JPH06102683B2 - Suspension polymerization method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel suspension polymerization method capable of easily controlling the particle size distribution of product particles, and particularly to a conventional suspension polymerization method. The present invention relates to a suspension polymerization method suitable for producing particles having a particle size of 5 to 50 μm, which has been difficult to obtain.

(Prior Art) In recent years, the importance of the particle industry utilizing the function of the particles themselves has been increasing, and examples thereof include a gap-maintaining agent, a slipperiness-imparting agent, a functional carrier, monodisperse particles having surface activity, standard particles, and toner. It is applied in the field of functional fillers that control the fluidity and gloss properties of paints. Various methods are known for obtaining these particles by a polymerization method, and the most commonly used method is the emulsion polymerization method. When used for special purposes, soap-free polymerization, dispersion polymerization, seed polymerization, swelling polymerization, etc. are also used. However,
These polymerization methods have several drawbacks. For example, the emulsion polymerization method has the advantage that particles having a narrow particle size distribution can be obtained, but it is very difficult to remove non-negligible impurities such as emulsifiers, and the particle size of the obtained particles is There is a limit. According to dispersion polymerization, seed polymerization, swelling polymerization, etc., particles having a large particle size can be obtained.
Since the method is complicated, requires a long time, and causes a great cost disadvantage, it is not suitable for mass production, and there is a problem that it can be applied only to a special purpose.

On the other hand, the suspension polymerization method has relatively few problems in the above-mentioned polymerization method and has a feature that the obtained product is in the form of particles. Therefore, it is used in, for example, electrophotography. It has been proposed to be applied to the production of a toner.

However, the suspension polymerization method has a problem that it is generally difficult to control the particle size and the particle size distribution. That is, in suspension polymerization, the droplets that are agitated and dispersed have various diameters, and during dispersion, the droplets repeatedly break up and coalesce, so the particle size distribution of the obtained particles becomes extremely wide. It is difficult to obtain monodisperse particles having a narrow diameter distribution.

In the products used in the various application fields described above, the non-uniformity of the particle size distribution is caused by the mechanical strength of the polymer, the chemical resistance,
It has important relationships with performance such as hue, transparency and moldability,
Control of particle size and particle size distribution is an important issue.

Therefore, establishment of a suspension polymerization technique capable of easily obtaining homogeneous polymer particles having a desired particle size has been an important issue in this field.

(Problems to be Solved by the Invention) The reason why particles are obtained in suspension polymerization is as follows. The disperse phase and the continuous phase, which should be separated in the stationary state originally,
The dispersed phase is split by the energy of stirring or the like and becomes a so-called droplet state, which exists in the continuous phase. This droplet is
In this state as it is, it is generally unstable which repeats fragmentation and coalescence, but the droplets are polymerized by the supply of energy such as heat and become rigid particles which can no longer be fragmented or coalesced. Therefore, in order to control the size of the particles by the suspension polymerization method, some control may be applied to the size of the droplets and the division and coalescence. However, considering the factors related to the droplet size,
Characteristics, structure, shape, size of disperser (agitator), size, shape of reaction vessel, charge amount of reaction liquid, phase ratio of reaction liquid, viscosity, kind and amount of dispersant, etc. ,
It cannot be controlled substantially in a unified manner. Therefore,
In reality, fixing some of these many elements,
Under the current circumstances, it is unavoidable to determine certain conditions for the particles to be obtained. However, this method is too trial-and-error and it is difficult to react to changes in conditions such as scale-up. This point is a serious obstacle to manufacturing, and so-called manufacturing flexibility is lacking, especially for the purpose of using the product in powder form.

