JPS61110511A - Granulation of water-soluble polymer gel - Google Patents

Abstract

PURPOSE:To make solubility of a water-soluble vinyl series polymer easy, by a method wherein the water-soluble vinyl series polymer is made to retain for more than 3min, pulverized and made into a fine particle in a sphere of a vertical cutting machine constituted with a stationary blade and rotating blade. CONSTITUTION:A polymer obtained by polymerizing a water solution of a water-soluble vinyl series monomer is pulverized into the diameter of 3-5mm by a vertical cutting machine circumscribing a screen 4 provided on the external circumference along the circumference in which rotating blade 1 rotates and a sphere having the identical diameter with the circular arc of the screen 4 and having a retention sphere of more than 3min. Then cut-off polymer gels, having diameter smaller than that DS of a hole of the screen 4, among those being moved within a sphere (a) are splashed in an external direction through centrifugal force, passed through the hole of the screw 4, discharged from the sphere (a) and separated from the bulky polymer gels. The polymer gels can be pulverized and made into fine particles.

Description

[Detailed description of the invention] [Industrial application field 1 The present invention relates to a method for refining water-soluble polymer gels.

More specifically, the present invention relates to a method in which a water-soluble polymer gel obtained by polymerizing an aqueous solution of a water-soluble vinyl spinning wheel is crushed and then further refined into fine particles using a vertical cutter comprising a fixed blade and a rotating blade.

[Prior Art] Conventionally, acrylamide homopolymers, copolymers mainly composed of acrylamide with other polymerizable monomers, or alkaline hydrolysates thereof have been used as paper strength agents and thickeners. It is widely used as a soil conditioner, crude oil recovery agent, wastewater treatment agent, etc.

Methods for producing water-soluble acrylamide polymers include bulk polymerization, suspension polymerization, emulsion polymerization, and solution polymerization, but it is important to produce a polymer that is essentially a polymer dust. Therefore, aqueous solution polymerization method is usually adopted in many cases.

In order to obtain a polymer with a very high molecular weight and good water solubility using the aqueous solution polymerization method, polymerization is carried out at a relatively low concentration to prevent crosslinking in the polymerization reaction stage. There is a need.

However, in recent years, transport] strikes, storage costs, etc.
Because performance is important, powder products are now the mainstream of production rather than liquid products, and when water-soluble polymerization is used at low concentrations, it is difficult to powder the resulting polymer. It has the disadvantage that a large amount of water must be volatilized and dried, and the cost of powdering is increased.

In order to eliminate such drawbacks, research has been conducted to reduce cotality costs in the powdering stage by polymerizing at the highest possible monomer concentration, and numerous patent applications have been filed.

However, vinyl monomers such as acrylamide and acrylic acid inherently have a very strong tendency to crosslink and become three-dimensional, so crosslinking is inevitably prevented.
Under mild conditions, especially regarding the concentration of i-J III M1, for example, in the case of anionic or nonionic compounds, the concentration can be maintained at a relatively low level of at most 20 to 30% (wt%, the same applies hereinafter). must be polymerized.

When m-degree acrylamide or a monolayer solution mainly composed of acrylamide as described above is polymerized, a gel-like material having no fluidity and having a hard or high elasticity 14 is obtained. Therefore, for example, if you try to volatilize the water contained in a mass or sheet of gel-like polymer without mechanically crushing it, it will take a very long time.
It is necessary to leave the product under high temperature, and as a result, the molecular weight of the high molecular weight polymer that has been carefully prepared decreases, and crosslinking of the polymer due to thermal changes is promoted, resulting in a significant decrease in commercial value. Therefore, the commonly used method is to coarsely crush the obtained polymer gel lumps or sheets by some mechanical means into small agglomerated particles, and then dry them by heating to remove water. . Generally, a method is widely adopted in which a polymer gel obtained by polymerization is formed into a strand shape using an extruder such as a meat grinder, and then heated and dried. However, when using an extrusion molding machine such as a meat grinder, especially when the polymer gel is extremely hard, the friction on the machine wall is large, causing a loss of machine efficiency, and the polymer gel itself This is not a very preferable method because it is subject to deterioration due to frictional heat and physical forces, resulting in a decrease in molecular weight due to molecular cleavage.

The present inventors proposed a method for crushing a polymer gel obtained by polymerizing an aqueous solution of a water-soluble vinyl monomer, which does not involve a decrease in molecular weight and in which the crushed pieces of polymer gel adhere to each other. The company developed a method that was difficult to use, and filed a patent application on November 6, 1981 (title of the invention: ``Method for crushing water-soluble polymer gel'', hereinafter referred to as the application).

