JP2009249415A - Method for producing powdery polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a powdery polymer for easily performing crushing sufficiently finely, even on a highly adhesive hydrous gelatinous polymer to obtain a powdery polymer with a high molecular weight. <P>SOLUTION: The method for producing a powdery polymer includes a polymerization process for polymerizing a water-soluble monomer in an aqueous medium to obtain a hydrous gelatinous polymer, a rough crushing process for roughly crushing the hydrous gelatinous polymer by an extruder with a rotary blade to obtain beads-shaped polymer gel, a cutting and crushing process for cutting and crushing the beads-shaped polymer gel by means of a body rotational drum type crusher 1, which has a main drum rotation part 10 with a tilted rotation axis and one or more polymer gel stirring baffle plates extending from the inside wall face to the rotation axis X, to obtain granular polymer gel, and a drying and crushing process for drying and crushing the granular polymer gel to obtain the powdery polymer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a powdery polymer.

Water-soluble acrylamide-based or (meth) acrylate-based polymers or copolymers thereof are widely used as sludge treatment, paper chemicals, and soil conditioners because of their excellent aggregation performance. Many of the water-soluble polymers used in these applications generally exhibit better agglomeration performance as the molecular weight is higher.
Examples of the industrial production method of acrylamide polymer include solution polymerization methods such as bulk polymerization method, suspension polymerization method, emulsion polymerization method, and aqueous solution polymerization method, but high molecular weight polymers are easily obtained. In view of this, an aqueous solution polymerization method is often used.

High molecular weight polymers obtained by aqueous solution polymerization are generally water-containing gel-like polymers containing a large amount of water and are rarely used as they are, and many are used as dry powder polymers. Is done. Therefore, in order to produce a powdery polymer (product) such as an acrylamide polymer, a drying step for drying the hydrogel polymer is required.
As a method of increasing the drying efficiency of the hydrogel polymer, the bulk hydrogel polymer is finely granulated using an apparatus such as an extruder with a rotary blade, an extruder, a pelletizer, and the finely granulated one is rotated. A method of drying with hot air using a dryer or a band dryer is known.

In this method, the hydrogel polymer that emerges from each hole in the perforated plate provided at the outlet of the extruder with a rotary blade becomes a rosary polymer gel having a string shape and a cut. However, in the case of the aforementioned acrylamide-based or (meth) acrylate-based water-containing polymer, the bead-like polymer gels coming out from the holes of the perforated plate cause mutual adhesion due to their adhesive properties. As a result, it becomes a cylindrical aggregate. Although the adhesive properties of the hydrogel polymer vary depending on the monomer composition and degree of polymerization, the columnar aggregate is usually about the same as the diameter of each hole in the perforated plate and 20 to 40 cm in length. become.
Even if such a columnar aggregate is directly dried with hot air using a rotary drier or a band drier, only the surface is dried and a lump product with an undried inside is formed, and uniform drying can be performed. It was difficult. Moreover, such a lump product has low solubility in water.

In addition, in the acrylamide polymer, the residual monomer causes an environmental load and the like when used in the above application. For this reason, in recent years, there has been an increasing need to reduce the content of residual monomers in acrylamide polymers in response to environmental problems and the strengthening of labor safety regulations.
As a method for reducing the residual monomer amount in the acrylamide polymer, a method of adding a sulfite compound and an inorganic alkali agent to a bead polymer gel and drying is used. However, if the acrylamide-based hydrogel polymer is processed by an extruder with a rotary blade, the bead-like polymer gel forms a cylindrical aggregate as described above. In some cases, the chemical treatment is stopped only on the surface of the columnar aggregate, the effect of reducing the residual monomer amount is industrially insufficient, and a product with uneven drying may be obtained.

For the above reasons, as a production method for obtaining a powdery polymer having a high molecular weight and good water solubility, even a highly gelling hydrogel polymer was sufficiently finely crushed. There has been a demand for a method capable of obtaining a fine polymer gel. Therefore, the following method is shown as a method for crushing an acrylamide-based hydrogel polymer into fine particles.
Extruded from the die plate or slit plate using a crushing device having a die plate or slit plate provided with a cutting blade on the primary side and a rotating body having blades provided on the secondary side of the die plate or slit plate A method of shredding and crushing a string-like water-containing gel-like polymer that has been cut into pieces with the rotating body (Patent Document 1).
An agent that reduces the amount of residual monomer using a scissors-type cutting machine having a fixed blade and a rotary blade and a region in which the hydrogel polymer to be crushed stays after coarsely crushing an acrylamide hydrogel polymer A method of obtaining a fine granular polymer gel by adding and cutting (Patent Document 2).
A hydrogel polymer is continuously supplied to a crusher having a pair of roller-type cutters rotating in a meshing direction, a rotary blade and a fixed blade by a movable support, and the hydrogel is fed by the roller-type cutter. A method in which a short polymer is cut into strips, and then the short hydrous polymer is cut into strips with a rotary blade and a fixed blade (Patent Document 3).
Japanese Patent No. 278048 Japanese Patent Publication No. 63-16401 Japanese Patent Publication No. 4-7887

  However, in the method of Patent Document 1, a fine polymer gel is obtained by chopping and crushing using a rotating body having a rotation axis perpendicular to the extrusion direction of the hydrogel polymer from a die plate or a slit plate. In order to obtain this, the fine polymer gel was sometimes trapped inside the box-shaped main body having the rotating body in the crushing apparatus. When the puddle occurs, a part of the fine granular polymer gel is kneaded at that portion to form a lump, which is mixed into the fine granular polymer gel discharged from the crushing device, so that it does not appear in the dried product. Dry lumps could get mixed in.

  Moreover, in the method of Patent Document 2, there is a space where the rotary blade does not reach inside the main body of the vertical cutter, and the fine polymer gel puddle may occur in that space. Therefore, in the same manner as in the method of Patent Document 1, a lump that is partially kneaded is mixed into the fine granular polymer gel, and undried lumps may be mixed into the dried product. In this method, the coarsely crushed hydrogel polymer is cut with a vertical cutter and then partially hydrolyzed using a vertical stirrer having a ridge inside the main body. Because there is a space that does not reach, there was a case where the dried product was mixed for the same reason. In addition, when a part of the fine granular polymer gel becomes a lump, since the chemical treatment is stopped only on the surface of the lump, the effect of reducing the residual monomer amount cannot be sufficiently obtained.

  Further, in the method of Patent Document 3, it is necessary to continuously bite the hydrogel polymer to be cut into a roller-type cutter, the shape of the hydrogel polymer that can be processed is limited to a sheet shape, and the thickness thereof There are also limitations. Therefore, a bulk polymer obtained by polymerization in the pot, a bead-like polymer gel obtained by an extruder with a rotary blade, or a crushed hydrous gel-like polymer cannot be used as it is.