As a result of intensive studies on the above problems, the present inventors have previously proposed a novel suspension polymerization method that can easily solve these problems. That is, a method has been proposed in which the disperse phase component and the continuous phase component are simultaneously and continuously supplied to a disperser through independent paths, and the resulting dispersion liquid is introduced into a polymerization tank and polymerized. As a result of further study on this method, the present inventors have found that the particle size distribution of the polymer particles to be produced is such that the supply rate of the continuous phase component and the disperse phase component at the time of supplying to the disperser and the speed ratio thereof are important factors. It was found that the feeding rate and rate ratio of both phase components as well as the feeding method are important factors for controlling the particle size distribution. That is, even if both phase components are simply fed into the disperser through the pipe, a preliminary dispersion phenomenon occurs at the time of mixing the two, and at that time, a droplet phase having a considerably wide particle size distribution is generated, and this phenomenon is caused by the feed rate. It has been confirmed that the value becomes particularly remarkable when the value is relatively large or when the speed ratio of both phase components is large. This phenomenon significantly impedes the purpose of always applying a constant shearing force to the dispersed phase, which is an undesirable phenomenon in producing polymer particles having a narrow particle size distribution.

The present invention has been made in view of the above situation.

Therefore, an object of the present invention is to provide a suspension polymerization method capable of easily controlling the particle size and particle size distribution of polymer particles produced.

Therefore, another object of the present invention is to provide a suspension polymerization method in which the above-mentioned preliminary dispersion phenomenon does not occur.

(Means for Solving the Problems) In the suspension polymerization method of the present invention, when a polymer or a polymer composition is produced by suspension polymerization of a monomer composition, a dispersed phase composed of the monomer composition is used. The components and the continuous phase component composed of the aqueous medium are held in independent tanks, respectively, and the dispersed phase component and the continuous phase component are introduced from these tanks into double pipes through independent paths, respectively, It is continuously and continuously supplied to the vicinity of the rotor for applying shearing force of the disperser to form a dispersion having droplets of a desired size by applying shearing force, and then the dispersion is placed in a polymerization tank. It is characterized by being introduced to complete the polymerization to obtain a polymer or a polymer composition.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an example of an apparatus used for carrying out the present invention, and FIG. 2 is a sectional view of a disperser in the apparatus of FIG.

In FIG. 1, 1 is a continuous phase tank, 2 is a dispersion phase tank, and they are connected to a disperser 5 equipped with a rotor that applies a shearing force by flow paths 8 and 9, respectively. 3 is a reaction tank equipped with a condenser 6 and a heating jacket 7, and is connected to the disperser 5 by a flow path 10. 4 is a metering pump.

In addition, 11 in FIG. 2 is a rotor rotation shaft, and at the tip thereof,
A rotor 12 is provided as a rotor for applying a shearing force, and is rotatably supported in a disperser main body 14 by a bearing 13. The inside of the disperser main body 14 is liquid-tight by a stirring seal 15. A double pipe 16 is opened near the rotor 12. The double pipe 16 is composed of an inner pipe 17 and an outer pipe 18, and is attached to the disperser main body 14 by an opening diameter adjusting flange 19. 20 is the dispersion liquid discharge port, 21 is the inner pipe inlet port, 22
Is the outer pipe inlet.

When carrying out the present invention using the apparatus shown in these drawings, the continuous phase component consisting of an aqueous medium is held in the continuous phase tank 1, and the dispersed phase component consisting of the monomer composition is placed in the dispersion phase tank 2. Hold. Each of these components is simultaneously and continuously supplied to the disperser 5 equipped with a rotor for applying a shearing force by driving the metering pumps 4 and 4 provided in the independent flow paths 8 and 9, respectively. . In that case, the dispersed phase component and the continuous phase component are respectively the inner pipe inlet 21 or the outer pipe inlet 22.
Is introduced into the double pipe from and is discharged in the vicinity of the rotor 15.
The released rotor is dispersed by being applied with a shearing force by a rotating rotor to form a dispersion liquid including a dispersed phase and a continuous phase. The formed dispersion liquid is discharged from the dispersion liquid discharge port 20, sent to the reaction tank 3 through the flow path 10, and suspension polymerization is carried out by a usual method.

In the present invention, as described above, the dispersed phase component and the continuous phase component are supplied to the disperser by an outer pipe having an appropriate inner diameter and a double pipe having an inner pipe arranged therein. The continuous phase component and the dispersed phase component may be supplied to any of the outer tubes. Then, the opening of the inner tube is preferably installed close to the rotor which gives a shearing force.