However, the strip-shaped polymer gel obtained by the method according to the above application is a relatively large angular polymer gel of 3 to 20 u, and even if you try to dry it by heating in this state, there will be some particles inside the polymer gel. It is difficult for moisture to evaporate. As a result, the drying time becomes shorter, and an increase in the volume required for drying (hereinafter referred to as drying capacity) is unavoidable.

It is easy to infer that in order to reduce the drying capacity, the polymer gel particles before drying should be made as small as possible and the drying time should be shortened. In an extrusion molding machine like a machine, the above 3 to 205 m
It is indecipherable to refine the polymer gel until it becomes angular in size.

[Problems to be Solved by the Invention] The present invention solves the problem by further reducing the size of the crushed polymer gel, preferably the polymer gel cut into squares of 3 to 20 iui, and drying the crushed polymer gel. This was done to solve the problem that heat drying is not easy when the combined gel is coarse.

[Means for Solving Problem E] When refining a polymer gel, the present inventors have developed an aqueous solution of a water-soluble vinyl monomer as a method for preventing the refined particles from adhering to each other. We conducted extensive research on the following: 1. Keeping the concentration as high as possible during polymerization, 2. Using an anti-blocking agent or blowing cold air when making particles into fine particles, and 2. Changing the crushing method. As a result, we have arrived at the present invention.

That is, in the present invention, after crushing a polymer gel obtained by polymerizing an aqueous solution of a water-soluble vinyl monomer, a region consisting of a fixed blade and a rotating blade, in which the polymer gel to be crushed remains. A fine particle of a water-soluble polymer gel, characterized in that the crushed polymer gel is further cut into fine particles by a vertical cutter having an average crushing residence time of at least 3 minutes or more. Regarding the granulation method.

[Example] Examples of water-soluble vinyl monomers used in the present invention include water-soluble vinyl monomers such as acrylamide, methacrylamide, acrylic acid, methacrylic acid, vinylsulfonic acid, acrylamide-methylpropanesulfonic acid, and itaconic acid. (meth)acrylic acid dialkylaminoalkyl esters, salts or acidic salts thereof, or 4@ compounds thereof, dialkylaminoalkylacrylamides, salts or acidic salts thereof, or 4
Examples include, but are not limited to, diallylamines such as graded compounds, diallylamine acid salts, and diallyldialkylammonium salts. These may be used alone or in combination of two or more.

The water-soluble vinyl monomers include monomers that are essentially insoluble in water to the extent that the resulting polymer is water-soluble, such as acrylonitrile, (meth)acrylates, vinyl acetate, and styrene. Hydrophobic monomers such as these may also be blended.

There are no particular limitations on the method of polymerizing the water-soluble vinyl monomer, such as thermal polymerization using a radical polymerization initiator such as a known persulfate or an azo initiator, a method using known persulfates/amines, or Common methods include a redox polymerization method using a redox polymerization initiator such as persulfate/sulfite, a photopolymerization method using a photopolymerization initiator such as benzoin or benzoin alkyl ether, or a radiation polymerization method. Usually, by such a method, an aqueous solution of a water-soluble vinyl monomer of a predetermined concentration is polymerized until it no longer flows freely. When polymerizing an aqueous solution of a water-soluble vinyl monomer as described above by irradiating ultraviolet rays, especially when the aqueous solution is formed into a thin film and irradiating it with ultraviolet rays, the induction time for polymerization is very short, and the time required for polymerization is very short. is shorter than the other -8 methods. As a result, the equipment required for polymerization is compact and equipment costs are low. Furthermore, it is preferable to transfer the polymer in a continuous, thin layer to the movable support, since this has the advantage that subsequent crushing and pulverization can be carried out continuously.

It is preferable that the polymer gel obtained using a water-soluble vinyl monomer be as concentrated as possible from the viewpoint of improving productivity, and also to reduce stickiness during crushing and prevent crushed materials from adhering to each other. It is also preferable from the viewpoint of prevention. Generally, nonionic or anionic polymer gel obtained using acrylamide or acrylic acid has a content of 20 to 60%,
It is preferably 30 to 45%, while in the case of a cationic polymer gel using dialkylaminoalkyl acrylate or its acid salt or quaternary salt, it is 50 to 90%.
%, preferably 60 to 80%.

