) acrylamides such as acrylamide; Hydroxyalkyl (meth) acrylates such as hydroxylethyl (meth) acrylates; Dialkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylates; Dialkylaminopropyls Examples thereof include dialkylaminoalkyl (meth) acrylamides such as (meth) acrylamide; ethylene oxide-added methoxy (meth) acrylate and ethylene oxide-attached (meth) aryl ether.

Among these, (meth) acrylamide is preferable.

[0014] As the monomer, a hydrophobic monomer other than this may be used in combination with the water-soluble monomer within the range that does not adversely affect the resulting polymer. Examples of such monomers Examples thereof include methoxyethyl (meth) acrylate, butoxychetyl (meth) acrylate, ethyl carbitol (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate and butyl acetate.

[0015] These monomers can be used alone or in admixture of two or more.

[0016] 2) (B) Compound having two or more ethylenically unsaturated soots

The component (B) functions as a so-called crosslinker of the component (A).

As the component (B), various compounds can be used as long as they have two or more ethylenically unsaturated groups.

As the ethylenically unsaturated group, a (meth) ataryloyl group, a vinyl group and an aryl group are preferred.

In the component (B), examples of the compound having a (meth) atalyloyl group include bis (meth) acrylamides such as methylenebis (meth) acrylamide and ethylenebis (meth) acrylamide; polyethylene glycol di (meth) acrylate and polypropylene glycol Poly (alkylene glycol) di- (meth) acrylates such as di (meth) acrylate; Isocyanuric acid ethylene oxide-modified di (meth) acrylate, etc. Isocyanuric acid alkylene oxide-modified di (meth) acrylate; Poly (poly) methacrylates such as (meth) acrylate and trimethylol propane tri (meth) acrylate; and polyol alkylenes such as tri (methyl) propane ethylene oxide adduct tri (meth) acrylate. Poly (meth) Atari rate, and the like Sid adduct.

Examples of the compound having a bur group include dibulene benzene and the like. Examples of the compound having a allyl group include allylic compounds of isocyanuric acid such as triallyl isocyanurate; triarylcyanurate compounds such as trisulyloxytriazine; allylic carboxylic acid such as diallyl phthalic acid. Compounds; and aryloxyalkanes such as triallyloxetane.

Examples of the compound having a (meth) atalyloyl group and a vinyl group include N-but (meth) acrylamide and the like, and an example of a compound having a (meth) atalyloyl group and an aryl group is N-methyla. Examples include rylacrylamide.

In addition, as a polymer having two or more unsaturated groups in the skeleton, a poly (meth) acrylic acid moiety It is also possible to use a glycidyl (meth) atarylate adduct or the like.

The component (B) is preferably a compound having 2 to 3 ethylenically unsaturated groups.

[0017] (B) The proportion of the components is a ^{^{3 X 10- 5 ~1 X 10- 3}} mmolZg on the total amount of components (A) and component (B). If this ratio is less than 3 X 10- ⁵ mmol / g, improvement for the linear polymer as the water-soluble polymer obtained often performance is insufficient, and when it exceeds 1 X lO 'mmol / g, Even if the polymer becomes extremely water-insoluble and the shearing force that it gives becomes excessive, making it difficult to produce, or even if a water-soluble polymer is obtained, it is obtained due to excessive shearing force. Moreover, since the molecular weight of the polymer is too small, the agglomeration performance is too low.

[0018] 3) 7k melting: ¾ report method

In the production method of the present invention, after the components (A) and (B) are polymerized in an aqueous solution, a mechanical shearing force is applied to the water-swelling gel of the obtained water-soluble polymer to form a water-soluble polymer. It is a method to do.

[0019] As a method for aqueous solution polymerization, a method of polymerizing a monomer mixture of the components (A) and (B) in an aqueous medium, which is satisfactory according to a conventional method, is preferable.

[0020] For example, a monomer aqueous solution having a monomer concentration of 10 to 80% by mass, preferably 25 to 60% by mass, in the absence of oxygen, using a polymerization initiator and a polymerization initiation temperature of 0 to 35 Examples include a method of polymerizing by polymerization at a temperature of 100 ° C. or lower and a polymerization temperature of 0.1 to: LO time.

[0021] Specific examples of the polymerization initiator in this case include persulfates such as sodium persulfate and potassium persulfate, organic peracids such as benzoyl peroxide, 2, 2'-azobis- (Amidinopropane) Noid Mouth Chloride, Azobiscyanovaleric Acid, 2,2'-Azobisisobutyronitrile and 2,2'-Azobis [2-methyl-N- (2-hydroxyethyl) ) -Propionamide] and the like, and redox catalysts having a combination power of hydrogen peroxide, sodium persulfate and sodium bisulfite, ferrous sulfate and the like.