In the present invention, the inner diameters of the inner pipe and the outer pipe and their inner diameter ratios are determined by the feed rates of the two-phase components and their speed ratios.
Generally, it is preferable to feed the phase component having the smaller feed rate through the inner tube. If the feed rate ratio of both phase components is large, increase the inner diameter ratio of the outer pipe and inner pipe of the double pipe, and if the sum of feed rates of both phase components is large, increase the inner diameter of the double pipe itself. do it.

In the present invention, the supply rates of the two-phase components are determined by the number of rotations, the size, and the ability of the rotor, and thus are appropriately selected and determined. The supply speed ratio of both phase components is usually 0.1 to 10.0.
The range is preferably.

Also, the inner diameter of the inner tube is 0.1 ~ 0.5 of the diameter of the rotor of the disperser.
The diameter of the rotor of the disperser is
It is preferably in the range of 0.5 to 1.0 times.

In the above case, if the desired particle size cannot be obtained by one pass through the shearing area, another disperser is further provided, and the dispersion liquid that has passed through the first-stage disperser is passed through the second-stage disperser. It may be passed through the disperser. Since the obtained dispersion has a sufficiently large interfacial energy, coalescence hardly occurs even under normal stirring conditions.

In the present invention, the continuous phase is formed by the continuous phase component consisting of an aqueous medium. It is preferred to include a suspension stabilizer in the continuous phase.

Examples of suspension stabilizers generally used in suspension polymerization include surface-active substances having a hydrophilic group and a hydrophobic group in the molecule. These surface-active substances have polar groups such as hydroxyl groups, carboxyl groups and salts thereof, sulfone groups and salts thereof as hydrophilic groups, and are composed of non-polar groups such as aliphatic and aromatic groups as hydrophobic groups. The compound has the ability to prevent and stabilize the coalescence of the monomer composition particles formed by the dispersion step.

Examples of such suspension stabilizers include polyvinyl alcohol, casein, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose and other cellulose derivatives, starch and its derivatives, poly (meth) acrylic acid and salts thereof. During the polymerization, these suspension polymers cover the surface of the droplets and serve to prevent the droplets from coalescing and agglomerating.

A neutral salt such as sodium chloride or sodium sulfate may be added to the continuous phase for the purpose of preventing emulsification. Also,
Further, a thickener such as glycerin or ethylene glycol may be added for the purpose of preventing coalescence of the monomer composition particles formed in the dispersion step.

On the other hand, the dispersed phase is formed by the dispersed phase component composed of the monomer composition.

The polymerizable monomer used as the main component of the monomer composition is not particularly limited as long as it can be used for suspension polymerization, and examples thereof include those described below. You can

For example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene,
p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene , Pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, and other styrenes and their derivatives; ethylene, propylene, butylene, isobutylene, and other ethylenically unsaturated monoolefins; vinyl chloride, vinylidene chloride. , Vinyl halides such as vinyl bromide and vinyl fluoride; organic acid vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylic acid Acid n-butyl, n-octyl methacrylate, dodecyl methacrylate, meta 2-ethylhexyl acrylate,
Methacrylic acid and its derivatives such as stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate. , N-octyl acrylate, dodecyl acrylate,
Acrylic acid and its derivatives such as 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl methyl ketone, vinyl hexyl ketone , Vinyl isopropenyl ketone, and other vinyl ketones; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, and other N-vinyl compounds; vinyl naphthalene; acrylonitrile, methacrylonitrile, acrylamide, and other polymerizations Examples of the monomer include a polymerizable monomer.

These monomers may be used alone or in combination of two or more as needed in various compositions.

A pigment and other components can be added to the above polymerizable monomer, if necessary. For example, when a pigment such as carbon black is added, it can be applied to the production of an electrophotographic toner.

In the present invention, a polymerization initiator is used, but the polymerization initiator is preferably soluble in the polymerizable monomer. Examples of such a polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis- (2,4-dimethylvaleronitrile) and 2,2'-azobis-4-methoxy-2. Examples include 4,4-dimethylvaleronitrile, other azo or diazo polymerization initiators; benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, other peroxide polymerization initiators and the like.