In order to efficiently cut the polymer gel with a pair of roller-type cutters rotating in mutually interlocking directions as described in the A application specification, the polymer gel must be smoothly embedded into the roller-type cutters. Therefore, the thickness of the polymer gel is preferably 2 to 30 an+, preferably 5 to 15 u, in the form of a thin layer. For example, when a water-soluble vinyl monomer aqueous solution is polymerized using a dish-shaped, flat-plate-shaped, or tray-shaped container or a movable belt, it can be formed into a thin layer. A method in which polymerization is carried out in a thin layer on a movable belt is a preferable method because the subsequent crushing process is continuous.

In the present invention, the polymer gel obtained as described above is used as shown in FIGS.
Crushing using a crusher as shown in one embodiment in FIG.
It is preferably crushed into 3 to 201 square pieces.

If the size of the crushed material exceeds the average particle size of 20i1, the cutting ability of the vertical cutter in the next step tends to decrease, and the polymer with an average particle size that is too coarse, exceeding 20ffll, tends to decrease. If too much gel is supplied to the vertical cutting machine, poor cutting will occur, and agglomerates of polymer gel will form inside the cutting machine, and at the same time frictional heat will be generated due to stickiness, creating an undesirable vicious cycle.

The polymer gel is fed to the crusher from above the crusher as shown in FIG. 4, for example. The supplied polymer gel is cut by roller type cutters (13) and (14) shown in FIG. 6, which is a top view of the crusher shown in FIGS. 4 and 5, for example, into short pieces. It is made into strands.

On the surfaces of the roller type cutters (13) and (14), cutter blades are formed in a concave and convex shape so that the concave and convex portions engage with each other, as shown in FIG. 6, more specifically, FIG. 7. These mutually meshing roller type cutters have, for example, a direction\1 direction and rotate in the meshing direction at the same rotational speed. The width, depth, and size of the unevenness of the blades formed to interlock with each other may be determined so that the crushed polymer gel has a desired size, that is, an average particle size of 3 to 2011 m. In figure 8, width (X+)
The depth of the concave part of the blade is about 2 to 10 mm (X4) F1
Approximately 0 to 15 + am, height of convex part x 5) is 10 to 15
11, and even when the concave part and the convex part are most deeply engaged, the gap ((X3) in Figure 8) necessary for the cut polymer gel to pass through is usually about 10 to 25 mm. is formed. The blades on the surface of the roller cutters (13) and (14) are formed in this shape, and the rotation axis f8) of the roller cutter is formed as shown in Fig. 6.
, +91 with two roller type cutters (13),
(14) is rotated as shown in Fig. 5 (cross-sectional view taken along line c-c' in Fig. 4), - the polymer gel supplied from above is caught and cut, and the polymer gel is supplied downward; According to
The polymer gel can be easily cut into strands, for example.

In order to supply the polymer gel to the roller type cutters (13) and (14), there is a method in which the polymer gel is continuously taken out from the other end of a movable support, such as an endless belt, and then inserted into the roller type cutter. When performed continuously using , ■-13-, -.

The process can be made continuous and production efficiency can be improved.

Roller-type cutters (1) that rotate in the direction of mutual engagement
3) and (14), the polymer gel strands cut into short pieces, for example, have <L(15) shown in FIG.
, (16) is peeled off from the outer periphery of the roller cutter blade (A) shown in FIG.
and <L, (16), and reaches the position of the fixed blade (12) provided at the lower end of <L (16). Normally, the polymer gel strands do not stick to the outer blade (B) of a roller type cutter. The short strand-like strands that reach the position of the fixed blade (12) and protrude downward from that position are similar to those shown in FIGS.
Rotating blade <11) and fixed blade (12) provided on the outer periphery of
and 0, and are cut into strips, preferably rectangular strips with an average particle size of 3 to 20 nv.

The cross-sectional shape of the short piece in the horizontal direction is determined by the reduced dimensions of the roller cutters (13) and (14) after assembly, that is, the width of the unevenness of the blade (×1) in Fig. 8, and the depth of engagement. X2), the height (x4), (Xs), and the rotational speed of the roller type cutters (13) and (14). The short strip-like longitudinal shape is provided on the rotational speed of the rotary body (10) and the rotational body (10) which rotates at a speed synchronized with the rotational speed of the roller type cutters (13) and (14). By adjusting the number of rotary blades (11) (six in FIG. 5), the length to be cut into strips can be determined.

Next, the crushed polymer gel, preferably 3 to 2 ha
A cutting 1lFi machine and a method thereof used to finely granulate a polymer gel crushed into squares of m size will be described.

