JPH06192305A - Suspension polymerization - Google Patents

Abstract

PURPOSE:To produce polymer beads having a uniform particle size with a high polymerization degree by polymerizing droplets of a polymerizable monomer formed through a porous member in a suspension while generating Taylor vortex and allowing each droplet to react without division and/or coalescence. CONSTITUTION:A suspension prepared by introducing a polymerizable monomer through a porous member into a dispersant-containing continuous phase and containing a group of dispersed polymerizable monomer droplets is subjected to polymerization by rotating a rotatable inner cylinder in a static outer cylinder of a coaxial double crank cylinder and controlling the rotation of the inner cylinder so as to have Taylor number of 40 to 15000 at the circular part, thus producing the objective polymer beads. Preferably rotation is carried out so that Taylor number may be 2100 to 15000. The group of liquid droplets of the polymerizable monomer is formed by applying vibration to the monomer. The dispersion containing the group of dispersed polymerizable monomer droplets is prepared so that the ration of the continuous phase to that of the groups of liquid droplets may be >=0.98 to 1.02 or 0.96 to 1.02.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension polymerization method, and more particularly, to a suspension in which a group of polymerizable monomer droplets formed through a porous member is dispersed to form an outer cylinder and an inner cylinder. The present invention relates to a suspension polymerization method in which a suspension vortex polymerization is performed while a Taylor vortex is generated in an annular portion of a coaxial double-rotating cylinder having a.

[0002]

2. Description of the Related Art A special vortex flow is generated by filling a fluid between two cylinders sharing a central axis, keeping an outer cylinder stationary, and rotating an inner cylinder above a certain critical value. It is known. In such a device, the flow velocity near the inner cylinder is higher than that near the outer cylinder, so that the centrifugal force of the fluid mass rotating near the inner cylinder is greater than the centrifugal force of the fluid mass rotating near the outer cylinder. The fluid mass near the inner cylinder becomes jetted as a discharge flow toward the outer cylinder, and instead, the fluid mass near the outer cylinder flows as a return flow toward the inner cylinder. Since such a discharge flow and a return flow are regularly arranged in the axial direction of the cylinder, a donut-shaped vortex is formed so as to wind the inner cylinder. This vortex is called the Taylor vortex.

A device for producing this Taylor vortex may be any device having a coaxial rotating cylinder structure having a stationary outer cylinder and a rotatable inner cylinder.
There is one disclosed in Japanese Patent Publication No. 56-139122.

Further, as a suspension polymerization method, conventionally,
Usually, a method of producing polymer beads by introducing a continuous phase liquid containing a dispersant and a polymerizable monomer into a tank reactor having a stirring blade to carry out a polymerization reaction is adopted.

However, this method has a drawback that the size of the obtained polymer beads varies, and as a result, the particle size distribution of the polymer beads becomes wide. Therefore, methods for obtaining polymer beads having a uniform particle size by adjusting the degree of stirring or by using an appropriate dispersion stabilizer have been investigated, but at present, no effective method has been obtained. is there.

Therefore, prior to the polymerization, an oil-in-water dispersion of a polymerizable monomer having a uniform particle size is produced in another apparatus, and then the dispersion is supplied into a polymerization reactor to carry out suspension polymerization. Is being considered. In Japanese Patent Laid-Open No. 57-102905, a polymerizable monomer is jetted through a nozzle, and the jet stream is subjected to mechanical vibration to produce an oil-in-water dispersion of the polymerizable monomer having a uniform particle size. JP-A-3-249931 discloses a method of suspension polymerization of a polymerizable monomer in water having a uniform particle diameter using a nozzle plate in which a large number of ejection holes are annularly arranged. Disclosed is a method of producing an oil-type dispersion and subjecting it to suspension polymerization.

As a result of intensive studies on the method of polymerizing a suspension in which a group of polymerizable monomer droplets having a uniform particle diameter are dispersed, the inventors of the present invention have found that a polymerizable monomer liquid formed through a porous member is used. Polymer beads of uniform particle size are produced by carrying out suspension polymerization of a suspension in which droplets are dispersed while producing Taylor vortices in the annular part of a coaxial double rotating cylinder having an outer cylinder and an inner cylinder. This has led to the completion of the present invention.