In the present invention, for the purpose of controlling the molecular weight and the molecular weight distribution, or for the purpose of controlling the reaction time, it is preferable to use two or more of the above polymerization initiators in combination in various compositions. Further, if necessary, a water-soluble initiator such as ammonium persulfate or potassium persulfate may be used in combination.

The amount of the polymerization initiator used is 100 parts of the polymerizable monomer,
It is usually 0.1 to 20 parts, preferably 1 to 5 parts.

The above-mentioned dispersed phase component and continuous phase component were introduced into a disperser through a double tube as described above to prepare a dispersion having a predetermined particle size and particle size distribution, and then the dispersion was subjected to suspension polymerization. However, the suspension polymerization reaction is usually carried out at a polymerization temperature of 50 ° C. or higher, and the temperature is set in consideration of the decomposition temperature of the polymerization initiator. If the set temperature is too high, the polymerization initiator will be rapidly decomposed and the molecular weight will be affected, which is not preferable.

(Operation) The operation of the present invention will be described in relation to the conventional art.

Needless to say, it is important to control the size of droplets before the polymerization reaction in order to control the size of the particles obtained in the suspension polymerization method. The droplets are broken by the turbulent flow energy of the stirring of the reaction liquid or the shearing force of the stirring blade. On the other hand, the coalescence of the droplets is caused by the contact between the droplets. The final droplet size is determined by the balance of this fragmentation and coalescence.

Looking first at the fragmentation, in order to obtain droplets with a particle size of 50 μm or less (10 μm or less in the case of toner), the shearing force of the stirring blade of the disperser is the main factor that controls the fragmentation. It turned out that At this time, the size of the liquid droplets produced by the division is determined by the state before the division, the magnitude of the shearing force, the number of times of repeating the shearing, and the like. In the conventional disperser, large droplets and small droplets are subjected to the same shearing force, so large droplets are subjected to shearing force and split into droplets of a certain size, but small droplets are supplied. Even in that case, the droplets are further broken up into smaller droplets and eventually broken down to an emulsified state. The emulsified components cannot coalesce again into large particles, resulting in loss. In addition, in a general disperser (stirrer), droplets on a circulating flow generated by stirring are subdivided when passing through a shear region, and even in a turbulent flow field existing in the entire device. There is an opportunity to be subdivided by turbulent energy. However, since the movement of the droplets flowing in the apparatus is almost random, it is inevitable that the conditions of the subdivision that each droplet encounters will have a distribution.

Therefore, it is a necessary condition for controlling the size of the droplets that all the droplets are exposed to the shear force as often as possible. Further, in order to control the particle size distribution, it is important to supply the liquid to be dispersed in a constant state to the shearing force-applying portion of the disperser.

On the other hand, coalescence is considered to occur due to contact between droplets. Generally, the smaller the particle size of the particles, the larger the surface energy per unit volume, and the particles can exist stably. Further, a factor that causes the particle size distribution to be broadened is that large droplets are mixed with small droplets in the same system. When a small droplet collides with a large droplet, there is a phenomenon that it is easily absorbed by it. By the way, in order to make the droplet small enough to have a sufficiently stable interfacial energy, it is necessary to supply such a large amount of energy, so it is effective to break the droplet intensively in a narrow shear region, In addition, it is important to bring about a condition that the droplets are regularly divided so that the shearing force is evenly applied to all the droplets.

In the present invention, as described above, the dispersed phase component and the continuous phase component are respectively held in independent tanks, and they pass through independent paths at the same time in the vicinity of the rotor that imparts the shearing force by the double pipe. Since they are continuously supplied, the dispersion conditions such as the amount, size, or phase ratio of the liquid droplets passing through the shear region are completely controlled. Since the shearing force is directly applied without the two phase components being mixed with each other, the preliminary dispersion phenomenon described above is prevented and a droplet phase having a narrow particle size distribution is generated. Moreover, since each component is supplied in a constant state and all droplets are exposed to the shearing force with equal frequency, it is possible to form a dispersion liquid having a desired particle size and a narrow particle size distribution. become. Further, since the obtained dispersion has a sufficiently large interfacial energy, coalescence hardly occurs even under normal stirring conditions. Therefore, if the obtained dispersion is subsequently subjected to suspension polymerization, a polymer or polymer composition having a desired particle size and particle size distribution can be obtained.