FIG. 1 is a schematic top view of the main parts of a vertical cutter used for finely pulverizing the crushed polymer gel used in the present invention, and FIGS. 2 and 3 are cross-sectional views. It is.

In Figure 1, (1) is a rotating blade, (2) and (2-)
are the first and second fixed blades, (3) is the buri cutter, (4) is the screen, (5) is the rotating shaft of the rotary blade (1), (6) is the bottom, and (7) is the discharge hole. be.

The feature of the vertical cutting machine used in the present invention shown in FIG. iQi! screen (4) and the same diameter (DO) as its arc
It circumscribes the area with , and when viewed from above, it has a half-moon shape.
It has a retention area (C) where retention is possible for 3 minutes or more, and has a drive rotating shaft (rotary blade shaft (5) in Figures 1 and 2).
is facing the vertical direction F, that is, it is a vertical point.

In Fig. 3-1, among the angular polymer gels of 3 to 20 mm to be supplied, as shown in Fig. 1, the axis of the rotary blade (1) installed inside the vertical cutting machine main body is By rotating the cutting blade at the tip of the pre-cutter (3) fixed to (5), a relatively large polymer gel with an inner diameter of 10 to 20 mm is cut out of the 3 to 20 seconds square polymer gel. Shattered.

At this time, the first method of the present invention is to supply (drop) 3 to 20g1i of angular polymer gel from above the axis of the rotary blade shaft (5) toward the rotary blade shaft (5). This is the main point. By doing so, the polymer gel having a coarse diameter can be selectively converged to a diameter in the range of 3 to 51 mm. The 3-20+ am angular polymer gel thus supplied is first aligned to 3-5 mm. The polymer gel cut in the range of 3 to 5++v in this way is
The first fixed blade (21) assembled in the main body of the vertical cutting machine as shown in Fig. 1 is inserted into the gap of 1- or less between the rotating rotary blade (1), and is cut at the same time as it is inserted. .When viewed from above, the cut polymer gel has an arc-shaped screen (4), the outer peripheral edge of the rotating rotary blade (1), and 1
The area (a) surrounded by the second fixed blade (2) and the second fixed blade (2-) is moved along the rotating direction of the rotary blade (1) to the second fixed blade (2').

The second point of the method of the present invention is that among the cut polymer gels moving in the region (a), the polymerized-16 integral gel having a diameter smaller than the pore size (Ds) of the screen (4) is Due to centrifugal force, it scatters outward and forms a screen (4
), and is discharged from region (a) to the discharge hole +71, where it is separated from the polymer gel, which is coarser than the pore size (O5) of the screen.

On the other hand, among the cut polymer gels moving in the area (a), the polymer gels with a diameter larger than the pore size (O5) of the screen (4) are again placed in the second position as shown in FIG. The area 14 (b) is sandwiched between the fixed blade (2') and the rotating blade (1), and after being cut, the area 14 (b ) has a rotating blade (
It enters along the rotation direction of 1). and area (b)
The moving polymer gel is again caught in the gap between the first fixed blade (2) and the rotating blade (1) and cut.
Similar cuts are repeated.

In this way, the diameter 1 of the polymer gel of 3 to 20 mm, which is supplied (dropped) from above the axis of the rotating shaft (5) of the vertical cutting machine to the rotating shaft (5) located below, is cut vertically. The discharge hole of the mold cutting machine (by force) is separated into pieces smaller than the hole diameter (portion S) of the screen (4), and is continuously screened out, making it possible to cut as desired. hole (for holes larger than ¥, use the second fixed blade (2-) like 1j ho)
and the rotary blade (1) to reduce the diameter of the polymer gel, but what is important in the 3rd fi is that after this, the area (b
) where the cut polymer gel that has entered the area remains (C)
It is to become stagnant. Then, the polymer gel, which resides for an average of at least 3 minutes in the retention zone (C),
As the rotary blade rotates, the fixed blades (2), (2-) and the rotary blade (1) cut again, and the cutting process described above is repeated. The average residence time exceeds at least 3 minutes, and the polymer gel staying in the residence area (C) is mixed very vigorously due to the centrifugal force of the rotating blade (1).
As a result of being rounded by the granulation effect caused by stirring, the shape of the particles in the dried powder product approaches the desired spherical shape.

As described above, the method of the present invention has the desirable effect of not only refining the crushed polymer gel but also making the shape of the refined polymer gel closer to a spherical shape.