[0022] The polymerization can also be carried out by ultraviolet irradiation. For example, the polymerization can be carried out using a photopolymerization initiator of ketal type, acetophenone type or the like.

The amount of the polymerization initiator used should be determined according to the degree of polymerization and viscosity of the target polymer. Usually, the total amount of all monomers and the polymerization initiator is from 100,000 to 20,000. ppm It is preferable to use it.

[0023] The molecular weight of the polymer can be adjusted by changing the type and ratio of the monomer and the polymerization initiator used, in addition to the chain transfer agent.

[0024] Examples of the chain transfer agent in this case include thiol compounds such as mercaptoethanol and mercaptopropionic acid, and reducing inorganic salts such as sodium sulfite, sodium bisulfite and sodium hypophosphite.

[0025] In the case of producing a polymer having a high molecular weight to be used as a flocculant, the amount thereof is preferably 10 to 2000 ppm when producing a polymer to be used as a papermaking agent. 100-20,000 ppm is preferred! / ヽ.

[0026] The gel polymer obtained by the water-soluble polymerization contains a relatively large amount of the component (B) and is therefore a water-insoluble polymer. In the present invention, the polymer has a mechanical shearing force. To make a water-soluble polymer.

In general, the shearing force is a force that causes slipping in opposite directions with respect to a certain surface. In the present invention, the water-swelling gel polymer that is insolubilized or a bridge point in the molecule is defined. It means the energy required for cutting and making it water soluble.

[0027] Specific examples of the machine for applying the mechanical shearing force include a meat chopper, an ader and a grinder. These are commercially available, the meat chopper is a chopper made by Hiraga Kogyo Co., Ltd., and the Nieda Etastruder is made by Technobel KWZ series, Seiwa Iron Works Co., Ltd. KRC--Daiichi manufactured by Tokoro Corporation. The grinder is also called a grinder, and examples thereof include Super Masco Mouth Idar manufactured by Masuyuki Sangyo Co., Ltd.

[0028] The shearing force in this case may be appropriately set according to the polymer to be used, the mechanical shearing machine to be used, and the time, so that the water-swollen gel polymer can be converted into water-soluble. It is optional as long as it has a strong shear.

[0029] As the mechanical shear force in the present invention, a shear force is applied to the water-insoluble polymer so that the 0.1% insoluble content of the obtained water-soluble polymer is 10 ml or less. The 0.1% insoluble content is preferably 5 ml or less. In the present invention, the insoluble content of the polymer means a value measured according to the following method.

[0030] (0.1% insoluble content)

The polymer is dissolved in pure water to prepare 400 ml of a 0.1% by mass (in terms of solid content) solution. The total amount of this solution is filtered through a sieve with a diameter of 20 cm and a mesh of 83 mesh. The insoluble matter remaining on the sieve is collected and the volume is measured.

[0031] Depending on the polymer component, when the mechanical shearing force is applied, the above-described component (B) can be additionally added.

[0032] When using a meat chopper or the like having a relatively low shearing force, it is sufficient to repeat the shearing force addition treatment (in this case, the chobbing treatment) until the polymer becomes water-soluble. When a strong force-kinder or grinder is used, the polymer can be made water-soluble by applying a shearing force once to several times.

In the present invention, it is preferable to use a kneader and a grinder because the polymer can be made water-soluble by one to several shear treatments.

[0033] Since the gel itself may be blocked after the shearing force is applied, it can be cut and shredded by a known method for the purpose of loosening the gel. In this case, examples of the cutting method employed include a meat chopper method.

[0034] The chopped polymer is dried at a temperature of about 60 to 150 ° C using a dryer such as a band dryer, a rotary dryer, a far-infrared dryer, and a vibratory fluid dryer. In the case of using a roll type pulverizer or the like to form a powder polymer by adjusting the particle size and using it as a polymer flocculant, additives and the like are added as necessary.

[0035] By the above method, a powdery water-soluble polymer can be produced.

[0036] 2.

The polymer obtained by the production method of the present invention can be applied to various uses. Examples thereof include polymer flocculants, thickeners for paints, and base materials for plaster, and are particularly useful as polymer flocculants. As the polymer flocculant, it can be preferably used as a papermaking agent in a papermaking process such as a sludge dehydrating agent and a yield improving agent.