[0008]

According to the present invention, a suspension in which a polymerizable monomer droplet group formed by introducing a polymerizable monomer into a continuous phase containing a dispersant through a porous member is dispersed. The liquid is an annular part of a coaxial double rotating cylinder with a stationary outer cylinder and a rotatable inner cylinder, with a Taylor number of 40 to 15,000.
There is provided a suspension polymerization method characterized in that polymer beads having a uniform particle size are produced by polymerizing while rotating the inner cylinder so that

The Taylor number defines the generation of Taylor vortices, and is represented by the following equation: Ta = (Ri.ω.d / ν) (d / Ri) ^1/2 (where Ta is the Taylor number, Ri is the outer diameter of the inner cylinder, ω is the rotational angular velocity of the inner cylinder, d is the width of the annular portion of the inner and outer cylinders, and ν is the kinematic viscosity). That is, the Taylor vortex is determined by each parameter of the outer diameter of the inner cylinder, the rotational angular velocity of the inner cylinder, the width of the annular portion of the inner and outer cylinders, and the kinematic viscosity.

In the present invention, the Taylor number is 15,000.
When it exceeds, the vortex disappears and a turbulent state where the whole becomes uniform is not preferable. Further, when the Taylor number is less than 40, vortices are not generated and the mixing becomes insufficient, which is not preferable. Therefore, it is suitable that the Taylor number is in the range of 40 to 15000, and more preferably in the range of 2100 to 15000.

In the present invention, the Taylor number is the specific gravity (indicated by ρ _C ) of the continuous phase containing the dispersant and the polymerizable monomer droplet group in the suspension in which the polymerizable monomer droplet group is dispersed. It is appropriately changed depending on the specific gravity of (denoted by ρ _D ). That is, when the difference between the specific gravity of the continuous phase and the specific gravity of the polymerizable monomer droplet group is large, the influence of buoyancy or gravity on the droplets of the polymerizable monomer is large, and therefore, if the Taylor number is small, the droplets are A large Taylor number is preferable because it causes a short pass in the reactor. For example,
Ratio of specific gravity of continuous phase to specific gravity of polymerizable monomer droplet group (ρ
_{When D} / ρ _C ) is 0.98 or less or 1.02 or more, the Taylor number is preferably in the range of 2100 to 15000, and ρ _D
When / ρ _C is 0.96 or less or 1.04 or more, the Taylor number is preferably in the range of 2500 to 15000. Within the above Taylor number range, polymer beads having a uniform particle size can be obtained.

The uniformity of particles in the present invention is represented by a dispersion coefficient [(standard deviation / average diameter) × 100]. According to the suspension polymerization method of the present invention, the dispersion coefficient is 20%.
Hereinafter, polymer beads having a particle size distribution of preferably 15% or less, more preferably 10% or less are produced.

The suspension in which the polymerizable monomer droplets in the present invention are dispersed is placed in the reactor (that is, the annular portion of the coaxial double rotating cylinder having a stationary outer cylinder and a rotatable inner cylinder). It may be prepared or may be prepared outside the reactor, and the suspension may be fed into the reactor after preparation. The method for preparing a suspension in which the polymerizable monomer droplet groups are dispersed in the present invention will be described below.

The polymerizable monomer droplet group of the present invention is formed by using a porous member. As the porous member, for example, a multi-nozzle, a porous orifice plate, a porous membrane or the like can be used. The polymerizable monomer droplet group in the suspension preferably has a uniform particle diameter, and the polymerizable monomer droplet group formed through the porous member as described above has a sufficiently uniform particle diameter. However, by applying the vibration method or the electric field method at the same time, the uniformity of the particle diameter can be further improved.

The hole diameter of the ejection holes of the multi-nozzle or the multi-orifice plate is affected by various factors such as the physical properties of the continuous phase liquid containing the dispersant and the polymerizable monomer as the liquid to be formed into liquid droplets, vibration, and the like. , Mainly determined by the target droplet size. Generally, the particle diameter of the polymerizable monomer droplets is preferably 5 to 10,000 μm, and thus the diameter of the ejection holes is preferably 2 to 5000 μm, more preferably 3 to 2000 μm. Further, the arrangement pitch of the ejection holes is suitably 10 to 200 times the hole diameter, and more preferably 15 to 100 times.