(Example) Hereinafter, the present invention will be specifically described based on Examples.

Example 1 Polyacrylic acid as a continuous phase component (Wako Pure Chemical Industries, Ltd.)
An aqueous solution containing 3% of water having a viscosity of 8,000 to 12,000 centipoise at 30 ° C.) and 3% of sodium sulfate with respect to water was prepared and placed in the continuous phase tank of the apparatus shown in FIG. As a dispersed phase component, a solution prepared by dissolving 15 g of 2,2′-azobisisobutyronitrile in a mixed solution of 400 g of styrene and 100 g of butyl acrylate was prepared, and the dispersed phase tank of the apparatus shown in FIG. 1 was prepared. I put it in.

Dispersed phase components were fed to the disperser at 50 ml / min and continuous phase components at 250 ml / min. The disperser used was a stator-rotor type, and the rotor was operated at 9000 rpm. The minimum diameter of the rotor was 50 mm. Further, the structure of the double pipe used at this time was such that the outer pipe had an inner diameter of 40 mm, the inner pipe had an inner diameter of 10 mm, and the inner pipe had a wall thickness of 2 mm. The dispersed phase components were introduced into the inner pipe of the double pipe, and the continuous layer components were introduced into the outer pipe of the double pipe, and were supplied immediately before the rotor for dispersion. Next, the formed dispersion liquid was introduced into a reaction vessel and reacted at 85 ° C. for 8 hours while stirring at 300 rpm with a turbine-type stirring blade.

The polymer composition obtained as described above was cooled and filtered, then sufficiently washed with water, a slurry of polymer particles was obtained by centrifugation, and this was dried to obtain polymer particles.

The particle size of the obtained polymer particles was measured using a Coulter counter (aperture 100 μm) (number distribution)
Is shown in FIG. The polymer particles had a narrow particle size distribution as shown in FIG. 3, and the mode value was about 7.5 μm.

Example 2 In Example 1, the supply rate of the dispersed phase component was 30 ml / min,
The continuous phase component supply rate is 270 ml / min, the disperser rotation speed is 95
The operation was performed in the same manner as in Example 1 except that the rpm was set to 00 rpm.

The particle size of the obtained polymer particles was measured using a Coulter counter (aperture 100 μm) (number distribution)
Is shown in FIG. The polymer particles had a narrow particle size distribution as shown in FIG. 4, and the mode value was about 5.5 μm.

Example 3 In Example 1, the dispersion phase component feed rate was 30 ml / min,
The continuous phase component supply rate is 320 ml / min, the disperser rotation speed is 95
The operation was performed in the same manner as in Example 1 except that the rpm was 00 rpm and the inner diameter of the outer tube of the double tube was 45 mm.

The particle size of the obtained polymer particles was measured using a Coulter counter (aperture 100 μm) (number distribution)
Is shown in FIG. The polymer particles had a narrow particle size distribution as shown in FIG. 5, and the mode value was about 5.5 μm.

Example 4 In Example 1, the feed rate of the dispersed phase component was 100 ml / min,
Continuous phase component supply rate is 300 ml / min, disperser rotation speed is 95
The operation was performed in the same manner as in Example 1, except that the inner diameter of the outer pipe of the double pipe was 45 mm, and the inner diameter of the inner pipe was 15 mm.

The particle size of the obtained polymer particles was measured using a Coulter counter (aperture 100 μm) (number distribution)
Is shown in FIG. The polymer particles had a narrow particle size distribution as shown in FIG. 6, and the mode value was about 7.0 μm.

Example 5 In Example 1, the supply rate of the dispersed phase component was 30 ml / min,
Continuous phase component supply rate is 300 ml / min, disperser rotation speed is 95
The operation was performed in the same manner as in Example 1 except that the rpm was 00 rpm, the inner diameter of the outer tube of the double tube was 50 mm, and the inner diameter of the inner tube was 10 mm.