Further, if the hydrogel polymer is to be crushed sufficiently finely, the molecular weight of the polymer may decrease due to mechanical or physical friction.
For the reasons described above, even a massive hydrogel polymer with very high tackiness can be easily finely crushed without causing a decrease in the molecular weight of the polymer due to mechanical or physical friction. A technique capable of obtaining a fine granular polymer gel is desired.

  Accordingly, the object of the present invention is to provide a method for producing a powdery polymer that can be easily finely pulverized to obtain a high molecular weight powdery polymer even if it is a highly tacky hydrogel polymer. To do.

The method for producing a powdery polymer of the present invention comprises a polymerization step of polymerizing a water-soluble monomer in an aqueous medium to obtain a hydrogel polymer, and the hydrogel polymer is roughened by an extruder with a rotary blade. A crushing step of crushing to obtain a beaded polymer gel, a crushing and crushing step of obtaining a fine granular polymer gel by crushing and crushing the beaded polymer gel with a main body rotating drum type crusher shown below, And a drying and pulverizing step of drying and pulverizing the fine granular polymer gel to obtain a powdery polymer.
Main body rotating drum type crusher: A crusher that cuts and crushes bead-like polymer gel to obtain a fine granular polymer gel, and includes a main body drum rotating portion with an inclined rotation axis, and the main body drum rotation A main body rotating type drum crusher in which one or more baffles for stirring polymer gel extending from the inner wall surface toward the rotation axis are formed on the inner wall surface of the unit.

Further, in the method for producing a powdery polymer according to the present invention, the contact portion between the bead polymer gel and the fine polymer gel in the main body rotating drum type crusher is coated with a coating agent for preventing corrosion. It is preferable.
In the cutting and crushing step, it is preferable that an additive for reducing the amount of residual monomer and / or a release agent is mixed in the bead-shaped polymer gel in the state of an aqueous medium slurry or an aqueous solution.
The additive is preferably at least one selected from the group consisting of alkali metal sulfites, alkali metal hydrogen sulfites, alkali metal pyrosulfites, and alkaline substances.
Moreover, it is preferable that the said polymerization process is a process of polymerizing an acrylamide type monomer and / or a (meth) acrylate type monomer in an aqueous medium, and obtaining a hydrogel polymer.

  According to the production method of the present invention, even a highly tacky hydrogel polymer can be easily and finely crushed, and a high molecular weight powdery polymer can be obtained.

The method for producing a powdered polymer of the present invention comprises a polymerization step of polymerizing a water-soluble monomer in an aqueous medium to obtain a water-containing gel polymer, and roughening the water-containing gel polymer by an extruder with a rotary blade. A crushing step for crushing to obtain a beaded polymer gel, a crushing and crushing step for obtaining a fine polymer gel by cutting and crushing the beaded polymer gel with a main body rotating drum type crusher, A drying and pulverizing step of drying and pulverizing the combined gel to obtain a powdery polymer.
The rosary polymer gel in the present invention is a water-containing gel-like polymer having a string-like shape and discharged from an extruder with a rotary blade. Further, the fine granular polymer gel is a hydrogel polymer that has been finely cut and crushed and discharged from the main-body rotating drum crusher.

[Main body rotary drum crusher]
Hereinafter, an embodiment of a main body rotating drum crusher used in the production method of the present invention will be described in detail with reference to FIGS.
As shown in FIG. 1, the main body rotating drum type crusher 1 includes a main body drum rotating unit 10 that cuts and crushes the bead-shaped polymer gel, a gantry 12 that supports the main body drum rotating unit 10, and an inclination of the gantry 12. A jack 14 that adjusts the inclination angle of the main body drum rotating unit 10 to adjust the angle, a main body drum rotating rotor 16 that rotates the main body drum rotating unit 10 (hereinafter referred to as the rotor 16), and a rotor that drives the rotor 16. A driving motor 18; a gel charging unit 20 for charging a bead-like polymer gel into the main body drum rotating unit 10; and a gel discharging unit 22 for discharging a fine granular polymer gel obtained by cutting and crushing. Yes.

  The main body drum rotating unit 10 is a cylindrical drum and is a part that cuts and crushes the bead-like polymer gel. On the inner wall surface 10a of the main body drum rotating portion 10, as shown in FIGS. 2 (a), 2 (b) and 3, a polymer gel agitation extending from the inner wall surface 10a toward the rotation axis X of the main body drum rotating portion 10 is performed. A baffle plate 24 (hereinafter referred to as a baffle plate 24) is formed to be inclined with respect to the rotation axis X of the main body drum rotation unit 10. Further, as shown in FIGS. 2A, 2B, and 4, the slit plate 26 is provided on the gel discharging unit 22 side of the main body drum rotating unit 10. The slit plate 26 is formed with an opening 28 at the center thereof and an openable / closable gel outlet 30 for discharging the fine polymer gel on the outer peripheral side.

The shape of the baffle plate 24 is not particularly limited as long as the bead-like polymer gel can be stirred inside the main body drum rotating unit 10, and is preferably an elongated plate shape.
The length of the baffle plate 24 is preferably 1/2 or less with respect to the length along the rotation axis X direction of the main body drum rotating unit 10. The width of the baffle plate 24 is preferably 1/10 or less with respect to the inner diameter of the main body drum rotating unit 10.
Only one baffle plate 24 may be formed, or two or more baffle plates 24 may be formed.

  The length of the main body drum rotating portion 10 along the rotation axis X direction of the main body drum rotating portion 10 is that the bead polymer gel is easily finely cut and crushed without causing the bead-like polymer gels to adhere to each other. It is particularly preferable that six or more baffle plates 24 having a width of 1/3 or less and a width of 1/20 or less of the inner diameter of the main body drum rotating portion 10 are formed.

The baffle plate 24 in the main body rotating drum type crusher of the present invention may be formed in a parallel direction or a vertical direction with respect to the rotation axis X of the main body drum rotating unit 10, but FIG. ), It is preferably formed to be inclined with respect to the rotation axis X of the main body drum rotating portion 10.
That is, the inclination angle θ of the baffle plate 24 with respect to the rotation axis X of the main body drum rotating unit 10 (FIGS. 2A and 2B) is 0 ° ≦ θ ≦ 90 °, and the bead-like polymer gels are adhered to each other. It is preferable that 0 ° ≦ θ ≦ 10 ° from the viewpoint that it is easy to cut and pulverize sufficiently finely.

The arrangement of the baffle plate 24 is not particularly limited as long as the bead-like polymer gel can be cut and crushed to uniformly loosen the finely divided fine polymer gel.
For example, when six baffle plates 24 are provided on the inner wall surface 10a of the main body drum rotating portion 10, as shown in FIG. The three sets of baffle plates 24 are arranged in the circumferential direction of the pair of baffle plates 24 located along the rotation axis X direction and in the center of the main body drum rotating unit 10 in the rotation axis X direction, and on both ends thereof. The form provided so that it may shift | deviate from the position of the circumferential direction of the two sets of baffle plates 24 located is mentioned.