The vertical cutter II machine used in the present invention differs from commercially available typical C1 general pulverizers, such as Fuzer Mill and Fitz Mill, in that it maintains an average pulverization residence time of 0.1 for the material to be pulverized for 3 minutes or more. As a result, the polymer gel is constructed with a very small number of cuts without undergoing multiple cuts, resulting in a uniform fine-grained gel. The structure of the cutting machine is characterized by adjusting the gap between the vertical fixed blades (2), (2') and the rotary blade (1), which are installed vertically inside the cutting machine. By changing the hole diameter (Ds) and by arranging a plurality of vertical cutters in series, that is, by passing the cutter two to several times, the residence time of crushing can be reduced to 1,111111 make it possible,
For example, it is easy to adapt to polymer gels with small particle diameters such as 1111φ or smaller. and 11
Another point is that the shape of a small coalesced gel with a small particle size of 1φ or less has the desirable effect of approaching a sphere. A technique for refining crushed polymer gel using a vertical cutting machine having such a structure has not been established in the past.

For example, in the first step, when cutting is performed using a cutting machine equipped with a 3ii+φ screen, a finely divided polymer gel having a uniform particle size of about 3illφ or less can be obtained. Then, as a second step, the grains are finely divided using a cutting machine equipped with a screen of 2 mm diameter, and as a third step, the grains are refined using a cutting machine equipped with a screen of 111 diameter. Fine particles with In this way, by selecting a screen that matches the target particle size, the target particle size can be obtained.

Furthermore, when the method of the present invention is adopted, almost no dust is generated during the step of refining the polymer gel, which is essentially in a wet state, and the particle size distribution can be changed to a uniform particle size distribution that is close to monodisperse. It will be done.

In order to increase the cutting efficiency when crushing the polymer gel and making it into fine particles, and to prevent the re-adhesion of the obtained fragment-shaped polymerized-20 integral gel and the further fine-grained polymer gel. In addition, it is preferable to keep the temperature of the polymer gel as low as possible during cutting.

Methods for lowering the temperature of the polymer gel include cooling sufficiently during the polymerization stage when crushing it into small pieces, and cooling the polymer gel obtained by polymerization by blowing cold air etc. before crushing it with a crusher. This can be achieved by forced cooling, but usually 10 to 30°C, preferably 20°C
It is preferable to adjust as follows.

Furthermore, if the crushing process is cooled by passing cold air, preferably cold air of 25°C or less, during the crushing process, for example, a strand of short pieces is produced, and then the strand is further cut into small pieces. It can reduce the possibility that the polymer gel becomes sticky due to frictional heat or the driving heat of a roller cutter, etc., or that the cut pieces of polymer gel stick to each other and form blocks. .

In addition, when the polymer gel that has been made into fine particles is further made into fine particles, the crushed polymer gel to be made into fine particles may be strongly cooled in advance, as in the case where the polymer gel is made into fine pieces. If the granulation step is carried out while cooling the particles by passing through cold air, preferably cold air at 25° C. or lower, the same effect as in the case of forming into small pieces can be obtained.

In addition, when crushing and refining the T culm, polyethylene glycol, nonionic surfactants, anionic surfactants, etc. may be added to the crusher or vertical cutting machine as necessary, or the surface of the polymer gel or crushed It may also be applied to the surface of the polymer gel to prevent re-adhesion of the fragmented polymer gel or finely granulated polymer gel.

In carrying out the method of the present invention, an aqueous solution of a water-soluble vinyl monomer is polymerized into a thin film on a movable support such as an endless belt to obtain a polymer gel, and then continuously (By crushing into h+v square shapes, and then fine-graining to an average particle size of about 03 to 31- by a vertical cutter Ii, it is possible to make the whole part continuous as in ■.Furthermore, if an ultraviolet irradiation method is used for polymerization, A polymer gel can be obtained in a short time, and if the crushing and pulverization are carried out while passing cold air at 25° C. or lower, the crushing efficiency and pulverization efficiency can be improved.

Since the method of the present invention is a method of refining a polymer gel that is essentially in a wet state, when the method of the present invention is adopted,
Generation of fine powder due to dust generation, as seen in the generally used dry pulverization method (in other words, when the drying process is completed, the polymer is pulverized in the dry state, hereinafter referred to as dry pulverization). It is possible to overcome drawbacks such as (1) crushing heat generated during crushing, (2) reduction in molecular weight due to crushing heat, and generation of water-insoluble substances.