[0037] When used as a polymer flocculant, the weight average molecular weight is several million to several million In particular, coalescence is preferred, and a 0.5% salt viscosity measured by the following measurement method is preferably 5 to 200 mPa's.

[0038] (0.5% salt viscosity)

Dissolve the polymer in 4% by weight aqueous sodium chloride solution to prepare a 0.5% by weight polymer solution. Using a B-type viscometer, measure the viscosity of the polymer solution after 5 minutes at a temperature of 25 ° C and 60 rpm.

[0039] The polymer flocculant of the present invention is particularly useful as a sludge dehydrating agent and a yield improving agent. Hereinafter, the sludge dehydrating agent and the yield improving agent will be described.

[0040] 1) Sludge dewatering agent

When the polymer obtained by the production method of the present invention is used as a sludge dehydrating agent, it is used by mixing with known additives such as sodium hydrogen sulfate, sodium sulfate and sulfamic acid as long as the dehydrating treatment is not adversely affected. May be.

[0041] The sludge dehydrating agent of the present invention is added to various sludges to form a floc having excellent balance of floc strength, filtration rate and moisture content. Addition method to sludge, floc formation The methods currently used are applicable without any problems, and the applicable sludges are not particularly limited. Specific examples of sludge that can be applied include domestic wastewater treatment sludge, food industry wastewater treatment sludge, chemical Examples include industrial wastewater treatment sludge, pig farm wastewater treatment sludge, and pulp or paper industry sludge.

[0042] The sludge dehydrating agent of the present invention can be used alone, but can also be used in combination with an inorganic flocculant or an organic cationic compound. Examples of the inorganic flocculant include aluminum sulfate, polyaluminum chloride, and salty soot. Examples of the organic cationic compound include polymer polyamines, polyamidines, and cationic surfactants.

[0043] If necessary, a cationic polymer flocculant, a ionic polymer flocculant and an amphoteric polymer flocculant other than the present invention can be used in combination.

Examples of the cationic polymer flocculant include a homopolymer of the aforementioned cationic monomer and a copolymer of the aforementioned cationic monomer and nonionic monomer.

As the ionic polymer flocculant, homopolymers of the aforementioned ionic monomers and Examples thereof include a copolymer of the anionic monomer and the nonionic monomer.

Examples of the amphoteric polymer flocculant include a copolymer of the aforementioned cationic monomer, ionic monomer, and nonionic monomer.

[0044] In particular, when the sludge dewatering agent of the present invention is amphoteric, the method of adding the sludge dewatering agent to the sludge to which the inorganic flocculant has been added is more efficient as a dewatering method. After adding the inorganic flocculant, it is preferable to adjust the pH to 4 to 8, more preferably 5 to 7.

[0045] The amount of the sludge dehydrating agent of the present invention added to the sludge is usually 0.1 to 3% by weight of the dried sludge of Z sludge, preferably 0.2 to 2% of the dried sludge of Z sludge. 0. If the amount is less than 1% by mass, the recovery rate of sludge suspension is not sufficient.

[0046] The formed floc can be dehydrated using a dehydrating device such as a screw press dehydrator, a belt press dehydrator, a filter-and-press dehydrator, a screw decanter, etc. to obtain a dehydrated cake.

[0047] The flocculant of the present invention can also be applied to a dehydration method using a granulation concentration tank having a filtration part. Specifically, an inorganic flocculant is added to sludge, and sludge is further added. After adding the dehydrating agent or together with the sludge dewatering agent, the sludge is introduced into a granulation concentration tank having a filtration part, and the filtration part is filtered and granulated, and the granulated product is dehydrated. For example, a method of dehydrating with

[0048] 2) Mukoju agent and law

When the polymer obtained by the production method of the present invention is used as a yield improver, the powder is dissolved in water and used as an aqueous solution as described above. The solid content in this case is preferably 0.01 to 0.5% by mass, more preferably 0.01 to 0.1% by mass.

[0049] The paper making method using the yield improver of the present invention is good if paper is made after the composition of the present invention is added to the paper stock that is good according to a conventional method.

For example, the yield improver may be added in accordance with conventional methods. For example, it is added at the time of diluting the paper stock to the final concentration to be fed into the paper machine or after the dilution.