The particle size of the obtained polymer particles was measured using a Coulter counter (aperture 100 μm) (number distribution)
Is shown in FIG. The polymer particles had a narrow particle size distribution as shown in FIG. 7, and the mode value was about 5.0 μm.

Comparative Example In Example 1, instead of the double tube in the disperser,
A T-tube with an inner diameter of 10 mm was connected to the disperser. The dispersed phase and the continuous phase were respectively supplied from both sides of the T-shaped tube, and were supplied to the disperser in a state of being mixed at the connection part of the T-shaped tube. The obtained dispersion was treated in the same manner as in Example 1 to obtain polymer particles.

FIG. 8 shows the result (number distribution) of the particle size of the obtained polymer particles measured by using a cloth Coulter counter (aperture 100 μm). The polymer particles had a wide particle size distribution as shown in FIG.

(Effect of the Invention) The suspension polymerization method of the present invention has the above-mentioned constitution and can easily control the particle size and the particle size distribution. Therefore, a polymer or a polymer having a desired particle size and a narrow particle size distribution can be used. It is possible to produce a coalesced composition. Therefore, the present invention is useful for producing a material that requires a fine particle size and a narrow particle size distribution.

Furthermore, according to the invention, the dispersion can be carried out in a narrow, enclosed area, so that less foaming occurs when obtaining the dispersion. Further, since the dispersed phase component and the continuous phase component are prepared by independent devices and supplied through separate paths, even if the phase ratio is changed, other manufacturing factors are less affected. Furthermore, unlike the conventional batch reactor, there is an advantage that it is not affected by the size of the reaction vessel. Therefore, the so-called flexibility in the production of the polymer or the polymer composition can be expanded, and it is possible to easily deal with the change of conditions such as scale-up.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of an example of an apparatus for use in the suspension polymerization method of the present invention, FIG. 2 is a sectional view of a disperser used in the present invention, and FIG. FIG. 8 to FIG. 8 are graphs showing particle size distributions of polymer particles of Examples 1 to 5 and Comparative Example, respectively. 1 ... Continuous phase tank, 2 ... Dispersion phase tank, 3 ... Reaction tank, 4 ...
... metering pump, 5 ... disperser, 6 ... condenser, 7 ... heating jacket, 8, 9 and 10 ... flow path, 11 ... rotor shaft, 12 ... rotor, 13 ... bearing, 14 …… Disperser body, 15 …… Stirrer seal, 16 …… Double pipe, 17 …… Inner pipe, 18
...... Outer pipe, 19 …… Flange for adjusting opening diameter, 20 …… Dispersion liquid discharge port, 21 …… Inner pipe inlet, 22 …… Outer pipe inlet.

Claims (3)

[Claims] 1. When producing a polymer or a polymer composition by suspension polymerization of a monomer composition, a dispersed phase component composed of the monomer composition and a continuous phase component composed of an aqueous medium are respectively prepared. It is held in independent tanks, and from these tanks, the dispersed phase component and the continuous phase component are guided to the double pipe from independent paths, respectively, and at the same time in the vicinity of the rotor that imparts the shearing force of the disperser from the double pipe. A dispersion liquid having droplets of a desired size is formed by continuously supplying and applying a shearing force, and then the dispersion liquid is introduced into a polymerization tank to complete the polymerization. A suspension polymerization method, which comprises obtaining a composition. 2. In the above double pipe, the inner pipe is a dispersed phase component supply pipe, and the inner diameter thereof is 0 of the diameter of the rotor of the disperser.
The range of 1 to 0.5 times, the outer tube is a continuous phase component supply tube, the inner diameter is in the range of 0.5 to 1.0 times the diameter of the rotor of the disperser. The suspension polymerization method according to item 1. 3. The double pipe as described above, wherein the inner pipe is a continuous phase component supply pipe, and the inner diameter thereof is equal to the diameter of the rotor of the disperser.
The range of 1 to 0.5 times, the outer tube is a dispersed phase component supply tube, the inner diameter is in the range of 0.5 to 1.0 times the diameter of the rotor of the disperser. The suspension polymerization method according to item 1.