The ejection velocity of the polymerizable monomer, which is the liquid to be dropletized and is ejected from the ejection hole, is determined by the Reynolds number, and it is necessary to form a laminar flow in order to obtain a droplet group having a uniform particle size. is there. The Reynolds number is the following formula: Re = D · u · ρ / μ (where Re is the Reynolds number, D is the diameter of the ejection hole, u is the ejection velocity, ρ is the density of the liquid to be dropletized, and μ is It is obtained by the viscosity of the liquid to be dropletized).

In the present invention, when the Reynolds number is less than 10, the flow rate becomes small and the production efficiency decreases, which is not preferable. Further, when it exceeds 2000, a turbulent flow region is formed and uniform droplet groups are not generated, which is not preferable.
Therefore, the Reynolds number is suitably in the range of 10 to 2000, more preferably in the range of 20 to 1000. By setting the ejection speed of the polymerizable monomer, which is the liquid to be formed into droplets, within the range of the Reynolds number, a droplet group of the polymerizable monomer having a uniform particle size can be obtained.

When a suspension in which the polymerizable monomer droplets are dispersed is prepared in the reactor, the jetting holes of the polymerizable monomer are provided on the lower surface or the upper surface of the annular portion of the double rotating cylinder. Alternatively, it may be provided on the side surface of the annular portion. Also, when preparing a suspension outside the reactor,
It is possible to provide a droplet generation unit having a jet port outside the reactor, and to supply the suspension prepared therein into the reactor.

When a multi-nozzle, a porous orifice plate or a porous membrane is used as the porous member, a continuous phase containing a dispersant and / or a jetting agent is added in order to enhance the uniformity of particle diameter in the polymerizable monomer droplets. It is preferable to vibrate the liquid to be dropletized of the polymerizable monomer ejected from the holes.

As the vibration method, any method may be used as long as it has a vibration characteristic capable of dispersing the jet flow into a uniform droplet group, and its frequency is generally 10 to 100,000 Hz, and 20 to 50,000 Hz is suitable. Is more preferable. Specific vibrating means include, for example, mechanical oscillators, electroacoustic oscillators,
A hydroacoustic oscillator, an electromagnetic oscillator, a magnetoresistive transducer, a piezoelectric oscillator, or the like can be used. The oscillator may be connected to a nozzle to vibrate the nozzle, or may be connected to a reactor or a droplet generation device outside the reactor to connect the liquid of the polymerizable monomer in the reactor or the droplet generation device. The liquid to be dropletized may be vibrated.

As described above, by forming a group of polymerizable monomer droplets while vibrating both the continuous phase containing the dispersant and the polymerizable monomer as the liquid to be dropletized, or either one of them. It is possible to obtain a suspension in which droplets having a uniform particle size are dispersed.

When a multi-nozzle or a multi-orifice plate is used as the porous member, it is also preferable to apply the electric field method in order to enhance the uniformity of the particle size of the polymerizable monomer droplets. As the electric field method, for example, a method in which an electrode is provided in a continuous phase containing a dispersant, and an AC or DC voltage is applied between the electrode and the ejection hole to miniaturize the liquid to be dropletized of the polymerizable monomer Can be applied. Appropriate voltage application conditions are an AC frequency of 1 to 30000 Hz and a voltage of 200 to 5000 V in the case of an AC electric field, and a voltage of 10 to 5000 V in the case of a DC electric field.

As a method for forming a group of polymerizable monomer droplets using a porous film, for example, the polymerizable monomer is pressed and dispersed into a continuous phase containing a dispersant through a porous film having uniform pores. This makes it possible to apply a method of preparing a group of polymerizable monomer droplets having uniform particle diameters. In this method, under normal operating conditions (for example, pressure conditions), the particle size depends only on the pore size and not on the polymerizable monomer liquid flow rate. The pore size is adjusted according to the droplet size.
It can be appropriately selected within the range of 50 nm to 50 μm.