The shape of the opening 28 of the slit plate 26 is not particularly limited, but is preferably circular.
When the opening 28 is circular, the inner diameter d (FIG. 4) of the opening 28 is such that the bead-like polymer gel can be sufficiently finely cut and crushed without causing the beads to adhere to each other. The inner diameter D (FIG. 4) is preferably 1/5 or more, and more preferably about 3/5. In addition, the slit plate 26 is formed with a gel outlet 30 that can be opened and closed as in the present embodiment, since it is easy to cut and crush sufficiently finely without causing the bead-like polymer gels to adhere to each other. More preferably.
The number of slit plates 26 may be one, or two or more.

The gantry 12 is a table that supports the main body drum rotating unit 10 and fixes the inclination angle of the rotation axis X of the main body drum rotating unit 10 with respect to the horizontal direction to a desired angle. The gantry 12 may be fixed at a constant inclination angle, or may be one in which the inclination angle can be arbitrarily set by the jack 14 like the crusher 1 of the present embodiment.
The jack 14 is not particularly limited as long as it can adjust the inclination angle of the rotation axis X of the main body drum rotating unit 10 by adjusting the inclination angle of the gantry 12.

The inclination angle of the rotation axis X of the main body drum rotating unit 10 with respect to the horizontal direction may be within a range in which the bead-like polymer gel is cut and crushed to the fine-particle polymer gel, and is preferably 3 to 30 °. More preferably, it is 5 to 15 °.
If the inclination angle is 3 ° or more, the residence time of the fine granular polymer gel in the crusher 1 is shortened, and the processing efficiency in the cutting and crushing step is improved. If the inclination angle is 30 ° or less, the residence time of the bead-like polymer gel in the crusher 1 is increased, and the degree of cutting and crushing is improved. It becomes easy to obtain a coalescence gel.

The rotor 16 is a rotor that rotates the main body drum rotating unit 10. The rotor 16 only needs to be able to rotate the main body drum rotating unit 10. For example, as illustrated in FIG. 1, the outer surface of the rotor 16 is brought into contact with the outer peripheral surface of the main body drum rotating unit 10. An example is one in which the main body drum rotating unit 10 is rotated in the reverse direction to the rotor 16 by rotating the (rotating axis Y).
The rotor driving motor 18 is a motor that drives the rotor 16. The rotor driving motor 18 is not particularly limited as long as it can drive the rotor 16.

  The shape of the gel injection | throwing-in part 20 will not be specifically limited if a bead polymer gel can be injected | thrown-in. Moreover, the shape of the gel discharge part 22 will not be specifically limited if a fine granular polymer gel can be discharged | emitted.

  Further, in the main body rotating drum type crusher in the present invention, it is particularly preferable that a portion in contact with the bead polymer gel and the fine polymer gel is coated with a coating agent for preventing corrosion. This makes it easy to suppress the bead-like polymer gel and the fine-grain polymer gel from adhering to the inside of the main body rotating drum type crusher when the bead-like polymer gel is cut and crushed. In the crusher 1, the parts that come into contact with the bead-like polymer gel and the fine-grain polymer gel are the inner wall surfaces of the gel feeding unit 20, the main body drum rotating unit 10, and the gel discharging unit 22, the slit plate 26, and the baffle plate. There are 24 surfaces.

  The coating agent for preventing corrosion is not particularly limited as long as it does not adversely affect the main body rotating drum type crusher and the resulting powdery polymer (product), but it has acid resistance, alkali resistance, solvent resistance, etc. From the viewpoint of superiority, a fluororesin such as polytetrafluoroethylene (PTFE) or ethylene-tetrafluoroethylene copolymer (ETFE) is preferable.

The powdery polymer in the present invention is preferably a powdery water-soluble polymer mainly composed of structural units derived from acrylamide monomers and / or (meth) acrylate monomers. .
Examples of acrylamide monomers include acrylamide, methacrylamide, N, N′-dimethylacrylamide, N, N′-dimethylmethacrylamide, N, N′-dimethylaminopropylacrylamide, N, N′-dimethylaminopropyl. N, N′-dialkylaminoalkyl (meta ) Acrylamide and salts thereof, acrylamide alkanesulfonic acid such as 2-acrylamido-2-methylpropanesulfonic acid, N-monomethylacrylamide, N-monoethylacrylamide and the like.

  Examples of (meth) acrylate monomers include N, N′-dimethylaminoethyl acrylate, N, N′-dimethylaminoethyl methacrylate, N, N′-dimethylaminopropyl acrylate, and N, N′-dimethylamino. N, N′-dialkylaminoalkyl such as propyl methacrylate, N, N′-diethylaminoethyl acrylate, N, N′-diethylaminoethyl methacrylate, N, N′-diethylaminopropyl acrylate, N, N′-diethylaminopropyl methacrylate ) Acrylates and salts thereof, and lower alkyl esters such as diethylamino-2-hydroxypropyl acrylate and diethylamino-2-hydroxypropyl methacrylate.

  The powdery polymer may be a homopolymer composed of only one type of water-soluble monomer, or may be a copolymer composed of two or more types of water-soluble monomers. Further, it is a copolymer of an acrylamide monomer and / or a (meth) acrylate monomer and a copolymerizable monomer other than an acrylamide monomer or a (meth) acrylate monomer. May be.

  Examples of copolymerizable monomers other than acrylamide monomers and (meth) acrylate monomers include, for example, acrylic acid, methacrylic acid and their salts, N-vinylpyrrolidone, acrylonitrile, methacrylonitrile, etc. Is mentioned.

  In the case of using an acrylamide monomer as a water-soluble monomer, the pulverulent polymer in the present invention may be partially modified by a methylolation reaction, a Mannich reaction, or the like during or after the polymerization. It may be a coalescence.

[Production method]
Hereinafter, a method using the above-mentioned crusher 1 will be described as an example of an embodiment of the method for producing a powdery polymer of the present invention.
The method for producing a powdery polymer of the present embodiment includes a polymerization step of polymerizing a water-soluble monomer to obtain a hydrogel polymer, and crushing the hydrogel polymer with an extruder with a rotary blade. A crushing step for obtaining a beaded polymer gel, a crushing and crushing step for obtaining a fine granular polymer gel by cutting and crushing the beaded polymer gel with the crusher 1, and drying and crushing the fine granular polymer gel. And a dry pulverization step for obtaining a powdery polymer.

(Polymerization process)
The polymerization step is a step of producing a hydrogel polymer by polymerizing a water-soluble monomer in an aqueous medium. Examples of the aqueous medium include pure water, ion exchange water, tap water, and industrial water, and pure water is preferable. The water-soluble monomer is preferably the above-mentioned acrylamide monomer or (meth) acrylate monomer.
Examples of the polymerization method include an aqueous solution polymerization method using a radical initiator, an emulsion polymerization method, and a dispersion polymerization method. The aqueous solution polymerization method is preferably used from the viewpoint that a high molecular weight polymer is easily obtained.