[0050] The paper material to which the yield improver is applied is one used in a normal paper making process. Usually, it contains at least pulp and filler, and optionally contains additives other than filler, specifically, sizing agent, fixing agent, paper strength enhancer, colorant and the like. The yield improver of the present invention can be preferably applied to a pulp having a relatively high ratio of used paper such as deinked used paper in the pulp. The yield improver of the present invention can be preferably applied to a papermaking system, a neutral papermaking system, and a high-speed papermaking system having a high filler ratio.

Examples of the filler include clay, kaolin, agarite, talc, calcium carbonate, magnesium carbonate, lime sulfate, barium sulfate, zinc oxide and titanium oxide. Examples of the sizing agent include acrylic acid styrene copolymer. Examples of the fixing agent include sulfuric acid band, force thione starch and alkyl ketene dimer. Examples of the paper strength enhancer include starch and cationic. Or amphoteric polyacrylamide etc. are mentioned.

[0051] The preferred addition ratio of the yield improver is 100-500 ppm force per dry pulp mass in the stock.

The pH of the stock after the addition of the yield improver is preferably 5 to 8 and more preferably 5 to 8 when maintained at LO. After adding the yield improver, the stock is immediately fed into the paper machine.

[0052] According to the method for producing a water-soluble polymer of the present invention, the water-soluble polymer is excellent in water solubility even when used as a powder, and the obtained water-soluble polymer has a high concentration when used as a polymer flocculant. Even in sludge and papermaking processes under high shear, it has excellent agglomeration performance.

BEST MODE FOR CARRYING OUT THE INVENTION

[0053] The present invention, components (A) and (B) component force becomes, 3 X 10- ⁵ ~1 X 10 relative to the total amount of (B) the proportion of component (A) component and the (B) component — A water-soluble polymer obtained by water-polymerizing a monomer mixture of ³ mmolZg and then adding mechanical shearing force to the water-swollen gel of the resulting water-insoluble polymer to form a water-soluble polymer. It relates to the manufacturing method.

The mechanical shear force is preferably added to the water-swelling gel of the water-insoluble polymer so that the 0.1% insoluble content of the resulting water-soluble polymer is 10 ml or less. The obtained water-soluble polymer is preferably dried as it is if it is chopped, and if it is not chopped, it is further shredded and dried to obtain a powdery body. The water-soluble polymer obtained by the production method of the present invention can be preferably used as a polymer flocculant. As the polymer flocculant, it can be preferably used as a sludge dehydrating agent and a yield improving agent.

Example

[0054] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

In the following, “%” means mass%, and “part” means mass part.

[0055] Example 1

In a stainless steel reaction vessel, as component (A), dimethylaminoethyl acrylate methyl chloride quaternary salt (hereinafter referred to as DAC) aqueous solution and acrylamide (hereinafter referred to as AM) aqueous solution are placed. Distilled water was added so that the total monomer concentration was 55% and the total weight was 1. Okg at a molar ratio of 0. The amounts of DAC and AM in the aqueous monomer mixture solution were 516.5 g and 33.4 g, respectively, and the total monomer weight was 550 g.

Subsequently, while nitrogen gas was blown into the solution for 60 minutes, the solution temperature was adjusted to 10 ° C. to obtain an aqueous monomer mixture solution.

Furthermore, total monomer weight with respect to the, (B) methylene bisacrylamide as a component (hereinafter, referred to as MBA) components (A) and component (B) the total amount with respect to 100wtppm (65 X 10- ⁵ mmol Zg of ), And azobisamidinopropane hydrochloride (hereinafter referred to as V-50) and sodium bisulfite as polymerization initiators were adjusted to 900 ppm and 20 ppm with respect to the total amount of the monomers, respectively. From the upper side of the reaction vessel, polymerization was carried out using a 100 W black light at an irradiation intensity of 6. Om WZcm ² for 60 minutes to obtain a water-containing gel-like water-soluble polymer.

The water-containing gel-like water-soluble polymer is taken out of the container, subjected to mechanical shearing with KRC-Da (manufactured by Kurimoto Kyosho Co., Ltd.), and then a small meat chopper (MD22 K]. This was dried at a temperature of 80 ° C. for 5 hours and then pulverized to obtain a powdery water-soluble polymer.

The water-soluble polymer was measured for 0.1% insoluble content and 0.5% salt viscosity. Table 1 shows the results.

[0056] Example 2, Comparative Examples 1 to 4 A powdery water-soluble polymer was obtained in the same manner as in Example 1 except that the components (A), (B), the type of machine, the number of gel treatments, and the like were changed to those shown in Table 1.

The obtained water-soluble polymer was measured for 0.1% insoluble content and 0.5% salt viscosity. The results are shown in Table 1.