When a group of polymerizable monomer droplets is formed using a porous membrane, the continuous phase is vibrated to prevent the droplets of the polymerizable monomer from adhering to the surface of the porous membrane. It is possible to form a group of polymerizable monomer droplets having a more uniform particle size.

The polymerizable monomer applicable to the suspension polymerization method of the present invention may be any polymerizable monomer generally used in suspension polymerization. Examples of the water-insoluble polymerizable monomer include styrene, α-methylstyrene, divinylbenzene, acrylonitrile, acrylic acid ester,
A vinyl-based monomer such as methacrylic acid ester or a mixture thereof can be applied. If necessary, the polymerizable monomer can be diluted with a solvent, and as the diluent, for example, toluene, hexane or the like can be used. As the water-soluble polymerizable monomer,
For example, acrylamide, methacrylamide, fumaramide, ethacrylamide, acrylic acid, acrylate,
Methacrylic acid, methacrylic acid salt, etc. can be applied.

In suspension polymerization, a polymerization initiator is generally dissolved and reacted in a polymerizable monomer. As a polymerization initiator, for a water-insoluble polymerizable monomer, for example, benzoyl peroxide, lauroyl peroxide or the like is used. Organic peroxides and azo compounds such as azobisisobutylnitrile can be used. For water-soluble polymerizable monomers, for example, water-soluble free radical initiators such as persulfate and hydrogen peroxide are used. can do.

As the continuous phase liquid used for the water-insoluble polymerizable monomer, water or a mixture of water and one or more water-miscible organic solvents can be used. Examples of water-miscible organic solvents include methanol, ethanol and the like. The continuous phase liquid used for the water-soluble polymerizable monomer may be an aromatic hydrocarbon, an aliphatic hydrocarbon or the like which is immiscible with water, and specifically, for example, heptane, benzene, xylene, cyclohexane. , Toluene and the like.

As the dispersant, any dispersant generally used in suspension polymerization may be used. For the aqueous continuous phase, for example, a polymer protective colloid, a surfactant, or a water-insoluble inorganic substance is used. Specific examples thereof include polyvinyl alcohol, gelatin, starch, methylcellulose derivatives, polyacrylic acid salts, anionic surfactants, nonionic surfactants, calcium phosphate, calcium carbonate, and magnesium pyrophosphate. For the continuous phase immiscible with water, for example, sorbitan fatty acid esters, polymer dispersants, etc. can be used, and specifically, for example, sorbitan monostearate, sorbitan monolaurate, ethyl cellulose, benzyl cellulose, ethyl. Examples include hydroxyethyl cellulose.

The suspension polymerization method of the present invention includes a batch method and a continuous method. In the batch method, for example, a device as shown in FIG. 1 is used. The batch method will be described with reference to FIG. The continuous phase containing the dispersant and the polymerizable monomer solution are supplied to the droplet generator 7 from the continuous phase containing tank 10 and the polymerizable monomer storage tank 11. After the slurry of the polymerizable monomer droplet group is formed by the droplet generation device 7, the slurry of the polymerizable monomer droplet group is supplied to the gap between the outer cylinder 2 and the inner cylinder 1. At this time, the gap between the outer cylinder 2 and the inner cylinder 1 may be previously filled with a continuous phase containing a dispersant. This device has an exhaust port 5. The inner cylinder 1 is rotated at a predetermined rotation speed by a motor 4. After supplying a predetermined amount of slurry of the polymerizable monomer droplets, warm water is supplied to the jacket 3 through the warm water inlet 8 and the warm water outlet 9.
By further discharging and circulating, the inside of the reactor is adjusted to a predetermined temperature to carry out the polymerization reaction. After the reaction is completed, the slurry of polymer beads is discharged from the slurry outlet 6. The polymer beads thus obtained have a uniform particle size.

In the apparatus shown in FIG. 1, the droplet generator 7 is installed in the lower part of the reactor. The apparatus in which the droplet generator 7 is installed in the lower part of the reactor is a polymerizable monomer. This is effective when the specific gravity of the droplet group is smaller than that of the continuous phase. When the specific gravity of the polymerizable monomer droplet group is higher than the specific gravity of the continuous phase, it is preferable to install the droplet generating device 7 at the upper part of the reactor as shown in FIG.