Examples of the radical initiator include inorganic peroxides such as persulfate and hydrogen peroxide, organic peroxides such as benzoyl peroxide and cumene hydroperoxide, and these and tertiary amines, sulfites, and Redox initiators combined with reducing agents such as monoiron salts, azobisisobutyronitrile, 2,2′-azobis- (2-amidinopropane) dihydrochloride, 4,4′-azobis- (4- Azo initiators such as cyanovaleric acid), combined use initiators of the redox initiator and the azo initiator, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,2- Dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, benzophenone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydride Xyl-2-methyl-1-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- Acetophenone initiators such as (4-morpholinophenyl) -1-butanone, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, bis (2,4,6-trimethyl) Photopolymerization initiator that generates an initiation radical by light, such as an acyl phosphine oxide initiator such as benzoyl) -phenylphosphine oxide, a combined initiator of the acetophenone initiator and the acyl phosphine oxide initiator And known initiators.
Depending on the selection of the initiator, the polymerization reaction can be carried out by either the adiabatic polymerization method or the photopolymerization reaction method.

  The form of the reaction vessel used for the polymerization is not particularly limited. For example, in the case of the adiabatic polymerization method, a kettle type reaction vessel is mentioned, and in the case of the photopolymerization method, a dish-like, flat plate type, thin-layer reaction vessel is mentioned. It is done. In addition, a method of polymerizing a thin layer monomer aqueous solution on a movable belt may be used.

  The concentration of the water-soluble monomer in the aqueous solution is preferably 5 to 70% by mass, and more preferably 20 to 65% by mass. If the concentration of the water-soluble monomer is 5% by mass or more, it is possible to produce a hydrogel polymer with sufficient productivity, and to reduce the adhesion of the obtained hydrogel polymer to be too high. Easy to do. Moreover, if the density | concentration of a water-soluble monomer is 70 mass% or less, it will be easy to suppress that a water-containing gel-like polymer becomes too hard and becomes difficult to crush.

Although the pH of the aqueous solution of the water-soluble monomer in the polymerization varies depending on the composition of the water-soluble monomer to be used, it is preferably set to pH 2.0 to 9.5. If the pH is 2.0 or more, it is easy to obtain a sufficient polymerization rate and polymerization rate, and it is easy to obtain a high-productivity and good-quality powdery polymer. Furthermore, sulfite is added to the hydrogel polymer. It becomes easy to suppress the generation of SO ₂ odor when the compound is added. In addition, when the pH is 9.5 or less, particularly when an acrylamide monomer is used, it is easy to suppress generation of an ammonia odor due to alkaline hydrolysis of the amide group, and quality is improved.

Moreover, you may use a chain transfer agent for superposition | polymerization as needed.
Examples of the chain transfer agent include phosphorous acid, hypophosphorous acid, phosphonic acid, and salts thereof.

(Crushing process)
The coarse crushing step is a step of obtaining a beaded polymer gel by crushing the massive hydrogel polymer obtained in the polymerization step with an extruder with a rotary blade.
It is preferable to crush the hydrogel polymer into a bead polymer gel having an average particle size of 5 to 15 mm by the crushing step.
The extruder with a rotary blade is not particularly limited as long as it can coarsely crush the hydrogel polymer, and an extruder with a rotary blade that is usually used for producing a powdery polymer can be used. As an extrusion molding machine with a rotary blade, for example, MEAT CHOPER M-22 (manufactured by Nanjo Tekko Co., Ltd.) and the like can be mentioned.

(Cutting and crushing process)
The cutting and crushing step is a step of obtaining a fine granular polymer gel by cutting and crushing the bead-like polymer gel with the crusher 1. The main body drum rotating unit 10 is rotated, and a bead-like polymer gel is introduced from the gel inlet 20. Thereby, the bead-like polymer gel is cut and crushed by the baffle plate 24 to obtain a fine granular polymer gel.

  The rotation speed of the main body drum rotating unit 10 is within a range in which a bead-like polymer gel is cut and crushed to obtain a fine granular polymer gel, and the cut and crushed fine granular polymer gels are reattached by centrifugal force. As long as it does not. The number of rotations of the main body drum rotating unit 10 is preferably 5 to 100 rpm, and more preferably 10 to 50 rpm, from the viewpoint of cutting and crushing efficiency.

In the cutting and crushing step, it is preferable to add an additive and / or a release agent for reducing the amount of residual monomer in the obtained powder polymer to the bead polymer gel.
Examples of the additive include one or more selected from the group consisting of alkali metal sulfites, alkali metal hydrogen sulfites, alkali metal pyrosulfites, and alkaline substances.

  Examples of the alkali metal salt include sodium salt and potassium salt. Of these, sodium salts are preferred because they are excellent in the effect of reducing the amount of residual monomers, improve the quality of the resulting powdery polymer, and increase the solubility of the powdery polymer in water.

  Examples of the alkaline substance include sodium hydroxide, potassium hydroxide, and an aqueous solution thereof. Among them, water is excellent because it is excellent in the effect of reducing the amount of residual monomers, the quality of the obtained powder polymer is good, the solubility of the powder polymer in water is high, and the handleability is easy. An aqueous sodium oxide solution is preferred.

  Examples of the release agent include silicone oils and silicone emulsions mainly composed of silicon dioxide, polyalkylsiloxane, sorbitan fatty acid ester, glycerin fatty acid ester, sodium carboxymethyl cellulose, and fatty acid alkali metal salts such as sodium stearate. And aqueous solutions thereof, polyalkylene glycols such as polyethylene glycol, alkyldimethylbenzylammonium chlorides, polyoxyalkylene alkyl ethers, polyoxyalkylene alkyl ether fatty acid esters, polyalkyl ethers, polyoxyethylene nonylphenyl ether, etc. Examples thereof include cationic and nonionic surfactants which are used as various constituent components. Especially, when the bead polymer gel is cut and crushed by the crusher 1, the adhesive property of the rosary polymer gel is suppressed, and a finely pulverized fine granular polymer gel is easily obtained. A silicone emulsion is preferred.

  When the additive is an aqueous medium or aqueous solution of a sulfite compound such as alkali metal sulfite, alkali metal bisulfite, alkali metal bisulphite, the amount added is the amount of residual monomer in the resulting powdery polymer. It is sufficient that the concentration can be adjusted to a desired concentration, and it is preferably added so that the mass ratio of the sulfite compound to the total mass (100 mass%) of the beaded polymer gel is 0.01 to 15 mass%. It is more preferable to add so that it may become 0.02-2.0 mass%. When the mass ratio of the sulfite compound is 0.01% by mass or more, it becomes easy to reduce the amount of residual monomer in the obtained powdery polymer. Moreover, if the mass ratio of a sulfite compound shall be 15 mass% or less, it will be easy to prevent that the viscosity at the time of making the obtained powdery polymer into aqueous solution falls too much.

