JP3474232B2 - Water swellable polymer particles having a large particle size, a method for producing the same and a method for using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a cationic polymer bridge.
Regarding large-sized water-swellable polymer particles composed of bridges
It also relates to its manufacturing method and its use method.
It is something.

[0002]

2. Description of the Related Art Water-absorbent resins having a swelling property with respect to water of 10 times or more are known and are used in sanitary products, disposable diapers, sealing agents, anti-condensation agents and the like. Further, a cationic superabsorbent resin, which is a crosslinkable polymer of an acrylic cationic monomer, is disclosed in JP-A-58-154709, and is less susceptible to salt concentration than an anionic water absorbent resin. It is written. Further, since it has a high ability to adsorb microorganisms, a technique of using it as a bioreactor carrier is disclosed in JP-A-63-7785 and JP-A-63-73785.
Application to a fluidized bed type biological treatment apparatus is proposed in Japanese Patent Laid-Open No. 4898. Further, JP-A-64-15130 describes a method of obtaining a dispersion liquid of a cross-linked cationic polymer by causing a cross-linking reaction of cationic polymer fine particles dispersed in a polyvalent anion salt aqueous solution.

[0003]

The crosslinked polymer obtained according to JP-A-64-15130 is fine particles, and when used as a microorganism carrier in a fluidized bed biological treatment apparatus, the carrier having adsorbed microorganisms tends to be washed away. is there. When used as a carrier, it is desirable that the particles have a spherical shape with a large particle size, but in suspension polymerization in an organic solvent, there is a drawback that the difference in specific gravity between the dispersion liquid and the polymer is large and sedimentation easily occurs. An object of the present invention is to provide a method for efficiently producing a crosslinked cationic polymer having a large particle size, which has a strong adsorptivity for microorganisms.

[0004]

The present invention is configured as follows to achieve the above object. The following formula (Formula 1) water-soluble vinyl monomer and a polyvalent vinyl compounds containing cationic vinyl monomer 20 wt% or more represented by the deposited poly
The present invention is characterized in that water-swellable polymer particles are obtained by polymerizing with stirring in a polyvalent anionic inorganic salt aqueous solution that approximates the specific gravity of mer particles .

[Chemical 1]

The particle size of the polymer particles in the salt water is 1 to
It is characterized by being 10 mm.

As the polyvalent anionic inorganic salt suitable for producing such polymer particles, a sulfate such as sodium sulfate, potassium sulfate, ammonium sulfate, magnesium sulfate, aluminum sulfate, or a phosphate salt or a hydrogen phosphate salt is used. It These polyvalent anionic inorganic salts are used as an aqueous salt solution having a concentration of 15% by weight or more.

Typical examples of the cationic vinyl monomer represented by the formula (1) used in the present invention are dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminohydroxypropyl (meth) acrylate, Dimethylaminopropyl (meth) acrylamide quaternized with an alkyl halide having 4 to 10 carbon atoms or monohalomethylbenzene can be used, but any monomer satisfying the formula (1) can be used.

A monomer quaternized with an alkyl halide having less than 4 carbon atoms is not preferable because the resulting polymer becomes semi-dissolved in an aqueous salt solution, and a monomer quaternized with an alkyl halide having more than 10 carbon atoms is not preferable. The monomer does not dissolve in the salt solution, which is not preferable.

The vinyl compound having crosslinking reactivity is a compound containing two or more vinyl groups, for example, methylenebisacrylamide, N-acrylamide, 1,
Examples include 3,5-triacroylhexahydro-S-triazine, polyethylene glycol diacrylic acid ester having a molecular weight of 400 or more, dimethacrylic acid ester, and the like, and vinyl having a cross-linking reactivity showing appropriate solubility in an aqueous salt solution. Any compound can be used without being limited to the above examples. The addition amount is 0.00 with respect to all monomers.
It is 2 to 20 mol%, and is determined by the desired water absorption capacity.

As the copolymerizable monomer, a monomer soluble in an aqueous salt solution can be used. For example, nonionic monomers such as acrylamide, N-alkylacrylamide, N, N-dialkylacrylamide, or methacrylamide, N-alkylmethacrylamide, N, N-dialkylmethacrylamide can be used. Further, as the cationic water-soluble monomer, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth)
Acrylate, dimethylaminohydroxypropyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide neutralized with hydrochloric acid or sulfuric acid, or quaternized with methyl chloride, dimethyl sulfuric acid, or the like is fried.

Further, it is also possible to copolymerize acrylonitrile, methyl acrylate, ethyl acrylate, etc. within the range in which the monomer is dissolved in the salt solution. A dispersant may be added during the polymerization to prevent the deposited polymer particles from adhering to the vessel wall.

The amount of the dispersant added is 1 to 20 with respect to the total amount of the monomers.
% By weight. As a dispersant, JP-A-61-2361
No. 0 or JP-A No. 62-20502, that is, ethylene glycol, glycerin,
Polyethylene glycol, (meth) acryloyloxyethyltrialkylammonium hydrochloride polymer, (meth)
Examples thereof include acrylamidopropyltrimethylammonium hydrochloride polymer and the like.

Further, by approximating the specific gravity of the polyvalent anionic inorganic salt aqueous solution to the specific gravity of the precipitated polymer particles, the stirring speed can be reduced and the shearing force can be weakened to easily obtain a polymer having a large particle size.