In the continuous method, for example, a device as shown in FIG. 2 is used. The continuous method will be described with reference to FIG. The continuous phase containing the dispersant and the polymerizable monomer solution are continuously supplied to the droplet generation device 7 from the continuous phase containing tank 10 and the polymerizable monomer storage tank 11. After the slurry of the polymerizable monomer droplet group is formed by the droplet generation device 7, the slurry of the polymerizable monomer droplet group is continuously supplied to the gap between the outer cylinder 2 and the inner cylinder 1. At this time, the gap between the outer cylinder 2 and the inner cylinder 1 may be previously filled with a continuous phase containing a dispersant. The inner cylinder 1 is rotated at a predetermined rotation speed by a motor 4. A constant flow rate slurry of droplets of polymerizable monomer is continuously fed to the reactor. Hot water is supplied to the jacket 3 from the hot water inlet 8, discharged from the hot water outlet 9 and circulated to adjust the temperature inside the reactor to a predetermined temperature to allow the polymerization reaction to proceed. The polymer beads in which the reaction has progressed may be completed in the present reactor, or after being discharged from the present reactor, an aging tank having an exhaust port 5.
The reaction may be completed at 12. The slurry of polymer beads which has completed the reaction is continuously discharged from the slurry outlet 6. The polymer beads thus obtained have a uniform particle size.

In the case of the continuous method, the droplet generator 7 may be installed at either the lower part or the upper part of the reactor, but in practice, the specific gravity and the polymerizable property of the continuous phase and the polymerizable monomer droplet group are high. It is appropriately selected in consideration of the particle size of the monomer droplet group, the continuous phase, the flow rate of the liquid droplet of the polymerizable monomer, and the like. The polymerization temperature can be appropriately selected in consideration of the decomposition temperature of the polymerization initiator used, the boiling point of the continuous phase, etc., but is generally preferably 40 to 95 ° C.

[0033]

According to the suspension polymerization method of the present invention, the inner cylinder is formed so that the Taylor number is 40 to 15,000 in the annular portion of the coaxial double rotating cylinder having the stationary outer cylinder and the rotatable inner cylinder. While rotating, a polymerization reaction is carried out in a suspension in which a polymerizable monomer droplet group formed by introducing a polymerizable monomer into a continuous phase containing a dispersant through a porous member is dispersed.

When suspension polymerization is carried out in this way,
Due to the good and uniform degree of radial mixing in the annulus of the coaxial double-rotating cylinder, the polymerizable monomer droplets in the Taylor vortex proceed the reaction without splitting / coalescing,
Polymer beads with a uniform particle size will be produced. Further, in the axial direction of the annular portion of the coaxial double-rotation cylinder, the degree of mixing is small and it is close to the plug flow. Therefore, by continuously supplying the polymerizable monomer droplets to the apparatus, polymer beads having a high polymerization rate can be obtained. Will be continuously manufactured.

[0035]

【Example】

Example 1 A polymerizable monomer solution with uniform particle size (lauryl acrylate / vinyl acetate / divinylbenzene / lauroyl peroxide = 80 /) was prepared in a droplet generator filled with a 1 wt% polyvinyl alcohol aqueous solution (specific gravity 0.99). 10/9
/ 1; specific gravity 0.88; ρ _D / ρ _C = 0.89). The droplet generator is installed in the lower part of the coaxial double rotation cylindrical reactor, and a piezoelectric vibrator is mounted in the lower part of the droplet generator. 19 orifice holes, pitch width 1.5m
m, the pore size is 80 μm. The polymerizable monomer solution was jetted from the orifice holes into the continuous phase containing the dispersant at a flow rate of 1.0 g / min per hole, and a sine wave vibration of 2600 Hz was applied. Further, a 1% by weight polyvinyl alcohol aqueous solution which is a continuous phase containing a dispersant was continuously supplied to the droplet generation part at a flow rate of 57 g / min.