  When the additive is an alkaline substance, the additive amount may be an amount that can make the concentration of the residual monomer in the obtained powdery polymer a desired concentration, and the total mass of the bead-shaped polymer gel (100 mass). %) Is preferably added so that the mass ratio of the alkaline substance is 0.01 to 5 mass%, and more preferably 0.01 to 1.2 mass%. When the mass ratio of the alkaline substance is 0.01% by mass or more, it becomes easy to reduce the amount of residual monomer in the obtained powdery polymer. Moreover, if the mass ratio of an alkaline substance is 5 mass% or less, it is easy to prevent the hydrolysis rate of the amide group of the obtained powdery polymer from increasing too much.

  The addition amount of the release agent cannot be generally limited because the effect varies depending on the type of the release agent, but it is an amount that can suppress the mutual adhesion of the fine granular polymer gel discharged from the crusher 1. It is preferable to add the release agent so that the mass ratio of the release agent to the total mass (100 mass%) of the bead polymer gel charged into the crusher 1 is 0.005 to 2 mass%. It is more preferable to add so that it may become -0.5 mass%. When the mass ratio of the release agent is 0.005% by mass or more, it becomes easy to suppress the adhesion characteristics of the resulting fine granular polymer gel and prevent mutual adhesion. Moreover, if the mass ratio of a mold release agent shall be 2 mass% or less, it will be easy to prevent the mutual adhesion of the powdery polymer after a dry grinding process. Furthermore, the release agent may be added in advance to the monomer aqueous solution before polymerization in the polymerization step as long as the polymerization reaction is not hindered.

  An additive and / or a mold release agent can be added in the state of an aqueous medium slurry, an aqueous solution, an emulsion, or the like. Moreover, the addition of the additive and the release agent is not limited to the above-described method, and it may be added at any stage in the cutting and crushing process after the polymerization process, and the quality of the obtained powdery polymer is lowered. If it is a range which does not make it too much, you may add when the polymerization reaction is not complete | finished completely. Further, after cutting and crushing the bead-like polymer gel, the powdered weight such as a method in which an additive or a release agent is directly added to the obtained fine particle polymer gel and stirred, or a method in which it is sprayed and stirred is used. It may be an addition method usually used for production of a coalescence.

  In the cutting and crushing step, it is preferable that the average particle size of the fine granular polymer gel is 3 to 13 mm in consideration of the drying efficiency in the drying and crushing step. By rotating and stirring with the crusher 1 having the baffle plate 24, the fine polymer gel having an average particle size of 3 to 13 mm is cut and crushed, and at the same time, additives such as sulfites and ant-kari substances and mold release agents are evenly distributed. Can be mixed into a finely divided polymer gel.

(Dry grinding process)
The drying and pulverizing step is a step of obtaining a powdery polymer by drying and pulverizing the fine granular polymer gel obtained by the cutting and pulverizing step.
The drying method of the fine granular polymer gel is not particularly limited, and examples thereof include a method of drying with hot air using a drier usually used for producing a powdered polymer such as a rotary drier, a band drier, or a fluid drier. . It is preferable that the moisture content of the fine granular polymer gel is 10% or less by this drying.
Drying conditions are preferably 50 to 150 ° C. and about 30 to 90 minutes. Under these conditions, the fine granular polymer gel is easily dried to a moisture content of 10% or less.

Moreover, the method normally used for manufacture of a powdery polymer can be used for the grinding method after drying, For example, the method of pulverizing with a grinder etc. is mentioned.
A powdery polymer is obtained by the method as described above.

The production method of the present invention described above can be easily and sufficiently crushed even if it is a highly adhesive hydrogel polymer such as an acrylamide polymer or a (meth) acrylate polymer. Moreover, it can suppress that the molecular weight fall of the polymer by mechanical or physical friction at the time of crushing can be suppressed, and a high molecular weight powdery polymer can be obtained.
This is because the main body rotary drum type crusher used in the cutting and crushing step in the present invention is provided with a main body drum rotating portion, and cutting and crushing with a baffle for stirring the polymer gel while rotating the main body drum rotating portion. For this reason, the occurrence of spraying of the fine granular polymer gel is suppressed, and it is thought that the cause is that a lump partly kneaded into the fine granular polymer gel is not substantially mixed.

In addition, the production method of the present invention can greatly improve the efficiency of chemical treatment by the addition of additives, and can efficiently produce a powdery polymer with a reduced amount of residual monomers.
This is considered to be because, in the present invention, a fine granular polymer sufficiently finely pulverized by a main body rotating drum type pulverizer can be obtained, so that the chemical treatment can be suppressed from stopping only on the surface.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited by the following description.
The evaluation of the powdery polymers obtained in the examples and comparative examples in this example was performed by measuring the following physical properties.
When lower alkyl esters such as N, N′-dimethylaminoethyl acrylate and N, N′-dimethylaminoethyl methacrylate are constituents of the powdered polymer, the residual monomer concentration is measured (Method A). The amount of water-insoluble component was measured by measuring the monomer concentration and the amount of water-insoluble component (Method A). Further, when the lower alkyl ester is not contained in the powdered polymer, the residual monomer concentration is measured by the residual monomer concentration measurement (Method B), and the water insoluble component amount is measured by the measurement of the water insoluble component amount (Method B). The amount of the sex component was measured.
Further, 0.5% salt viscosity measurement, 1.0% salt viscosity measurement, and water content measurement were performed on the powdered polymer.

[Measurement of water content]
After weighing 5.0 g of the powdered polymer in an aluminum dish, air-dried at 105 ° C. for 90 minutes and then weighed again, the amount of water contained in the powdered polymer by the weight loss method by mass measurement before and after air-drying Was measured.
In addition, the mass of the following polymer active ingredients is obtained by subtracting the amount of water from the mass of the powdery polymer.

[Residual monomer concentration measurement (Method A)]
2.5 g (polymer active ingredient) of the obtained powdery polymer was added to 25.0 ml of a mixed solution of acetone and water (acetone / water (volume ratio) = 80/20) and shaken at 30 ° C. for 24 hours. Then, the obtained monomer extract was measured by high performance liquid chromatography (column; TSK gel ODS-100V, φ4.6 × 150 mm, carrier: 50 mM phosphoric acid aqueous solution, wavelength 207 nm, flow rate 0.8 ml / min).

[Residual monomer concentration measurement (Method B)]
2.5 g (polymer active ingredient) of the obtained powdery polymer was added to 25.0 ml of a mixed solution of methanol and water (methanol / water (volume ratio) = 80/20) and shaken at 30 ° C. for 24 hours. Then, the obtained monomer extract was measured by high performance liquid chromatography (column; TSK gel ODS-100V, φ4.6 × 150 mm, carrier: 50 mM phosphoric acid aqueous solution, wavelength 207 nm, flow rate 0.8 ml / min).

[Measurement of amount of water-insoluble component (Method A)]
500 g of a polymer aqueous solution obtained by dissolving the obtained powdered polymer in a 4.0% sodium chloride aqueous solution so that the active polymer component is 0.5% by mass is filtered through a sieve having a diameter of 20 cm and an opening of 180 μm. The water was wiped off, and the water-insoluble components remaining on the sieve were collected and the mass was measured.