When the polymer particle dispersion thus obtained is put into a biological treatment apparatus in which microorganisms coexist, microorganisms are adsorbed on the swollen surface of the polymer particles and a microbial film is formed on the particle surface as the microorganisms grow. Form.

By adsorbing silt, coral powder, or inorganic fine particles such as ferrite before the operation for adsorbing the microorganism, the specific gravity of the microorganism adsorbing carrier can be increased and the sedimentation / separation property can be improved.

[0016]

The object of the present invention is to have a large particle size and a specific gravity with water.
A cation with a small difference that does not easily settle in water and is easily dispersed.
-Swelling Polymer Particles with Large Particle Size Made of Crosslinkable Polymer
The purpose is to develop a child. Such a water-swellable
In order to produce the limer particles, the cutout represented by the formula (Formula 1) is used.
Water-soluble, containing 20% by weight or more of ON vinyl monomer
Vinyl monomers and polyvalent vinyl compounds are used as polyvalent anions.
It is possible by polymerizing in an aqueous salt solution with stirring.
The cationic vinyl monomer has a hydrophobic group and is a monomer.
In the case of, it is soluble in the polyvalent anion salt aqueous solution and becomes a polymer.
Apply the property of becoming insoluble. During the polymerization, a polymer particle having a large particle size can be obtained by coexistence of a polyvalent vinyl monomer.
Sedimentation of polymer particles can be prevented by the effect of adjusting specific gravity by polymerization in a salt aqueous solution. The dispersant has a strong effect of preventing the deposited polymer from adhering to the vessel wall.

[0017]

Example (Synthesis Example 1) Contents A polymerization catalyst was prepared by weighing out and dissolving 10 g of polyacryloyloxyethyltrimethylammonium hydrochloride, 207 g of ammonium sulfate, and 683 g of ion-exchanged water in a 1000 ml glass separable flask. Further, 99.7 g of acryloyloxyethylbenzyldimethylammonium hydrochloride,
Charge 0.3 g of NN'-methylenebisacrylamide, heat to 50 ° C, replace with nitrogen, add 40 mg of 2,2'-azobisamidinopropane hydrochloride, and heat at 50 ° C with a stirrer rotation speed of 200 rpm. The reaction was carried out for 10 hours. The polymer particle diameter in the obtained dispersion was 3 to 4 mm, and the polymer particle dispersion was free flowing. The water-absorbing ability of the obtained polymer particles was such that 22 g of 1N saline solution was absorbed per 1 g of polymer pure content. This dispersion is referred to as Sample-1.

(Example) The following test was conducted using a slurry prepared by dispersing Sample-1 in 20 times the amount of tap water. A continuous water flow test was conducted using an aerobic microbial treatment device having an aeration tank volume of 1 liter and having an air lift pipe for flowing a carrier in the tank. As a comparative example, the aeration tank volume is 5%
Experiments were carried out using polystyrene beads (average particle diameter 1 mm) and vinyl chloride columnar pellets (diameter 1 mm, length 1 mm). As seed sludge, 900 ml of surplus sludge (sludge concentration: 4200 ppm) of city sewage and 100 ml of each carrier were charged into the aeration tank, and 2
After continuing aeration for 4 hours, artificial wastewater (oxidized starch 250 pp
m, peptone 250 ppm, potassium phosphate 15 pp
m) is 3 liters / d by a mini pump made by Perista
It was quantitatively supplied at the rate of ay. The aeration tank temperature during water flow is 2
Hold at 5 ° C. The BOD of this artificial wastewater is 420 pp
m. The quality of the supernatant water of the treated water was analyzed 1 week, 2 weeks, and 4 weeks after the start of water flow, and the results are shown in Table 1.

[0019]

[Table-1]

[0020]

As shown in Table 1, the polymer of the present invention exhibits a good wastewater treatment capacity. The polymer dispersion of the present invention has excellent dispersibility even if it is added to water without forming mamako.

Claims (3)

(57) [Claims] 1. A water-soluble vinyl monomer containing 20% by weight or more of a cationic vinyl monomer represented by the following formula (Formula 1) and a polyvalent vinyl compound are prepared in a ratio of precipitated polymer particles.
In concentration of 15 wt% or more <br/> polyvalent anionic inorganic salt aqueous solution for the purpose of approximating the heavy, the polyvalent anionic inorganic salt aqueous solution prepared by polymerizing under stirring
Water-swellable polymer particles in which the particle size of the polymer particles in 1 is 10 mm . [Formula 1] 2. A water-soluble vinyl monomer containing 20% by weight or more of a cationic vinyl monomer represented by the above formula (Formula 1) and a polyvalent vinyl compound are mixed in a ratio of precipitated polymer particles.
Polymerization under stirring in an aqueous solution of polyvalent anionic inorganic salt having a concentration of 15% by weight or more for approximating the weight of the polyvalent anionic inorganic salt aqueous solution.
The method for producing water-swellable polymer particles, wherein the particle size of the polymer particles is 1 to 10 mm . 3. The polyvalent anionic compound according to claim 1.
Particle size of polymer particles in machine salt solution is 1 to 10 m
m water-swellable polymer particles as microbial adsorption carrier
how to use.