The slurry of the formed droplet group was continuously supplied to the lower portion of the coaxial double-rotation cylindrical reactor from the upper portion of the droplet generation device to advance the polymerization reaction. The outer diameter of the inner cylinder of the coaxial double rotation cylindrical reactor is 100 mm, the inner diameter of the outer cylinder is 150 mm, the height is 1000 mm, the reactor volume is 9800 ml, and the inner cylinder is 150 rpm.
Rotated (Taylor number 13875). The inside of the inner cylinder has a structure in which a heat medium flows, and the temperature inside the reactor was set to 75 ° C. The residence time was about 2 hours, and a slurry of polymer beads having a uniform particle size was continuously obtained from the upper part of the reactor. As a result of measuring the particle size of the obtained polymer beads (measuring instrument: LS-130, manufactured by Coulter, Inc.), the volume average diameter was 220 μm and the dispersion coefficient was 8%.

Example 2 Using the droplet generator used in Example 1, a monomer solution of lauryl acrylate / methyl methacrylate / divinylbenzene / lauroyl peroxide = 67/23/9/1 (specific gravity 0.97, ρ _D / Ρ _C = 0.98) was formed. Monomer is 1.0g / min per hole from orifice hole
Was ejected at a flow rate of 2600 Hz, and a sine wave vibration of 2600 Hz was applied. 57% of 1% by weight polyvinyl alcohol aqueous solution was applied to the droplet generator.
It was continuously fed at a flow rate of g / min. The slurry of the formed droplet group was used in the reactor used in Example 1 in the inner cylinder 23.
The polymerization reaction was carried out by rotating at rpm (Taylor number 2128).
The average residence time was 2.0 hours. As a result of measuring the particle size of the polymer beads obtained in the same manner as in Example 1, the volume average diameter was 220 μm and the dispersion coefficient was 9%.

Example 3 In a droplet generating apparatus in which 10 glass porous membranes having a diameter of 10 mm, a length of 180 mm and an average pore diameter of 0.9 μm were arranged, and a continuous phase was filled with a 1 wt% polyvinyl alcohol aqueous solution, A polymerizable monomer having the same composition as 1 was pressed into a continuous phase through a glass porous film to form droplet groups. Further, a vibrator is attached to the droplet generation device, and the continuous phase is vibrated to disperse the polymerizable monomer. The polymerizable monomer was continuously supplied at a flow rate of 19 g / min, and the continuous phase was continuously supplied at a flow rate of 57 g / min. The slurry of the formed droplet group was continuously supplied to the lower portion of the coaxial double-rotation cylindrical reactor from the upper portion of the droplet generation device to advance the polymerization reaction. The temperature in the reactor was 75 ° C, and the average residence time was 2.0 hours. Inner cylinder 28 rpm (Taylor number 259
Polymerization was carried out by rotating in 1). As a result of measuring the particle size of the polymer beads obtained in the same manner as in Example 1, the volume average diameter was 5 μm and the dispersion coefficient was 17%.

Example 4 In a droplet generating apparatus in which 10 glass porous membranes having a diameter of 10 mm, a length of 180 mm and an average pore diameter of 0.9 μm were arranged, and a continuous phase was filled with a 1% by weight polyvinyl alcohol aqueous solution, A polymerizable monomer having the same composition as 1 was pressed into a continuous phase through a glass porous film to form droplet groups. The polymerizable monomer was continuously supplied at a flow rate of 19 g / min, and the continuous phase was continuously supplied at a flow rate of 57 g / min. The slurry of the formed droplet group was continuously supplied to the lower portion of the coaxial double-rotation cylindrical reactor from the upper portion of the droplet generation device to advance the polymerization reaction. 28 rpm inner cylinder (Taylor number 2591)
It was rotated by and the polymerization reaction was performed. The temperature in the reactor is 75
C., average residence time was 2.0 hours. As a result of measuring the particle size of the polymer beads obtained in the same manner as in Example 1,
The volume average diameter was 5 μm, and the dispersion coefficient was 19%.