More specifically, the vertical cutting machine used in the present invention has an average crushing residence time of at least 3 minutes and has a vertical structure, so it is not as effective as a commonly used crusher used in a dry state. Unlike the case where the grinding residence time is short, the generation of fine powder can be prevented by the water content contained in the polymer gel that is atomized in the wet state, and the cutting time is sufficient. By providing this, it is possible to refine the particle shape until it can be kept uniform.

The particle size distribution of the fine particles obtained by the method of the present invention is almost monodisperse, and such a unique and excellent distribution has never been obtained by conventional methods.

1. Under wet conditions as in the present invention. In the case of II cutting, unlike in the case of dry grinding, much of the heat generated during cutting and grinding is replaced by the latent heat of vaporization of the abundant water (for example, 30 to IO%) held by the polymer gel. This will not result in a significant upper layer of grinding concentration. This effect of suppressing the grinding temperature can prevent deterioration of polymer quality, such as a decrease in molecular weight and the formation of water-insoluble substances.

As described above, the method of the present invention has a significantly superior advantage in terms of preventing quality deterioration. Therefore, compared to commonly used dry grinding, the amount of heat generated during grinding is replaced by the latent heat of vaporization of the sufficient amount of water contained in the polymer gel, reducing the grinding to an undesirable = 24 - undesirable level. It is possible to prevent the temperature from dropping. As a result, undesirable phenomena such as deterioration of polymer quality, such as reduction in molecular weight and formation of water-insoluble substances, can be avoided.

Next, the method of the present invention will be explained based on examples.

Example 1 A polymerization device with 11 cages (length 200IIID, width 300m5
.

^Square 50111 square container 1. F section (without lid) was installed.

Acrylamide 200o from which dissolved oxygen was sufficiently removed with nitrogen gas in a 1i2 oxygen tank (cylindrical type with a capacity of 1a)
was dissolved in 275 g of deionized water to a monomer aqueous solution,
After adding 5% potassium persulfate aqueous solution 5- and 5% sodium sulfite aqueous solution 1lli5IRIl and continuing deoxidizing with nitrogen gas for several minutes, the mixture was introduced into the polymerization apparatus installed in a room sealed with nitrogen gas. , initiated the polymerization. Water at 25°C was passed through the jacket. Polymerization is about 1
Starting after 0 minutes, the aqueous monolayer solution gradually thickened. At the time point when 15 minutes had passed after the start of polymerization, the monomer aqueous solution was in a state of gently flowing.

Approximately 2 hours after the start of polymerization, the polymer became a hard gel. The polymer gel was approximately 8 ml thick.

The resulting polymer gel was passed through a crusher as shown in Figures 4 to 6 through a roller-type cutter with a width of 4 mm of unevenness, a depth of 10 mm of concave portions, and a height of 10 m3 of convex portions. Gap required to do so (X3)) 12
11. Surface speed of roller type cutter 10.5cm
When crushing at 20°C by adjusting the rotation speed of the rotary blade at 20 to 100 r/min, approximately 3 x 8 x 3
Im horns were cut. After that, about 3X (3X
3 IIm angular polymer gel is supplied and dropped, approximately 1
3IIllφ as the first step while passing cold air at 5℃
It is cut with a vertical cutting machine equipped with a screen, then a 21Ilφ screen is cut in the second stage, and a 11Ilφ screen is cut in the third stage.
■It was cut using a vertical cutting machine equipped with a φ screen. A thinned polymer gel having a size of approximately 1 φ was obtained.

When the obtained polymer gel of approximately iii+φ was dried with hot air at 80° C., it was transformed into a powder with a moisture content of 10% or less and a uniform particle size in about 25 minutes. The powder has an intrinsic viscosity of 23 dl/
(1), it became an aqueous solution containing no water-insoluble substances and was useful as a flocculant.

Comparative Example 1 When the 3 x 8 x 3 +U angular polymer gel obtained in Example 1 was dried with hot air at 80°C, it took about 60 minutes to finally become powder with a moisture content of 10% or less. It was a pellet-like powder and needed to be further crushed.

When the powder was pulverized using a Fitzmill-type pulverizer having a screen of approximately 11 Ilφ, the generation of ultrafine powder of 100 mesh passes was significant (approximately 3.43%), resulting in a powder with a large amount of dust.

The inherent mucus of the obtained powder product was 21.5 dl/Q,
The powder contained a large amount of water-insoluble substances, and the quality had clearly deteriorated during the drying and grinding stages.