When mechanical shear is added by a meat chopper, it also serves as a shredding process, so further shredding is unnecessary.

[table 1]

〇 Example 3

As the sludge to be treated, Tokyo Metropolitan Sewage Mixed Raw Sludge (ρΗ = 6.1 SS = 27000mg / U VS S = 20000mg / l) was used.

Collect 200ml of mixed raw sludge in a 500ml beaker, add 0.2% aqueous solution of Polymer No. 8-1, and then stir for 90 seconds with a stirrer to generate sludge floc. The diameter was measured.

Thereafter, the sludge floc dispersion was gravity filtered using an 80 mesh net as a filter. The filtrate volume after 10 seconds was measured and indicated as the filtration rate. The obtained cake was squeezed and dehydrated with a mini belt press (surface pressure 0.5 kgZcm2, 3 stages), and the water content was measured. These evaluation results are shown in Table 2.

[0059] 〇 Comparative Example 5 and 6

In Example 2, sludge flocs were produced in the same manner as in Example 2 except that a 0.2% aqueous solution of the polymer shown in Table 2 was used, and the floc particle size was measured.

Thereafter, the filtration rate and water content were measured in the same manner as in Example 2. The evaluation results are shown in Table 2.

[0060] [Table 2]

As is apparent from the results in Table 2, in Example 3, all the performances of the floc diameter, the filtration rate and the water content were excellent.

On the other hand, although it is a water-soluble polymer, the proportion of component (B) does not satisfy the lower limit of the present invention, Comparative Example 5 using B-1 produced in an amount, and component (B) In Comparative Example 6 using B-4 produced by using B-4 in all cases, all the performances of the block diameter, the filtration rate and the moisture content were insufficient as compared with the Examples. This was remarkable when the specific addition amount was high.

The polymer (B-2) obtained in Comparative Example 2 is insoluble in water, and the polymer (B-3) obtained in Comparative Example 3 has a large amount of water-insoluble components. As a force that can not be used.

[0062] Example 4

In the same container as in Example 1, the DAC aqueous solution and the AM aqueous solution are put as the component (A), and the molar ratio is 10.0 and 90.0 respectively, the total monomer concentration is 40%, and the total weight. 1. To become Okg Distilled water was added. The amounts of DAC and AM in the aqueous monomer mixture were 9 3. Og and 307. Og, respectively, and the total monomer weight was 400 g.

Subsequently, while nitrogen gas was blown into the solution for 60 minutes, the solution temperature was adjusted to 15 ° C. to obtain an aqueous monomer mixture solution.

Furthermore, based on the total monomer weight, as component (B), polyethylene glycol dichlorate (having an average ethylene glycol unit number of 9; hereinafter referred to as NEGDA) is used as component (A) and component (B). 120wtppm (78 X 10 " ⁵ mmol / g) with respect to the total amount of the components, V-50 and sodium bisulfite as the polymerization initiator, 1000 ppm and 15ppm with respect to the total amount of the monomers, respectively In this manner, from the upper side of the reaction vessel, the polymerization was carried out by irradiating with ultraviolet rays under the same conditions as in Example 1 to obtain a water-containing water-soluble polymer.

The water-containing water-soluble polymer in the form of a hydrogel was taken out of the container, subjected to mechanical shearing with the same solder as in Example 1, and then chopped using the same chopper as in Example 1. This was dried at a temperature of 80 ° C. for 5 hours and then pulverized to obtain a powdery water-soluble polymer.

The water-soluble polymer was measured for 0.1% insoluble content and 0.5% salt viscosity. Table 3 shows the results.

[0063] Example 5, Comparative Examples 7-8

A powdery water-soluble polymer was obtained in the same manner as in Example 4 except that the components (A), (B), the type of machine, the number of gel treatments, and the like were changed to those shown in Table 3.

The obtained water-soluble polymer was measured for 0.1% insoluble content and 0.5% salt viscosity. Table 3 shows the results.