Example 5 In a droplet generator of Example 1 filled with cyclohexane which is a continuous phase containing ethyl cellulose as a dispersant, a polymerizable monomer solution having a uniform particle size [510 g of 80% by weight acrylic acid was added]. 30% by weight aqueous sodium hydroxide solution 60
Neutralize with 0 g, 0.4 g of potassium persulfate as a polymerization initiator, and Denacol EX-810 (Nagase Chemical Industry Co., Ltd.) as a cross-linking agent.
20.4 g) was added together with 40 g of ion-exchanged water to prepare droplets having a specific gravity of 1.20]. The polymerizable monomer solution was jetted into the continuous phase from the orifice hole at a flow rate of 1.4 g / min per hole, and a sine wave vibration of 2000 Hz was applied. Cyclohexane, which is a continuous phase, was continuously supplied at a flow rate of 50 g / min.

In a coaxial double-rotating cylindrical reactor filled with cyclohexane (specific gravity 0.78, ρ _D / ρ _C = 1.54) containing ethyl cellulose as a dispersant, the formed droplet groups were continuously fed into the upper part of the reactor. Was further supplied to advance the polymerization reaction. The inner cylinder was rotated at 195 rpm (Taylor number 14040). The temperature in the reactor was 72 ° C, and the average residence time was 2.0 hours. As a result of measuring the particle size of the polymer beads obtained in the same manner as in Example 1, the volume average diameter was 170 μm, and the dispersion coefficient was 8%.
Met.

[0042]

EFFECTS OF THE INVENTION According to the suspension polymerization method of the present invention, the inner part of a coaxial double rotating cylinder having a stationary outer cylinder and a rotatable inner cylinder has a Taylor number of 40 to 15,000. By rotating the cylinder, a Taylor vortex is generated in the suspension in which the droplets of the polymerizable monomer formed by introducing the polymerizable monomer into the continuous phase containing the dispersant through the porous member are dispersed. While carrying out the polymerization reaction.

When suspension polymerization is carried out in this way,
Due to the good and uniform degree of radial mixing in the annulus of the coaxial double-rotating cylinder, the polymerizable monomer droplets in the Taylor vortex proceed without fragmentation / coalescence. Therefore, according to this method, polymer beads having a uniform particle diameter can be produced.

Further, in the axial direction of the annular portion of the coaxial double-rotating cylinder, the degree of mixing is small and it is close to the plug flow. The rate of polymer beads can be produced continuously.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus used in the batch method of the present invention.

FIG. 2 is a schematic view of an apparatus used in the continuous method of the present invention.

FIG. 3 is a schematic view of an apparatus used in the batch method of this reaction.

[Explanation of symbols]

 1 Inner Cylinder 2 Outer Cylinder 3 Jacket 4 Motor 5 Exhaust Port 6 Slurry Outlet 7 Droplet Generator 8 Hot Water Inlet 9 Hot Water Outlet 10 Continuous Phase Reservoir 11 Polymeric Monomer Reservoir 12 Aging Tank

Claims (5)

[Claims] 1. A suspension in which a polymerizable monomer droplet group formed by introducing a polymerizable monomer into a continuous phase containing a dispersant through a porous member is dispersed is rotatable with a stationary outer cylinder. In the annular portion of the coaxial double-rotating cylinder having a large inner cylinder, polymerization is performed while rotating the inner cylinder so that the Taylor number becomes 40 to 15,000, thereby producing polymer beads having a uniform particle size. Suspension polymerization method. 2. The suspension polymerization method according to claim 1, wherein the inner cylinder is rotated so that the Taylor number becomes 2100 to 15000. 3. The polymerizable monomer droplet group is formed while vibrating both or both of the dispersant-containing continuous phase and the polymerizable monomer.
The suspension polymerization method according to. 4. A suspension in which the polymerizable monomer droplet groups are dispersed has a ratio of the specific gravity of the continuous phase and the specific gravity of the polymerizable monomer droplet groups in the suspension is 0.98 or less or 1.02 or more. The suspension polymerization method according to claim 1 or 3, wherein the inner cylinder is rotated so that the Taylor number becomes 2100 to 15000. 5. The suspension in which the polymerizable monomer droplets are dispersed has a ratio of the specific gravity of the continuous phase and the specific gravity of the polymerizable monomer droplets in the suspension is 0.96 or less or 1.04 or more. The suspension polymerization method according to claim 1 or 3, wherein the inner cylinder is rotated so that the Taylor number is 2500 to 15000.