[Measurement of amount of water-insoluble component (Method B)]
500 g of a polymer aqueous solution obtained by dissolving the obtained powdered polymer in a 4.0% sodium chloride aqueous solution so that the active polymer component is 0.1% by mass is filtered through a sieve having a diameter of 20 cm and an opening of 180 μm. The water was wiped off, and the water-insoluble components remaining on the sieve were collected and the mass was measured.

[0.5% salt viscosity measurement]
An aqueous polymer solution was prepared by dissolving the obtained powdered polymer in a 4.0% sodium chloride aqueous solution so that the active polymer component was 0.5% by mass. A B-type viscometer (Toki Sangyo Co., Ltd.) The salt viscosity of the aqueous polymer solution after 5 minutes was measured under the conditions of a temperature of 25 ° C. and a rotor rotational speed of 60 rpm.

[1.0% salt viscosity measurement]
An aqueous polymer solution was prepared by dissolving the obtained powdery polymer in 4.0% sodium chloride aqueous solution so that the active polymer component was 1.0% by mass, and a B-type viscometer (Toki Sangyo Co., Ltd.). The salt viscosity of the aqueous polymer solution after 5 minutes was measured under the conditions of a temperature of 25 ° C. and a rotor rotational speed of 6 rpm.

Hereinafter, examples and comparative examples will be described.
[Example 1]
(Polymerization process)
50% by mass aqueous acrylamide solution (1998 g), 50% by mass acrylic acid aqueous solution (66 g), 50% by mass sodium 2-acrylamido-2-methylpropanesulfonate (156 g), 30% by mass aqueous sodium hydroxide solution (62 g) and pure A monomer reaction solution was prepared by sequentially introducing and mixing water (1365 g) into a reaction vessel with a stainless steel jacket having a capacity of 5000 ml.
Subsequently, the solution temperature was adjusted to 10 ° C. while blowing nitrogen gas into the monomer reaction solution. Then, 10 mass% 2,2′-azobis-2-amidinopropane dihydrochloride aqueous solution (12.4 g), 1 mass% ammonium persulfate aqueous solution (3.7 g), 1 mass% sodium hydrogen sulfite aqueous solution (37.0 g) Were sequentially added to the monomer reaction solution to initiate a polymerization reaction, thereby obtaining a massive hydrogel polymer.

(Crushing process, cutting crushing process)
Next, the obtained bulk hydrogel polymer was converted into a bead polymer gel having an average particle diameter of 5 to 15 mm using an extruder with a rotating blade (MEAT CHOPER M-22, manufactured by Nanjo Tekko Co., Ltd.). After crushing, it was cut and crushed using the crusher 1 illustrated in FIGS. The crusher 1 set the rotation speed of the main body drum rotation part 10 to 30 rpm, and the inclination angle to 10 degrees. Further, the number of baffle plates 24 is six, the length of which is 1/3 with respect to the length along the rotation axis X direction of the main body drum rotating portion 10, and the width is 1 with respect to the inner diameter of the main body drum rotating portion 10. / 15.
Moreover, the cutting and crushing of the bead-like polymer gel was performed while dropping a silicone emulsifier (4.2 g) as a release agent from the gel inlet 20. Thereby, a fine granular polymer gel having an average particle diameter of 3 to 13 mm was obtained.
Further, when the inside of the main body drum rotating unit 10 was confirmed after cutting and crushing, the bead polymer gel and the fine polymer gel were hardly attached, and the obtained fine polymer gel was sufficiently fine. I was loose.

(Dry grinding process)
Next, the fine granular polymer gel obtained was spread on a nylon mesh so that the thickness was 20 mm or less, and hot air dried at a temperature of 90 ° C. for 1.5 hours using a hot air dryer, and then a Willet grinder. The powdery polymer (A-1) was obtained by pulverizing with.

[Example 2]
(Polymerization process)
A monomer reaction solution was prepared by sequentially charging and dissolving a 50% by mass acrylamide aqueous solution (1924 g) and pure water 1723 g into a stainless steel jacketed reaction tank with a capacity of 5000 ml.
Subsequently, a bulk water-containing gel-like polymer was obtained by starting the polymerization reaction in the same manner as in Example 1.
(Crushing process, cutting crushing process)
The obtained bulk hydrogel polymer was roughly crushed and cut and crushed in the same manner as in Example 1 to obtain a finely divided polymer gel having an average particle size of 4 to 13 mm. Further, when the inside of the main body drum rotating unit 10 was confirmed after cutting and crushing, the bead polymer gel and the fine polymer gel were hardly attached, and the obtained fine polymer gel was sufficiently fine. I was loose.
(Dry grinding process)
Next, the fine granular polymer gel obtained was spread on a nylon mesh so that the thickness was 20 mm or less, and hot air dried at a temperature of 90 ° C. for 1.5 hours using a hot air dryer, and then a Willet grinder. The powdery polymer (A-2) was obtained by pulverizing.

[Example 3]
(Polymerization process)
50 mass% acrylamide aqueous solution (1804 g), 50 mass% acrylic acid aqueous solution (356 g), pure water (1157 g) and 30 mass% sodium hydroxide aqueous solution (330 g) were sequentially charged into a 5000 ml capacity stainless steel jacketed reaction vessel, A monomer reaction solution was prepared by dissolution.
Subsequently, a bulk water-containing gel-like polymer was obtained by starting the polymerization reaction in the same manner as in Example 1.
(Crushing process, cutting crushing process)
The obtained bulk hydrogel polymer was roughly crushed and cut and crushed in the same manner as in Example 1 to obtain a finely divided polymer gel having an average particle size of 4 to 13 mm. Further, when the inside of the main body drum rotating unit 10 was confirmed after cutting and crushing, the bead polymer gel and the fine polymer gel were hardly attached, and the obtained fine polymer gel was sufficiently fine. I was loose.
(Dry grinding process)
Next, the fine granular polymer gel obtained was spread on a nylon mesh so that the thickness was 20 mm or less, and hot air dried at a temperature of 90 ° C. for 1.5 hours using a hot air dryer, and then a Willet grinder. The powdery polymer (A-3) was obtained by pulverizing with.