-27-Example 2 Hot to cold water was sprayed on the back side of a stainless steel endless belt with a width of 4501 Ill and an effective length of 3.00011 mm and a tetrafluoroethylene-ethylene copolymer film (thickness 50 μm) was attached to the surface. A vine structure was installed as a movable support for polymerization in a room completely filled with nitrogen gas, and it was moved at a constant speed of 30 cm/min.
Water at 25° C. was sprayed on the back side of the belt.

N with a concentration of 75% adjusted to pH 4 with a 10% aqueous hydrochloric acid solution,
Approximately 30 μm of an aqueous solution of N,N-trimethylaminoethyl methacrylate chloride monomer was sufficiently degassed with nitrogen gas, and was quantitatively fed onto the belt in operation at a rate of 10 μm/hour from one end of the belt.

In addition, 5% potassium persulfate solution and sodium sulfite solution were placed as polymerization initiators in two temporary storage tanks (5d1M) with a stirrer installed above the belt, and each was continuously supplied at a rate of 70d/hour. , was added to the above monomer aqueous solution while mixing, and fed to the Pel tote while being mixed uniformly.

Under the above conditions, polymerization started approximately 20 minutes after the supply.

The time for polymerization of the 7-mer aqueous solution on the belt is 10
0 minutes, the layer of 7-mer aqueous solution during polymerization is approximately 12 mm.
And the total polymerization time was 2 hours.

120 minutes after the start of supply of the seven-mer aqueous solution, a sheet-like polymer having a thickness of about 12 i+m was transferred from the other end of the endless belt. The obtained polymer was easily peeled off from the belt surface by hand, and continuous polymerization for about 3 hours was possible.

The temperature of the resulting polymer gel was about 28°C.

The polymer gel sheet continuously obtained from the other end of the endless belt is passed through a crusher as shown in Figs. 4 to 6 using a roller-type cutter (13) that rotates in the direction of engagement as shown in Fig. 5. , (14) is continuously supplied from above,
It was crushed, and a angular polymer gel of approximately 5 x 12 x 511 m was obtained from the crusher outlet.

After that, a vertical cutting machine as shown in Figures 1 and 2 is used.
As shown in FIG. 3, the angular polymer gel was supplied from vertically above the shaft (5) of the rotary blade. This vertical cutting machine was equipped with a screen in which the diameter of the hole in the screen was approximately 3 msφ. Cutting is carried out while blowing cold air at about 15°C from the top of a vertical cutting machine, and then cutting is performed using a cutting machine equipped with a 2smφ screen and then a 1i+mφ screen, resulting in fine particles of approximately 1im+φ. I got the gel.

The resulting finely divided polymer gel of about 11 Iφ was dried at 80°C in a ventilation band type dryer, resulting in a particle size of about 1
Powder with a moisture content of 10% or less was obtained in 5 minutes.

The water solubility of the obtained granular material was that it contained no water-insoluble substances and had an intrinsic viscosity of 7.0 dl/g.

Comparative Example 2 When the approximately 5 x 12 x 511 angular polymer gel obtained in Example 2 was dried under the same conditions as in Example 2, the moisture content decreased to below 10% in about 40 minutes. The aqueous solution of the dried product had an intrinsic viscosity of 6.8 d110 and contained some water-insoluble substances.

Example 3 Stainless steel RL+4501m, 44 effect 3.
000U endless belt is equipped with a tetrafluoroethylene-ethylene copolymer film whose back side is vapor-deposited with aluminum, and has a structure that allows dry to cold water to be sprayed onto the endless belt from below. The support was placed in a room completely filled with nitrogen gas, operated at a constant speed of 100 u+/min, and water at 15 DEG C. was sprayed from below the bell 1-. In addition, a low-pressure mercury lamp was installed as an ultraviolet irradiation source on the upper part of the movable support, and the intensity of the ultraviolet rays was set to 50 W/m''.

14. with a concentration of 75% adjusted to pl-14 with a 10% aqueous hydrochloric acid solution. The HJ-trimethylaminoethyl methacrylate chloride monomer aqueous solution layer 401 was sufficiently degassed with nitrogen gas, and the bell 1-1, which was in operation, was heated by +3.5 d.
A constant feed was applied from one end of the belt at a rate of 1/hr.

In addition, a temporary storage tank (5a) with a stirrer installed above the belt.
A 5% methanol solution of benzoin isopropyl ether as a polymerization initiator was supplied into the above monomer aqueous solution at a rate of 30 m/hour from the volume), and polymerization was performed by ultraviolet irradiation while uniformly mixing the monomer aqueous solution and the polymerization initiator. .