[0064] [Table 3] Example 4 Example 5 Comparative Example 7 Comparative Example 8

Polymerization 0. A-3 A-4 Β-5 Β-6

(A) D A C 1 0 1 0 1 0 1 0

(mol¾)

A M 9 0 9 0 9 0 9 0

(mol¾)

(B) N E! O G D A 1 2 0 1 2 0 0 1 2 0

(wtppm)

(Picture l / g) 7 8 7 8 0 7 8

x it) - ⁵

Monomer concentration 4 0 4 0 4 0 4 0

(wt¾)

Mouth child o Start temperature 1 5 1 5 1 5 1 5

Condition (.c)

V-50 (ppm) 1000 1000 1000 1000

1 5 1 5 1 5 1 5 Machine Machine type Double-sided Λ ° —Choice Λ. 1Chiyo 8 °-Target processing times 1 1 5 1 8

(Number of times)

Shredding Machine type Chiyohachi. — — — —

Number of processing 1

(Number of times)

Physical properties 0.5% salt viscosity 5 4 7 5 7 2 9 8

(mPas)

0. Insoluble 1 0 0 4 8

Minute (ml) O Example 6 and 7

Bleached hardwood pulp (hereinafter referred to as LB 。. Canadian standard freeness = 320 ± 10ml) as a target pulp slurry for the yield improver test 0.8% wt. 15 parts and 1.5 parts of sulfuric acid band (8%) LBKP added with 1.5 parts were used. The pH of this pulp slurry was 7.4 force to 8.8, and the electric conductivity was 420 force to 470 μS / cm.

400 g of the prepared pulp slurry was collected in a dynamic drainage jar (Dynamic Drain age Jar, hereinafter referred to as DDJ, using a 200 mesh net) and stirred at the stirring speed shown in Table 4 while polymer No. A-3 and A — A 0.05% aqueous solution of 4 was added to 1 kg of LBKP so that the amount of polymer added was 250 mg. Filtration was started 10 seconds after the addition, and the yield rate was determined by measuring the amount of suspended solids (SS) in the drained filtrate. An evaluation was also conducted when no polymer was added as a blank.

These evaluation results are shown in Table 4.

[0066] 〇 Comparative Example 9

In Examples 6 and 7, the yield rate was measured in the same manner as in Example 4 except that a 0.05% aqueous solution of the polymer shown in Table 4 was used.

Table 4 shows the evaluation results.

[0067] [Table 4]

[0068] As is clear from the results in Table 4, in Examples 6 and 7, a high yield rate was shown with respect to the blank. In addition, even when the DDJ stirring speed, which is a high shear condition, was increased, the yield rate decreased only slightly.

In contrast, Comparative Example 9 using B-5 produced without using the component (B) shows a constant yield rate under low shear with a low DDJ stirring speed, but stirring Under high shear conditions where the speed was increased, the yield rate decreased significantly.

Note that the polymer (B-6) obtained in Comparative Example 8 had a large amount of water-insoluble components, and thus could not be used as a yield improver.

Industrial applicability

[0069] The present invention is useful as a method for producing a water-soluble polymer, and the obtained polymer is useful as a polymer flocculant, a paper strength enhancer, and a thickener. It is useful as a polymer flocculant such as a yield improver.

Claims

The scope of the claims

[1] It contains (A) a radically polymerizable water-soluble monomer and (B) a compound having two or more ethylenically unsaturated groups, and the proportion of (B) component is that of (A) and (B) after the monomer mixture which is a ^{3 X 10- 5 ~1 X 1 0-} 3 mmolZg and aqueous solution polymerization based on the total amount, to water swollen gel of the resulting water-soluble polymer, mechanical shearing A method for producing a water-soluble polymer, characterized in that a water-soluble polymer is formed by applying force.

[2] The process for producing a water-soluble polymer according to claim 1, wherein mechanical shearing force is applied so that the 0.1% insoluble content of the obtained water-soluble polymer is 10 ml or less.

[3] The method for producing a water-soluble polymer according to claim 1 or 2, wherein the obtained water-soluble polymer is further shredded as necessary and then dried to form a powder.

[4] (A) a radically polymerizable water-soluble monomer and (B) a compound having two or more ethylenically unsaturated groups, wherein the proportion of component (B) is that of component (A) and component (B) after the monomer mixture which is a ^{3 X 10- 5 ~1 X 1 0-} 3 mmolZg and aqueous solution polymerization based on the total amount, to water swollen gel of the resulting water-soluble polymer, mechanical shearing A polymer flocculant made of water-soluble polymer by adding force.

[5] The polymer flocculant according to claim 4, wherein a mechanical shear force is added so that the 0.1% insoluble content of the obtained water-soluble polymer is 10 ml or less.

[6] The polymer flocculant according to claim 4 or 5, wherein the obtained water-soluble polymer is a powder.

[7] A sludge dewatering agent comprising the polymer flocculant according to any one of claims 4 to 6.

[8] A yield improving agent for papermaking, comprising the polymer flocculant according to any one of claims 4 to 6.