[Example 4]
(Polymerization process)
A massive hydrogel polymer was obtained in the same manner as in Example 2.
(Crushing process, cutting crushing process)
Subsequently, the obtained massive hydrogel polymer was roughly crushed into a bead-shaped polymer gel having an average particle diameter of 5 to 15 mm using an extruder with a rotating blade (MEAT CHOPPER M-22, manufactured by Nanjo Tekko Co., Ltd.). Then, it cut and crushed using the crusher 1 illustrated in FIGS. The crusher 1 set the rotation speed of the main body drum rotation part 10 to 30 rpm, and set the inclination angle to 10 °. Further, the number of baffle plates 24 is six, the length thereof is 1/3 with respect to the length along the rotation axis X direction of the main body drum rotating portion 10, and the width is 1 with respect to the inner diameter of the main body drum rotating portion 10. / 15.
Moreover, the cutting and crushing of the bead-shaped polymer gel is carried out by using a silicone emulsifier (4.2 g) as a release agent from the gel inlet 20, and a 15 mass% sodium sulfite aqueous solution (32 g), 24 mass% sodium hydroxide as additives. Aqueous solution (20 g) was added dropwise at the same time. As a result, a fine polymer gel having an average particle size of 4 to 13 mm was obtained.
Also, after the cutting and crushing was completed, the inside of the main body drum rotating unit 10 was confirmed. As a result, there was almost no adhesion of the bead polymer gel and the fine polymer gel, and the fine polymer gel obtained was sufficiently fine. I was loose.
(Dry grinding process)
Next, the fine granular polymer gel obtained was spread on a nylon net so that the thickness was 20 mm or less, and hot-air dried at a temperature of 90 ° C. for 1.5 hours using a hot-air dryer, and then a Willet pulverizer. The powdery polymer (A-4) was obtained by pulverizing the powder.

[Example 5]
(Polymerization process)
50% by mass acrylamide aqueous solution (699 g), 79% by mass dimethylaminoethyl methyl chloride salt salt aqueous solution (75 g), 80.5% by mass dimethylaminoethyl methyl chloride salt salt aqueous solution (56 g), 50% by mass acrylic acid aqueous solution ( 3 g) and pure water (281 g) were sequentially added to a 2000 mL brown heat-resistant bottle to prepare a monomer reaction solution.
Subsequently, 10 mass% phosphorous acid aqueous solution (2.0 g) was used as a chain transfer agent, and 2.5 mass% 2-hydroxy-2-methyl-1-phenylpropan-1-one aqueous solution (6.7 g) was used as a photoinitiator. After sequentially charging the monomer reaction solution, the solution temperature was adjusted to 15 ° C. while blowing nitrogen gas. Thereafter, the monomer reaction solution was transferred to a flat reaction vessel made of stainless steel (bottom area 540 cm ² ) under a nitrogen atmosphere. Then, using a chemical lamp, the polymerization reaction was carried out by irradiating light from below the flat reaction vessel to the bottom of the vessel while spraying water at 15 ° C. to obtain a sheet-like hydrogel polymer.
(Crushing process, cutting crushing process)
Next, the obtained massive hydrogel polymer was roughly crushed into a bead polymer gel having an average particle size of 6 to 15 mm by an extruder with a rotating blade (MEAT CHOPPER M-22, manufactured by Nanjo Tekko Co., Ltd.). Then, it cut and crushed using the crusher 1 illustrated in FIGS. The crusher 1 set the rotation speed of the main body drum rotation part 10 to 30 rpm, and the inclination angle to 10 degrees. Further, the number of baffle plates 24 is six, the length of which is 1/3 with respect to the length along the rotation axis X direction of the main body drum rotating portion 10, and the width is 1 with respect to the inner diameter of the main body drum rotating portion 10. / 15.
Moreover, the cutting and crushing of the bead-like polymer gel was performed while dropping a silicone emulsifier (3.7 g) as a release agent from the gel inlet 20. Thereby, a fine granular polymer gel having an average particle diameter of 5 to 12 mm was obtained.
Further, when the inside of the main body drum rotating unit 10 was confirmed after cutting and crushing, the bead polymer gel and the fine polymer gel were hardly attached, and the obtained fine polymer gel was sufficiently fine. I was loose.
(Dry grinding process)
Next, the fine granular polymer gel obtained was spread on a nylon mesh so that the thickness was 20 mm or less, and hot air dried at a temperature of 90 ° C. for 1.5 hours using a hot air dryer, and then a Willet grinder. The powdery polymer (A-5) was obtained by pulverizing with the above.

[Example 6]
(Polymerization process)
A sheet-like hydrogel polymer was obtained in the same manner as in Example 5.
(Crushing process, cutting crushing process)
Next, the obtained massive hydrogel polymer was roughly crushed into a bead polymer gel having an average particle size of 6 to 15 mm by an extruder with a rotating blade (MEAT CHOPPER M-22, manufactured by Nanjo Tekko Co., Ltd.). Then, it cut and crushed using the crusher 1 illustrated in FIGS. The crusher 1 set the rotation speed of the main body drum rotation part 10 to 30 rpm, and the inclination angle to 10 degrees. Further, the number of baffle plates 24 is six, the length of which is 1/3 with respect to the length along the rotation axis X direction of the main body drum rotating portion 10, and the width is 1 with respect to the inner diameter of the main body drum rotating portion 10. / 15.
Moreover, the cutting and crushing of the bead-like polymer gel is carried out by using a silicone emulsifier (3.7 g) as a release agent from the gel inlet 20, and a 30% by mass sodium bisulfite-7.5% by mass sodium sulfite mixed aqueous solution as an additive. (19 g) was added dropwise at the same time. Thereby, a fine granular polymer gel having an average particle diameter of 5 to 12 mm was obtained.
Further, when the inside of the main body drum rotating unit 10 was confirmed after cutting and crushing, the bead polymer gel and the fine polymer gel were hardly attached, and the obtained fine polymer gel was sufficiently fine. I was loose.
(Dry grinding process)
Next, the fine granular polymer gel obtained was spread on a nylon mesh so that the thickness was 20 mm or less, and hot air dried at a temperature of 90 ° C. for 1.5 hours using a hot air dryer, and then a Willet grinder. The powdery polymer (A-6) was obtained by pulverizing with the above.

[Comparative Example 1]
A massive hydrogel polymer was obtained in the same manner as in Example 2.
Subsequently, the obtained bulk hydrogel polymer is roughly crushed by an extruder with a rotating blade (MEAT CHOPER M-22, manufactured by Nanjo Tekko Co., Ltd.), and the average particle size discharged at that time is 4 to 13 mm. A silicone emulsion (4.2 g) as a release agent was added dropwise to the bead polymer gel.
Next, the obtained beaded polymer gel was dried in the same manner as in Example 2. As a result, a dry polymer containing a number of lumpy polymers having a maximum particle size of about 3 cm was obtained. Next, the dried polymer containing lumps was pulverized with a Willet pulverizer. However, the dry polymer was kneaded in the pulverizer, so that all of the dry polymer could not be crushed, and finally a dry polymer (R-1) containing lumps was obtained.