Under the above conditions, the time period during which the aqueous monomer solution was subjected to polymerization on the belt was 30 minutes, and the layer of the aqueous monomer solution during polymerization was about 5 cm.

Thirty minutes after the start of supply of the monomer aqueous solution, a sheet-like polymer having a thickness of 51 mm was transferred from the other end of the endless belt. The obtained polymer was in a state where it could be easily peeled off manually from the belt surface, and continuous polymerization for about 3 hours was possible.

The temperature of the resulting polymer gel was 20°C.

The polymer gel sheet continuously obtained from the other end of the endless belt is passed through a crusher as shown in Figs.
As shown in the figure, the roller type cutters (13) and (14) rotating in the interlocking direction were continuously supplied from above and crushed to obtain a 3×5×51 square polymer gel.

Next, while blowing cold air at about 15°C, the above is cut from vertically above the shaft (5) of the rotary blade as shown in Fig. 3 using a cutting machine as shown in Figs. Supplying angular polymer gel and pulverizing it,
Subsequently, the polymer gel was cut through a cutting machine equipped with a screen of about 2-φ and a screen of about 111φ in this order to obtain a finely divided polymer gel having a size of about 11Iφ.

The resulting finely divided polymer gel of about 11 Iφ was dried at 80°C in a ventilation band type dryer, resulting in a particle size of about 13
Powder with a moisture content of 10% or less was changed in minutes.

The water solubility of the obtained powder and granules does not contain any water-insoluble substances,
The intrinsic viscosity was 7.8d110.

Comparative Example 3 When the angular polymer gel of about 3 x 5 x 511 obtained in Example 3 was dried under the same conditions as in Example 3, about 35
The moisture content decreased to 10% or less in minutes.

The aqueous solution of the dried product obtained has an intrinsic viscosity of 7.5 dl/Q
It contains some water-insoluble substances.

[Effects of the Invention] By using the method of the present invention, (1) the polymer gel can be continuously crushed and made into 111 particles; (2) the polymer gel can be made into extremely fine particles;
As a result, the drying efficiency of the next process can be improved by preventing the adhesion of the fine particles of polymer gel to each other.■ The amount of fine powder, for example, 100 mesh pes, contained in the fine particles (powder) is This eliminates the generation of dust, which was considered a problem in the past. There is almost no decrease in the degree of polymerization or molecular weight when crushing or crushing the polymer gel. (Improvement is required) ■ The product (powder) obtained by pulverizing the polymer gel and drying it has a spherical shape and has the remarkable effect of improving the fluidity of the product (powder). You can get the effect of

[Brief explanation of the drawing]

Figures 1 to 3-1 are explanatory diagrams relating to one embodiment of the cutting machine used in the present invention; Figure 3-2 is an explanatory diagram showing only the structure of the screen used in Figure 3-1 in three dimensions; Figures 4 to 6
The figure is an explanatory diagram of a practical embodiment of the crusher for producing the shredded material used in the present invention, FIG. 7 is an explanatory diagram of the engaging part of the roller type cutter shown in FIG. 6, and FIG. FIG. 8 is an enlarged explanatory diagram for explaining in detail the meshing portion shown in FIG. 7; (Main symbols in the drawing) (1): Rotating blade +21: 1st fixed blade (2°): 2m fixed blade (cl: 1 station area (2): 1st fixed blade Figure 3-1) 3-2, Figure 4-C, 1'5, Figure 26, off view/.

Claims (1)

[Claims] 1. After crushing a polymer gel obtained by polymerizing an aqueous solution of a water-soluble vinyl monomer, the blade is composed of a fixed blade and a rotating blade, and the polymer gel to be crushed remains. Fine granules of a water-soluble polymer gel, characterized in that the polymer gel is further cut into fine particles by further cutting the pulverized polymer gel using a vertical cutter having a pulverization area and an average pulverization residence time of at least 3 minutes or more. method. 2. A polymer gel obtained by polymerizing an aqueous solution of a water-soluble vinyl monomer into a thin film on a movable support is continuously
Claim 1: The product is crushed into square shapes of ~20 mm, and then refined to an average particle size of 0.3 to 3 mm using a vertical cutter.
The method described in section. 3. The method according to claim 1 or 2, wherein the polymer gel is a polymer gel obtained by irradiating an aqueous solution of a water-soluble vinyl monomer in the form of a thin film with ultraviolet rays. 4. The method according to claim 1, 2, or 3, in which the particles are continuously crushed while passing through cold air at 25° C. or lower to further refine the particles.