[Comparative Example 2]
A massive hydrogel polymer was obtained in the same manner as in Example 4.
Subsequently, the obtained bulk hydrogel polymer is roughly crushed by an extruder with a rotating blade (MEAT CHOPER M-22, manufactured by Nanjo Tekko Co., Ltd.), and the average particle size discharged at that time is 4 to 13 mm. A silicone emulsion (4.2 g) as a release agent and a 15% by mass sodium sulfite aqueous solution (32 g) and a 24% by mass sodium hydroxide aqueous solution (20 g) were simultaneously added dropwise to the bead polymer gel.
Then, the obtained beaded polymer gel was dried in the same manner as in Example 4. As a result, a dry polymer containing a large number of lumpy polymers having a maximum particle size of about 3 cm was obtained. Next, the dried polymer containing lumps was pulverized with a Willet pulverizer. However, the dry polymer was kneaded in the pulverizer, so that all of the dry polymer could not be crushed, and finally a dry polymer (R-2) containing lumps was obtained.

[Comparative Example 3]
A massive hydrogel polymer was obtained in the same manner as in Example 5.
Subsequently, the obtained bulk hydrogel polymer is roughly crushed by an extruder with a rotating blade (MEAT CHOPER M-22, manufactured by Nanjo Tekko Co., Ltd.), and the average particle size discharged at that time is 6 to 15 mm. A silicone emulsion (3.7 g) was dropped to the bead polymer gel as a release agent.
Next, the obtained beaded polymer gel was dried in the same manner as in Example 5. As a result, a dry polymer containing a large number of lumpy polymers having a maximum particle size of about 3 cm was obtained. Next, the dried polymer containing lumps was pulverized with a Willet pulverizer. However, the dry polymer was kneaded in the pulverizer, so that all of the dry polymer could not be crushed, and finally a dry polymer (R-3) containing lumps was obtained.

[Comparative Example 4]
A massive hydrogel polymer was obtained in the same manner as in Example 5.
Next, the obtained bulk hydrogel polymer is coarsely crushed by an extruder with a rotary blade, and a silicone emulsion as a release agent is formed into a bead-shaped polymer gel having an average particle diameter of 6 to 15 mm discharged at that time. Liquid (3.7 g) and 30.0% by mass sodium bisulfite-7.5% by mass sodium sulfite mixed aqueous solution (19.0 g) were simultaneously added dropwise as an additive.
Next, the obtained beaded polymer gel was dried in the same manner as in Example 5. As a result, a dry polymer containing a large number of lumpy polymers having a maximum particle size of about 3 cm was obtained. Next, the dried polymer containing lumps was pulverized with a Willet pulverizer. However, the dry polymer was kneaded in the pulverizer, so that all the dry polymer could not be crushed, and finally a dry polymer (R-4) containing lumps was obtained.

  About the powdered polymer obtained in the examples and the dried polymer obtained in the comparative example, 1.0% salt viscosity, 0.5% salt viscosity, water-insoluble component amount, residual monomer concentration, water content The measured results are shown in Table 1. Table 1 also describes the pulverization situation together with the measurement results. Regarding the pulverization status, those that became a powdery polymer with a Wiley pulverizer were evaluated as “good”, and those that were kneaded within the Wiley pulverizer and could not be pulverized were determined as “bad”. Moreover, AAm in Table 1 is acrylamide.

As shown in Table 1, in Examples 1-6 which are the manufacturing methods of this invention, it obtained by cutting and crushing the bead-like polymer gel obtained by the extrusion molding machine with a rotary blade with the crusher 1. The fine polymer gel was substantially free of lumps and was sufficiently finely loosened. Further, it was confirmed that the powdered polymers obtained in Examples 1 to 6 had a low water content and were sufficiently dried.
Further, in Examples 4 and 6, the effect of the chemical treatment with the addition of sulfite for the purpose of reducing the residual monomer amount is sufficiently expressed, and the residual monomer amount in the obtained powdery polymer is sufficiently reduced. It had been.
Moreover, in Examples 1-6, the salt viscosity was high and the high molecular weight powdery polymer was obtained.

On the other hand, in Comparative Examples 1 to 4 in which the dry pulverization process was performed directly on the bead-shaped polymer gel discharged from the extruder with a rotary blade without using the main body rotary drum type crusher in the present invention, The water content and water-insoluble component amount of the obtained dried polymer were both high, and it was confirmed that the drying efficiency was poor and the amount of the active ingredient was small.
Further, in Comparative Examples 2 and 4 in which sulfite is added for the purpose of reducing the amount of residual monomer, the effect of chemical treatment is not sufficiently obtained, and the amount of residual monomer in the dry polymer is increased, and the salt viscosity is also high. It had dropped significantly.

  According to the production method of the present invention, even a hydrogel polymer with very high adhesiveness can be obtained as a finely divided finely divided polymer gel. A molecular weight polymer is obtained. Moreover, the residual monomer reduction efficiency by additives, such as a sulfite compound, can be improved significantly, and a powdery polymer can be manufactured efficiently. Therefore, it can be suitably used for the production of acrylamide-based or (meth) acrylate-based powder polymers.

It is the front view which showed an example of embodiment of the main body rotation type drum crusher in this invention. FIG. 2 is a cross-sectional view of the main body drum rotating unit of FIG. 1 cut along a plane including a rotation axis X. FIG. 2 is a cross-sectional view of a central portion in the longitudinal direction of the main body drum rotating portion of FIG. 1 cut along a plane orthogonal to a rotation axis X. It is the side view which looked at the main-body drum rotation part of Drawing 1 from the gel discharge part side.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Main body rotation type drum type crusher 10 Main body drum rotation part 10a Inner wall surface 24 Baffle plate for polymer gel stirring

Claims (5)

A polymerization step for polymerizing a water-soluble monomer in an aqueous medium to obtain a hydrogel polymer, and crushing the hydrogel polymer with an extruder with a rotary blade to obtain a bead polymer gel A cutting and crushing step of obtaining a fine granular polymer gel by crushing and crushing the bead-like polymer gel with a rotating drum type crusher shown below, and drying and crushing the fine granular polymer gel A method for producing a powdery polymer comprising a drying and pulverizing step for obtaining a polymer.
Main body rotating drum type crusher: A crusher that cuts and crushes bead-like polymer gel to obtain a fine granular polymer gel, and includes a main body drum rotating portion with an inclined rotation axis, and the main body drum rotation A main body rotating type drum crusher in which one or more baffles for stirring polymer gel extending from the inner wall surface toward the rotation axis are formed on the inner wall surface of the unit.   2. The powder polymer according to claim 1, wherein a contact portion between the bead polymer gel and the fine polymer gel in the main body rotating drum type crusher is coated with a coating agent for preventing corrosion. Production method.   The said cutting | disintegration process WHEREIN: The additive and / or mold release agent which reduce the amount of residual monomers are mixed in the said bead-like polymer gel in the state of an aqueous medium slurry or aqueous solution. A method for producing a powdery polymer.   The method for producing a powdery polymer according to claim 3, wherein the additive is at least one selected from the group consisting of alkali metal sulfites, alkali metal hydrogen sulfites, alkali metal pyrosulfites, and alkaline substances.   The said polymerization process is a process of polymerizing an acrylamide type monomer and / or a (meth) acrylate type monomer in an aqueous medium, and obtaining a hydrogel polymer in any one of Claims 1-4. A method for producing a powdery polymer.

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